Curable resin, process for making and electronic part protective coating

Abstract

A novel curable polyimide resin of structural formula (1) or (2) is provided wherein R.sup.1 and R.sup.2 are independently substituted or unsubstituted monovalent C.sub.1-10 hydrocarbon groups, R.sup.3 is a divalent C.sub.1-10 organic group, X is a tetravalent organic group containing an aromatic or aliphatic ring, Y is a divalent organic group, Z is a divalent organic group containing an aromatic ring, W is a trivalent organic group containing an aromatic ring, m is an integer of 1 to 3, and n is an integer of at least 1. It can be prepared by reacting a polyimide with a silicon compound. The curable resin forms with a solvent a solution having a low viscosity and shelf stability and cures at relatively low temperatures below 300.degree. C. into coatings having heat resistance, mechanical strength, electrical properties, solvent resistance and substrate adherence. ##STR1##

Dependencies are inferred from the claim text.