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:
Nov. 15, 1994
Filed:
Nov. 04, 1992
Applicant:
Inventor:
Tomoyuki Kotani, Machida, JP;
Assignee:
Diafoil Hoechst Company, Limited, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B32B / ;
U.S. Cl.
CPC ...
428323 ; 428328 ; 428329 ; 428480 ; 4286 / ; 4286 / ; 428900 ;
Abstract
A laminated polyester film for a magnetic recording medium having at least three layers, in which each of a top layer and a bottom layer of the at least three layers contains inorganic particles having a Moh's hardness of at least 8 and an average particle size of 0.005 to 0.5 .mu.m in an amount of 0.25 to 5% by weight based on the weight of the polyester of the respective layer and, in total, not larger than 0.20% by weight based on the whole weight of the polyesters of all the layers including an intermediate layer, and exposed surfaces of the top and bottom layers have coefficients of friction and surface roughness which satisfy the specific conditions.