4 alkyl, R3 is hydrogen, a C1 -C4 alkyl, ##STR24## where Y is hydroxyl or halogen, ##STR25## where n is an integer 1 or more and X- is an anion, and (ii) from about 95 mole percent to 0 mole percent of at least one monoethylenically unsaturated amide monomer, the amount of prepolymer (2) employed in preparing the graft copolymer particles being from about 2 parts to about 10 parts by weight for ea