Patent US4894357A successfully refreshed from Google Patents.
US4894357A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for adjusting the structural and/or surface character of oxides
Assignee: Kali Chemie AG
•
Filing: 1985-10-31
•
Granted: 1990-01-16
•
Expires: 2005-10-31
Abstract
Abstract A process for adjusting at least one of the structural and surface characteristics of an oxide material, e.g. SiO 2 or Al 2 O 3 , by dehydration of a water-containing oxide gel under supercritical conditions by extracting the water with an extraction agent such as CO 2 at a pressure above the critical pressure of the extraction agent.
Inventors
- 👤 Bernd Hupe
- 👤 Robert Walter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:07
CPC Classifications
B; B01; B01D; B01D11/00; B01D11/02; B01D11/0203; B01J; B01J13/00; B01J13/0091; C; C01; C01B; C01B13/00; C01B13/14; C01B13/145; C01B33/00; C01B33/113; C01B33/12; C01B33/14; C01B33/157; C01B33/158; C01B33/1585; C01F; C01F5/00; C01F5/02; C01F7/00; C01F7/02; C01F7/44; C01F7/447; C01F7/448; C01G; C01G23/00; C01G23/04; C01G23/047; C01G25/00; C01G25/02; C01G27/00; C01G27/02; C01G9/00; C01G9/02; C01P; C01P2004/00; C01P2004/30; C01P2004/32; C01P2006/00; C01P2006/12; C01P2006/14; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/54
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
112 words
A process for dehydration of a water-containing, inorganic oxide gel under supercritical conditions, wherein a water-containing, inorganic oxide gel having a water content from about 30 to about 95 weight percent is produced by combining an aqueous solution of a salt selected from the group consisting of salts of magnesium, aluminum, silicon, zinc, titanium, zirconium, hafnium and mixtures thereof with an inorganic acid followed by base exchange treatment, and is dehydrated to a free water content of less than 1 percent by treatment with an extraction agent which is gaseous at standard temperature and pressure, and said treatment is carried out at a pressure above the critical pressure of the extraction agent.
Claim 2
Dependent Claim
112 words
A process for dehydration of a water-containing, inorganic oxide gel under supercritical conditions, wherein a water-containing, inorganic oxide gel having a water content from about 30 to about 95 weight percent is produced by combining an aqueous solution of a salt selected from the group consisting of salts of magnesium, aluminum, silicon, zinc, titanium, zirconium, hafnium and mixtures thereof with an inorganic acid followed by base exchange treatment, and is dehydrated to a free water content of less than 1 percent by treatment with an extraction agent which is gaseous at standard temperature and pressure, and said treatment is carried out at a pressure above the critical pressure of the extraction agent.
Claim 3
Dependent Claim
38 words
A process according to claim 1, wherein the oxide gel is formed of material selected from the group consisting of oxides of magnesium, aluminum, silicon, zinc, titanium, zirconium, hafnium, and mixtures of one or more of the foregoing.
Claim 4
Dependent Claim
28 words
A process according to claim 2, wherein said oxide comprises a material selected from the group consisting of oxides of silicon, aluminum and mixtures of silicon and aluminum.
Claim 5
Dependent Claim
22 words
A process according to claim 1, wherein the oxide gel has a water content from about 40 to about 90 weight percent.
Claim 6
Dependent Claim
33 words
A process according to claim 1, wherein the oxide gels which are treated are gels which have not been subjected to a temperature over 100 C. prior to treatment with the extraction agent.
Claim 7
Dependent Claim
26 words
A process according to claim 5, wherein the oxide gels which are treated and gels which have not been subjected to a temperature over 50 C.
Claim 8
Dependent Claim
85 words
A process according to claim 1, wherein the extraction agent is selected from the group consisting of CO 2 , CHF 3 , CF 3 --CF 3 , CHC1═CF 2 , CF 3 --CH 3 ,CHF 2 --CH 3 , CHF 2 C1, CF 3 C1, CF 2 =CF 2 , CF 2 C1 2 , C 3 F 8 , SF 6 , N 2 O, SO 2 , ethane, ethylene, propane, propylene, propylene, air, N 2 , NH 3 , methylamine, and ethylamine.
Claim 9
Dependent Claim
14 words
A process according to claim 7, wherein the extraction agent is CO 2 .
Claim 10
Dependent Claim
17 words
A process according to claim 1, wherein the dehydration is performed at a temperature above 10 C.
Claim 11
Dependent Claim
17 words
A process according to claim 9, wherein the dehydration is performed at a temperature above 25° C.
Claim 12
Dependent Claim
20 words
A process according to claim 1, wherein the dehydration is carried out at a temperature not greater than 100° C.
Claim 13
Dependent Claim
27 words
A process according to claim 1, wherein the dehydration is carried out at a pressure above the critical pressure of the extraction agent up to 1000 bar.
Claim 14
Dependent Claim
28 words
A process according to claim 12, wherein the dehydration process is carried out at a pressure above the critical pressure of the extraction agent up to 500 bar.
Claim 15
Dependent Claim
17 words
A process according to claim 1, wherein the treated oxide gel is in the form of balls.
Claim 16
Dependent Claim
127 words
A process for dehydration of a water-containing, inorganic oxide gel under supercritical conditions, wherein an inorganic oxide gel comprising a solvent having a water content of at least 50 weight percent of the total solvent, whereby said gel comprises at least about 30 weight percent water, is produced by combining an aqueous solution of a salt selected from the group consisting of salts of magnesium, aluminum, silicon, zinc, titanium, zirconium, hafnium and mixtures thereof with an inorganic acid followed by base exchange treatment, and is dehydration to a free water content of less than 1 percent by treatment with an extraction agent which is gaseous at standard temperature and pressure, and said treatment is carried out at a pressure above the critical pressure of the extraction agent.
Claim 17
Dependent Claim
127 words
A process for dehydration of a water-containing, inorganic oxide gel under supercritical conditions, wherein an inorganic oxide gel comprising a solvent having a water content of at least 50 weight percent of the total solvent, whereby said gel comprises at least about 30 weight percent water, is produced by combining an aqueous solution of a salt selected from the group consisting of salts of magnesium, aluminum, silicon, zinc, titanium, zirconium, hafnium and mixtures thereof with an inorganic acid followed by base exchange treatment, and is dehydration to a free water content of less than 1 percent by treatment with an extraction agent which is gaseous at standard temperature and pressure, and said treatment is carried out at a pressure above the critical pressure of the extraction agent.
Claim 18
Dependent Claim
19 words
A process according to claim 15, wherein said solvent has a water content of at least 70 weight percent.
Claim 19
Dependent Claim
19 words
A process according to claim 15, wherein said solvent has a water content of at least 90 weight percent.
Claim 20
Dependent Claim
13 words
A process according to claim 15, wherein said solvent consists essentially of water.
References Cited (Backward Citations)
US2093454A
Cited
US2978298A
Cited
GB946026A
Cited
US3969196A
Cited
US3977993A
Cited
US4246139A
Cited
US4389385A
Cited
US4055904A
Cited
US4511508A
Cited
EP0065106A2
Cited
US4632837A
Cited
US4432956A
Cited
US4478987A
Cited
US4717708A
Cited
EP0171722A2
Cited
US4667417A
Cited
US4619908A
Cited
US4622310A
Cited
US4610863A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-15 | 1993-07-17 | 1994-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-15 | 1997-07-17 | 1998-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-15 | 2001-07-17 | 2002-01-16 | $7700.00 | Window Closed / Lapsed |