US2549261A
Expired / Lapsed
US
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Calcium sulfate-extended titanium dioxide pigments
Assignee: EIDP Inc
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Filing: 1948-02-21
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Granted: 1951-04-17
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Expires: 1968-02-21
Abstract
No abstract record available.
Inventors
- 👤 Roy W Sullivan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:18
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/0081; C09C1/0084; C01; C01P; C01P2004/00; C01P2004/80; C01P2006/00; C01P2006/12; C01P2006/60; C01P2006/80; C01P2006/90
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
78 words
IN A PROCESS FOR THE PRODUCTION OF AN IMPROVED HYDROPHILIC COMPOSITE PIGMENT COMPRISING INSOLUBEL ANHYDRITE CALCIUM SULFATE AND RUTILE TITANIUM DIOXIDE, THE STEPS OF SUBJECTING FINELY DIVIDED GYPSUM TO A TEMPERATURE BETWEEN 600* C. AND 825* C. UNTIL CONVERSION TO A POROUS ANHYDRITE FORM OF CALCIUM SULPHATE RESULTS, BLENDING SAID ANHYDRITE WITH PIGMENTARY TITANIUM DIOXIDE IN THE RUTILE CRYSTILLINE FORM AND SUBJECTING THE RESULTING MIXTURE TO DUAL GRINDING TREATMENT CONSISTING OF PRESSURE PULVERIZATION FOLLOWED BY FLUID ENERGY MILLING.
Claim 2
Dependent Claim
78 words
IN A PROCESS FOR THE PRODUCTION OF AN IMPROVED HYDROPHILIC COMPOSITE PIGMENT COMPRISING INSOLUBEL ANHYDRITE CALCIUM SULFATE AND RUTILE TITANIUM DIOXIDE, THE STEPS OF SUBJECTING FINELY DIVIDED GYPSUM TO A TEMPERATURE BETWEEN 600* C. AND 825* C. UNTIL CONVERSION TO A POROUS ANHYDRITE FORM OF CALCIUM SULPHATE RESULTS, BLENDING SAID ANHYDRITE WITH PIGMENTARY TITANIUM DIOXIDE IN THE RUTILE CRYSTILLINE FORM AND SUBJECTING THE RESULTING MIXTURE TO DUAL GRINDING TREATMENT CONSISTING OF PRESSURE PULVERIZATION FOLLOWED BY FLUID ENERGY MILLING.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-04-16 | 1954-10-16 | 1955-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-04-16 | 1958-10-16 | 1959-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-04-16 | 1962-10-16 | 1963-04-17 | $7700.00 | Window Closed / Lapsed |