Patent US4684572A successfully refreshed from Google Patents.
US4684572A
Expired / Lapsed
US
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Magnetic recording medium
Assignee: Konica Minolta Inc
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Filing: 1985-04-23
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Granted: 1987-08-04
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Expires: 2005-04-23
Abstract
Abstract A magnetic recording medium having a magnetic layer and a backing layer on opposite sides of a support is disclosed. The backing layer comprises a binder resin, a conductive carbon black and an organic powder.
Inventors
- 👤 Yoshitaka Yasufuku
- 👤 Masaji Nara
- 👤 Shigeru Akutsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:30
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/73; G11B5/735; G11B5/7356; G11B5/7358; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/25; Y10T428/254; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
123 words
A magnetic recording medium comprising a support, a magnetic layer on said support and a backing coat layer formed on the other side of said support, wherein said backing layer consists essentially of a binder resin, a conductive carbon black having a mean particle size of from 0.02 μm to 0.029 μm in the range of 25% to 100% by weight of said binder, an organic powder having a mean particle size of from 0.01 μm to 0.5 μm in the range of 1% to 50% by weight of said binder, and said backing layer having a surface roughness in the range of 0.005 μm to 0.035 μm and an electric resistivity in the range of 10Ω cm to 10 6 Ω cm.
Claim 2
Dependent Claim
123 words
A magnetic recording medium comprising a support, a magnetic layer on said support and a backing coat layer formed on the other side of said support, wherein said backing layer consists essentially of a binder resin, a conductive carbon black having a mean particle size of from 0.02 μm to 0.029 μm in the range of 25% to 100% by weight of said binder, an organic powder having a mean particle size of from 0.01 μm to 0.5 μm in the range of 1% to 50% by weight of said binder, and said backing layer having a surface roughness in the range of 0.005 μm to 0.035 μm and an electric resistivity in the range of 10Ω cm to 10 6 Ω cm.
Claim 3
Dependent Claim
25 words
The magnetic recording medium of claim 1, wherein oil-absorbing amount of said carbon black is in the range of from 90ml/100 g to 500ml/100 g.
Claim 4
Dependent Claim
17 words
The magnetic recording medium of claim 1, wherein said binder contains a urethane resin and a isocyanate.
Claim 5
Dependent Claim
13 words
The magnetic recording medium of claim 3, wherein said binder contains a nitrocellurose.
Claim 6
Dependent Claim
25 words
The magnetic recording medium of claim 1, wherein said backing coat layer has the thickness in the range of from 0.1 μm to 1.5 μm.
Claim 7
Dependent Claim
40 words
The magnetic recording medium of claim 1 wherein said organic powder is selected from the group consisting of benzoguanamine resin powder, melamine resin powder, phthalocyanine resin powder, polyolefin resin powder, polyester resin powder, polyamide resin powder and polyimide resin powder.
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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) | 1990-08-03 | 1991-02-02 | 1991-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-03 | 1995-02-02 | 1995-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-03 | 1999-02-02 | 1999-08-04 | $7700.00 | Window Closed / Lapsed |