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:
Jun. 20, 1989
Filed:
Oct. 06, 1987
Applicant:
Inventors:
Seiji Sakamoto, Machida, JP;
Kiyoshi Yasumura, Yokohama, JP;
Assignee:
Diafoil Company, Limited, Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
B32B / ;
U.S. Cl.
CPC ...
428141 ; 428409 ; 428480 ; 523181 ; 528398 ;
Abstract
A polyester film suitable for use as the magnetic tape base for video recording, capable of high density recording and having stable slidability or running characteristics. The polyester film is made of a polyester which contains 0.05-1 wt % particles containing calcium and phosphorus and of which the number n of the second interference fringes (number/mm.sup.2) and the average centerline roughness (.mu.m) satisfy the following relationships: