Patents by Inventor Erhard Leicht

Erhard Leicht 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: 5652047
    Abstract: Preparation of binder resins having improved flow properties in the manufacture of curable fiber composites of natural or synthetic fiber materials, which are based on thermosetting novolaks which contain crosslinking agents and contain practically no free mononuclear phenols, by admixing polyglycols and/or polycarboxylic acids or anhydrides thereof and/or acid esters of polyglycols and polycarboxylic acids, preferably in amounts of in total up to 20% by weight, to the novolaks in the melt, pulverizing the mixture, after cooling to room temperature, and mixing it intimately with the required amount of pulverulent crosslinking agent.
    Type: Grant
    Filed: May 20, 1996
    Date of Patent: July 29, 1997
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Wolfgang Hesse, Erhard Leicht, Richard Sattelmeyer, Ralph Schaefer
  • Patent number: 5591509
    Abstract: The ski described is characterized by the use of a selected fiber reinforced material comprising a sheetlike textile material and a thermoset resin, the fiber content being 30-70% by weight and the fiber being not less than 30% by weight synthetic. This material is notable for high flexibility and high restoring forces and confers excellent properties on the ski, for example good vibration damping.
    Type: Grant
    Filed: December 20, 1991
    Date of Patent: January 7, 1997
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Georg M. Lorenz, Walter Fester, Ulrich Schuster, Erhard Leicht, Ralph Sch afer
  • Patent number: 5426152
    Abstract: Preparation of vulcanizable rubber mixtures and vulcanized compounds thereof having improved adhesion to reinforcing supports based on steel cord and textile fibers, in which effective amounts of modified novolaks are added to the rubber mixtures as adhesion promotors, which are prepared by simultaneous reaction of polyhydric phenols with aldehydes and unsaturated hydrocarbons with acid catalysis at elevated temperature and do not contain any troublesome proportions of free starting phenols. Rubber mixtures according to the invention can be processed in an easy advantageous manner without liberating toxic substances which might be detrimental to persons working in processing and/or to the environment.
    Type: Grant
    Filed: October 17, 1994
    Date of Patent: June 20, 1995
    Assignee: Hoechst AG
    Inventors: Wolfgang Hesse, Erhard Leicht, Richard Sattelmeyer
  • Patent number: 5288741
    Abstract: Polymers which contain units of 4-hydroxystyrene and/or of 4-acetoxystyrene, where appropriate in a mixture with other comonomer units, in particular butadiene, can be used in place of phenolic or resorcinol resins as reinforcing resins and adhesion promoters in rubber mixtures. These polymers are distinguished by the fact that, coupled with at least equally good effectiveness, they do not release any phenolic materials into the environment on incorporation into rubber mixtures.
    Type: Grant
    Filed: July 28, 1992
    Date of Patent: February 22, 1994
    Assignee: Roussel-Uclaf
    Inventors: Albert Bender, Erhard Leicht, Richard Sattelmeyer
  • Patent number: 5096996
    Abstract: Modified novolaks based on phenols which are trifunctional with respect to formaldehyde and contain, as modifying components, terpenes and unsaturated carboxylic acids or derivatives of these compounds, the weight ratio between the terpenes and the unsaturated carboxylic acids or derivatives thereof being in the range from 98.5:2.5 to 2.5:98.5 and the weight ratio between the phenolic component and the sum of the modified components being in the range from 95:5 to 5:95 and the modified novolaks having a melting point greater than 45.degree. C.Process for the preparation of the modified novolaks by admixing the modifying components indicated with non-modified novolaks in the necessary amounts at temperatures between 80.degree. and 300.degree. C.Use of the modified novolaks as reinforcing resins for rubber and elastomers, as tackifying agents for rubber, as binders for friction linings, curable molding compositions, impregnants, coatings, paints and binders for finely divided inorganic substrates.
    Type: Grant
    Filed: October 2, 1989
    Date of Patent: March 17, 1992
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Wolfgang Hesse, Erhard Leicht, Richard Sattelmeyer
  • Patent number: 5089589
    Abstract: The preparation of novolaks from phenols or mixtures of different phenols, and oxo compounds or mixtures of oxo compounds by condensation of the reactants in a medium having a low water content in homogeneous phase at temperature of .gtoreq.110.degree. C., preferably between 115.degree. and 200.degree. C. and preferably at normal pressure, in the presence of water-immiscible and/or only partially water-miscible inert organic solvents and of acids as catalysts with removal of water by distillation, the medium having a low water content being prepared or maintained by distilling off water from the reaction mixture, preferably by azeotropic distillation. Particular advantages are obtained when readily volatile oxo compounds, in particular aqueous formaldehyde solutions, are used.
    Type: Grant
    Filed: January 22, 1990
    Date of Patent: February 18, 1992
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Wolfgang Hesse, Klaus Hofmann, Erhard Leicht