Kuraray's Kashima Plant (Kamisu-machi, Kashima-gun, Ibaraki Prefecture) has completed the expansion of its liquid isoprene rubber (LIR) manufacturing facilities by 1,000 tons per year, and commenced operations in October 2004. Production capacity following the expansion will be 4,600 tons per year.

LIR is a liquid form of polyisoprene rubber with adhesive properties developed in 1977 by Kuraray through the application of the Company's proprietary polymer manufacturing technology. Nowadays used in the production of tires and other rubber products, it is also used in viscous adhesives and a wide spectrum of other applications.

The use of LIR in natural and synthetic rubber products makes it possible to reduce the material's viscosity without degrading its dynamic properties, thereby enhancing workability and productivity. For this reason, demand is active in Asia, and particularly in China, where tire manufacturing is on the increase. Furthermore, in the increasingly high-tech field of precision molding of rubber parts and components, demand for LIR as a performance-enhancing additive is expanding.

With the current worldwide move to eliminate organic solvents, growth in demand is forecast for LIR as a non-solvent adhesive, for binding rubber products to textile and metals by viscous adhesive and transformed adhesive. In addition, it is increasingly used as a raw material in the manufacture of UV-cured adhesives.

Kuraray will place increased emphasis on user needs in its product development system, and plans to strengthen and expand the role of LIR in its elastomer business.

The Facilities Expansion

Location Kuraray's Kashima Plant
Kamisu-machi, Kashima-gun, Ibaraki Prefecture
Plant manager Takayoshi Osaki
Production capacity
Production capacity 3,600 tons per year
Expansion 1,000 tons per year
Total production capacity 4,600 tons per year
Commencement of operations October 2004
Capital investment Approximately ¥400 million
  • * LIR is primarily used as a reactive plasticizer in natural and synthetic rubbers. The LIR developed by Kuraray has an extremely high molecular weight in comparison to common process oil, in the 30,000 to 50,000 range as compared to a few hundred. The Company has used this extremely high molecular weight to develop a new market.