JPS6031516A - Production of epoxy resin - Google Patents

Abstract

PURPOSE:To obtain an epoxy resin having a low hydrolyzable chlorine content, by reacting a phenol with epichlorohydrin in the presence of an alkali metal hydroxide, an ether compound and an aprotic polar solvent. CONSTITUTION:A monohydric or polyhydric phenol (A), such as phenol or bisphenol A, is mixed with about 2.5-20mol, per mol of component A, of epichlorohydrin (B), about 10-100pts.wt., per 100pts.wt. component B, cyclic or linear ether compound (C) (e.g., dioxane or diethoxyethane), and about 2-50pts.wt., per 100pts.wt. component B, aproptic polar solvent (D) (e.g., dimethyl sulfoxide). The mixture is reacted with agitation by adding, in portions, about 1mol, per mol of the phenolic hydroxide group, of an alkali metal hydroxide (e.g., sodium hydroxide) to obtain the purpose epoxy resin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is particularly applicable to electrical and electronic devices. The present invention relates to a method for producing an epoxy resin suitable for use in the acetic acid industry.

i in epoxy resins used as electrical and electronic materials
, a low content of hydrolyzable chlorine is essential and this is widely recognized in the industry. That is, hydrolytic chlorine has adverse effects such as a decrease in electrical insulation and corrosion of lead wires. In particular, in epoxy resins used as raw materials for encapsulating integrated circuits using semiconductors, it is essential that the content of hydrolyzable chlorine be low.

For example, an integrated circuit with a density of 64 kilobits or more is required to have a hydrolyzable chlorine content of 600 ppm or less.

Various manufacturing methods have been proposed to reduce hydrolyzable chlorine. For example, Japanese Patent Publication No. 5B-86000 describes a method for producing glycidyl ether of bisphenol A by gradually supplying an aqueous sodium hydroxide solution to m1IX in which bisphenol A and epichlorohydrin are dissolved. A method is described in which the epichlorohydrin that is removed by azeotroping with the hydrochloric acid and distilled off is recycled into the reaction system. In the examples of this patent, the hydrolyzable chlorine content is 1,200 to 4,500 ppm, and a sufficient improvement effect is not obtained. Japanese Patent Publication No. 54-9
No. 0400, No. 54-18596, and U.S. Pat. No. 8,121,727 describe a method for producing glycidyl ether of polyhydric phenol, in which alcohol is added to a solution of polyhydric phenol and shrimp halohydrin. has been done. In the case of JP-A No. 54-90400, the hydrolyzable chlorine of glycidyl ether of bisphenol A obtained from bisphenols and epichlorohydrin is about 1000 ppm, and the total chlorine content is 1500 to 8500 ppm. ppm, and in the case of JP-A-54-18596, the hydrolyzable chlorine of glycidyl ether of phenol novolak obtained from phenol novolak and epichlorohydrin is 150 ppm.
A sufficient improvement effect was not obtained, such as 0 ppm. Furthermore, the patent and the like state that it is not necessary to remove water from the reaction system, and it is known that epichlorohydrin decomposes even when it coexists with water, which is industrially disadvantageous.

As a result of intensive research to obtain an epoxy resin with a low content of hydrolyzable chlorine, the present inventors discovered that this objective could be achieved by using a specific solvent during the epoxidation reaction, leading to the present invention. .

That is, the present invention is characterized in that monovalent or polyvalent phenols and epichlorohydrin are reacted in the presence of an alkali metal hydroxide, a cyclic or straight polyhydric compound, and an aprotic polar solvent. This is a method for producing epoxy resin.

The monohydric or polyhydric phenols used in the present invention are monohydric or polyhydric phenols consisting of phenol units substituted or unsubstituted with halogen, alkyl group, allyl group, alkenyl group, aryl group, or aralkyl group. and
Specifically, phenol, ortho-I cresol, meta-cresol, para-cresol, diphenol methane (bisphenol F), diphenol ethane, diphenol propane (bisphenol A'), and bisphenol A tetrabromide.
% 1.1-bis-(4-hydroxyphenyl)-1-
Phenyletano, 1,1-his-(4-hydroxyphenyl)-1,1-dimethylmethane, phenol novolak, brominated phenol novolak, cresol novolak, brominated cresol novolak, resorcinol novolac, brominated resorcinol novolak, resorcinol, hydroquinone , methylresorcinol, bisphenol A tetrachloride
Examples include, but are not limited to, the following.

The alkali metal hydroxide used in the present invention is specifically sodium hydroxide, potassium hydroxide, etc., but is not limited thereto. The usage of alkali metal hydroxide is 4 equivalent moles per 1 mole of phenolic hydroxyl group.
The degree of presentation is preferable. When the amount of alkali metal hydroxide used is small, fewer gel groups are produced as by-products, which is advantageous in production, but hydrolyzable chlorine remains. If the amount of alkali metal hydroxide used is large, the amount of gel increases, which is disadvantageous in production.

The ether compounds used in the present invention are cyclic or straight ether compounds, and specifically, dioxane,
Examples include, but are not limited to, jetoxyethane. The usage of these lanoether compounds is to-100ffi per 2100 parts of epichlorohydrin.
Parts by weight are preferred. If the amount used is 10 parts by weight or less, the effects of the present invention will not be so significant. If the amount used is too large, intermolecular reactions will proceed, the epoxy equivalent (measured per mole of epoxy group) will increase, and the quality of the epoxy resin will deteriorate. Considering this, 100 parts by weight or less is preferable.

Specific examples of the aprotic polar solvent used in the present invention include, but are not limited to, dimethylsulfoxide, dimethylsulfono, dimethylformamide, dimethylanadamide, tetramethylurea, and hexamethylphosphoramide. isn't it. The amount of these aprotonal polar solvents used is 2 parts by weight per 100 parts by weight of epichlorohydrin.
~5o, ff1f& parts are preferred. If the amount of air used is less than 2 parts by weight, the effect of the present invention is not so significant. If the amount used is large, intermolecular reactions will proceed, the epoxy equivalent will increase, and the quality of the epoxy resin will deteriorate. Considering this, 50
Parts by weight or more are preferred.

The amount of epichlorohydrin used in the present invention is preferably 2.5 mol to 20 mol, more preferably 4 mol to 15 mol, per 1 mol i of phenolic hydroxyl groups.

This means that if the amount of epichlorohydrin used is small,
This is because the production of high molecular weight products due to intermolecular reactions causes quality deterioration such as an increase in the melt viscosity of the epoxy resin, and further increases the amount of gel formation, which is disadvantageous to the industry. This is because the volume of the reaction mixture increases, resulting in industrial disadvantages such as decreased productivity.

In the present invention, the epoxidation reaction of phenols can be carried out by a known method, except that a specific compound of the present invention is used as a solvent. For example, it can be carried out as follows. First, -hydric or polyhydric phenol and epichlorohydrin are mixed in the proportions previously described.

Solid phenols are also dissolved in epichlorohydrin to form a homogeneous solution. A cyclic or linear ether compound and an aprotic polar solvent are further added and mixed. Next, the alkali metal hydroxide is added and the reaction is carried out while stirring and mixing.

This reaction is carried out under normal pressure or reduced pressure at a temperature of about 100°C.
Dehydration is carried out at ~110°C under reduced pressure, with the oil separated depending on the pressure being returned to the reaction system.

Addition of alkali metal hydroxide makes the reaction uniform,
Add in small portions or continuously over 2 to 7 hours. If it is temporarily added, the reaction will progress locally and a gel will be formed, which is not preferable. After the reaction is completed, unreacted epichlorohydrin and cyclic or linear ether compounds are first removed by distillation, and then dissolved in ketones such as methyl isobutyl ketone or aromatic hydrocarbon solvents such as toluene to remove insoluble alkali metals. Salt is distributed door to door.

Further, the aprotic polar solvent is removed by washing with water, and the solvent is removed by distillation to obtain an epoxy resin.

The epoxy equivalent as used in the present invention is defined as the molecular weight per mole of epoxy group. Hydrolyzable chlorine is obtained by dissolving epoxy resin in dioxane, adding an alcoholic solution of potassium hydroxide, and heating it for 30 minutes under reflux.The chlorine ions released are determined by back titration with a silver nitrate solution. It is expressed as the heavy charge percentage of chlorine atoms in a compound. The present invention will be explained in detail with examples below.
It is not limited to these.

Examples 1 to 6 and Comparative Examples 1 to 8 Thermometer, dropping funnel for continuous addition of aqueous alkali gold tetrahydroxide solution, stirring blade, and cooling and liquefaction of water, epichlorohydrin, and ether compounds that evaporate from the reaction system. The organic layer and the aqueous layer are separated based on their specific gravity difference, the organic layer is returned to the reaction system, and the aqueous layer is removed using a baffled separable flask with a capacity of 1 liter and equipped with a separation tube equipped with a condenser, as shown in Table 1. Various types and amounts of phenols were reacted with epichlorohydrin. The reaction was carried out in the presence of an ether compound and an aprotic polar solvent of the type and amount shown in Table 1 while continuously adding an aqueous sodium hydroxide solution in the amount shown in Table 1 over a period of 5 hours.

After the reaction is complete, unreacted epichlorohydrin is removed by vacuum distillation, and the by-product salt and glycidyl ether of phenols containing an aprotic polar solvent are dissolved in methyl isobutyl ketone to separate the by-product salt and aprotic polar solvent. The polar solvent was removed by washing with water. Furthermore, methyl isobutyl ketone was removed by vacuum distillation to obtain an epoxy resin. The hydrolyzable chlorine content and epoxy equivalent of the epoxy resin thus obtained are shown in Table 1.

In Example 1 using an ether compound and an aprotic polar solvent, the amount of hydrolyzable chlorine is 200 ppm. On the other hand, in Comparative Example 1 in which neither the ether compound nor the aprotonal polar solvent was used, the amount of hydrolyzable chlorine was 650 ppm. In addition, in Comparative Example 2 using only an ether compound, the amount of hydrolyzable chlorine was 880 pp
In Comparative Example 8 in which only the m 1 aprotic polar solvent was used, the amount of hydrolyzable chlorine was a a o ppm. That is, the effect of using both the etherified diprotic polar solvent is significant.

Claims (1)

[Claims] A method for producing an epoxy resin, which comprises reacting a monovalent or polyvalent phenol with epichlorohydrin in the presence of an alkali metal hydroxide, a cyclic or linear ether compound, and an aprotic polar solvent.