URETHANE-MODIFIED ALKYD RESIN, RESIN COMPOSITION FOR WATER-BASED URETHANE-MODIFIED ALKYD COATING AND METHOD FOR PRODUCING THEM

摘要

PROBLEM TO BE SOLVED: To obtain a resin composition for a water-based alkyd coating, which is friendly to the environment, has improved adhesivity, excellent color tone, weather resistance, slight thermal discoloration and stable qualities and to provide a method for producing the same.;SOLUTION: The resin composition for a water-based urethane modified alkyd coating comprises an urethane modified alkyd resin (A) which is obtained by using a natural fatty acid ester and a polycarboxylic acid anhydride as acid components and a 2-50C polyhydric alcohol as an alcohol component in the presence of a polymerization catalyst containing at least an aluminum compound to produce a polyester polyol, reacting the polyester polyol with an organic diisocyanate compound and if necessary, a chain extender having a molecular weight of 500 and has a urethane group concentration of 300-5,000 equivalents/10⁶ g, reduced viscosity of 0.2-1.0 dl/g and an acid value of ≥50 equivalents/10⁶ g and a curing agent (B) and is adjusted so as to satisfy a neutralization ratio of 1-2,000% by using a neutralizer (C) to the acid value of the resin (A).;COPYRIGHT: (C)2008,JPO&INPIT