Preparation of silane, SiH.sub.4

US4499063A · kind A · utility

Assignee

• Rhone-Poulenc Specialities Chimiques · FR

Inventors

• Jean Grosbois · Persan, FR
• Serge Jacubert · Viroflay, FR
• Jean-Michel Verdier · Paris, FR

Key dates

• Filing date: Sep 27, 1983
• Grant date: Feb 12, 1985
• Expiry date: Sep 27, 2003

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S423/12
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Essentially pure silane, SiH.sub.4, is facilely prepared in plural reactors, by (i) reacting chlorosilane with lithium hydride in a mixture of molten salts which comprises lithium chloride and potassium chloride, in a discrete first reaction zone, said mixture of molten salts being essentially eutectic in composition, the amount of chlorosilane being at least 5% less than that amount stoichiometrically required for reaction with the lithium hydride, and the amount of lithium hydride comprising at most 20 mole % of said mixture of molten salts, (ii) recovering product silane from said discrete first reaction zone, (iii) transferring said mixture of molten salts comprising unreacted lithium hydride dissolved therein from said discrete first reaction zone to a discrete second reaction zone, (iv) reacting chlorosilane with said unreacted lithium hydride dissolved in said mixture of molten salts in said discrete second reaction zone, the amount of chlorosilane being at least 2% in excess of that amount stoichiometrically required for reaction with said unreacted lithium hydride, and (v) recovering product silane from said discrete second reaction zone.