US3900593A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing magnetic metal oxide films bonded to a substrate
Assignee: Corning Glass Works
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Filing: 1972-06-16
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Granted: 1975-08-19
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Expires: 1992-06-16
Abstract
Abstract A method of producing magnetic metal oxide films bonded to an inorganic, non-magnetic substrate comprising the steps of applying a coating to the surface of the substrate, which coating consists of a very fine magnetic metal oxide powder dispersed in a suitable liquid. The applied coating and substrate are then heated to a temperature sufficient to evaporate the liquid constituent of the coating and form a thin, dense, magnetic, metal oxide film chemically bonded to the substrate.
Inventors
- 👤 Andrew Herczog
- 👤 Margaret M Layton
- 👤 Dale W Rice
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:31
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; G11B5/842
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
126 words
A METHOD OF FORMING A MAGNETIC FILM DEVICE COMPRISING THE STEPS OF PROVIDING AN INORGANIC, NON-MAGNETIC SUBSTRATE, APPLYING TO SAID SUBSTRATE A COATING OF A MAGNETIC METAL OXIDE POWDER DISPERSED IN A LIQUID VEHICLE, HEATING SAID SUBSTRATE AND APPLIED COATING TO A TEMPRATURE CORRESPONDING TO AT LEAST THE VAPORIZING TEMPERATURE OF SAID LIQUID TO VOLATILIZE SAID LIQUID AND LEAVE A FILM OF MAGNETIC METAL OXIDE POWDER ON SAID SUBSTRATE, AND BONDING SAID FILM OF MAGNETIC METAL OXIDE TO SAID SUBSTRATE BY FURTHER HEATING AT LEAST THE INTERFACE BETWEEN SAID FILM AND SAID SUBSTRATE TO A TEMPERATURE UP TO THE LOWER OF THE SOFTENING OR SINTERING TEMPRATURE OF THE SUBSTRATE AND FILM MATERIALS FOR A TIME SUFFICIENT FOR SAID FILM ITSELF TO CHEMICALLY BOND TO SAID SUBSTATE.
Claim 2
Independent Claim
126 words
A METHOD OF FORMING A MAGNETIC FILM DEVICE COMPRISING THE STEPS OF PROVIDING AN INORGANIC, NON-MAGNETIC SUBSTRATE, APPLYING TO SAID SUBSTRATE A COATING OF A MAGNETIC METAL OXIDE POWDER DISPERSED IN A LIQUID VEHICLE, HEATING SAID SUBSTRATE AND APPLIED COATING TO A TEMPRATURE CORRESPONDING TO AT LEAST THE VAPORIZING TEMPERATURE OF SAID LIQUID TO VOLATILIZE SAID LIQUID AND LEAVE A FILM OF MAGNETIC METAL OXIDE POWDER ON SAID SUBSTRATE, AND BONDING SAID FILM OF MAGNETIC METAL OXIDE TO SAID SUBSTRATE BY FURTHER HEATING AT LEAST THE INTERFACE BETWEEN SAID FILM AND SAID SUBSTRATE TO A TEMPERATURE UP TO THE LOWER OF THE SOFTENING OR SINTERING TEMPRATURE OF THE SUBSTRATE AND FILM MATERIALS FOR A TIME SUFFICIENT FOR SAID FILM ITSELF TO CHEMICALLY BOND TO SAID SUBSTATE.
Claim 3
Dependent Claim
57 words
The method of claim 1 wherein said powder is a metal oxide selected from the group consisting of magnetite; gamma ferric oxide; magnetite in combination with at least one of cobalt, nickel, copper, zinc, manganese, and magnesium; gamma ferric oxide in combination with at least one of cobalt, nickel, copper, zinc, manganese, and magnesium; and mixtures thereof.
Claim 4
Dependent Claim
24 words
The method of claim 1 wherein the grain size of said magnetic metal oxide powder is between about 100 A and about 1 micrometer.
Claim 5
Dependent Claim
63 words
The method of claim 3 wherein said softening or sintering temperature of said substrate material is higher than the sintering temperature of film material further comprising the step of sintering said magnetic metal oxide powder to form a solid, non-particulate metal oxide film on said substrate by heating said substrate and magnetic metal oxide powder to the sintering temperature of said metal oxide.
Claim 6
Dependent Claim
29 words
The method of claim 3 wherein said heating of said bonding step comprises focusing light through saId substrate onto said interface, said substrate being substantially transparent to said light.
Claim 7
Dependent Claim
24 words
The method of claim 1 wherein the grain size of said magnetic metal oxide powder is between about 100 A and about 1000 A.
Claim 8
Dependent Claim
23 words
The method of claim 1 wherein said liquid vehicle is a liquid selected from the group consisting of water, alcohol, and screening oil.
Claim 9
Dependent Claim
22 words
The method of claim 1 wherein said substrate is formed of material selected from the group consisting of glass, glass-ceramic and ceramic.
Claim 10
Dependent Claim
65 words
The method of claim 1 wherein said softening or sintering temperature of said substrate material is higher than the sintering temperature of said film material further comprising the step of sintering said magnetic metal oxide powder to form a solid, non-particulate magnetic metal oxide film on said substrate by heating said substrate and magnetic metal oxide powder to the sintering temperature of said metal oxide.
Claim 11
Dependent Claim
29 words
The method of claim 1 wherein said heating of said bonding step comprises focusing light through said substrate onto said interface, said substrate being substantially transparent to said light.
Claim 12
Independent Claim
143 words
A method of forming a magnetic recording and storage device comprising the steps of providing an inorganic, non-magnetic substrate, applying to said substrate a coating of alpha ferric oxide powder dispersed in a liquid vehicle, heating said substrate and applied coating to a temperature corresponding to at least the vaporizing temperature of said liquid to volatilize said liquid and leave a film of alpha ferric oxide powder on said substrate, bonding said film of alpha ferric oxide to said substrate by further heating at least the interface between said film and said substrate to a temperature up to the lower of the softening or sintering temperature of the substrate and alpha ferric oxide for a time sufficient for said film itself to chemically bond to said substrate, and thereafter convering said film of alpha ferric oxide to a film of magnetic iron oxide.
Claim 13
Independent Claim
143 words
A method of forming a magnetic recording and storage device comprising the steps of providing an inorganic, non-magnetic substrate, applying to said substrate a coating of alpha ferric oxide powder dispersed in a liquid vehicle, heating said substrate and applied coating to a temperature corresponding to at least the vaporizing temperature of said liquid to volatilize said liquid and leave a film of alpha ferric oxide powder on said substrate, bonding said film of alpha ferric oxide to said substrate by further heating at least the interface between said film and said substrate to a temperature up to the lower of the softening or sintering temperature of the substrate and alpha ferric oxide for a time sufficient for said film itself to chemically bond to said substrate, and thereafter convering said film of alpha ferric oxide to a film of magnetic iron oxide.
Claim 14
Dependent Claim
23 words
The method of claim 11 wherein said magnetic iron oxide film is selected from the group consisting of magnetite and gamma ferric oxide.
Claim 15
Dependent Claim
25 words
The method of claim 12 wherein the grain size of said alpha ferric oxide powder is between about b 100 A and about 1 micrometer.
Claim 16
Dependent Claim
65 words
The method of claim 13 wherein said softening or sintering temperature of said substrate material is higher than the sintering temperature of alpha ferric oxide further comprising the step of sintering said alpha ferric oxide powder to form a solid, non-particulate alpha ferric oxide film on said substrate by heating said substrate and alpha ferric oxide powder to the sintering temperature of alpha ferric oxide.
Claim 17
Dependent Claim
29 words
The method of claim 13 wherein said heating of said bonding step comprises focusing light through said substrate onto said interface, said substrate being substantially transparent to said light.
Claim 18
Dependent Claim
24 words
The method of claim 11 wherein the grain size of said alpha ferric oxide powder is between about 100 A and about 1 micrometer.
Claim 19
Dependent Claim
24 words
The method of claim 11 wherein the grain size of said alpha ferric oxide powder is between about 100 A and about 1000 A.
Claim 20
Dependent Claim
23 words
The method of claim 11 wherein said liquid vehicle is a liquid selected from the group consisting of water, alcohol, and screening oil.
Claim 21
Dependent Claim
22 words
The method of claim 11 wherein said substrate is formed of material selected from the group consisting of glass, glass-ceramic, and ceramic.
Claim 22
Dependent Claim
65 words
The method of claim 11 wherein said softening or sintering temperature of said substrate material is higher than the sintering temperature of alpha ferric oxide further comprising the step of sintering said alpha ferric oxide powder to form a solid, non-particulate alpha ferric oxide film on said substrate by heating said substrate and alpha ferric oxide powder to the sintering temperature of alpha ferric oxide.
Claim 23
Dependent Claim
29 words
The method of claim 11 wherein said heating of said bonding step coMprises focusing light through said substrate onto said interface, said substrate being substantially transparent to said light.
Claim 24
Independent Claim
24 words
A METHOD OF FORMING A MAGNETIC RECORDING AND STORAGE DEVICE COMPRISING THE STEPS OF PROVIDING A SUBSTRATE FORMED OF AN ION-EXCHANGE STRENGTH ENED GLASS,
Claim 25
Independent Claim
24 words
A METHOD OF FORMING A MAGNETIC RECORDING AND STORAGE DEVICE COMPRISING THE STEPS OF PROVIDING A SUBSTRATE FORMED OF AN ION-EXCHANGE STRENGTH ENED GLASS,
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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) | 1978-08-18 | 1979-02-17 | 1979-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-18 | 1983-02-17 | 1983-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-18 | 1987-02-17 | 1987-08-19 | $7700.00 | Window Closed / Lapsed |