US4673590A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing a magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1986-02-25
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Granted: 1987-06-16
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Expires: 2006-02-25
Abstract
Abstract A process for preparing a magnetic recording medium is disclosed, which comprises (1) subjecting a surface of a non-magnetic support having a surface roughness of not less than 0.01 mu m to an abrasion treatment or a calendering treatment, (2) coating a layer containing a compound polymerizable by radiation exposure on the surface of non-magnetic support, (3) exposing the layer to radiation to polymerize and harden the same, and (4) providing a magnetic layer on the radiation exposed layer. The thus prepared magnetic recording medium is not accompanied by dropout due to "fish eyes" and is suitable for high density recording.
Inventors
- 👤 Hiroshi Hashimoto
- 👤 Tsutomu Okita
- 👤 Noburo Hibino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:09
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; G11B5/62; G11B5/73
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
164 words
A process for preparing a magnetic recording medium having a non-magnetic support having a surface roughness of not less than 0.01 μm and which is not accompanied by dropout due to protrusions having a height of about 0.2 μm or more which comprises (1) subjecting a surface of a non-magnetic support having a surface roughness of not less than 0.01 μm to an abrasion treatment or a calendering treatment to remove said protrusions having a height of about 0.2 μm or more but retaining the surface roughness of not less than 0.01 μm, (2) coating a layer containing a compound polymerizable by radiation exposure on the surface of said non-magnetic support, (3) exposing the layer to radiation to polymerize and harden the same, and (4) providing a magnetic layer on the radiation exposed layer wherein said radiation exposed layer has a surface roughness of less than 0.01 μm and wherein said calendering treatment is carried out at a temperature of 40° to 200° C.
Claim 2
Dependent Claim
164 words
A process for preparing a magnetic recording medium having a non-magnetic support having a surface roughness of not less than 0.01 μm and which is not accompanied by dropout due to protrusions having a height of about 0.2 μm or more which comprises (1) subjecting a surface of a non-magnetic support having a surface roughness of not less than 0.01 μm to an abrasion treatment or a calendering treatment to remove said protrusions having a height of about 0.2 μm or more but retaining the surface roughness of not less than 0.01 μm, (2) coating a layer containing a compound polymerizable by radiation exposure on the surface of said non-magnetic support, (3) exposing the layer to radiation to polymerize and harden the same, and (4) providing a magnetic layer on the radiation exposed layer wherein said radiation exposed layer has a surface roughness of less than 0.01 μm and wherein said calendering treatment is carried out at a temperature of 40° to 200° C.
Claim 3
Dependent Claim
27 words
The process as claimed in claim 1, wherein said compound polymerizable by radiation exposure is a compound having at least one carbon-carbon unsaturated bond in its molecule.
Claim 4
Dependent Claim
28 words
The process as claimed in claim 2, wherein said compound polymerizable by radiation exposure is a compound having 2 or more acryloyl and/or methacryloyl groups in its molecule.
Claim 5
Dependent Claim
16 words
The process as claimed in claim 1, wherein the radiation is electron beam or ultraviolet radiation.
Claim 6
Dependent Claim
14 words
The process as claimed in claim 4, wherein the radiation is electron beam radiation.
Claim 7
Dependent Claim
22 words
The process as claimed in claim 1, wherein said calendering treatment is carried out at a pressure of 5 to 600 kg/cm.
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) | 1990-06-15 | 1990-12-15 | 1991-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-15 | 1994-12-15 | 1995-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-15 | 1998-12-15 | 1999-06-16 | $7700.00 | Window Closed / Lapsed |