Thermal insulating flexible ceramic containing flame hydrolysis produced

Abstract

A thermal insulating flexible ceramic based on a microporous oxide aerogel obtained from flame hydrolysis, especially a silica aerogel with elastically bending or limply bending inorganic fibers and possibly additional additive substances, such as opacifiers, has a portion by weight between about 10 and 30% of the flexible ceramic in the form of fibers with a length of more than 10 mm with a comparatively high bulk density of about 200 to 250 kg/m.sup.3, especially of about 350 kg/m.sup.3. Although no binder such as e.g. phenol resin is contained therein, said flexible ceramic in the case of a given high content of long fibers, has a high bending strength, but at the same time it is very resistant to breakage in the case even of multiple bendings around relatively small bending radii. For such a flexible ceramic, one may produce pliable thermal insulating foils (5) with low thicknesses (d) of, if necessary less than 1 mm, which still have considerable stability of shape, but which may be bent very well and may even be stamped. Furthermore, the flexible ceramic may be used for the formation of covered up insulating layers or of insulating layers laminated on both sides in thermal insulating elements possibly also of a more complicated molding. In order to be able to admix the high portion of long fibers without the formation of local fiber agglomerations, said fibers are admixed separated, e.g. by flakes, as a last component to the already finished premixture of the raw material.