Wacker Chemie Ag

Konrad Hindelang

Richard Weidner

Dominik Jantke

Torsten Gottschalk-Gaudig

The invention relates to a method for producing hydrophilic silicia moulded bodies, in which i) a mixture containing hydrophilic silicic acid is added at a maximum temperature of 55&#xb0; C. to hydrophobic means and ii) the mixture obtained in step i) is compacted after a maximum storage time of 30 days to form moulded bodies, iii) during steps ii and iii and until the moulded bodies are used, the temperature is at a maximum of 55&#xb0; C.

Method for producing hydrophobic silica mouldings

Granular and/or shaped hydrophobic silica useful for thermal insulation materials are prepared by mixing hydrophilic silica with a hydrophobicizing agent at low temperature so the hydrophobicizing agent does not appreciably react, followed by deaeration and compaction.

Method for producing hydrophobic silica granules

Hydrophobic shaped silica bodies having low density and low thermal conductivity are produced by forming a dispersion of silica in a solution of binder and organic solvent, and removing the solvent and shaping to form a shaped body. The shaped bodies retain their hydrophobicity, are stable with regards to shape, and are useful in acoustic and thermal insulation.

Silica molded bodies having low thermal conductivity

It is an object of the invention to provide a rapid and economically viable process which is notable for efficient use of material, especially of the silylating agent, and by means of which organically modified lyo- or aerogels are obtained in a rapid and simple manner. This object is achieved by virtue of the invention providing a process for producing organically modified gels selected from lyo- and aerosols by (i) emulsifying a basic polar phase comprising water and starting materials for silicatic gels in a nonpolar phase containing a water-immiscible precursor for an active silylating agent, (ii) starting formation of gel and ageing by lowering the pH, and then (iii) starting the silylation and the exchange of solvent by lowering the pH. If the gels are aerogels, the gels provided can be used for thermal and/or acoustic insulation.

Economically viable process for producing organically modified lyo- or aerogels

The problem addressed by the invention is that of producing aerogels which have as high and permanent a hydrophobicity as possible and which have a reduced combustibility, that is as low a carbon content as possible, and are simultaneously less rigid and brittle than known systems, i.e. which with reduced combustibility have a high flexibility and high stability at the same time, that is high mechanical load-bearing capacity. Said problem is solved in that the invention provides gels chosen from lyogel or aerogel, which are synthesised from oxide units and [RSiO] units, wherein the primary particles have a change of concentration in [RSiO] units from the inside to the outside, wherein x can be the same or different and is 1 or 2, and R can be the same or different and is hydrogen or an organic substituted or unsubstituted radical, and wherein the oxide units contain [SiO] units, and a method for producing same. The gels provided can be used in cosmetic, medical or for chromatographic applications, and as a catalyst or catalyst support. If the gels are aerogels, same are preferably used for thermal and/or acoustic insulation.

Hydrophobic aerogels comprising low occupancy of monofunctional units

It is an object of the invention to provide an economically viable process for the production of hydrophobized aerogels which works both inexpensively and in a resource-conserving manner. 2.2. This object is achieved by the provision of a process for producing organically modified aerogels by producing a sol containing [SiO] units and [RSiO] a units, where x may be the same or different and is 1, 2 or 3, and R may be the same or different and is hydrogen or an organic substituted or unsubstituted radical, using the sol to form a gel, surface-modifying the gel obtained in the presence of more than 0.1% by weight of a phase modifier in a mixture comprising organosiloxane and initiator, wherein the mixture contains at least 20% by weight of organosiloxane and wherein the initiator consists of acid or organosiloxane or mixtures thereof and the gels obtained are dried. 2.3. The aerogels provided can be used as insulating materials, especially in thermal insulation.

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Munich, Germany

Konrad Hindelang