Patents by Inventor Gilbert Sielfeld

Gilbert Sielfeld 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: 4659794
    Abstract: A process for the production of polymers of vinyl chloride by suspension polymerization, uses as the suspension stabilizer either(A) a methylhydroxypropylcellulose with a methoxy substitution degree of 20-32%, a hydroxypropoxy substitution degree of 2-10%, and a viscosity of 30-70 mPa.s; and/or(B) a suspension agent combination consisting essentially of:(a) methylcellulose with a methoxy substitution degree of 22-34% and a viscosity of 7-20 mPa.s, and(b) methylcellulose with a methoxy substitution degree of 22-34% and a viscosity of 50 mPa.s-4,000 mPa.s and/or methylhydroxypropylcellulose with a methoxy substitution degree of 20-32%, a hydroxypropoxy substitution degree of 2-10%, and a viscosity of 100-3,000 mPa.s,and polymerizes in the presence of 0.4-8% by weight of an ethylene-vinyl acetate copolymer. The resultant polymers are suitable for lowering viscosity of polyvinyl chloride plastisols.
    Type: Grant
    Filed: February 5, 1985
    Date of Patent: April 21, 1987
    Assignee: Huels Aktiengesellschaft
    Inventor: Gilbert Sielfeld
  • Patent number: 4540759
    Abstract: A process for producing vinyl chloride polymers and copolymers by suspension polymerization is carried out in the presence of small amounts of ethylene/vinyl acetate copolymers with a vinyl acetate content of 38% by weight to 55% by weight and with a viscosity number of 95-210 ml/g, the catalyst being added to the polymerization charge in dissolved form. The resultant polymers are suitable for lowering the viscosity of polyvinyl chloride plastisols.
    Type: Grant
    Filed: August 20, 1982
    Date of Patent: September 10, 1985
    Assignee: Chemische Werke Huels AG
    Inventor: Gilbert Sielfeld
  • Patent number: 4525559
    Abstract: Vinyl chloride polymers and copolymers are produced by suspension polymerization in the presence of a small amount of specific ethylene-vinyl acetate copolymers. The catalysts, the ethylene-vinyl acetate copolymer, and the monomer or monomer mixture are added to the polymerization charge before the suspension agent. The resultant polyvinyl chloride is especially suitable for lowering the viscosity of polyvinyl chloride plastisols.
    Type: Grant
    Filed: August 20, 1982
    Date of Patent: June 25, 1985
    Assignee: Chemische Werke Huels AG
    Inventors: Gilbert Sielfeld, Rudolf de Jong
  • Patent number: 4472561
    Abstract: Production of suspension polyvinyl chloride suitable for reducing the viscosity of polyvinyl chloride plastisols is effected by suspension polymerization in the presence of small amounts of(a) an ethylene/propylene/ethylidene norbornene terpolymer having a propylene content of 40-50% by weight, with 5-15 double bonds per 1,000 carbon atoms and with a viscosity of 4-20 mPa s, measured with 2% solutions in trichloroethylene at 25.degree. C.;and/or(b) a polyvinyl isobutyl ether having a K value of 80-150, measured with 0.5% solutions in isooctane at 20.degree. C., wherein the catalysts, the ethylene/propylene/ethylidene norbornene terpolymer and/or the polyvinyl isobutyl ether and the monomer or comonomer mixture are added to the polymerization batch before adding the suspension agent or the suspension agent mixture. These suspension polymers are used as additives for polyvinyl chloride plastisols.
    Type: Grant
    Filed: May 16, 1983
    Date of Patent: September 18, 1984
    Assignee: Chemische Werke Huels, AG
    Inventor: Gilbert Sielfeld
  • Patent number: 4438244
    Abstract: Vinyl chloride is polymerized in suspension using as the suspension stabilizer a copolymer of 65-85 molar percent of 2-isopropyl-.DELTA..sup.2 -oxazoline and 35-15 molar percent of 2-methyl-.DELTA..sup.2 -oxazoline, having a viscosity number of 35-80 ml/g, measured at 25.degree. C. in an isopropanol/water mixture (50 volume percent of isopropanol) in a concentration of 0.5% (weight/volume of solution).
    Type: Grant
    Filed: May 24, 1982
    Date of Patent: March 20, 1984
    Assignee: Chemische Werke Huels, AG
    Inventors: Gilbert Sielfeld, Paul Sunder-Plassmann
  • Patent number: 4368307
    Abstract: In a process for preparing a vinyl chloride resin by polymerizing vinyl chloride alone or with up to 20% by weight of other polymerizable unsaturated monomers, in an aqueous suspension, in the presence of a monomer-soluble free radical catalyst and a suspension stabilizer which is partially hydrolyzed polyvinyl acetate or cellulose ether, there is an improvement wherein the polymerization is conducted in the presence of 0.02-0.3% by weight, based on the amount of monomer to be polymerized, of a cosuspension stabilizer which is a copolymer of 2-n-propyl-.DELTA..sup.2 -oxazoline, 2-isopropyl-.DELTA..sup.2 -oxazoline or both and 2-methyl-.DELTA..sup.2 oxazoline, 2-ethyl-.DELTA..sup.2 -oxazoline or both, the copolymer having a viscosity number of 35-70 (ml/g), measured at 25.degree. C. in an isopropanol/water mixture (50 vol-% of isopropanol), in a concentration of 0.5% (weight/volume of the solution).
    Type: Grant
    Filed: September 11, 1981
    Date of Patent: January 11, 1983
    Assignee: Chemische Werke Huls AG
    Inventors: Gilbert Sielfeld, Paul Sunder-Plassmann