US4828905A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording medium
Assignee: Proterial Ltd
•
Filing: 1987-06-11
•
Granted: 1989-05-09
•
Expires: 2007-06-11
Abstract
Abstract In a magnetic recording medium in which a metallic base layer and a magnetic layer are provided on a nonmagnetic nonmetallic substrate, an intermediate layer is additionally formed between the substrate and the metallic base layer in order to improve peeling-off resistance of the metallic base layer for durability against magnetic head contact-start-stop operation. The intermediate layer is a metal oxide layer including at least one of specified elements, or a composite layer made up of the metal oxide layer and a metal or alloy layer including at least one of the same specified elements and formed on the metal oxide layer. The specified element include Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and Mn. Oxygen concentration in the oxide layer may decrease toward the metallic base layer. The oxide layer may be replaced by nitride layer of these metals.
Inventors
- 👤 Toshiaki Wada
- 👤 Masateru Nose
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:29
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/73; G11B5/739; G11B5/73911; G11B5/73921; G11B5/7368; G11B5/7369; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
82 words
A disk shaped magnetic recording medium comprising a metallic base layer and a magnetic layer laminatedly provided on a nonmagnetic nonmetallic substrate which is selected from among ceramics and glass and further comprising an intermediate layer which comprises a metal oxide layer consisting essentially of oxide(s) of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and Mn, wherein the intermediate layer is located between said substrate and said metallic base layer.
Claim 2
Dependent Claim
82 words
A disk shaped magnetic recording medium comprising a metallic base layer and a magnetic layer laminatedly provided on a nonmagnetic nonmetallic substrate which is selected from among ceramics and glass and further comprising an intermediate layer which comprises a metal oxide layer consisting essentially of oxide(s) of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and Mn, wherein the intermediate layer is located between said substrate and said metallic base layer.
Claim 3
Dependent Claim
29 words
The magnetic recording medium as set forth in claim 1, wherein oxygen concentration is said oxide layer along the thickness direction thereof decreases continuously toward said metallic base layer.
Claim 4
Dependent Claim
31 words
The magnetic recording medium as set forth in claim 1, wherein said oxide layer has a thickness ranging from 1/1000 to 5 times relative to that of said metallic base layer.
Claim 5
Dependent Claim
16 words
The magnetic recording medium as set forth in claim 1, wherein said oxide layer is Cr-oxide.
Claim 6
Dependent Claim
21 words
The magnetic recording medium as set forth in claim 4, wherein said Cr-oxide layer has a thickness less than 50 angstrom.
Claim 7
Dependent Claim
17 words
The magnetic recording medium as set forth in claim 1, wherein said nonmetallic substrate is glass-glazed ceramics.
Claim 8
Dependent Claim
17 words
The magnetic recording medium as set forth in claim 1, wherein said nonmetallic substrate is tempered glass.
Claim 9
Dependent Claim
29 words
The magnetic recording medium as set forth in claim 1, wherein oxygen concentration is said oxide layer along the thickness direction thereof decreases stepwise toward said metallic base layer.
Claim 10
Dependent Claim
138 words
A disk shaped magnetic recording medium comprising a metallic base layer and a magnetic layer laminatedly provided on a nonmagnetic nonmetallic substrate which is selected from among ceramics and glass and further comprising an intermediate layer structure comprising a metal oxide layer and a metal or alloy layer wherein the intermediate layer structure is located between said substrate and said metallic base layer, said metal oxide layer being disposed on said substrate and consisting essentially of the oxides of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, No, W and Mn, and said metal or alloy layer being disposed on said metal oxide layer and consisting essentially of at least on element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and Mn.
Claim 11
Dependent Claim
138 words
A disk shaped magnetic recording medium comprising a metallic base layer and a magnetic layer laminatedly provided on a nonmagnetic nonmetallic substrate which is selected from among ceramics and glass and further comprising an intermediate layer structure comprising a metal oxide layer and a metal or alloy layer wherein the intermediate layer structure is located between said substrate and said metallic base layer, said metal oxide layer being disposed on said substrate and consisting essentially of the oxides of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, No, W and Mn, and said metal or alloy layer being disposed on said metal oxide layer and consisting essentially of at least on element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and Mn.
Claim 12
Dependent Claim
29 words
The magnetic recording medium as set forth in claim 9, wherein oxygen concentration in said oxide layer along the thickness direction thereof decreases continuously toward said metallic base layer.
Claim 13
Dependent Claim
31 words
The magnetic recording medium as set forth in claim 9, wherein said oxide layer has a thickness ranging from 1/1000 to 5 times relative to that of said metallic base layer
Claim 14
Dependent Claim
30 words
The magnetic recording medium as set forth in claim 9, wherein said metal or alloy layer has a thickness ranging from 1/10 to 10 times that of said oxide layer.
Claim 15
Dependent Claim
16 words
The magnetic recording medium as set forth in claim 9, wherein said oxide layer is Cr-oxide.
Claim 16
Dependent Claim
21 words
The magnetic recording medium as set forth in claim 13, wherein said Cr-oxide layer has a thickness less than 50 angstrom.
Claim 17
Dependent Claim
17 words
The magnetic recording medium as set forth in claim 9, wherein said nonmetallic substrate is glass-glazed ceramics.
Claim 18
Dependent Claim
17 words
The magnetic recording medium as set forth in claim 9, wherein said nonmetallic substrate is tempered glass.
Claim 19
Dependent Claim
29 words
The magnetic recording medium as set forth in claim 9, wherein oxygen concentration in said oxide layer along the thickness direction thereof decreases stepwise toward said metallic base layer.
Claim 20
Dependent Claim
81 words
A disk shaped magnetic recording medium comprising a metallic base layer and a magnetic layer laminatedly provided on a nonmagnetic nonmetallic substrate which is selected from among ceramics and glass and further comprising an intermediate layer comprising a metal nitride layer consisting essentially of nitride(s) of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and Mn wherein the intermediate layer is located between said substrate and said metallic base layer.
Claim 21
Dependent Claim
81 words
A disk shaped magnetic recording medium comprising a metallic base layer and a magnetic layer laminatedly provided on a nonmagnetic nonmetallic substrate which is selected from among ceramics and glass and further comprising an intermediate layer comprising a metal nitride layer consisting essentially of nitride(s) of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and Mn wherein the intermediate layer is located between said substrate and said metallic base layer.
Claim 22
Dependent Claim
29 words
The magnetic recording medium as set forth in claim 18, wherein nitrogen concentration in said nitride layer along the thickness direction thereof decreases continuously toward said metallic base layer.
Claim 23
Dependent Claim
15 words
The magnetic recording medium as set forth in claim 18, wherein said nitride is Cr-nitride.
Claim 24
Dependent Claim
29 words
The magnetic recording medium as set forth in claim 18, wherein nitrogen concentration in said nitride layer along the thickness direction thereof decreases stepwise toward said metallic base layer.
Claim 25
Dependent Claim
138 words
A disk shaped magnetic recording medium comprising a metallic base layer and a magnetic layer laminatedly provided on a nonmagnetic nonmetallic substrate which is selected from among ceramics and glass and further comprising an intermediate layer structure which comprises a metal nitride layer and a metal or alloy layer wherein the intermediate layer structure is located between said substrate and said metallic base layer, said metal nitride layer being disposed on said substrate and consisting essentially of nitrate of at least on element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and Mn, and said metal or alloy layer being disposed on said metal nitride layer and consisting essentially of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and Mn.
Claim 26
Dependent Claim
138 words
A disk shaped magnetic recording medium comprising a metallic base layer and a magnetic layer laminatedly provided on a nonmagnetic nonmetallic substrate which is selected from among ceramics and glass and further comprising an intermediate layer structure which comprises a metal nitride layer and a metal or alloy layer wherein the intermediate layer structure is located between said substrate and said metallic base layer, said metal nitride layer being disposed on said substrate and consisting essentially of nitrate of at least on element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and Mn, and said metal or alloy layer being disposed on said metal nitride layer and consisting essentially of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and Mn.
Claim 27
Dependent Claim
29 words
The magnetic recording medium as set forth in claim 22, wherein nitrogen concentration in said nitride layer along the thickness direction thereof decreases continuously toward said metallic base layer.
Claim 28
Dependent Claim
15 words
The magnetic recording medium as set forth in claim 22, wherein said nitride is Cr-nitride.
Claim 29
Dependent Claim
29 words
The magnetic recording medium as set forth in claim 22, wherein nitrogen concentration in said nitride layer along the thickness direction thereof decreases stepwise toward said metallic base layer.
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) | 1992-05-08 | 1992-11-07 | 1993-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-08 | 1996-11-07 | 1997-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-08 | 2000-11-07 | 2001-05-09 | $7700.00 | Window Closed / Lapsed |