Patent ID: 8795389

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, chlorine, ( + NR 3 ) 0-1 or both, 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 or hydroxy, m is 1, 2 or 3, 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, in a tanning bath, the tanning bath having a pH of from 6 to 10 at the beginning of tanning step.