Patents by Inventor Thomas A. Rettig

Thomas A. Rettig 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).

  • Patent number: 4612057
    Abstract: A method for the recovery of silver from photographic film having a polyester base and a macromolecular organic polymer coating to which is adhered a light sensitive silver emulsion layer. The process includes mixing small film pieces in a hot aqueous liquid having a solids concentration level of at least 25 percent by volume. The mixture is subjected to conditions of high shear to remove the silver emulsion. The liquid containing the silver emulsion is then separated from the film pieces and the silver is recovered from the liquid.
    Type: Grant
    Filed: January 22, 1985
    Date of Patent: September 16, 1986
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Kenneth R. Buser, Thomas A. Rettig
  • Patent number: 4602046
    Abstract: A method for the recovery of plastic material such as polyester from scrap material such as photographic film having a polyester base and at least one layer of a macromolecular organic polymer. The process includes mixing small pieces of the scrap material in a solution having a scrap solids concentration level of at least 25 percent by volume. The mixture is subjected to conditions of high shear to remove and comminute the polymer layer to particles of a maximum size particle dimension substantially smaller than the minimum size in the longest dimension of the scrap pieces. The polymer particles are then separated from the remaining pure polyester.
    Type: Grant
    Filed: January 22, 1985
    Date of Patent: July 22, 1986
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Kenneth R. Buser, Thomas A. Rettig