JPH07206992A - Resin composition for laminated sheet - Google Patents

Abstract

PURPOSE:To obtain a resin composition for laminated sheets, consisting essentially of an epoxidized polybutadiene, etc., having a low dielectric constant, excellent in high frequency characteristics, reactivity, heat resistance and flame retardancy and useful as a printed wiring board, etc. CONSTITUTION:This resin composition for laminated sheets is obtained by blending (A) 100 pts.wt. epoxidized polybutadiene having, e.g. 150-300 epoxy equiv. with (B) preferably 20-80 pts.wt. maleimide compound having phenolic hydroxyl group such as 4-hydroxyphenylmaleimide and (C) preferably 50-150 pts.wt. bismaleimide resin such as bismalemide resin prepared by reacting 4,4'- diaminodiphenylmethane with maleic anhydride or (D) a compound containing bromine such as monobromophenol as essential components.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for a low dielectric constant laminated board which is applicable to a printed wiring board of information equipment used for mobile communication, multimedia and the like and which has excellent high frequency characteristics.

[0002]

2. Description of the Related Art In order to increase the speed of electric signals, a material for a printed wiring board (hereinafter abbreviated as a substrate) is required to have a low dielectric constant. Fluororesin (ε =
2.1) and polyethylene (ε = 2.3), etc., each of which is commercialized as a copper-clad laminate. But,
Fluororesin substrates have drawbacks such as high cost and poor adhesion to circuit materials such as copper foil, and polyethylene resin has its own problems such as poor heat resistance At present, it is only used for various purposes. Moreover, with the recent trend toward smaller and lighter electronic devices, multilayering and thinning are required, but poor adhesiveness,
It is not used as a material for multilayer wiring boards because of its high melt viscosity. Therefore, in order to reduce the dielectric constant of the resin for laminates, various methods using liquid polybutadiene as disclosed in, for example, JP-A-61-126162 and JP-A-4-114027 have been proposed. . However, these have not been put into practical use because of their poor heat resistance and difficulty in flame retardation. From such a background, the present invention has been achieved as a result of earnestly studying a material that is easily flame-retarded, has good heat resistance, and is suitable for multilayering.

[0003]

Hydrocarbon resins such as polybutadiene have a low dielectric constant because they do not have polar groups. However, since these resins have poor reactivity and heat resistance, it is difficult to use them as they are as resins for laminated plates. An object of the present invention is to provide a resin for a laminate, which has improved reactivity, heat resistance or flame retardancy while maintaining a low dielectric constant.

[0004]

That is, the present invention has a molecular weight of 5
The present invention relates to a low dielectric constant resin composition containing, as essential components, a maleimide compound having 00 or more epoxidized polybutadiene, a phenolic hydroxyl group, and a bismaleimide resin. Further, the present invention relates to a low dielectric constant resin composition containing epoxidized polybutadiene having a molecular weight of 500 or more, a maleimide compound having a phenolic hydroxyl group, and a bromine-containing compound as essential components.
To further explain the present invention in detail, epoxidized polybutadiene is reacted with a maleimide compound having a phenolic hydroxyl group, and a bismaleimide resin or a bromine-containing compound is added thereto to improve heat resistance while maintaining a low dielectric constant. Since it can be obtained and has a low melt viscosity, it is optimal as a resin for a low dielectric constant laminate. Further, by reacting the double bond existing in the epoxidized polybutadiene and the double bond of the maleimide group with an organic peroxide, a crosslinking reaction occurs and the heat resistance can be further improved.

The epoxidized polybutadiene used in the present invention is obtained by epoxidizing liquid polybutadiene by various methods and has an epoxy equivalent of 150 to 300. For example, R-45EPI (Idemitsu Petrochemical Co., Ltd.) is used.
Trade name), BF-1000 (trade name of Adeka Argus Co.) and the like. As the maleimide having a phenolic hydroxyl group, 4-hydroxyphenylmaleimide, 3-hydroxyphenylmaleimide, 4-hydroxy-4'-maleimidodiphenylmethane, 4-hydroxy-4'-maleimidodiphenylisopropylidene, 4
-Hydroxy-4'-maleimidodiphenyl sulfone,
4-hydroxy-4'-maleimido diphenyl ether etc. are mentioned. As the bismaleimide resin, 4,
4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, m-phenylene-bis- (4-aminophenylisopropylidene), p-phenylene-bis (4-aminophenylisopropylidene) ), Bis- (p-aminophenoxyphenyl) propane-2,2, bis (p-aminophenoxyphenyl) sulfone, bis- (m-aminophenoxyphenyl) and other aromatic diamines are reacted with maleic anhydride. And a bismaleimide resin that can be used. As the bromine-containing compound, compounds having a phenolic hydroxyl group such as monobromophenol, dibromophenol, tribromophenol, tetrabromophenol-A and brominated phenol novolac resin are preferable. The reaction of the epoxidized polybutadiene with a maleimide having a phenolic hydroxyl group and a bismaleimide resin or a bromine-containing compound is carried out in a solvent in the presence of a catalyst at a temperature of 5
It is carried out at 0 to 200 ° C. Examples of the reaction solvent include ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, and polar solvents such as N, N′-dimethylformamide, N, N′-dimethylacetamide, N-methylpyrrolidone, and dimethyl sulfoxide. The catalyst is not particularly limited as long as it is a catalyst used for the reaction between an epoxy group and a phenolic hydroxyl group, such as tertiary amine, quaternary ammonium halide and imidazoles. The reaction between the double bond of the epoxidized polybutadiene and that of the maleimide reacts only by heating, but an organic peroxide may be added. As the organic peroxide, benzoyl peroxide, dicumyl peroxide,
Dibutyl peroxide, cumene hydroperoxide, t
-Butyl hydroperoxide and the like. If necessary, an epoxy resin or the like may be added for modification. The compounding ratio of the epoxidized polybutadiene, the maleimide compound having a phenolic hydroxyl group, and the bismaleimide resin should be determined according to the characteristics of the copper-clad laminate, and is not particularly limited. Epoxidized polybutadiene 1 is one that has both low dielectric constant and heat resistance.
20 to 80 parts by weight of a phenolic hydroxyl group-containing maleimide compound, and 50 to 50 parts by weight of a bismaleimide resin.
150 parts by weight is preferred. In addition, flame retardancy (UL-94
It is preferable that the bromine-containing compound blended in order to satisfy V-0) satisfies the required flame retardancy to a minimum.
Moreover, it is preferable that all of them react with the epoxidized polybutadiene. If the unreacted material remains, it causes a decrease in dielectric constant and heat resistance.

[0006]

The epoxidized polybutadiene and the maleimide compound having a phenolic hydroxyl group or the bromine-containing compound reacts at the epoxy group and the phenolic hydroxyl group. The heat resistance of the maleimide compound itself and the heat resistance are further improved by the crosslinking reaction between the double bond of the epoxidized polybutadiene and the maleimide compound. Hereinafter, the present invention will be specifically described with reference to examples.

[0007]

【Example】

[Synthesis Example 1 of low dielectric constant resin] 220 g of epoxidized polybutadiene (R-45EPI), 140 g of 4-hydroxyphenylmaleimide, 2-ethyl-4-methylimidazole were placed in a 2 l flask equipped with a stirrer, a thermometer, and a cooler. Charge 4.4 g and 435 g of cyclohexanone 15
The reaction was carried out at 0 ° C for 4 hours. It was confirmed by liquid chromatography that 4-hydroxyphenylmaleimide reacted 80%. To this reaction liquid, 180 g of 4,4′-bismaleimidediphenylmethane was added and dissolved at 80 ° C. with stirring. After cooling to room temperature, dicumyl peroxide 4.3
5 g was added, stirred and dissolved to synthesize a varnish. [Synthesis example 2 of low dielectric constant resin] 220 g of epoxidized polybutadiene (R-45EPI), 100 g of 4-hydroxyphenylmaleimide, 1,8-diazabicyclo (5, 5) were placed in a 2 l flask equipped with a stirrer, a thermometer, and a cooler.
4,0) Undecene-7 (6.3 g) and N, N′-dimethylformamide (449 g) were charged and reacted at 130 ° C. for 3 hours. It was confirmed by liquid chromatography that unreacted 4-hydroxyphenylmaleimide was 10% or less. To this, 150 g of bis- (4-maleimidophenoxyphenyl) propane-2,2 was added and dissolved by stirring at 80 ° C. to give a varnish.

[Synthesis Example 3 of low dielectric constant resin] 220 g of epoxidized polybutadiene (R-45 EPI), 120 g of tribromophenol, 2-ethyl-4-methyl were placed in a 2 liter flask equipped with a stirrer, a thermometer and a condenser. Charge 4.4 g of imidazole and 435 g of cyclohexanone.
The reaction was carried out at 0 ° C for 4 hours. It was confirmed by liquid chromatography that there was no unreacted tribromophenol. 95 g of 4-hydroxyphenylmaleimide was added to this reaction solution, and the reaction was continued at the same temperature for 4 hours. Although there was 15% of unreacted 4-hydroxyphenylmaleimide, the reaction was completed by cooling to room temperature. 4.35 g of dicumyl peroxide was added to this, stirred and dissolved to synthesize a varnish. [Synthesis example 4 of low dielectric constant resin] 220 g of epoxidized polybutadiene (R-45 EPI) and tribromophenol 6 were placed in a 2 liter flask equipped with a stirrer, a thermometer, and a cooler.
0 g, benzyl dimethyl amine 4.4 g, and N, N'- dimethylformamide 449 g were prepared and it was made to react at 130 degreeC for 3 hours. After confirming that there is no unreacted tribromophenol, tetrabromobisphenol-A
37 g was added and the reaction was continued at 130 ° C. for 2 hours. To this, 132 g of 4-hydroxyphenylmaleimide was added and reacted at 150 ° C. for 4 hours, 150 g of 4,4′-bismaleimidediphenylmethane was further added, and the mixture was stirred at 80 ° C. and dissolved to give a varnish. [Comparative Resin] As a comparative example, 100 parts by weight of a low-bromine content epoxy resin (Dow Chemical Company trade name DER-515), 20 parts by weight of a novolac type epoxy resin (Dow Chemical Company trade name DEN-438), and a curing agent 5 parts by weight of dicyandiamide, 2-ethyl-4 as a curing accelerator
A resin composition having the same composition as that of a commercially available glass cloth-based epoxy resin copper-clad laminate, which has a resin content of 50% using 1 part by weight of methylimidazole and dimethylformamide, methylcellosolve, and methylethylketone which are solvents, is prepared. did. The above-synthesized four types of varnish and an epoxy resin varnish as a comparative material were applied to a glass cloth and dried to prepare a prepreg. Eight sheets of the prepreg were stacked, copper foils on both sides were stacked, and pressure-molded at a pressure of 4 MPa and a temperature of 170 ° C. for 1 hour to prepare a double-sided copper-clad laminate. The characteristics of the laminated plate were measured according to JIS-C-6481. The thermogravimetric analysis and the glass transition point (Tg) were measured using a thermal analyzer 1090B manufactured by DuPont. The results are summarized in Tables 1 and 2.

[0009]

[Table 1]

[0010]

[Table 2]

[0011]

As shown in the examples, the present invention has a lower dielectric constant than general glass-based epoxy resin laminates,
Since the other properties show almost the same properties and moldability, it has become possible to provide a printed circuit wiring board having a low dielectric constant without changing the conventional process.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeshi Horiuchi 1500 Ogawa, Shimodate, Ibaraki Pref., Shimodate Research Laboratory, Hitachi Chemical Co., Ltd. Shimodate Research Center

Claims (3)

[Claims] 1. A resin composition for a laminate, which comprises epoxidized polybutadiene, a maleimide compound having a phenolic hydroxyl group, and a bismaleimide resin as essential components. 2. A resin composition for a laminate, which comprises epoxidized polybutadiene, a maleimide compound having a phenolic hydroxyl group, and a bromine-containing compound as essential components. 3. The resin composition for a laminate according to claim 1, wherein the epoxy equivalent of the epoxidized polybutadiene is 150 to 300.