Patent US3607044A successfully refreshed from Google Patents.
US3607044A
Expired / Lapsed
US
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Process of improving formed silica gels
Assignee: Huels AG
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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 12:27
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.
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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) | 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 |