Non-metal tanning process
Tanned leather, skin or pelt is produced 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 a formula (I), wherein X signifies fluorine or chlorine, and/or ( + NR 3 ) 0-1 , wherein R is a substituted or unsubstituted C 1 to C 6 alkyl group, a substituted or unsubstituted C 6 to C 10 aryl or a C 5 to C 6 heteroaryl group, R1 signifies hydrogen, C 1-8 -alkyl or an alkyleneoxy radical of a formula (Ia), —(—C 2-3 alkylene-O—) q —H (Ia), R2 signifies hydrogen, hydroxyl, C 1-4 -alkyl or C 1-4 -alkoxy, m, signifies 1 or 2, n signifies 0 to 2, q is of from 1 to 10, M signifies 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, wherein the bated hide or skin or pelt is subjected to tanning with (A) without previous pickling.
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 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.
2. A process according to claim 1 , wherein the tanning agent (A) is an aqueous composition (T) free of metal compounds of tanning activity.
3. A process according to claim 1 , wherein the 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.
4. A process according to claim 3 , wherein the composition (T1) further comprises an agent (D) to protect against the damaging action of microorganisms, a polysaccharide-based thickener (E) or a mixture thereof.
5. A process according to claim 1 , wherein aqueous composition (T1) comprises a thickener (E).
6. 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.
7. A process according to claim 1 , wherein the tanning step with the tanning agent (A) is a pre-tanning, a main tanning or a full tanning or a pretanning and a main tanning.
8. A process according to claim 7 , 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.
9. A process according to claim 8 , 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.
10. A process according to claim 8 , wherein the leather, skin or pelt is tanned with tanning agent (A) in a main or full tanning and then are subjected to a complementary tanning with the non-mineral tanning agent (F).
11. A process according to claim 8 , wherein the non-mineral tanning agent (F) is employed in a smaller amount compared with the amount of the tanning agent (A).
12. A tanning agent (A) in a tanning process comprising 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.
13. A process according to claim 1 , further comprising 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.
14. A process according to claim 1 , further comprising a further treatment comprising retanning with a non-mineral tanning agent (F).
15. A process as according to claim 1 , further comprising a further treatment comprising retanning with non-mineral tanning agent (F), fat-liquoring and optionally dyeing, finishing or a mixture thereof.
16. Tanned leather, skin or pelt made by the process according to claim 1 .