Patent US4814239A successfully refreshed from Google Patents.
US4814239A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vertical magnetic recording medium and method of manufacturing the same
Assignee: Ube Corp
•
Filing: 1988-03-24
•
Granted: 1989-03-21
•
Expires: 2008-03-24
Abstract
Abstract A vertical magnetic recording medium excellent in durability and recording property in which a first magnetic film comprising Co--Cr or Co--Cr--W as the main ingredient is formed on a substrate and the second magnetic film comprising Co--Cr--W--C as the main ingredient is formed on the first magnetic film, as well as the production process therefor are provided.
Inventors
- 👤 Kazuo Inoue
- 👤 Motozo Yoshikiyo
- 👤 Shizuka Yoshii
- 👤 Iwao Okamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:15
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/66; G11B5/672; G11B5/84; G11B5/85; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/12; Y10T428/12465; Y10T428/12493; Y10T428/12771; Y10T428/12861; Y10T428/12931
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
78 words
A vertical magnetic recording medium wherein a first magnetic film comprising Co--Cr as the main ingredient is formed on a substrate, and a second magnetic film comprising Co--Cr--W--C as the main ingredient which has the Co content of from 40 to 73.5 at%, the Cr content of from 25 to 35 at%, the W content of from 1 to 10 at% and the C content of from 0.5 to 15 at%, is formed on said first magnetic film.
Claim 2
Dependent Claim
78 words
A vertical magnetic recording medium wherein a first magnetic film comprising Co--Cr as the main ingredient is formed on a substrate, and a second magnetic film comprising Co--Cr--W--C as the main ingredient which has the Co content of from 40 to 73.5 at%, the Cr content of from 25 to 35 at%, the W content of from 1 to 10 at% and the C content of from 0.5 to 15 at%, is formed on said first magnetic film.
Claim 3
Dependent Claim
35 words
A vertical magnetic recording medium as defined in claim 1, wherein the first magnetic film has the Co content of from 70 to 90 at% and the Cr content of from 10 to 30 at%.
Claim 4
Dependent Claim
88 words
A process for producing a vertical magnetic recording medium as defined in claim 1, wherein the second magnetic film is formed by using a vacuum vapor deposition process, in which an alloy having the Co content of from 40 to 75 at%, the Cr content of from 25 to 35 at%, the W content of from 1 to 10 at% and the C content of from 0.5 to 15 at% is used as an evaporation source and the evaporation source is heated by the irradiation of laser beams.
Claim 5
Dependent Claim
88 words
A process for producing a vertical magnetic recording medium as defined in claim 2, wherein the second magnetic film is formed by using a vacuum vapor deposition process, in which an alloy having the Co content of from 40 to 73.5 at%, the Cr content of from 25 to 35 at%, the W content of from 1 to 10 at% and the C content of from 0.5 to 15 at% is used as an evaporation source and the evaporation source is heated by the irradiation of laser beams.
Claim 6
Dependent Claim
78 words
A vertical magnetic recording medium, wherein a first magnetic film comprising Co--Cr--W as the main ingredient is formed on a substrate, and a second magnetic film comprising Co--Cr--W--C as the main ingredient which has the Co content of from 40 to 73.5 at%, the Cr content of from 25 to 35 at%, the W content of from 1 to 10 at% and the C content of from 0.5 to 15 at%, is formed on said first magnetic film.
Claim 7
Dependent Claim
78 words
A vertical magnetic recording medium, wherein a first magnetic film comprising Co--Cr--W as the main ingredient is formed on a substrate, and a second magnetic film comprising Co--Cr--W--C as the main ingredient which has the Co content of from 40 to 73.5 at%, the Cr content of from 25 to 35 at%, the W content of from 1 to 10 at% and the C content of from 0.5 to 15 at%, is formed on said first magnetic film.
Claim 8
Dependent Claim
44 words
A vertical magnetic recording medium as defined in claim 5, wherein the first magnetic film has the Co dcontent of from 50 to 90 at%, the Cr content of from 8 to 25 at% and the W content of from 1.3 to 15 at%.
Claim 9
Dependent Claim
88 words
A process for producing a vertical magnetic recording medium as defined in claim 5, wherein the second magnetic film is formed by using a vacuum vapor deposition process, in which an alloy having the Co content of from 40 to 73.5 at%, the Cr content of from 25 to 35 at%, the W content of from 1 to 10 at% and the C content of from 0.5 to 15 at% is used as an evaporation source and the evaporation source is heated by the irradiation of laser beams.
Claim 10
Dependent Claim
88 words
A process for producing a vertical magnetic recording medium as defined in claim 6, wherein the second magnetic film is formed by using a vacuum vapor deposition process, in which an alloy having the Co content of from 40 to 73.5 at%, the Cr content of from 25 to 35 at%, the W content of from 1 to 10 at% and the C content of from 0.5 to 15 at% is used as an evaporation source and the evaporation source is heated by the irradiation of laser beams.
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) | 1992-03-20 | 1992-09-19 | 1993-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-20 | 1996-09-19 | 1997-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-20 | 2000-09-19 | 2001-03-21 | $7700.00 | Window Closed / Lapsed |