Patents by Inventor John A. Nimmo

John A. Nimmo 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).

  • Production of pigment compositions
    Patent number: 5366546
    Abstract: A process for the production of a pigment composition, comprising combining a) a dispersion of one or more non-polar components of a surface coating vehicle, or a non-polar additive for the pigment composition in an aqueous solution of a salt of a polar pigment additive, with b) an aqueous slurry of a pigment or a precursor thereof, before, during or after the synthesis of the pigment; and then isolating the pigment composition so obtained.
    Type: Grant
    Filed: November 17, 1992
    Date of Patent: November 22, 1994
    Assignee: Ciba-Geigy Corporation
    Inventors: James M. McCrae, Anne M. Keirs, John A. Nimmo
  • Zinc sulfide or selenosulfide material
    Patent number: 5152229
    Abstract: A pigment comprises a material comprising crystalline zinc selenide or selenosulphide below 40% of whose zinc atoms and optionally some of whose selenium and sulphur atoms are substituted to lower the band gap energy but retain the essential crystal lattice of the zinc selenide or silenosulphide, the resulting lattice containing a greater percentage of zinc atoms than of sulphur atoms. The material wherein at least 0.1% of the zinc atoms are substituted is a new composition of matter.
    Type: Grant
    Filed: October 22, 1990
    Date of Patent: October 6, 1992
    Assignee: Johnson Matthey Public Limited Company
    Inventor: John A. Nimmo