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. 09, 1990
Filed:
Nov. 06, 1987
Henry N Beck, Walnut Creek, CA (US);
Edgar S Sanders, Jr, Pittsburg, CA (US);
G Glenn Lipscomb, II, Walnut Creek, CA (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
The invention is a composition useful for the preparation of POWADIR membranes of a bisphenol-based polycarbonate wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogenated, wherein the halogen is Cl or Br, the composition comprising (i) a bisphenol-based polycarbonate wherein at least 25 percent by weight of the bisphenol moieties are tetrahalogenated, wherein the halogen is Cl or Br, (ii) a solvent for such polycarbonate, and (iii) a non-solvent for such polycarbonate. The composition is useful for extruding membranes wherein the membranes formed are POWADIR membranes with a discriminating region capable of separating oxygen from nitrogen. The composition of this invention allows the formation of membranes with excellent physical properties, good separation factors for oxygen and nitrogen, with excellent fluxes.