HK1181081B - Non-metal tanning process - Google Patents

Description

Non-metal tanning method

In the preparation of leather, the tanning process is of decisive importance for the properties and quality of the leather obtained. Among the various tannages known in the art (i.e. mineral, vegetable and synthetic), chromium-based tanning is a conventional and widely used way of tanning, which is very suitable to be carried out on an industrial scale on most different kinds of hides and hides, and provides tanned leathers with satisfactory properties (such as high shrinkage temperature Ts, softness and suitability for subsequent processing such as neutralization, retanning, fatliquoring, dyeing, finishing).

However, chromium-based tanning agents and tanning are considered environmentally unfriendly and it is therefore desirable to provide other tanning methods.

In WO 02/50313a2 it is proposed to add a specific laccase derived enzyme in the tanning bath with synthetic or vegetable tanning agents, followed by an oxidizing agent. However, this adds some other steps to tanning and in addition requires particularly precise control of the enzyme activity.

In WO 94/10345a1 a metal tanning process is described in which in a first step (a) a substrate is pretreated with a compound of the specific formula (1) defined therein and comprising two substituents selected from carboxyl and hydroxyl groups and defined reactive groups; and metal tanning in a second step (b). The pretreatment (a) is carried out to improve the tanning with a metal tanning agent in the subsequent step (b).

In the literature referred to in the introduction to WO 94/10345a1 and relating to the pretreatment of specific collagen substrates with 1, 2-dicarboxylic acids followed by aluminium tanning Evans et al, j.a.l.c.a., volume 82 (1987), pages 88-95, the treatment of lambskins with 2-N- [ bis- (3',4' -dicarboxyphenyl) methyl ] methylamino-4, 6-dichloro-s-triazine followed by tanning with aluminium sulphate alkali is described. In this document, a pretreatment is also carried out to improve the tanning with a metal tanning agent (alkalinizing aluminium sulphate) in the subsequent tanning step.

Some Crosslinking tests carried out on denatured animal tendons (kangaroo tail tendon, KTT) with various Crosslinking compounds (which do not necessarily have to be used entirely as tanning material per se) are described in the literature "Crosslinking of Collagen", j.appl.chem., 15, 7.1965 by j.w.c. ater, to evaluate their Crosslinking ability; the crosslinking compounds are, in particular, difluorodinitrodiphenyl sulfone, diisocyanates, a number of aldehydes (formaldehyde, glyoxal, malondialdehyde, succinaldehyde, glutaraldehyde, adipaldehyde, acrolein and dialdehyde starch), cyanuric chloride and a number of cyanuric chloride derivatives (methoxy derivatives, amino derivative hydrochlorides, sulfonic acid derivative sodium salts, 5-sulfonaphthalen-1-ylamino derivative sodium salts and bis-4, 4 '-diaminostilbene-2, 2' -disulfonic acid derivative sodium salts) which can be combined with conventional tanning materials to improve the resistance to deterioration due to moist heat and respiration. Finally, they conclude from their measurements: aldehydes (glutaraldehyde) appear to be the most promising due to the amount and stability of crosslinking, while cyanuric chloride derivatives are less useful as crosslinkers in collagen.

It has now been surprisingly found that non-metallic tanning with excellent quality can be obtained by using the tanning agents defined below-in particular even as fully tanned material-and tanning process, which also allows omitting the pickling process normally carried out before chrome tanning or aldehyde tanning, unless it has to be carried out for other reasons such as degreasing. The present invention relates to said tanning process, the defined tanning agent composition, the use of said tanning agent and compositions thereof, tanned leather, skins or hides and their use for further processing.

In this context, non-metallic tanning process means tanning without using any cationic metal compound having tanning activity, i.e. polyvalent metal compounds, mainly chromium, aluminium, iron, zirconium or titanium salts and the like. In this context, non-metallic tanning agents are meant to be tanning agents which do not comprise any cationic metal compounds having tanning activity, i.e. polyvalent metal compounds, mainly chromium, aluminum, iron, zirconium or titanium salts and the like.

Hereinafter, alkyl means a straight-chain or branched alkyl group unless otherwise specified.

Accordingly, the present invention provides firstly a process for the preparation of tanned leather, skins or hides by non-metal tanning, comprising the step of tanning a softened hide, skin or hide with a tanning agent (a) in a tanning bath, wherein the tanning agent (a) is at least one compound of formula (I):

wherein

X represents fluorine, chlorine and/or (C)⁺NR₃)_0-1Wherein R is substituted C₁-C₆Alkyl or unsubstituted C₁-C₆Alkyl, unsubstituted C₆-C₁₀Aryl or substituted C₆-C₁₀Aryl or C₅-C₆A heteroaryl group;

r1 represents hydrogen or C₁₈Alkyl or alkyleneoxy of formula (Ia):

-(-C_2-3alkylene-O-)_q-H (Ia)

R2 represents hydrogen, hydroxy, C₁₄Alkyl or C₁₄An alkoxy group;

m represents 1 or 2;

n represents 0 to 2;

q is 1 to 10;

m represents hydrogen or an alkali metal cation or an ammonium cation which is a protonated tertiary amine or quaternary ammonium cation;

wherein the tanning bath has a pH value of 6 to 10 at the beginning of the tanning step, wherein the softened hide or skin or hide is tanned with (A) without prior pickling.

The tanning agent (a) may consist of more than one compound of formula (I). In the case of tanning agents (a) containing groups of formula (Ia), it may be a mixture of compounds of formula (I), wherein q may also be calculated and expressed as the average number of alkyleneoxy units in the alkyleneoxy group of formula (Ia) per compound of formula (I), based on all groups of formula (Ia) in the mixture. Preferably the tanning agent (A) is only one compound of formula (I), in which case R1 is not a group of formula (Ia). In the case where R1 is a group of formula (Ia), the tanning agent (a) may also comprise compounds of formula (I) wherein the chain length of the group of formula (Ia) has a certain distribution.

X preferably represents chlorine or fluorine. More preferably, X represents chlorine.

In case q is 2-10, the alkyleneoxy group of formula (Ia) may also comprise a mixture of both ethyleneoxy units and propyleneoxy units.

If q is from 2 to 10, the radical of the formula (Ia) preferably comprises at least two ethyleneoxy units.

In the case of compounds of formula (I) wherein q >5, preferably at least 40% of the total number of alkyleneoxy units in the group of formula (Ia) are ethyleneoxy groups.

In case the tanning agent (a) is a mixture of two or more compounds of formula (I) wherein R1 in these compounds of formula (I) is an alkyleneoxy group of formula (Ia), preferably the average number q of alkyleneoxy units per compound of formula (I) in said mixture is from 1.0 to 10.0.

Any propylene group in the alkyleneoxy group of the formula (Ia) is preferably a1, 2-propylene group.

R1 preferably represents hydrogen or C_1-4An alkyl group.

More preferably R1 is selected from hydrogen, methyl or ethyl.

R2 preferably represents hydrogen, hydroxy, methyl or methoxy.

If m is 1, the carboxyl group is ortho, meta or para with respect to the amino group-N (R1) -in formula (I). If m represents 2, the two carboxyl groups are preferably in the 3 and 5 or 3 and 4 positions.

n preferably represents 0 to 1.

When M is an alkali metal cation or an ammonium cation, then it can be any of the alkali metal cations or ammonium cations commonly used to form salts with anionic compounds.

Preferably, the alkali metal cation is selected from the group consisting of lithium, sodium and potassium, more preferably the alkali metal cation is sodium. Preferably the ammonium cation is a cation of formula (Ib):

wherein

R10, R11, R12 and R13 are the same or different and are each independently selected from H, C_1-4Alkyl radical, C_2-3Hydroxyalkyl and benzyl, provided that only one of the 4 substituents R10, R11, R12 and R13 may be H.

Preferably, the first and second electrodes are formed of a metal,

r10 is H or C_1-4Alkyl radical, and

r11, R12 and R13 are the same or different and are each independently selected from C_1-4Alkyl radical, C_2-3A hydroxyalkyl group; or

R10, R11, R12 and R13 are the same or different and are each independently C_1-4An alkyl group; or

R10, R11 and R12 are the same or different and are each independently C_1-4Alkyl or C_2-3Hydroxyalkyl, and

r13 is benzyl.

More preferably, the ammonium cation is selected from the group consisting of: mono-hydrogen tri (C)_2-3Alkanolammonium, tetra (C)_1-4Alkyl) ammonium, tri (C)_1-4Alkyl) -mono (C)_2-3Alkanolammonium, di (C)_2-3Alkanol) -di (C)_1-4Alkyl) ammonium, mono (C)_1-4Alkyl) -tri (C)_2-3Alkanolammonium, monobenzyltris (C)_1-4Alkyl) ammonium and monobenzyltris (C)_2-3Alkanol) ammonium.

The ammonium cation is in particular a quaternary ammonium cation.

More particularly, M is preferably an alkali metal cation, and even more particularly, M is sodium.

Preferred compounds of formula (I) are (I-I):

more preferably a compound of formula (I-II).

The compounds of formula (I) are known or can be prepared according to known methods, preferably by reacting a compound of formula (II) with a compound of formula (III):

wherein X, R1, R2, M, n and M have the meanings given above and all preferred embodiments thereof.

The compounds of formula (III) are commercially available or can be prepared according to known methods from known starting materials. For example, compounds of formula (III) wherein R1 is other than H can be prepared by alkylation of compounds of formula (IIIa):

including alkylation with alkylating agents suitable for introducing the group R1, such as the corresponding chlorides or epoxides. Alkylation is carried out, if appropriate, by acetylation of one of the two hydrogens attached to the nitrogen of the intermediate protective formula (IIIa), and subsequent hydrolysis after alkylation of the resulting acetamide group.

The reaction of the compound of formula (II) with the compound of formula (III) is a reaction for removing the acid H-X.

The reaction of the compound of formula (II) with the compound of formula (III) can be carried out in an aqueous, aqueous/organic or organic medium. Preferably, an aqueous solution or dispersion of the compound of formula (III) is mixed with the compound of formula (II). The compounds of the formula (II) are preferably in the form of anhydrous compounds, organic solutions or dispersions or aqueous dispersions. Preferably, an aqueous solution or dispersion of the compound of formula (III) is added to an aqueous dispersion of the compound of formula (II). In another preferred embodiment, the anhydrous compound of formula (II) is stirred into a preferably aqueous solution or dispersion of the compound of formula (III). The reaction is preferably carried out in the presence of a base or other reactant suitable for binding the acid H-X.

Suitable organic media include, for example, ethanol, isopropanol, acetone, methyl ethyl ketone, dimethyl sulfoxide, chloroform, chlorobenzene or toluene. Preferably the reaction is carried out in an aqueous medium.

Preference is given to using 1.00. + -. 0.05 mol of compound of the formula (II) per mol of compound of the formula (III).

The concentration of the compound of formula (II) is, for example, from 2 to 70% by weight, preferably from 5 to 50% by weight, where the% by weight is based on the total weight of the reaction mixture comprising the compound of formula (II), (III) and the aqueous, aqueous/organic or organic medium.

When the compound of formula (II) is dissolved in an organic medium, its concentration is preferably high, in particular close to saturation, so as to minimize the amount of solvent to be evaporated after the end of the reaction.

The dispersion, preferably an aqueous dispersion, of the compound of the formula (II) or of the compound of the formula (III) can be obtained by simple stirring or else by using suitable surfactants (B) which act as dispersants.

For dispersing, preferably in water, the compound of formula (II) or the compound of formula (III) wherein the sulfonic acid group of the compound of formula (III) is in protonated form, a suitable effective concentration of surfactant (B) may be used, e.g. the weight ratio of surfactant (B) to the compound of formula (II) or the weight ratio of surfactant (B) to the compound of formula (III) is preferably from 0.002 to 2, more preferably from 0.004 to 1, even more preferably from 0.005 to 0.5.

The compounds of formula (III) may be used in the form of salts, preferably alkali metal salts, more preferably sodium salts, of sulphonic acids. The compound of formula (III) in the form of a salt is generally soluble in water and it is suitably used in the form of an aqueous solution or dispersion (at a higher concentration than the saturated solution), preferably in an amount of from 2 to 70% by weight, more preferably from 10 to 50% by weight, wherein the% by weight is based on the total weight of the solution or dispersion of the compound of formula (III). Preferably, the solution or dispersion also contains the dispersant (B) described above in a concentration as described above suitable for dispersing the compound of formula (II) when the latter is added as an anhydrous product and stirred into solution.

According to a preferred embodiment, the compound of formula (II) is stirred into an aqueous solution of the compound of formula (III) comprising the surfactant (B).

When R1 is a group of formula (Ia) wherein q is 2 to 10, the amount of surfactant (B) may be reduced or even eliminated.

The surfactant (B) is preferably selected from the group consisting of:

(B1) a non-ionic surfactant, a surfactant,

(B2) an anionic surfactant, a surfactant,

(B3) a cationic surfactant,

(B4) an amphoteric surfactant, and a surfactant component,

and mixtures of two or more thereof,

with the proviso that the surfactant (B) has no substituents, in particular no primary or secondary amino groups, which are capable of reacting with the compounds of the formula (II) under the selected reaction conditions. Preferred mixtures are mixtures of (B2) with (B1) and/or (B4), (B3) with (B1) and/or (B4) or (B1) with (B4).

Preferably, the nonionic surfactant (B1) is selected from the group consisting of: oligo-or polyglycol ethers of aliphatic alcohols, oligo-or polyglycol esters of aliphatic carboxylic acids, alkoxylated fatty acid amides, and alkoxylated partial esters of glycerol or sorbitol with fatty acids.

Preferably, the alkoxylation of the fatty acid amides and of partial esters of glycerol or sorbitol with fatty acids leads to oligo-or polyglycol ether chains.

Preferably any oligo-or polyglycol ether chain contains 2 to 60, more preferably 2 to 24 alkyleneoxy units which are ethyleneoxy and optionally propyleneoxy units, of which preferably at least 40 mole%, more preferably at least 50 mole% are ethyleneoxy units, and preferably the nonionic surfactant (B1) contains at least two ethyleneoxy groups.

Preferably the lipophilic aliphatic group of the aliphatic alcohol, aliphatic carboxylic acid, fatty acid amide and fatty acid comprises 8 to 24 carbon atoms.

The aliphatic groups may be saturated or unsaturated (preferably containing only one double bond) and may be straight-chain or branched, with the branched groups preferably being saturated.

As examples of aliphatic alcohols, mention may be made of lauryl, cetyl, myristyl, stearyl or oleyl alcohol and C_9-15Oxo-synthesis of alcohols.

As examples of aliphatic carboxylic acids and fatty acid amides, mention may be made of lauric acid or amide, palmitic acid or amide, myristic acid or amide, stearic acid or amide, behenic acid or amide, arachidic acid or amide, oleic acid or amide.

The oligo-or polyglycol ethers of aliphatic alcohols can be prepared by ethoxylation (propoxylation, if a propyleneoxy group is also present) of the corresponding aliphatic alcohol.

Alkoxylated fatty acid amides can be prepared, for example, by ethoxylation (propoxylation if a propyleneoxy group is also present) of the corresponding fatty acid amide, such as an aliphatic acid diethanolamide or diisopropanolamide.

Oligo-or polyglycol esters and sorbitol monoesters can be prepared, for example, by esterification of the corresponding oligo-or polyglycol ethers (and optionally polypropylene glycol ethers) or sorbitol. The monoglycerides may be partial saponification products of the corresponding natural triglycerides.

Preferably, the anionic surfactant (B2) is selected from the group consisting of: anionic polycarboxylates, aliphatic fatty acids (soaps) in salt form, methyltaurates of aliphatic fatty acids and anionic derivatives of nonionic surfactants, preferably anionic derivatives of nonionic surfactants (B1), in particular carboxymethylated or carboxyethylated products of nonionic surfactants (B1), or sulfuric or phosphoric monoesters (in particular in alkali metal salt form) of nonionic surfactants (B1). Preferred anionic polycarboxylates are polyacrylates and polymethacrylates.

Preferably, the cationic surfactant (B3) is selected from the group consisting of: tertiary or preferably quaternary derivatives of fatty amines, e.g. having 8 to 24 carbon atoms in the fatty amine chain, and in which the substituent of the tertiary or quaternary amino group is C_1-4Alkyl (preferably methyl or ethyl) or hydroxy C_1-4Alkyl groups (preferably ethanol or isopropanol) and optionally benzyl groups, and wherein the tertiary or quaternary amino groups may also contain oligo-or polyglycol ether chains if desired (similar to that described above in nonionic surfactant (B1)). As examples of fatty amines, mention may be made of laurylamine, cetylamine, myristylamine, stearylamine or oleylamine, and the amino group may be substituted by two methyl or ethyl groups and optionally a methyl or benzyl group, or by three methyl or ethyl groups or by two ethanol groups. If the tertiary or quaternary amino group is alkoxylated, it may preferably comprise a total of 2 to 40, more preferably 2 to 24 alkyleneoxy groups, preferably at least 40 mole% of which are ethyleneoxy groups and the remainder propyleneoxy groups. The tertiary amino groups preferably being protonated, e.g. with hydrochloric acid, phosphoric acid or C_2-20Alkanoic acid, preferably C_2-5The alkanoic acid is protonated.

Preferably, the amphoteric surfactant (B4) is an anionic derivative of (B3), such as carboxymethylation product of (B3), carboxyethylation product of (B3), sulfuric acid or sulfamic acid monoester of (B3), phosphoric acid mono-or diester of those cationic surfactants (B3) containing hydroxyl groups, betaine and sulfobetaine.

Preferably, the surfactant (B) is a nonionic surfactant (B1).

Preference is given, in particular, to using, if R1 in formula (I) denotes hydrogen-a nonionic surfactant (B1), more preferably a nonionic surfactant (B1) which is a compound of formula (IV) (polyglycol ether):

R3—O—(X-O)_r—H (IV)

wherein

R3 represents C_8-24Alkyl or C_8-24An alkenyl group which is a radical of an alkylene group,

x is selected from-CH₂-CH₂-、-CH₂-CH(CH₃)-、-CH(CH₃)-CH₂-and combinations thereof, preferably selected from-CH₂-CH₂-、-CH₂-CH(CH₃) -and combinations thereof,

r represents a number of 2 to 60,

in case the nonionic surfactant (B1) of formula (IV) consists of more than one compound of formula (IV), r can also be calculated and expressed as the average number of groups of formula (IV) in the mixture, with the proviso that the compound of formula (IV) comprises at least two ethyleneoxy units and with the proviso that at least 40% of the total number of alkyleneoxy units in the compound of formula (IV) are ethyleneoxy.

The reaction of the compound of the formula (II) with the compound of the formula (III) is preferably carried out at a temperature of less than 40 ℃, more preferably from-10 ℃ to 40 ℃, even more preferably from-10 ℃ to +25 ℃, particularly preferably from 0 to 15 ℃.

Preferably the reaction of the compound of formula (II) with the compound of formula (III) is carried out under acidic to neutral pH conditions, more preferably at a pH of 2 to 7, even more preferably under acidic conditions, especially preferably at a pH of 2.5 to 6.

The base or other reactant which can be used to bind the acid H-X and which can be used to adjust the pH during the reaction of the compound of formula (II) with the compound of formula (III) is preferably selected from the group consisting of alkali metal bases, quaternary ammonium hydroxides and carbonates.

The alkali metal base is preferably selected from the group consisting of hydroxides, carbonates and bicarbonates of lithium, sodium, potassium and mixtures thereof.

The quaternary ammonium hydroxide and carbonate are preferably selected from the group consisting of hydroxides and carbonates of tetramethylammonium, tetraethylammonium and benzyltrimethylammonium.

If an organic solvent has been used, this can be removed by evaporation and the resulting product can be dissolved or dispersed in water, if desired. If an anhydrous product is desired, this can be obtained in a manner conventional per se from aqueous solutions or dispersions of the reaction product, for example by precipitation (e.g. salting out) and filtration, or by evaporation under controlled conditions.

Tanning agents (a) comprising more than one compound of formula (I) may be prepared by using more than one compound of formula (III) in the reaction of a compound of formula (II) with a compound of formula (III), or by physically mixing compounds of formula (I). The physical mixing can be carried out in anhydrous form and/or in dissolved or dispersed form, preferably in dissolved or dispersed form in water.

The tanning agent (a) can be used as such, in the prepared form, preferably in anhydrous form or more preferably in the form of an aqueous solution or dispersion.

According to a particular aspect of the invention, the tanning agent (a) is in the form of an aqueous composition (T) free of any metal-based compound having tanning activity, wherein the aqueous composition (T) comprises the tanning agent (a) and water, and preferably in addition also a surfactant (B).

Therefore, another subject of the present invention is a tanning process as described above and all its preferred embodiments in which the tanning agent (a) is used in the form of an aqueous composition (T) free of metal compounds having tanning activity.

More preferably, the composition (T) comprises from 2 to 70% by weight, especially from 10 to 50% by weight, of the tanning agent (a), wherein the% by weight is based on the total weight of the composition (T).

When a surfactant (B) is present in the composition (T), the weight ratio of surfactant (B) to tanning agent (a) in the composition (T) is preferably from 0.001 to 1, more preferably from 0.002 to 0.4, even more preferably from 0.005 to 0.1.

Preferably, the surfactant (B) in the composition (T) is a nonionic surfactant (B1). If an anionic, cationic or amphoteric surfactant (B2), (B3) or (B4) is used, it is preferably used in an amount of 0.001 to 10 mol%, wherein the mol% is relative to the total molar amount of the tanning agent (A). More preferably, the surfactant (B) is only a nonionic surfactant (B1). If the surfactant (B2) is a polycarboxylate, it is preferably used in an amount of <5 wt.%, more preferably 0.01 to 4 wt.%, even more preferably 0.05 to 2 wt.%, wherein the wt.% is always based on the total weight of the tanning agent (a).

The composition (T) preferably has an acidic to neutral pH, more preferably an acidic pH. For adjusting the pH, a suitable buffer may be used, and thus the composition (T) preferably further comprises a buffer (C1) to maintain an acidic to neutral pH, preferably an acidic pH, more preferably a pH of 1-7, even more preferably a pH of 1-5.

The buffer (C1) is preferably selected from the group consisting of: sodium and/or potassium phthalate, oxalate and citrate, sodium and/or potassium monohydrogen and dihydrogen phosphates, mixtures of phosphoric acid with sodium and/or potassium dihydrogen phosphates, and mixtures thereof, preferably KH₂PO₄Or NaH₂PO₄With Na₂HPO₄Or K₂HPO₄Combinations of (a) and (b).

The amount of buffer (C1) in composition (T) is preferably selected in such a way that the above-mentioned desired pH value is obtained. The amount of buffer (C1) is preferably from 0.1 to 5% by weight, where the% by weight is based on the total weight of the composition (T).

The composition (T) may advantageously further comprise an agent (D) for protection against the destructive action of microorganisms, the agent (D) being a bacteriostatic additive and/or a microbicide, for example a fungicide.

As reagent (D) commercially available products can be used, which can be used in low concentrations, especially in concentrations according to commercial recommendations. The amount of agent (D) in composition (T) is preferably from 0 to 10% by weight, more preferably from 0.01 to 10% by weight, even more preferably from 0.02 to 1% by weight, where the% by weight is based on the total weight of composition (T).

According to another particular feature of the invention, the aqueous composition (T) may further comprise a polysaccharide-based thickener (E).

As thickener (E) products known per se can be used, in particular gums, carbohydrates, carbohydrate derivatives, such as pectins and hydrophilic cellulose derivatives, which form viscous solutions (colloidal solutions or true solutions) with water. Mention may be made of gums obtainable by fermentation and optionally chemical modification of natural plant exudates, such as xanthan gum, tragacanth gum, guar gum, carrageenan, alginate gum, agar gum, ghatti gum; and water-soluble carbohydrate derivatives, especially pectins, such as pectins and amylopectin (e.g. from corn starch or potato starch) obtained from fruits such as lemon fruit or apple, and hydroxyethyl cellulose. The gums, carbohydrates and carbohydrate derivatives may also be chemically modified, provided that they do not contain any substituents that are capable of reacting with the tanning agent (a) under the conditions of storage and use, in particular they do not contain any basic amino groups, in particular do not contain any primary or secondary amino groups.

The thickener (E) can be used in the composition (T) in small proportions, in particular in an amount sufficient to adjust the viscosity of (T) so that it is still flowable. When the thickener (E) is used in the composition (T), it is preferably added in a concentration such that the viscosity of the composition (T) is preferably ≦ 10,000 mPas, more preferably 200 ≦ 10,000 mPas, even more preferably 300 ≦ 2,500 mPas, and particularly preferably 600 ≦ 1,500 mPas at 20 ℃. The viscosity is brookfield rotational viscosity, spindle No. 3, 20 rpm.

Preferably, the amount of thickener (E) in the composition (T) is from 0 to 5% by weight, more preferably from 0.1 to 5% by weight, said% by weight being based on the total weight of the composition (T).

Preferably composition (T) is composition (T1) which, in addition to tanning agent (a), comprises surfactant (B) and/or buffer (C1), more preferably comprises surfactant (B) or surfactant (B) and buffer (C1); preferably, the composition (T1) further comprises an agent (D) and/or a thickener (E).

Therefore, another preferred embodiment of the present invention is a tanning process as described above and all its preferred embodiments, wherein composition (T) is an aqueous composition (T1) comprising a tanning agent (a) and further comprising a surfactant (B) and/or a buffer (C1) for maintaining an acidic to neutral pH.

Therefore, another preferred embodiment of the present invention is a tanning process as described above and all its preferred embodiments, wherein composition (T) is an aqueous composition (T1) of tanning agent (a) comprising surfactant (B) and/or buffer (C1) and further comprising agent (D) for protection against the destructive action of microorganisms and/or polysaccharide based thickener (E).

Preferably composition (T) is composition (T1) comprising:

2-70 wt.%, preferably 10-50 wt.% of tanning agent (a), wherein wt.% is based on the total weight of composition (T1);

a surfactant (B), wherein the weight ratio of surfactant (B) to tanning agent (a) is from 0.001 to 1, more preferably from 0.002 to 0.4, even more preferably from 0.005 to 0.1;

a buffer (C1) in an amount such that a pH value of 1-7, more preferably a pH value of 1-5 is obtained in the composition (T1), preferably the amount of buffer (C1) is 0.1-5% by weight, wherein the% by weight is based on the total weight of the composition (T1);

0-10 wt.%, preferably 0.01-10 wt.%, more preferably 0.02-1 wt.% of agent (D), wherein wt.% is based on the total weight of composition (T1);

thickener (E) in an amount such that the viscosity of the composition (T1) (Brookfield rotational viscosity measured with spindle number 3 at 20 rpm) at 20 ℃ is not more than 10,000 mPas, preferably 200-10,000 mPas, more preferably 300-2,500 mPas, even more preferably 600-1,500 mPas, in particular thickener (E) is used in an amount of 0 to 5% by weight, more preferably 0.1 to 5% by weight, based on the total weight of the composition (T1);

and the dry matter content of the composition (T1) is preferably 4 to 75 wt.%, more preferably 10 to 60 wt.%, wherein wt.% is based on the total weight of the composition (T1).

The dry matter content of (T) or (T1) can be evaluated in a manner which is conventional per se, for example by calculation based on the reactants and components used — in most cases by simple addition of the amounts of the individual substances added for the preparation of (T) or (T1) (in dry form) and subtraction of the water formed during the reaction — or preferably by subtraction of the amount of water determined in a conventional manner, for example by titration, such as karl fischer titration, from the total weight of (T) or (T1).

Particular preference is given to compositions (T) or (T1) being compositions (T2) which comprise thickeners (E) in an amount of preferably ≥ 0.1% by weight, more preferably 0.1-5% by weight (E), where the% by weight is based on the total weight of composition (T2). The viscosity (Brookfield rotational viscosity measured at 20rpm with a rotor No. 3) of the composition (T2) at 20 ℃ is preferably 300-2,500 mPas, more preferably 600-1,500 mPas.

The composition (T2) has satisfactory stability, is suitable for storage and transport and can be used directly. It can be easily diluted with water and can be metered directly into the tanning drum, if desired.

As substrate for the treatment with the tanning agent (a), in particular for tanning, any conventional animal hides, skins and hides usually used for tanning can be used, for example hides obtained from cows, calves or buffalos (for example also split hides), skins obtained from goats, sheep or pigs, deer hides and hides; and other hides and skins, such as skins obtained from other mammals (foal, camel, alpaca, kangaroo, wallaby), reptiles (snakes, lizards), fish (sharks) or birds (ostrich), dehaired (wood) and fur.

The bating substrate (animal hide, skin or hide) may be processed, i.e. trimmed, soaked, liming, delimed and bating, in a conventional manner in a preparation plant prior to tanning. Prior to deliming, the liming hides, skins or hides are usually fleshed, if necessary split and optionally pushed clean, shaved, etc., and if necessary degreased and/or unhaired.

The bating hides, skins and hides to be used as substrates in the process of the invention can be prepared in a conventional manner in a preparation plant, in particular by deliming and bating the delimed substrate using known reagents for the process steps.

The deashing can be carried out in a conventional manner using known compounds such as acids, ammonium salts of low molecular weight aliphatic carboxylic acids, ammonium sulfate or sodium phosphate. Optionally, the deliming composition may comprise an enzyme, such as an enzyme described below, such that softening and deliming may be at least partially combined, if desired.

For softening, known deproteinizing softeners can be used, especially in the form of softening compositions based on conventional proteolytic enzymes, mainly bacterial proteases, fungal proteases and pancreatin. Occasionally, other enzymes, such as lipases, amylases, and hydrolases, may also be used. Preferably, pancreatin is used alone or in a mixture with other enzymes, such as lipases, amylases and other hydrolases. Commercial forms of such enzymes may be formulated with other components, especially with some inorganic carriers, sugars or polysaccharides and/or hydrotropes. For the purposes of the present invention, substrates which are generally softened with a pancreatin-based softening composition are very suitable.

The above softening compositions have an optimum activity in the weakly alkaline pH range, more particularly at alkaline pH values of 11 or less, and therefore the pH of the softening substrate is preferably in the weakly alkaline range, especially in the pH range of 7.5 to 11, more preferably 7.5 to 10.

In case the substrate has been delimed with an acid, an acidic softener may also be used, such as pepsin, for example in the form of an aqueous solution of 2% pepsin and having a pH of 3-4.

The tanning process of the invention is based on a true tanning using a tanning agent (a) to obtain leathers, skins and hides having true tanning characteristics, such as reduced or eliminated swelling, reduced deformability and increased hardness, reduced volume, surface and thickness shrinkage by drying, increased porosity of the fibrous structure and further increased shrinkage temperature and resistance of the collagen fibres to hot water, without rotting.

By "step" in the tanning process of the invention is meant any tanning step in the tanning process wherein the tanning agent (a) is allowed to act on the untanned or incompletely tanned substrate, i.e. pre-tanning, main tanning or complete or full tanning (also including combination tanning). Thus, tanning (a) can be used for pre-tanning, for main tanning, for full (i.e. full) tanning or for both pre-tanning and main tanning, as well as for combined tanning. However, the use of the tanning agent (a) as a whole tanning agent or as both a pretanning agent and a main tanning agent is the most relevant aspect of the present invention.

The tanning process of the invention, which can be a one-step tanning (i.e. full tanning), or a two-step tanning (i.e. pre-tanning followed by main tanning), or a combined tanning, can be carried out directly after softening.

The tanning process using the tanning agent (a) of the invention can be carried out in aqueous, aqueous/organic or organic medium; suitable organic media include, for example, ethanol, isopropanol, acetone, methyl ethyl ketone, dimethyl sulfoxide, chloroform, chlorobenzene, and toluene. It is preferably carried out in a water bath, for example at a bath length (bath length) of 30-400 wt.%, preferably 40-200%, most preferably 40-100% water, wherein the wt.% is based on the total weight of the fleshed or (if the hide has been split) split substrate, and preferably at a temperature of 10-50 ℃, more preferably 10-40 ℃, even more preferably 15-40 ℃. Preferably tanning is started at a temperature of 10-35 ℃, more preferably 15-30 ℃ and at the end, the temperature is allowed to rise preferably by 5-20 ℃, more preferably 8-15 ℃ to reach a final temperature of 20-40 ℃, preferably 25-40 ℃.

For the tanning process of the invention, the tanning agent (a) is added to the tanning bath in an effective concentration, preferably in a concentration of 0.5 to 20% by weight, more preferably 1 to 10% by weight, wherein the% by weight is based on the weight of the fleshed or split substrate. The tanning agent (a) can be added in dry form or preferably in the form of an aqueous composition, preferably the above-mentioned composition (T).

Particularly preferred surfactants, especially the above-mentioned surfactant (B), preferably a non-ionic surfactant (B1), and/or a buffer (C2) for adjusting the pH to an almost neutral to alkaline pH, especially a pH of ≥ 6, may be added to the tanning bath in a weight ratio suitable for obtaining the desired pH at the start of the tanning step.

Therefore, another preferred aspect of the present invention is the above tanning process and all its preferred embodiments, wherein the tanning bath comprises a buffer (C2) to obtain an almost neutral to alkaline pH value at the beginning of the tanning step.

As the buffer (C2), a known buffer can be used, which is preferably selected from the group consisting of: sodium and/or potassium bicarbonate, sodium and/or potassium carbonate, sodium and/or potassium phosphate, sodium borate, and tris. Preferably, the buffer (C2) is KH₂PO₄Or NaH₂PO₄And K₂HPO₄Or Na₂HPO₄Combinations of (a) and (b). For the tanning process of the invention, it is particularly advantageous to use the above-mentioned composition (T), which preferably already contains a surfactant (B) and optionally also an agent (D) and/or a thickener (E). The buffer (C2) can be added directly to the tanning bath. Preferably a buffer (C2) is added in the two-step tanning before the main tanning step to set the pH value of the main tanning bath. Composition (T), especially composition (T1), is particularly effective for tanning. The composition may comprise some salts as by-products from the synthesis of the compound of formula (I) from the reaction of the compound of formula (II) with the compound of formula (III).

The tanning process of the invention starts at a pH value of 6 to 10, preferably 6 to 9, more preferably 6.5 to 8.5, in particular a pH value suitable for initiating the reaction of the tanning agent (a) with the substrate.

During tanning, the pH value gradually and spontaneously drops by several pH units, especially 1-4 pH units, to a pH value in the almost neutral to weakly acidic pH range, especially to a pH value of 7-3.5, preferably 6.5-3.5. Thus, the method may be performed under self-regulating pH conditions. However, if desired, the tanning reaction can be influenced by adding small proportions of acids (for example mineral acids such as sulfuric acid or phosphoric acid; or low molecular weight carboxylic acids, for example having 1 to 4 carbon atoms, preferably 1 or 2 carbon atoms, for example formic acid or acetic acid) or by adding small proportions of bases, for example to promote or slow down the reaction and/or to shift the pH somewhat to a more neutral value.

In the method of the present invention, pickling is not essential and may be omitted. The subject of the present invention is therefore also the tanning process described above and all its preferred embodiments, in which the softened hides or skins or hides are tanned with a tanning agent (a) without prior pickling.

If the tanning process is started under almost neutral conditions, in particular at a pH value of 6-7.5, it is also possible to first keep the pH value within this range or to obtain a pH value range of 6-9 by adding alkali to increase it.

As pickling and deacidification are not performed, pre-tanning or full tanning can be performed directly on the softened substrate. The pH at the start of the tanning process is preferably almost neutral to alkaline, in particular 6.5-10, preferably 6.8-9; and gradually and spontaneously decreases several pH units, in particular 1-4 pH units, during the treatment, so that an almost neutral to weakly acidic pH value range, in particular 7-4, preferably 6.5-4.5, is achieved. The temperature is preferably from 10 to 40 ℃ and more preferably from 15 to 35 ℃. More particularly, tanning is preferably started at 10-30 ℃, more preferably at 15-25 ℃ and at the end allows a temperature increase of 5-20 ℃, preferably 8-15 ℃, to reach 20-40 ℃, preferably 25-40 ℃.

The tanning process of the invention is very simple and can be carried out in a relatively short time, in particular in about 5 to 24 hours, preferably 6 to 12 hours.

After tanning, the spent tanning bath may be drained and the tanned leather, skin or hide may be rinsed or washed, for example with water (e.g. 100-. If desired, biocides, such as those described above for agent (D), can also be added during the process, for example in the last washing bath, as preservatives for the resulting tanned hides, skins or hides.

If desired, other non-mineral tanning agents (F) which are different from (a) and have anionic and/or olefinic unsaturation and/or contain basic groups can be applied before, after or together with the tanning agent (a) in the pre-tanning, main tanning or full tanning, preferably for pre-tanning before the main tanning agent is carried out with (a), or in combination with (a) in the main tanning agent or full tanning, and/or preferably for supplementary tanning after the main tanning agent or full tanning with (a), or even for retanning.

(F) Preferably selected from the group consisting of:

(F1) a vegetable tanning agent, which is a mixture of vegetable tanning agents,

(F2) a synthetic tanning agent is prepared by mixing a raw material,

(F3) synthetic, semi-synthetic or natural resins or polymers,

(F4) natural or modified tanning oils,

and mixtures thereof.

As the vegetable tanning agent (F1), known vegetable tanning agents can be used, in particular pyrogallol-based tanning agents or pyrogallol-based tannins, such as valonia, wattle, teri, tara, oak, pine, sumac, quebracho and chestnut.

As syntan (F2), use may be made of known syntans, in particular syntans derived from sulfonated phenols and/or naphthols, and/or sulfones, or polymers of sulfones and/or sulfonated phenols and/or sulfonated naphthols with formaldehyde or acetaldehyde and optionally urea, with sulfone-based products being preferred.

As synthetic or semi-synthetic or natural resins or polymers (F3), it is possible to use, for example, the known polyacrylates, polymethacrylates, copolymers of maleic anhydride and styrene, condensation products of formaldehyde with melamine or dicyandiamide, lignins and natural powders. Among synthetic or semi-synthetic or natural resins or polymers (F3), those having anionic character (such as polyacrylates, polymethacrylates, lignosulfonates and copolymers of maleic anhydride with styrene) and not containing basic amino groups are referred to herein as (F3-I).

As natural or modified oil (F4), use may be made of known natural triglycerides, such as rapeseed oil, fish oil or oxidized derivatives thereof, sulphated, sulphonated or oxy-sulphited fish oil or oxidized derivatives thereof or substitutes thereof.

Tanning with (a) can be carried out in the form of full tanning, or in the form of pre-tanning before non-metallic main tanning, which can be carried out with vegetable tanning agents other than (a) or with syntans such as (F) above, but also with tanning agent (a) of the invention, or in the form of main tanning after non-metallic or even non-mineral pre-tanning, which can be vegetable or synthetic, for example with (F) above. When the tanning using invention (a) is carried out in the form of main tanning after vegetable pre-tanning or synthetic pre-tanning with syntans, the pH value can be adjusted, if desired, to the value required for the inventive tanning process of 6 to 10, for example by adding alkali metal carbonates, bicarbonates or formates.

According to a particular feature of the invention, the tanning agent (a) can be used in combination with other non-mineral tanning agents (F), preferably (F-I), wherein (F-I) is selected from (F1), (F2) and (F3-I), wherein the weight ratio of (a) to (F-I) is for example between 0.05 and 20, more preferably between 2 and 10. The concentration of the combination tanning agent may be the amount required to obtain a certain tanning, e.g. 0.5-20 wt%, preferably 1-10 wt%, wherein wt% is based on the weight of the fleshed substrate.

According to another particularly preferred feature of the invention, the substrate is first tanned with (a) in one or two steps and then additionally tanned with a non-mineral tanning agent (F), preferably (F-II), wherein (F-II) is selected from (F1) or (F2) and (F3). By complementary tanning, it is meant herein a further tanning step which is carried out after main or full tanning with (a) and which does not substantially alter the characteristics of the leather, skin or hide tanned with tanning agent (a) but rather can improve some typical tanning properties. It is usually carried out with a smaller amount of supplementary tanning agent (F) than the amount of main or total tanning agent (a), preferably 5 to 80% by weight, preferably 10 to 60% by weight of (F), wherein the% by weight is based on the weight of the amount of (a). This additional tanning can advantageously be carried out after tanning with (a), under the temperature conditions described above (for example 10-40 ℃), preferably under the conditions of bath length (for example 40-200% by weight of water, where% by weight is based on the weight of the fleshed or (if the hide has been split) split substrate) used for tanning (a) and pH resulting from tanning with (a), preferably after rinsing with water, which pH can generally be 4-7.

The complementary tanning carried out using (F), preferably (F-II), can be carried out directly in the tannery after tanning, or even after rinsing, drying and optionally mechanical treatment of the tanned leather, skin or hide.

At the end of the tanning process, after draining the spent tanning bath or replenishing the tanning bath, if necessary, treatment with one or more conventional additives, such as one or more surfactants (preferably those mentioned above as (B), mainly (B1) or (B3)) to protect the grain from damaging rubbing and/or treatment with preservatives (preferably those mentioned above as (D)).

As mentioned above, the tanned leather, skin or hide prepared according to the invention can be further processed in a conventional manner, i.e. controlled water, dried and mechanically treated as is usual for storage and/or transport.

According to another preferred feature of the invention, the substrate is first tanned with (A), optionally with (F) or (F-II), in one or two steps, and then retanned with (F).

Retanning with (F) can be carried out after rinsing, drying and optionally mechanical treatment of the tanned leather, skin or hide, for example in a dyeing cabinet.

The process of the invention can be carried out in a very economical and simple manner since pickling and deacidification can be omitted, and moreover, the tanning itself can be carried out with a small amount of water and it is not necessary to carry out neutralization as conventionally carried out, for example after metal tanning.

By the process of the present invention, it is possible to obtain metal-free tanned leather, skins or hides (especially "wet white" metal-free leather) which have excellent properties, especially shrink temperature, softness and tightness, such as a hard grain structure, and which have satisfactory fastness, especially when (a) or (T) is used for main tanning or full tanning, respectively. If no vegetable tanning agent is used at all or if only white to yellowish vegetable tanning agents are also used, it is possible according to the invention to obtain "non-metallic white tanned" leathers, skins and hides, in particular non-metallic "wet-white" leathers, which are of high quality and very light self-colour (i.e. almost white). When a light brown to light red vegetable tanning agent is also used, the hue of the resulting tanned leathers, hides and greens is correspondingly slightly darker light brown or light red. A further increased shrinkage temperature Ts can be obtained when (a) is used for full tanning or for pre-tanning and main tanning and subsequently (F), especially (F-II) is used for supplementary tanning.

The tanned leathers, skins and hides prepared as described are suitable for further processing in conventional manner, mainly retanning and/or fatliquoring and optionally dyeing and/or finishing. The fatliquoring may be carried out using known fatliquoring agents. Retanning is preferably carried out with (F). By retanning and fatliquoring it with (F), high quality crust leather can be obtained after drying. Dyeing may be carried out using known leather dyes (for example as defined in "Colour Index by Society of Dyers and Colourists and synthetic associates of Textile Chemists and Colourists", and especially those listed therein), and dyeing with satisfactory properties, mainly bleed, Colour yield and fastness, may be obtained. With those leathers, skins or hides which have a very light self-colour, i.e. almost white, as described above, it is also possible to obtain a dyeing effect of elegant shades (bluish shades) or very pleasant shades. If desired, conventional leather finishes can also be used for finishing.

Therefore, another subject of the present invention is the use of the tanned leather, skin or hide prepared according to the above process and all its preferred embodiments for further processing by at least one other treatment method selected from the group consisting of:

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

(b) the fat is added into the mixture,

(c) dyeing, and

(d) and (7) coating.

Preferably a and b and optionally c and/or d.

In the examples below, the percentages are by weight; and the viscosity is the brookfield rotational viscosity measured at 20 ℃ and 20rpm using a No. 3 rotor, unless otherwise specified.

Examples

Example 1

500 parts of water and 500 parts of crushed ice are charged into the reactor with stirring. At this temperature, 185 parts of cyanuric chloride are added and stirring is continued for 10 to 15 minutes. In parallel therewith, 30% by weight of sodium hydroxide) is used to adjust the pH of a mixture of 135 parts of 4-aminobenzoic acid in 500 parts of water to 5. Then, a slightly acidic solution was added to the cyanuric chloride dispersion over 60 minutes. At this point, 230 parts of 30% by weight aqueous sodium hydroxide solution (with weight% based on the weight of the solution) were added over 1-2 hours, with the temperature being kept below 10 ℃ and the pH being kept at 6-7. Near the end of the addition of sodium hydroxide solution, the temperature was raised to 14 ℃. A white-light yellow emulsion (composition 1) comprising the compound of formula (1) was obtained.

Examples 2 to 20

The following table includes compounds of formulae I-III, which can be prepared by using the corresponding starting materials in analogy to the procedure described in example 1.

Example 21

Under stirring, 1,000g of the product obtained from example 1 and 400ml of dimethyl sulfoxide were charged into a reactor, and 71g of triethanolamine were added. The mixture was kept at 40 ℃ for 12-15 hours with stirring. A white-pale yellow dispersion (composition 21) comprising the compound of formula (21) was obtained.

Example 22

1,000g of composition 1 obtained according to example 1 were previously set at 20-25 ℃ and 10.2g of disodium hydrogen phosphate, 8.7g of monosodium dihydrogen phosphate and 2.0g ofBIT 20 (a commercial biocide from Nipa LAB's Ltd. based on 1, 2-benzothiazolin-3-ones, available from Nipa laboratory GmbH, Germany). A white-pale yellow dispersion (composition 22) was obtained.

Example 23

100g of water are heated to 50-55 ℃. At this temperature, 4g of hydroxyethyl cellulose (viscosity of a 2% solution thereof at 25 ℃ and pH 7.0: 5,500 mPas) was added and stirring was continued for 1 hour. 104g of hydroxyethylcellulose solution are obtained.

1,000g of the composition 22 obtained in example 22 was previously set to 20-25 ℃, and 103.8g of a hydroxyethylcellulose solution was added with stirring. A white-pale yellow suspension (composition 23) having a viscosity of 1,250 mPas at 20 ℃ was obtained.

Examples 24 to 61

The compositions of examples 2-20 were converted to obtain examples 24-61 as described for composition 1 in example 22 and composition 22 in example 23.

Example 62

1,000g of composition 21 obtained according to example 21 were previously set at 20-25 ℃ and 10.2g of disodium hydrogenphosphate, 8.7g of monosodium dihydrogenphosphate and 2.0g of sodium dihydrogenphosphate were added with stirringBIT 20(A commercial biocide of Nipa LAB's ltd. based on 1, 2-benzothiazolin-3-ones, available from Nipa laboratory GmbH, germany). A white-light yellow emulsion (composition 62) was obtained.

Example 63

100g of water are heated to 50-55 ℃. At this temperature, 4g of hydroxyethyl cellulose (viscosity of a 2% solution thereof at 25 ℃ and pH 7.0: 5,500 mPas) was added and stirring was continued for 1 hour. 104g of hydroxyethylcellulose solution are obtained.

1,000g of the composition 62 obtained in example 62 was previously set to 20-25 ℃, and 103.8g of a hydroxyethylcellulose solution was added with stirring. A white-light yellow suspension (composition 63) was obtained.

In the application examples below, unless otherwise stated, the percentages stated in application examples a-Ea) and Ia) are relative to the weight of the split skins, to the weight of the fleshed skins in application examples Fa), Ga), Ha) and Hb), to the weight of the softened skins in application examples Fb), Gb) and Ib), to the weight of the deacidified substrate in application example Hc), to the weight of the deacidified sheep skin in application example J and to the wet weight of the tanned leather in application example K. The shrinkage temperature Ts is determined according to standard method IUP 16/ISO 3380-. When treatment is indicated overnight, this means 10-12 hours of treatment. If not stated otherwise, the pH is increased by addition of a 10% by weight aqueous solution of sodium formate (where% by weight is based on the weight of the solution), or is decreased by addition of a 10% formic acid solution (where% by weight is based on the weight of the solution). The dye is in a commercially available form blended with sodium chloride, wherein the dye content is about 60%, "c.i." means "colour index".

Application example A

a) Deliming and softening:

liming cattle hide (30kg weight grade Swiss cattle hide) fleshed and sliced to a thickness of 2.4-2.6mm was filled with water at 200%25 ℃ and 0.1% destuffFat agents (C ethoxylated with 7 moles of ethylene oxide per mole of alkanol_12-15Alkanol) and 0.2% ammonium based deliming agent (ammonium chloride and ammonium sulphate) and treated with tumbling for 20 minutes. The bath was then drained and the drum was charged with a fresh bath of 50%35 ℃ water, 0.1% of the above-mentioned degreasing agent and 0.5% of the above-mentioned ammonium-based deliming agent and the drum treatment was continued for 15 minutes. 0.5% ammonium based deliming agent and 0.8% of a mixture of 70% boric acid and 30% mixed organic acids (equal parts of adipic, glutaric and succinic acids) were added and tumbled for 90 minutes. Adding 0.6 percent of the mixtureBate PB1p (pancreatin-based softener of Clariant, switzerland) and continued the tumbling for 30 minutes before discharging the bath. 300% water was added and the drum treated at 35 ℃ for 15 minutes, then the bath was drained.

b) Tanning:

a fresh bath of 50%20 ℃ water and 10% of the composition 22 according to example 22 was added and tumbling was carried out for 60 minutes, after which the bath was heated to 30 ℃ over 120 minutes and tumbling was continued overnight at 30-35 ℃. The bath was then drained. 300%20 ℃ water was added and the drum treatment continued for 30 minutes, then the bath was drained and the leather was removed and mared.

If necessary, 0.2 percentWB (biological biocide from Bayer, germany) was added to the last 300% water added.

The leather thus obtained is then wrung and shaved to 2.0-2.2 mm.

Application example B

The procedure described in application example a was repeated until tanning treatment with composition 2 and tumbling treatment at 30-35 ℃ overnight.

Supplementary tanning:

after the drum treatment overnight, 1% of a syntan based on sulfomethylated dihydroxydiphenyl sulfone reacted with formaldehyde was added for additional tanning and the drum treatment was continued for 120 minutes before draining the bath. 300%20 ℃ water was added and the drum treatment continued for 30 minutes, then the bath was drained and the leather was removed and mared. The leather thus obtained is then wrung and shaved to 2.0-2.2 mm.

If necessary, 0.2 percentWB was added to the last 300% water added.

Application example C

The procedure described in application example C was repeated until the tanning treatment with composition 3 and drum treatment were carried out overnight.

Supplementary tanning:

after the drum treatment overnight, 1% of a syntan based on sulfomethylated dihydroxydiphenyl sulfone reacted with formaldehyde was added for additional tanning and the drum treatment was continued for 120 minutes before draining the bath. 300%20 ℃ water was added and the drum treatment continued for 30 minutes, then the bath was drained and the leather was removed and mared. The leather thus obtained is then wrung and shaved to 2.0-2.2 mm.

Application example D

a) Deliming and softening:

delipidated and uncracked liminated calfs (30kg weight scale of spanish calfs) were loaded with 200%25 ℃ water, 0.1% degreasing agent (C ethoxylated with 7 moles of ethylene oxide per mole of alkanol)_12-15Alkanol) and 0.2% ammonium based deliming agent (ammonium chloride and ammonium sulphate) and treated with tumbling for 20 minutes. The bath was then drained and the drum was charged with a fresh bath of 50%35 ℃ water, 0.1% of the above-mentioned degreasing agent and 0.5% of the above-mentioned ammonium-based deliming agent and the drum treatment was continued for 15 minutes. 0.5% ammonium deliming agent and 0.8% 70% boric acid was added with 30% mixed organic acids (equal parts of adipic, glutaric and succinic acids)) And treated with tumbling for 90 minutes. The pH was 7.8 and the peel cross-section was colorless to the phenolphthalein indicator solution. Adding 0.6 percent of the mixtureBate PB1p and continued the tumbling for 30 minutes, after which the bath was drained. 300% water was added and the drum treated at 35 ℃ for 15 minutes, then the bath was drained.

b) Tanning:

a fresh bath of 50%20 ℃ water was added. The pH was measured and adjusted to 8. 15% of composition 23 according to example 23 was added and tumbling was carried out for 60 minutes, after which the bath was heated to 30 ℃ and tumbling was continued overnight at 30-35 ℃. The bath was then drained. 300%20 ℃ water was added and drum treatment continued for 20 minutes.

If necessary, 0.2 percentWB was added to the last 300% water added.

The bath was then drained, the leathers were removed and set aside. The leather thus obtained is then wrung, split and shaved to 1.4-1.6 mm.

Application example E

a) Deliming and softening:

delipidated and uncracked liminated calfs (30kg weight scale of spanish calfs) were loaded with 200%25 ℃ water, 0.1% degreasing agent (C ethoxylated with 7 moles of ethylene oxide per mole of alkanol)_12-15Alkanol) and 0.2% ammonium based deliming agent (ammonium chloride and ammonium sulphate) and treated with tumbling for 20 minutes. The bath was then drained and the drum was charged with a fresh bath of 50%35 ℃ water, 0.1% of the above-mentioned degreasing agent and 0.5% of the above-mentioned ammonium-based deliming agent and the drum treatment was continued for 15 minutes. 0.5% ammonium based deliming agent and 0.8% of a mixture of 70% boric acid and 30% mixed organic acids (equal parts of adipic, glutaric and succinic acids) were added and tumbled for 90 minutes. A pH value of 7.8, andthe cross section of the skin was colorless to the phenolphthalein indicator solution. Adding 0.6 percent of the mixtureBate PB1p and continued the tumbling for 30 minutes, after which the bath was drained. 300% water was added and the drum treated at 35 ℃ for 15 minutes, then the bath was drained.

b) Pickling and deacidifying:

70%20 ℃ water and 7% sodium chloride were added and the drum treatment was repeated for 10 minutes. 0.8% formic acid diluted 1:3 with water was added and the drum treatment was continued for 30 minutes, then 1.5% sulfuric acid diluted 1:10 with water was added and the drum treatment was continued for 3 hours, then the pickling bath with skin was allowed to stand overnight with the drum treatment being intermittent for 5 minutes every 1 hour. After this treatment, the pH was 2.7-2.9. The bath was drained, and the skins were removed and wrung. The drum was charged with 100%20 ℃ water and 10% sodium chloride, the drum was opened and drum treatment continued for 10 minutes, then the skin was charged into the drum and drum treated for 30 minutes, then 1% sodium bicarbonate was added and drum treatment continued for 120 minutes, then the drum was stopped and the deacidification bath with the skin was allowed to stand overnight. The pH was about 8. The bath was then drained and the skins rinsed with 200%20 ℃ water for 15 minutes before draining the bath.

c) Tanning

50% water was added and the pH was adjusted to 8 by the addition of 0.5% sodium bicarbonate and 0.5% sodium formate. The pH of the skin cross-section was 8 (measured with phenolphthalein indicator). 15% of composition 1 according to example 1 was added and drum treated for 1 hour, then the bath was heated to 35 ℃ and drum treatment continued overnight at 35 ℃. The bath was then drained. 300%20 ℃ water was added and the drum treatment was continued for 20 minutes.

If necessary, 0.2 percentWB was added to the last 300% water added.

The bath was then drained, the leathers were removed and set aside. The leather thus obtained is then wrung, split and shaved to 1.4-1.6 mm.

Application example F

a) Deliming and softening

Delipidated and split to a thickness of 2.4-2.5mm of liminated hides (30kg weight class of Spanish hides) were loaded with 200%25 ℃ water, 0.1% degreasing agent (C ethoxylated with 7 moles of ethylene oxide per mole of alkanol)_12-15Alkanol) and 0.2% ammonium based deliming agent (ammonium chloride and ammonium sulphate) and treated with tumbling for 20 minutes. The bath was then drained and the drum was charged with a fresh bath of 50%35 ℃ water, 0.1% of the above-mentioned degreasing agent and 0.5% of the above-mentioned ammonium-based deliming agent and the drum treatment was continued for 15 minutes. 0.5% ammonium based deliming agent and 0.8% of a mixture of 70% boric acid and 30% mixed organic acids (equal parts of adipic, glutaric and succinic acids) were added and tumbled for 90 minutes. The pH was 7.8 and the peel cross-section was colorless to the phenolphthalein indicator solution. Adding 0.6 percent of the mixtureBate PB1p (pancreatin-based softener of Clariant, switzerland) and continued the tumbling for 30 minutes before discharging the bath. 300% water was added and the drum treated at 35 ℃ for 15 minutes, then the bath was drained.

b) Tanning:

a fresh bath of 50%20 ℃ water was added. The pH was 8. 10% of composition 1 according to example 1 was added and drum treated for 60 minutes, then the bath was heated to 30 ℃ over 120 minutes and drum treatment was continued overnight at 30-35 ℃.

c) Supplementary tanning:

after tumbling overnight, 2% Tara (a commercial plant tanning agent which is an aqueous composition of Caesalpinia Spinosa (Caesalpinia Spinosa) pod extract at a concentration of 50% by weight, based on the weight of the composition) was added and tumbling was continued for 3 hours at 35 ℃. The bath was then drained. 300%20 ℃ water was added and the drum treatment was continued for 30 minutes. The bath was then drained, the leathers were removed and set aside. The leather thus obtained is then wrung and shaved to 2.0-2.2 mm.

Application example G

a) Acid removal:

the softened and pickled sheepskin was placed in a rotating drum with 100%20 ℃ water and 10% sodium chloride and treated with the drum for 10 minutes. Add 1% sodium bicarbonate and 1% sodium carbonate and continue the drum treatment for 10 minutes before draining the bath. Addition of 150% water and 2% degreasing agent (C ethoxylated with 7 moles of ethylene oxide per mole of alkanol)_12-15Alkanol) and continued tumbling for 1 hour before draining the bath, adding a fresh bath of 150% water and 2% degreaser, continued tumbling for 1 hour before draining the bath. The skin was washed twice, each time with 300%20 ℃ water, and then drained from the bath. The pH was 8.

b) Tanning:

50%20 ℃ water and 20% composition 23 were added and tumbling continued for 2 hours, then the temperature was slowly raised to 35 ℃ and tumbling continued overnight at 35 ℃. The pH was 5.5. A fresh bath of 300%20 ℃ water was added, and after 30 minutes of drum treatment, the bath was drained, the leathers were removed, marbled and wrung.

Application example H

The leather obtained in application example D was retanned, fatliquored and dyed as follows:

the leather is loaded into a tumbler, 200% of 25 ℃ water is added, followed by 0.3% of a degreasing agent (C ethoxylated with 7 moles of ethylene oxide per mole of alkanol)_12-15Alkanol) open the drum and drum treat for 20 minutes. 0.5% acetic acid was added at a dilution ratio of 1:10 and the tumbling was continued for 20 minutes. The pH was 4.5 and the leather cross-section turned Green when tested with Bromocresesol Green indicator. The bath was drained. 100% water at 25 ℃ was added, followed by 1.6% fatliquoring agent (oxysulfided fish oil) and tumbling continued for 20 minutes. Addition of 5% based on formaldehydeThe retanning syntan of reacted sulfomethylated dihydroxydiphenyl sulfone and 5% phenol syntan (reaction product of sulfonated phenol with formaldehyde and urea) were drum treated for 2 hours. The bath was left to stand overnight and tumbled intermittently for 5 minutes every 1 hour, then 0.5% formic acid diluted 1:10 was added and tumbled for 20 minutes, then the bath was drained and the leather was rinsed with 200% water. The bath was drained. 100%50 ℃ water was added followed by 5% fatliquoring agent (3.5% alkyl sulfosuccinate and 1.5% oxysulfided fish oil) and tumbling was continued for 1 hour. After addition of 0.5% formic acid, the drum was treated for 20 minutes and then the bath was drained. The leather was rinsed with 200%20 ℃ water for 5 minutes. The bath was then drained. 50% of 20 ℃ water and 5% of the black dye c.i. acid black 210 were added and the tumbling continued for 1 hour, then 200% of 50 ℃ water and 1% formic acid were added and the tumbling continued for 10 minutes, then further 1% formic acid was added and the tumbling continued for 20 minutes, and then the bath was drained. Adding 200% of 20 ℃ water and 1.5% of cationic surfactant 2- (8-heptadecenyl) -4, 5-dihydro-1, 3-bis (2-hydroxyethyl) -1H-imidazoleChloride and drum treatment for 15 minutes, then discharge the bath and remove the leather. After 24 hours from the start, dried under vacuum at 60 ℃ for 2 minutes, hung to dry and pulled soft. A black dyed leather with satisfactory properties is obtained.

Brown dyed leather with satisfactory properties was obtained by using the 2% brown dye c.i. acid brown 237 instead of the 5% black dye c.i. acid black 210.

Analogously, the leather obtained from application example D and the leather obtained from the respective applications examples a-C, E-G were retanned, fatliquored and dyed according to the procedure described in application example H.

In the application examples described above, leather of a satisfactory commercial grade is obtained, in particular with satisfactory grain compactness, structural tightness (obtained, for example, from some typical properties such as tensile strength, resistance to tearing loads and resistance to seam tearing), softness, fastness and overall appearance. In the dyeing examples, further dyed leathers having satisfactory properties (especially hue, dye penetration and color yield and color fastness) were obtained.

Application example I

a) Deliming and softening:

delipidated and split to a thickness of 2.4-2.5mm of liminated hides (30kg weight class of Spanish hides) were loaded with 200%25 ℃ water, 0.1% degreasing agent (C ethoxylated with 7 moles of ethylene oxide per mole of alkanol)_12-15Alkanol) and 0.2% ammonium based deliming agent (ammonium chloride and ammonium sulphate) and treated with tumbling for 20 minutes. The bath was then drained and the drum was charged with a fresh bath of 50%35 ℃ water, 0.1% of the above-mentioned degreasing agent and 0.5% of the above-mentioned ammonium-based deliming agent and the drum treatment was continued for 15 minutes. 0.5% ammonium based deliming agent and 0.8% of a mixture of 70% boric acid and 30% mixed organic acids (equal parts of adipic, glutaric and succinic acids) were added and tumbled for 90 minutes. The pH was 7.8 and the peel cross-section was colorless to the phenolphthalein indicator solution. Adding 0.8 percent of the mixtureBate PB1p (pancreatin-based softener of Clariant, switzerland) and continued the tumbling for 30 minutes before discharging the bath. 300% water was added and the drum treated at 35 ℃ for 15 minutes, then the bath was drained.

b) Tanning:

a fresh bath of 50%20 ℃ water was added. The pH was 8. 20% of the composition 63 according to example 63 was added and subjected to tumbling for 60 minutes, after which the bath was heated to 30 ℃ over 120 minutes and the tumbling continued overnight at 30-35 ℃.

c) Supplementary tanning:

after tumbling overnight, 2% Tara (a commercially available vegetable tanning agent, which is an aqueous composition of the Caesalpinia spinosa extract at a concentration of 50% by weight, based on the weight of the composition) was added and tumbling was continued at 35 ℃ for 3 hours. However, the device is not suitable for use in a kitchenAnd then discharged from the bath. 300%20 ℃ water was added and the drum treatment was continued for 30 minutes. The bath was then drained, the leathers were removed and set aside. The leather thus obtained is then wrung and shaved to 2.0-2.2 mm. If necessary, 0.2 percentWB was added to the last 300% water added.

Claims (16)

1. A process for preparing tanned leather, skin or hide by non-metal tanning comprising the step of tanning a softened hide, skin or hide with a tanning agent a in a tanning bath, wherein said tanning agent a is at least one compound of formula I:

wherein

X represents fluorine or chlorine, and/or (C)⁺NR₃)_0-1Wherein R is substituted C₁-C₆Alkyl or unsubstituted C₁-C₆Alkyl, unsubstituted C₆-C₁₀Aryl or substituted C₆-C₁₀Aryl or C₅-C₆A heteroaryl group;

r1 represents hydrogen or C_1-8Alkyl or alkyleneoxy of formula Ia:

-(-C_2-3alkylene-O-)_q-H Ia

R2 represents hydrogen, hydroxy, C_1-4Alkyl or C_1-4An alkoxy group;

m represents 1 or 2;

n represents 0 to 2;

q is 1 to 10;

m represents hydrogen or an alkali metal cation or an ammonium cation which is a protonated tertiary amine or quaternary ammonium cation;

the tanning bath has a pH value of 6 to 10 at the beginning of the tanning step, wherein the softened hide or skin or hide is tanned with tanning agent A without prior pickling.

2. A process according to claim 1, wherein the tanning agent a is used in the form of an aqueous composition T free of metal compounds having tanning activity.

3. The method according to claim 1 or 2, wherein the composition T is composition T1, the composition T1 further comprising surfactant B and/or buffer C1 for maintaining an acidic to neutral pH.

4. The method according to claim 3, wherein said composition T1 further comprises an agent D for protection against the destructive action of microorganisms and/or a polysaccharide based thickener E.

5. The method according to claim 4, wherein the aqueous composition T1 comprises a polysaccharide-based thickener E.

6. Process according to claim 1 or 2, wherein the tanning bath comprises a buffer C2 to obtain an almost neutral to alkaline pH value at the beginning of the tanning step.

7. A process for the preparation of non-metal tanned leather, skin or hide according to claim 1 or 2, wherein the tanning step using tanning agent a is pre-tanning, main tanning or full tanning or pre-tanning and main tanning.

8. Process according to claim 7, wherein before, after or together with tanning agent A, a further non-mineral tanning agent F, which is different from tanning agent A as defined in claim 1 and has anionic and/or olefinic unsaturation and/or contains basic groups, is used in pre-tanning, main tanning or full tanning, or in combination with tanning agent A in full tanning.

9. The method according to claim 8, wherein the non-mineral tanning agent F is selected from the group consisting of:

F1. a vegetable tanning agent, which is a mixture of vegetable tanning agents,

F2. a synthetic tanning agent is prepared by mixing a raw material,

F3. synthetic, semi-synthetic or natural resins or polymers,

F4. natural or modified tanning oils,

and mixtures thereof.

10. A process according to claim 7 wherein the substrate is tanned with tanning agent A in main or full tanning and then additionally tanned with non-mineral tanning agent F as defined in claim 8 or 9.

11. A process according to claim 8, 9 or 10 wherein the non-mineral tanning agent F is used in a smaller amount compared to the amount of tanning agent a.

12. Use of a tanning composition T1 as defined in claim 3, 4 or 5 as tanning agent a in a tanning process as defined in any one of claims 1 to 11.

13. Use of tanned leather, skins or hides prepared according to the process defined in any one of claims 1 to 11 for further processing by at least one further treatment selected from the group consisting of:

a. retanning with a non-mineral tanning agent F as defined in claim 8 or 9 different from tanning agent A as defined in claim 1,

b. the fat is added into the mixture,

c. dyeing, and

d. and (7) coating.

14. Use of tanned leather, skins or hides prepared by a process as defined in any one of claims 1 to 11 for further processing by further treatment comprising retanning with a non-mineral tanning agent F as defined in claim 8 or 9.

15. Use of tanned leather, skin or hide prepared according to the process defined in any one of claims 1 to 11 for further processing by further treatment comprising retanning with a non-mineral tanning agent F as defined in claim 8 or 9, fatliquoring and optionally dyeing and/or finishing.

16. Tanned leather, skins or hides obtainable by a process according to any one of claims 1 to 11.