Method for producing hydroxyphenyl (meth)acrylate

Abstract

To provide a method for producing high-purity hydroxyphenyl (meth)acrylate with minimal discoloration without using sulfur components or toluene in the process. [Solution] A method for producing hydroxyphenyl (meth)acrylate, characterized by comprising the step of reacting divalent phenols and (meth)acrylic anhydride in the presence of a phosphorus-based oxo salt to prepare a reaction solution containing hydroxyphenyl (meth)acrylate and a by-product, phenylenedi (meth)acrylate.

Description

Technical Field

[0001] The present invention relates to a method for producing hydroxyphenyl (meth) acrylate.

Background Art

[0002] Since hydroxyphenyl (meth) acrylate has both a phenolic hydroxyl group and a polymerizable group in its molecule, it is known that a copolymer obtained using this shows good properties as a resist resin or the like. In particular, due to having a phenolic hydroxyl group, it exhibits excellent adhesion to metal materials and is widely used in fields such as semiconductor applications and display applications. However, hydroquinone used as a raw material when synthesizing hydroxyphenyl (meth) acrylate and compounds containing a phenolic hydroxyl group such as the synthesized hydroxyphenyl (meth) acrylate are easily oxidized by heat or acid, and it is known that the resulting hydroxyphenyl (meth) acrylate has a deteriorated hue.

[0003] As a method for producing hydroxyphenyl (meth) acrylate, for example, a method of reacting dihydric phenols with (meth) acrylic anhydride is disclosed in Patent Document 1, and it is shown that high purity can be obtained by repeating washing with water and reprecipitation using toluene and hexane after the reaction. However, since p-toluenesulfonic acid is used as a reaction catalyst, there is a concern that a trace amount of sulfur remains and corrodes metals such as wiring. Also, although high purity purification using toluene is performed during the process, toluene may be incorporated into the crystals of hydroxyphenyl (meth) acrylate. In recent years, from the perspective of environmental response, there are cases where monomers and the like are required to be toluene-free, and it has not been preferable for toluene to be incorporated into the crystals of hydroxyphenyl (meth) acrylate.

[0004] Furthermore, Patent Document 2 discloses a method for reacting divalent phenols with (meth)acrylic acid in the presence of a strong sulfonic acid, and discloses a step of repeatedly washing with methylcyclohexane and then with water after the reaction. However, although these production methods can obtain hydroxyphenyl (meth)acrylate, sulfur from the catalyst may remain, and discoloration may occur because the reaction is carried out in the presence of a strong acid.

[0005] Furthermore, Patent Document 3 discloses a method for obtaining hydroxyphenyl (meth)acrylate by reacting methacrylic anhydride and hydroquinone at 120°C. This method does not use sulfur-containing compounds, so there is no risk of sulfur residue causing corrosion of metal materials. However, there is a risk of hydroxyphenyl (meth)acrylate becoming discolored due to heat, and furthermore, because toluene is used for high-purity processing, toluene-free hydroxyphenyl (meth)acrylate could not be obtained. Therefore, conventional manufacturing methods could not produce high-purity hydroxyphenyl (meth)acrylate that does not contain sulfur or toluene and does not produce discoloration. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2007-204448 [Patent Document 2] Re-tabled publication 2013 / 015055 [Patent Document 3] Japanese Patent Publication No. 2008-273929 [Overview of the project] [Problems that the invention aims to solve]

[0007] The object of the present invention is to provide a method for producing high-purity hydroxyphenyl (meth)acrylate with minimal discoloration without using sulfur components or toluene in the process. [Means for solving the problem]

[0008] As a result of diligent research conducted by the present inventors to solve the above problems, they have found that the above problems can be solved by a method for producing hydroxyphenyl (meth)acrylate, which includes the step of reacting divalent phenols and (meth)acrylic anhydride in the presence of a phosphorus-based oxo salt to prepare a reaction solution containing hydroxyphenyl (meth)acrylate and a by-product, phenylenedi (meth)acrylate. In other words, the present invention relates to the following [1] to [3].

[0009] [1] A method for producing hydroxyphenyl (meth)acrylate, characterized by comprising the step of reacting divalent phenols and (meth)acrylic anhydride in the presence of a phosphorus oxo salt to prepare a reaction solution containing hydroxyphenyl (meth)acrylate and a by-product, phenylenedi (meth)acrylate. [2] The method for producing hydroxyphenyl (meth)acrylate according to [1], further comprising the step of adding an aliphatic hydrocarbon solvent to the reaction solution to obtain crude crystals of hydroxyphenyl (meth)acrylate and washing the crude crystals. [3] A method for producing hydroxyphenyl (meth)acrylate according to [2] above, further comprising the step of washing the washed crude crystals with water to remove divalent phenols. [Effects of the Invention]

[0010] The present invention makes it possible to obtain high-purity hydroxyphenyl (meth)acrylate with minimal discoloration without using sulfur components or toluene in the process. [Modes for carrying out the invention]

[0011] The embodiments for carrying out the present invention will be described in more detail below. The present invention provides a method for producing hydroxyphenyl (meth)acrylate, characterized by a step of reacting divalent phenols and (meth)acrylic anhydride in the presence of a phosphorus-based oxo salt to prepare a reaction solution containing hydroxyphenyl (meth)acrylate and a by-product, phenylenedi(meth)acrylate. Preferably, an aliphatic hydrocarbon solvent is added to the reaction solution to prepare crude crystals of hydroxyphenyl (meth)acrylate. In this invention, (meth)acrylate means acrylate or methacrylate, and (meth)acrylic means acrylic or methacrylic.

[0012] In this invention, divalent phenols refer to compounds having two hydroxyl groups on one benzene ring. Specifically, these include hydroquinone, resorcinol, and catechol. These compounds may also have substituents such as alkyl or alkoxy groups having 1 to 4 carbon atoms.

[0013] [Divalent phenols] Divalent phenols include, specifically, hydroquinone, resorcinol, catechol, 2-methylhydroquinone, 2-ethylhydroquinone, 2-n-propylhydroquinone, 2-isopropylhydroquinone, 2-n-butylhydroquinone, 2-sec-butylhydroquinone, 2-tert-butylhydroquinone, 2-methylresorcinol, 2-ethylresorcinol, 2-n-propylresorcinol, 2-isopropylresorcinol, 2-n-butylresorcinol, 2-sec-butylresorcinol, 2-tert-butylresorcinol, 4-methylresorcinol, 4-ethylresorcinol, 4-n-propylresorcinol, 4-isopropylresorcinol, 4-n-butylresorcinol, 4-sec-butylresorcinol, 4-tert-butylresorcinol, 5-methylresorcinol, 5-ethylresorcinol, 5-n-propylresorcinol, 5-isopropylresorcinol, 5-n-butylresorcinol, 5-sec-butylresorcinol Examples include methylresorcinol, 5-tert-butylresorcinol, 3-methylcatechol, 3-ethylcatechol, 3-n-propylcatechol, 3-isopropylcatechol, 3-n-butylcatechol, 3-sec-butylcatechol, 3-tert-butylcatechol, 4-methylcatechol, 4-ethylcatechol, 4-n-propylcatechol, 4-isopropylcatechol, 4-n-butylcatechol, 4-tert-butylcatechol, 3-methoxycatechol, methoxyresorcinol, and methoxyhydroquinone, which are readily available. Hydroquinone, resorcinol, catechol, 2-methylhydroquinone, 2-tert-butylhydroquinone, 2-methylresorcinol, 5-methylresorcinol, 3-methylcatechol, 4-methylcatechol, 4-tert-butylcatechol, 3-methoxycatechol, and methoxyhydroquinone are preferred, with hydroquinone being particularly preferred, due to their availability.

[0014] [Esterification reaction] The first step in the present invention is to react divalent phenols with (meth)acrylic anhydride in the presence of a phosphorus-based oxo salt (hereinafter, this reaction may also be referred to as an esterification reaction) to prepare a reaction solution containing hydroxyphenyl (meth)acrylate and the by-product phenylenedi (meth)acrylate. Phosphorus oxoates function as catalysts for the esterification reaction described above and as reducing agents to prevent discoloration. In this esterification reaction, it is not necessary to use sulfonic acid-based strong acid catalysts, so the amount of sulfur in the synthesized hydroxyphenyl (meth)acrylate can be reduced. In the present invention, the molar ratio when reacting divalent phenols with (meth)acrylic anhydride is preferably 0.3 to 1.5 moles, more preferably 0.4 to 1.0 moles, and even more preferably 0.5 to 0.8 moles of (meth)acrylic anhydride per 1.0 mole of divalent phenols. A ratio of 0.3 moles or more of (meth)acrylic anhydride per 1.0 mole of divalent phenols is preferable because it increases the yield ratio to the amount charged and improves manufacturing efficiency. Furthermore, when the amount of (meth)acrylic anhydride is 1.5 moles or less, the amount of phenylenedi(meth)acrylate produced decreases, and hydroxyphenyl(meth)acrylate after purification is obtained in high purity.

[0015] When reacting divalent phenols with (meth)acrylic anhydride, the amount of phosphorus-based oxoate used is preferably 0.1 to 5 parts by mass, and more preferably 0.5 to 3 parts by mass, per 100 parts by mass of divalent phenols. If the amount of phosphorus-based oxoate used is 0.1 parts by mass or more, the reaction proceeds more easily, and if it is 5 parts by mass or less, the discoloration of the final purified product is more easily suppressed.

[0016] In the present invention, a solvent may be used in the esterification reaction, and preferred solvents are methacrylic acid, acetic acid, dimethylformamide, N-methylpyrrolidone, and methyl ethyl ketone. In particular, methacrylic acid is preferred from the viewpoint of increasing the yield and improving production efficiency by crystallizing hydroxyphenyl(meth)acrylate from the reaction solution. By using these solvents, the dissolution of divalent phenols can be suppressed and the formation of phenylenedi(meth)acrylate can be suppressed. The amount of solvent used depends on the solubility of the divalent phenols, but from the viewpoint of improving production efficiency, it is preferably 50 to 300 parts by mass, and more preferably 100 to 250 parts by mass, per 100 parts by mass of divalent phenols.

[0017] In this invention, a phosphorus-based oxo salt, which acts as both a reaction catalyst and a reducing agent, is added during the esterification reaction to suppress discoloration during the reaction. A phosphorus-based oxo salt is a compound in which at least one oxo group (=O) and at least one hydroxyl group (-OH) are bonded to a phosphorus atom, and the hydrogen atom of the hydroxyl group is substituted with an alkali metal or alkaline earth metal. Examples of phosphorus-based oxo salts include sodium phosphate, disodium phosphate, trisodium phosphate, calcium phosphate, sodium pyrophosphate, calcium pyrophosphate, sodium metaphosphate, potassium metaphosphate, magnesium metaphosphate, sodium tripolyphosphate, sodium pentapolyphosphate, sodium phosphite, and sodium hypophosphite, but sodium hypophosphite is preferred. The amount of phosphorus-based oxo salt used is preferably 0.1 to 3.0 parts by mass, and more preferably 0.5 to 2.0 parts by mass, per 100 parts by mass of divalent phenols used in the preparation. When the amount of phosphorus-based oxo salt used is 0.1 to 3.0 parts by mass, it acts as a reaction catalyst, which shortens the reaction time, and it can suppress the discoloration of the resulting hydroxyphenyl (meth)acrylate by acting as a reducing agent.

[0018] The esterification reaction is preferably carried out at a temperature at which the diphenols are easily soluble. The temperature in the esterification reaction is preferably 60 to 160 °C, more preferably 90 to 140 °C, and even more preferably 110 to 130 °C. The reaction time of the esterification reaction is preferably about 0.5 to 6 hours. When the reaction temperature is 60 °C or higher, the reaction easily proceeds and the diphenols are easily dissolved. Further, when the reaction temperature is 160 °C or lower, the coloring of the obtained hydroxyphenyl (meth)acrylate can be suppressed.

[0019] In the initial stage of the reaction, since a large amount of unreacted diphenols is present, when adding the (meth)acrylic anhydride, by dissolving the diphenols in a solvent, the production amount of phenylenedi(meth)acrylate as a by-product can be reduced.

[0020] The production rate (mol%) of hydroxyphenyl (meth)acrylate can be calculated from formula (1) using gas chromatography (GC). In formula (1), the GC area ratio of each of hydroxyphenyl (meth)acrylate (A), diphenols (B), and phenylenedi(meth)acrylate (C) is obtained by calculating the percentage of the peak area of each component with respect to the total peak area of (A), (B), and (C) in the GC measurement.

[0021]

Number

[0022] During the reaction, a polymerization-inhibiting gas can be blown in or a polymerization inhibitor can be used as appropriate to prevent polymerization, and it is preferable to blow in a polymerization-inhibiting gas. Known polymerization inhibitors can be used, and examples of polymerization-inhibiting gases include air and oxygen / nitrogen mixed gases. Methods for blowing in the polymerization-inhibiting gas include blowing it into the gas phase of the reaction vessel or blowing it into the liquid phase. The flow rate of the blown gas is not particularly limited as long as it is an amount that can prevent polymerization, but for example, in the case of air, an amount of 5.0 to 15.0 mL / min for a 1 L reaction vessel is sufficient.

[0023] As described above, the esterification reaction prepares a reaction solution containing hydroxyphenyl(meth)acrylate and the by-product phenylenedi(meth)acrylate.

[0024] [Preparation of slurry] It is preferable to obtain crude crystals of hydroxyphenyl (meth)acrylate by adding an aliphatic hydrocarbon solvent to the reaction solution after the esterification reaction. Specifically, a slurry is prepared by adding an aliphatic hydrocarbon solvent to the reaction solution and stirring at 25°C or below. By adding an aliphatic hydrocarbon solvent to the reaction solution or a neutralized reaction solution, hydroxyphenyl(meth)acrylate is selectively precipitated during slurry formation, and crude crystals are obtained by filtering the slurry containing the crude crystals using a known method. This step selectively removes the by-product phenylenedi(meth)acrylate and increases the yield of the final hydroxyphenyl(meth)acrylate.

[0025] As the aliphatic hydrocarbon solvent, a solvent that is a good solvent for phenylenedi(meth)acrylate and a poor solvent for hydroxyphenyl(meth)acrylate is preferred. The molecular structure may be linear or branched. Aromatic hydrocarbon solvents cannot be used. The type of aliphatic hydrocarbon solvent is not particularly limited, but is preferably an aliphatic hydrocarbon compound having 6 to 10 carbon atoms, and more preferably an aliphatic hydrocarbon compound having 6 to 7 carbon atoms. Examples of aliphatic hydrocarbon solvents include hexane, 2-methylpentane, 3-methylpentane, 2,3-dimethylbutane, 2,2-dimethylbutane, heptane, octane, nonane, cyclohexane, and methylcyclohexane. Hexane, 2-methylpentane, 3-methylpentane, 2,3-dimethylbutane, 2,2-dimethylbutane, heptane, cyclohexane, and methylcyclohexane are preferred, and hexane, heptane, cyclohexane, and methylcyclohexane are more preferred. Aromatic hydrocarbon solvents, such as toluene and xylene, cannot be used because, due to π-electron interactions with hydroxyphenyl (meth)acrylate, the aromatic hydrocarbon solvent cannot be completely removed in the purification and drying steps and remains. The amount of aliphatic hydrocarbon solvent is preferably 50 to 200 parts by mass, and more preferably 80 to 150 parts by mass, per 100 parts by mass of divalent phenols before the reaction. By setting the amount of aliphatic hydrocarbon solvent within this range, high-purity hydroxyphenyl (meth)acrylate with few by-products can be obtained.

[0026] The reaction solution temperature at which the aliphatic hydrocarbon solvent is added is preferably 50°C or higher, and more preferably 60°C or higher. When the reaction solution temperature is 50°C or higher, the aliphatic hydrocarbon solvent is added before the crystallization of hydroxyphenyl(meth)acrylate, which suppresses the crystallization of phenylenedi(meth)acrylate, thus producing high-purity hydroxyphenyl methacrylate with fewer by-products, which is more preferable. The upper limit of the reaction solution temperature at which the aliphatic hydrocarbon solvent is added is not particularly limited and can be adjusted as appropriate depending on the type of solvent, but the reaction solution temperature is, for example, 120°C or lower, and preferably 100°C or lower.

[0027] [Washing of crude crystals] It is preferable to obtain crude crystals by filtering the resulting slurry, and then wash the crude crystals. Specifically, it is preferable to prepare washed crude crystals by washing the crude crystals with an aliphatic hydrocarbon solvent and then with water. It is preferable to wash first with an aliphatic hydrocarbon solvent. This is because if washing with water is performed first, there is a risk that hydroxyphenyl (meth)acrylate may dissolve in the washing water due to the influence of (meth)acrylic acid, which is a decomposition product of residual (meth)acrylic anhydride, and the reaction solvent. Furthermore, there is a risk that phenylenedi (meth)acrylate remaining in the reaction solution attached to the crude crystals may crystallize when water is added, leading to a decrease in purity. Therefore, it is preferable to wash first with an aliphatic hydrocarbon solvent.

[0028] Washing with an aliphatic hydrocarbon solvent involves contacting the crude crystals with the aliphatic hydrocarbon solvent to reduce the phenylenedi(meth)acrylate content. Washing with an aliphatic hydrocarbon solvent is preferably performed multiple times to further reduce the phenylenedi(meth)acrylate content. The amount of aliphatic hydrocarbon solvent is preferably 30 to 300 parts by mass, more preferably 50 to 200 parts by mass, and particularly preferably 70 to 150 parts by mass, per 100 parts by mass of divalent phenols before the reaction. By setting the amount of aliphatic hydrocarbon solvent within this range, efficient removal of phenylenedi(meth)acrylate can be achieved. The type of aliphatic hydrocarbon solvent used for washing the crude crystals is not particularly limited, but for example, the aliphatic hydrocarbon solvents exemplified in the process of preparing the crude crystals described above can be used.

[0029] Washing with an aliphatic hydrocarbon solvent is preferably repeated until the phenylenedi(meth)acrylate content is 0.3 mol% or less. When the phenylenedi(meth)acrylate content is 0.3 mol% or less, the phenylenedi(meth)acrylate content in the final hydroxyphenyl(meth)acrylate is reduced, which can suppress the increase in molecular weight and gelation during polymerization.

[0030] For washing with water, the content of divalent phenols is reduced by bringing the crude crystals into contact with water. The temperature of the washing water is preferably 10 to 60°C, and it is preferable to wash with water two or more times. When washing with water two or more times, it is preferable to wash at different temperatures, and it is even more preferable to wash multiple times while increasing the water temperature. More specifically, it is preferable to wash with water at 10 to 30°C to reduce the content of divalent phenols to 30 mol% or less relative to hydroxyphenyl (meth)acrylate, and then wash with water at a temperature of 30 to 60°C to further reduce the content of divalent phenols. Washing at 10 to 30°C first is preferable because it reduces the amount of hydroxyphenyl (meth)acrylate that dissolves in water, thus increasing the yield and allowing for higher purity because the amount of phenylenedi(meth)acrylate relative to hydroxyphenyl (meth)acrylate is relatively small.

[0031] The amount of washing water used per wash is preferably 50 to 200 parts by mass per 100 parts by mass of the divalent phenols before the reaction. Washing with water is preferably repeated until the content of divalent phenols is 0.5 mol% or less.

[0032] After washing with an aliphatic hydrocarbon solvent and water, the washed crude crystals may be further purified by recrystallization or crystallization, and it is preferable to perform crystallization with a water-soluble solvent and water. This operation can suppress discoloration and further reduce the amount of divalent phenols used as raw materials. After dissolving the washed crude crystals in a water-soluble solvent, water is added to precipitate the crystals, and high-purity hydroxyphenyl (meth)acrylate can be obtained by filtering and drying.

[0033] The water-soluble solvent can be any solvent that can dissolve the washed crude crystals and is also miscible with water. Examples include methanol, ethanol, acetone, dimethylformamide, and N-methylpiperidone, with methanol, ethanol, and acetone being preferred. The temperature of the water-soluble solvent during dissolution is preferably 25°C or higher.

[0034] The amount of water-soluble solvent is preferably 30 to 200 parts by mass, and more preferably 50 to 150 parts by mass, per 100 parts by mass of the obtained crude crystals. The amount of water is preferably 200 to 600 parts by mass, and more preferably 300 to 500 parts by mass, per 100 parts by mass of the water-soluble solvent.

[0035] While known drying methods can be used, vacuum drying is preferred from the viewpoint of manufacturing efficiency, with a drying temperature of 20-60°C being preferred and 30-40°C more preferred. From the viewpoint of suppressing the formation of insoluble matter during vacuum drying, a gas having polymerization inhibitory properties may be introduced during drying.

[0036] As described above, the manufacturing method of the present invention yields hydroxyphenyl (meth)acrylate with minimal coloration and high purity. Therefore, the hydroxyphenyl (meth)acrylate obtained by the present invention can be suitably used as a raw material monomer for resist resins. [Examples]

[0037] The present invention will be described in more detail below with reference to examples and comparative examples.

[0038] [Analysis method] • Purity of hydroxyphenyl (meth)acrylate, and content of divalent phenols and phenylenedi(meth)acrylate Using gas chromatography (GC), the content of hydroxyphenyl (meth)acrylate (A), divalent phenols (B), and phenylenedi(meth)acrylate (C) was calculated from the percentage of the peak area of ​​each component relative to the total peak area of ​​(A), (B), and (C) under the following conditions. GC conditions Equipment: GC-2014 (manufactured by Shimadzu Corporation) Column: DB-1 Injection temperature: 300℃ Detector temperature: 300℃ Temperature rise profile: Hold at 40°C for 5 minutes → Increase temperature at 20°C / min → Increase temperature to 300°C and hold for 2 minutes Injection volume: 2μL Detector: FID Range 1 Carrier gas: Nitrogen 70kPa Split ratio: 1 / 30 Diluting solvent: Acetone Sample concentration: 1 wt%

[0039] Based on the gas chromatography (GC) analysis described above, the phenylenedi(meth)acrylate (C) content was evaluated according to the following criteria. ◎: Phenylenedi(meth)acrylate content: Less than 0.5% ○: Phenylenedi(meth)acrylate content: 0.5% or more, less than 1.0% ×: Phenylenedi(meth)acrylate amount: 1.0 or more

[0040] • Hydrocarbon solvent content Using gas chromatography (GC), the respective contents of hexane (D) and toluene (E) were calculated from the percentage of the peak area of ​​each component relative to the sum of the peak areas of (A), (B), (C), (D), and (E) under the following conditions. GC conditions Equipment: GC-2014 (manufactured by Shimadzu Corporation) Column: DB-1 Injection temperature: 300℃ Detector temperature: 300℃ Temperature rise profile: Hold at 40°C for 5 minutes → Increase temperature at 20°C / min → Increase temperature to 300°C and hold for 2 minutes Injection volume: 2μL Detector: FID Range 1 Carrier gas: Nitrogen 70kPa Split ratio: 1 / 30 Diluting solvent: Dimethylformamide Sample concentration: 10 wt%

[0041] Based on the analysis of toluene content by gas chromatography (GC) as described above, the following criteria were used for evaluation. ○: Does not contain toluene ×: Contains toluene

[0042] ·Sulfur content The sulfur content is expressed as the content relative to 100% by mass of the total hydroxyphenyl (meth)acrylate, and while there are no particular restrictions on its measurement, it can be measured by known methods. For example, it can be measured and calculated using an inductively coupled plasma mass spectrometer (ICP-MS). The measurement was performed using an inductively coupled plasma mass spectrometer (ICP-MS, manufactured by Agilent, product name Agilent 8900 triple quadrupole ICP-MS).

[0043] ·Hue The degree of coloration of hydroxyphenyl (meth)acrylate was evaluated using the Hazen color number of a 10 wt% hydroxyphenyl (meth)acrylate solution (solvent: methanol). Equipment: OEM-2000 (manufactured by Nippon Denshoku Co., Ltd.) Light source: Halogen lamp 12V 12W Cell: Borosilicate glass (optical path length = 50 mm) ○: Hazen has fewer than 20 colors. ×: Hazen has more than 20 colors.

[0044] • Corrosion test The corrosiveness of hydroxyphenyl (meth)acrylate to copper was investigated by immersing copper foil in a 40 wt% hydroxyphenyl (meth)acrylate solution (solvent: isopropanol) and leaving it standing in a 60°C constant temperature bath for 72 hours. After standing, the copper foil was removed and its appearance was evaluated. ○: No change in the appearance of the copper foil. ×: The copper foil has corroded (black)

[0045] In each example and comparative example, a purity of hydroxyphenyl (meth)acrylate of 99.0% or higher is considered high purity, and a hue (Hazen color number) of 20 or less is considered low coloration.

[0046] [Example 1] (Esterification reaction) 1000g of hydroquinone (HQ), 1564g of methacrylic acid, 700g of methacrylic anhydride, and 10g of sodium hypophosphite were added to a 5L separable flask and reacted at 120°C for 1 hour. [Preparation of slurry] After cooling the reaction solution from 120°C to 65°C, 1000 g of hexane was slowly added dropwise while maintaining the temperature at 65°C. After adding the hexane, the mixture was cooled to 15°C and stirred for 30 minutes to prepare a slurry containing crude crystals of hydroxyphenyl methacrylate.

[0047] [Washing of crude crystals] The obtained slurry was filtered to recover crude hydroxyphenyl methacrylate crystals. The obtained crude crystals were then washed with 800 g of hexane by stirring, followed by filtration to recover the crude crystals. Subsequently, the crude crystals were washed again with 800 g of hexane by stirring, followed by filtration to recover the crude crystals. Next, the obtained crude crystals were washed with 1000 g of water prepared at 15°C by stirring, followed by filtration to recover the crude crystals. Subsequently, the crude crystals were washed again with 1000 g of water prepared at 15°C by stirring, followed by filtration to recover the crude crystals. Next, the obtained crude crystals were washed with hot water heated to 40°C, and the crude crystals were recovered by filtration. Then, they were washed again with 1000g of hot water heated to 40°C, and the washed crude crystals were recovered by filtration. The amount of hydroquinone in the crude crystals was measured to be 0.15%. The crude hydroxyphenyl methacrylate crystals were repeatedly washed with water, and the resulting hydroxyphenyl methacrylate crystals were dissolved in 437 g of acetone. Reprecipitation was then performed by adding deionized water. After recovering the obtained hydroxyphenyl methacrylate crystals, vacuum drying was performed at an ambient temperature of 40°C to obtain 420 g of white 4-hydroxyphenyl methacrylate crystals (divalent phenol: ND, phenylenedi(meth)acrylate: 0.3%, purity: 99.7%, Hazen color number in 10 wt% MeOH solution: 4, yield: 26%). The evaluation results are shown in Table 1. In the table, "ND" means that the substance was not detected.

[0048] [Example 2] In the esterification reaction, the same procedure as in Example 1 was followed, except that 770 g of methacrylic anhydride was added to the initial hydroquinone. 440 g of white crystals were obtained (divalent phenol: ND, phenylenedi(meth)acrylate: 0.4%, purity: 99.6%, Hazen color number in 10 wt% MeOH solution: 5, yield: 27%). The evaluation results are shown in Table 1.

[0049] [Example 3] In the esterification reaction, the same procedure as in Example 2 was followed, except that 840 g of methacrylic anhydride was added to the initial hydroquinone. 481 g of white crystals were obtained (divalent phenol: ND, phenylenedi(meth)acrylate: 0.7%, purity: 99.3%, Hazen color number in 10 wt% MeOH solution: 7, yield: 30%). The evaluation results are shown in Table 1.

[0050] [Example 4] [Esterification reaction] 100g of hydroquinone (HQ), 100g of methyl ethyl ketone, 77g of methacrylic anhydride, and 1g of sodium hypophosphite were added to a 1L separable flask and reacted at 65°C for 5 hours.

[0051] [Preparation of slurry] 100 g of hexane was slowly added dropwise to the reaction solution while maintaining the temperature at 65°C. After adding the hexane, the mixture was cooled to 15°C and stirred for 30 minutes to prepare a slurry containing crude crystals of hydroxyphenyl methacrylate. [Washing of crude crystals] The obtained slurry was filtered to recover crude hydroxyphenyl methacrylate crystals. The obtained crude crystals were then stirred and washed with 80 g of hexane, followed by filtration to recover the crude crystals. Subsequently, the crude crystals were stirred and washed again with 80 g of hexane, followed by filtration to recover the crude crystals. Next, the obtained crude crystals were stirred and washed with 100 g of water prepared at 15°C, followed by filtration to recover the crude crystals. Subsequently, the crude crystals were stirred and washed again with 100 g of water prepared at 15°C, followed by filtration to recover the crude crystals. Next, the obtained crude crystals were washed with hot water heated to 40°C, and the crude crystals were recovered by filtration. Then, 60.2g of washed crude crystals were recovered by washing again with 100g of hot water heated to 40°C, and filtration. The amount of hydroquinone in the crude crystals was measured to be 0.04%. The crude hydroxyphenyl methacrylate crystals obtained were dissolved in 36 g of acetone, and then reprecipitation was performed by adding deionized water. After recovering the obtained hydroxyphenyl methacrylate crystals, vacuum drying was performed at an ambient temperature of 40°C to obtain 35.1 g of white 4-hydroxyphenyl methacrylate crystals (divalent phenol: ND, phenylenedi(meth)acrylate: 0.6%, purity: 99.4%, Hazen color number in 10 wt% MeOH solution: 3, yield: 22%). The evaluation results are shown in Table 1. In the table, "ND" means that it was not detected.

[0052] [Example 5] In the washing step for washing the crude crystals using water, the procedure was the same as in Example 2, except that stirring washing with water prepared at 15°C was omitted, and washing was performed only with water prepared at 40°C. 264 g of white crystals were obtained (divalent phenol: ND, phenylenedi(meth)acrylate: 0.6%, purity: 99.4%, Hazen color number in 10 wt% MeOH solution: 7, yield: 16%). The evaluation results are shown in Table 1.

[0053] [Example 6] In the slurry preparation process, the same procedure as in Example 1 was followed, except that the slurry temperature during hexane charging was changed from 65°C to 25°C. 455 g of white crystals were obtained (divalent phenol: ND, phenylenedi(meth)acrylate: 0.9%, purity: 99.1%, Hazen color number in 10 wt% MeOH solution: 8, yield: 28%). The evaluation results are shown in Table 1.

[0054] [Comparative Example 1] (Esterification reaction) Under a 7% oxygen / nitrogen gas atmosphere, 540g of hydroquinone (HQ), 1269g of methacrylic acid, 11g of p-toluenesulfonic acid (PTS), and 2.2g of sodium hypophosphite were added to a 3L separable flask. After adjusting the internal temperature to 120-130°C, the pressure was reduced to 40kPa absolute pressure until the water content in the reaction solution was 0.5% or less. When the production rate of 4-hydroxyphenyl methacrylate relative to the initial hydroquinone reached 55 mol%, the reduced pressure was immediately released, and the reaction was terminated by cooling. After confirming that the reaction solution had cooled to below 80°C, 37.2 g of triethylamine was added to neutralize the solution.

[0055] [Preparation of slurry] 540 g of hexane was slowly added dropwise while maintaining the temperature at 65°C. After adding the hexane, the mixture was cooled to 15°C and stirred for 30 minutes to prepare the slurry. [Washing of crude crystals] The obtained slurry was filtered to recover crude hydroxyphenyl methacrylate crystals. The obtained crude crystals were then stirred and washed with 432 g of hexane, followed by filtration to recover the crude crystals. Subsequently, the crude crystals were stirred and washed again with 432 g of hexane, followed by filtration to recover the crude crystals. Next, the obtained crude crystals were stirred and washed with 540 g of water prepared at 15°C, followed by filtration to recover the crude crystals. Subsequently, the crude crystals were stirred and washed again with 540 g of water prepared at 15°C, followed by filtration to recover the crude crystals. Next, the obtained crude crystals were washed with hot water heated to 40°C, and the crude crystals were recovered by filtration. Then, 540g of the crude crystals were washed again with hot water heated to 40°C, and the washed 517g was recovered by filtration. The amount of hydroquinone in the crude crystals was measured to be 0.09%. The crude hydroxyphenyl methacrylate crystals were repeatedly washed with water, dissolved in 310 g of acetone, and then reprecipitation was performed by adding deionized water. After recovering the obtained hydroxyphenyl methacrylate crystals, 302 g of white 4-hydroxyphenyl methacrylate crystals were obtained by vacuum drying at an ambient temperature of 40°C (divalent phenol: ND, phenylenedi(meth)acrylate: 0.2%, purity: 99.8%, Hazen color number in 10 wt% MeOH solution: 60, yield: 35%). The evaluation results are shown in Table 2. In the table, "ND" means that it was not detected.

[0056] [Comparative Example 2] In the esterification reaction, the same procedure as in Example 2 was followed, except that sodium hypophosphite was not added, and 10 g of p-toluenesulfonic acid was added to the hydroquinone as an acid catalyst. 480 g of white crystals were obtained (divalent phenol: ND, phenylenedi(meth)acrylate: 0.4%, purity: 99.6%, Hazen color number in 10 wt% MeOH solution: 30, yield: 30%). The evaluation results are shown in Table 2.

[0057] [Comparative Example 3] 240 g of the white crystals obtained in Comparative Example 2 were mixed with 360 g of toluene, and the temperature was raised to 80°C to dissolve 4-hydroxyphenyl methacrylate. Then, recrystallization was performed by cooling the mixture to 10°C at a rate of -2°C / min while stirring. After collecting the obtained hydroxyphenyl methacrylate crystals, vacuum drying was performed at an ambient temperature of 40°C to obtain 216 g of needle-shaped 4-hydroxyphenyl methacrylate crystals (divalent phenol: ND, phenylenedi(meth)acrylate: 0.1%, purity: 99.9%, Hazen color number in 10 wt% MeOH solution: 5, yield: 27%). The evaluation results are shown in Table 2.

[0058] [Comparative Example 4] In the esterification reaction, the procedure was the same as in Example 2, except that sodium hypophosphite was not added and the reaction was carried out at 120°C for 5 hours. 435 g of white crystals were obtained (divalent phenol: ND, phenylenedi(meth)acrylate: 0.4%, purity: 99.6%, Hazen color number in 10 wt% MeOH solution: 100, yield: 28%). The evaluation results are shown in Table 2.

[0059] [Table 1]

[0060] [Table 2]

[0061] As shown in Examples 1 to 6, it was found that the manufacturing method of the present invention yields high-purity hydroxyphenyl (meth)acrylate with minimal discoloration and free from sulfur and toluene components. In contrast, Comparative Examples 1 and 2, which are obtained by reacting hydroquinone with (meth)acrylic acid or methacrylic anhydride under a strongly acidic catalyst, do not yield high-purity hydroxyphenyl (meth)acrylate with little discoloration and no sulfur content. Furthermore, since recrystallization using toluene shows some effect in improving the hue and reducing the sulfur content, Comparative Example 3, which was implemented using this method, showed some effect in reducing discoloration and sulfur content, but did not yield high-purity hydroxyphenyl (meth)acrylate that does not contain sulfur or toluene. In Comparative Example 4, hydroxyphenyl (meth)acrylate was obtained using a method that does not include a phosphorus-based oxoacid catalyst, and although it did not contain sulfur, it did not yield high-purity hydroxyphenyl (meth)acrylate with little discoloration. In all of these manufacturing methods, the results were inferior to the manufacturing methods of the Examples.

Claims

1. A method for producing hydroxyphenyl (meth)acrylate, characterized by comprising the step of reacting divalent phenols and (meth)acrylic anhydride in the presence of a phosphorus-based oxo salt to prepare a reaction solution containing hydroxyphenyl (meth)acrylate and a by-product, phenylenedi (meth)acrylate.

2. The method for producing hydroxyphenyl (meth)acrylate according to claim 1, further comprising the step of adding an aliphatic hydrocarbon solvent to the reaction solution to obtain crude crystals of hydroxyphenyl (meth)acrylate, and washing the crude crystals.

3. A method for producing hydroxyphenyl (meth)acrylate according to claim 2, further comprising the step of washing the washed crude crystals with water to remove divalent phenols.

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