The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 27, 1982
Filed:
Apr. 22, 1980
Guy von Dardel, S-222 24 Lund, SE;
Sten A Henning, S-240 10 Dalby, SE;
Leif O Svensson, S-240 10 Dalby, SE;
Other;
Abstract
Silica aerogel in the form of a substantially crack-free, preferably transparent block is described, together with a method for the preparation of such aerogel and use thereof in solar panels. The preparation is effected by means of hydrolysis of a tetraalkoxysilane, preferably tetramethoxysilane, in an alcohol, preferably methanol, in the presence of a catalyst, preferably ammonia, for the formation of an alcogel which is aged for approximately 10 days and washed with alcohol for removing water. The alcogel is thereafter treated in an autoclave by means of a temperature increase to above the critical point of the alcohol, isothermic pressure drop by means of the release of alcohol vapor, and temperature drop. The temperature increase, the pressure drop and the temperature drop take place at the such low mean rates that the aerogel does not crack. To this end, a total treatment time in the autoclave of at least 24 hours is required. After the autoclave treatment, a heat treatment at 500.degree. to 750.degree. C. is possibly carried out for further improving the transparency of the aerogel.