US4666784A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Toyobo Co Ltd
•
Filing: 1986-07-21
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Granted: 1987-05-19
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Expires: 2006-07-21
Abstract
Abstract A magnetic recording medium having a magnetic layer of superior smoothness and excellent abrasion resistance and durability. The magnetic layer contains a polyurethane resin having a metal sulfonate group in the amount of 10-1000 equivalents/106g of the polymer; an ester of C10-C18 fatty acid with butyl cellosolve and ferromagnetic fine particles.
Inventors
- 👤 Chyuji Inukai
- 👤 Eizi Chino
- 👤 Yoshio Tojima
- 👤 Hideki Komagata
- 👤 Masanori Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:56
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/708; G11B5/702; G11B5/7021; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/25; Y10T428/30; Y10T428/31504; Y10T428/31551; Y10T428/31609; Y10T428/31971
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
71 words
A magnetic recording medium characterized in that a magnetic layer containing (A) a polyurethane resin having a metal sulfonate group of 10 to 1000 equivalents/10 6 g of the polymer, (B) one or more members selected from the esters of C 10 -C 18 fatty acids with butyl cellosolve and (C) ferromagnetic fine particles, the ratio of (B) to (A) being 1 to 20 wt.%, is applied to a non-magnetic substrate.
Claim 2
Dependent Claim
71 words
A magnetic recording medium characterized in that a magnetic layer containing (A) a polyurethane resin having a metal sulfonate group of 10 to 1000 equivalents/10 6 g of the polymer, (B) one or more members selected from the esters of C 10 -C 18 fatty acids with butyl cellosolve and (C) ferromagnetic fine particles, the ratio of (B) to (A) being 1 to 20 wt.%, is applied to a non-magnetic substrate.
Claim 3
Dependent Claim
27 words
A magnetic recording medium as claimed in claim 1, wherein the magnetic layer contains the cyclic trimer of hexamethylenediisocyanate of 5 to 100 wt.% based on (A).
Claim 4
Dependent Claim
17 words
A magnetic recording medium as claimed in claim 1, wherein (B) is n-butylcellosolve palmitate or n-butylcellosolve stearate.
Claim 5
Dependent Claim
23 words
A magnetic recording medium as claimed in claim 1, wherein the magnetic layer contains nitrocellulose of 3 to 200 wt.% based on (A).
Claim 6
Dependent Claim
28 words
A magnetic recording medium as claimed in claim 1, wherein the magnetic layer contains fine particles of carbon and/or graphite of 3 to 16 wt.% based on (A).
Claim 7
Dependent Claim
36 words
A magnetic recording medium as claimed in claim 1, wherein the magentic layer contains fine particles of a non-magnetic substrate having a Mohs' hardness of 6 or more of 5 to 30 wt.% based on (A).
Claim 8
Dependent Claim
18 words
A magnetic recording medium as claimed in claim 1 which is a flexible and disc-like magnetic recording medium.
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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) | 1990-05-18 | 1990-11-17 | 1991-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-18 | 1994-11-17 | 1995-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-18 | 1998-11-17 | 1999-05-19 | $7700.00 | Window Closed / Lapsed |