JP2000007763A - Epoxy resin composition and insulating substrate using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition with high heat resistance, low dielectric dissipation factor and excellent adhesion by compounding a combination of an epoxy compound having at least two epoxy groups in a molecule and a one kind of a polyfunctional epoxy compound, a phenol modified polyphenylene ether, a cyanate compound and a curing accelerator as essential components. SOLUTION: An epoxy compound having at least two epoxy groups in a molecule is not particularly limited. An epoxy compound which is combined is selected from compounds represented by formula I (wherein R1 and R2 are each H, or R1 is Me and R2 is tBu), formulas II and III. A modified polyphenylene ether is prepared by re-distribution reacting a polyphenylene ether with a phenol in the presence of a radical initiator. A cyanate compound is an aromatic compound having at least two cyanate groups in a molecule. As a curing accelerator, a metal salt of octenoic acid and Zn, or the like is employed. An insulated-substrate is obtained by impregnating a glass base material with an epoxy resin composition and curing the resultant product.

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 and an insulating substrate using the epoxy resin composition. More specifically, the present invention relates to an epoxy resin composition used for an electronic material such as a printed wiring board. It is about.

[0002]

2. Description of the Related Art An epoxy resin composition used for an insulating substrate such as a laminated board or a printed wiring board is one that is impregnated into a base material, and is used in the information and communication fields as described above. Insulating substrates are required to have excellent electrical characteristics in order to cope with a high-frequency range from the MHz band to the GHz band, and in particular, to have a low dielectric constant (ε) and a low dielectric loss tangent (tan δ).

[0003]

Heretofore, as one of the substrates having such electric characteristics, a material obtained by mixing a polyphenylene ether resin (also referred to as a PPO resin) with an epoxy resin has been used. This material has a lower dielectric constant than ordinary epoxy resin materials, and has high heat resistance, but compared to other expensive high-frequency materials such as Teflon resin, bismaleimide triazine resin, polyimide resin, etc. However, there are drawbacks that the glass transition temperature (Tg) is low and the dielectric loss tangent is high.

Therefore, the present inventors have disclosed a method for further improving heat resistance and electric characteristics by blending a cyanate and a self-polymer thereof with a material obtained by mixing a polyphenylene ether resin with an epoxy resin, as disclosed in Japanese Patent Application No. Hei 9-71333. And Japanese Patent Application No. 9-82850.

However, when such an epoxy resin composition is used for an insulating substrate such as a laminated board or a printed wiring board, there has been a problem that adhesion and heat resistance are deteriorated.

The present invention has been made in view of the above-mentioned facts, and has as its object to provide an epoxy resin composition having high heat resistance, a low dielectric loss tangent, and excellent adhesion. An object of the present invention is to provide an insulating substrate using an epoxy resin composition.

[0007]

The epoxy resin composition according to claim 1 of the present invention comprises an epoxy compound having at least two epoxy groups in one molecule by the following formulas (I), (II) and (II). A phenol-modified polyphenylene ether and a cyanate compound obtained by redistributing a polyphenylene ether with a phenol and a radical initiator in the presence of a polyfunctional epoxy compound selected from the group [III]; And a curing accelerator as an essential component.

[0008]

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[0009]

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[0010]

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The epoxy resin composition according to claim 2 of the present invention is characterized in that the essential component is at least one acid anhydride selected from the group consisting of tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride and methylhymic anhydride. It is characterized in that a product is blended.

The epoxy resin composition according to claim 3 of the present invention is characterized in that the phenol-modified polyphenylene ether has a number average molecular weight of 10,000 or less.

An insulating substrate using the epoxy resin composition according to claim 4 of the present invention is obtained by impregnating a glass substrate with the epoxy resin composition according to any one of claims 1 to 3 and curing the glass substrate. It is characterized by.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail.

The epoxy resin composition according to the present invention is characterized in that the epoxy compound having at least two epoxy groups in one molecule is selected from the group consisting of the following formulas (I), (II) and (III): Phenol-modified polyphenylene ether obtained by redistributing polyphenylene ether with phenols and a radical initiator in the presence of a radical initiator using a polyfunctional epoxy compound or a cyanate compound, and a curing accelerator as essential components It contains.

[0016]

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[0017]

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[0018]

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The epoxy resin is not particularly limited as long as it has two or more epoxy groups per molecule. Examples thereof include bisphenol A type epoxy resin, bisphenol F type epoxy resin, and phenol novolak type epoxy resin. Resins, naphthalene-type epoxy resins, biphenyl-type epoxy resins, and brominated epoxy resins thereof. These are used alone or in combination of two or more.

The polyfunctional epoxy compound is represented by any one selected from the group consisting of the formulas [I], [II] and [III].

These have good reactivity with polyphenylene ethers during the curing process, and can increase the number of crosslinking points to produce a cured product having high heat resistance. Furthermore, since unreacted substances in the cured product are reduced, when the cured product is heated, volatile components are reduced, and a cured product excellent in heat resistance and adhesion can be produced.

The compounding amount of these epoxies is preferably from 15 to 35 parts by weight. If the amount is less than this, curing failure will occur and the heat resistance will be degraded. .

The above-mentioned polyphenylene ethers are not particularly limited as long as they have at least one hydroxyl group at a terminal, but those having a molecular weight of 10,000 or less are preferable because of good fluidity and high reactivity with an epoxy resin. . In order to obtain a low-molecular-weight product from commercially available polyphenylene ether, a phenol such as bisphenol A and a peroxide may be used as an initiator and heated in a solvent such as toluene. A low molecular weight product is obtained.

The above cyanate compound is used in an amount of 2 per molecule.
An aromatic compound having at least two cyanate groups. For example, 2,2-bis (4-cyanatophenyl) propane, bis (3,5dimethyl-4-cyanatophenyl)
Methane, 2,2-bis (4-cyanatophenyl) ethane and the like can be mentioned. These are used alone or in combination of two or more.

It is considered that a cured product of the above cyanate compound has excellent electrical properties and also participates in a curing reaction between epoxy and polyphenylene ethers to form a crosslinked structure, so that the glass transition temperature also increases.

The mixing ratio of the above cyanate compound is 1 to 1 with respect to the epoxy resin and the polyphenylene ether.
It is effective in the range of 30% by weight. If more than this,
There are problems of impregnation deterioration and crystal precipitation.

Examples of the reaction accelerator include organic acids such as octanoic acid, stearic acid, acetylacetonate, naphthenic acid and salicylic acid, metal salts such as Zn and Cu, and tertiary amines such as triethylamine and triethanolamine. −
Imidazoles such as ethyl-4-imidazole and 4-methylimidazole are effective. These are used alone or in combination of two or more.

These metal organic acid salts are considered to contribute to the reaction of cyanate, and the imidazole compound is considered to mainly contribute to the reaction between epoxy and polyphenylene ethers.

When the above essential components are blended with at least one acid anhydride selected from the group consisting of tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride and methylhymic anhydride, the epoxy compound and the polyphenylene ether Are preliminarily reacted. This reaction proceeds easily in the presence of the imidazole compound. However, if the reaction is performed too much, the viscosity increases, which has an adverse effect.

The acid anhydride is at least one selected from the group consisting of tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride and methylhymic anhydride.

By blending these, the amount of unreacted substances in the cured product is reduced, so that when the cured product is heated, the volatile components are reduced and a cured product excellent in heat resistance and adhesion can be produced. it can.

The amount of these acid anhydrides is preferably from 1 to 30 parts by weight. If the amount is less than this, curing failure will occur and the heat resistance will be degraded. Become.

The epoxy resin composition of the present invention can be used as an insulating substrate such as a laminated board or a printed wiring board by impregnating a glass substrate in an appropriate solvent, drying and heating and curing. You can do it.

The present invention utilizes the good electrical properties of a cured product of an aromatic compound having a cyanate group and the reactivity with a polyfunctional epoxy or polyphenylene ether. That is, heat resistance and adhesion are improved by being incorporated into the curing system.

[0035]

Embodiments of the present invention will be described below in detail.

(Example 1) As an epoxy resin, 150 g of a bisphenol A type epoxy resin and a bromide thereof (DER542 manufactured by Dow Chemical), and a trifunctional epoxy resin represented by the following formula [I] (Epicoat 1032H60 manufactured by Yuka Shell) Of poly (2,6-dimethyl-1,4-phenylene ether) (manufactured by GE) as polyphenylene ethers and bisphenol A 8.2.
g, a reaction initiator (4.5 g of benzoyl peroxide (manufactured by Nacalai Tesque)) reacted by heating (number average molecular weight: about 4000) was used. 62.5 g of 2,2-bis (4-cyanatophenyl) propane (manufactured by Ciba-Geigy) as a cyanate compound, 0.016 g of zinc acetylacetonate and 0.6 g of 2-ethyl-4-imidazole as a catalyst Was. These are treated with toluene 100
g) to prepare a resin varnish of the epoxy resin composition.

[0037]

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Example 2 An epoxy resin composition was prepared in the same manner as in Example 1 except that bisphenol A type epoxy and its bromide were used in an amount of 150 g, and a trifunctional epoxy represented by the following formula [II] was used in an amount of 55 g. Was synthesized.

[0039]

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Example 3 An epoxy resin composition was prepared in the same manner as in Example 1 except that 100 g of bisphenol A type epoxy and its bromide were used, and 75 g of a tetrafunctional epoxy represented by the following formula [III] was used. Was synthesized.

[0041]

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Example 4 In Example 1, 62.5 g of 2,2-bis (4-cyanatophenyl) propane (manufactured by Ciba Geigy) was used as a cyanate compound, and tetrahydrophthalic anhydride was used as an acid anhydride. 23g
A resin varnish of an epoxy resin composition was prepared with the same composition except that it was used.

Example 5 A resin varnish of an epoxy resin composition was prepared in the same manner as in Example 4, except that 22 g of methylhexahydrophthalic anhydride was used as the acid anhydride.

Example 6 A resin varnish of an epoxy resin composition was prepared in the same manner as in Example 4, except that 20 g of methylhymic anhydride was used as the acid anhydride.

Comparative Example 1 205 g of a bisphenol A type epoxy resin and a bromide thereof (DER542 manufactured by Dow Chemical) were used as epoxy resins, and poly (2,6-dimethyl-1,4-phenylene ether) was used as polyphenylene ethers ( GE) 60g and bisphenol A
8.2 g, and a reaction initiator (4.5 g of benzoyl peroxide) which had been heated and reacted as a reaction initiator (number average molecular weight: about 4000) were used. Etacure 5.2 as a curing agent
g, 5.2 g of zinc acetylacetonate as a catalyst,
3.6 g of 2-ethyl-4-imidazole was used. These were mixed to prepare a resin varnish of an epoxy resin composition.

(Comparative Example 2) As an epoxy resin, 205 g of bisphenol A type epoxy resin and a bromide thereof (DER542 manufactured by Dow Chemical Co., Ltd.), and poly (2,6-dimethyl-1,4-phenylene ether) as polyphenylene ethers ( GE) 60g and bisphenol A
8.2 g and a reaction initiator (4.5 g of benzoyl peroxide) as a reaction initiator (number average molecular weight of about 4000) were used. As the cyanate compound, 2,
1.2 g of zinc acetylacetonate was added to 62.5 g of 2-bis (4-cyanatophenyl) propane (manufactured by Ciba Geigy) and prepolymerized at 120 ° C. for 3 hours (average molecular weight: 500). 0.016 g of zinc acetonate and 0.6 g of 2-ethyl-4-imidazole were used. These were mixed in 100 g of toluene to prepare a resin varnish of the epoxy resin composition.

The evaluation methods for the epoxy resin compositions of Examples 1 to 6 and Comparative Examples 1 and 2 obtained as described above are as follows.

A resin varnish of an epoxy resin composition is impregnated into E glass cloth to prepare a prepreg, and four prepregs are laminated and pressed at 200 ° C. for 2 hours to prepare a laminate as an insulating substrate.

The evaluation of the physical properties of this laminated plate was conducted according to JIS-C
6481. The oven heat resistance was determined by keeping five laminated plates in a dryer at 260 ° C. for 30 minutes, and visually observing the occurrence of blisters. The number of blisters among the five laminates was evaluated as a defect occurrence rate.

The glass transition temperature (indicated by Tg in the table), the dielectric constant (indicated by ε in the table), the dielectric loss tangent (indicated by tan δ in the table), the peel strength, and the defect occurrence rate The results are shown in Table 1 below in Examples 1 to 6 and Comparative Example 1.
2 are summarized.

[0051]

[Table 1]

As can be seen from comparison between Examples 1 to 6 and Comparative Examples 1 and 2, in each case, those of Examples 1 to 6 are far more than those of Comparative Examples 1 and 2. Excellent results have been obtained, from this, the epoxy resin composition of the present invention, with high heat resistance,
It can be seen that the material has a low dielectric loss tangent and is excellent in adhesion.

[0053]

According to the epoxy resin composition according to the first aspect of the present invention, the epoxy resin composition has high heat resistance, low dielectric loss tangent, and excellent adhesion.

According to the epoxy resin composition of claim 2 or 3 of the present invention, in addition to the case of claim 1, the epoxy resin composition has high heat resistance and low dielectric loss tangent more reliably, and Will surely be better.

According to the insulating substrate using the epoxy resin composition according to claim 4 of the present invention, a substrate having high heat resistance, a low dielectric loss tangent, and excellent adhesion can be obtained. Quality can be improved.

Claims (4)

[Claims] An epoxy compound having at least two epoxy groups in one molecule is represented by the following formula [I], formula [II],
A phenol-modified polyphenylene ether obtained by redistributing a polyphenylene ether with a phenol and a radical initiator in combination with any one of polyfunctional epoxy compounds selected from the group of the formula [III]; An epoxy resin composition comprising a compound and a curing accelerator as essential components. Embedded image Embedded image Embedded image 2. The method according to claim 1, wherein at least one acid anhydride selected from the group consisting of tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride and methylhymic anhydride is blended with the essential components. The epoxy resin composition according to claim 1, 3. The epoxy resin composition according to claim 1, wherein the phenol-modified polyphenylene ether has a number average molecular weight of 10,000 or less. 4. An insulating substrate using an epoxy resin composition, wherein the epoxy resin composition according to claim 1 is impregnated into a glass substrate and cured.