Patents by Inventor Helmut Zecha

Helmut Zecha 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: 9650507
    Abstract: Methods for producing protective-colloid-stabilized aqueous dispersions of vinyl ester, polymers having weight-average particle diameters Dw of 120 nm to 1,500 nm and a polydispersity PD<1.6 include radically initiated emulsion polymerizations of one or more vinyl esters and optionally one or more additional ethylenically unsaturated monomers in aqueous medium in the presence of one or more protective colloids, wherein an aqueous mixture containing 0 to 90 grams of one more protective colloids per liter of water is provided to the receiver (concentration (C)), and starting with or after the start of the metered addition of one or more initiators, one or more protective colloids and the total amount of vinyl esters used are added in a metered manner, the emulsion polymerizations being performed in the absence of vinyl halogenides.
    Type: Grant
    Filed: April 2, 2013
    Date of Patent: May 16, 2017
    Assignee: WACKER CHEMIE AG
    Inventors: Helmut Zecha, Hans-Peter Weitzel
  • Publication number: 20150057405
    Abstract: Methods for producing protective-colloid-stabilized aqueous dispersions of vinyl ester, polymers having weight-average particle diameters Dw of 120 nm to 1,500 nm and a polydispersity PD<1.6 include radically initiated emulsion polymerizations of one or more vinyl esters and optionally one or more additional ethylenically unsaturated monomers in aqueous medium in the presence of one or more protective colloids, wherein an aqueous mixture containing 0 to 90 grams of one more protective colloids per liter of water is provided to the receiver (concentration (C)), and starting with or after the start of the metered addition of one or more initiators, one or more protective colloids and the total amount of vinyl esters used are added in a metered manner, the emulsion polymerizations being performed in the absence of vinyl halogenides.
    Type: Application
    Filed: April 2, 2013
    Publication date: February 26, 2015
    Inventors: Helmut Zecha, Hans-Peter Weitzel
  • Patent number: 8586686
    Abstract: A process for preparing a vinyl acetate-ethylene copolymer by means of free-radically initiated emulsion polymerization of vinyl acetate and ethylene and, optionally, further comonomers, performed in the presence of at least one protective colloid and at least one nonionic, ethoxylated emulsifier with an alkyl radical or at least one ethylene oxide-propylene oxide copolymer, and in the absence of chain transfer agent, and, before the initiation of the polymerization, 10% to 70% by weight of the vinyl acetate monomer and 40% to 100% by weight of the ethylene monomer are included in the initial charge, up to 100% by weight of the protective colloid fraction is included in the initial charge, at least 25% by weight of the emulsifier fraction is included in the initial charge, and the remaining fractions of monomers, protective colloid and emulsifier are metered in during the polymerization. A defined criterion of process COP is met.
    Type: Grant
    Filed: February 19, 2010
    Date of Patent: November 19, 2013
    Assignee: Wacker Chemie AG
    Inventors: Helmut Zecha, Gerhard Kögler
  • Publication number: 20130131261
    Abstract: The invention provides processes for preparing vinyl acetate-ethylene copolymers by means of free-radical initiated emulsion polymerization of vinyl acetate, ethylene and optionally one or more further comonomers in the presence of at least one protective colloid and optionally at least one emulsifier, characterized in that the vinyl acetate-ethylene copolymers contain 18 to 45% by weight of ethylene units, based on the total weight of the vinyl acetate-ethylene copolymers, and at least 70% by weight of ethylene units, based on the total weight of the ethylene units and of the further comonomer units of the vinyl acetate-ethylene copolymers, and the free-radical initiated emulsion polymerization is performed in the presence of A) 0.5 to 20% by weight, based on the total weight of the monomers used overall, of one or more solvents, or B) 0.1 to 20% by weight, based on the total weight of monomers used overall, of one or more solvents, and 0.
    Type: Application
    Filed: July 25, 2011
    Publication date: May 23, 2013
    Applicant: Wacker Chemie AG
    Inventors: Helmut Zecha, Gerhard Kögler
  • Publication number: 20120015201
    Abstract: The invention provides a process for preparing vinyl acetate-ethylene copolymers by means of free-radically initiated emulsion polymerization of vinyl acetate and 18% to 34% by weight of ethylene, based on the total weight of the vinyl acetate and ethylene monomers, and, optionally, further comonomers, characterized in that polymerization takes place in the presence of at least one protective colloid and of 0.
    Type: Application
    Filed: February 19, 2010
    Publication date: January 19, 2012
    Applicant: Wacker Chemie AG
    Inventors: Helmut Zecha, Gerhard Kögler
  • Patent number: 7649067
    Abstract: The present invention relates to a vinyl ester based polymer latex composition obtainable by free radical emulsion polymerization in substantial absence of a protective colloid and in the presence of no or small amounts of a surfactant, and to a process of making the same. The invention further pertains to a dispersion incorporating said vinyl ester based polymer latex composition, products comprising said dispersion, and various uses of the dispersion.
    Type: Grant
    Filed: October 19, 2005
    Date of Patent: January 19, 2010
    Assignee: Wacker Polymers, L.P.
    Inventors: Helmut Zecha, Holger Kuenstle
  • Publication number: 20070088120
    Abstract: The present invention relates to a vinyl ester based polymer latex composition obtainable by free radical emulsion polymerization in substantial absence of a protective colloid and in the presence of no or small amounts of a surfactant, and to a process of making the same. The invention further pertains to a dispersion incorporating said vinyl ester based polymer latex composition, products comprising said dispersion, and various uses of the dispersion.
    Type: Application
    Filed: October 19, 2005
    Publication date: April 19, 2007
    Inventors: Helmut Zecha, Holger Kuenstle
  • Patent number: 6794466
    Abstract: The present invention elates to a vinyl acetate based polymer latex composition obtained by emulsion polymerization of: (a) polyvinyl alcohol, (c) a monomer mixture comprising vinyl acetate, and (d) optionally one or more additional co-monomer(s), in presence of (c) 0.0001-0.05 wt. % of a chain transfer agent, based on total monomer weight, said vinyl acetate based polymer latex composition having a weight average particle size ≧400 nm and a higher shear thinning factor than the vinyl acetate based polymer latex composition (a), (b) and (d) obtained in the absence of the chain transfer agent (c). According to one embodiment, emulsion polymerization is carried out in presence of 0.001 to 0.05 wt. % of a chain transfer agent selected from the group consisting of aldehydes and chain transfer agents having a similar chain transfer constant with regard to vinyl acetate as the monomer. According to another embodiment, emulsion polymerization is carried out in presence of 0.0001 to 0.01 wt.
    Type: Grant
    Filed: October 19, 2001
    Date of Patent: September 21, 2004
    Assignee: Air Products Polymers, L.P.
    Inventors: Helmut Zecha, Rudolf Weissgerber, Francis Petrocelli
  • Publication number: 20030109620
    Abstract: The present invention elates to a vinyl acetate based polymer latex composition obtained by emulsion polymerization of:
    Type: Application
    Filed: October 19, 2001
    Publication date: June 12, 2003
    Inventors: Helmut Zecha, Rudolf Weissgerber, Francis Petrocelli
  • Patent number: 6552115
    Abstract: The present invention relates to a vinyl acetate based polymer latex composition obtained by emulsion polymerization, the polymer comprising PVOH, and a monomer mixture, said monomer mixture comprising vinyl acetate, and a pre-crosslinking monomer selected from one or more polyethylenically unsaturated compounds wherein said pre-crosslinking monomer is present in amount of less than 0.01% by weight based on the total monomer content and which pre-crosslinking monomer is initially charged to the polymerization reaction mixture. The invention further relates to use of the vinyl acetate based polymer latex in an adhesive, preferably a woodworking adhesive and to an adhesive, preferably a woodworking adhesive comprising said latex.
    Type: Grant
    Filed: October 17, 2000
    Date of Patent: April 22, 2003
    Assignee: Air Products Polymers, L.P.
    Inventors: Helmut Zecha, Rudolf Weissgerber, Frank Geiger