PREPARATION OF OIL-RESISTANT RUBBER COMPOSITION

PURPOSE:To form an oil-resistant rubber composition with excellent workability suitable for use in circumferential rubber parts for an automobile engine, rubber parts for joining roads, etc., by compounding a specified chlorinated polyethylene with an acrylonitrile-butadiene copolymer rubber. CONSTITUTION:50-90pts.wt. chlorinated polyethylene powder of chlorine content 25-40wt%, obtd. by the aqueous suspension chlorination of low-density polyethylene of melt index 0.2-10 and density about 0.91-0.93 at a temp.>= m.p. thereof, is compounded with 50-10pts.wt. chlorinated polyethylene of chlorine content 30-50wt% obtd. by the aqueous suspension chlorination of high-density polyethylene of melt index 0.01-0.4 and density 0.94-0.96 at a high temp., to form a chlorinated polyethylene mixt. An oil-resistant rubber composition is obtd. by compounding 95-5pts.wt. said mixt. with 5-95pts.wt. acrylonitrile-butadiene copolymer rubber.