Monomer composition

Abstract

To provide a monomer composition comprising cyclocarbonate (meth)acrylate and glycerin tri(meth)acrylate that prevents the decomposition of glycerin tri(meth)acrylate during high-temperature storage and suppresses discoloration and thickening. [Solution] A monomer composition characterized by containing 94 to 99.8% by mass of a cyclocarbonate-containing (meth)acrylate (A) represented by formula (1), 0.01 to 5% by mass of glycerin tri(meth)acrylate (B), 0.001 to 0.5% by mass of a hydroxycarboxylic acid or its salt (C) with a molecular weight of 500 or less, and 0.0001 to 0.5% by mass of a polymerization inhibitor (D). JPEG2026047828000010.jpg3599 (In formula (1), R 1 is H or CH3, and R 2 is H or an alkyl group having 1 to 4 carbon atoms, R 3 (This refers to an alkylene group with 1 to 4 carbon atoms.)

Description

[Technical Field]

[0001] This invention relates to monomer compositions. [Background technology]

[0002] (Meth)acrylic acid esters having a cyclocarbonate structure, such as cyclocarbonate (meth)acrylate, are known to be usable as raw materials for functional polymers, paints, pesticides, and the like (Patent Document 1). Patent Document 2 describes a method for synthesizing cyclocarbonate (meth)acrylate by adding carbon dioxide to glycidyl (meth)acrylate under a suitable catalyst. However, this method involves high-pressure conditions and a closed reaction, raising safety concerns due to the risk of polymerization of glycidyl (meth)acrylate during production.

[0003] As another method for synthesizing cyclocarbonate (meth)acrylate, Patent Document 3 describes a method of transesterifying glycerin carbonate and (meth)acrylate in the presence of a metal acetylacetonate catalyst. This production method can be carried out at atmospheric pressure and in an open system, and is generally safer than the method of adding carbon dioxide to glycidyl (meth)acrylate. On the other hand, glycerin, which is the raw material for glycerin carbonate, remains, and since glycerin reacts with (meth)acrylate, the cyclocarbonate (meth)acrylate obtained by this method contains glycerin tri(meth)acrylate. Since glycerol tri(meth)acrylate is a trifunctional (meth)acrylate monomer, when synthesizing copolymers using cyclocarbonate (meth)acrylate by radical polymerization, a change in the ratio of glycerin tri(meth)acrylate in the cyclocarbonate (meth)acrylate significantly affects the viscosity, elasticity, and flexibility of the copolymer. Therefore, in order to manufacture copolymer products using cyclocarbonate (meth)acrylate with stable quality, it is necessary to maintain a constant ratio of glycerin tri(meth)acrylate in the cyclocarbonate (meth)acrylate.

[0004] On the other hand, glycerin tri(meth)acrylate in cyclocarbonate (meth)acrylate is prone to degradation due to polymerization, etc., and gradually decomposes and deteriorates in quality when stored in summer or in high-temperature regions. Therefore, there has been a need for a method to suppress the decrease of glycerin tri(meth)acrylate in cyclocarbonate (meth)acrylate when stored at high temperatures. In addition, cyclocarbonate (meth)acrylate is prone to thickening and gelation due to polymerization when stored at high temperatures, which causes quality deterioration when stored in summer or in high-temperature regions, so there has been a need for a method to suppress polymerization during storage. Patent document 4 mentions polymerization inhibitors such as phenolic polymerization inhibitors such as methoquinone as a method to suppress polymerization, but this can cause discoloration and spoil the appearance of the product, so there has been a need for a method to suppress polymerization during high-temperature storage without causing discoloration. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2011-219394 [Patent Document 2] U.S. Patent No. 4835289 [Patent Document 3] U.S. Patent No. 7414147 [Patent Document 4] International Publication No. 2007 / 074750 [Overview of the project] [Problems that the invention aims to solve]

[0006] Given the background described above, the object of the present invention is to provide a monomer composition comprising cyclocarbonate (meth)acrylate and glycerin tri(meth)acrylate that prevents the decomposition of glycerin tri(meth)acrylate during high-temperature storage and suppresses discoloration and thickening. [Means for solving the problem]

[0007] In light of the above issues, the inventors have conducted diligent studies and have found that a composition containing a cyclocarbonate-containing (meth)acrylate (A) represented by general formula (1), a glycerin tri(meth)acrylate (B) represented by general formula (2), a hydroxycarboxylic acid or its salt with a molecular weight of 500 or less (C), and a polymerization inhibitor (D), each in a specific range of content, can prevent the decomposition of the glycerin tri(meth)acrylate in the cyclocarbonate (meth)acrylate during high-temperature storage, and can also suppress discoloration and thickening. In other words, the present invention relates to the following [1].

[0008] [1] A monomer composition characterized by containing 94 to 99.8% by mass of a cyclocarbonate-containing (meth)acrylate (A) represented by the following general formula (1), 0.01 to 5% by mass of a glycerin tri(meth)acrylate (B) represented by the following general formula (2), 0.001 to 0.5% by mass of a hydroxycarboxylic acid or its salt (C) with a molecular weight of 500 or less, and 0.0001 to 0.5% by mass of a polymerization inhibitor (D). [ka] (In formula (1), R 1 is H or CH3, and R 2 is H or an alkyl group having 1 to 4 carbon atoms, R 3 (This refers to an alkylene group with 1 to 4 carbon atoms.) [ka] (In formula (2), R 4 is H or CH3, and R 5 and R 6 These are each an alkylene group with 1 to 4 carbon atoms. [Effects of the Invention]

[0009] According to the present invention, there is provided a monomer composition containing a cyclo-carbonate-containing (meth)acrylate, which can prevent the decomposition of glycerol tri(meth)acrylate during high-temperature storage and suppress coloring and thickening.

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described. In this specification, a numerical range defined using the symbol "~" shall include the numerical values at both ends (upper limit and lower limit) of "~". For example, "2~5" represents 2 or more and 5 or less.

[0011] [Monomer Composition] The monomer composition of the present invention contains 94 to 99.8% by mass of a cyclo-carbonate-containing (meth)acrylate (A) represented by the following general formula (1), 0.01 to 5% by mass of glycerol tri(meth)acrylate (B) represented by the following general formula (2), 0.001 to 0.5% by mass of a hydroxycarboxylic acid having a molecular weight of 500 or less or a salt thereof (C), and 0.0001 to 0.5% by mass of a polymerization inhibitor (D). Hereinafter, each component contained in the monomer composition of the present invention will be described.

[0012] [Cyclo-Carbonate-Containing (Meth)Acrylate (A)] The cyclo-carbonate-containing (meth)acrylate (A) is represented by the following general formula (1). [Chemical Formula] In formula (1), R 1 is H or CH3, and CH3 is preferred from the viewpoint of easy availability of raw materials. Also, R 2 is H or an alkyl group having 1 to 4 carbon atoms, and the alkyl group may be linear or branched. R 2 is preferably H from the viewpoint of easy availability of raw materials. R 3The group is an alkylene group having 1 to 4 carbon atoms, preferably an alkylene group having 1 to 2 carbon atoms, and more preferably a methylene group (CH2). The alkylene group may be linear or branched. Cyclocarbonate-containing (meth)acrylate (A) can be used as a single or multiple-type mixture.

[0013] <Glycerin tri(meth)acrylate(B)> Glycerin tri(meth)acrylate (B) is represented by the following general formula (2). [ka] In formula (2), R 4 is H or CH3, with CH3 being more preferred. In formula (2), R 5 and R 6 Each of these is independently an alkylene group having 1 to 4 carbon atoms, preferably an alkylene group having 1 to 2 carbon atoms, and more preferably a methylene group (CH2). The alkylene group may be linear or branched. Glycerin tri(meth)acrylate (B) can be used as a single or multiple-type mixture.

[0014] <Hydroxycarboxylic acid and its salt (C)> Examples of hydroxycarboxylic acids and their salts having a molecular weight of 500 or less include glycolic acid, lactic acid, 2-hydroxybutyric acid, citramalic acid, glyceric acid, malic acid, tartaric acid, tartonic acid, citric acid, isocitric acid, leucic acid, mevalonic acid, pantoic acid, and their salts, which can be used individually or as a mixture of several types.

[0015] From the viewpoint of suppressing the decomposition of glycerin tri(meth)acrylate during high-temperature storage, hydroxycarboxylic acids having two or more carboxyl groups or two or more hydroxyl groups are preferred, and among these compounds, citramalic acid, glyceric acid, malic acid, tartaric acid, tartonic acid, citric acid, isocitric acid, leucic acid, mevalonic acid, pantoic acid, or salts thereof are more preferred. Furthermore, from the viewpoint of ease of obtaining raw materials, malic acid, tartaric acid, citric acid, or their salts are preferred. Examples of the above salts include alkali metal salts and alkaline earth metal salts, with alkali metal salts being preferred. Examples of alkali metals mentioned above include lithium, sodium, potassium, rubidium, and cesium. Among these, lithium, sodium, and potassium are preferred, and sodium and potassium are more preferred. Examples of the alkaline earth metals mentioned above include magnesium, calcium, strontium, and barium, with magnesium and calcium being preferred among them. Furthermore, from the viewpoint of suppressing decomposition such as hydrolysis of cyclocarbonate-containing (meth)acrylate, sodium salts and potassium salts are more preferred, and citric acid, isocitric acid, and sodium salts or potassium salts, which are tertiary alcohols that do not readily undergo transesterification with cyclocarbonate-containing (meth)acrylate, are even more preferred. Among these, sodium citrate is particularly preferred from the viewpoint of easily preventing the decomposition of glycerin tri(meth)acrylate during high-temperature storage and further suppressing coloration and thickening of the monomer composition.

[0016] In hydroxycarboxylic acids and their salts (C), the molecular weight of the hydroxycarboxylic acid is 500 or less. If the molecular weight of the hydroxycarboxylic acid exceeds 500, the inhibitory effect on the decomposition of glycerin tri(meth)acrylate decreases. The molecular weight of the hydroxycarboxylic acid is preferably 50 to 500, more preferably 120 to 400, and even more preferably 160 to 250.

[0017] <Polymerization inhibitor (D)> Examples of polymerization inhibitors include known compounds such as phenolic compounds, quinone compounds, nitroso compounds, and phenothiazine compounds. Examples of phenolic compounds include hydroquinone, 4-methoxyphenol, dibutylhydroxytoluene, 4-tert-butylcatechol, ditert-butylphenol, and tert-butyldimethylphenol. From the viewpoint of suppressing discoloration during high-temperature storage, 4-methoxyphenol, dibutylhydroxytoluene, and ditert-butylphenol are more preferred. Examples of quinone compounds include tert-butylhydroquinone, tert-butylbenzoquinone, and benzoquinone. Examples of nitroso compounds include cuperone, N-nitroso-N-phenylhydroxylamine aluminum, and N,N-diethylhydroxylamine. Examples of phenothiazine compounds include phenothiazine. From the viewpoint of suppressing discoloration during high-temperature storage, phenolic compounds are more preferred. Polymerization inhibitor (D) can be used as a single agent or as a mixture of multiple agents.

[0018] <Other ingredients> The monomer composition of the present invention may contain other components besides the cyclocarbonate-containing (meth)acrylate (A), glycerin tri(meth)acrylate (B), hydroxycarboxylic acid or its salt with a molecular weight of 500 or less (C), and polymerization inhibitor (D) described above. Other components include, for example, catalysts, pH adjusters, antioxidants, and UV absorbers.

[0019] <Content of each ingredient> The content of the cyclocarbonate-containing (meth)acrylate (A) relative to 100% by mass of the monomer composition of the present invention may be 94 to 99.8% by mass, but from the viewpoint of suitably using the monomer composition of the present invention as a monomer material for copolymerizing the cyclocarbonate-containing (meth)acrylate (A), it is preferably 95% by mass or more, more preferably 96% by mass or more, and even more preferably 97% by mass or more.

[0020] The content of glycerin tri(meth)acrylate (B) relative to 100% by mass of the monomer composition of the present invention may be 0.01 to 5% by mass, but from the viewpoint of suitably using the copolymer obtained when the cyclocarbonate-containing (meth)acrylate (A) is used as the monomer material, it is preferably 4% by mass or less, and more preferably 3% by mass or less. If there is too much glycerin tri(meth)acrylate (B), the elasticity of the coating film obtained from the monomer composition will decrease.

[0021] The content of the hydroxycarboxylic acid and its salt (C) per 100% by mass of the monomer composition of the present invention may be 0.001 to 0.5% by mass, but 0.01 to 0.5% by mass is preferred from the viewpoint of suppressing the decomposition of glycerin tri(meth)acrylate (B) during high-temperature storage. Furthermore, 0.001 to 0.5% by mass is more preferred, and 0.001 to 0.3% by mass is even more preferred, from the viewpoint of suppressing the decomposition of cyclocarbonate group-containing (meth)acrylate (A) during high-temperature storage. If cyclocarbonate-containing (meth)acrylate (A) decomposes, the coating strength and adhesion of the copolymer may decrease.

[0022] The content of the polymerization inhibitor (D) per 100% by mass of the monomer composition of the present invention may be 0.0001 to 0.5% by mass, but is preferably 0.001 to 0.5% by mass or less from the viewpoint of suppressing the decomposition of glycerin tri(meth)acrylate (B) during high-temperature storage. Furthermore, from the viewpoint of suppressing discoloration during high-temperature storage, is more preferably 0.001 to 0.3% by mass, and even more preferably 0.001 to 0.1% by mass.

[0023] <Method for producing monomer compositions> The method for producing the monomer composition of the present invention is not particularly limited, but examples include the following methods. A mixture of cyclocarbonate-containing (meth)acrylate (A) and glycerin tri(meth)acrylate (B) can be synthesized by a known production method that involves a transesterification reaction between glycerin carbonate and (meth)acrylic acid ester in the presence of a transesterification catalyst such as a metal chelate. Subsequently, the composition of the monomer composition can be adjusted by adding glycerin tri(meth)acrylate (B), hydroxycarboxylic acid (C), and polymerization inhibitor (D) to achieve the desired monomer composition. Glycerin tri(meth)acrylate (B), hydroxycarboxylic acid (C), and polymerization inhibitor (D) may be added during the synthesis process of a mixture of cyclocarbonate-containing (meth)acrylate (A) and glycerin tri(meth)acrylate (B) to adjust the composition of the monomer composition. [Examples]

[0024] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited in any way to these examples.

[0025] <Evaluation of color change, viscosity change ratio, and glycerin tri(meth)acrylate retention rate in high-temperature storage stability tests> 100g of the monomer composition was placed in a 200ml glass bottle and stored at 70°C for 240 hours. The change in color, viscosity change ratio, and glycerin tri(meth)acrylate retention rate before and after storage were measured.

[0026] <Evaluation of chromaticity changes> After filtering with ADOVANTEC quantitative filter paper No. 5A, the change in color at 25°C before and after the high-temperature storage stability test was measured using a Gardner colorimeter (instrument name: COMPARTOR ILLUMINATOR, manufactured by Daylite). Chromaticity change X = Gardner chromaticity after storage - Gardner chromaticity before storage (Judgment criteria) ◎: 0 chromaticity change ○: Chromaticity change is 1 ≤ X ≤ 2 ×: Chromaticity change is 3 ≤ X

[0027] <Evaluation of viscosity change ratio> Viscosity was measured using a Brookfield DV-I Prime digital viscometer at 25°C with spindle LV-1, and the viscosity change ratio before and after the high-temperature storage stability test was calculated. Viscosity change ratio Y = Viscosity after storage / Viscosity before storage (Judgment criteria) ◎: Y≦1.10 〇:1.10 <Y≦1.20 ×:Y>1.20

[0028] <Percentage retention of glycerin tri(meth)acrylate> Using gas chromatography (GC), the area ratio of the glycerin tri(meth)acrylate peak was measured relative to the total peaks of the monomer composition (set to 100), and the retention rate of glycerin tri(meth)acrylate was calculated. Glycerin tri(meth)acrylate retention rate Z (%) = (Ratio of peak area of ​​glycerin tri(meth)acrylate after storage stability test / Ratio of peak area of ​​glycerin tri(meth)acrylate before storage stability test) × 100 GC conditions: Simazdu GC-2014, Column: Agilent Technologies DB-1 0.25mmφ×30m, Column temperature: 80℃, Heating increase 20℃ / min to 300℃, Detector temperature: 300℃, Carrier gas: Nitrogen, Detector: FID (Hydrogen 50kPa, Air 50kPa), Sample injection volume: 1.0μL, Injection temperature: 300℃. (Judgment criteria) ◎:Z≧98 〇:98>Z≧95 ×:95>Z

[0029] (Synthesis Example 1: Synthesis of a mixture of cyclocarbonate-containing (meth)acrylate (A-1) and glycerin tri(meth)acrylate (B-1)) In a 1 L four-necked flask equipped with a stirring blade and thermometer, 160 g of glycerin carbonate, 2034 g of methyl methacrylate, and 12.3 g of zirconium acetylacetonate were charged and stirred at 80°C for 15 hours. The resulting reaction mixture was mixed with 500 g of 10 wt% phosphoric acid aqueous solution and stirred at room temperature for 10 minutes. After filtration using ADVANTEC FILTER PAPER 5A to remove precipitates, the aqueous layer was removed. The resulting reaction mixture was then mixed with 500 g of 0.5% NaOH aqueous solution and stirred for 10 minutes, after which the aqueous layer was removed. The resulting reaction mixture was then mixed with 500 g of deionized water, and the aqueous layer was removed. This procedure was repeated twice. The resulting reaction mixture was then dried at 60°C and 100 torr for 3 hours to remove methyl methacrylate, yielding 178 g of a mixture of A-1 and B-1. The obtained mixture was analyzed by GC, and the weight ratio was converted from the GC area ratio to A-1 / B-1 = 99.7 / 0.2. Furthermore, the chromaticity of the obtained mixture was measured using a Gardner chromatometer (instrument name: COMPARTOR ILLUMINATOR, manufactured by Daylite), and the Gardner chromaticity was 3, with a viscosity of 60 mPa·S.

[0030] (Synthesis Example 2: Synthesis of a mixture of cyclocarbonate-containing (meth)acrylate (A-2) and glycerin tri(meth)acrylate (B-2)) In a 1 L four-necked flask equipped with a stirring blade and thermometer, 160 g of glycerin carbonate, 1749 g of methyl acrylate, and 12.3 g of zirconium acetylacetonate were charged and stirred at 80°C for 15 hours. The resulting reaction mixture was mixed with 500 g of 10 wt% phosphoric acid aqueous solution and stirred at room temperature for 10 minutes. After filtration using ADVANTEC quantitative filter paper No. 5A to remove precipitates, the aqueous layer was removed. The resulting reaction mixture was then mixed with 500 g of 0.5% NaOH aqueous solution and stirred for 10 minutes, after which the aqueous layer was removed. The resulting reaction mixture was then mixed with 500 g of deionized water, and the aqueous layer was removed. This procedure was repeated twice. The resulting reaction mixture was then dried at 60°C and 100 torr for 3 hours to remove methyl acrylate, yielding a mixture of 160 g of A-2 and B-2. The obtained mixture was analyzed by GC, and the weight ratio was converted from the GC area ratio to A-2 / B-2 = 97.0 / 2.9. Furthermore, the chromaticity of the obtained mixture was measured using a Gardner chromatometer (instrument name: COMPARTOR ILLUMINATOR, manufactured by Daylite), and the Gardner chromaticity was 3, and the viscosity was 60 mPa·S.

[0031] Table 1 below shows the structures of the cyclocarbonate-containing (meth)acrylates (A-1) and (A-2) and the glycerin tri(meth)acrylates (B-1) and (B-2) from the synthesis examples described above. The cyclocarbonate-containing (meth)acrylates (A-1) and (A-2) are composed of R in the general formula (1) above. 1 , R 2 and R 3 The compounds are as shown in Table 1, and glycerin tri(meth)acrylate (B-1) and (B-2) are R in the general formula (2) above. 4 , R 5、 R 6 The compounds are as shown in Table 1.

[0032] [Table 1]

[0033] (Example 1) A monomer composition was prepared by adding sodium citrate (0.10 g) and 4-methoxyphenol (0.050 g) to a mixture of A-1 (99.7 g) and B-1 (0.2 g) obtained in Synthesis Example 1, and stirring at 25°C for 30 minutes. The prepared monomer composition was subjected to a high-temperature storage stability test, and the change in color before and after the storage test, the ratio of viscosity change before and after the storage test, and the glycerin tri(meth)acrylate retention rate were measured.

[0034] (Example 2) To the mixture of A-1 and B-1 obtained in Synthesis Example 1, B-1, sodium citrate, and 4-methoxyphenol were further added and stirred at 25°C for 30 minutes to prepare monomer compositions with the amounts of each component shown in Table 2. High-temperature storage stability tests were conducted on the prepared monomer compositions, and the change in color before and after the storage test, the ratio of viscosity change before and after the storage test, and the glycerin tri(meth)acrylate retention rate were measured.

[0035] (Example 3) To the mixture of A-1 and B-1 obtained in Synthesis Example 1, B-1, sodium citrate, and 4-methoxyphenol were further added and stirred at 25°C for 30 minutes to prepare monomer compositions with the amounts of each component shown in Table 2. High-temperature storage stability tests were conducted on the prepared monomer compositions, and the change in color before and after the storage test, the ratio of viscosity change before and after the storage test, and the glycerin tri(meth)acrylate retention rate were measured.

[0036] (Example 4) To the mixture of A-1 and B-1 obtained in Synthesis Example 1, B-1, sodium tartrate, and 4-methoxyphenol were further added and stirred at 25°C for 30 minutes to prepare monomer compositions with the amounts of each component shown in Table 2. High-temperature storage stability tests were conducted on the prepared monomer compositions, and the change in color before and after the storage test, the ratio of viscosity change before and after the storage test, and the glycerin tri(meth)acrylate retention rate were measured.

[0037] (Example 5) To the mixture of A-1 and B-1 obtained in Synthesis Example 1, B-1, sodium malate, and 4-methoxyphenol were further added and stirred at 25°C for 30 minutes to prepare monomer compositions with the amounts of each component shown in Table 2. High-temperature storage stability tests were conducted on the prepared monomer compositions, and the change in color before and after the storage test, the ratio of viscosity change before and after the storage test, and the glycerin tri(meth)acrylate retention rate were measured.

[0038] (Example 6) To the mixture of A-1 and B-1 obtained in Synthesis Example 1, B-1, citric acid, and 4-methoxyphenol were further added and stirred at 25°C for 30 minutes to prepare monomer compositions with the amounts of each component shown in Table 2. High-temperature storage stability tests were conducted on the prepared monomer compositions, and the change in color before and after the storage test, the ratio of viscosity change before and after the storage test, and the glycerin tri(meth)acrylate retention rate were measured.

[0039] (Example 7) A monomer composition was prepared by adding sodium citrate (0.1 g) and 4-methoxyphenol (0.05 g) to a mixture of A-2 (97.0 g) and B-2 (2.9 g) obtained in Synthesis Example 2, and stirring at 25°C for 30 minutes. The prepared monomer composition was subjected to a high-temperature storage stability test, and the change in color before and after the storage test, the ratio of viscosity change before and after the storage test, and the glycerin tri(meth)acrylate retention rate were measured.

[0040] (Example 8) To the mixture of A-1 and B-1 obtained in Synthesis Example 1, B-1, sodium citrate, and phenothiazine were further added and stirred at 25°C for 30 minutes to prepare monomer compositions with the amounts of each component shown in Table 2. High-temperature storage stability tests were conducted on the prepared monomer compositions, and the change in color before and after the storage test, the ratio of viscosity change before and after the storage test, and the glycerin tri(meth)acrylate retention rate were measured.

[0041] (Comparative Example 1) To the mixture of A-1 and B-1 obtained in Synthesis Example 1, B-1, 4-methoxyphenol was further added and stirred at 25°C for 30 minutes to prepare monomer compositions with the amounts of each component shown in Table 3. The prepared monomer compositions were subjected to high-temperature storage stability tests, and the change in color before and after the storage test, the ratio of viscosity change before and after the storage test, and the glycerin tri(meth)acrylate retention rate were measured.

[0042] (Comparative Example 2) To the mixture of A-1 and B-1 obtained in Synthesis Example 1, B-1, 4-methoxyphenol was further added and stirred at 25°C for 30 minutes to prepare monomer compositions with the amounts of each component shown in Table 3. The prepared monomer compositions were subjected to high-temperature storage stability tests, and the change in color before and after the storage test, the ratio of viscosity change before and after the storage test, and the glycerin tri(meth)acrylate retention rate were measured.

[0043] (Comparative Example 3) To the mixture of A-1 and B-1 obtained in Synthesis Example 1, B-1 and phenothiazine were further added, and the mixture was stirred at 25°C for 30 minutes to prepare monomer compositions with the proportions of each component as shown in Table 3. High-temperature storage stability tests were conducted on the prepared monomer compositions, and the change in color before and after the storage test, the ratio of viscosity change before and after the storage test, and the glycerin tri(meth)acrylate retention rate were measured.

[0044] (Comparative Example 4) To the mixture of A-1 and B-1 obtained in Synthesis Example 1, B-1 and sodium citrate were further added, and the mixture was stirred at 25°C for 30 minutes to prepare monomer compositions with the proportions of each component as shown in Table 3. High-temperature storage stability tests were conducted on the prepared monomer compositions, and the change in color before and after the storage test, the ratio of viscosity change before and after the storage test, and the glycerin tri(meth)acrylate retention rate were measured.

[0045] Tables 2-3 below show the evaluation results for Examples 1-8 and Comparative Examples 1-4.

[0046] [Table 2]

[0047] [Table 3]

[0048] From the results in the table above, Examples 1 to 8 of the present invention all received good evaluations in terms of color change, viscosity change ratio, and glycerin tri(meth)acrylate retention rate before and after the high-temperature storage stability test. In particular, Examples 1, 2, and 7 showed good color change, viscosity change ratio, and glycerin tri(meth)acrylate retention rate before and after the high-temperature storage stability test. On the other hand, Comparative Example 1 did not contain hydroxycarboxylic acid or its salt, and the viscosity change ratio and glycerin tri(meth)acrylate retention rate deteriorated. Comparative Examples 2 and 3 did not contain hydroxycarboxylic acid or its salt, but due to the large amount of polymerization inhibitor added, the glycerin tri(meth)acrylate retention rate and viscosity change ratio were good, but the color change deteriorated. Comparative Example 4 did not contain polymerization inhibitor (D), and the viscosity change ratio and glycerin tri(meth)acrylate retention rate deteriorated.

Claims

[Claim 1] A monomer composition characterized by containing 94 to 99.8% by mass of a cyclocarbonate-containing (meth)acrylate (A) represented by the following general formula (1), 0.01 to 5% by mass of a glycerin tri(meth)acrylate (B) represented by the following general formula (2), 0.001 to 0.5% by mass of a hydroxycarboxylic acid or its salt (C) with a molecular weight of 500 or less, and 0.0001 to 0.5% by mass of a polymerization inhibitor (D). 【Chemistry 1】 (In formula (1), R １ is H or CH ３ And R ２ is H or an alkyl group having 1 to 4 carbon atoms, R ３ (This refers to an alkylene group having 1 to 4 carbon atoms.) 【Chemistry 2】 (In formula (2), R ４ is H or CH ３ And R ５ and R ６ These are each an alkylene group having 1 to 4 carbon atoms.

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