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. 03, 1989
Filed:
Jul. 06, 1987
Robert E Kesting, Eisenfeld, DE;
Alfred K Fritzsche, Manchester, MO (US);
Milton K Murphy, Clayton, MO (US);
Alan C Handermann, Matthews, NC (US);
Clint A Cruse, St. John, MO (US);
Raymond F Malon, Edmundson, MO (US);
Permea, Inc., St. Louis, MO (US);
Abstract
A process for forming high free volume, asymmetric gas separation membranes having graded density skins and macrovoid-free morphology from a solvent system comprising a Lewis acid, Lewis base, and a Lewis acid:base complex which dissolve hydrophobic polymers. The dopes have high total solids, high viscosity and low coagulation (g) values which enhance rapid gelation without the formation of macrovoids and which minimize densification. The dope solvent system complexes are readily disassociated by the coagulation medium and the component molecules are miscible in the medium which provides for rapid desolvation of the formed membrane thus providing a membrane having low residual solvent retention.