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. 24, 1993
Filed:
Aug. 30, 1991
Kevin E Kinzer, Cottage Grove, MN (US);
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
Abstract
A method for preparing an oriented microporous shaped article is provided. The method comprises the steps of melt blending thermoplastic polymer with a solubilizing amount of a compatible liquid to form a homogeneous solution, forming a shaped article from the solution, cooling the shaped article at a rate and to a temperature sufficient to initiate thermodynamic, non-equilibrium liquid-liquid phase separation and then to solidify the thermoplastic polymer, stretching the article in a first direction sufficient to permanently attenuate the article and effect orientation of the polymer, and removing at least a substantial portion of the compatible liquid before or after the stretching step to form an oriented microporous shaped article.