US4717708A
Expired / Lapsed
US
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Inorganic oxide aerogels and their preparation
Assignee: Akzo Nobel Inc
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Filing: 1983-12-27
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Granted: 1988-01-05
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Expires: 2003-12-27
Abstract
Abstract The invention is directed to inorganic oxide aerogels and the method of preparing such inorganic oxide aerogels which are characterized by high surface areas and high pore volume. The preparation comprises dissolving the inorganic alkoxide or metal salt in a solvent optionally containing a catalytic amount of an acid or base and hydrolyzing to form a gelled or colloidal material which is further treated with a fluid at or above its critical temperature and pressure to extract the solvent which is then dried to remove surface water.
Inventors
- 👤 Chung-Ping Cheng
- 👤 Paul A. Iacobucci
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 10:38
CPC Classifications
C; C01; C01G; C01G23/00; C01G23/04; C01G23/047; C01G23/053; C01B; C01B13/00; C01B13/14; B; B01; B01J; B01J13/00; B01J13/0004; B01J13/0047; B01J21/00; B01J21/06; B01J21/063; B01J21/066; B01J21/12; B01J23/00; B01J23/06; B01J35/00; B01J35/60; B01J35/61; B01J35/617; B01J35/63; B01J35/638; B01J37/00; B01J37/02; B01J37/03; B01J37/036; C01B13/18; C01B13/185; C01B13/32; C01B33/00; C01B33/113; C01B33/12; C01B33/14; C01B33/157; C01B33/158; C01B33/1585; C01F; C01F7/00; C01F7/02; C01F7/34; C01F7/36; C01G9/00; C01G9/02; C08; C08F; C08F10/00; B01J35/30; B01J35/31; B01J35/32; B01J37/031; B01J37/033; C01P; C01P2002/00; C01P2002/80; C01P2002/84; C01P2004/00; C01P2004/51; C01P2004/60; C01P2004/61; C01P2004/80; C01P2004/82; C01P2004/84; C01P2006/00; C01P2006/10; C01P2006/12; C01P2006/14
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
59 words
A method of preparing inorganic oxide aerogels comprising: (a) hydrolyzing a compound comprising at least one metal dissolved in a solvent, to produce a gel; (b) ageing the gel produced; (c) contacting the aged gel in an autoclave with a fluid above the critical temperature and pressure of the fluid to extract the solvent; and (d) drying the gel.
Claim 2
Independent Claim
59 words
A method of preparing inorganic oxide aerogels comprising: (a) hydrolyzing a compound comprising at least one metal dissolved in a solvent, to produce a gel; (b) ageing the gel produced; (c) contacting the aged gel in an autoclave with a fluid above the critical temperature and pressure of the fluid to extract the solvent; and (d) drying the gel.
Claim 3
Dependent Claim
42 words
The method of claim 1 further comprising depressurizing the vessel after step (c) at a rate necessary to maintain the temperature above the critical temperature of the fluid for the time necessary to prevent condensation and to obtain the solid dry aerogel.
Claim 4
Dependent Claim
26 words
The method of claim 1 wherein the metal is selected from Groups II to VI, Group VIIB and Group VIII of the Periodic Table of Elements.
Claim 5
Dependent Claim
10 words
The method of claim 3 wherein the metal is silicon.
Claim 6
Dependent Claim
10 words
The method of claim 3 wherein the metal is titanium.
Claim 7
Dependent Claim
10 words
The method of claim 3 wherein the metal is aluminum.
Claim 8
Dependent Claim
11 words
The method of claim 1 wherein the compound is an alkoxide
Claim 9
Dependent Claim
11 words
The method of claim 1 wherein the compound is a salt.
Claim 10
Dependent Claim
19 words
The method of claim 1 wherein the hydrolysis is conducted by the addition of a stoichiometric amount of water.
Claim 11
Dependent Claim
23 words
The method of claim 9 wherein the water added is from about 2 to about 10 times in excess of the stoichiometric amount.
Claim 12
Dependent Claim
21 words
The method of claim 10 wherein the water added is from about 2 to about 5 times in excess of stoichiometry.
Claim 13
Dependent Claim
16 words
The method of claim 1 wherein the hydrolysis is conducted in the presence of a catalyst.
Claim 14
Dependent Claim
11 words
The method of claim 12 wherein the catalyst is an acid.
Claim 15
Dependent Claim
11 words
The method of claim 12 wherein the catalyst is a base.
Claim 16
Dependent Claim
17 words
The method of claim 1 wherein the gel is aged from about 1 to about 14 days.
Claim 17
Dependent Claim
13 words
The method of claim 1 wherein the gel is washed prior to extraction.
Claim 18
Dependent Claim
13 words
The method of claim 16 wherein the gel is washed with a solvent.
Claim 19
Dependent Claim
16 words
The method of claim 17 wherein the solvent is a C 1 to C 5 alcohol.
Claim 20
Dependent Claim
16 words
The method of claim 1 wherein the extraction fluid has a low critical temperature and pressure.
Claim 21
Dependent Claim
12 words
The method of claim 19 wherein the fluid is CO 2 .
Claim 22
Dependent Claim
22 words
The method of claim 1 wherein the solvent used to dissolve the metal containing compound is a C 1 -C 5 alcohol.
Claim 23
Dependent Claim
10 words
The method of claim 21 wherein the alcohol is ethanol.
Claim 24
Dependent Claim
10 words
The method of claim 21 wherein the alcohol is isopropanol.
Claim 25
Dependent Claim
10 words
The method of claim 21 wherein the alcohol is sec-butanol.
Claim 26
Independent Claim
64 words
The method of preparing inorganic oxide aerogels comprising hydrolyzing a metal alkoxide dissolved in a solvent to produce a gel, ageing the gel and contacting the aged gel in an autoclave with an extraction fluid at not less than the critical temperature and pressure of the extraction fluid such that the solvent is extracted and drying the gel to obtain the dried aerogel product.
Claim 27
Independent Claim
64 words
The method of preparing inorganic oxide aerogels comprising hydrolyzing a metal alkoxide dissolved in a solvent to produce a gel, ageing the gel and contacting the aged gel in an autoclave with an extraction fluid at not less than the critical temperature and pressure of the extraction fluid such that the solvent is extracted and drying the gel to obtain the dried aerogel product.
Claim 28
Independent Claim
60 words
A method of preparing inorganic oxide aerogels comprising hydrolyzing a metal containing compound dissolved in a solvent to produce a gel, ageing the gel and contacting the aged gel in an autoclave with an extraction fluid at not less than its critical temperature and pressure such that the solvent is extracted, drying the gel to obtain the dried aerogel product.
Claim 29
Independent Claim
60 words
A method of preparing inorganic oxide aerogels comprising hydrolyzing a metal containing compound dissolved in a solvent to produce a gel, ageing the gel and contacting the aged gel in an autoclave with an extraction fluid at not less than its critical temperature and pressure such that the solvent is extracted, drying the gel to obtain the dried aerogel product.
Claim 30
Dependent Claim
44 words
The methed of claim 26 further comprising depressurizing the vessel after extraction of the solvent at a rate necessary to maintain the temperature above the critical temperature of the fluid for the time necessary to prevent condensation and to obtain the solid dry aerogel.
Claim 31
Dependent Claim
12 words
An inorganic oxide aerogel product, produced by the method of claim 1.
Claim 32
Dependent Claim
11 words
An inorganic oxide aerogel produced by the method of claim 26.
Claim 33
Dependent Claim
12 words
The inorganic oxide aerogel of claim 28 wherein the product is silica.
Claim 34
Dependent Claim
12 words
The inorganic oxide aerogel of claim 28 wherein the product is alumina.
Claim 35
Dependent Claim
15 words
The inorganic oxide aerogel of claim 28 wherein the product is a zinc oxide aerogel.
Claim 36
Dependent Claim
14 words
The inorganic oxide aerogel of claim 28 wherein the product is a silica-titania complex.
Claim 37
Dependent Claim
14 words
The inorganic oxide aerogel of claim 28 wherein the product is a zirconia-silica complex.
Claim 38
Dependent Claim
14 words
The inorganic oxide aerogel of claim 28 wherein the product is a silica-alumina complex.
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) | 1991-01-04 | 1991-07-06 | 1992-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-04 | 1995-07-06 | 1996-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-04 | 1999-07-06 | 2000-01-05 | $7700.00 | Window Closed / Lapsed |