Cytec

The acid process has been operated since 1970 by Cytec Canada Inc. (Niagara Falls, Canada) and since 1980 by Albright and Wilson Ltd. (Oldbury, England). Many of the details of the process are considered to be proprietary because of its specialized nature. Nippon Chemicals has also been producing phosphine, probably by the acid process, in Japan since the early to mid-1980s. Typical properties of phosphine are given in Table 1. 

Semiconductors. Phosphine is commonly used in the electronics industry as an -type dopant for siUcon semiconductors (6), and to a lesser extent for the preparation of gaUium—indium—phosphide devices (7). For these end uses, high purity, electronic-grade phosphine is required normally >99.999% pure. The main impurities that occur in phosphine manufactured by the acid process are nitrogen [7727-37-9] hydrogen [1333-74-0] arsine [7784-42-17, carbon dioxide [124-38-9], oxygen [7782-44-7], methane [74-82-8], carbon monoxide [630-08-0], and water [7732-42-1]. Phosphine is purified by distillation under pressure to reduce the level of these compounds to <1 ppm by volume. The final product is sold as CYPURE (Cytec Canada Inc.) phosphine. 

This provides a durable finish which, unlike many other flame retardants, can withstand repeated (50—100) launderiags without a loss of efficiency. An added advantage is that the feel of the cloth (hand) is Htde effected. Principal markets are ia the treatment of iadustrial protective clothing, military uniforms, and, ia Europe, for furnishings. These products are available from Albright Wilson Ltd. and Cytec Industries Inc. 

Flotation Reagents. Only one sulfide mineral flotation collector is manufactured from phosphine, ie, the sodium salt of bis(2-methylpropyl)phosphinodithioic acid [13360-78-6]. It is available commercially from Cytec Industries Inc. as a 50% aqueous solution and is sold as AEROPHINE 3418A promoter. The compound is synthesized by reaction of 2-methyl-1-propene [115-11-7] with phosphine to form an iatermediate dialkylphosphine which is subsequently treated with elemental sulfur [7704-34-9] and sodium hydroxide [1310-73-2] to form the final product (14). The reactions described ia equations 10 and 11... 

Beginning in approximately 1975, both IMG and Ereeport Minerals operated large uranium recovery plants in the United States using this technology. Several plants continue to mn but a number have been closed because of the depressed uranium prices that resulted when uranium from the former Soviet Union flooded Western markets. A relatively small plant is operated by Prayon in Belgium (40). TOPO is available from Cytec Industries Inc. as CYANEX 921 extractant. D2EHPA is available from Albright Wilson Ltd. and is also sold by Daihachi as DP-8R. 

A. J. Robertson, private communication, Cytec Canada Inc., Phosphine Technical Centre, Jan. 1994. 

Technical brochure, CYAJSIEIK 923 Extractant, SPT-032a, Cytec Industries, Inc., West Paterson, N.J., 1987. 

Prevention of Soil Crusting. Acid-based fertilizers such as Unocal s N/Furic (a mixture of urea with sulfuric acid), acidic polymers such as FMC s Spersal (a poly(maleic acid) derivative originally developed to treat boiler scale) (58), the anionic polyacrylamides described previously, as weU as lower molecular weight analogues such as Cytec s Aerotil L Soil Conditioner, have all been used successfully in at least some circumstances to prevent the formation of soil cmsts. It is difficult to prove benefits in the laboratory, and field tests may give variable results depending on local weather conditions. 

Most of the surface sizes used in North America are modified styrene maleic anhydride (SMA) copolymers. Commercially available materials include Scripset (Monsanto/Hercules Inc.), Cypres (Cytec), Sursize (Akzo Nobel), MSA (Morton), NovaCote (Georgia Pacific), and HTl (Hopton Technologies). Styrene acrylate emulsions that are commonly used include Jetsize and Unibond (Akzo Nobel), Basoplast (BASF), and Cypres (Cytec). Other materials used as surface sizes include acrylonitrile acrylate copolymer (Basoplast, BASF), stearylated melamine resin (Sequapel, Sequa), polyurethane (Graphsize, Vining Chemicals), and diisobutylene maleic anhydride copolymers (Baysynthol, Bayer). 

Fig. 2. Decomposition of commercial sodium isopropyl xanthate solutions. Courtesy of Cytec Industries Inc.

Fig. 3. Wedge test crack length as a function of maximum Cu buildup at the oxide-metal interface. The adhesive was Cytec FM-123. The surfaces were prepared with the Forest Products Laboratory etch. The oxide morphology was kept constant. Data are from Ref. 115].

China Petrochemical Development Corp. (Taiwan) Cytec... 

CYREN , clilorpyrifos, 49 Cytec hidustries Inc., 225 CYTHION , malathion, 49 Czech Chemical Society (CZCH), 259... 

ASARCO, General Chemical, Arch Chemical, Colonial Chemical, Phelps Dodge, Kennecott Corp., Cytec Industries, El Dorado Chemical, many others. 

There are dozens of suppliers, some of which are Air Products and Chemicals, Cytec Industries, LaRoche Industries, Coyne Chemical, Hill Brothers Chemical, and J.R. Simplot Co. 

Cytec, BP Amoco, DuPont, Sterling Chemical, Solutia. 

Acknowledgements We thank the National Science Foundation, Petroleum Research Fund, Exxon Education Foundation, Union Carbide, DuPont, and Cytec Canada for support of our studies in this area. 

Natural Sciences and Engineering Research Council of Canada (NSERC) provided financial support via Mechanical and Chemi-mechanical Pnlps Network, Strategic, and Discovery grants, while contributions from Paprican, Cytec of Canada, and Colonial Metals Inc. (for loans of RuCl3-3H20) are also acknowledged. 

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