US4837046A
Expired / Lapsed
US
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Method for forming ferrite film
Assignee: Nippon Paint Co Ltd
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Filing: 1987-08-07
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Granted: 1989-06-06
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Expires: 2007-08-07
Abstract
Abstract Disclosed is a method for forming a ferrite film comprising, flowing downward or spraying an aqueous oxidizing agent solution on a substrate in a deoxidized atmosphere and simultaneously supplying an aqueous deoxidized solution containing at least ferrous ions, to effect a ferrite crystallization reaction on the substrate. This ferrite film is used for magnetic recording media, photomagnetic recording media, magnetic heads, etc.
Inventors
- 👤 Masao Oishi
- 👤 Takao Saito
- 👤 Katsukiyo Ishikawa
- 👤 Masanori Abe
- 👤 Yutaka Tamaura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 05:09
CPC Classifications
H; H01; H01F; H01F41/00; H01F41/14; H01F41/24; G; G11; G11B; G11B5/00; G11B5/84; G11B5/858
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
81 words
A method for forming a ferrite film on a substrate comprising flowing downward or spraying an aqueous oxidizing agent solution on a substrate in an atmosphere which is substantively free of oxygen and simultaneously supplying an aqueous deoxidized solution containing at least ferrous ions under such conditions that both solutions are fluidized on the substrate so that they continuously flow over the substrate by the force of gravity or by centrifugal force, to effect a ferrite crystallization reaction on the substrate.
Claim 2
Independent Claim
81 words
A method for forming a ferrite film on a substrate comprising flowing downward or spraying an aqueous oxidizing agent solution on a substrate in an atmosphere which is substantively free of oxygen and simultaneously supplying an aqueous deoxidized solution containing at least ferrous ions under such conditions that both solutions are fluidized on the substrate so that they continuously flow over the substrate by the force of gravity or by centrifugal force, to effect a ferrite crystallization reaction on the substrate.
Claim 3
Dependent Claim
16 words
The method as claimed in claim 1, wherein the aqueous oxidizing agent solution contains a nitrite.
Claim 4
Dependent Claim
18 words
The method as claimed in claim 1, wherein the aqueous oxidizing agent solution is water containing dissolved oxygen.
Claim 5
Dependent Claim
19 words
The method as claimed in claim 1, wherein the aqueous deoxidized solution containing ferrous ions only contains ferrous ions.
Claim 6
Dependent Claim
98 words
The method as claimed in claim 1, wherein the aqueous deoxidized solution contains, in addition to the ferrous ions, Zn 2+ , Co 2+ , Co 3+ , Ni 2- , Mn 2 . Mn 3+ , Fe 3+ , Cu 2+ , V 3+ , V 4+ , V 5+ , Sb 5+ , Li + , Mo 4+ , Mo 5+ , Ti 4+ , Pd 2+ , Mg 2+ , Al 3+ , Si 4+ , Cr 3+ , Sn 2+ , Sn 4+ , Ca 2+ , Cd 2+ , or a mixture thereof.
Claim 7
Dependent Claim
31 words
The method as claimed in claim 1, wherein the aqueous deoxidized solution is divided into two or more portions when it contains ion species which can form precipitates with each other.
Claim 8
Dependent Claim
32 words
The method as claimed in claim 1, wherein the aqueous deoxidized solution is flowed downward or sprayed on the substrate from a nozzle different from that for the aqueous oxidizing agent solution.
Claim 9
Dependent Claim
17 words
The method as claimed in claim 1, wherein the surface of the substrate is pretreated with plasma.
Claim 10
Dependent Claim
26 words
The method as claimed in claim 1, wherein the aqueous solutions on the substrate continuously flow out from the surface of the substrate due to fluidity.
References Cited (Backward Citations)
US2956900A
Cited
US3642521A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-05 | 1992-12-05 | 1993-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-05 | 1996-12-05 | 1997-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-05 | 2000-12-05 | 2001-06-06 | $7700.00 | Window Closed / Lapsed |