Non metal tanning
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 or hydroxyl, m, signifies 1, 2 or 3, q is of from 1 to 10, M signifies hydrogen or an alkali metal cation or an ammonium cation, being a protonated tertiary amine or a quaternary ammonium cation, in a tanning bath having a pH of from 6 to 10 at the beginning of tanning step.
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, ( + 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.
2. A 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 a bated and pickled hide, skin or pelt is pickled and is 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 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 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 , 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 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 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 agent (A) comprising 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.
15. A process according to 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. A process as defined in claim 1 , further comprising processing by retanning with a non-mineral tanning agent (F).
17. A process as defined in claim 1 further comprising retanning with non-mineral tanning agent (F), fat-liquoring and optionally dyeing, finishing or a mixture thereof.
18. Tanned leather, skins or pelts made by the process according to claim 1 .