Patents by Inventor Otmar Hafner

Otmar Hafner 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).

  • Addition compounds, a process for the preparation, and their use, based on epoxy novolac-fatty amine adducts
    Patent number: 5070159
    Abstract: Addition compounds which are suitable as dispersants for solids in organic media are obtained from polyepoxides based on novolaks having 3 to 11 nuclei and a mixture of aliphatic, aromatic and/or heterocyclic amines.
    Type: Grant
    Filed: June 16, 1989
    Date of Patent: December 3, 1991
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Erwin Dietz, Andreas Sommer, Adolf Kroh, Jurgen Hohn, Otmar Hafner, Wolfgang Rieper
  • Powdered azo pigments with improved rheological properties, process for their preparation and their use
    Patent number: 5066687
    Abstract: Powdered azo pigments with improved rheological properties for use in paint systems on an alkyd/melamine, acrylic/melamine, acrylate/isocyanate or polyester/isocyanate basis, both of a conventional nature and also of a modern nature of the "high solids" type, to which--as appropriate before, during or after finishing--1 to 20% by weight of the active substance of a paint additive of the polyurethane series, prepared by reacting polyisocyanurates which still carry free isocyanate groups and are based on toluylene diisocyanate, hexamethylene diisocyanate or mixtures thereof, with (1) aliphatic mono- or polyhydroxycarbonylic acid C.sub.1 -C.sub.20 -alkyl esters (degree of polycondensation 2-50), (2) polyethylene glycols (molecular weight 500-1,500) and (3) 5- or 6-membered, saturated or unsaturated heterocyclic compounds which contain at least one nitrogen atom in the ring and reactive amino or hydroxy-C.sub.1 -C.sub.
    Type: Grant
    Filed: May 2, 1990
    Date of Patent: November 19, 1991
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Wolfgang Rieper, Otmar Hafner
  • Powdered pigments with improved rheological properties, processes for their preparation and their use with a content of at least 5% of unsubstituted quinacridone
    Patent number: 4732618
    Abstract: Powdered pigments which contain at least 5% of unsubstituted quinacridone and have improved rheological properties for use in paint systems on an alkyd/melamine, acrylic/melamine, acrylate/isocyanate or polyester/isocyanate basis, both of a conventional nature and also of a modern nature of the "high solids" type, onto which--as appropriate before, during or after finishing--1 to 20% by weight of the active substance of a paint additive, prepared by reacting polyisocyanurates which still carry free isocyanate groups and are based on tolylene diisocyanate, hexamethylene diisocyanate or mixtures thereof, with (1) aliphatic mono- or poly-(hydroxycarboxylic acid) C.sub.1 -C.sub.20 -alkyl esters (degree of polymerization 2-50), (2) polyethylene glycols (molecular weight 500-1,500) and (3) 5- or 6-membered, saturated or unsaturated heterocyclic compounds which contain at least 1 nitrogen atom in the ring and reactive amino or hydroxy-C.sub.1 -C.sub.
    Type: Grant
    Filed: August 11, 1986
    Date of Patent: March 22, 1988
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Ernst Spietschka, Adolf Kroh, Otmar Hafner
  • Addition compounds and process for their preparation
    Patent number: 4631330
    Abstract: Addition products formed from polymeric diphenylmethane 4,4'-diisocyanates, amines, monoactive and diactive polymers are suitable for use as dispersants for solids in organic media.
    Type: Grant
    Filed: December 16, 1985
    Date of Patent: December 23, 1986
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Erwin Dietz, Albert Munkel, Otmar Hafner, Wolfgang Rieper, Adolf Kroh