Patents by Inventor Thomas R. Keenan

Thomas R. Keenan 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).

  • Diffusion transfer image-receiving element having polyvinylpyridine layer treated with hydrophilic colloid/ammonia solution
    Patent number: 4009031
    Abstract: Coating a solution comprising a hydrophilic colloid and ammonia over a receiving layer comprising polyvinylpyridine in an image-receiving element of a photographic film unit significantly reduces haze and facilitates the separation of the image-receiving element from the remainder of the film unit subsequent to diffusion transfer processing.
    Type: Grant
    Filed: June 6, 1975
    Date of Patent: February 22, 1977
    Assignee: Polaroid Corporation
    Inventors: David P. Carlson, Thomas R. Keenan, Douglas L. Marks