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. 24, 1984
Filed:
Oct. 14, 1981
Teijin Limited, Osaka, JP;
Abstract
A polyester film characterized by having many uneven units on its surface, each of said uneven units being composed of a fine projection and a depression existing therearound, and a process for producing aforesaid polyester film, which comprises pre-heating an unstretched polyester film containing internal particles attributed to an inert additive having an average particle diameter of 0.05 to 5 .mu.m and/or a catalyst residue to a temperature of 80.degree. to 120.degree. C.; stretching the film in a first axial direction to 2.6 to 3.5 times at a temperature of 110.degree. to 145.degree. C.; thereafter, stretching the film in a second axial direction at right angles to the first axial direction to 3.0 to 4.0 times at a temperature of 100.degree. to 150.degree. C.; and then heat-setting the stretched film at a temperature of 160.degree. to 240.degree. C.