Japan Composite Co., Ltd.

Japan Composite Co., Ltd. (ジャパンコンポジット株式会社) is a Japanese chemical manufacturer specializing in unsaturated polyester resins, molding compounds, and press-molded fiber-reinforced plastic (FRP) products. It was established on April 1, 2003 as a joint venture between Mitsui Chemicals, Inc. and Nippon Shokubai Co., Ltd., created to strengthen both companies' unsaturated polyester resin and molding materials businesses. Mitsui Chemicals holds 65% of the shares and Nippon Shokubai holds 35%, with stated capital of 1,005 million yen. The company operates an integrated business model spanning raw materials, unsaturated polyester resins, molding compounds (SMC, TMC, BMC), and press-molded finished parts. Its flagship resin brands include Polyhope® (unsaturated polyester resin), Prominate® (high-performance and corrosion-resistant resin), Vinyl Ester® (environmentally responsive resin), and Polymer Matt® (molding compound). These materials are used in automotive parts, housing equipment such as bathroom and kitchen components, building materials, corrosion-resistant applications, casting and coatings, and other industrial uses. The company highlights properties such as water and hot-water resistance, high strength with weight reduction, flame retardancy, and large-part moldability with durability. Japan Composite is headquartered in the Muromachi Furukawa Mitsui Building (COREDO Muromachi 2) in Nihonbashi Muromachi, Chuo-ku, Tokyo. It also maintains an Osaka branch, a Shimizu Plant in Shizuoka City, a Narita Plant in Tomisato City, Chiba Prefecture, and a research department at the Shimizu Plant. As of April 1, 2026, the company reported 248 employees. Its representative director and president is Daisuke Suzuki. The company began operations on December 1, 2020 according to its website, and has since pursued business expansion in resin and molding materials. In 2026 it reported that a material reducing molding cycle time by 20% was adopted for the first time in outboard motors by Yamaha Motor Co., Ltd. It also experienced a fire at its Narita Plant in August 2026, followed by a partial resumption of production. Japan Composite remains an active, privately held joint venture serving Japanese and international industrial customers.

Japan Composite Co., Ltd. was established on April 1, 2003 as a joint venture between Mitsui Chemicals, Inc. and Nippon Shokubai Co., Ltd. The company was formed to strengthen the two parent companies' unsaturated polyester resin and molding materials businesses, combining their respective technologies and market positions into a single integrated entity. Mitsui Chemicals took a 65% stake and Nippon Shokubai a 35% stake, with stated capital of 1,005 million yen. From its founding, Japan Composite pursued an integrated business model covering raw materials, unsaturated polyester resins, molding compounds such as SMC, TMC, and BMC, and press-molded finished products. This vertical integration allowed the company to leverage group synergies and respond quickly to customer needs in automotive, housing equipment, building materials, corrosion-resistant applications, and casting and coatings markets. The company developed and marketed several branded resin lines, including Polyhope® for unsaturated polyester resins, Prominate® for high-performance and corrosion-resistant resins, Vinyl Ester® for environmentally responsive resins, and Polymer Matt® for molding compounds. These products are used in applications requiring water and hot-water resistance, high strength with weight reduction, flame retardancy, and large-part moldability with durability. Japan Composite is headquartered in the Muromachi Furukawa Mitsui Building (COREDO Muromachi 2) in Nihonbashi Muromachi, Chuo-ku, Tokyo. It operates an Osaka branch, a Shimizu Plant in Shizuoka City, Shizuoka Prefecture, a Narita Plant in Tomisato City, Chiba Prefecture, and a research department at the Shimizu Plant. According to its website, the company began operations on December 1, 2020, and as of April 1, 2026, it employed 248 people. Daisuke Suzuki serves as representative director and president. In 2026, the company announced that a material reducing molding cycle time by 20% was adopted for the first time in outboard motors by Yamaha Motor Co., Ltd. In August 2026, a fire occurred at the Narita Plant, and the company issued apologies and reports, followed by a notice of partial resumption of production later that month. Japan Composite remains an active joint venture in the Japanese chemical industry.

• Established as a joint venture between Mitsui Chemicals (65%) and Nippon Shokubai (35%).

• Began operations according to the company website.

• Material reducing molding cycle time by 20% first adopted for Yamaha Motor outboard motors.

• Fire occurred at Narita Plant; company issued an apology.

• Partial resumption of production at Narita Plant announced.

Integrated manufacturer of unsaturated polyester resins and FRP molding materials, leveraging the combined technologies of Mitsui Chemicals and Nippon Shokubai.

• Polyhope®

  Unsaturated polyester resin.

• Prominate®

  High-performance and corrosion-resistant resin.

• Vinyl Ester®

  Environmentally responsive resin.

• Polymer Matt®

  Molding compound.

1. 1ジャパンコンポジット株式会社j-comp.co.jp
2. 2会社概要 | ジャパンコンポジット株式会社j-comp.co.jp
3. 3Japan Composite Co., Ltd. (Japan) - Wikidatawikidata.org