Prime Polymer Co., Ltd. (プライムポリマー株式会社) is a Japan-based manufacturer of polyolefins and a member of the Mitsui Chemicals Group. The company develops, produces, and supplies polyethylene (HDPE, LDPE, LLDPE, including metallocene-based grades) and polypropylene resins and compounds for a wide range of industrial uses.
Its materials are used in packaging films, consumer and industrial containers, pipes, molded parts, automotive components, and household appliances. Prime Polymer’s portfolio spans general-purpose to high-performance grades designed for processing efficiency, durability, and lightweighting. The company engages in application development with converters and brand owners to tailor resin performance to end-use requirements.
Prime Polymer serves customers in Japan and international markets and is active in initiatives to enhance circularity in polyolefins, including developing materials compatible with mechanical and chemical recycling and supporting mass-balance approaches for bio-based and recycled feedstocks.
MOU (Sept 2025) and definitive agreement (Dec 2025) formalize PP/LLDPE business integration; overseas antitrust reviews are ongoing and the deal will close after their clearance.
Starting January 2026, Natural Lawson stores will use Prasus™ bio-based and recycled polyethylene bags, marking an industry first for mass balance approach adoption.
