Composition containing ester compound and method for producing same, polymerizable composition, (meth) acrylic polymer and method for producing same

Abstract

The purpose of the present invention is to provide: a composition containing an ester compound, which can be efficiently produced and has excellent storage stability; a method for producing the composition; a polymerizable composition using the composition containing an ester compound; a (meth) acrylic polymer; a composition containing an ester compound, which contains an ester compound (I) that is one or more specific alkyl (meth) acrylates and at least one component selected from the group consisting of components A1 to A5, i.e., specific aldehyde compounds, specific acetal compounds, specific ketal compounds, specific carboxylic acid compounds, and specific alcohols, the content of the ester compound (I) is 95-99.99 mass% with respect to the total mass of the composition containing the ester compound.

Description

Technical Field

[0001] The present invention relates to a composition containing an ester compound and a method for producing the same, a polymerizable composition, a (meth)acrylic acid polymer and a method for producing the same.

[0002] This application claims priority based on Japanese Patent Application No. 2022-174445, Japanese Patent Application No. 2022-174450, and Japanese Patent Application No. 2022-174455 filed in Japan on October 31, 2022, the contents of which are incorporated herein by reference. Background Art

[0003] (Meth)acrylic acid-based polymers obtained using (meth)acrylates are used in various fields such as coating materials, adhesives, resin modifiers, artificial marbles, and latex for paper coating.

[0004] As a method for producing (meth)acrylate, for example, the following method is known: a raw material (meth)acrylate alkyl ester is subjected to an ester exchange reaction with an alkyl alcohol in the presence of Ti(OR)4 (R is an alkyl group) as a catalyst to produce a target (meth)acrylate alkyl ester (for example, Patent Document 1).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2009-274986 Summary of the invention

[0008] If the ester compound-containing composition containing (meth)acrylate is stored for a certain period of time after production, the quality of the ester compound-containing composition may be reduced.

[0009] An object of the present invention is to provide an ester compound-containing composition which can be efficiently produced and has excellent storage stability, a method for producing the same, a polymerizable composition using the ester compound-containing composition, a (meth)acrylic polymer, and a method for producing the same.

[0010] The present inventors have conducted intensive research and found that during storage of a composition containing an ester compound, the concentration of the pure component decreases due to the generation of impurities such as dimers of (meth)acrylate esters. Impurities such as dimers of (meth)acrylate esters may be a factor that causes the physical properties of (meth)acrylic acid-based polymers to decrease.

[0011] The present inventors have conducted further studies and have found that the formation of impurities such as dimers of (meth)acrylates is suppressed and the storage stability is improved by containing specific components in the composition containing an ester compound, thereby completing the present invention.

[0012] That is, the present invention includes the following aspects.

[0013] [1] A composition containing an ester compound, comprising:

[0014] one or more compounds selected from the group consisting of a compound represented by the following formula (A1), a compound represented by the following formula (A2), a compound represented by the following formula (A3), a compound represented by the following formula (A4), and a compound represented by the following formula (A5), and

[0015] An ester compound (I) represented by the following formula (1),

[0016] The content of the ester compound (I) is 95 to 99.99% by mass based on the total mass of the ester compound-containing composition.

[0017]

[0018] (In the above formula (1), R 1 is a hydrogen atom or a methyl group, R 2 It is a monovalent hydrocarbon group having 4 carbon atoms.

[0019]

[0020] (In the above formulas (A1) to (A3), R 11 and R 21 Each R is independently a linear or branched alkyl group having 1 to 20 carbon atoms. 22 and R 23 , R 31 and R 32 , R 33 and R 34 Each of them may be independently a linear or branched alkyl group having 1 to 20 carbon atoms, or may be a divalent group having 1 to 20 carbon atoms which may independently have an ether bond in combination with each group.

[0021]

[0022] (In the above formula (A4), R 41 It is a linear or branched alkyl group having 1 to 20 carbon atoms.

[0023] R 51 -OH …(A5)

[0024] (In the above formula (A5), R 51 It is a linear or branched alkyl group having 5 carbon atoms.

[0025] [2] The composition containing an ester compound according to [1], wherein the ester compound (I) comprises one or more selected from butyl (meth)acrylate and isobutyl (meth)acrylate.

[0026] [3] The composition containing an ester compound according to [1] or [2], wherein the compounds represented by the above formulas (A1) to (A5) are butyraldehyde, 1,1-dibutoxybutane, 2,2-dibutoxypropane, 2,4-dimethyl-1,3-dibutyl ether Alkane, 2,2,4-trimethyl-1,3-di Alkane, 2-ethyl-4-methyl-1,3-di Alkane, 1,3,5-trimethyl-2,4,6-tri At least one of alkane, acetic acid, butyric acid, 1-pentanol, 2-methyl-1-butanol and 3-methyl-1-butanol.

[0027] [4] The composition containing an ester compound according to any one of [1] to [3], wherein the total content of the compounds represented by the above formulae (A1) to (A5) is 1 to 1500 ppm by mass.

[0028] [5] The composition containing an ester compound according to any one of [1] to [4], further comprising a polymerization inhibitor as component B.

[0029] [6] The composition containing an ester compound according to [5], wherein the component B is at least one polymerization inhibitor selected from phenolic compounds, quinone compounds, nitrobenzene compounds, nitroxide radical compounds, amine compounds, phosphorus-containing compounds, sulfur-containing compounds, iron-containing compounds, copper-containing compounds and manganese-containing compounds.

[0030] [7] The composition containing an ester compound according to [5], wherein the component B is at least one polymerization inhibitor selected from the group consisting of phenolic compounds, nitroxide radical compounds, amine compounds, phosphorus-containing compounds and sulfur-containing compounds.

[0031] [8] The composition containing an ester compound according to [5], wherein the component B is at least one polymerization inhibitor selected from the group consisting of hydroquinone, 4-methoxyphenol, 2,4-dimethyl-6-tert-butylphenol and 2,6-di-tert-butyl-4-methylphenol.

[0032] [9] The composition containing an ester compound according to any one of [1] to [8], wherein the content of the ester compound (I) is 99 to 99.99% by mass.

[0033]

[10] The composition containing an ester compound according to any one of [1] to [9], which is a composition containing an ester compound that has been stored for one day or more.

[0034]

[11] A method for producing a composition containing an ester compound, comprising:

[0035] A transesterification reaction of methyl (meth)acrylate and a monohydric alcohol (II) having 4 carbon atoms is carried out in the presence of one or more compounds selected from the group consisting of a compound represented by the following formula (A1), a compound represented by the following formula (A2), a compound represented by the following formula (A3), a compound represented by the following formula (A4) and a compound represented by the following formula (A5).

[0036]

[0037] (In the above formula (1), R 1 is a hydrogen atom or a methyl group, R 2 It is a monovalent hydrocarbon group having 4 carbon atoms.

[0038]

[0039] (In the above formulas (A1) to (A3), R 11 and R 21 Each R is independently a linear or branched alkyl group having 1 to 20 carbon atoms. 22 and R 23 , R 31 and R 32 , R 33 and R 34 Each of them may be independently a linear or branched alkyl group having 1 to 20 carbon atoms, or may be a divalent group having 1 to 20 carbon atoms which may independently have an ether bond in combination with each group.

[0040]

[0041] (In the above formula (A4), R 41 It is a linear or branched alkyl group having 1 to 20 carbon atoms.

[0042] R 51 -OH …(A5)

[0043] (In the above formula (A5), R 51 It is a linear or branched alkyl group having 5 carbon atoms.

[0044]

[12] The method for producing a composition containing an ester compound according to

[11] , wherein the monohydric alcohol (II) is at least one of n-butanol and isobutanol.

[0045]

[13] The method for producing a composition containing an ester compound according to

[11] or

[12] , wherein the compounds represented by the above formulas (A1) to (A5) are butyraldehyde, 1,1-dibutoxybutane, 2,2-dibutoxypropane, 2,4-dimethyl-1,3-dibutyl ether, Alkane, 2,2,4-trimethyl-1,3-di Alkane, 2-ethyl-4-methyl-1,3-di Alkane, 1,3,5-trimethyl-2,4,6-tri At least one of alkanes, acetic acid, butyric acid, 1-pentanol, 2-methyl-1-butanol and 3-methyl-1-butanol.

[0046]

[14] A polymerizable composition for producing a (meth)acrylic polymer, comprising the composition containing an ester compound according to any one of [1] to

[10] .

[0047]

[15] The polymerizable composition according to

[14] , further comprising a monomer copolymerizable with the ester compound (I).

[0048]

[16] A (meth)acrylic acid-based polymer obtained by polymerizing the polymerizable composition described in

[14] .

[0049]

[17] A (meth)acrylic acid-based polymer obtained by polymerizing the polymerizable composition described in

[15] .

[0050]

[18] A method for producing a (meth)acrylic polymer, comprising polymerizing the polymerizable composition described in

[14] .

[0051]

[19] A method for producing a (meth)acrylic acid-based polymer, comprising polymerizing the polymerizable composition described in

[15] .

[0052] According to the present invention, there are provided an ester compound-containing composition that can be efficiently produced and has excellent storage stability, a method for producing the same, a polymerizable composition using the ester compound-containing composition, a (meth)acrylic polymer, and a method for producing the same. DETAILED DESCRIPTION

[0053] The present invention will be described in detail below. The following embodiments are merely examples for describing the present invention, and are not intended to limit the present invention to these embodiments. The present invention can be implemented in various forms without departing from the gist of the present invention.

[0054] The following terms in this specification and claims are defined as follows.

[0055] "Monomer" refers to a compound having a polymerizable carbon-carbon double bond.

[0056] "(Meth)acrylate" is selected from "acrylate" and "methacrylate".

[0057] "(Meth)acrylic acid" is selected from "acrylic acid" and "methacrylic acid".

[0058] In the present specification, a numerical range expressed using "to" indicates a range including the numerical values ​​described before and after "to" as the lower limit and the upper limit. For example, "2 to 20" indicates 2 or more and 20 or less.

[0059] [Composition containing an ester compound]

[0060] The ester compound-containing composition of the embodiment contains an ester compound (I) described below and component A described below.

[0061] The composition containing an ester compound of the embodiment may contain a polymerization inhibitor as a component B in addition to the ester compound (I) and the component A, as required. In addition, the composition containing an ester compound of the embodiment may further contain at least one of a compound other than the ester compound (I), the component A and the component B, and water, as long as the effects of the present invention are not impaired.

[0062] (Ester compound (I))

[0063] The ester compound (I) is a compound represented by the following formula (1).

[0064]

[0065] In the above formula (1), R 1 is a hydrogen atom or a methyl group, R 2 It is a monovalent hydrocarbon group having 4 carbon atoms.

[0066] R 2 The hydrocarbon group may be a saturated hydrocarbon group or an unsaturated hydrocarbon group.

[0067] R 2 The hydrocarbon group may be straight chain, branched chain, or have a ring. 2 When the hydrocarbon group has a ring, the ring may be an aliphatic ring or an aromatic ring.

[0068] As R 2 Examples of the hydrocarbon group include n-butyl, isobutyl, sec-butyl, tert-butyl, crotyl, 3-butenyl, and cyclopropylmethyl.

[0069] From the viewpoint that the ester compound (I) is easily available and can be easily handled in terms of physical properties, R 2 , preferably n-butyl, isobutyl, sec-butyl, tert-butyl or crotyl, more preferably n-butyl, isobutyl, sec-butyl or tert-butyl, particularly preferably n-butyl or isobutyl, most preferably n-butyl.

[0070] Examples of the ester compound (I) include butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, crotyl (meth)acrylate, 3-butenyl (meth)acrylate, and cyclopropylmethyl (meth)acrylate.

[0071] From the viewpoint of being relatively easy to obtain and being relatively easy to handle in terms of physical properties, the ester compound (I) is preferably butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate or crotonyl (meth)acrylate, more preferably butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate or tert-butyl (meth)acrylate, particularly preferably butyl (meth)acrylate or isobutyl (meth)acrylate, and most preferably butyl (meth)acrylate.

[0072] The ester compound (I) may be used alone or in combination of two or more.

[0073] (ingredient A)

[0074] Component A is one or more compounds selected from the group consisting of compounds represented by the following formula (A1), compounds represented by the following formula (A2), compounds represented by the following formula (A3), compounds represented by the following formula (A4), and compounds represented by the following formula (A5).

[0075] Hereinafter, the compound represented by the formula (A1) is also referred to as compound (A1), and the same applies to compounds represented by other formulae.

[0076]

[0077] In the above formulas (A1) to (A3), R 11 and R 21 Each R is independently a linear or branched alkyl group having 1 to 20 carbon atoms. 22 and R 23 , R 31 and R 32 , R 33 and R 34 Each of them may be independently a linear or branched alkyl group having 1 to 20 carbon atoms, or may be a divalent group having 1 to 20 carbon atoms which may independently have an ether bond in combination with the respective groups.

[0078] Hereinafter, the compounds represented by formulae (A1) to (A3) are also referred to as “component A1”, “component A2”, and “component A3”, respectively.

[0079]

[0080] In the above formula (A4), R 41 It is a linear or branched alkyl group having 1 to 20 carbon atoms.

[0081] Hereinafter, the compound represented by formula (A4) is also referred to as "component A4".

[0082] R 51 -OH …(A5)

[0083] In the above formula (A5), R 51 It is a linear or branched alkyl group having 5 carbon atoms.

[0084] Hereinafter, the compound represented by formula (A5) is also referred to as "component A5".

[0085] When the ester compound-containing composition contains Component A, the dimerization reaction of the ester compound (I) during storage is suppressed, thereby providing an ester compound-containing composition with excellent storage stability. The reason for this is not clear, but is presumed as follows.

[0086] The dimerization reaction of the ester compound (I) occurs when ultraviolet rays such as sunlight generate free radicals and react with the ester compound (I). Since components A1 to 3 have CH bonds that are easily cleaved, they can capture the free radicals. As a result, components A1 to 3 can inhibit the dimerization reaction of the ester compound (I) and further inhibit the oxidation reaction of the ester compound (I).

[0087] In addition, the dimerization reaction of the ester compound (I) also proceeds by anionic polymerization under alkaline conditions. The carboxylic acid compound has weak acidity and can capture anions that cause anionic polymerization. Therefore, component A4 can inhibit the dimerization reaction of the ester compound (I) caused by anionic polymerization.

[0088] Furthermore, since alcohol has weak acidity and can capture anions that cause anionic polymerization, Component A5 can suppress the dimerization reaction of the ester compound (I) caused by anionic polymerization.

[0089] Furthermore, during the storage of the composition containing the ester compound, free radicals derived from ultraviolet rays, such as hydroxyl radicals generated by oxygen molecules absorbing ultraviolet rays from sunlight, are generated. Such free radicals can cause the generation of oxidation products of the ester compound (I). The hydroxyl radicals react with the alcohol as component A5 and are converted into alkoxy radicals with lower reactivity, thereby suppressing the generation of oxidation products of the ester compound (I). At this time, if there are few structural similarities between the alcohol and the ester compound (I), the ratio of the reaction of the hydroxyl radical with the alcohol and the ester compound (I) can be biased towards the alcohol.

[0090] R of compound (A1) 11 The alkyl group may be linear or branched.

[0091] R 11 The number of carbon atoms in the alkyl group is preferably 1-10, more preferably 1-5.

[0092] As R 11 The alkyl group includes, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, etc. Among them, n-propyl, isopropyl or n-butyl is preferred, and n-propyl or isopropyl is more preferred.

[0093] Examples of the compound (A1) include acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, and valeraldehyde. The compound (A1) may be used alone or in combination of two or more.

[0094] From the viewpoint of achieving better storage stability of the composition containing the ester compound, the compound (A1) preferably contains at least one selected from butyraldehyde and isobutyraldehyde, and more preferably contains butyraldehyde.

[0095] R of compound (A2) 21 ~R 23 The alkyl group may be linear or branched.

[0096] R 21 The number of carbon atoms in the alkyl group is preferably 1-10, more preferably 1-5.

[0097] As R 21 The alkyl group includes, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, etc. Among them, methyl, ethyl, n-propyl or isopropyl is preferred, methyl, n-propyl or isopropyl is more preferred, and methyl or n-propyl is most preferred.

[0098] R 22 and R 23 The number of carbon atoms of the alkyl groups is preferably 1-10, more preferably 1-5, each independently.

[0099] As R 22and R 23 The alkyl group includes, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, etc. Among them, n-butyl or isobutyl is preferred, and n-butyl is more preferred.

[0100] As R 22 and R 23 Examples of the divalent groups having 1 to 20 carbon atoms which may be linked to each other and have ether bonds include 1,3-propylene, 1,3-butylene, 1,4-butylene, or -CH(-CH3)-O-CH(-CH3)-, etc. Among them, 1,3-butylene or -CH(-CH3)-O-CH(-CH3)- is preferred.

[0101] Examples of the compound (A2) include 1,1-diethoxyethane, 1,1-dibutoxyethane, 1,1-diisobutoxyethane, 1,1-diethoxybutane, 1,1-dibutoxybutane, 1,1-diethoxyisobutane, 1,1-diisobutoxyisobutane, 2-methyl-1,3-dimethoxyethane, Alkane, 2,4-dimethyl-1,3- Alkane, 2,5-dimethyl-1,3- Alkane, 2-ethyl-4-methyl-1,3- Alkane, 1,3,5-trimethyl-2,4,6-tri The compound (A2) may be used alone or in combination of two or more.

[0102] From the viewpoint of better storage stability of the composition containing the ester compound, the compound (A2) preferably contains 1,1-diethoxybutane, 1,1-dibutoxybutane, 1,1-diisobutoxyisobutane, 2,4-dimethyl-1,3-dimethoxybutane, Alkane, 2-ethyl-4-methyl-1,3- Alkane and 1,3,5-trimethyl-2,4,6-tri More preferably, it contains 1,1-dibutoxybutane, 2,4-dimethyl-1,3-di 1,3,5-trimethyl-2,4,6-tri alkyl.

[0103] R of compound (A3) 31 ~R 34 The alkyl group may be linear or branched.

[0104] R 31 and R 32 The number of carbon atoms of the alkyl groups is preferably 1-10, more preferably 1-5, each independently.

[0105] As R 31 and R 32 The alkyl group includes, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, etc. Among them, methyl, ethyl, n-propyl or isopropyl is preferred, and methyl or ethyl is more preferred.

[0106] As R 31 and R 32 Examples of the divalent group having 1 to 20 carbon atoms which may have an ether bond connected to each other include 1,4-butylene, 1,5-pentylene, and 1,6-hexylene. Among them, 1,5-pentylene is preferred.

[0107] R 33 and R 34 The number of carbon atoms of the alkyl groups is preferably 1-10, more preferably 1-5, each independently.

[0108] As R 33 and R 34 The alkyl group includes, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, etc. Among them, n-butyl or isobutyl is preferred, and n-butyl is more preferred.

[0109] As R 33 and R 34 Examples of the divalent groups having 1 to 20 carbon atoms which may be linked to each other and have ether bonds include 1,3-propylene, 1,3-butylene, 1,4-butylene, or -CH(-CH3)-O-CH(-CH3)-, etc. Among them, 1,3-butylene or -CH(-CH3)-O-CH(-CH3)- is preferred.

[0110] Examples of the compound (A3) include 2,2-dimethoxypropane, 2,2-diethoxypropane, 2,2-dibutoxypropane, 2,2-diisobutoxypropane, 2,2-dimethyl-1,3-dimethoxypropane, Alkane, 2,2,4-trimethyl-1,3-di The compound (A3) may be used alone or in combination of two or more.

[0111] From the viewpoint of better storage stability of the composition containing the ester compound, the compound (A3) preferably contains a 2,2-diethoxypropane, 2,2-dibutoxypropane, 2,2-diisobutoxypropane and 2,2,4-trimethyl-1,3-diisobutyloxypropane. More preferably, it contains 2,2-dibutoxypropane or 2,2,4-trimethyl-1,3-dimethoxypropane. alkyl.

[0112] R of compound (A4) 41The alkyl group may be linear or branched.

[0113] R 41 The number of carbon atoms in the alkyl group is preferably 1-20, more preferably 1-10, particularly preferably 1-7, most preferably 1-5.

[0114] As R 41 The alkyl group includes, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, etc. Among them, methyl, ethyl, n-propyl or isopropyl is preferred, and methyl or n-propyl is more preferred.

[0115] Examples of the compound (A4) include acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, lauric acid, tridecanoic acid, palmitic acid, and stearic acid. The compound (A4) may be used alone or in combination of two or more.

[0116] From the viewpoint of further improving the storage stability of the composition containing the ester compound, the compound (A4) preferably contains one or more selected from acetic acid, propionic acid, butyric acid and isobutyric acid, and more preferably contains at least one of acetic acid and butyric acid.

[0117] R of compound (A5) 51 The alkyl group may be linear or branched.

[0118] As R 51 Examples of the alkyl group include n-pentyl, 2-pentyl, 3-pentyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-2-butyl, 3-methyl-2-butyl, and neopentyl. Among them, n-pentyl, 2-methyl-1-butyl, and 3-methyl-1-butyl are more preferred.

[0119] Examples of the compound (A5) include 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 2-methyl-2-butanol, 3-methyl-2-butanol, and neopentyl alcohol. The compound (A5) may be used alone or in combination of two or more.

[0120] From the viewpoint of better storage stability of the composition containing the ester compound, the compound (A5) is preferably at least one selected from 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 2-methyl-2-butanol, 3-methyl-2-butanol and neopentyl alcohol, and more preferably at least one selected from 1-pentanol, 2-methyl-1-butanol and 3-methyl-1-butanol.

[0121] From the viewpoint of better storage stability of the composition containing the ester compound, it is particularly preferred that component A contains butyraldehyde, 1,1-dibutoxybutane, 2,2-dibutoxypropane, 2,4-dimethyl-1,3-dimethoxypropane, Alkane, 2,2,4-trimethyl-1,3-di Alkane, 2-ethyl-4-methyl-1,3- Alkane, 1,3,5-trimethyl-2,4,6-tri At least one of alkanes, acetic acid, butyric acid, 1-pentanol, 2-methyl-1-butanol and 3-methyl-1-butanol.

[0122] (ingredient B)

[0123] Component B is a polymerization inhibitor.

[0124] By including component B in the composition containing an ester compound, the polymerization reaction of the ester compound (I) based on the free radical polymerization mechanism during storage is suppressed, and the concentration reduction of the ester compound (I) is easily suppressed. In addition, during storage, the oxygen molecules in the composition containing an ester compound absorb ultraviolet rays from sunlight, thereby generating hydroxyl radicals. However, the inhibitor can capture hydroxyl radicals. Therefore, by including component B in the composition containing an ester compound, even if hydroxyl radicals are generated, the amount of hydroxyl radicals can be reduced by component B. Therefore, the dimerization of the ester compound (I) and the generation of oxidation products can be more efficiently suppressed.

[0125] In addition, the "polymerization inhibitor" in the present invention refers to a compound having a function of inhibiting the polymerization reaction of the ester compound (I).

[0126] Examples of component B include phenolic compounds, quinone compounds, nitrobenzene compounds, nitroxide radical compounds, amine compounds, phosphorus-containing compounds, sulfur-containing compounds, iron-containing compounds, copper-containing compounds, and manganese-containing compounds.

[0127] Examples of the phenolic compound include alkylphenols, hydroxyphenols, aminophenols, nitrophenols, nitrosophenols, alkoxyphenols, and tocopherol.

[0128] Examples of the alkylphenol include o-cresol, m-cresol, p-cresol, 2-tert-butyl-4-methylphenol, 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, 2-tert-butylphenol, 4-tert-butylphenol, 2,4-di-tert-butylphenol, 2-methyl-4-tert-butylphenol, 4-tert-butyl-2,6-dimethylphenol, 2,2'-methylene-bis(6-tert-butyl-4-methylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), and 3,5-di-tert-butyl-4-hydroxytoluene.

[0129] Examples of the hydroxyphenol include hydroquinone, 2-methylhydroquinone, 2-tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, 2,6-dibutylhydroquinone, 2,5-di-tert-amylhydroquinone, 2-tert-butylmethoxyhydroquinone, 2,3,5-trimethylhydroquinone, 2,5-dichlorohydroquinone, 1,2-dihydroxybenzene, 2-acetylhydroquinone, 4-methylcatechol, 4-tert-butylcatechol, 2-methylresorcinol, 4-methylresorcinol, and 2,3-dihydroxyacetophenone.

[0130] Examples of the aminophenol include o-aminophenol, m-aminophenol, p-aminophenol, 2-(N,N-dimethylamino)phenol, and 4-(ethylamino)phenol.

[0131] Examples of the nitrophenol include o-nitrophenol, m-nitrophenol, p-nitrophenol, and 2,4-dinitrophenol.

[0132] Examples of the nitrosophenol include o-nitrosophenol, m-nitrosophenol, p-nitrosophenol, and α-nitroso-β-naphthol.

[0133] Examples of the alkoxyphenol include 2-methoxyphenol, 2-ethoxyphenol, 2-isopropoxyphenol, 2-tert-butoxyphenol, 4-methoxyphenol, 4-ethoxyphenol, 4-propoxyphenol, 4-butoxyphenol, 4-tert-butoxyphenol, 4-heptyloxyphenol, hydroquinone monobenzyl ether, tert-butyl-4-methoxyphenol, di-tert-butyl-4-methoxyphenol, pyrogallol-1,2-dimethyl ether, and hydroquinone monobenzoate.

[0134] Examples of tocopherol include α-tocopherol and 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran.

[0135] Examples of the quinone compound 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.

[0136] Examples of the nitrobenzene-based compound include nitrobenzene, o-dinitrobenzene, m-dinitrobenzene, p-dinitrobenzene, 2,4-dinitrobenzene, dinitrodurene, and 2,2-diphenyl-1-picrylhydrazyl.

[0137] Examples of the nitroxide radical compound include 4-hydroxy-2,2,6,6-tetramethyl-piperidine-nitroxide radical, 4-oxo-2,2,6,6-tetramethyl-piperidine-nitroxide radical, 4-acetoxy-2,2,6,6-tetramethyl-piperidine-nitroxide radical, 2,2,6,6-tetramethyl-piperidine-nitroxide radical, piperidine-1-oxy radical, 4-(dimethylamino)-2,2,6,6-tetramethyl-piperidine-nitroxide radical, 4-amino-2,2,6,6-tetramethyl-piperidine-nitroxide radical, 4-vinyloxy-2,2,6,6-tetramethyl-piperidine-nitroxide radical, 4-benzoyloxy-2,2,6,6-tetramethyl-piperidine-nitroxide radical, 2,2,5,5-tetramethyl-piperidinyl-nitroxide free radical, 3-amino-2,2,5,5-tetramethyl-piperidinyl-nitroxide free radical, 4,4',4"-tris(2,2,6,6-tetramethyl-piperidinyl-nitroxide free radical)phosphite, 3-oxo-2,2,5,5-tetramethylpyrrolidine-nitroxide free radical, pyrrolidine-1-oxy free radical, 2,2,5,5-tetramethyl-1-oxa-3-azacyclopentyl-3-oxy free radical, 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 free radical, di-tert-butylnitroxide, di-tert-amylnitroxide, etc.

[0138] Examples of the amine compound include N,N-diphenylamine, alkylated diphenylamine, 4,4'-dicumyl diphenylamine, 4,4'-dioctyl diphenylamine, 4-amino diphenylamine, p-nitroso diphenylamine, N-nitrosodinaphthylamine, N-nitroso diphenylamine, N-nitrosophenylnaphthylamine, N-nitrosophenylhydroxylamine, N,N'-dialkyl p-phenylenediamine (the alkyl groups may be the same or different and each independently have 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, N, N'-di(2-naphthyl)-p-phenylenediamine, N,N-diethylhydroxylamine, 1,4-phenylenediamine, N-(1,4-dimethylpentyl)-N'-phenyl-1,4-phenylenediamine, 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, butyral-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, 1-hydroxy-4-benzoyloxy-2,2,6,6-tetramethylpiperidine, etc.

[0139] Examples of the phosphorus-containing compound include triphenylphosphine, triphenyl phosphite, triethyl phosphite, tris(isodecyl) phosphite, tris(tridecyl) phosphite, phenyl diisooctyl phosphite, phenyl diisodecyl phosphite, phenyl di(tridecyl) phosphite, diphenyl isooctyl phosphite, diphenyl isodecyl phosphite, diphenyl tridecyl phosphite, [1,1-diphenyl-4,4'-diyl-bis[tetrakis-2,4-bis(1,1-dimethylethyl)phenyl]]phosphonate, triphenyl phosphite, tris(nonylphenyl) phosphite, 4,4'-isopropylidene diphenol alkyl phosphite, tris(2,4-di-tert-butylphenyl) phosphite, and terphenyl phosphite. Ester, distearyl pentaerythritol diphosphite, di(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, di(nonylphenyl) pentaerythritol diphosphite, phenyl bisphenol A pentaerythritol diphosphite, tetra(tridecyl)-4,4'-butylidene bis(3-methyl-6-tert-butylphenol) diphosphite, hexa(tridecyl)-1,1,3-tri(2-methyl-4-hydroxy-5-tert-butylphenyl) butane triphosphite, 3,5-di-tert-butyl-4-hydroxybenzyl phosphate diethyl ester, bis(4-tert-butylphenyl) phosphate sodium salt, 2,2'-methylene-bis(4,6-di-tert-butylphenyl) phosphate sodium salt, 1,3-bis(diphenoxyphosphoryloxy)benzene, etc.

[0140] Examples of the sulfur-containing compound include diphenyl sulfide, phenothiazine, 3-oxophenothiazine, 5-oxophenothiazine, phenothiazine dimer, 1,4-dimercaptobenzene, 1,2-dimercaptobenzene, 2-mercaptophenol, 4-mercaptophenol, 2-(methylthio)phenol, and 3,7-bis(dimethylamino)phenothiazine. Chloride, sulfur (elemental), etc.

[0141] Examples of the iron-containing compound include iron (III) chloride and the like.

[0142] Examples of the copper-containing compound 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.

[0143] Examples of the manganese-containing compound include manganese dialkyldithiocarbamate, manganese diphenyldithiocarbamate, manganese formate, manganese acetate, manganese octoate, manganese naphthenate, manganese permanganate, and manganese salt of ethylenediaminetetraacetic acid. The alkyl group of the manganese dialkyldithiocarbamate is any one of methyl, ethyl, propyl, and butyl, and may be the same or different.

[0144] From the viewpoint of easily exhibiting the effect of further improving the storage stability of the composition containing the ester compound, as component B, preferably at least one polymerization inhibitor selected from phenolic compounds, nitroxide compounds, amine compounds, phosphorus-containing compounds and sulfur-containing compounds, more preferably at least one polymerization inhibitor selected from hydroquinone, 4-methoxyphenol, 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, 4-hydroxy-2,2,6,6-tetramethylpiperidine-nitroxide, N,N-diphenylamine, N-nitrosodiphenylamine, triphenyl phosphite and phenothiazine, and particularly preferably at least one polymerization inhibitor selected from hydroquinone, 4-methoxyphenol, 2,4-dimethyl-6-tert-butylphenol and 2,6-di-tert-butyl-4-methylphenol.

[0145] Component B may be used alone or in combination of two or more.

[0146] When the composition containing an ester compound contains a compound belonging to both component A1 and component B, the compound is regarded as component A1. When the composition containing an ester compound contains component A1 and component B, it means that the composition containing an ester compound contains component B different from the above compound.

[0147] When the composition containing an ester compound contains two or more compounds belonging to both Component A1 and Component B, the compound having the highest molar concentration in the composition containing an ester compound is regarded as Component A1, and the other compounds are regarded as Component B.

[0148] Components A2 to 5 are also treated in the same manner as component A1.

[0149] (Ingredient C)

[0150] Component C is a compound other than the ester compound (I), component A and component B.

[0151] Examples of component C include release agents, lubricants, plasticizers, antioxidants, antistatic agents, light stabilizers, ultraviolet absorbers, flame retardants, flame retardant aids, fillers, pigments, dyes, silane coupling agents, leveling agents, defoaming agents, fluorescent agents and other additives.

[0152] The composition containing an ester compound may contain unreacted raw materials such as methyl (meth)acrylate, alcohol, and (meth)acrylic acid when producing the composition containing an ester compound.

[0153] The composition containing an ester compound may also contain impurities such as diacetyl generated when producing the composition containing an ester compound, but from the viewpoint of reducing the coloration of the composition containing an ester compound, the concentration of diacetyl is preferably 5 mass ppm or less, more preferably 2 mass ppm or less, further preferably 1 mass ppm or less, and particularly preferably 0.1 mass ppm or less.

[0154] The composition containing an ester compound may contain a (meth)acrylate other than the ester compound (I).

[0155] (composition)

[0156] The content of the ester compound (I) in the composition containing the ester compound is 95 to 99.99% by mass relative to the total mass of the composition containing the ester compound. When the concentration of the ester compound (I) is 95% by mass or more, the amount of impurities when the (meth) acrylic polymer is produced by polymerization of the composition containing the ester compound can be reduced to prevent adverse effects on the physical properties of the above-mentioned polymer. In addition, when the concentration of the ester compound (I) is 99.99% by mass or less, the purification cost can be reduced. The concentration of the ester compound (I) is preferably 95% by mass or more, more preferably 96% by mass or more, further preferably 98% by mass or more, particularly preferably 99% by mass or more, and most preferably 99.5% by mass or more.

[0157] The content of component A in the composition containing an ester compound is not particularly limited, and is preferably 1 to 10,000 ppm by mass relative to the total mass of the composition containing an ester compound. By being 1 ppm by mass or more, the effect of inhibiting the formation of dimers of the ester compound (I) can be fully obtained. In addition, by being 10,000 ppm by mass or less, the amount of impurities when the (meth) acrylic polymer is produced by polymerization of the composition containing an ester compound of the present invention can be reduced, thereby preventing adverse effects on the physical properties of the above-mentioned polymer. The content of component A is more preferably 3 ppm by mass or more, further preferably 5 ppm by mass or more, and particularly preferably 10 ppm by mass or more. The content of component A is more preferably 7,500 ppm by mass or less, further preferably 5,000 ppm by mass or less, further preferably 2,500 ppm by mass or less, further 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.

[0158] The lower limit and upper limit of the preferred content of Component A may be arbitrarily combined, and for example, it is preferably 1 to 1500 mass ppm, and more preferably 10 to 1000 mass ppm.

[0159] The content of component B in the composition containing the ester compound is not particularly limited, and is preferably 1 to 1000 mass ppm relative to the total mass of the composition containing the ester compound. By being 1 mass ppm or more, the effect of inhibiting the formation of dimers of the ester compound (I) can be fully obtained. In addition, by being 1000 mass ppm or less, the amount of impurities when the (meth) acrylic polymer is produced by polymerization of the composition containing the ester compound of the present invention can be reduced to prevent adverse effects on the physical properties of the above-mentioned polymer. The content of component B is more preferably 3 mass ppm or more, further preferably 5 mass ppm or more, and particularly preferably 10 mass ppm or more. The content of component B is more preferably 750 mass ppm or less, further preferably 500 mass ppm or less, further preferably 250 mass ppm or less, particularly preferably 100 mass ppm or less, and most preferably 50 mass ppm or less.

[0160] The lower limit and upper limit of the preferred content of Component B may be arbitrarily combined, and for example, it is preferably 1 to 750 mass ppm, more preferably 3 to 500 mass ppm, and even more preferably 5 to 100 mass ppm.

[0161] The water content of the composition containing the ester compound is preferably 5000 mass ppm or less, more preferably 4000 mass ppm or less, further preferably 3000 mass ppm or less, particularly preferably 2000 mass ppm or less, and most preferably 1000 mass ppm or less, relative to the total mass of the composition containing the ester compound. If the water content of the composition containing the ester compound is below the above upper limit, the physical properties of the (meth)acrylic polymer obtained by polymerizing the composition containing the ester compound can be better maintained.

[0162] The lower limit of the water content of the composition containing the ester compound is 0 mass ppm.

[0163] (Analysis of Composition Containing Ester Compound)

[0164] Component A, component B, component C, and water contained in the composition containing an ester compound can be confirmed by, for example, GC-MS measurement.

[0165] In the GC-MS spectrum of the composition containing an ester compound, if there is a peak at the same retention time as the standard of component A, and the m / z value of the peak detected by mass spectrometry is consistent with the exact mass of component A, the composition containing an ester compound can be judged to contain component A. In the case where a standard of component A is not available, if the mass spectrum of the peak appearing in the GC-MS spectrum of the composition containing an ester compound is consistent with the mass spectrum of component A included in the mass spectrum database, it can be judged that the peak is the peak of component A and the composition containing an ester compound contains component A. Examples of mass spectrum databases include NIST20, NIST17, NIST14, and NIST14s. In addition, in the case where the volatility is low and cannot be detected by GC-MS measurement, LC-MS can be used for detection. Component B, component C, and water can also be confirmed by the same method as component A.

[0166] The content of the ester compound (I) can be calculated by performing GC-FID measurement on a composition containing an ester compound, determining the amount by using an area percentage method, and correcting the amount using the amount of water determined by a Karl Fischer titrator.

[0167] The concentration of component A can be quantified, for example, by performing GC measurement or GC-MS measurement on the composition containing the ester compound and using an internal standard method or an absolute standard curve method. When a standard sample of component A is not available and quantification by the internal standard method or the absolute standard curve method is not possible, GC-FID measurement can be performed on any organic compound with a known concentration under the same conditions as the composition containing the ester compound, and the concentration of component A can be calculated using the following formula.

[0168]

[0169] In the above formula, N is the number of carbon atoms contained in one molecule of any organic compound. A is the number of carbon atoms contained in one molecule of component A, S A is the peak area of ​​component A, S is the peak area of ​​an arbitrary organic compound, and M is the content (mass ppm) of an arbitrary organic component.

[0170] When volatility is low and quantification by GC area is not possible, chromatographic methods such as LC can be used for quantification.

[0171] The contents of component B and component C can also be calculated by the same method as that of component A.

[0172] The water content of the composition containing the ester compound can be confirmed by the Karl Fischer method.

[0173] [Method for producing a composition containing an ester compound]

[0174] The composition containing an ester compound according to an example of an embodiment of the present invention can be produced by, for example, performing an ester exchange reaction between methyl (meth)acrylate and a monohydric alcohol (II) having 4 carbon atoms in the presence of Component A.

[0175] Methyl (meth)acrylate has a tendency to dimerize and oxidize particularly easily among (meth)acrylates. However, by carrying out the transesterification reaction in the presence of component A, dimerization of methyl (meth)acrylate is suppressed, resulting in an increase in the yield of the ester compound (I). In addition, by carrying out the transesterification reaction in the presence of component A and component B, the yield of the ester compound (I) is further increased.

[0176] By carrying out an ester exchange reaction between methyl (meth)acrylate and monohydric alcohol (II) in the presence of Component A, an ester compound-containing composition containing the ester compound (1) can be produced.

[0177] More specifically, for example, in a reactor, in the presence of a catalyst and component A, methyl (meth)acrylate and monohydric alcohol (II) are transesterified as shown in the following formula (2). 1 and R 2 With R in formula (1) 1 and R 2 same.

[0178]

[0179] The monohydric alcohol (II) may be linear or branched.

[0180] Examples of the monohydric alcohol (II) include n-butanol, isobutanol, sec-butanol, tert-butanol, crotyl alcohol, and cyclopropylcarbinol.

[0181] As the monohydric alcohol (II), at least one of n-butanol and isobutanol is preferred.

[0182] The monool (II) may be used alone or in combination of two or more.

[0183] As the monohydric alcohol (II), alcohols derived from biomass can be used.

[0184] The biomass-derived alcohol is not particularly limited, and for example, butanol obtained by the ABE method, which produces acetone, butanol, and ethanol by fermentation of biomass using Clostridium as bacteria, can be used.

[0185] The reactor is preferably a reactor equipped with a distillation column. Since the transesterification reaction is an equilibrium reaction, the productivity is improved by separating the by-produced methanol using a distillation column. For example, it is preferred to carry out the transesterification reaction while separating methanol as an azeotropic mixture with methyl (meth)acrylate to the outside of the system.

[0186] Examples of such a reactor include a reactor equipped with a distillation tower on the top of a reaction vessel called a reactor, a distillation tower using a distillation pot as a reaction vessel, etc. Examples of the distillation tower include a packed tower type and a tray type distillation tower.

[0187] From the viewpoint of high separation capability and stable operation, the theoretical number of stages of the distillation column is preferably 5 or more, more preferably 7 or more.

[0188] The ratio of the charging amount of methyl (meth)acrylate to the monool (II) can be appropriately determined. From the viewpoint of improving productivity, the ratio of methyl (meth)acrylate to 1 mol of the monool (II) is preferably 0.1 to 10 mol, more preferably 0.3 to 4 mol.

[0189] The catalyst used is not particularly limited, and examples thereof 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 tert-butoxide; 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 them, titanium alkoxides, dibutyltin oxide, and dioctyltin oxide are preferred from the viewpoint of fewer side reactions of the Michael addition reaction product in the transesterification reaction and high catalyst activity. The catalyst may be used alone or in combination of two or more.

[0190] The catalyst may be supplied to the reactor alone, or may be supplied to the reactor in a state dissolved in the same alcohol as the raw material monool (II) or in a state dissolved in the raw material methyl (meth)acrylate. For example, there may be mentioned a method of supplying the catalyst dissolved in the entire monool (II) used in the reaction to the reactor, a method of supplying the catalyst dissolved in a part of the monool (II) used in the reaction to the reactor, and the like.

[0191] The amount of the catalyst used is preferably 0.001 to 1 mol%, more preferably 0.01 to 0.1 mol%, based on 1 mol of the monohydric alcohol (II).

[0192] A solvent may be used in the transesterification reaction. When a solvent is used, it is preferred to use a solvent that forms an azeotropic composition with methanol produced as a by-product.

[0193] Examples of the solvent include n-pentane, n-hexane, n-heptane, n-octane, 2,3-dimethylbutane, 2,5-dimethylhexane, 2,2,4-trimethylpentane, cyclohexane, benzene, and toluene. Among them, n-hexane, n-heptane, and cyclohexane are preferred. The solvent may be used alone or in combination of two or more.

[0194] The reaction temperature of the transesterification reaction also varies depending on the types of the monohydric alcohol (II) and the solvent, but is preferably 60 to 150°C.

[0195] The reaction pressure of the transesterification reaction is not particularly limited, and the reaction may be carried out under any pressure of reduced pressure, normal pressure, or increased pressure.

[0196] The form of the transesterification reaction is not particularly limited, and the reaction can be carried out by a commonly used method such as a batch reaction or a continuous reaction.

[0197] After the transesterification reaction, the reaction solution can be purified to separate unreacted raw materials and by-products. For purification, for example, known methods such as distillation, crystallization, extraction, and column chromatography can be used.

[0198] The method for producing the ester compound-containing composition according to the present embodiment is not limited to the above method.

[0199] For example, other (meth)acrylates other than methyl (meth)acrylate may be used as a raw material instead of methyl (meth)acrylate.

[0200] The ester compound (I) can also be produced by an esterification reaction of the monohydric alcohol (II) and (meth)acrylic acid.

[0201] In addition, component B may be formulated in a liquid containing the ester compound (I) and component A after the transesterification reaction. In this case, a liquid (liquid B) containing the ester compound (I) and component B may be prepared separately from the liquid (liquid A) containing the ester compound (I) and component A, and the liquids A and B may be mixed to prepare a composition containing an ester compound. In addition, the ester compound (I), liquid A and liquid B may be mixed to prepare a composition containing an ester compound.

[0202] [Evaluation Method of Storage Stability and Thermal Stability of Composition Containing Ester Compound]

[0203] The quality stability of the composition containing an ester compound of the present invention during storage is high. As an evaluation method for the quality stability of the composition containing an ester compound during storage, for example, a method of actually storing the composition containing an ester compound for a long time and confirming the amount of dimer and oxidation product of the ester compound (I), and the content of the ester compound (I) can be cited. In addition, from the viewpoint of simplicity of operation, a method of heating the composition containing an ester compound for a short time and confirming the amount of dimer and oxidation product of the ester compound (I) and the content of the ester compound (I) can also be used. In the case of heating for a short time, the heating temperature is preferably 50 to 100°C, and the heating time is preferably 1 to 24 hours. In the present invention, the quality stability of the composition containing an ester compound during storage is evaluated based on the amount of dimer and oxidation product of the ester compound (I) and the content of the ester compound (I) when the composition containing an ester compound is stored at 25°C for 14 days or heated at 70°C for 7 to 20 hours.

[0204] [Polymerizable composition]

[0205] A polymerizable composition according to an example of an embodiment of the present invention is a polymerizable composition for producing a (meth)acrylic polymer, and includes the composition containing an ester compound according to the above-mentioned embodiment of the present invention.

[0206] In one embodiment, the composition containing an ester compound that has been stored for one day or more after production can be used in the polymerizable composition.

[0207] The storage time of the composition containing an ester compound may be 1 day or more, 3 days or more, 7 days or more, or 14 days or more. In addition, the storage time of the composition containing an ester compound may be 180 days or less, 150 days or less, 120 days or less, or 90 days or less. It should be noted that the "storage time" is not limited to the time left to stand under a specific environment, but refers to the time elapsed from the time of production including the time of transportation, etc.

[0208] The material of the storage container for the composition containing an ester compound is not particularly limited, and for example, a metal container such as stainless steel, a resin container, or a glass container can be used. Either a transparent container or an opaque container can be used.

[0209] The temperature when storing the composition containing the ester compound is preferably -10°C or higher, more preferably 0°C or higher, and preferably 60°C or lower, more preferably 50°C or lower. By setting the temperature to -10°C or higher, the load on the cooling device can be reduced, and by setting the temperature to 60°C or lower, the generation of dimers and oxidation products of the (meth)acrylate can be easily suppressed.

[0210] The oxygen concentration in the gas phase during storage of the composition containing the ester compound is preferably 5% by volume or more, more preferably 7% by volume or more, and preferably 30% by volume or less, more preferably 22% by volume or less. By setting the oxygen concentration in the gas phase to 5% by volume or more, it is easy to prevent the ester compound from being accidentally polymerized by the polymerization prevention effect of oxygen, and by setting it to 30% by volume or less, it is easy to suppress the (meth)acrylate from being oxidized by oxygen to generate various impurities.

[0211] In an embodiment, the ester compound-containing composition after storage may be used in a polymerizable composition without further adding a monomer, or may be prepared by further adding a monomer copolymerizable with the ester compound (I) (hereinafter also referred to as "other monomer") to the ester compound-containing composition after storage.

[0212] In one embodiment, the produced composition containing an ester compound may be stored in a state where other monomers are added and then used as a polymerizable composition. In this case, it is preferred that a polymerization initiator is not added during storage.

[0213] The content of the ester compound (I) based on the total mass of monomers in the polymerizable composition is preferably 10% by mass or more, more preferably 20% by mass or more, and is preferably 90% by mass or less, more preferably 80% by mass or less.

[0214] The above upper and lower limits of the content of the ester compound (I) may be arbitrarily combined. For example, the content of the ester compound (I) is preferably 10 to 90% by mass, more preferably 20 to 80% by mass.

[0215] Examples of other monomers include methyl (meth)acrylate, unsaturated carboxylic acids, unsaturated carboxylic anhydrides, maleimide, hydroxyl-containing vinyl monomers, vinyl esters, nitrogen-containing vinyl monomers, epoxy-containing monomers, aromatic vinyl monomers, alkylene glycol di(meth)acrylates, polyoxyalkylene glycol di(meth)acrylates, and vinyl monomers having two or more ethylenically unsaturated bonds in the molecule.

[0216] Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, and itaconic acid.

[0217] As unsaturated carboxylic anhydride, maleic anhydride, itaconic anhydride, etc. are mentioned, for example.

[0218] Examples of maleimide include N-phenylmaleimide and N-cyclohexylmaleimide.

[0219] Examples of the hydroxyl group-containing vinyl monomer include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate.

[0220] Examples of the vinyl ester include vinyl acetate and vinyl benzoate.

[0221] Examples of the nitrogen-containing vinyl monomer include methacrylamide and acrylonitrile.

[0222] As a monomer containing an epoxy group, glycidyl acrylate, glycidyl methacrylate, etc. are mentioned, for example.

[0223] Examples of the aromatic vinyl monomer include styrene and α-methylstyrene.

[0224] Examples of the alkanediol di(meth)acrylate 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.

[0225] Examples of the polyoxyalkylene glycol di(meth)acrylate 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.

[0226] Examples of the vinyl monomer having two or more ethylenically unsaturated bonds in the molecule include divinylbenzene and the like.

[0227] As other monomers, vinyl chloride, vinylidene chloride and derivatives thereof, unsaturated polyester prepolymers obtained from at least one polycarboxylic acid including an ethylenically unsaturated polycarboxylic acid and at least one diol, and vinyl ester prepolymers obtained by acrylic acid-modifying the ends of epoxy groups may be used.

[0228] The other monomers may be used alone or in combination of two or more.

[0229] When component A is a monomer copolymerizable with the ester compound (I), component A may be used as the monomer copolymerizable with the ester compound (I), or a monomer copolymerizable with the ester compound (I) other than component A may be used.

[0230] In the polymerizable composition, the content of other monomers is preferably 0 to 50 parts by mass relative to 100 parts by mass of the ester compound (I). Thus, a (meth)acrylic polymer with high transparency can be obtained. The upper limit of the content of other monomers is more preferably 40 parts by mass or less, and further preferably 30 parts by mass or less, relative to 100 parts by mass of the ester compound (I). The lower limit of the content of other monomers is more preferably 0.01 parts by mass or more, further preferably 0.1 parts by mass or more, and particularly preferably 1 part by mass or more, relative to 100 parts by mass of the ester compound (I).

[0231] For example, the content of other monomers is preferably 0 to 50 parts by mass, more preferably 0.01 to 40 parts by mass, further preferably 0.1 to 30 parts by mass, and particularly preferably 1 to 30 parts by mass, relative to 100 parts by mass of the ester compound (I).

[0232] The polymerizable composition of the present embodiment preferably contains a polymerization initiator.

[0233] Examples of the polymerization initiator include azo compounds, organic peroxides, persulfate compounds, and redox polymerization initiators.

[0234] The polymerization initiator may be used alone or in combination of two or more.

[0235] Examples of the azo compound 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(cyclohexanecarbonitrile), and dimethyl 2,2'-azobisisobutyrate.

[0236] Examples of the organic peroxide include benzoyl peroxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 1,1-bis(tert-butylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)-3,5,5-trimethylcyclohexane, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyisobutyrate, tert-butyl peroxybenzoate, tert-hexyl peroxybenzoate, tert-butyl peroxyisopropyl monocarbonate, tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxylaurate, tert-butyl peroxyacetate, tert-hexyl peroxyisopropyl monocarbonate, and tert-butyl peroxyisopropyl monocarbonate. Ester, tert-hexyl peroxy-2-ethylhexanoate, tert-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 peroxyisononanoate, 1,1,2-trimethylpropyl peroxy-isononanoate, di-tert-butyl peroxide, di-tert-hexyl peroxide, lauroyl peroxide, dilauroyl peroxide, etc.

[0237] Examples of the persulfate compound include potassium persulfate and the like.

[0238] The amount of the polymerization initiator added is not particularly limited, and may be, for example, 0.005 to 5 parts by mass based on 100 parts by mass of the total mass of the monomers in the polymerizable composition.

[0239] The polymerizable composition of this embodiment may contain other additives such as chain transfer agent, release agent, lubricant, plasticizer, antioxidant, antistatic agent, light stabilizer, ultraviolet absorber, flame retardant, flame retardant aid, filler, pigment, dye, silane coupling agent, leveling agent, defoaming agent, fluorescent agent, etc. as needed.

[0240] The other additives may be used alone or in combination of two or more.

[0241] [Method for producing (meth)acrylic acid polymer]

[0242] By polymerizing the polymerizable composition as an example of the present embodiment, a (meth)acrylic polymer can be produced.

[0243] The polymerization method is not particularly limited, and examples thereof include bulk polymerization, solution polymerization, emulsion polymerization, suspension polymerization, etc. Bulk polymerization is preferred from the viewpoint of environmental load due to the use of solvents and the transparency of the obtained (meth)acrylic polymer.

[0244] The specific method of the bulk polymerization method is not particularly limited, and examples thereof include known injection molding polymerization methods such as a unit casting method and a continuous casting method.

[0245] The injection molding polymerization method is a method of injecting a polymerizable composition into a mold consisting of two inorganic glass plates or metal plates (eg, SUS plates) which are arranged opposite to each other at a predetermined interval and sealed with a gasket such as a soft resin tube, and polymerizing the composition to obtain a (meth)acrylic polymer.

[0246] The casting mold for injection molding polymerization is not particularly limited, and a known casting mold can be used. As a casting mold for unit casting, for example, a casting mold in which two plate-like bodies such as inorganic glass plates, chrome-plated metal plates, stainless steel plates are arranged relative to each other at a predetermined interval and gaskets are arranged at their edges to form a sealed space by the plate-like body and the gasket. As a casting mold for continuous casting, for example, a casting mold in which a sealed space is formed by the opposite 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 belt on both sides of the endless belt can be cited.

[0247] The gap of the mold is appropriately adjusted so as to obtain a resin plate of a desired thickness, and is generally 1 to 30 mm.

[0248] The polymerization temperature is preferably 125 to 210°C, more preferably 130 to 180°C.

[0249] The polymerization time is preferably 0.5 to 24 hours.

[0250] The weight average molecular weight (Mw) of the (meth)acrylic acid-based polymer is not particularly limited, and may be, for example, 100000 to 1000000. The larger the Mw of the (meth)acrylic acid-based polymer, the higher the solvent resistance and chemical resistance.

[0251] The Mw of the (meth)acrylic polymer can be controlled by adjusting the polymerization temperature, polymerization time, the amount of the polymerization initiator added, and the like.

[0252] The (meth)acrylic acid polymer of the present invention has excellent heat resistance and solubility. For example, a granular (meth)acrylic acid polymer that can store a large amount of resin per unit volume and has a low energy cost for storage and transportation needs to be dissolved and melted when used. However, the (meth)acrylic acid polymer of the present invention is easy to melt, has excellent kneading properties with other resins, and also has excellent solubility in monomers, solvents, etc.

[0253] The present invention will be described in detail below with reference to Examples, but the present invention is not limited to the following descriptions. "%" and "ppm" in Examples and Comparative Examples represent "mass %" and "mass ppm" unless otherwise specified.

[0254] The water concentration was calculated by the Karl Fischer method. The composition of the constituent components of the ester compound-containing composition before storage was calculated from the amount of each raw material added. The dimer and oxidation product of the ester compound (I) in the ester compound-containing composition before and after storage were quantified by the absolute calibration curve method using GC-MS.

[0255] [GC-MS measurement]

[0256] Apparatus: GC-MS measuring apparatus (product name: QP-2010, manufactured by Shimadzu Corporation)

[0257] (GC conditions)

[0258] Column (Product name: DB-FFAP, manufactured by Agilent Technologies, Ltd.)

[0259] Length: 30m, inner diameter: 0.25mm, film thickness: 0.25μm

[0260] Injection volume: 1.0 μL

[0261] Gasification chamber temperature: 240℃

[0262] Column oven temperature: maintained at 60°C for 3 minutes, increased from 60°C to 240°C at a rate of 10°C / min, and maintained at 240°C for 4 minutes.

[0263] Carrier gas: Helium

[0264] Injection mode: split (split ratio 30)

[0265] Control mode: Constant linear speed (50.0 cm / s)

[0266] Pressure: 116.3KPa

[0267] Total flow rate: 61.3mL / min

[0268] Purge flow rate: 3.0mL / min

[0269] Column flow rate: 1.88mL / min

[0270] (MS conditions)

[0271] Ionization method: EI (Electron Ionization)

[0272] Ion source temperature: 240°C

[0273] Interface temperature: 240℃

[0274] m / z detection range: 10~500

[0275] Detection time: 25 minutes

[0276] [Determination of water content]

[0277] The moisture content was quantified by the Karl Fischer method using a micro-automatic moisture measuring device (product name: CA-21, manufactured by Nitto Seiko Analytical Science Co., Ltd.).

[0278] [Example 1]

[0279] To 9.919 g of butyl methacrylate (BMA, manufactured by Tokyo Chemical Industry Co., Ltd., water content: 120 mass ppm) as the ester compound (I) was added 0.020 g of 2-methyl-1-butanol as the component A to prepare a liquid A.

[0280] Separately, 0.020 g of 2,4-dimethyl-6-tert-butylphenol as component B was added to 9.924 g of BMA (water content: 120 mass ppm) as the ester compound (I) to prepare a liquid B.

[0281] Next, 0.050 g of the A solution and 0.050 g of the B solution were added to 9.850 g of BMA (water content: 120 mass ppm) as the ester compound (I) to prepare a composition containing an ester compound.

[0282] The obtained composition containing an ester compound was stored at 25°C for 14 days under white LED lighting, and then measured by GC-MS. The content of BMA dimer (mg / L) and the content of butyl pyruvate (mg / L) were determined using the absolute standard curve method, and the changes (production amounts) before and after storage were calculated.

[0283] [Examples 2 to 37, Comparative Examples 1 to 8]

[0284] A composition containing an ester compound was prepared in the same manner as in Example 1 except that the compositions of liquid A, liquid B, liquid C (liquid containing component C) and the composition containing an ester compound were changed as shown in Tables 1 to 3, and the generated amounts of BMA dimer and butyl pyruvate were determined.

[0285] [Table 1]

[0286]

[0287] [Table 2]

[0288]

[0289] [Table 3]

[0290]

[0291] The abbreviations in Tables 1 to 3 have the following meanings.

[0292] · BMA: Butyl methacrylate.

[0293] ·DMTBP: 2,4-dimethyl-6-tert-butylphenol.

[0294] ·MEHQ: 4-methoxyphenol.

[0295] IPPDA: 4-isopropylaminodiphenylamine.

[0296] PTZ: phenothiazine.

[0297] · HO-TEMPO: 4-Hydroxy-2,2,6,6-tetramethyl-piperidinyl-nitroxide free radical.

[0298] ·AMX: 4-acetamide-2,2,6,6-tetramethyl-piperidinyl-nitroxide free radical.

[0299] Tables 4 and 5 show the results of measuring the production amounts of BMA dimer and butyl pyruvate in Examples 1 to 37 and Comparative Examples 1 to 8.

[0300] [Table 4]

[0301]

[0302] [Table 5]

[0303]

[0304] As shown in Tables 4 and 5, the ester compound-containing compositions of Examples 1 to 37, in which BMA was 95% by mass or more and contained Component A, showed lower amounts of BMA dimer and butyl pyruvate produced after storage than the ester compound-containing compositions of Comparative Examples 1 to 8, in which BMA was less than 95% by mass or did not contain Component A.

[0305] [Example 38]

[0306] To 10.001 g of butyl methacrylate (BMA, manufactured by Tokyo Chemical Industry Co., Ltd., water content: 120 mass ppm) as the ester compound (I) was added 0.020 g of butyraldehyde as the component A to prepare a liquid A.

[0307] Separately, 0.020 g of 2,4-dimethyl-6-tert-butylphenol as component B was added to 10.002 g of BMA (water content: 120 mass ppm) as the ester compound (I) to prepare a liquid B.

[0308] Next, 0.050 g of the A solution and 0.052 g of the B solution were added to 9.845 g of BMA (water content: 120 mass ppm) as the ester compound (I) to prepare a composition containing an ester compound.

[0309] The obtained ester compound-containing composition was stored at 25°C for 14 days under white LED illumination, and then measured by GC-MS. The content (mg / L) of BMA dimer was determined by the absolute standard curve method, and the change (production amount) before and after storage was calculated.

[0310] [Examples 39 to 55, Comparative Examples 5 to 6]

[0311] Except that the compositions of liquid A, liquid B, and the composition containing an ester compound were changed as shown in Table 6, a composition containing an ester compound was prepared in the same manner as in Example 38, and the amount of BMA dimer generated was determined.

[0312] [Table 6]

[0313]

[0314] The abbreviations in Table 6 have the following meanings.

[0315] · BMA: Butyl methacrylate.

[0316] ·DMTBP: 2,4-dimethyl-6-tert-butylphenol.

[0317] Table 7 shows the results of measuring the amount of BMA dimer produced in Examples 38 to 55 and Comparative Examples 5 to 6.

[0318] [Table 7]

[0319]

[0320] As shown in Table 7, the ester compound-containing compositions of Examples 38 to 55 containing Component A all showed smaller amounts of BMA dimer generated after storage than the ester compound-containing compositions of Comparative Examples 5 to 6 not containing Component A.

[0321] [Example 56]

[0322] To 10.001 g of isobutyl methacrylate (IBMA, manufactured by Tokyo Chemical Industry Co., Ltd., water content: 110 mass ppm) as the ester compound (I) was added 0.020 g of 2-methyl-1-butanol as the component A to prepare a liquid A.

[0323] Separately, 0.020 g of 2,4-dimethyl-6-tert-butylphenol as component B was added to 10.084 g of IBMA (water content: 110 mass ppm) as the ester compound (I) to prepare a liquid B.

[0324] Next, 0.050 g of the A solution and 0.051 g of the B solution were added to 9.850 g of IBMA (water content: 110 mass ppm) as the ester compound (I) to prepare a composition containing an ester compound.

[0325] The obtained composition containing an ester compound was stored at 70°C for 7 hours under white LED lighting, and then measured by GC-MS. The contents (mg / L) of IBMA dimer and isobutyl pyruvate were determined by the absolute standard curve method, and the changes (production amounts) before and after storage were calculated.

[0326] [Examples 57 to 75, Comparative Examples 9 to 12]

[0327] The compositions of liquid A, liquid B, liquid C (liquid containing component C) and the composition containing an ester compound were changed as shown in Tables 8 and 9, and a composition containing an ester compound was prepared in the same manner as in Example 56, and the amounts of IBMA dimer and isobutyl pyruvate produced were determined.

[0328] [Table 8]

[0329]

[0330] [Table 9]

[0331]

[0332] The abbreviations in Tables 8 and 9 have the following meanings.

[0333] IBMA: isobutyl methacrylate.

[0334] ·DMTBP: 2,4-dimethyl-6-tert-butylphenol.

[0335] Table 10 shows the results of measuring the production amounts of IBMA dimer and isobutyl pyruvate in Examples 56 to 75 and Comparative Examples 9 to 12.

[0336] [Table 10]

[0337]

[0338] As shown in Table 10, the ester compound-containing compositions of Examples 56 to 75 containing Component A showed less production of IBMA dimer and isobutyl pyruvate after storage than the ester compound-containing compositions of Comparative Examples 9 to 12 not containing Component A.

[0339] Industrial Applicability

[0340] According to the present invention, a composition containing an ester compound that can be used as a raw material for a (meth)acrylic polymer can be efficiently produced and can be stably stored for a long period of time, and is industrially useful.

Claims

1. A composition containing an ester compound, comprising: one or more compounds selected from the group consisting of a compound represented by the following formula (A1), a compound represented by the following formula (A2), a compound represented by the following formula (A3), a compound represented by the following formula (A4), and a compound represented by the following formula (A5), and An ester compound (I) represented by the following formula (1), The content of the ester compound (I) is 95 to 99.99% by mass relative to the total mass of the composition containing the ester compound. In the formula (1), R 1 is a hydrogen atom or a methyl group, R 2 is a monovalent hydrocarbon group having 4 carbon atoms, In the formulas (A1) to (A3), R 11 and R 21 are each independently a linear or branched alkyl group having 1 to 20 carbon atoms, R 22 and R 23 , R 31 and R 32 , R 33 and R 34 Each of them may be independently a linear or branched alkyl group having 1 to 20 carbon atoms, or may be a divalent group having 1 to 20 carbon atoms which may independently have an ether bond in combination with each group, In the formula (A4), R 41 is a linear or branched alkyl group having 1 to 20 carbon atoms, R 51 -OH…(A5) In the formula (A5), R 51 It is a linear or branched alkyl group having 5 carbon atoms.

2. The composition containing an ester compound according to claim 1, wherein The ester compound (I) contains one or more selected from butyl (meth)acrylate and isobutyl (meth)acrylate.

3. The composition containing an ester compound according to claim 1, wherein The compounds represented by the formulas (A1) to (A5) are butyraldehyde, 1,1-dibutoxybutane, 2,2-dibutoxypropane, 2,4-dimethyl-1,3-di Alkane, 2,2,4-trimethyl-1,3-di Alkane, 2-ethyl-4-methyl-1,3-di Alkane, 1,3,5-trimethyl-2,4,6-tri At least one of alkane, acetic acid, butyric acid, 1-pentanol, 2-methyl-1-butanol and 3-methyl-1-butanol.

4. The composition containing an ester compound according to claim 1, wherein The total content of the compounds represented by the formulae (A1) to (A5) is 1 to 1500 ppm by mass.

5. The composition containing an ester compound according to claim 1, wherein It further contains component B, a polymerization inhibitor.

6. The composition containing an ester compound according to claim 5, wherein The component B is at least one polymerization inhibitor selected from phenolic compounds, quinone compounds, nitrobenzene compounds, nitroxide free radical compounds, amine compounds, phosphorus-containing compounds, sulfur-containing compounds, iron-containing compounds, copper-containing compounds and manganese-containing compounds.

7. The composition containing an ester compound according to claim 5, wherein The component B is at least one polymerization inhibitor selected from phenolic compounds, nitroxide free radical compounds, amine compounds, phosphorus-containing compounds and sulfur-containing compounds.

8. The composition containing an ester compound according to claim 5, wherein The component B is at least one polymerization inhibitor selected from the group consisting of hydroquinone, 4-methoxyphenol, 2,4-dimethyl-6-tert-butylphenol and 2,6-di-tert-butyl-4-methylphenol.

9. The composition containing an ester compound according to claim 1, wherein The content of the ester compound (I) is 99 to 99.99% by mass. 10 . The composition containing an ester compound according to claim 1 , which is a composition containing an ester compound that has been stored for one day or more.

11. A method for producing a composition containing an ester compound, comprising: In the presence of one or more compounds selected from the group consisting of a compound represented by the following formula (A1), a compound represented by the following formula (A2), a compound represented by the following formula (A3), a compound represented by the following formula (A4) and a compound represented by the following formula (A5), a transesterification reaction of methyl (meth)acrylate with a monohydric alcohol (II) having 4 carbon atoms is carried out, In the formula (1), R 1 is a hydrogen atom or a methyl group, R 2 is a monovalent hydrocarbon group having 4 carbon atoms, In the formulas (A1) to (A3), R 11 and R 21 are each independently a linear or branched alkyl group having 1 to 20 carbon atoms, R 22 and R 23 , R 31 and R 32 , R 33 and R 34 Each of them may be independently a linear or branched alkyl group having 1 to 20 carbon atoms, or may be a divalent group having 1 to 20 carbon atoms which may independently have an ether bond in combination with each group, In the formula (A4), R 41 is a linear or branched alkyl group having 1 to 20 carbon atoms, R 51 -OH…(A5) In the formula (A5), R 51 It is a linear or branched alkyl group having 5 carbon atoms.

12. The method for producing a composition containing an ester compound according to claim 11, wherein The monohydric alcohol (II) is at least one of n-butanol and isobutanol.

13. The method for producing a composition containing an ester compound according to claim 11, wherein The compounds represented by the formulae (A1) to (A5) include butyraldehyde, 1,1-dibutoxybutane, 2,2-dibutoxypropane, 2,4-dimethyl-1,3-di Alkane, 2,2,4-trimethyl-1,3-di Alkane, 2-ethyl-4-methyl-1,3-di Alkane, 1,3,5-trimethyl-2,4,6-tri At least one of alkane, acetic acid, butyric acid, 1-pentanol, 2-methyl-1-butanol and 3-methyl-1-butanol. 14 . A polymerizable composition for producing a (meth)acrylic polymer, comprising the composition containing an ester compound according to claim 1 .

15. The polymerizable composition according to claim 14, wherein The present invention further comprises a monomer copolymerizable with the ester compound (I). 16 . A (meth)acrylic acid-based polymer obtained by polymerizing the polymerizable composition according to claim 14 .

17. A (meth)acrylic polymer obtained by polymerizing the polymerizable composition according to claim 15.

18. A method for producing a (meth)acrylic polymer, comprising polymerizing the polymerizable composition according to claim 14.

19. A method for producing a (meth)acrylic polymer, comprising polymerizing the polymerizable composition according to claim 15.