Patent ID: 8053533

Claim:
A solvent-free polyimide silicone resin composition, which comprises: (A) a polyimide silicone resin having recurring units represented by the following formula (1) and a weight average molecular weight of 5,000 to 150,000: wherein W represents a tetravalent organic group, X represents a divalent group having a phenolic hydroxyl group, Y represents a divalent silicone residue represented by the following formula (2) wherein R 1 and R 2 may be the same or different and represent an alkyl group having 1 to 6 carbon atoms, and a and b are, respectively, an integer of 1 to 20 provided that 1≦a+b≦20 and 0.1≦b/(a+b+2)≦0.5, and Z represents a divalent organic group other than X and Y, and p, q and r are such that 0.15≦p≦0.6, 0.05≦q≦0.8 and 0≦r≦0.75 are respectively satisfied provided that the total of p, q and r is at 1; (B) an epoxy resin comprising a liquid epoxy resin and a solid epoxy resin in a weight ratio of 100:0 to 100:100; and (C) an epoxy resin curing agent, the resin composition having a fluidity at 25° C. and being free of a solvent, wherein a content of said polyimide silicone resin (A) relative to the total of said polyimide silicone resin, said epoxy resin (B), and said epoxy resin curing agent (C) ranges from 1 to 20 wt %, and wherein said solvent-free polyimide silicone resin composition has a viscosity of not greater than 10,000 Pa·second at 25° C.