Japanese Water-soluble Polyurethane Modified Polyester Coating Compound

Japanese researchers have invented a water-soluble polyurethane-modified polyester coating compound that has good resistance to cracking. This coating compound can be used as an intermediate coating and topcoat system for primers, such as paints for automotive bodywork. It consists of the following components: (A) a polyurethane-modified polyester resin having a hydroxyl group and an NCO group; (B) a cross-linking agent; (C) a hollow resin particle. The specific process formula is: 0.2 parts of trimethylol propane, 0.8 parts of 1,6-hexanediol, 0.4 parts of cyclohexane hexacarboxylic acid, and 0.3 parts of fatty acid are mixed and reacted; then 0.05 is added. Mol of trimeric anhydride to form 100 parts of polyester, which is derived from 10 parts of the reaction product-cyclohexyl isocyanate; (D) 130 parts of butanone solution is derived from 2 mol and 1 mol of dimethyl urethane The resulting polyurethane derivatives were mixed to obtain a dispersion solution having an alkali concentration of 90 mg KOH/g solution, an acid concentration of 38 mg KOH/g solution, an NCO concentration of 10, and a Mn content of 2,000. The resulting coating composition contained 75 parts of the above dispersion solution, 25 parts of polyacrylonitrile resin 325 (trimethylene nitrile resin), 10 parts of JSR-SX866B (hollow rubber sphere), 60 parts of titanium white, and 0.5 parts of carbon black , Has good anti-fragmentation performance.