Patents by Inventor Stefan Wieditz

Stefan Wieditz 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: 5635564
    Abstract: A process for the preparation of multicoat coatings in which a pigmented aqueous basecoat composition is used which comprises a water-thinnable emulsion polymer as the film-former. The water-thinnable emulsion polymer is prepared in a two-stage emulsion polymerization. The first stage gives rise to a polymer having a glass transition temperature (T.sub.G1) of +30.degree. to +110.degree. C. In the second stage a mixture of monomers is polymerized in the presence of the polymer prepared in the first stage which by an exclusive polymerization gives rise to a polymer having a glass transition temperature (T.sub.G2) of -60.degree. to +20.degree. C. The hydroxyl value of the emulsion polymer is between 2 and 100.
    Type: Grant
    Filed: June 24, 1994
    Date of Patent: June 3, 1997
    Assignee: BASF Lacke + Farben, AG
    Inventors: Stefan Wieditz, Jurgen Niemann, Arnold Dobbelstein
  • Patent number: 5503939
    Abstract: The invention relates to a process for the production of two-coat finishes, in which a pigmented aqueous basecoat is applied, the basecoat obtained is coated over with a clearcoat, and basecoat and clearcoat are baked together. The process according to the invention is distinguished in that the aqueous basecoat contains an emulsion polymer which has been prepared in the presence of a reaction product (A), the reaction product (A) being obtained by reacting(i) a butadiene homo- or copolymer,(ii) at least one fatty acid of a drying oil or at least one drying oil or a mixture of at least one fatty acid of a drying oil and at least one drying oil, and(iii) maleic anhydridein a mass ratio of (i):(ii):(iii)=1.0:0.1 to 0.6:0.1 to 0.6 and, after adding a basic aqueous solution, converting the reaction product to an aqueous dispersion.
    Type: Grant
    Filed: December 9, 1994
    Date of Patent: April 2, 1996
    Assignee: BASF Lacke + Farben, AG
    Inventors: Heinz P. Rink, Susanne Piontek, Bernhard Lettmann, Stefan Wieditz, Birgit Peitz, Achim Gast
  • Patent number: 5256453
    Abstract: A process for the production of a multi-layer paint coating in which base paints are employed which contain 5 to 20% by weight of crosslinked polymer microparticles, 2 to 15% by weight of a cellulose ester and 5 to 20% by weight of an epoxidized fatty acid ester, the weight percentages relating to the total content of nonvolatile constituents, excluding pigments and inorganic fillers, and the cellulose ester being so selected that a solution of 15 parts by weight of the cellulose ester in 85 parts by weight of a 9:1 mixture of acetone and ethanol at 23.degree. C. has a viscosity of 200 to 600 mPa.s.
    Type: Grant
    Filed: December 31, 1991
    Date of Patent: October 26, 1993
    Assignee: BASF Lacke + Farben Aktiengesellschaft
    Inventors: Monika Heithorn, Stefan Wieditz, Gerold Mahr, Arnold Dobbelstein, deceased
  • Patent number: 5212242
    Abstract: The invention relates to a coating composition containingA) 50 to 90% by weight of one or more hydroxyl-containing addition polymers, prepared by copolymerization of ethylenically unsaturated monomers which are in part hydroxyalkyl esters of .alpha.,.beta.-ethylenically unsaturated carboxylic acids andB) 10 to 50% by weight of one or more amino resin crosslinking agentsthe sum of the proportions by weight of A and B being 100% by weight, and suitable auxiliaries and additives, optionally pigments, optionally fillers, organic solvent and an acid catalyst.The coating composition is one wherein the acid catalyst used comprises1) sulfo- or sulfonio[sic]-succinic esters which each contain at least one hydroxyl group and/or2) sulfo- or sulfonio[sic]-succinic polyesters which each contain at least one hydroxyl group.The invention furthermore relates to a process for the preparation of the coating compositions according to the invention and to their use as an automobile repair finish or as a stoving paint.
    Type: Grant
    Filed: October 29, 1991
    Date of Patent: May 18, 1993
    Assignee: BASF Lache+Farben Aktiengesellschaft
    Inventors: Lutz-Werner Gross, Stefan Wieditz, Werner-Alfons Jung