Process for the Production of an Aerogel Material

Abstract

A process for the production of an aerogel material comprises the following steps:a) preparation of a silicon oxide sol in an alcoholic solvent mixture;b) triggering of the gelation of the sol by adding base, whereby a gel is formed, and optionally aging of the gel;c) hydrophobicization of the optionally aged gel;d) removal of the solvent mixture by subcritical drying, whereby the aerogel material is formed.The silicon oxide sol formed in step a) comprises at least one acid-catalytically activatable hydrophobicization agent, wherein the volume fraction of the hydrophobicization agent in the sol is 5 to 60%. The hydrophobicization in step c) is induced as a result of release or addition of at least one hydrophobicization catalyst acting in combination with the hydrophobicization agent.

Description

[0001]This application claims priority from POT application No. PCT / EP2014 / 066213 filed Jul. 28, 2014 which claims priory from European application No. EP 13179185.7 filed on Aug. 2, 2013, the disclosures of which are incorporated herein by reference.TECHNICAL FIELD[0002]The invention relates to a process for the production of an aerogel material. Furthermore, the invention relates to an insulant panel formed from an aerogel material and to a precursor product for producing an aerogel material.PRIOR ART[0003]Aerogels find increased application in building technologies as highly insulating is insulation materials. Numerous methods for their preparation are known. With increasing industrialization of these materials since the turn of the millennium, the manufacturing processes used therefor have continuously been simplified. Basically, one can distinguish between water glass (sodium silicate) and alkoxide-based compounds such as tetraethylorthosilicate (TEOS) and tetramethylorthosilic...

AI Technical Summary

Benefits of technology

The invention describes a process for producing silicate-aerogel materials, which is simpler and more efficient compared to existing methods. The process involves a hydrophobicization step which can be carried out at the same time as the gelation process, using a hydrophobicization agent. This results in significantly reduced solvent consumption and allows for the production of granulate, monolithic or composite materials. The hydrophobicization catalyst is formed by decomposing chlorine-containing organic compounds using UV or other known initiators. The sol also contains a polymerizable monomer to strengthen the gel structure. The drying process can occur at reduced pressure, resulting in aerogel materials with less residual moisture. At the end of the drying process, the temperature is lower and the drying process faster.

Problems solved by technology

The main cost contributors for these insulation materials, which presently are still comparatively expensive, are the costs due to the laborious type of processing, solvent, solvent losses and concomitant VOC release, as well as raw materials and hydrophobicization agents.

This process is very time-consuming and energy-intensive.

Moreover, operating with supercritical alcohol is a significant safety risk due to the high pressures and temperatures used in combination with the flammability of the alcohol.

The process allows producing an aerogel granulate material with a significantly lower time consumption, but a is significant disadvantage consists in the washing with ethanol, which is required in order to remove the water from the hydrogel phase.

The processing of the water alcohol mixture requires large amounts of energy, which is a great disadvantage of this process for a large-scale industrial production.

A central point to be mentioned is the composition of the void fluid before drying, which is a mixture of alcohol and hydrophobicization agent A disadvantage in the process according to WO2013 / 053951 A1 is that the hydrophobicization agent and, optionally, a corresponding catalyst are added only after the gelation and aging of the gel to form a solid.

Particularly in the case of bulky charges the hydrophobicization agent can penetrate into the interior of the gels only in a diffusion-limited manner, i.e. gradually, so that depending on the thickness of the material the hydrophobicization step takes a long time.