JP3318871B2 - 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 a novel epoxy resin composition suitable mainly for the electric and electronic industries. More specifically, the present invention relates to a composition containing a polyglycidyl ether of a co-condensed novolak resin, which is a novel resin, and to an epoxy resin composition capable of achieving low water absorption and low stress in a molded article formed from the composition.

[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 ICs in the field of electronics, which has undergone rapid technological innovation in recent years. It is attracting attention as a sealing material. Generally, the epoxy resin composition used for these epoxy resin molding materials comprises an epoxy resin, a curing agent, a curing accelerator, a filler, a flame retardant, a coupling agent, a release agent, and a coloring agent, and these are kneaded. It is used as a molding material.

Conventionally, orthocresol novolak 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 multilayering of laminated boards have been progressing. Epoxy resins for both of these applications have been further improved in heat resistance and low water absorption. And low stress are required.

[0004]

DISCLOSURE OF THE INVENTION The present inventors have conducted various studies on an epoxy resin composition which gives a molded article having a low water absorption and a low stress, and as a result, have completed the present invention. Another object of the present invention is to provide an epoxy resin composition from which a molded article having high heat resistance, low water absorption and low stress can be obtained.

[0005]

The gist of the present invention is to provide an epoxy resin component containing at least 10% by weight or more of polyglycidyl ether of a co-condensed novolak resin represented by the formula (1) and an epoxy curing agent as an essential component. Epoxy resin composition.

[0006]

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However, G is

[0008]

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Or

[0010]

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Wherein R ₁ represents a hydrocarbon group having 10 or less carbon atoms which may be substituted with a hydrogen atom or a halogen atom. Further, when R ₁ represents an aromatic hydrocarbon group, the hydrogen atom in R ₁ may be further substituted with a group OG or (and) a halogen atom. X represents a phenol residue of an equimolar addition reaction product of phenol and an aromatic vinyl compound, and Y represents a residue of a monovalent or (and) divalent phenol. The terminal residue of the formula (1) may be any of X, X and Y, Y or X, Y. n and m represent 0 or an integer of 1 to 9, and n + m is an integer of 10 or less. The molar ratio of X: Y is 1: 9 to 9: 1, and the bonding mode of the co-condensation may be random or block.

Preferably, the polyglycidyl ether of the co-condensed novolak resin of the present invention is a polyglycidyl ether of a co-condensed novolak resin obtained by reacting monostyrenated phenol and orthocresol with formalin or paraformaldehyde.

The polyglycidyl ether of the co-condensed novolak resin is represented by the formula (2)

[0014]

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An equimolar addition product of a phenol and an aromatic vinyl compound represented by the formula, ie, a styrenated phenol and a monohydric or (and) dihydric phenol, and formula (3) R ₁ -CHO (3) (wherein Wherein R ₁ represents a hydrogen atom, a lower alkyl group, a phenyl group, a hydroxyphenyl group or a halogen-substituted phenyl group), and the condensation reaction is carried out in the presence of an acidic catalyst to form a styrenated phenol skeleton. A novolak resin containing 1 to 10 styrenated phenol skeletons and 1 to 10 phenol skeletons (where the total number of skeletons is 12 or less) having a phenol skeleton bonded randomly or in a block is used as a precursor. This is epoxidized by a conventional method to obtain polyglycidyl ether.

In the present invention, specific examples of an equimolar addition product of a phenol represented by the formula (2) and an aromatic vinyl compound, that is, styrenated phenols are described in JP-A-58-115185 and JP-A-2-11533. The production method disclosed in Japanese Unexamined Patent Publication (Kokai) No. 1993, that is, phenol and styrene are converted to ALCL ₃ , SbCL ₃ , H ₂ SO ₄ , H
It can be obtained by reacting ₃ PO ₄ , activated clay, sulfonic acid type cation exchange resin or the like as a catalyst.

Styrenated phenols suitable for the present invention are phenol or 1 mole of styrene or alkyl styrene,
It is preferable that the purity of a monostyrenated phenol (hereinafter, referred to as a styrenated phenol) to which an aromatic vinyl hydrocarbon such as halogenated styrene is added is increased by vacuum distillation or the like in advance.

Specific examples of the monohydric and / or dihydric phenols of the present invention include phenol, cresol, xylenol, para-tert-butylphenol, nonylphenol, parachlorophenol, parabromophenol, orthophenylphenol, para-isopropenylphenol. Or a condensed ring monophenol such as α-naphthol, β-naphthol, or resorcinol, hydroquinone, bisphenol A, tetrabromobisphenol A, bisphenol F, bisphenol S, bisphenol AD, 4,4′-dihydroxybiphenyl, Bifunctional phenols such as 9,9'-bis (4-hydroxyphenyl) fluorene can be exemplified. Usually, one kind selected from these phenols is used, but if necessary, two or more kinds can be used in combination.

In the present invention, the aldehyde represented by the formula (3) specifically includes formaldehyde, paraformaldehyde, acetaldehyde, propylaldehyde, butyraldehyde, p-hydroxybenzaldehyde, chlorbenzaldehyde, bromobenzaldehyde and the like. In this case, formaldehyde and paraformaldehyde are preferred.

The co-condensed novolak resin which is a precursor of the polyglycidyl ether of the present invention is obtained by adding the aldehyde component to a mixture of a styrenated phenol and a phenol.
It is prepared by adding 0.5 to 1.1 times mol and condensing 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; and Lewis acids such as boron trifluoride, 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 mixture of a styrenated phenol and a phenol and a catalyst are charged into a reaction vessel and aldehydes are added dropwise over 1 to 3 hours. Is charged into a reaction vessel, and the catalyst is added dropwise over 1 to 3 hours. The desired cocondensed novolak resin can be obtained by any of the methods (random structure in a one-step reaction method).
Can be obtained.

Alternatively, a method may be employed in which an aldehyde component is added only to the styrenated phenol and condensed in the presence of an acidic catalyst, and then a phenol and an aldehyde component are added and condensed (block structure in a two-stage reaction method). In this case, the charged molar ratio of the styrenated phenol to the phenol can be arbitrarily selected in the range of 10 to 90 to 90 to 10. Further, as described above, phenols may be used in a mixture of two or more.

The reaction temperature is from 50 to 200 ° C., and the reaction time is from 1 to 10 hours. At the time of 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 co-condensed novolak resin of the present invention can be obtained by reacting the co-condensed novolak resin synthesized by the above method with epichlorohydrin. This reaction is carried out according to a conventionally known method for obtaining a 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 with respect to the phenolic hydroxyl group of the novolak type resin, and 30-120.
The reaction is carried out at a temperature of 0.5 DEG C. for 0.5 to 10 hours, or a quaternary ammonium salt such as tetraethylammonium chloride is added as a catalyst to the novolak resin and excess epichlorohydrin, and the reaction is carried out at a temperature of 50 to 150 DEG C. for 1 to 5 hours. To obtain a polyglycidyl ether by adding an alkali metal hydroxide such as caustic soda to the resulting polyhalohydrin ether as a solid (powder or finely granular) or a concentrated aqueous solution and reacting at a temperature of 30 to 120 ° C. for 1 to 10 hours. There is.

In the above reaction, the amount of epichlorohydrin used is 3 to 2 with respect to the hydroxyl group in the co-condensed novolak resin.
The molar amount is 0 times, preferably 5 to 10 times, and the amount of the alkali metal hydroxide such as caustic soda is 0.85 to 5 times the hydroxyl group in the co-condensed novolak resin.
It is in the range of 1.1 times mol.

Since the polyglycidyl ether of the styrenated phenol co-condensed 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. Furthermore, the target polyglycidyl ether can be obtained by removing the alkali metal halide by a method such as extraction with water and filtration.

In the present invention, a polyglycidyl ether of a styrenated phenol co-condensed novolak resin can be mixed with another epoxy resin at an appropriate ratio and used. Bisphenol A is used as the epoxy resin to be mixed.
Epoxy resin, bisphenol F epoxy resin, tetrabromobisphenol A epoxy resin, phenol novolak epoxy resin, brominated phenol novolak epoxy resin, orthocresol novolak epoxy resin, N, N diglycidylaminophenylglycidyl ether, N , N, N, N-tetraglycidyldiaminodiphenylmethane, 1,1,2,2-tetrakis (glycidyloxyphenyl) ethane, biphenyl type epoxy resin, fluorene type epoxy resin, and the like, but are not limited thereto. . As the mixing amount of these epoxy resins, the ratio of polyglycidyl ether of 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 by 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, triethylene tetramine,
Isophoronediamine, metaxylylenediamine, metaphenylenediamine, paraphenylenediamine, 4,4 '
Amines such as diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylether, and aniline-formalin resin. Phthalic anhydride, hexahydrophthalic anhydride, nadic anhydride, methylnadic anhydride, trimellitic anhydride,
Acid anhydrides such as 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. Novolak resin obtained by the condensation reaction of phenol, cresol, xylenol, resorcin, etc. with formalin. Polyphenols, dicyandiamide,
It contains a latent curing agent such as adipic dihydrazide and sebacic hydrazide.

Of these, for use as a molding material for sealing, it is preferable to cure with a novolak resin, 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. The amounts of these curing agents used in the novel epoxy resin composition of the present invention are amines, polyamide resins,
In the case of polysulfide resin, boron trifluoride amine complex, novolak resin, polyphenol, the amount of epoxy groups in the epoxy resin component,
In the case of an acid anhydride, the amount of active hydrogen in the curing agent is 0.5 to 1.5 equivalents, preferably 0.8 to 1.2 equivalents. 0.5 to 1.0 acid equivalent, preferably 0.7
In the case of dicyandiamide, the amount of active hydrogen is preferably from 0.3 to 0.7 equivalent so as to be 0.9 to 0.9 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-butyltriphenylphosphonium bromide; imidazoles such as 2-methylimidazole; 2-ethyl-4-methylimidazole; and organic acid salts 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 curing agent and, if necessary, a curing accelerator. Ketones such as acetone and methyl ethyl ketone; cyclic ethers such as dioxane and tetrahydrofuran;
Dissolve in amides such as dimethylformamide and dimethylacetamide, and aromatic hydrocarbons such as benzene, toluene and xylene, add a curing agent and, if necessary, a curing accelerator, and uniformly disperse or dissolve it. The solvent can be removed for curing.

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
Release agents such as natural waxes, paraffins and metal salts of straight-chain fatty acids, flame retardants such as paraffin chloride and hexabromobenzene, coloring agents such as titanium white, carbon black and red iron, silane coupling agents, etc. are appropriately added. You may mix. Since the cured product of the novel epoxy resin composition of the present invention has a small water absorption and is excellent in reducing stress, it is suitable for molding materials for sealing and laminated materials for printed circuits.

[0034]

EXAMPLES The present invention will be described below in more detail with reference to Examples, but it should not be construed that the invention is limited thereto.

Reference Example 1 Synthesis of co-condensed novolak resin (1) 200 parts of styrenated phenol (monostyrenated phenol content: 96.5% by weight, phenolic hydroxyl equivalent: 200 g / equivalent), 108 parts of orthocresol, 92% by weight
60 parts of paraformaldehyde 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, 14 parts of a 10% by weight aqueous solution of p-toluenesulfonic acid was added dropwise over 60 minutes. The mixture was further reacted at a temperature of 95 to 100 ° C. for 4 hours, and 3.1 parts of 10% by weight sodium hydroxide 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 180 ° C. under a reduced pressure of 5 mmHg and dried to obtain 325 parts of a co-condensed novolak resin. This is a pale yellow transparent brittle solid with a hydroxyl equivalent of 168,6.
g / equivalent, softening point was 97 ° C. In addition, styrenated
The molar ratio of enol to orthocresol was 5: 5.
Was.

Reference Example 2 Synthesis of co-condensed novolak resin (2) Same as in Reference Example 1, 200 parts of styrenated phenol, 92 parts
29% by weight of paraformaldehyde, 3 parts of distilled water and 6 parts of distilled water were charged into a glass separable flask and stirred while stirring.
Warmed to 0 ° C. While maintaining the same temperature, 11, 4 parts of a 10% by weight aqueous solution of paratoluenesulfonic acid were added dropwise over 30 minutes. Further, the reaction was carried out at a temperature of 95 to 100 ° C. for 3 hours.
After completion of the reaction, 72 or 4 parts of orthocresol was added, and
37% formalin 4 while maintaining the temperature at ~ 100 ° C.
8, 9 parts were added dropwise in one hour. The mixture was further reacted at the same temperature for 3 hours, and 2 and 5 parts of a 10% by weight aqueous sodium hydroxide solution were added. Further, 1,8 parts of a 10 wt% oxalic acid aqueous solution was added. Thereafter, the same treatment as in Reference Example 1 was performed to obtain 299 parts of a co-condensed novolak resin. This is a pale yellow transparent brittle solid having a hydroxyl equivalent of 178, 7 g / equivalent and a softening point of 9
4 ° C. In addition, styrenated phenol and orthocrete
The sol molar ratio was 6: 4 .

Reference Example 3 Synthesis of polyglycidyl ether of co-condensed novolak resin (1) Epichlorohydrin 494 was added to 150 parts of co-condensed novolak resin obtained in Reference Example 1 in a glass separable flask.
Parts and diethylene glycol dimethyl ether 98, 8
Was added and dissolved. Thereafter, while reducing the inside of the system to a reduced pressure of 150 mmHg and maintaining the temperature at 65 to 70 ° C, 72 and 6 parts of 49% by weight caustic soda were added dropwise over 6 hours. During this time, epichlorohydrin was azeotroped with water, and the distilled water was separated and removed from the system. After the completion of the reaction, unreacted epichlorohydrin was recovered by evaporation under reduced pressure, 460 parts of methyl isobutyl ketone was added, and the resulting polyglycidyl ether was dissolved. 175 parts of water was added to dissolve the salt by-produced,
The mixture was allowed to stand, and the lower layer of saline was separated and removed. Thereafter, 15 parts of 10% by weight of sodium hydroxide was added, and the mixture was reacted at 85 ° C. for 2 hours, neutralized with a phosphoric acid aqueous solution, and then the resin solution was washed with water until the washing solution became neutral. Under reduced pressure of 5 mmHg,
Heat to 190 ° C to distill off methyl isobutyl ketone,
196 parts of the desired polyglycidyl ether were obtained. It is a pale yellow transparent brittle solid with an epoxy equivalent of 273.
g / equivalent, total chlorine content 540 ppm, softening point 74 ° C. In addition, styrenated phenol and orthocresol
Is 5: 5 as in Reference Example 1 .

REFERENCE EXAMPLE 4 Synthesis of polyglycidyl ether of co-condensed novolak resin- (2) Epichlorohydrin 466 was added to 150 parts of co-condensed novolak resin obtained in Reference Example 2 in a glass separable flask.
Parts, 93 parts of diethylene glycol dimethyl ether and 1, 5 parts of benzyltrimethylammonium chloride were added and reacted at 100 to 110 ° C. for 3 hours. Thereafter, while reducing the pressure to 150 mmHg and maintaining the temperature at 65 to 70 ° C, 64 parts and 4 parts of a 49% by weight aqueous sodium hydroxide solution were added dropwise over 4 hours. During this time, epichlorohydrin was azeotroped with water, and the distilled water was separated and removed from the system. After the completion of the reaction, 145 parts of water was added to dissolve the salt produced as a by-product, and the mixture was allowed to stand to remove a lower layer saline solution.

Unreacted epichlorohydrin was evaporated and recovered under reduced pressure, and 460 parts of methyl isobutyl ketone was added to dissolve the polyglycidyl ether formed. Then 1
24 parts of a 0% by weight aqueous solution of caustic soda was added and reacted at 85 ° C. for 2 hours. Thereafter, the same treatment as in Reference Example 3 was performed to obtain 192 parts of the target polyglycidyl ether. This was a pale yellow transparent brittle solid having an epoxy equivalent of 276 g / equivalent, a total chlorine content of 840 ppm, and a softening point of 73 ° C. In addition, styrenated phenol and ortho
The molar ratio of cresol is 6: 4 as in Reference Example 2 .

[Examples 1-4, Comparative Examples 1-2] Evaluation as molding material for sealing Epoxy resin obtained in Reference Example 3, epoxy resin obtained in Reference 4, orthocresol novolak epoxy YD
CN-702P (Toto Kasei Co., Ltd., epoxy equivalent 2
03g / equivalent, softening point 75 ° C), phenol novolak resin BRG-557 (manufactured by Showa Polymer Co., Ltd., hydroxyl equivalent 105g / equivalent, softening point 86 ° C), brominated epoxy resin YDB-400 (manufactured by Toto Kasei Co., Ltd.) Epoxy equivalent 400g / equivalent, bromine content 49.3% by weight, softening point 6
6 ° C.), triphenylphosphine (Kishida Chemical Co., Ltd., reagent grade), fused silica (Tatsumori Co., Hulex RD-8), antimony trioxide (Nippon Seiko Co., Ltd., ATOX-S), A mixture of calcium stearate (manufactured by Seido Chemical Co., Ltd.), carbon black (manufactured by Mitsubishi Kasei Corporation, MA-100) and a silane coupling agent (manufactured by Nippon Unicar Co., Ltd., A-187) are shown in Table 1, Using a twin screw kneader S1KRC kneader (manufactured by Kurimoto Tekko Co., Ltd.), the mixture was melt-mixed at 80 to 100 ° C., quenched, and then pulverized to obtain a molding material. Next, using a mold, 65K
It was compression-molded under the conditions of g / cm 2, 120 ° C. and 10 minutes, and was pre-cured. Thereafter, it was cured at 180 ° C. for 8 hours to obtain a test piece for measuring physical properties. Table 1 shows the results of the physical property measurement.

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 50 mm diameter, 2 mm thick disk-shaped molded product using a pre-shooker tester
Weight change after 40 hours at atmospheric pressure, 150 ° C. and 100% RH.

[0042]

When the epoxy composition according to the present invention is used as a molding material as shown in Table 1, the epoxy composition has the effects of low water absorption and low flexural modulus (low stress).

[0043]

[Table 1]

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor, Keitaka Ban 2-9-12, Tenjin-cho, Fuchu-shi, Tokyo (56) References JP-A-55-160020 (JP, A) JP-A-55-16047 (JP) JP-A-5-140265 (JP, A) JP-A-5-132544 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 59/20-59/32 H01L 23/29

Claims (2)

(57) [Claims] 1. An epoxy resin composition comprising an epoxy resin component containing at least 10% by weight or more of a polyglycidyl ether of a co-condensed novolak resin represented by the formula (1) and an epoxy curing agent as essential components. Embedded image Where G is Or R ₁ represents a hydrocarbon group having 10 or less carbon atoms which may be substituted with a hydrogen atom or a halogen atom. Further, when R ₁ represents an aromatic hydrocarbon group, the hydrogen atom in R ₁ may be further substituted with a group OG or (and) a halogen atom. X represents a phenol residue of an equimolar addition reaction product of phenol and an aromatic vinyl compound, and Y represents a residue of a monovalent and / or divalent phenol. The terminal residue of the formula (1) may be any of X, X and Y, Y or X, Y. n and m are 0 or 1
Represents an integer of 9, and R ₁ represents a hydrogen atom or a hydrocarbon group having 10 or less carbon atoms which may be substituted with a halogen atom. Further, when R ₁ represents an aromatic hydrocarbon group,
The hydrogen atom in R ₁ may be further substituted with a group OG or (and) a halogen atom. X represents a phenol residue of an equimolar addition reaction product of phenol and an aromatic vinyl compound, and Y represents a residue of a monovalent and / or divalent phenol. The terminal residues of formula (1) are X, X and Y, Y
Alternatively, any of X and Y may be used. n and m represent 0 or an integer of 1 to 9, and n + m is an integer of 10 or less. The molar ratio of X: Y is 1: 9 to 9: 1, and the bonding mode of the co-condensation may be random or block. 2. The composition according to claim 1, wherein the polyglycidyl ether of the co-condensed novolak resin is a polyglycidyl ether of a co-condensed novolak resin obtained by reacting monostyrenated phenol and orthocresol with formalin or paraformaldehyde .