Studies on the Optimizing the Properties of Thermoset Polyurethane Resin for In-mold Coating

Abstract

The thermoset polyurethanes for in-mold coating system were prepared by using XP 2488, a polyester polyol, and C 1100, a polycarbonate diol, as polyols and Desmodur N 3600, a hexamethylene diisocyanate trimer-type, as a cur-ing agent. It was revealed that tensile strength, elongation at break increased with increasing content of XP 2488. Poly-urethanes prepared with C 1100 content of 25 wt% showed the highest value of adhesion (Class 0). Thermal and light stability increased with increasing C 1100 in the polyurethanes. And polyurethane prepared with a polyol consisting of 25 wt% XP 2488 and 75 wt% C 1100 exhibits an excellent self-healing ability, i.e. the scratch formed on the surface can be repaired instantly.