Spherical, hydrophilic silica, method of its preparation and use

US4976943A · kind A · utility

Assignee

• Degussa AG · DE

Inventors

• Ingo Pauli · Alzenau, DE
• Peter Kleinschmit · Hanau, DE
• Rudolf Schwarz · Alzenau, DE

Key dates

• Filing date: May 12, 1989
• Grant date: Dec 11, 1990
• Expiry date: May 12, 2009

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C01P2006/90
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A spherical, hydrophilic silica consisting of compact, massive, non-crystalline particles without inner pores with a particle size of 0.5 to 10 .mu.m, preferably 0.5 to 4 .mu.m and especially 1 to 3 .mu.m with a BET surface of <50 m.sup.2 /g, preferably of 1 to 10 m.sup.2 /g is prepared by heating water vapor and gaseous silicon tetrachloride separately to a temperature of 300.degree. to 400.degree. C., mixing them with each other in a molar ratio of 2:1 to 6.7:1 and reacting the mixture at a temperature of 600.degree. to 1200.degree. C.