Patent US5540062A successfully refreshed from Google Patents.
US4411966A
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Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1982-04-28
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Granted: 1983-10-25
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Expires: 2002-04-28
Abstract
Abstract The present invention relates to an improved magnetic recording medium comprising a magnetic recording layer on the surface of a non-magnetic support, in which the magnetic recording layer contains a fatty acid, high viscosity silicone oil and fatty acid ester.
Inventors
- 👤 Nobutaka Yamaguchi
- 👤 Nobuo Tsuji
- 👤 Yasutoshi Okuzawa
- 👤 Norio Nasu
- 👤 Masaaki Fujiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:38
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/71; Y; Y10; Y10S; Y10S428/00; Y10S428/90
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
94 words
A magnetic recording medium comprising a magnetic recording layer on the surface of a non-magnetic support, the magnetic recording layer comprising a ferromagnetic powder, 0.1 to 2% by weight based on the weight of the ferromagnetic powder of a saturated or unsaturated fatty acid having 6 to 22 carbon atoms, 0.01 to 1% by weight based on the weight of the ferromagnetic powder of a polysiloxane and 0.1 to 2% by weight based on the weight of the ferromagnetic powder of a fatty acid ester having a melting point of at most 60° C.
Claim 2
Dependent Claim
94 words
A magnetic recording medium comprising a magnetic recording layer on the surface of a non-magnetic support, the magnetic recording layer comprising a ferromagnetic powder, 0.1 to 2% by weight based on the weight of the ferromagnetic powder of a saturated or unsaturated fatty acid having 6 to 22 carbon atoms, 0.01 to 1% by weight based on the weight of the ferromagnetic powder of a polysiloxane and 0.1 to 2% by weight based on the weight of the ferromagnetic powder of a fatty acid ester having a melting point of at most 60° C.
Claim 3
Dependent Claim
36 words
The magnetic recording medium of claim 1, wherein the saturated or unsaturated fatty acid is selected from the group consisting of capric acid, lauric acid, myristic acid, oleic acid, stearic acid, erucic acid and behenic acid.
Claim 4
Dependent Claim
92 words
The magnetic recording medium of claim 1, wherein the magnetic recording layer contains a ferromagnetic powder selected from the group consisting of fine powders of γ-Fe 2 O 3 , Co-doped γ-Fe 2 O 3 , Fe 3 O 4 , Co-doped Fe 3 O 4 , Berthollide compounds of γ-Fe 2 O 3 and Fe 3 O 4 , Co-doped Berthollide compounds of γ-Fe 2 O 3 and Fe 3 O 4 , CrO 2 , Co-Ni-P alloys, Co-Ni-Fe alloys, Co-Ni-Fe-B alloys, Fe-Ni-Zn alloys, Fe-Mn-Zn alloys, Fe-Co-Ni-P alloys and Ni-Co alloys.
Claim 5
Dependent Claim
45 words
The magnetic recording medium of claim 1, wherein the fatty acid ester having a melting point of at most 60° C. is selected from the group consisting of methyl stearate, ethyl stearate, butyl stearate, amyl stearate, butyl palminate, butyl mysistate, oleyl oleate and butyl laurate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-10-24 | 1987-04-25 | 1987-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-24 | 1991-04-25 | 1991-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-24 | 1995-04-25 | 1995-10-25 | $7700.00 | Window Closed / Lapsed |