Patents by Inventor Christian Lettmann

Christian Lettmann 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: 9085506
    Abstract: The invention relates to an improved process for preparing 3-aminomethyl-3,5,5-trimethylcyclohexylamine, referred to hereinafter as isophoronediamine or, in abbreviated form, IPDA, by: I. preparation of isophorone by catalyzed aldol condensations with acetone as reactant; II. reaction of isophorone with HCN to form isophoronenitrile (IPN, 3-cyano-3,5,5-trimethylcyclohexanone); III. catalytic hydrogenation and/or catalytic reductive amination (also referred to as aminative hydrogenation) of 3-cyano-3,5,5-trimethylcyclohexanone, hereinafter called isophoronenitrile or, in abbreviated form, IPN, to give the isophoronediamine.
    Type: Grant
    Filed: November 18, 2011
    Date of Patent: July 21, 2015
    Assignee: Evonik Degussa GmbH
    Inventors: Markus Galle, Gerda Grund, Axel Hengstermann, Michael D Hinton, Rolf Hirsch, Robert Jansen, Cord Knoop, Christian Lettmann, Juergen Lippe, Martin Maier, Joerg-Joachim Nitz, Matthias Orschel, Martina Ortelt, Norbert Richter, Armin Rix, Markus Schwarz, Guido Streukens
  • Patent number: 9029412
    Abstract: Method for preparing diamino-dianhydro-dideoxyhexitols, particularly 2,5-diamino-1,4:3,6-dianhydro-2,5-dideoxy-D-hexitol. The invention related to a method for preparing diamino-dianhydro-dideoxyhexitols, particularly preferably 2,5-diamino-1,4:3,6-dianhydro-2,5-dideoxy-D-hexitol.
    Type: Grant
    Filed: June 28, 2011
    Date of Patent: May 12, 2015
    Assignee: Evonik Degussa GmbH
    Inventors: Guido Streukens, Christian Lettmann, Sven Schneider
  • Patent number: 8877976
    Abstract: The invention relates to an improved process for preparing 3-aminomethyl-3,5,5-trimethylcyclohexylamine, referred to hereinafter as isophoronediamine or IPDA for short, by means of catalytic hydrogenation and/or catalytic reductive amination (also referred to as aminating hydrogenation) of 3-cyano-3,5,5-trimethylcyclohexanone, also called isophoronenitrile or IPN for short hereinafter.
    Type: Grant
    Filed: November 17, 2011
    Date of Patent: November 4, 2014
    Assignee: Evonik Degussa GmbH
    Inventors: Christian Lettmann, Guido Streukens, Matthias Orschel, Gerda Grund
  • Publication number: 20130261341
    Abstract: The invention relates to an improved process for preparing 3-aminomethyl-3,5,5-trimethylcyclohexylamine, referred to hereinafter as isophoronediamine or IPDA for short, by means of catalytic hydrogenation and/or catalytic reductive amination (also referred to as aminating hydrogenation) of 3-cyano-3,5,5-trimethylcyclohexanone, also called isophoronenitrile or IPN for short hereinafter.
    Type: Application
    Filed: November 17, 2011
    Publication date: October 3, 2013
    Applicant: Evonik Degussa GmbH
    Inventors: Christian Lettmann, Guido Streukens, Matthias Orschel, Gerda Grund
  • Publication number: 20130253226
    Abstract: The invention relates to an improved process for preparing 3-aminomethyl-3,5,5-trimethylcyclohexylamine, referred to hereinafter as isophoronediamine or, in abbreviated form, IPDA, by: I. preparation of isophorone by catalyzed aldol condensations with acetone as reactant; II. reaction of isophorone with HCN to form isophoronenitrile (IPN, 3-cyano-3,5,5-trimethylcyclohexanone); III. catalytic hydrogenation and/or catalytic reductive amination (also referred to as aminative hydrogenation) of 3-cyano-3,5,5-trimethylcyclohexanone, hereinafter called isophoronenitrile or, in abbreviated form, IPN, to give the isophoronediamine.
    Type: Application
    Filed: November 18, 2011
    Publication date: September 26, 2013
    Applicant: Evonik Degussa GmbH
    Inventors: Markus Galle, Gerda Grund, Axel Hengstermann, Michael D. Hinton, Rolf Hirsch, Robert Jansen, Cord Knoop, Christian Lettmann, Juergen Lippe, Martin Maier, Joerg-Joachim Nitz, Matthias Orschel, Martina Ortelt, Norbert Richter, Armin Rix, Markus Schwarz, Guido Streukens
  • Patent number: 8536370
    Abstract: Low chlorine, multi-staged method for producing cycloaliphatic diisocyanates. The invention relates to a multi-staged method for the continuous low-chlorine production of cycloaliphatic diisocyanates, comprising the synthesis of diaminodipheynl alkanes, the hydration thereof into the corresponding cycloaliphatic diamines and the subsequent conversion of cycloaliphatic diamines to the corresponding cycloalkylene biscarbamates and the thermal cleaving of the latter into the cycloaliphatic diisocyanates and alcohol.
    Type: Grant
    Filed: May 18, 2009
    Date of Patent: September 17, 2013
    Assignee: Evonik Degussa GmbH
    Inventors: Gerda Grund, Manfred Kreczinski, Stephan Kohlstruk, Christian Lettmann
  • Publication number: 20130118128
    Abstract: The present invention relates to multilayer packaging films with at least one layer containing a thermoplastic, where a coating containing at least one silicone has been applied on that side of the packaging film that faces towards the product requiring packaging, and to use of these, and to packaging processes using the packaging films mentioned.
    Type: Application
    Filed: November 14, 2012
    Publication date: May 16, 2013
    Inventors: Andreas LUECKE, Andre Ebbers, Christian Lettmann
  • Publication number: 20130116451
    Abstract: Method for preparing diamino-dianhydro-dideoxyhexitols, particularly 2,5-diamino-1,4:3,6-dianhydro-2,5-dideoxy-D-hexitol. The invention related to a method for preparing diamino-dianhydro-dideoxyhexitols, particularly preferably 2,5-diamino-1,4:3,6-dianhydro-2,5-dideoxy-D-hexitol.
    Type: Application
    Filed: June 28, 2011
    Publication date: May 9, 2013
    Applicant: EVONIK DEGUSSA GmbH
    Inventors: Guido Streukens, Christian Lettmann, Sven Schneider
  • Patent number: 8378127
    Abstract: The invention relates to a method for producing 2,6-dioxabicyclo-(3.3.0)-octane-4,8-dione (I), comprising the oxidation of dianhydrohexitols (II-IV), or of corresponding hydroxy ketones, with an oxygen-containing gas in the presence of a catalyst composition, the reaction proceeding without the addition of halogen sources.
    Type: Grant
    Filed: January 26, 2010
    Date of Patent: February 19, 2013
    Assignee: Evonik Degussa GmbH
    Inventors: Uwe Dingerdissen, Jan Pfeffer, Thomas Tacke, Thomas Haas, Harald Schmidt, Michael Volland, Michael Rimbach, Christian Lettmann, Roger Sheldon, Michiel Janssen
  • Publication number: 20110269977
    Abstract: The invention relates to a method for producing 2,6-dioxabicyclo-(3.3.0)-octane-4,8-dione (I), comprising the oxidation of dianhydrohexitols (II-IV), or of corresponding hydroxy ketones, with an oxygen-containing gas in the presence of a catalyst composition, the reaction proceeding without the addition of halogen sources.
    Type: Application
    Filed: January 26, 2010
    Publication date: November 3, 2011
    Applicant: EVONIK DEGUSSA GmbH
    Inventors: Uwe Dingerdissen, Jan Pfeffer, Thomas Tacke, Thomas Haas, Harald Schmidt, Michael Volland, Michael Rimbach, Christian Lettmann, Roger Sheldon, Michiel Janssen
  • Patent number: 8003826
    Abstract: The invention relates to an improved process for preparing trimethylhexamethylenediamine, hereinafter referred to as TMD for short, by hydrogenation of trimethylhexamethylenedinitrile, hereinafter referred to as TMN for short, in the presence of a shaped hydrogenation catalyst of the Raney type.
    Type: Grant
    Filed: January 30, 2008
    Date of Patent: August 23, 2011
    Assignee: Evonik Degussa GmbH
    Inventors: Christian Lettmann, Gerda Grund, Juergen Lippe, Cord Knoop
  • Publication number: 20110028755
    Abstract: Low chlorine, multi-staged method for producing cycloaliphatic diisocyanates. The invention relates to a multi-staged method for the continuous low-chlorine production of cycloaliphatic diisocyanates, comprising the synthesis of diaminodipheynl alkanes, the hydration thereof into the corresponding cycloaliphatic diamines and the subsequent conversion of cycloaliphatic diamines to the corresponding cycloalkylene biscarbamates and the thermal cleaving of the latter into the cycloaliphatic diisocyanates and alcohol.
    Type: Application
    Filed: May 18, 2009
    Publication date: February 3, 2011
    Applicant: EVONIK DEGUSSA GmbH
    Inventors: Gerda Grund, Manfred Kreczinski, Stephan Kohlstruk, Christian Lettmann
  • Publication number: 20100094058
    Abstract: Process for preparing trimethylhexamethylenediamine The invention relates to an improved process for preparing trimethylhexamethylenediamine, hereinafter referred to as TMD for short, by hydrogenation of trimethylhexamethylenedinitrile, hereinafter referred to as TMN for short, in the presence of a shaped hydrogenation catalyst of the Raney type.
    Type: Application
    Filed: January 30, 2008
    Publication date: April 15, 2010
    Applicant: Evonik Degussa GmbH
    Inventors: Christian Lettmann, Gerda Grund, Juergen Lippe, Cord Knoop
  • Publication number: 20100041921
    Abstract: The invention relates to an improved process for preparing 3-aminomethyl-3,5,5-trimethylcyclohexylamine, referred to hereinafter as isophoronediamine or IPD for short, by aminating hydrogenation of 3-cyano-3,5,5-trimethylcyclohexanone, referred to hereinafter as isophoronenitrile or IPN for short, in the presence of a shaped Raney hydrogenation catalyst.
    Type: Application
    Filed: January 25, 2008
    Publication date: February 18, 2010
    Applicant: EVONIK DEGUSSA GmbH
    Inventors: Christian Lettmann, Gerda Grund, Juergen Lippe, Cord Knoop
  • Publication number: 20090198024
    Abstract: The invention relates to formaldehyde-free, carbonyl- and ring-hydrogenated ketone-aldehyde resins based on alkyl aryl ketones and formaldehyde and having a low OH-functionality, a low fraction of crystallisable compounds, low viscosity, very low colour number, and very high heat stability and light stability, and also to a process for preparing them.
    Type: Application
    Filed: May 14, 2007
    Publication date: August 6, 2009
    Applicant: EVONIK DEGUSSA GmbH
    Inventors: Patrick Glöckner, Christian Lettmann, Michael Ewald, Andreas Wenning
  • Publication number: 20090099332
    Abstract: The invention relates to formaldehyde-free, OH-functional, carbonyl- and ring-hydrogenated ketone-aldehyde resins based on alkyl aryl ketones and formaldehyde and having a low fraction of crystallisable compounds, low viscosity, very low colour number, broad solubility, and very high heat stability and light stability, and also to a process for preparing them.
    Type: Application
    Filed: May 15, 2007
    Publication date: April 16, 2009
    Applicant: Evonik Degussa GMBH
    Inventors: Patrick Glockner, Christian Lettmann, Michael Ewald, Andreas Wenning
  • Publication number: 20090048466
    Abstract: The invention relates to a process for preparing amines by conditioning the catalyst with ammonia.
    Type: Application
    Filed: November 29, 2006
    Publication date: February 19, 2009
    Applicant: EVONIK DEGUSSA GmbH
    Inventors: Christian Lettmann, Juergen Lippe
  • Publication number: 20090012245
    Abstract: The invention relates to formaldehyde-free, carbonyl-hydrogenated ketone-aldehyde resins based on formaldehyde and having a low fraction of crystallizable compounds, low viscosity, very low color number, and very high heat stability and light stability, and also to a process for preparing them.
    Type: Application
    Filed: November 28, 2006
    Publication date: January 8, 2009
    Applicant: EVONIK DEGUSSA GmbH
    Inventors: Patrick Glockner, Andreas Wenning, Christian Lettmann, Peter Denkinger
  • Patent number: 7091384
    Abstract: The invention relates to a process for increasing the selectivity of the hydrogenation of 4,4?-diaminodiphenylmethane (4,4?-MDA) to diaminodicyclohexylmethane (4,4?-HMDA) by catalytic hydrogenation of a mixture containing 4,4?-MDA as the main component and its mono-N-methyl derivative as a secondary component. According to the invention, the hydrogenation is terminated before a conversion of 4,4?-MDA to 4,4?-HMDA of 99% is achieved. Under these conditions, a substantially smaller proportion of the N-methyl-4,4?-MDA is hydrogenated to N-methyl-4,4-HMDA.
    Type: Grant
    Filed: June 25, 2003
    Date of Patent: August 15, 2006
    Assignee: Degussa AG
    Inventors: Bernd Jaeger, Thomas Haas, Guido Stochniol, Christian Lettmann, Willi Hofen, Klaus Stadtmueller, Joerg Lotz
  • Patent number: 7052914
    Abstract: The invention relates to an automated method for carrying out reactions with high spatial resolution on libraries of different materials and for analysis of the products obtained using a simple robot system and an analyzer, for example a mass spectrometer.
    Type: Grant
    Filed: October 29, 2001
    Date of Patent: May 30, 2006
    Assignee: hte Aktiengesellschaft the high throughput experimentation company
    Inventors: Wilhelm Maier, Matthias Orschel, Jens Klein, Christian Lettmann, Hans Werner Schmidt