JP2012067059A - Method for producing mono(meth)acrylates of divalent phenols - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an economically advantageous method for producing mono(meth)acrylates of divalent phenols which exhibit little coloration and contain little solvent-insoluble content, and are of a high purity.SOLUTION: The method for producing mono(meth)acrylates of divalent phenols by carrying out esterification reaction of divalent phenols and (meth)acrylic acid in the presence of a strong acidic ion exchange resin includes a step of carrying out esterification reaction while moisture in the reaction system is removed by heating and under reduced pressure.

Description

  The present invention relates to a method for obtaining a highly pure dihydric phenol mono (meth) acrylate with little coloring and solvent insolubles, and an economically advantageous production method.

As a method for producing a dihydric phenol mono (meth) acrylate, a method of reacting a dihydric phenol with (meth) acrylic anhydride or (meth) acrylic acid chloride is known (for example, Patent Document 1). See).
In addition, as a method of obtaining a high-purity dihydric phenol mono (meth) acrylate, a dihydric phenol and a (meth) acrylic anhydride are reacted to obtain a dihydric phenol mono (meth) acrylate and a by-product. A step of preparing a reaction solution containing di (meth) acrylates which are: a step of preparing crude crystals by removing unreacted dihydric phenols in the reaction solution by washing with water, the crude crystals A step of preparing a solution by dissolving the solvent with a solvent, and a step of removing the dihydric phenol di (meth) acrylate in the solution by contacting the solution with a poor solvent. A method for obtaining dihydric phenol mono (meth) acrylate has been reported (Patent Document 2).
Furthermore, dihydric phenols are heated to reflux with (meth) acrylic acid in the presence of a strong acid catalyst in a hydrophobic solvent, the distilled water is removed, and the amount of removed water is 40 to 100% of the number of moles of dihydric phenols. A method for producing a dihydric phenol mono (meth) acrylate, which is completed when it is reached, has been reported (Patent Document 3).

  However, when (meth) acrylic acid chloride is used in the method of Patent Document 1, there is a problem that the reaction vessel is corroded, and a large amount of waste liquid containing halide is generated, which is not industrially advantageous. Since the halide is used, the obtained dihydric phenol mono (meth) acrylate composition is not suitable for use in electric and electronic parts. On the other hand, when (meth) acrylic anhydride is used in the method of Patent Document 1, the above-mentioned problem does not occur, but the purity of the dihydric phenol di (meth) acrylate is relatively high. Only low dihydric phenol mono (meth) acrylate compositions can be obtained. Since this dihydric phenol di (meth) acrylate becomes a crosslinking component during polymerization, there is a problem in that the solvent solubility of the polymer is lowered, or in some cases, gelation is caused during polymerization.

  This problem has been solved by the method of Patent Document 2, but since expensive (meth) acrylic anhydride is used, it cannot be said to be an economically advantageous method when considering production at an industrial level. As an economically advantageous method, the method of Patent Document 3 has been reported, but the dihydric phenol mono (meth) acrylate obtained by this method is more colored than the product obtained by the method described in Patent Document 2. In addition, a solvent-insoluble component tends to be generated, which is not satisfactory in terms of purity. In particular, when a synthesized dihydric phenol mono (meth) acrylate is polymerized and used in a photoresist or the like, it is fatal that a solvent-insoluble component is generated.

Japanese Patent Publication No.49-34667 JP 2007-204448 A JP 2007-106749 A

  Accordingly, an object of the present invention is to provide a high-purity dihydric phenol mono (meth) acrylate that does not use (meth) acrylic acid chloride, is economical, is colored, and has little solvent-insoluble content.

  Accordingly, as a result of diligent research and development, the present inventors have carried out an esterification reaction of dihydric phenols and (meth) acrylic acid in the presence of a strongly acidic ion exchange resin to produce a monohydric phenol (meta). In the production of (acrylate), it has been found that the above-mentioned problems can be solved by carrying out an esterification reaction while removing water in the reaction system by heating under reduced pressure.

  According to the present invention, a highly pure dihydric phenol mono (meth) acrylate with little coloring and solvent insoluble components can be produced economically advantageously. Thereby, the problem of corroding the reaction vessel and the treatment of the waste liquid containing halide, which are generated when (meth) acrylic acid chloride is used, can be solved. Moreover, generation | occurrence | production of the dihydric phenol di (meth) acrylate which byproduces a lot when (meth) acrylic anhydride is used can be suppressed. The dihydric phenol di (meth) acrylate as an impurity causes a problem in that the solvent solubility of the polymer is lowered, and in some cases, gelation occurs during polymerization. In addition, the present invention is an economically advantageous production method that can obtain a dihydric phenol mono (meth) acrylate without using an expensive (meth) acrylic anhydride.

It is a figure showing the transmittance | permeability of the polymer using the hydroxyphenyl methacrylate obtained by refine | purifying the product of Example 1 and Comparative Example 2. FIG.

Hereinafter, embodiments of the present invention will be described in detail.
The method for producing a dihydric phenol mono (meth) acrylate according to the present invention is to remove dihydric phenols and (meth) acrylic acid in the presence of a strongly acidic ion exchange resin by heating and reducing pressure in the reaction system. Esterification reaction is performed.

  The “dihydric phenol” used in the method of the present invention refers to a compound having two hydroxyl groups in one benzene ring. Specifically, droquinone, resorcin, and catechol. Moreover, about these compounds, you may have substituents, such as a C1-C4 alkyl group and an alkoxy group. Specifically, 2-methylhydroquinone, 2-ethylhydroquinone, 2-n-propylhydroquinone, 2-isopropylhydroquinone, 2-n-butylhydroquinone, 2-sec-butylhydroquinone, 2-tert-butylhydroquinone, 2- Methyl resorcin, 2-ethyl resorcin, 2-n-propyl resorcin, 2-isopropyl resorcin, 2-n-butyl resorcin, 2-sec-butyl resorcin, 2-tert-butyl resorcin, 4-methyl resorcin, 4-ethyl resorcin 4-n-propyl resorcin, 4-isopropyl resorcin, 4-n-butyl resorcin, 4-sec-butyl resorcin, 4-tert-butyl resorcin, 5-methyl resorcin, 5-ethyl resorcin, 5-n-propyl resorcin , 5- Sopropyl resorcin, 5-n-butyl resorcin, 5-sec-butyl resorcin, 5-tert-butyl resorcin, 3-methyl catechol, 3-ethyl catechol, 3-n-propyl catechol, 3-isopropyl catechol, 3-n -Butyl catechol, 3-sec-butyl catechol, 3-tert-butyl catechol, 4-methyl catechol, 4-ethyl catechol, 4-n-propyl catechol, 4-isopropyl catechol, 4-n-butyl catechol, 4-tert -Butyl catechol, methoxy catechol, methoxy resorcin, methoxy hydroquinone, etc. are illustrated.

  (Meth) acrylic acid used in the present invention is acrylic acid or methacrylic acid.

  In this invention, the molar ratio at the time of making bihydric phenol and (meth) acrylic acid react is (meth) acrylic acid 1.0-10.0 mol with respect to 1.0 mol of dihydric phenols, Preferably it is 2.0-5.5 mol. More preferably, it is 3.0-4.0 mol. When the amount of (meth) acrylic acid is less than 1.0 mol with respect to 1.0 mol of the dihydric phenol, the solubility of the dihydric phenol as the raw material is poor, which is not preferable for uniform stirring. Also, if the reaction is carried out with poor solubility of dihydric phenols, the amount of by-product dihydric phenol di (meth) acrylate tends to increase, resulting in a decrease in yield after removing impurities. It is not preferable. On the contrary, when (meth) acrylic acid exceeds 10.0 mol, the ratio of the yield with respect to the preparation amount falls and production efficiency is not good. From these viewpoints, it is optimal to react at 3.0 to 4.0 moles.

  In the reaction, an aprotic polar organic solvent such as dioxane or tetrahydrofuran can be used. The amount of the solvent used is about 0 to 500 parts by mass with respect to 100 parts by mass of the dihydric phenols, and is added for the purpose of improving the solubility of the raw dihydric phenols or for easily controlling the reaction temperature. I can do it. However, it is better not to use hydrophobic solvents such as toluene and xylene. Hydrophobic solvents are effective for the purpose of removing condensed water, but tend to reduce the solubility of dihydric phenols and consequently increase the generation of by-product dihydric phenol di (meth) acrylates There is. Moreover, there exists a tendency for a solvent insoluble matter to generate | occur | produce in the dihydric phenol mono (meth) acrylate finally obtained. The solvent-insoluble component is a component having a relatively large molecular weight and is a polymer.

  Examples of the strongly acidic ion exchange resin used in the present invention include a styrene / divinylbenzene copolymer having a sulfonic acid group as a functional group. Specifically, various catalyst grades such as Diaion manufactured by Mitsubishi Chemical Corporation and Amberlyst manufactured by Organo Corporation can be used. As for the usage-amount of an ion exchange resin, 1-20 mass parts is preferable with respect to 100 mass parts of (meth) acrylic acid. When the amount of ion exchange resin used is less than 1 part by mass, the progress of the reaction is slow, which is not preferable. Since the ion exchange resin swells in the solution, when it exceeds 20 parts by mass, it is difficult to mix uniformly, which is not preferable. Moreover, it is further more preferable to react at 3-15 mass parts from an economical surface. The ion exchange resin is preferably removed by filtration after the reaction. The reaction can be carried out in the presence of a strongly acidic ion exchange resin at 100 to 120 ° C. for about 1 to 24 hours. The upper limit of the reaction temperature at this time depends on the heat resistance temperature of the ion exchange resin, and the reaction temperature can be increased when the heat resistance temperature of the ion exchange resin is higher.

  Even when an acid catalyst such as sulfuric acid or p-toluenesulfonic acid used in general esterification reaction is used, the esterification reaction proceeds. However, esterification of dihydric phenols with (meth) acrylic acid is not possible. In such a case, a general method of heating and refluxing in a hydrophobic solvent such as toluene and advancing the reaction while removing distilled water has a problem that a solvent-insoluble component is generated. In addition, when the reaction is carried out in the absence of a solvent below the boiling point, the problem of insoluble solvent is solved, but the obtained dihydric phenol mono (meth) acrylate is colored.

  When an esterification reaction is performed between dihydric phenols and (meth) acrylic acid in the presence of a strongly acidic ion exchange resin, condensed water is generated, and the esterification reaction and the hydrolysis reaction reach an equilibrium state. In order to prioritize the esterification reaction, that is, to improve the yield of the dihydric phenol mono (meth) acrylate, it is necessary to remove the condensed water generated in the reaction. For that purpose, it is necessary to remove the condensed water by reducing the pressure in the reaction system. In addition, a method is generally known in which a condensed solvent is removed from the system by azeotroping with condensed water using a hydrophobic solvent such as toluene. In addition, since there is a tendency to increase the generation of by-product dihydric phenol di (meth) acrylate, a method of removing condensed water by heating under reduced pressure is preferable. The moisture in the reaction system varies depending on the reaction rate of esterification. For example, when esterification proceeds 30%, hydrolysis is preferential when it exceeds 1.3% by mass. It is preferable to keep the water in the reaction system at 0.5% by mass or less. The concentration of water in this case is the concentration with respect to the total mass of substances present in the reaction system at the time of measurement, and when a solvent is used for the reaction, the mass of the solvent is not considered.

  The timing for starting the removal of condensed water by heating under reduced pressure is not particularly limited. However, when distillation under heating under reduced pressure is performed at the same time as the esterification reaction is started, the main component of the distillate is (meth) acrylic acid as a raw material. Absent. In that respect, it is preferred to start after the esterification has reached the initial equilibrium.

  In the initial stage of the esterification reaction, a large amount of unreacted dihydric phenols are present. If the esterification reaction is continued, the amount of di (meth) acrylate generated as a by-product increases. . Unreacted dihydric phenols and by-product dihydric phenols di (meth) acrylate must be finally removed by purification. From this viewpoint, it is preferable to finish the reaction when the production rate of the dihydric phenol mono (meth) acrylate with respect to the charged dihydric phenol is 40 to 70 mol%.

  During the esterification reaction, a polymerization inhibitor that blows air can be used as appropriate for the purpose of preventing polymerization.

  After completion of the esterification reaction, the ion exchange resin is preferably removed by filtration. The reaction solution from which the ion exchange resin has been removed contains unreacted dihydric phenols, dihydric phenols mono (meth) acrylate, and dihydric phenols di (meth) acrylate as a by-product. By washing this reaction solution with water, the content of unreacted dihydric phenols can be reduced. When the unreacted dihydric phenols are removed by sufficiently washing with water, crude crystals are precipitated in water. Here, unreacted dihydric phenols are 1.0 mol% with respect to a total of 100 mol% of unreacted dihydric phenols, dihydric phenols mono (meth) acrylate and dihydric phenols di (meth) acrylate. It is preferable to repeat the water washing until it becomes the following. When the unreacted dihydric phenol exceeds 1.0 mol%, the purity of the finally obtained dihydric phenol mono (meth) acrylate is lowered. Monohydric phenols are not preferred because they act as polymerization inhibitors.

  In addition, the dihydric phenol di (meth) acrylate can be removed by washing the reaction solution with a hydrophobic solvent. Specific examples of the hydrophobic solvent used for washing include hexane, cyclohexane, methylcyclohexane, ethylcyclohexane, heptane, and the like, and at least one of them can be used. The hydrophobic solvent here is a solvent for the dihydric phenol di (meth) acrylate and a poor solvent for the dihydric phenol mono (meth) acrylate. Therefore, by adding a hydrophobic solvent, the dihydric phenol mono (meth) acrylate is precipitated as crude crystals and collected. Moreover, 1.0 mol of dihydric phenol di (meth) acrylate is added to 100 mol% of the total of unreacted dihydric phenol, dihydric phenol mono (meth) acrylate and dihydric phenol di (meth) acrylate. It is preferable to repeat the washing with a hydrophobic solvent until it becomes less than or equal to%. When the dihydric phenol di (meth) acrylate remains in excess of 1.0 mol%, the purity of the finally obtained dihydric phenol mono (meth) acrylate decreases, and this is used as a raw material for polymerization. Since the dihydric phenol di (meth) acrylate is a cross-linking component, the molecular weight of the polymer may be abnormally increased, or in some cases, gelation may occur, or solvent solubility may be deteriorated.

Either washing with water or washing with a hydrophobic solvent may be performed first as the washing order, but an optimum method can be selected depending on the composition when the reaction is completed. When the water washing is performed first, it is preferable to dissolve the crude crystals precipitated in water with a solvent after the water washing is completed. Examples of the solvent used for dissolution include toluene, xylene, or a mixture thereof. These are poor solvents for the raw material dihydric phenols, but they are solvents for the crude crystals after the completion of water washing. By using such a solvent, the yield of the finally obtained dihydric phenol mono (meth) acrylate composition is improved. When dissolving the crude crystal with a solvent, it is preferable to use 50 to 300 parts by mass, more preferably 100 to 200 parts by mass of the solvent with respect to 100 parts by mass of the crude crystal, and dissolve by heating if necessary. Good. At that time, the water contained in the crude crystals is preferably separated and removed from the solvent layer containing the crude crystals. Thereafter, the solvent layer is washed with the hydrophobic solvent. As a specific method, a method in which the solvent layer in which the crude crystals are dissolved is put into the hydrophobic solvent, or a method in which the hydrophobic solvent is added to the solvent layer in which the crude crystals are dissolved. Thus, the crystal | crystallization of a bihydric phenol mono (meth) acrylate is precipitated by dissolving a crude crystal with a solvent and making a hydrophobic solvent contact the solvent in which this crude crystal dissolved. By this method, the purity of the finally obtained dihydric phenol mono (meth) acrylate is improved.
In addition, when washing with a hydrophobic solvent is performed first, the reaction solution and the hydrophobic solvent are brought into contact with each other to produce a crude crystal containing a dihydric phenol mono (meth) acrylate and an unreacted dihydric phenol. The crude crystals are washed with water to obtain dihydric phenol mono (meth) acrylate crystals.

  After washing with water and washing with a hydrophobic solvent, liquid removal and drying are performed to obtain a high-purity dihydric phenol mono (meth) acrylate with little coloring and solvent insoluble matter.

  Although the dihydric phenol mono (meth) acrylate obtained by the production method of the present invention is solid at room temperature and is relatively stable to heat and light, the polymerization property is general (meta). ) Equivalent to acrylic ester.

  When a polymer is synthesized using the dihydric phenol mono (meth) acrylate obtained by the production method of the present invention, it has excellent solvent solubility, alkali solubility, transparency, heat discoloration, etc., high Tg, and high thermal decomposition. A polymer with a high refractive index is obtained. Therefore, it can be applied to alkali developing type photoresists used for semiconductor manufacturing, display members, printing plate making materials, and the like, and protective films requiring transparency and heat discoloration. It is also useful as a curing agent such as an epoxy resin.

  In addition, the dihydric phenol mono (meth) acrylate obtained by the production method of the present invention has good copolymerizability with not only a homopolymer but also other unsaturated group-containing polymerizable compound. Specific examples of such unsaturated group-containing polymerizable compounds include, for example, acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, maleic anhydride, fumaric anhydride, Citraconic anhydride, mesaconic anhydride, itaconic anhydride, vinyl benzoic acid, o-carboxyphenyl (meth) acrylate, m-carboxyphenyl (meth) acrylate, p-carboxyphenyl (meth) acrylate, o-carboxyphenyl (meth) Acrylamide, m-carboxyphenyl (meth) acrylamide, p-carboxyphenyl (meth) acrylamide, succinic acid mono [2- (meth) acryloyloxyethyl], phthalic acid mono [2- (meth) acryloyloxyethyl], ω-carboxypolycaprolactone mono ( ) Acrylate, 5-carboxybicyclo [2.2.1] hept-2-ene, 5,6-dicarboxybicyclo [2.2.1] hept-2-ene, 5-carboxy-5-methylbicyclo [ 2.2.1] Hept-2-ene, 5-carboxy-5-ethylbicyclo [2.2.1] hept-2-ene, 5-carboxy-6-methylbicyclo [2.2.1] hept- 2-ene, 5-carboxy-6-ethylbicyclo [2.2.1] hept-2-ene, 5,6-dicarboxybicyclo [2.2.1] hept-2-ene anhydride, tricyclo [5 .2.1.02,6] decan-8-yl (meth) acrylate, tricyclo [5.2.1.02,6] decan-8-yloxyethyl (meth) acrylate,

  Methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, n-lauryl (meth) acrylate, tridecyl (meth) acrylate, n-stearyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-methylcyclohexyl (meth) acrylate, isobornyl (meth) acrylate, hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, diethylene glycol mono (meth) acrylate, 2,3- Hydroxypropyl (meth) acrylate, 2- (meth) acryloyloxyethyl glycoside,

  Phenyl (meth) acrylate, benzyl (meth) acrylate, o-methoxyphenyl (meth) acrylate, m-methoxyphenyl (meth) acrylate, p-methoxyphenyl (meth) acrylate,

  Diethyl maleate, diethyl fumarate, diethyl itaconate, bicyclo [2.2.1] hept-2-ene, 5-methylbicyclo [2.2.1] hept-2-ene, 5-ethylbicyclo [2. 2.1] hept-2-ene, 5-methoxybicyclo [2.2.1] hept-2-ene, 5-ethoxybicyclo [2.2.1] hept-2-ene, 5,6-dimethoxybicyclo [2.2.1] hept-2-ene, 5,6-diethoxybicyclo [2.2.1] hept-2-ene, 5-t-butoxycarbonylbicyclo [2.2.1] hept-2 -Ene, 5-cyclohexyloxycarbonylbicyclo [2.2.1] hept-2-ene, 5-phenoxycarbonylbicyclo [2.2.1] hept-2-ene, 5,6-di (t-butoxycarbonyl ) Bicyclo 2.2.1] Hept-2-ene, 5,6-di (cyclohexyloxycarbonyl) bicyclo [2.2.1] hept-2-ene, 5- (2′-hydroxyethyl) bicyclo [2.2 .1] Hept-2-ene, 5,6-dihydroxybicyclo [2.2.1] hept-2-ene, 5,6-di (hydroxymethyl) bicyclo [2.2.1] hept-2-ene 5,6-di (2′-hydroxyethyl) bicyclo [2.2.1] hept-2-ene, 5-hydroxy-5-methylbicyclo [2.2.1] hept-2-ene, 5- Hydroxy-5-ethylbicyclo [2.2.1] hept-2-ene, 5-hydroxymethyl-5-methylbicyclo [2.2.1] hept-2-ene,

  Styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, 1,3-butadiene, isoprene, 2,3-dimethyl -1,3-butadiene, acrylonitrile, methacrylonitrile, vinyl chloride, vinylidene chloride, acrylamide, methacrylamide, vinyl acetate, o-hydroxyphenyl (meth) acrylamide, m-hydroxyphenyl (meth) acrylamide, p-hydroxyphenyl ( (Meth) acrylamide, 3,5-dimethyl-4-hydroxybenzyl (meth) acrylamide, phenylmaleimide, hydroxyphenylmaleimide, cyclohexylmaleimide, benzylmaleimide, trifluoromethyl (meth) acyl Rate, glycidyl acrylate, glycidyl methacrylate, glycidyl α-ethyl acrylate, 3,4-epoxybutyl acrylate, 3,4-epoxybutyl methacrylate, 3,4-epoxybutyl acrylate, Acrylic acid-6,7-epoxyheptyl, methacrylic acid-6,7-epoxyheptyl, α-ethylacrylic acid-6,7-epoxyheptyl, vinyl glycidyl ether, allyl glycidyl ether, isopropenyl glycidyl ether, o-vinyl benzyl Glycidyl ether, m-vinylbenzylglycidyl ether, p-vinylbenzylglycidyl ether, vinylcyclohexene monooxide, 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate And so on.

  Polymerization uses azo initiators typified by azobisisobutyronitrile, organic peroxides typified by benzoyl peroxide, etc., methanol, ethanol, 1-propanol, isopropyl alcohol, butanol, ethylene glycol , Acetone, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, dioxane, toluene, xylene, ethyl acetate, isopropyl acetate, normal propyl acetate, butyl acetate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, acetic acid 3-methoxybutyl, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether Conducted in an organic solvent such as acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, 3-methoxybutanol, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, ethyl lactate be able to.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples, Comparative Examples, Reference Examples and Comparative Reference Examples, but the present invention is not limited to the following examples. Moreover, the composition ratio, hue, and turbidity in Examples, Comparative Examples, and Reference Examples were investigated by the following methods.

(Composition ratio)
^{By 1} H-NMR measurement, each component was calculated with the total of dihydric phenols, dihydric phenols mono (meth) acrylate, and dihydric phenols di (meth) acrylate being 100 mol%.
(Hue)
The degree of coloring at the end of the reaction was visually observed.
○: Almost not colored, Δ: Slightly colored, ×: Colored (turbidity)
The reaction solution at the end of the reaction was diluted 4 times by mass with propylene glycol monomethyl ether acetate and visually observed.
○: Transparent, △: Slightly cloudy, ×: Cloudy

[Example 1]
Synthesis of 4-hydroxyphenylmethacrylate 100 parts by mass of hydroquinone, 235 parts by mass of methacrylic acid in a 1 L separable flask equipped with a condenser, thermometer and stirring blades, strongly acidic ion exchange resin amberlist manufactured by Organo Corp. 15. 10 parts by mass of DRY was charged and the reaction was started at 120 ° C. When the reaction reached equilibrium and the product composition became constant, the water content in the system was measured and found to be 1.2% by mass. Thereafter, the reaction was continued while distilling off under reduced pressure so that the water in the system was kept at less than 0.2% by mass at 120 ° C. The esterification reaction was terminated when the proportion of hydroxyphenyl methacrylate reached 56.8% of the number of moles charged with hydroquinone. The composition ratio, hue, and turbidity are as shown in Table 1.

[Example 2]
15. A 1 L separable flask equipped with a cooler, thermometer, and stirring blade, 100 parts by weight of hydroquinone, 86 parts by weight of methacrylic acid, and strongly acidic ion exchange resin Amberlyst manufactured by Organo Corporation as an ion exchange resin. When 10 parts by mass of DRY was charged and reacted at 120 ° C. for 1.5 hours, the ratio of the reaction product became constant, and thus the water in the system was removed by distillation under reduced pressure. When the reaction was again carried out at 120 ° C. for 1.5 hours, the ratio of the reaction product became constant, and thus the water in the system was removed by distillation under reduced pressure. This operation was repeated, and the esterification reaction was terminated when the proportion of hydroxyphenyl methacrylate reached 38.9% of the number of moles charged with hydroquinone. The composition ratio, hue, and turbidity are as shown in Table 1.

[Example 3]
Synthesis of 4-hydroxyphenylmethacrylate 100 parts by mass of hydroquinone, 235 parts by mass of methacrylic acid in a 1 L separable flask equipped with a condenser, thermometer and stirring blades, strongly acidic ion exchange resin amberlist manufactured by Organo Corp. 15. 10 parts by mass of DRY was charged and the reaction was started at 120 ° C. When the reaction reached equilibrium and the product composition became constant, the water content in the system was measured and found to be 1.2%. Thereafter, the reaction was continued while distilling off under reduced pressure so that water in the system maintained at 0.5 to 1.0% at 120 ° C. The esterification reaction was terminated when the proportion of hydroxyphenyl methacrylate reached 37.1% of the number of moles charged with hydroquinone. In this case, equilibrium was reached at 37%, and esterification did not proceed any further. The composition ratio, hue, and turbidity are as shown in Table 1.

[Example 4]
Synthesis of 2-hydroxyphenyl acrylate 100L part of catechol, 235 parts by weight of methacrylic acid in a 1L separable flask equipped with a condenser, thermometer and stirring blades, strongly acidic ion exchange resin amber list manufactured by Organo Corporation as ion exchange resin 15. 10 parts by mass of DRY was charged and the reaction was started at 120 ° C. When the reaction reached equilibrium and the product composition became constant, the water content in the system was measured and found to be 1.3%. Thereafter, the reaction was continued while distilling off under reduced pressure so that the water in the system was kept at less than 0.2% by mass at 120 ° C. The esterification reaction was terminated when the proportion of hydroxyphenyl methacrylate reached 49.5% of the number of moles charged with catechol. The composition ratio, hue, and turbidity are as shown in Table 1.

[Comparative Example 1]
Synthesis of 4-hydroxyphenyl methacrylate In a 1 L separable flask equipped with a reflux condenser, a water separator, a thermometer and a stirring blade, 100 parts by mass of hydroquinone, 85 parts by mass of methacrylic acid, 4.0 parts by mass of p-toluenesulfonic acid Then, 100 parts by mass of toluene was charged, and the reaction was performed while refluxing. Distillation of an azeotropic mixture of toluene and water started at 120 ° C., and the reaction was carried out at 120 ° C. for 5 hours while removing the water separated by the water separator from the system. The esterification reaction was terminated when the proportion of hydroxyphenyl methacrylate reached 37.0% of the number of moles charged with hydroquinone. The composition ratio, hue, and turbidity are as shown in Table 1.

[Comparative Example 2]
Synthesis of 4-hydroxyphenyl methacrylate A 1 L separable flask equipped with a condenser, a thermometer, and a stirring blade was charged with 100 parts by mass of hydroquinone, 86 parts by mass of methacrylic acid, and 4.0 parts by mass of p-toluenesulfonic acid at 145 ° C. When the reaction was carried out for 1.5 hours, the ratio of the reaction product became constant, and thus water in the system was removed by distillation under reduced pressure. When the reaction was again carried out at 145 ° C. for 1.5 hours, the ratio of the reaction product became constant, and thus the water in the system was removed by distillation under reduced pressure. This operation was repeated, and the esterification reaction was terminated when the proportion of hydroxyphenyl methacrylate reached 35.1% of the number of moles charged with hydroquinone. The composition ratio, hue, and turbidity are as shown in Table 1.

[Comparative Example 3]
Synthesis of 4-hydroxyphenyl methacrylate A 1 L separable flask equipped with a reflux condenser, a water separator, a thermometer, and a stirring blade, 100 parts by weight of hydroquinone, 86 parts by weight of methacrylic acid, and strong acid manufactured by Organo Corporation as an ion exchange resin Ion exchange resin amber list 15. 10 parts by mass of DRY and 100 parts by mass of toluene were charged, and the reaction was carried out while refluxing. Distillation of an azeotropic mixture of toluene and water started at 120 ° C., and the reaction was carried out at 120 ° C. for 16 hours while removing the water separated by the water separator out of the system. The esterification reaction was terminated when the proportion of hydroxyphenyl methacrylate reached 51.3% of the number of moles charged with hydroquinone. The composition ratio, hue, and turbidity are as shown in Table 1.

[Reference Example 1]
Purification of 4-hydroxyphenyl methacrylate The ion exchange resin was filtered off from the reaction solution obtained in Example 1 and washed repeatedly with methylcyclohexane. When the molar fraction of phenylene dimethacrylate became 0.1, methylcyclohexane was obtained. The washing with was finished. Here, a crude crystal from which phenylene dimethacrylate was removed was obtained. Next, this washing of the crude crystals with water was repeated, and the water washing was terminated when the molar fraction of unreacted dihydric phenol reached 0.5. Subsequently, the solution was drained and dried to obtain 65.7 parts by mass (yield: 40.6%) of white crystals.
The molar fraction of hydroquinone: hydroxyphenyl methacrylate: phenylene dimethacrylate was 0.2: 99.2: 0.6.

Polymerization of 4-hydroxyphenyl methacrylate In a 1 L separable flask equipped with a condenser, thermometer, and stirring blade, 100 parts by mass of the obtained white crystals, 300 parts by mass of propylene glycol monoethyl ether acetate, azobisisobutyronitrile 4 Then, 0.0 part by mass was charged and reacted at 70 ° C. for 6 hours to obtain a polymer solution.

Measurement of polymer permeability The obtained polymer solution was filtered through a 0.1 μm Teflon (registered trademark) filter. The film was applied to a glass plate with a 50 μm applicator and dried on a 110 ° C. hot plate for 90 seconds to obtain a coating film having a thickness of 3 μm. Furthermore, the transmittance | permeability in wavelength 400nm when it heat-processes in 230 degreeC oven for 0, 1, 2, 3 hours was measured with the ultraviolet visible spectrophotometer, respectively. The results are shown in FIG. A polymer using uncolored hydroxyphenyl methacrylate as a raw material is good with little change in transmittance even when heated.

[Comparative Reference Example 1]
The reaction solution obtained in Comparative Example 1 was purified in the same manner as in Reference Example 1 to obtain a brown powder. Polymerization was performed in the same manner as in Reference Example 1 using the obtained brown powder to obtain a polymer solution. Subsequently, the obtained polymer solution was filtered with a 0.1 μm Teflon (registered trademark) filter, but could not be filtered due to clogging. This is considered due to the high turbidity.

[Comparative Reference Example 2]
The reaction solution obtained in Comparative Example 2 was purified in the same manner as in Reference Example 1 to obtain a brown powder. Polymerization was performed in the same manner as in Reference Example 1 using the obtained brown powder to obtain a polymer solution. Subsequently, the transmittance of the coating film was measured in the same manner as in Reference Example 1 using the obtained polymer solution. The results are shown in FIG. A polymer using colored hydroxyphenyl methacrylate as a raw material has a large change in transmittance when heated, and cannot be applied to uses requiring transparency.

Claims (8)

  A process for producing a dihydric phenol mono (meth) acrylate by subjecting a dihydric phenol and (meth) acrylic acid to an esterification reaction in the presence of a strongly acidic ion exchange resin, A method for producing a dihydric phenol mono (meth) acrylate, comprising a step of carrying out an esterification reaction while removing water by heating under reduced pressure.   The dihydric phenol mono (2) according to claim 1, wherein the esterification reaction is terminated when the production rate of the di (phenol) mono (meth) acrylate with respect to the charged dihydric phenol reaches 40 to 70 mol%. A method for producing a (meth) acrylate.   The dihydric phenol mono (meta) according to claim 1 or 2, wherein the heating and depressurization starts after the esterification reaction and the hydrolysis reaction of water and esterified product in the reaction system are in an equilibrium state. A method for producing acrylates.   The method for producing a dihydric phenol mono (meth) acrylate according to any one of claims 1 to 3, wherein water in the reaction system after heating under reduced pressure is 1.0 mass% or less.   The method for producing a dihydric phenol mono (meth) acrylate according to any one of claims 1 to 4, wherein the water content in the reaction system after heating under reduced pressure is 0.5 mass% or less.   The molar ratio at the time of esterifying the dihydric phenol and (meth) acrylic acid is 3.0 to 4.0 mol of (meth) acrylic acid with respect to 1.0 mol of the dihydric phenol. The method to manufacture the bihydric phenol mono (meth) acrylate as described in any one of Claims 1-5.   The method for producing a dihydric phenol mono (meth) acrylate according to any one of claims 1 to 6, wherein the esterification reaction is performed in a non-hydrophobic solvent.   The method for producing a divalent phenol mono (meth) acrylate according to any one of claims 1 to 7, wherein the dihydric phenol is hydroquinone or catechol.

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