JP3146320B2 - Epoxy resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition suitable mainly for the electric and electronic industries. More specifically, the present invention relates to an epoxy resin composition containing polyglycidyl ether of a styrenated phenol novolak resin, which is a novel resin, and whose molded product can achieve low water absorption and low stress.

[0002]

2. Description of the Related Art Epoxy resins are used as a base material for electronic devices or electronic components typified by LSIs and laminates, and are particularly used for sealing ICs in the field of electronics in which technical innovation has been intensifying in recent years. It is attracting attention as a stopping material. Epoxy resin compositions generally used for these epoxy resin molding materials include an epoxy resin, a curing agent, a curing accelerator, a filler, a flame retardant, a coupling agent, a release agent,
It is produced by mixing a colorant, and is kneaded to form a composition, which is used as a molding material.

Conventionally, orthocresol novolac type epoxy resins have been widely used as epoxy resins for these molding materials because of their excellent heat resistance, moldability and electrical properties. However, in recent years, high integration of semiconductor elements, miniaturization and thinning of packages, and multi-layering of laminated boards have been progressing, and in these epoxy resins for both uses, higher heat resistance, Low water absorption and low stress are required.

[0004]

SUMMARY OF THE INVENTION The present inventor has studied a resin having a low water absorption and a low stress, and as a result, has found a novel epoxy resin, and has completed the present invention. An object of the present invention is to provide an epoxy resin composition excellent in low water absorption and low stress, which cannot be achieved by the above.

[0005]

The gist of the present invention is to provide a styrenated phenol-novolak resin represented by the following formula- (1) comprising at least 10% by weight of a polyglycidyl ether.
An epoxy resin composition containing the epoxy resin component and the epoxy curing agent contained above as essential components.

[0006]

Embedded image Here, in the formula (1), G represents the following formula (2) or formula (3).

[0007]

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[0008]

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In the formula, R ₁ and R ₂ represent a hydrogen atom or a hydrocarbon group having 10 or less carbon atoms which may be substituted with a halogen atom, and R ₁ is an aromatic group which may be substituted with a halogen atom. In the case of representing a hydrocarbon group, at least one of the hydrogen atoms in R ₁ may be further substituted with a group OG. N represents 0 or an integer of 1 to 10. The styrenated phenolic volak resin in the present invention is represented by the following formula.

[0010]

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Formula- (3) R-CHO wherein R represents a hydrogen atom, a lower alkyl group, a phenyl group, a hydroxyphenyl group or a halogen-substituted phenyl group. This is epoxidized by a conventional method to form a polyglycidyl ether of a styrenated phenol novolak resin.

The aldehyde of the present invention represented by the formula (3) specifically includes formaldehyde, paraformaldehyde, acetaldehyde, propylaldehyde, butyraldehyde, p-hydroxybenzaldehyde, chlorbenzaldehyde, bromobenzaldehyde, etc. Of these, formaldehyde and paraformaldehyde are preferred.

The styrenated phenol novolak resin of the present invention is prepared by adding 0.5 to 1.1 times mol of the above aldehyde component to the styrenated phenol and condensing it in the presence of an acidic catalyst.

Specific examples of the acidic catalyst include protonic acids such as hydrochloric acid, phosphoric acid, sulfuric acid, nitric acid, and toluenesulfonic acid, boron trifluoride, Lewis acids such as aluminum chloride, tin chloride, zinc chloride and iron chloride; Oxalic acid, monochloroacetic acid and the like can be used. Among these, it is preferable to use toluenesulfonic acid and oxalic acid. The amount of these catalysts used is 0.001 to
0.03 mol times is good.

As a reaction method, a method in which a styrenated phenol and a catalyst are charged in a reaction vessel and aldehydes are added dropwise over 1 to 3 hours, a method in which the styrenated phenol and the aldehyde are charged in the reaction vessel, There is a method in which the catalyst is added dropwise over 1 to 3 hours, and the desired styrenated phenol novolak resin can be obtained by any of the methods.

The reaction temperature is 50 to 200 ° C., and the reaction time is 1 to 10 hours. During the reaction, a reaction solvent such as benzene, toluene, xylene, chlorobenzene, dichlorobenzene, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether may be used as necessary.

The polyglycidyl ether of the styrenated phenol novolak resin of the present invention can be obtained by reacting the styrenated phenol novolak resin synthesized by the above method with epichlorohydrin. This reaction is carried out according to a conventionally known method for obtaining polyglycidyl ether from epichlorohydrin on a phenol novolak type resin. For example, an alkali metal hydroxide such as caustic soda or the like is added as a solid or concentrated aqueous solution to a mixture of epichlorohydrin in a molar excess relative to the phenolic hydroxyl group of the novolak type resin, and the mixture is added at a temperature of 30 to 120 ° C. for 0.5 minute. -10
The reaction is allowed to proceed for a period of time or a quaternary ammonium salt such as tetraethylammonium chloride is added as a catalyst to the novolak resin and excess epichlorohydrin.
An alkali metal oxide such as caustic soda is added to the polyhalohydrin ether obtained by reacting at a temperature of 0 ° C. for 1 to 5 hours as a solid (powder or fine particles) or a concentrated aqueous solution, and the temperature is 30 to 120 ° C. For 1 to 10 hours to obtain polyglycidyl ether.

In the above reaction, the amount of epichlorohydrin used is in the range of 3 to 20 moles, preferably 5 to 10 moles relative to the hydroxyl group in the novolak resin.
The amount of the alkali metal hydroxide such as caustic soda used is in the range of 0.85 to 1.1 times mol based on the hydroxyl group in the novolak resin. Since the polyglycidyl ether of the styrenated phenol-novolak resin obtained by these reactions contains unreacted epichlorohydrin and a halide of an alkali metal, unreacted epichlorohydrin is removed by evaporation from the reaction mixture. The desired polyglycidyl ether can be obtained by removing the alkali metal halide by a method such as extraction with water or filtration.

The polyglycidyl ether of the present invention has an epoxy equivalent of 450 g / equivalent or less and a total chlorine content of 1000 ppm or less, preferably 700 ppm or less. By using such a polyglycidyl ether, an epoxy resin composition aimed at by the present invention can be obtained.

In the present invention, a polyglycidyl ether of a styrenated phenol novolak resin may be mixed with another epoxy resin at an appropriate ratio and used.
As the epoxy resin to be mixed, bisphenol A type epoxy resin, bisphenol F type epoxy resin, tetrabromobisphenol A type epoxy resin, phenol novolak type epoxy resin, brominated phenol novolak epoxy resin, orthocreso -Lunovolak type epoxy resin, N, N-diglycidylaminophenylglycidyl ether, N, N, N, N-tetraglycidyldiaminodiphenylmethane, 1,1,2,2-tetrakis (glycidyloxyphenyl) ethane and the like. However, the present invention is not limited to these. The mixing amount of these epoxy resins is such that the ratio of the polyglycidyl ether of the styrenated phenol novolak resin to these epoxy resins is 100: 0 to 10:90 by weight.

The novel epoxy resin composition of the present invention can be cured with a conventionally known epoxy curing agent. Epoxy curing agents that can be used for this include amines, acid anhydrides, aminopolyamide resins, polysulfide resins, phenol novolak resins, boron trifluoride amine complexes, dicyandiamide and the like.

Specific examples include diethylene triamine,
Triethylenetetramine, isophoronediamine, metaxylylenediamine, metaphenylenediamine, paraphenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 4,4 '
Amines such as diaminodiphenyl ether and aniline-formalin resin; Acid anhydrides such as phthalic anhydride, hexahydrophthalic anhydride, nadic anhydride, methylnadic anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenonetetracarboxylic anhydride.
Aminopolyamide resin which is a condensate of dimer acid with diethylenetriamine, triethylenetetramine and the like. A polysulfide resin having a mercaptan group at the end. Boron trifluoride amine complex of boron trifluoride and aniline, benzylamine, ethylamine, etc. A novolak resin obtained by a condensation reaction of formalin such as phenol, cresol, xylene and resorcin. Includes latent curing agents such as dicyandiamide, adipic dihydrazide, sebacic hydrazide and the like. Among these, it is preferable to cure with a novolak resin for the use of a molding material for sealing, and a phenol novolak resin is particularly preferable.
On the other hand, in the use of a printed circuit board, it is often cured with dicyandiamide.

In the case of amines, polyamide resins, polysulfide resins, boron trifluoride amine complexes, and novolak resins, the amount of these curing agents used in the novel epoxy resin composition of the present invention is The amount of active hydrogen in these curing agents is 0.5 to 1.5 equivalents, preferably 0.8 to the amount of epoxy groups.
To 1.2 equivalents, in the case of an acid anhydride, 0.5 to the amount of epoxy groups in the epoxy resin component.
It is preferably from 1.0 to 1.0 acid equivalent, preferably from 0.7 to 0.9 equivalent, and in the case of dicyandiamide, the amount of active hydrogen is preferably from 0.3 to 0.7 equivalent.

In the novel epoxy resin composition of the present invention, a curing accelerator can be used if necessary. Specific examples of the curing accelerator include tertiary amines such as triethylamine, tributylamine, dimethylbenzylamine and diethylbenzylamine, quaternary ammonium salts such as benzyltrimethylammonium chloride and benzyltriethylammonium chloride, triethylphosphine and triphenylphosphine. Phosphines such as n-
Phosphonium salts such as butyltriphenylphosphonium bromide, 2-methylimidazole, 2-ethyl-4
Imidazoles such as -methylimidazole, and organic acid salts thereof such as acetic acid.
Among these, preferred curing accelerators are imidazoles and phosphines.

The epoxy resin composition of the present invention can be cured as it is by adding the above-mentioned curing agent and, if necessary, a curing accelerator. Ketones such as acetone and methyl ethyl ketone, cyclic ethers such as dioxane and tetrahydrofuran, dimethylformamide , Dissolved in amides such as dimethylacetamide, aromatic hydrocarbons such as benzene, toluene, xylene, etc., added with a curing agent and, if necessary, a curing accelerator, and uniformly dispersed or dissolved. It can be removed and cured.

When the epoxy resin composition of the present invention is used as a sealing resin, a curing agent and, if necessary, a curing accelerator, as well as silica powder, alumina, antimony trioxide, talc, calcium carbonate, Inorganic fillers such as natural waxes, paraffins, release agents such as metal salts of straight-chain fatty acids, flame retardants such as paraffin chloride, hexabromobenzene, coloring agents such as titanium white, carbon butac, and bengara, silane A coupling agent or the like may be appropriately added and blended.

(Function) The cured product of the novel epoxy resin composition of the present invention is suitable for molding materials for sealing and laminated materials for printed circuits because of its low water absorption and excellent low stress. Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to the examples.

Reference Example 1 Synthesis of styrenated phenol novolak resin 400 parts of styrenated phenol (monostyrenated phenol content: 96.5% by weight, phenolic hydroxyl group equivalent: 200 g / equivalent), 400 parts, 92 parts by weight % Paraformaldehyde 58.
7 parts and 12 parts of distilled water were charged into a glass separable flask and heated to 80 ° C. while stirring. While maintaining the same temperature, a 10% by weight aqueous solution of paratoluenesulfonic acid 1
3.7 parts were added dropwise over 30 minutes. 95-100 ° C
For 4 hours, and 3.0 parts of 10% by weight caustic soda was added. A further 1.8 parts of 10% by weight of oxalic acid were added.

Thereafter, the mixture was heated to 165 ° C. and dehydrated.
The mixture was heated to 170 ° C. under a reduced pressure of 5 mmHg and dried to obtain 420 parts of a styrenated phenol novolak resin. It is a pale yellow transparent brittle solid with a hydroxyl equivalent of 22.
9.7 g / equivalent, softening point was 89 ° C., and analysis by gel permeation chromatography (GPC) revealed that the average number of nuclei was 4.2.

Reference Example 2 Synthesis of styrenated phenol-novolak epoxy resin In a glass separable flask, 423 parts of epichlorohydrin and 1.5 parts of benzyltriethylammonium chloride were added to 150 parts of the styrenated phenol-novolak resin of Reference Example 1 and 85 parts of diethylene glycol dimethyl ether was added, and the mixture was stirred and reacted at 100 to 110 ° C. for 3 hours. Thereafter, the pressure was reduced to 150 mmHg, and
50% caustic soda while maintaining the temperature at 0 ° C.
One part was added dropwise over 4 hours. During this time, epichlorohydrin was azeotroped with water, and distilled water was removed from the system. After the completion of the reaction, 115 parts of water was added to dissolve the salt by-produced,
The mixture was allowed to stand, and the lower saline solution was removed. Unreacted epichlorohydrin was recovered by evaporation under reduced pressure, and 430 parts of methyl isobutyl ketone was added to dissolve the generated epoxy resin.
Thereafter, 20 parts of 10% by weight of caustic soda was added, and 85 parts of caustic soda was added.
After reacting at 2 ° C. for 2 hours and neutralizing with a phosphoric acid aqueous solution, the resin solution was washed with water until the washing solution became neutral. 5m
The mixture was heated to 190 ° C. under a reduced pressure of mHg to distill off methyl isobutyl ketone, and the desired polyglycidyl ether 1
85 parts were obtained. This is a pale yellow transparent brittle solid, epoxy equivalent 325 g / equivalent, total chlorine content 700 pp
m, softening point was 76 ° C.

(Examples 1 to 3, Comparative Examples 1 to 2) Evaluation as molding material for sealing Epoxy resin obtained in Reference Example 2, orthocresol-novolak epoxy YDCN-702P (Toto Kasei Co., Ltd.)
Epoxy equivalent 203g / equivalent, softening point 75 ° C), phenol novolak resin BRG-557 (manufactured by Showa Polymer Co., Ltd., phenolic hydroxyl equivalent 105g / equivalent, softening point 86 ° C) brominated epoxy resin YDB -400 (manufactured by Toto Kasei Co., Ltd., epoxy equivalent: 400 g / equivalent, bromine content: 49.3% by weight, softening point: 66 ° C.), triphenylphosphine (manufactured by Kishida Chemical Co., reagent special grade), fused silica (( Hyulex RD-8, manufactured by Tatsumori Co., Ltd., antimony trioxide (ATOX-S, manufactured by Nippon Seimitsu Co., Ltd.), calcium stearate (manufactured by Seido Chemical Co., Ltd.), carbon black (Mitsubishi Chemical Corporation) (Manufactured by Nippon Unicar Co., Ltd., A-187) and a biaxial kneader S1KRC kneader at a mixing ratio shown in the following table.
The mixture was melt-kneaded at 80 to 100 ° C. using (made by Kurimoto Tekko Co., Ltd.), quenched and then pulverized to obtain a molding material. Next, using a metal mold, compression molding was performed under conditions of 65 kg / cm ² , 120 ° C., and 10 minutes, and pre-cured. Thereafter, it was cured at 180 ° C. for 8 hours to obtain a test piece for measuring physical properties. The results of the physical property measurements are shown in the following table.

The physical properties were measured by the following methods. Glass transition temperature (Tg): Measured with a thermomechanical analyzer (TMA) TMC-30 manufactured by Shimadzu Corporation. Flexural strength and flexural modulus: based on JIS K6911. Water absorption: 4.8 using a pre-cooker tester for a disk-shaped molded product having a diameter of 50 mm and a thickness of 2 mm.
Weight change after 40 hours at atmospheric pressure, 150 ° C. and 100% RH.

[0033]

The epoxy composition according to the present invention, when used as a molding material as shown in the following table, has the effects of low water absorption and low flexural modulus (low stress).

[0034]

[Table 1]

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-132544 (JP, A) JP-A-63-183966 (JP, A) JP-A-63-17922 (JP, A) JP-A 57-132 8221 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C08G 59/20-59/32 C08G 59/08

Claims (2)

(57) [Claims] An epoxy resin composition comprising an epoxy resin component containing at least 10% by weight or more of a polyglycidyl ether of a styrenated phenol novolak resin represented by the following formula (1) and an epoxy curing agent as essential components: . Embedded image However, in the formula (1), G represents a group of the following formula (2) or formula (3). Embedded image Embedded image In the formula, R ₁ and R ₂ represent a hydrogen atom or a hydrocarbon group having 10 or less carbon atoms which may be substituted with a halogen atom, and R ₁ is an aromatic hydrocarbon group which may be substituted with a halogen atom. In the formula, at least one of the hydrogen atoms in R ₁ may be further substituted with a group OG. N represents 0 or an integer of 1 to 10. 2. The polyglycidyl ether of a novolak resin obtained by reacting a monostyrenated phenol with formalin or paraformaldehyde as the polyglycidyl ether of a styrenated phenol novolak resin. Epoxy resin composition.