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, 1995
Filed:
Dec. 09, 1993
Takashi Matsui, Tsuruga, JP;
Nobuki Watanabe, Hyuga, JP;
Masayuki Arimura, Eugene, OR (US);
Eiji Kanemaru, Hyuga, JP;
Yuzo Horinouchi, Nobeoka, JP;
Mutsuhiro Ito, Hyuga, JP;
Fuji-Davison Chemical Ltd., , JP;
Abstract
This invention provides a method for manufacturing silica gels in a form of scales or needles having a pore volume and a specific surface area being relatively large and being controlled. Silicic acid sol is frozen, crystallized and deposited in gaps among crystal faces of crystals of solvent of the sol, thus obtaining the frozen silica hydrogels in the form of scales or needles. After unfreezing the frozen silica hydrogels, a hydrothermal polymerization is carried out. Subsequently, the silica hydrogels are dried, thus obtaining the silica gels in the form of scales or needles. Furthermore in the invention, by controlling the gelation time period of silica sol, the silica gels with their configuration controlled can result from even inexpensive silica sol. The invention has the advantage that a freeze-drying step is not required: just through freezing, unfreezing, washing and hydrothermal polymerization steps, the physical properties of the silica gels can be controlled.