September 2003: Japan Polyethylene Corporation succeeded the polyethylene business of Japan Polychem Corporation and Japan Polyolefins Corporation and has been established the largest polyethylene company in Japan.
Japan Polychem Corporation is a wholly owned subsidiary of Mitsubishi Chemical Corporation, and owns Japan Polyethylene Corporation and Japan Polypropylene Corporation.
October 2003: Japan Polypropylene Corporation succeeded the polypropylene business of Japan Polychem and JNC Petrochemical Corporation and has been established the largest polypropylene company in Japan.