Block copolymers of alpha c1-4 alkyl styrene and ethylene

Claim 1

A PROCESS FOR PRODUCING HIGH MOLECULAR WEIGHT BLOCK COPOLYMERS OF ALPHA-C1-4 ALKYL STYRENE AND ETHYLENE COMPOSED OF ONE OR MORE BLOCKS EACH CONTAINING 50-100 MOL PERCENT OF ETHYLENE UNITS AND ONE OR MORE BLOCKS EACH CONTAINING 50-100 MOL PERCENT OF ALPHA-C1-4ALKYL STYRENE, SUCH BLOCK POLYMERS BEING PREPARED BY COPOLYMERIZING ETHYLENE AND ALPHA-ALKYL STYRENE IN A MOLE RATIO BETTWEEN 1:10 AND 10:1 IN A POLAR-CONTAINING ORGANIC SOLVENT SELECTED FROM THE GROUP CONSISTING OF AN OXYGEN CONTAINING AND A SULFUR-CONTAINING ORGANIC SOLVENT AND WITH AN ORGANO LITHIUM CATALYST AT A TEMPERATURE BETWEEN 0*C. AND 50*C. AND A PRESSURE BETWEEN 5,000 AND 100,OOO P.S.I. FOR A SUBSTANTIAL PERIOD OF TIME, AND CONTINUING THE COPOLYMERIZATION UNDER THE SAME DITIONS FOR AN ADDITIONAL PERIOD OF TIME BETWEEN -100* C. AND 0*C. AND AT A PRESSURE BELOW 5,000 P.S.I., THE RESULTING BLOCK POLYMER HAVING A MOLECULAR WEIGHT OF FROM 6,000 TO 500,000.