Patent ID: 6414065
Filing Date: 2002-07-02
Classification: B41M,C09D,D21H

Abstract:
A method for preparing a paper coating composition comprising an aqueous dispersion of fine particle size calcium carbonate, containing 20 to 30% solids, which comprises:mixing dry poly(vinyl alcohol) particles in an aqueous dispersion of calcium carbonate particles, the calcium carbonate particles having a mean surface area of at least 60 m2/g, until the poly(vinyl alcohol) particles dissolve, to form a dispersion of calcium carbonate particles in an aqueous poly(vinyl alcohol) solution, the dispersion of calcium carbonate particles in the aqueous poly(vinyl alcohol) solution comprising 0.1 to 50 parts poly(vinyl alcohol) per 100 parts calcium carbonate, the poly(vinyl alcohol) having a degree of polymerization of 150 to 300 and being 87 to 89 mole % hydrolyzed, and the poly(vinyl alcohol) particles having an average particle size of 180 &mgr;m or less.