Patents by Inventor Jakob Kuhn

Jakob Kuhn 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).

  • Photographic four-color material for the silver dye bleach process
    Patent number: 4837133
    Abstract: There is disclosed a photographic four-color material for the silver dye bleach process, which material, in addition to containing the customary yellow, magenta and cyan image dyes, contains a black layer which is sensitive to infra-red light.The material is suitable e.g. for testing dotted or continuous tone color separation positives.
    Type: Grant
    Filed: December 9, 1986
    Date of Patent: June 6, 1989
    Assignee: Ciba-Geigy AG
    Inventor: Jakob Kuhn
  • Polyazo dyestuffs having high UV absorption
    Patent number: 4701525
    Abstract: Compounds of the formula(B--L.sub.m --A--L'--B'.sub.n, (1)in which A is the radical of a bisazo or trisazo dye, L and L' are organic radicals and B and B' are cyclic organic radicals and at least one of the radicals B and B' has spectral absorption in the UV region and one of the radicals B and B' is different from 2,4-dihydroxyphenyl, m is 1 or 2 and n is 0, 1 or 2.The compounds are suitable for use as image dyes in photographic silver dye bleach materials.
    Type: Grant
    Filed: June 2, 1986
    Date of Patent: October 20, 1987
    Assignee: Ciba-Geigy AG
    Inventors: Thomas-Markus Rohr, Jakob Kuhn
  • UV-absorbent compounds, process for their preparation and their use as image dyes in photographic materials for the silver dye bleach process
    Patent number: 4609609
    Abstract: Compounds of the formula(B--L).sub.m A--L'--B').sub.n (1),in which A is the radical of a bisazo or trisazo dye, L and L' are organic radicals and B and B' are cyclic organic radicals and at least one of the radicals B and B' has spectral absorption in the UV region and one of the radicals B and B' is different from 2,4-dihydroxyphenyl, m is 1 or 2 and n is 0, 1 or 2.The compounds are suitable for use as image dyes in photographic silver dye bleach materials.
    Type: Grant
    Filed: July 19, 1985
    Date of Patent: September 2, 1986
    Assignee: Ciba Geigy AG
    Inventors: Thomas-Markus Rohr, Jakob Kuhn