Grades phosphine

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. 

Excess calcium hydroxide is precipitated by usiag carbon dioxide and the calcium carbonate, calcium hydroxide, and calcium phosphite are removed by filtration. The filtered solution is treated with an equivalent amount of sodium sulfate or sodium carbonate to precipitate calcium sulfate or carbonate. Sodium hypophosphite monohydrate [10039-56-2] is recovered upon concentration of the solution. Phosphinic acid is produced from the sodium salt by ion exchange (qv). The acid is sold as a 50 wt %, 30—32 wt %, or 10 wt % solution. The 30—32 wt % solution is sold as USP grade (Table 12) (63). Phosphinic acid and its salts are strong reduciag agents, especially ia alkaline solution (65). 

Red phosphorus has been used as an effective PBT FR, is non-halogen-based, and very high in active ingredient [55, 56], However, red phosphorus melt blending requires some special considerations. The potential generation of phosphine gas and acidic decomposition products under incorrect melt processing conditions is a concern. Recently, encapsulated grades of red phosphorus have minimized some of these potential issues. Red P blends are also limited in color capability. 

To make butyraldehyde, the precursor for NBA, the so-called Oxo process is used, reacting chemical grade propylene with hydrogen and. carbon monoxide at 250-300°F and 3500-4000 psi. See Figure 14-4.) Under those conditions, both feeds are liquids. The catalyst is an oil-soluble cobalt carbonyl complex dissolved in the propylene. If rhodium-based catalysts or complexes based on rhodium carbonyls and triphenyl phosphine... 

Table 5.10 Comparison of phosphine formation of various grades of red phosphorus (at 25°C and 65% humidity).

Contracts for acetylene-grade carbide are usually based on size and gas yidd specification, and indude penalties for carbide that fails to meet specified gas yidd. The sizes generally available in the trade are based on established U.S. Government specifications. In general gas yidds range from 280—300 L/kg and depend on the screen size of the carbide. The most important standard is the method of expressing gas yidd, which in the United States is at 15°C and 101 kPa (1 atm). Gas impurities are typically 0.05% by volume phosphine, 0.15% by volume hydrogen sulfide, and 0.001% arsine. 

The procedure described for the preparation of ethylenediamine-bisborane is general for the synthesis of amine-boranes and of borane adducts of other electron donors in which elements such as phosphorus and sulfur serve as the donor atom. In addition to the procedure used here for triphenylphosphine-borane, borane adducts of phosphines have been prepared by Analytical reagent grade (Mallinckrodt). 

Phosphine-modified cobalt hydroformylation is only used commercially by Shell. It is tightly coupled to Shell s Higher Olefins Process (SHOP, see Metathesis Polymerization Processes by Homogeneous Catalysis) that produces a C4 through C20 mixture of linear, internal alkenes for hydroformylation to detergent-grade alcohols. 

Grade Technical, containing 98% acetylene and not more than 0.05% by volume of phosphine or hydrogen sulfide 99.5%. 

Materials. The commercial grade Exxpro elastomer, BrXPSO (Exxon Chemical Co., Baytown, TX), triphenyl phosphine(Aldrich F. Wt. 262.29, M.P. 79-81 C), sodium tetraphenyl borate(Aldrich, 99.5+ %), tetrahydrofiiran(Baker, reagent grade), methanol and isopropanol(Baker, reagent grade) were purchased and were used as such. 

Besides the TPPTS-system a number of other sulfonated phosphine ligand systems were investigated and tested on a pilot plant scale. Among them are systems which are derived from biphenyl (BISBIS = sulfonated bis(diphenylphosphinomethyl)biphenyl, varying grades of snlfonation of... 

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