Patents by Inventor Richard L. Shadrach

Richard L. Shadrach 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).

  • Positive working color proofing system comprising polyvinyl acetal/polyvinyl alcohol/polyvinyl acetate resin
    Patent number: 4948693
    Abstract: This invention relates to positive working photosensitized sheet constructions which, upon exposure to an actinic radiation source through a screened image, can accurately reproduce said image. The construction is useful as a color proofing film which can be employed to predict the image quality from a lithographic printing process.
    Type: Grant
    Filed: August 29, 1988
    Date of Patent: August 14, 1990
    Assignee: Hoechst Celanese Corporation
    Inventors: Richard L. Shadrach, Stephan J. W. Platzer, Gabor I. Koletar
  • Optical brightener containing positive working color proofing system
    Patent number: 4869993
    Abstract: This invention relates to positive working photosensitized sheet constructions which, upon exposure to an actinic radiation source through a screened image, can accurately reproduce said image. The construction is useful as a color proofing film which can be employed to predict the image quality from a lithographic printing process. The element is composed of a substrate, colored photosensitive layer and adhesive layer. The adhesive layer contains an optical brightener compound which reduces residual yellow staining derived from the naphthoquinone diazide sensitizer.
    Type: Grant
    Filed: August 29, 1988
    Date of Patent: September 26, 1989
    Inventors: Wahib Farahat, Dennis J. Bellville, Richard L. Shadrach
  • Positive working naphthoquinone diazide color proofing element with polyvinyl acetate adhesive layer
    Patent number: 4772533
    Abstract: This invention relates to positive working photosensitized sheet constructions which, upon exposure to an actinic radiation source through a screened image, can accurately reproduce said image. The construction is useful as a color proofing film which can be employed to predict the image quality from a lithographic printing process.
    Type: Grant
    Filed: November 5, 1986
    Date of Patent: September 20, 1988
    Assignee: American Hoechst Corporation
    Inventors: Stephan J. W. Platzer, Gabor I. Koletar, Richard L. Shadrach
  • Positive working naphthoquinone diazide color proofing transfer process
    Patent number: 4659642
    Abstract: This invention relates to positive working photosensitized sheet constructions which, upon exposure to an actinic radiation source through a screened image, can accurately reproduce said image. The construction is useful as a color proofing film which can be employed to predict the image quality from a lithographic printing process.
    Type: Grant
    Filed: October 22, 1984
    Date of Patent: April 21, 1987
    Assignee: American Hoechst Corporation
    Inventors: Stephan J. W. Platzer, Gabor I. Koletar, Richard L. Shadrach