Patents by Inventor Michael D. Purol

Michael D. Purol 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: 5500125
    Abstract: A method of treating photoprocessing wash water, comprising in sequence, the steps of:A) contacting the wash water with an acrylic anion exchange resin to remove silver thiosulfate complex in the water; andB) contacting the water from step A) with an oxidizing agent that converts thiosulfate ions to sulfate ions.C) recirculating continuously through the photoprocessing wash tank and steps A) and B).
    Type: Grant
    Filed: May 19, 1994
    Date of Patent: March 19, 1996
    Assignee: Eastman Kodak Company
    Inventors: Richard R. Horn, Christine K. Gaskell, Susan R. Krauss, Michael D. Purol
  • Patent number: 5264323
    Abstract: An improved photographic developing solution is free of dihydroxybenzene developing agents such as hydroquinone, has a pH in the range of from 9.5 to 11.5 and comprises (1) an ascorbic acid developing agent, (2) an auxiliary super-additive developing agent and (3) a carbonate buffering agent in a concentration of at least 0.5 molar. The developing solution is broadly useful in black-and-white development but is most advantageously employed in a process for forming a high-contrast image utilizing a silver halide photographic element comprising a hydrazine compound which functions as a nucleating agent and an amino compound which functions as an incorporated booster. The developing solution is ecologically advantageous, exhibits excellent stability with respect to seasoning effects, and provides high speed and good upper scale contrast combined with a low level of pepper fog and a moderate degree of chemical spread.
    Type: Grant
    Filed: December 14, 1992
    Date of Patent: November 23, 1993
    Assignee: Eastman Kodak Company
    Inventors: Michael D. Purol, Paul A. Zielinski, Donald L. Kerr
  • Patent number: 5236816
    Abstract: An improved photographic developing solution is free of dihydroxybenzene developing agents such as hydroquinone, has a pH in the range of from 9.5 to 11.5 and comprises (1) an ascorbic acid developing agent, (2) an auxiliary super-additive developing agent and (3) a carbonate buffering agent in a concentration of at least 0.5 molar. The developing solution is broadly useful in black-and-white development but is most advantageously employed in a process for forming a high-contrast image utilizing a silver halide photographic element comprising a hydrazine compound which functions as a nucleating agent and an amino compound which functions as an incorporated booster. The developing solution is ecologically advantageous, exhibits excellent stability with respect to seasoning effects, and provides high speed and good upper scale contrast combined with a low level of pepper fog and a moderate degree of chemical spread.
    Type: Grant
    Filed: April 10, 1992
    Date of Patent: August 17, 1993
    Assignee: Eastman Kodak Company
    Inventors: Michael D. Purol, Paul A. Zielinski, Donald L. Kerr
  • Patent number: 4264716
    Abstract: Photographic color developer compositions containing a primary aromatic amino color developing agent and an hydroxylamine are stabilized by incorporating therein a combination of sequestering agents, one of which is an aminopolyphosphonic acid compound and another of which is an aromatic polyhydroxy compound. Decomposition of the hydroxylamine, in the presence of heavy metals such as iron which act to catalyze the decomposition, and resultant formation of ammonia is effectively prevented by the presence in the developer composition of this combination of sequestering agents. Undesirable precipitate formation is also effectively avoided.
    Type: Grant
    Filed: September 10, 1979
    Date of Patent: April 28, 1981
    Assignee: Eastman Kodak Company
    Inventors: Sheridan E. Vincent, Michael D. Purol