Mutsubishi Rubber Co., Ltd.

Mutsubishi Rubber Co., Ltd. (六菱ゴム株式会社) is a Japanese industrial rubber manufacturer headquartered in Kobe, Hyogo Prefecture. Founded in 1922 as Mutsubishi Rubber Manufacturing Works in Nagata-ku, Kobe, the company has built a century-long reputation for custom-engineered rubber and sealing products. Its core expertise lies in rubber compounding, molding, and integrated production, serving demanding industries such as steel manufacturing, shipbuilding, industrial machinery, railway, defense, civil engineering, water supply and sewerage, energy, and pharmaceuticals. The company operates on an integrated production system that covers proposal-based sales, product development and design, material compounding, manufacturing and assembly, testing and inspection, and after-sales service. This vertical integration allows Mutsubishi Rubber to offer tailor-made solutions, often developed in close collaboration with customers. Its product portfolio includes oil seals, dust seals, O-rings, expansion dome seals, tube seals, hexaplugs, vibration-damping rubber, watertight doors, and various custom sealing devices. Many of these products are used in critical infrastructure and high-safety environments, including nuclear power plants, LNG carriers, and tunnel boring machines. Mutsubishi Rubber has a notable history of innovation. In 1955, it jointly developed practical silicone rubber with Tokyo Shibaura Electric (now Toshiba). In 1979, it developed the world's first tube seal for the Monju nuclear reactor. The company has also supplied seals for major projects such as the Channel Tunnel and the Tokyo Bay Aqua-Line. Its products are used globally, and it has expanded internationally with a subsidiary in Taiwan (Taiwan Mutsubishi Rubber Co., Ltd.) and a presence in China through Kunshan Jiadi Sealing Co., Ltd. The company is led by President Goji Wada. It emphasizes agile management and digital transformation (DX) to contribute to Japan's national resilience. Mutsubishi Rubber is a private company and operates as part of a small group that includes Nippon Victaulic Co., Ltd. (a pipe joint manufacturer) and Javico Co., Ltd. (a trading company for sealing materials). With a history spanning over 100 years, Mutsubishi Rubber continues to focus on developing unique, high-quality rubber products that meet evolving customer needs.

Mutsubishi Rubber Co., Ltd. was founded in 1922 (Taisho 11) as Mutsubishi Rubber Manufacturing Works (六菱ゴム製造所) in Nagata-ku, Kobe, with an initial investment of 3,000 yen. The company began manufacturing rubber products for industrial use. In 1931, it established a technical exchange with Nippon Victaulic regarding rubber for Victaulic joints and industrial rubber. In 1944, it was reorganized as Mutsubishi Rubber Manufacturing Co., Ltd. (六菱護謨製造株式会社) with capital of 500,000 yen, focusing on Victaulic rubber rings, other industrial rubber products, and aircraft rubber products. After World War II, the company was renamed Mutsubishi Rubber Industrial Works Co., Ltd. (株式会社六菱ゴム工業所) in 1952. In 1955, it jointly developed practical silicone rubber with Tokyo Shibaura Electric (now Toshiba). In 1958, it changed its name to Mutsubishi Rubber Co., Ltd. (六菱ゴム株式会社). A silicone rubber factory was added in 1959, and production of silicone rubber packing for Victaulic joints for coal-fired power plants began. In 1963, production of bell packing for blast furnaces started. In 1966, a press molding factory was established, and buffer rubber for horizontal draw cranes was successfully produced. In 1971, the company began supplying track rubber for Japanese National Railways. In 1976, it first delivered pool gate packing for nuclear power, and completed the Hexaplug. In 1978, it supplied viaduct joint material for the Tohoku Shinkansen. In 1979, it successfully developed the world's first tube seal for the Monju reactor, and completed the universal seal and prop seal. In 1980, it developed wall penetration seals and delivered dome seals for LPG carriers. In 1981, the Kobe head office building was constructed, and duster rings and dust wipers were completed; patents were filed in seven countries, and packing for plutonium storage containers was completed. In 1983, it first delivered LNG dome seals. In 1985, it developed ultra-high-pressure seals (withstand pressure 2,000 kg/cm²) and completed closure plugs for nuclear nozzles; the Ministry of Construction adopted Hexaplug (diameter 3,200 mm) for the North Chiba diversion channel. In 1986, it developed seals for the Channel Tunnel boring machine and SW-type oil seals. In 1990, the Technical Development Office and Experiment Building were constructed. In 1992, it delivered emergency seals for the Tokyo Bay Aqua-Line shield machine to various companies. In 1995, the Great Hanshin-Awaji Earthquake occurred on January 17. In 1997, the Oita Sales Office was opened. In 1998, the Fukuoka Branch was established, and ISO9001 was acquired on July 30. In 1999, the factory was relocated from Nagata-ku to Nishi-ku, Kobe. In 2004, the Osaka Head Office was relocated, and the company was certified for "Kobe-originated excellent technology" by the Kobe City Industrial Promotion Foundation. In 2005, the Fukuoka Branch was relocated. In 2006, the Taiwan Kaohsiung Branch opened. In 2007, ISO14001 was acquired. In 2008, the Tokyo Branch was relocated. In 2009, the Taiwan Kaohsiung Branch was localized as Taiwan Mutsubishi Rubber Co., Ltd. (台灣六菱橡膠股份有限公司). In 2020, the Kisarazu Sales Office was opened. Today, Mutsubishi Rubber continues to operate as a specialist manufacturer of industrial rubber products, with a focus on integrated production, agile management, and digital transformation. It serves a wide range of industries and maintains a global presence through its subsidiaries and partners.

• 1999

  Factory relocated from Nagata-ku to Nishi-ku, Kobe.

• 1998

  Fukuoka Branch established; acquired ISO9001 on July 30.

• 1997

  Oita Sales Office opened.

• 1995

  Great Hanshin-Awaji Earthquake occurred on January 17.

• 1992

  Delivered emergency seals for Tokyo Bay Aqua-Line shield machine.

• 1990

  Technical Development Office and Experiment Building constructed.

• 1986

  Developed seals for Channel Tunnel boring machine; developed SW-type oil seals.

• 1985

  Developed ultra-high-pressure seals (2,000 kg/cm²); completed closure plugs for nuclear nozzles; Hexaplug (3,200 mm diameter) adopted for North Chiba diversion channel.

• 1983

  First delivery of LNG dome seals.

• 1981

  Kobe head office constructed; duster rings and dust wipers completed; patents filed in 7 countries; packing for plutonium storage containers completed.

• 1980

  Developed wall penetration seals; delivered dome seals for LPG carriers.

• 1979

  Developed world's first tube seal for Monju reactor; completed universal seal and prop seal.

• 1978

  Supplied viaduct joint material for Tohoku Shinkansen.

• 1976

  First delivery of pool gate packing for nuclear power; completed Hexaplug.

• 1971

  Began supplying track rubber to Japanese National Railways.

• 1966

  New press molding factory established; successfully produced buffer rubber for horizontal draw cranes.

• 1963

  Started production of bell packing for blast furnaces.

• 1959

  Silicone rubber factory added; production of silicone rubber packing for Victaulic joints for coal-fired power plants began.

• 1958

  Renamed Mutsubishi Rubber Co., Ltd.

• 1955

  Jointly developed practical silicone rubber with Tokyo Shibaura Electric.

• 1952

  Renamed Mutsubishi Rubber Industrial Works Co., Ltd.

• 1944

  Reorganized as Mutsubishi Rubber Manufacturing Co., Ltd. with capital of 500,000 yen.

• 1931

  Technical exchange with Nippon Victaulic for rubber and industrial rubber.

• 1922

  Founded as Mutsubishi Rubber Manufacturing Works in Nagata-ku, Kobe, with capital of 3,000 yen.

Specialist manufacturer of custom industrial rubber and sealing solutions, emphasizing integrated production, agile management, and contribution to national resilience.

• Hexaplug

  A long-selling product for maintenance work on gas and oil pipelines.

• Tube seal

  World's first tube seal developed for the Monju reactor; also used in tunnel construction entrance seals.

• Expansion dome seal

  Used in LNG carriers; supplied globally.

• Vibration-damping rubber

  Supplied for railway tracks to reduce vibration and noise.

• Watertight doors

  Flood protection products for critical infrastructure.

• Oil seals and dust seals

  Heat-resistant seals for steel manufacturing equipment rotating shafts.

• O-rings for diesel engines

  Excellent compression set resistance due to original compounding.

• Valve maintenance balloons

  For safety valve maintenance, certified by major classification societies.

• Silicone rubber products

  Developed jointly with Toshiba; used in various industrial applications.

1. 1六菱ゴム株式会社 公式サイトmutsubishi.co.jp
2. 2会社沿革 – 六菱ゴム株式会社mutsubishi.co.jp
3. 3グループ会社のご案内 – 六菱ゴム株式会社mutsubishi.co.jp
4. 4ご挨拶 – 六菱ゴム株式会社mutsubishi.co.jp
5. 5Wikidata: Mutsubishi Rubber Co., Ltd. (Japan)wikidata.org