Patents by Inventor Wilhelm Lechner

Wilhelm Lechner 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: 4397968
    Abstract: A process for the production of an aqueous dispersion stabilized by a water-soluble polyvinyl alcohol and based on copolymers that comprise at least 60% by weight of monomer units selected from the group consisting of esters of acrylic acid, esters of methacrylic acid, styrene, and substituted styrene and mixtures thereof, consisting essentially of subjecting a stabilized dispersion of a monomer mixture containing at least 60% by weight of monomers selected from the group consisting of esters of acrylic acid, esters of methacrylic acid, styrene, substituted styrene and mixtures thereof, said dispersion being an aqueous dispersion stabilized by a water-soluble polyvinyl alcohol, to polymerization at a temperature in excess of 60.degree. C.
    Type: Grant
    Filed: December 4, 1981
    Date of Patent: August 9, 1983
    Assignee: Wacker-Chemie GmbH
    Inventors: Herbert Eck, Klaus Adler, Manfred Hannebaum, Wilhelm Lechner
  • Patent number: 4263191
    Abstract: An additive composition used in the preparation of low air pore, plastic-containing, hydraulically-setting binders consisting essentially of a mixture of (1) an aqueous copolymer dispersion having a solids content of between 30% and 65% by weight, a glass transition temperature of the solid copolymer of between -10.degree. C. and +40.degree. C., and a K-value of the solid copolymer of from 35 to 80, which aqueous copolymer dispersion being produced from monomer units of vinyl chloride, vinyl acetate and one or more additional copolymerizable monomers selected from the group consisting of ethylene, vinyl alkanoates having from 8 to 18 carbon atoms in the alkanoyl, and (meth)acrylic acid esters with alkanols having 3 to 8 carbon atoms, by free-radical polymerization in the presence of from 1.5% to 5% by weight of protective colloids and from 0 to 3% by weight of nonionic surface-active agents, both based on the dispersion, with (2) from 0.
    Type: Grant
    Filed: May 21, 1979
    Date of Patent: April 21, 1981
    Assignee: Wacker-Chemie GmbH
    Inventors: Herbert Eck, Paul-Gerhard Kirst, Wilhelm Lechner
  • Patent number: 4035329
    Abstract: A process for the continuous manufacture of an aqueous ethylene/vinyl acetate copolymer dispersion which comprises continuously copolymerizing ethylene and vinyl acetate and optionally other .alpha.-olefinically unsaturated monomers, in an aqueous emulsion in the presence of an emulsifier and/or a protective colloid, and in the presence of a free-radical-forming redox catalyst system of a reducing agent and an oxidizing agent as well, optionally, as a heavy metal salt, and recovering said ethylene/vinyl acetate copolymer dispersion, characterized by (a) the presence of a molar excess of at least 3 times, preferably from 3 to 10 times, said reducing agent over said oxidizing agent dosed into the reaction medium and (b) adding the monomers continuously to the reaction mixture at such a rate that the concentration of unreacted monomers at no place in the reaction zone exceeds 15% by weight of the total weight of the reaction mixture.
    Type: Grant
    Filed: November 19, 1975
    Date of Patent: July 12, 1977
    Assignee: Wacker-Chemie GmbH
    Inventors: Hubert Wiest, Josef Hanzalik, Wilhelm Lechner, Erwin Lieb
  • Patent number: 3954687
    Abstract: An improvement in the production of polyvinyl ester dispersions by polymerization of vinyl esters or copolymerization of vinyl esters with up to 40% by weight of oil-soluble, mono-olefinically-unsaturated monomers in an aqueous emulsion in the presence of water-soluble radical-forming polymerization catalysts, protective colloids and optionally emulsifiers and polymerization aids, the improvement comprising using carboxymethyl celluloses having a substitution degree of at least 10 as said protective colloids; as well as stable mixtures of the said polyvinyl ester dispersions and dextrin.
    Type: Grant
    Filed: October 2, 1974
    Date of Patent: May 4, 1976
    Assignee: Wacker Chemie GmbH
    Inventors: Hubert Wiest, Wilhelm Lechner