US4354909A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for production of magnetic recording medium
Assignee: Sekisui Chemical Co Ltd
•
Filing: 1980-02-25
•
Granted: 1982-10-19
•
Expires: 2000-02-25
Abstract
Abstract A magnetic recording medium comprising a non-magnetic substrate such as polyethylene terephthalate film, and deposited on the surface of the substrate by an ionized cluster beam deposition method, at least one ferro-magnetic material selected from the group consisting of cobalt, cobalt-containing alloys, mixtures of cobalt with other elements, and chromium dioxide; and a process for production thereof. The magnetic recording medium is characterized by having superior magnetic properties, especially superior coercive force, residual magnetic flux density and squareness ratio, and high mechanical strength.
Inventors
- 👤 Toshinori Takagi
- 👤 Shinsaku Nakata
- 👤 Kazuhiko Kanki
- 👤 Masahiro Hotta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:50
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/65; G11B5/658; C; C23; C23C; C23C14/00; C23C14/0021; G11B5/84; G11B5/851; H; H01; H01F; H01F10/00; H01F10/08; H01F10/10; H01F10/18; H01F41/00; H01F41/14; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
106 words
A process for producing a magnetic recording medium, which comprises heating a closed type crucible having an injection nozzle and containing at least one ferromagnetic material selected from the group consisting of cobalt, cobalt-containing alloys and mixtures of cobalt with other elements in a vacuum chamber kept at 10 -3 to 10 -8 torr thereby to generate a cluster of the atoms of the ferromagnetic material from the injection nozzle, impinging electron beams generated by an electron beam generator against the cluster to ionize it, accelerating the generated cluster ions in an electric field, and depositing the ions on a substrate composed of a non-magnetic material.
Claim 2
Dependent Claim
106 words
A process for producing a magnetic recording medium, which comprises heating a closed type crucible having an injection nozzle and containing at least one ferromagnetic material selected from the group consisting of cobalt, cobalt-containing alloys and mixtures of cobalt with other elements in a vacuum chamber kept at 10 -3 to 10 -8 torr thereby to generate a cluster of the atoms of the ferromagnetic material from the injection nozzle, impinging electron beams generated by an electron beam generator against the cluster to ionize it, accelerating the generated cluster ions in an electric field, and depositing the ions on a substrate composed of a non-magnetic material.
Claim 3
Dependent Claim
63 words
A process for producing a magnetic recording medium, which comprises depositing at least one ferromagnetic material selected from the group consisting of cobalt, cobalt-containing alloys and mixtures of cobalt with other elements on a substrate composed of a non-magnetic material by ionized cluster beam deposition in the presence of a magnetic field applied in a direction parallel to the surface of the substrate.
Claim 4
Dependent Claim
63 words
A process for producing a magnetic recording medium, which comprises depositing at least one ferromagnetic material selected from the group consisting of cobalt, cobalt-containing alloys and mixtures of cobalt with other elements on a substrate composed of a non-magnetic material by ionized cluster beam deposition in the presence of a magnetic field applied in a direction parallel to the surface of the substrate.
Claim 5
Dependent Claim
32 words
A process for producing a magnetic recording medium, which comprises depositing a ferromagnetic material composed predominantly of chromium dioxide on a substrate composed of a non-magnetic material by cluster ion beam deposition.
Claim 6
Dependent Claim
32 words
A process for producing a magnetic recording medium, which comprises depositing a ferromagnetic material composed predominantly of chromium dioxide on a substrate composed of a non-magnetic material by cluster ion beam deposition.
Claim 7
Dependent Claim
96 words
The process of claim 5 which comprises heating a closed type crucible having an injection nozzle and containing metallic chromium or chromium oxide and simultaneously supplying oxygen to the vicinity of the injection nozzle in a vacuum chamber kept at 10 -3 to 10 -8 torr thereby to generate a cluster of metallic chromium or chromium oxide, impinging electron beams generated by an electron beam generator provided within the same vacuum chambber against the cluster thereby to ionize the cluster, accelerating the generated cluster ions in an electric field, and depositing the ions on the substrate.
Claim 8
Dependent Claim
21 words
The process of claim 1 or 4 wherein the accelerating voltage in the electric field is -0.1 KV to -15 KV.
Claim 9
Dependent Claim
40 words
The process of claim 5 wherein the accelerating voltage in the electric field is -4 KV to -15 KV in the early stage of the ionized cluster beam deposition, and -0.1 KV to -4 KV in the later stage thereof.
References Cited (Backward Citations)
US4152478A
Cited
US4226681A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-10-18 | 1986-04-19 | 1986-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-18 | 1990-04-19 | 1990-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-18 | 1994-04-19 | 1994-10-19 | $7700.00 | Window Closed / Lapsed |