Evonik Degussa Gmbh

Degussa Aktiengesellschaft

Matthias Rochnia

Jürgen Meyer

Kai Schumacher

Mario Scholz

Juergen Meyer

Stipan Katusic

Rainer Golchert

Günther Michael

Monika Oswald

Harald Alff

Thorsten Schultz

Juri Tschernjaew

Naruyasu Ishibashi

Takeyoshi Shibasaki

Hauke Jacobsen

Andreas Hille

Helmut Roth

Ralph Brandes

Horst Miess

Volker Hamm

Rüdiger Mertsch

Katharina Schulz

Florian Felix Kneisel

Fumed silica having a BET surface area of 200&#xb1;15 m2/g, a grindometer value of less than 30 &#x3bc;m and a median value by PCS of 65 to 85 nm is prepared by grinding a fumed silica having a surface area of 200&#xb1;25 m2/g, and silicone rubber containing this silica.

Fumed silica

The present invention relates to innovative antifouling additives, to a process for producing them, to coating systems comprising the antifouling systems of the invention, to a process for producing the coating systems, and to the use of the antifouling additives and coating systems of the invention for preventing the underwater fouling of surfaces of objects which are in contact or come into contact with water.

Microstructured multifunctional inorganic coating additives for preventing fouling (growth of biofilm) in aquatic applications

Process for the production of doped metal oxide particles, wherein the doping component is present on the surface in the form of domains, wherein in a first reaction zone, an oxidizable and/or &#x2014;hydrolysable metal compound as dopant together with an atomization gas is atomized into a flow of metal oxide particles in a carrier gas, wherein the mass flow of the metal oxide particles und &#x2014;the mass flow of the dopant are selected such that the doped metal oxide particles contain 10 ppm to 10 wt. % of the doping component, where the quantity of dopant to be introduced is calculated as the corresponding oxide, and wherein the temperature in the first reaction zone is &#x2014;selected such that it is below the boiling temperature of the dopant under the prevailing reaction conditions, and then, in a second reaction zone, the flow from the first &#x2014;reaction zone and optionally at least as much oxygen and/or steam are &#x2014;introduced that the quantity of oxygen and/or steam at least suffices completely to convert the dopant, wherein the temperature is from 300 to 2000&#xb0; C., &#x2014;preferably 500 to 1000&#xb0; C., and the reaction mixture is then cooled or allowed to cool and the doped metal oxide particles are separated from the gaseous substances.

Process for the production of doped metal oxide particles

Provided is a pyrogenically prepared SiOpowder in the form of aggregated primary particles having a statistical thickness surface area (STSA) of 10-500 m/g, a thickening action based on the STSA of 4-8 mPas&#xb7;g/m, and a micropore volume of 0.03-0.07 cm/g, and a process for preparing the pyrogenic SiOpowder, which involves: introducing hydrolyzable silicon compounds, a primary gas comprising oxygen, and a primary combustion gas into a mixing chamber to produce a mixture; igniting the mixture in a burner to produce a flame, which is burned into a reaction chamber to produce the pyrogenic SiOpowder and gaseous substances; and separating the pyrogenic SiOpowder from the gaseous substances, wherein a ratio of the amount of primary combustion gas introduced to a stoichiometric amount of primary combustion gas required is referred to as gammaand has a value of less than 1, and wherein a ratio of the amount of primary gas comprising oxygen introduced to a stoichiometric amount of primary gas comprising oxygen required is referred to as lambdaand has a value of greater than 1.

Pyrogenically prepared silicon dioxide with a low thickening effect

Mixed oxide powder consisting of particles with the components zirconium dioxide, aluminium oxide and at least a third component selected from the group including yttrium oxide, magnesium oxide or calcium oxide, wherein mixed oxide powder has an aluminium oxide content 0.01 to 10 wt. % and is homogeneously distributed in the mixed oxide particles, the content of aluminium oxide, zirconium dioxide and yttrium oxide is at least 99.5 wt. %, based on the total quantity of the powder, and the BET surface area is 20 to 80 m2/g. It is obtained by atomising a solution containing at least one starting compound for each of aluminium oxide, zirconium dioxide and the third component, allowing the atomised solution to react with oxygen in a reaction chamber at a reaction temperature 700 to 15000&#xb0; C., cooling the hot gases and the solid products and then separating the solid product from the gases. It can be used as a dental material.

Stabilised aluminium zirconium mixed oxide powder

Pyrogenically produced silicon dioxide powder in the form of aggregates of primary particles having a BET surface area of 90&#xb1;15 m/g, wherein the aggregates display an average surface area of 10000 to 20000 nm, an average equivalent circle diameter (ECD) of 90 to 130 nm and an average circumference of 1000 to 1400 nm. It is produced by a pyrogenic process in which silicon tetrachloride and a second silicon component comprising HSiCl, HSiCl, HSiCl, CHSiCl, (CH)SiCl, (CH)SiCl and/or (n-CH)SiClare mixed with primary air and a combustion gas and burnt into a reaction chamber, secondary air also being introduced into the reaction chamber, and the feed materials being chosen such that an adiabatic flame temperature of 1810 to 1890&#xb0; C. is obtained. Dispersion containing the pyrogenically produced silicon dioxide powder.

Pyrogenically produced silicon dioxide powder and dispersion thereof

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Ortenberg-Bleichenbach, Germany

Matthias Rochnia