Evonik Degussa Gmbh

Degussa Aktiengesellschaft

Other

Degussa - Huls Ag

Degussa Gmbh

Degussa Akiengesellscahft

Evonik Operations Gmbh

Karl Meier

Christian Panz

Helga Obladen

Rene Allerdisse

Siegfried Wolff

Mario Scholz

Markus Ruf

Michael Kempf

Dieter Kuhn

Josef Steff

Robert Kuhlmann

Gunter Turk

Heinz Esch

Udo Goerl

Mustafa Siray

Roland Bergmann

Karl-Heinz Trieb

Gerold Schmidt

Mario Loebbus

Ulrich Brinkmann

Anja Lukas

Doris Misselich

Frank Menzel

Ralf Schmoll

Hans-Dieter Christian

Wolfgang Leonhardt

Ralf Rausch

Udo Gorl

Christian Goetz

Gottlieb-Georg Lindner

Florian Paulat

Christian Götz

Matthew Romaine

Guido Titz

James Toth

Matt Romaine

Werner Nagel

Hans Dieter Christian

Gottlieb Lindner

Heinz-G&uuml;nter Lux

Astrid M&uuml;ller

Rolf Oelm&uuml;ller

Anja Ramb

Aziz El Moussaoui

Marian Chjonowski

Walter Meon

Guenter Tuerk

Klaus Benner

Ralf Stoffels

Christof Schilling

René Allerdisse

James J Toth

A precipitated silica having an SiOHabsorbance ratio of greater than or equal to 1.5, a silanol group density of 1 to 3.0 SiOH/nm, a modified tapped density of 1 to 50 g/l, and a pH of 3-5, when measured as a aqueous suspension of 5.00 g of the precipitated silica in 100 ml. of deionized water allows preparation of storage-stable RTV-1 silicone rubber formulations without stabilizer. A process for preparing the precipitated silica and its use in thickening sealants is provided.

Precipitated silicas for storage-stable RTV-1 silicone rubber formulations without stabilizer

The invention relates to matted UV varnishes comprising silicon dioxide, the surface thereof having been modified by means of treatment with a multiple bond organopolysiloxane so as to be particularly well-suited for use as a matting material for UV varnishes, and to a method for producing same.

Matting agent for UV varnishes

The present invention provides a process for generating fine particles in a jet mill which operates at a pressure of a milling gas of less than or equal to 4 bar in abs value and a temperature of the mill of less than 100&#xb0; C., a process for simultaneous milling and surface modifications of the fine particles, a jet mill for operating the process and products obtained by the process.

Low-pressure milling process

Hydrophilic precipitated silicas which combine a particularly low initial moisture content with low moisture absorption over time, a low tapped density and a low silanol group density, have the following physicochemical parameters: equilibrium moisture content (at 70% relative humidity/20&#xb0; C.) of 0.5%-5.0% by weight, based on the weight of the hydrophilic precipitated silica, BET surface area of 50-250 m/g, CTAB surface area of 50-250 m/g, and DBP (anhydrous) of 200-350 g/100 g.

Hydrophilic silica for sealants

A hydrophobic precipitated silica having a BET of less than 110 m/g, a CTAB of less than 150 m/g, a BET/CTAB ratio of less than 3, a carbon content of greater than 3.1%, a pH of 9.7 to 10.5, a DBP of less than 230 g/(100 g), and a methanol wettability of more than 50%. The hydrophobic precipitated silica is used in compositions including defoamers, silicone rubber and HTV crosslinkable silicone rubber compositions. The hydrophobic precipitated silica is also useful as a flow assistant and carrier or anti-blocking agent.

Hydrophobic precipitated silica for defoamer formulations

A thermal insulation material comprising a precipitated silica having a modified tapped density of less than or equal to 70 g/l.

Thermal insulation material comprising precipitated silica

A process for milling amorphous solids using a milling apparatus can result in particles having a median particle diameter dof &#x3c;1.5 &#x3bc;m. The process includes: operating a mill in a milling phase with an operating medium selected from the group consisting of gas, vapor, steam, a gas containing steam and mixtures thereof, and heating a milling chamber in a heat-up phase before the actual operation with the operating medium in such a way that a temperature in the milling chamber, the mill exit or both, is higher than a dew point of the operating medium.

Amorphous submicron particles

Precipitated silicas with a high pH and their use in applications as defoamers having optimum silanol group density and a process for preparing precipitated silicas and to their use, particularly in defoamer formulations.

Hydrophilic precipitated silica for defoamer formulations

A precipitated silica having a d-value of from 150 to 2000 nm, a d-value of from 500 to 7000 nm, a silanol group density of from 2.5 to 8 OH/nm, and a modified tapped density of less than or equal to 70 g/l is useful for thickening and providing thixotropy in liquid systems and shows superior efficiency at thickening and creating thixotropy compared to existing grades of precipitated silica. The precipitated silica functions best as a thixotrope in non-polar or intermediate polar liquid systems such as unsaturated polyester (UPE) resin systems.

Precipitated silica for thickening and creating thixotropic behavior in liquid systems

Precipitated silicas having an SiOHabsorbance ratio of greater than or equal to 1, may be used as reinforcers and thickeners for sealants.

Precipitated silicas having special surface properties

A precipitated silica having the following physico-chemical characteristics: 

High-structure precipitated silicas

A hydrophobic precipitated silica is prepared by a process comprising:

Process for preparing high-whiteness hydrophobic precipitated silica with ultralow moisture absorption

A partially hydrophobic precipitated silica having a methanol wettability of 10 to 49%, in particular with a DBP uptake on a dry basis of greater than 250 g/100 g and a mean particle size of 1 to 12 &mgr;m and/or a carbon content of 0.3 to 1.85% and/or a loss on drying of 2.6 to 10.0% and/or a pH value of 5.5 to 10.0, is prepared by mixing the amount of water-repellent agent with the precipitated silica suspension at very short residence time and low pH value, filtering off the solid substance, washing free of salt, drying, post-treating thermally and milling. The partially hydrophobic precipitated silica can be used in active substance formulations and active substance formulations of hydrolysis-sensitive substance and in defoaming agents.

Partially hydrophobic precipitated silicas

A process for preparing microporous separating elements for batteries by intensive mixing of a high molecular weight polyethylene with a precipitated silica having specific chemical and physical characteristics, a process liquid and a stabilizer to form a powder mixture, which is extruded to form a film, from which the process liquid is removed, thereby leaving the desired microporous separating elements which are recovered.

Precipitated silica

Growing community of inventors

Alfter, Germany

Karl Meier