Patents by Inventor Volker Siekermann

Volker Siekermann 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: 5498471
    Abstract: A thermostable substrate for flexible circuit boards having excellent flame-resistance, handling, and storage qualities may be produced by treating a substrate of a nonwoven fabric or paper with a flame-resistant, halogen-free polymeric composition. The polymeric composition comprises an aqueous mixture of a copolymerizate of acrylic acid esters and styrene, and an aminoplastic or phenoplastic precondensate to which a mixture of fine-particle red phosphorus and fine-particle ammonium polyphosphate is also added.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: March 12, 1996
    Assignee: Firma Carl Freudenberg
    Inventors: Jorg Hausdorf, Thomas Kuhlmann, Rolf Schneider, Steffen Kosack, Werner Schafer, Volker Siekermann
  • Patent number: 5316832
    Abstract: A biodegradable substrate in sheet form which acts as a source of carbon and hydrogen in oxygen-poor water in biological water-treatment stages. The substrate is covered with at least one layer of a population of spontaneously growing denitrifiers. The substrate is a spun-bonded non-woven fabric weighing 10 to 1500 g/m.sup.2. It has a prescribed effective area that results in an ideal rate of denitrification per clarification stage at a prescribed rate of flow per area and time. The fabric is comprised of at least 50% continuous poly-.epsilon.-caprolactone filament with a mean molecular weight of 20,000 to 70,000. The individual filaments adhere to each other at their intersections.
    Type: Grant
    Filed: May 4, 1993
    Date of Patent: May 31, 1994
    Assignee: Carl Freudenberg
    Inventors: Robert Groten, Gerhard Heidecke, Thomas Mannsbart, Volker Siekermann
  • Patent number: 5229192
    Abstract: A flame-resistant cover film for flexible circuit boards having excellent flame-resistance, handling, and storage qualities may be produced by treating an insulating film of a nonwoven polymer fabric with a flame-resistant, halogen-free polymeric adhesive. The polymeric adhesive comprises an aqueous mixture of a copolymerizate of acrylic acid esters and styrene, and an aminoplastic or phenoplastic precondensate to which a mixture of fine-particle red phosphorus and fine-particle ammonium polyphosphate is also added.
    Type: Grant
    Filed: August 21, 1991
    Date of Patent: July 20, 1993
    Assignee: Firma Carl Freudenberg
    Inventors: Horst Kober, Thomas Kuhlmann, Jorg Hausdorf, Steffen Kosack, Werner Schafer, Volker Siekermann
  • Patent number: 4799967
    Abstract: Disclosed is a cleaning agent and method for the cleaning of apparatus used for the fabrication of reactive, multiple-component mixtures containing isocyanate. The cleaning agent consists of 50 to 75 weight-percent of a plasticizer from the group of short to medium chain length phthalic acid esters or alkylsulfonic acid esters of phenols, and 50 to 25 weight-percent of a mineral oil fraction of an aliphatic, naphthenic and/or aromatic hydrocarbon, or mixtures thereof, in the range of from 8 to 17 carbon atoms.
    Type: Grant
    Filed: December 16, 1987
    Date of Patent: January 24, 1989
    Assignee: Firma Carl Freudenberg
    Inventors: Jorg Hausdorf, Joachim Kandler, Volker Siekermann
  • Patent number: 4699945
    Abstract: Disclosed is a self-adhesive coating for polypropylene foams. The coating is the chemical crosslinking product of 2-chlorobutadiene/methacrylic acid copolymer and a prepolymer of an aminoplastic or phenolic plastic containing methylol groups.
    Type: Grant
    Filed: March 21, 1986
    Date of Patent: October 13, 1987
    Assignee: Firma Carl Freudenberg
    Inventors: Jorg Hausdorf, Joachim Kandler, Volker Siekermann, Wilfried Getrost