Patent US4759954A successfully refreshed from Google Patents.
US4759954A
Expired / Lapsed
US
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Magnetic recording medium and preparation
Assignee: TDK Corp
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Filing: 1986-12-08
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Granted: 1988-07-26
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Expires: 2006-12-08
Abstract
Abstract In a magnetic recording medium comprising a substrate and a magnetic layer thereon, the magnetic layer is formed by coating a composition of a binder, preferably radiation-curable binder and a needle magnetic material, passing the coating through a magnetic field to forcedly re-orient the magnetic particles to form pores having an average pore area of 6×10 -5 to 7×10 -1 μm 2 , and curing the coating, thereby minimizing output fluctuation and improving durability. Preferably lubricant is present in the pores.
Inventors
- 👤 Yuichi Kubota
- 👤 Yasufumi Takasugi
- 👤 Yousuke Hitomi
- 👤 Tsunehiko Ikarashi
- 👤 Fuminori Tokuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:09
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/71; G11B5/702; G11B5/7026; G11B5/84; G11B5/842; G11B5/845; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249955
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
69 words
A method for preparing a disk-shaped magnetic recording medium, comprising: applying a magnetic coating composition comprising a needle magnetic material and a binder to a nonmagnetic flexible resin substrate to form a magnetic layer, and subjecting the magnetic layer to random orientation to form therein pores having an average pore area of 6×10 -5 to 7×10 -1 μm 2 , and punching the coated substrate into a disk shape.
Claim 2
Independent Claim
69 words
A method for preparing a disk-shaped magnetic recording medium, comprising: applying a magnetic coating composition comprising a needle magnetic material and a binder to a nonmagnetic flexible resin substrate to form a magnetic layer, and subjecting the magnetic layer to random orientation to form therein pores having an average pore area of 6×10 -5 to 7×10 -1 μm 2 , and punching the coated substrate into a disk shape.
Claim 3
Dependent Claim
29 words
A method for preparing a disk-shaped magnetic recording medium according to claim 1, further comprising curing said randomly oriented magnetic layer at temperature between 50° C. and 80° C.
Claim 4
Independent Claim
75 words
A method for preparing a disk-shaped magnetic recording medium, comprising: applying a magnetic coating composition comprising a needle magnetic material and a binder to a nonmagnetic flexible-resin substrate to form a magnetic layer, subjecting the magnetic layer to random orientation to form therein pores with an average pore area of 6×10 -5 to 7×10 -1 μm 2 , applying a lubricant at least into the pores, and punching the coated substrate into a disk shape.
Claim 5
Independent Claim
75 words
A method for preparing a disk-shaped magnetic recording medium, comprising: applying a magnetic coating composition comprising a needle magnetic material and a binder to a nonmagnetic flexible-resin substrate to form a magnetic layer, subjecting the magnetic layer to random orientation to form therein pores with an average pore area of 6×10 -5 to 7×10 -1 μm 2 , applying a lubricant at least into the pores, and punching the coated substrate into a disk shape.
Claim 6
Dependent Claim
29 words
A method for preparing a disk-shaped magnetic recording medium according to claim 3, further comprising curing said randomly oriented magnetic layer at temperatures between 50° C. and 80° C.
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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) | 1991-07-26 | 1992-01-25 | 1992-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-26 | 1996-01-25 | 1996-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-26 | 2000-01-25 | 2000-07-26 | $7700.00 | Window Closed / Lapsed |