Heat resistant resin composition

A heat resistant resin coating composition comprising:

• (A) a polyamideimide resin obtained by reacting the following components in a phenolic solvent:
• (a) A polyisocyanate containing an isocyanurate ring in an amount of 0 to 30 equivalent percents based on the total isocyanate equivalent;
• (b) a diisocyanate free of an isocyanurate ring;
• (c) a lactam;
• (d) a tricarboxylic acid anhydride, and
• (e) a compound different from the component (d) and having the formula:
• ##STR3## wherein X and X' are independently a carboxyl group or an acid anydride group;
• Y is a carboxyl group, a hydroxyl group, and acid anhydride group or an amino group;
• n is an integer of 1 or more;
• r is a residue of aromatic aliphatic, alicyclic or heterocyclic group, or a group of the formula:
• --(R.sub.1).sub.m --Z(R.sub.2).sub.l ( 2)
• in which R.sub.1 and R.sub.2 are independently a residue of aromatic, aliphatic, alicyclic or heterocyclic group;
• Z is --CH.sub.2 --, --CO--, --SO.sub.2 -- or --O--;
• and m and l are independently an integer of 1 or 2, in an amount of 0 to 30 equivalent percents based on the total carboxyl equivalent;
• said polyamideimide resin (A) being a branched polyamideimide obtained from components (b), (c) and (d) and at least one of components (a) and (e), and
• (B) at least one member selected from the group consisting of a polyester resin, a polyesteramide resin, a polyesterimide resin and a polyesteramideimide resin;
• the component (B) and the (A) being reacted with each other at a temperature of 120.degree. to 220.degree. C. in the presence of an ester interchange catalyst and said phenolic solvent;
• the amount of the component (A) being 1 to 400 parts by weight based on 100 parts by weight on the component (B).