US4701375A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: TDK Corp
•
Filing: 1986-10-24
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Granted: 1987-10-20
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Expires: 2006-10-24
Abstract
Abstract A magnetic recording medium, comprising a non-magnetic substrate, a magnetic recording layer of ferromagnetic film formed on one side of said substrate, and a topcoat layer comprising an antioxidant and a lubricant and formed on the surface of said magnetic recording layer.
Inventors
- 👤 Masaharu Nishimatsu
- 👤 Suguru Takayama
- 👤 Hiroyuki Arioka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:15
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/72; G11B5/722; G11B5/725; G11B5/7253; G11B5/726; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
58 words
A magnetic recording medium comprising a non-magnetic substrate, a feromagnetic film of the non-binder type formed on one side of said substrate; and, on the surface of the magnetic recording layer, a topcoat layer from 10 anqstroms to 100 angstroms thick comprising a lubricant and an antioxidant which is a phosphoric ester of the type curable by radiation.
Claim 2
Dependent Claim
58 words
A magnetic recording medium comprising a non-magnetic substrate, a feromagnetic film of the non-binder type formed on one side of said substrate; and, on the surface of the magnetic recording layer, a topcoat layer from 10 anqstroms to 100 angstroms thick comprising a lubricant and an antioxidant which is a phosphoric ester of the type curable by radiation.
Claim 3
Dependent Claim
27 words
A magnetic recording medium according to claim 1, wherein the topcoat layer is formed by applying a mixture of said radiation curable phosphoric ester and said lubricant.
Claim 4
Dependent Claim
48 words
A magnetic recording medium according to claim 1, wherein the topcoat layer comprises two layers a first layer which is applied directly to the ferromagnetic film and contains the radiation curable phosphoric ester, and a second layer which is applied to the first layer and contains the lubricant.
Claim 5
Dependent Claim
15 words
A magnetic recording medium according to claim 1, wherein the lubricant is curable by radiation.
Claim 6
Dependent Claim
39 words
A magnetic recording medium according to claim 1, which further comprises a backcoat layer formed of an applied coat containing an inorganic pigment, an organic binder, and a lubricant and deposited on the opposite side of said non-magnetic substrate.
Claim 7
Dependent Claim
21 words
A magnetic recording medium according to claim 5, wherein said organic binder of said backcoat layer is of the curable type.
Claim 8
Dependent Claim
24 words
A magnetic recording medium according to claim 5, wherein said lubricant in said topcoat layer and said backcoat layer contains a radiation curable lubricant.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1990-10-19 | 1991-04-20 | 1991-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-19 | 1995-04-20 | 1995-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-19 | 1999-04-20 | 1999-10-20 | $7700.00 | Window Closed / Lapsed |