Patent · US Expired

Process for production of porous glass membrane tubes

US4042359A · kind A · utility

22Cited by

4References

13Claims

0Family size

Assignee

Jenaer Glaswerk, Schott & Gen. · DE

Inventors

Roland Schnabel · Hofheim, DE
Alexander Holzel
Kurt Gotter · Mainz, DE

Key dates

Filing date	Nov 13, 1975
Grant date	Aug 16, 1977
Priority date	—
Expiry date	Nov 13, 1995

Classification

Technology area (CPC B)Performing Operations; Transporting
CPC primaryB01D2323/12
WIPO fieldChemical engineering
WIPO sectorChemistry

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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.