US4305993A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Maxell Ltd
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Filing: 1980-10-07
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Granted: 1981-12-15
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Expires: 2000-10-07
Abstract
Abstract A magnetic recording medium which comprises a base material and a magnetic layer provided on its surface, said magnetic layer comprising metallic magnetic particles, a binder and a salt of lanolin fatty acid wherein the oxidation resistance of the metallic magnetic particles is highly improved and the metallic magnetic particles are in a good dispersion state so that the magnetic recording medium shows an increased maximum magnetic flux density is disclosed.
Inventors
- 👤 Hiroshi Zaitsu
- 👤 Shigeyuki Hosoo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:40
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/712; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/25; Y10T428/256; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
54 words
A magnetic recording medium which comprises a base material and a magnetic layer provided on its surface, said magnetic layer comprising metallic magnetic particles, a synthetic resin binder and a salt of lanolin fatty acid in an amount of 0.7 to 5% by weight on the basis of the weight of the metallic particles.
Claim 2
Dependent Claim
54 words
A magnetic recording medium which comprises a base material and a magnetic layer provided on its surface, said magnetic layer comprising metallic magnetic particles, a synthetic resin binder and a salt of lanolin fatty acid in an amount of 0.7 to 5% by weight on the basis of the weight of the metallic particles.
Claim 3
Dependent Claim
20 words
The magnetic recording medium according to claim 1, wherein the metallic magnetic particles comprise metallic iron as the main component.
Claim 4
Dependent Claim
19 words
The magnetic recording medium according to claim 1, wherein the salt of lanolin fatty acid is the calcium salt.
Claim 5
Dependent Claim
25 words
The magnetic recording medium according to claim 1, wherein the metallic magnetic particles are coated with the salt of lanolin fatty acid on the surfaces.
Claim 6
Dependent Claim
59 words
Coated particles useful for the preparation of a magnetic coating composition for magnetic recording media comprising synthetic resin binder and metallic magnetic particles comprising metallic magnetic particles the surfaces of which are coated with a salt of lanolin fatty acid in an amount of 0.7 to 5% by weight on the basis of the weight of the metallic particles.
Claim 7
Dependent Claim
59 words
Coated particles useful for the preparation of a magnetic coating composition for magnetic recording media comprising synthetic resin binder and metallic magnetic particles comprising metallic magnetic particles the surfaces of which are coated with a salt of lanolin fatty acid in an amount of 0.7 to 5% by weight on the basis of the weight of the metallic particles.
Claim 8
Dependent Claim
19 words
The metallic magnetic particles according to claim 5, wherein the salt of lanolin fatty acid is the calcium salt.
Claim 9
Dependent Claim
32 words
A process for preparing the metallic magnetic particles according to claim 5, which comprises admixing metallic magnetic particles with a solution of a salt of lanolin fatty acid in an organic solvent.
Claim 10
Dependent Claim
18 words
The process according to claim 7, wherein the metallic magnetic particles comprise metallic iron as the main component.
Claim 11
Dependent Claim
17 words
The process according to claim 7, wherein the salt of lanolin fatty acid is the calcium salt.
Claim 12
Dependent Claim
12 words
The process according to claim 7, wherein the organic solvent is toluene.
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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) | 1984-12-14 | 1985-06-15 | 1985-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-14 | 1989-06-15 | 1989-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-14 | 1993-06-15 | 1993-12-15 | $7700.00 | Window Closed / Lapsed |