To obtain the subject composition excellent in low dielectric constant, low dielectric loss tangent, adhesion to metals, etc., for use in printed wiring boards by including a siloxane-modified polyimide and specific two kinds of compound.
This composition is obtained by including (A) 100 pts.wt. of a siloxane-modified polyimide and 10-900 pts.wt. of a mixture of (B) a compound having two methylallyl groups and shown by formula I and (C) a compound having two or more maleimide groups in the molar equivalent ratio of the methylallyl group in the component B to the maleimide group in the component C of 0.1-2.0; wherein it is preferable that the component A is composed of 90-40 mol% of structural unit of formula II (X is a tetravalent aromatic group such as 3,3',4,4'-diphenylsulfone structure or 3,3',4,4'-biphenyl structure; Ar is a bivalent group such as of formula III or formula IV) and 10-60 mol% of structural unit of formula V (R is a 1-10C alkylene or CH2OC6H4 where the methylene is bound to Si; (n) is 1-20).
KOBAYASHI MASAHARU
SATO TAKESHI
ORINO DAISUKE
