Patent ID: 8790416

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 one compound of formula (I), wherein X is fluorine or chlorine ( + NR 3 ) 0-1 or a combination thereof, wherein R is a substituted C 1 to C 6 alkyl group, an unsubstituted C 1 to C 6 alkyl group, an unsubstituted C 6 to C 10 aryl group, a substituted C 6 to C 10 aryl group or a C 5 to C 6 heteroaryl group. R1 is hydrogen, C 1-8 -alkyl or an alkyleneoxy radical of formula (Ia), —(—C 2-3 alkylene-O—) q —H (Ia) R2 is hydrogen, hydroxy, C 1-4 -alkyl or C 1-4 -alkoxy, m is 1 or 2, n is 0 to 2, q is of from 1 to 10, M is hydrogen, an alkali metal cation or an ammonium cation, the ammonium cation being a protonated tertiary amine or a quaternary ammonium cation, in a tanning bath, the tanning bath having a pH of from 6 to 10 at the beginning of tanning step, wherein the bated hide or skin or pelt is subjected to tanning with (A) without previous pickling.