JPH0791360B2 - Process for producing glycidyl ether of polyphenol - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a method for producing an epoxy resin, which is preferably used for electrical and electronic industries, particularly for encapsulating electronic parts, and a laminate material.

<Prior Art> Epoxy resins for electronic materials are required to have heat resistance and low hygroscopicity. At present, glycidyl ether of o-cresol novolac is the mainstream, but higher performance is required.

Glycidyl ether of tris (hydroxyphenyl) methane is used as a heat resistant epoxy resin for paints, adhesives,
Widely applied to fiber reinforced resin, etc.

Further, it is expected to be applied to the electric and electronic industries such as for sealing electronic parts or for laminated plates.

For use in the fields of electricity and electronics, there is a demand for a resin having high purity, particularly a resin having a low content of hydrolyzable chlorine.

On the other hand, tris (hydroxyphenyl) methane is apt to cause high molecular weight or gelation due to an intermolecular reaction during glycidyl etherification.

Polymers that have been polymerized by intermolecular reaction are not preferred because the epoxy equivalent becomes high, the crosslink density when cured into a molded product decreases, and the heat resistance deteriorates.

In order to control the intermolecular reaction and obtain a resin having a low epoxy equivalent, various measures have been conventionally performed.

For example, Industrial and Engineering Chemistr
y) VOL 45 , 2715 (1953) describes a method in which a sodium salt of tris (hydroxyphenyl) methane is added to epichlorohydrin in a molar amount of 5 times the phenolic hydroxyl group.

Further, in JP-B-57-13571, at least 10-fold mole of epihalohydrin is used per mole of phenolic hydroxyl group, the reaction is carried out in the presence of a coupling catalyst in the first step, and the base is added in the second step. A method of adding and glycidyl etherification is described.

Further, JP-A-57-141419 discloses that a polyhydric phenol obtained by condensing a phenol such as phenol, an alkyl mono-substituted phenol, a halogen-substituted phenol and an aromatic aldehyde is converted into a glycidyl ether by a well-known general-purpose method. Is disclosed.

<Problems to be solved by the invention> Industrial and engineering mentioned above
According to the chemistry method, the epoxy value of the product is
As low as 0.32 (that is, the epoxy equivalent is as high as 313) and the yield is as low as 54%, it is not a satisfactory method.

Also, the epoxy equivalent of the product of Japanese Patent Publication No. 57-13571 is
158, which is close to the theoretical value.

However, the hydrolyzable chlorine content is so high that it is not satisfactory for use in the electrical and electronic industries.

This method also uses a large amount of epihalohydrin,
In other words, productivity is low and it cannot be said that this method is industrially advantageous.

Glycidyl ether obtained by the method disclosed in JP-A-57-141419 has low purity, and particularly contains a large amount of hydrolyzed chlorine, and needs further improvement.

<Means for Solving the Problems> The present invention has the general formula (I) (In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ are a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a phenyl group.

R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , and R ¹² are hydrogen atoms, or alkyl groups and alkoxy groups having 1 to 4 carbon atoms.

X is a chlorine atom or a bromine atom.

a, b, c, d, and e are numbers 0 or 1, and n is a number 0 to 5 on average. ) In the method for producing a glycidyl ether of a polyhydric phenol by reacting a polyhydric phenol represented by and epichlorohydrin in the presence of an alkali metal hydroxide, the reaction between the polyhydric phenol and epichlorohydrin, A high-purity glycidyl ether of the polyhydric phenol characterized by treating the crude glycidyl ether of the polyhydric phenol with an alkaline substance in an organic solvent, followed by treatment in the presence of an aprotic polar solvent. A manufacturing method is provided.

Specific examples of R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ in the general formula (1) include hydrogen, methyl group, ethyl group, propyl group, butyl group, amyl group and hexyl group. , A phenyl group and the like.

Further, specific examples of R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , and R ¹² are a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, a methoxy group, an ethoxy group, and the like, It is preferably a hydrogen atom or a methyl group. n is an average number of repeating units and is 0 to 5.

When n exceeds 0, that is, the oligomer is more preferable in terms of heat resistance, but when it exceeds 5 and becomes too large, the melt viscosity becomes high, and the operability and the moldability are deteriorated.

The polyhydric phenols represented by the general formula (1) can be obtained, for example, by the general formula (II) (In the formula, R corresponds to R ¹¹ and R ¹² in the general formula (1), and R ′,
R ″ corresponds to R ⁷ , R ⁸ , R ⁹ and R ¹⁰ of the general formula (I), and Y
Corresponds to X _b and X _d in the general formula (I). ) Is obtained by condensation of an aromatic carbonyl compound represented by

Specific examples of the aromatic carbonyl compound include hydroxybenzaldehyde, methylhydroxybenzaldehyde, methoxyhydroxybenzaldehyde, dimethylhydroxybenzaldehyde, chlorohydroxybenzaldehyde, bromobenzaldehyde, hydroxyacetophenone, hydroxyphenylethylketone and hydroxyphenylbutylketone.

A small amount of another carbonyl compound may be used in combination with the aromatic carbonyl compound.

For example, formaldehyde, acetaldehyde, crotonaldehyde, acrolein, glyoxal, benzaldehyde and the like.

Examples of phenols include phenol, cresol, ethylphenol, propylphenol, butylphenol, amylphenol, hexylphenol, methoxyphenol, phenylphenol, methylpropylphenol, methylbutylphenol, methylhexylphenol, methylphenylphenol, chlorophenol, bromo. Phenol, chlorcresol, bromocresol and the like.

Condensation of aromatic carbonyl compounds with phenols requires 0.5-1 phenols per mole of aromatic carbonyl compound.
Well-known acidic catalysts for synthesizing novolac, for example, mineral acids such as hydrochloric acid, sulfuric acid, phosphoric acid; organic acids such as oxalic acid and toluenesulfonic acid;
It is carried out in the presence of a salt such as zinc acetate.

At this time, an aromatic solvent such as toluene or chlorobenzene may be used.

In order to increase the number of repeating units as an oligomer, the ratio of phenols may be decreased, the temperature may be increased, and the catalyst may be increased.

The polyhydric phenols thus obtained can be halogenated with chlorine or bromine by a known method.

Next, the amount of epichlorohydrin used for the glycidyl etherification reaction of polyhydric phenols is preferably 2.5 to 8 mols per mol of phenolic hydroxyl groups.

When the amount of epichlorohydrin used is small, the production of high molecular weight products by intermolecular reaction causes quality deterioration such as increase in melt viscosity of the glycidyl ether of the polyhydric phenol and further increases gel production, which is industrially disadvantageous. It is not preferable because the volume of the reaction mixture increases only when the amount of epichlorohydrin is increased more than necessary, which is not preferable because it causes industrial disadvantages such as reduction in productivity.

The alkali metal hydroxide used in the present invention is specifically sodium hydroxide, potassium hydroxide or the like.

The amount of the alkali metal hydroxide used is preferably about equimolar to 1 mol of the phenolic hydroxyl group.

When the amount of the alkali metal hydroxide used is small, unreacted phenolic hydroxyl groups remain, which is not preferable.

If the amount of alkali metal hydroxide used is large, the amount of gel increases, which is disadvantageous in manufacturing.

The alkali metal hydroxide is used as an aqueous solution, but a high concentration is preferable because water is removed in the reaction system.

The aprotic polar solvent used in the present invention is specifically dimethyl sulfoxide, dimethyl sulfone, dimethylacetamide, tetramethylurea, hexamethylphosphoramide and the like.

The amount of these aprotic polar solvents used is preferably 200 parts by weight or more and 100 parts by weight or less with respect to 100 parts by weight of epichlorohydrin.

When the amount used is small, the effect of reducing hydrolyzable chlorine is not so remarkable.

In addition, if used in excess of necessity, intermolecular reaction proceeds,
The epoxy equivalent (molecular weight per 1 mol of epoxy group) becomes large, the quality as an epoxy resin deteriorates, and the productivity also decreases, which is not preferable.

In the present invention, the glycidyl etherification reaction of the polyhydric phenols can be carried out, for example, as follows.

First, the polyhydric phenol, epichlorohydrin, and aprotic polar solvent are mixed in the above-described proportions to form a uniform solution.

Then, while stirring and mixing, an alkali metal hydroxide is added to carry out the reaction.

This reaction is carried out at a temperature of 20 ° C to 80 ° C.

More preferably, it is in the range of 30 to 70 ° C.

In the case of the present invention, the influence of the reaction temperature is large, and the lower the temperature, the higher the selectivity of the reaction and the lower the content of hydrolyzable chlorine.

If the temperature exceeds 80 ° C., the effect of the present invention is small, and if the temperature is too low, the reaction rate becomes slow and the productivity decreases, which is not desirable.

In this reaction, volatile components are condensed under reduced pressure at a temperature of 20 ° C. to 80 ° C., and the condensate is separated into an oil phase and an aqueous phase and only the oil phase is returned to the reaction system for dehydration.

At this time, the water content in the reaction system is 0.5 to 5.0 wt%, preferably,
Set the temperature / pressure conditions such that 0.5 to 3.0 wt%.

If the water content in the reaction system is high, the amount of hydrolyzable chlorine is increased, the epoxy equivalent is increased, and other adverse effects are exerted. Further, epichlorohydrin is decomposed and the loss is increased, which is not preferable.

The pressure is inevitably determined if the temperature is determined according to the composition of the reaction system.

The alkali metal hydroxide is added in small portions in a divided manner or continuously over a period of 2 to 7 hours in order to uniformly react.

If it is temporarily added, the reaction locally proceeds to form a gel or it becomes impossible to maintain a predetermined water concentration, which is not preferable.

Removal of unreacted substances and by-products after completion of the reaction is carried out by a well-known and commonly used method.

For example, first, unreacted epichlorohydrin and residual water are removed by distillation, then dissolved in a kettle such as methyl isobutyl ketone or an aromatic hydrocarbon solvent such as toluene, and an insoluble alkali metal salt is filtered off. That's the way to go.

Subsequently, the aprotic polar solvent is removed by washing with water.

Then, the solvent is removed by distillation to obtain a crude glycidyl ether.

In the present invention, it is further treated with an alcal substance while being dissolved in the above organic solvent.

The alkaline substance is an alkali metal hydroxide, an alkaline earth metal hydroxide, an alkali metal carbonate or the like, and sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate and the like are used.

The amount of alkali used is 0.01 mol to 0.10 mol per mol of the phenolic hydroxyl group as the raw material.

When the amount used is small, the effect of reducing hydrolyzable chlorine is small,
In addition, if the amount used is too large, high molecular weight tends to occur,
Not preferable.

The alkaline substance is a fine powder or an aqueous solution mixed with the glycidyl ether organic solvent liquid of the polyhydric phenol,
React at 40 ℃ -100 ℃.

When the temperature is 40 ° C. or lower, the effect of reducing hydrolyzable chlorine is small, and when the temperature is 100 ° C. or higher, a high molecular weight reaction easily occurs, which is not preferable.

Excess alkaline substance is neutralized with phosphoric acid, carbon dioxide gas, etc., the neutralized salt is removed by filtration or washing with water, and the organic solvent is removed by distillation to obtain a highly pure glycidyl ether of the polyhydric phenol. obtain.

<Effect of the Invention> According to the present invention, a polyhydric phenol is epoxidized in the presence of a specific aprotic polar solvent, and further purified by an alkali in an organic solvent to reduce hydrolyzable chlorine, High-purity glycidyl ether having a small epoxy equivalent can be industrially obtained with high productivity.

Such a glycidyl ether has higher heat resistance than conventionally known ones, and is a highly pure epoxy resin material suitable for the electronic or electrical industry, particularly for highly integrated semiconductor encapsulation or laminates. Becomes

<Examples> Hereinafter, the present invention will be described with reference to Examples.

In the examples, the epoxy equivalent is defined as the molecular weight of the epoxy resin per epoxy group.

Hydrolyzable chlorine is an epoxy resin dissolved in dioxane, an alcohol solution of potassium hydroxide is added, and chlorine ions desorbed when heated at reflux for 30 minutes are quantified by titration with a silver nitrate solution, It is expressed as a weight percentage of chlorine atoms in the inside.

The water content in the reaction system was measured by the Karl Fischer method.

In addition, the average molecular weight and the average number of repeating units n are the gel permeation chromatograph (Nihon Bunko Kogyo Co., Ltd.).
Manufactured by TRIROTAR SR-II).

Reference Example 1 376 g of phenol and 48.8 p-hydroxybenzaldehyde were placed in a reactor equipped with a thermometer, a stirrer and a condenser.
g and p-toluenesulfonic acid (monohydrate) 0.38 g 95 to 10
The mixture was reacted at 5 ° C. for 6 hours under reflux with stirring.

Then, it was neutralized with a 10% sodium hydroxide solution, dissolved in toluene 1, washed twice with water, and then toluene and unreacted monomers were removed by distillation to obtain a condensed polyhydric phenol.

The average molecular weight was 411 and the average number of repeating units was 0.6.

Reference Example 2 A condensed polyhydric phenol was obtained in the same manner as in Reference Example 1 except that 75.2 g was used instead of 376 g of phenol.

The average molecular weight was 945, and the average number of repeating units n was 3.3.

Reference Example 3 A condensed polyhydric phenol was obtained in the same manner as in Reference Example 1 except that 432 g of o-cresol was used instead of 376 g of phenol.

The average molecular weight was 384, and the average number of repeating units n was 0.3.

Reference Example 4 A condensed polyhydric phenol was obtained in the same manner as in Reference Example 1 except that 657 g of 2-t-butyl-5-methylphenol was used instead of 376 g of phenol. Average molecular weight is 48
9, the average number of repeating units n was 0.2.

Reference Example 5 A condensed polyhydric phenol was obtained in the same manner as in Reference Example 1 except that 131.2 g of 2-t-butyl-5-methylphenol was used instead of 376 g of phenol.

The average molecular weight was 888, and the average number of repeating units n was 1.7.

Reference Example 6 In the same manner as in Reference Example 1 except that 98.4 g of 2-t-butyl-5-methylphenol and 21.6 g of m-cresol were used instead of 376 g of phenol, a polyhydric phenol as a condensate was obtained. .

The average molecular weight was 952, and the average number of repeating units n was 2.2.

Reference Example 7 In place of 376 g of phenol, 98.4 g of 2-t-butyl-5-methylphenol and 21.6 g of o-cresol were replaced with 48.8 g of p-hydroxybenzaldehyde, and 39 g of p-hydroxybenzaldehyde and 6.67 g of 36% formaldehyde. A condensed polyhydric phenol was obtained in the same manner as in Reference Example 1 except that the polyphenol was used.

The average molecular weight was 930, and the average number of repeating units n was 2.2.

Reference Example 8 In a reactor equipped with a thermometer, a stirrer, and a condenser, 376 g of phenol and 54.4 g of p-hydroxyacetophenone were charged, and HCl gas was bubbled for 4 hours while maintaining the temperature at 40 ° C.

The mixture was kept warm at 40 ° C. for 2 hours, neutralized with a 10% aqueous sodium hydroxide solution, and then post-treated in the same manner as in Reference Example 1 to obtain a condensed polyhydric phenol.

The average molecular weight was 327 and the average number of repeating units n was 0.1.

Examples 1 to 10 Thermometer, dropping funnel for continuously adding an alkali metal hydroxide aqueous solution, water evaporated from a stirring blade and reaction system, epichlorohydrin is cooled and liquefied, and an organic layer and a water layer are different in specific gravity. The separated organic layer is returned to the reaction system, and the aqueous layer is removed. A separable flask with a baffle having a volume of 1 having a separation tube with a cooling tube is used, and polyphenols and epichlorohydrin of the types and amounts shown in Table 1 are used. It was made to react.

The reaction was carried out in the presence of dimethyl sulfoxide as an aprotic polar solvent in an amount shown in Table 1 while continuously adding an aqueous sodium hydroxide solution in an amount shown in Table 1 for 4 hours.

After the reaction was completed, unreacted epichlorohydrin was removed by distillation under reduced pressure, and the glycidyl ether of polyphenols containing the by-product salt and aprotic polar solvent obtained at this time was dissolved in 250 g of methyl isobutyl ketone to produce a by-product. The salt and aprotic polar solvent were removed by washing with water.

Further, while maintaining the methyl isobutyl ketone solution at 80 ° C., an amount of 10% sodium hydroxide aqueous solution shown in Table 1 was added in about 10 minutes. After the lapse of 2 hours, carbon dioxide gas was blown in for neutralization, and the produced by-product salt was filtered off. Subsequently, the solvent was removed by distillation to obtain a glycidyl ether of polyhydric phenols.

The evaluation results are shown in Table 1.

Comparative Example 1 In the same manner as in Example 1, the reaction with the 10% aqueous sodium hydroxide solution in the methyl isobutyl ketone solution after the glycidylation reaction was omitted, and the solvent was directly removed by distillation to obtain glycidyl ether.

The evaluation results are shown in Table 1.

Comparative Example 2 The procedure of Example 1 was repeated except that the aprotic polar solvent was not used.

The evaluation results of the obtained glycidyl ether are shown in Table 1.

Comparative Example 3 Using the tris (hydroxyphenyl) methane obtained in Reference Example 1, glycidyl etherification was carried out in the same manner as in Example 3 of JP-B-57-13571.

Into a separable flask with a baffle having a thermometer and a stirring blade condenser and having a volume of 1, was charged 97.3 g of tris (hydroxyphenyl) methane and 925 g of epichlorohydrin, and after dissolution,
The temperature was raised to reflux.

In addition, benzyltrimethylammonium chloride
A 60% aqueous solution (9.7 g) was added and kept warm for 1 hour.

At this time, the temperature was 119 ° C to 120 ° C.

After cooling to 50 ° C., 100 g of 40 wt% sodium hydroxide aqueous solution was added, and the mixture was reacted at 50 ° C. for 1 hour.

After standing, the aqueous layer was separated, 50 g of 40 wt% sodium hydroxide aqueous solution was further added, and the mixture was reacted at 50 ° C. for 1 hour.

After standing still again, the water layer is separated and 300 ml of 1 wt% acetic acid aqueous solution
After washing with water, it was further washed with 300 ml of pure water four times.

Subsequently, epichlorohydrin was removed by distillation under reduced pressure to obtain glycidyl ether.

The epoxy equivalent was 163 and hydrolyzable chlorine was 1360 ppm.

 ─────────────────────────────────────────────────── --Continued from the front page (56) Reference JP-A-57-141419 (JP, A) JP-A-61-42530 (JP, A) JP-A-60-31516 (JP, A) JP-A-60- 31517 (JP, A) JP 57-118577 (JP, A) JP 57-133116 (JP, A) JP 58-134112 (JP, A) JP 59-33317 (JP, A) JP 59-25813 (JP, A)

Claims (1)

[Claims] 1. A general formula (I) (In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ are hydrogen atoms, alkyl groups having 1 to 10 carbon atoms, or phenyl groups. R ⁷ , R ⁸ , R ⁹ , and R ¹⁰ , R ¹¹ and R ¹² are a hydrogen atom, or an alkyl group or an alkoxy group having 1 to 4 carbon atoms, X is a chlorine atom or a bromine atom, and a, b, c, d, e are 0 or 1 And n is an average number from 0 to 5.) A polyhydric phenol represented by (4) and epichlorohydrin are reacted in the presence of an alkali metal hydroxide to produce a glycidyl ether of the polyhydric phenol. In the method described above, the reaction between the polyhydric phenol and epichlorohydrin is carried out in the presence of an aprotic polar solvent, and the resulting crude glycidyl ether of the polyhydric phenol is treated with an alkaline substance in an organic solvent. High purity of the polyhydric phenol greens characterized by Manufacturing method of Jill ether.