Emulsion polymerization of ethylene with chain transfer agents to form copolymers

Claim 1

AN EMULSION POLYMERIZATION PROCESS FOR PREPARING AN OI SOLUBLE COPOLYMER USEFUL FOR IMPROVEING THE FLOW PROPERTIES O PETROLEUM FUEL OILS, SAID COPOLYMER CONSISTING ESSENTIALLY O ABOUT 4 TO 15 MOLAR PROPORTIONS OF ETHYLENE PER MOLAR PROPORTION OF VINYL ACETATE, SAID COPOLYMER HAVING A NUMBER AVERAGE MOLECULAR WEIGHT OF ABOUT 3500 TO 15,000, WHICH PROCESS COMPRISES FORMING AN AQUEOUS EMULSIFIED SYSTEM COMPRISING WATER, VINYL ACETATE, A WATER SOLUBLE FREE RADICAL INITIATOR, AN EMULSIFIER AND A CHAIN TRANSFER AGENT, INTRODUCING ETHYLENE AND COPOLYMERIZING SAID ETHYLENE AND SAID VINYL ACETATE FOR ABOUT 6 TO 600 MINUTES UNDER ETHYLENE PRESSURE OF 50 TO 500 ATOMOSPHERES, AT A TEMPERATURE IN THE RANGE OF ABOUT 60* TO 120*C., AND RECOVERING SAID COPOLYMER, WHEREIN SAID CHAIN TRANSFER AGENT IS SELECTED FROM THE GROUP CONSISTING OF C1 TO C18 ALKYL MERCAPTAN AND C1 TO C4 CHLOROALKANES CONTAINING UP TO 4 CHLORINE ATOMS PER MOLECULE, WHEREIN SAID INITIATOR IS PRESENT IN AN AMOUNT OF 0.001 TO 0.05 MOLE PRE MOLE OF SAID VINYL ACETATE, WHEREIN SAID CHAIN TRANSFER AGENT IS PRESENT IN THE AMOUNT OF 0.005 TO 0.25 MOLE PER MOLE OF SAID PRESENT IN TATE, WHEREIN THE AQUEOUS PHASE IS CONTINUOUS, AND WHEREIN SAID VINYL ACETATE AND SAID CHAIN TRANSFER AGENTS ARE IN THE DISPERSED PHASE.