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. 16, 1999
Filed:
Jul. 18, 1996
Applicant:
Inventors:
Assignee:
Mitsui Chemicals, Inc., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D / ;
U.S. Cl.
CPC ...
21050036 ; 21050027 ; 56-4 ; 264 41 ;
Abstract
A microporous film of high molecular weight polyolefin useful in the prepration of filter mediums or non-aqueous battery separators and a process for producing the film are disclosed. The microporous film of high molecular weight polyolefin contains leaf vein-like fibrils as a main constituent on each of which fibrils indeterminate-form crystallites of not more than 1 .mu.m in size flocculate and has an intrinsic viscosity, �.eta.!, of 4 dl/g or more and, preferably, has: