THERMAL INSULATING COMPOSITION BASED ON FUMED SILICA GRANULATES, PROCESSES FOR ITS PREPARATION AND USES THEREOF

摘要

Thermal insulating composition based on silica granulates The present invention relates to: - a thermal insulating composition, containing 5 to 60 % by weight of a hydrophobized granular material comprising fumed silica and at least one IR-opacifier, and 40 to 95 % by weight of an inorganic and/ or an organic binder, whereby the hydrophobized granular material has a content of free hydroxyl groups of no greater than 0.12 mmol/g as determined by the reaction with lithium aluminium hydride. - the use of this composition for thermal and/or acoustic insulation of walls, roofs, houses, industrial plants, parts of industrial apparatuses, pipelines. - two alternative processes for producing a thermal insulating composition, comprising the following steps: a) mixing a hydrophilic fumed silica with at least one IR-opacifier; b) densifying the mixture obtained in step a) to give a hydrophilic granular material; c-1) subjecting the hydrophilic granular material produced in step b) to thermal treatment at a temperature of 200 to 1200°C; OR c-2) treating the hydrophilic granular material produced in step b) with ammonia; d) hydrophobizing the hydrophilic granular material subjected to thermal or chemical treatment in step c) with a hydrophobizing agent to obtain a hydrophobized granular material; e) mixing the hydrophobized granular material produced in step d) with an inorganic and/or an organic binder.