Patents Assigned to Harmon Colors
  • Patent number: 4099980
    Abstract: A method is provided for the production of gamma quinacridone solid solutions which comprises ring-closing a mixture comprising 80-99 weight percent of dianilinoterephthalic acid and 1-20 weight percent of di(ortho-substituted) anilinoterephthalic acid, 4,11-disubstituted quinacridone, or mixtures thereof, and drowning the product into a water miscible alcohol containing from 1 to 3 carbon atoms.
    Type: Grant
    Filed: January 17, 1977
    Date of Patent: July 11, 1978
    Assignee: Harmon Colors Corporation
    Inventor: Robert Jarl North
  • Patent number: 4100162
    Abstract: A method is provided for the direct production of gamma quinacridone pigment comprising ring closure of 2,5-dianilinoterephthalic acid in polyphosphoric acid and diluting the mixture by addition thereof into a water-miscible alcohol containing 1-3 carbon atoms, e.g. methanol, while maintaining the temperature of the alcohol-acid at between 0.degree. and 25.degree. C.
    Type: Grant
    Filed: January 17, 1977
    Date of Patent: July 11, 1978
    Assignee: Harmon Colors
    Inventor: Robert Jarl North
  • Patent number: 4064129
    Abstract: A process is described for making quinarcridone and its derivatives, useful as organic pigments, wherein a 2,5-diarylaminoterephthalic acid and an acid catalyst are heated in a two phase liquid system, comprising ethylene glycol and an organic liquid which is immiscible with water and ethylene glycol, wherein the ethylene glycol is present in an amount of about 0.25 to 4 parts by weight per part of 2,5-diarylaminoterephthalic acid and the organic liquid is present in an amount of at least about 2 parts by weight per part of ethylene glycol, at a temperature sufficient to remove by-product water from the liquid system by vaporization.
    Type: Grant
    Filed: September 17, 1976
    Date of Patent: December 20, 1977
    Assignee: Harmon Colors Corporation
    Inventors: Herman Gerson, John Francis Santimauro, Lawrence Robert Lerner