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:
Feb. 11, 1992
Filed:
Oct. 18, 1990
Applicant:
Inventors:
Kichinojo Tomitaka, Nagahama, JP;
Masumi Koizumi, Kawasaki, JP;
Assignee:
Diafoil Company, Limited, Tokyo, JP;
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B32B / ; B32B / ;
U.S. Cl.
CPC ...
428480 ; 2642358 ; 428220 ; 428910 ;
Abstract
The present invention provide a biaxially oriented polyester film for use in a floppy disc, which has a coefficient of thermal expansion (.alpha..sub.T) in film plane of (1.0.+-.0.5).times.10.sup.-5 mm/mm/.degree.C. and a heat shrinkage of not higher than 0.09% after treatment the film for 72 hours under conditions of a temperature of 60.degree. C. and a humidity of 80% RH in any directions in film plane, and simultaneously satisfies the following equations (1) to (5):