Patents by Inventor Willis J. Ludwig

Willis J. Ludwig 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).

  • Soap having improved carbonless imaging properties
    Patent number: 4461496
    Abstract: Soap composition having improved imaging properties. The composition comprises (1) at least one metal cation which produces an image when reacted with by a dye precursor which is a derivative of dithiooxamide, (2) at least one rosin soap, and (3) at least one metallic soap. The presence of the metallic soap results in a higher level of metal cation available for image formation, thus improving speed of image formation and image quality.
    Type: Grant
    Filed: August 17, 1982
    Date of Patent: July 24, 1984
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Willis J. Ludwig
  • Pressure-sensitive marking materials
    Patent number: 4201404
    Abstract: Hot-melt imaging compositions useful for solventless coating on paper substrates. The imaging compositions comprise imaging microcapsules having melamine-urea-formaldehyde condensation polymer shells and an organic liquid dye precursor dispersed in a hot-melt binder. The compositions can be coated on paper substrates by conventional coating techniques to provide carbonless papers.
    Type: Grant
    Filed: May 17, 1978
    Date of Patent: May 6, 1980
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Jack W. Charbonneau, Richard S. Law, Willis J. Ludwig, Wayne O. Otteson