US4546044A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Konica Minolta Inc
•
Filing: 1983-04-18
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Granted: 1985-10-08
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Expires: 2003-04-18
Abstract
Abstract A magnetic recording medium having a magnetic layer containing a urethane resin having a tensile strength of less than 200 kg/cm 2 and an elongation at break of 900% or more, and another urethane resin having a tensile strength of 200 kg/cm 2 or more and an elongation at break of less than 900%. This recording medium has good surface properties, good magnetic particles' orientation, great durability, and high wear resistance and produces high output.
Inventors
- 👤 Masao Asano
- 👤 Tetsuro Sunaga
- 👤 Hideki Murata
- 👤 Kazumasa Matsumoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:52
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31511; Y10T428/31551; Y10T428/31609; Y10T428/31971
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
74 words
A magnetic recording medium having a magnetic layer containing a urethane resin having a tensile strength of less than 175 kg/cm 2 and an elongation at break of 1000% or more, and another urethane resin having a tensile strength of 225 kg/cm 2 or more and an elongation at break of less than 800% wherein the mixing ratio of said urethane to said another urethane is from 80:20 to 20:80 on a weight basis.
Claim 2
Dependent Claim
74 words
A magnetic recording medium having a magnetic layer containing a urethane resin having a tensile strength of less than 175 kg/cm 2 and an elongation at break of 1000% or more, and another urethane resin having a tensile strength of 225 kg/cm 2 or more and an elongation at break of less than 800% wherein the mixing ratio of said urethane to said another urethane is from 80:20 to 20:80 on a weight basis.
Claim 3
Dependent Claim
17 words
A magnetic recording medium according to claim 1 wherein said magnetic layer further includes a cellulosic resin.
Claim 4
Dependent Claim
14 words
A magnetic recording medium according to claim 2 wherein said cellulosic resin is nitrocellulose.
Claim 5
Dependent Claim
21 words
A magnetic recording medium according to claim 1 wherein said magnetic layer further includes an epoxy resin or a derivative thereof.
Claim 6
Dependent Claim
20 words
A magnetic recording medium according to claim 4 wherein said epoxy resin is a bisphenol A diglycidyl ether type polymer.
Claim 7
Dependent Claim
19 words
A magnetic recording medium according to claim 4 wherein said epoxy resin derivative is a polyhydroxy ether type polymer.
Claim 8
Dependent Claim
15 words
A magentic recording medium according to claim 6 wherein said polymer is a phenoxy resin.
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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) | 1988-10-07 | 1989-04-08 | 1989-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-07 | 1993-04-08 | 1993-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-07 | 1997-04-08 | 1997-10-08 | $7700.00 | Window Closed / Lapsed |