Preparation of vinylidene chloride interpolymers of improved solubility

Claim 1

THE PROCESS FOR PRODUCING INTERPOLYMERS CONSISTING ESSENTIALLY OF 5-95% BY WEIGHT OF VINYLIDENE CHLORIDE AND 95-5% BY WEIGHT OF ONE DIFFERENT POLYMERIZABLE MONOETHYLENIC MONOMER, CHARACTERIZED BY IMPROVED SOLUBILITY CHARACTERISTICS, WHICH CONSISTS IN CONTINUOUSLY AND PROGRESSIVELY INTRODUCING INTO A SINGLE POLYMERIZING ZONE UNDER POLYMERIZING CONDITIONS INCREMENTAL PORTIONS OF (1) MONOETHENOID MONOMERIC MATERIAL CONSISTING OF VINYLIDENE CHLORIDE AND A DIFFERENT MONOMER FROM THE GROUP CONSISTING OF ACRYLONITRILE AND METHACRYLONITRILE, (2) AN AQUEOUS POLYMERIZATION MEDIUM AND (3) POLYMERIZATION CATALYST, MAINTAINING EACH INCREMENT OF THE RESULTING ADMIXTURE IN SAID POLYMERIZING ZONE, WHILE MAINTAINING SAID POLYMERIZING CONDITIONS SUBSTANTIALLY UNCHANGED, FOR A TIME SUFFICIENT TO EFFECT SUBSTANTIAL INTERPOLYMERIZATION OF SAID VINYLIDENE CHLORIDE AND SAID DIFFERENT MONOMER, AND CONTINUOUSLY AND PROGRESSIVELY WITHDRAWING A DISPERSION OF INTERPOLYMER PRODUCT FROM SAID POLYMERIZATION ZONE AT A RATE CORRELATED TO THE TOTAL RATE OF ADDITION OF (1), (2) AND (3) WHEREBY THE ADMIXTURE IN SAID POLYMERIZING ZONE REMAINS SUBSTANTIALLY UNCHANGED IN COMPOSITION DURING SAID CONTINUOUS INTRODUCING OF (1), (2) AND (3) AND SAID CONTINUOUS WITHDRAWING OF PRODUCT, SAID CONTINUOUS AND PROGRESSIVE INTRODUCING OF EACH OF (1), (2) AND (3) BEING CONTINUED AT A CONSTANT RATE SUBSTANTIALLY THROUGHOUT THE POLYMERIZATION, SAID VINYLIDENE CHLORIDE AND SAID DIFFERENT MONOMER BEING INTRODUCED IN A CONSTANT RATIO WITHIN THE RANGE OF 5 TO 95% BY WEIGHT OF SAID VINYLIDENE CHLORIDE AND FROM 95 TO 5% BY WEIGHT OF SAID DIFFERENT MONOMER.