Patent US4309482A successfully refreshed from Google Patents.
US4309482A
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US
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Magnetic recording medium
Assignee: Panasonic Holdings Corp
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Filing: 1979-07-19
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Granted: 1982-01-05
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Expires: 1999-07-19
Abstract
Abstract A thin film type magnetic recording medium having a coating of ultraviolet ray setting epoxy resin containing a lubricant at least on one major surface. Degradation of resistance to wear may be minimized and stable recording and reproduction characteristics may be ensured even at high temperatures and at high humidity.
Inventors
- 👤 Takashi Suzuki
- 👤 Isao Sumita
- 👤 Akihiro Imai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:30
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/72; G11B5/725; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31511; Y10T428/31652; Y10T428/31663
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
68 words
A magnetic recording medium comprising a thin ferromagnetic film on a base and at least one surface of said magnetic recording medium being coated with a thin film of an ultraviolet ray hardened coating, said coating before ultraviolet ray hardening consisting essentially of unreacted epoxy resin, aromatic diazonium salts of complexes of halides which form a Lewis acid when irradiated by ultraviolet rays, a gelation inhibitor and lubricant.
Claim 2
Dependent Claim
68 words
A magnetic recording medium comprising a thin ferromagnetic film on a base and at least one surface of said magnetic recording medium being coated with a thin film of an ultraviolet ray hardened coating, said coating before ultraviolet ray hardening consisting essentially of unreacted epoxy resin, aromatic diazonium salts of complexes of halides which form a Lewis acid when irradiated by ultraviolet rays, a gelation inhibitor and lubricant.
Claim 3
Dependent Claim
34 words
A magnetic recording medium as set forth in claim 1 further characterized in that said lubricant is selected from the group consisting of aliphatic esters of polyhydric alcohols, denatured silicone and denatured fluoride oil.
Claim 4
Dependent Claim
19 words
A magnetic recording medium as set forth in claim 2 wherein the lubricant is pentaerythritol stearate or denatured silicone.
Claim 5
Dependent Claim
43 words
A magnetic recording medium as set forth in claim 1 further characterized in that said unreacted epoxy resins contain cyclic aliphatic type epoxy resins in a quantity more than one half by weight based on the total weight of said unreacted epoxy resins.
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) | 1985-01-04 | 1985-07-06 | 1986-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-01-04 | 1989-07-06 | 1990-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-01-04 | 1993-07-06 | 1994-01-05 | $7700.00 | Window Closed / Lapsed |