JP2005220300A - Method for manufacturing epoxy resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an efficient method for manufacturing an epoxy resin which exhibits excellent heat stability of its cured product and is useful for various composite materials, adhesives, coating materials, and the like. <P>SOLUTION: This epoxy resin is obtained by glycidylating a condensed phenol which is represented by formula (1) (wherein R is H or a ≤4C hydrocarbon chain; (m) is an integer of 0-5; and (n) is 1 or 2) and has ≥70 area% tetraphenol represented by a specific chemical formula with an epihalohydrin. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an efficient method for producing a highly crystalline epoxy resin that gives a cured product having extremely high heat resistance.

  Epoxy resins are generally cured with various curing agents, resulting in cured products with excellent mechanical properties, water resistance, chemical resistance, heat resistance, electrical properties, etc., adhesives, paints, laminates, moldings It is used in a wide range of fields such as materials and casting materials. Conventionally, as an epoxy resin most used industrially, a compound obtained by reacting bisphenol A with epichlorohydrin is known. In applications such as semiconductor encapsulants, cresol novolac epoxy resins are widely used because heat resistance is required. In addition, since surface mounting is common and semiconductor packages are often directly exposed to high temperatures during solder reflow, high filler filling is effective to reduce the water absorption rate and linear expansion coefficient of the entire sealing material. Has been proposed. In order to enable high filler filling, a low melt viscosity of the epoxy resin is a necessary condition. In order to satisfy such a demand, recently, an epoxy resin using tetramethylbiphenol as a raw material has been widely used. Since this epoxy resin has crystallinity, it exhibits a very low melt viscosity in the molten state.

  Although the epoxy resin made from tetramethylbiphenol as described above has a low melt viscosity and can be filled with a high filler, the heat resistance of the resin itself is extremely low. In recent years, for example, electrical and electronic parts such as semiconductors have been increasingly mounted around automobile engines. In such applications, the resin used is required to have extremely high heat resistance because it is exposed to a high temperature around 180 ° C. for a long time. In response to such problems, an epoxy resin using tetraphenol as a raw material has been proposed. (Patent Documents 1 and 2)

JP 09-003162 A JP-A No. 2004-10877

  The process for producing an epoxy resin using tetraphenol as a raw material, specifically, in Patent Document 2, the reaction mixture is washed with water after the reaction is completed, excess epichlorohydrin, reaction solvent, and the like are removed from the oil layer under heating and reduced pressure, and then the organic solvent is removed. In addition, it is cooled and the crystals are precipitated. However, the product crystals are precipitated in the reaction vessel during the process of removing excess epichlorohydrin, reaction solvent, etc. under heating and reduced pressure. Problems arise. In this case, since the solvent is taken into the product crystals, it is difficult to remove the solvent. In addition, when the crystal comes out, the crystal is applied to the stirring blade and cannot be stirred, which may cause damage to the apparatus. Further, in the recrystallization method based on the temperature difference, the crystal is not completely precipitated, and it is difficult to stabilize the purity and yield of the crystal due to the recrystallization time and the like, and the production efficiency is generally not good.

  In light of these circumstances, the present inventors have intensively studied methods for producing epoxy resins that are extremely high in heat resistance and useful for various composite materials, adhesives, paints, and the like. As a result, the crystallinity using tetraphenol as a raw material is high. An efficient method for producing an epoxy resin has been found and the present invention has been completed.

That is, the present invention
(1) General formula (1)

（式中複数存在するＲはＨもしくは炭素数４以下の炭化水素鎖を示す。ｍは０〜５の整数を示す。ｎは１又は２を示す。）で表される縮合フェノール類であって、一般式（２）

(In the formula, a plurality of Rs represent H or a hydrocarbon chain having 4 or less carbon atoms, m represents an integer of 0 to 5, and n represents 1 or 2). And general formula (2)

（式中複数存在するＲはＨもしくは炭素数４以下の炭化水素鎖を示す。ｎは１又は２を示す。）で表されるテトラフェノール体が７０面積％（高速液体クロマトグラフィーにおける測定波長２５０〜３００ｎｍの範囲の測定値）以上を占める縮合フェノール類を、エピハロヒドリンによりグリシジル化した後、エピハロヒドリンより３０℃以上沸点の高い溶媒であって、該グリシジル化物の良溶媒の存在下にエピハロヒドリンを留去し、得られた該グリシジル化物の溶液に該グリシジル化物の貧溶媒を添加し、析出した結晶を採取することを特徴とする、エポキシ樹脂の製造、
（２）一般式（２）においてＲがＨである（１）に記載のエポキシ樹脂の製造法、
に関する。

(A plurality of R in the formula represents H or a hydrocarbon chain having 4 or less carbon atoms. N represents 1 or 2) 70% by area (measurement wavelength 250 in high performance liquid chromatography) (Measured value in the range of ~ 300 nm) After glycidylation of condensed phenols occupying more than epihalohydrin, it is a solvent having a boiling point higher than that of epihalohydrin by 30 ° C or more, and the epihalohydrin is distilled off in the presence of a good solvent for the glycidylate. And adding a poor solvent for the glycidylated product to the resulting glycidylated product solution, and collecting the precipitated crystals,
(2) The method for producing an epoxy resin according to (1), wherein R is H in the general formula (2),
About.

  The production method of the epoxy resin of the present invention, which is extremely useful for a wide range of applications such as electrical / electronic materials, molding materials, casting materials, laminated materials, paints, adhesives, resists, optical materials, etc., yields compared to conventional methods Therefore, it is an industrially useful production method that allows the crystals to be taken out in powder form safely and easily.

  The raw material used in the production method of the present invention is a condensed phenol represented by the general formula (1), and the proportion of the tetraphenol compound represented by the general formula (2) is 70 area% (high speed Condensed phenols occupying more than (measured value by liquid chromatography) are used, and the proportion is preferably 80 area% or more, more preferably 98 area% or more. The UV measurement wavelength of the high performance liquid chromatography may be any wavelength as long as the absorption wavelength of the benzene ring is in the range of 250 to 300 nm. In the general formulas (1) and (2), R is a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, or a tert-butyl group, and the substitution position is ortho. Of the positions or meta positions, the meta position is preferred, and the number of substitutions is preferably 1 of 1 or 2. In the general formula (1), the carbon chain may be substituted at any of the ortho, meta, and para positions. In the present invention, condensed phenols in which R is a hydrogen atom are preferred, and 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane is preferred as the tetraphenol form of the general formula (2). A known method can be adopted as a method for obtaining a tetraphenol compound. For example, a phenol is subjected to a condensation reaction with glyoxal in the presence of an acid catalyst. In particular, as a method for synthesizing a high-purity tetraphenol compound, it is preferable to employ the methods shown in Japanese Patent No. 2897850 and Japanese Patent No. 3381819.

  In the production method of the present invention, first, the condensed phenol represented by the general formula (1) is reacted with epihalohydrin in the presence of an alkali metal hydroxide. In the present invention, a solvent having a boiling point 30 ° C. or higher than epihalohydrin (hereinafter referred to as HBS) is used. HBS may be coexisted during the reaction of the condensed phenols and epihalohydrin or may be added to the system after the reaction. .

  Examples of HBS here include amide compounds such as dimethylformamide (boiling point 153 ° C.), dimethylacetamide (boiling point 165.5 ° C.), diglyme (boiling point 162 ° C.), triglyme (boiling point 216 ° C.), tetraglyme (boiling point 275 ° C.). ), Ethers such as cycloheptanone (boiling point 179 to 180 ° C.), ketones such as cyclohexanone (boiling point 155 ° C.), dimethyl sulfoxide (boiling point 189 ° C.), and the like, but higher than the boiling point of epihalohydrin used in the reaction What is necessary is just a good solvent of the epoxy resin obtained by the manufacturing method of this invention with a boiling point of 30 degreeC or more, and it is not limited to what was illustrated. In the present invention, dimethyl sulfoxide is particularly preferable.

  The amount of HBS used is usually 30 to 1000% by weight with respect to the amount of condensed phenols represented by the general formula (1), but considering the crystal precipitation and yield, the preferred range is 100 to 100%. 600% by weight.

  In the production method of the present invention, the alkali metal hydroxide may be a solid or an aqueous solution. When an aqueous solution is used, the alkali metal hydroxide aqueous solution is continuously added to the reaction system, and water and epihalohydrin are distilled off continuously under reduced pressure or normal pressure, and the distillate is further separated. Alternatively, water may be removed and epihalohydrin may be continuously returned to the reaction system. The usage-amount of an alkali metal hydroxide is 0.9-2.5 mol normally with respect to 1 mol of hydroxyl groups of condensed phenol represented by General formula (1), Preferably it is 0.95-2.0 mol. It is.

  In this reaction, a quaternary ammonium salt can be added as a catalyst to facilitate the reaction. Examples of quaternary ammonium salts that can be used include tetramethylammonium chloride, tetramethylammonium bromide, and trimethylbenzylammonium chloride. The amount of the quaternary ammonium salt used is usually 0.1 to 15 g, preferably 0.2 to 10 g based on 1 equivalent of the hydroxyl group of the condensed phenol represented by the general formula (1).

  The usage-amount of epihalohydrin is 0.8-12 equivalent normally with respect to 1 equivalent of hydroxyl groups of condensed phenol represented by General formula (1), Preferably it is 0.9-11 equivalent. Examples of the epihalohydrin to be used include epichlorohydrin, epibromohydrin and the like, but an epichlorohydrin derivative is industrially easy to use, and epichlorohydrin (boiling point 116 ° C.) is preferred in the present invention. At this time, in order to enhance the solubility of the condensed phenols represented by the general formula (1), alcohols such as methanol, ethanol and isopropyl alcohol, aprotic polar solvents such as dimethylsulfone, dimethylsulfoxide, tetrahydrofuran and dioxane, etc. It is preferable to carry out the reaction by adding.

  When using alcohol, the amount of its use is 2-50 weight% normally with respect to the usage-amount of epihalohydrin, Preferably it is 4-30 weight%. Moreover, when using an aprotic polar solvent, it is 5-100 weight% normally with respect to the usage-amount of epihalohydrin, Preferably it is 10-80 weight%.

  The reaction temperature is usually 30 to 90 ° C., preferably 35 to 80 ° C. The temperature may be constant or may be changed with time. The reaction time is usually 0.5 to 10 hours, preferably 1 to 8 hours.

  In the production method of the present invention, after completion of the reaction, if necessary, the reaction solution is washed with water, or the reaction solution is cooled to room temperature and then filtered to remove salts generated during the reaction. It is important to perform this operation because the salt may be mixed into the crystal during the precipitation of the epoxy resin.

  When HBS is not used in this reaction, HBS is added after completion of the reaction or after removing the salt.

  The reaction mixture containing the reaction product, epihalohydrin, HBS and the like is heated under reduced pressure to distill off excess epihalohydrin and the like to obtain an HBS solution. The conditions of heating and depressurization vary depending on the solvent used. For example, when epichlorohydrin is used as epihalohydrin and dimethyl sulfoxide is used as HBS, the heating is performed at 50 to 100 ° C., and the degree of depressurization is about 0.1 kPa to 25 kPa. Good. It is not preferable that the epihalohydrin remains in the product because of environmental influences, and it is preferable to remove the epihalohydrin as much as possible at this point.

  The salt precipitated during the reaction may be removed at this time after preparing the HBS solution except for epihalohydrin and the like.

  The target epoxy resin is precipitated as crystals by adding a poor solvent while stirring the obtained HBS solution.

  As the poor solvent that can be used for precipitating the epoxy resin obtained by the production method of the present invention, a poor solvent that is compatible with the used HBS and is difficult to dissolve the target epoxy resin is preferable. In the case of the present invention, lower alcohols such as methanol, ethanol and isopropyl alcohol, and aliphatic or aromatic hydrocarbon compounds such as water, toluene, xylene and cyclohexane may be used, and two or more kinds may be used in combination. Absent. However, since salt may remain in the system, it is preferable to use water or a lower alcohol such as methanol.

  The poor solvent may be added all at once or in divided portions. Since the conditions vary depending on the solvent used, the range cannot be specified in general, but generally 50% by weight or more is used with respect to the amount of HBS used. However, an excessively poor poor solvent requires a large amount of energy for the treatment, so 50 to 500% by weight is preferable. The temperature conditions at the time of addition are adjusted as appropriate. It is also possible to adjust the purity of the epoxy resin obtained by the production method of the present invention by adjusting the amount of the poor solvent to be added.

  The precipitated crystals are filtered using a normal pressure or vacuum filter to obtain a crystalline epoxy resin obtained by the production method of the present invention. The obtained epoxy resin is preferably further washed with the above organic solvent, alcohols such as methanol and ethanol, and water.

EXAMPLES Next, the present invention will be described more specifically with reference to examples. In the following, parts are parts by weight unless otherwise specified. The content was determined by high performance liquid chromatography (column: Intersil ODS-2.5 μm, 2.1 × 250 mm; measurement temperature: 40 ° C .; solvent: acetonitrile / H ₂ O: 0 min 50% / 50%, 20 min 90% / 10% gradient, 40 min 90% / 10%; flow rate: 0.2 mL / min; measured wavelength: 254 nm), melting peak temperature is the differential scanning calorimetry (DSC: Differential Scanning Calorimetry, Seiko Instruments Inc.). , EXSTAR6000).

Example 1
A condensate of glyoxal and phenol (including 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane content: 98 while applying nitrogen gas purge to a flask equipped with a thermometer, dropping funnel, condenser, and stirrer 9.9 area%) 99.5 parts, 740 parts of epichlorohydrin, and 108 parts of methanol were charged and heated to about 70 ° C. with stirring to be dissolved. Next, 40 parts of flaky sodium hydroxide was added in portions over 90 minutes, and then reacted at reflux temperature (69-80 ° C.) for 1 hour. After completion of the reaction, 250 parts of water was added and washed to remove the generated salt, etc., and then 250 parts of dimethyl sulfoxide was added. Was distilled off. While maintaining the residual solution at 50 ° C., 100 parts of methanol was added and stirred for 15 minutes, and then the temperature was further raised to 70 ° C., and 500 parts of water was gradually added. After cooling to room temperature, the crystalline epoxy resin of the present invention was obtained by filtration under reduced pressure. Further, the crystal was sufficiently washed with a mixed solution of 100 parts of methanol and 300 parts of water and dried to give 141 parts (yield 90%) of the crystalline epoxy resin obtained by the production method of the present invention as colorless powdery crystals. Obtained. Among them, 1,1,2,2-tetrakis (4-glycidyloxyphenyl) ethane was contained by 79.3 area%. When the melting peak temperature was measured by DSC at a heating rate of 10 K / min, it was 455.1 K.

Example 2
A condensate of glyoxal and phenol (including 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane content: 98 while applying nitrogen gas purge to a flask equipped with a thermometer, dropping funnel, condenser, and stirrer 9.9 area%) 99.5 parts, 740 parts of epichlorohydrin and 554 parts of dimethyl sulfoxide were charged, and the temperature was raised to about 45 ° C. with stirring. Next, 40 parts of flaky sodium hydroxide was added in portions over 90 minutes, and then further reacted at 45 ° C. for 2 hours, 60 ° C. for 1 hour, and 70 ° C. for 30 minutes. After completion of the reaction, excess epichlorohydrin and the like were distilled off using a rotary evaporator at 80 ° C. and 0.2 kPa for 2 hours. The resulting residual solvent was filtered under reduced pressure to remove the generated salt. While keeping the obtained filtrate at 50 ° C., 100 parts of methanol was added and stirred for 15 minutes, and then 250 parts of water was added. Thereafter, the temperature was further raised to 70 ° C., stirred for 15 minutes, cooled to 50 ° C., and 300 parts of water was gradually added again. The target epoxy resin was obtained by filtering under reduced pressure after cooling to room temperature. Further, the crystal was sufficiently washed with 300 parts of warm water of 70 ° C. and dried to obtain 135 parts (yield 86%) of a crystalline epoxy resin obtained by the production method of the present invention as a slightly yellowish powdery crystal. %). Among them, 1,1,2,2-tetrakis (4-glycidyloxyphenyl) ethane was contained by 71.5 area%. The melting peak temperature was 452.8K as measured by DSC at a heating rate of 10K / min.

Example 3
Except for using 99.5 parts of a condensate of glyoxal and phenol (including 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane content: 83.1 area%) as phenols in Example 1. The same operation as in Example 1 was performed. As a result, 138 parts (yield 88%) of a crystalline epoxy resin obtained by the production method of the present invention was obtained as colorless powdery crystals. Among them, 1,3.7,2-tetrakis (4-glycidyloxyphenyl) ethane was contained in 63.7 area%. When the melting peak temperature was measured by DSC at a heating rate of 10 K / min, it was 446.1 K.

  From the above results, it can be said that the production method of the present invention is an efficient production method capable of producing a crystalline epoxy resin simply and stably.

Claims (2)

General formula (1)

(In the formula, a plurality of Rs represent H or a hydrocarbon chain having 4 or less carbon atoms, m represents an integer of 0 to 5, and n represents 1 or 2). And general formula (2)

(A plurality of R in the formula represents H or a hydrocarbon chain having 4 or less carbon atoms. N represents 1 or 2) 70% by area (measurement wavelength 250 in high performance liquid chromatography) (Measured value in the range of ~ 300 nm) After glycidylation of condensed phenols occupying more than epihalohydrin, it is a solvent having a boiling point higher than that of epihalohydrin by 30 ° C or more, and the epihalohydrin is distilled off in the presence of a good solvent for the glycidylate. Then, a poor solvent for the glycidylated product is added to the resulting solution of the glycidylated product, and the precipitated crystals are collected. The method for producing an epoxy resin according to claim 1, wherein R is H in the general formula (2).