Patents by Inventor Brian H. Johnston

Brian H. Johnston 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: 5292621
    Abstract: Electrostatographic toner materials are disclosed which contains a yellow pigment which is a metal coordination complex having the formula: ##STR1## wherein R is preferably hydrogen, or SO.sub.2 NHR.sup.2 (R.sup.2 being alkyl or aryl), Z is an electron withdrawing group, Z.sup.1 is preferably alkyl, aryl or N(R.sup.3).sub.2 (R.sup.3 being alkyl, aryl or hydrogen), Me is a coordinate metal ion and L is a ligand. These pigments are formulated with fusible polymeric binders to provide a toner which exhibits excellent triboelectric properties and improved yellow color and hue when utilized in the electrostatographic process to produce colored electrophotographic images.
    Type: Grant
    Filed: May 27, 1992
    Date of Patent: March 8, 1994
    Assignee: Eastman Kodak Company
    Inventors: Brian H. Johnston, Thomas H. Whitesides
  • Patent number: 5286592
    Abstract: Electrostatographic toner materials containing a cyan pigment which is a metal coordination complex of a substituted 6-heterocycloazo-3-pyridinol compound are disclosed. These pigments are formulated with fusible polymeric binders to provide a toner which exhibits excellent triboelectric properties and improved cyan color and hue when utilized in the electrostatographic process to produce colored electrophotographic images.
    Type: Grant
    Filed: May 27, 1992
    Date of Patent: February 15, 1994
    Assignee: Eastman Kodak Company
    Inventors: Brian H. Johnston, Thomas H. Whitesides
  • Patent number: 5283147
    Abstract: Electrostatographic toner materials containing a magenta pigment which is a metal coordination complex of a substituted 6-arylazo-3-pyridinol compound are disclosed. These pigments are formulated with fusible polymeric binders to provide a toner which exhibits excellent triboelectric properties and improved magenta color and hue when utilized in the electrostatographic process to produce colored electrophotographic images.
    Type: Grant
    Filed: May 27, 1992
    Date of Patent: February 1, 1994
    Assignee: Eastman Kodak Company
    Inventors: Brian H. Johnston, Thomas H. Whitesides
  • Patent number: 4853319
    Abstract: Novel pyrazolone photographic couplers contain in the coupling position a coupling-off group represented by the formula: ##STR1## wherein: L.sub.1 and L.sub.2 individually are unsubstituted or substituted methylene or ethylene;m and n individually are 0 or 1;Y is R.sub.1 or ZR.sub.2 ;R.sub.1 is an unsubstituted or substituted aryl or heterocyclic group, or is a secondary or tertiary carbon group represented by ##STR2## wherein R.sub.3 and R.sub.4 are selected from the group consisting of halogen, R.sub.2 and Z.sub.1 R.sub.b ; wherein Z is O, S, or NR.sub.a ; Z.sub.1 is O, S, or NR.sub.c ; and R.sub.2 is an unsubstituted or substituted alkyl, aryl, or heterocyclic group. R.sub.5, R.sub.6, R.sub.a, R.sub.b and R.sub.c are as defined in the specification. R.sub.3 optionally joins together with at least one of R.sub.4 and R.sub.
    Type: Grant
    Filed: December 14, 1987
    Date of Patent: August 1, 1989
    Assignee: Eastman Kodak Company
    Inventors: Sundaram Krishnamurthy, Brian H. Johnston, Kenneth N. Kilminster, David C. Vogel, Paul R. Buckland