Non metal tanning

1. 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 and/or ( + NR 3 ) 0-1 , 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 substituted or unsubstituted C 2 to C 8 alkylenesulphonic acid, substituted or unsubstituted C 2 to C 8 alkylenecarboxylic acid, an alkyleneoxy radical of formula (Ib),

—(—C 2-3 alkylene-O—) m —Y  (Ib)

or an alkylene sulfonyl alkyleneoxy radical of formula (Ic),

—(C 2-3 alkylene-O) p —C 2-3 alkylene-SO 2 CH 2 CH 2 O—Y  (Ic)

m is 1 or 2,

p is 0 or 1,

q is of from 1 to 10,

Y is hydrogen or —SO 3 M,

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.

2. A tanning process according to claim 1 , wherein the bated hide or skin or pelt is subjected to tanning with the tanning agent (A) without previous pickling.

3. A process according to claim 1 , wherein the bated and hide, skin or pelt is pickled and subsequently depickled to a pH in the range of 6 to 10 before tanning with the tanning agent (A).

4. A process according to claim 1 , wherein the tanning agent (A) is in the form of an aqueous composition (T) free of metal compounds of tanning activity.

5. A process according to claim 4 , wherein the aqueous composition (T) is a composition (T1), the composition (T1) further comprising a surfactant (B) a buffer (C 1 ) or a mixture thereof, to keep an acidic to neutral pH.

6. A process according to claim 5 , wherein the aqueous composition (T1) further comprises an agent (D) to protect against the damaging action of microorganisms, a polysaccharide-based thickener (E) or a mixture thereof.

7. A process according to claim 6 , wherein aqueous composition (T 1 ) comprises a thickener (E).

8. A process according to claim 1 , wherein the tanning bath comprises a buffer (C2) to achieve a nearly neutral to basic pH at the beginning of the tanning step.

9. A process according to claim 1 , for the production of non-metal tanned leather, skin or pelt, wherein the tanning step with the tanning agent (A) is a pre-tanning, a main tanning, a full tanning or a pretanning and a main tanning.

10. A process according to claim 9 , wherein a non-mineral tanning agent (F), which is different from the tanning agent (A), is used before, after or together with tanning agent (A) in pre-tanning, in main tanning or in full tanning, or in combination with tanning agent (A) in full tanning.

11. A process according to claim 10 wherein the non-mineral tanning agent (F) is selected from the group consisting of

(F1) a vegetable tanning agent,

(F2) a syntan,

(F3) a synthetic, semisynthetic or natural resin or polymer,

(F4) a tanning natural oil or modified oil, and

mixtures thereof.

12. A process according to claim 9 , wherein the tanned leather, skin or pelt are tanned with tanning agent (A) in a main or full tanning and then are subjected to a complementary tanning with a non-mineral tanning agent (F).

13. A process according to claim 10 , wherein the non-mineral tanning agent (F) is employed in a smaller amount compared with the amount of the tanning agent (A).

14. A tanning composition (T1) comprising a tanning agent (A), the tanning agent (A) being at least one compound of formula (I),

wherein

X is fluorine, chlorine and/or ( + NR 3 ) 0-1 , 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 substituted or unsubstituted C 2 to C 8 alkylenesulphonic acid, substituted or unsubstituted C 2 to C 8 alkylenecarboxylic acid, an alkyleneoxy radical of formula (Ib),

—(—C 2-3 alkylene-O—) m —Y  (Ib)

or an alkylene sulfonyl alkyleneoxy radical of formula (Ic),

—(C 2-3 alkylene-O) p —C 2-3 alkylene-SO 2 CH 2 CH 2 O—Y  (Ic)

m is 1 or 2,

p is 0 or 1,

q is of from 1 to 10,

Y is hydrogen or —SO 3 M,

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.

15. The process of claim 1 , further comprising processing by at least one further treatment selected from the group consisting of

(a) retanning with a non-mineral tanning agent (F), which is different from the tanning agent (A),

(b) fat-liquoring,

(c) dyeing, and

(d) finishing.

16. The process of claim 1 , further comprising the step of retanning with a non-mineral tanning agent (F).

17. The process of claim 1 comprising retanning with non-mineral tanning agent (F), fat-liquoring and optionally dyeing, finishing or a mixture thereof.

18. A tanned leather, skin or pelt made in accordance with the process of claim 1 .