Method of insulating an electrical conductor with a copolymer comprising ethylene and propylene or 1-butene or 2-butene

Claim 1

IN A METHOD OF INSULATING AN ELECTRICAL CONDUCTOR WITH A PLASTIC COATING HAVING IMPROVED THERMAL PROPERTIES WHICH COMPRISES HEATING TO A FLUID CONDITION A COPOLYMER OF ETHYLENE AND AT LEAST ONE MONOOLEFIN SELECTED FROM THE GROUP CONSISTING OF PROPYLENED, 1-BUTENE AND 2-BUTENE, SAID COPOLYMER BEING A POLYMERIZATE OF A MONOMER SYSTEM HAVING BEEN SUBJECTED TO POLYMERIZING CONDITIONS INCLUDING A TEMPERATURE BETWEEN 150 AND 450* F. AND SUFFICIENT PRESSURE TO MAINTAIN THE REACTANTS IN THE LIQUID PHASE IN THE PRESENCE OF AN INERT AND LIQUID DILUENT AND A POLYMERIZATION CATALYST, EXTRUDING SAID COPOLYMER IN A CONTINUOUS COATING ON SAID CONDUCTOR, AND UNIFORMLY COOLING SAID COATING TO A TEMPERATURE BELOW THE SOFTENING TEMPERATURE OF SAID COPOLYMER TO GIVE A VOID-FREE INSULATION, THE IMPROVEMENT WHICH COMPRISES EMPOLYING AS SAID COPOLYMER A COPOLYMER WHICH IS A POLYMERIZATE OF A MONOMER SYSTEM COMPRISING FROM 70 TO .7 WEIGHT PERCENT ETHYLENE AND WHICH IS CHARACTERIZED BY A SOFTENING TEMPERATURE OF FROM 235 TO 250*F., A DENSITY OF AT LEAST 0.92 AND MELT INDEX OF LESS THAN 1.