BigPatents India

A method for preparing a paper coating composition comprising an aqueous dispersion of pigment particles containing predominantly fine particle size calcium carbonate, wherein the coating composition comprises 10 to 32% solids, which method comprises; mixing dry poly(vinyl alcohol) particles in an aqueous dispersion of pigment particles containing predominantly fine particle size calcium carbonate, having a mean surface area of at least 60 m2/g, until the poly(vinyl alcohol) particles dissolve, to form a dispersion of pigment particles in an aqueous poly(vinyl alcohol) solution, the dispersion of pigment particles in the aqueous poly(vinyl alcohol) solution comprising 0.1 to 50 parts poly(vinyl alcohol) per 100 parts pigment particles, the poly(vinyl alcohol) having a degree of polymerization of 50 to 600 and being 85 to 90 mole % hydrolyzed, and the poly(vinyl alcohol) particles having an average particle size of 200 µm or less, and optionally mixing other coating additives with the dispersion of pigment particles in the aqueous solution of poly(vinyl alcohol). (FIG. - Nil)