Preparation of monolithic silica aerogels, the aerogels thus obtained and their use for the preparation of silica glass articles and of heat-insulating materials
US4432956A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 1, 1982 |
| Grant date | Feb 21, 1984 |
| Priority date | — |
| Expiry date | Jun 1, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S65/901
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The invention relates to a process for the preparation of monolithic silica aerogels by drying silica gels under hypercritical conditions, which is characterized by the absence of washing of the silica gel, a high heating rate in the autoclave and purging of the autoclave after substantial removal of the solvent. Other preferred conditions are the use of an amount of water not exceeding 1.5 times the stoichiometric amount for the hydrolysis, hypercritical conditions corresponding to a temperature of 265.degree.-275.degree. C. and to a pressure of 150-200 bars, and so on. Use of the aerogels for the preparation of silica glass bodies or articles and of heat-insulating materials.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.