Patents by Inventor Rolf Hafner

Rolf 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).

  • Method for producing high-purity sulphuric acid
    Patent number: 6740302
    Abstract: The invention relates to a novel method for producing high-purity sulfuric acid for use in the semiconductor industry. The method comprises the addition of a hydrogen peroxide solution to an engineered oelum in order to reduce the SO2 concentration, evaporation of the SO3 and separation of acid traces. The high-purity SO3 is then enriched with inert gas and the SO3 is absorbed into sulfuric acid.
    Type: Grant
    Filed: June 26, 2002
    Date of Patent: May 25, 2004
    Assignee: Merck Patent GmbH
    Inventors: Martin Hostalek, Werner Büttner, Rolf Hafner, Chih-Peng Lu, Ching-Jung Kan, Ekkehart Seitz, Ernst Friedel
  • Method for producing high-purity sulphuric acid
    Publication number: 20020192144
    Abstract: The invention relates to a novel method for producing high-purity sulfuric acid for use in the semiconductor industry. The method comprises the addition of a hydrogen peroxide solution to an engineered oelum in order to reduce the SO2 concentration, evaporation of the SO3 and separation of acid traces. The high-purity SO3 is then enriched with inert gas and the SO3 is absorbed into sulfuric acid.
    Type: Application
    Filed: June 26, 2002
    Publication date: December 19, 2002
    Inventors: Martin Hostalek, Werner Buttner, Rolf Hafner, Chih-Peng Lu, Ching-Jung Kan, Erkehart Seitz, Ernst Friedel