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:
Jul. 12, 1994
Filed:
Dec. 02, 1992
Applicant:
Inventor:
Gunilla E Gillberg-LaForce, Summit, NJ (US);
Assignee:
Hoechst Celanese Corp., Somerville, NJ (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B32B / ;
U.S. Cl.
CPC ...
4283155 ; 428195 ; 428213 ; 4283157 ; 4283159 ; 428409 ; 264145 ; 2642902 ;
Abstract
The process for forming a microporous polymeric semi-crystalline film, involving the steps of cold compressive extruding a precursor film, preferably in a biaxial fashion, so as to compress the film by a factor of about 2 to 1 to about 10 to 1, stretching the film by about 100 to about 500 percent, preferably in a biaxial fashion, and heat annealing either before, during, or preferably after the stretching step at a temperature up to the alpha transition temperature of the polymer for a time sufficient to maintain the microporous character of the final film.