Patent EP0454239A2 successfully refreshed from Google Patents.
EP0454239A2
Expired / Lapsed
EP
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Inorganic oxide aerogel microbeads of narrow pore diameter distribution and the method for their preparation
Assignee: Enichem SpA
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Filing: 1991-04-19
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Granted: —
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Expires: 2011-04-19
Abstract
Abstract Microbeads of aerogels of one or more oxides are characterised by a high porosity and the fact that at least 90% of the pores present have a diameter lying within a very narrow range. The surface area exceeds 300 m²/g and more frequently exceeds 500 m²/g, the total pore volume exceeding 1 ml/g.
Inventors
- 👤 Guido Cogliato
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 23:34
CPC Classifications
C; C01; C01B; C01B13/00; C01B13/14; C01B13/32; C01B33/00; C01B33/113; C01B33/12; C01B33/14; C01B33/157; C01B33/158; C01B33/1585; C01P; C01P2002/00; C01P2002/30; C01P2002/34; C01P2006/00; C01P2006/12; C01P2006/14; C01P2006/16
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
72 words
Microbeads of aerogels of one or more oxides of metals of Groups II to VI, VIIB and VIII of the Periodic Table and characterised by a surface area exceeding 300 m²/g, a total pore volume exceeding 1 ml/g, and the fact that at least 90% of the pores present have a diameter lying within a very narrow range, the difference between the maximum and minimum of this range never exceeding 50 Å.
Claim 2
Dependent Claim
30 words
Aerogel microbeads as claimed in the preceding claim, wherein the oxide metal is preferably chosen as one or more from Al, Si, Ti, B, La, Zr, Cr, Sn and Mg.
Claim 3
Dependent Claim
13 words
Aerogel microbeads as claimed in the preceding claims, wherein the oxide is SiO₂.
Claim 4
Dependent Claim
14 words
Aerogel microbeads as claimed in claim 2, wherein the oxide is an SiO₂-TiO₂ mixture.
Claim 5
Dependent Claim
14 words
Aerogel microbeads as claimed in claim 2, wherein the oxide is an SiO₂-MgO mixture.
Claim 6
Dependent Claim
59 words
A process for preparing the aerogels of one or more metal oxides claimed in claim 1, comprising the following operations: - hydrolyzing at least one derivative of the metals of interest; - transforming the colloidal solution into sol droplets; - transforming the sol droplets into gel particles; - washing the gel particles; - drying these latter under hypercritical conditions.
Claim 7
Dependent Claim
29 words
A process for preparing aerogels of one or more metal oxides as claimed in the preceding claim, wherein the initial hydrolysis is effected on at least one metal alkoxide.
Claim 8
Dependent Claim
34 words
A process for preparing aerogels of one or more metal oxides as claimed in claim 6, wherein the initial hydrolysis is effected on a mixture of alkoxides and halides of the metals of interest.
Claim 9
Dependent Claim
35 words
A process for preparing aerogels of one or more metal oxides as claimed in claim 6, wherein the initial hydrolysis is effected in the presence of a catalyst chosen from acids, bases and inorganic salts.
Claim 10
Dependent Claim
47 words
A process for preparing aerogels of one or more metal oxides as claimed in the preceding claim, wherein the hydrolysis is effected in the presence of a substance which favours the obtaining of the desired porosity, this substance being chosen from ethylene glycol, dimethylformamide and oxalic acid.
Claim 11
Dependent Claim
32 words
A process for preparing aerogels of one or more metal oxides as claimed in claim 9, characterised in that the preliminary hydrolysis is accompanied by the removal of part of the solvent.
Claim 12
Dependent Claim
27 words
A process for preparing aerogels of one or more metal oxides as claimed in the preceding claim, wherein the solvent is removed by evaporation at low temperature.
Claim 13
Dependent Claim
39 words
A process for preparing aerogels of one or more metal oxides as claimed in claim 9, characterised in that the drying under hypercritical conditions is effected in the presence of an alcohol containing a small number of carbon atoms.
Claim 14
Dependent Claim
32 words
A process for preparing aerogels of one or more metal oxides as claimed in claim 9, characterised in that the drying under hypercritical conditions is effected in the presence of carbon dioxide.
References Cited (Backward Citations)
No citation records indexed.
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