US3021191A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Prussian blue pigment
Assignee: Standard Ultramarine and Color Co
•
Filing: 1958-06-09
•
Granted: 1962-02-13
•
Expires: 1978-06-09
Abstract
No abstract record available.
Inventors
- 👤 William H Rhodes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:56
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/22; C09C1/26; C01; C01P; C01P2006/00; C01P2006/60
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
126 words
IN A PROCESS FOR FORMING PRUSSIAN BLUE PIGMENT IN WHICH A WASHED BERLIN WHITE IS MADE INTO AN AMMONIUM COMPLEX IN AN AQUEOUS SLURRY AND THE SLURRY THEN OXIDIZED UNDER ALKALINE CONDITIONS, THE IMPROVEMENT WHICH COMPRISES COMPLETELY OXIDIZING THE COMPLEX FERROUS FERROCYANIDE TO THE FERRID FERROCYANIDE BY ADDING HYDROGEN PEROXIDE TO THE SLURRY IN AN AMOUNT EQUAL TO AT LEAST 75% OF THE STOICHIOMETRIC AMOUNT REQUIRED FOR OXIDATION OF THE FERROUS IRON PRESENT IN THE FROM OF AN INDEPENDENT CATION IN ITS SALTS, THEREBY FORMING A PIGMENT SLURRY CHARACTERIZED BY THE FULLY DEVELOPED RED SHADE OF PRUSSIAN BLUE, FREEDOM FROM GRIT, AND BEING CAPABLE OF BEING FLUSHED DIRECTLY INTO PAINT AND INK MEDIA WITHOUT NECESSITY FOR FURTHER COLOR DEVELOPMENT BY ELEVATED TEMPERATURE AIR DRYING AND OXIDATION.
Claim 2
Dependent Claim
126 words
IN A PROCESS FOR FORMING PRUSSIAN BLUE PIGMENT IN WHICH A WASHED BERLIN WHITE IS MADE INTO AN AMMONIUM COMPLEX IN AN AQUEOUS SLURRY AND THE SLURRY THEN OXIDIZED UNDER ALKALINE CONDITIONS, THE IMPROVEMENT WHICH COMPRISES COMPLETELY OXIDIZING THE COMPLEX FERROUS FERROCYANIDE TO THE FERRID FERROCYANIDE BY ADDING HYDROGEN PEROXIDE TO THE SLURRY IN AN AMOUNT EQUAL TO AT LEAST 75% OF THE STOICHIOMETRIC AMOUNT REQUIRED FOR OXIDATION OF THE FERROUS IRON PRESENT IN THE FROM OF AN INDEPENDENT CATION IN ITS SALTS, THEREBY FORMING A PIGMENT SLURRY CHARACTERIZED BY THE FULLY DEVELOPED RED SHADE OF PRUSSIAN BLUE, FREEDOM FROM GRIT, AND BEING CAPABLE OF BEING FLUSHED DIRECTLY INTO PAINT AND INK MEDIA WITHOUT NECESSITY FOR FURTHER COLOR DEVELOPMENT BY ELEVATED TEMPERATURE AIR DRYING AND OXIDATION.
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) | 1965-02-12 | 1965-08-14 | 1966-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-02-12 | 1969-08-14 | 1970-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-02-12 | 1973-08-14 | 1974-02-13 | $7700.00 | Window Closed / Lapsed |