US4091143A
Expired / Lapsed
US
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Magnetic recording media
Assignee: BASF SE
•
Filing: 1975-10-22
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Granted: 1978-05-23
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Expires: 1995-10-22
Abstract
Abstract Magnetic recording media, the magnetic coating of which consists of a dispersion of elongated ferromagnetic chromium dioxide particles in an organic binder, the dispersions exhibiting particularly good storage stability. This is achieved by admixing 0.5 to 6% by weight, based on the amount of chromium dioxide pigment, of the zinc salt of an aliphatic carboxylic acid of 8 to 18 carbon atoms, during the manufacture of the chromium dioxide dispersions. Chromium dioxide dispersions with good storage stability and a high degree of orientation of the elongated magnetic particles in the magnetic coating are thus obtained in a simple manner.
Inventors
- 👤 Hans Joerg Hartmann
- 👤 Guenter Vaeth
- 👤 Helmut Kopke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:08
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; G11B5/7028; G11B5/706; G11B5/70626; G11B5/70636; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/25; Y10T428/256
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
80 words
A magnetic recording media having high orientation ratios which comprises: (a) a polyethylene terephthalate base film; and (b) a magnetic coating on said film, said magnetic coating consisting essentially of elongated ferromagnetic chromium dioxide particles dispersed in a synthetic, organic, polymeric binder, the amount of said binder being about 0.13 to 0.5 parts per part by weight of chromium dioxide, said binder further containing from 0.5 to 6% by weight based on the amount of chromium dioxide of zinc oleate.
Claim 2
Dependent Claim
80 words
A magnetic recording media having high orientation ratios which comprises: (a) a polyethylene terephthalate base film; and (b) a magnetic coating on said film, said magnetic coating consisting essentially of elongated ferromagnetic chromium dioxide particles dispersed in a synthetic, organic, polymeric binder, the amount of said binder being about 0.13 to 0.5 parts per part by weight of chromium dioxide, said binder further containing from 0.5 to 6% by weight based on the amount of chromium dioxide of zinc oleate.
Claim 3
Dependent Claim
31 words
A magnetic recording media as set forth in claim 1 wherein the amount of zinc oleate is from 1 to 3% by weight based on the weight of said chromium dioxide.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-05-22 | 1981-11-21 | 1982-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-22 | 1985-11-21 | 1986-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-22 | 1989-11-21 | 1990-05-23 | $7700.00 | Window Closed / Lapsed |