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US3843403A Expired / Lapsed US ⏱️ 0.0 years remaining

Methods of manufacturing ferromagnetic carbon modified chromium oxide and compositions and recording media containing same

Assignee: International Business Machines Corp
•
Filing: 1971-12-27
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Granted: 1974-10-22
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Expires: 1991-12-27
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Abstract

Abstract 1. A PROCESS FOR PRODUCING FERROMAGNETIC CARBON MODIFIED CHROMIUM OXIDE COMPOSITIONS OF TETRAGONAL CRYSTAL STRUCTURE CONTAINING ABOUT 58.5% TO 62%, BY WEIGHT, OF CHROMIUM, AND ABOUT 0.05% TO 0.90%, BY WEIGHT, OF CARBON WHICH COMPRISES; FORMING A CHROMIUM MODIFIED CARBON BY MIXING A MODIFYING CHROMIUM SALT WHICH CARBON IN ITS ELEMENTAL FORM, SAID CHROMIUM SALT SELECTED FROM THOSE CHROMIUM COMPOUNDS CAPABLE OF BEING ABSORBED OR ADSORBED BY SAID CARBON, AND EXCLUDING THE OXIDES AND HYDROXIDES OF CHROMIUM LACKING ADDITIONAL ELEMENTALS; MIXING THE MODIFIED CARBON THUS FORMED WITH CHROMIUM TRIOXIDE TO FORM A REACTION MIXTURE; AND THEN HEATING THE MIXTURE AT A TEMPERATURE WITHIN THE RANGE OF ABOUT 450*F. TO 850*F. AND UNDER A PRESSURE OF AT LEAST 730P.S.I.

Inventors

  • 👤 R Haines

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 19:19
CPC Classifications
C; C01; C01G; C01G37/00; C01G37/02; B; B82; B82Y; B82Y30/00; G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/706; G11B5/70626; G11B5/70636; H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/0302; H01F1/0311; H01F1/0313; C01P; C01P2004/00; C01P2004/10; C01P2004/54; C01P2004/60; C01P2004/61; C01P2004/62; C01P2004/64; C01P2006/00; C01P2006/42; C01P2006/80

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 117 words
A PROCESS FOR PRODUCING FERROMAGNETIC CARBON MODIFIED CHROMIUM OXIDE COMPOSITIONS OF TETRAGONAL CRYSTAL STRUCTURE CONTAINING ABOUT 58.5% TO 62%, BY WEIGHT, OF CHROMIUM, AND ABOUT 0.05% TO 0.90%, BY WEIGHT, OF CARBON WHICH COMPRISES; FORMING A CHROMIUM MODIFIED CARBON BY MIXING A MODIFYING CHROMIUM SALT WHICH CARBON IN ITS ELEMENTAL FORM, SAID CHROMIUM SALT SELECTED FROM THOSE CHROMIUM COMPOUNDS CAPABLE OF BEING ABSORBED OR ADSORBED BY SAID CARBON, AND EXCLUDING THE OXIDES AND HYDROXIDES OF CHROMIUM LACKING ADDITIONAL ELEMENTALS; MIXING THE MODIFIED CARBON THUS FORMED WITH CHROMIUM TRIOXIDE TO FORM A REACTION MIXTURE; AND THEN HEATING THE MIXTURE AT A TEMPERATURE WITHIN THE RANGE OF ABOUT 450*F. TO 850*F. AND UNDER A PRESSURE OF AT LEAST 730P.S.I.
Claim 2
Dependent Claim 117 words
A PROCESS FOR PRODUCING FERROMAGNETIC CARBON MODIFIED CHROMIUM OXIDE COMPOSITIONS OF TETRAGONAL CRYSTAL STRUCTURE CONTAINING ABOUT 58.5% TO 62%, BY WEIGHT, OF CHROMIUM, AND ABOUT 0.05% TO 0.90%, BY WEIGHT, OF CARBON WHICH COMPRISES; FORMING A CHROMIUM MODIFIED CARBON BY MIXING A MODIFYING CHROMIUM SALT WHICH CARBON IN ITS ELEMENTAL FORM, SAID CHROMIUM SALT SELECTED FROM THOSE CHROMIUM COMPOUNDS CAPABLE OF BEING ABSORBED OR ADSORBED BY SAID CARBON, AND EXCLUDING THE OXIDES AND HYDROXIDES OF CHROMIUM LACKING ADDITIONAL ELEMENTALS; MIXING THE MODIFIED CARBON THUS FORMED WITH CHROMIUM TRIOXIDE TO FORM A REACTION MIXTURE; AND THEN HEATING THE MIXTURE AT A TEMPERATURE WITHIN THE RANGE OF ABOUT 450*F. TO 850*F. AND UNDER A PRESSURE OF AT LEAST 730P.S.I.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1977-10-21 1978-04-22 1978-10-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1981-10-21 1982-04-22 1982-10-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1985-10-21 1986-04-22 1986-10-22 $7700.00 Window Closed / Lapsed

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