초록 ▼

Provided by the invention is a thermosetting adhesive composition suitable for use in the preparation of metal foil-laminated base sheets of flexible printed circuit boards and laminated product related thereto such as coverlay films and bonding sheets. The adhesive composition is a uniform blend wh

Provided by the invention is a thermosetting adhesive composition suitable for use in the preparation of metal foil-laminated base sheets of flexible printed circuit boards and laminated product related thereto such as coverlay films and bonding sheets. The adhesive composition is a uniform blend which comprises: (A) an epoxy resin including a brominated epoxy resin to exhibit flame retardancy; (B) a combination of two or three kinds of different nitrile rubbers distinguishable relative to the iodine value and content of carboxyl groups at the molecular chain ends in a specified weight proportion; (C) a curing agent for the epoxy resin; and (D) a curing accelerator, with optional admixture of (E) an inorganic filler; and/or (F) a vulcanizing agent for the nitrile rubbers.

대표청구항 ▼

[ What is claimed is:] [1.] A thermosetting adhesive composition which comprises, as a uniform blend:(A) 100 parts by weight of an epoxy resin;(B) from 30 to 150 parts by weight of a combination of nitrile rubbers consisting of(B1) a first nitrile rubber, of which the weight fraction of the acryloni

[ What is claimed is:] [1.] A thermosetting adhesive composition which comprises, as a uniform blend:(A) 100 parts by weight of an epoxy resin;(B) from 30 to 150 parts by weight of a combination of nitrile rubbers consisting of(B1) a first nitrile rubber, of which the weight fraction of the acrylonitrile moiety is in the range from 20% to 50%, having an iodine value in the range from 200 to 350 g l.sub.2 /100 g and containing carboxyl groups as functional groups at the molecular chain ends in an amount in the range from 0.005% to 5% by weight,(B2) a second nitrile rubber, of which the weight fraction of the acrylonitrile moiety is in the range from 20% to 50%, having an iodine value not exceeding 60 g l.sub.2 /100 g and free from functional groups at the molecular chain ends, and(B3) a third nitrile rubber, of which the weight fraction of the acrylonitrile moiety is in the range from 20% to 50%, having an iodine value in the range from 200 to 350 g l.sub.2 /100 g and free from functional groups at the molecular chain ends, in such a weight proportion that the ratio of (B1+B3):B2 is in the range from 85:15 to 40:60 and the ratio of B1:(B2+B3) is in the range from 85:15 to 40:60;(C) from 2 to 20 parts by weight of a curing agent for the epoxy resin; and(D) from 0.1 to 3 parts by weight of a curing accelerator selected from the group consisting of imidazole compounds, borofluoride compounds and metal salts of octoic acid.