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. 31, 1993
Filed:
Dec. 20, 1991
Applicant:
Inventors:
Howard J Troffkin, Potomac, MD (US);
Burton M Rein, Mountain Lakes, NJ (US);
Robert M Spotnitz, Catonsville, MD (US);
Richard T Giovannoni, Columbia, MD (US);
Yihong Guo, Columbia, MD (US);
Assignee:
W. R. Grace & Co.-Conn., New York, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B29C / ; B29C / ; B32B / ;
U.S. Cl.
CPC ...
264 28 ; 264 41 ; 264154 ; 264171 ; 2642093 ; 2642102 ; 2642356 ; 264564 ; 429254 ;
Abstract
A process of having a microporous multiply sheet product which is capable of becoming non-porous at a predetermined elevated transformation temperature is formed by first forming a non-porous, multiply initial sheet product having at least one first ply and at least one second ply, each with its own viscosity profile. The initial sheet product is then stretched and annealed to impart porosity to the sheet product.