US4411953A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1982-01-19
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Granted: 1983-10-25
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Expires: 2002-01-19
Abstract
Abstract A magnetic recording medium having a magnetic layer on one surface of a nonmagnetic base and a back coating on the opposite surface is disclosed. An undercoat is formed between the nonmagnetic base and the back coating and the back coating is not thicker than 2 mu .
Inventors
- 👤 Takahito Miyoshi
- 👤 Nobuo Tsuji
- 👤 Toshimitu Okutu
- 👤 Masaaki Fujiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:54
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/73; G11B5/735; G11B5/739; G11B5/73923; G11B5/73927; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
78 words
A magnetic recording medium, comprising: a non-magnetic support base; a magnetic layer provided on a first surface of said support base; an undercoat formed on a second surface of said support base opposite said first surface, said undercoat having a thickness of 0.4μ or less; and a back coating on said undercoat, said back coating having a thickness of 0.2-2μ; and comprising a particulate inorganic substance and a binder contained in a weight ratio of 2.5:1 to 0.1:1.
Claim 2
Dependent Claim
78 words
A magnetic recording medium, comprising: a non-magnetic support base; a magnetic layer provided on a first surface of said support base; an undercoat formed on a second surface of said support base opposite said first surface, said undercoat having a thickness of 0.4μ or less; and a back coating on said undercoat, said back coating having a thickness of 0.2-2μ; and comprising a particulate inorganic substance and a binder contained in a weight ratio of 2.5:1 to 0.1:1.
Claim 3
Dependent Claim
22 words
A magnetic recording medium, as claimed in claim 1, wherein said undercoat has a glass transition temperature of 70° C. or less.
Claim 4
Dependent Claim
16 words
A magnetic recording medium, as claimed in claim 1, wherein said ratio is 1.5:1 to 0.8:1.
Claim 5
Dependent Claim
30 words
A magnetic recording medium, as claimed in claim 1, wherein said nonmagnetic base comprises a polyester and said undercoat comprises a saturated polyester resin intimately contacted with said support base.
Claim 6
Dependent Claim
23 words
A magnetic recording medium, as claimed in claim 1, wherein said back coating thickness is within the range of from 0.4 to 1.0μ.
Claim 7
Dependent Claim
23 words
A magnetic recording medium, as claimed in claim 5, wherein said back coating thickness is within the range of from 0.5 to 0.8μ.
Claim 8
Dependent Claim
35 words
A magnetic recording medium, as claimed in claim 1, wherein said undercoat comprises a soft polymer having a lower modulus of elasticity than the modulus of elasticity of said back coating and said nonmagnetic base.
Claim 9
Dependent Claim
23 words
A magnetic recording medium as claimed in claim 1, wherein said undercoat has a thickness within the range of from 0.1 to 0.2μ.
References Cited (Backward Citations)
US4135032A
Cited
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 |