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:
Nov. 06, 1990
Filed:
Aug. 25, 1989
Applicant:
Inventor:
Robert A Hay, Dudley, MA (US);
Assignee:
Norton Company, Worcester, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D / ; B01D / ; B01D / ;
U.S. Cl.
CPC ...
210490 ; 210492 ; 21049701 ; 21050023 ; 21050025 ; 21050026 ; 210506 ; 2105101 ; 427244 ; 427246 ; 427247 ; 4273762 ; 427380 ; 4273835 ;
Abstract
Strong and durable alpha alumina ultrafiltration membranes with effective separating layers having effective pore diameters less than about 50 nm, and particularly at almost any point within the range of about 10 to about 50 nm, can be produced by seeding boehmite sols with appropriate seeds, such as very fine alpha alumina with a specific surface area of more than 100 sq. m. per g, gelling a thin layer of the sol by contact with a microfilter support, drying the gel, followed by controlled heating of the coated support both to convert the boehmite to alpha alumina and to simultaneously control the effective pore diameter of the resultant membrane.