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. 28, 1992
Filed:
Jan. 31, 1990
Henkel Kommanditgesellschaft auf Aktien, Duesseldorf, DE;
Abstract
The direct hydrothermal production of high purity potassium silicate solutions having a high SiO.sub.2 : K.sub.2 O molar ratio by reaction of a silicon dioxide source with aqueous potassium hydroxide solutions is made possible by using a silicon dioxide source that contains a sufficient fraction of cristobalite phase, or by conditioning other crystalline forms of silicon dioxide by heating at or above 1100.degree. C., but below the melting point of silica, before the hydrothermal treatment. Preferably the potassium hydroxide solution has a concentration range of 10 to 40% by weight, and the reaction is carried out in a closed pressure reactor at temperatures of 150.degree. to 300.degree. C. and under saturated steam pressures corresponding to those temperatures.