Patents by Inventor David K. Bulloch

David K. Bulloch 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: 4298681
    Abstract: An N,N, disubstituted p-phenylenediamine salt of a phosphoric acid selected from the group consisting of ortho-phosphoric acid, pyrophosphoric acid and polyphosphoric acid. Such a phosphate is incorporated as a color developing agent in a liquid packaged developer concentrate which subsequently is mixed with other materials contained in a multi-package receptacle and the mixture is diluted with water to form a color developer working solution (bath) for developing a colored film. The developer concentrate has the advantage that the color developing agent therein does not tend to deteriorate upon standing, as do present-day widely used commercial N,N, disubstituted p-phenylenediamine color developing agents in developer liquid concentrates, e.g.
    Type: Grant
    Filed: February 23, 1973
    Date of Patent: November 3, 1981
    Assignee: Philip A. Hunt Chemical Corp.
    Inventors: David K. Bulloch, Hong Z. Kim
  • Patent number: 4161406
    Abstract: A high speed color reversal cine film with latent images recorded thereon is so processed as to color-develop the latent images and concurrently reduce the high contrast at the dark end of the tone scale which is inherent in the prior art development of such film. The new method utilizes in the color developer bath increased amounts (in comparison with prior art color developer baths) of a competing coupler such as citrazinic acid and of a silver halide solvent such as ethylene diamine and reduces the amount of a reversal agent such as t-butylamine borane, and also includes a competing non-coupling developer such as 4-hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidone, or phenidone, or a derivative thereof.
    Type: Grant
    Filed: December 7, 1977
    Date of Patent: July 17, 1979
    Assignee: Philip A. Hunt Chemical Corp.
    Inventor: David K. Bulloch