Patent US4487802A successfully refreshed from Google Patents.
US4487802A
Expired / Lapsed
US
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Magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1983-01-19
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Granted: 1984-12-11
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Expires: 2003-01-19
Abstract
Abstract A magnetic recording medium is disclosed. The medium is comprised of a non-magnetic flexible support having a subbing layer coated thereon with a magnetic layer coated on the subbing layer. The subbing layer is comprised of a copolymer of a diolefin and a vinyl monomer. The subbing layer provides excellent adhesiveness between the support and the magnetic layer and can be produced without the use of organic solvents. Accordingly, the subbing layer can be economically produced without environmental pollution.
Inventors
- 👤 Takahito Miyoshi
- 👤 Toshimitu Okutu
- 👤 Masaaki Fujiyama
- 👤 Sumitaka Tatsuta
- 👤 Nobuo Tsuji
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:15
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/73; G11B5/735; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/31504; Y10T428/31786; Y10T428/31797; Y10T428/31855; Y10T428/31931; Y10T428/31938
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
89 words
A magnetic recording medium comprising: a non-magnetic flexible support; a subbing layer having a thickness of from 0.01 to 1.0 μm coated on a surface of the support, wherein the subbing layer consists essentially of a copolymer of 10 to 60 wt% of a diolefin and 90 to 40 wt% of a styrene based on the weight of the copolymer and has a gel fraction of 60 wt% or more and a glass transition temperature of 90° C. or less; and a magnetic layer coated on the subbing layer.
Claim 2
Dependent Claim
89 words
A magnetic recording medium comprising: a non-magnetic flexible support; a subbing layer having a thickness of from 0.01 to 1.0 μm coated on a surface of the support, wherein the subbing layer consists essentially of a copolymer of 10 to 60 wt% of a diolefin and 90 to 40 wt% of a styrene based on the weight of the copolymer and has a gel fraction of 60 wt% or more and a glass transition temperature of 90° C. or less; and a magnetic layer coated on the subbing layer.
Claim 3
Dependent Claim
23 words
A magnetic recording medium as claimed in claim 1, wherein the diolefin is selected from the group consisting of butadiene, isoprene and chloroprene.
Claim 4
Dependent Claim
32 words
A magnetic recording medium as claimed in claim 1, wherein the diolefin is present in the copolymer in an amount of 15 to 40 wt% based on the weight of the copolymer.
Claim 5
Dependent Claim
32 words
A magnetic recording medium as claimed in claim 1, wherein the styrene is present within the copolymer in an amount of 70 to 40 wt% based on the weight of the copolymer.
Claim 6
Dependent Claim
22 words
A magnetic recording medium as claimed in claim 1, wherein the subbing layer has a thickness of from 0.1 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) | 1987-12-11 | 1988-06-11 | 1988-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-11 | 1992-06-11 | 1992-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-11 | 1996-06-11 | 1996-12-11 | $7700.00 | Window Closed / Lapsed |