JP3525745B2 - Epoxy resin composition and insulating substrate using this 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 and an insulating substrate using this epoxy resin composition, and more specifically, an epoxy resin composition used for electronic materials such as printed wiring boards. It is about.

[0002]

2. Description of the Related Art Epoxy resin compositions used for insulating substrates for laminated boards, printed wiring boards, etc. are those for impregnating a base material and are used in the field of information communication as described above. Since the insulating substrate corresponds to a high frequency region from the MHz band to the GHz band, it has been required to have excellent electric characteristics, and particularly to have a low dielectric constant (ε) and a low dielectric loss tangent (tan δ).

[0003]

Conventionally, as one of the substrates having such electrical characteristics, a material in which a polyphenylene ether resin (also referred to as PPO resin) is mixed with an epoxy resin has been used. This material has a lower dielectric constant and a higher heat resistance than a normal epoxy resin material, but when compared with other expensive high-frequency materials such as Teflon resin, bismaleimide triazine resin, and polyimide resin. The glass transition temperature (Tg) is low and the dielectric loss tangent is high.

Therefore, the inventors of the present invention have proposed a method of further improving heat resistance and electric properties by blending a cyanate and its self-polymer into a material obtained by mixing an epoxy resin with a polyphenylene ether resin, and Japanese Patent Application No. 9-71333. And a proposal as shown in 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 is a problem that adhesion and heat resistance deteriorate.

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

[0007]

The epoxy resin composition according to claim 1 of the present invention has the following formula [I], formula [ II ], formula
Any one multifunctional epoxy selected from the group of [ III ]
Shi compounds, and which at least epoxy groups in one molecule other than a combination of an epoxy compound having two or more polyphenylene ether phenol-modified polyphenylene obtained by redistribution reaction in the presence of a phenol and a radical initiator Ether and 2 or more cyanes per molecule
A cyanate compound having a carboxylate group and a curing accelerator are contained as essential components.

[0008]

[Chemical 4]

[0009]

[Chemical 5]

[0010]

[Chemical 6]

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

An epoxy resin composition according to a third aspect 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 it. Is characterized by.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below.

The epoxy resin composition according to the present invention, the following
A compound selected from the group consisting of formula [I], formula [ II ] and formula [ III ]
One of these polyfunctional epoxy compounds and another epoxy compound having at least two epoxy groups in one molecule are used in combination, and polyphenylene ether is added in the presence of phenols and a radical initiator. Phenol-modified polyphenylene ether obtained by redistribution reaction and one molecule
A cyanate compound having two or more cyanate groups and a curing accelerator are contained as essential components.

[0016]

[Chemical 7]

[0017]

[Chemical 8]

[0018]

[Chemical 9]

The above-mentioned epoxy resin is not particularly limited as long as it has two or more epoxy groups per molecule, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin. Examples thereof include resins, naphthalene type epoxy resins, biphenyl type epoxy resins, and brominated epoxy resins thereof. These may be used alone or in combination of two or more.

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

These have good reactivity with polyphenylene ethers in the curing process, and by increasing the number of crosslinking points, a highly heat-resistant cured product can be produced. Furthermore, since unreacted substances in the cured product are reduced, when the cured product is heated, the volatile components are reduced, and a cured product excellent in heat resistance and adhesion can be produced.

The amount of the epoxy compounded is preferably 15 to 35 parts by weight. If the amount is less than this range, curing failure will occur and the heat resistance will be deteriorated. On the contrary, if it exceeds this range, the electrical characteristics will be deteriorated. .

The polyphenylene ether is not particularly limited as long as it has one or more hydroxyl groups at the terminal, but a molecular weight of 10,000 or less is preferable because it has good fluidity and high reactivity with an epoxy resin. . In order to obtain low molecular weight compounds from commercially available polyphenylene ethers, phenols 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 has 2 molecules per molecule.
It is an aromatic compound having one or more cyanate groups. For example, 2,2-bis (4-cyanatophenyl) propane, bis (3,5dimethyl-4-cyanatophenyl)
Examples thereof include methane and 2,2-bis (4-cyanatophenyl) ethane. These may be used alone or in combination of two or more.

The cured product of the above cyanate compound is excellent in electrical characteristics and also participates in the curing reaction between the epoxy and the polyphenylene ether to form a crosslinked structure, so that the glass transition temperature is considered to rise.

The compounding ratio of the above cyanate compound is 1 to epoxy resin and polyphenylene ethers.
Effective in the range of 30% by weight. More than this,
There are problems of impregnating property 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 may be used alone or in combination of two or more.

It is considered that these metal organic acid salts contribute to the reaction of cyanate, and the imidazole compound mainly contributes to the reaction of epoxy and polyphenylene ethers.

The above-mentioned essential compounds are blended with at least one acid anhydride selected from the group consisting of tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, and methylhymic acid anhydride. The above-mentioned epoxy compound and polyphenylene ether This is a preliminary reaction of the class. This reaction easily proceeds in the presence of the imidazole compound. However, if the reaction is carried out too much, the viscosity will increase, which has the opposite effect.

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

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

The content of these acid anhydrides is preferably 1 to 30 parts by weight. If the amount is less than this, curing failure occurs and the heat resistance is deteriorated. 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 base material in a suitable solvent, drying and then heating and curing. It is possible.

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

[0035]

EXAMPLES Examples of the present invention will be described in detail below.

Example 1 As an epoxy resin, 150 g of a bisphenol A type epoxy resin and its bromide (DER542 made by Dow Chemical), and a trifunctional epoxy resin of the following formula [I] (Epicoat 1032H60 made by Yuka Shell) are used. 80 g, poly (2,6-dimethyl-1,4-phenylene ether) (manufactured by GE) as polyphenylene ethers, and bisphenol A8.2.
g, benzoyl peroxide (manufactured by Nacalai Tesque) (4.5 g) as a reaction initiator was heated and reacted (number average molecular weight of about 4000). As the cyanate compound, 2,2-bis (4-cyanatophenyl) propane (manufactured by Ciba Geigy) 62.5 g, zinc acetylacetonate as a catalyst 0.016 g, and 2-ethyl-4-imidazole 0.6 g are used. I was there. Toluene 100
The mixture was mixed in g to prepare a resin varnish of the epoxy resin composition.

[0037]

[Chemical 10]

Example 2 An epoxy resin composition having the same composition except that in Example 1 150 g of bisphenol A type epoxy and its bromide and 55 g of trifunctional epoxy of the following formula [II] were used. The resin varnish of was synthesized.

[0039]

[Chemical 11]

Example 3 An epoxy resin composition having the same composition as in Example 1 except that 100 g of bisphenol A type epoxy and its bromide and 75 g of tetrafunctional epoxy of the following formula [III] were used. The resin varnish of was synthesized.

[0041]

[Chemical 12]

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

Comparative Example 1 As an epoxy resin, 205 g of a bisphenol A type epoxy resin and its bromide (DER542 made by Dow Chemical) and poly (2,6-dimethyl-1,4-phenylene ether) (as polyphenylene ethers) ( GE) 60 g and bisphenol A
Further, 8.2 g of benzoyl peroxide (4.5 g of which the number average molecular weight was about 4000) was reacted by heating was used as a reaction initiator. 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 and the resin varnish of the epoxy resin composition was produced.

Comparative Example 2 As an epoxy resin, 205 g of a bisphenol A type epoxy resin and its bromide (DER542 manufactured by Dow Chemical) and poly (2,6-dimethyl-1,4-phenylene ether) (as polyphenylene ethers) ( GE) 60 g and bisphenol A
Further, 8.2 g of benzoyl peroxide (4.5 g of which the number average molecular weight was about 4000) was reacted by heating was used as a reaction initiator. The cyanate compound is 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), acetyl as a catalyst. 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.

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.

E glass cloth was impregnated with a resin varnish of an epoxy resin composition to prepare a prepreg, and four prepregs were stacked and press-molded at 200 ° C. for 2 hours to prepare a laminate as an insulating substrate.

The physical properties of this laminate were evaluated according to JIS-C with respect to glass transition temperature, dielectric constant, dielectric loss tangent and peel strength.
6481. The oven heat resistance was evaluated by visually observing the occurrence of blistering and the like after keeping the five laminated plates in a dryer at 260 ° C. for 30 minutes. Then, of the five laminated plates, the number of occurrences of blistering or the like was evaluated as a defect occurrence rate.

The glass transition temperature (denoted by Tg in the table), the dielectric constant (denoted by ε in the table), the dielectric loss tangent (denoted 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.
I have summarized each of the above.

[0051]

[Table 1]

As can be seen from comparison between Examples 1 to 6 and Comparative Examples 1 and 2, the items of Examples 1 to 6 are far better than those of Comparative Examples 1 and 2 in any item. It has been obtained results that exceed, from this, the epoxy resin composition of the present invention, high heat resistance,
It can be said that it has a low dielectric loss tangent and excellent adhesion.

[0053]

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

According to the epoxy resin composition according to claim 2 or claim 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 surely, and has good adhesion. As a result, it will surely become superior.

According to the insulating substrate using the epoxy resin composition according to the fourth aspect of the present invention, a substrate having high heat resistance and low dielectric loss tangent and excellent adhesion can be obtained. As a result, The quality can be improved.

Continuation of front page (56) Reference JP-A-5-239183 (JP, A) JP-A-9-291148 (JP, A) JP-A-9-235349 (JP, A) JP-A-7-242732 (JP , A) JP-A-10-292031 (JP, A) JP-A-10-265669 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08G 59/00-59/72 H05K 1/03-1/05

Claims (4)

(57) [Claims] 1. The following formulas [I], [ II ] and [ III ]
Any one polyfunctional epoxy compound selected from the group,
And, other than this at least epoxy groups in one molecule in combination with an epoxy compound having two or more polyphenylene ether phenol-modified polyphenylene ether obtained by redistribution reaction in the presence of a phenol and a radical initiator and 1 Has two or more cyanate groups per molecule
An epoxy resin composition containing a cyanate compound and a curing accelerator as essential components. [Chemical 1] [Chemical 2] [Chemical 3] 2. The above essential component is blended with at least one acid anhydride selected from the group consisting of tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, and methylhymic anhydride. The epoxy resin composition according to claim 1. 3. The epoxy resin composition according to claim 1 or 2, 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, which 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.