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:
Mar. 21, 1989
Filed:
Mar. 14, 1988
Takashi Nohmi, Tokyo, JP;
Toshibumi Fukai, Shizuoka, JP;
Asahi Kasei Kogyo Kabushiki Kaisha, Osaka, JP;
Abstract
There is disclosed a composite membrane comprising [A] a polysulfone type porous membrane capable of rejecting 90% or more of dextran molecules having a weight average molecular weight of 70,000 and [B] a specific styrene type resin coated on at least one side of the polysulfone type porous membrane in a thickness of 5 .mu.m or less and in an amount of 1.times.10.sup.-7 g/cm.sup.2 of the polysulfone type porous membrane, the styrene type resin being selected from the group consisting of (I) a specific styrene type linear polymer having a weight average molecular weight of 1.times.10.sup.-5 or more, (II) a specific blend polymer prepared by blending at least two different styrene type linear polymers each as defined above and (III) a specific crosslinked polymer selected from the group consisting of (i) a crosslinked polymer prepared by crosslinking a styrene type linear polymer having a weight average molecular weight of 1.times.10.sup.-3 or more and (ii) a crosslinked polymer prepared by blending at least two different styrene type linear polymers each having a weight average molecular weight of 1.times.10.sup.3. Such a composite membrane has been found to be advantageously employed for gas separation because of its high gas permeability and high selective gas permeability.