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:
Sep. 25, 1990
Filed:
Sep. 26, 1989
UBE Industries, Yamaguchi, JP;
Abstract
A pervaporation method of separating a liquid organic compound mixture at a high speed and efficiency through an aromatic polyimide asymmetric separating membrane produced from an aromatic tetracarboxylic acid component comprising at least 70 molar % of biphenyl or diphenylether tetracarboxylic dianhydride and an aromatic diamine component comprising 85 molar % or more of an aromatic diamine having 2 to 3 benzene ring structure, or 15 molar % or more of 9,10-di(aminophenyl)anthracene, di(aminophenoxy)diphenylsulfone, di(aminophenoxy)biphenyl or di(aminophenoxy)diphenylalkane compounds, or a mixture of 15 to 50 molar % of an aromatic diamine having alone benzene or pyridine ring structure and 50 to 85 molar % of an aromatic diamine having a 2 to 3 benzene ring structure.