Biscationic disazo and trisazo compounds having optionally further substituted 6-hydroxy-4-methy-3-N-pyridiniumpyridone-2 coupling component radicals, dyes compositions comprising them and their use

摘要

Disazo and trisazo compounds free of sulfo groups which contain 6-hydroxy-4-methyl-3-N-pyridiniumpyridone-2 coupling component radicals, the preferred compounds being of the formula wherein R is a tetrazo component radical, each R1 is independently hydrogen, C1-4alkyl, C2-4hydroxyalkyl the hydroxy group of which is in other than the 1-position or -NR3R4, wherein each of R3 and R4 is independently n-C1-4alkyl, each R2 is independently hydrogen, n-C1-4alkyl, n-C1-4hydroxyalkyl or C1-4alkoxy, and each A(-) is an anion, and liquid and granulated dye compositions comprising such compounds, are useful for dyeing paper and basically dyeable substrates such as polymers and copolymers of acrylonitrile and dicyanoethylene and synthetic polyesters and polyamides modified to contain acid groups. Dyeings on paper are brilliant and possess good light fastness and good fastness to water and alcohol.