US4664964A
Expired / Lapsed
US
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Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1985-04-23
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Granted: 1987-05-12
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Expires: 2005-04-23
Abstract
Abstract A magnetic recording medium is described, comprising a non-magnetic support having coated thereon an intermediate layer and a magnetic layer having ferromagnetic particles dispersed in a binder, wherein the surface roughness of the coated surface of the support is 0.01 μm or more, the intermediate layer is formed by using a compound that is polymerizable by radiation exposure being exposed to radiation, and the magnetic layer is formed by using a compound as a binder that is polymerizable by electron beam exposure being exposed to an electron beam.
Inventors
- 👤 Tsutomu Okita
- 👤 Hiroshi Hashimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:48
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; G11B5/7026; G11B5/73; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24355; Y10T428/24372; Y10T428/24413; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/24975; Y10T428/31504; Y10T428/31551; Y10T428/31609; Y10T428/31855; Y10T428/31935
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
150 words
A magnetic recording medium comprising a non-magnetic support having coated thereon an intermediate layer and a magnetic layer having ferromagnetic particles dispersed in a binder, wherein the surface roughness of the coated surface of the support is 0.01 μm or more, the intermediate layer is formed by using a compound that is polymerizable by radiation exposure being exposed to radiation, and the magnetic layer is formed by using a compound as the binder that is polymerizable by electron beam exposure being exposed to an electron beam, wherein the magnetic layer is provided on the intermediate layer after subjecting the intermediate layer to exposure to radiation and further wherein the intermediate layer has a thickness of 0.5 to 1.2 μm, a surface roughness of 0.01 μm or less and wherein the compound is polymerizable by radiation exposure used to form the intermediate layer has a molecular weight of 500 to 10,000.
Claim 2
Dependent Claim
150 words
A magnetic recording medium comprising a non-magnetic support having coated thereon an intermediate layer and a magnetic layer having ferromagnetic particles dispersed in a binder, wherein the surface roughness of the coated surface of the support is 0.01 μm or more, the intermediate layer is formed by using a compound that is polymerizable by radiation exposure being exposed to radiation, and the magnetic layer is formed by using a compound as the binder that is polymerizable by electron beam exposure being exposed to an electron beam, wherein the magnetic layer is provided on the intermediate layer after subjecting the intermediate layer to exposure to radiation and further wherein the intermediate layer has a thickness of 0.5 to 1.2 μm, a surface roughness of 0.01 μm or less and wherein the compound is polymerizable by radiation exposure used to form the intermediate layer has a molecular weight of 500 to 10,000.
Claim 3
Dependent Claim
30 words
A magnetic recording medium as in claim 1, wherein the compound used in forming the intermediate layer is a compound having at least one carbon-carbon unsaturated bond per monomer molecule.
Claim 4
Dependent Claim
33 words
A magnetic recording medium as in claim 2, wherein the compound used in forming the intermediate layer is an acrylate compound having at least two methacryloyl groups or acryloyl groups per monomer molecule.
Claim 5
Dependent Claim
31 words
A magnetic recording medium as in claim 1, wherein the compound used in forming the intermediate layer is a compound selected from the group consisting of polyesterpolyacrylate oligomers and polyetherpolyacrylate oligomers.
Claim 6
Dependent Claim
21 words
A magnetic recording medium as in claim 1, wherein the magnetic layer has a thickness of from 1.5 to 10 μm.
Claim 7
Dependent Claim
34 words
A magnetic recording medium as in claim 1, wherein the compound used in forming the magnetic layer is at least one compound selected from the group consisting of urethane acrylate oligomers and acrylate monomers.
Claim 8
Dependent Claim
22 words
A magnetic recording medium as in claim 6, wherein the urethane acrylate oligomer has a molecule weight of from 3,000 to 50,000.
Claim 9
Dependent Claim
23 words
A magnetic recording medium as in claim 6, wherein the acrylate monomer has at least two acryloyl or methacryloyl groups per monomer molecule.
Claim 10
Dependent Claim
24 words
A magnetic recording medium as in claim 6, wherein the compounds used in forming the magnetic layer are urethane acrylate oligomers and acrylate monomers.
Claim 11
Dependent Claim
41 words
A magnetic recording medium as in claim 1, wherein the binder for the magnetic layer comprises (1) a cellulose type resin or a vinyl chloride-vinyl acetate type resin, (2) a urethane resin or a urethane acrylate oligomer, and (3) a monomer.
Claim 12
Dependent Claim
22 words
A magnetic recording medium as in claim 10, wherein a cellulose type resin is nitrocellulose, cellulose acetate butyrate or cellulose acetate propionate.
Claim 13
Dependent Claim
50 words
A magnetic recording medium as in claim 10, wherein the monomer is selected from the group consisting of acrylic acid esters, acrylamides, methacrylic acid esters, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, heterocyclic vinyl compounds, N-vinyl compounds, styrenes, acrylic acid, methacrylic acid, crotonic acids, itaconic acids, olefins and the like.
Claim 14
Dependent Claim
41 words
A magnetic recording medium as in claim 10, wherein the amount of components (1), (2), and (3) is from 25 to 70 parts by weight, from 10 to 40 parts by weight, and from 10 to 60 parts by weight, respectively.
Claim 15
Dependent Claim
24 words
A magnetic recording medium as in claim 9, wherein the weight ratio of urethane acrylate oligomer to acrylate monomer is from 60/40 to 90/10.
Claim 16
Dependent Claim
24 words
A magnetic recording medium as in claim 9, wherein the weight ratio of urethane acrylate oligomer to acrylate monomer is from 70/30 to 85/15.
Claim 17
Dependent Claim
26 words
A magnetic recording medium as in claim 1, wherein the surface roughness of the coated surface of the support is from 0.015 μm to 0.5 μm.
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 |