US3973072A
Expired / Lapsed
US
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Magnetic recording medium having binder-free phosphide coating
Assignee: 3M Co
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Filing: 1973-02-20
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Granted: 1976-08-03
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Expires: 1993-02-20
Abstract
Abstract Magnetic recording medium having a binder-free magnetizable coating of M2P where M consists essentially of a combination of at least two transition metals, preferably iron, nickel and/or cobalt, which medium has high coercivity and low Curie temperature, making it especially useful as an intermediate transfer medium for thermoremanent contact duplication.
Inventors
- 👤 Gerald S. Anderson
- 👤 John D. Holm
- 👤 Richard L. Jacobson
- 👤 Ronald E. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:53
CPC Classifications
H; H01; H01F; H01F10/00; H01F10/08; H01F10/10; H01F10/18; H01J; H01J2237/00; H01J2237/03; H01J2237/038; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
84 words
Magnetic recording medium comprising: a backing member of low permeability comprising nonmagnetic metal, glass or a polymer which has good high temperature properties and a binder-free thin film coating about 50 A to 5 micrometers in thickness and of approximately M 2 P wherein P is primarily phosphorus and M consists essentially of a combination of at least two transition metals, providing a Curie temperature of 50°-350°C, a B r of at least 1500 gauss and an H c of at least 500 oersteds.
Claim 2
Dependent Claim
84 words
Magnetic recording medium comprising: a backing member of low permeability comprising nonmagnetic metal, glass or a polymer which has good high temperature properties and a binder-free thin film coating about 50 A to 5 micrometers in thickness and of approximately M 2 P wherein P is primarily phosphorus and M consists essentially of a combination of at least two transition metals, providing a Curie temperature of 50°-350°C, a B r of at least 1500 gauss and an H c of at least 500 oersteds.
Claim 3
Dependent Claim
17 words
Magnetic recording medium as defined in claim 1 wherein the backing member is a beryllium copper belt.
Claim 4
Dependent Claim
24 words
Magnetic recording medium as defined in claim 1 wherein M is 80-90 mole percent iron, 10-20 mole percent cobalt and 0-5 mole percent nickel.
Claim 5
Dependent Claim
18 words
Magnetic recording medium as defined in claim 1 wherein P includes a small amount of arsenic or boron.
Claim 6
Dependent Claim
27 words
Magnetic recording medium as defined in claim 1 wherein the backing member is a copper-based alloy, aluminum, an aluminum-based alloy, a cobalt-based alloy, stainless steel or glass.
Claim 7
Dependent Claim
92 words
Magnetic recording medium comprising: a backing member of low permeability comprising nonmagnetic metal, glass or a polymer which has good high temperature properties and a binder-free thin film coating about 0.4 to 5 micrometers in thickness and of approximately M 2 P wherein P is phosphorous and M consists essentially of a combination of at least iron plus nickel and/or cobalt and comprises at least 80 mole percent iron, providing a Curie temperature of 50°-160°C, a B r of at least 1500 gauss and an H c of at least 500 oersteds.
Claim 8
Dependent Claim
92 words
Magnetic recording medium comprising: a backing member of low permeability comprising nonmagnetic metal, glass or a polymer which has good high temperature properties and a binder-free thin film coating about 0.4 to 5 micrometers in thickness and of approximately M 2 P wherein P is phosphorous and M consists essentially of a combination of at least iron plus nickel and/or cobalt and comprises at least 80 mole percent iron, providing a Curie temperature of 50°-160°C, a B r of at least 1500 gauss and an H c of at least 500 oersteds.
Claim 9
Dependent Claim
107 words
Magnetic recording medium onto which magnetic signals can be exactingly copied from a master tape by thermoremanent contact duplication and in turn copied onto unrecorded magnetic tape by magnetically stimulated contact duplication, said medium comprising a metal backing member of low permeability and a binder-free thin film coating about 50 A to 5 micrometers in thickness and of approximately M 2 P wherein P is phosphorus and M is 80-90 mole percent iron, 10-20 mole percent cobalt and 0-5 mole percent nickel, which coating has an H c of at least 1500 oersteds, a B r of at least 1800 gauss and a Curie temperature of 80°-160°C.
Claim 10
Dependent Claim
107 words
Magnetic recording medium onto which magnetic signals can be exactingly copied from a master tape by thermoremanent contact duplication and in turn copied onto unrecorded magnetic tape by magnetically stimulated contact duplication, said medium comprising a metal backing member of low permeability and a binder-free thin film coating about 50 A to 5 micrometers in thickness and of approximately M 2 P wherein P is phosphorus and M is 80-90 mole percent iron, 10-20 mole percent cobalt and 0-5 mole percent nickel, which coating has an H c of at least 1500 oersteds, a B r of at least 1800 gauss and a Curie temperature of 80°-160°C.
Claim 11
Dependent Claim
54 words
Magnetic recording medium comprising a metal backing member of low permeability and a binder-free thin film coating about 0.4 to 5 micrometers in thickness and of approximately (Fe.sub..85 Co.sub..15) 2 P providing a Curie temperature of 50°-350°C, a B r of at least 1500 gauss and an H c of at least 500 oersteds.
Claim 12
Dependent Claim
54 words
Magnetic recording medium comprising a metal backing member of low permeability and a binder-free thin film coating about 0.4 to 5 micrometers in thickness and of approximately (Fe.sub..85 Co.sub..15) 2 P providing a Curie temperature of 50°-350°C, a B r of at least 1500 gauss and an H c of at least 500 oersteds.
Claim 13
Dependent Claim
74 words
Magnetic recording medium comprising: a metal backing member of low permeability and a binder-free thin film coating about 0.4 to 5 micrometers in thickness and of approximately M 2 P wherein P is primarily phosphorus and M consists essentially of a combination of at least iron plus nickel and/or cobalt to provide a Curie temperature of 50°-350°C, a B r of at least 1500 gauss and an H c of at least 500 oersteds.
Claim 14
Dependent Claim
74 words
Magnetic recording medium comprising: a metal backing member of low permeability and a binder-free thin film coating about 0.4 to 5 micrometers in thickness and of approximately M 2 P wherein P is primarily phosphorus and M consists essentially of a combination of at least iron plus nickel and/or cobalt to provide a Curie temperature of 50°-350°C, a B r of at least 1500 gauss and an H c of at least 500 oersteds.
References Cited (Backward Citations)
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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) | 1979-08-03 | 1980-02-02 | 1980-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-03 | 1984-02-02 | 1984-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-03 | 1988-02-02 | 1988-08-03 | $7700.00 | Window Closed / Lapsed |