Patent US2900348A successfully refreshed from Google Patents.
US2900348A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of silica sols
Assignee: WR Grace and Co
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Filing: 1954-02-02
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Granted: 1959-08-18
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Expires: 1974-02-02
Abstract
No abstract record available.
Inventors
- 👤 Ahlberg Jacob Elston
- 👤 Edgar A Simpson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:07
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/14; C01B33/141; Y; Y10; Y10S; Y10S260/00; Y10S260/15; Y10S260/16
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
142 words
A METHOD OF PREPARING A SILICA SOL STABLE AT SILICA CONCENTRATIONS UP TO 30% WHICH COMPRISES PREPARING AN ALKALINE SILICA HYDROGEL BY INCOMPLETELY NEUTRALIZING AN ALKALI METAL SILICATE SOLUTION BY COMMINGLING THEREWITH LESS THAN THE STOICHIOMETRIC AMOUNT OF ACID REQUIRED TO NEUTRALIZE THE ALKALI IN THE SILICATE SOLUTION, WASHING SAID HYDROGEL WITH DEIONIZED WATER TO REMOVE SOFUBLE ALKALI METALS SALTS, GRADUALLY RAISING THE TEMPERATURE OF SAID HYDROGEL AT A PH BETWEEN 9 AND 9.5 UNDER NON-EVEPORATIVE CONDITIONS OVER A PERIOD OF ABOUT 6 HOURS TO 95*-100* C. MAINTAING THE HYDROGEL AT SAID TEMPERATURE THEREBY CONVERTING BETWEEN 98% AND 100% OF SAID HYDROGEL TO SILICA HYDROSOL, FURTHER HEAT TREATING SAID HYDROSOL UNDER NON-EVAPORATIVE CONDITIONS AT A FIXED TEMPERATURE WITHIN THE RANGE 160*-210* C. FOR A PERIOD OF 45-90 MINUTES TO STABLIZE THE MICELLES OF THE COLLOID AGAINST FURTHER GROWTH, AND CONCENTRATING THE SOL.
Claim 2
Independent Claim
142 words
A METHOD OF PREPARING A SILICA SOL STABLE AT SILICA CONCENTRATIONS UP TO 30% WHICH COMPRISES PREPARING AN ALKALINE SILICA HYDROGEL BY INCOMPLETELY NEUTRALIZING AN ALKALI METAL SILICATE SOLUTION BY COMMINGLING THEREWITH LESS THAN THE STOICHIOMETRIC AMOUNT OF ACID REQUIRED TO NEUTRALIZE THE ALKALI IN THE SILICATE SOLUTION, WASHING SAID HYDROGEL WITH DEIONIZED WATER TO REMOVE SOFUBLE ALKALI METALS SALTS, GRADUALLY RAISING THE TEMPERATURE OF SAID HYDROGEL AT A PH BETWEEN 9 AND 9.5 UNDER NON-EVEPORATIVE CONDITIONS OVER A PERIOD OF ABOUT 6 HOURS TO 95*-100* C. MAINTAING THE HYDROGEL AT SAID TEMPERATURE THEREBY CONVERTING BETWEEN 98% AND 100% OF SAID HYDROGEL TO SILICA HYDROSOL, FURTHER HEAT TREATING SAID HYDROSOL UNDER NON-EVAPORATIVE CONDITIONS AT A FIXED TEMPERATURE WITHIN THE RANGE 160*-210* C. FOR A PERIOD OF 45-90 MINUTES TO STABLIZE THE MICELLES OF THE COLLOID AGAINST FURTHER GROWTH, AND CONCENTRATING THE SOL.
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) | 1962-08-17 | 1963-02-16 | 1963-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-08-17 | 1967-02-16 | 1967-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-08-17 | 1971-02-16 | 1971-08-18 | $7700.00 | Window Closed / Lapsed |