Cationic latices and their electrodeposition

Claim 1

Process of making a latex comprising copolymerizing monomer X as hereinafter defined with monomer A as hereinafter defined in a A:X mole ratio of about 100 to 5:1, by the following steps: (a) in a polymerization zone, copolymerizing at about 70°-85° C. in water substantially all of monomer X with about 5-20% of the total of monomer A to form a seed latex particle in which at least 50% of the amine groups are at the surface; (b) adding the balance of monomer A to the polymerization zone, whereby said monomer A enters the latex particle as filler core polymer; (c) continuing the polymerization for at least 90 minutes; (d) thereby to provide a latex with about 15-50% solids; (e) and thereby to provide a latex in which the individual particle is characterized as follows: (1) it consists essentially of polymeric molecules made up of carbon-to-carbon chains; said polymer molecules consisting essentially of moieties of monomers A and X in which A is the residue of at least one ethylenically unsaturated monomer and X is the residue of an ethylenically unsaturated monomer containing protonated tertiary and/or quaternary nitrogen within ten atoms of a hydrophilic moiety; X being I, II, or III, or a mixture, viz.: ##STR3## in which B is O or NH; R 1 , R 2 , R 3 , R 5 , and R 6 are H, C n H 2n+1 in which n is 1-5, or phenyl, and may be the same or different; R 4 is --(C a H 2a )--, in which a is 1-10; ##STR4## R 8 is H or C n H 2n+1 in which n is 1-10; a being the residue of an ethylenically unsaturated monomer, IV or V, or a mixture, viz.: ##STR5## in which the R's, R 9 -R 18 inclusive, are the same or different, and are H, C n H 2n+1 , in which n is 1-10, carboxylate ester, phenyl, hydroxy, chloride, amine, cyano, vinyl, or thiol; (2) the weight average molecular weight of polymers in the particle is 10,000 to 1,000,000; (3) the total number of amine groups per particle is about 0.8×10 8 to 1.2×10 14 (4) of the aforesaid total number, at least about 50% are at the surface of the particle and the balance are below the surface; (5) the number of said surface amine groups per square Angstrom of surface is about 0.5 to 25; (6) a hydrophilic group is within 10 atoms of the amine group; (7) the particles form a latex with a pH stability within the range 6-12; and (8) the quantity of electrical current needed to deposit one gram of particles on the cathode is about 10 to 80 coulombs.