Patents by Inventor Wilfried Keller

Wilfried Keller 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).

  • Process for the production of polychloroprene latices rich in solid matter
    Patent number: 4338238
    Abstract: A process for polymerizing chloroprene which may contain as much as 50% by weight of a copolymerizable monomer, in an alkaline aqueous emulsion, of which the alkali ions at least partially consist of potassium, into a latex rich in solid matter having a solid content of from 50 to 65% by weight in the presence of an alkali salt of disproportionated abietic acid and a formaldehyde condensate with naphthalene sulphonic acid and also an alkali hydroxide, whereby polymerization is carried out until there is a conversion of more than 90% characterized in that(a) the aqueous phase contains from 2.8 to 3.8 parts by weight of an alkali salt of disproportionated abietic acid, from 0.3 to 2.0 parts by weight of a formaldehyde condensate of a naphthalene sulphonic acid and from 0.25 to 0.75 parts by weight of an alkali phosphate and/or polyphosphate, based on 100 parts by weight of monomer, and(b) polymerization is initiated using formamidine sulphinic acid.
    Type: Grant
    Filed: October 29, 1980
    Date of Patent: July 6, 1982
    Assignee: Bayer Aktiengesellschaft
    Inventors: Wilfried Nolte, Wilfried Keller, Heinz Esser
  • Process for the production of a polychloroprene latex which is stable to freezing and thawing
    Patent number: 4155891
    Abstract: Polychloroprene latex which is stable to freezing and thawing can be obtained by adding a betaine of a formula given below before, during or after polymerization.
    Type: Grant
    Filed: January 18, 1977
    Date of Patent: May 22, 1979
    Assignee: Bayer Aktiengesellschaft
    Inventors: Hans-Jurgen Pettelkau, Rudolf Hombach, Heinz Esser, Wilfried Keller
  • Process for working up liquid copper-containing catalyst waste from isomerization reactions of dichlorobutene
    Patent number: 4070405
    Abstract: Improved working up of the waste from an isomerization reaction of dichlorobutene by precipitating the copper catalyst used in said process by adding a polar solvent and removing the resulting precipitate by filtration.
    Type: Grant
    Filed: July 13, 1976
    Date of Patent: January 24, 1978
    Assignee: Bayer Aktiengesellschaft
    Inventors: Rolf Baatz, Gunter Beilstein, Dieter Grenner, Wilfried Keller, Dimitry Steinbach
  • Non-aqueous polymer dispersions of water-soluble monomers
    Patent number: 4029622
    Abstract: Stable non-aqueous dispersion of water-soluble polymers of extremely high molecular weight coupled with relatively low viscosity and rapid dilutability with water to form a polymer solution are obtained by polymerization of at least one water-soluble .alpha.,.beta.-monoolefinically unsaturated monomer such as acrylamide and dimethyl aminoethyl methacrylate in water-in-oil emulsion with the aid of at least one photo-initiator and UV-light, and azeotropical distillation from water, before or after the addition of a water-soluble wetting agent, to a residual water content of less than 5% by weight, based on polymer. The dispersions are eminently suitable for the preparation of aqueous solution, as retention agents for fillers and water-removal accelerators in the production of paper.
    Type: Grant
    Filed: April 21, 1975
    Date of Patent: June 14, 1977
    Assignee: Bayer Aktiengesellschaft
    Inventors: Wilfried Keller, Friedhelm Muller