By Means Specialized To Puddle Metal Patents (Class 266/203)
  • Dyeing preparations and their use for preparing developing dyes
    Patent number: 4242094
    Abstract: Developing dyes are especially easily produced by using preparations containing molar amounts of diazo or coupling components per weight or volume unit or a multiple or a fraction thereof in simple numerical ratios. Since the diazo component is the free finely dispersed amine these preparations are stable and allow the reaction of stoichiometric amounts. Thus, multicolor effects are feasible which hitherto could not be obtained at all or with difficulties only.
    Type: Grant
    Filed: February 21, 1979
    Date of Patent: December 30, 1980
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Erich Feess, Willy Gronen