Patent US2748753A successfully refreshed from Google Patents.
Patent US4634627A successfully refreshed from Google Patents.
US4634627A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium comprising a surface-treated abrasive
Assignee: Victor Company of Japan Ltd
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Filing: 1985-11-08
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Granted: 1987-01-06
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Expires: 2005-11-08
Abstract
Abstract A magnetic recording medium comprising a nonmagnetic support, and a magnetic recording layer formed on said support. The magnetic recording layer comprises a magnetic powder and an abrasive powder dispersed in a resin binder. The abrasive powder has a coating of an isocyanate compound having at least two isocyanate groups in one molecule thereof and is used in an amount of from 0.5 to 20 parts by weight per 100 parts by weight of the magnetic powder.
Inventors
- 👤 Kuniharu Fujiki
- 👤 Hiroshi Togashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:29
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/708; G11B5/7085; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/25; Y10T428/256; Y10T428/257; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998; Y10T428/31504; Y10T428/31551; Y10T428/31609
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
83 words
A magnetic recording medium comprising a nonmagnetic support, and a magnetic recording layer formed on said support, said magnetic recording layer being formed of a composition which comprises a magnetic powder and an abrasive powder dispersed in a resin binder, said abrasive powder having a coating of an isocyanate compound having at least two isocyanate groups in one molecule thereof and being used in an amount of from 0.5 to 20 parts by weight per 100 parts by weight of said magnetic powder.
Claim 2
Dependent Claim
83 words
A magnetic recording medium comprising a nonmagnetic support, and a magnetic recording layer formed on said support, said magnetic recording layer being formed of a composition which comprises a magnetic powder and an abrasive powder dispersed in a resin binder, said abrasive powder having a coating of an isocyanate compound having at least two isocyanate groups in one molecule thereof and being used in an amount of from 0.5 to 20 parts by weight per 100 parts by weight of said magnetic powder.
Claim 3
Dependent Claim
27 words
A magnetic recording medium according to claim 1, wherein said abrasive powder is a metal oxide powder having an average size of from 0.2 to 1 μm.
Claim 4
Dependent Claim
17 words
A magnetic recording medium according to claim 2, wherein said metal oxide powder is chromium oxide powder.
Claim 5
Dependent Claim
30 words
A magnetic recording medium according to claim 1, wherein said isocyanate compound is a member selected from the group consisting of compounds of the following formulas (1) through (5) ##STR2##
Claim 6
Dependent Claim
20 words
A magnetic recording medium according to claim 4, wherein said isocyanate compound is a compound of the following formula ##STR3##
Claim 7
Dependent Claim
28 words
A magnetic recording medium according to claim 1, wherein said isocyanate compound is coated in an amount of from 3 to 20 wt% of said metal oxide powder.
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) | 1990-01-05 | 1990-07-07 | 1991-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-05 | 1994-07-07 | 1995-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-05 | 1998-07-07 | 1999-01-06 | $7700.00 | Window Closed / Lapsed |