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. 15, 2003
Filed:
Nov. 20, 2001
Ieyasu Kobayashi, Sagamihara, JP;
Toshifumi Osawa, Sagamihara, JP;
Teijin Limited, Osaka, JP;
Abstract
A biaxially oriented laminated polyester film which is excellent in film winding properties and handling properties and provides excellent electromagnetic conversion characteristics when it is used as a base film for high-density magnetic recording media, particularly digital recording magnetic recording media. This film consists of a polyester A layer and a polyester B layer formed on one side of the polyester A layer and is characterized in that: (1) the polyester A layer contains three different types of fine particles which differ from one another in average particle diameter and has a surface roughness WRa of 5 to 20 nm and a WRz of 100 to 300 nm, (2) the polyester B layer has a surface roughness WRa of 2 to 10 nm and a WRz of 30 to 150 nm, and (3) the film has a friction coefficient of 0.5 or less.