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:
Oct. 25, 1988
Filed:
Apr. 12, 1984
Applicant:
Inventors:
Assignee:
Jenaer Glaswerk, Schott & Gen., Mainz, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B32B / ; B01D / ; B01D / ;
U.S. Cl.
CPC ...
428398 ; 65 301 ; 65 31 ; 428391 ; 428392 ; 428 36 ; 21050023 ; 21050024 ; 210506 ; 210509 ;
Abstract
The invention relates to a process for producing a tubular glass membrane with wall thicknesses between 5 and 30 microns and reproducible pore sizes between 11 A and 50 A. Alkali borosilicate glass is drawn into discrete hollow tubes and immediately cooled. The tubes are thermally treated to effect a phase separation into a coherent silicon dioxide phase and a boron oxide phase rich in alkali borate. The boron oxide phase is leached out with mineral acid. The tubes can be subsequently treated to give enlarged or reduced pores, asymmetric pores and coated surfaces.