AQUEOUS SOLUTION OF A SYNTHETIC TANNING AGENT

摘要

Aqueous solutions of synthetic tanning agents composed of (A) a lithium salt of a synthetic anionic aromatic tanning agent or its anionic non-condensed precursor and optionally (B) a water-soluble chromium, aluminium, iron or zirconium salt or its mixtures and (C) an alkali metal salt of ethylenediaminetetraacetic acid or of a pyrophosphate are prepared by mixing an aqueous solution of the components (A) and optionally (C) with the component (B) which is optionally present as an aqueous solution, and are used as tanning agents for tanning pelts or for retanning leather of all types. The lithium salts forming the component (A) are new and can be used as anti-staining agents for polyamide fibres or to improve the wet fastness of dyeings on polyamide fibres.