Flame retarding binder for printed circuit - comprising e.g. soln. of bisphenol di:cyanate pre-polymer and bisphenol=A epoxy resin

摘要

A flame-retarding binder for prepn. of the base materials for printed circuits is a one-component system contg. a mixt. of 100 pts. wt. of bisphenol A dicyanate pre-polymer with B time (at 433 deg. K) of 4-8 h, 17-175 pts. of bisphenol A epoxy resin with epoxide equiv. of 170-400 and less than 0.1 wt. % of easily hydrolysed Cl and/or 43-145 pts. wt. of a mixt. with average epoxy equiv. of 300-400, Br content of 37-49 wt. % and less than 0.1 wt. % of easily hydrolysed Cl, of novolac epoxy resin and tetrabromobisphenol A epoxy resin and reaction prods. with tetrabisphenol A, and 5-33 pts. wt. of bisphenol A and/or tetrabromobisphenol A, as a soln. with 20-80 wt. % solids, in an organic solvent or mixt. e.g. aliphatic ketones and/or aromatic hydrocarbons. ADVANTAGE - The compsn. is of technical and economic advantage in prodn. of high quality base materials for printed circuits, with good Cu bonding at 533 deg. K stability on storage, high Tg, and low solvent absorption.