| 摘要 |
Triphenylmethane dyes of the formula <IMAGE> +TR <IMAGE> where each R1 is independently of the others hydrogen or substituted or unsubstituted C1-C6-alkyl, or two R1 radicals together with the nitrogen atom joining them form a heterocyclic radical, R2 and R5 is independently of the others hydrogen or C1-C4-alkyl, R3 and R4 is independently of the others hydrogen, C1-C4-alkyl, C1-C4-alkoxy or halogen, An(-) is one equivalent of an anion, and n is 1 or 2, preparable from piperazine derivatives as intermediates, are useful for coloring paper.
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