US4579778A
Expired / Lapsed
US
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Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1984-04-25
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Granted: 1986-04-01
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Expires: 2004-04-25
Abstract
Abstract A magnetic recording medium is disclosed which comprises a non-magnetic support, having a Young's modulus of 7×10 10 to 1×10 13 dyn/cm 2 , having coated on opposite surfaces, a magnetic recording layer comprising ferromagnetic particles and a fatty acid ester and a backing layer comprising a cellulose resin.
Inventors
- 👤 Nobutaka Yamaguchi
- 👤 Norio Nasu
- 👤 Eiichi Tadokoro
- 👤 Masaaki Fujiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:07
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/71; G11B5/73; G11B5/735; G11B5/739; G11B5/73923; G11B5/73927; G11B5/73929; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/31504; Y10T428/31678; Y10T428/31786
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
63 words
A magnetic recording medium comprising a non-magnetic support, having a Young's modulus of 7×10 10 to 1×10 13 dyn/cm 2 , having coated on opposite surfaces, a magnetic recording layer comprising ferro-magnetic particles and a fatty acid ester and a backing layer comprising a cellulose resin, wherein said fatty acid ester is selected from the group consisting of butyl stearate and amyl stearate.
Claim 2
Dependent Claim
63 words
A magnetic recording medium comprising a non-magnetic support, having a Young's modulus of 7×10 10 to 1×10 13 dyn/cm 2 , having coated on opposite surfaces, a magnetic recording layer comprising ferro-magnetic particles and a fatty acid ester and a backing layer comprising a cellulose resin, wherein said fatty acid ester is selected from the group consisting of butyl stearate and amyl stearate.
Claim 3
Dependent Claim
26 words
The magnetic recording medium as claimed in claim 1, wherein said non-magnetic support has a Young's modulus of 8×10 10 to 8×10 11 dyn/cm 2 .
Claim 4
Dependent Claim
32 words
The magnetic recording medium as claimed in claim 1, wherein said non-magnetic support is comprised of a material selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polyamide, polyimide, and triacetylcellulose.
Claim 5
Dependent Claim
29 words
The magnetic recording medium as claimed in claim 3, wherein said non-magnetic support is comprised of a material selected from the group consisting of polyethylene terephthalate, polyamide and polyimide.
Claim 6
Dependent Claim
25 words
The magnetic recording medium as claimed in claim 1, wherein said non-magnetic support has provided thereon a vapor-deposited layer of aluminum, copper, nickel or zinc.
Claim 7
Dependent Claim
37 words
The magnetic recording medium as claimed in claim 1, wherein said fatty acid ester is employed in an amount of from 0.01 to 10 parts by weight based on 100 parts by weight of the ferromagnetic particles.
Claim 8
Dependent Claim
37 words
The magnetic recording medium as claimed in claim 6, wherein said fatty acid ester is employed in an amount of from 0.1 to 5 parts by weight based on 100 parts by weight of the ferromagnetic particles.
Claim 9
Dependent Claim
30 words
The magnetic recording medium as claimed in claim 1, wherein said cellulose resin is selected from the group consisting of cellulose acetate butyrate, cellulose acetate propionate, nitrocellulose, and mixtures thereof.
Claim 10
Dependent Claim
15 words
The magnetic recording medium as claimed in claim 8, wherein said cellulose resin is nitrocellulose.
Claim 11
Dependent Claim
32 words
The magnetic recording medium as claimed in claim 1, wherein said cellulose resin is contained in an amount of 5 to 100% by weight based on the total weight of the binder.
Claim 12
Dependent Claim
32 words
The magnetic recording medium as claimed in claim 10, wherein said cellulose resin is contained in an amount of 7 to 50% by weight based on the total weight of the binder.
Claim 13
Dependent Claim
32 words
The magnetic recording medium as claimed in claim 11, wherein said cellulose resin is contained in an amount of 10 to 25% by weight based on the total weight of the binder.
Claim 14
Dependent Claim
21 words
The magnetic recording medium as claimed in claim 1, wherein said backing layer has a thickness of 0.05 to 5 μm.
Claim 15
Dependent Claim
21 words
The magnetic recording medium as claimed in claim 13, wherein said backing layer has a thickness of 0.1 to 3 μm.
Claim 16
Dependent Claim
21 words
The magnetic recording medium as claimed in claim 14, wherein said backing layer has a thickness of 0.5 to 2 μm.
Claim 17
Dependent Claim
20 words
The magnetic recording medium as claimed in claim 1, wherein said Young's modulus is that measured in the machine direction.
Claim 18
Dependent Claim
24 words
The magnetic recording medium as claimed in claim 1, wherein said Young's modulus is that measured in the machine direction and the transverse direction.
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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) | 1989-03-31 | 1989-09-30 | 1990-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-31 | 1993-09-30 | 1994-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-31 | 1997-09-30 | 1998-04-01 | $7700.00 | Window Closed / Lapsed |