US3607044A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of improving formed silica gels
Assignee: Huels AG
•
Filing: 1968-09-27
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Granted: 1971-09-21
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Expires: 1988-09-27
Abstract
Abstract Formed bodies of silica gel are hardened, without adversely influencing activity, by treating the bodies with vapor of a low molecular weight alcohol (e.g. methanol) containing up to 3 volume percent of water vapor, at a temperature gradually rising from 100* to 350* C., during a period of 20-120 minutes, and thereafter slowly cooling the so-treated bodies.
Inventors
- 👤 Ferdinand List
- 👤 Helmut Alfs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:41
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/02; B01J20/10; B01J20/103; C; C01; C01B; C01B33/00; C01B33/113
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
34 words
The process defined in claim 1 in which the temperature of the formed gel-alcohol mixture is slowly increased through the range from 240* to 300* C. in a period of at least 30 minutes.
Claim 2
Dependent Claim
23 words
The process defined in claim 1 in which the formed silica gel is maintained in motion during a substantial part of the treatment.
References Cited (Backward Citations)
US2093454A
Cited
US2698305A
Cited
US2757073A
Cited
US2865782A
Cited
US3079234A
Cited
US3053627A
Cited
US3161468A
Cited
US3328124A
Cited
US3208953A
Cited
US3250726A
Cited
US3367742A
Cited
US3363979A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-20 | 1975-03-22 | 1975-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-20 | 1979-03-22 | 1979-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-20 | 1983-03-22 | 1983-09-21 | $7700.00 | Window Closed / Lapsed |