Patents by Inventor Paul A. Zielinski

Paul A. Zielinski 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: 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: 4345085
    Abstract: A method for preparing 2-pyrazolin-5-ones from 1,2,4-oxadiazoles is described. The method comprises forming a liquid reaction system of a base catalyst and a 1,2,4-oxadiazole in an organic liquid reaction medium and heating the reaction system to a temperature sufficient to cause the 1,2,4-oxadiazole to be rearranged to a 2-pyrazolin-5-one.
    Type: Grant
    Filed: December 29, 1980
    Date of Patent: August 17, 1982
    Assignee: Eastman Kodak Company
    Inventors: Chang Kyu Kim, Cataldo A. Maggiulli, Paul A. Zielinski