Patent FR2429667B3 successfully refreshed from Google Patents.
US5122291A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal insulating material based on pigment containing silica aerogels
Assignee: BASF SE
•
Filing: 1990-05-04
•
Granted: 1992-06-16
•
Expires: 2010-05-04
Abstract
Abstract A thermal insulating material based on a pigment-containing silica aerogel is obtainable by a) reacting an aqueous dispersion of sodium silicate and a pigment with a strong acid or sodium silicate with a pigment-containing strong acid to give a pigment-containing silica hydrogen, the pigment being such that it scatters, absorbs or reflects infrared radiation of wavelength 3-10 μm, b) substantially freeing the resulting pigment-containing silica hydrogel from ionic constituents by washing with water, c) displacing the water in the hydrogen by a low-boiling liquid which is inert toward the pigment-containing silica gel, d) heating the liquid-containing silica gel thus obtained under supercritical conditions while completely covered with the liquid, and e) subsequently removing the liquid from the solid by flash vaporization at supercritical temperature.
Inventors
- 👤 Bernardo Wolff
- 👤 Manfred Mielke
- 👤 Guenther Seybold
- 👤 Werner Ostertag
- 👤 Jochen Fricke
- 👤 Roland Caps
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:16
CPC Classifications
F; F16; F16L; F16L59/00; F16L59/02; F16L59/028; C; C04; C04B; C04B14/00; C04B14/02; C04B14/04; C04B14/06; C04B14/064; C04B30/00; F16L59/08
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
123 words
A thermal insulating material based on a pigment-containing silica aerogel, obtainable by a) reacting an aqueous dispersion of sodium silicate and a pigment with a strong acid or sodium silicate with a pigment-containing strong acid to give a pigment-containing silica hydrogel, the pigment being such that it scatters, absorbs or reflects infrared radiation of wavelength 3-10 μm, b) substantially freeing the resulting pigment-containing silica hydrogel from ionic constituents by washing with water, c) displacing the water in the hydrogel by a low-boiling liquid which is inert toward the pigment-containing silica gel, d) heating the liquid-containing silica gel thus obtained under supercritical conditions while completely covered with the liquid, and e) subsequently removing the liquid from the solid by flash vaporization at supercritical temperature.
Claim 2
Dependent Claim
123 words
A thermal insulating material based on a pigment-containing silica aerogel, obtainable by a) reacting an aqueous dispersion of sodium silicate and a pigment with a strong acid or sodium silicate with a pigment-containing strong acid to give a pigment-containing silica hydrogel, the pigment being such that it scatters, absorbs or reflects infrared radiation of wavelength 3-10 μm, b) substantially freeing the resulting pigment-containing silica hydrogel from ionic constituents by washing with water, c) displacing the water in the hydrogel by a low-boiling liquid which is inert toward the pigment-containing silica gel, d) heating the liquid-containing silica gel thus obtained under supercritical conditions while completely covered with the liquid, and e) subsequently removing the liquid from the solid by flash vaporization at supercritical temperature.
Claim 3
Dependent Claim
20 words
A thermal insulating material as claimed in claim 1, wherein the pigment content is from 0.5 to 75% by weight.
Claim 4
Dependent Claim
20 words
A thermal insulating material as claimed in claim 2, wherein the pigment content is from 5 to 40% by weight.
Claim 5
Dependent Claim
35 words
A thermal insulating material as claimed in claim 1, wherein the reaction product formed in stage (a) of claim 1 is cast as a shaped article before being gelled to form the coherent silica hydrogel.
Claim 6
Dependent Claim
39 words
A thermal insulating material as claimed in claim 1, wherein the silica aerogel obtainable in stages (d) and (e) of claim 1 has been comminuted into free-flowing granules having an average largest dimension of from 0.01 to 15 mm.
Claim 7
Dependent Claim
32 words
A thermal insulating material as claimed in claim 1, obtainable by reacting the components of stage (a) in a mixing nozzle and spraying the reaction product in the form of fine droplets.
Claim 8
Dependent Claim
29 words
A thermal insulating material as claimed in claim 1, wherein the supercritical treatment in stage (d) has been carried out in the presence of an organosilicon compound hydrophobizing agent.
Claim 9
Dependent Claim
129 words
A process for preparing a thermal insulating material on the basis of a pigment-containing silica aerogel, which comprises a) reacting an aqueous dispersion of sodium silicate and a pigment with a strong acid or sodium silicate with a pigment-containing strong acid to give a pigment-containing silica hydrogel, the pigment being such that it scatters, absorbs or reflects infrared radiation of wavelength 3-10 μm, b) substantially freeing the resulting pigment-containing silica hydrogel from ionic constituents by washing with water, c) displacing the water in the hydrogel by a low-boiling liquid which is inert toward the pigment-containing silica gel, d) heating the liquid-containing silica gel thus obtained under supercritical conditions while completely covered with the liquid, and e) subsequently removing the liquid from the solid by flash vaporization at supercritical temperature.
Claim 10
Dependent Claim
129 words
A process for preparing a thermal insulating material on the basis of a pigment-containing silica aerogel, which comprises a) reacting an aqueous dispersion of sodium silicate and a pigment with a strong acid or sodium silicate with a pigment-containing strong acid to give a pigment-containing silica hydrogel, the pigment being such that it scatters, absorbs or reflects infrared radiation of wavelength 3-10 μm, b) substantially freeing the resulting pigment-containing silica hydrogel from ionic constituents by washing with water, c) displacing the water in the hydrogel by a low-boiling liquid which is inert toward the pigment-containing silica gel, d) heating the liquid-containing silica gel thus obtained under supercritical conditions while completely covered with the liquid, and e) subsequently removing the liquid from the solid by flash vaporization at supercritical temperature.
References Cited (Backward Citations)
US3669899A
Cited
DE2103243A1
Cited
US3840382A
Cited
US4011096A
Cited
DE2806367A1
Cited
US4212925A
Cited
US4221672A
Cited
EP0013387A1
Cited
DE3038142A1
Cited
US4403023A
Cited
US4667417A
Cited
US4786618A
Cited
US4954327A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-06-16 | 1995-12-16 | 1996-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-16 | 1999-12-16 | 2000-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-16 | 2003-12-16 | 2004-06-16 | $7700.00 | Window Closed / Lapsed |