Patent US3890249A successfully refreshed from Google Patents.
US3890249A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silica preparation
Assignee: Phillips Petroleum Co
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Filing: 1972-11-29
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Granted: 1975-06-17
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Expires: 1992-11-29
Abstract
Abstract A method of producing a xerogel which involves passing a solvent in which water is soluble through a hydrogel under conditions to remove water from the hydrogel and to form a xerogel.
Inventors
- 👤 Richard E Dietz
- 👤 Joseph A Delap
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:42
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/16; B; B01; B01D; B01D12/00; B01J; B01J13/00; B01J13/0052; B01J13/0056; B01J21/00; B01J21/06; B01J21/08; B01J37/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
104 words
A METHOD OF PREPARING A SILICA-CONTAINING XEROGEL WHICH COMPRISES: A. CONTACTING A SILICA-CONTAINING HYDROGEL WITH AN ORGANIC SOLVENT IN WHICH WATER IS SOLUBLE SAID SOLVENT AT A FIRST TEMPERATURE ELEVATED ABOVE THE ATMOSPHERIC BOILING POINT OF SAID ORGANIC SOLVENT SAID SOLVENT BEING MAINTAINED IN THE LIQUID PHASE BY SUPERATMOSPHERIC PRESSURE, TO REMOVE WATER FROM SAID HYDROGEL AND TO FORM A XEROGEL AND TO FORM A SOLVENT-WATER SOLUTION; B. SEPARATING SAID SOLVENT-WATER SOLUTION FROM SAID XEROGEL; C. COOLING SAID SOLVENT-WATER SOLUTION TO A SECOND TEMPERATURE LESS THAN SAID FIST TEMPERATURE TO FORM A WATER-RICH PHASE AND A SOLVENT-RICH PHASE; AND D. RECOVERING THE SILICA-CONTAINING XEROGEL.
Claim 2
Independent Claim
104 words
A METHOD OF PREPARING A SILICA-CONTAINING XEROGEL WHICH COMPRISES: A. CONTACTING A SILICA-CONTAINING HYDROGEL WITH AN ORGANIC SOLVENT IN WHICH WATER IS SOLUBLE SAID SOLVENT AT A FIRST TEMPERATURE ELEVATED ABOVE THE ATMOSPHERIC BOILING POINT OF SAID ORGANIC SOLVENT SAID SOLVENT BEING MAINTAINED IN THE LIQUID PHASE BY SUPERATMOSPHERIC PRESSURE, TO REMOVE WATER FROM SAID HYDROGEL AND TO FORM A XEROGEL AND TO FORM A SOLVENT-WATER SOLUTION; B. SEPARATING SAID SOLVENT-WATER SOLUTION FROM SAID XEROGEL; C. COOLING SAID SOLVENT-WATER SOLUTION TO A SECOND TEMPERATURE LESS THAN SAID FIST TEMPERATURE TO FORM A WATER-RICH PHASE AND A SOLVENT-RICH PHASE; AND D. RECOVERING THE SILICA-CONTAINING XEROGEL.
Claim 3
Dependent Claim
34 words
The method of claim 1 in which said solvent-rich phase is separated from said water-rich phase and said solvent-rich phase is heated and introduced into contact with saiD hydrogel as defined in step (a).
Claim 4
Dependent Claim
35 words
The method of claim 1 in which said solvent is introduced into contact with said hydrogel at a first pressure and the solvent-water solution is cooled at a second pressure less than said first pressure.
Claim 5
Dependent Claim
24 words
The method of claim 2 in which said organic solvent is selected from the group consisting of aliphatic esters, aliphatic ketones and aliphatic alcohols.
Claim 6
Dependent Claim
24 words
The method of claim 1 in which said solvent is introduced into contact with said hydrogel and is cooled at a substantially constant pressure.
Claim 7
Dependent Claim
13 words
The method of claim 2 in which said solvent-rich phase comprises ethyl acetate.
Claim 8
Dependent Claim
21 words
The method of claim 2 in which said xerogel is contacted with said solvent in the vapor state prior to recovery.
Claim 9
Dependent Claim
19 words
The method of claim 2 in which said hydrogel comprises silica, a chromium compound and, optionally, a titanium compound.
Claim 10
Dependent Claim
23 words
The method of claim 7 in which said xerogel is contacted with nitrogen after being contacted with said solvent in the vapor state.
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) | 1978-06-16 | 1978-12-16 | 1979-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-16 | 1982-12-16 | 1983-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-16 | 1986-12-16 | 1987-06-17 | $7700.00 | Window Closed / Lapsed |