| 摘要 |
A process for the preparation of storage-stable concentrated fluid dye compositions of water-soluble dyes, wherein an aqueous solution or suspension of at least one anionic crude dye is passed over a semi-permeable membrane containing ionic groups and having a pore diameter of 1 to 500 ANGSTROM , to remove salts and synthesis by-products of molecular weights less than 500 and to partially remove water, optionally dried, and mixed with a water-miscible organic solvent and, if desired, further additives, before and/or after passage over the semi-permeable membrane. The fluid dye compositions obtained are particularly suitable for use in spray solutions for dyeing leather, as well as for the dying and printing of textile materials, in particular cellulosic fibres.
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