Patents Assigned to Ciba-Geigy Corporatioin
  • Dyeing and printing of cellulosic fibre materials with vat dyes with mono- or di-hydroxyacetone as reducing agent
    Patent number: 4950306
    Abstract: Process for dyeing and printing cellulosic fiber materials with vat dyes in the presence of enediols as reducing agents and alkali, using in addition small amount of organic water-miscible solvents, for example low molecular weight alcohols, when reducing the vat dyes. The vatting of the vat dyes proceeds uniformly and completely within a relatively short time, and the resulting vat dyes are reproducible and notable for high levelness and fastness properties.
    Type: Grant
    Filed: July 27, 1989
    Date of Patent: August 21, 1990
    Assignee: Ciba-Geigy Corporatioin
    Inventors: Walter Marte, Paul Rys