Nippon Zeon

Acrylonitrile fibers treated with hydroxides have been reported to be useful for adsorption of uranium from seawater (105). Tubular fibers for reverse osmosis gas separations, ion exchange, ultrafiltration, and dialysis are a significant new appHcation of acryUc fibers and other synthetics. Commercial acryUc fibers have already been developed by Nippon Zeon, Asahi, and Rhc ne-Poulenc. 

Nippon Zeon estimated that the break-even cost of its tire pyrolysis pilot plant was 0.25 per tire (29,30). One study indicates that pyrolysis of tires and other polymers should be considered as a means for disposing of scrap within environmental constraints. A plant processing 81,000 t/yr of scrap could be profitable, based on sales of reclaimed products (31). 

M. Matsuo, personal communication, Nippon Zeon of America, New York, Dec. 21, 1981. 

Two suppliers to the U.S. market are Bayer and Nippon Zeon. The estimated volume used in the United States is 500 700 t/yr. Hydrogenated nitrile mbber (HSN or HNBR) compounds compete with EKM, EVMQ, ECO, ACM, and high ACN content nitrile mbbers. Big applications include automotive timing belts, blowout preventors, drill pipe protectors, and numerous oil and fuel pump components. 

Jptt Kokai Tokkyo Koho JP 01,158,960 (fune 22,1989), T. Ueda and co-workers (to Nippon Zeon Co., Ltd.). 

Highly saturated nitrile elastomers (HSN) have become available. These mbbers are prepared by (nearly complete) hydrogenation of the nitrile mbber copolymer. The resulting product has better heat and oxidation resistance than conventional nitrile mbber but still retains some double bonds for vulcanization. Trade names for HSN are Zetpol (Nippon Zeon), Therbar (Bayer), and Tormac (Polysar). HSN has been used, and is being developed, for oil field chemical, automotive, power station, aerospace, military, and industrial appHcations (66). 

In the United States, Europe, and Japan, DCPD streams of 70—95 wt% purity are available. Estimates of recoverable DCPD production capacity in the United States for 1990 for all grades of DCPD is >127, 000 metric tons (39) and in Europe is 48,000 metric tons (40). The vast majority of this production is from hydrocarbon steam-cracking operations. Based on the total operations, more CPD is produced than indicated above, but because of the relatively small quantities available at a single location, much of the cyclopentadiene caimot be recovered profitably. Important producers in the U.S. are Dow, Exxon, LyondeU, SheU, and Texm ark in Europe, Dow and SheU and in Japan, Nippon Zeon (40). 

Poly(dicyclopentadiene). The development of polydicyclopentadiene [25038-78-2] for reaction injection molding is an area which has generated much interest. The polyDCPD is obtained via metathesis polymerization of high purity (usually greater than 98%) DCPD. Excellent reviews (61—62) of the chemistry and properties of polyDCPD have been pubHshed. The patent Hterature of polyDCPD synthesis, catalysts, modifiers, and appHcations is dominated by Hercules (44 patents) and B. F. Goodrich (43 patents) in the U.S. Other participants are Orkem, SheU, Nippon Zeon, and Teijin. 

The catalysts for these compounds are based on aluminum (Nippon Zeon) or tin (Daiso) (12,13). The preferred catalysts are triaLkylalurninum—water combinations used with or without a chelating agent such as acetylacetone. Except for minor variations, few changes in catalyst composition have been made since it was first formulated. 

Hercules and B. F. Goodrich are no longer in the polyether manufacturing business. In 1986, Hercules sold its polyether elastomer operation to B. F. Goodrich, which, after operating it for several years, in turn sold it and their whole specialty elastomer division to Zeon Chemicals USA, Inc., in 1989 (14). Zeon Chemicals USA, Inc., is a subsidiary of the Nippon Zeon Co., Ltd. At the present time, manufacture of polyethers is done by Zeon Chemicals in Hattiesburg, Mississippi, Nippon Zeon in Tokuyama, Japan, and Daiso in Mizushima, Japan. Total production is estimated to be 13,000 to 15,000 tons per year. 

Currentiy, i7j -l,4-polyisoprene is manufactured in the United States only by The Goodyear Tire Rubber Co. at Beaumont, Texas. In Western Europe, only the Shell Nederland Chemie (Royal Dutch/SheU Group) commercially produces i7j -l,4-polyisoprene in Japan, the producers are Japan Synthetic Rubber Co., Ltd. and Nippon Zeon Co., Ltd. The sole world producer of /n j -l,4-polyisoprene is Kuraray Co., Ltd. in Japan. 

Commercial manufacture of this polymer was first announced by CdF Chimie in 1975 following about 10 years of study on the Diels-Alder reactions of alkenes with cyclopentadiene. In 1976 a plant with a capacity of 5000 tonnes per annum was put on stream and product marketed as Norsorex. Manufacturing under licence is now being extended to American Cyanamid whilst CdF Chimie has also signed a marketing agreement with Nippon Zeon. 

This approach was used in the development of the epichlorhydrin rubbers which became commercially available around 1965 from Goodrich (Hydrin) and Hercules (Herclor). Both homopolymers of epichlorhydrin (Hydrin 100, Herclor H) and copolymers of epichlorhydrin with ethylene oxide (Hydrin 200, Herclor C) became available. (In 1986 Hercules sold their interest in these materials to Goodrich, who in turn later sold this to Nippon Zeon). 

Nippon Zeon, See Zeon (Japan), 187 Nissan Chemical hidustries Ltd., 187 Nitrapyrm, 98 Nitrates, 98... 

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