wherein the carboxyl groups are in the acid form and also such polymers wherein the carboxyl groups are in the salt form provided said salts are water dispersible such salts include the ammonium salts the alkali metal salts and others which are water dispersible hydrolysis can be carried out in any suitable fashion for example by heating an aqueous solution of the polymer with a suitable amount of sodium hydroxide examples of copolymers which can be used in the practice of the invention include the water dispersible copolymers resulting from the polymerization of acrylamide or methacrylamide with an ethylenically unsaturated monomer it is desirable that sufficient acrylamide or methacrylamide be present in the monomer mixture to impart to the resulting copolymer the above described water dispersible properties any suitable ratio of monomers meeting this condition can be used under proper conditions of use examples of suitable ethylenically unsaturated monomers include acrylic acid methacrylic acid vinylsulfonic acid vinylbenzylsulfonic acid vinylbenzenesulfonic acid vinyl acetate acrylonitrile methyl acrylonitrile vinyl alkyl ether vinyl chloride maleic anhydride vinyl substituted cationic quaternary ammonium compounds and the like various methods are known in the art for preparing said copolymers for example see u s pat nos 2 625 529 2 740 522 2 727 557 2 831 841 and 2 909 508 these copolymers can be used in the hydrolyzed form as discussed above for the homopolymers a group of copolymers useful.