kansai paint patents
water-based coating
Patent No. U.S. 7,357,962 B2
Kansai Paint has obtained a patent for an automobile body-used light-colored water-based coating consisting of a water dispersion prepared by water-dispersing a block copolymer resin comprised of a block obtained by polymerizing a monomer component containing an olefin monomer and a block obtained by polymerizing a monomer component containing a carboxyl group-containing or carboxylic anhydride group-containing vinyl monomer, a hydroxyl group-containing resin, a curing agent, a water dispersion prepared by water-dispersing a resin particle containing in the same particle a copolymer of an olefin monomer and a copolymer of a vinyl monomer or an urethane emulsion and a color pigment, the hydroxyl group-containing resin being a polyester resin containing as essential components an alicyclic polybasic acid and an alicyclic polyhydric alcohol, a content of the alicyclic polybasic acid and the alicyclic polyhydric alcohol being in the range of 20%-70% by weight based on a total solid content of monomers constituting the polyester resin, the curing agent including a blocked polyisocyanate curing agent blocked with a pyrazole compound consisting of 3, 5-dimethylpyrazole, a resulting coating film having a lightness L* value in accordance with a L*a*b* color system as defined in JIS Z 9729 in the range of 80 or more, and showing excellent anti-chipping properties.