曹達 (Tokuyama) 

Tokuyama Corporation produces and sells various chemical products in Japan. The company operates through six segments: Chemicals, Cement, Electronics Materials, Life Science, Eco Business, and Others. The Chemicals segment offers caustic soda, soda ash, calcium chloride, sodium silicate, vinyl chloride monomer, polyvinyl chloride resin, propylene oxide, chlorinated solvents, and hydrogen. The Cement segment provides cement, ready-mixed concrete, and cement-type stabilizer, as well as engages in the resource recycling business. The Electronic Materials segment provides polycrystalline silicon; fumed silica and tetrachlorosilane; aluminum nitride; high-purity chemicals for electronics manufacturing and photoresist developer; and isopropyl alcohol. The Life Science segment provides medical diagnosis systems, dental materials and equipment, pharmaceutical ingredients and intermediates, plastic lens-related materials for glasses, and microporous film. The Eco Business segment offers plastic window sashes, ion exchange membranes, as well as engages in waste gypsum board recycling activity. The company was formerly known as Tokuyama Soda Co., Ltd. and changed its name to Tokuyama Corporation in April 1994. Tokuyama Corporation was incorporated in 1918 and is headquartered in Tokyo, Japan.