US4128691A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of a magnetic recording medium
Assignee: Fujifilm Holdings Corp
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Filing: 1976-07-27
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Granted: 1978-12-05
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Expires: 1996-07-27
Abstract
Abstract The process for the production of a magnetic recording medium by electroless plating comprises carrying out the plating in a plating aqueous solution containing at least one ferromagnetic metal ion, barium ion and hypophosphite ion as a reducing agent, and thus forming a magnetic metal thin film.
Inventors
- 👤 Ryuji Shirahata
- 👤 Tatsuji Kitamoto
- 👤 Masaaki Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:46
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/64; G11B5/65; G11B5/658; H; H01; H01F; H01F41/00; H01F41/14; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
81 words
A process for the production of a magnetic recording medium by electroless plating onto a substrate, which comprises carrying out the electroless plating in a plating aqueous solution containing 0.02 to 0.6 mol/l of cobalt ion, 0 to 0.02 mol/l of nickel ion, 0.0002 to 0.005 mol/l of barium ion, 0.03 to 0.4 mol/l of hypophosphite ion and a complexing agent at a temperature of 60° C.-95° C. and wherein the pH of the aqueous solution ranges from 6.5 to 9.0.
Claim 2
Dependent Claim
81 words
A process for the production of a magnetic recording medium by electroless plating onto a substrate, which comprises carrying out the electroless plating in a plating aqueous solution containing 0.02 to 0.6 mol/l of cobalt ion, 0 to 0.02 mol/l of nickel ion, 0.0002 to 0.005 mol/l of barium ion, 0.03 to 0.4 mol/l of hypophosphite ion and a complexing agent at a temperature of 60° C.-95° C. and wherein the pH of the aqueous solution ranges from 6.5 to 9.0.
Claim 3
Dependent Claim
29 words
The process of claim 1, wherein said cobalt ion or cobalt ion plus nickel ion are released from inorganic salts, inorganic acid salts, organic acid salts or complex salts.
Claim 4
Dependent Claim
40 words
The process of claim 1, wherein said substrate is selected from the group consisting of non-conductive materials such as polyethylene terephthalate, polyimide, polyvinyl chloride, cellulose triacetate, polycarbonate, polyethylene naphthalate, glass and ceramics, and conductive materials such as aluminum and brass.
Claim 5
Dependent Claim
13 words
The process of claim 1, wherein said substrate is subjected to a pretreatment.
Claim 6
Dependent Claim
22 words
The process of claim 1, wherein said electroless plating is carried out to give a film thickness of 0.05 to 1.0 micron.
Claim 7
Dependent Claim
11 words
A magnetic recording medium produced by the process of claim 1.
Claim 8
Dependent Claim
49 words
A process according to claim 1, wherein said barium ion is released from a barium salt selected from the group consisting of barium chloride, barium oxide, barium nitrate, barium nitrite, barium iodide, barium chlorate, barium hypophosphite, barium perchlorate, barium permanganate, barium dithionate, barium acetate, barium bromide and barium butyrate.
Claim 9
Dependent Claim
30 words
The process of claim 1, wherein said complexing agent is selected from the group consisting of malonic acid, succinic acid, tartaric acid, citric acid, ammonium salts thereof and mixtures thereof.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-12-04 | 1982-06-05 | 1982-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-04 | 1986-06-05 | 1986-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-04 | 1990-06-05 | 1990-12-05 | $7700.00 | Window Closed / Lapsed |