PURPOSE: The titled copolymer excellent in compression set resistance and low- temperature resistance, prepared by chlorinating and chlorosulfonating a specified ethylene/α-olefin copolymer to impact specified physical properties thereto.
CONSTITUTION: A starting material comprising an ethylene/α-olefin copolymer having a content of 3W8C α-olefins (e.g., butene-1) of 4W20mol%, a density of 0.88W0.9g/cm3, a melt flow rate (190°C, 2,160g) of 0.1W300g/(10min) and an Mw/ Mn≤3.5 is dissolved in a solvent (e.g., carbon tetrachloride) to a concentration of about 5W20wt%. Chlorine and sulfuryl chloride are blown into the solution and reacted with the copolymer at about 50W180°C and a pressure of about normal W8kg/cm2G to obtain a chlorinated copolymer having a chlorine content of 10W50wt%, a sulfur content of 0.3W3wt%, a Mooney viscosity (ML1+4, 100°C) of 20W130, and an Mw/Mn≤3.5.
SAKANAKA YASUHIRO
EMURA TOKUAKI
