US4664965A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1984-12-20
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Granted: 1987-05-12
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Expires: 2004-12-20
Abstract
Abstract A magnetic recording medium is disclosed, which comprises a non-magnetic support having a surface roughness of not less than 0.01 μm having thereon an intermediate layer and a magnetic layer, the intermediate layer comprising a polyester polyol having at least two acryloyl and/or methacryloyl groups in the molecule thereof, which has been polymerization-hardened by exposure to radiation. The magnetic recording medium has markedly improved video sensitivity, C/N ratio and adhesiveness between the support and the magnetic layer.
Inventors
- 👤 Tsutomu Okita
- 👤 Hiroshi Hashimoto
- 👤 Yoshito Mukaida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:37
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/73; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24355; Y10T428/24372; Y10T428/24413; Y10T428/24942; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/31504; Y10T428/31551; Y10T428/31609; Y10T428/31855; Y10T428/31935
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
84 words
A magnetic recording medium comprising a non-magnetic support having a surface roughness of not less than 0.01 μm and a magnetic layer, and an intermediate layer between the support and the magnetic layer which comprises a polyester polyol having at least two acryloyl and/or methacryloyl groups in the molecule thereof which has been polymerization-hardened by exposure to radiation, wherein the surface roughness of the intermediate layer is less and 0.01 μm and wherein the polyester polyol has a molecular weight of 500 to 5,000.
Claim 2
Dependent Claim
84 words
A magnetic recording medium comprising a non-magnetic support having a surface roughness of not less than 0.01 μm and a magnetic layer, and an intermediate layer between the support and the magnetic layer which comprises a polyester polyol having at least two acryloyl and/or methacryloyl groups in the molecule thereof which has been polymerization-hardened by exposure to radiation, wherein the surface roughness of the intermediate layer is less and 0.01 μm and wherein the polyester polyol has a molecular weight of 500 to 5,000.
Claim 3
Dependent Claim
22 words
The magnetic recording medium as claimed in claim 1, wherein the surface roughness of the support is from 0.015 to 0.5 μm.
Claim 4
Dependent Claim
18 words
The magnetic recording medium as claimed in claim 1, wherein the radiation is electron beam or ultraviolet radiation.
Claim 5
Dependent Claim
17 words
The magnetic recording medium as claimed in claim 1, wherein said polyester polyol is a polyester diacrylate.
Claim 6
Dependent Claim
21 words
The magnetic recording medium as claimed in claim 1, wherein the thickness of the intermediate layer is 0.1 to 2 μm.
Claim 7
Dependent Claim
21 words
The magnetic recording medium as claimed in claim: 5, wherein the thickness of the intermediate layer is 0.1 to 1.5 μm.
Claim 8
Dependent Claim
36 words
The magnetic recording medium as claimed in claim 1, wherein the radiation is electron beam irradiation, the thickness of the intermediate layer is 0.1 to 2μ, and the magnetic layer comprises ferromagnetic particles and a binder.
Claim 9
Dependent Claim
30 words
The magnetic recording medium as claimed in claim 1, wherein the intermediate layer further comprises a monomer polymerizable by radiation exposure which has a molecular weight of less than 500.
Claim 10
Dependent Claim
20 words
The magnetic recording medium as claimed in claim 8, wherein the monomer has a molecular weight of less than 300.
Claim 11
Dependent Claim
33 words
The magnetic recording medium as claimed in claim 8, wherein the amount of the monomer is 10 to 60 wt % based on the total amount of the monomer and the polyester polyol.
Claim 12
Dependent Claim
33 words
The magnetic recording medium as claimed in claim 10, wherein the amount of the mcnomer is 15 to 50 wt % based on the total amount of the monomer and the polyester polyol.
Claim 13
Dependent Claim
19 words
The magnetic recording medium as claimed in claim 1, wherein the magnetic layer comprises ferromagnetic particles and a binder.
Claim 14
Dependent Claim
19 words
The magnetic recording medium as claimed in claim 1, wherein the magnetic layer is a ferromagnetic thin metal film.
Claim 15
Dependent Claim
45 words
The magnetic recording medium as claimed in claim 1, wherein a back coating layer is provided on the surface of the support opposite the surface which carries the magnetic layer where the surface roughness of the back coating layer is not less than 0.01 μm.
Claim 16
Dependent Claim
45 words
The magnetic recording medium as claimed in claim 1, wherein a back coating layer is provided on the surface of the support opposite the surface which carries the magnetic layer where the surface roughness of the back coating layer is not less than 0.015 μm.
Claim 17
Dependent Claim
17 words
The magnetic recording medium as claimed in claim 7, wherein the polyester polyol is a polyester diacrylate.
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) | 1990-05-11 | 1990-11-10 | 1991-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-11 | 1994-11-10 | 1995-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-11 | 1998-11-10 | 1999-05-12 | $7700.00 | Window Closed / Lapsed |