WATER-SOLUBLE SULFUR DYE, AND ITS PREPARATION AND APPLICATION

摘要

The black water-soluble sulphur dyes of the formula in which e.g. F is the dye chromophore of C.I. Leuco Sulphur Black 1, R<1> is hydrogen or alkyl, M<(+)> is an alkali metal cation, and n is a number such that the dye contains from 5 to 20% by weight of COO<(-)> groups, are outstandingly suitable, inter alia, for the production of recording fluids.