Patents by Inventor Michael Kröll

Michael Kröll has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11078083
    Abstract: Process for producing a silicon-carbon composite powder in which a) a gas stream A containing at least one starting compound of silicon selected from the group consisting of SiH4, Si2H6 and Si3H8, and b) a gas stream B containing at least one starting compound of carbon selected from the group consisting of methane, ethane, propane, ethylene and acetylene are reacted in a hot wall reactor at a temperature of less than 900° C., the reaction mixture is cooled or allowed to cool and the pulverulent reaction product is separated from gaseous materials.
    Type: Grant
    Filed: February 28, 2017
    Date of Patent: August 3, 2021
    Assignee: Evonik Operations GmbH
    Inventors: Julia Lyubina, Michael Kroell
  • Publication number: 20190002352
    Abstract: The invention relates to a method for producing a shaped body that contains at least 85 vol. % crystalline silicon carbide and at most 15 vol. % silicon, comprising the following steps: a) providing a powdered mixture that contains at least 60 vol. % amorphous silicon carbide and at most 40 vol. % silicon having a crystallite size of 3-50 nm; b) shaping the mixture by b1) hot pressing, or b2) compacting at room temperature and subsequent sintering or hot pressing, wherein the sintering or hot pressing is carried out in an inert gas or vacuum at a temperature of at least 1400° C. The volume ratio SiC:Si in the powdered mixture is 95:5-99:1.
    Type: Application
    Filed: December 22, 2016
    Publication date: January 3, 2019
    Applicant: Evonik Degsussa GmbH
    Inventors: Julia LYUBINA, Michael KROELL
  • Publication number: 20170342095
    Abstract: Organofunctional silicon particles are covalently functionalized on their surface with at least one organic compound, for example a plurality of —O—(C1-C48)-alkyl compounds. The functionalization of the surface of the silicon particles makes it possible to adjust the properties of fluids in terms of their profile of properties by addition of the modified silicon particles. For instance, the alkoxy-functionalized silicon particles may preferably be added to a motor oil as additives for reducing viscosity.
    Type: Application
    Filed: May 24, 2017
    Publication date: November 30, 2017
    Applicant: Evonik Degussa GmbH
    Inventors: Juergen Erwin LANG, Bodo FRINGS, Michael KROELL, Goswin UEHLENBRUCK
  • Publication number: 20160152836
    Abstract: Silicon-containing particles are used for protection of industrial materials, such as electrooptical layers or electrooptical components, from electromagnetic radiation in the UV range and optionally in the visible as far as the IR range, wherein the particles take the form of primary particles having a particle size in the range from 1 to 100 nm and may optionally take the form of clusters of the primary particles. A particular advantage is the possibility of matching the absorption of the electromagnetic radiation to the wavelength region to be absorbed that is of interest in a defined manner via the particle size and the particle size distribution. The silicon-containing particles can be used as biocompatible and biodegradable UV protection in industrial applications and compositions for industrial applications as formulations, such as preferably in coating compositions, such as paint.
    Type: Application
    Filed: November 24, 2015
    Publication date: June 2, 2016
    Applicant: Evonik Degussa GmbH
    Inventors: Juergen Erwin Lang, Michael Kroell, Goswin Uehlenbruck
  • Publication number: 20160151254
    Abstract: Silicon-containing particles are used for protection of human cells from electromagnetic radiation in the UV range and optionally in the visible as far as the IR range, where the particles preferably take the form of clusters of primary particles having a particle size in the range from 5 to 100 nm. A particular advantage is the possibility of matching the absorption of the electromagnetic radiation to the wavelength region to be absorbed in a defined manner via the particle size. The silicon-containing particles can be used for biocompatible and biodegradable UV protection in cosmetic or medical formulations, such as preferably a sunscreen, or else in a cosmetic formulation for the UV protection of hair.
    Type: Application
    Filed: November 24, 2015
    Publication date: June 2, 2016
    Applicant: Evonik Degussa GmbH
    Inventors: Juergen Erwin LANG, Michael KROELL, Goswin UEHLENBRUCK
  • Patent number: 8764992
    Abstract: A method of fractionating a dispersion of oxidic nanoparticles wherein at least one step of the method is a membrane crossflow filtration step, the flow of the dispersion over the membrane being brought about by means of driven rotating parts; and dispersions of oxidic nanoparticles that are obtainable by the method.
    Type: Grant
    Filed: April 1, 2010
    Date of Patent: July 1, 2014
    Assignee: Evonik Degussa GmbH
    Inventors: Roland Wursche, Goetz Baumgarten, Wolfgang Lortz, Michael Kroell
  • Publication number: 20120083188
    Abstract: Aqueous dispersion comprising cerium oxide and silicon dioxide, obtainable by first mixing a cerium oxide starting dispersion and a silicon dioxide starting dispersion while stirring, and then dispersing at a shear rate of 10000 to 30000 s?1, wherein a) the cerium oxide starting dispersion—contains 0.5 to 30% by weight of cerium oxide particles as the solid phase, —a d5o of the particle size distribution of 10 to 100 nm—and has a pH of 1 to 7, and b) the silicon dioxide starting dispersion—contains 0.1 to 30% by weight of colloidal silicon dioxide particles as the solid phase, has a d5o of the particle size distribution of 3 to 50 nm and has a pH of 6 to 11.5, d) with the proviso that the d5o of the particle size distribution of the cerium oxide particles is greater than that of the silicon dioxide particles, the cerium oxide/silicon dioxide weight ratio is >1 and the amount of cerium oxide starting dispersion is such that the zeta potential of the dispersion is negative.
    Type: Application
    Filed: May 18, 2010
    Publication date: April 5, 2012
    Applicants: BASF SE, EVONIK DEGUSSA GMBH
    Inventors: Michael Kroell, Wolfgang Lortz, Stefan Heberer, Mario Brands, Yuzhuo Li, Bettina Drescher, Diana Franz
  • Patent number: 8008201
    Abstract: Aqueous cerium oxide dispersion Aqueous cerium oxide dispersion, containing 5 to 60% by weight cerium oxide. It can be used to polish SiO2 in the semiconductor industry.
    Type: Grant
    Filed: March 8, 2006
    Date of Patent: August 30, 2011
    Assignee: Evonik Degussa GmbH
    Inventors: Michael Kröll, Stefan Heberer, Stipan Katusic, Michael Krämer, Wolfgang Lortz
  • Patent number: 7968070
    Abstract: Process for the production of a metal oxide powder having a BET surface area of at least 20 m2/g by reacting an aerosol with oxygen in a reaction space at a reaction temperature of more than 700° C. and then separating the resulting powder from gaseous substances in the reaction space, wherein the aerosol is obtained by atomisation using a multi-component nozzle of at least one starting material, as such in liquid form or in solution, and at least one atomising gas, the volume-related mean drop diameter D30 of the aerosol is from 30 to 100 ?m and the number of aerosol drops larger than 100 ?m is up to 10%, based on the total number of drops, and metal oxide powder obtainable by this process.
    Type: Grant
    Filed: February 19, 2009
    Date of Patent: June 28, 2011
    Assignee: Evonik Degussa GmbH
    Inventors: Stipan Katusic, Michael Kraemer, Michael Kroell, Peter Kress, Edwin Staab
  • Publication number: 20110147641
    Abstract: Surface-modified superparamagnetic oxidic particles, characterized by the following physicochemical characteristics: BET surface area 20 to 75 m2/g; Carbon content 0.5 to 6.0% by weight; Tamped density 150 to 500 g/l; Chlorine content 50 to 1000 ppm; Drying loss 0.1 to 4.0% by weight are prepared by contacting the oxides with the surface modifier either by spraying or vapour deposition and then heat-treating them. The surface-modified oxidic particles can be used as a filler in adhesives. Further fields of application are use for data carriers, as a contrast agent in imaging processes, for biochemical separation and analysis processes, for medical applications, as an abrasive, as a catalyst or as a catalyst support, as a thickener, for thermal insulation, as a dispersing assistant, as a flow assistant and in ferrofluids.
    Type: Application
    Filed: March 30, 2009
    Publication date: June 23, 2011
    Applicant: Evonik Degussa GMBH
    Inventors: Juergen Meyer, Markus Pridoehl, Guido Zimmermann, Michael Kroell, Stipan Katusic
  • Publication number: 20110114872
    Abstract: Process for polishing silicon surfaces, in which a dispersion which comprises cerium oxide particles, at least one polymeric, anionic dispersing additive and at least one oxidizing agent and which has a pH of 7 to 10.5 is used, said cerium oxide particles having a positive charge and polymeric, anionic dispersing additive and oxidizing agent being soluble in the liquid phase of the dispersion.
    Type: Application
    Filed: December 12, 2008
    Publication date: May 19, 2011
    Applicant: EVONIK DEGUSSA GMBH
    Inventors: Michael Kroell, Michael Kraemer, Gerfried Zwicker, Michael Torkler
  • Publication number: 20100307068
    Abstract: A dispersion comprising particles of cerium oxide and particles of cerium oxide and colloidal silicon dioxide, where —the zeta potential of the silicon dioxide particles is negative and that of the cerium oxide particles is positive or equal to zero, and the zeta potential of the dispersion is negative overall, —the mean diameter of the cerium oxide particles is not more than 200 nm silicon dioxide particles is less than 100 nm, —the proportion, based in each case on the total amount of the dispersion, of cerium oxide particles is from 0.1 to 5% by weight silicon dioxide particles is from 0.01 to 10% by weight and —the pH of the dispersion is from 3.5 to <7.5.
    Type: Application
    Filed: December 1, 2008
    Publication date: December 9, 2010
    Applicant: EVONIK DEGUSSA GmbH
    Inventor: Michael Kroell
  • Publication number: 20100308258
    Abstract: A dispersion comprising particles of cerium oxide and sheet silicate, where—the zeta potential of the sheet silicate particles is negative and that of the cerium oxide particles is positive or equal to zero, and the zeta potential of the dispersion is negative overall, —the mean diameter of the cerium oxide particles is not more than 200 nm sheet silicate particles is less than 100 nm, —the proportion, based in each case on the total amount of the dispersion, of cerium oxide particles is from 0.1 to 5% by weight sheet silicate particles is from 0.01 to 10% by weight and—the pH of the dispersion is from 3.5 to <7.5.
    Type: Application
    Filed: November 26, 2008
    Publication date: December 9, 2010
    Applicant: Evonik Degussa GmbH
    Inventor: Michael Kroell
  • Publication number: 20100187174
    Abstract: A method of fractionating a dispersion of oxidic nanoparticles wherein at least one step of the method is a membrane crossflow filtration step, the flow of the dispersion over the membrane being brought about by means of driven rotating parts; and dispersions of oxidic nanoparticles that are obtainable by the method.
    Type: Application
    Filed: April 1, 2010
    Publication date: July 29, 2010
    Applicant: EVONIK DEGUSSA GmbH
    Inventors: Roland WURSCHE, Goetz BAUMGARTEN, Wolfgang LORTZ, Michael KROELL
  • Publication number: 20100171069
    Abstract: A dispersion comprising particles of cerium oxide and sheet silicate and one or more aminocarboxylic acids and/or salts thereof, where the zeta potential of sheet silicate particles is negative and that of the cerium oxide particles is positive or equal to zero, and the zeta potential of the dispersion is negative overall, the mean diameter of the•cerium oxide particles is not more than 200 nm•sheet silicate particles is less than 100 nm, the content, based in each case on the total amount of the dispersion, of•cerium oxide particles is from 0.1 to 5% by weight•sheet silicate particles is from 0.01 to 10% by weight and•aminocarboxylic acid or salt thereof is from 0.01 to 5% by weight and the pH of the dispersion is from 7.5 to 10.5.
    Type: Application
    Filed: May 5, 2008
    Publication date: July 8, 2010
    Applicant: Evonik Degussa GmbH
    Inventors: Michael Kroell, Stefan Heberer, Katharina Dauth
  • Publication number: 20100163785
    Abstract: A dispersion comprising particles of cerium oxide and colloidal silicon dioxide and in each case one or more aminocarboxylic acids and/or salts thereof, where the zeta potential of the silicon dioxide particles is negative and that of the cerium oxide particles is positive or equal to zero, and the zeta potential of the dispersion is negative overall, the mean diameter of the • cerium oxide particles is not more than 200 nm silicon dioxide particles is less than 100 nm, the content, based in each case on the total amount of the dispersion, of • cerium oxide particles is from 0.1 to 5% by weight silicon dioxide particles is from 0.01 to 10% by weight and • aminocarboxylic acid or salt thereof is from 0.01 to 5% by weight and —the pH of the dispersion is from 7.5 to 10.5.
    Type: Application
    Filed: May 5, 2008
    Publication date: July 1, 2010
    Applicant: EVONIK DEGUSSA GMBH
    Inventors: Michael Kroell, Stefan Heberer, Katharina Dauth
  • Publication number: 20100102268
    Abstract: A dispersion comprising cerium oxide particles and colloidal silicon dioxide particles, where—the zeta potential of the silicon dioxide particles is negative and that of the cerium oxide particles is positive or equal to zero, and the zeta potential of the dispersion is negative overall, and—the mean particle diameter of the cerium oxide particles is not more than 200 nm and that of the silicon dioxide particles is not more than 100 nm, the mean particle diameter of the cerium oxide particles being greater than that of the silicon dioxide particles—the cerium oxide/silicon dioxide weight ratio is from 1.1:1 to 100:1 and—the pH of the dispersion is from 7.5 to 10.5.
    Type: Application
    Filed: November 9, 2007
    Publication date: April 29, 2010
    Applicant: Evonik Degussa GmbH
    Inventors: Michael Kroell, Stefan Heberer, Katharina Dauth
  • Publication number: 20100083584
    Abstract: A dispersion comprising cerium oxide particles and particles of one or more sheet silicates, where the zeta potential of the sheet silicate particles is negative and that of the cerium oxide particles is positive or equal to zero, and the zeta potential of the dispersion is negative overall, the mean particle diameter of the cerium oxide particles and the mean particle diameter of the sheet silicate particles is not more than 100 nm and the pH of the dispersion is from 7.5 to 10.5, preferably from 9 to 10.
    Type: Application
    Filed: December 19, 2007
    Publication date: April 8, 2010
    Applicant: EVONIK DEGUSSA GmbH
    Inventors: Michael Kroell, Stefan Heberer, Katharina Dauth
  • Publication number: 20100029080
    Abstract: Aqueous cerium oxide dispersion Aqueous cerium oxide dispersion, containing 5 to 60% by weight cerium oxide. It can be used to polish SiO2 in the semiconductor industry.
    Type: Application
    Filed: March 8, 2006
    Publication date: February 4, 2010
    Inventors: Michael Kröll, Stefan Heberer, Stipan Katusic, Michael Krämer, Wolfgand Lortz
  • Publication number: 20100008872
    Abstract: Zinc silicon oxide particles with a core-shell structure which have a Zn/Si ratio of from 2 to 75, in atom %/atom %, whose fraction of Zn, Si and O is at least 99% by weight, based on the zinc silicon oxide particles, which have a BET surface area of from 10 to 60 m2/g, a weight-averaged primary particle diameter of from 10 to 75 nm an average aggregate area of less than 40 000 nm2 and an average aggregate diameter (ECD) of less than 200 nm, whose core is crystalline and consists of aggregated primary particles of zinc oxide and whose shell surrounds the aggregated zinc oxide primary particles and consists of one or more compounds containing the elements Si and O. Dispersion, coating composition and sunscreen formulation comprise the zinc silicon oxide particles.
    Type: Application
    Filed: June 26, 2007
    Publication date: January 14, 2010
    Applicant: EVONIK DEGUSSA GmbH
    Inventors: Stipan Katusic, Sven Hill, Michael Kroell, Guido Zimmermann, Peter Kress