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:
Jul. 13, 1976
Filed:
Jul. 02, 1973
Applicant:
Inventor:
Ralph K Iler, Wilmington, DE (US);
Assignee:
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01J / ;
U.S. Cl.
CPC ...
2523 / ; 252314 ; 252317 ;
Abstract
Aqueous silica sols having a pH from 8 to 11 containing 1 to 40% by weight of colloidal silica and soluble salts can be purified and concentrated by filtering the soluble salt from the sol using a microporous membrane filter while maintaining the salt concentration within a range determined by the concentration of silica in the sol. In one embodiment, colloidal silica particles are grown to a larger size by starting with a sol of nuclei, and adding sodium silicate solution and acid.