JPH0377815B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a resin composition for laminates that has excellent heat resistance, heat discoloration resistance, copper foil adhesion, etc., and relates to a laminate that can be suitably used as a printed wiring board, etc. This is what we provide. [Conventional technology and its problems] As the goals of electronic device design are toward miniaturization, high reliability, and low cost through high-density wiring, printed wiring boards are also moving toward meeting these demands. It has been improved and developed. When laminates are manufactured using epoxy resin and phenol novolac resin, which is inexpensively manufactured, as a curing agent to reduce costs, the electrical performance is very good, but the heat resistance, heat discoloration resistance, and copper foil are very good. It had a drawback of poor adhesion. [Means for Solving the Problems] In order to eliminate the drawbacks that occur when laminates are manufactured using the above-mentioned phenol novolac resin as a curing agent for epoxy resin, the present invention utilizes various novolac resins as a curing agent. As a result of intensive studies on the suitability of P-alkylphenol and its catalyst, we found that heat resistance and heat discoloration resistance are dramatically improved when a novolac resin containing P-alkylphenol as the main component is used as a curing agent, and imidazole trimellitic acid addition. It was discovered that copper foil adhesion was dramatically improved by using a catalyst alone or in combination with an imidazole, and this work was completed based on this knowledge. That is, the present invention provides a novolak resin which is mainly composed of an epoxy resin having two or more epoxy groups in the molecule and P-alkylphenol, has an average degree of polymerization of 3 to 6, and has a free phenol content of 0.6% or less.
This is a resin composition for a laminate using a 2-ethyl-4-methylimidazole trimellitic acid adduct alone or in combination with an imidazole as a catalyst. The epoxy resin of the present invention is not particularly limited, but specifically includes bisphenol A epoxy resin, bisphenol F epoxy resin, phenol novolak epoxy resin, and halogenated bisphenol A epoxy resin. resins, halogenated bisphenol F-based epoxy resins, halogenated phenol novolak-type epoxy resins, polyglycol-based epoxy resins, etc., and these may be used alone or in combination of two or more. The novolac resin of the present invention is one which contains P-alkylphenol as a main component, has an average degree of polymerization of 3 to 6, and has a free phenol content of 0.6% or less. As P-alkylphenol, P-cresol, P
-nonylphenol and the like are exemplified. By using a phenol having an alkyl group at the P position, the phenol is prevented from forming a quinone structure under heating or in an oxidizing atmosphere, so the effect of preventing discoloration due to heating is greatly exhibited. Presumed. Moreover, when the average degree of polymerization is 7 or more, the compatibility with the epoxy resin deteriorates, and the impregnability into the base material also deteriorates. If the content of free phenols exceeds 0.6%, the heat resistance of the laminate deteriorates and causes significant discoloration during heating. The blending ratio of the epoxy resin of the present invention and the P-alkylphenol novolak resin is preferably such that the phenolic hydroxyl group is 0.7 to 1.5 equivalents, more preferably 0.8 to 1.2 equivalents, per equivalent of the epoxy resin. . The catalyst of the present invention is a 2-ethyl-4-methylimidazole trimellitic acid adduct alone or a combination thereof with an imidazole. Examples of the imidazole include 2-ethyl-4-methylimidazole, 1-cyanoethyl- Examples include 2-ethyl-4-methylimidazole. The amount used is 0.05 to 0.5% of the resin component, preferably 0.1 to 0.3%.
% range. The composition of the present invention has the above-mentioned components as essential components, but may also contain various additives such as other curing accelerators or curing catalysts, known diluents, fillers, pigments, heat resistant agents, etc., if desired. For example, benzyldimethylamine can be used as a curing accelerator or curing catalyst. Examples of the base material for the laminate include glass cloth, glass nonwoven fabric, glass mat, glass paper, carbon fiber cloth, and paper. [Example] The present invention will be further explained below with reference to Examples. Example 1 Bisphenol A type epoxy resin (Epicote 828: Yuka Ciel Epoxy Co., Ltd.) was used so that the equivalent ratio of phenolic hydroxyl groups to epoxy groups was 0.9.
(manufactured by Dainippon Ink Co., Ltd., epoxy equivalent: 184-194) and 25 wt parts of P-alkylphenol novolac resin (Petit Raiohen LF-511: manufactured by Dainippon Ink Co., Ltd., free phenols 0.1% or less). 2-ethyl-4-methylimidazole trimellitic acid adduct (manufactured by Shikoku Kasei Co., Ltd., 2E4M-
CNS) 0.45wt part and acetone and N as solvent,
A varnish for laminates was prepared by adding N-dimethylformamide. Thickness of this varnish treated with epoxy silane is 0.18
A prepreg with a resin content of 40 wt% was prepared by impregnating and coating a glass cloth with a diameter of 40 mm and drying it at 155°C for 60 minutes.
Next, add 8 sheets of this prepreg with a thickness of 18μ on both sides.
90% copper foil at a temperature of 170℃ and a pressure of 20Kg/ ^cm2.
A double-sided copper-clad laminate with a thickness of 1.6 mm was obtained by lamination molding under the following conditions. The properties of the obtained laminate are shown in Table 1. Example 2 In Example 1, 2-ethyl-4-methylimidazole trimellitic acid adduct (manufactured by Shikoku Kasei Co., Ltd.,
The procedure was the same except that 0.2 wt part of 2E4M-CNS) and 0.1 wt part of 2-ethyl-4-methylimidazole were used together. The properties of the obtained laminate are shown in Table 1. Comparative Example 1 The procedure of Example 1 was repeated except that 0.25 wt part of 2-ethyl-4-methylimidazole was used as a catalyst for preparing a varnish for a laminate. The properties of the obtained laminate are shown in Table 1. Comparative Example 2 In Example 1, a phenol novolak resin was used instead of the P-alkylphenol novolak resin used for preparing the varnish for the laminate, and 2-ethyl-4-methylimidazole was used as a catalyst.
The same procedure was used except that 0.25wt part was used. The properties of the obtained laminate are shown in Table 1. [Operations and effects of the invention] As described above, the laminate made of the resin composition for laminates of the present invention has excellent heat resistance, heat discoloration resistance, copper foil adhesion, etc., and can be used as a good laminate. This is something that can be provided.

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Claims (1)

[Claims] 1 The main components are epoxy resin having two or more epoxy groups in the molecule and P-alkylphenol, and the average degree of polymerization is 3 to 6, with free phenols being 0.6%.
A resin composition for a laminate comprising the following novolac resin and a 2-ethyl-4-methylimidazole trimellitic acid adduct alone or in combination with an imidazole as a catalyst.