Process for preparing high solids concentrated latex

Claim 1

IN A PROCESS FOR PREPARING SYNTHETIC RUBBERY POLYMER LATEX BY EMULSION POLYMERIZATION INCLUDING THE STEP OF POLYMERIZING ETHYLENICALLY UNSATURATED MONOMERIC MATERIAL WHICH PRODUCES LATEX OF A SYNTHETIC RUBBERY POLYMER UPON POLYMERIZATION WHILE DISPERSED IN AN AQUEOUS MEDIUM IN THE PRESENCE OF A MICELLE PRODUCING SURFACTANT FOR THE EMULSION POLYERIZATION OF THE SAID MONOMERIC MATERIAL AND A POLYMERIZATION CATALYST THEREFOR, THE SAID MONOMERIC MATERIAL BEING AT LEAST ONE SUBSTANCE SELECTED FROM THE GOUP CONSISTING OF CHLOROPRENE, CONJUGATED DIOLEFINS HOMOPOLYMERIZABLE TO PRODUCE RUBBERY POLYMERS AND MIXTURES OF CONJUGATED DIOLEFINS AND MONOETHYLENICALLY UNSATURATED MONOOMERS COPOLYMERIZABLE THEREWITH TO PRODUCE RUBBERY COPOLYMERS, SAID MIXTURES CONTAINING UP TO 50% BY WEIGHT OF THE MONOETHYLENICALY UNSATURATED MONOMER, THE IMPROVEMENT WHICH COMPRISES: (A) POLYMERIZING A FIRST INCREMENT OF THE SAID MONOMERIC MATERIAL IN THE PRESENCE OF THE SURFACTANT AND THE POLYMERIZATION CATALYST UNTIL A PORTION OF THE SAID FIRST INCREMENT OF MONOMERIC MATERIAL HAS BEEN CONVERTED TO POLYMER AND UNREACTED MONOMERIC MATERIAL HAS BEEN ABSORBED BY THE POLYMER PARTICLES, (B) SUBJECTING THE RESULTING LATEX TO SUFFICIENTLY VIGOROUS AGITATION TO CAUSE AGGLOMERATION OF POLYMER PARTICLES CONTAINING ABSORBEDUNREACTED MONOMERIC MATERIAL TO THEREBY PRODUCE A RELATIVELY LARGE AVERAGE POLYMER PARTICLE SIZE AND RELEASE FREE SURFACTANT INTO THE AQUEOUS PHASE OF THE LATEX, THE LATEX BEING AGGLOMERATED BY AGITATION WITH A RADIAL AGITATOR OPERATING AT A PERIPHERAL SPEED OF ABOUT 800-4000 FEET PER MINUTE, (C) ADDING AT LEAST ONE ADDITIONAL INCREMENT OF THE SAID MONOMERIC MATERIAL TO THE LATEX, THE ADDITIONAL INCREMENT OF THE SAID MONOMERIC MATERIAL HAVING ABOUT THE SAME MONOMERIC COMPOSITION AS THE SAID FIRST INCREMENT AND BEING ADDED IN AN AMOUNT WHEREBY FREE MONOMERIC MATERIAL IS PRESENT IN THE LATEX AND NEW POLYMER PARTICLES ARE FORMED WITH CONTINUED POLYMERIZATION IN THE PRESENCE OF FREE SURFACTANT AND THE POLYMERIZATION CATALYST, AND (D) SUBJECTING THE LATEX CONTAINING THE SAID FREE ADDED MONOMERIC MATERIAL TO FURTHER POLYMERIZATION IN THE PRESENCE OF FREE SURFACTANT AND THE POLYMERIZATION CATALYST UNDER RELATIVELY MILD AGITATION CONDITIONS TO THEREBY PRODUCE ADDITIONAL SMALL POLYMER PARTICLES IN THE LATEX.