Claims
- 1. Process for the sub-critical drying of a lyogel to form an aerogel, characterized in that the lyogel is treated with a heat-transfer liquid having a temperature above the boiling temperature of the pore liquid of the lyogel under system pressure, and the dried aerogel is then separated from the heat-transfer liquid.
- 2. Process according to claim 1, characterized in that the heat transfer liquid is only partially miscible with the pore liquid of the lyogel.
- 3. Process according to claim 1, characterized in that the heat-transfer liquid is not partially miscible with the pore liquid of the lyogel.
- 4. Process according to claim 1, characterized in that, for drying, a heat-transfer liquid is selected that barely wets or does not wet the dry aerogel.
- 5. Process according to claim 1, characterized in that, for drying, a heat-transfer liquid is selected that does not wet the dry aerooel.
- 6. Process according to claim 1, characterized in that SiO.sub.2 lyogels which have been rendered hydrophobic by surface modification are dried.
- 7. Process according to claim 1, characterized in that water is used as the heat-transfer liquid.
- 8. Process according to claim 1, characterized in that the dried aerogel is separated from the heat-transfer liquid by using the density difference between wet and dry material.
- 9. Process according to claim 1, characterized in that the aerogel, using its buoyancy in the heat-transfer liquid, is carried to the surface and is skimmed off from the surface.
- 10. Process according to claim 1, characterized in that the lyogel is placed on a band filter and the heat-transfer liquid is applied to the lyogel by means of a washing device.
Parent Case Info
This application is a 371 of PCT/EP97/00879, filed Feb. 24, 1997, which is a continuation of U.S. application Ser. No. 08/611,058, filed Mar. 5, 1996, U.S. Pat. No. 5,680,713.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
102e Date |
371c Date |
PCT/EP97/00879 |
2/24/1997 |
|
|
7/2/1999 |
7/2/1999 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO97/32662 |
9/12/1997 |
|
|
US Referenced Citations (6)
Number |
Name |
Date |
Kind |
2503913 |
Kimberlin et al. |
Apr 1950 |
|
4667417 |
Graser et al. |
May 1987 |
|
5243769 |
Wang et al. |
Sep 1993 |
|
5473826 |
Kirkbir et al. |
Dec 1995 |
|
5680713 |
Forbert et al. |
Oct 1997 |
|
5811031 |
Jansen et al. |
Sep 1998 |
|
Foreign Referenced Citations (1)
Number |
Date |
Country |
4316540 A1 |
Nov 1994 |
DEX |
Non-Patent Literature Citations (1)
Entry |
PCT Application, WO 94/25149, World Intellectual Property Organization, Nov. 1994. |
Continuations (1)
|
Number |
Date |
Country |
Parent |
611058 |
Mar 1996 |
|