Patent US4888211A successfully refreshed from Google Patents.
US4888211A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparation of vertical magnetic recording medium
Assignee: Toray Industries Inc
•
Filing: 1988-11-02
•
Granted: 1989-12-19
•
Expires: 2008-11-02
Abstract
Abstract A vertical magnetic recording medium is prepared by a process for vacuum-depositing a metal selected from cobalt and iron to form a magnetic layer on a substrate, wherein an oxygen gas and at least one gas chemically inactive in the vacuum deposition system, which is selected from nitrogen, argon, helium, neon, xenon, radon, methane and ethane, are introduced into the vacuum to an extent such that the pressure in the vicinity of the substrate is 1×10 -3 to 5×10 -2 Torr.
Inventors
- 👤 Tetsuo Oka
- 👤 Kenji Hayashi
- 👤 Takayoshi Akamatsu
- 👤 Satoshi Horiuchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:08
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; G11B5/85; G11B5/62; G11B5/64; G11B5/65; G11B5/658; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249955; Y10T428/249956; Y10T428/26; Y10T428/268; Y10T428/31504; Y10T428/3154; Y10T428/31544
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
129 words
A process for the preparation of a vertical magnetic recording medium, which comprises vacuum-evaporating a metal selected from the group consisting of cobalt and iron on a surface of a substrate to form a magnetic layer, wherein the metal is melted and evaporated in a vacuum chamber and a vapor stream thereof is flowed so as to be incident on the substrate surface substantially perpendicular to the substrate surface, while an oxygen gas and at least one gas chemically inactive in the vacuum deposition system, which gas is selected from the group consisting of nitrogen, orgon, helium, neon, xenon, radon, methane and ethane, are introduced into the vacuum chamber to an extent such that the pressure in the vicinity of the substrate is 1×10 -3 to 5×10 -2 Torr.
Claim 2
Dependent Claim
129 words
A process for the preparation of a vertical magnetic recording medium, which comprises vacuum-evaporating a metal selected from the group consisting of cobalt and iron on a surface of a substrate to form a magnetic layer, wherein the metal is melted and evaporated in a vacuum chamber and a vapor stream thereof is flowed so as to be incident on the substrate surface substantially perpendicular to the substrate surface, while an oxygen gas and at least one gas chemically inactive in the vacuum deposition system, which gas is selected from the group consisting of nitrogen, orgon, helium, neon, xenon, radon, methane and ethane, are introduced into the vacuum chamber to an extent such that the pressure in the vicinity of the substrate is 1×10 -3 to 5×10 -2 Torr.
Claim 3
Dependent Claim
27 words
A process according to claim 1, wherein oxygen and the chemically inactive gas are introduced on the downstream side relatively to the moving direction of the substrate.
Claim 4
Dependent Claim
43 words
A process according to claim 1, wherein an oxygen-containing gas is introduced on the downstream side relatively to the moving direction of the substrate and the chemically inactive gas is introduced on the upstream side relatively to the moving direction of the substrate.
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) | 1992-12-18 | 1993-06-19 | 1993-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-18 | 1997-06-19 | 1997-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-18 | 2001-06-19 | 2001-12-19 | $7700.00 | Window Closed / Lapsed |