US5104750A
Expired / Lapsed
US
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Magnetic recording medium
Assignee: Toshiba Corp
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Filing: 1990-03-30
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Granted: 1992-04-14
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Expires: 2010-03-30
Abstract
Abstract In the magnetic recording medium according to the present invention comprising a magnetic recording medium layer where a magnetic paint containing Ba ferrite magnetic powder is coated on the substrate, Hc in the oriented direction ranging from 900 to 1500 Oe, the squareness in the oriented direction being 0.80 or more, and the ratio Hr(90°)/Hr(0°) of the remanence coercive force Hr(0°) in the oriented direction (0°) and the remanence coercive force Hr (90°) in the direction (90°) perpendicular to the oriented direction ranging from 1<Hr(90°)/Hr(0°)≦2.6-10 -3 . Hc are controllable.
Inventors
- 👤 Osamu Kubo
- 👤 Tutomu Nomura
- 👤 Tadashi Ido
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:12
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/706; G11B5/70626; G11B5/70642; G11B5/70678; Y; Y10; Y10S; Y10S428/00; Y10S428/90
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
91 words
A magnetic recording medium having a Ba ferrite coated magnetic recording material layer oriented vertically on the surface of a substrate or in the surface direction thereof, wherein the coercive force Hc in the oriented direction ranges from 900 Oe to 1500 Oe, the squareness in the oriented direction is 0.80 or more, and the ratio of the remanence coercive force Hr(0°) in the oriented direction (0°) and the remanence coercive force Hr(90°) in the direction (90°) perpendicular to the oriented direction is in the following range: 1<Hr(90°) / Hr(0°)≦2.6-10.sup.-3 ·Hc
Claim 2
Dependent Claim
91 words
A magnetic recording medium having a Ba ferrite coated magnetic recording material layer oriented vertically on the surface of a substrate or in the surface direction thereof, wherein the coercive force Hc in the oriented direction ranges from 900 Oe to 1500 Oe, the squareness in the oriented direction is 0.80 or more, and the ratio of the remanence coercive force Hr(0°) in the oriented direction (0°) and the remanence coercive force Hr(90°) in the direction (90°) perpendicular to the oriented direction is in the following range: 1<Hr(90°) / Hr(0°)≦2.6-10.sup.-3 ·Hc
Claim 3
Dependent Claim
58 words
The magnetic recording medium of claim 1, wherein the Ba ferrite is represented by the general formula; BaO·n{(Fe.sub.1-m M.sub.m).sub.2 O.sub.3 } (wherein M is at least one element selected from Co, Ti, Zn, Sn, Ni, Mn, In, Cu, Ge, Zr, Hf, V, Ta, Al, Cr, and Sb; m is 0.2 or less; and n is 5 or more).
Claim 4
Dependent Claim
41 words
The magnetic recording medium of claim 1, wherein the magnetic recording material layer is formed by coating the substrate with a magnetic paint, the magnetic paint comprising at least a Ba ferrite magnetic powder and a binder dissolved in a solvent.
Claim 5
Dependent Claim
20 words
The magnetic recording medium of claim 3, the magnetic paint further comprising a dispersing agent, a lubricant, and an abrasive.
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) | 1995-04-14 | 1995-10-14 | 1996-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-04-14 | 1999-10-14 | 2000-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-04-14 | 2003-10-14 | 2004-04-14 | $7700.00 | Window Closed / Lapsed |