Grinding or dispersing agents for pigments

Claim 1

A stable, highly concentrated aqueous slurry of an inorganic pigment selected from the group consisting of chalk, clay from primary and secondary deposits, satin white, titanium dioxide, kaolin, and dolomite, said slurry having a viscosity largely unaffected by temperature change between 25° C. and 70° C.; wherein the slurry is stabilized by a dispersant which is a copolymer of: (a) 40 to 90 percent by weight of an ethylenically unsaturated aliphatic carboxylic acid selected from the group consisting of acrylic and methacrylic acids, (b) 10 to 60 percent by weight of a compound having the formula: ##STR4## where R is hydrogen or methyl X is --NH-- or --O-- A is C 1 to C 8 alkylene or C 1 to C 3 substituted alkylene, and Me is hydrogen, sodium potassium, or ammonium; and (c) 0 to 10 percent by weight of another ethylenically unsaturated copolymerizable monomer selected from the group consisting of acrylate and methacrylate esters of C 1 -C 4 alcohols, C 1 -C 4 esters or half esters of maleic acid, acrylo- and methacrylonitrile, acryl- and methacrylamide; said copolymer dispersant having a K-value of 15 to 50 and an adjusted pH value of 7 to 8 in one percent solution at 20° C. and being used in an amount of 0.05 to 1.0 percent by weight based on the amount of pigment being dispersed.