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:
Aug. 17, 1993
Filed:
Oct. 18, 1991
Applicant:
Inventors:
Assignee:
Dainippon Ink and Chemicals, Inc., Itabashi, JP;
Primary Examiner:
Int. Cl.
CPC ...
B01D / ;
U.S. Cl.
CPC ...
21050035 ; 264 41 ; 264 451 ; 264D / ; 264D / ;
Abstract
An asymmetric polymer membrane is disclosed characterized by being formed by irradiating a monomer and/or an oligomer polymerizable with an energy ray and having a pore diameter distribution in the thickness direction of the membrane, a ratio of a permeability flux of oxygen to nitrogen of 0.9-1.1, and communicating pores.