US3235331A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing finely divided siliceous pigments
Assignee: Evonik Operations GmbH
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Filing: 1962-03-02
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Granted: 1966-02-15
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Expires: 1982-03-02
Abstract
No abstract record available.
Inventors
- 👤 Nauroth Peter
- 👤 Becker Adam
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:02
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/18; B; B82; B82Y; B82Y30/00; C01B33/187; C01B33/193; C08; C08K; C08K3/00; C08K3/34; C08K3/36; C01P; C01P2004/00; C01P2004/60; C01P2004/64; C01P2006/00; C01P2006/12; C01P2006/22
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
137 words
A METHOD OF PREPARING FINELY DIVIDED SICEOUS PIGMENT WHICH COMPRISES ESTABLISHING AN AQUEOUS POOL OF ALKALI METAL SILICATE CONTAINING FROM 5 TO 25 GRAMS PER LITER OF SIO2 AND HAVING A PH OF 10 TO 12, ADDING SEPARATELY TO THE POOL FURTHER ALKALI METAL SILICATE AND AN ACIDIFICATION AGENT REACTIVE WITH ALKALI METAL SILICATE TO PRODUCE SILICEOUS PRODUCT, AND CONTINUING SAID ADDITION OF ACIDIFICATION AGENT AND SAID SILICATE UNTIL THE SIO2 CONTENT OF THE SLURRY IS AT LEAST ABOUT 50 GRAMS PER LITER AND THE VISCOSITY OF THE POOL RISES THROUGH A MAXIMUM AND THEN FALLS TO A SUBSTANTIALLY LOWER VISCOSITY THAN SAID MAXIMUM VISCOSITY AND PROPORTIONING THE AMOUNT OF ALKALI METAL SILICATE AND ACIDIFICATION AGENT BEING ADDED WHEREBY TO MAINTAIN THE PH OF THE POOL AT 10 TO 11.5 THROUGHOUT THE MAJOR PORTION OF THE REACTION.
Claim 2
Independent Claim
137 words
A METHOD OF PREPARING FINELY DIVIDED SICEOUS PIGMENT WHICH COMPRISES ESTABLISHING AN AQUEOUS POOL OF ALKALI METAL SILICATE CONTAINING FROM 5 TO 25 GRAMS PER LITER OF SIO2 AND HAVING A PH OF 10 TO 12, ADDING SEPARATELY TO THE POOL FURTHER ALKALI METAL SILICATE AND AN ACIDIFICATION AGENT REACTIVE WITH ALKALI METAL SILICATE TO PRODUCE SILICEOUS PRODUCT, AND CONTINUING SAID ADDITION OF ACIDIFICATION AGENT AND SAID SILICATE UNTIL THE SIO2 CONTENT OF THE SLURRY IS AT LEAST ABOUT 50 GRAMS PER LITER AND THE VISCOSITY OF THE POOL RISES THROUGH A MAXIMUM AND THEN FALLS TO A SUBSTANTIALLY LOWER VISCOSITY THAN SAID MAXIMUM VISCOSITY AND PROPORTIONING THE AMOUNT OF ALKALI METAL SILICATE AND ACIDIFICATION AGENT BEING ADDED WHEREBY TO MAINTAIN THE PH OF THE POOL AT 10 TO 11.5 THROUGHOUT THE MAJOR PORTION OF THE REACTION.
References Cited (Backward Citations)
US2358201A
Cited
US2496736A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-02-14 | 1969-08-16 | 1970-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-02-14 | 1973-08-16 | 1974-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-02-14 | 1977-08-16 | 1978-02-15 | $7700.00 | Window Closed / Lapsed |