Wacker-chemie Gmbh

Wacker Chemie Ag

Mario Heinemann

Herbert Barthel

August Altenbuchner

Johann Doppelberger

Franz Herrmann

Bernd Pachaly

Torsten Gottschalk-Gaudig

Johann Schuster

Oliver Schaefer

Andreas Bauer

Johann Bindl

Helmut Maginot

Otto Rothenaicher

Stephan Loskot

Hans P Scherm

Lutz Eismann

Ute V&ouml;lkel

Franz Gr&uuml;nwald

Ute Voelkel

Ute Völkel

Aqueous dispersions contain at least two chemically different particle types having a diameter on average of less than 100 &#x3bc;m. The dispersions are resistant to sedimentation and gelling for long periods of time, and can be used for many purposes, such as the polishing of optical surfaces, and in paints and adhesives.

Dispersion which contains at least 2 types of particles

Surface-modified solids bearing groups of the formula ISiR&#x2014;R&#x2014;NH&#x2003;&#x2003;(I),are prepared by reacting a solid having OH groups on a surface thereof with a cyclic silazane of the general formula IIwhere

Solids surface-modified with amino groups

Silylated silica is prepared by silylating silica with an organosiloxane composed of A units of the formula (I)(RSiO)&#x2003;&#x2003;(I)and B units of the formulae (IIa-c)(RSiO), and/or&#x2003;&#x2003;(IIa)(RSiO), and/or&#x2003;&#x2003;(IIb)(SiO)&#x2003;&#x2003;(IIc),optionally having 1 or 2 attached groups &#x2014;X on Si atoms, where

Silica with homogeneous layer of silylating agent

A silylated silica having an SiOH density per nm of less than 0.6, based on the BET-method surface area (DIN 66131 and 66132), is prepared by silylating silica in a process where loading, reacting, and purifying are performed in separate steps.

Low-silanol silica

The invention relates to crosslinkable materials based on organopolysiloxanes. Said materials are characterized in that in addition to organopolysiloxanes they contain at least one low-molecular organosilicon compound with 2 to 17 silicon atoms comprising units of the formula (I) R R (OR ) SiO , R , R , R , a, b and c having the meaning given in claim 1 provided that low-molecular organosilicon compounds comprising units of the formula (I) where b is 0 have at least one unit of the formula (I) in which a is 0 or 1, and at least one unit of the formula (I) in which a is 3.

Crosslinkable organopolysiloxane materials

The invention relates to silicon dioxide which bears partially or fully silylated polysilicic acid chains on its surface, wherein the sum of silanol groups of the silicon dioxide surface (SiOH) and grafted-on silylating agent radicals (SiR,) is greater than the number of silanol groups on the surface of untreated silicon dioxide, where a can be 1, 2 or 3 and R can be identical or different and are each a substituted or unsubstituted hydrocarbon radical.

Silicon dioxide which bears partially or fully silylated polysilicic acid chains on its surface

The invention relates to a process for the silylation of very finely divided inorganic oxides, in which the very finely divided inorganic oxides are treated with at least one silylating agent which is relatively nonvolatile in the temperature range of the overall process, with the proviso that the relatively nonvolatile silylating agent is admixed with the very finely divided inorganic oxides as a liquid, in the form of a very finely atomized aerosol. Furthermore, the invention relates to a highly apolar, pyrogenic silica prepared by this process.

Process for the silylation of inorganic oxides

The invention relates to a process for preparing highly dispersed metal oxides whose surfaces are modified by an ammonium-functional organopolysiloxane as a charge controlling substance for positive chargeable toners, in which the highly dispersed metal oxides are reacted with an organopolysiloxane which contains silicon-bonded terminal hydroxyl and/or alkoxy groups, diorganosiloxane units, in which the two organic radicals are monovalent hydrocarbon radicals, and siloxane units in which the organic radicals contain a positive charged nitrogen which is bonded to silicon via carbon.

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Burghausen, Germany

Mario Heinemann