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:
Sep. 03, 1985
Filed:
Aug. 26, 1983
Koichi Abe, Kyoto, JP;
Kenichi Kawakami, Ohtsu, JP;
Toshiya Yoshii, Ohtsu, JP;
Toshihide Inoue, Ichinomiya, JP;
Toray Industries, Inc., Tokyo, JP;
Abstract
A magnetic recording material which comprises a film of a polyester and a magnetic layer formed on at least one side of said film, said polyester containing more than 85 mol % of the repeating unit represented by the formula below and having an intrinsic viscosity of 0.3 to 1.4, and said film of said polyester having a refractive index ratio of 0.935 to 0.975 in the thickness direction and a density index of 0.02 to 0.08. ##STR1## (where X is a halogen atom selected from fluorine, chlorine, and bromine, or an alkyl group of carbon number 1 to 3; and l and m are an integer of 1 to 2, p is an integer of 2 to 6, and q is an integer of 2 to 4.) Although the magnetic recording material is extremely thin, it exhibits outstanding running performance and electromagnetic conversion characteristics. It makes it possible to miniaturize the magnetic tape cassette and extend the recording time. It is useful for long-time video tape and portable 8-mm video tape.