Ester compound-containing composition and method for producing the same, polymerizable composition, (meth)acrylic polymer and method for producing the same

Abstract

The purpose of the present invention is to provide: an ester compound-containing composition having excellent storage stability, and a method for producing same; a polymerizable composition; and a (meth)acrylic polymer and a method for producing same.　A methacrylic acid-containing composition contains an ester compound (I) and a component (A). The content of the ester compound (I) is 95.00-99.99 mass% of the total mass.　Ester compound (I): one or more compounds selected from the group consisting of an ester compound (1), an ester compound (2), a compound (3), an ester compound (4) and an ester compound (5).　Component (A): one or more components selected from the group consisting of a component A1, a component A2, a component A6, a component A7, a component A8, a component A9 and a component A10.

Description

Technical Field

[0001] The present invention relates to an ester compound-containing composition, a method for producing the same, a polymerizable composition, a (meth)acrylic polymer, and a method for producing the same. This application claims priority based on Japanese Patent Application Nos. 2022-174242, 2022-174342, 2022-174417, 2022-174628, 2022-174460, and 2022-174760, filed with the Japan Patent Office on October 31, 2022, and incorporates the contents herein by reference.

Background Art

[0002] (Meth)acrylic polymers obtained using (meth)acrylic acid esters are used in various fields such as paints, adhesives, resin modifiers, artificial marble, and paper latex. For example, in the presence of a catalyst Ti(OR)4 (where R is an alkyl group), the target (meth)acrylic acid alkyl ester can be produced by utilizing the transesterification reaction between the raw material (meth)acrylic acid alkyl ester and an alkyl alcohol (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When an ester compound-containing composition containing a (meth)acrylic acid ester is stored for a certain period after production, the quality of the ester compound-containing composition may deteriorate.

[0005] The present invention aims to provide an ester compound-containing composition with excellent storage stability and a method for producing the same, a polymerizable composition obtained from the ester compound-containing composition, a (meth)acrylic polymer and a method for producing the same. [Means for solving the problem]

[0006] The inventors conducted extensive research. As a result, they discovered that the inclusion of a specific component in the ester compound-containing composition suppresses the formation of impurities such as (meth)acrylic acid ester dimers, and also improves storage stability.

[0007] According to one aspect of the present invention, the following ester compound-containing composition is provided. Ester compound (I) represented by the following formula (I), One or more compounds selected from the group consisting of the compounds represented by the following formula (a1), the compounds represented by the following formula (a2), the compounds represented by the following formula (a6), the compounds represented by the following formula (a7), the compounds represented by the following formula (a8), the compounds represented by the following formula (a9), and the compounds represented by the following formula (a10), Includes, An ester compound-containing composition wherein the content of the ester compound (I) is 95.00 to 99.99% by mass of the total mass. CH2=CR 150 -C(=O)-OR 200 ...(I) In formula (I), R 150 is a hydrogen atom or a methyl group, R 200 This is a monovalent hydrocarbon group having 2 to 20 carbon atoms, which may have substituents, or a monovalent group having 2 to 8 carbon atoms and having an ether bond.

[0008] [ka]

[0009] In formula (a1), R 11 , R 12 and R 13may each independently be a group selected from a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxy group, an alkoxy group, an amino group, a carbonyl group, and a monovalent group containing an ether bond and / or a sulfide bond, or R 11 and R 12 and R 13 may each be a divalent group which may have a substituent in combination with any of the groups.

[0010]

Chemical formula

[0011] In formula (a2), R 21 and R 22 and R 23 may each independently be a monovalent group selected from a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxy group, an alkoxy group, an amino group, or a monovalent group containing a carbonyl group, an alkylthio group or an arylthio group, or R 24 may be a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxy group, an alkoxy group, an amino group, a carbonyl group, or a monovalent group containing an ether group, or R 21 and R 22 and R 23 and R 24 may each be a divalent group which may have a substituent in combination with any of the groups. However, except when R 21 = H, R 22 = H, R 23 = R 150 and R 24 = R 200 i.e., except when the compound represented by formula (a2) is the same as the ester compound (I).

[0012] In formula (a6), R 61 and R 62 and R 63Each of these may independently be a monovalent group containing a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, or a carbonyl group, or a monovalent group selected from an alkylthio group or an arylthio group, and R 64 This may be a monovalent group selected from an alkyl group, alkenyl group, aryl group, hydroxyl group, alkoxy group, amino group, carbonyl group, or ether group, or an alkylthio group or arylthio group, or R 61 , R 62 , R 63 and R 64 Each of these groups may be a divalent group that may have substituents in combination with any of the other groups. However, R 61 =H and R 62 =H and R 63 =R 150 And R 64 =OR 200 This excludes the case where the compound represented by formula (a6) is the same as the ester compound (I).

[0013] [ka]

[0014] In formula (a7), R 71 , R 72 , R 73 , R 74 , R 75 , R 76 and R 77 Each of these is independently a monovalent group selected from a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, or a carbonyl group, or an alkylthio group or an arylthio group.

[0015] [ka]

[0016] In formula (a8), R 81 , R 82, R 83 , R 84 , R 85 and R 86 Each of these is independently a monovalent group selected from a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, or a carbonyl group, and R 81 , R 82 , R 83 , R 84 , R 85 and R 86 The total number of carbon atoms is 2 or more.

[0017] [ka]

[0018] In formula (a9), R 91 This group may have substituents and is an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an aryl group having 1 to 12 carbon atoms.

[0019] [ka]

[0020] In formula (a10), R 101 , R 102 , R 103 and R 104 Each of these may independently be a monovalent group selected from a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, a carbonyl group, and a heteroatom and / or an unsaturated bond, or an alkylthio group or an arylthio group, or R 101 , R 102 , R 103 and R 104 Each of these groups may have substituents, as well as heteroatoms and / or unsaturated bonds, and may be divalent groups. These groups may further have substituents.

[0021] According to another aspect of the present invention, a method for producing the ester compound-containing composition, In the presence of at least one compound selected from the group consisting of the compound represented by formula (a1), the compound represented by formula (a2), the compound represented by formula (a6), the compound represented by formula (a7), the compound represented by formula (a8), the compound represented by formula (a9), and the compound represented by formula (a10), One or more alcohols selected from the group consisting of monoalcohols with 2 to 20 carbon atoms, ether-containing alcohols with 2 to 8 carbon atoms, dialcohols with 2 to 8 carbon atoms, and trialcohols with 2 to 8 carbon atoms, Methyl (meth)acrylate and, A method for producing an ester compound-containing composition is provided, which includes carrying out a transesterification reaction.

[0022] According to yet another aspect of the present invention, a polymerizable composition comprising the ester compound-containing composition is provided.

[0023] According to yet another aspect of the present invention, a (meth)acrylic polymer is provided, obtained by polymerizing the polymerizable composition.

[0024] According to yet another aspect of the present invention, a method for producing a (meth)acrylic polymer is provided, comprising polymerizing the polymerizable composition. [Effects of the Invention]

[0025] According to the present invention, the formation of (meth)acrylic acid ester dimers and pyruvate esters during storage is suppressed. Therefore, it is possible to provide an ester compound-containing composition with excellent storage stability and a method for producing the same, a polymerizable composition obtained from the ester compound-containing composition, a (meth)acrylic polymer and a method for producing the same. [Modes for carrying out the invention]

[0026] The following describes in detail some embodiments of the ester compound-containing composition according to the present invention. The following embodiments are merely illustrative for illustrative purposes and do not limit the present invention to these embodiments. Furthermore, the present invention can be implemented in various forms without departing from its spirit.

[0027] The meanings of the following terms are as follows: A "monomer" refers to a compound that has a polymerizable carbon-carbon double bond. "(Meth)acrylate" is selected from "acrylate" and "methacrylate". "(Meth)acrylic acid" is selected from "acrylic acid" and "methacrylic acid". Furthermore, in this specification, numerical ranges expressed using "~" mean a range that includes the numbers written before and after "~" as the lower and upper limits. For example, "1~20" means a range of 1 or more and 20 or less. New numerical ranges can be created by arbitrarily combining the lower and upper limits of the numerical ranges disclosed in this specification.

[0028] 1. First aspect The first aspect of the embodiment will be described below.

[0029] The ester compound-containing composition according to the first embodiment contains the ester compound (I) described below and the compound (component A1) described below. The content of ester compound (I) is 95.00 to 99.99% by mass.

[0030] The ester compound-containing composition according to the first embodiment may further contain, in addition to the ester compound (I), a polymerization inhibitor (component B) described below. The ester compound-containing composition may, if necessary, further contain component B in addition to ester compound (I) and component A1, as long as it does not impair the effects of the present invention, and may further contain at least one of ester compound (I), component A1 and component B (hereinafter also referred to as "component C") and water.

[0031] (Ester compound (I)) Ester compounds (I) are compounds represented by the following formula (I). CH2=CR 150 -C(=O)-OR 200 ...(I)

[0032] In formula (I), R 150 is a hydrogen atom or a methyl group, R 200 This is a monovalent hydrocarbon group having 2 to 20 carbon atoms, which may have substituents, or a monovalent group having 2 to 8 carbon atoms and having an ether bond.

[0033] As ester compound (I), one type may be used alone, or two or more types may be used in combination. As ester compound (I), one or more selected from the group consisting of ester compound (1), ester compound (2), ester compound (3), ester compound (4), and ester compound (5) described below are preferred. These ester compounds will be described below.

[0034] Ester compound (1) is a (meth)acrylic acid ester represented by the following formula (1). CH2=CR 1a -C(=O)-OR 2a ...(1) In formula (1), R 1a R is a hydrogen atom or a methyl group. 2a It is a hydrocarbon group having 2 to 20 carbon atoms.

[0035] In ester compound (1), R 2a The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. Also, R 2a The hydrocarbon group may be linear, branched, or have a ring. 2a If the hydrocarbon group has a ring, the ring may be an aliphatic ring or an aromatic ring. Also, R 2aThe number of carbon atoms in the hydrocarbon group is 2 to 20, preferably 2 to 18, and more preferably 2 to 12.

[0036] R 2a Examples of hydrocarbon groups include C2-C20 alkyl groups, C3-C20 cycloalkyl groups, C2-C20 alkenyl groups, C3-C20 cycloalkenyl groups, C2-C20 alkynyl groups, C6-C20 aryl groups, and C7-C20 aromatic alkyl groups. "Aromatic alkyl group" refers to a group in which one or more hydrogen atoms of an alkyl group are substituted with an aryl group.

[0037] R 2a Examples of alkyl groups include ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, lauryl group, and stearyl group. R 2a Examples of cycloalkyl groups include cyclopropyl, cyclohexyl, and isobornyl groups. R 2a Examples of alkenyl groups include vinyl groups and allyl groups. R 2a Examples of cycloalkenyl groups include cyclopentenyl, cyclopentadienyl, and cyclohexenyl groups. R 2a An example of an alkynyl group is the propynyl group. R 2a Examples of aryl groups include the phenyl group and the naphthyl group. R 2a Examples of aromatic alkyl groups include the benzyl group.

[0038] Since ester compound (1) is relatively easy to obtain and relatively easy to handle in terms of physical properties, R 2aExamples thereof include an alkyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and an aromatic alkyl group having 7 to 20 carbon atoms. An ethyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a 2-ethylhexyl group, a lauryl group, a stearyl group, a cyclohexyl group, an isobornyl group, an allyl group, a phenyl group, and a benzyl group are more preferable.

[0039] Examples of the ester compound (1) include ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, allyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, and the like.

[0040] Since it is relatively easy to obtain and relatively easy to handle in terms of physical properties, as the ester compound (1), 2a alkyl (meth)acrylate in which R is a linear or branched alkyl group having 2 to 20 carbon atoms, 2a cycloalkyl (meth)acrylate in which R is a cycloalkyl group having 3 to 20 carbon atoms, 2a alkenyl (meth)acrylate in which R is an alkenyl group having 2 to 20 carbon atoms, 2a aryl (meth)acrylate in which R is an aryl group having 6 to 20 carbon atoms, 2a aromatic alkyl (meth)acrylate in which R is an aromatic alkyl group having 7 to 20 carbon atoms are preferable, and ethyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, allyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate are more preferable.

[0041] The ester compound (1) may be used alone or in combination of two or more kinds.

[0042] The ester compound (2) is a (meth)acrylate represented by the following formula (2). The ester compound (3) is a (meth)acrylate represented by the following formula (3). The ester compound (4) is a (meth)acrylate represented by the following formula (4).

[0043]

Chemical formula

[0044] In formula (2), formula (3) and formula (4), R 1b , R 3b , R 5b , R 6b , R 8b and R 9b are each independently a hydrogen atom or a methyl group. R 2b and R 4b are each independently a linear or branched alkylene group or hydroxyalkylene group having 2 to 8 carbon atoms. R 7b is a linear or branched trivalent hydrocarbon group having 2 to 8 carbon atoms.

[0045] In the ester compound (2) and the ester compound (3), the alkylene group or hydroxyalkylene group of R 2b and R 4b has 2 to 8 carbon atoms, preferably 2 to 6 carbon atoms. R 2b and R 4b Examples of the alkylene group include an ethylene group, a propylene group, an isopropylene group, and a butylene group. R 2b and R 4b Examples of the hydroxyalkylene group include a hydroxyethylene group, a hydroxypropylene group, and a hydroxybutylene group.

[0046] R7b The number of carbon atoms in the trivalent hydrocarbon group is 2 to 8, preferably 2 to 4. R 7b Examples of trivalent hydrocarbon groups include -(CH2)-C(-CH2-)(-CH3)-CH2-, etc.

[0047] Examples of ester compounds (2) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 3-hydroxypropyl (meth)acrylate. Examples of ester compounds (3) include ethylene glycol di(meth)acrylate, 1,3-propanediol di(meth)acrylate, 1,2-propanediol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate. Examples of ester compounds (4) include trimethylolpropane tri(meth)acrylate.

[0048] When ester compound (I) contains ester compounds (2) to (4), it is preferable that it contains one or more selected from the group consisting of ethylene glycol di(meth)acrylate, 2-hydroxyethyl(meth)acrylate, 3-hydroxypropyl(meth)acrylate, and trimethylolpropanetri(meth)acrylate, from the viewpoint of being relatively easy to obtain.

[0049] Ester compound (5) is a (meth)acrylic acid ester represented by the following formula (5). CH2=CR 1c -C(=O)-OR 2c ...(5) In formula (5), R 1c R is a hydrogen atom or a methyl group, 2c It is a monovalent group with 2 to 8 carbon atoms that has an ether bond.

[0050] In ester compound (5), R 2cThe number of etheric oxygen atoms in the monovalent group having 2 to 8 carbon atoms is preferably one, but is not limited to one, and may be two or more. R 2c The monovalent group having 2 to 8 carbon atoms may be linear, branched, or have a ring. 2c If the monovalent group having 2 to 8 carbon atoms has a ring, the ring may or may not contain an etheric oxygen atom. R 2c The number of carbon atoms in the monovalent group having an ether bond is 2 to 8, preferably 2 to 7.

[0051] R 2c Examples of such groups include 2-methoxyethyl group, 2-(2-methoxyethoxy)ethyl group, 2-[2-(2-methoxyethoxy)ethoxy]ethyl group, glycidyl group, and tetrahydrofurfuryl group. Because it is relatively easy to obtain and relatively easy to handle in terms of physical properties, R 2c The preferred group is a 2-methoxyethyl group, a glycidyl group, or a tetrahydrofurfuryl group.

[0052] Examples of ester compounds (5) include 2-methoxyethyl (meth)acrylate, glycidyl (meth)acrylate, 2-(2-methoxyethoxy)ethyl (meth)acrylate, 2-[2-(2-methoxyethoxy)ethoxy]ethyl (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate.

[0053] As for the ester compound (5), 2-methoxyethyl (meth)acrylate, glycidyl (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate are preferred because they are relatively easy to handle in terms of physical properties.

[0054] (Component A1) The ester compound-containing composition according to the first embodiment contains a compound represented by formula (a1) (component A1).

[0055] [ka]

[0056] In formula (a1), R 11 , R 12 and R 13 Each of these may independently be a group selected from a monovalent group comprising a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, a carbonyl group, and an ether bond and / or a sulfide bond, or R 11 , R 12 and R 13 Each of these groups may be a divalent group that may have substituents in combination with any of the other groups.

[0057] The "α-hydrogen" in component A1 refers to a hydrogen atom bonded to a carbon atom adjacent to the carbon atom of the carbonyl group. In the ester compound-containing composition according to the first embodiment, the presence of component A1 can suppress the formation of (meth)acrylic acid ester dimers and pyruvate esters. Furthermore, the coexistence of the ester compound having α-hydrogens (component A1) with component B (polymerization inhibitor), described later, can more efficiently suppress the formation of (meth)acrylic acid ester dimers and pyruvate esters. The mechanism for this can be presumed to be as follows.

[0058] Component B, described later, suppresses the polymerization reaction of ester compound (I) by radical polymerization by trapping radicals generated in ester compound (I). However, the dimerization reaction of ester compound (I) also proceeds by anionic polymerization under basic conditions. Ester compounds with α-hydrogens are weakly acidic and can trap anions that cause anionic polymerization; therefore, component A1 can suppress the dimerization reaction of ester compound (I) by anionic polymerization. On the other hand, pyruvate ester is produced when ester compound (I) is oxidized by hydroxyl radicals and oxygen molecules. Component B can trap hydroxyl radicals, and component A1 can trap the radical intermediate produced by the reaction of hydroxyl radicals and ester compound (I), and convert the intermediate back to ester compound (I). Therefore, it is thought that the coexistence of component A1 and component B can efficiently suppress the formation of pyruvate ester.

[0059] The molecular weight of component A1 is preferably 1000 or less. By having a molecular weight of 1000 or less, the number of α-hydrogen atoms per unit mass in component A1 can be increased, so that the effects of the present invention can be obtained with a small mass. Furthermore, the molecular weight of component A1 is more preferably 800 or less, even more preferably 600 or less, and particularly preferably 400 or less.

[0060] In formula (a1), R 11 , R 12 and R 13 Each of these may independently be a group selected from a monovalent group comprising a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, a carbonyl group, and an ether bond and / or a sulfide bond, or R 11 , R 12 and R 13 Each of these groups may be a divalent group that may have substituents in combination with any of the other groups. 11 and R 12 , R 12 and R 13 , R 13 and R 11These may be the same or different.

[0061] Generally, the α-hydrogens of ester compounds have the property of reacting with anions and radicals, but their reactivity may decrease depending on the type of substituent they possess. 11 , R 12 and R 13 If the above conditions are met, the reactivity of the α-hydrogen of component A1 with anions and radicals is maintained, and thus the effects of the present invention can be obtained.

[0062] R 11 and R 12 The substituent is preferably a hydrogen atom, a C1-C5 alkyl group, a hydroxyl group, a C1-C6 alkoxy group, an amino group, a carbonyl group, or a C1-C5 alkylthio group; more preferably a hydrogen atom or a C1-C5 alkyl group; and even more preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group. Because these substituents are highly stable, they can prevent component A1 from changing into other compounds during storage. Furthermore, because the above substituents have low electron-donating properties, the acidity of the α-hydrogen of component A1 is improved.

[0063] R 13Preferably, the substituent is a linear or cyclic alkyl group having 1 to 20 carbon atoms, a linear alkenyl group having 2 to 5 carbon atoms, an aryl group having 5 to 12 carbon atoms, a hydroxyalkylene group having 2 to 8 carbon atoms, an alkyl group having at least one acyloxy group having 2 to 20 carbon atoms, or a hydrocarbon group having etheric oxygen between carbon atoms. More preferably, it is a linear alkyl group having 1 to 10 carbon atoms, an allyl group, a 2-hydroxyethyl group, a 2-hydroxypropyl group, a 2-methoxyethyl group, a glycidyl group, or a tetrahydrofurfuryl group. Even more preferably, it is a butyl group, an isobutyl group, a t-butyl group, an allyl group, or a 2-hydroxyethyl group. Particularly preferably, it is a butyl group or an isobutyl group, and most preferably, it is a butyl group. Since these substituents are similar to those of ester compound (I), they can prevent adverse effects on the physical properties of the polymer when a (meth)acrylic polymer is produced by polymerization of an ester compound-containing composition.

[0064] Alkyl groups are linear (linear or branched) alkyl groups or cyclic alkyl groups. In the case of linear alkyl groups, those having 1 to 20 carbon atoms are preferred, those having 1 to 10 carbon atoms are more preferred, and those having 1 to 5 carbon atoms are even more preferred. Examples of linear alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, hexyl, octyl, and decyl groups, with methyl, ethyl, n-propyl, and isopropyl groups being preferred. In the case of cyclic alkyl groups, those having 3 to 20 carbon atoms are preferred, those having 4 to 10 carbon atoms are more preferred, and those having 5 to 7 carbon atoms are even more preferred. Examples of cyclic alkyl groups include cyclopentyl, cyclohexyl, and cyclooctyl groups. Aromatic alkyl groups may also be used.

[0065] The alkenyl group is either a linear (linear or branched) alkenyl group or a cyclic alkenyl group. In the case of a linear alkenyl group, a linear alkenyl group having 2 to 20 carbon atoms is preferred, a linear alkenyl group having 2 to 10 carbon atoms is more preferred, and a linear alkenyl group having 2 to 5 carbon atoms is even more preferred. Examples of linear alkenyl groups include vinyl, 1-propenyl, isopropenyl, 2-butenyl, 1,3-butadienyl, 2-pentenyl, and 2-hexenyl groups. In the case of a cyclic alkenyl group, a cyclic alkenyl group having 3 to 20 carbon atoms is preferred, a cyclic alkenyl group having 4 to 10 carbon atoms is more preferred, and a cyclic alkenyl group having 5 to 7 carbon atoms is even more preferred. Examples of cyclic alkenyl groups include cyclopentenyl and cyclohexenyl groups.

[0066] The aryl group is preferably an aryl group having 5 to 20 carbon atoms, and more preferably an aryl group having 5 to 12 carbon atoms. The aryl group includes heteroaryl groups containing oxygen, nitrogen, sulfur, etc. Examples of aryl groups include phenyl group, mesityl group, naphthyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 2,3-dimethylphenyl group, 2,4-dimethylphenyl group, 2,5-dimethylphenyl group, 2,6-dimethylphenyl group, 2-ethylphenyl group, isoxazolyl group, isothiazolyl group, imidazolyl group, oxazolyl group, thiazolyl group, thiadiazolyl group, thienyl group, thiophenyl group, triazolyl group, Examples include tetrazolyl group, pyridyl group, pyrazinyl group, pyrimidinyl group, pyridadinyl group, pyrazolyl group, pyrrolyl group, pyranyl group, furyl group, fluzanyl group, imidazolidinyl group, isoquinolyl group, isoindolyl group, indolyl group, quinolyl group, pyridothiazolyl group, benzimidazolyl group, benzoxazolyl group, benzothiazolyl group, benzotriazolyl group, benzofuranyl group, imidazopyridinyl group, triazopyridinyl group, and prinyl group.

[0067] Examples of monovalent groups containing a hydroxyl group include the hydroxyl group, hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 2-hydroxypropyl group, and 3-hydroxypropyl group.

[0068] The alkoxy group is preferably an alkoxy group having 1 to 20 carbon atoms, more preferably an alkoxy group having 1 to 10 carbon atoms, and even more preferably an alkoxy group having 1 to 6 carbon atoms. Examples of alkoxy groups include methoxy, ethoxy, butoxy, and phenoxy groups.

[0069] The amino group includes an amino group (-NH2) with no substituent on the nitrogen atom, and an amino group in which some or all of the hydrogen atoms bonded to the nitrogen atom are substituted with carbon atoms. The number of carbon atoms in the carbon-substituted amino group is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 5. Examples of amino groups include methylamino group, ethylamino group, propylamino group, butylamino group, dimethylamino group, diethylamino group, anilino group, toluidino group, anisidino group, diphenylamino group, and N-methyl-N-phenylamino group.

[0070] Examples of monovalent groups containing a carbonyl group include formyl group, acyl group, acyloxy group, carboxyl group, amide group, alkoxycarbonyl group, thiocarboxyl group, and thioester group.

[0071] An acyl group is a substituent formed by linking a carbonyl group with an alkyl group, alkenyl group, or aryl group. The total number of carbon atoms derived from the carbonyl group (1) and the alkyl group, alkenyl group, or aryl group of the acyl group is preferably 2 to 20, more preferably 2 to 10, and even more preferably 2 to 6. Examples of acyl groups include acetyl, propionyl, butyryl, isobutyryl, valeryl, acryloyl, methacryloyl, and benzoyl groups.

[0072] An acyloxy group is a substituent formed by linking a carbonyl group to an alkyl group, alkenyl group, or aryl group, and further linking the carbonyl group to an ether bond. The total number of carbon atoms derived from the carbonyl group (1) and the alkyl group, alkenyl group, or aryl group of the acyl group is preferably 2 to 20, more preferably 2 to 10, and even more preferably 2 to 6. Examples of acyloxy groups include acetyloxy, propionyloxy, butyryloxy, isobutyryloxy, valeryloxy, acryloyloxy, methacryloyloxy, and benzoyloxy groups. Examples of monovalent groups containing an acyloxy group include 2-acyloxyethyl, 2-acyloxypropyl, and 2,2-bis(acyloxymethyl)butyl.

[0073] The amide group includes an amide group (-CONH2) without substituents on the nitrogen atom, and an amide group in which some or all of the hydrogen atoms bonded to the nitrogen atom are substituted with carbon atoms. The number of carbon atoms in the amide group is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 5, which is the sum of the number of carbon atoms derived from the carbonyl group (1) and the number of carbon atoms substituted on the nitrogen atom. Examples of amide groups include an unsubstituted amide group, an N-methylamide group, an N-ethylamide group, an N-phenylamide group, an N,N-dimethylamide group, and an N-methyl-N-phenylamide group.

[0074] An alkoxycarbonyl group is a substituent formed by linking a carbonyl group and an alkoxy group, and is also called an ester group. The total number of carbon atoms from the carbonyl group (1) and the alkoxy group is preferably 2 to 20, more preferably 2 to 10, and even more preferably 2 to 6. Examples of alkoxycarbonyl groups include methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl, and phenoxycarbonyl groups.

[0075] A thioester group is a substituent in which a carbonyl group is linked to a sulfide bond, or a sulfide bond is linked to an alkyl or aryl group. The total number of carbon atoms derived from the carbonyl group (1) and the alkyl or aryl group is preferably 2 to 20, more preferably 2 to 10, and even more preferably 2 to 6. Examples of thioester groups include methylthiocarbonyl group, ethylthiocarbonyl group, butylthiocarbonyl group, and phenylthiocarbonyl group.

[0076] For example, a monovalent group containing a carbonyl group may be a substituent in which one or more hydrogen atoms of an alkyl group are substituted with a carbonyl group. Examples of such substituents include 2-acetoxyethyl group, 2-acetoethyl group, and 2-(acetoacetoxy)ethyl group.

[0077] Examples of monovalent groups containing an ether bond include groups having an etheric oxygen atom between two carbon atoms. The number of etheric oxygen atoms in the above group is preferably one, but is not limited to two or more. The above group may be linear, branched, or have a ring. If the above group has a ring, the ring may or may not contain an etheric oxygen atom. The number of carbon atoms in the above group is preferably 2 to 8, and more preferably 2 to 7. Examples of such substituents include 2-methoxyethyl group, 2-(2-methoxyethoxy)ethyl group, 2-[2-(2-methoxyethoxy)ethoxy]ethyl group, glycidyl group, and tetrahydrofurfuryl group.

[0078] Examples of groups containing a sulfide bond include alkylthio groups. An alkylthio group is a substituent in which an alkyl group and a sulfide bond are linked, and alkylthio groups having 1 to 20 carbon atoms are preferred, alkylthio groups having 1 to 10 carbon atoms are more preferred, and alkylthio groups having 1 to 5 carbon atoms are even more preferred. Examples of alkylthio groups include methylthio groups, ethylthio groups, propylthio groups, and isopropylthio groups.

[0079] R 11 and R 12 , R 12 and R 13 , R 13 and R 11 They may be connected to each other to form a ring. 11 and R 12 Compounds in which R is linked to form a ring, and R 13 and R 11 Examples of compounds in which these molecules are linked to form a ring include methyl cyclohexanecarboxylate and methyl cyclopentanecarboxylate. 12 and R 13 Examples of compounds in which these molecules are linked to form a ring include α-methyl-δ-valerolactone and α-methyl-γ-butyrolactone.

[0080] Among the compounds that satisfy the above conditions, from the viewpoint of quality stability during storage of ester compound-containing compositions, component A1 includes methyl isobutyrate, butyl isobutyrate, methyl butyrate, isobutyl butyrate, methyl propionate, ethyl propionate, butyl propionate, isobutyl propionate, butyl butyrate, isobutyl butyrate, ethyl isobutyrate, phenyl isobutyrate, butyl isobutyrate, isobutyl isobutyrate, methyl isovalerate, methyl 2-methylbutyrate, isoamyl isobutyrate, methyl lactate, methyl 2-methoxypropionate, N,N-dimethylglycine methyl, dimethyl malonate, methyl methylthioacetate, methyl 3-butenate, (R)-(-)-3-hydroxyisobutyrate, methyl acetate, and ethyl acetate. Butyl acetate, isobutyl acetate, phenyl acetate, methyl cyclohexanecarboxylate, methyl cyclopentanecarboxylate, α-methyl-δ-valerolactone or α-methyl-γ-butyrolactone are preferred, butyl butyrate, isobutyl butyrate, butyl propionate, butyl acetate, methyl isobutyrate, methyl isovalerate, methyl 2-methylbutyrate, isoamyl isobutyrate, methyl lactate, N,N-dimethylglycine methyl, dimethyl malonate, methyl methylthioacetate, methyl 3-butenate, (R)-(-)-3-hydroxyisobutyrate or methyl cyclohexanecarboxylate are more preferred, and methyl isobutyrate, methyl propionate, isobutyl isobutyrate or 2-methylbutyrate are even more preferred.

[0081] Component A1 may be one type or two or more types.

[0082] (Polymerization inhibitor (component B)) The ester compound-containing composition according to the first embodiment may further contain a polymerization inhibitor (component B). A polymerization inhibitor is a compound that has the function of suppressing the polymerization reaction of the ester compound (I). The inclusion of component B in the ester compound-containing composition suppresses the progression of the polymerization reaction of ester compound (I) via the radical polymerization mechanism during storage. Furthermore, during storage, oxygen molecules in the ester compound-containing composition may absorb ultraviolet light from sunlight, generating hydroxyl radicals. However, polymerization inhibitors can trap these hydroxyl radicals. Therefore, if the ester compound-containing composition contains both component A1 and component B, the amount of hydroxyl radicals can be reduced through two different mechanisms: component A1 suppresses the generation of hydroxyl radicals, and component B removes any hydroxyl radicals generated by component B. Thus, the dimerization of ester compound (I) and the formation of oxidation products can be suppressed more efficiently.

[0083] Examples of polymerization inhibitors include phenolic compounds, quinone compounds, nitrobenzene compounds, N-oxyl compounds, amine compounds, phosphorus-containing compounds, sulfur-containing compounds, iron-containing compounds, copper-containing compounds, and manganese-containing compounds. Furthermore, as described above, the coexistence of component A1 and component B effectively suppresses the formation of methyl pyruvate through the oxidation of ester compound (I).

[0084] Examples of phenolic compounds include alkylphenols, hydroxyphenols, aminophenols, nitrophenols, nitrosophenols, alkoxyphenols, and tocopherols.

[0085] Examples of alkylphenols include o-cresol, m-cresol, p-cresol, 2-t-butyl-4-methylphenol, 2,4-dimethyl-6-t-butylphenol, 2,6-di-t-butyl-4-methylphenol, 2-t-butylphenol, 4-t-butylphenol, 2,4-di-t-butylphenol, 2-methyl-4-t-butylphenol, 4-t-butyl-2,6-dimethylphenol, 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol), and 3,5-di-t-butyl-4-hydroxytoluene.

[0086] Examples of hydroxyphenols include hydroquinone, 2-methylhydroquinone, 2-t-butylhydroquinone, 2,5-di-t-butylhydroquinone, 2,6-di-t-butylhydroquinone, 2,5-di-t-amylhydroquinone, 2-t-butylmethoxyhydroquinone, 2,3,5-trimethylhydroquinone, 2,5-dichlorohydroquinone, 1,2-dihydroxybenzene, 2-acetylhydroquinone, 4-methylcatechol, 4-t-butylcatechol, 2-methylresorcinol, 4-methylresorcinol, and 2,3-dihydroxyacetophenone.

[0087] Examples of aminophenols include o-aminophenol, m-aminophenol, p-aminophenol, 2-(N,N-dimethylamino)phenol, and 4-(ethylamino)phenol.

[0088] Examples of nitrophenols include o-nitrophenol, m-nitrophenol, p-nitrophenol, and 2,4-dinitrophenol.

[0089] Examples of nitrosophenols include o-nitrosophenol, m-nitrosophenol, p-nitrosophenol, and α-nitroso-β-naphthol.

[0090] Examples of alkoxyphenols include 2-methoxyphenol, 2-ethoxyphenol, 2-isopropoxyphenol, 2-t-butoxyphenol, 4-methoxyphenol, 4-ethoxyphenol, 4-propoxyphenol, 4-butoxyphenol, 4-t-butoxyphenol, 4-heptoxyphenol, hydroquinone monobenzyl ether, t-butyl-4-methoxyphenol, di-t-butyl-4-methoxyphenol, pyrogallol-1,2-dimethyl ether, and hydroquinone monobenzoate.

[0091] Examples of tocopherols include α-tocopherol and 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran.

[0092] Examples of quinone compounds include p-benzoquinone, chloro-p-benzoquinone, 2,5-dichloro-p-benzoquinone, 2,6-dichloro-p-benzoquinone, tetrachloro-p-benzoquinone, tetrabromo-p-benzoquinone, 2,3-dimethyl-p-benzoquinone, 2,5-dimethyl-p-benzoquinone, methoxy-p-benzoquinone, and methyl-p-benzoquinone.

[0093] Examples of nitrobenzene compounds include nitrobenzene, o-dinitrobenzene, m-dinitrobenzene, p-dinitrobenzene, 2,4-dinitrobenzene, dinitrojulen, and 2,2-diphenyl-1-picrylhydrazine.

[0094] Examples of N-oxyl compounds include 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-oxo-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-acetoxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, 2,2,6,6-tetramethyl-piperidine-N-oxyl, piperidine-1-oxyl, 4-(dimethylamino)-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-amino-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-ethenoloxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, and 4-benzoyloxy-2,2,6,6-tetramethyl-piperidine-N-oxyl Examples include tris(2,2,5,5-tetramethyl-piperidine-N-oxyl), 3-amino-2,2,5,5-tetramethyl-piperidine-N-oxyl, 4,4',4”-tris(2,2,6,6-tetramethyl-piperidine-N-oxyl) phosphite, 3-oxo-2,2,5,5-tetramethylpyrrolidine-N-oxyl, pyrrolidine-1-oxyl, 2,2,5,5-tetramethyl-1-oxa-3-azacyclopentyl-3-oxyl, 2,2,5,5-tetramethyl-3-pyrrolinyl-1-oxy-3-carboxylic acid, 2,2,3,3,5,5,6,6-octamethyl-1,4-diazacyclohexyl-1,4-dioxyl, di-t-butyl nitroxide, di-t-amyl nitroxide, etc.

[0095] Examples of amine compounds include N,N-diphenylamine, alkylated diphenylamine, 4,4'-dicumyl-diphenylamine, 4,4'-dioctyldiphenylamine, 4-aminodiphenylamine, p-nitrosodiphenylamine, N-nitrosodinaphthylamine, N-nitrosodiphenylamine, N-nitrosophenylnaphthylamine, N-nitrosophenylhydroxylamine, N,N'-dialkyl-p-phenylenediamine (the alkyl groups may be the same or different, each independently having 1 to 4 carbon atoms, and may be linear or branched), N,N'-diphenyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, and N-(1,3-dimethylbutyl)-N'-phenyl-1,4 Examples include -phenylenediamine, N,N'-di-2-naphthyl-p-phenylenediamine, N,N-diethylhydroxylamine, 1,4-benzenediamine, N-(1,4-dimethylpentyl)-N'-phenyl-1,4-benzenediamine, 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, aldol-α-naphthylamine, N-phenyl-β-naphthylamine, 4-hydroxy-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 1,4-dihydroxy-2,2,6,6-tetramethylpiperidine, and 1-hydroxy-4-benzoylioxy-2,2,6,6-tetramethylpiperidine.

[0096] Phosphorus-containing compounds include, for example, triphenylphosphine, triphenyl phosphite, triethyl phosphite, tris(isodecyl) phosphite, tris(tridecyl) phosphite, phenyldiisooctyl phosphite, phenyldiisodecyl phosphite, phenyldi(tridecyl) phosphite, diphenylisooctyl phosphite, diphenylisodecyl phosphite, diphenyltridecyl phosphite, phosphonic acid [1,1-diphenyl-4,4'-diylbistetrakis-2,4-bis(1,1-dimethylethyl)phenyl] ester, triphenyl phosphite, tris(nonylphenyl) phosphite, 4,4'-isopropylidenediphenolalkyl phosphite, tris(2,4-di-t-butylphenyl) phosphite, tris(biphenyl) phosphite, dist Examples include allyl pentaerythritol diphosphite, di(2,4-di-t-butylphenyl) pentaerythritol diphosphite, di(nonylphenyl) pentaerythritol diphosphite, phenylbisphenol A pentaerythritol diphosphite, tetra(tridecyl)-4,4'-butylidenebis(3-methyl-6-t-butylphenol) diphosphite, hexa(tridecyl)-1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane triphosphite, 3,5-di-t-butyl-4-hydroxybenzyl phosphate diethyl ester, sodium-bis(4-t-butylphenyl) phosphate, sodium-2,2'-methylene-bis(4,6-di-t-butylphenyl) phosphate, and 1,3-bis(diphenoxyphosphonyloxy)benzene.

[0097] Examples of sulfur-containing compounds include diphenyl sulfide, phenothiazine, 3-oxofhenothiazine, 5-oxofhenothiazine, phenothiazine dimers, 1,4-dimercaptobenzene, 1,2-dimeltocaptobenzene, 2-mercaptophenol, 4-mercaptophenol, 2-(methylthio)phenol, 3,7-bis(dimethylamino)phenothiazinium chloride, and elemental sulfur.

[0098] Examples of iron-containing compounds include iron(III) chloride.

[0099] Examples of copper-containing compounds include copper dimethyldithiocarbamate, copper diethylthiocarbamate, copper dibutylthiocarbamate, copper salicylate, copper acetate, copper thiocyanate, copper nitrate, copper chloride, copper carbonate, copper hydroxide, copper acrylate, and copper methacrylate.

[0100] Examples of manganese-containing compounds include manganese dialkyldithiocarbamate (the alkyl group is one of methyl, ethyl, propyl, or butyl groups, and may be the same or different), manganese diphenyldithiocarbamate, manganese formate, manganese acetate, manganese octanoate, manganese naphthenate, manganese permanganate, and manganese salts of ethylenediaminetetraacetic acid.

[0101] Since it is easier to exhibit an effect that further improves the storage stability of ester compound-containing compositions, component B is preferably at least one polymerization inhibitor selected from the group consisting of phenolic compounds, N-oxyl compounds, amine compounds, phosphorus-containing compounds, and sulfur-containing compounds, such as hydroquinone, 4-methoxyphenol, 2,4-dimethyl-6-t-butylphenol, 2,6-di-t-butyl-4-methylphenol, 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, N,N-diphenylamine, N- It is more preferable that the polymerization inhibitor is at least one selected from the group consisting of nitrosodiphenylamine, triphenylphosphite, and phenothiazine, and it is particularly preferable that the polymerization inhibitor is at least one selected from the group consisting of hydroquinone, 4-methoxyphenol, 2,4-dimethyl-6-t-butylphenol, 2,6-di-t-butyl-4-methylphenol, 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, N,N-diphenylamine, N-nitrosodiphenylamine, and phenothiazine.

[0102] Component B may be used alone or in combination of two or more types.

[0103] If an ester compound-containing composition contains a compound that corresponds to both component A1 and component B, that compound shall be considered as component A1. If an ester compound-containing composition contains both component A1 and component B, it means that the ester compound-containing composition contains a component B that is different from the compound A1. If an ester compound-containing composition contains two or more compounds that fall under both component A1 and component B, the compound with the highest molar concentration in the ester compound-containing composition shall be considered component A1, and the other compounds shall be considered component B.

[0104] (Component C) Component C is a compound other than ester compound (I), component A1, and component B. The ester compound-containing composition according to the present invention may contain component C, provided that the content of ester compound (I) is in the range of 95.00 to 99.99% by mass relative to the total mass of the ester compound-containing composition. Component C includes impurities generated during the manufacturing process of ester compound (I), such as mold release agents, lubricants, plasticizers, antioxidants, antistatic agents, light stabilizers, UV absorbers, flame retardants, flame retardant aids, polymerization inhibitors, fillers, pigments, dyes, silane coupling agents, leveling agents, defoamers, fluorescent agents, and other additives.

[0105] The ester compound-containing composition may contain unreacted raw materials from the production of the ester compound-containing composition, such as methyl (meth)acrylate, alcohol, and (meth)acrylic acid.

[0106] Furthermore, the ester compound-containing composition may contain impurities such as diacetyl, which are generated during the production of the ester compound-containing composition. Diacetyl may be present as an impurity, for example, when the ester compound is produced by the C4 direct oxidation method. From the viewpoint of reducing the coloration of the ester compound-containing composition, it is preferable that the composition does not contain diacetyl. However, if diacetyl is present as an unavoidable impurity, from the above viewpoint, it is preferable that the diacetyl content per liter of the ester compound-containing composition be 5 ppm by mass or less, more preferably 2 ppm by mass or less, even more preferably 1 ppm by mass or less, and particularly preferably 0.1 ppm by mass or less.

[0107] Furthermore, the ester compound-containing composition may also contain (meth)acrylic acid esters other than ester compound (I).

[0108] (Content of ester compound (I)) The content of ester compound (I) in the ester compound-containing composition is 95.00 to 99.99% by mass relative to the total mass of the ester compound-containing composition. If the content of ester compound (I) is above the lower limit, the amount of impurities produced when a (meth)acrylic polymer is manufactured by polymerization of the ester compound-containing composition can be reduced, preventing adverse effects on the physical properties of the polymer. Furthermore, if the content of ester compound (I) is below the upper limit, the purification cost can be suppressed. The content of ester compound (I) is preferably 96.00% by mass or more, more preferably 97.00% by mass or more, even more preferably 98.00% by mass or more, particularly preferably 99.00% by mass or more, and most preferably 99.50% by mass or more.

[0109] If ester compound (I) contains ester compound (1) but does not contain ester compound (2), ester compound (3), ester compound (4), and ester compound (5), the content of ester compound (I) is equal to the concentration of ester compound (1).

[0110] If ester compound (I) contains ester compound (5) and does not contain ester compound (1), ester compound (2), ester compound (3), and ester compound (4), the content of ester compound (I) is equal to the concentration of ester compound (5).

[0111] If ester compound (I) contains at least one selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4), and does not contain ester compound (1) and ester compound (5), then the content of ester compound (I) is the concentration of at least one selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4).

[0112] The content of component A1 per liter of the ester compound-containing composition is not particularly limited, but is preferably 1 to 10,000 ppm by mass. If the content of component A1 is above the lower limit, a sufficient effect can be obtained to suppress the dimerization of ester compound (I) and the decrease in purity of ester compound (I) due to the formation of oxidation products. If the content of component A1 is below the upper limit, the amount of impurities generated when a (meth)acrylic polymer is produced by polymerization of the ester compound-containing composition can be suppressed, and adverse effects on the physical properties of the polymer can be prevented. The lower limit of the content of component A1 is more preferably 3 ppm by mass or more, even more preferably 5 ppm by mass or more, and particularly preferably 10 ppm by mass or more. The upper limit of the content of component A1 is more preferably 7500 ppm by mass or less, even more preferably 5000 ppm by mass or less, particularly preferably 1000 ppm by mass or less, and most preferably 500 ppm by mass or less.

[0113] The content of component B per liter of the ester compound-containing composition is not particularly limited, but 1 to 1000 ppm by mass is preferred. If the content of component B is above the lower limit, a sufficient effect can be obtained to suppress the dimerization of ester compound (I) and the decrease in purity of ester compound (I) due to the formation of oxidation products. If the content of component B is below the upper limit, the amount of impurities when a (meth)acrylic polymer is produced by polymerization of the ester compound-containing composition can be reduced, and adverse effects on the physical properties of the polymer can be prevented. The content of component B is more preferably 3 ppm by mass or more, even more preferably 5 ppm by mass or more, and particularly preferably 10 ppm by mass or more. Furthermore, the content of component B is more preferably 750 ppm by mass or less, even more preferably 500 ppm by mass or less, even more preferably 250 ppm by mass or less, particularly preferably 100 ppm by mass or less, and most preferably 50 ppm by mass or less.

[0114] The water content of the ester compound-containing composition is preferably 5000 ppm by mass or less, more preferably 4000 ppm by mass or less, even more preferably 3000 ppm by mass or less, particularly preferably 2000 ppm by mass or less, and most preferably 1000 ppm by mass or less, relative to the total mass of the ester compound-containing composition. If the water content of the ester compound-containing composition is below the above upper limit, the physical properties of the (meth)acrylic polymer obtained by polymerizing the ester compound-containing composition can be maintained more favorably. The lower limit of the water content of an ester compound-containing composition is 0 ppm by mass.

[0115] [Analysis of ester compound-containing compositions] The components A1, B, C, and water contained in the ester compound-containing composition can be identified, for example, by GC-MS measurement. In a GC-MS chart of an ester compound-containing composition, if a peak appears at the same retention time as the standard of component A1, and the m / z value detected in the mass spectrum of that peak matches the exact mass of component A1, then the ester compound-containing composition can be determined to contain component A1. If a standard of component A1 is unavailable, if the mass spectrum pattern of the peak appearing in the GC-MS chart of the ester compound-containing composition matches the mass spectrum pattern of component A1 recorded in a mass spectrum database, then that peak is the peak of component A1, and the ester compound-containing composition can be determined to contain component A1. Examples of mass spectrum databases include NIST20, NIST17, NIST14, and NIST14s. Furthermore, if the volatility is low and detection by GC-MS measurement is not possible, detection can be performed using LC-MS. Components B, C, and water can be confirmed in the same manner as component A1.

[0116] The content of ester compound (I) can be calculated by performing GC-FID measurement on the ester compound-containing composition, quantifying it using the area percentage method, and correcting it using the moisture content quantified with a Karl Fischer moisture meter.

[0117] The content of component A1 can be quantified, for example, by performing GC measurement on an ester compound-containing composition and using the internal standard method. If a standard sample of component A1 cannot be obtained and quantification cannot be performed by the internal standard method, the content of component A1 can be calculated by performing GC-FID measurement on any organic compound with a known content and using the following formula.

[0118]

number

[0119] In the formula, N is the number of carbon atoms contained in one molecule of an organic compound with a known concentration. A1 is the number of carbon atoms contained in one molecule of component A1, and S A1∫ is the peak area of ​​component A1, S is the peak area of ​​any organic compound, and M is the content (mass ppm) of any organic compound. If the volatility is low and quantification by GC area is not possible, quantification can be performed using chromatographic methods such as LC.

[0120] The content of components B and C can also be calculated using the same method as for component A1. The water content of an ester compound-containing composition can be determined by the Karl Fischer method.

[0121] (Method for producing ester compound-containing compositions) The method for producing an ester compound-containing composition according to the first embodiment is a method for producing an ester compound-containing composition comprising one or more ester compounds (I) selected from the group consisting of the above-mentioned ester compounds (1), ester compound (2), ester compound (3), ester compound (4), and ester compound (5).

[0122] The above-mentioned ester compound-containing composition can be produced, for example, by carrying out a transesterification reaction between methyl (meth)acrylate and various alcohols in the presence of components A1 and B. Methyl (meth)acrylate is particularly prone to dimerization and oxidation to produce pyruvate esters among (meth)acrylic acid esters. However, by carrying out the transesterification reaction in the presence of components A1 and B, the dimerization of methyl (meth)acrylate and the production of methyl pyruvate are suppressed, resulting in an improved yield of ester compound (I).

[0123] A method for producing an ester compound-containing composition according to the first embodiment includes step E, in which a transesterification reaction is carried out between methyl (meth)acrylate and an alcohol (component D) in the presence of component A1 and component B. If ester compound (I) contains ester compound (1), a monoalcohol having 2 to 20 carbon atoms is used as component D in step E. If ester compound (I) contains one or more selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4), then one or more alcohols selected from the group consisting of dialcohols having 2 to 8 carbon atoms and trialcohols having 2 to 8 carbon atoms are used as component D in step E. If ester compound (I) contains ester compound (5), an ether-containing alcohol with 2 to 8 carbon atoms is used as component D in step E.

[0124] For example, to obtain an ester compound-containing composition containing ester compound (1) as ester compound (I), transesterification of methyl (meth)acrylate and a monoalcohol having 2 to 20 carbon atoms is carried out in a reactor in the presence of a catalyst, component A1, and component B, as shown in formula (II) below.

[0125] [ka]

[0126] R in equation (II) 1a and R 2a R in equation (1) 1a and R 2a It is the same as this.

[0127] Examples of monoalcohols having 2 to 20 carbon atoms include ethanol, n-butanol, isobutanol, t-butanol, 2-ethylhexanol, lauryl alcohol, stearyl alcohol, isobornyl alcohol, allyl alcohol, phenol, and benzyl alcohol. Monoalcohols having 2 to 20 carbon atoms may be used individually or in combination of two or more. The monoalcohols having 2 to 20 carbon atoms preferably include linear or branched monoalcohols having 2 to 20 carbon atoms, and more preferably include n-butanol and isobutanol.

[0128] To obtain an ester compound-containing composition containing one or more ester compounds selected from the group consisting of ester compounds (2), ester compounds (3), and ester compounds (4) as ester compound (I), for example, in a reactor, in the presence of a catalyst, component A1, and component B, methyl (meth)acrylate is transesterified with one or more alcohols selected from the group consisting of dialcohols having 2 to 8 carbon atoms and trialcohols having 2 to 8 carbon atoms.

[0129] For example, in a reactor, in the presence of a catalyst and components A1 and B, transesterification reactions can be carried out as shown by the following formulas (IV) and (V), respectively.

[0130] [ka]

[0131] R in equations (IV) and (V) 1b , R 2b , R 3b , R 5b , R 6b and R 7b R in equations (2), (3), and (4) is 1b , R 2b , R 3b , R 5b , R 6b and R 7b It is the same as R. 41b R is a linear or branched alkylene group having 2 to 8 carbon atoms. 42b This is a linear or branched hydroxyalkylene group having 2 to 8 carbon atoms.

[0132] Examples of dialcohols and trialcohols having 2 to 8 carbon atoms include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,6-hexanediol, and trimethylolpropane. In particular, it is preferable that the dialcohols and trialcohols having 2 to 8 carbon atoms include one or more selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, and trimethylolpropane. Dialcohols and trialcohols having 2 to 8 carbon atoms may be used individually or in combination of two or more.

[0133] To obtain an ester compound-containing composition containing ester compound (5) as ester compound (I), for example, in a reactor, in the presence of a catalyst and component A1, methyl (meth)acrylate and an ether-bonded alcohol having 2 to 8 carbon atoms are transesterified as shown in formula (III) below.

[0134] [ka]

[0135] R in equation (III) 1c and R 2c R in equation (5) 1c and R 2c It is the same as this.

[0136] In ether-bonded alcohols having 2 to 8 carbon atoms, it is preferable that there be one ether bond, but it is not limited to this. Examples of ether-bonded alcohols having 2 to 8 carbon atoms include 2-methoxyethanol, glycidyl alcohol, and tetrahydrofurfuryl alcohol. In particular, it is preferable that the ether-bonded alcohol contains one selected from 2-methoxyethanol, glycidyl alcohol, and tetrahydrofurfuryl alcohol. Alcohols containing ether bonds with 2 to 8 carbon atoms may be used individually or in combination of two or more.

[0137] The reactor is preferably equipped with a distillation column. Since this transesterification reaction is an equilibrium reaction, productivity can be improved by separating the by-product methanol using a distillation column. For example, it is preferable to carry out the transesterification reaction while separating methanol from the system as an azeotropic mixture with methyl (meth)acrylate. Examples of such reactors include those equipped with a distillation column on top of a reaction vessel called a reaction kettle, and distillation columns in which a distillation boiler can be used as a reaction vessel. Examples of distillation columns include packed column type and tray type distillation columns. The theoretical number of stages in a distillation column is preferably five or more, and more preferably seven or more, from the standpoint of high separation capacity and stable operation.

[0138] The ratio of methyl (meth)acrylate to alcohol can be determined as appropriate. From the viewpoint of increasing productivity, the ratio of methyl (meth)acrylate to 1 mole of alcohol is preferably 0.1 to 10 moles, and more preferably 0.3 to 4 moles.

[0139] The catalysts used are not particularly limited, but examples include hydroxides, carbonates, and bicarbonates of alkali metals such as lithium, sodium, and potassium; oxides, hydroxides, and carbonates of alkaline earth metals such as magnesium and calcium; alkali metal alkoxides such as lithium methoxide, sodium methoxide, sodium ethoxide, and potassium t-butoxy; alkali metal amides such as lithium amide, sodium amide, and potassium amide; titanium alkoxides such as tetramethyl titanate, tetraethyl titanate, tetrapropyl titanate, tetraisopropyl titanate, tetrabutyl titanate, and tetra(2-ethylhexyl) titanate; and tin compounds such as dibutyltin oxide and dioctyltin oxide. Among these, titanium alkoxides, dibutyltin oxide, and dioctyltin oxide are preferred because they produce fewer by-products of the Michael addition reaction during the transesterification reaction and have high catalytic activity. The above catalysts may be used individually or in combination of two or more.

[0140] The catalyst can be supplied to the reactor on its own. Alternatively, the catalyst can be supplied to the reactor dissolved in the same alcohol as the raw material, or dissolved in the methyl (meth)acrylate raw material. For example, one method is to supply the catalyst directly dissolved in the entire amount of alcohol used in the reaction to the reactor, or to supply the catalyst dissolved in a portion of the alcohol used in the reaction to the reactor. The amount of catalyst used is preferably 0.001 to 1 mol%, and more preferably 0.01 to 0.1 mol%, per 1 mol of alcohol.

[0141] A solvent may be used in the transesterification reaction. If a solvent is used, it is preferable to use a solvent that forms an azeotropic composition with the by-product methanol. Examples of solvents include n-pentane, n-hexane, n-heptane, n-octane, 2,3-dimethylbutane, 2,5-dimethylhexane, 2,2,4-trimethylpentane, cyclohexane, benzene, and toluene. Among these, n-hexane, n-heptane, and cyclohexane are preferred. The solvent may be used alone or in combination of two or more.

[0142] The reaction temperature for transesterification varies depending on the type of alcohol and solvent, but 60 to 150°C is preferred. The reaction pressure for the transesterification reaction is not particularly limited, and the reaction may be carried out under any pressure: reduced pressure, atmospheric pressure, or increased pressure. The form of the transesterification reaction is not particularly limited and can be carried out using commonly used methods such as batch reactions or continuous reactions. After the transesterification reaction, unreacted starting materials and by-products may be separated by purifying the reaction mixture. Various methods can be used for purification, such as distillation, crystallization, extraction, and column chromatography.

[0143] In step E, component B may be added to the reaction solution before carrying out the transesterification reaction. The presence of component B in addition to component A1 further suppresses the dimerization of methyl (meth)acrylate and the formation of methyl pyruvate, thus making it easier to obtain an improved yield of ester compound (I).

[0144] Component B may be added to the solution containing the ester compound (I) and component A1 after the transesterification reaction. In this case, a separate solution containing the ester compound (I) and component B (solution B) can be prepared in addition to the solution containing the ester compound (I) and component A1 (solution A), and solutions A and B can be mixed to obtain an ester compound-containing composition. Alternatively, the ester compound (I), solution A, and solution B can be mixed to obtain an ester compound-containing composition.

[0145] The method for producing the ester compound-containing composition is not limited to the method described above. For example, instead of methyl (meth)acrylate as a raw material, other (meth)acrylic acid esters other than methyl (meth)acrylate may be used. Ester compound (1) may be produced by carrying out an esterification reaction between an alcohol and (meth)acrylic acid.

[0146] (Method for evaluating the storage stability and thermal stability of ester compound-containing compositions) Ester compound-containing compositions exhibit high quality stability during storage. Methods for evaluating the quality stability of ester compound-containing compositions during storage include, for example, actually storing the ester compound-containing composition for a long period and confirming the amount of ester compound (I) dimers and oxidation products produced, as well as the ester compound (I) content. Alternatively, from the viewpoint of ease of operation, a method of briefly heating the ester compound-containing composition and confirming the amount of ester compound (I) dimers and oxidation products produced, as well as the ester compound (I) content, may be used. When heating for a short time, the heating temperature is preferably 50-100°C, and the heating time is preferably 1-24 hours. The quality stability of ester compound-containing compositions during storage is evaluated based on the amount of ester compound (I) dimers and oxidation products produced, and the ester compound (I) content, when the ester compound-containing composition is stored at 25°C for 14 days or heated at 70°C for 7-20 hours.

[0147] [Polymerizable composition] The polymerizable composition according to the first embodiment is a polymerizable composition for producing a (meth)acrylic polymer, and includes the ester compound-containing composition according to the first embodiment described above. In one example, an ester compound-containing composition that has been stored for one day or more after production can be used as the polymerizable composition.

[0148] The storage time for ester compound-containing compositions may be 1 day or more, 3 days or more, 7 days or more, or 14 days or more. Alternatively, the storage time for ester compound-containing compositions may be 180 days or less, 150 days or less, 120 days or less, or 90 days or less. "Storage time" is not limited to the time spent standing in a specific environment, but includes transportation time, etc., and refers to the elapsed time from immediately after manufacture.

[0149] The material of the storage container for the ester compound-containing composition is not particularly limited, and for example, metal containers such as stainless steel, resin containers, and glass containers can be used. In this case, for example, either a transparent container or an opaque container can be used.

[0150] The storage temperature for ester compound-containing compositions is preferably -10°C or higher, more preferably 0°C or higher, and preferably 60°C or lower, and more preferably 50°C or lower. Setting the storage temperature to -10°C or higher reduces the load on the cooling system, and setting it to 60°C or lower makes it easier to suppress the formation of (meth)acrylic acid ester dimers and oxidation products.

[0151] The oxygen concentration in the gas phase when storing an ester compound-containing composition is preferably 5% by volume or more, more preferably 7% by volume or more, preferably 30% by volume or less, and more preferably 22% by volume or less. By setting the oxygen concentration in the gas phase during storage to 5% by volume or more, it is easier to prevent the ester compound from unintentionally polymerizing due to the polymerization-inhibiting effect of oxygen, and by setting it to 30% by volume or less, it is easier to suppress the oxidation of (meth)acrylic acid ester by oxygen and the generation of various impurities.

[0152] For example, the ester compound-containing composition after storage may be used as a polymerizable composition without further addition of monomers, or a monomer copolymerizable with ester compound (1) (hereinafter also referred to as "other monomers") may be further added to the ester compound-containing composition after storage to form a polymerizable composition. In another example, the ester compound-containing composition may be stored with other monomers added after manufacturing and then used as a polymerizable composition. In this case, it is preferable not to add polymerization initiators during storage.

[0153] The content of ester compound (I) relative to the total mass of monomers in the polymerizable composition is preferably 10% by mass or more, more preferably 20% by mass or more, preferably 90% by mass or less, and more preferably 80% by mass or less. The aforementioned upper and lower limits for the content of ester compound (I) can be combined in any way. For example, the content of ester compound (I) is preferably 10 to 90% by mass, and more preferably 20 to 80% by mass.

[0154] Other monomers include methyl (meth)acrylate, unsaturated carboxylic acids, unsaturated carboxylic acid anhydrides, maleimides, hydroxyl group-containing vinyl monomers, vinyl esters, nitrogen-containing vinyl monomers, epoxy group-containing monomers, aromatic vinyl monomers, alkanediol di(meth)acrylate, polyoxyalkylene glycol di(meth)acrylate, and vinyl monomers having two or more ethylenically unsaturated bonds in the molecule.

[0155] Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, and itaconic acid. Examples of unsaturated carboxylic acid anhydrides include maleic anhydride and itaconic anhydride. Examples of maleimides include N-phenylmaleimide and N-cyclohexylmaleimide.

[0156] Examples of hydroxyl group-containing vinyl monomers include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate. Examples of vinyl esters include vinyl acetate and vinyl benzoate. Examples of nitrogen-containing vinyl monomers include methacrylamide and acrylonitrile. Examples of epoxy group-containing monomers include glycidyl acrylate and glycidyl methacrylate.

[0157] Examples of aromatic vinyl monomers include styrene and α-methylstyrene. Examples of alkanediol di(meth)acrylates include ethylene glycol di(meth)acrylate, 1,2-propylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate.

[0158] Examples of polyoxyalkylene glycol di(meth)acrylates include diethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, triethylene glycol (meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and neopentyl glycol di(meth)acrylate. Examples of vinyl monomers having two or more ethylenically unsaturated bonds in their molecules include divinylbenzene.

[0159] Other monomers that may be used include, for example, vinyl chloride, vinylidene chloride and their derivatives, unsaturated polyester prepolymers obtained from at least one polycarboxylic acid and at least one diol, including ethylenically unsaturated polycarboxylic acids, and vinyl ester prepolymers obtained by modifying the epoxy group terminals with acrylic. Other monomers may be used individually or in combination of two or more.

[0160] If component A1 is a monomer copolymerizable with ester compound (I), component A1 may be used as a monomer copolymerizable with ester compound (I), or a monomer copolymerizable with ester compound (I) may be used separately from component A1.

[0161] In the polymerizable composition, the content of other monomers is preferably 0 to 50 parts by mass per 100 parts by mass of ester compound (I). This makes it possible to obtain a highly transparent (meth)acrylic polymer. The upper limit of the content of other monomers is more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less, per 100 parts by mass of ester compound (I). The lower limit of the content of other monomers is more preferably 0.01 parts by mass or more, even more preferably 0.1 parts by mass or more, and particularly preferably 1 part by mass or more, per 100 parts by mass of ester compound (I). The aforementioned upper and lower limits for the content of other monomers can be combined arbitrarily. For example, the content of other monomers is preferably 0 to 50 parts by mass, more preferably 0.01 to 40 parts by mass, even more preferably 0.1 to 30 parts by mass, and particularly preferably 1 to 30 parts by mass, per 100 parts by mass of ester compound (I).

[0162] The polymerizable composition preferably contains a polymerization initiator. Examples of polymerization initiators include azo compounds, organic peroxides, persulfate compounds, and redox polymerization initiators. Polymerization initiators may be used individually or in combination of two or more.

[0163] Examples of azo compounds include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2-methylpropionitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4,4-trimethylpentane), 2,2'-azobis(2-methylpropane), 1,1-azobis(cyclohexanecarbonitride), and dimethyl-2,2'-azobisisobutyrate.

[0164] Examples of organic peroxides include benzoyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, 1,1-bis(t-butylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)-3,5,5-trimethylcyclohexane, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxybenzoate, t-hexylperoxybenzoate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, t-butylperoxyacetate, and t-hexylperoxyisopropyl monocarbonate. Examples include t-hexyl peroxy-2-ethylhexanoate, t-amyl peroxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutyl peroxyethylhexanoate, 1,1,2-trimethylpropyl peroxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutyl peroxyisopropyl monocarbonate, 1,1,2-trimethylpropyl peroxyisopropyl monocarbonate, 1,1,3,3-tetramethylbutyl peroxyisononate, 1,1,2-trimethylpropyl peroxyisononate, di-t-butyl peroxide, di-t-hexyl peroxide, lauroyl peroxide, and dilauroyl peroxide.

[0165] Examples of persulfate compounds include potassium persulfate. The amount of polymerization initiator added is not particularly limited, and can be, for example, 0.005 to 5 parts by mass per 100 parts by mass of the total mass of monomers in the polymerizable composition.

[0166] The polymerizable composition may further contain, as needed, other additives such as chain transfer agents, mold release agents, lubricants, plasticizers, antioxidants, antistatic agents, light stabilizers, ultraviolet absorbers, flame retardants, flame retardant aids, polymerization inhibitors, fillers, pigments, dyes, silane coupling agents, leveling agents, defoamers, and fluorescent agents. Other additives may be used individually or in combination of two or more.

[0167] [Meth)acrylic polymer manufacturing method] (Meth)acrylic polymers can be produced by polymerizing polymerizable compositions. The polymerization method is not particularly limited and includes, for example, bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization. Among these, bulk polymerization is preferred from the viewpoint of environmental impact due to solvent use and the transparency of the resulting (meth)acrylic polymer.

[0168] The bulk polymerization method is not particularly limited and can include various casting polymerization methods such as cell casting and continuous casting. Cast polymerization is a method for obtaining a (meth)acrylic polymer by injecting a polymerizable composition into a mold consisting of two inorganic glass plates or metal plates (e.g., SUS plates) that are placed opposite each other at a predetermined distance and sealed around the periphery with a gasket such as a flexible resin tube, and allowing polymerization to proceed. The mold for casting polymerization is not particularly limited, and various types of molds can be used. For example, a mold for cell casting may be made by arranging two plate-like bodies, such as inorganic glass plates, chrome-plated metal plates, or stainless steel plates, opposite each other at a predetermined distance, and placing a gasket on the edge thereof to form a sealed space with the plate-like bodies and the gasket. For example, a mold for continuous casting may be made by forming a sealed space with the opposing surfaces of a pair of endless belts traveling in the same direction at the same speed, and gaskets traveling at the same speed as the endless belts on both sides of the endless belts.

[0169] The spacing of the voids in the mold is adjusted as needed to obtain a resin plate of the desired thickness, but it is generally between 1 and 30 mm.

[0170] The polymerization temperature is preferably 125 to 210°C, and more preferably 130 to 180°C. The polymerization time is preferably 0.5 to 24 hours.

[0171] The weight-average molecular weight (Mw) of the (meth)acrylic polymer is not particularly limited and can be, for example, 100,000 to 1,000,000. The higher the Mw of the (meth)acrylic polymer, the better the solvent resistance and chemical resistance. The Mw of (meth)acrylic polymers can be controlled by adjusting the polymerization temperature, polymerization time, and the amount of polymerization initiator added.

[0172] The (meth)acrylic polymer of the first embodiment has excellent heat resistance and meltability. For example, granular (meth)acrylic polymers, which have a large amount of resin that can be stored per unit volume and low energy costs during storage and transportation, need to be dissolved or melted when used. The (meth)acrylic polymer of the first embodiment is easily melted, has excellent kneadability with other resins, and has excellent solubility in monomers and solvents.

[0173] 2. Second aspect A second aspect of the embodiment will be described below.

[0174] [Ester compound-containing composition] The ester compound-containing composition according to the second embodiment is at least one selected from the group consisting of ester compound (I) described below and compound (component A2) and compound (component A6) described below. The content of ester compound (I) is 95.00 to 99.99% by mass.

[0175] The ester compound-containing composition may further contain the polymerization inhibitor (component B) described below, in addition to the ester compound (I) and component A2 or component A6. The ester compound-containing composition may optionally contain component B, other compounds (component C), or water, as long as it does not impair the effects of the present invention.

[0176] (Ester compound (I)) Ester compounds (I) are compounds represented by the following formula (I). CH2=CR 150 -C(=O)-OR 200...(I)

[0177] In formula (I), R 150 is a hydrogen atom or a methyl group, R 200 This is a monovalent hydrocarbon group having 2 to 20 carbon atoms, which may have substituents, or a hydrocarbon group having etheric oxygen between carbon atoms of a group having 2 to 8 carbon atoms.

[0178] As ester compound (I), one type may be used alone, or two or more types may be used in combination. As ester compound (I), one or more selected from the group consisting of ester compound (1), ester compound (2), ester compound (3), ester compound (4), and ester compound (5) described below are preferred. These ester compounds will be described below.

[0179] Ester compound (1) is a (meth)acrylic acid ester represented by the following formula (1). CH2=CR 1a -C(=O)-OR 2a ...(1) In formula (1), R 1a R is a hydrogen atom or a methyl group. 2a It is a hydrocarbon group having 2 to 20 carbon atoms.

[0180] R 2a The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. R 2a The hydrocarbon group may be linear, branched, or have a ring. 2a If the hydrocarbon group has a ring, the ring may be an aliphatic ring or an aromatic ring. R 2a The number of carbon atoms in the hydrocarbon group is 2 to 20, preferably 2 to 18, and more preferably 2 to 12.

[0181] R 2aExamples of hydrocarbon groups include C2-C20 alkyl groups, C3-C20 cycloalkyl groups, C2-C20 alkenyl groups, C3-C20 cycloalkenyl groups, C2-C20 alkynyl groups, C6-C20 aryl groups, and C7-C20 aromatic alkyl groups. "Aromatic alkyl group" refers to a group in which one or more hydrogen atoms of an alkyl group are substituted with an aryl group.

[0182] R 2a Examples of alkyl groups include ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, lauryl group, and stearyl group. R 2a Examples of cycloalkyl groups include cyclopropyl, cyclohexyl, and isobornyl groups. R 2a Examples of alkenyl groups include vinyl groups and allyl groups. R 2a Examples of cycloalkenyl groups include cyclopentenyl, cyclopentadienyl, and cyclohexenyl groups. R 2a An example of an alkynyl group is the propynyl group. R 2a Examples of aryl groups include the phenyl group and the naphthyl group. R 2a Examples of aromatic alkyl groups include the benzyl group.

[0183] Since ester compound (1) is relatively easy to obtain and relatively easy to handle in terms of physical properties, R 2aPreferably, the group is an alkyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aromatic alkyl group having 7 to 20 carbon atoms. More preferably, the group is an ethyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a 2-ethylhexyl group, a lauryl group, a stearyl group, a cyclohexyl group, an isobornyl group, an allyl group, a phenyl group, or a benzyl group. Particularly preferred are the n-butyl group and an isobutyl group, with the n-butyl group being the most preferred.

[0184] Examples of ester compounds (1) include ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, allyl (meth)acrylate, phenyl (meth)acrylate, and benzyl (meth)acrylate.

[0185] Because it is relatively easy to obtain and relatively easy to handle in terms of physical properties, R is used as the ester compound (1). 2a Alkyl (meth)acrylates, R, are linear or branched alkyl groups having 2 to 20 carbon atoms. 2a Cycloalkyl (meth)acrylates, which are cycloalkyl groups with 3 to 20 carbon atoms, R 2a Alkenyl (meth)acrylates, which are alkenyl groups with 2 to 20 carbon atoms, R 2a aryl(meth)acrylates, which are aryl groups with 6 to 20 carbon atoms, R 2aAromatic alkyl (meth)acrylates, in which the compound is an aromatic alkyl group having 7 to 20 carbon atoms, are preferred. Ethyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, allyl (meth)acrylate, phenyl (meth)acrylate, and benzyl (meth)acrylate are more preferred. Butyl (meth)acrylate and isobutyl (meth)acrylate are particularly preferred, and butyl (meth)acrylate is most preferred.

[0186] Ester compound (1) may be used alone or in combination of two or more types.

[0187] Ester compound (2) is a (meth)acrylic acid ester represented by the following formula (2). Ester compound (3) is a (meth)acrylic acid ester represented by the following formula (3). Ester compound (4) is a (meth)acrylic acid ester represented by the following formula (4).

[0188] [ka]

[0189] In equations (2), (3), and (4), R 1b , R 3b , R 5b , R 6b , R 8b and R 9b Each of these is independently either a hydrogen atom or a methyl group. 2b and R 4b Each of these is independently a linear or branched alkylene group or hydroxyalkylene group having 2 to 8 carbon atoms. 7b It is a linear or branched trivalent hydrocarbon group having 2 to 8 carbon atoms.

[0190] R 2b and R4b The number of carbon atoms in the alkylene group or hydroxyalkylene group is 2 to 8, preferably 2 to 6. R 2b and R 4b Examples of alkylene groups include ethylene, propylene, isopropylene, and butylene groups. R 2b and R 4b Examples of hydroxyalkylene groups include hydroxyethylene, hydroxypropylene, and hydroxybutylene groups.

[0191] R 7b The number of carbon atoms in the trivalent hydrocarbon group is 2 to 8, preferably 2 to 4. R 7b Examples of the trivalent hydrocarbon group include -(CH2)-C(-CH2-)(-CH3)-CH2-.

[0192] Examples of ester compounds (2) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 3-hydroxypropyl (meth)acrylate. Examples of ester compounds (3) include ethylene glycol di(meth)acrylate, 1,3-propanediol di(meth)acrylate, 1,2-propanediol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate. Examples of ester compounds (4) include trimethylolpropane tri(meth)acrylate.

[0193] Because they are relatively easy to obtain, one or more ester compounds (2), (3), and (4) are preferably selected from the group consisting of ethylene glycol di(meth)acrylate, 2-hydroxyethyl(meth)acrylate, 3-hydroxypropyl(meth)acrylate, and trimethylolpropanetri(meth)acrylate.

[0194] Ester compound (2), ester compound (3), and ester compound (4) may be used individually or in combination of two or more.

[0195] Ester compound (5) is a (meth)acrylic acid ester represented by the following formula (5). CH2=CR 1c -C(=O)-OR 2c ...(5) In formula (5), R 1c R is a hydrogen atom or a methyl group, 2c It is a monovalent group with 2 to 8 carbon atoms that has an ether bond.

[0196] R 2c The number of etheric oxygen atoms in the monovalent group having 2 to 8 carbon atoms and possessing an ether bond is preferably one, but is not limited to two or more. R 2c The monovalent group having 2 to 8 carbon atoms may be linear, branched, or have a ring. 2c If the ring is present, the ring may or may not contain etheric oxygen. R 2c The number of carbon atoms in the monovalent group having an ether bond is 2 to 8, preferably 2 to 7.

[0197] R 2c Examples of such groups include 2-methoxyethyl group, 2-(2-methoxyethoxy)ethyl group, 2-[2-(2-methoxyethoxy)ethoxy]ethyl group, glycidyl group, and tetrahydrofurfuryl group. Because it is relatively easy to obtain and relatively easy to handle in terms of physical properties, R 2c The preferred group is a 2-methoxyethyl group, a glycidyl group, or a tetrahydrofurfuryl group.

[0198] Examples of ester compounds (5) include 2-methoxyethyl (meth)acrylate, glycidyl (meth)acrylate, 2-(2-methoxyethoxy)ethyl (meth)acrylate, 2-[2-(2-methoxyethoxy)ethoxy]ethyl (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate.

[0199] Because they are relatively easy to handle in terms of physical properties, 2-methoxyethyl (meth)acrylate, glycidyl (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate are preferred as ester compounds (5).

[0200] The ester compound (5) may be used alone or in combination of two or more types.

[0201] (Components A2 and A6) The following describes each of these components.

[0202] Component A2 is a compound represented by the following formula (a2).

[0203] [ka]

[0204] In formula (a2), R 21 , R 22 and R 23 Each of these may independently be a monovalent group containing a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, or a carbonyl group, or a monovalent group selected from an alkylthio group or an arylthio group, and R 24 This may be a monovalent group containing a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, a carbonyl group, or an ether group, or R 21 , R 22 , R 23 and R 24 Each of these groups may be a divalent group that may have substituents in combination with any of the other groups. However, R 21 =H and R 22 =H and R 23 =R 150 And R 24 =R 200 Except in the case where the compound represented by formula (a2) is the same as the ester compound (I). H is a hydrogen atom, C is a carbon atom, and O is an oxygen atom.

[0205] Component A6 is a compound represented by the following formula (a6).

[0206] [ka]

[0207] In formula (a6), R 61 , R 62 and R 63 Each of these may independently be a monovalent group containing a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, or a carbonyl group, or a monovalent group selected from an alkylthio group or an arylthio group, and R 64 This may be a monovalent group selected from an alkyl group, alkenyl group, aryl group, hydroxyl group, alkoxy group, amino group, carbonyl group, or ether group, or an alkylthio group or arylthio group, or R 61 , R 62 , R 63 and R 64 Each of these groups may be a divalent group that may have substituents in combination with any of the other groups. However, R 61 =H and R 62 =H and R 63 =R 150 And R 64 =OR 200 This excludes the case where the compound represented by formula (a6) is the same as the ester compound (I).

[0208] The ester compound-containing composition according to the second embodiment contains one or more selected from the group consisting of component A2 and component A6, thereby suppressing the dimerization reaction of ester compound (I) and the formation of oxidation products of ester compound (I) during storage, resulting in an ester compound-containing composition with excellent storage stability. The reason for this is presumed to be as follows.

[0209] During storage of ester compound-containing compositions, ultraviolet-derived radicals are generated, such as hydroxyl radicals produced when oxygen molecules absorb ultraviolet light from sunlight. Such radicals can cause the formation of dimers of ester compound (I) or oxidation products of ester compound (I). Components A2 and A6 have conjugated double bonds and therefore absorb ultraviolet light, with the absorption wavelength varying depending on the type of substituent. Furthermore, components A2 and A6 can absorb ultraviolet light across a wide range of wavelengths. Therefore, when an ester compound-containing composition contains one or more compounds selected from the group consisting of components A2 and A6, ultraviolet light of a wide range of wavelengths is absorbed, and the generation of hydroxyl radicals is suppressed. Thus, it is considered that the generation of dimers of ester compound (I) and oxidation products of ester compound (I) can be efficiently suppressed, and the decrease in purity of ester compound (I) can be suppressed. Among the various organic compounds that absorb ultraviolet light, α,β-unsaturated carbonyl compounds have a molecular structure similar to that of ester compound (I). Therefore, when polymers are manufactured using the ester compound-containing composition as a raw material, the adverse effects of α,β-unsaturated carbonyl compounds being included as impurities can be reduced.

[0210] The molecular weights of component A2 and component A6 are preferably 1000 or less. By having a molecular weight of 1000 or less, the number of conjugated double bonds per unit mass in component A2 and component A6 can be increased, so that the effects of the present invention can be obtained with a small mass. The molecular weights of component A2 and component A6 are more preferably 800 or less, even more preferably 600 or less, and particularly preferably 400 or less.

[0211] In formula (a2), R 21, R 22 and R 23 Each of these may independently be a monovalent group containing a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, or a carbonyl group, or a monovalent group selected from an alkylthio group or an arylthio group, and R 24 This may be a monovalent group containing a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, a carbonyl group, or an ether group, or R 21 , R 22 , R 23 and R 24 Each of these groups may be a divalent group that may have substituents in combination with any of the other groups. 21 , R 22 , R 23 and R 24 These may be the same or different.

[0212] In formula (a6), R 61 , R 62 and R 63 Each of these may independently be a monovalent group containing a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, or a carbonyl group, or a monovalent group selected from an alkylthio group or an arylthio group, and R 64 This may be a monovalent group selected from an alkyl group, alkenyl group, aryl group, hydroxyl group, alkoxy group, amino group, carbonyl group, or ether group, or an alkylthio group or arylthio group, or R 61 , R 62 , R 63 and R 64 Each of these groups may be a divalent group that may have substituents in combination with any of the other groups. 61 , R 62 , R 63 and R 64 These may be the same or different.

[0213] R 21 , R 22 , R 23 , R 24 , R61 , R 62 , R 63 and R 64 When the above conditions are met, the π-conjugated system of component A2 and component A6 is maintained, so that it has the property of absorbing ultraviolet light of a wide range of wavelengths, and the effects of the present invention can be obtained.

[0214] R 21 , R 22 , R 23 , R 61 , R 62 and R 63 Preferably, the substituent is a hydrogen atom, a C1-C5 alkyl group, a C2-C5 alkenyl group, a C1-C12 aryl group, a C1-C6 alkoxy group, an amino group, a carbonyl group, a C1-C5 alkylthio group, or a C1-C12 arylthio group. Since these substituents are highly stable, they prevent components A2 and A6 from transforming into other compounds during storage. Furthermore, when these substituents are present, a sufficient amount of ultraviolet light can be absorbed by one molecule each of component A2 and A6. 21 , R 22 , R 23 , R 61 , R 62 and R 63 It is more preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and even more preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group.

[0215] R 24 It is preferable that the substituent is a monovalent group containing a hydrogen atom, a C1-C5 alkyl group, a C2-C5 alkenyl group, a C1-C12 aryl group, a C1-C6 alkoxy group, an amino group, or a carbonyl group, or a C1-C12 aromatic alkyl group or a C2-C8 monovalent group having an ether bond. Since these substituents are highly stable, they can prevent component A2 from changing into other compounds during storage. 24R is more preferably an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 1 to 5 carbon atoms, and even more preferably a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, clotyl group, n-pentyl group, 2-methyl-1-butyl group or isopentyl group. 24 When this structure is present, the quality stability of the ester compound-containing composition during storage can be improved.

[0216] R 64 The substituents are preferably C1-C5 alkyl groups, C2-C5 alkenyl groups, C1-C12 aryl groups, amino groups, C1-C5 alkylthio groups, or C1-C12 arylthio groups. These substituents are highly stable and can prevent component A6 from changing to other compounds during storage. 64 It is more preferably an alkyl group having 1 to 5 carbon atoms, and even more preferably a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, n-pentyl group, 2-methyl-1-butyl group, or isopentyl group. 64 When this structure is present, the quality stability of the ester compound-containing composition during storage can be improved.

[0217] The alkyl group is a linear (linear or branched) alkyl group or a cyclic alkyl group. C1 to C20 alkyl groups are preferred, C1 to C10 alkyl groups are more preferred, and C1 to C5 alkyl groups are even more preferred. Examples of linear alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n-pentyl group, neopentyl group, isopentyl group, 2-methyl-1-butyl group, hexyl group, octyl group, and decyl group. Among these, methyl group, ethyl group, n-propyl group, isopropyl group, n-pentyl group, isopentyl group, and 2-methyl-1-butyl group are preferred. Examples of cyclic alkyl groups include cyclopentyl group, cyclohexyl group, cyclooctyl group, and isobornyl group. Examples of alkyl groups containing a hydroxyl group include hydroxymethyl group, 1-hydroxyethyl group, and 2-hydroxyethyl group.

[0218] The alkenyl group is a linear (linear or branched) alkenyl group or a cyclic alkenyl group. Alkenyl groups having 2 to 20 carbon atoms are preferred, alkenyl groups having 2 to 10 carbon atoms are more preferred, and alkenyl groups having 2 to 5 carbon atoms are even more preferred. Examples of linear alkenyl groups include vinyl, 1-propenyl, isopropenyl, clotyl, 2-butenyl, 1,3-butadienyl, 2-pentenyl, and 2-hexenyl groups. Examples of cyclic alkenyl groups include cyclopentenyl and cyclohexenyl groups.

[0219] The aryl group is preferably an aryl group having 1 to 20 carbon atoms, and more preferably an aryl group having 1 to 12 carbon atoms. The aryl group includes heteroaryl groups containing oxygen, nitrogen, sulfur, etc. Examples of aryl groups include phenyl, mesityl, naphthyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 2-ethylphenyl, isoxazolyl, isothiazolyl, imidazolyl, oxazolyl, thiazolyl, thiadiazolyl, thienyl, triazolyl, tetrazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridadinyl, pyrazolyl, pyrrolyl, furyl, fluzanyl, isoquinolyl, isoindolyl, indolyl, quinolyl, pyridothiazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, benzotriazolyl, benzofuranyl, imidazopyridinyl, triazopyridinyl, and prinyl groups.

[0220] The aromatic alkyl group is preferably an aromatic alkyl group having 1 to 20 carbon atoms, and preferably an aromatic alkyl group having 1 to 12 carbon atoms. An example of an aromatic alkyl group is the benzyl group.

[0221] The alkoxy group is preferably an alkoxy group having 1 to 20 carbon atoms, more preferably an alkoxy group having 1 to 10 carbon atoms, and even more preferably an alkoxy group having 1 to 6 carbon atoms. Examples of alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, s-butoxy, t-butoxy, n-pentoxy, isopentoxy, and phenoxy groups.

[0222] The amino group includes an amino group (-NH2) with no substituent on the nitrogen atom, and an amino group in which some or all of the hydrogen atoms bonded to the nitrogen atom are substituted with carbon atoms. The number of carbon atoms in the carbon-substituted amino group is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 5. Examples of amino groups include methylamino group, ethylamino group, propylamino group, butylamino group, dimethylamino group, diethylamino group, anilino group, toluidino group, anisidino group, diphenylamino group, and N-methyl-N-phenylamino group.

[0223] Examples of monovalent groups containing a carbonyl group include formyl group, acyl group, carboxyl group, amide group, alkoxycarbonyl group, thiocarboxyl group, and thioester group.

[0224] An acyl group is a substituent formed by linking a carbonyl group to an alkyl group, alkenyl group, or aryl group. The total number of carbon atoms in the acyl group, derived from the carbonyl group (1) and derived from the alkyl group, alkenyl group, or aryl group, is preferably 2 to 20, more preferably 2 to 10, and even more preferably 2 to 6. Examples of acyl groups include acetyl, propionyl, butylcarbonyl, vinylcarbonyl, and benzoyl groups.

[0225] The amide group includes an amide group (-CONH2) without substituents on the nitrogen atom, and an amide group in which some or all of the hydrogen atoms bonded to the nitrogen atom are substituted with carbon atoms. The total number of carbon atoms in the amide group is the sum of the carbon atoms derived from the carbonyl group (1) and the carbon atoms substituted on the nitrogen atom, preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 5. Examples of amide groups include an unsubstituted amide group, an N-methylamide group, an N-ethylamide group, an N-phenylamide group, an N,N-dimethylamide group, and an N-methyl-N-phenylamide group.

[0226] An alkoxycarbonyl group is a substituent formed by linking a carbonyl group and an alkoxy group, and is also called an ester group. The total number of carbon atoms from the carbonyl group (1) and the alkoxy group is preferably 2 to 20, more preferably 2 to 10, and even more preferably 2 to 6. Examples of alkoxycarbonyl groups include methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl, and phenoxycarbonyl groups.

[0227] A thioester group is a substituent formed by linking a carbonyl group with an alkylthio group or an arylthio group. The total number of carbon atoms derived from the carbonyl group (1) and the alkylthio group or arylthio group is preferably 2 to 20, more preferably 2 to 10, and even more preferably 2 to 6. Examples of thioester groups include methylthiocarbonyl group, ethylthiocarbonyl group, butylthiocarbonyl group, and phenylthiocarbonyl group.

[0228] For example, a monovalent group containing a carbonyl group may be a substituent in which one or more hydrogen atoms of an alkyl group are substituted with a carbonyl group. Examples of such substituents include 2-acetoxyethyl group, 2-acetoethyl group, and 2-(acetoacetoxy)ethyl group.

[0229] The alkylthio group is preferably an alkylthio group having 1 to 20 carbon atoms, more preferably an alkylthio group having 1 to 10 carbon atoms, and even more preferably an alkylthio group having 1 to 5 carbon atoms. Examples of alkylthio groups include methylthio group, ethylthio group, propylthio group, and isopropylthio group.

[0230] The arylthio group is preferably an arylthio group having 1 to 20 carbon atoms, more preferably an arylthio group having 3 to 10 carbon atoms, and even more preferably an arylthio group having 6 to 10 carbon atoms. Examples of arylthio groups include phenylthio groups and tolylthio groups.

[0231] Examples of monovalent groups containing an ether group include groups having an etheric oxygen atom between two carbon atoms. The number of etheric oxygen atoms in the above group is preferably one, but is not limited to two or more. Furthermore, the above group may be linear, branched, or have a ring. As such substituents, monovalent groups having 2 to 8 carbon atoms and having an etheric oxygen atom are preferred. Examples of monovalent groups containing an ether group include 2-methoxyethyl group, 2-(2-methoxyethoxy)ethyl group, 2-[2-(2-methoxyethoxy)ethoxy]ethyl group, glycidyl group, and tetrahydrofurfuryl group.

[0232] R 21 and R 22 , R 22 and R 23 , R 23 and R 24 They may each be connected to each other to form a ring. Also, R 61 and R 62 , R 62 and R 63 , R 63 and R 64 They may be connected to each other to form a ring. 21 and R 22 Examples of compounds in which these molecules are linked to form a ring include methyl 2-cyclohexylidenepropionate and methyl 2-cyclopentylidenepropionate. 22 and R 23 Examples of compounds in which these molecules are linked to form a ring include methyl 1-cyclohexene-1-carboxylate and methyl 1-cyclopentene-1-carboxylate. 23 and R 24 Examples of compounds in which these molecules are linked to form a ring include α-methylene-δ-valerolactone and α-methylene-γ-butyrolactone.

[0233] Among the compounds that satisfy the above conditions, from the viewpoint of quality stability during storage of ester compound-containing compositions, the following are selected as component A2: methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, crotyl (meth)acrylate, n-pentyl (meth)acrylate, 2-methyl-1-butyl (meth)acrylate, isopentyl (meth)acrylate, butyl crotate, isobutyl crotate cis-butyl crotate, cis-isobutyl crotate, 2-methylene-3-butenate butyl, 2-methylene-3-butenate isobutyl, 3,3-dimethylacrylate butyl, 3,3-dimethylacrylate isobutyl, 2-ethylacrylate butyl, 2-ethylacrylate isobutyl, 2-pentenoate butyl, 2-pentenoate isobutyl, cinnamate butyl, cinnamate butyl, 3-methoxyacrylate butyl, 3-methoxyacrylate isobutyl, 3-butoxyacrylate butyl, 3-isobutoxyacrylate isobutyl Dibutyl fumarate, isobutyl fumarate, acrylic acid, methacrylic acid, crotonic acid, cis-crotonic acid, 3,3-dimethylacrylic acid, 2-ethylacrylic acid, 2-methylene-3-butenoic acid, butyl 2-cyclohexylidenepropionate, butyl 2-cyclopentylidenepropionate, butyl 1-cyclohexene-1-carboxylate, butyl 1-cyclopentene-1-carboxylate, α-methylene-δ-valerolactone, α-methylene-γ-butyrolactone are preferred, and methyl acrylate, ethyl (meth)acrylate, n-propyl Ropil (meth)acrylate, isopropyl (meth)acrylate, clotyl (meth)acrylate, n-pentyl (meth)acrylate, 2-methyl-1-butyl (meth)acrylate, isopentyl (meth)acrylate, acrylic acid, methacrylic acid, and crotonic acid are more preferred, and ethyl (meth)acrylate, n-propyl (meth)acrylate, clotyl (meth)acrylate, n-pentyl (meth)acrylate, 2-methyl-1-butyl (meth)acrylate, and isopentyl (meth)acrylate are even more preferred.

[0234] Examples of component A6 include acrylamide, methacrylamide, trans-3-hexen-2-one, and isopropenylmethyl ketone. Acrylamide, methacrylamide, and isopropenylmethyl ketone are preferred, and isopropenylmethyl ketone is more preferred.

[0235] In the following description of the second aspect, "component A" refers collectively to components A2 and A6. Component A of the ester compound-containing composition according to the second embodiment may be one type or two or more types.

[0236] (Component B) The ester compound-containing composition according to the second embodiment may further contain a polymerization inhibitor (component B). A polymerization inhibitor is a compound that has the function of suppressing the polymerization reaction of ester compound (I). Examples of polymerization inhibitors include phenolic compounds, quinone compounds, nitrobenzene compounds, N-oxyl compounds, amine compounds, phosphorus-containing compounds, sulfur-containing compounds, iron-containing compounds, copper-containing compounds, and manganese-containing compounds. By including component B, the polymerization reaction of ester compound (I) by the radical polymerization mechanism can be suppressed during storage of ester compound (I). In addition, component B can trap the aforementioned hydroxyl radicals that are generated during storage of ester compound (I). That is, when the ester compound-containing composition contains component B in addition to component A, the amount of hydroxyl radicals can be reduced by two different mechanisms: in addition to suppressing the generation of hydroxyl radicals by component A, the generated hydroxyl radicals can be removed by component B. Therefore, it is considered that the generation of dimers of ester compound (I) and oxidation products of ester compound (I) can be efficiently suppressed, and the decrease in purity of ester compound (I) can be efficiently suppressed.

[0237] Examples of polymerization inhibitors that are phenolic compounds include alkylphenols, hydroxyphenols, aminophenols, nitrophenols, nitrosophenols, alkoxyphenols, and tocopherols.

[0238] Examples of alkylphenols include o-cresol, m-cresol, p-cresol, 2-t-butyl-4-methylphenol, 2,4-dimethyl-6-t-butylphenol, 2,6-di-t-butyl-4-methylphenol, 2-t-butylphenol, 4-t-butylphenol, 2,4-di-t-butylphenol, 2-methyl-4-t-butylphenol, 4-t-butyl-2,6-dimethylphenol, 2,2'-methylenebis(6-t-butyl-4-methylphenol), 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol), and 3,5-di-t-butyl-4-hydroxytoluene.

[0239] Examples of hydroxyphenols include hydroquinone, 2-methylhydroquinone, 2-t-butylhydroquinone, 2,5-di-t-butylhydroquinone, 2,6-di-t-butylhydroquinone, 2,5-di-t-amylhydroquinone, 2-t-butylmethoxyhydroquinone, 2,3,5-trimethylhydroquinone, 2,5-dichlorohydroquinone, 1,2-dihydroxybenzene, 2-acetylhydroquinone, 4-methylcatechol, 4-t-butylcatechol, 2-methylresorcinol, 4-methylresorcinol, and 2,3-dihydroxyacetophenone.

[0240] Examples of aminophenols include o-aminophenol, m-aminophenol, p-aminophenol, 2-(N,N-dimethylamino)phenol, and 4-(ethylamino)phenol.

[0241] Examples of nitrophenols include o-nitrophenol, m-nitrophenol, p-nitrophenol, and 2,4-dinitrophenol. Examples of nitrosophenols include o-nitrosophenol, m-nitrosophenol, p-nitrosophenol, and α-nitroso-β-naphthol.

[0242] Examples of alkoxyphenols include 2-methoxyphenol, 2-ethoxyphenol, 2-isopropoxyphenol, 2-t-butoxyphenol, 4-methoxyphenol, 4-ethoxyphenol, 4-propoxyphenol, 4-butoxyphenol, 4-t-butoxyphenol, 4-heptoxyphenol, hydroquinone monobenzyl ether, t-butyl-4-methoxyphenol, di-t-butyl-4-methoxyphenol, pyrogallol-1,2-dimethyl ether, and hydroquinone monobenzoate.

[0243] Examples of tocopherols include α-tocopherol and 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran.

[0244] Examples of polymerization inhibitors that are quinone compounds include p-benzoquinone, chloro-p-benzoquinone, 2,5-dichloro-p-benzoquinone, 2,6-dichloro-p-benzoquinone, tetrachloro-p-benzoquinone, tetrabromo-p-benzoquinone, 2,3-dimethyl-p-benzoquinone, 2,5-dimethyl-p-benzoquinone, methoxy-p-benzoquinone, and methyl-p-benzoquinone.

[0245] Examples of polymerization inhibitors that are nitrobenzene compounds include nitrobenzene, o-dinitrobenzene, m-dinitrobenzene, p-dinitrobenzene, 2,4-dinitrotoluene, dinitrojulene, and 2,2-diphenyl-1-picrylhydrazyl.

[0246] Examples of polymerization inhibitors that are N-oxyl compounds include 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-oxo-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-acetoxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, 2,2,6,6-tetramethyl-piperidine-N-oxyl, piperidine-1-oxyl, 4-(dimethylamino)-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-amino-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-ethanoloxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, and 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl Examples include 2,2,5,5-tetramethyl-piperidine-N-oxyl, 3-amino-2,2,5,5-tetramethyl-piperidine-N-oxyl, 4,4',4''-tris(2,2,6,6-tetramethyl-piperidine-N-oxyl) phosphite, 3-oxo-2,2,5,5-tetramethylpyrrolidine-N-oxyl, pyrrolidine-1-oxyl, 2,2,5,5-tetramethyl-1-oxa-3-azacyclopentyl-3-oxy, 2,2,5,5-tetramethyl-3-pyrrolinyl-1-oxy-3-carboxylic acid, 2,2,3,3,5,5,6,6-octamethyl-1,4-diazacyclohexyl-1,4-dioxy, di-tert-butyl nitroxide, di-tert-amyl nitroxide, etc.

[0247] Examples of polymerization inhibitors that are amine compounds include N,N-diphenylamine, alkylated diphenylamine, 4,4'-dicumyl-diphenylamine, 4,4'-dioctyldiphenylamine, 4-aminodiphenylamine, p-nitrosodiphenylamine, N-nitrosodinaphthylamine, N-nitrosodiphenylamine, N-nitrosophenylnaphthylamine, N-nitrosophenylhydroxylamine, N,N'-dialkyl-p-phenylenediamine (the alkyl groups may be the same or different, and each group consists of 1 to 4 carbon atoms independently of each other, and may be linear or branched), N,N'-diphenyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-1,4-phenylenediamine, Examples include N,N'-di-2-naphthyl-p-phenylenediamine, N,N-diethylhydroxylamine, 1,4-benzenediamine, N-(1,4-dimethylpentyl)-N'-phenyl-1,4-benzenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-1,4-benzenediamine, 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, aldol-α-naphthylamine, N-phenyl-β-naphthylamine, 4-hydroxy-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 1,4-dihydroxy-2,2,6,6-tetramethylpiperidine, and 1-hydroxy-4-benzoylioxy-2,2,6,6-tetramethylpiperidine.

[0248] Examples of polymerization inhibitors containing phosphorus include triphenylphosphine, triphenyl phosphite, triethyl phosphite, tris(isodecyl) phosphite, tris(tridecyl) phosphite, phenyldiisooctyl phosphite, phenyldiisodecyl phosphite, phenyldi(tridecyl) phosphite, diphenylisooctyl phosphite, diphenylisodecyl phosphite, diphenyltridecyl phosphite, phosphonic acid [1,1-diphenyl-4,4'-diylbistetrakis-2,4-bis(1,1-dimethylethyl)phenyl] ester, triphenyl phosphite, tris(nonylphenyl) phosphite, 4,4'-isopropylidenediphenolalkyl phosphite, tris(2,4-di-tert-butylphenyl) phosphite, tris(biphenyl) phosphite, and distearyl phosphate. Examples include pentaerythritol diphosphite, di(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, di(nonylphenyl)pentaerythritol diphosphite, phenylbisphenol A pentaerythritol diphosphite, tetra(tridecyl)-4,4'-butylidenebis(3-methyl-6-tert-butylphenol) diphosphite, hexa(tridecyl)-1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane triphosphite, 3,5-di-tert-butyl-4-hydroxybenzyl phosphate diethyl ester, sodium-bis(4-tert-butylphenyl) phosphate, sodium-2,2'-methylene-bis(4,6-di-tert-butylphenyl) phosphate, and 1,3-bis(diphenoxyphosphonyloxy)benzene.

[0249] Examples of polymerization inhibitors containing sulfur include diphenyl sulfide, phenothiazine, 3-oxofhenothiazine, 5-oxofhenothiazine, phenothiazine dimers, 1,4-dimercaptobenzene, 1,2-dimercaptobenzene, 2-mercaptophenol, 4-mercaptophenol, 2-(methylthio)phenol, 3,7-bis(dimethylamino)phenothiazinium chloride, and elemental sulfur.

[0250] Examples of polymerization inhibitors that contain iron include iron(III) chloride.

[0251] Examples of polymerization inhibitors containing copper include copper dimethyldithiocarbamate, copper diethyldithiocarbamate, copper dibutyldithiocarbamate, copper salicylate, copper acetate, copper thiocyanate, copper nitrate, copper chloride, copper carbonate, copper hydroxide, copper acrylate, and copper methacrylate.

[0252] Examples of manganese-containing polymerization inhibitors include manganese dialkyldithiocarbamate (the alkyl group is one of methyl, ethyl, propyl, or butyl groups, and may be the same or different), manganese diphenyldithiocarbamate, manganese formate, manganese acetate, manganese octanoate, manganese naphthenate, manganese permanganate, and manganese salts of ethylenediaminetetraacetic acid.

[0253] In particular, from the viewpoint of quality stability during storage of the ester compound-containing composition, component B is preferably at least one polymerization inhibitor selected from the group consisting of phenolic compounds, N-oxyl compounds, amine compounds, phosphorus-containing compounds, and sulfur-containing compounds; more preferably at least one polymerization inhibitor selected from the group consisting of hydroquinone, 4-methoxyphenol, 2,4-dimethyl-6-t-butylphenol, 2,6-di-t-butyl-4-methylphenol, 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, N,N-diphenylamine, N-nitrosodiphenylamine, triphenyl phosphite, and phenothiazine; and even more preferably at least one polymerization inhibitor selected from the group consisting of hydroquinone, 4-methoxyphenol, 2,4-dimethyl-6-t-butylphenol, and 2,6-di-t-butyl-4-methylphenol.

[0254] Component B may be one type or two or more types. If an ester compound-containing composition contains a compound that corresponds to both component A2 and component B, that compound shall be considered as component A2. If an ester compound-containing composition contains both component A2 and component B, it means that the ester compound-containing composition contains a component B that is different from the compound A2. If an ester compound-containing composition contains two or more compounds that fall under both component A2 and component B, the compound with the highest molar concentration in the ester compound-containing composition shall be considered component A2, and the other compounds shall be considered component B. Similarly, with respect to component A6, if an ester compound-containing composition contains a compound that corresponds to both component A6 and component B, that compound shall be considered as component A6.

[0255] The content of component A is not particularly limited, but is preferably 1 to 10,000 ppm by mass. A content of 1 ppm by mass or more of component A sufficiently suppresses the formation of dimers of ester compound (I) and oxidation products of ester compound (I). Furthermore, a content of 10,000 ppm by mass or less of component A reduces the amount of impurities when a (meth)acrylic polymer is produced by polymerization of the ester compound-containing composition according to the second embodiment, preventing adverse effects on the properties of the polymer. A content of component A is more preferably 3 ppm by mass or more, even more preferably 5 ppm by mass or more, and particularly preferably 10 ppm by mass or more. A content of component A is more preferably 7,500 ppm by mass or less, even more preferably 5,000 ppm by mass or less, even more preferably 2,500 ppm by mass or less, even more preferably 1,500 ppm by mass or less, particularly preferably 1,000 ppm by mass or less, and most preferably 500 ppm by mass or less. The content of component A is the sum of the individual content of components A2 and A6.

[0256] The content of component B is not particularly limited, but is preferably 1 to 1000 ppm by mass. A component B content of 1 ppm by mass or more provides sufficient suppression of the formation of ester compound (I) dimers and oxidation products of ester compound (I). Furthermore, a component B content of 1000 ppm by mass or less reduces the amount of impurities when a (meth)acrylic polymer is produced by polymerization of the ester compound-containing composition according to the second embodiment, preventing adverse effects on the properties of the polymer. A component B content of 3 ppm by mass or more is more preferable, 5 ppm by mass or more is even more preferable, and 10 ppm by mass or more is particularly preferable. A component B content of 750 ppm by mass or less is more preferable, 500 ppm by mass or less is even more preferable, 250 ppm by mass or less is even more preferable, 100 ppm by mass or less is particularly preferable, and 50 ppm by mass or less is most preferable.

[0257] (Content of ester compound (I)) The content of ester compound (I) is 95.00 to 99.99% by mass. A content of ester compound (I) of 90% by mass or more reduces the amount of impurities when a (meth)acrylic polymer is produced by polymerization of the ester compound-containing composition, preventing adverse effects on the properties of the polymer. Furthermore, a content of ester compound (I) of 99.99% by mass or less reduces the purification cost. A content of ester compound (I) of 96.00% by mass or more is preferred, 97.00% by mass or more is more preferred, 98.00% by mass or more is even more preferred, 99.00% by mass or more is particularly preferred, and 99.50% by mass or more is most preferred.

[0258] If ester compound (I) contains ester compound (1) but does not contain ester compound (2), ester compound (3), ester compound (4), and ester compound (5), the content of ester compound (I) is equal to the concentration of ester compound (1).

[0259] If ester compound (I) contains ester compound (5) and does not contain ester compound (1a), ester compound (2), ester compound (3), and ester compound (4), the content of ester compound (I) is equal to the concentration of ester compound (5).

[0260] If ester compound (I) contains at least one selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4), and does not contain ester compound (1) and ester compound (5), then the content of ester compound (I) is the concentration of at least one selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4).

[0261] (Component C) The ester compound-containing composition according to the second embodiment may contain other compounds (component C) as long as the content of ester compound (I) satisfies 95.00 to 99.99% by mass. Examples of additives include mold release agents, lubricants, plasticizers, antioxidants, antistatic agents, light stabilizers, ultraviolet absorbers, flame retardants, flame retardant aids, polymerization inhibitors, fillers, pigments, dyes, silane coupling agents, leveling agents, defoamers, fluorescent agents, and the like. The ester compound-containing composition may contain unreacted raw materials from the production of the ester compound-containing composition, such as methyl (meth)acrylate, alcohol, and (meth)acrylic acid. The ester compound-containing composition may contain impurities generated during the production of the ester compound-containing composition, such as diacetyl. However, from the viewpoint of reducing the discoloration of the ester compound-containing composition, the concentration of diacetyl is preferably 5 ppm by mass or less, more preferably 2 ppm by mass or less, even more preferably 1 ppm by mass or less, and particularly preferably 0.1 ppm by mass or less. The ester compound-containing composition may also contain (meth)acrylic acid esters other than ester compound (1).

[0262] (Analysis of compositions containing ester compounds) The presence of ester compound-containing compositions as components A, B, C, and water can be confirmed, for example, by GC-MS measurement. If the GC-MS chart of the ester compound-containing composition shows a peak at the same retention time as the standard of component A2, and the m / z value detected in the mass spectrum of that peak matches the exact mass of component A2, then the ester compound-containing composition can be determined to contain component A. If a standard of component A2 is unavailable, the peak can be determined to be component A2 if the mass spectrum pattern of the peak appearing in the GC-MS chart of the ester compound-containing composition matches the mass spectrum pattern of component A2 recorded in a mass spectrum database. In other words, the ester compound-containing composition can be determined to contain component A. Examples of mass spectrum databases include NIST20, NIST17, NIST14, and NIST14s. Furthermore, if the volatility is low and detection by GC-MS measurement is not possible, detection can be performed using LC-MS. The presence of components A6, B, C, and water can also be confirmed by a similar method.

[0263] The content of ester compound (I) can be calculated, for example, by performing GC-FID measurement on the ester compound-containing composition, quantifying it using the area percentage method, and correcting it using the moisture content quantified with a Karl Fischer moisture meter.

[0264] The concentration of component A2 can be quantified, for example, by GC measurement or GC-MS measurement of an ester compound-containing composition, using the internal standard method or absolute calibration curve method. If a standard sample of component A2 cannot be obtained and quantification cannot be performed using the internal standard method or absolute calibration curve method, the concentration of component A2 can be calculated using the following formula by performing GC-FID measurement on any organic compound with a known concentration under the same conditions as the ester compound-containing composition.

[0265]

number

[0266] Here, N is the number of carbon atoms contained in one molecule of an organic compound with a known concentration. A2 is the number of carbon atoms contained in one molecule of component A2, S A2 ∫ is the peak area of ​​component A2, S is the peak area of ​​the organic compound with a known concentration, and M is the concentration (μmol / L) of the organic compound with a known concentration. If the volatility is low and quantification by GC measurement is not possible, quantification can be performed using chromatographic methods such as LC.

[0267] The concentrations of components A6, B, and C can also be calculated using the same method as for component A2. The presence of water in an ester compound-containing composition, and its concentration, can be confirmed by the Karl Fischer method.

[0268] (Method for producing ester compound-containing compositions) A method for producing an ester compound-containing composition is to produce a composition in the presence of one or more compounds selected from the group consisting of component A2 and component A6. One or more alcohols selected from the group consisting of monoalcohols with 2 to 20 carbon atoms, ether-containing alcohols with 2 to 8 carbon atoms, dialcohols with 2 to 8 carbon atoms, and trialcohols with 2 to 8 carbon atoms, This involves carrying out a transesterification reaction with methyl (meth)acrylate.

[0269] Methyl (meth)acrylate is particularly prone to dimerization and oxidation to produce methyl pyruvate among (meth)acrylic acid esters. However, by carrying out the transesterification reaction in the presence of component A, the dimerization of methyl (meth)acrylate and the production of methyl pyruvate are suppressed, resulting in an improved yield of ester compound (I).

[0270] For example, to obtain an ester compound-containing composition containing ester compound (1) as ester compound (I), transesterification of methyl (meth)acrylate and a monoalcohol having 2 to 20 carbon atoms is carried out in a reactor in the presence of a catalyst and component A, as shown in formula (II) below.

[0271] [ka]

[0272] R in equation (II) 1a and R 2a R in equation (1) 1a and R 2a It is the same as this.

[0273] Examples of monoalcohols having 2 to 20 carbon atoms include ethanol, n-butanol, isobutanol, t-butanol, 2-ethylhexanol, lauryl alcohol, stearyl alcohol, cyclohexanol, isobornyl alcohol, allyl alcohol, phenol, and benzyl alcohol. Monoalcohols having 2 to 20 carbon atoms may be used individually or in combination of two or more. The monoalcohols having 2 to 20 carbon atoms preferably include linear or branched monoalcohols having 2 to 20 carbon atoms, and more preferably include n-butanol and isobutanol.

[0274] For example, to obtain an ester compound-containing composition containing ester compound (5) as ester compound (I), transesterification is carried out in a reactor in the presence of a catalyst and component A, as shown in formula (III) below, between methyl (meth)acrylate and an ether-bonded alcohol having 2 to 8 carbon atoms.

[0275] [ka]

[0276] R in equation (III) 1c and R 2c R in equation (5) 1c and R 2c It is the same as this.

[0277] In ether-bonded alcohols with 2 to 8 carbon atoms, one ether bond is preferred, but not limited to that. Examples of ether-containing alcohols having 2 to 8 carbon atoms include 2-methoxyethanol, glycidyl alcohol, and tetrahydrofurfuryl alcohol. These ether-containing alcohols may be used individually or in combination of two or more. The ether-bonded alcohol having 2 to 8 carbon atoms preferably includes one selected from 2-methoxyethanol, glycidyl alcohol, and tetrahydrofurfuryl alcohol.

[0278] For example, to obtain an ester compound-containing composition containing at least one selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4) as ester compound (I), transesterification is carried out in a reactor in the presence of a catalyst and component A, with methyl (meth)acrylate and one or more alcohols selected from the group consisting of dialcohols having 2 to 8 carbon atoms and trialcohols having 2 to 8 carbon atoms, as shown in the following formulas (IV) and (V).

[0279] [ka]

[0280] R in equations (IV) and (V) 1b , R 2b , R 3b , R 5b , R 6b and R 7b R in equations (2), (3), and (4) is 1b , R 2b , R 3b , R 5b , R 6b and R 7b It is the same as R. 41b R is a linear or branched alkylene group having 2 to 8 carbon atoms. 42b This is a linear or branched hydroxyalkylene group having 2 to 8 carbon atoms.

[0281] Examples of dialcohols and trialcohols having 2 to 8 carbon atoms include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,6-hexanediol, and trimethylolpropane. In particular, it is preferable that the dialcohols and trialcohols having 2 to 8 carbon atoms include one or more selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, and trimethylolpropane. Dialcohols and trialcohols having 2 to 8 carbon atoms may be used individually or in combination of two or more.

[0282] The reactor is preferably equipped with a distillation column. Since this transesterification reaction is an equilibrium reaction, productivity can be improved by separating the by-product methanol using a distillation column. For example, it is preferable to carry out the transesterification reaction while separating methanol from the system as an azeotropic mixture with methyl (meth)acrylate.

[0283] Examples of such reactors include those equipped with a distillation column on top of a reaction vessel called a reaction kettle, and distillation columns in which a distillation boiler can be used as a reaction vessel. Examples of distillation columns include packed column type and tray type distillation columns. The theoretical number of stages in a distillation column is preferably five or more, and more preferably seven or more, from the standpoint of high separation capacity and stable operation.

[0284] The ratio of methyl (meth)acrylate to alcohol can be determined as appropriate. From the viewpoint of increasing productivity, the ratio of methyl (meth)acrylate to 1 mole of alcohol is preferably 0.1 mole to 10 moles, and more preferably 0.3 mole to 4 moles.

[0285] The catalysts used are not particularly limited, but examples include hydroxides, carbonates, and bicarbonates of alkali metals such as lithium, sodium, and potassium; oxides, hydroxides, and carbonates of alkaline earth metals such as magnesium and calcium; alkali metal alkoxides such as lithium methoxide, sodium methoxide, sodium ethoxide, and potassium t-butoxy; alkali metal amides such as lithium amide, sodium amide, and potassium amide; titanium alkoxides such as tetramethyl titanate, tetraethyl titanate, tetrapropyl titanate, tetraisopropyl titanate, tetrabutyl titanate, and tetra(2-ethylhexyl) titanate; and tin compounds such as dibutyltin oxide and dioctyltin oxide. Among these, titanium alkoxides, dibutyltin oxide, and dioctyltin oxide are preferred because they produce fewer by-products of the Michael addition reaction during the transesterification reaction and have high catalytic activity. The catalysts may be used alone or in combination of two or more.

[0286] The catalyst can be supplied to the reactor on its own. Alternatively, the catalyst can be supplied to the reactor dissolved in the same alcohol as the raw material, or dissolved in the (meth)acrylic acid ester of the raw material. For example, one method is to supply the catalyst directly dissolved in the entire amount of alcohol used in the reaction to the reactor, or to supply the catalyst dissolved in a portion of the alcohol used in the reaction to the reactor. The amount of catalyst used is preferably 0.001 mol% or more and 1 mol% or less per 1 mol of alcohol, and more preferably 0.01 mol% or more and 0.1 mol% or less.

[0287] A solvent may be used in the transesterification reaction. If a solvent is used, it is preferable to use a solvent that forms an azeotropic composition with the by-product methanol. Examples of solvents include n-pentane, n-hexane, n-heptane, n-octane, 2,3-dimethylbutane, 2,5-dimethylhexane, 2,2,4-trimethylpentane, cyclohexane, benzene, and toluene. Among these, n-hexane, n-heptane, and cyclohexane are preferred. The solvent may be used alone or in combination of two or more.

[0288] The reaction temperature for transesterification varies depending on the type of alcohol and solvent, but it is preferably between 60°C and 150°C. The reaction pressure for the transesterification reaction is not particularly limited, and the reaction may be carried out under any pressure: reduced pressure, atmospheric pressure, or increased pressure.

[0289] The form of the transesterification reaction is not particularly limited and can be carried out using commonly used methods such as batch reactions or continuous reactions. After the transesterification reaction, unreacted starting materials and by-products may be separated by purifying the reaction mixture. Various methods can be used for purification, such as distillation, crystallization, extraction, and column chromatography.

[0290] The transesterification reaction may also be carried out with component B added to the reaction solution. The presence of component B in addition to component A further suppresses the dimerization of methyl (meth)acrylate and the formation of methyl pyruvate, thus making it easier to obtain an improved yield of ester compound (I).

[0291] Component B may be added to the solution containing the ester compound (I) and component A after the transesterification reaction. In this case, a separate solution containing the ester compound (I) and component B (solution B) can be prepared in addition to the solution containing the ester compound (I) and component A (solution A), and solutions A and B can be mixed to obtain an ester compound-containing composition. Alternatively, the ester compound (I), solution A, and solution B can be mixed to obtain an ester compound-containing composition.

[0292] The method for producing the ester compound-containing composition is not limited to the method described above. For example, other (meth)acrylic acid esters may be used instead of methyl (meth)acrylate as a raw material. Ester compound (I) may be produced by carrying out an esterification reaction between an alcohol and (meth)acrylic acid.

[0293] (Method for evaluating the storage stability and thermal stability of ester compound-containing compositions) Ester compound-containing compositions exhibit high quality stability during storage. Methods for evaluating the quality stability of ester compound-containing compositions during storage include, for example, actually storing the ester compound-containing composition for a long period and confirming the amount of ester compound (I) dimers and oxidation products produced, as well as the ester compound (I) content. Alternatively, from the viewpoint of ease of operation, a method of briefly heating the ester compound-containing composition and confirming the amount of ester compound (I) dimers and oxidation products produced, as well as the ester compound (I) content, may be used. When heating for a short time, the heating temperature is preferably 50-100°C, and the heating time is preferably 1-24 hours. The quality stability of ester compound-containing compositions during storage is evaluated based on the amount of ester compound (I) dimers and oxidation products produced, and the ester compound (I) content, when the ester compound-containing composition is stored at 25°C for 14 days or heated at 70°C for 7-20 hours.

[0294] [Polymerizable composition] The polymerizable composition according to the second embodiment includes the ester compound-containing composition of the second embodiment described above. The polymerizable composition is a polymerizable composition for producing a (meth)acrylic polymer. For example, an ester compound-containing composition that has been stored for more than one day after manufacturing can be used in a polymerizable composition. The storage time for ester compound-containing compositions may be 1 day or more, 3 days or more, 7 days or more, or 14 days or more. Alternatively, the storage time for ester compound-containing compositions may be 180 days or less, 150 days or less, 120 days or less, or 90 days or less. "Storage time" is not limited to the time spent standing in a specific environment, but includes transportation time, etc., and refers to the elapsed time from immediately after manufacture.

[0295] The material of the storage container for the ester compound-containing composition is not particularly limited; for example, metal containers such as stainless steel, resin containers, and glass containers can be used. Either transparent or opaque containers can be used.

[0296] The storage temperature for ester compound-containing compositions is preferably -10°C or higher, more preferably 0°C or higher, preferably 60°C or lower, and more preferably 50°C or lower. A temperature of -10°C or higher reduces the load on the cooling system, and a temperature of 60°C or lower makes it easier to suppress the formation of (meth)acrylic acid ester dimers and oxidation products.

[0297] The oxygen concentration in the gas phase when storing an ester compound-containing composition is preferably 5% by volume or more, more preferably 7% by volume or more, preferably 30% by volume or less, and more preferably 22% by volume or less. Setting the oxygen concentration in the gas phase to 5% by volume or more makes it easier to prevent the ester compound from unintentionally polymerizing due to the polymerization-inhibiting effect of oxygen, and setting it to 30% by volume or less makes it easier to suppress the oxidation of (meth)acrylic acid ester by oxygen and the generation of various impurities.

[0298] For example, the ester compound-containing composition after storage may be used as a polymerizable composition without further addition of monomers, or other monomers copolymerizable with ester compound (I) may be further added to the ester compound-containing composition after storage to form a polymerizable composition. In another example, the ester compound-containing composition may be stored after production with other monomers copolymerizable with ester compound (I) before being used as a polymerizable composition. In this case, it is preferable not to include a polymerization initiator during storage.

[0299] The ratio of ester compound (I) to the total mass of monomers in the polymerizable composition is preferably 10% by mass or more, more preferably 20% by mass or more, preferably 90% by mass or less, and more preferably 80% by mass or less. This makes it possible to obtain a highly transparent (meth)acrylic polymer.

[0300] The ester compound-containing composition may contain other monomers copolymerizable with ester compound (I), or it may not contain other monomers copolymerizable with ester compound (I). Other monomers copolymerizable with ester compound (I) include, for example, Other monomers copolymerizable with ester compound (1); Other monomers copolymerizable with ester compound (5); other monomers copolymerizable with at least one selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4); These are some examples.

[0301] (Other monomers copolymerizable with ester compound (1)) Other monomers copolymerizable with ester compound (1) include, for example, methyl (meth)acrylate, unsaturated carboxylic acid, unsaturated carboxylic acid anhydride, maleimide, hydroxyl group-containing vinyl monomer, vinyl ester, nitrogen-containing vinyl monomer, epoxy group-containing monomer, aromatic vinyl monomer, alkanediol di(meth)acrylate, polyoxyalkylene glycol di(meth)acrylate, and vinyl monomers having two or more ethylenically unsaturated bonds in the molecule.

[0302] Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, and itaconic acid. Examples of unsaturated carboxylic acid anhydrides include maleic anhydride and itaconic anhydride. Examples of maleimides include N-phenylmaleimide and N-cyclohexylmaleimide.

[0303] Examples of hydroxyl group-containing vinyl monomers include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate. Examples of vinyl esters include vinyl acetate and vinyl benzoate. Examples of nitrogen-containing vinyl monomers include methacrylamide and acrylonitrile. Examples of epoxy group-containing monomers include glycidyl acrylate and glycidyl methacrylate.

[0304] Examples of aromatic vinyl monomers include styrene and α-methylstyrene. Examples of alkanediol di(meth)acrylates include ethylene glycol di(meth)acrylate, 1,2-propylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate.

[0305] Examples of polyoxyalkylene glycol di(meth)acrylates include diethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, triethylene glycol (meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and neopentyl glycol di(meth)acrylate. Examples of vinyl monomers having two or more ethylenically unsaturated bonds in their molecules include divinylbenzene.

[0306] Other monomers that may be used include vinyl chloride, vinylidene chloride and their derivatives, unsaturated polyester prepolymers obtained from at least one polycarboxylic acid and at least one diol, including ethylenically unsaturated polycarboxylic acids, and vinyl ester prepolymers obtained by modifying the ends of epoxy groups with acrylic. Other monomers may be used individually or in combination of two or more.

[0307] (Other monomers copolymerizable with at least one selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4)) Other monomers copolymerizable with at least one selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4) include, for example, the same monomers copolymerizable with ester compound (1).

[0308] (Other monomers copolymerizable with ester compound (5)) Other monomers copolymerizable with ester compound (5) include the same monomers copolymerizable with ester compound (1).

[0309] The polymerizable composition preferably further contains a polymerization initiator. Examples of polymerization initiators include azo compounds, organic peroxides, persulfate compounds, and redox polymerization initiators. A single polymerization initiator may be used, or two or more may be used in combination.

[0310] Examples of azo compounds include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2-methylpropionitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4,4-trimethylpentane), 2,2'-azobis(2-methylpropane), 1,1-azobis(cyclohexanecarbonitride), and dimethyl-2,2'-azobisisobutyrate.

[0311] Examples of organic peroxides include benzoyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, 1,1-bis(t-butylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)-3,5,5-trimethylcyclohexane, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxybenzoate, t-hexylperoxybenzoate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, t-butylperoxyacetate, and t-hexylperoxyisopropyl monocarbonate. Examples include t-hexyl peroxy-2-ethylhexanoate, t-amyl peroxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutyl peroxyethyl hexanoate, 1,1,2-trimethylpropyl peroxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutyl peroxyisopropyl monocarbonate, 1,1,2-trimethylpropyl peroxyisopropyl monocarbonate, 1,1,3,3-tetramethylbutyl peroxyisononoate, 1,1,2-trimethylpropyl peroxyisononoate, di-t-butyl peroxide, di-t-hexyl peroxide, lauroyl peroxide, and dilauroyl peroxide.

[0312] Examples of persulfate compounds include potassium persulfate.

[0313] The amount of polymerization initiator added is not particularly limited, and can be, for example, 0.005 to 5 parts by mass per 100 parts by mass of the total mass of monomers in the polymerizable composition.

[0314] For example, various additives such as mold release agents, lubricants, plasticizers, antioxidants, antistatic agents, light stabilizers, UV absorbers, flame retardants, flame retardant aids, polymerization inhibitors, fillers, pigments, dyes, silane coupling agents, leveling agents, defoamers, fluorescent agents, and chain transfer agents may be added to the ester compound-containing composition after storage, as needed.

[0315] [Meth)acrylic polymer manufacturing method] (Meth)acrylic polymers can be produced by polymerizing polymerizable compositions. The polymerization method is not particularly limited and includes, for example, bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization. Bulk polymerization is preferred from the viewpoint of environmental impact due to solvent use and the transparency of the resulting (meth)acrylic polymer. The method of bulk polymerization is not particularly limited and can include various casting polymerization methods such as cell casting and continuous casting. Cast polymerization is a method for obtaining a (meth)acrylic polymer by injecting a polymerizable composition into a mold consisting of two inorganic glass plates or metal plates (e.g., SUS plates) that are placed opposite each other at a predetermined distance and sealed around the periphery with a gasket such as a flexible resin tube, and allowing polymerization to proceed. The mold for casting polymerization is not particularly limited, and various types of molds can be used. For example, a mold for cell casting may be made by arranging two plate-like bodies, such as inorganic glass plates, chrome-plated metal plates, or stainless steel plates, opposite each other at a predetermined distance, and placing a gasket on the edge thereof to form a sealed space with the plate-like bodies and the gasket. For example, a mold for continuous casting may be made by forming a sealed space with the opposing surfaces of a pair of endless belts traveling in the same direction at the same speed, and gaskets traveling at the same speed as the endless belts on both sides of the endless belts. The spacing of the voids in the mold is adjusted as needed to obtain a resin plate of the desired thickness, but it is generally between 1 and 30 mm. The polymerization temperature is preferably between 125°C and 210°C, and more preferably between 130°C and 180°C. The polymerization time is preferably between 0.5 hours and 24 hours.

[0316] The weight-average molecular weight (Mw) of the (meth)acrylic polymer is not particularly limited and can be, for example, between 100,000 and 1,000,000. The higher the Mw of the (meth)acrylic polymer, the better the solvent resistance and chemical resistance. The Mw of (meth)acrylic polymers can be controlled by adjusting the polymerization temperature, polymerization time, and the amount of polymerization initiator added.

[0317] The (meth)acrylic polymer of the second embodiment exhibits excellent heat resistance and meltability. For example, granular (meth)acrylic polymers, which have a large amount of resin that can be stored per unit volume and low energy costs during storage and transportation, need to be dissolved or melted when used. The (meth)acrylic polymer of the second embodiment is easily melted, has excellent kneadability with other resins, and has excellent solubility in monomers and solvents. Furthermore, it also has the characteristic of having a low thermal weight loss rate in high-temperature environments.

[0318] 3. Third aspect A third aspect of the embodiment will be described below.

[0319] [Ester compound-containing composition] The ester compound-containing composition according to the third embodiment contains the ester compound (I) described below and the compound (component A7) described below. The content of ester compound (I) is 95.00 to 99.99% by mass.

[0320] The ester compound-containing composition may further contain, in addition to the ester compound (I) and component A7, a polymerization inhibitor (component B) described below. The ester compound-containing composition may optionally contain component B in addition to ester compound (I) and component A7, as long as it does not impair the effects of the present invention, and may further contain at least one of ester compound (I), component A7 and component B, a compound other than component C (hereinafter also referred to as component C), and water.

[0321] (Ester compound (I)) Ester compounds (I) are compounds represented by the following formula (I). CH2=CR 150 -C(=O)-OR 200 ...(I)

[0322] In formula (I), R 150 is a hydrogen atom or a methyl group, R 200 This is a monovalent hydrocarbon group having 2 to 20 carbon atoms, which may have substituents, or a monovalent group having 2 to 8 carbon atoms and having an ether bond.

[0323] As ester compound (I), one type may be used alone, or two or more types may be used in combination. As ester compound (I), one or more selected from the group consisting of ester compound (1), ester compound (2), ester compound (3), ester compound (4), and ester compound (5) described below are preferred. These ester compounds will be described below.

[0324] Ester compound (1) is a (meth)acrylic acid ester represented by the following formula (1). CH2=CR 1a -C(=O)-OR 2a ...(1) In formula (1), R 1a R is a hydrogen atom or a methyl group. 2a It is a hydrocarbon group having 2 to 20 carbon atoms.

[0325] R 2a The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. R 2a The hydrocarbon group may be linear, branched, or have a ring. 2a If the hydrocarbon group has a ring, the ring may be an aliphatic ring or an aromatic ring. R 2a The number of carbon atoms in the hydrocarbon group is 2 to 20, preferably 2 to 18, and more preferably 2 to 12.

[0326] R 2a Examples of hydrocarbon groups include C2-C20 alkyl groups, C3-C20 cycloalkyl groups, C2-C20 alkenyl groups, C3-C20 cycloalkenyl groups, C2-C20 alkynyl groups, C6-C20 aryl groups, and C7-C20 aromatic alkyl groups. "Aromatic alkyl group" refers to a group in which one or more hydrogen atoms of an alkyl group are substituted with an aryl group.

[0327] R 2a Examples of alkyl groups include ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, lauryl group, and stearyl group. R 2a Examples of cycloalkyl groups include cyclopropyl, cyclohexyl, and isobornyl groups. R 2a Examples of alkenyl groups include vinyl groups and allyl groups. R 2a Examples of cycloalkenyl groups include cyclopentenyl, cyclopentadienyl, and cyclohexenyl groups. R 2a An example of an alkynyl group is the propynyl group. R 2a Examples of aryl groups include the phenyl group and the naphthyl group. R 2a Examples of aromatic alkyl groups include the benzyl group.

[0328] Since ester compound (1) is relatively easy to obtain and relatively easy to handle in terms of physical properties, R 2aPreferably, the group is an alkyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aromatic alkyl group having 7 to 20 carbon atoms. More preferably, the group is an ethyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a 2-ethylhexyl group, a lauryl group, a stearyl group, a cyclohexyl group, an isobornyl group, an allyl group, a phenyl group, or a benzyl group. Particularly preferred are the n-butyl group and an isobutyl group, with the n-butyl group being the most preferred.

[0329] Examples of ester compounds (1) include ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, allyl (meth)acrylate, phenyl (meth)acrylate, and benzyl (meth)acrylate.

[0330] Because it is relatively easy to obtain and relatively easy to handle in terms of physical properties, R is used as the ester compound (1). 2a Alkyl (meth)acrylates, R, are linear or branched alkyl groups having 2 to 20 carbon atoms. 2a Cycloalkyl (meth)acrylates, which are cycloalkyl groups with 3 to 20 carbon atoms, R 2a Alkenyl (meth)acrylates, which are alkenyl groups with 2 to 20 carbon atoms, R 2a aryl(meth)acrylates, which are aryl groups with 6 to 20 carbon atoms, R 2aAromatic alkyl (meth)acrylates, in which the compound is an aromatic alkyl group having 7 to 20 carbon atoms, are preferred. Ethyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, allyl (meth)acrylate, phenyl (meth)acrylate, and benzyl (meth)acrylate are more preferred. Butyl (meth)acrylate and isobutyl (meth)acrylate are particularly preferred, and butyl (meth)acrylate is most preferred. Ester compound (1) may be used alone or in combination of two or more types.

[0331] Ester compound (2) is a (meth)acrylic acid ester represented by the following formula (2). Ester compound (3) is a (meth)acrylic acid ester represented by the following formula (3). Ester compound (4) is a (meth)acrylic acid ester represented by the following formula (4).

[0332] [ka]

[0333] In equations (2), (3), and (4), R 1b , R 3b , R 5b , R 6b , R 8b and R 9b Each of these is independently either a hydrogen atom or a methyl group. 2b and R 4b Each of these is independently a linear or branched alkylene group or hydroxyalkylene group having 2 to 8 carbon atoms. 7b It is a linear or branched trivalent hydrocarbon group having 2 to 8 carbon atoms.

[0334] R 2b and R 4bThe number of carbon atoms in the alkylene group or hydroxyalkylene group is 2 to 8, preferably 2 to 6. R 2b and R 4b Examples of alkylene groups include ethylene, propylene, isopropylene, and butylene groups. R 2b and R 4b Examples of hydroxyalkylene groups include hydroxyethylene, hydroxypropylene, and hydroxybutylene groups.

[0335] R 7b The number of carbon atoms in the trivalent hydrocarbon group is 2 to 8, preferably 2 to 4. R 7b Examples of the trivalent hydrocarbon group include -(CH2)-C(-CH2-)(-CH3)-CH2-.

[0336] Examples of ester compounds (2) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 3-hydroxypropyl (meth)acrylate. Examples of ester compounds (3) include ethylene glycol di(meth)acrylate, 1,3-propanediol di(meth)acrylate, 1,2-propanediol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate. Examples of ester compounds (4) include trimethylolpropane tri(meth)acrylate.

[0337] Because they are relatively easy to obtain, one or more ester compounds (2), (3), and (4) are preferably selected from the group consisting of ethylene glycol di(meth)acrylate, 2-hydroxyethyl(meth)acrylate, 3-hydroxypropyl(meth)acrylate, and trimethylolpropanetri(meth)acrylate.

[0338] Ester compound (2), ester compound (3), and ester compound (4) may be used individually or in combination of two or more.

[0339] Ester compound (5) is a (meth)acrylic acid ester represented by the following formula (5). CH2=CR 1c -C(=O)-OR 2c ...(5) In formula (5), R 1c R is a hydrogen atom or a methyl group, 2c It is a monovalent group with 2 to 8 carbon atoms that has an ether bond.

[0340] R 2c The number of etheric oxygen atoms in the monovalent group having 2 to 8 carbon atoms is preferably one, but is not limited to two or more. R 2c The monovalent group having 2 to 8 carbon atoms may be linear, branched, or have a ring. 2c If the ring is present, the ring may or may not contain an etheric oxygen atom. R 2c The number of carbon atoms in the monovalent group having an ether bond is 2 to 8, preferably 2 to 7.

[0341] R 2c Examples of such groups include 2-methoxyethyl group, 2-(2-methoxyethoxy)ethyl group, 2-[2-(2-methoxyethoxy)ethoxy]ethyl group, glycidyl group, and tetrahydrofurfuryl group. Because it is relatively easy to obtain and relatively easy to handle in terms of physical properties, R 2c The preferred group is a 2-methoxyethyl group, a glycidyl group, or a tetrahydrofurfuryl group.

[0342] Examples of ester compounds (5) include 2-methoxyethyl (meth)acrylate, glycidyl (meth)acrylate, 2-(2-methoxyethoxy)ethyl (meth)acrylate, 2-[2-(2-methoxyethoxy)ethoxy]ethyl (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate.

[0343] Because they are relatively easy to handle in terms of physical properties, 2-methoxyethyl (meth)acrylate, glycidyl (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate are preferred as ester compounds (5). Ester compound (5) may be used alone or in combination of two or more types.

[0344] (Ingredient A7) Component A7 is a compound represented by the following formula (a7). The inclusion of component A7 in the ester compound-containing composition suppresses the formation of dimers and oxidation products of ester compound (I) during storage, resulting in an ester compound-containing composition with excellent storage stability. The reason for this is presumed to be as follows.

[0345] During storage of ester compound-containing compositions, ultraviolet-derived radicals are generated, such as hydroxyl radicals produced when oxygen molecules absorb ultraviolet light from sunlight. Such radicals can cause the formation of dimers of ester compound (I) or oxidation products of ester compound (I). Component A7 is a π-conjugated compound having a benzene ring, and therefore absorbs ultraviolet light. Its absorption wavelength and intensity vary depending on the type of substituent. Because component A7 has an alkyl ether group with appropriate bulk and electron-donating properties bonded to the benzene ring, it can absorb ultraviolet light across a wide range of wavelengths. Therefore, when an ester compound-containing composition contains component A7, ultraviolet light across a wide range of wavelengths is absorbed, and the generation of hydroxyl radicals is suppressed. Thus, it is presumed that the formation of dimers of ester compound (I) and oxidation products of ester compound (I) is suppressed, and the decrease in the purity of ester compound (I) can be suppressed.

[0346] [ka]

[0347] In formula (a7), R 71 , R 72 , R 73 , R 74 , R 75 , R 76 and R 77 Each of these is independently a monovalent group selected from a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, a carbonyl group, an alkylthio group, or an arylthio group. R 71 , R 72 , R 73 , R 74 , R 75 , R 76 and R 77 They may be the same or different.

[0348] R 71 , R 72 , R 73 , R 74 , R 75 , R 76 and R 77 The alkyl group may be linear, branched, or have a ring. The alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10, and even more preferably 1 to 5 carbon atoms. Examples of linear or branched alkyl groups (hereinafter collectively referred to as "chain alkyl groups") include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n-pentyl group, isopentyl group, hexyl group, octyl group, decyl group, hydroxymethyl group, 1-hydroxyethyl group, and 2-hydroxyethyl group. Among these, methyl group, ethyl group, n-propyl group, isopropyl group, and t-butyl group are preferred. Examples of ring-containing alkyl groups (hereinafter also referred to as "cyclic alkyl groups") include cyclopentyl groups, cyclohexyl groups, and cyclooctyl groups.

[0349] R 71 , R 72 , R 73 , R 74 , R 75 , R 76 and R 77 The alkenyl group may be linear, branched, or have a ring. The number of carbon atoms in the alkenyl group is preferably 2 to 20, more preferably 2 to 10, and even more preferably 2 to 5. Examples of linear or branched alkenyl groups (hereinafter collectively referred to as "chain alkenyl groups") include vinyl groups, 1-propenyl groups, isopropenyl groups, 2-butenyl groups, 1,3-butadienyl groups, 2-pentenyl groups, and 2-hexenyl groups. Examples of ring-containing alkenyl groups (hereinafter also referred to as "cyclic alkenyl groups") include the cyclopentenyl group and the cyclohexenyl group.

[0350] R 71 , R 72 , R 73 , R 74 , R 75 , R 76 and R 77 The number of carbon atoms in the aryl group is preferably 1 to 20, and more preferably 1 to 12. The aryl group includes heteroaryl groups containing oxygen, nitrogen, sulfur, etc. Examples of aryl groups include phenyl, mesityl, naphthyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 2-ethylphenyl, isoxazolyl, isothiazolyl, imidazolyl, oxazolyl, thiazolyl, thiadiazolyl, thienyl, triazolyl, tetrazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridadinyl, pyrazolyl, pyrrolyl, furyl, fluzanyl, isoquinolyl, isoindolyl, indolyl, quinolyl, pyridothiazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, benzotriazolyl, benzofuranyl, imidazopyridinyl, triazopyridinyl, and prinyl groups.

[0351] R 71 , R 72 , R 73 , R 74 , R 75 , R 76 and R 77 The number of carbon atoms in the alkoxy group is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 6. Examples of alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, s-butoxy, t-butoxy, n-pentoxy, isopentoxy, and phenoxy groups.

[0352] R 71 , R 72 , R 73 , R 74 , R 75 , R 76 and R 77 The amino group in this compound includes an amino group (-NH2) that has no substituents on the nitrogen atom, and an amino group in which some or all of the hydrogen atoms bonded to the nitrogen atom are replaced by carbon atoms. The number of carbon atoms in the amino group substituted with carbon atoms is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 5. Examples of amino groups include unsubstituted amino groups, methylamino groups, ethylamino groups, propylamino groups, butylamino groups, dimethylamino groups, diethylamino groups, anilino groups, toluidino groups, anisidino groups, diphenylamino groups, and N-methyl-N-phenylamino groups.

[0353] R 71 , R 72 , R 73 , R 74 , R 75 , R 76 and R 77 Examples of monovalent groups containing a carbonyl group include formyl group, acyl group, carboxyl group, amide group, alkoxycarbonyl group, thiocarboxyl group, and thioester group.

[0354] An acyl group is a substituent formed by linking a carbonyl group to an alkyl group, alkenyl group, or aryl group. The total number of carbon atoms in the acyl group, derived from the carbonyl group (1) and derived from the alkyl group, alkenyl group, or aryl group, is preferably 2 to 20, more preferably 2 to 10, and even more preferably 2 to 6. Examples of acyl groups include acetyl, propionyl, butylcarbonyl, vinylcarbonyl, and benzoyl groups.

[0355] The amide group includes an amide group (-CONH2) that has no substituent on the nitrogen atom, and an amide group in which some or all of the hydrogen atoms bonded to the nitrogen atom are replaced by carbon atoms. The number of carbon atoms in the amide group is the sum of the carbon atoms derived from the carbonyl group (1) and the carbon atoms substituted on the nitrogen atom, preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 5. Examples of amide groups include unsubstituted amide groups, N-methylamide groups, N-ethylamide groups, N-phenylamide groups, N,N-dimethylamide groups, and N-methyl-N-phenylamide groups.

[0356] An alkoxycarbonyl group is a substituent formed by the linkage of a carbonyl group and an alkoxy group, and is also called an ester group. The total number of carbon atoms derived from the carbonyl group (1) and the alkoxy group is preferably 2 to 20, more preferably 2 to 10, and even more preferably 2 to 6. Examples of alkoxycarbonyl groups include methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl, and phenoxycarbonyl groups.

[0357] A thioester group is a substituent formed by linking a carbonyl group with an alkylthio group or an arylthio group. The total number of carbon atoms derived from the carbonyl group (1) and the alkylthio group or arylthio group is preferably 2 to 20, more preferably 2 to 10, and even more preferably 2 to 6. Examples of thioester groups include methylthiocarbonyl group, ethylthiocarbonyl group, butylthiocarbonyl group, and phenylthiocarbonyl group.

[0358] For example, a monovalent group containing a carbonyl group may be a substituent in which one or more hydrogen atoms of an alkyl group are substituted with a carbonyl group. Examples of such substituents include 2-acetoxyethyl group, 2-acetoethyl group, and 2-(acetoacetoxy)ethyl group.

[0359] R 71 , R 72 , R 73 , R 74 , R 75 , R 76 and R 77 The alkylthio group preferably has 1 to 20 carbon atoms, more preferably 1 to 10, and even more preferably 1 to 5 carbon atoms. Examples of alkylthio groups include methylthio groups, ethylthio groups, propylthio groups, and isopropylthio groups.

[0360] R 71 , R 72 , R 73 , R 74 , R 75 , R 76 and R 77The number of carbon atoms in the arylthio group is preferably 1 to 20, more preferably 3 to 10, and even more preferably 6 to 10. Examples of arylthio groups include phenylthio groups and tolylthio groups.

[0361] In formula (a7), R is directly bonded to the benzene ring. 71 , R 72 , R 73 , R 74 , R 75 , R 76 and R 77 If the steric hindrance is large, distortion occurs in the benzene ring, and the π-conjugated system cannot be maintained. However, R 71 , R 72 , R 73 , R 74 , R 75 , R 76 and R 77 When the above conditions are met, the bulk is of an appropriate size and the π-conjugated system of component A7 is maintained, so it has the property of absorbing ultraviolet light of a wide range of wavelengths, and the effects of the present invention can be obtained.

[0362] From the perspective of suppressing the generation of hydroxyl radicals by absorbing ultraviolet light across a wide range of wavelengths, R 71 , R 72 , R 73 , R 74 and R 75 It is preferably a monovalent group comprising a hydrogen atom, a C1-C5 alkyl group, a C2-C5 alkenyl group, a C1-C12 aryl group, a hydroxyl group, a C1-C6 alkoxy group, an amino group, or a carbonyl group; more preferably a hydrogen atom, a C1-C5 alkyl group, a hydroxyl group, or a C1-C5 alkoxy group; even more preferably a hydrogen atom, a methyl group, an ethyl group, a t-butyl group, a hydroxyl group, a methoxy group, a propoxy group, or a t-butoxy group; and particularly preferably a hydrogen atom, a methyl group, a t-butyl group, a hydroxyl group, or a methoxy group.

[0363] From the perspective of increasing the absorbance of ultraviolet light and suppressing the generation of hydroxyl radicals, R 76 and R 77It is preferably a monovalent group comprising a hydrogen atom, a C1-C5 alkyl group, a C2-C5 alkenyl group, a C1-C12 aryl group, a hydroxyl group, a C1-C6 alkoxy group, an amino group, or a carbonyl group; more preferably a hydrogen atom, a C1-C5 alkyl group, a hydroxyl group, or a C1-C5 alkoxycarbonyl group; even more preferably a hydrogen atom, a methyl group, an ethyl group, a t-butyl group, a hydroxyl group, a methoxycarbonyl group, or a butoxycarbonyl group; and particularly preferably a hydrogen atom, a methyl group, a methoxycarbonyl group, or a butoxycarbonyl group.

[0364] The molecular weight of component A7 is preferably 2000 or less. By having a molecular weight of 2000 or less, the number of benzene rings per unit mass in component A7 can be increased, so that the effects of the present invention can be obtained with a small mass. The molecular weight of component A7 is more preferably 1600 or less, even more preferably 1200 or less, and particularly preferably 800 or less.

[0365] Among the compounds that satisfy the above conditions, from the viewpoint of further improving the storage stability of the ester compound-containing composition, component A7 is selected from t-butylphenyl ether, isopropylphenyl ether, 1-isopropoxy-3-methylbenzene, 4-isopropoxyphenol, 1-t-butoxy-4-methylbenzene, 2-(2,4-dimethyl-6-t-butylphenoxy)-2-methylpropionate butyl, 2-(2,6-di-t-butyl-4-methylphenoxy)-2-methylpropionate butyl, 2-(4-methylphenoxy Butyl cyphenoxy)-2-methylpropionate or butyl 2-(4-hydroxyphenoxy)-2-methylpropionate is preferred, and isopropylphenyl ether, butyl 2-(2,4-dimethyl-6-t-butylphenoxy)-2-methylpropionate, butyl 2-(2,6-di-t-butyl-4-methylphenoxy)-2-methylpropionate, butyl 2-(4-methoxyphenoxy)-2-methylpropionate, or butyl 2-(4-hydroxyphenoxy)-2-methylpropionate is more preferred. Component A7 may be used alone or in combination of two or more types.

[0366] (Component B) Component B is a polymerization inhibitor. The inclusion of component B in the ester compound-containing composition suppresses the progression of the polymerization reaction of ester compound (I) via the radical polymerization mechanism during storage. Furthermore, during storage, oxygen molecules in the ester compound-containing composition may absorb ultraviolet light from sunlight, generating hydroxyl radicals. However, polymerization inhibitors can trap these hydroxyl radicals. Therefore, if the ester compound-containing composition contains both component A7 and component B, the amount of hydroxyl radicals can be reduced through two different mechanisms: component A7 suppresses the generation of hydroxyl radicals, and component B removes any hydroxyl radicals that are generated. Thus, the progression of dimerization of ester compound (I) and the generation of oxidation products can be suppressed more efficiently, and the decrease in the purity of ester compound (I) can be efficiently suppressed. A polymerization inhibitor is a compound that has the function of suppressing the polymerization reaction of ester compounds (I).

[0367] Examples of component B include phenolic compounds, quinone compounds, nitrobenzene compounds, N-oxyl compounds, amine compounds, phosphorus-containing compounds, sulfur-containing compounds, iron-containing compounds, copper-containing compounds, and manganese-containing compounds.

[0368] Examples of phenolic compounds include alkylphenols, hydroxyphenols, aminophenols, nitrophenols, nitrosophenols, alkoxyphenols, and tocopherols.

[0369] Examples of alkylphenols include o-cresol, m-cresol, p-cresol, 2-t-butyl-4-methylphenol, 2,4-dimethyl-6-t-butylphenol, 2,6-di-t-butyl-4-methylphenol, 2-t-butylphenol, 4-t-butylphenol, 2,4-di-t-butylphenol, 2-methyl-4-t-butylphenol, 4-t-butyl-2,6-dimethylphenol, 2,2'-methylenebis(6-t-butyl-4-methylphenol), 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol), and 3,5-di-t-butyl-4-hydroxytoluene.

[0370] Examples of hydroxyphenols include hydroquinone, 2-methylhydroquinone, 2-t-butylhydroquinone, 2,5-di-t-butylhydroquinone, 2,6-di-t-butylhydroquinone, 2,5-di-t-amylhydroquinone, 2-t-butylmethoxyhydroquinone, 2,3,5-trimethylhydroquinone, 2,5-dichlorohydroquinone, 1,2-dihydroxybenzene, 2-acetylhydroquinone, 4-methylcatechol, 4-t-butylcatechol, 2-methylresorcinol, 4-methylresorcinol, and 2,3-dihydroxyacetophenone.

[0371] Examples of aminophenols include o-aminophenol, m-aminophenol, p-aminophenol, 2-(N,N-dimethylamino)phenol, and 4-(ethylamino)phenol.

[0372] Examples of nitrophenols include o-nitrophenol, m-nitrophenol, p-nitrophenol, and 2,4-dinitrophenol.

[0373] Examples of nitrosophenols include o-nitrosophenol, m-nitrosophenol, p-nitrosophenol, and α-nitroso-β-naphthol.

[0374] Examples of alkoxyphenols include 2-methoxyphenol, 2-ethoxyphenol, 2-isopropoxyphenol, 2-t-butoxyphenol, 4-methoxyphenol, 4-ethoxyphenol, 4-propoxyphenol, 4-butoxyphenol, 4-t-butoxyphenol, 4-heptoxyphenol, hydroquinone monobenzyl ether, t-butyl-4-methoxyphenol, di-t-butyl-4-methoxyphenol, pyrogallol-1,2-dimethyl ether, and hydroquinone monobenzoate.

[0375] Examples of tocopherols include α-tocopherol and 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran.

[0376] Examples of quinone compounds include p-benzoquinone, chloro-p-benzoquinone, 2,5-dichloro-p-benzoquinone, 2,6-dichloro-p-benzoquinone, tetrachloro-p-benzoquinone, tetrabromo-p-benzoquinone, 2,3-dimethyl-p-benzoquinone, 2,5-dimethyl-p-benzoquinone, methoxy-p-benzoquinone, and methyl-p-benzoquinone.

[0377] Examples of nitrobenzene compounds include nitrobenzene, o-dinitrobenzene, m-dinitrobenzene, p-dinitrobenzene, 2,4-dinitrotoluene, dinitrojulene, and 2,2-diphenyl-1-picrylhydrazyl.

[0378] Examples of N-oxyl compounds include 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-oxo-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-acetoxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, 2,2,6,6-tetramethyl-piperidine-N-oxyl, piperidine-1-oxyl, 4-(dimethylamino)-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-amino-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-ethanoloxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, and 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl Examples include tris(2,2,5,5-tetramethyl-piperidine-N-oxyl), 3-amino-2,2,5,5-tetramethyl-piperidine-N-oxyl, 4,4',4''-tris(2,2,6,6-tetramethyl-piperidine-N-oxyl) phosphite, 3-oxo-2,2,5,5-tetramethylpyrrolidine-N-oxyl, pyrrolidine-1-oxyl, 2,2,5,5-tetramethyl-1-oxa-3-azacyclopentyl-3-oxyl, 2,2,5,5-tetramethyl-3-pyrrolinyl-1-oxy-3-carboxylic acid, 2,2,3,3,5,5,6,6-octamethyl-1,4-diazacyclohexyl-1,4-dioxyl, di-t-butyl nitroxide, di-t-amyl nitroxide, etc.

[0379] Examples of amine compounds include N,N-diphenylamine, alkylated diphenylamine, 4,4'-dicumyl-diphenylamine, 4,4'-dioctyldiphenylamine, 4-aminodiphenylamine, p-nitrosodiphenylamine, N-nitrosodinaphthylamine, N-nitrosodiphenylamine, N-nitrosophenylnaphthylamine, N-nitrosophenylhydroxylamine, N,N'-dialkyl-p-phenylenediamine (the alkyl groups may be the same or different, each independently having 1 to 4 carbon atoms, and may be linear or branched), N,N'-diphenyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-1,4-phenylenediamine, and N,N'-di-2 Examples include naphthyl-p-phenylenediamine, N,N-diethylhydroxylamine, 1,4-benzenediamine, N-(1,4-dimethylpentyl)-N'-phenyl-1,4-benzenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-1,4-benzenediamine, 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, aldol-α-naphthylamine, N-phenyl-β-naphthylamine, 4-hydroxy-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 1,4-dihydroxy-2,2,6,6-tetramethylpiperidine, and 1-hydroxy-4-benzoylioxy-2,2,6,6-tetramethylpiperidine.

[0380] Phosphorus-containing compounds include, for example, triphenylphosphine, triphenyl phosphite, triethyl phosphite, tris(isodecyl) phosphite, tris(tridecyl) phosphite, phenyldiisooctyl phosphite, phenyldiisodecyl phosphite, phenyldi(tridecyl) phosphite, diphenylisooctyl phosphite, diphenylisodecyl phosphite, diphenyltridecyl phosphite, phosphonic acid [1,1-diphenyl-4,4'-diylbistetrakis-2,4-bis(1,1-dimethylethyl)phenyl] ester, triphenyl phosphite, tris(nonylphenyl) phosphite, 4,4'-isopropylidenediphenolalkyl phosphite, tris(2,4-di-t-butylphenyl) phosphite, tris(biphenyl) phosphite, and dis Examples include tearyl pentaerythritol diphosphite, di(2,4-di-t-butylphenyl) pentaerythritol diphosphite, di(nonylphenyl) pentaerythritol diphosphite, phenylbisphenol A pentaerythritol diphosphite, tetra(tridecyl)-4,4'-butylidenebis(3-methyl-6-t-butylphenol) diphosphite, hexa(tridecyl)-1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane triphosphite, 3,5-di-t-butyl-4-hydroxybenzyl phosphate diethyl ester, sodium-bis(4-t-butylphenyl) phosphate, sodium-2,2'-methylene-bis(4,6-di-t-butylphenyl) phosphate, and 1,3-bis(diphenoxyphosphonyloxy)benzene.

[0381] Examples of sulfur-containing compounds include diphenyl sulfide, phenothiazine, 3-oxofhenothiazine, 5-oxofhenothiazine, phenothiazine dimers, 1,4-dimercaptobenzene, 1,2-dimercaptobenzene, 2-mercaptophenol, 4-mercaptophenol, 2-(methylthio)phenol, 3,7-bis(dimethylamino)phenothiazinium chloride, and elemental sulfur.

[0382] Examples of iron-containing compounds include iron(III) chloride.

[0383] Examples of copper-containing compounds include copper dimethyldithiocarbamate, copper diethyldithiocarbamate, copper dibutyldithiocarbamate, copper salicylate, copper acetate, copper thiocyanate, copper nitrate, copper chloride, copper carbonate, copper hydroxide, copper acrylate, and copper methacrylate.

[0384] Examples of manganese-containing compounds include manganese dialkyldithiocarbamate (the alkyl group is one of methyl, ethyl, propyl, or butyl groups, and may be the same or different), manganese diphenyldithiocarbamate, manganese formate, manganese acetate, manganese octanoate, manganese naphthenate, manganese permanganate, and manganese salts of ethylenediaminetetraacetic acid.

[0385] Since this is likely to exhibit an effect of further improving the storage stability of the ester compound-containing composition, component B is preferably at least one polymerization inhibitor selected from the group consisting of phenolic compounds, N-oxyl compounds, amine compounds, phosphorus-containing compounds, and sulfur-containing compounds, more preferably at least one polymerization inhibitor selected from the group consisting of hydroquinone, 4-methoxyphenol, 2,4-dimethyl-6-t-butylphenol, 2,6-di-t-butyl-4-methylphenol, 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, N,N-diphenylamine, N-nitrosodiphenylamine, triphenyl phosphite, and phenothiazine, and particularly preferably at least one polymerization inhibitor selected from the group consisting of hydroquinone, 4-methoxyphenol, 2,4-dimethyl-6-t-butylphenol, and 2,6-di-t-butyl-4-methylphenol.

[0386] Component B may be used alone or in combination of two or more types.

[0387] If an ester compound-containing composition contains a compound that corresponds to both component A7 and component B, that compound shall be considered as component A7. If an ester compound-containing composition contains both component A7 and component B, it means that the ester compound-containing composition contains a component B that is different from the compound A7. If an ester compound-containing composition contains two or more compounds that fall under both component A7 and component B, the compound with the highest molar concentration in the ester compound-containing composition shall be considered component A7, and the other compounds shall be considered component B.

[0388] (Component C) The ester compound-containing composition may contain other compounds (component C) as long as the content of ester compound (I) satisfies 95.00 to 99.99% by mass. Component C is a compound other than ester compound (1), component A7, and component B. Examples of component C include additives such as mold release agents, lubricants, plasticizers, antioxidants, antistatic agents, light stabilizers, UV absorbers, flame retardants, flame retardant aids, polymerization inhibitors, fillers, pigments, dyes, silane coupling agents, leveling agents, defoamers, and fluorescent agents. The ester compound-containing composition may contain unreacted raw materials from the production of the ester compound-containing composition, such as methyl (meth)acrylate, alcohol, and (meth)acrylic acid. The ester compound-containing composition may contain impurities such as diacetyl that are generated during the production of the ester compound-containing composition. However, from the viewpoint of reducing the discoloration of the ester compound-containing composition, the concentration of diacetyl is preferably 5 ppm by mass or less, more preferably 2 ppm by mass or less, even more preferably 1 ppm by mass or less, and particularly preferably 0.1 ppm by mass or less. The ester compound-containing composition may also contain (meth)acrylic acid esters other than ester compound (1).

[0389] The content of ester compound (I) is 95.00 to 99.99% by mass. A content of ester compound (I) of 90.00% by mass or more reduces the amount of impurities when a (meth)acrylic polymer is produced by polymerization of the ester compound-containing composition, preventing adverse effects on the properties of the polymer. Furthermore, a content of ester compound (I) of 99.99% by mass or less reduces the purification cost. A content of ester compound (I) of 96.00% by mass or more is preferable, 97.00% by mass or more is more preferable, 98.00% by mass or more is even more preferable, 99.00% by mass or more is particularly preferable, and 99.50% by mass or more is most preferable.

[0390] If ester compound (I) contains ester compound (1) but does not contain ester compound (2), ester compound (3), ester compound (4), and ester compound (5), the content of ester compound (I) is equal to the concentration of ester compound (1).

[0391] If ester compound (I) contains ester compound (5) and does not contain ester compound (1), ester compound (2), ester compound (3), and ester compound (4), the content of ester compound (I) is equal to the concentration of ester compound (5).

[0392] If ester compound (I) contains at least one selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4), and does not contain ester compound (1) and ester compound (5), then the content of ester compound (I) is the concentration of at least one selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4).

[0393] The content of component A7 is not particularly limited, but is preferably 1 to 10,000 ppm by mass. A component A7 content of 1 ppm by mass or more provides sufficient suppression of the formation of dimers and oxidation products of ester compound (I). Furthermore, a content of 10,000 ppm by mass or less reduces the amount of impurities when a (meth)acrylic polymer is produced by polymerization of the ester compound-containing composition according to the third embodiment, preventing adverse effects on the properties of the polymer. A component A7 content of 3 ppm by mass or more is more preferable, 5 ppm by mass or more is even more preferable, and 10 ppm by mass or more is particularly preferable. A component A7 content of 7,500 ppm by mass or less is more preferable, 5,000 ppm by mass or less is even more preferable, 2,500 ppm by mass or less is even more preferable, 1,500 ppm by mass or less is even more preferable, 1,000 ppm by mass or less is particularly preferable, and 500 ppm by mass or less is most preferable.

[0394] The content of component B is not particularly limited, but is preferably 1 to 1000 ppm by mass. A content of 1 ppm by mass or more of component B provides sufficient suppression of the formation of dimers of ester compound (I) and oxidation products of ester compound (I). Furthermore, a content of 1000 ppm by mass or less reduces the amount of impurities when a (meth)acrylic polymer is produced by polymerization of the ester compound-containing composition according to the third embodiment, preventing adverse effects on the properties of the polymer. The content of component A7 is more preferably 3 ppm by mass or more, even more preferably 5 ppm by mass or more, and particularly preferably 10 ppm by mass or more. The content of component A7 is more preferably 750 ppm by mass or less, even more preferably 500 ppm by mass or less, even more preferably 250 ppm by mass or less, particularly preferably 100 ppm by mass or less, and most preferably 50 ppm by mass or less.

[0395] The water content of the ester compound-containing composition is preferably 5000 ppm by mass or less, more preferably 4000 ppm by mass or less, even more preferably 3000 ppm by mass or less, particularly preferably 2000 ppm by mass, and most preferably 1000 ppm by mass or less, relative to the total mass of the ester compound-containing composition. If the water content of the ester compound-containing composition is below the above upper limit, the physical properties of the (meth)acrylic polymer obtained by polymerizing the ester compound-containing composition can be maintained more favorably. The lower limit of the water content of an ester compound-containing composition is 0 ppm by mass.

[0396] (Analysis of compositions containing ester compounds) The presence of ester compound-containing compositions as components A7, B, C, and water can be confirmed, for example, by GC-MS measurement. If the GC-MS chart of the ester compound-containing composition shows a peak at the same retention time as the standard for component A7, and the m / z value detected in the mass spectrum of that peak matches the exact mass of component A7, then the ester compound-containing composition can be determined to contain component A7. If a standard for component A7 is unavailable, the peak can be determined to be component A7 if the mass spectrum pattern of the peak appearing in the GC-MS chart of the ester compound-containing composition matches the mass spectrum pattern of component A7 recorded in a mass spectrum database. In other words, the ester compound-containing composition can be determined to contain component A7. Examples of mass spectrum databases include NIST20, NIST17, NIST14, and NIST14s. Furthermore, if the volatility is low and detection by GC-MS is not possible, detection can be performed using LC-MS. The presence of components B, C, and water can also be confirmed by a similar method.

[0397] The content of ester compound (I) can be calculated, for example, by performing GC-FID measurement on the ester compound-containing composition, quantifying it using the area percentage method, and correcting it using the moisture content quantified with a Karl Fischer moisture meter.

[0398] The content of component A7 can be quantified, for example, by GC measurement or GC-MS measurement of an ester compound-containing composition, using the internal standard method or absolute calibration curve method. If a standard sample of component A7 cannot be obtained and quantification cannot be performed using the internal standard method or absolute calibration curve method, the content of component A7 can be calculated by performing GC-FID measurement on any organic compound of known concentration under the same conditions as the ester compound-containing composition, using the following formula.

[0399]

number

[0400] Here, N is the number of carbon atoms contained in one molecule of an organic compound with a known concentration. A7 is the number of carbon atoms contained in one molecule of component A7, S A7 ∫ is the peak area of ​​component A7, S is the peak area of ​​the organic compound with a known concentration, and M is the concentration (mass ppm) of the organic compound with a known concentration. If the volatility is low and quantification by GC measurement is not possible, quantification can be performed using chromatographic methods such as LC.

[0401] The concentrations of components B and C can also be calculated using the same method as for component A7. The presence of water in an ester compound-containing composition, and its concentration, can be confirmed by the Karl Fischer method.

[0402] [Method for producing ester compound-containing compositions] A method for producing an ester compound-containing composition according to the third embodiment is, in the presence of component A7, One or more alcohols selected from the group consisting of monoalcohols with 2 to 20 carbon atoms, ether-containing alcohols with 2 to 8 carbon atoms, dialcohols with 2 to 8 carbon atoms, and trialcohols with 2 to 8 carbon atoms, This involves carrying out a transesterification reaction with methyl (meth)acrylate.

[0403] Methyl (meth)acrylate is particularly prone to dimerization and oxidation to produce methyl pyruvate among (meth)acrylic acid esters. However, by carrying out the transesterification reaction in the presence of component A7, the dimerization of methyl (meth)acrylate and the production of methyl pyruvate are suppressed, resulting in an improved yield of ester compound (I).

[0404] For example, to obtain an ester compound-containing composition containing ester compound (1) as ester compound (I), transesterification of methyl (meth)acrylate and a monoalcohol having 2 to 20 carbon atoms is carried out in a reactor in the presence of a catalyst and component A7, as shown in formula (II) below.

[0405] [ka]

[0406] R in equation (II) 1a and R 2a R in equation (1) 1a and R 2a It is the same as this.

[0407] Examples of monoalcohols having 2 to 20 carbon atoms include ethanol, n-butanol, isobutanol, t-butanol, 2-ethylhexanol, lauryl alcohol, stearyl alcohol, cyclohexanol, isobornyl alcohol, allyl alcohol, phenol, and benzyl alcohol. Monoalcohols having 2 to 20 carbon atoms may be used individually or in combination of two or more. The monoalcohols having 2 to 20 carbon atoms preferably include linear or branched monoalcohols having 2 to 20 carbon atoms, and more preferably include n-butanol and isobutanol.

[0408] For example, to obtain an ester compound-containing composition containing ester compound (5) as ester compound (I), transesterification is carried out in a reactor in the presence of a catalyst and component A7, as shown in formula (III) below, between methyl (meth)acrylate and an ether-bonded alcohol having 2 to 8 carbon atoms.

[0409] [ka]

[0410] R in equation (III) 1c and R 2c R in equation (5) 1c and R 2c It is the same as this.

[0411] In ether-bonded alcohols with 2 to 8 carbon atoms, one ether bond is preferred, but not limited to that. Examples of ether-containing alcohols having 2 to 8 carbon atoms include 2-methoxyethanol, glycidyl alcohol, and tetrahydrofurfuryl alcohol. These ether-containing alcohols may be used individually or in combination of two or more. The ether-bonded alcohol having 2 to 8 carbon atoms preferably includes one selected from 2-methoxyethanol, glycidyl alcohol, and tetrahydrofurfuryl alcohol.

[0412] For example, to obtain an ester compound-containing composition containing at least one selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4) as ester compound (I), transesterification is carried out in a reactor in the presence of a catalyst and component A7, as shown in the following formulas (IV) and (V), between methyl (meth)acrylate and one or more alcohols selected from the group consisting of dialcohols having 2 to 8 carbon atoms and trialcohols having 2 to 8 carbon atoms.

[0413] [ka]

[0414] R in equations (IV) and (V) 1b , R 2b , R 3b , R 5b , R 6b and R 7b R in equations (2), (3), and (4) 1b , R 2b , R 3b , R 5b , R 6b and R 7b It is the same as R. 41b R is a linear or branched alkylene group having 2 to 8 carbon atoms. 42b This is a linear or branched hydroxyalkylene group having 2 to 8 carbon atoms.

[0415] Examples of dialcohols and trialcohols having 2 to 8 carbon atoms include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,6-hexanediol, and trimethylolpropane. In particular, it is preferable that the dialcohols and trialcohols having 2 to 8 carbon atoms include one or more selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, and trimethylolpropane. Dialcohols and trialcohols having 2 to 8 carbon atoms may be used individually or in combination of two or more.

[0416] The reactor is preferably equipped with a distillation column. Since this transesterification reaction is an equilibrium reaction, productivity can be improved by separating the by-product methanol using a distillation column. For example, it is preferable to carry out the transesterification reaction while separating methanol from the system as an azeotropic mixture with methyl (meth)acrylate.

[0417] Examples of such reactors include those equipped with a distillation column on top of a reaction vessel called a reaction kettle, and distillation columns in which a distillation boiler can be used as a reaction vessel. Examples of distillation columns include packed column type and tray type distillation columns. The theoretical number of stages in a distillation column is preferably five or more, and more preferably seven or more, from the standpoint of high separation capacity and stable operation.

[0418] The ratio of methyl (meth)acrylate to alcohol can be determined as appropriate. From the viewpoint of increasing productivity, the ratio of methyl (meth)acrylate to 1 mole of alcohol is preferably 0.1 mole to 10 moles, and more preferably 0.3 mole to 4 moles.

[0419] The catalysts used are not particularly limited, but examples include hydroxides, carbonates, and bicarbonates of alkali metals such as lithium, sodium, and potassium; oxides, hydroxides, and carbonates of alkaline earth metals such as magnesium and calcium; alkali metal alkoxides such as lithium methoxide, sodium methoxide, sodium ethoxide, and potassium t-butoxy; alkali metal amides such as lithium amide, sodium amide, and potassium amide; titanium alkoxides such as tetramethyl titanate, tetraethyl titanate, tetrapropyl titanate, tetraisopropyl titanate, tetrabutyl titanate, and tetra(2-ethylhexyl) titanate; and tin compounds such as dibutyltin oxide and dioctyltin oxide. Among these, titanium alkoxides, dibutyltin oxide, and dioctyltin oxide are preferred because they produce fewer by-products of the Michael addition reaction during the transesterification reaction and have high catalytic activity. The catalysts may be used alone or in combination of two or more.

[0420] The catalyst can be supplied to the reactor on its own. Alternatively, the catalyst can be supplied to the reactor dissolved in the same alcohol as the raw material, or dissolved in the (meth)acrylic acid ester of the raw material. For example, one method is to supply the catalyst directly dissolved in the entire amount of alcohol used in the reaction to the reactor, or to supply the catalyst dissolved in a portion of the alcohol used in the reaction to the reactor. The amount of catalyst used is preferably 0.001 mol% or more and 1 mol% or less per 1 mol of alcohol, and more preferably 0.01 mol% or more and 0.1 mol% or less.

[0421] A solvent may be used in the transesterification reaction. If a solvent is used, it is preferable to use a solvent that forms an azeotropic composition with the by-product methanol. Examples of solvents include n-pentane, n-hexane, n-heptane, n-octane, 2,3-dimethylbutane, 2,5-dimethylhexane, 2,2,4-trimethylpentane, cyclohexane, benzene, and toluene. Among these, n-hexane, n-heptane, and cyclohexane are preferred. The solvent may be used alone or in combination of two or more.

[0422] The reaction temperature for transesterification varies depending on the type of alcohol and solvent, but it is preferably between 60°C and 150°C. The reaction pressure for the transesterification reaction is not particularly limited, and the reaction may be carried out under any pressure: reduced pressure, atmospheric pressure, or increased pressure.

[0423] The form of the transesterification reaction is not particularly limited and can be carried out using commonly used methods such as batch reactions or continuous reactions. After the transesterification reaction, unreacted starting materials and by-products may be separated by purifying the reaction mixture. Various methods can be used for purification, such as distillation, crystallization, extraction, and column chromatography.

[0424] The transesterification reaction may be carried out with component B added to the reaction solution. The presence of component B in addition to component A7 further suppresses the dimerization of methyl (meth)acrylate and the formation of methyl pyruvate, thus making it easier to obtain an improved yield of ester compound (I).

[0425] Component B may be added to the solution containing the ester compound (I) and component A7 after the transesterification reaction. In this case, a separate solution containing the ester compound (I) and component B (solution B) can be prepared in addition to the solution containing the ester compound (I) and component A7 (solution A), and solutions A and B can be mixed to obtain an ester compound-containing composition. Alternatively, the ester compound (I), solution A, and solution B can be mixed to obtain an ester compound-containing composition.

[0426] The method for producing the ester compound-containing composition is not limited to the method described above. For example, other (meth)acrylic acid esters may be used instead of methyl (meth)acrylate as a raw material. Ester compound (I) may be produced by carrying out an esterification reaction between an alcohol and (meth)acrylic acid.

[0427] (Method for evaluating the storage stability and thermal stability of ester compound-containing compositions) Ester compound-containing compositions exhibit high quality stability during storage. Methods for evaluating the quality stability of ester compound-containing compositions during storage include, for example, actually storing the ester compound-containing composition for a long period and confirming the amount of ester compound (I) dimers and oxidation products produced, as well as the ester compound (I) content. Alternatively, from the viewpoint of ease of operation, a method of briefly heating the ester compound-containing composition and confirming the amount of ester compound (I) dimers and oxidation products produced, as well as the ester compound (I) content, may be used. When heating for a short time, the heating temperature is preferably 50-100°C, and the heating time is preferably 1-24 hours. The quality stability of ester compound-containing compositions during storage is evaluated based on the amount of ester compound (I) dimers and oxidation products produced, and the ester compound (I) content, when the ester compound-containing composition is stored at 25°C for 14 days, or when heated at 70°C for 7-20 hours.

[0428] [Polymerizable composition] The polymerizable composition according to the third embodiment is a polymerizable composition for producing a (meth)acrylic polymer, and includes the ester compound-containing composition according to the third embodiment described above. For example, an ester compound-containing composition that has been stored for more than one day after manufacturing can be used in a polymerizable composition. The storage time for ester compound-containing compositions may be 1 day or more, 3 days or more, 7 days or more, or 14 days or more. Alternatively, the storage time for ester compound-containing compositions may be 180 days or less, 150 days or less, 120 days or less, or 90 days or less. "Storage time" is not limited to the time spent standing in a specific environment, but includes transportation time, etc., and refers to the elapsed time from immediately after manufacture.

[0429] The material of the storage container for the ester compound-containing composition is not particularly limited; for example, metal containers such as stainless steel, resin containers, and glass containers can be used. Either transparent or opaque containers can be used.

[0430] The storage temperature for ester compound-containing compositions is preferably -10°C or higher, more preferably 0°C or higher, preferably 60°C or lower, and more preferably 50°C or lower. A temperature of -10°C or higher reduces the load on the cooling system, and a temperature of 60°C or lower makes it easier to suppress the formation of (meth)acrylic acid ester dimers and oxidation products.

[0431] The oxygen concentration in the gas phase when storing an ester compound-containing composition is preferably 5% by volume or more, more preferably 7% by volume or more, preferably 30% by volume or less, and more preferably 22% by volume or less. Setting the oxygen concentration in the gas phase to 5% by volume or more makes it easier to prevent the ester compound from unintentionally polymerizing due to the polymerization-inhibiting effect of oxygen, and setting it to 30% by volume or less makes it easier to suppress the oxidation of (meth)acrylic acid ester by oxygen and the generation of various impurities.

[0432] For example, the ester compound-containing composition after storage may be used as a polymerizable composition without further addition of monomers, or a monomer copolymerizable with ester compound (I) (hereinafter also referred to as "other monomers") may be further added to the ester compound-containing composition after storage to form a polymerizable composition. In another example, the ester compound-containing composition may be stored with other monomers added after manufacturing and then used as a polymerizable composition. In this case, it is preferable not to add polymerization initiators during storage.

[0433] The ratio of ester compound (I) to the total mass of monomers in the polymerizable composition is preferably 10% by mass or more, more preferably 20% by mass or more, preferably 90% by mass or less, and more preferably 80% by mass or less. This makes it possible to obtain a highly transparent (meth)acrylic polymer.

[0434] The ester compound-containing composition may contain monomers copolymerizable with ester compound (I), or it may not contain monomers copolymerizable with ester compound (I). Examples of monomers copolymerizable with ester compound (I) include, Other monomers copolymerizable with ester compound (1); Other monomers copolymerizable with ester compounds (5); Other monomers copolymerizable with at least one selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4); These are some examples.

[0435] (Other monomers copolymerizable with ester compound (1)) Other monomers copolymerizable with ester compound (1) include, for example, methyl (meth)acrylate, unsaturated carboxylic acid, unsaturated carboxylic acid anhydride, maleimide, hydroxyl group-containing vinyl monomer, vinyl ester, nitrogen-containing vinyl monomer, epoxy group-containing monomer, aromatic vinyl monomer, alkanediol di(meth)acrylate, polyoxyalkylene glycol di(meth)acrylate, and vinyl monomers having two or more ethylenically unsaturated bonds in the molecule.

[0436] Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, and itaconic acid. Examples of unsaturated carboxylic acid anhydrides include maleic anhydride and itaconic anhydride. Examples of maleimides include N-phenylmaleimide and N-cyclohexylmaleimide.

[0437] Examples of hydroxyl group-containing vinyl monomers include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate. Examples of vinyl esters include vinyl acetate and vinyl benzoate. Examples of nitrogen-containing vinyl monomers include methacrylamide and acrylonitrile. Examples of epoxy group-containing monomers include glycidyl acrylate and glycidyl methacrylate.

[0438] Examples of aromatic vinyl monomers include styrene and α-methylstyrene. Examples of alkanediol di(meth)acrylates include ethylene glycol di(meth)acrylate, 1,2-propylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate.

[0439] Examples of polyoxyalkylene glycol di(meth)acrylates include diethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, triethylene glycol (meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and neopentyl glycol di(meth)acrylate. Examples of vinyl monomers having two or more ethylenically unsaturated bonds in their molecules include divinylbenzene.

[0440] Other monomers that may be used include vinyl chloride, vinylidene chloride and their derivatives, unsaturated polyester prepolymers obtained from at least one polycarboxylic acid and at least one diol, including ethylenically unsaturated polycarboxylic acids, and vinyl ester prepolymers obtained by modifying the ends of epoxy groups with acrylic. Other monomers may be used individually or in combination of two or more.

[0441] (Other monomers copolymerizable with at least one selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4)) Other monomers copolymerizable with at least one selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4) include, for example, the same monomers copolymerizable with ester compound (1).

[0442] (Other monomers copolymerizable with ester compound (5)) Other monomers copolymerizable with ester compound (5) include the same monomers copolymerizable with ester compound (1).

[0443] If component A7 is a monomer copolymerizable with ester compound (I), component A7 may be used as a monomer copolymerizable with ester compound (I), or a monomer copolymerizable with ester compound (I) may be used separately from component A7.

[0444] The polymerizable composition preferably contains a polymerization initiator. Examples of polymerization initiators include azo compounds, organic peroxides, persulfate compounds, and redox polymerization initiators. Polymerization initiators may be used individually or in combination of two or more.

[0445] Examples of azo compounds include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2-methylpropionitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4,4-trimethylpentane), 2,2'-azobis(2-methylpropane), 1,1-azobis(cyclohexanecarbonitride), and dimethyl-2,2'-azobisisobutyrate.

[0446] Examples of organic peroxides include benzoyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, 1,1-bis(t-butylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)-3,5,5-trimethylcyclohexane, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxybenzoate, t-hexylperoxybenzoate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, t-butylperoxyacetate, and t-hexylperoxyisopropyl monocarbonate. Examples include t-hexyl peroxy-2-ethylhexanoate, t-amyl peroxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutyl peroxyethyl hexanoate, 1,1,2-trimethylpropyl peroxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutyl peroxyisopropyl monocarbonate, 1,1,2-trimethylpropyl peroxyisopropyl monocarbonate, 1,1,3,3-tetramethylbutyl peroxyisononoate, 1,1,2-trimethylpropyl peroxyisononoate, di-t-butyl peroxide, di-t-hexyl peroxide, lauroyl peroxide, and dilauroyl peroxide.

[0447] Examples of persulfate compounds include potassium persulfate. The amount of polymerization initiator added is not particularly limited, and can be, for example, 0.005 to 5 parts by mass per 100 parts by mass of the total mass of monomers in the polymerizable composition.

[0448] The polymerizable composition may optionally contain other additives such as chain transfer agents, mold release agents, lubricants, plasticizers, antioxidants, antistatic agents, light stabilizers, UV absorbers, flame retardants, flame retardant aids, polymerization inhibitors, fillers, pigments, dyes, silane coupling agents, leveling agents, defoamers, and fluorescent agents. Other additives may be used individually or in combination of two or more.

[0449] [Meth)acrylic polymer manufacturing method] (Meth)acrylic polymers can be produced by polymerizing polymerizable compositions. The polymerization method is not particularly limited and includes, for example, bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization. Bulk polymerization is preferred from the viewpoint of environmental impact due to solvent use and the transparency of the resulting (meth)acrylic polymer.

[0450] The bulk polymerization method is not particularly limited and can include various casting polymerization methods such as cell casting and continuous casting. Cast polymerization is a method for obtaining a (meth)acrylic polymer by injecting a polymerizable composition into a mold consisting of two inorganic glass plates or metal plates (e.g., SUS plates) that are placed opposite each other at a predetermined distance and sealed around the periphery with a gasket such as a flexible resin tube, and allowing polymerization to proceed. The mold for casting polymerization is not particularly limited, and various types of molds can be used. For example, a mold for cell casting may be made by arranging two plate-like bodies, such as inorganic glass plates, chrome-plated metal plates, or stainless steel plates, opposite each other at a predetermined distance, and placing a gasket on the edge thereof to form a sealed space with the plate-like bodies and the gasket. For example, a mold for continuous casting may be made by forming a sealed space with the opposing surfaces of a pair of endless belts traveling in the same direction at the same speed, and gaskets traveling at the same speed as the endless belts on both sides of the endless belts.

[0451] The spacing of the voids in the mold is adjusted as needed to obtain a resin plate of the desired thickness, but it is generally between 1 and 30 mm.

[0452] The polymerization temperature is preferably 125 to 210°C, and more preferably 130 to 180°C. The polymerization time is preferably 0.5 to 24 hours.

[0453] The weight-average molecular weight (Mw) of the (meth)acrylic polymer is not particularly limited and can be, for example, 100,000 to 1,000,000. The higher the Mw of the (meth)acrylic polymer, the better the solvent resistance and chemical resistance. The Mw of (meth)acrylic polymers can be controlled by adjusting the polymerization temperature, polymerization time, and the amount of polymerization initiator added.

[0454] The (meth)acrylic polymer according to the third embodiment has excellent heat resistance and meltability. For example, granular (meth)acrylic polymers, which have a large amount of resin that can be stored per unit volume and low energy costs during storage and transportation, need to be dissolved or melted when used. The (meth)acrylic polymer according to the third embodiment is easily melted, has excellent kneadability with other resins, and has excellent solubility in monomers and solvents.

[0455] 4. Fourth aspect A fourth aspect of the embodiment will be described below.

[0456] [Ester compound-containing composition] The ester compound-containing composition according to the fourth embodiment contains the ester compound (I) described below and the compound (component A8) described below. The content of ester compound (I) is 95.00 to 99.99% by mass.

[0457] The ester compound-containing composition may further contain, in addition to the ester compound (I) and component A8, a polymerization inhibitor (component B) described below. The ester compound-containing composition may, if necessary, further contain at least one of ester compound (I), a compound other than ester compound (I), component A8, and component B (hereinafter also referred to as "component C"), and water, in addition to ester compound (I) and component A8, as long as the effects of the present invention are not impaired.

[0458] (Ester compound (I)) Ester compounds (I) are compounds represented by the following formula (I). CH2=CR150 -C(=O)-OR 200 ...(I)

[0459] In formula (I), R 150 is a hydrogen atom or a methyl group, R 200 This is a monovalent hydrocarbon group having 2 to 20 carbon atoms, which may have substituents, or a monovalent group having 2 to 8 carbon atoms and having an ether bond.

[0460] As ester compound (I), one type may be used alone, or two or more types may be used in combination. As ester compound (I), one or more selected from the group consisting of ester compound (1), ester compound (2), ester compound (3), ester compound (4), and ester compound (5) described below are preferred. These ester compounds will be described below.

[0461] Ester compound (1) is a (meth)acrylic acid ester represented by the following formula (1). CH2=CR 1a -C(=O)-OR 2a ...(1) In formula (1), R 1a R is a hydrogen atom or a methyl group. 2a It is a hydrocarbon group having 2 to 20 carbon atoms.

[0462] R 2a The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. R 2a The hydrocarbon group may be linear, branched, or have a ring. 2a If the hydrocarbon group has a ring, the ring may be an aliphatic ring or an aromatic ring. R 2a The number of carbon atoms in the hydrocarbon group is 2 to 20, preferably 2 to 18, and more preferably 2 to 12.

[0463] R 2aExamples of hydrocarbon groups include C2-C20 alkyl groups, C3-C20 cycloalkyl groups, C2-C20 alkenyl groups, C3-C20 cycloalkenyl groups, C2-C20 alkynyl groups, C6-C20 aryl groups, and C7-C20 aromatic alkyl groups. "Aromatic alkyl group" refers to a group in which one or more hydrogen atoms of an alkyl group are substituted with an aryl group.

[0464] R 2a Examples of alkyl groups include ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, lauryl group, and stearyl group. R 2a Examples of cycloalkyl groups include cyclopropyl, cyclohexyl, and isobornyl groups. R 2a Examples of alkenyl groups include vinyl groups and allyl groups. R 2a Examples of cycloalkenyl groups include cyclopentenyl, cyclopentadienyl, and cyclohexenyl groups. R 2a An example of an alkynyl group is the propynyl group. R 2a Examples of aryl groups include the phenyl group and the naphthyl group. R 2a Examples of aromatic alkyl groups include the benzyl group.

[0465] Since ester compound (1) is relatively easy to obtain and relatively easy to handle in terms of physical properties, R 2aPreferably, the group is an alkyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aromatic alkyl group having 7 to 20 carbon atoms. More preferably, the group is an ethyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a 2-ethylhexyl group, a lauryl group, a stearyl group, a cyclohexyl group, an isobornyl group, an allyl group, a phenyl group, or a benzyl group. Particularly preferred are the n-butyl group and an isobutyl group, with the n-butyl group being the most preferred.

[0466] Examples of ester compounds (1) include ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, allyl (meth)acrylate, phenyl (meth)acrylate, and benzyl (meth)acrylate.

[0467] Because it is relatively easy to obtain and relatively easy to handle in terms of physical properties, R is used as the ester compound (1). 2a Alkyl (meth)acrylates, R, are linear or branched alkyl groups having 2 to 20 carbon atoms. 2a Cycloalkyl (meth)acrylates, which are cycloalkyl groups with 3 to 20 carbon atoms, R 2a Alkenyl (meth)acrylates, which are alkenyl groups with 2 to 20 carbon atoms, R 2a aryl(meth)acrylates, which are aryl groups with 6 to 20 carbon atoms, R 2aAromatic alkyl (meth)acrylates, in which the compound is an aromatic alkyl group having 7 to 20 carbon atoms, are preferred. Ethyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, allyl (meth)acrylate, phenyl (meth)acrylate, and benzyl (meth)acrylate are more preferred. Butyl (meth)acrylate and isobutyl (meth)acrylate are particularly preferred, and butyl (meth)acrylate is most preferred.

[0468] Ester compound (1) may be used alone or in combination of two or more types.

[0469] Ester compound (2) is a (meth)acrylic acid ester represented by the following formula (2). Ester compound (3) is a (meth)acrylic acid ester represented by the following formula (3). Ester compound (4) is a (meth)acrylic acid ester represented by the following formula (4).

[0470] [ka]

[0471] In equations (2), (3), and (4), R 1b , R 3b , R 5b , R 6b , R 8b and R 9b Each of these is independently either a hydrogen atom or a methyl group. 2b and R 4b Each of these is independently a linear or branched alkylene group or hydroxyalkylene group having 2 to 8 carbon atoms. 7b It is a linear or branched trivalent hydrocarbon group having 2 to 8 carbon atoms.

[0472] R 2b and R4b The number of carbon atoms in the alkylene group or hydroxyalkylene group is 2 to 8, preferably 2 to 6. R 2b and R 4b Examples of alkylene groups include ethylene, propylene, isopropylene, and butylene groups. R 2b and R 4b Examples of hydroxyalkylene groups include hydroxyethylene, hydroxypropylene, and hydroxybutylene groups.

[0473] R 7b The number of carbon atoms in the trivalent hydrocarbon group is 2 to 8, preferably 2 to 4. R 7b Examples of the trivalent hydrocarbon group include -(CH2)-C(-CH2-)(-CH3)-CH2-.

[0474] Examples of ester compounds (2) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 3-hydroxypropyl (meth)acrylate. Examples of ester compounds (3) include ethylene glycol di(meth)acrylate, 1,3-propanediol di(meth)acrylate, 1,2-propanediol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate. Examples of ester compounds (4) include trimethylolpropane tri(meth)acrylate.

[0475] Because they are relatively easy to obtain, one or more ester compounds (2), (3), and (4) are preferably selected from the group consisting of ethylene glycol di(meth)acrylate, 2-hydroxyethyl(meth)acrylate, 3-hydroxypropyl(meth)acrylate, and trimethylolpropanetri(meth)acrylate.

[0476] Ester compound (2), ester compound (3), and ester compound (4) may be used individually or in combination of two or more.

[0477] Ester compound (5) is a (meth)acrylic acid ester represented by the following formula (5). CH2=CR 1c -C(=O)-OR 2c ...(5) In formula (5), R 1c R is a hydrogen atom or a methyl group, 2c It is a monovalent group with 2 to 8 carbon atoms that has an ether bond.

[0478] R 2c The number of etheric oxygen atoms in the monovalent group having 2 to 8 carbon atoms is preferably one, but is not limited to one, and may be two or more. R 2c The monovalent group having 2 to 8 carbon atoms may be linear, branched, or have a ring. 2c If the ring has a ring, the ring may or may not contain etheric oxygen. R 2c The number of carbon atoms in the monovalent group having an ether bond is 2 to 8, preferably 2 to 7.

[0479] R 2c Examples of such groups include 2-methoxyethyl group, 2-(2-methoxyethoxy)ethyl group, 2-[2-(2-methoxyethoxy)ethoxy]ethyl group, glycidyl group, and tetrahydrofurfuryl group. Because it is relatively easy to obtain and relatively easy to handle in terms of physical properties, R 2c The preferred group is a 2-methoxyethyl group, a glycidyl group, or a tetrahydrofurfuryl group.

[0480] Examples of ester compounds (5) include 2-methoxyethyl (meth)acrylate, glycidyl (meth)acrylate, 2-(2-methoxyethoxy)ethyl (meth)acrylate, 2-[2-(2-methoxyethoxy)ethoxy]ethyl (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate.

[0481] Because they are relatively easy to handle in terms of physical properties, 2-methoxyethyl (meth)acrylate, glycidyl (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate are preferred as ester compounds (5).

[0482] The ester compound (5) may be used alone or in combination of two or more types.

[0483] (Ingredient A8) Component A8 is a compound represented by the following formula (a8). The inclusion of component A8 in the ester compound-containing composition suppresses the dimerization reaction of ester compound (I) and the formation of oxidation products of ester compound (I) during storage, resulting in an ester compound-containing composition with excellent storage stability. The reason for this is presumed to be as follows.

[0484] During storage of ester compound-containing compositions, ultraviolet-derived radicals are generated, such as hydroxyl radicals produced when oxygen molecules absorb ultraviolet light from sunlight. Such radicals can cause the formation of dimers of ester compound (I) and oxidation products of ester compound (I). Component A8 is a π-conjugated compound having a benzene ring, and therefore absorbs ultraviolet light, with its absorption wavelength and intensity varying depending on the type of substituent. Because component A8 has an alkyl group with appropriate bulk and electron-donating properties bonded to the benzene ring, it can absorb ultraviolet light across a wide range of wavelengths. Therefore, when an ester compound-containing composition contains component A8, ultraviolet light across a wide range of wavelengths is absorbed, suppressing the generation of hydroxyl radicals. This is presumed to suppress the progression of dimerization of ester compound (I) via the radical polymerization mechanism and the generation of oxidation products, thereby preventing a decrease in the purity of ester compound (I).

[0485] [ka]

[0486] In formula (a8), R 81 , R 82 , R 83 , R 84 , R 85 and R 86 Each of these is independently a monovalent group selected from a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, or a carbonyl group, and R 81 , R 82 , R 83 , R 84 , R 85 and R 86 The total number of carbon atoms is 2 or more.

[0487] The molecular weight of component A8 is preferably 2000 or less. By having a molecular weight of 2000 or less, the number of benzene rings per unit mass in component A8 can be increased, so that the effects of the present invention can be obtained with a small mass. The molecular weight of component A8 is more preferably 1600 or less, even more preferably 1200 or less, particularly preferably 1000 or less, and most preferably 800 or less.

[0488] In formula (a8), R 81 , R 82 , R 83 , R 84 , R 85 and R 86 Each of these is independently a monovalent group selected from a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, or a carbonyl group, or an alkylthio group or an arylthio group. R 81 , R 82 , R 83 , R 84 , R 85 and R 86 These may be the same or different. 81 , R 82 , R 83 , R 84 , R 85 and R 86 At least one of them is preferably an alkyl group.

[0489] In equation (a8), R 81 , R 82 , R 83 , R 84 , R 85 and R 86 If the steric hindrance is large, distortion occurs in the benzene ring, and the π-conjugated system cannot be maintained. However, R 81 , R 82 , R 83 , R 84 , R 85 and R 86 When the above conditions are met, the bulk is of an appropriate size and the π-conjugated system of component A8 is maintained, so it has the property of absorbing ultraviolet light of a wide range of wavelengths, and the effects of the present invention can be obtained.

[0490] From the perspective of increasing the absorbance of ultraviolet light and suppressing the generation of hydroxyl radicals, R 81 , R 82 , R 83 , R 84 , R 85 and R 86 It is preferably a monovalent group comprising a hydrogen atom, a C1-C5 alkyl group, a C2-C5 alkenyl group, a C1-C12 aryl group, a hydroxyl group, a C1-C6 alkoxy group, an amino group, or a carbonyl group; more preferably a hydrogen atom, a C1-C5 alkyl group, a hydroxyl group, or a C1-C6 alkoxy group; even more preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a t-butyl group, a hydroxyl group, or a methoxy group; and particularly preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, or a t-butyl group.

[0491] R 81 , R 82 , R 83 , R 84 , R 85 and R 86 The alkyl group may be linear, branched, or have a ring. The alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 10, and even more preferably 1 to 5 carbon atoms. Examples of linear or branched alkyl groups (hereinafter collectively referred to as "chain alkyl groups") include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n-pentyl group, isopentyl group, hexyl group, octyl group, decyl group, hydroxymethyl group, 1-hydroxyethyl group, and 2-hydroxyethyl group. Among these, methyl group, ethyl group, n-propyl group, isopropyl group, and t-butyl group are preferred. Examples of ring-containing alkyl groups (hereinafter also referred to as "cyclic alkyl groups") include the cyclopentyl group, the cyclohexyl group, and the cyclooctyl group.

[0492] R 81 , R 82 , R 83 , R 84 , R 85 , R 86 and R 87 The alkenyl group may be linear, branched, or have a ring. The number of carbon atoms in the alkenyl group is preferably 2 to 20, more preferably 2 to 10, and even more preferably 2 to 5. Examples of linear or branched alkenyl groups (hereinafter collectively referred to as "chain alkenyl groups") include vinyl groups, 1-propenyl groups, isopropenyl groups, 2-butenyl groups, 1,3-butadienyl groups, 2-pentenyl groups, and 2-hexenyl groups. Examples of ring-containing alkenyl groups (hereinafter also referred to as "ring alkenyl groups") include the cyclopentenyl group and the cyclohexenyl group.

[0493] R 81 , R 82 , R 83 , R 84 , R 85 and R 86 The number of carbon atoms in the aryl group is preferably 1 to 20, more preferably 1 to 12, and even more preferably 6 to 12. The aryl group includes heteroaryl groups containing oxygen, nitrogen, sulfur, etc. Examples of aryl groups include phenyl, mesityl, naphthyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 2-ethylphenyl, isoxazolyl, isothiazolyl, imidazolyl, oxazolyl, thiazolyl, thiadiazolyl, thienyl, triazolyl, tetrazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridadinyl, pyrazolyl, pyrrolyl, furyl, fluzanyl, isoquinolyl, isoindolyl, indolyl, quinolyl, pyridothiazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, benzotriazolyl, benzofuranyl, imidazopyridinyl, triazopyridinyl, and prinyl groups.

[0494] R 81 , R 82 , R 83 , R 84 , R 85 and R 86 The number of carbon atoms in the alkoxy group is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 6. Examples of alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, s-butoxy, t-butoxy, n-pentoxy, isopentoxy, and phenoxy groups.

[0495] R 81 , R 82 , R 83 , R 84 , R 85 and R 86 The amino group in this context includes an amino group (-NH2) that does not have substituents on the nitrogen atom, and an amino group in which some or all of the hydrogen atoms bonded to the nitrogen atom are replaced by carbon atoms. The number of carbon atoms in the amino group substituted with carbon atoms is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 5. Examples of amino groups include unsubstituted amino groups, methylamino groups, ethylamino groups, propylamino groups, butylamino groups, dimethylamino groups, diethylamino groups, anilino groups, toluidino groups, anisidino groups, diphenylamino groups, and N-methyl-N-phenylamino groups.

[0496] R 81 , R 82 , R 83 , R 84 , R 85 and R 86 Examples of monovalent groups containing a carbonyl group include formyl group, acyl group, carboxyl group, amide group, alkoxycarbonyl group, thiocarboxyl group, and thioester group.

[0497] An acyl group is a substituent formed by linking a carbonyl group to an alkyl group, alkenyl group, or aryl group. The total number of carbon atoms in the acyl group, derived from the carbonyl group (1) and derived from the alkyl group, alkenyl group, or aryl group, is preferably 2 to 20, more preferably 2 to 10, and even more preferably 2 to 6. Examples of acyl groups include acetyl, propionyl, butylcarbonyl, vinylcarbonyl, and benzoyl groups.

[0498] The amide group includes an amide group (-CONH2) that does not have substituents on the nitrogen atom, and an amide group in which some or all of the hydrogen atoms bonded to the nitrogen atom are replaced by carbon atoms. The number of carbon atoms in the amide group is the sum of the carbon atoms derived from the carbonyl group (1) and the carbon atoms substituted on the nitrogen atom, preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 5. Examples of amide groups include unsubstituted amide groups, N-methylamide groups, N-ethylamide groups, N-phenylamide groups, N,N-dimethylamide groups, and N-methyl-N-phenylamide groups.

[0499] An alkoxycarbonyl group is a substituent formed by the linkage of a carbonyl group and an alkoxy group, and is also called an ester group. The total number of carbon atoms derived from the carbonyl group (1) and the alkoxy group is preferably 2 to 20, more preferably 2 to 10, and even more preferably 2 to 6. Examples of alkoxycarbonyl groups include methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl, and phenoxycarbonyl groups.

[0500] A thioester group is a substituent formed by linking a carbonyl group with an alkylthio group or an arylthio group. The total number of carbon atoms derived from the carbonyl group (1) and the alkylthio group or arylthio group is preferably 2 to 20, more preferably 2 to 10, and even more preferably 2 to 6. Examples of thioester groups include methylthiocarbonyl group, ethylthiocarbonyl group, butylthiocarbonyl group, and phenylthiocarbonyl group.

[0501] For example, a monovalent group containing a carbonyl group may be a substituent in which one or more hydrogen atoms of an alkyl group are substituted with a carbonyl group. Examples of such substituents include 2-acetoxyethyl group, 2-acetoethyl group, and 2-(acetoacetoxy)ethyl group.

[0502] R 81 , R 82 , R 83 , R 84 , R 85 and R 86 The alkylthio group preferably has 1 to 20 carbon atoms, more preferably 1 to 10, and even more preferably 1 to 5 carbon atoms. Examples of alkylthio groups include methylthio groups, ethylthio groups, propylthio groups, and isopropylthio groups.

[0503] R 81 , R 82 , R 83 , R 84 , R 85 and R 86 The number of carbon atoms in the arylthio group is preferably 1 to 20, more preferably 3 to 10, and even more preferably 6 to 10. Examples of arylthio groups include phenylthio groups and tolylthio groups.

[0504] Among the compounds that satisfy the above conditions, from the viewpoint of further improving the storage stability of the ester compound-containing composition, component A8 is selected from o-xylene, m-xylene, p-xylene, ethylbenzene, n-propylbenzene, cumene, t-butylbenzene, mesitylene, butyl 2-phenylisobutyrate, 2-phenylisobutyric acid, 2-isopropylhydroquinone, 2-isopropyl-4-methoxyphenol, 2-methyl-2-phenylpropionamide, butyl 2-(2-hydroxy-5-methoxyphenyl)-2-methylpropionate, and 2-(2,5-dihydro Butyl xyphenyl-2-methylpropionate is preferred, o-xylene, m-xylene, p-xylene, ethylbenzene, n-propylbenzene, cumene, t-butylbenzene, butyl 2-phenylisobutyrate, 2-phenylisobutyric acid, 2-isopropylhydroquinone, and 2-isopropyl-4-methoxyphenol are more preferred, o-xylene, m-xylene, p-xylene, ethylbenzene, n-propylbenzene, cumene, and t-butylbenzene are particularly preferred, and o-xylene, m-xylene, p-xylene, and ethylbenzene are most preferred.

[0505] Component A8 may be used alone or in combination of two or more types.

[0506] (Component B) Component B is a polymerization inhibitor. The inclusion of component B in the ester compound-containing composition suppresses the progression of the polymerization reaction of ester compound (I) via the radical polymerization mechanism during storage. Furthermore, during storage, oxygen molecules in the ester compound-containing composition may absorb ultraviolet light from sunlight, generating hydroxyl radicals. However, polymerization inhibitors can trap these hydroxyl radicals. Therefore, if the ester compound-containing composition contains both component A8 and component B, the amount of hydroxyl radicals can be reduced through two different mechanisms: component A8 suppresses the generation of hydroxyl radicals, and component B removes any hydroxyl radicals that are generated. Thus, the progression of dimerization of ester compound (I) and the generation of oxidation products can be suppressed more efficiently, and the decrease in the purity of ester compound (I) can be efficiently suppressed. A polymerization inhibitor is a compound that has the function of suppressing the polymerization reaction of ester compounds (I).

[0507] Examples of component B include phenolic compounds, quinone compounds, nitrobenzene compounds, N-oxyl compounds, amine compounds, phosphorus-containing compounds, sulfur-containing compounds, iron-containing compounds, copper-containing compounds, manganese-containing compounds, and the like.

[0508] Examples of phenolic compounds include alkylphenols, hydroxyphenols, aminophenols, nitrophenols, nitrosophenols, alkoxyphenols, and tocopherols.

[0509] Examples of alkylphenols include o-cresol, m-cresol, p-cresol, 2-t-butyl-4-methylphenol, 2,4-dimethyl-6-t-butylphenol, 2,6-di-t-butyl-4-methylphenol, 2-t-butylphenol, 4-t-butylphenol, 2,4-di-t-butylphenol, 2-methyl-4-t-butylphenol, 4-t-butyl-2,6-dimethylphenol, 2,2'-methylenebis(6-t-butyl-4-methylphenol), 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol), and 3,5-di-t-butyl-4-hydroxytoluene.

[0510] Examples of hydroxyphenols include hydroquinone, 2-methylhydroquinone, 2-t-butylhydroquinone, 2,5-di-t-butylhydroquinone, 2,6-di-butylhydroquinone, 2,5-di-t-amylhydroquinone, 2-t-butylmethoxyhydroquinone, 2,3,5-trimethylhydroquinone, 2,5-dichlorohydroquinone, 1,2-dihydroxybenzene, 2-acetylhydroquinone, 4-methylcatechol, 4-t-butylcatechol, 2-methylresorcinol, 4-methylresorcinol, and 2,3-dihydroxyacetophenone.

[0511] Examples of aminophenols include o-aminophenol, m-aminophenol, p-aminophenol, 2-(N,N-dimethylamino)phenol, and 4-(ethylamino)phenol.

[0512] Examples of nitrophenols include o-nitrophenol, m-nitrophenol, p-nitrophenol, and 2,4-dinitrophenol.

[0513] Examples of nitrosophenols include o-nitrosophenol, m-nitrosophenol, p-nitrosophenol, and α-nitroso-β-naphthol.

[0514] Examples of alkoxyphenols include 2-methoxyphenol, 2-ethoxyphenol, 2-isopropoxyphenol, 2-t-butoxyphenol, 4-methoxyphenol, 4-ethoxyphenol, 4-propoxyphenol, 4-butoxyphenol, 4-t-butoxyphenol, 4-heptoxyphenol, hydroquinone monobenzyl ether, t-butyl-4-methoxyphenol, di-t-butyl-4-methoxyphenol, pyrogallol-1,2-dimethyl ether, and hydroquinone monobenzoate.

[0515] Examples of tocopherols include α-tocopherol and 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran.

[0516] Examples of quinone compounds include p-benzoquinone, chloro-p-benzoquinone, 2,5-dichloro-p-benzoquinone, 2,6-dichloro-p-benzoquinone, tetrachloro-p-benzoquinone, tetrabromo-p-benzoquinone, 2,3-dimethyl-p-benzoquinone, 2,5-dimethyl-p-benzoquinone, methoxy-p-benzoquinone, and methyl-p-benzoquinone.

[0517] Examples of nitrobenzene compounds include nitrobenzene, o-dinitrobenzene, m-dinitrobenzene, p-dinitrobenzene, 2,4-dinitrobenzene, dinitrojulen, and 2,2-diphenyl-1-picrylhydrazine.

[0518] Examples of N-oxyl compounds include 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-oxo-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-acetoxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, 2,2,6,6-tetramethyl-piperidine-N-oxyl, piperidine-1-oxyl, 4-(dimethylamino)-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-amino-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-ethenoloxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, and 4-benzoyloxy-2,2,6,6-tetramethyl-piperidine-N-oxyl Examples include tris(2,2,5,5-tetramethyl-piperidine-N-oxyl), 3-amino-2,2,5,5-tetramethyl-piperidine-N-oxyl, 4,4',4”-tris(2,2,6,6-tetramethyl-piperidine-N-oxyl) phosphite, 3-oxo-2,2,5,5-tetramethylpyrrolidine-N-oxyl, pyrrolidine-1-oxyl, 2,2,5,5-tetramethyl-1-oxa-3-azacyclopentyl-3-oxyl, 2,2,5,5-tetramethyl-3-pyrrolinyl-1-oxy-3-carboxylic acid, 2,2,3,3,5,5,6,6-octamethyl-1,4-diazacyclohexyl-1,4-dioxyl, di-t-butyl nitroxide, di-t-amyl nitroxide, etc.

[0519] Examples of amine compounds include N,N-diphenylamine, alkylated diphenylamine, 4,4'-dicumyl-diphenylamine, 4,4'-dioctyldiphenylamine, 4-aminodiphenylamine, p-nitrosodiphenylamine, N-nitrosodinaphthylamine, N-nitrosodiphenylamine, N-nitrosophenylnaphthylamine, N-nitrosophenylhydroxylamine, N,N'-dialkyl-p-phenylenediamine (the alkyl groups may be the same or different, each independently having 1 to 4 carbon atoms, and may be linear or branched), N,N'-diphenyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, and N-(1,3-dimethylbutyl)-N'-phenyl-1,4 Examples include -phenylenediamine, N,N'-di-2-naphthyl-p-phenylenediamine, N,N-diethylhydroxylamine, 1,4-benzenediamine, N-(1,4-dimethylpentyl)-N'-phenyl-1,4-benzenediamine, 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, aldol-α-naphthylamine, N-phenyl-β-naphthylamine, 4-hydroxy-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 1,4-dihydroxy-2,2,6,6-tetramethylpiperidine, and 1-hydroxy-4-benzoylioxy-2,2,6,6-tetramethylpiperidine.

[0520] Phosphorus-containing compounds include, for example, triphenylphosphine, triphenyl phosphite, triethyl phosphite, tris(isodecyl) phosphite, tris(tridecyl) phosphite, phenyldiisooctyl phosphite, phenyldiisodecyl phosphite, phenyldi(tridecyl) phosphite, diphenylisooctyl phosphite, diphenylisodecyl phosphite, diphenyltridecyl phosphite, phosphonic acid [1,1-diphenyl-4,4'-diylbistetrakis-2,4-bis(1,1-dimethylethyl)phenyl] ester, triphenyl phosphite, tris(nonylphenyl) phosphite, 4,4'-isopropylidenediphenolalkyl phosphite, tris(2,4-di-t-butylphenyl) phosphite, tris(biphenyl) phosphite, dist Examples include allyl pentaerythritol diphosphite, di(2,4-di-t-butylphenyl) pentaerythritol diphosphite, di(nonylphenyl) pentaerythritol diphosphite, phenylbisphenol A pentaerythritol diphosphite, tetra(tridecyl)-4,4'-butylidenebis(3-methyl-6-t-butylphenol) diphosphite, hexa(tridecyl)-1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane triphosphite, 3,5-di-t-butyl-4-hydroxybenzyl phosphate diethyl ester, sodium-bis(4-t-butylphenyl) phosphate, sodium-2,2'-methylene-bis(4,6-di-t-butylphenyl) phosphate, and 1,3-bis(diphenoxyphosphonyloxy)benzene.

[0521] Examples of sulfur-containing compounds include diphenyl sulfide, phenothiazine, 3-oxofhenothiazine, 5-oxofhenothiazine, phenothiazine dimers, 1,4-dimercaptobenzene, 1,2-dimeltocaptobenzene, 2-mercaptophenol, 4-mercaptophenol, 2-(methylthio)phenol, 3,7-bis(dimethylamino)phenothiazinium chloride, and elemental sulfur.

[0522] Examples of iron-containing compounds include iron(III) chloride.

[0523] Examples of copper-containing compounds include copper dimethyldithiocarbamate, copper diethylthiocarbamate, copper dibutylthiocarbamate, copper salicylate, copper acetate, copper thiocyanate, copper nitrate, copper chloride, copper carbonate, copper hydroxide, copper acrylate, and copper methacrylate.

[0524] Examples of manganese-containing compounds include manganese dialkyldithiocarbamate (the alkyl group is one of methyl, ethyl, propyl, or butyl groups, and may be the same or different), manganese diphenyldithiocarbamate, manganese formate, manganese acetate, manganese octanoate, manganese naphthenate, manganese permanganate, and manganese salts of ethylenediaminetetraacetic acid.

[0525] Since this is likely to exhibit an effect of further improving the storage stability of the ester compound-containing composition, component B is preferably at least one polymerization inhibitor selected from the group consisting of phenolic compounds, N-oxyl compounds, amine compounds, phosphorus-containing compounds, and sulfur-containing compounds, more preferably at least one polymerization inhibitor selected from the group consisting of hydroquinone, 4-methoxyphenol, 2,4-dimethyl-6-t-butylphenol, 2,6-di-t-butyl-4-methylphenol, 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, N,N-diphenylamine, N-nitrosodiphenylamine, triphenyl phosphite, and phenothiazine, and particularly preferably at least one polymerization inhibitor selected from the group consisting of hydroquinone, 4-methoxyphenol, 2,4-dimethyl-6-t-butylphenol, and 2,6-di-t-butyl-4-methylphenol.

[0526] Component B may be used alone or in combination of two or more types.

[0527] If an ester compound-containing composition contains a compound that corresponds to both component A8 and component B, that compound shall be considered as component A8. If an ester compound-containing composition contains both component A8 and component B, it means that the ester compound-containing composition contains a component B that is different from the compound A8. If an ester compound-containing composition contains two or more compounds that fall under both component A8 and component B, the compound with the highest molar concentration in the ester compound-containing composition shall be considered component A8, and the other compounds shall be considered component B.

[0528] (Component C) The ester compound-containing composition may contain other compounds (component C) as long as the content of ester compound (I) satisfies 95.00 to 99.99% by mass. Component C is a compound other than ester compound (1), component A8, and component B. Examples of component C include additives such as mold release agents, lubricants, plasticizers, antioxidants, antistatic agents, light stabilizers, UV absorbers, flame retardants, flame retardant aids, polymerization inhibitors, fillers, pigments, dyes, silane coupling agents, leveling agents, defoamers, and fluorescent agents. The ester compound-containing composition may contain unreacted raw materials from the production of the ester compound-containing composition, such as methyl (meth)acrylate, alcohol, and (meth)acrylic acid. The ester compound-containing composition may contain impurities such as diacetyl that are generated during the production of the ester compound-containing composition. However, from the viewpoint of reducing the discoloration of the ester compound-containing composition, the concentration of diacetyl is preferably 5 ppm by mass or less, more preferably 2 ppm by mass or less, even more preferably 1 ppm by mass or less, and particularly preferably 0.1 ppm by mass or less. The ester compound-containing composition may also contain (meth)acrylic acid esters other than ester compound (1).

[0529] The content of ester compound (I) is 95.00 to 99.99% by mass relative to the total mass of the ester compound-containing composition. A content of 90% by mass or more of ester compound (I) reduces the amount of impurities when a (meth)acrylic polymer is produced by polymerization of the ester compound-containing composition, preventing adverse effects on the properties of the polymer. Furthermore, a content of 99.99% by mass or less of ester compound (I) reduces purification costs. A content of 96.00% by mass or more of ester compound (I) is preferable, more preferably 97.00% by mass or more, even more preferably 98.00% by mass or more, particularly preferably 99.00% by mass or more, and most preferably 99.50% by mass or more.

[0530] If ester compound (I) contains ester compound (1) but does not contain ester compound (2), ester compound (3), ester compound (4), and ester compound (5), the content of ester compound (I) is equal to the concentration of ester compound (1).

[0531] If ester compound (I) contains ester compound (5) and does not contain ester compound (1), ester compound (2), ester compound (3), and ester compound (4), the content of ester compound (I) is equal to the concentration of ester compound (5).

[0532] If ester compound (I) contains at least one selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4), and does not contain ester compound (1) and ester compound (5), then the content of ester compound (I) is the concentration of at least one selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4).

[0533] The content of component A8 is not particularly limited, but it is preferably 1 to 10,000 ppm by mass relative to the total mass of the ester compound-containing composition. A component A8 content of 1 ppm by mass or more provides sufficient suppression of the formation of ester compound (I) dimers and oxidation products of ester compound (I). Furthermore, a component A8 content of 10,000 ppm by mass or less reduces the amount of impurities when a (meth)acrylic polymer is produced by polymerization of the ester compound-containing composition, preventing adverse effects on the properties of the polymer. A component A8 content of 3 ppm by mass or more is more preferable, 5 ppm by mass or more is even more preferable, and 10 ppm by mass or more is particularly preferable. A component A8 content of 7,500 ppm by mass or less is more preferable, 5,000 ppm by mass or less is even more preferable, 2,500 ppm by mass or less is even more preferable, 1,500 ppm by mass or less is even more preferable, 1,000 ppm by mass or less is particularly preferable, and 500 ppm by mass or less is most preferable.

[0534] The content of component B is not particularly limited, but it is preferably 1 to 1000 ppm by mass relative to the total mass of the ester compound-containing composition. By having a component B content of 1 ppm by mass or more, the effect of suppressing the formation of dimers of ester compound (I) and oxidation products of ester compound (I) can be sufficiently obtained. Furthermore, by having a component B content of 1000 ppm by mass or less, the amount of impurities when a (meth)acrylic polymer is produced by polymerization of the ester compound-containing composition according to the fourth embodiment can be reduced, and adverse effects on the physical properties of the polymer can be prevented. The content of component B is more preferably 3 ppm by mass or more, even more preferably 5 ppm by mass or more, and particularly preferably 10 ppm by mass or more. The content of component B is more preferably 750 ppm by mass or less, even more preferably 500 ppm by mass or less, even more preferably 250 ppm by mass or less, particularly preferably 100 ppm by mass or less, and most preferably 50 ppm by mass or less.

[0535] The water content of the ester compound-containing composition is preferably 5000 ppm by mass or less, more preferably 4000 ppm by mass or less, even more preferably 3000 ppm by mass or less, particularly preferably 2000 ppm by mass, and most preferably 1000 ppm by mass or less, relative to the total mass of the ester compound-containing composition. If the water content of the ester compound-containing composition is below the above upper limit, the physical properties of the (meth)acrylic polymer obtained by polymerizing the ester compound-containing composition can be maintained more favorably. The lower limit of the water content of an ester compound-containing composition is 0 ppm by mass.

[0536] (Analysis of compositions containing ester compounds) The presence of ester compound-containing compositions as components A8, B, C, and water can be confirmed, for example, by GC-MS measurement. If the GC-MS chart of the ester compound-containing composition shows a peak at the same retention time as the standard for component A8, and the m / z value detected in the mass spectrum of that peak matches the exact mass of component A8, then the ester compound-containing composition can be determined to contain component A8. If a standard for component A8 is unavailable, the peak can be determined to be component A8 if the mass spectrum pattern of the peak appearing in the GC-MS chart of the ester compound-containing composition matches the mass spectrum pattern of component A8 recorded in a mass spectrum database. In other words, the ester compound-containing composition can be determined to contain component A8. Examples of mass spectrum databases include NIST20, NIST17, NIST14, and NIST14s. Furthermore, if the volatility is low and detection by GC-MS is not possible, detection can be performed using LC-MS. The presence of components B, C, and water can also be confirmed by a similar method.

[0537] The content of ester compound (I) can be calculated, for example, by performing GC-FID measurement on the ester compound-containing composition, quantifying it using the area percentage method, and correcting it using the moisture content quantified with a Karl Fischer moisture meter.

[0538] The content (concentration) of component A8 can be quantified, for example, by GC measurement or GC-MS measurement of an ester compound-containing composition, using the internal standard method or absolute calibration curve method. If a standard sample of component A8 cannot be obtained and quantification cannot be performed using the internal standard method or absolute calibration curve method, the content of component A8 can be calculated by performing GC-FID measurement on any organic compound of known concentration under the same conditions as the ester compound-containing composition, using the following formula.

[0539]

number

[0540] Here, N is the number of carbon atoms contained in one molecule of an organic compound with a known concentration. A8 is the number of carbon atoms contained in one molecule of component A8, S A8 ∫ is the peak area of ​​component A8, S is the peak area of ​​the organic compound with a known concentration, and M is the content (mass ppm) of the organic compound with a known concentration. If the volatility is low and quantification by GC measurement is not possible, quantification can be performed using chromatographic methods such as LC.

[0541] The content of components B and C can also be calculated using the same method as for component A8 described above. The presence of water in an ester compound-containing composition, and its concentration, can be confirmed by the Karl Fischer method.

[0542] [Method for producing ester compound-containing compositions] A method for producing an ester compound-containing composition according to the fourth embodiment is, in the presence of component A8, One or more alcohols selected from the group consisting of monoalcohols with 2 to 20 carbon atoms, ether-containing alcohols with 2 to 8 carbon atoms, dialcohols with 2 to 8 carbon atoms, and trialcohols with 2 to 8 carbon atoms, This involves carrying out a transesterification reaction with methyl (meth)acrylate.

[0543] Methyl (meth)acrylate is particularly prone to dimerization and oxidation to produce methyl pyruvate among (meth)acrylic acid esters. However, by carrying out the transesterification reaction in the presence of component A8, the dimerization of methyl (meth)acrylate and the production of methyl pyruvate are suppressed, resulting in an improved yield of ester compound (I).

[0544] For example, to obtain an ester compound-containing composition containing ester compound (1) as ester compound (I), transesterification of methyl (meth)acrylate and a monoalcohol having 2 to 20 carbon atoms is carried out in a reactor in the presence of a catalyst and component A8, as shown in formula (II) below.

[0545] [ka]

[0546] R in equation (II) 1a and R 2a R in equation (1) 1a and R 2a It is the same as this.

[0547] Examples of monoalcohols having 2 to 20 carbon atoms include ethanol, n-butanol, isobutanol, t-butanol, 2-ethylhexanol, lauryl alcohol, stearyl alcohol, cyclohexanol, isobornyl alcohol, allyl alcohol, phenol, and benzyl alcohol. Monoalcohols having 2 to 20 carbon atoms may be used individually or in combination of two or more. The monoalcohols having 2 to 20 carbon atoms preferably include linear or branched monoalcohols having 2 to 20 carbon atoms, and more preferably include n-butanol and isobutanol.

[0548] For example, to obtain an ester compound-containing composition containing ester compound (5) as ester compound (I), transesterification is carried out in a reactor in the presence of a catalyst and component A8, as shown in formula (III) below, between methyl (meth)acrylate and an ether-bonded alcohol having 2 to 8 carbon atoms.

[0549] [ka]

[0550] R in equation (III) 1c and R 2c R in equation (5) 1c and R 2c It is the same as this.

[0551] In ether-bonded alcohols with 2 to 8 carbon atoms, one ether bond is preferred, but not limited to that. Examples of ether-containing alcohols having 2 to 8 carbon atoms include 2-methoxyethanol, glycidyl alcohol, and tetrahydrofurfuryl alcohol. These ether-containing alcohols may be used individually or in combination of two or more. The ether-bonded alcohol having 2 to 8 carbon atoms preferably includes one selected from 2-methoxyethanol, glycidyl alcohol, and tetrahydrofurfuryl alcohol.

[0552] For example, to obtain an ester compound-containing composition containing at least one selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4) as ester compound (I), transesterification is carried out in a reactor in the presence of a catalyst and component A8, as shown in the following formulas (IV) and (V), between methyl (meth)acrylate and one or more alcohols selected from the group consisting of dialcohols having 2 to 8 carbon atoms and trialcohols having 2 to 8 carbon atoms.

[0553] [ka]

[0554] R in equations (IV) and (V) 1b , R 2b , R 3b , R 5b , R 6b and R 7b R in equations (2), (3), and (4) is 1b , R 2b , R 3b , R 5b , R 6b and R 7b It is the same as R. 41b R is a linear or branched alkylene group having 2 to 8 carbon atoms. 42b This is a linear or branched hydroxyalkylene group having 2 to 8 carbon atoms.

[0555] Examples of dialcohols and trialcohols having 2 to 8 carbon atoms include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,6-hexanediol, and trimethylolpropane. In particular, it is preferable that the dialcohols and trialcohols having 2 to 8 carbon atoms include one or more selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, and trimethylolpropane. Dialcohols and trialcohols having 2 to 8 carbon atoms may be used individually or in combination of two or more.

[0556] The reactor is preferably equipped with a distillation column. Since this transesterification reaction is an equilibrium reaction, productivity can be improved by separating the by-product methanol using a distillation column. For example, it is preferable to carry out the transesterification reaction while separating methanol from the system as an azeotropic mixture with methyl (meth)acrylate.

[0557] Examples of such reactors include those equipped with a distillation column on top of a reaction vessel called a reaction kettle, and distillation columns in which a distillation boiler can be used as a reaction vessel. Examples of distillation columns include packed column type and tray type distillation columns. The theoretical number of stages in a distillation column is preferably five or more, and more preferably seven or more, from the standpoint of high separation capacity and stable operation.

[0558] The ratio of methyl (meth)acrylate to alcohol can be determined as appropriate. From the viewpoint of increasing productivity, the ratio of methyl (meth)acrylate to 1 mole of alcohol is preferably 0.1 mole to 10 moles, and more preferably 0.3 mole to 4 moles.

[0559] The catalysts used are not particularly limited, but examples include hydroxides, carbonates, and bicarbonates of alkali metals such as lithium, sodium, and potassium; oxides, hydroxides, and carbonates of alkaline earth metals such as magnesium and calcium; alkali metal alkoxides such as lithium methoxide, sodium methoxide, sodium ethoxide, and potassium t-butoxy; alkali metal amides such as lithium amide, sodium amide, and potassium amide; titanium alkoxides such as tetramethyl titanate, tetraethyl titanate, tetrapropyl titanate, tetraisopropyl titanate, tetrabutyl titanate, and tetra(2-ethylhexyl) titanate; and tin compounds such as dibutyltin oxide and dioctyltin oxide. Among these, titanium alkoxides, dibutyltin oxide, and dioctyltin oxide are preferred because they produce fewer by-products of the Michael addition reaction during the transesterification reaction and have high catalytic activity. The catalysts may be used alone or in combination of two or more.

[0560] The catalyst can be supplied to the reactor on its own. Alternatively, the catalyst can be supplied to the reactor dissolved in the same alcohol as the raw material, or dissolved in the (meth)acrylic acid ester of the raw material. For example, one method is to supply the catalyst directly dissolved in the entire amount of alcohol used in the reaction to the reactor, or to supply the catalyst dissolved in a portion of the alcohol used in the reaction to the reactor. The amount of catalyst used is preferably 0.001 mol% or more and 1 mol% or less per 1 mol of alcohol, and more preferably 0.01 mol% or more and 0.1 mol% or less.

[0561] A solvent may be used in the transesterification reaction. If a solvent is used, it is preferable to use a solvent that forms an azeotropic composition with the by-product methanol. Examples of solvents include n-pentane, n-hexane, n-heptane, n-octane, 2,3-dimethylbutane, 2,5-dimethylhexane, 2,2,4-trimethylpentane, cyclohexane, benzene, and toluene. Among these, n-hexane, n-heptane, and cyclohexane are preferred. The solvent may be used alone or in combination of two or more.

[0562] The reaction temperature for transesterification varies depending on the type of alcohol and solvent, but it is preferably between 60°C and 150°C. The reaction pressure for the transesterification reaction is not particularly limited, and the reaction may be carried out under any pressure: reduced pressure, atmospheric pressure, or increased pressure.

[0563] The form of the transesterification reaction is not particularly limited and can be carried out using commonly used methods such as batch reactions or continuous reactions. After the transesterification reaction, unreacted starting materials and by-products may be separated by purifying the reaction mixture. Various methods can be used for purification, such as distillation, crystallization, extraction, and column chromatography.

[0564] The transesterification reaction may be carried out with component B added to the reaction solution. The presence of component B in addition to component A8 further suppresses the dimerization of methyl (meth)acrylate and the formation of methyl pyruvate, thus making it easier to obtain an improved yield of ester compound (I).

[0565] Component B may be added to the solution containing the ester compound (I) and component A8 after the transesterification reaction. In this case, a separate solution containing ester compound (I) and component B (solution B) can be prepared in addition to the solution containing ester compound (I) and component A8 (solution A), and solutions A and B can be mixed to obtain an ester compound-containing composition. Alternatively, ester compound (I), solution A, and solution B can be mixed to obtain an ester compound-containing composition.

[0566] The method for producing the ester compound-containing composition is not limited to the method described above. For example, other (meth)acrylic acid esters may be used instead of methyl (meth)acrylate as a raw material. Ester compound (I) may be produced by carrying out an esterification reaction between an alcohol and (meth)acrylic acid.

[0567] (Method for evaluating the storage stability and thermal stability of ester compound-containing compositions) Ester compound-containing compositions exhibit high quality stability during storage. Methods for evaluating the quality stability of ester compound-containing compositions during storage include, for example, actually storing the ester compound-containing composition for a long period and confirming the amount of ester compound (I) dimers and oxidation products produced, as well as the ester compound (I) content. Alternatively, from the viewpoint of ease of operation, a method of briefly heating the ester compound-containing composition and confirming the amount of ester compound (I) dimers and oxidation products produced, as well as the ester compound (I) content, may be used. When heating for a short time, the heating temperature is preferably 50-100°C, and the heating time is preferably 1-24 hours. The quality stability of ester compound-containing compositions during storage is evaluated based on the amount of ester compound (I) dimers and oxidation products produced, and the ester compound (I) content, when the ester compound-containing composition is stored at 25°C for 14 days, or when heated at 70°C for 7-20 hours.

[0568] [Polymerizable composition] The polymerizable composition according to the fourth embodiment is a polymerizable composition for producing a (meth)acrylic polymer, and includes the ester compound-containing composition according to the fourth embodiment described above. For example, an ester compound-containing composition that has been stored for more than one day after manufacturing can be used in a polymerizable composition. The storage time for ester compound-containing compositions may be 1 day or more, 3 days or more, 7 days or more, or 14 days or more. Alternatively, the storage time for ester compound-containing compositions may be 180 days or less, 150 days or less, 120 days or less, or 90 days or less. "Storage time" is not limited to the time spent standing in a specific environment, but includes transportation time, etc., and refers to the elapsed time from immediately after manufacture.

[0569] The material of the storage container for the ester compound-containing composition is not particularly limited; for example, metal containers such as stainless steel, resin containers, and glass containers can be used. Either transparent or opaque containers can be used.

[0570] The storage temperature for ester compound-containing compositions is preferably -10°C or higher, more preferably 0°C or higher, preferably 60°C or lower, and more preferably 50°C or lower. A temperature of -10°C or higher reduces the load on the cooling system, and a temperature of 60°C or lower makes it easier to suppress the formation of (meth)acrylic acid ester dimers and oxidation products.

[0571] The oxygen concentration in the gas phase when storing an ester compound-containing composition is preferably 5% by volume or more, more preferably 7% by volume or more, preferably 30% by volume or less, and more preferably 22% by volume or less. Setting the oxygen concentration in the gas phase to 5% by volume or more makes it easier to prevent the ester compound from unintentionally polymerizing due to the polymerization-inhibiting effect of oxygen, and setting it to 30% by volume or less makes it easier to suppress the oxidation of (meth)acrylic acid ester by oxygen and the generation of various impurities.

[0572] For example, the ester compound-containing composition after storage may be used as a polymerizable composition without further addition of monomers, or a monomer copolymerizable with ester compound (1) (hereinafter also referred to as "other monomers") may be further added to the ester compound-containing composition after storage to form a polymerizable composition. In another example, the ester compound-containing composition may be stored with other monomers added after manufacturing and then used as a polymerizable composition. In this case, it is preferable not to add polymerization initiators during storage.

[0573] The ratio of ester compound (I) to the total mass of monomers in the polymerizable composition is preferably 10% by mass or more, more preferably 20% by mass or more, preferably 90% by mass or less, and more preferably 80% by mass or less. This makes it possible to obtain a highly transparent (meth)acrylic polymer.

[0574] The ester compound-containing composition may contain other monomers copolymerizable with ester compound (I), or it may not contain other monomers copolymerizable with ester compound (I). Other monomers copolymerizable with ester compound (I) include, for example, Other monomers copolymerizable with ester compound (1); Other monomers copolymerizable with ester compounds (5); Other monomers copolymerizable with at least one selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4); These are some examples.

[0575] (Other monomers copolymerizable with ester compound (1)) Other monomers copolymerizable with ester compound (1) include, for example, methyl (meth)acrylate, unsaturated carboxylic acid, unsaturated carboxylic acid anhydride, maleimide, hydroxyl group-containing vinyl monomer, vinyl ester, nitrogen-containing vinyl monomer, epoxy group-containing monomer, aromatic vinyl monomer, alkanediol di(meth)acrylate, polyoxyalkylene glycol di(meth)acrylate, and vinyl monomers having two or more ethylenically unsaturated bonds in the molecule.

[0576] Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, and itaconic acid. Examples of unsaturated carboxylic acid anhydrides include maleic anhydride and itaconic anhydride. Examples of maleimides include N-phenylmaleimide and N-cyclohexylmaleimide.

[0577] Examples of hydroxyl group-containing vinyl monomers include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate. Examples of vinyl esters include vinyl acetate and vinyl benzoate. Examples of nitrogen-containing vinyl monomers include methacrylamide and acrylonitrile. Examples of epoxy group-containing monomers include glycidyl acrylate and glycidyl methacrylate.

[0578] Examples of aromatic vinyl monomers include styrene and α-methylstyrene. Examples of alkanediol di(meth)acrylates include ethylene glycol di(meth)acrylate, 1,2-propylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate.

[0579] Examples of polyoxyalkylene glycol di(meth)acrylates include diethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, triethylene glycol (meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and neopentyl glycol di(meth)acrylate. Examples of vinyl monomers having two or more ethylenically unsaturated bonds in their molecules include divinylbenzene.

[0580] Other monomers that may be used include vinyl chloride, vinylidene chloride and their derivatives, unsaturated polyester prepolymers obtained from at least one polycarboxylic acid and at least one diol, including ethylenically unsaturated polycarboxylic acids, and vinyl ester prepolymers obtained by modifying the ends of epoxy groups with acrylic. Other monomers may be used individually or in combination of two or more.

[0581] (Other monomers copolymerizable with at least one selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4)) Other monomers copolymerizable with at least one selected from the group consisting of ester compound (2), ester compound (3), and ester compound (4) include, for example, the same monomers copolymerizable with ester compound (1).

[0582] (Other monomers copolymerizable with ester compound (5)) Other monomers copolymerizable with ester compound (5) include the same monomers copolymerizable with ester compound (1).

[0583] If component A8 is a monomer copolymerizable with ester compound (I), component A8 may be used as a monomer copolymerizable with ester compound (I), or a monomer copolymerizable with ester compound (I) may be used separately from component A8.

[0584] When the ester compound-containing composition contains other monomers copolymerizable with ester compound (I), the content of the other monomers copolymerizable with ester compound (I) is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 1 part by mass or more, per 100 parts by mass of ester compound (I). Furthermore, it is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less. This makes it possible to obtain a highly transparent (meth)acrylic polymer.

[0585] The polymerizable composition preferably contains a polymerization initiator. Examples of polymerization initiators include azo compounds, organic peroxides, persulfate compounds, and redox polymerization initiators. Polymerization initiators may be used individually or in combination of two or more.

[0586] Examples of azo compounds include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 2,2'-azobis(2-methylpropionitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4,4-trimethylpentane), 2,2'-azobis(2-methylpropane), 1,1-azobis(cyclohexanecarbonitride), and dimethyl-2,2'-azobisisobutyrate.

[0587] Examples of organic peroxides include benzoyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, 1,1-bis(t-butylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)-3,5,5-trimethylcyclohexane, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxybenzoate, t-hexylperoxybenzoate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, t-butylperoxyacetate, and t-hexylperoxyisopropyl monocarbonate. Examples include t-hexyl peroxy-2-ethylhexanoate, t-amyl peroxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutyl peroxyethylhexanoate, 1,1,2-trimethylpropyl peroxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutyl peroxyisopropyl monocarbonate, 1,1,2-trimethylpropyl peroxyisopropyl monocarbonate, 1,1,3,3-tetramethylbutyl peroxyisononate, 1,1,2-trimethylpropyl peroxyisononate, di-t-butyl peroxide, di-t-hexyl peroxide, lauroyl peroxide, and dilauroyl peroxide.

[0588] Examples of persulfate compounds include potassium persulfate. The amount of polymerization initiator added is not particularly limited, and can be, for example, 0.005 to 5 parts by mass per 100 parts by mass of the total mass of monomers in the polymerizable composition.

[0589] The polymerizable composition may optionally contain other additives such as chain transfer agents, mold release agents, lubricants, plasticizers, antioxidants, antistatic agents, light stabilizers, ultraviolet absorbers, flame retardants, flame retardant aids, polymerization inhibitors, fillers, pigments, dyes, silane coupling agents, leveling agents, defoamers, and fluorescent agents. Other additives may be used individually or in combination of two or more.

[0590] [Meth)acrylic polymer manufacturing method] (Meth)acrylic polymers can be produced by polymerizing polymerizable compositions. The polymerization method is not particularly limited and includes, for example, bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization. Bulk polymerization is preferred from the viewpoint of environmental impact due to solvent use and the transparency of the resulting (meth)acrylic polymer.

[0591] The bulk polymerization method is not particularly limited and can include various casting polymerization methods such as cell casting and continuous casting. Cast polymerization is a method for obtaining a (meth)acrylic polymer by injecting a polymerizable composition into a mold consisting of two inorganic glass plates or metal plates (e.g., SUS plates) that are placed opposite each other at a predetermined distance and sealed around the periphery with a gasket such as a flexible resin tube, and allowing polymerization to proceed. The mold for casting polymerization is not particularly limited, and various types of molds can be used. For example, a mold for cell casting may be made by arranging two plate-like bodies, such as inorganic glass plates, chrome-plated metal plates, or stainless steel plates, opposite each other at a predetermined distance, and placing a gasket on the edge thereof to form a sealed space with the plate-like bodies and the gasket. For example, a mold for continuous casting may be made by forming a sealed space with the opposing surfaces of a pair of endless belts traveling in the same direction at the same speed, and gaskets traveling at the same speed as the endless belts on both sides of the endless belts.

[0592] The spacing of the voids in the mold is adjusted as needed to obtain a resin plate of the desired thickness, but it is generally between 1 and 30 mm.

[0593] The polymerization temperature is preferably 125 to 210°C, and more preferably 130 to 180°C. The polymerization time is preferably 0.5 to 24 hours.

[0594] The weight-average molecular weight (Mw) of the (meth)acrylic polymer is not particularly limited and can be, for example, 100,000 to 1,000,000. The higher the Mw of the (meth)acrylic polymer, the better the solvent resistance and chemical resistance. The Mw of (meth)acrylic polymers can be controlled by adjusting the polymerization temperature, polymerization time, and the amount of polymerization initiator added.

[0595] The (meth)acrylic polymer according to the fourth embodiment has excellent heat resistance and meltability. For example, granular (meth)acrylic polymers, which have a large amount of resin that can be stored per unit volume and low energy costs during storage and transportation, need to be dissolved or melted when used. The (meth)acrylic polymer according to the fourth embodiment is easily melted, has excellent kneadability with other resins, and has excellent solubility in monomers and solvents.

[0596] 5. Fifth aspect A fifth aspect of the embodiment will be described below.

[0597] [Ester compound-containing composition] The ester compound-containing composition according to the fifth embodiment contains the ester compound (I) described below and the compound (component A9) described below. The content of ester compound (I) is 95.00 to 99.99% by mass.

[0598] The ester compound-containing composition may further contain, in addition to the ester compound (I) and component A9, a polymerization inhibitor (component B) described below. The ester compound-containing composition may optionally contain component B in addition to ester compound (I) and component A9, as long as it does not impair the effects of the present invention, and may further contain at least one of ester compound (I), component A9 and component B (hereinafter also referred to as "component C") and water.

[0599] (Ester compound (I)) Ester compounds (I) are compounds represented by the following formula (I). CH2=CR 150 -C(=O)-OR 200 ...(I)

[0600] In formula (I), R 150 is a hydrogen atom or a methyl group, R 200 This is a monovalent hydrocarbon group having 2 to 20 carbon atoms, which may have substituents, or a monovalent group having 2 to 8 carbon atoms and having an ether bond.

[0601] As ester compound (I), one type may be used alone, or two or more types may be used in combination. As ester compound (I), one or more selected from the group consisting of ester compound (1), ester compound (2), ester compound (3), ester compound (4), and ester compound (5) described below are preferred. These ester compounds will be described below.

[0602] Ester compound (1) is a (meth)acrylic acid ester represented by the following formula (1). CH2=CR 1a -C(=O)-OR 2a ...(1) In formula (1), R 1a R is a hydrogen atom or a methyl group. 2a It is a hydrocarbon group having 2 to 20 carbon atoms.

[0603] R 2a The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. R 2a The hydrocarbon group may be linear, branched, or have a ring. 2a If the hydrocarbon group has a ring, the ring may be an aliphatic ring or an aromatic ring. R 2a The number of carbon atoms in the hydrocarbon group is 2 to 20, preferably 2 to 18, and more preferably 2 to 12.

[0604] R 2aExamples of hydrocarbon groups include C2-C20 alkyl groups, C3-C20 cycloalkyl groups, C2-C20 alkenyl groups, C3-C20 cycloalkenyl groups, C2-C20 alkynyl groups, C6-C20 aryl groups, and C7-C20 aromatic alkyl groups. "Aromatic alkyl group" refers to a group in which one or more hydrogen atoms of an alkyl group are substituted with an aryl group.

[0605] R 2a Examples of alkyl groups include ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, lauryl group, and stearyl group. R 2a Examples of cycloalkyl groups include cyclopropyl, cyclohexyl, and isobornyl groups. R 2a Examples of alkenyl groups include vinyl groups and allyl groups. R 2a Examples of cycloalkenyl groups include cyclopentenyl, cyclopentadienyl, and cyclohexenyl groups. R 2a An example of an alkynyl group is the propynyl group. R 2a Examples of aryl groups include the phenyl group and the naphthyl group. R 2a Examples of aromatic alkyl groups include the benzyl group.

[0606] Since ester compound (1) is relatively easy to obtain and relatively easy to handle in terms of physical properties, R 2aPreferably, the group is an alkyl group having 2 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aromatic alkyl group having 7 to 20 carbon atoms. More preferably, the group is an ethyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, a 2-ethylhexyl group, a lauryl group, a stearyl group, a cyclohexyl group, an isobornyl group, an allyl group, a phenyl group, or a benzyl group. Particularly preferred are the n-butyl group and an isobutyl group, with the n-butyl group being the most preferred.

[0607] Examples of ester compounds (1) include ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, allyl (meth)acrylate, phenyl (meth)acrylate, and benzyl (meth)acrylate.

[0608] Because it is relatively easy to obtain and relatively easy to handle in terms of physical properties, R is used as the ester compound (1). 2a Alkyl (meth)acrylates, R, are linear or branched alkyl groups having 2 to 20 carbon atoms. 2a Cycloalkyl (meth)acrylates, which are cycloalkyl groups with 3 to 20 carbon atoms, R 2a Alkenyl (meth)acrylates, which are alkenyl groups with 2 to 20 carbon atoms, R 2a aryl(meth)acrylates, which are aryl groups with 6 to 20 carbon atoms, R 2aAromatic alkyl (meth)acrylates, in which the compound is an aromatic alkyl group having 7 to 20 carbon atoms, are preferred. Ethyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, allyl (meth)acrylate, phenyl (meth)acrylate, and benzyl (meth)acrylate are more preferred. Butyl (meth)acrylate and isobutyl (meth)acrylate are particularly preferred, and butyl (meth)acrylate is most preferred.

[0609] Ester compound (1) may be used alone or in combination of two or more types.

[0610] Ester compound (2) is a (meth)acrylic acid ester represented by the following formula (2). Ester compound (3) is a (meth)acrylic acid ester represented by the following formula (3). Ester compound (4) is a (meth)acrylic acid ester represented by the following formula (4).

[0611] [ka]

[0612] In equations (2), (3), and (4), R 1b , R 3b , R 5b , R 6b , R 8b and R 9b Each of these is independently either a hydrogen atom or a methyl group. 2b and R 4b Each of these is independently a linear or branched alkylene group or hydroxyalkylene group having 2 to 8 carbon atoms. 7b It is a linear or branched trivalent hydrocarbon group having 2 to 8 carbon atoms.

[0613] R 2b and R4b The number of carbon atoms in the alkylene group or hydroxyalkylene group is 2 to 8, preferably 2 to 6. R 2b and R 4b Examples of alkylene groups include ethylene, propylene, isopropylene, and butylene groups. R 2b and R 4b Examples of hydroxyalkylene groups include hydroxyethylene, hydroxypropylene, and hydroxybutylene groups.

[0614] R 7b The number of carbon atoms in the trivalent hydrocarbon group is 2 to 8, preferably 2 to 4. R 7b Examples of the trivalent hydrocarbon group include -(CH2)-C(-CH2-)(-CH3)-CH2-.

[0615] Examples of ester compounds (2) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 3-hydroxypropyl (meth)acrylate. Examples of ester compounds (3) include ethylene glycol di(meth)acrylate, 1,3-propanediol di(meth)acrylate, 1,2-propanediol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate. Examples of ester compounds (4) include trimethylolpropane tri(meth)acrylate.

[0616] Because they are relatively easy to obtain, one or more ester compounds (2), (3), and (4) are preferably selected from the group consisting of ethylene glycol di(meth)acrylate, 2-hydroxyethyl(meth)acrylate, 3-hydroxypropyl(meth)acrylate, and trimethylolpropanetri(meth)acrylate.

[0617] Ester compound (2), ester compound (3), and ester compound (4) may be used individually or in combination of two or more.

[0618] Ester compound (5) is a (meth)acrylic acid ester represented by the following formula (5). CH2=CR 1c -C(=O)-OR 2c ...(5) In formula (5), R 1c R is a hydrogen atom or a methyl group, 2c It is a monovalent group with 2 to 8 carbon atoms that has an ether bond.

[0619] R 2c The number of etheric oxygen atoms in the monovalent group having 2 to 8 carbon atoms is preferably one, but is not limited to one, and may be two or more. R 2c The monovalent group having 2 to 8 carbon atoms may be linear, branched, or have a ring. 2c If the ring has a ring, the ring may or may not contain etheric oxygen. R 2c The number of carbon atoms in the monovalent group having an ether bond is 2 to 8, preferably 2 to 7.

[0620] R 2c Examples of such groups include 2-methoxyethyl group, 2-(2-methoxyethoxy)ethyl group, 2-[2-(2-methoxyethoxy)ethoxy]ethyl group, glycidyl group, and tetrahydrofurfuryl group. Because it is relatively easy to obtain and relatively easy to handle in terms of physical properties, R 2c The preferred group is a 2-methoxyethyl group, a glycidyl group, or a tetrahydrofurfuryl group.

[0621] Examples of ester compounds (5) include 2-methoxyethyl (meth)acrylate, glycidyl (meth)acrylate, 2-(2-methoxyethoxy)ethyl (meth)acrylate, 2-[2-(2-methoxyethoxy)ethoxy]ethyl (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate.

[0622] Because they are relatively easy to handle in terms of physical properties, 2-methoxyethyl (meth)acrylate, glycidyl (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate are preferred as ester compounds (5).

[0623] The ester compound (5) may be used alone or in combination of two or more types.

[0624] (Ingredient A9) Component A9 is a compound represented by the following formula (a9). The inclusion of component A9 in the ester compound-containing composition suppresses the dimerization reaction of ester compound (I) and the formation of oxidation products of ester compound (I) during storage, resulting in an ester compound-containing composition with excellent storage stability. The reason for this is presumed to be as follows.

[0625] The dimerization reaction of ester compound (I) proceeds via a cationic mechanism or an ene reaction in the presence of an acid catalyst. Since component A9 is weakly basic, it is thought that it can trap trace amounts of acidic substances present in the ester compound-containing composition, inhibiting its function as an acid catalyst and suppressing the dimerization reaction of ester compound (I). Furthermore, while ester compound (I) undergoes hydrolysis under basic conditions, component A9 is weakly basic and does not possess strong basicity sufficient to cause hydrolysis of ester compound (I). Therefore, component A9 is effective as a basic substance that traps trace amounts of acidic substances. On the other hand, the oxidation product of ester compound (I) is generated when ester compound (I) is oxidized by hydroxyl radicals and oxygen molecules. Component A9 is thought to be able to trap the intermediate formed by the reaction of hydroxyl radicals and ester compound (I), and convert the intermediate back to ester compound (I), thereby suppressing the formation of the oxidation product of ester compound (I).

[0626] [ka]

[0627] In formula (a9), R 91 This group may have substituents and is an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an aryl group having 1 to 12 carbon atoms.

[0628] The molecular weight of component A9 is preferably 1000 or less. By having a molecular weight of 1000 or less, the number of cyano groups per unit mass in component A9 can be increased, so that the effects of the present invention can be obtained with a small mass. The molecular weight of component A9 is more preferably 800 or less, even more preferably 600 or less, and particularly preferably 400 or less.

[0629] R in equation (a9) 91 R is an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an aryl group having 1 to 12 carbon atoms. 91 It may have one or more substituents, and the substituents are R 91 It is a monovalent group with 0 to 18 carbon atoms, independent of the carbon number of the given element.

[0630] R 91 The number of carbon atoms in R is the number of carbon atoms in the alkyl group, alkenyl group, or aryl group, excluding the carbon atoms of these substituents. For example, if component A9 is 4-(methylthio)benzonitrile, 91 The substituent is a 4-(methylthio)phenyl group, and the 4-(methylthio)phenyl group is considered to be a C6 aryl group having a methylthio group, which is an alkylthio group, as a substituent.

[0631] R 91 The group is an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an aryl group having 1 to 12 carbon atoms. Preferably, it is an alkyl group having 1 to 3 carbon atoms, an alkenyl group having 2 to 3 carbon atoms, or an aryl group having 1 to 8 carbon atoms, more preferably a methyl group, an ethyl group, a 2-alkoxyethyl group, an isopropyl group, a 2-alkoxyisopropyl group, a vinyl group, an isopropenyl group, or a phenyl group, and even more preferably a methyl group, an ethyl group, a 2-alkoxyethyl group, a 2-alkoxyisopropyl group, a vinyl group, an isopropenyl group, or a phenyl group.

[0632] R 91 When the above conditions are met, the weak basicity of component A9 and its reactivity with acidic substances and radicals are maintained, thus achieving the effects of the present invention. Furthermore, because it is a highly stable group, it is possible to prevent component A9 from changing into other compounds during storage.

[0633] R 91 The alkyl group may be linear, branched, or have a ring. The alkyl group has 1 to 5 carbon atoms, and preferably 1 to 3 carbon atoms. Examples of linear or branched alkyl groups (hereinafter collectively referred to as "chain alkyl groups") include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, and isopentyl groups. Among these, methyl, ethyl, n-propyl, and isopropyl groups are preferred, and methyl, ethyl, or isopropyl groups are more preferred. Examples of ring-containing alkyl groups (hereinafter also referred to as "cyclic alkyl groups") include the cyclopropyl group, the cyclobutyl group, and the cyclopentyl group.

[0634] R 91 The alkenyl group may be linear, branched, or have a ring. The alkenyl group has 2 to 5 carbon atoms, preferably 2 to 3. Examples of linear or branched alkenyl groups (hereinafter collectively referred to as "chain alkenyl groups") include vinyl groups, 1-propenyl groups, isopropenyl groups, 2-butenyl groups, 1,3-butadienyl groups, and 2-pentenyl groups. Among these, vinyl groups, 1-propenyl groups, and isopropenyl groups are preferred, with vinyl groups or isopropenyl groups being more preferred. Examples of ring-containing alkenyl groups (hereinafter also referred to as "ring alkenyl groups") include the cyclopropenyl group, the cyclobutenyl group, and the cyclopentenyl group.

[0635] R 91 The aryl group has 1 to 12 carbon atoms, with 1 to 8 being more preferable. In other respects, R 91 The aryl group preferably has 6 to 12 carbon atoms, and more preferably 6 to 8. The aryl group includes heteroaryl groups containing oxygen, nitrogen, sulfur, etc. Examples of aryl groups include phenyl, mesityl, naphthyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 2-ethylphenyl, isoxazolyl, isothiazolyl, imidazolyl, oxazolyl, thiazolyl, thiadiazolyl, thienyl, triazolyl, tetrazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridadinyl, pyrazolyl, pyrrolyl, furyl, fluzanyl, isoquinolyl, isoindolyl, indolyl, quinolyl, pyridothiazolyl, benzimidazolyl, benzoxazolyl, benzothiazolyl, benzotriazolyl, benzofuranyl, imidazopyridinyl, triazopyridinyl, and prinyl groups.

[0636] R 91When the substituent is an alkyl group, alkenyl group, or aryl group, examples of substituents include monovalent groups containing alkyl groups, alkenyl groups, aryl groups, hydroxyl groups, alkoxy groups, amino groups, or carbonyl groups, as well as monovalent groups selected from alkylthio groups and arylthio groups. Among these, monovalent groups containing hydroxyl groups, alkoxy groups, amino groups, or carbonyl groups, and alkylthio groups are preferred, and hydroxyl groups, methoxy groups, n-butoxy groups, isobutoxy groups, amino groups, acetyl groups, and methylthio groups are more preferred. The molecular weight of the substituent is preferably 200 or less, more preferably 100 or less, and even more preferably 50 or less.

[0637] The alkyl group as a substituent has 1 to 18 carbon atoms, more preferably 1 to 6, and even more preferably 1 to 3. 1a The above-mentioned alkyl group is the same as the alkyl group insofar as it is an alkyl group having 1 to 5 carbon atoms excluding the substituted carbon atom, an alkenyl group having 2 to 5 carbon atoms excluding the substituted carbon atom, or an aryl group having 1 to 12 carbon atoms excluding the substituted carbon atom.

[0638] The number of carbon atoms in the alkenyl group as a substituent is 2 to 18, more preferably 2 to 6, and even more preferably 2 to 3. 91 Insofar as it is an alkyl group having 1 to 5 carbon atoms excluding the substituted carbon atom, an alkenyl group having 2 to 5 carbon atoms excluding the substituted carbon atom, or an aryl group having 1 to 12 carbon atoms excluding the substituted carbon atom, it is the same as the alkenyl group described above.

[0639] The aryl group as a substituent has 1 to 18 carbon atoms, more preferably 6 to 11, even more preferably 6 to 9, and particularly preferably 6 to 7. 91 Insofar as it is an alkyl group having 1 to 5 carbon atoms excluding the substituted carbon atom, an alkenyl group having 2 to 5 carbon atoms excluding the substituted carbon atom, or an aryl group having 1 to 12 carbon atoms excluding the substituted carbon atom, it is the same as the aryl group described above.

[0640] The alkoxy group used as a substituent has 1 to 18 carbon atoms, more preferably 1 to 6, and even more preferably 1 to 4. Examples of alkoxy groups used as substituents include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, s-butoxy, t-butoxy, n-pentoxy, isopentoxy, and phenoxy groups.

[0641] The amino group as a substituent includes an amino group (-NH2) that does not have a substituent on the nitrogen atom, and an amino group in which some or all of the hydrogen atoms bonded to the nitrogen atom are replaced by carbon atoms. The number of carbon atoms in the amino group substituted with carbon atoms is 1 to 18, more preferably 1 to 6, and even more preferably 1 to 3. Examples of amino groups used as substituents include methylamino group, ethylamino group, propylamino group, butylamino group, dimethylamino group, diethylamino group, anilino group, toluidino group, anisidino group, and N-methyl-N-phenylamino group.

[0642] Examples of monovalent groups containing a carbonyl group as a substituent include formyl group, acyl group, carboxyl group, amide group, alkoxycarbonyl group, thiocarboxyl group, and thioester group.

[0643] An acyl group is a substituent formed by linking a carbonyl group with an alkyl group, alkenyl group, or aryl group. The total number of carbon atoms in the acyl group, derived from the carbonyl group (1) and derived from the alkyl group, alkenyl group, or aryl group, is 2 to 18, preferably 2 to 7, and more preferably 2 to 4. Examples of acyl groups include acetyl, propionyl, butylcarbonyl, vinylcarbonyl, and benzoyl groups.

[0644] The amide group includes an amide group (-CONH2) that does not have substituents on the nitrogen atom, and an amide group in which some or all of the hydrogen atoms bonded to the nitrogen atom are replaced by carbon atoms. The total number of carbon atoms in the amide group, including the carbon atom derived from the carbonyl group (1) and the carbon atoms substituted on the nitrogen atom, is 1 to 18, preferably 1 to 7, and more preferably 1 to 4. Examples of amide groups include unsubstituted amide groups, N-methylamide groups, N-ethylamide groups, N-phenylamide groups, N,N-dimethylamide groups, and N-methyl-N-phenylamide groups.

[0645] An alkoxycarbonyl group is a substituent formed by the linkage of a carbonyl group and an alkoxy group, and is also called an ester group. The total number of carbon atoms derived from the carbonyl group (1) and the alkoxy group is 2 to 18, preferably 2 to 7, and more preferably 2 to 4. Examples of alkoxycarbonyl groups include methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl, and phenoxycarbonyl groups.

[0646] A thioester group is a substituent formed by linking a carbonyl group with an alkylthio group or an arylthio group. The total number of carbon atoms derived from the carbonyl group (1) and the alkylthio group or arylthio group is 2 to 18, preferably 2 to 7, and more preferably 2 to 4. Examples of thioester groups include methylthiocarbonyl group, ethylthiocarbonyl group, butylthiocarbonyl group, and phenylthiocarbonyl group.

[0647] For example, a monovalent group containing a carbonyl group may be a substituent in which one or more hydrogen atoms of an alkyl group are substituted with a carbonyl group. Examples of such substituents include 2-acetoxyethyl group, 2-acetoethyl group, and 2-(acetoacetoxy)ethyl group.

[0648] The alkylthio group used as a substituent has 1 to 18 carbon atoms, preferably 1 to 6, and more preferably 1 to 3. Examples of alkylthio groups used as substituents include methylthio, ethylthio, propylthio, and isopropylthio groups.

[0649] The arylthio group used as a substituent has 1 to 18 carbon atoms, preferably 6 to 11, more preferably 6 to 9, and even more preferably 6 to 7. Examples of arylthio groups used as substituents include phenylthio groups and tolthio groups.

[0650] Among the compounds that satisfy the above conditions, from the viewpoint of further improving the storage stability of the ester compound-containing composition, component A9 is preferably methacrylonitrile, acetonitrile, propionitrile, acrylonitrile, benzonitrile, cyclohexanecarbonitride, 3-hydroxypropionitrile, 3-methoxypropionitrile, 3-butoxypropionitrile, 3-isobutoxypropionitrile, 3-hydroxyisobutyronitrile, 3-methoxyisobutyronitrile, 3-butoxyisobutyronitrile, 3-isobutoxyisobutyronitrile, 2-hydroxypropionitrile, 2-aminopropionitrile, 4-cyanophenol, 4-aminobenzonitrile, 4'-cyanoacetophenone, or 4-(methylthio)benzonitrile, and methacrylonitrile, acetonitrile, acetonitrile, 4'-cyanoacetophenone, 4'-(methylthio)benzonitrile, and methacrylonitrile, acetonitrile, 4'-cyanophenol, 4'-cyanobenzonitrile, 4'-cyanoacet...

Claims

1. Ester compound (I) represented by the following formula (I), The compound represented by the following formula (a1), Includes, An ester compound-containing composition wherein the content of the ester compound (I) is 95.00 to 99.99% by mass of the total mass. CH ２ =CR １５０ -C(=O)-O-R ２００ ・・・(I) In formula (I), R １５０ is a hydrogen atom or a methyl group, R ２００ These are n-butyl group, isobutyl group, 2-methoxyethyl group, 2-hydroxyethyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, glycidyl group, or tetrahydrofurfuryl group. 【Chemistry 1】 In formula (a1), R １１ , R １２ and R １３ may each independently be a group selected from a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxy group, an alkoxy group, an amino group, a carbonyl group, and a monovalent group containing an ether bond and / or a sulfide bond, or R １１ , R １２ and R １３ may each be a divalent group which may have a substituent in combination with any of the groups.

2. The ester compound-containing composition according to claim 1, further comprising one or more compounds selected from the group consisting of a compound represented by the following formula (a2), a compound represented by the following formula (a6), a compound represented by the following formula (a7), a compound represented by the following formula (a8), a compound represented by the following formula (a9), and a compound represented by the following formula (a10). 【Chemistry 2】 In formula (a2), R ２１ , R ２２ and R ２３ Each of these may independently be a monovalent group containing a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, or a carbonyl group, or a monovalent group selected from an alkylthio group or an arylthio group, and R ２４ R may be a monovalent group containing a hydrogen atom, alkyl group, alkenyl group, aryl group, hydroxyl group, alkoxy group, amino group, carbonyl group, or ether group, or R ２１ , R ２２ , R ２３ and R ２４ Each of these groups may be a divalent group that may have substituents in combination with any of the other groups. However, R ２１ = H, R ２２ = H, R ２３ = R １５０ And R ２４ = R ２００ This excludes the case where the compound represented by formula (a2) is the same as the ester compound (I). In formula (a6), R ６１ , R ６２ and R ６３ Each of these may independently be a monovalent group containing a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, or a carbonyl group, or a monovalent group selected from an alkylthio group or an arylthio group, and R ６４ This may be a monovalent group selected from an alkyl group, alkenyl group, aryl group, hydroxyl group, alkoxy group, amino group, carbonyl group, or ether group, or an alkylthio group or arylthio group, or R ６１ , R ６２ , R ６３ and R ６４ Each of these groups may be a divalent group that may have substituents in combination with any of the other groups. However, R ６１ = H, R ６２ = H, R ６３ = R １５０ And R ６４ = OR ２００ This excludes the case where the compound represented by formula (a6) is the same as the ester compound (I). 【Transformation 3】 In formula (a7), R ７１ , R ７２ , R ７３ , R ７４ , R ７５ , R ７６ and R ７７ Each of these is independently a monovalent group selected from a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, or a carbonyl group, or an alkylthio group or an arylthio group. 【Chemistry 4】 In formula (a8), R ８１ , R ８２ , R ８３ , R ８４ , R ８５ and R ８６ Each is independently a monovalent group selected from a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, or a carbonyl group, and R ８１ , R ８２ , R ８３ , R ８４ , R ８５ and R ８６ The total number of carbon atoms is 2 or more. 【Transformation 5】 In formula (a9), R ９１ This group may have substituents and is an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, or an aryl group having 1 to 12 carbon atoms. 【Transformation 6】 In formula (a10), R １０１ , R １０２ , R １０３ and R １０４ Each of these may independently be a monovalent group selected from a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, a carbonyl group, and a heteroatom and / or an unsaturated bond, or an alkylthio group or an arylthio group, or R １０１ , R １０２ , R １０３ and R １０４ Each of these groups may have substituents, as well as a heteroatom and / or an unsaturated bond, and may be a divalent group. These groups may further have substituents.

3. The ester compound-containing composition according to claim 1, further comprising a polymerization inhibitor.

4. The ester compound-containing composition according to claim 2, wherein the total content of the compound represented by formula (a1), the compound represented by formula (a2), the compound represented by formula (a6), the compound represented by formula (a7), the compound represented by formula (a8), the compound represented by formula (a9), and the compound represented by formula (a10) is 1 ppm by mass or more and 10,000 ppm by mass or less.

5. The ester compound-containing composition according to claim 4, wherein the total content of the compound represented by formula (a1), the compound represented by formula (a2), the compound represented by formula (a6), the compound represented by formula (a7), the compound represented by formula (a8), the compound represented by formula (a9), and the compound represented by formula (a10) is 5 ppm by mass or more and 1500 ppm by mass or less.

6. The ester compound-containing composition according to claim 3, wherein the total content of the polymerization inhibitor is 1 ppm by mass or more and 1,000 ppm by mass or less.

7. The ester compound-containing composition according to claim 6, wherein the total content of the polymerization inhibitor is 5 ppm by mass or more and 100 ppm by mass or less.

8. The ester compound-containing composition according to claim 2, wherein the molecular weight of one or more compounds selected from the group consisting of the compound represented by formula (a1), the compound represented by formula (a2), the compound represented by formula (a6), the compound represented by formula (a7), the compound represented by formula (a8), the compound represented by formula (a9), and the compound represented by formula (a10) is 1000 or less.

9. The ester compound-containing composition according to claim 3, wherein the polymerization inhibitor is at least one polymerization inhibitor selected from the group consisting of phenolic compounds, quinone compounds, nitrobenzene compounds, N-oxyl compounds, amine compounds, phosphorus-containing compounds, sulfur-containing compounds, iron-containing compounds, copper-containing compounds, and manganese-containing compounds.

10. The ester compound-containing composition according to claim 3, wherein the polymerization inhibitor is at least one polymerization inhibitor selected from the group consisting of phenolic compounds, N-oxyl compounds, amine compounds, phosphorus-containing compounds, and sulfur-containing compounds.

11. The ester compound-containing composition according to claim 3, wherein the polymerization inhibitor is at least one polymerization inhibitor selected from the group consisting of hydroquinone, 4-methoxyphenol, 2,4-dimethyl-6-t-butylphenol, and 2,6-di-t-butyl-4-methylphenol.

12. In formula (a1), R １１ and R １２ The ester compound-containing composition according to claim 1, wherein each of them is independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

13. In formula (a1), R １３ The ester compound-containing composition according to claim 1, wherein is a chain alkyl group having 1 to 10 carbon atoms, an allyl group, a 2-hydroxyethyl group, a 2-hydroxypropyl group, a 2-methoxyethyl group, a glycidyl group, or a tetrahydrofurfuryl group.

14. In equations (a2) and (a6), R ２１ , R ２２ , R ２３ , R ６０ , R ６１ , R ６２ and R ６３ Each of these is independently a hydrogen atom, a C1-C5 alkyl group, a C2-C5 alkenyl group, or a C1-C12 aryl group. R ２４ This group has an etheric oxygen atom between the carbon atoms of a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, an aryl group having 1 to 12 carbon atoms, an aromatic alkyl group having 1 to 12 carbon atoms, or a hydrocarbon group having 2 to 8 carbon atoms. R ６４ However, these are alkyl groups having 1 to 5 carbon atoms, alkenyl groups having 2 to 5 carbon atoms, aryl groups having 1 to 12 carbon atoms, amino groups, alkylthio groups having 1 to 5 carbon atoms, or arylthio groups having 1 to 12 carbon atoms. The ester compound-containing composition according to claim 2.

15. In equations (a2) and (a6), R ２１ , R ２２ , R ２３ , R ６０ , R ６１ , R ６２ and R ６３ Each of these is independently a hydrogen atom and an alkyl group having 1 to 5 carbon atoms. R ２４ These are alkyl groups having 1 to 5 carbon atoms, and alkenyl groups having 2 to 5 carbon atoms. R ６４ The ester compound-containing composition according to claim 2, wherein the alkyl group has 1 to 5 carbon atoms.

16. In formula (a2), R ２１ , R ２２ and R ２３ are each independently a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group, R ２４ The ester compound-containing composition according to claim 2, wherein is a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a clotyl group, an n-pentyl group, a 2-methyl-1-butyl group, or an isopentyl group.

17. In formula (a7), R ７１ , R ７２ , R ７３ , R ７４ , R ７５ , R ７６ and R ７７ are each independently a monovalent group containing a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, an aryl group having 1 to 12 carbon atoms, a hydroxy group, an alkoxy group having 1 to 6 carbon atoms, an amino group or a carbonyl group. The ester compound-containing composition according to claim 2.

18. In formula (a7), R ７１ , R ７２ , R ７３ , R ７４ and R ７５ The ester compound-containing composition according to claim 2, wherein each of them is independently a hydrogen atom, a C1-C5 alkyl group, a hydroxyl group, a C1-C5 alkoxy group, or a C2-C6 alkoxycarbonyl group.

19. In formula (a7), R ７１ , R ７２ , R ７３ , R ７４ and R ７５ The ester compound-containing composition according to claim 2, wherein each of them is independently a hydrogen atom, a methyl group, a t-butyl group, a hydroxyl group, or a methoxy group.

20. In formula (a7), R ７６ and R ７７ The ester compound-containing composition according to claim 2, wherein each of them is independently a hydrogen atom, a C1-C5 alkyl group, a hydroxyl group, or a C1-C5 alkoxycarbonyl group.

21. In formula (a7), R ７６ and R ７７ The ester compound-containing composition according to claim 2, wherein each of them is independently a hydrogen atom, a methyl group, a methoxycarbonyl group, or a butoxycarbonyl group.

22. In formula (a8), the R ８１ , R ８２ , R ８３ , R ８４ , R ８５ and R ８６ The ester compound-containing composition according to claim 2, wherein each is independently a monovalent group comprising a hydrogen atom, a C1-C5 alkyl group, a C2-C5 alkenyl group, a C1-C12 aryl group, a hydroxyl group, a C1-C6 alkoxy group, an amino group, or a carbonyl group.

23. In formula (a8), the R ８１ , R ８２ , R ８３ , R ８４ , R ８５ and R ８６ The ester compound-containing composition according to claim 2, wherein each is independently a hydrogen atom, a C1-C5 alkyl group, a hydroxyl group, or a C1-C6 alkoxy group.

24. In formula (a8), the R ８１ , R ８２ , R ８３ , R ８４ , R ８５ and R ８６ The ester compound-containing composition according to claim 2, wherein each of these is independently a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and a t-butyl group.

25. In formula (a9), the R ９１ The ester compound-containing composition according to claim 2, wherein is an alkyl group having 1 to 3 carbon atoms which may have substituents, an alkenyl group having 2 to 3 carbon atoms which may have substituents, or an aryl group having 1 to 8 carbon atoms which may have substituents.

26. In formula (a9), the R ９１ The ester compound-containing composition according to claim 2, wherein is a methyl group, an ethyl group, a 2-alkoxyethyl group, a 2-alkoxyisopropyl group, a vinyl group, an isopropenyl group, or a phenyl group.

27. In formula (a10), the R １０１ , R １０２ , R １０３ and R １０４ The ester compound-containing composition according to claim 2, wherein each is independently a hydrogen atom, a C1-C5 alkyl group, or a C1-C6 alkoxy group.

28. In formula (a10), the R １０１ , R １０２ , R １０３ and R １０４ The ester compound-containing composition according to claim 2, wherein each is independently a hydrogen atom, a methyl group, an ethyl group, an isopropyl group, a methoxy group, an ethoxy group, or an isopropoxy group.

29. The ester compound-containing composition according to claim 1, wherein the content of the ester compound (I) is 98 to 99.99% by mass.

30. The aforementioned R ２００ The ester compound-containing composition according to claim 1, further comprising a compound in which is a linear or branched alkyl group having 2 to 20 carbon atoms.

31. The ester compound-containing composition according to claim 1, further comprising one or more selected from the group consisting of ethylene glycol di(meth)acrylate and trimethylolpropane tri(meth)acrylate.

32. The ester compound-containing composition according to claim 1, which is an ester compound-containing composition that has been stored for one day or more.

33. A method for producing the ester compound-containing composition described in claim 1, In the presence of the compound represented by formula (a1), One or more alcohols selected from the group consisting of monoalcohols with 2 to 20 carbon atoms, ether-containing alcohols with 2 to 8 carbon atoms, dialcohols with 2 to 8 carbon atoms, and trialcohols with 2 to 8 carbon atoms, Methyl (meth)acrylate and A method for producing an ester compound-containing composition, comprising carrying out a transesterification reaction.

34. The manufacturing method according to claim 33, comprising carrying out a transesterification reaction in the presence of a polymerization inhibitor in addition to the compound represented by formula (a1).

35. The manufacturing method according to claim 34, wherein the polymerization inhibitor is at least one polymerization inhibitor selected from the group consisting of phenolic compounds, quinone compounds, nitrobenzene compounds, N-oxyl compounds, amine compounds, phosphorus-containing compounds, sulfur-containing compounds, iron-containing compounds, copper-containing compounds, and manganese-containing compounds.

36. The manufacturing method according to claim 34, wherein the polymerization inhibitor is at least one polymerization inhibitor selected from the group consisting of phenolic compounds, N-oxyl compounds, amine compounds, phosphorus-containing compounds, and sulfur-containing compounds.

37. The manufacturing method according to claim 34, wherein the polymerization inhibitor is at least one polymerization inhibitor selected from the group consisting of hydroquinone, 4-methoxyphenol, 2,4-dimethyl-6-t-butylphenol, and 2,6-di-t-butyl-4-methylphenol.

38. In formula (a1), R １１ and R １２ The manufacturing method according to claim 33, wherein each of them is independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.

39. In formula (a1), R １３ The manufacturing method according to claim 33, wherein is a chain alkyl group having 1 to 10 carbon atoms, an allyl group, a 2-hydroxyethyl group, a 2-hydroxypropyl group, a 2-methoxyethyl group, a glycidyl group, or a tetrahydrofurfuryl group.

40. A polymerizable composition comprising an ester compound-containing composition according to any one of claims 1 to 32.

41. A (meth)acrylic polymer obtained by polymerizing the polymerizable composition described in claim 40.

42. The (meth)acrylic polymer according to claim 41, wherein the polymerizable composition contains 0.01 parts by mass or more of a monomer copolymerizable with the ester compound (I) per 100 parts by mass of the ester compound (I).

43. A method for producing a (meth)acrylic polymer, comprising polymerizing the polymerizable composition described in claim 40.

44. The manufacturing method according to claim 43, wherein the polymerizable composition contains 0.01 parts by mass or more of a monomer copolymerizable with the ester compound (I) per 100 parts by mass of the ester compound (I).

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