Patents by Inventor Charles J. Pfeiffer

Charles J. Pfeiffer 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).

  • Method of making flowable alkaline thiosulfate/alkaline sulfite and the product thereof
    Patent number: 5328814
    Abstract: A method for making flowable alkaline thiosulfate, flowable alkaline sulfite, or a combination of the two, by blending an alkaline thiosulfate, an alkaline sulfite, or a combination of the two, with an alkali metal arylsulfonate.formaldehyde in an amount effective to render the alkaline thiosulfate, the alkaline sulfite, or the combination freely flowable, and the product of this method. It has been found that the product of this method, such as freely flowable ammonium thiosulfate powder mixture, can be stored in a freely flowable condition for extended periods of time and can be dissolved into solution readily to form a clear non-turbid solution. The freely flowable ammonium thiosulfate powdered mixture of the present invention is particularly useful as a photographic fixative and bleach fixative for processing photographic elements.
    Type: Grant
    Filed: September 10, 1993
    Date of Patent: July 12, 1994
    Assignee: Fuji Hunt Photographic Chemicals, Inc.
    Inventors: Hongzoon Kim, Charles J. Pfeiffer
  • Method of making flowable alkaline thiosulfate/alkaline sulfite and the product thereof
    Patent number: 5270154
    Abstract: A method for making flowable alkaline thiosulfate, flowable alkaline sulfite, or a combination of the two, by blending an alkaline thiosulfate, an alkaline sulfite, or a combination of the two, with an alkali metal arylsulfonate.formaldehyde in an amount effective to render the alkaline thiosulfate, the alkaline sulfite, or the combination freely flowable, and the product of this method. It has been found that the product of this method, such as freely flowable ammonium thiosulfate powder mixture, can be stored in a freely flowable condition for extended periods of time and can be dissolved into solution readily to form a clear non-turbid solution. The freely flowable ammonium thiosulfate powdered mixture of the present invention is particularly useful as a photographic fixative and bleach fixative for processing photographic elements.
    Type: Grant
    Filed: January 31, 1992
    Date of Patent: December 14, 1993
    Assignee: Fuji Hunt Photographic Chemicals Inc.
    Inventors: Hongzoon Kim, Charles J. Pfeiffer
  • Method of making flowable alkaline thiosulfate/alkaline sulfite and the product thereof
    Patent number: RE35795
    Abstract: A method for making flowable alkaline thiosulfate, flowable alkaline sulfite, or a combination of the two, by blending an alkaline thiosulfate, an alkaline sulfite, or a combination of the two, with an alkali metal .?.arylsulfonate.formaldehyde.!. .Iadd.arylsulfonate.cndot.formaldehyde .Iaddend.in an amount effective to render the alkaline thiosulfate, the alkaline sulfite, or the combination freely flowable, and the product of this method. It has been found that the product of this method, such as freely flowable ammonium thiosulfate powder mixture, can be stored in a freely flowable condition for extended periods of time and can be dissolved into solution readily to form a clear non-turbid solution. The freely flowable ammonium thiosulfate powdered mixture of the present invention is particularly useful as a photographic fixative and bleach fixative for processing photographic elements.
    Type: Grant
    Filed: July 5, 1996
    Date of Patent: May 12, 1998
    Assignee: Fuji Hunt Photographic Chemicals, Inc.
    Inventors: Hongzoon Kim, Charles J. Pfeiffer