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. 04, 1995
Filed:
Mar. 01, 1994
Charles N Jolliffe, Circleville, OH (US);
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
A method is provided for the production of ultrathin films having a thickness of 2.5 microns or less, including film having a thickness as low as about 0.2 microns. Film of thermoplastic polymer, preferably polyester film, less than 25 microns in thickness and in thermal equilibrium with the surrounding air is simultaneously stretched at least twice and up to about five times its original dimensions in the machine and cross-machine directions under conditions such that thicker regions are maintained at an elevated temperature by radiant heating and at least a 0.1.degree. C. temperature differential is established between the thicker (hotter) regions and the thinner (cooler) regions of the film prior to stretching the film beyond its elastic limit. The ultrathin films produced according to this invention have acceptable uniform thickness necessary for commercial applications thus providing consistent electrical performance when used as the dielectric medium in miniature capacitors and uniform heat transfer characteristics suited for high resolution thermal transfer media or digital stencils.