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. 08, 1994
Filed:
Mar. 16, 1994
Takao Chujo, Sagamihara, JP;
Hisashi Hamano, Sagamihara, JP;
Masanori Nishiyama, Sagamihara, JP;
Yasuhiro Saeki, Sagamihara, JP;
Tatsuya Ogawa, Sagamihara, JP;
Kouhei Endou, Anpachi, JP;
Teijin Limited, Osaka, JP;
Abstract
There is provided a biaxially oriented polyester base film for a magnetic tape for use in a cassette for a digital audio tape recorder. The film has (a) a stress when the biaxially oriented polyester base film is extended in the longitudinal direction by 5% of at least 12 kg/mm.sup.2, (b) a residual extension in the longitudinal direction of 0.2 % or less and a residual extension in the transverse direction of 0.3% or less, (c) a heat shrinkage in the longitudinal direction of 1.5% or less, (d) at least one surface of which has a surface roughness, Ra, of 25 nm or less, and (e) a film thickness of in the range of from 3 to 12 .mu. m. A magnetic tape for use in a cassette for a digital audio tape recorder is also provided.