The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 10, 1978
Filed:
Jan. 26, 1976
Axel Volling, Rheinfelden, DT;
Deutsche Gold- und Silber-Scheideanstalt vormals Roessler, Frankfurt am Main, DT;
Abstract
Process for the production of finely divided silicon dioxide having a surface of more than about 380 m.sup.2 /g BET which comprises converting a volatile silicon halide in an inert gas vehicle with a gas forming water upon combustion and oxygen gas or air in a flame, the quantity of oxygen being sufficient for the practically complete combustion of the combustible gas, and the quantities of oxygen or air and combustible gas being sufficient to produce a quantity of water which will at least suffice for the hydrolysis of the volatile silicon halide, said volatile silicon halide consisting essentially of trichlorosilane and said inert gas vehicle consisting for instance of nitrogen, carbon dioxide, noble gases or others the amount of trichlorosilane vapor being about 410-565 g trichlorosilane vapor per Nm.sup.3 /h total gas, the molar ratio of trichlorosilane vapor to nitrogen being about 0.5:1 - 5:1, the molar ratio of hydrogen in the combustible gas to oxygen being about 0.5:1 - 1.3:1, and separating the resulting silicon dioxide from other reaction products. Finely divided silicon dioxide prepared according to this process is also provided. The finely divided silicon dioxide is useful as a thickening agent in liquid systems.