Abstract:
Copolymer having an average molecular weight of 500 to 10,000, a glass transition temperature of 40* to 70*C and an acid number of 55 to 120 mg of KOH/g of copolymer, said copolymer being the product of free radical copolymerization of a monomer mixture of I. 0 to 55 mol % of styrene, Alpha -methylstyrene, methylmethacrylate or mixtures thereof; II. 10 to 25 mol % of acrylic acid, methacrylic acid or mixtures thereof; III. 0 to 70 mol % of at least one ester of methacrylic acid containing 2 to 18 carbon atoms in the alcohol component and IV. 20 to 50 mol % of at least one ester of acrylic acid containing 1 to 18 carbon atoms in the alcohol component, AND PROCESS OF PRODUCING SAID COPOLYMER BY CONTINUOUSLY POLYMERIZING SAID MONOMER MIXTURE IN A CONTINUOUSLY FED PROCESS UNDER STEADY STATE AND PERFECTLY AGITATED CONDITIONS TO A CONVERSION OF 35 TO 60 MOL % AND THEN POLYMERIZING RESULTING POLYMERIZATION REACTION MIXTURE TO A CONVERSION OF AT LEAST 94 MOL % UNDER NON-STEADY STATE CONDITIONS WHICH PREVENT BACK MIXING OF THE POLYMER PRODUCED IN SAID SECOND POLYMERIZATION STEP WITH POLYMERIZATION REACTION MIXTURE FROM SAID FIRST POLYMERIZATION REACTION STEP IN A TUBULAR PLUG FLOW REACTOR UNDER NON-STEADY STATE CONDITIONS.
Abstract:
PROCESS FOR THE PRODUCTION OF PARTIALLY OR COMPLETELY SAPONIFIED ETHYLENE-VINYL ACETATE COPOLYMERS HAVING A PARTICLE SIZE OF 0.1 TO 0.7 MM. AND APPARATUS THEREFOR, THE PROCESS INVOLVING GELLING HOT SAPONIFICATION SOLUTION CONTAINING ORGANIC SOLVENT BY COOLING, EXTRUDING GELLED SOLUTION TO FORM FILAMENTS OF SPECIFIED DIAMETER, PRODUCING PARTICLES OF SPECIFIED LENGTH FROM SAID FILAMENTS, REMOVING ORGANIC SOLVENT AND SAPONIFICATION CATALYST FROM SAID PARTICLES AND ISOLATING RESULTING COPOLYMER PARTICLES.