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:
Feb. 14, 1984
Filed:
May. 17, 1982
Thomas E Davis, Lafayette, CA (US);
Dana C Overman, III, Pleasant Hill, CA (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
An improved process for drying water-wet, cellulose ester membranes is described. It has been found that by contacting one side of the membrane with a liquid mixture of a water-miscible, volatile C.sub.1 to C.sub.6 hydrocarbon and a water-immiscible organic compound, while an inert gas stream or vacuum is maintained on the other surface of the membrane, water can be displaced from the membrane economically, rapidly and without adversely affecting the structure of the membrane. A 1 to 1 volume mixture of isopropanol and isooctane is particularly preferred in this step. The essentially water-free membrane is then dried by applying reduced pressure or an inert gas stream to produce a membrane having exceptional separation characteristics.