Persulfate stabilized latices

Claim 1

A PROCESS FOR PREPARING SURFACTANT-FREE LATEX FROM A TOTAL MONOMERIC MIXTURE COMPRISING 30-80 PARTS PER 100 PARTS OF MIXTURE OF A CONJUGATED DIOLEFIN, 20-70 PARTS PER 100 PARTS OF MIXTURE OF ARYL VINYL MONOMER, AND 0-10 PARTS PER 100 PARTS OF MIXTURE OF ONE MORE MONOMERS COPOLYMERIZABLE THEREWITH, SAID PROCESS COMPRISING: A. FORMING AN AQUEOUS ACIDIC EMULSION OF ABOUT 30-50 PERCENT BY WEIGHT OF THE MONOMERIC MIXTURE IN WATER CONTAINING 0.4 TO 1.5 PARTS OF A PERSULFATE POLYMERIZATION INITIATOR AND 0.5 TO 2.0 PARTS OF N-METHYLOLACRYLAMIDE PER 100 PARTS OF MONOMER; SAID WATER BEING USED IN AN AMOUNT SUCH THAT THE TOTAL SOLIDS CONTENT OF THE RESULTING LATEX WILL BE 20-300 PERCENT; B. POLYMERIZING SAID AQUEOUS ACIDIC EMULSION AT A TEMPERATURE OF 50*-100*C. TO ESSENTIALLY COMPLETE CONVERSION TO FORM A LATEX; C. ADDING TO SAID LATEX THE REMAINING 50-70 PERCENT BY WEIGHT PORTION OF THE MONOMER MIXTURE, AN ADDITIONAL 0.4 TO 1.5 PARTS OF PERSULFATE INITIATOR, AND 0.5-2.0 PARTS OF N-METHYLOLACRYLAMIDE PER 100 PARTS OF MONOMER; AND D. POLYMERIZING THE RESULTING MIXTURE IN AQUEOUS EMULSION AT A TEMPERATURE OF 50*-100*C, TO COMPLETE CONVERSION TO FORM A LATEX HAVING FROM 35-55 PERCENT SOLIDS, SAID LATEX BEING STABLE TO MECHANICAL SHEAR AND MULTIVALENT CATIONS AT PH 2.0-6.0.