Methyl methacrylate-containing composition, method for preserving methyl methacrylate-containing composition, and method for producing methyl methacrylate polymer.

Abstract

The object of the present invention is to provide a methyl methacrylate-containing composition that exhibits high quality stability during storage. [Solution] The problem is solved by a methyl methacrylate-containing composition comprising methyl methacrylate and a pyrazine compound represented by formula (2) (component A2), wherein the concentration of methyl methacrylate is 99 to 99.99% by mass.

Description

[Technical Field]

[0001] The present invention relates to a methyl methacrylate-containing composition, a method for preserving a methyl methacrylate-containing composition, and a method for producing a methyl methacrylate polymer. [Background technology]

[0002] Methyl methacrylate (hereinafter also referred to as "MMA") is known to be an extremely useful substance used as a raw material for various types of polymers and applications. For example, polymethyl methacrylate, a homopolymer of methyl methacrylate, is used in signage, lighting equipment, automotive parts, building materials, light guide plates for flat displays, and light diffusers, taking advantage of its excellent transparency and weather resistance. Furthermore, copolymers of methyl methacrylate with other monomers are used in paints, adhesives, resin modifiers, artificial marble, and paper latex. Various methods have been developed for the industrial production of methyl methacrylate, such as the acetone cyanohydrin (ACH) method, the new acetone cyanohydrin (new ACH) method, the C4 direct oxidation method, the direct methacrylate method, the ethylene method, and the new ethylene method (Non-patent Literature 1). In these production methods, purification such as distillation is performed to remove unreacted raw materials and by-products contained in the produced methyl methacrylate to obtain methyl methacrylate of a quality suitable for the intended application.

[0003] Because methyl methacrylate is easily polymerized, it is known that polymerization inhibitors are added to maintain the quality of methyl methacrylate during its production and storage (Non-Patent Document 2). For example, Patent Document 1 states that hydroquinone methyl ether (MEHQ) is particularly preferred among various polymerization inhibitors. Patent Document 2 states that N,N'-dialkyl-p-phenylenediamine and N-oxyl are preferred among various polymerization inhibitors. Patent Document 3 describes distilling methyl methacrylate in the presence of a phenolic polymerization inhibitor. Patent Document 4 describes using a diphenylamine derivative as a polymerization inhibitor. Patent Document 5 describes using a benzenetriamine derivative as a polymerization inhibitor. Furthermore, Patent Document 6 describes a method for producing a copolymer containing methyl methacrylate using a composition containing methyl methacrylate and a vinyl compound. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2004-155757 [Patent Document 2] Special Publication No. 2005-502695 [Patent Document 3] Special Publication No. 10-504553 [Patent Document 4] Special Publication No. 2002-533309 [Patent Document 5] Special Publication No. 2002-513034 [Patent Document 6] Japanese Patent Application Publication No. 50-37882 [Non-patent literature]

[0005] [Non-Patent Document 1] Kuroda, Toru, "Development of a catalyst for the production of methyl methacrylate," Catalysis, The Catalysis Society of Japan, 2003, Vol. 45, No. 5, pp. 366-371. [Non-Patent Document 2] Takayuki Otsu, "On the Function of Polymerization Inhibitors," Organic Synthesis Chemistry, The Society of Organic Synthesis, 1975, Vol. 33, No. 8, pp. 634-640. [Overview of the project] [Problems that the invention aims to solve]

[0006] However, even when polymerization inhibitors described in Patent Documents 1 to 5 were added, methyl methacrylate sometimes deteriorated in quality during storage. Furthermore, Patent Document 6 is a document concerning the production of copolymers and does not describe the storage stability of methyl methacrylate. Given these circumstances, the object of the present invention is to provide a methyl methacrylate-containing composition with high quality stability during storage. [Means for solving the problem]

[0007] The inventors diligently conducted research to achieve the above objectives. As a result, they found that when methyl methacrylate deteriorates in quality during storage, the methyl methacrylate concentration decreases, and methyl methacrylate dimers and methyl pyruvate are formed. The presence of methyl methacrylate dimers in methyl methacrylate can alter the structure of the methyl methacrylate polymer obtained by polymerization, potentially adversely affecting its physical properties. Furthermore, the presence of methyl pyruvate in methyl methacrylate can cause discoloration of the methyl methacrylate polymer obtained by polymerization. The inventors then discovered that by including a pyrazine compound with a specific structural formula in the methyl methacrylate-containing composition, the quality stability during storage is improved, and the formation of methyl methacrylate dimers and methyl pyruvate is suppressed, thus completing the present invention.

[0008] In other words, the present invention is as follows [1] to

[39] . [1]: A methyl methacrylate-containing composition comprising methyl methacrylate, a pyrazine compound represented by the following formula (1) (component A1), and a polymerization inhibitor (component B1), A methyl methacrylate-containing composition having a methyl methacrylate concentration of 99 to 99.99% by mass. [ka] (In the above formula (1), R 1 , R 2 , R 3 and R 4 Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, a carbonyl group (all monovalent), an alkylthio group, or an arylthio group. [2]: The methyl methacrylate-containing composition according to [1], wherein the concentration of component A1 is MA1 (μmol / L) and the concentration of component B1 is MB1 (μmol / L), and MB1 / MA1 is 0.001 to 100. [3]: The methyl methacrylate-containing composition according to [1] or [2], wherein the concentration of component A1 is MA1 (μmol / L), and MA1 is 1 to 65,000 μmol / L. [4]: The methyl methacrylate-containing composition according to [3], wherein MA1 is 10 to 30,000 μmol / L. [5]: A methyl methacrylate-containing composition according to any one of [1] to [4], wherein the concentration of component B1 is MB1 (μmol / L), and MB1 is 1 to 7000 μmol / L. [6]: The methyl methacrylate-containing composition according to [5], wherein MB1 is 10 to 1000 μmol / L. [7]: A methyl methacrylate-containing composition according to any one of [1] to [6], wherein the molecular weight of component A1 is 1000 or less. [8]: The component B1 is a phenolic compound, a quinone compound, a nitrobenzene compound, an N-oxyl compound, an amine compound, a phosphorus-containing compound, a sulfur-containing compound, or an iron-containing compound. The methyl methacrylate-containing composition according to any one of [1] to [7], which is at least one polymerization inhibitor selected from the group consisting of a compound, a copper-containing compound, and a manganese-containing compound. [9]: The methyl methacrylate-containing composition according to any one of [1] to [8], wherein the component B1 is at least one polymerization inhibitor selected from the group consisting of a phenolic compound, an N-oxyl compound, an amine compound, a phosphorus-containing compound, and a sulfur-containing compound.

[10] : The methyl methacrylate-containing composition according to any one of [1] to [9], wherein the component B1 is 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.

[11] : In the formula (1), R 1 , R 2 , R 3 and R 4 are each independently 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 alkoxy group having 1 to 6 carbon atoms, an amino group having 0 to 6 carbon atoms, a monovalent group having 1 to 6 carbon atoms containing a carbonyl group, an alkylthio group having 1 to 5 carbon atoms, or an arylthio group having 6 to 10 carbon atoms. The methyl methacrylate-containing composition according to any one of [1] to

[10] .

[12] : In the formula (1), R 1 , R 2 , R 3 and R 4 are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. The methyl methacrylate-containing composition according to any one of [1] to

[11] .

[13] : In the formula (1), R 1 , R 2 , R 3 and R 4A methyl methacrylate-containing composition according to any one of [1] to

[12] , wherein each of them independently is a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, or a methoxy group.

[14] : A methyl methacrylate-containing composition according to any one of [1] to

[13] , wherein the concentration of methyl methacrylate is 99.8 to 99.99% by mass.

[15] : A methyl methacrylate-containing composition according to any one of [1] to

[14] , which does not contain diacetyl, or contains diacetyl at a concentration of 55 μmol / L or less.

[16] : A methyl methacrylate-containing composition comprising methyl methacrylate and a pyrazine compound represented by the following formula (2) (component A2), A methyl methacrylate-containing composition having a methyl methacrylate concentration of 99 to 99.99% by mass. [ka] (In the above equation (2), R 5 , R 6 , R 7 and R 8 Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group having 3 or more carbon atoms, an aryl group, a hydroxyl group, an alkoxy group, an amino group, a monovalent group containing a carbonyl group, an alkylthio group, or an arylthio group.

[17] : The methyl methacrylate-containing composition according to

[16] , wherein the concentration of component A2 is MA2 (μmol / L), and MA2 is 1 to 65,000 μmol / L.

[18] : The methyl methacrylate-containing composition according to

[17] , wherein the MA2 is 10 to 30,000 μmol / L.

[19] : A methyl methacrylate-containing composition according to any one of

[16] to

[18] , wherein the molecular weight of component A2 is 1000 or less.

[20] : In equation (2) above, R 5 , R 6 , R 7 and R 8 Each of them independently, a hydrogen atom, A methyl methacrylate-containing composition according to any one of

[16] to

[19] , comprising an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 3 to 5 carbon atoms, an aryl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an amino group having 0 to 6 carbon atoms, a monovalent group having 1 to 6 carbon atoms including a carbonyl group, an alkylthio group having 1 to 5 carbon atoms, or an arylthio group having 6 to 10 carbon atoms.

[21] : In equation (2) above, R 5 , R 6 , R 7 and R 8 A methyl methacrylate-containing composition according to any one of

[16] to

[20] , wherein each of them independently is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.

[22] : In equation (2) above, R 5 , R 6 , R 7 and R 8 A methyl methacrylate-containing composition according to any one of

[16] to

[21] , wherein each of them independently is a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, or a methoxy group.

[23] : A methyl methacrylate-containing composition according to any one of

[16] to

[22] , wherein the concentration of methyl methacrylate is 99.8 to 99.99% by mass.

[24] : A methyl methacrylate-containing composition according to any one of

[16] to

[23] , which does not contain diacetyl or contains diacetyl at a concentration of 55 μmol / L or less.

[25] : A methyl methacrylate-containing composition comprising methyl methacrylate, a pyrazine compound represented by the following formula (1) (component A1), and an ester compound having an α-hydrogen represented by the following formula (3) (component B2), A methyl methacrylate-containing composition having a methyl methacrylate concentration of 99 to 99.99% by mass. [ka] (In the above formula (1), R 1 , R 2 , R 3 and R 4Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, a carbonyl group (all monovalent), an alkylthio group, or an arylthio group. [ka] (In the above equation (3), R 9 and R 10 Each of these independently represents a monovalent group containing a hydrogen atom, an alkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an amino group, or a carbonyl group, or an alkylthio group. 11 R represents an alkyl or aryl group. 9 and R 10 , R 10 and R 11 , R 11 and R 9 (These may be connected to each other to form a ring.)

[26] : The methyl methacrylate-containing composition according to

[25] , wherein when the concentration of component A1 is MA1 (μmol / L) and the concentration of component B2 is MB2 (μmol / L), MB2 / MA1 is 0.01 to 1000.

[27] : The methyl methacrylate-containing composition according to

[25] or

[26] , wherein the concentration of component A1 is MA1 (μmol / L), and MA1 is 1 to 65,000 μmol / L.

[28] : When the concentration of component B2 is MB2 (μmol / L), MB2 is 1 to 50,000 μmol / L, the methacrylate according to any one of

[25] to

[27] . A composition containing ru.

[29] : In equation (3) above, R 9 and R 10 Each of these is independently a hydrogen atom, a C1-C5 alkyl group, a hydroxyl group, a C1-C6 alkoxy group, a C0-C6 amino group, a C1-C6 carbonyl group, a C1-C6 monovalent group, or a C1-C5 alkylthio group, R 11 A methyl methacrylate-containing composition according to any one of

[25] to

[28] , wherein is an alkyl group having 1 to 5 carbon atoms or an aryl group having 1 to 12 carbon atoms.

[30] : A methyl methacrylate-containing composition according to any one of

[25] to

[29] , wherein the concentration of methyl methacrylate is 99.8 to 99.99% by mass.

[31] : A methyl methacrylate-containing composition comprising methyl methacrylate, a pyrazine compound represented by the following formula (1) (component A1), and an α,β-unsaturated carbonyl compound represented by the following formula (4) (component B3), A methyl methacrylate-containing composition having a methyl methacrylate concentration of 99 to 99.99% by mass. [ka] (In the above formula (1), R 1 , R 2 , R 3 and R 4 Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, a carbonyl group (all monovalent), an alkylthio group, or an arylthio group. [ka] (In the above formula (4), R 12 , R 13 and R 14 Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, a carbonyl group (monovalent group), an alkylthio group, or an arylthio group. 15 R represents a monovalent group including an alkyl group, alkenyl group, aryl group, hydroxyl group, alkoxy group, amino group, or carbonyl group, an alkylthio group, or an arylthio group. 12 and R 13 , R 13 and R 14 , R 14 and R 15 They may each be connected to each other to form a ring. However, R 12 =H and R 13 =H and R 14 =CH3 and R 15Except when the case is OCH3, i.e., when the α,β-unsaturated carbonyl compound represented by formula (4) is methyl methacrylate. (H represents a hydrogen atom, C represents a carbon atom, and O represents an oxygen atom.)

[32] : The methyl methacrylate-containing composition according to

[31] , wherein when the concentration of component A1 is MA1 (μmol / L) and the concentration of component B3 is MB3 (μmol / L), MB3 / MA1 is 0.01 to 1000.

[33] : The methyl methacrylate-containing composition according to

[31] or

[32] , wherein the concentration of component A1 is MA1 (μmol / L), and MA1 is 1 to 65,000 μmol / L.

[34] : When the concentration of component B3 is MB3 (μmol / L), MB3 is 1 to 85000 μmol / L, the methacrylate according to any one of

[31] to

[33] . A composition containing ru.

[35] : In equation (4) above, R 12 , R 13 and R 14 Each of these is independently 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 alkoxy group having 1 to 6 carbon atoms, an amino group having 0 to 6 carbon atoms, a monovalent group having 1 to 6 carbon atoms including a carbonyl group, or an alkylthio group having 1 to 5 carbon atoms, R 15 A methyl methacrylate-containing composition according to any one of

[31] to

[34] , wherein is a monovalent group having 1 to 6 carbon atoms, including 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 hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, an amino group having 0 to 6 carbon atoms, or a carbonyl group, or an alkylthio group having 1 to 5 carbon atoms.

[36] : A methyl methacrylate-containing composition according to any one of

[31] to

[35] , wherein the concentration of methyl methacrylate is 99.8 to 99.99% by mass.

[37] : A method for storing a methyl methacrylate-containing composition, wherein the methyl methacrylate-containing composition described in any of [1] to

[36] is stored at 0 to 50°C.

[38] : A method for producing a methyl methacrylate polymer, comprising the step of polymerizing a polymerizable composition containing the methyl methacrylate-containing composition described in any of [1] to

[36] .

[39] : A method for producing a methyl methacrylate polymer according to

[38] , wherein the polymerizable composition comprises a monomer copolymerizable with methyl methacrylate. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a methyl methacrylate-containing composition with high quality stability in which the formation of methyl methacrylate dimers and methyl pyruvate during storage is suppressed. [Modes for carrying out the invention]

[0010] The following describes embodiments of the present invention, but the present invention is not limited to the following. In this specification, a numerical range represented by "~" means a range that includes the numbers written before and after "~" as the lower and upper limits, and "A~B" means that it is greater than or equal to A and less than or equal to B.

[0011] [Methyl methacrylate-containing composition 1] The first embodiment of the methyl methacrylate-containing composition according to this embodiment is a methyl methacrylate-containing composition comprising methyl methacrylate, a pyrazine compound represented by the following formula (1) (component A1), and a polymerization inhibitor (component B1), wherein the concentration of methyl methacrylate is 99 to 99.99% by mass. [ka]

[0012] In the above equation (1), R 1 , R 2 , R 3 and R 4 Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, a carbonyl group (all monovalent), an alkylthio group, or an arylthio group. Furthermore, the methyl methacrylate-containing composition may also contain components B2 and B3, other compounds (component C), and water, as long as the concentration of methyl methacrylate satisfies 99 to 99.99% by mass. Each item will be explained in detail below.

[0013] (Methyl methacrylate) A first embodiment of the methacrylic acid-containing composition according to this embodiment contains methyl methacrylate. Methyl methacrylate can be produced, for example, by the acetone cyanohydrin (ACH) method, the new acetone cyanohydrin (new ACH) method, the C4 direct oxidation method, the direct methacrylate method, the ethylene method, or the new ethylene method. The methyl methacrylate contained in the methyl methacrylate-containing composition is preferably produced by the C4 direct oxidation method, and more preferably produced by the C4 direct oxidation method using biomass-derived isobutanol as a starting material.

[0014] (Component A1) The first embodiment of the methyl methacrylate-containing composition according to this embodiment includes a pyrazine compound (component A1) represented by formula (1). The coexistence of component A1 and component B1, described later, can suppress the formation of methyl methacrylate dimer and methyl pyruvate. The reason for this is presumed to be as follows.

[0015] Methyl methacrylate dimers are generated by radicals that occur during the storage of methyl methacrylate. An example of such radicals is the hydroxyl radical, which is generated when an oxygen molecule absorbs ultraviolet light from sunlight. Hydroxyl radicals also cause the production of methyl pyruvate through the oxidation of methyl methacrylate. Pyrazine compounds have an aromatic ring and therefore absorb ultraviolet light, and the absorption wavelength changes depending on the type of substituent. Pyrazine compounds having the structure represented by formula (1) can absorb ultraviolet light across a wide range of wavelengths. Therefore, when a methyl methacrylate-containing composition contains component A1, ultraviolet light across a wide range of wavelengths is absorbed, and the generation of hydroxyl radicals is suppressed. Furthermore, by including component B1, which will be described later, the generated hydroxyl radicals can be trapped. Therefore, the coexistence of component A1 and component B1 allows for the reduction of the amount of hydroxyl radicals through two different mechanisms: component A1 suppresses the generation of hydroxyl radicals, and component B1 removes the generated hydroxyl radicals. Thus, it is considered that the generation of methyl methacrylate dimers and methyl pyruvate can be efficiently suppressed.

[0016] The molecular weight of component A1 is preferably 1000 or less. This increases the number of pyrazine rings per unit mass of component A1, so that the effects of the present invention can be obtained with a small amount of component A1. The molecular weight of component A1 is more preferably 800 or less, even more preferably 600 or less, and particularly preferably 400 or less.

[0017] In equation (1) above, R 1 , R 2 , R 3 and R 4 Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, a carbonyl group (monovalent group), an alkylthio group, or an arylthio group. 1 , R 2 , R 3 and R 4 They may be the same or different. From the viewpoint of increasing the absorbance of ultraviolet light and suppressing the generation of hydroxyl radicals, R 1 , R2 , R 3 and R 4 The group is preferably 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 alkoxy group having 1 to 6 carbon atoms, an amino group having 0 to 6 carbon atoms, a monovalent group having 1 to 6 carbon atoms including a carbonyl group, an alkylthio group having 1 to 5 carbon atoms, or an arylthio group having 6 to 10 carbon atoms; more preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms; and even more preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, or a methoxy group.

[0018] Alkyl groups are linear (linear or branched) alkyl groups or cyclic alkyl groups. Alkyl groups having 1 to 20 carbon atoms are preferred, alkyl groups having 1 to 10 carbon atoms are more preferred, and alkyl groups having 1 to 5 carbon atoms 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, isopentyl group, hexyl group, octyl group, Examples of cyclic alkyl groups include decyl groups, hydroxymethyl groups, 1-hydroxyethyl groups, and 2-hydroxyethyl groups, with methyl groups, ethyl groups, n-propyl groups, and isopropyl groups being preferred. Examples of cyclic alkyl groups include cyclopentyl groups, cyclohexyl groups, and cyclooctyl groups.

[0019] The alkenyl group is a linear (linear or branched) alkenyl group or a cyclic alkenyl group. Alkenyl groups with 2 to 20 carbon atoms are preferred, alkenyl groups with 2 to 10 carbon atoms are more preferred, and alkenyl groups with 2 to 5 carbon atoms are even more preferred. Examples of linear alkenyl groups include vinyl, 1-propenyl, isopropenyl, 2-butenyl, 1,3-butadienyl, 2-pentenyl, and 2-hexenyl groups. Examples of cyclic alkenyl groups include cyclopentenyl and cyclohexenyl groups.

[0020] 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 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, triazolyl group, tetrazolyl group, pyridyl group, pyrazinyl group, pyrimidinyl group, pyridadinyl group, pyrazolyl group, pyrrolyl group, furyl group, fluzanyl 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.

[0021] 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.

[0022] The amino group includes an amino group (-NH2) (0 carbon atoms) with 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 substituted with carbon atoms. The number of carbon atoms in the amino group in which some or all of the hydrogen atoms bonded to the nitrogen atom are substituted with carbon atoms is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 6. Examples of amino groups include an unsubstituted amino group (-NH2), 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.

[0023] Examples of monovalent groups containing a carbonyl group include formyl group, acyl group, carboxyl group, amide group, alkoxycarbonyl group, thiocarboxyl group, and thioester group.

[0024] 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 group, propionyl group, butylcarbonyl group, vinylcarbonyl group, and benzoyl group.

[0025] 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 number of carbon atoms derived from the carbonyl group (1) and the number of carbon atoms substituted on the nitrogen atom, which is 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.

[0026] 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 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 group, ethoxycarbonyl group, butoxycarbonyl group, and phenoxycarbonyl group.

[0027] 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.

[0028] Furthermore, the 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.

[0029] 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.

[0030] 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.

[0031] Among the compounds that satisfy the above conditions, from the viewpoint of ease of acquisition and synthesis, 2,3,5,6-tetramethylpyrazine, pyrazine, 2,3,5-trimethylpyrazine, 2-methoxypyrazine, 2-isopropyl-3-methoxypyrazine, 2,5-dimethylpyrazine, 2,5-diisopropylpyrazine, 2-ethyl-3,5-dimethylpyrazine, 2,5-dimethyl-3-isobutylpyrazine, 2-isopropyl-3-methoxy-5-isobutylpyrazine, 2-aminopyrazine, 2-(methylthio)pyrazine, 2,5-dimethyl-3-(methylthio)pyrazine, 2-pyrazinemethanol, pyrazinemethylamine, 2-pyrazinecarboxylate methyl, 2-vinylpyrazine, and 2-phenylpyrazine are preferred as component A1, and 2,3,5,6-tetramethylpyrazine, pyrazine, 2,3,5-trimethylpyrazine, 2-methoxypyrazine, 2-isopropyl-3-methoxypyrazine, and 2,5-dimethylpyrazine are more preferred.

[0032] In the first embodiment of the methyl methacrylate-containing composition according to this embodiment, component A1 may be one type or two or more types.

[0033] (ingredient B1) The first aspect of the methyl methacrylate-containing composition according to this embodiment includes a polymerization inhibitor (component B1). In this specification, a polymerization inhibitor means a compound that has the function of suppressing the polymerization reaction of methyl methacrylate. 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 B1, the polymerization reaction of methyl methacrylate by the radical polymerization mechanism can be suppressed during storage of methyl methacrylate. In addition, component B1 can trap the aforementioned hydroxyl radicals that are generated during storage of methyl methacrylate. That is, when the methyl methacrylate-containing composition contains component B1 in addition to component A1, the amount of hydroxyl radicals can be reduced by two different mechanisms: component A1 suppresses the generation of hydroxyl radicals, and component B1 removes the generated hydroxyl radicals. Therefore, it is considered that the generation of methyl methacrylate dimers and methyl pyruvate can be efficiently suppressed.

[0034] Examples of polymerization inhibitors that are phenolic compounds include alkylphenols, hydroxyphenols, aminophenols, nitrophenols, nitrosophenols, alkoxyphenols, and tocopherols.

[0035] 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'-methylene-bis(6-t-butyl-4-methylphenol), 2,2'-methylene-bis(4-ethyl-6-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol), and 3,5-di-t-butyl-4-hydroxytoluene.

[0036] 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- Examples include butylcatechol, 2-methylresorcinol, 4-methylresorcinol, and 2,3-dihydroxyacetophenone.

[0037] Examples of aminophenols include o-aminophenol, m-aminophenol, p-aminophenol, 2-(N,N-dimethylamino)phenol, and 4-(ethylamino)phenol.

[0038] 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.

[0039] 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, and di-t-butyl-4-methoxyphenol. Examples include pyrogallol-1,2-dimethyl ether and hydroquinone monobenzoate.

[0040] Examples of tocopherols include α-tocopherol and 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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, and N-phenyl-N'-isopropyl-p-phenylenediamine. Amine, N-(1,3-dimethylbutyl)-N'-phenyl-1,4-phenylenediamine, 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-tetramethyl Examples include lupiperidine, 1,4-dihydroxy-2,2,6,6-tetramethylpiperidine, and 1-hydroxy-4-benzoyloxy-2,2,6,6-tetramethylpiperidine.

[0045] 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, tris(nonylphenyl) phosphite, 4,4'-isopropylidenediphenolalkyl phosphite, tris(2,4-di-tert-butylphenyl) phosphite, tris(biphenyl) phosphite, and distearylpentaerythritol. Examples include 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.

[0046] 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.

[0047] Examples of polymerization inhibitors that contain iron include iron(III) chloride.

[0048] 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.

[0049] 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.

[0050] Among the above, from the viewpoint of quality stability during storage of the methyl methacrylate-containing composition, component B1 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, It is more preferable that the polymerization inhibitor is at least one selected from the group consisting of N-nitrosodiphenylamine, triphenylphosphite, and phenothiazine, and even more preferable that the polymerization inhibitor is at least one selected from the group consisting of hydroquinone, 4-methoxyphenol, 2,4-dimethyl-6-t-butylphenol, N,N-diphenylamine, triphenylphosphite, and phenothiazine.

[0051] Component B1 may be one type or two or more types. Furthermore, if a methyl methacrylate-containing composition contains a compound that corresponds to both component A1 and component B1, that compound shall be considered as component B1. In other words, the methyl methacrylate-containing composition must contain a component A1 that is different from the compound in question. Furthermore, if two or more compounds that correspond to both component A1 and component B1 are contained, the compound with the highest molar concentration in the methyl methacrylate-containing composition shall be considered as component B1, and the other compounds shall be considered as component A1.

[0052] (Concentrations of components A1 and B1) When the concentration of component A1 is MA1 (μmol / L) and the concentration of component B1 is MB1 (μmol / L), from the viewpoint of efficiency in suppressing the formation of methyl pyruvate, MB1 / MA1 is preferably 0.001 or higher, and more preferably 0.005 or higher. Furthermore, the upper limit of MB1 / MA1 is preferably 100 or less, more preferably 50 or less, even more preferably 30 or less, and particularly preferably 10 or less.

[0053] MA1 is preferably 1 to 65,000 μmol / L. A MA1 of 1 μmol / L or higher provides sufficient suppression of methyl methacrylate dimer and methyl pyruvate formation. Furthermore, a MA1 of 65,000 μmol / L or less reduces the amount of impurities when a methyl methacrylate polymer is produced by polymerization of the methyl methacrylate-containing composition according to this embodiment, preventing adverse effects on the properties of the polymer. The lower limit of MA1 is more preferably 10 μmol / L or higher, and even more preferably 50 μmol / L or higher. The upper limit of MA1 is more preferably 30,000 μmol / L or lower, and even more preferably 10,000 μmol / L or lower.

[0054] The MB1 is preferably 1 to 7000 μmol / L. An MB1 of 1 μmol / L or more provides sufficient suppression of the formation of methyl methacrylate dimers and methyl pyruvate. An MB1 of 7000 μmol / L or less reduces the amount of impurities when a methyl methacrylate polymer is produced by polymerization of the methyl methacrylate-containing composition according to this embodiment, preventing adverse effects on the properties of the polymer. The lower limit of MB1 is more preferably 10 μmol / L or more, and even more preferably 40 μmol / L or more. The upper limit of MB1 is more preferably 5000 μmol / L or less, even more preferably 1000 μmol / L or less, and particularly preferably 600 μmol / L or less.

[0055] (Concentration of methyl methacrylate) In the first embodiment, the concentration of methyl methacrylate in the methyl methacrylate-containing composition according to this embodiment is 99 to 99.99% by mass. A concentration of 99% by mass or higher reduces the amount of impurities produced when a methyl methacrylate polymer is manufactured by polymerization of the methyl methacrylate-containing composition, thereby preventing adverse effects on the properties of the polymer. Furthermore, a concentration of 99.99% by mass or lower reduces the purification cost. The lower limit of the methyl methacrylate concentration is preferably 99.8% by mass or higher.

[0056] (Component C) The first embodiment of the methyl methacrylate-containing composition according to this embodiment may contain other compounds (component C) as long as the concentration of methyl methacrylate satisfies 99 to 99.99% by mass. Good. Component C can be impurities generated during the production of methyl methacrylate. For example, methyl methacrylate may contain diacetyl as an impurity, but from the viewpoint of reducing the coloration of the methyl methacrylate-containing composition, the concentration of diacetyl is preferably 55 μmol / L or less, more preferably 20 μmol / L or less, even more preferably 10 μmol / L or less, and particularly preferably 1 μmol / L or less.

[0057] (Analysis of methyl methacrylate-containing compositions) The presence of methyl methacrylate-containing compositions in components A1, B1, B2 and B3 (described later), C, and water can be confirmed, for example, by GC-MS measurement. If the GC-MS chart of the methyl methacrylate-containing composition shows a peak 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 mass of component A1, then it can be determined that the methyl methacrylate-containing composition contains component A1. If a standard of component A1 is not available, the peak can be determined to be the component A1 peak if the mass spectrum pattern of the peak appearing in the GC-MS chart of the methyl methacrylate-containing composition matches the mass spectrum pattern of component A1 recorded in a mass spectrum database. In other words, it can be determined that the methyl methacrylate-containing composition contains component A1. Examples of mass spectrum databases include NIST20, NIST17, NIST14, and NIST14s. Furthermore, if the volatility is low (boiling point above 500°C) and detection by GC-MS is not possible, detection can be performed using LC-MS. The presence of component B1, components B2 and B3 (described later), component C, and water can also be confirmed by the same method. Furthermore, the concentration of methyl methacrylate can be calculated by performing a GC-FID measurement of the methyl methacrylate-containing composition, quantifying it using the area percentage method, and correcting it using the moisture concentration quantified with a Karl Fischer moisture meter. The concentration of component A1 can be quantified by performing a GC measurement of the methyl methacrylate-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 concentration of component A1 can be calculated by performing a GC-FID measurement of any organic compound with a known concentration under the same conditions as the methacrylate-containing composition and using the following formula.

number

[0058] [Methyl Methacrylate-containing Composition 2] The second aspect of the methyl methacrylate-containing composition according to the present embodiment is a methyl methacrylate-containing composition containing methyl methacrylate and a pyrazine compound (component A2) represented by the following formula (2), wherein the concentration of methyl methacrylate is 99 to 99.99% by mass. [Chemical formula]

[0059] In the above formula (2), R 5 , R 6 , R 7 and R 8 each independently represents a hydrogen atom, an alkyl group, an alkenyl group having 3 or more carbon atoms, an aryl group, a hydroxy group, an alkoxy group, an amino group, a monovalent group containing a carbonyl group, an alkylthio group or an arylthio group. Also, as long as the methyl methacrylate-containing composition satisfies the concentration of methyl methacrylate of 99 to 99.99% by mass, it may contain the component B1, component B2 and component B3 described later, other compounds (component C), and water. Each item will be described in detail below.

[0060] (Methyl Methacrylate) The second aspect of the methacrylic acid-containing composition according to this embodiment contains methyl methacrylate. The preferred embodiment of methyl methacrylate is the same as that of the first aspect.

[0061] (Component A2) The second aspect of the methyl methacrylate-containing composition according to this embodiment contains a pyrazine compound (Component A2) represented by the formula (2). When the methyl methacrylate-containing composition contains Component A2, Component A2 can strongly absorb ultraviolet light having a wavelength that causes the generation of hydroxyl radicals and can sufficiently suppress the generation of hydroxyl radicals. Therefore, even if Component B1 that traps the generated hydroxyl radicals does not exist, the generation of methyl methacrylate dimer and methyl pyruvate can be suppressed. On the other hand, from the viewpoint of further suppressing the generation of methyl methacrylate dimer and methyl pyruvate, in the second aspect, it is preferable that the methyl methacrylate-containing composition contains the Component B1.

[0062] The molecular weight of Component A2 is preferably 1000 or less. Thereby, since the number of pyrazine rings per unit mass of Component A2 increases, the effects of the present invention can be obtained with a small amount of Component A2. The molecular weight of Component A2 is more preferably 800 or less, further preferably 600 or less, and particularly preferably 400 or less.

[0063] In the formula (2), R 5 , R 6 , R 7 and R 8 each independently represent a hydrogen atom, an alkyl group, an alkenyl group having 3 or more carbon atoms, an aryl group, a hydroxy group, an alkoxy group, an amino group, a monovalent group containing a carbonyl group, an alkylthio group or an arylthio group. R 5 , R 6 , R 7 and R 8 may be the same or different. From the viewpoint of increasing the absorbance of ultraviolet light and suppressing the generation of hydroxyl radicals, R 5 , R 6 , R 7 and R 8The group is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 3 to 5 carbon atoms, an aryl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an amino group having 0 to 6 carbon atoms, a monovalent group having 1 to 6 carbon atoms including a carbonyl group, an alkylthio group having 1 to 5 carbon atoms, or an arylthio group having 6 to 10 carbon atoms; more preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms; and even more preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, or a methoxy group.

[0064] The preferred forms of the alkyl group, aryl group, alkoxy group, amino group, monovalent group including carbonyl group, alkylthio group, and arylthio group in formula (2) are the same as those in formula (1).

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

[0066] Among the compounds that satisfy the above conditions, from the viewpoint of ease of acquisition and synthesis, 2,3,5,6-tetramethylpyrazine, pyrazine, 2,3,5-trimethylpyrazine, 2-methoxypyrazine, 2-isopropyl-3-methoxypyrazine, 2,5-dimethylpyrazine, 2,5-diisopropylpyrazine, 2-ethyl-3,5-dimethylpyrazine, 2,5-dimethyl-3-isobutylpyrazine, 2-isopropyl-3-methoxy-5-isobutylpyrazine, 2-aminopyrazine, 2-(methylthio)pyrazine, 2,5-dimethyl-3-(methylthio)pyrazine, 2-pyrazinemethanol, pyrazinemethylamine, 2-pyrazinecarboxylate methyl, and 2-phenylpyrazine are preferred as component A2, and 2,3,5,6-tetramethylpyrazine, pyrazine, 2,3,5-trimethylpyrazine, 2-methoxypyrazine, 2-isopropyl-3-methoxypyrazine, and 2,5-dimethylpyrazine are more preferred.

[0067] In the second embodiment of the methyl methacrylate-containing composition according to this embodiment, component A2 may be one type or two or more types.

[0068] (ingredient B1) When the methyl methacrylate-containing composition contains component B1, the preferred form of component B1 is the same as in the first embodiment. Furthermore, component B1 may be one type or two or more types. Furthermore, if a methyl methacrylate-containing composition contains a compound that corresponds to both component A2 and component B1, that compound shall be considered as component A2. In other words, if a methyl methacrylate-containing composition contains both component A2 and component B1, it means that it contains a different component B1. Furthermore, if two or more compounds that correspond to both component A2 and component B1 are contained, the compound with the highest molar concentration in the methyl methacrylate-containing composition shall be considered as component A2, and the other compounds shall be considered as component B1.

[0069] (Concentrations of components A2 and B1) When the concentration of component A2 is MA2 (μmol / L), from the viewpoint of the efficiency of suppressing the formation of methyl pyruvate, MB1 / MA2 is preferably 0.001 or higher, and more preferably 0.005 or higher. Furthermore, the upper limit of MB1 / MA2 is preferably 100 or less, more preferably 50 or less, even more preferably 30 or less, and particularly preferably 10 or less.

[0070] The MA2 concentration is preferably 1 to 65,000 μmol / L. A MA2 concentration of 1 μmol / L or higher is sufficient to suppress the formation of methyl methacrylate dimers and methyl pyruvate. Furthermore, a MA2 concentration of 65,000 μmol / L or lower reduces the amount of impurities produced when a methyl methacrylate polymer is produced by polymerization of the methyl methacrylate-containing composition according to this embodiment, preventing adverse effects on the properties of the polymer. The lower limit of MA2 is more preferably 10 μmol / L or higher, and even more preferably 50 μmol / L or higher. The upper limit of MA2 is more preferably 30,000 μmol / L or lower, and even more preferably 10,000 μmol / L or lower.

[0071] The preferred configuration of MB1 is the same as that of the first configuration.

[0072] (Concentration of methyl methacrylate) The preferred embodiment of the concentration of methyl methacrylate is the same as in the first embodiment.

[0073] (Component C) A preferred embodiment of component C is the same as that of the first embodiment.

[0074] (Analysis of methyl methacrylate-containing compositions) The method for confirming that a methyl methacrylate-containing composition contains component A2, component B1, component C, and water, and the method for measuring the concentrations of methyl methacrylate, component A2, component B1, component C, and water, are the same as in the first embodiment.

[0075] [Methyl methacrylate-containing composition 3] A third aspect of the methyl methacrylate-containing composition according to this embodiment is a methyl methacrylate-containing composition comprising methyl methacrylate, a pyrazine compound represented by the following formula (1) (component A1), and an ester compound having an α-hydrogen represented by the following formula (3) (component B2), wherein the concentration of methyl methacrylate is 99 to 99.99% by mass.

[0076] [ka]

[0077] In the above equation (1), R 1 , R 2 , R 3 and R 4 Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, a carbonyl group (all monovalent), an alkylthio group, or an arylthio group.

[0078] [ka]

[0079] In equation (3) above, R 9 and R 10 Each of these independently represents a monovalent group containing a hydrogen atom, an alkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an amino group, or a carbonyl group, or an alkylthio group. 11 R represents an alkyl or aryl group. 9 and R 10 , R 10 and R 11 , R 11 and R 9 These may be connected to each other to form a ring.

[0080] Furthermore, the methyl methacrylate-containing composition may also contain component B1, component B3 (described later), other compounds (component C), and water, as long as the concentration of methyl methacrylate is 99 to 99.99% by mass. Each item will be explained in detail below.

[0081] (Methyl methacrylate) A third embodiment of the methacrylic acid-containing composition according to this embodiment includes methyl methacrylate. The preferred embodiment of methyl methacrylate is the same as that of the first embodiment.

[0082] (Component A1) A third aspect of the methyl methacrylate-containing composition according to this embodiment includes a pyrazine compound (component A1) represented by formula (1). The coexistence of component A1 and component B2, described later, can suppress the formation of methyl methacrylate dimers and methyl pyruvate. The reason for this is presumed to be as follows. As mentioned above, methyl methacrylate dimers are mainly formed by hydroxyl radicals generated during the storage of methyl methacrylate, and component A1 suppresses the generation of hydroxyl radicals, thus inhibiting the formation of methyl methacrylate dimers. However, the dimerization reaction of methyl methacrylate also proceeds under basic conditions via an anionic mechanism. Ester compounds with α-hydrogens are weakly acidic and can trap anions, so component B2 can suppress the dimerization reaction of methyl methacrylate via the anionic mechanism. Therefore, it is thought that the coexistence of components A1 and B2 allows for the efficient suppression of the dimerization reaction of methyl methacrylate through different mechanisms. On the other hand, as mentioned above, methyl pyruvate is produced when methyl methacrylate is oxidized by hydroxyl radicals and oxygen molecules. Component A1 can suppress the generation of hydroxyl radicals, and component B2 can trap the radical intermediate produced by the reaction of hydroxyl radicals and methyl methacrylate, and convert the intermediate back to methyl methacrylate. Therefore, it is thought that the coexistence of components A1 and B2 can efficiently suppress the generation of methyl pyruvate. A preferred embodiment of component A1 is the same as that of the first embodiment.

[0083] (Component B2) A third embodiment of the methyl methacrylate-containing composition according to this embodiment includes an ester compound having an α-hydrogen represented by formula (3) (component B2). "α-hydrogen" refers to a hydrogen atom bonded to a carbon atom adjacent to a carbon atom of the carbonyl group.

[0084] The molecular weight of component B2 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 B2 can be increased, so that the effects of the present invention can be obtained with a small mass. The molecular weight of component B2 is more preferably 800 or less, even more preferably 600 or less, and particularly preferably 400 or less.

[0085] R in equation (3) above 9 and R 10 Each of these independently represents a monovalent group containing a hydrogen atom, an alkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an amino group, or a carbonyl group, or an alkylthio group. 9 and R 10 They may be the same or different. Also, R in formula (3) above 11 R represents an alkyl group or aryl group. 11 and R 9 , and R 11 and R 10 They may be the same or different. Also, R 9 and R 10 , R 10 and R 11 , R 11 and R 9 These may be connected to each other to form a ring.

[0086] 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. 9 , R 10 and R 11 When the above conditions are met, the reactivity of the α-hydrogen of component B2 with anions and radicals is maintained, and thus the effects of the present invention can be obtained. 9 and R 10Preferably, the substituent is a monovalent group having 1 to 6 carbon atoms, including a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, an amino group having 0 to 6 carbon atoms, or a carbonyl group, or an alkylthio group having 1 to 5 carbon atoms. Because these substituents are highly stable, they prevent component B2 from changing into other compounds during storage. Furthermore, their low electron-donating ability improves the acidity of the α-hydrogen of component B2. 9 and R 10 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. Also, R 11 Alky is a molecule with 1 to 5 carbon atoms. It is more preferable that the substituent be an aryl group or an aryl group having 1 to 12 carbon atoms. These are highly stable substituents and can prevent component B2 from changing to other compounds during storage. 11 It is more preferably an alkyl group having 1 to 5 carbon atoms, and even more preferably a methyl group.

[0087] Preferred forms of the alkyl group, alkenyl group, alkoxy group, amino group, monovalent group including carbonyl group, alkylthio group, and aryl group are the same as those in formula (1) above. R 9 and R 10 , R 10 and R 11 , R 11 and R 9 They may be connected to each other to form a ring. 9 and R 10 Examples of compounds in which these molecules are linked to form a ring include methyl cyclohexanecarboxylate and methyl cyclopentanecarboxylate. 10 and R 11 Compounds in which R is linked to form a ring, and 11 and R 9 Examples of compounds in which these molecules are linked to form a ring include α-methyl-δ-valerolactone and α-methyl-γ-butyrolactone.

[0088] Among the compounds that satisfy the above conditions, from the viewpoint of the quality stability during storage of the methyl methacrylate-containing composition, component B2 includes methyl isobutyrate, methyl propionate, 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, methyl acetate, ethyl acetate, phenyl acetate, ethyl propionate, ethyl isobutyrate, phenyl isobutyrate, methyl butyrate, and cyclohexanecal. Methyl benzoate, methyl cyclopentanecarboxylate, α-methyl-δ-valerolactone, or α-methyl-γ-butyrolactone are preferred, methyl isobutyrate, methyl propionate, isobutyl 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 methyl 2-methylbutyrate are even more preferred.

[0089] In the third embodiment of the methyl methacrylate-containing composition according to this embodiment, component B2 may be one type or two or more types. Furthermore, if a methyl methacrylate-containing composition contains a compound that corresponds to both component A1 and component B2, that compound shall be considered as component A1. In other words, the methyl methacrylate-containing composition must contain a component B2 that is different from that compound. Furthermore, if two or more compounds that correspond to both component A1 and component B2 are contained, the compound with the highest molar concentration in the methyl methacrylate-containing composition shall be considered as component A1, and the other compounds shall be considered as component B2.

[0090] (Concentrations of components A1 and B2) When the concentration of component B2 is MB2 (μmol / L), from the viewpoint of the efficiency of suppressing the formation of methyl pyruvate, MB2 / MA1 is preferably 0.01 or higher, more preferably 0.1 or higher, and even more preferably 0.5 or higher. Furthermore, the upper limit of MB2 / MA1 is preferably 1000 or less, more preferably 500 or less, even more preferably 100 or less, particularly preferably 50 or less, and most preferably 10 or less.

[0091] The preferred mode of MA1 is the same as that of the first mode.

[0092] The MB2 concentration is preferably 1 to 50,000 μmol / L. A MB2 concentration of 1 μmol / L or higher is sufficient to effectively suppress the formation of methyl methacrylate dimers and methyl pyruvate. Furthermore, an MB2 concentration of 50,000 μmol / L or lower is preferable. This reduces the amount of impurities when a methyl methacrylate polymer is produced by polymerization of the methyl methacrylate-containing composition according to this embodiment, thereby preventing adverse effects on the physical properties of the polymer. The lower limit of MB2 is more preferably 10 μmol / L or more, and even more preferably 50 μmol / L or more. The upper limit of MB2 is more preferably 30,000 μmol / L or less, and even more preferably 10,000 μmol / L or less.

[0093] (Concentration of methyl methacrylate) The preferred embodiment of the concentration of methyl methacrylate is the same as in the first embodiment.

[0094] (Component C) A preferred embodiment of component C is the same as that of the first embodiment.

[0095] (Analysis of methyl methacrylate-containing compositions) The method for confirming that a methyl methacrylate-containing composition contains component A1, component B2, component C, and water, and the method for measuring the concentrations of methyl methacrylate, component A1, component B2, component C, and water, are the same as in the first embodiment.

[0096] [Methyl methacrylate-containing composition 4] A fourth aspect of the methyl methacrylate-containing composition according to this embodiment is a methyl methacrylate-containing composition comprising methyl methacrylate, a pyrazine compound represented by the following formula (1) (component A1), and an α,β-unsaturated carbonyl compound represented by the following formula (4) (component B3), wherein the concentration of methyl methacrylate is 99 to 99.99% by mass.

[0097] [ka]

[0098] In the above equation (1), R 1 , R 2 , R 3 and R 4 Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, a carbonyl group (all monovalent), an alkylthio group, or an arylthio group.

[0099] [ka]

[0100] In the above equation (4), R 12 , R 13 and R 14 Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, a carbonyl group (monovalent group), an alkylthio group, or an arylthio group. 15 R represents a monovalent group including an alkyl group, alkenyl group, aryl group, hydroxyl group, alkoxy group, amino group, or carbonyl group, an alkylthio group, or an arylthio group. 12 and R 13 , R 13 and R 14 , R 14 and R 15 They may each be connected to each other to form a ring. However, R 12 =H and R 13=H and R 14 =CH3 and R 15 =OCH3 Except in the case where the α,β-unsaturated carbonyl compound represented by formula (4) is methyl methacrylate. H represents a hydrogen atom, C represents a carbon atom, and O represents an oxygen atom.

[0101] Furthermore, the methyl methacrylate-containing composition may also contain the aforementioned components B1 and B2, other compounds (component C), and water, as long as the concentration of methyl methacrylate satisfies 99 to 99.99% by mass. Each item will be explained in detail below.

[0102] (Methyl methacrylate) A fourth embodiment of the methacrylic acid-containing composition according to this embodiment includes methyl methacrylate. The preferred embodiment of methyl methacrylate is the same as that of the first embodiment.

[0103] (Component A1) A fourth aspect of the methyl methacrylate-containing composition according to this embodiment includes a pyrazine compound (component A1) represented by formula (1). The coexistence of component A1 and component B3, described later, can suppress the formation of methyl methacrylate dimer and methyl pyruvate. The reason for this is presumed to be as follows. As mentioned above, methyl methacrylate dimers and methyl pyruvate are generated by hydroxyl radicals that occur during the storage of methyl methacrylate. Component A1 absorbs ultraviolet light and suppresses the generation of hydroxyl radicals, thus suppressing the formation of methyl methacrylate dimers. On the other hand, the α,β-unsaturated carbonyl compound represented by formula (4) (component B3) also absorbs ultraviolet light because it has a conjugated double bond, but its absorption wavelength is different from that of component A1. Therefore, it is thought that the coexistence of component A1 and component B3 allows for the absorption of ultraviolet light across a wide range of wavelengths, thereby efficiently suppressing the generation of hydroxyl radicals. A preferred embodiment of component A1 is the same as that of the first embodiment.

[0104] (Component B3) A fourth aspect of the methyl methacrylate-containing composition according to this embodiment includes an α,β-unsaturated carbonyl compound (component B3) represented by formula (4).

[0105] The molecular weight of component B3 is preferably 1000 or less. By having a molecular weight of 1000 or less, the number of conjugated double bonds per unit mass in component B3 can be increased, so that the effects of the present invention can be obtained with a small mass. The molecular weight of component B3 is more preferably 800 or less, even more preferably 600 or less, and particularly preferably 400 or less.

[0106] R in equation (4) above 12 , R 13 and R 14 Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, a carbonyl group, a monovalent group, an alkylthio group, or an arylthio group. Also, in formula (4) above, R 15 R represents a monovalent group including an alkyl group, alkenyl group, aryl group, hydroxyl group, alkoxy group, amino group, or carbonyl group, an alkylthio group, or an arylthio group. 12 , R 13 , R 14 and R 15 These may be the same or different.

[0107] R 12 、 R 13 、 R 14 and R 15 When the above conditions are met, the π-conjugated system of component B3 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. 12 , R 13 and R 14Preferably, the substituent is 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 alkoxy group having 1 to 6 carbon atoms, an amino group having 0 to 6 carbon atoms, a carbonyl group, or a monovalent group having 1 to 6 carbon atoms, or an alkylthio group having 1 to 5 carbon atoms. Because these substituents are highly stable, they prevent component B3 from changing into other compounds during storage. Furthermore, when these substituents are present, a sufficient amount of ultraviolet light can be absorbed by one molecule of component B3. 12 , R 13 and R 14 It is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. More preferably, it is a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group.

[0108] Also, R 15 Preferably, the substituent is a monovalent group having 1 to 6 carbon atoms, including 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 hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, an amino group having 0 to 6 carbon atoms, or a carbonyl group, or an alkylthio group having 1 to 5 carbon atoms. Since these substituents are highly stable, they can prevent component A1 from changing into other compounds during storage. 15 R is more preferably an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms, and even more preferably a methyl group, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group or isopentoxy group. 15 When this structure is present, the quality stability of the methyl methacrylate-containing composition during storage can be improved.

[0109] Preferred forms of monovalent groups including alkyl groups, alkenyl groups, aryl groups, alkoxy groups, amino groups, and carbonyl groups, alkylthio groups, and arylthio groups are the same as those in formula (1) above. R 12 and R 13 , R 13 and R 14 , R14 and R 15 They may be connected to each other to form a ring. 12 and R 13 Examples of compounds in which these molecules are linked to form a ring include methyl 2-cyclohexylidenepropionate and methyl 2-cyclopentylidenepropionate. 13 and R 14 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. 14 and R 15 Examples of compounds in which these molecules link to form a ring include α-methyl Examples include n-δ-valerolactone and α-methylene-γ-butyrolactone.

[0110] Among the compounds that satisfy the above conditions, from the viewpoint of quality stability during storage of methyl methacrylate-containing compositions, the following are considered as component B3: methyl acrylate, butyl acrylate, ethyl methacrylate, methyl crotonic acid, cis-methyl crotonic acid, isobutyl methacrylate, butyl methacrylate, propyl methacrylate, isopentyl methacrylate, methyl 2-methylene-3-butenate, methyl 3,3-dimethylacrylate, methyl 2-ethylacrylate, methyl 2-pentenoate, methyl cinnamate, methyl 3-methoxyacrylate Dimethyl fumarate, methacrylamide, acrylic acid, methacrylic acid, crotonic acid, cis-crotonic acid, 3,3-dimethylacrylic acid, 2-ethylacrylic acid, 2-methylene-3-butenoic acid, trans-3-hexen-2-one, isopropenylmethyl ketone, methyl 2-cyclohexylidenepropionate, methyl 2-cyclopentylidenepropionate, methyl 1-cyclohexen-1-carboxylate, methyl 1-cyclopentene-1-carboxylate, α-methylene-δ-valerolactone, α-methylene-γ-butyrate Lolactone or isopropenylmethyl ketone is preferred, along with methyl acrylate, butyl acrylate, ethyl methacrylate, methyl crotate, cis-methyl crotate, isobutyl methacrylate, butyl methacrylate, propyl methacrylate, isopentyl methacrylate, methyl 2-methylene-3-butenate, methyl 3,3-dimethylacrylate, methyl 2-ethylacrylate, methyl 2-pentenoate, methyl cinnamate, methyl 3-methoxyacrylate, dimethyl fumarate, and 1-cyclohexene-1-carboxylic acid Tyl, methacrylamide, acrylic acid, methacrylic acid, crotonic acid, cis-crotonic acid, 3,3-dimethylacrylic acid, 2-ethylacrylic acid, 2-methylene-3-butenic acid, trans-3-hexen-2-one, or isopropenylmethyl ketone are more preferred, and methyl acrylate, ethyl methacrylate, methyl crotonic acid, isobutyl methacrylate, butyl methacrylate, propyl methacrylate, isopentyl methacrylate, methyl 3,3-dimethylacrylate, and isopropenylmethyl ketone are even more preferred.

[0111] In the fourth embodiment of the methyl methacrylate-containing composition according to this embodiment, component B3 may be one type or two or more types. Furthermore, if a methyl methacrylate-containing composition contains a compound that corresponds to both component A1 and component B3, that compound shall be considered as component A1. In other words, the methyl methacrylate-containing composition must contain a component B3 that is different from that compound. Furthermore, if two or more compounds that correspond to both component A1 and component B3 are contained, the compound with the highest molar concentration in the methyl methacrylate-containing composition shall be considered as component A1, and the other compounds shall be considered as component B3.

[0112] (Concentrations of components A1 and B3) When the concentration of component B3 is MB3 (μmol / L), from the viewpoint of the efficiency of suppressing the formation of methyl pyruvate, the MB3 / MA1 ratio is preferably 0.01 or higher, more preferably 0.1 or higher, and even more preferably 0.5 or higher. Furthermore, the upper limit of MB3 / MA1 is preferably 1000 or less, more preferably 500 or less, even more preferably 100 or less, particularly preferably 50 or less, and most preferably 10 or less.

[0113] The preferred mode of MA1 is the same as that of the first mode.

[0114] The MB3 concentration is preferably 1 to 85,000 μmol / L. An MB3 concentration of 1 μmol / L or higher is sufficient to suppress the formation of methyl methacrylate dimers and methyl pyruvate. Furthermore, an MB3 concentration of 85,000 μmol / L or lower reduces the amount of impurities when a methyl methacrylate polymer is produced by polymerization of the methyl methacrylate-containing composition according to this embodiment, preventing adverse effects on the properties of the polymer. The lower limit of MB3 is more preferably 10 μmol / L or higher, and even more preferably 50 μmol / L or higher. The upper limit of MB3 is more preferably 40,000 μmol / L or lower, even more preferably 20,000 μmol / L or lower, and particularly preferably 15,000 μmol / L or lower.

[0115] (Concentration of methyl methacrylate) The preferred embodiment of the concentration of methyl methacrylate is the same as in the first embodiment.

[0116] (Component C) A preferred embodiment of component C is the same as that of the first embodiment.

[0117] (Analysis of methyl methacrylate-containing compositions) The method for confirming that a methyl methacrylate-containing composition contains component A1, component B3, component C, and water, and the method for measuring the concentrations of methyl methacrylate, component A1, component B3, component C, and water, are the same as in the first embodiment.

[0118] [Method for producing a methyl methacrylate-containing composition] A method for producing the methyl methacrylate-containing composition according to this embodiment includes adding component A1 or component A2 (hereinafter collectively referred to as "component A") and component B1, component B2, or component B3 (hereinafter collectively referred to as "component B") to methyl methacrylate. Methyl methacrylate may be a commercially available product, or methyl methacrylate produced by known methods such as the acetone cyanohydrin (ACH) method, the new acetone cyanohydrin (new ACH) method, the C4 direct oxidation method, the direct methacrylate method, the ethylene method, or the new ethylene method may be used. Components A and B may be commercially available products, or synthesized by known methods. When using methyl methacrylate produced by known methods such as the acetone cyanohydrin (ACH) method, the new acetone cyanohydrin (new ACH) method, the C4 direct oxidation method, the direct methacrylate method, the ethylene method, or the new ethylene method, component A or component B may be used as raw materials or in the manufacturing process. The methyl methacrylate-containing composition may be produced by adding it during the process. Furthermore, if component A or component B is produced as a by-product in the methyl methacrylate production process, the methyl methacrylate-containing composition may be produced by leaving a portion of the produced component A or component B.

[0119] [Methods for evaluating storage stability and thermal stability] The methyl methacrylate-containing composition according to this embodiment exhibits high quality stability during storage. Methods for evaluating the quality stability of the methyl methacrylate-containing composition during storage include, for example, actually storing the methyl methacrylate-containing composition for a long period and confirming the amount of methyl methacrylate dimer and methyl pyruvate produced. Alternatively, from the viewpoint of ease of operation, a method of heating the methyl methacrylate-containing composition for a short time and confirming the amount of methyl methacrylate dimer and methyl pyruvate produced may be used. When 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 this invention, the quality stability of the methyl methacrylate-containing composition during storage is evaluated based on the amount of methyl methacrylate dimer and methyl pyruvate produced when the methyl methacrylate-containing composition is stored at 25°C for 14 days.

[0120] [Method for storing methyl methacrylate-containing compositions] The storage method for the methyl methacrylate-containing composition according to this embodiment is to store the methyl methacrylate-containing composition according to this embodiment at 0 to 50°C. The lower limit of the storage temperature is preferably 5°C or higher. The upper limit of the storage temperature is preferably 45°C or lower, and more preferably 40°C or lower. The storage period is not particularly limited, and is suitable for storing, for example, a methyl methacrylate-containing composition for one day or more, but may be stored for seven days or more, or for 30 days or more. The upper limit of the storage period is not particularly limited, but is preferably three years or less, more preferably one year or less, and even more preferably ninety days or less.

[0121] [Methacrylate Polymer Production Method] The method for producing a methyl methacrylate polymer according to this embodiment includes a step of polymerizing a polymerizable composition containing the methyl methacrylate-containing composition according to this embodiment.

[0122] <Polymerizable composition> The polymerizable composition may optionally contain monomers copolymerizable with methyl methacrylate and other additives.

[0123] (A monomer copolymerizable with methyl methacrylate) Examples of monomers copolymerizable with methyl methacrylate include the following: Methacrylic acid esters such as ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, 2-ethylhexyl methacrylate, phenyl methacrylate, or benzyl methacrylate; Acrylic acid esters such as methyl acrylate, ethyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, or 2-ethylhexyl acrylate; Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, or itaconic acid; Unsaturated carboxylic acid anhydrides such as maleic anhydride or itaconic anhydride; Maleimides such as N-phenylmaleimide or N-cyclohexylmaleimide; 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, or 2-hydroxypropyl methacrylate, or other hydroxyl group-containing vinyl monomers; Vinyl esters such as vinyl acetate or vinyl benzoate; Vinyl chloride, vinylidene chloride, and their derivatives; Nitrogen-containing vinyl monomers such as methacrylamide or acrylonitrile; Epoxy group-containing monomers such as glycidyl acrylate or glycidyl methacrylate; Aromatic vinyl monomers such as styrene or α-methylstyrene; Alkane diol di(meth)acrylates such as ethylene glycol di(meth)acrylate, 1,2-propylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, or 1,6-hexanediol di(meth)acrylate; Polyoxyalkylene glycol di(meth)acrylates such as diethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, triethylene glycol (meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, or neopentyl glycol di(meth)acrylate; Vinyl monomers having two or more ethylenically unsaturated bonds in their molecules, such as divinylbenzene; Unsaturated polyester prepolymer obtained from at least one polycarboxylic acid containing an ethylenically unsaturated polycarboxylic acid and at least one diol; Vinyl ester prepolymer obtained by modifying the ends of epoxy groups with acrylic;

[0124] Among the above, the monomer copolymerizable with methyl methacrylate is preferably at least one selected from the group consisting of methacrylic acid esters and acrylic acid esters. This makes it possible to obtain a methyl methacrylate polymer with an excellent balance of transparency, heat resistance, and moldability by polymerizing the polymerizable composition. The monomer copolymerizable with methyl methacrylate is more preferably an acrylic acid ester, and is particularly preferably at least one selected from the group consisting of methyl acrylate, ethyl acrylate, and n-butyl acrylate.

[0125] The monomer copolymerizable with methyl methacrylate may be one type or two or more types. Furthermore, if component A or component B is a monomer copolymerizable with methyl methacrylate, component A or component B may be used as the monomer copolymerizable with methyl methacrylate, or a monomer copolymerizable with methyl methacrylate may be used separately from component A or component B.

[0126] In polymerizable compositions, the lower limit of the content of monomers copolymerizable with methyl methacrylate is preferably 0.01 parts by mass or more per 100 parts by mass of methyl methacrylate. This makes it possible to obtain a highly transparent methyl methacrylate polymer. The upper limit of the content of monomers copolymerizable with methyl methacrylate 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 per 100 parts by mass of methyl methacrylate. The lower limit of the content of monomers copolymerizable with methyl methacrylate is 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 methyl methacrylate.

[0127] (Other additives) Other additives preferably include polymerization initiators. Additionally, 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, fluorescent agents, etc. The other additives may be one type or two or more types.

[0128] Examples of polymerization initiators include the following: Azo compounds such as 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; 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, t-hexylperoxyisopropyl monocarbonate, t-hexyl peroxy Organic peroxides such as -oxy-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; Persulfate compounds such as potassium persulfate; Redox polymerization initiators;

[0129] Among the above, from the viewpoint of storage stability and reactivity with methyl methacrylate and copolymerizable monomers, the polymerization initiator is preferably at least one selected from the group consisting of azo compounds and organic peroxides. The amount of polymerization initiator used is preferably 0.0001 to 1 part by mass per 100 parts by mass of methyl methacrylate and monomers copolymerizable with methyl methacrylate.

[0130] <Method for polymerizing polymerizable compositions> Polymerization methods include, 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 methyl methacrylate polymer.

[0131] The specific methods for bulk polymerization are not particularly limited, but it can be manufactured using known casting polymerization methods such as the cell casting method or the continuous casting method. Cast polymerization is a method for obtaining a methyl methacrylate 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.

[0132] The mold for casting polymerization is not particularly limited, and known molds can be used. Examples of molds for cell casting include those in which two plate-like bodies such as inorganic glass plates, chrome-plated metal plates, and stainless steel plates are placed facing each other at a predetermined distance, and gaskets are placed on the edges thereof to form a sealed space with the plate-like bodies and gaskets. Examples of molds for continuous casting include those in which a sealed space is formed by 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.

[0133] The polymerization temperature is preferably 70 to 210°C. This allows for obtaining an appropriate polymerization rate. The lower limit of the polymerization temperature is more preferably 80°C or higher, even more preferably 100°C or higher, particularly preferably 125°C or higher, and most preferably 130°C or higher. The upper limit is more preferably 180°C or lower, and even more preferably 150°C or lower. The polymerization time is not particularly limited, for example, 0.5 to It can be set to 24 hours. [Examples]

[0134] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. Unless otherwise specified, "%" and "ppm" in the examples and comparative examples mean "weight percent" and "weight ppm". The water concentration in the methyl methacrylate reagent was calculated using the Karl Fischer method. The composition of the methyl methacrylate-containing composition before storage was calculated from the amount of each raw material added. After storage, the methyl methacrylate dimer and methyl pyruvate in the methyl methacrylate-containing composition were quantified using GC-MS with an absolute calibration curve. The GC-MS measurement conditions are shown below.

[0135] Equipment: GC-MS measurement equipment (product name: QP-2010SE, manufactured by Shimadzu Corporation) [GC conditions] Column (Product name: DB-WAX, manufactured by Agilent Technologies) Length: 60m, Inner diameter: 0.32mm, Film thickness: 1.00μm Injection volume: 1.0μL Evaporation chamber temperature: 210℃ Column oven temperature: Hold at 35°C for 10 minutes, increase temperature from 35°C to 150°C at a rate of 5°C / min, hold at 150°C for 17 minutes, increase temperature from 150°C to 220°C at a rate of 5°C / min, hold at 220°C for 6 minutes. Carrier gas: Helium Injection mode: Split (Split ratio 50) Control mode: Constant linear velocity (25.0 cm / sec) Pressure: 26.1 kPa Total flow: 52.5mL / min Purge flow rate: 3.0 mL / min Column flow rate: 0.97 mL / min

[0136] [MS conditions] Ionization method: EI (Electron Ionization) Ion source temperature: 250℃ Interface temperature: 250℃ m / z detection range: 10-300 Detection time: 70 minutes The moisture concentration was quantified using the Karl Fischer method with an automated moisture analyzer (product name: AQV-2200, manufactured by Hiranuma Sangyo Co., Ltd.).

[0137] (Example 1) Using 2,3,5,6-tetramethylpyrazine as component A, 0.0214 g of component A was added to 10.0196 g of reagent methyl methacrylate (water concentration 240 ppm) to prepare a methyl methacrylate solution (Solution A-1). The concentration of component A in Solution A-1 is shown in Table 1. Using 2,4-dimethyl-6-t-butylphenol as component B, 0.0829 g of component B was added to 40.0221 g of reagent methyl methacrylate (water concentration 240 ppm) to prepare a methyl methacrylate solution (Solution B-1). The concentration of component B in Solution B-1 is shown in Table 1. Next, 0.1017 g of Solution A-1 and 0.1016 g of Solution B-1 were added to 20.0861 g of reagent methyl methacrylate (water concentration 240 ppm) to prepare a methyl methacrylate-containing composition. The concentrations of each component in the methyl methacrylate-containing composition are shown in Table 3. In Table 3, MA1 and MA2 are collectively referred to as "MA," and MB1, MB2, and MB3 are referred to as " They are collectively referred to as "MB". The obtained methyl methacrylate-containing composition was stored at 25°C for 14 days. Table 3 shows the amounts of methyl methacrylate dimer and methyl pyruvate produced in the methyl methacrylate-containing composition after storage.

[0138] (Examples 2-6) Solution A-1 was prepared in the same manner as in Example 1, except that the compound shown in Table 1 was used as component A, and the amounts of methyl methacrylate and component A in the reagent were changed as shown in Table 1. Solution B-1 was prepared using the same method as in Example 1. Next, a methyl methacrylate-containing composition was prepared in the same manner as in Example 1, except that the amounts of methyl methacrylate, solution A-1, and solution B-1 were changed as shown in Table 2. The concentrations of each component in the methyl methacrylate-containing composition are shown in Table 3. The obtained methyl methacrylate-containing composition was stored in the same manner as in Example 1. The amounts of methyl methacrylate dimer and methyl pyruvate formed in the methyl methacrylate-containing composition after storage are shown in Table 3.

[0139] (Examples 7 to 9) An A-1 solution was prepared in the same manner as in Example 1, except that the compounds shown in Table 1 were used as Component A and the amounts of methyl methacrylate as the reagent and Component A were changed as shown in Table 1. A B-1 solution was prepared in the same manner as in Example 1, except that the amounts of methyl methacrylate as the reagent and Component B were changed as shown in Table 1. Next, a methyl methacrylate-containing composition was prepared in the same manner as in Example 1, except that the amounts of methyl methacrylate as the reagent, the A-1 solution, and the B-1 solution were changed as shown in Table 2. The concentrations of each component in the methyl methacrylate-containing composition are shown in Table 3. The obtained methyl methacrylate-containing composition was stored in the same manner as in Example 1. The amounts of methyl methacrylate dimer and methyl pyruvate formed in the methyl methacrylate-containing composition after storage are shown in Table 3.

[0140] (Examples 10 to 17) An A-1 solution was prepared in the same manner as in Example 1. A B-1 solution was prepared in the same manner as in Example 1, except that the compounds shown in Table 1 were used as Component B and the amounts of methyl methacrylate as the reagent and Component B were changed as shown in Table 1. Next, a methyl methacrylate-containing composition was prepared in the same manner as in Example 1, except that the amounts of methyl methacrylate as the reagent, the A-1 solution, and the B-1 solution were changed as shown in Table 2. The concentrations of each component in the methyl methacrylate-containing composition are shown in Table 3. The obtained methyl methacrylate-containing composition was stored in the same manner as in Example 1. The amounts of methyl methacrylate dimer and methyl pyruvate formed in the methyl methacrylate-containing composition after storage are shown in Table 3.

[0141] (Example 18) A B-1 solution was prepared in the same manner as in Example 1. Next, using 2,3,5,6-tetramethylpyrazine as component A, 0.0210 g of component A and 0.1021 g of solution B-1 were added to 20.0176 g of reagent methyl methacrylate (water concentration 240 ppm) to prepare a methyl methacrylate-containing composition. The concentrations of each component in the methyl methacrylate-containing composition are shown in Table 3. The obtained methyl methacrylate-containing composition was stored in the same manner as in Example 1. Table 3 shows the amounts of methyl methacrylate dimer and methyl pyruvate produced in the methyl methacrylate-containing composition after storage.

[0142] (Example 19) Solution B-1 was prepared using the same method as in Example 1. Next, a methyl methacrylate-containing composition was prepared in the same manner as in Example 18, except that the amounts of methyl methacrylate, component A, and B-1 solution were changed as shown in Table 2. The concentrations of each component in the methyl methacrylate-containing composition are shown in Table 3. The obtained methyl methacrylate-containing composition was stored in the same manner as in Example 1. Table 3 shows the amounts of methyl methacrylate dimer and methyl pyruvate produced in the methyl methacrylate-containing composition after storage.

[0143] (Example 20) Solution A-1 and Solution B-1 were prepared in the same manner as in Example 1. Next, a methyl methacrylate-containing composition was prepared in the same manner as in Example 1, except that the amounts of methyl methacrylate, solution A-1, and solution B-1 were changed as shown in Table 2. The concentrations of each component in the methyl methacrylate-containing composition are shown in Table 3. The obtained methyl methacrylate-containing composition was stored in the same manner as in Example 1. Table 3 shows the amounts of methyl methacrylate dimer and methyl pyruvate produced in the methyl methacrylate-containing composition after storage.

[0144] (Examples 21-22) Solution A-1 was prepared using the same method as in Example 1. Solution B-1 was prepared in the same manner as in Example 1, except that the amounts of methyl methacrylate and component B in the reagent were changed as shown in Table 1. Next, a methyl methacrylate-containing composition was prepared in the same manner as in Example 1, except that the amounts of methyl methacrylate, solution A-1, and solution B-1 were changed as shown in Table 2. The concentrations of each component in the methyl methacrylate-containing composition are shown in Table 3. The obtained methyl methacrylate-containing composition was stored in the same manner as in Example 1. Table 3 shows the amounts of methyl methacrylate dimer and methyl pyruvate produced in the methyl methacrylate-containing composition after storage.

[0145] (Example 23) Solution A-1 was prepared using the same method as in Example 1. Next, 0.1025 g of Solution A-1 was added to 20.0016 g of reagent methyl methacrylate (water concentration 240 ppm) to prepare a methyl methacrylate-containing composition. The concentrations of each component in the methyl methacrylate-containing composition are shown in Table 3. The obtained methyl methacrylate-containing composition was stored in the same manner as in Example 1. Table 3 shows the amounts of methyl methacrylate dimer and methyl pyruvate produced in the methyl methacrylate-containing composition after storage.

[0146] (Example 24) Solution A-1 was prepared in the same manner as in Example 1, except that the compound shown in Table 1 was used as component A, and the amounts of methyl methacrylate and component A in the reagent were changed as shown in Table 1. Solution B-1 was prepared in the same manner as in Example 1, except that the amounts of methyl methacrylate and component B in the reagent were changed as shown in Table 1. Next, a methyl methacrylate-containing composition was prepared in the same manner as in Example 1, except that the amounts of methyl methacrylate, solution A-1, and solution B-1 were changed as shown in Table 2. The concentrations of each component in the methyl methacrylate-containing composition are shown in Table 3. The obtained methyl methacrylate-containing composition was stored in the same manner as in Example 1. Table 3 shows the amounts of methyl methacrylate dimer and methyl pyruvate produced in the methyl methacrylate-containing composition after storage.

[0147] (Examples 25-26) Solution A-1 was prepared in the same manner as in Example 1, except that the compound shown in Table 1 was used as component A, and the amounts of methyl methacrylate and component A in the reagent were changed as shown in Table 1. Next, a methyl methacrylate-containing compound was prepared in the same manner as in Example 23, except that the amounts of methyl methacrylate and solution A-1 were changed as shown in Table 2. The concentrations of each component in the methyl methacrylate-containing composition are shown in Table 3. The obtained methyl methacrylate-containing composition was stored in the same manner as in Example 1. Table 3 shows the amounts of methyl methacrylate dimer and methyl pyruvate produced in the methyl methacrylate-containing composition after storage.

[0148] (Examples 27-29) Solution A-1 was prepared using the same method as in Example 1. Solution B-1 was prepared in the same manner as in Example 1, except that the compound shown in Table 1 was used as component B, and the amounts of methyl methacrylate and component B in the reagent were changed as shown in Table 1. Next, a methyl methacrylate-containing composition was prepared in the same manner as in Example 1, except that the amounts of methyl methacrylate, solution A-1, and solution B-1 were changed as shown in Table 2. The concentrations of each component in the methyl methacrylate-containing composition are shown in Table 3. The obtained methyl methacrylate-containing composition was stored in the same manner as in Example 1. Table 3 shows the amounts of methyl methacrylate dimer and methyl pyruvate produced in the methyl methacrylate-containing composition after storage.

[0149] (Examples 30-33) Solution A-1 was prepared in the same manner as in Example 1, except that the compound shown in Table 1 was used as component A, and the amounts of methyl methacrylate and component A in the reagent were changed as shown in Table 1. Solution B-1 was prepared in the same manner as in Example 1, except that the compound shown in Table 1 was used as component B, and the amounts of methyl methacrylate and component B in the reagent were changed as shown in Table 1. Next, a methyl methacrylate-containing composition was prepared in the same manner as in Example 1, except that the amounts of methyl methacrylate, Solution A-1, and Solution B-1 of the reagent were changed as shown in Table 2. The concentrations of each component in the methyl methacrylate-containing composition are shown in Table 3. The obtained methyl methacrylate-containing composition was stored in the same manner as in Example 1. The amounts of methyl methacrylate dimer and methyl pyruvate produced in the methyl methacrylate-containing composition after the storage are shown in Table 3.

[0150] (Comparative Example 1) Solution B-1 was prepared in the same manner as in Example 1, except that the amounts of methyl methacrylate and Component B of the reagent were changed as shown in Table 1. Next, 0.2213 g of Solution B-1 was added to 40.0273 g of methyl methacrylate (water concentration 240 ppm) of the reagent to prepare a methyl methacrylate-containing composition. The concentrations of each component in the methyl methacrylate-containing composition are shown in Table 3. The obtained methyl methacrylate-containing composition was stored in the same manner as in Example 1. The amounts of methyl methacrylate dimer and methyl pyruvate produced in the methyl methacrylate-containing composition after the storage are shown in Table 3.

[0151] (Comparative Example 2) 40.0000 g of methyl methacrylate (water concentration 240 ppm) of the reagent was used as a methyl methacrylate-containing composition and stored in the same manner as in Example 1. The amounts of methyl methacrylate dimer and methyl pyruvate produced in the methyl methacrylate-containing composition after the storage are shown in Table 3.

[0152] (Comparative Example 3) Solution B-1 was prepared in the same manner as in Comparative Example 1. Using diacetyl as Component C, 0.0205 g of Component C was added to 9.9913 g of methyl methacrylate (water concentration 240 ppm) of the reagent to prepare a methyl methacrylate solution (Solution C-1). The concentration of Component C in the Solution C-1 is shown in Table 1. Next, 0.2151 g of solution B-1 and 0.2069 g of solution C-1 were added to 40.0218 g of reagent methyl methacrylate (water concentration 240 ppm) to prepare a methyl methacrylate-containing composition. The concentrations of each component in the methyl methacrylate-containing composition are shown in Table 3. The obtained methyl methacrylate-containing composition was stored in the same manner as in Example 1. Table 3 shows the amounts of methyl methacrylate dimer and methyl pyruvate produced in the methyl methacrylate-containing composition after storage.

[0153] (Comparative Example 4) Solution B-1 was prepared using the same method as in Example 1. Next, a methyl methacrylate-containing composition was prepared in the same manner as in Example 18, except that the amounts of methyl methacrylate, component A, and B-1 solution were changed as shown in Table 2. The concentrations of each component in the methyl methacrylate-containing composition are shown in Table 3. The obtained methyl methacrylate-containing composition was stored in the same manner as in Example 1. Table 3 shows the amounts of methyl methacrylate dimer and methyl pyruvate produced in the methyl methacrylate-containing composition after storage.

[0154] (Comparative Example 5) Solution A-1 and Solution B-1 were prepared in the same manner as in Example 1. Next, 0.0980 g of Solution A-1, 0.1014 g of Solution B-1, and 0.2940 g of pure water were added to 20.0017 g of reagent methyl methacrylate (water concentration 240 ppm) to prepare a methyl methacrylate-containing composition. The concentrations of each component in the methyl methacrylate-containing composition are shown in Table 3. The obtained methyl methacrylate-containing composition was stored in the same manner as in Example 1. Table 3 shows the amounts of methyl methacrylate dimer and methyl pyruvate produced in the methyl methacrylate-containing composition after storage.

[0155] (Comparative Example 6) Solution A-1 was prepared in the same manner as in Example 24. Next, a methyl methacrylate-containing composition was prepared in the same manner as in Example 23, except that the amounts of methyl methacrylate and solution A-1 were changed as shown in Table 2. The concentrations of each component in the methyl methacrylate-containing composition are shown in Table 3. The obtained methyl methacrylate-containing composition was stored in the same manner as in Example 1. Table 3 shows the amounts of methyl methacrylate dimer and methyl pyruvate produced in the methyl methacrylate-containing composition after storage.

[0156] [Table 1]

[0157] [Table 2]

[0158] [Table 3]

[0159] As shown in Tables 1, 2, and 3, Examples 1 to 33, in which the methyl methacrylate-containing composition contains the specified components A and B, show suppressed formation of both methyl methacrylate dimer and methyl pyruvate in the methyl methacrylate-containing composition after storage, indicating high quality stability during storage. Furthermore, Examples 23, 25, and 26, which contain the component corresponding to component A2, also show suppressed formation of both methyl methacrylate dimer and methyl pyruvate in the methyl methacrylate-containing composition after storage, even without containing component B, indicating high quality stability during storage. Furthermore, polymerizable composition containing the methyl methacrylate-containing composition obtained in this embodiment is polymerized. By doing so, a methyl methacrylate polymer can be obtained. [Industrial applicability]

[0160] According to the present invention, a methyl methacrylate-containing composition that can be used as a raw material for acrylic resins, etc., can be stored stably for a long period of time, making it industrially useful.

Claims

1. A methyl methacrylate-containing composition comprising methyl methacrylate and a pyrazine compound represented by the following formula (2) (component A2), A methyl methacrylate-containing composition having a methyl methacrylate concentration of 99 to 99.99% by mass. 【Chemistry 1】 (In the above formula (2), R ５ , R ６ , R ７ and R ８ Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group having three or more carbon atoms, an aryl group, a hydroxyl group, an amino group, a formyl group, an acyl group, a carboxyl group, an amide group, an alkoxycarbonyl group, a thiocarboxyl group, a thioester group, an alkylthio group, or an arylthio group.

2. The methyl methacrylate-containing composition according to claim 1, wherein the concentration of component A2 is MA2 (μmol / L), and MA2 is 1 to 65,000 μmol / L.

3. The methyl methacrylate-containing composition according to claim 2, wherein the MA2 is 10 to 30,000 μmol / L.

4. The methyl methacrylate-containing composition according to claim 1, wherein the molecular weight of component A2 is 1000 or less.

5. In the above formula (2), R ５ , R ６ , R ７ and R ８ The methyl methacrylate-containing composition according to claim 1, wherein each of these is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 3 to 5 carbon atoms, an aryl group having 1 to 12 carbon atoms, an amino group having 0 to 6 carbon atoms, a formyl group, an acyl group, a carboxyl group, an amide group, an alkoxycarbonyl group, a thiocarboxyl group, a thioester group, an alkylthio group having 1 to 5 carbon atoms, or an arylthio group having 6 to 10 carbon atoms.

6. In the formula (2), R ５ , R ６ , R ７ and R ８ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. The methyl methacrylate-containing composition according to claim 1.

7. In the above formula (2), R ５ , R ６ , R ７ and R ８ The methyl methacrylate-containing composition according to claim 1, wherein each of them is independently a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group.

8. The methyl methacrylate-containing composition according to claim 1, wherein the concentration of methyl methacrylate is 99.8 to 99.99% by mass.

9. The methyl methacrylate-containing composition according to claim 1, wherein it does not contain diacetyl, or the concentration of diacetyl contained is 55 μmol / L or less.

10. A methacrylic acid comprising methyl methacrylate, a pyrazine compound represented by the following formula (1) (component A1), and an ester compound having an α-hydrogen represented by the following formula (3) (component B2). A methyl acid-containing composition, A methyl methacrylate-containing composition having a methyl methacrylate concentration of 99 to 99.99% by mass. 【Chemistry 2】 (In the above formula (1), R １ , R ２ , R ３ and R ４ Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an amino group, a formyl group, an acyl group, a carboxyl group, an amide group, an alkoxycarbonyl group, a thiocarboxyl group, a thioester group, an alkylthio group, or an arylthio group. 【Transformation 3】 (In the above formula (3), R ９ and R １０ Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group, a hydroxyl group, an alkoxy group, an amino group, a formyl group, an acyl group, a carboxyl group, an amide group, an alkoxycarbonyl group, a thiocarboxyl group, a thioester group, or an alkylthio group. １１ R represents an alkyl group or aryl group. ９ and R １０ , R １０ and R １１ , R １１ and R ９ (These may be connected to each other to form a ring.)

11. The methyl methacrylate-containing composition according to claim 10, wherein when the concentration of component A1 is MA1 (μmol / L) and the concentration of component B2 is MB2 (μmol / L), MB2 / MA1 is 0.01 to 1000.

12. The methyl methacrylate-containing composition according to claim 10, wherein the concentration of component A1 is MA1 (μmol / L), and MA1 is 1 to 65,000 μmol / L.

13. The methyl methacrylate-containing composition according to claim 10, wherein the concentration of component B2 is MB2 (μmol / L), and MB2 is 1 to 50,000 μmol / L.

14. In the above formula (3), R ９ and R １０ Each of these is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, an amino group having 0 to 6 carbon atoms, a formyl group, an acyl group, a carboxyl group, an amide group, an alkoxycarbonyl group, a thiocarboxyl group, a thioester group, or an alkylthio group having 1 to 5 carbon atoms, R １１ The methyl methacrylate-containing composition according to claim 10, wherein is an alkyl group having 1 to 5 carbon atoms or an aryl group having 1 to 12 carbon atoms.

15. The methyl methacrylate-containing composition according to claim 10, wherein the concentration of methyl methacrylate is 99.8 to 99.99% by mass.

16. A methacrylate comprising methyl methacrylate, a pyrazine compound represented by the following formula (1) (component A1), and an α,β-unsaturated carbonyl compound represented by the following formula (4) (component B3), A methyl methylate-containing composition, A methyl methacrylate-containing composition having a methyl methacrylate concentration of 99 to 99.99% by mass. 【Chemistry 4】 (In the above formula (1), R １ , R ２ , R ３ and R ４ Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an amino group, a formyl group, an acyl group, a carboxyl group, an amide group, an alkoxycarbonyl group, a thiocarboxyl group, a thioester group, an alkylthio group, or an arylthio group. 【Transformation 5】 (In the above formula (4), R １２ , R １３ and R １４ Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a hydroxyl group, an alkoxy group, an amino group, a formyl group, an acyl group, a carboxyl group, an amide group, an alkoxycarbonyl group, a thiocarboxyl group, a thioester group, an alkylthio group, or an arylthio group. １５ R represents an alkyl group, alkenyl group, aryl group, hydroxyl group, alkoxy group, amino group, formyl group, acyl group, carboxyl group, amide group, alkoxycarbonyl group, thiocarboxyl group, thioester group, alkylthio group, or arylthio group. １２ and R １３ , R １３ and R １４ , R １４ and R １５ They may each be connected to each other to form a ring. However, R １２ = H, R １３ = H, R １４ =CH ３ And R １５ = OCH ３ Except in the case where the α,β-unsaturated carbonyl compound represented by formula (4) is methyl methacrylate. (H represents a hydrogen atom, C represents a carbon atom, and O represents an oxygen atom.)

17. The methyl methacrylate-containing composition according to claim 16, wherein when the concentration of component A1 is MA1 (μmol / L) and the concentration of component B3 is MB3 (μmol / L), MB3 / MA1 is 0.01 to 1000.

18. The methyl methacrylate-containing composition according to claim 16, wherein the concentration of component A1 is MA1 (μmol / L), and MA1 is 1 to 65,000 μmol / L.

19. The methyl methacrylate-containing composition according to claim 16, wherein the concentration of component B3 is MB3 (μmol / L), and MB3 is 1 to 85,000 μmol / L.

20. In the above formula (4), R １２ , R １３ and R １４ Each of these is independently 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 alkoxy group having 1 to 6 carbon atoms, an amino group having 0 to 6 carbon atoms, a formyl group, an acyl group, a carboxyl group, an amide group, an alkoxycarbonyl group, a thiocarboxyl group, a thioester group, or an alkylthio group having 1 to 5 carbon atoms, R １５ is a carbon atom number of 1 to 5 The methyl methacrylate-containing composition according to claim 16, wherein the group is an alkyl group, an alkenyl group having 2 to 5 carbon atoms, an aryl group having 1 to 12 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, an amino group having 0 to 6 carbon atoms, a formyl group, an acyl group, a carboxyl group, an amide group, an alkoxycarbonyl group, a thiocarboxyl group, a thioester group, or an alkylthio group having 1 to 5 carbon atoms.

21. The methyl methacrylate-containing composition according to claim 16, wherein the concentration of methyl methacrylate is 99.8 to 99.99% by mass.

22. A method for storing a methyl methacrylate-containing composition according to any one of claims 1 to 21, wherein the composition is stored at 0 to 50°C.

23. A method for producing a methyl methacrylate polymer, comprising the step of polymerizing a polymerizable composition containing the methyl methacrylate-containing composition described in any one of claims 1 to 21.

24. The method for producing a methyl methacrylate polymer according to claim 23, wherein the polymerizable composition comprises a monomer copolymerizable with methyl methacrylate.

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