Patents by Inventor Lothar Feistel

Lothar Feistel 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: 6924317
    Abstract: The present invention relates to a process for producing monodisperse anion-exchanger gels with high stability, purity and coarse particle size greater than 800 ?m starting from a monodisperse bead polymer with a swelling index of from 2.5 to 7.5 and more than one subsequent feed procedure without any separation between the polymerization steps and then modifying to give the anion exchanger.
    Type: Grant
    Filed: April 1, 2003
    Date of Patent: August 2, 2005
    Assignee: Bayer Aktiengesellschaft
    Inventors: Lothar Feistel, Gerold Schade, Hubertus Mittag
  • Publication number: 20050046059
    Abstract: Disclosed herein is the polymerization of monodisperse microencapsulated monomer droplets to produce monodisperse non-microencapsulated bead polymers through the addition strong alkalis or strong acids during the polymerization.
    Type: Application
    Filed: August 24, 2004
    Publication date: March 3, 2005
    Inventors: Lothar Feistel, Rudiger Seidel, Hubertus Mittag, Gerold Schade, Wolfgang Podszun, Claudia Schmid
  • Publication number: 20030191201
    Abstract: The present invention relates to a process for producing monodisperse anion-exchanger gels with high stability, purity and coarse particle size greater than 800 &mgr;m starting from a monodisperse bead polymer with a swelling index of from 2.5 to 7.5 and more than one subsequent feed procedure without any separation between the polymerization steps and then modifying to give the anion exchanger.
    Type: Application
    Filed: April 1, 2003
    Publication date: October 9, 2003
    Inventors: Lothar Feistel, Gerold Schade, Hubertus Mittag
  • Patent number: 6624206
    Abstract: The invention relates to processes for the preparation of free-flowing end products of strongly acidic cation exchangers. In the case of the strongly acidic cation exchangers prepared by the processes described in Patent Application P 195 48 012.0, the particle beds of the end products are not free-flowing. By additions of wetting agents or water-soluble initiators or surfactants in the polymerization stage or after the filtration of the end product and/or process engineering means, a permanent or temporary free flowability of the particle beds of the strongly acidic cation exchangers is achieved using the following processes. 1. By additions of known wetting agents in amounts of 0.25 g/l of aqueous phase or water-soluble initiators in amounts of 0.05 to 20 g/l of aqueous phase to the copolymerization system 20 minutes to 120 minutes after reaching the gel point. 2. By treatment of the strongly acidic cation exchangers with aqueous solutions of surface-active substances having a content of 0.
    Type: Grant
    Filed: February 11, 2002
    Date of Patent: September 23, 2003
    Assignee: IAB Ionenaustauscher GmbH Bitterfeld
    Inventors: Reinhard Bachmann, Lothar Feistel, Rüdiger Seidel, Karl-Heinz Siekiera, Kurt Wegewitz
  • Publication number: 20020072546
    Abstract: The invention relates to processes for the preparation of free-flowing end products of strongly acidic cation exchangers. In the case of the strongly acidic cation exchangers prepared by the processes described in Patent Application P 195 48 012.0, the particle beds of the end products are not free-flowing.
    Type: Application
    Filed: February 11, 2002
    Publication date: June 13, 2002
    Inventors: Reinhard Bachmann, Lothar Feistel, Rudiger Seidel, Karl-Heinz Siekiera, Kurt Wegewitz
  • Patent number: 6384092
    Abstract: Sulfonated strongly acidic cation exchangers are rendered free-flowing by treatment with wetting agents or water soluble initiators, washing with water at temperatures of at least 60° C. and heat drying.
    Type: Grant
    Filed: January 10, 2001
    Date of Patent: May 7, 2002
    Assignee: IAB Ionenaustauscher GmbH Bitterfeld
    Inventors: Reinhard Bachmann, Lothar Feistel, Rüdiger Seidel, Karl-Heinz Siekiera, Kurt Wegewitz
  • Patent number: 6365683
    Abstract: The invention relates to a process for preparing substantially monodisperse crosslinked bead polymers useful as precursors for ion exchangers.
    Type: Grant
    Filed: December 14, 2000
    Date of Patent: April 2, 2002
    Assignee: Bayer Aktiengesellschaft
    Inventors: Wolfgang Podszun, Lothar Feistel, Olaf Halle, Claudia Schmid, Alfred Mitschker
  • Publication number: 20010051664
    Abstract: The invention relates to processes for the preparation of free-flowing end products of strongly acidic cation exchangers. In the case of the strongly acidic cation exchangers prepared by the processes described in Patent Application P 195 48 012.0, the particle beds of the end products are not free-flowing.
    Type: Application
    Filed: January 10, 2001
    Publication date: December 13, 2001
    Inventors: Reinhard Bachmann, Lothar Feistel, Rudiger Seidel, Karl-Heinz Siekiera, Kurt Wegewitz
  • Publication number: 20010009928
    Abstract: The invention relates to a process for preparing substantially monodisperse crosslinked bead polymers useful as precursors for ion exchangers.
    Type: Application
    Filed: December 14, 2000
    Publication date: July 26, 2001
    Inventors: Wolfgang Podszun, Lothar Feistel, Olaf Halle, Claudia Schmid, Alfred Mitschker
  • Publication number: 20010002656
    Abstract: The present invention relates to a process for preparing mono-disperse adsorber resin gels by polymerizing monomer droplets to give monodisperse polymers, followed by haloalkylating and crosslinking the resultant polymers, and also relates to the use of these resins.
    Type: Application
    Filed: November 29, 2000
    Publication date: June 7, 2001
    Inventors: Ulrich Schnegg, Georg Martin, Lothar Feistel, Werner Struver, Michael Holzbrecher
  • Patent number: 6228896
    Abstract: The invention relates to a process for the preparation of mechanically and osmotically stable, high-capacity strongly acidic cation exchangers having a particle size of ≧0.1 mm by sulphonation of gel-like or porous bead polymers with sulphuric acid without the use of inert chlorine-containing swelling agents and/or of comonomers based on acrylonitrile. According to the invention, such strongly acidic cation exchangers can be prepared by sulphonation of gel-like and porous bead polymers, prepared by copolymerization of styrene and divinylbenzene having a crosslinker content of up to 65% by weight of divinylbenzene with and without inert composition, with 80-96% strength sulphuric acid at temperatures of 125-180° C. and a reaction time of up to 20 h.
    Type: Grant
    Filed: June 17, 1998
    Date of Patent: May 8, 2001
    Assignee: IAB Ionennaustauscher GmbH Bitterfeld
    Inventors: Reinhard Bachmann, Lothar Feistel, Rüdiger Seidel, Karl-Heinz Siekiera