Magnetic recording material
US4539260A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 1983 |
| Grant date | Sep 3, 1985 |
| Priority date | — |
| Expiry date | Aug 26, 2003 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31786
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.