Abstract: The present invention provides an improved process for isolating 2,4-bis-(2,4-dihydroxyphenyl)-6-(4-methoxyphenyl)-1,3,5-triazine (DIOPAT) from an aqueous alkaline mixture M having a pH of 10 or more and comprising the 2,4-bis-(2,4-dihydroxyphenyl)-6-(4-methoxyphenyl)-1,3,5-triazine, 2,4-dihydroxybenzophenone, and aluminum salts, wherein the process comprises a nanofiltration step, a precipitation step, and a further filtration step.

Abstract: The present invention provides an improved process for isolating 2,4-bis-(2,4-dihydroxyphenyl)-6-(4-methoxyphenyl)-1,3,5-triazine (DIOPAT) from an aqueous alkaline mixture M having a pH of 10 or more and comprising the 2,4-bis-(2,4-dihydroxyphenyl)-6-(4-methoxyphenyl)-1,3,5-triazine, 2,4-dihydroxybenzophenone, and aluminum salts, wherein the process comprises a nanofiltration step, a precipitation step, and a further filtration step.

Abstract: The present invention relates to an aqueous direct dye formulation, comprising (a) 5 to 25% by weight of a dye composition comprising (a1) 50-99% by weight of one or more dyes obtainable by reduction or thermal treatment of Direct Yellow 11, and (a2) 1-50% by weight of a blue, black and/or red direct dye, (all based on the dye composition); (b) up to 0.9% by weight of a saturated, cyclic or acyclic water-soluble amine comprising a primary, secondary or tertiary amino group and at least one further functional group selected from primary, secondary and tertiary amino groups, OH groups and ether groups; and (c) up to 0.9% by weight of urea; and (d) water, wherein the percentages for (a), (b), and (c) relate to the total weight of the aqueous direct dye formulation. The invention moreover relates to a process for their preparation and the use thereof for the dyeing, in particular of paper, as well as paper which has been dyed with this aqueous direct dye formulation.

Abstract: The present invention relates to an aqueous direct dye formulation, comprising (a) 5 to 25% by weight of a dye composition comprising (a1) 50-99% by weight of one or more dyes obtainable by reduction or thermal treatment of Direct Yellow 11, and (a2) 1-50% by weight of a blue, black and/or red direct dye, (all based on the dye composition); (b) up to 0.9% by weight of a saturated, cyclic or acyclic water-soluble amine comprising a primary, secondary or tertiary amino group and at least one further functional group selected from primary, secondary and tertiary amino groups, OH groups and ether groups; and (c) up to 0.9% by weight of urea; and (d) water, wherein the percentages for (a), (b), and (c) relate to the total weight of the aqueous direct dye formulation. The invention moreover relates to a process for their preparation and the use thereof for the dyeing, in particular of paper, as well as paper which has been dyed with this aqueous direct dye formulation.