Patent ID: 8801804

Claim:
A process for the production of tanned leather, skin or pelt by non-metal tanning, comprising the step of tanning a bated hide, skin or pelt with a tanning agent (A), the tanning agent (A) being at least a mixture of compounds of formula (I) and formula (II), wherein Hal is fluorine or chlorine, R1 is hydrogen, C 1-8 -alkyl or an alkyleneoxy radical of formula (III), —(—C 2-3 alkylene—O—) q —H (III) R2 is a) phenyl, mono- or di-substituted with SO 3 M or COOM and optionally substituted also with hydroxyl or C 1-4 -alkyl or C 1-4 -alkoxy, or b) naphthyl, mono- or di- or tri-substituted with SO 3 M and optionally substituted also with hydroxyl, or c) C 1-8 -alkylene, substituted with (SO 3 M) or (COOM), or d) a radical of formula (IV), —(—C 2-3 alkylene—O—) p —Y (IV) e) or a radical of formula (IVa), —(C 2-3 alkylene—O) p —C 2-3 alkylene-SO 2 CH 2 CH 2 O—Y (IVa) m is 1 or 2, p is 0 or 1, Y is hydrogen or —SO 3 M, q is of from 1 to 10, M is hydrogen or an alkali metal cation or an ammonium cation, the ammonium cation being a protonated tertiary amine or a quaternary ammonium cation, R3 is hydrogen or chlorine, in a tanning bath, the tanning bath having a pH of from 6 to 10 at the beginning of tanning step.