| abstract |
PURPOSE: To obtain the title ink which has excellent heat resistance, flexibility and adhesive properties and is suitable for various wiring boards after low-temp. short-time heat treatment by incorporating polyparabanic acid, an aminated butadiene-acrylonitrile copolymer rubber and an epoxy resin. n CONSTITUTION: In a solder resist ink for a cover coat for a wiring base sheet using a solvent, polyparabanic acid {a synthetic resin of formula I [wherein R is a divalent org. group (e.g. formulas II, III, IV, V, etc., wherein R 1 and R 2 are each H or CH 3 ; (n) is 4-12)]}, and aminated butadiene-acrylonitrile copoly mer rubber [e.g. a copolymer of formula VI (wherein R is a prim. or sec. amino group; (n) and (m) are each an interger)] and an epoxy resin are incorporated as essential ingredients. As this ink has excellent heat resistance, flexibility and adhesive properties at the same time after low-temp. short-time heat treat ment, it is suitable for various wiring base sheets, especially a flexible printed wiring board. n COPYRIGHT: (C)1992,JPO&Japio |