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:
May. 12, 1998
Filed:
Feb. 22, 1996
Petroleum Energy Center, Tokyo, JP;
Abstract
A homogeneous membrane or an asymmetric membrane which is made of polyimide resin containing fluorine as a main component and has high separation and permeation properties, is used in a method of separating unsaturated hydrocarbon from a mixture of unsaturated and saturated hydrocarbon. The method includes the steps of contacting the mixture onto the membrane made of the polyimide resin having a repeating unit shown in the following formula as a main component, selectively permeating unsaturated hydrocarbon through the membrane, and separating unsaturated hydrocarbon from the mixture. The membrane satisfies the condition of a solubility coefficient ratio between unsaturated and saturated hydrocarbon.gtoreq.1.2 at 25.degree. C. and more than 50 Torr when the absorption of hydrocarbon to the polyimide resin is in equilibrium. ##STR1##