COATING COMPOSITION FOR PRECOATED METAL

摘要

PROBLEM TO BE SOLVED: To provide a coating composition for precoated metals which forms a coating film excellent in chemical resistance, flexibility, adhesiveness and the like. SOLUTION: In the coating composition for precoated metals comprising a main component and a latent hardener, the latent hardener comprises a prepolymer (a) having an NCO-group terminal obtained by reacting TDI (1) with a polyester polyol (2) having an Mn=500-5,000 and a prepolymer (b) having an NCO-group terminal obtained by reacting TDI (1) with a low molecular weight polyol (3) having an Mn=less than 500. The latent hardener is a blocked isocyanate obtained by encapsulating the NCO group in a polyisocyanate mixture (A) having (a)/(b)=50/50-95/5 (mass ratio) with a blocking agent (B). COPYRIGHT: (C)2006,JPO&NCIPI