Sumitomo Bakelite Company Limited

Kochi Tanaka

Tsutomu Watanabe

Sigenori Yamaoka

This invention provides an adhesive composition for use in flexible printed circuits, comprising a phenol-formaldehyde resin, a polyepoxy compound, an acrylonitrile-butadiene copolymer and/or a polyvinylacetal resin, and a styrenic copolymer containing as structural units maleic anhydride and/or an alkyl maleate. Being excellent in adhesive strength, flow property, rapid curability, and heat resistance after curing, the present composition is especially suitable for the continuous bonding of insulating plastic films, particularly a polyimide film, to conductor foils by use of a roll-laminator and gives heat-resistant metal-clad laminates excellent for flexible printed circuits which can be soldered at high temperatures. This invention further provides an adhesive composition having added thereto a compound consisting of an anhydride or a half-ester of cyclohexenepolycarboxylic acid in order to increase the flow property and adhesive strength of the adhesive composition at the time of bonding by means of a roll-laminator. All of the aforesaid adhesive composition not only permit the economical and technically advantageous production of laminates for heat resistant flexible printed circuits, but also can serve as an adhesive for either an overlay film for use in highly heat-resistant flexible printed circuits or an interlayer adhesive film.

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Yokohama, Japan

Kochi Tanaka