Patents by Inventor Siegfried Bildstein

Siegfried Bildstein 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).

  • Process for the separation and recovery of naphthalene-sulfonic acids from aqueous solutions
    Patent number: 5028736
    Abstract: The invention relates to a process for the separation and recovery of naphthalenesulfonic acids from aqueous solutions. In this, the naphthalenesulfonic acids are adsorbed on basic ion exchangers and subsequently desorbed again, preferably with the aid of an alkaline liquor, from which the alkali metal sulfonates are then precipitated by cooling.
    Type: Grant
    Filed: May 24, 1990
    Date of Patent: July 2, 1991
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Ulrich Girrbach, Siegbert Rittner, Siegfried Bildstein, Klaus Schmiedel
  • Process for the manufacture of naphthalene-monosulfonic acids
    Patent number: 4110365
    Abstract: Preparation of naphthalene-monosulfonic acids from naphthalene and sulfuric acid at elevated temperatures.
    Type: Grant
    Filed: June 26, 1975
    Date of Patent: August 29, 1978
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Siegfried Bildstein, Rudolf Lademann, Siegfried Pietzsch, Georg Schaeffer