Title of Invention	A PROCESS AND A FORMULATION FOR TREATING LEATHER/FUR TO IMPART WATER REPELLENCY
Abstract	The present invention relates to a formulation for treating leather or fur to impart water repellency, comprising from 1 to 30% by weight, based on the formulation, of a mixture of polysiloxanes comprising from 10 to 90% by weight, based on the mixture, of one or more carboxyl-containing polysiloxanes, from 90 to 10% by weight, based on the mixture, of one or more carboxyl-free polysiloxanes and from 3 to 25% by weight, based on the formulation, of at least one emulsifier. The present invention also relates to a process for treating leather or fur to impart water repellency.

Title of Invention

A PROCESS AND A FORMULATION FOR TREATING LEATHER/FUR TO IMPART WATER REPELLENCY

Abstract

The present invention relates to a formulation for treating leather or fur to impart water repellency, comprising from 1 to 30% by weight, based on the formulation, of a mixture of polysiloxanes comprising from 10 to 90% by weight, based on the mixture, of one or more carboxyl-containing polysiloxanes, from 90 to 10% by weight, based on the mixture, of one or more carboxyl-free polysiloxanes and from 3 to 25% by weight, based on the formulation, of at least one emulsifier. The present invention also relates to a process for treating leather or fur to impart water repellency.

Full Text	Imparting water repellency to leather and For SKins The present invention relates to a process for imparting water repeilency to leather and fur skins, wherein leather or fur skin is treated, before, during or after the retanning, with one or more formulations comprising from 1 to 30% by weight, based on the fomiulation, of a mixture of polysiloxanes comprising from 10 to 90% by weight, based on the mixture, of one or more carboxyl-containing polysiloxanes, from 90 to 10% by weight, based on the mixture, of one or more carboxyl-free polysiloxanes and from 3 to 25% by weight, based on the formulation, of at least one emulsifier. EP 0 213 480 B discloses a process for imparting water repeilency to leather and fur skins, in which an aqueous emulsion of a silicone oil or an anhydrous mixture of a silicone oil and an alkanolamine salt of an amino acid is allowed to act on leather or skins before, during or after the retanning. Examples of polysiloxanes are: dimethylpolysiloxane in which 3% of the methyl groups have been replaced by mercaptopropyl (examples 1 to 7), dimethylpolysiloxane having a viscosity from 80 to 110 mPas, phenylmethylpolysiloxanes having a viscosity from 85 to 120 mPas and dimethylpolysiloxanes having on average from 2 to 10 carboxyl groups per molecule. The performance characteristics of such water repellent formulations can however still be improved. Furthermore, the leathers produced with the aid of the polysiloxanes disclosed can in some cases also be improved with regard to performance characteristics, WO 95/22627 discloses a process for imparting water repeilency to leather and fur skins using carboxyl-containing polysiloxanes in aqueous emulsion, in which polysiloxanes which are branched in a comb-like manner and may have the formula A are used: COOH I A I The structural units may, for example, be randomly distributed. The variables are defined as follows: R are identical or different and, independently of one another, are hydrogen, hydroxy!, C1-C4-alkyl, phenyl, CrC4-alkoxy, amino, mono- or di-C1-C4-amino, chlorine or fluorine, it also being possible in each case for a radical R to be the group Z-A-COOH at the chain ends; A is a linear or branched C5-C25-alkylene group and Z is a direct bond, an oxygen atom or an amino, carbonyl, amido or ester group. On average, preferably from 2.5 to 15 carboxyl groups are present per molecule (page 4, line 17). Leather and fur skin treated with the aid of such comb-like polysiloxanes generally have very good water repellency. WO 98/04748 discloses a process for retanning leathers produced using polymeric tanning agents and, if required, aldehyde tanning agents, which leathers are treated with polymer tanning agents and with comb-like polysiloxanes of the fomriula A defined above. EP-A1 087 021 discloses that leather treatment compositions comprising a combination of polysiloxanes substituted by carboxyl or carboxyiic anhydride groups at the α,-position, the carboxyl groups of the polysiloxane being present in neutralized form, with certain amphiphilic polymers, an emulsifier and an oil or wax are suitable as leather treatment compositions. With the aid of the combination products disclosed, full and soft leathers which were readily washable were produced. However, it is observed that leather and fur skin obtained according to the publications cited above have in many cases a dyeing with an undesirably low degree of levelness. Moreover, the high price of the polysiloxanes branched in a comb-like manner is to be regarded as disadvantageous. It is an object of the present invention to provide a process for the production of leather and fur skins which does not have the abovementioned disadvantages. It is furthermore an object of the present invention to provide leather having advantageous performance characteristics. It is moreover an object of the present invention to provide novel formulations having advantageous performance characteristics. We have found that this object is achieved by the process defined at the outset. According to the invention, leather is treated with a formulation before, during or after the retanning. At least one formulation used in the novel process comprises from 1 to 30, preferably from 5 to 20, particularly preferably from 7 to 12.5, % by weight, based on the weight of the formulation, of a mixture of two or more polysiloxanes. From 10 to 90% by weight, based on the mixture, of the polysiloxanes comprised in at least one formulation are carboxyl-containing polysiloxanes. In an embodiment, carboxyl-containing polysiloxanes are those which contain the structural elements of the formulae I and II and optionally structural elements III a and/or III b. The structural elements defined above are each arranged in such a way that Si-O-Si-0 chains are formed. Formation of Si-Si groups is theoretically possible but plays a minor role in most cases. In the formulae I, II, III a and III b, the variables are defined as follows: R"* are identical or different and, independently of one another, are hydrogen, hydroxyl, Ci-C4-alkyl, such as methyl, ethyl, n-propyl, isopropyl. n-butyl, isobutyl, sec-butyl and tert-butyl; in particular methyl; C6-Ci4-aryl, for example phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl. 2-anthryl. 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl and 9-phenanthryl, preferably phenyl, 1-naphthyl and 2-naphthyl, particularly preferably phenyl; C1-C4-alkoxy, such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy and tert-butoxy; amino, mono-C1-C4-alkylamino, for example -NHCH3. -NHC2H5. -NH(CH2)2CH3, -NH(CH2)3CH3. -NH.CH(CH3)2. NHC(CH3)3; dl-C1-C4-alkylamino. -N(CH3)2. -N(C2H5)2. -N(CH3)(C2H5). -N[(CH2)2CH3]2, -N(CH3)CH(CH3)2. or Z1-A1-COOH. In a preferred embodiment of the present invention, all R1 are identical and are each methyl. In another preferred embodiment, the structural elements I are identical in each case, in I in each case one R1 being methyl and the other R1 being phenyl. In an embodiment of the present invention, the structural elements of the fomiula III a are selected from the following groups: Si(CH3)3, Si(CH3)2C6H5, Si(CH3)20H, Si(CH3)C6H50H. A' are identical or different and are linear or branched C5-C25-alkylene, unsubstituted or substituted by one or more C1-C4-alkyl or phenyl, for example .(CH2)5.. -(CH2)6-. -(CH2)r, -(CH2)8-. -(CHzV. -(CH2)io-, -(CH2)ir. -(082)12-. -(CH2)i3-. -(CH2)i4-. -CH(CH3)-CH2-CH2-CH2-CH(CH3)-,-C(CH3)2-CH2-CH2-CH2-CH(CH3)-; -CH(C6H5)-CH2-CH2-CH2-CH(CH3)-; preferably -(CH2)8-. -(082)9-, -(CH2)io-, -(CH2)ir, -(CH2)irI it being possible for C5-C25-alkylene to be interrupted by 1 to 8 oxygen atoms not directly bonded to one another. Z1 is a direct bond, oxygen an amino group of the formula -NR2- a carbonyl group, an amido group of the formula -NR^-CO- or -CO-NR^- or an ester group of the formula CO-0 or 0-CO; R2 are identical or different and, independently of one another, are selected from hydrogen, C1-C4-alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl. Polysiloxanes which comprise the structural elements of the formulae I, II and optionally Ilia and/or III b may be linear or have a cyclic or branched structure. Branched polysiloxanes which comprise the structural elements I, II and optionally III a and/or III b generally additionally comprise structural elements, for example of the formula IV a or IV b in which the variables are defined as above. Cyclic straight-chain polysiloxanes which comprise the structural elements of the formula I or II usually comprise no structural elements of the formulae III a and III b. The structural elements 1,11 and optionally IV a and IV b can be distributed alternately, biockwise and preferably randomly in carboxyl-containing polysiloxane molecules. In an embodiment of the present invention, carboxyl-comprising polysiloxanes contain from 1 to 50, preferably from 2 to 25, particulariy preferably from 2.5 to 15, carboxyl groups per molecule. Usually, the molecular weight Mw of the carboxyl-containing polysiloxanes used according to the invention and having the structural elements I, II, optionally III a. III b, IV a and IV b is from 5 000 to 150 000, preferably from 10 000 to 100 000, g/mol. The molecular weight determination can be carried out by methods known to a person skilled in the art, for example by light scattering methods or viscosity determinations. In an embodiment of the present invention, all or at least a certain proportion, for example a third or a half, of the carboxyl groups in the carboxyl-containing polysiloxanes are neutralized. For example, basic salts, such as hydroxides or carbonates of the alkali metals, for example Na or K, are suitable for the neutralization. Ammonia, alkylamines, such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine and ethylenediamine, and alkanolamines, such as ethanolamine, diethanolamine, triethanolamine. N-methylethanolamine, N-methyl-diethanolamine or N-(n-butyl)diethanolamine, are furthermore suitable. The mixtures used according to the invention comprise, for example, from 10 to 90, preferably from 40 to 60, particulariy preferably about 50. % by weight, of carboxyl-containing polysiloxane. The mixtures used according to the invention furthermore comprise polysiloxanes which comprise no carboxyl groups. Such polysiloxanes generally comprise structural units of the above-defined formulae I. optionally III a. Ill b and IV a, the variables being defined as above, but R1 is not Z1-A1-COOH. Carboxyl-free polysiloxanes used according to the invention are preferably composed of structural elements of the above-defined formulae I, optionally III a. III b and IV a. Particulariy preferably used carboxyl-free polysiloxanes are poly(dimethyl)siloxanes Carboxyl-free polysiloxanes which comprise the structural elements of the fomnulae I and optionally III a, ill b and IV a may have a linear or cyclic or branched structure. Branched carboxyl-free polysiloxanes which comprise the structural elements I and optionally III a and/or III b generally additionally comprise structural elements, for example of the formula IV a. Cyclic straight-chain carboxyl-free polysiloxanes which comprise the structural elements of the formula I usually comprise no structural elements of the formulae III a and III b. In a preferred embodiment of the present invention, all R1 in carboxyl-free polysiloxanes are identical and are each methyl. In another preferred embodiment, the structural elements I in carboxyl-free polysiloxanes are in each case identical, in I in each case one R1 being methyl and the other R1 being phenyl. In an embodiment of the present invention, the structural elements of the formula III a in carboxyl-free polysiloxanes are selected from the following groups: Si(CH3)3. Si(CH3)2C6H5. Si(CH3)20H. Si(CH3)C6H50H. Usually, the molecular weight Mw of the carboxyl-free polysiloxanes used according to the invention and having the structural elements 1,11, optionally III a. Ill b and IV a is from 500 to 150 000, preferably up to 10 000, g/mol. In a preferred embodiment of the present invention, carboxyl-containing and carboxyl-free polysiloxanes are chosen so that the molecular weight of the carboxyl-containing polysiloxane is higher than the molecular weight of the carboxyl-free polysiloxane. The mixtures used according to the invention comprise, for example, from 10 to 90, preferably from 40 to 60, particulariy preferably about 50, % by weight of carboxyl-free polysiloxane. The formulations used according to the invention comprise one or more emulsifiers. For example, from 3 to 25, preferably from 5 to 20, particulariy preferably from 8 to 18, % by weight, based on the formulation, of one or more emulsifiers are. In principle, all compounds which are surface-active in aqueous systems and may be nonionic, anionic, cationic or zwitterionic can be used as emulsifiers. Particularly suitable emulsifiers are N-acylated amino acid derivatives, for example of the formula V in which the variables are defined as follows: R1 is hydrogen, C1-C4-alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl, in particular methyl; C6-C14-aryl, for example phenyl, 1-naphthyl. 2-naphthyl, 1-anthryl. 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl. 4-phenanthryl and 9-phenanthryl, preferably phenyl, 1-naphthyl and 2-naphthyl, particulariy preferably phenyl; R1 is C1-C4-alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl; in particular methyl; The group CO-R1 is usually derived from saturated or unsaturated fatty acids. Saturated fatty acids are to be understood as meaning carboxylic acids which have Cg-C2o-alkyl and may be linear or branched, substituted or unsubstituted. R1 may be, for example, n-nonyl, n-decyl, n-dodecyl, n-tetradecyl, n-pentadecyl, n-octadecyl or n-eicosyl. CO-R® may be derived from an unsaturated fatty acid of 9 to 20 carbon atoms and one having up to 5 C-C double bonds, it being possible for the C-C double bonds to be, for example, isolated or allylic, for example the acyl radical of linoleic acid, of linolenic acid and very particulariy preferably of oleic acid. In an embodiment of the present invention, all or at least a certain proportion, for example a third or a half, of the carboxyl groups are neutralized in N-acylated amino acid derivatives used as emulsifiers. For example, basic salts such as hydroxides or carbonates of the alkali metals, for example, Na or K, are suitable for neutralization. Ammonia, alkylamines, such as methylamine, dimethylamine. trimethylamine, ethyl-amine, diethylamine, triethylamine and ethylenediamine, and particularly preferably alkanolamines, such as ethanolamine, diethanolamine, triethanolamine, N-methyl-ethanolamine, N-methyldiethanolamine or N-(n-butyl)diethanolamine, are furthermore suitable for the neutralization. Typical examples of compounds of the fomnula V are N-oleylsarcosine, N-stearyl-sarcosine, Nlauroylsarcosine and N-isononanoylsarcosine and the respective ethanolammonium salts, diethanolammonium salts and N-methyldiethanolammonium salts. In an embodiment of the present invention, sulfur-containing emulsifier is used. Sulfur-containing emulsifiers which may be used are in principle all sulfur-containing compounds which are surface-active in aqueous systems and may be nonionic, anionic, cationic or zwitterionic. Particularly suitable compounds are those of the formula VI in which the variables are defined as follows: R1 and R1 are identical or preferably different and are selected from hydrogen, C1-Cao-alkyl. branched or straight-chain, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl. sec-pentyl, neopentyl. 1,2-dimethylpropyl. isoamyl. n-hexyl, isohexyl. sec-hexyl. n-heptyl. isoheptyl, n-octyl, n-nonyl. n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetra-decyl, n-hexadecyl, n-octadecyl and n-eicosyl, preferably p-branched radicals of the fomiula VI a (CH2CH20)x-O-R or [CH(CH3)CH20)x-O-R, where x is an integer in the range from 1 to 20, C6-C14-aryl. for example phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl. 3-phenanthryl, 4-phenanthryl and 9-phenanthryl. preferably phenyl, 1-naphthyl and 2-naphthyl, particularly preferably phenyl; R® is selected from C1-C4-alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl and in particular hydrogen; R® and R1° are identical or preferably different and are selected from C1-C27-alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, sec-pentyl, neopentyl, 1,2-dimethylpropyl. isoamyl, n-hexyl, isohexyl, sec-hexyl, n-heptyl. isoheptyl. n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl. n-tridecyl. n-tetradecyl, n-hexadecyl, n-octadecyl, n-eicosyl; the sum of the carbon atoms of R1 and R"'° being not more than 30. R1 preferably has two carbon atoms more than R1°; for example, the combinations R® = n-undecyl and R1° = n-nonyl. R® = n-dodecyl and R1° = n-decyl. R® = n-tridecyl and R1° = n-undecyl. R® = n-tetradecyl and R1° = n-dodecyl. R® = n-pentadecyl and R'° = n-tridecyl, are preferred, R""* is selected from C1-C4-alkyl such as methyl, ethyl, n-propyl. isopropyl. n-butyl. isobutyl. sec-butyl, tert-butyl. phenyl, ortho-tolyl, meta-tolyl and para-tolyl and in particular hydrogen. In a prefen-ed embodiment of the present invention, exactly one of the radicals R1 and R1 is hydrogen and the other radical is selected from C1-C20-alkyl. In a particularly preferred embodiment of the present invention, a mixture of a plurality of sulfur-containing compounds is chosen, for example of the formula VI, \Arhich may differ, for example, in that, in the first compound of the formula VI, R® is hydrogen and R1 is selected from C1-C20-alkyI and. in the second one. R® is hydrogen and R1 is selected from C1-C20-alkyl. In an embodiment of the present invention, all or at least a certain proportion, for example a third or a half, of the sulfonyl groups in sulfur-containing compounds used as emulsifiers are neutralized. For example, basic salts, such as hydroxides or carbonates, of the alkali metals, such as, for example. Na or K, are suitable for the neutralization. Ammonia, alkylamines, such as, for example, methylamine, dimethyl-amine, trimethylamine, ethylamine, diethylamine, triethylamine or ethylenediamine, and very particularly alkanolamines, such as, for example, ethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N-methyldiethanolamine or N-(n-butyl)-diethanolamine, are furthemiore suitable for the neutralization. The preparation of compounds of the formula VI is known per se and is described in WO 01/68584. It is effected, for example, by mono- or diesterification of dicarboxylic anhydrides of the general fonnula VII with corresponding alcohols, which need not be present in pure form, followed by a reaction with disulfite. Instead of pure sulfur-containing compounds, for example sulfur-containing compounds of the formula V, it is possible to use mixtures of different sulfur-containing compounds. For example, it is possible to use, for the esterification, the mixture known as oxo oil 135 or 0X0 thick oil 135 (WO 01/68584). In an embodiment of the present invention, formulations used in the process according to the invention may comprise up to 40% by weight, preferably up to 20% by weight, based on the fonnulation, of at least one alcohol of the fomiula VIII where, in formula VIII, the variables R1 and R1° are defined as above. In an embodiment of the present invention, formulations used in the process according to the invention may comprise up to 50% by weight, preferably up to 30% by weight, based on the formulation, of at least one compound of the formula VIII. In a preferred embodiment of the present invention, formulations used in the process according to the invention may comprise up to 40% by weight, particularly preferably up to 20% by weight, of mixtures which comprise at least one alcohol of the general formula VIII; oxo oil 135 and oxo oil 13 may be mentioned by way of example of such mixtures. The formulation or the formulations used according to the invention is or are preferably aqueous. In an embodiment of the present invention, at least one formulation used according to the invention comprises at least one further hydrophobic compound. At least one further hydrophobic compound is a carbon-based compound, for example natural or synthetic wax, natural or synthetic oil or natural or synthetic fat. Examples of natural waxes are beeswax, cork wax, montan waxes and Camauba wax. Examples of synthetic waxes are polyethylene waxes or ethylene copolymer waxes, as obtainable, for example, by free radical polymerization of ethylene or free radical copolymerization of ethylene with, for example, (meth)acrylic acid or by Ziegler-Natta catalysis. Polyisobutylene waxes may furthermore be mentioned. Paraffin mixtures may also be mentioned; these are to be understood as meaning mixtures of hydrocarbons which have 12 or more carbon atoms and usually have a melting point of from 25 to 45'C. Such paraffin mixtures can be obtained, for example, in refineries or crackers and are known to a person skilled in the art as paraffin slack wax and sasol waxes. Montan ester waxes are a further example of synthetic waxes. Examples of natural oils are triglycerides which are liquid at room temperature, for example fish oil, neatsfoot oil, olive oil, cotton seed oil, castor oil, sunflower oil and peanut oil. Examples of synthetic oils are white oil, liquid paraffin, functionalized parafTins, such as chlorinated or sulfochlorinated paraffins, and polyalkylene glycols, such as polyethylene glycol. Examples of natural fats are natural triglycerides which are solid at room temperature, such as lanolin, shellac wax and mixtures thereof. In a prefen"ed embodiment of the present invention, the further hydrophobic compound is at least one natural triglyceride. In a further preferred embodiment, a combination of at least one natural triglyceride which is solid or liquid at room temperature and a paraffin mixture having a melting point of from 25 to 40oC is used. The ratio is not critical per se, and weight ratios of natural triglyceride to paraffin mixture of from 10 :1 to 1 :10 are suitable. According to the invention, from about 10 to 70, preferably from 20 to 40, % by weight, based on the formulation, of one or more further hydrophobic compounds can be used. For canying out the novel process, leather or fur skin is treated in a liquor, before, during or after the retanning, with the formulations used according to the invention. The novel treatment can be carried out once or repeatedly. The leathers to be treated may have been produced by any desired method, for example by mineral tanning, in particular chrome tanning, or by polymer tanning, tanning v^th syntans, resin tanning, tanning with vegetable tanning agents or tanning with combinations of the abovementioned tanning agents. In an embodiment of the novel process, at least one novel formulation is added in one or more portions to the leather to be treated or to the skins to be treated. This addition can be effected in an aqueous liquor. Preferably, the liquor length may be from 50 to 2 000, preferably from 100 to 400, % by weight, based on the shaved weight of the leathers or the wet weight of the fur skin. In an embodiment of the novel process, the components carboxyl-containing polysiloxane, carboxyl-free polysiloxane and emulsifier are added separately to the leather and/or leather and liquor and the novel formulation is prepared in situ. The novel process is carried out in general by drumming the leather to be treated or the fur skin to be treated in suitable vessels, for example in barrels, in particular in rotatable barrels having intemals. Other methods known to a person skilled in the art are also possible for thorough mixing. Temperatures of from 20 to 65'oC, preferably from 30 to 60oC, can be chosen as the temperature for the novel process. The pressure conditions of the novel process are in general not critical. Atmospheric pressure (1 atm) is preferably employed, but it is also possible to employ reduced pressure, for example from 0.5 to 0.99 atm, or superatmospheric pressure, for example from 1.01 to 2 atm. A pH of from 4 to 8, preferably from 4.5 to 8, can be established as the pH at the beginning of the novel treatment. At the end of the novel treatment, the pH can be reduced by adding an acid, for example fonnic acid, to a pH of from 3 to 5. The novel treatment is generally complete after a time of from 20 minutes to 24 hours, preferably from 30 minutes to 12 hours. If the treatment is earned out repeatedly, the term novel treatment steps is used in the context of the present invention. The amount of the formulation used according to the invention may be from 0.1 to 20, in particular from 0.5 to 15, % by weight, based on the shaved weight of the leathers to be treated or the wet weight of the skins to be treated. During the novel treatment, conventional leather dyes can be added to the liquor. Suitable examples are acidic, substantive or basic aniline dyes, which can be used in amounts customary in tanning. If it is desired to carry out the novel treatment during the retanning, any desired tanning agents customary in the tannery can, for example mineral tanning agents, in particular chrome tanning agents, or polymer tanning agents, syntans, resin tanning agents, vegetable tanning agents or combinations of the abovementioned tanning agents. During the novel treatment, organic solvents, for example alcohols, can be added. However, the procedure is preferably carried out without addition of organic solvents. The novel treatment can be supplemented by an aftertreatment with tanning agents customary in the tannery, for example mineral tanning agents, in particular chrome tanning agents, or with polymer tanning agents, syntans, resin tanning agents, vegetable tanning agents or combinations of the abovementioned tanning agents. After the novel treatment, the leathers obtained or fur skins obtained according to the invention can be worked up in the manner customary in tanning. The present invention furthermore relates to leathers produced by the novel process. Said leathers have very good performance characteristics, for example very good water repellency, very good handle and outstandingly level dyeing. The present invention furthemiore relates to the use of the novel leathers for the production of articles of clothing, for example jackets, coats, shoes and in particular boots. The present invention furthermore relates to the use of the novel leather for the production of pieces of furniture and furniture parts, for example leather sofas, leather armchairs, arm rests for chairs, arm chairs or sofes or benches. The present invention furthermore relates to the use of the novel leathers for the production of automotive parts, for example automobile seats, parts of dashboards and interior trim parts, for example in car doors. The present invention furthermore relates to fur skins treated by the novel process. The present invention furthermore relates to formulations comprising from 1 to 20% by weight, based on the formulation, of a mixture of polysiloxanes, comprising from 10 to 90% by weight, based on the mixture, of one or more carboxyl-containing polysiloxanes, from 90 to 10% by weight, based on the mixture, of one or more carboxyl-free polysiloxanes, and from 3 to 25. preferably from 5 to 20, particularly preferably from 8 to 18, % by weight, based on the formulation, of at least one emulsifier. In an embodiment of the present invention, the novel formulations are formulations wherein the carboxyl-containing polysiloxanes are those polysiloxanes which comprise the structural elements of the formulae I, II and optionally III a and III b. The structural elements of the fomiulae I, II, III a and III b are defined as above. The carboxyl-containing polysiloxanes comprised in the novel formulations may furthermore comprise structural elements of the formulae IV a and IV b. In an embodiment of the present invention, the carboxyl-free polysiloxanes comprised in the novel formulations are those polysiloxanes which generally comprise structural elements of the above-defined formulae I and optionally III a. Ill b and IV a, the variables being defined as above. Preferred carboxyl-free polysiloxanes comprised in the novel formulation are composed of structural elements of the above-defined formulae I comprise and optionally III a, III b and/or IV a. In principle, all compounds which are surface-active in aqueous systems and may be nonionic, anionic, cationic or zwitterionic may be mentioned as emuisifiers in the novel formulations. Particularty suitable emulsifiers are N-acylated amino acid derivatives, for example of the formula V, in which the variables are defined as above. Other suitable emulsifiers are sulfur-containing emulsifiers. In principle, all sulfur-containing compounds which are surface-active in aqueous systems and may be nonionic, anionic, cationic or zwitterionic may be mentioned as sulfur-containing emulsifiers in the formulations according to the invention. Particulariy suitable emulsifiers are sulfur-containing compounds, for example of the fonmula VI, in which the variables are defined as above. In an embodiment of the present invention, the novel formulations are those formulations which comprise from 10 to 70% by weight, based on the formulation, of at least one further hydrophobic compound. In an embodiment of the present invention, further hydrophobic compounds are a combination of at least one natural triglyceride which is solid or liquid at room temperature and a paraffin mixture. The novel fomiulations may have a pH of 7 or more. Preferably, they have a pH of from 7 to not more than 10. The novel formulations can preferably be aqueous formulations having a solids content of up to 50% by weight, based on the total fonmulation. The novel formulations have a very good shelf life. Moreover, the novel formulations are excellent for use in the novel process. The present invention furthermore relates to a process for the preparation of the novel formulations, also refermed to below as novel preparation process. The novel preparation process can be carried out in general by mixing together the components carboxyl-free polysiloxane, carboxyl-containing polysiloxane and one or more emulsifiers and, if required, a hydrophobic compound or hydrophobic compounds. The sequence of the addition of the individual components is not critical. This can be effected, for example, by simple stirring of the components, for example using a mixer or an Ultra-Turrax stirrer. In some cases, further homogenization is effected, for example by means of a slot homogenizer. Novel formulations having a particulariy good shelf life are obtained if further homogenization is carried out The examples which follow illustrate the invention. 1. Preparation of novel formulations 1.1 to 1.4 from carboxyl-containing polysiloxane, carboxyl-free polysiloxane, emulsifier and hydrophobic substances The components mentioned below and shown in table 1 were stinted in a beaker at room temperature. Carboxyl-containing polysiloxane PS 1: all R1 are CH3, A2 is -(CH2)10- and Z1 is a single bond, kinematic viscosity v 500 - 850 mm2/s. determined at room temperature, molecular weight Mn: 10 000 g/mol, on statistical average 127 structural elements I and 2 or 3 structural elements 11 per molecule, structural elements II are randomly distributed. Carboxyl-free polysiloxane PS 2: all R" are CH3, kinematic viscosity v 350 mm^/s, determined at room temperature, molecular weight Mn: 7 500 g/mol. Emulsifier: N-oleylsarcosine as sodium salt, commercially available from BASF Aktiengesellschaft. Natural triglyceride: lipoderm oil, a neatsfoot oil. Synthetic oil: 36/38 paraffin slack wax, commercially available from Shell and from TotalFina. The novel formulations 1.1 to 1.4 and, for comparative experiments, the formulations V 1.5 and V 1.6 were prepared. The composition of the formulations is shown in table 1. For quality control of the emulsions thus obtained, 10 ml were taken and made up to 100 ml with water. Emulsions having a good shelf life fomned overnight. Example 2: Treatment of leather Example 2.1 Treatment of leather with the novel fonnulations 1.1 The following general method was employed. The data in % by weight are based in each case on the shaved weight, unless stated othenvise. In all operations, the barriell was rotated about 10 times per minute, unless stated otherwise. In a rotatable 501 barrel having internals. 100% by weight of water, 3% by weight of sodium formate and 1% by weight of MgO were added to 2.5 kg of chrome-tanned cattle leather (wet blue) having a shaved thickness of 2.5 mm. After 15 minutes, 0.6% by weight of NaHCOs was added and deacidification was effected at 35'C over a period of 150 minutes so that a pH of 4.8 resulted. 3% by weight of the following substance having the following characteristic data were then added to the leather 30% strength by weight aqueous polymer solution partly neutralized with NaOH; homopolymer of methacrylic acid, Mp of about 10 000; Fikentscher K value: 12, viscosity of the 30% strength by weight solution: 65 mPas (DIN EN ISO 3219, 23X), pH5.1. Stirring was carried out for a further 30 minutes. In the first treatment step, 2% by weight of formulation 1.1 was added and dmmming was canied out for a further 30 minutes. 3% by weight of the vegetable tanning agent mimosa extract and 2% by weight of the leather dye Luganil® Black NT, commercially available from BASF Aktiengesellschaft, were then added in the course of 10 minutes. Moreover, 2% by weight of the resin tanning agent Relugan® D, commercially available from BASF Aktiengesellschaft, 3% by weight of the vegetable tanning agent Chestnut® and 3% by weight of the syntan Basyntan SL®, commercially available from BASF Aktiengesellschaft, were added. The treatment was continued over a period of one hour. In the second treatment step, a further 7.5% by weight of formulation 1.1 were added and drumming was continued at a pH of 4.7 for 12 hours. 100% by weight of water at about 70C were then added so that a temperature of SO'^C resulted, and a pH of 3.6 was established by adding formic acid a little at a time over a period of 80 minutes. The liquor was discharged and the leather was washed with twice 200% by weight of water at 40'C. 100% by weight of water was then added to the top and the top dye was canied out at 40'oC with a mixture of 0.2% by weight of Leather Black VM and 0.3% by weight of the leather dye Luganil® Black AS, commercially available from BASF Aktiengesellschaft, and 0.2% by weight of fonnic acid at a pH of 3.6. Thereafter, the liquor was discharged, 100% by weight of water was added and treatment was effected with 3% by weight of chromium(lll) sulfate at a pH of 3.5. Finally, washing was carried out twice with water, drying was effected and working up was effected in a manner customary in tanning. The novel leather 3.1 was obtained. The properties of the leathers obtained are shown in table 2. Example 2.2 Example 1 was repeated except that formulation 1.2 was used in each case instead of 1.1 in the first and in the second treatment step. The novel leather 3.2 was obtained. Example 2.3 Example 1 v^s repeated except that formulation 1.3 was used in each case instead of 1.1 in the first and in the second treatment step. The novel leather 3.3 was obtained. Example 2.4 Example 1 was repeated except that formulation 1.4 was used in each case instead of 1.1 in the first and in the second treatment step. The novel leather 3.4 was obtained. Comparative example V 2.5 Example 1 was repeated except that fomiulation 1.5 was used in each case instead of 1.1 in the first and in the second treatment step. The comparative leather sample V 3.5 was obtained. Comparative example V 2.6 Example 1 was repeated except that formulation 1.6 was used in each case instead of 1.1 in the first and in the second treatment step. The comparative leather sample V 3.6 was obtained. Table 2: Properties of the novel leathers and of the leathers obtained in the comparative experiments The Maeser measurements were carried out using a Maeser tester according to ASTM D 2099, in each case as double determinations. The static water absorption was carried out at 15% compression and stated in % by weight, based on the finished leather. The dyeing was assessed by visual inspection by a team of testers. The evaluations were effected using ratings: 1 (very good) to 6 (inadequate). 4. Preparation of sulfur-containing emulsifiers 4.1. Preparation of the sulfur-containing E 4.1 115 g (0.3 mol) of the branched alcohol of the fonnula VIII. 1 were initially taken, in the absence of moisture, in a 1000 ml three-necked flask equipped with stirrer, internal thermometer and reflux condenser and were heated to 100oC in an oil bath. 29.4 g (0.3 mol) of maleic anhydride were then introduced with stimng, and the mixture thus obtainable was stin-ed for 5 hours at 100X. The monoester thus obtainable was cooled to 40C and stin-ed into 210 ml of water and partially neutralized by adding 17 g (0.21 mol) of 50% by weight aqueous NaOH, and the mixture obtained was heated to 80oC. Thereafter, 28.5 g of sodium disulfite were added with stining, and the mixture was further stirred over a period of 6 hours at 80*C. Cooling to 40oC was then effected. 4.2. Preparation of the sulfur-containing emulsifier E 4.2 The procedure was as above but, instead of 115 g of the branched alcohol VIII.1., 148.9 g (0.3 equivalent, calculated from the OH number) of oxo thick oil 135 were used. 5. Preparation of formulation 5.1 according to the invention using carboxyl-containing polysiloxane, carboxyl-free polysiloxane, sulfur-containing sulfur-containing emulsifier E 4.1 and hydrophobic substances The components according to Table 1 which are mentioned below were stirred in a beaker at room temperature using a mixer. Carboxyl-containing polysiloxane "PS 1": all R1 = CH3. A1: -(CH2)10-. Z1: single bond, kinematic viscosity v in the range 500 - 850 mm^/s, determined at room temperature, molecular weight Mn: 10 000 g/mol, on statistical average 127 structural element I and 2 or 3 stoictural elements II per molecule, structural elements II randomly distributed. Carboxyl-free polysiloxane "PS 2": all R" = CH3, kinematic viscosity v of 350 mm^/s, determined at room temperature, molecular weight Mn: 7500 g/mol. Emulsifier E 4.1. Natural triglyceride: lipoderm oil, a neatsfoot oil. Synthetic oil: slack wax 36/38, commercially available from Shell and from Total-Fina. The mixture thus obtainable was then homogenized with the aid of an SHL 105 gap homogenizer from Brau and Luebbe, a pressure of 150 bar and a temperature of 50X being chosen. Formulation 5.1 according to the invention was obtained. An analogous procedure was adopted for the preparation of formulations 5.2 and 5.3 according to the invention and of comparative formulations V 5.4 and V 5.5 except that in each case compositions according to Table 3 were chosen. The composition of the formulations is shown in Table 3. For quality control of the emulsions thus obtained, in each case 10 ml were taken and made to 100 ml with water. Emulsions which were storage-stable overnight resulted. Table 3 For example 5.6, example 5.1 was repeated, but with 25 g of sulfur-containing emulsifier E 4.2 instead of E 4.1. Example 6: treatment of leather Example 6.1 Treatment of leather with formulation 5.1 according to the invention The following general recipe was followed. The data in % by weight are based in each case on the shaved weight, unless stated otherwise. In all operations, the ban-el was rotated 10 times per minute, unless stated otherwise. In a rotatable 501 barrel having intemals, 100% by weight of water. 3% by weight of sodium formate and 1% by weight of MgO were added to 2.5 kg of chrome-tanned cattle leather (wet blue) having a shaved thickness of 2.5 mm. After 15 minutes, 0.6% by weight of NaHCOs was added and deacidification was effected at 35X over a period of 150 minutes so that a pH of 4.8 resulted. 3% by weight of polymer having the following characteristic data were then added: 30% strength by weight aqueous polymer solution partially neutralized with NaOH; homopolymer of methacrylic acid, Mn about 10 000, Fikentscher K value: 12, viscosity of 30% strength by weight solution: 65 mPas (DIN EN ISO 3219, 23X), pH 5.1. Tanning was carried out for a further 30 minutes. In the first treatment step, 10% by weight of formulation 5.1 was added and drumming was canied out for a further 30 minutes. 3% by weight of the vegetable tanning agent mimosa extract and 2% by weight of the leather tanning agent Luganil® Black NT, commercially available from BASF Aktiengesellschaft, were then added in the course of 10 minutes. Moreover, 2% by weight of the resin tanning agent ReluganCg) D. commercially available from BASF Aktiengesellschaft, 3% by weight of the vegetable tanning agent Chestnut® and 3% by weight of the sulfone tanning agent from EP-B 0 459 168, example K1, were added. The treatment was continued over a period of one hour. In the second treatment step a further 7.5% by weight of formulation 5.1 were added and drumming was continued at a pH of 4.7 for 12 hours. 100% by weight of water at about 70^ were then added so that a temperature of 50*C resulted, and a pH of 3.6 was established by adding formic acid a little at a time over a period of 80 minutes. The liquor was discharged and the leather was washed twice with 200% by weight of water at 40'C. 100% by weight of water was then added to the top and the top dyeing was carried out at 40'C with a mixture of 0.2% by weight of Leather Black VM and 0.3% by weight of the leather dye Luganil® Black AS, commercially available from BASF Aktiengesellschaft, and 0.2% by weight of formic acid at a pH of 3.6. Thereafter, the liquor was discharged, 100% by weight of water was added and treatment was effected with 3% by weight of chromium(lll) sulfate at a pH of 3.5. Finally, washing was canied out twice with water, drying was effected and working up was effected in a manner customary in tanning. The leather 6.1 according to the invention was obtained. The properties of the leathers obtained are shown in Table 4. Examples 6.2 and 6.5 and comparative examples V 6.3 and V 6.4 Example 6.1 was repeated, except that formulations 5.2 and 5.3, V 5.4 and 5.5 were used in each case instead of 5.1 in the first and in the second treatment step. Leathers 6.2 and 6.3 and comparative leather samples V 6.4 and V 6.5 were obtained. Table 4: Properties of the leathers according to the invention and of the comparative leather samples obtained in the comparative experiments We claim:- 1. A process for imparting water repellency to leather and fur skins, wherein leather or fur skin is treated, before, during or after the retanning, with one or more formulations comprising from 1 to 30% by weight, based on the formulation, of a mixture of polysiloxanes comprising from 10 to 90% by weight, based on the mixture, of one or more carboxyl-containing polysiloxanes, from 90 to 10% by weight, based on the mixture, of one or more carboxyl-free polysiloxanes, and from 3 to 25% by weight, based on the formulation, of at least one emulsifier. 2. A process according to claim 1, wherein the carboxyl-containing polysiloxanes are polysiloxanes which comprise structural elements of the formulae I, II and optionally III a and III b where the variables are defined as follows: R1 are identical or different and, independently of one another, are hydrogen, hydroxy!, C1-C14alkyl, C6-C14-aryl, C1-C4-alkoxy, amino, mono-C1-C4-alkylamino, di-CrC4-alkylamino or Z1-A1-COOH; A1 are identical or different and are linear or branched C5-C25-alkylene and Z1 is a direct bond, oxygen or an amino, carbonyl, amido or ester group. 3. A process according to claim 1 or 2, wherein the formulation comprises from 10 to 70% by weight, based on the formulation, of at least one further hydrophobic compound. 4. A process according to any of the preceding claims, wherein at least one emulsifier is an N-acylated amino acid. 5. A process according to any of claims 1 to 3, wherein at least one emulsifier is a sulfur-containing emulsifier. 6. A process according to claim 5, wherein at least one sulfur-containing emulsifier comprises one or more compounds of the general formula VI where the variables are defined as follows R6 and R7 are identical or different and are selected from hydrogen, C1-C30-alkyl and C6-C14-aryl, R8 is CrC4-alkyl or hydrogen. 7. A process according to any of the preceding claims, wherein the further hydrophobic compound is a combination of at least one natural triglyceride solid or liquid at room temperature and a paraffin mixture. 8. A process according to any of the preceding claims, wherein the treatment is carried out at a pH of from 4 to 9. 9. A process according to any of the preceding claims, wherein the treatment is carried out at from 20 to 65°C. 10. A leather produced by a process according to any of claims 1 to 9. 11. The use of a leather according to claim 10 for the production of articles of clothing, pieces of furniture or automotive parts. 12. A fur skin produced according to any of claims 1 to 9. 13. A formulation comprising from 1 to 20% by weight, based on the formulation, of a mixture of polysildxanes comprising from 10 to 90% by weight, based on the mixture, of one or more carboxyl- containing polysiioxanes, from 90 to 10% by weight, based on the mixture, of one or more carboxyl-free polysiioxanes, and from 3 to 25% by weight, based on the formulation, of at least one emulsifier. 14. A formulation according to claim 12, wherein the carboxyl-containing polysiioxanes are polysiioxanes which comprise structural elements of the formulae i, II and optionally III a and III b. 15. A formulation according to claim 13 or 14, which comprises from 10 to 70% by weight based on the formulation, of at least one further hydrophobic compound. 16. A formulation according to any of claims 13 to 15, wherein further hydrophobic compounds are a combination of at least one natural triglyceride solid or liquid at room temperature and a paraffin mixture. 17. A process for the preparation of a formulation according to any of claims 13 to 16 by mixing the components carboxyl-free polysiloxane, carboxyl-containing polysiloxane and one or more emulsifiers.

Full Text

Imparting water repellency to leather and For SKins
The present invention relates to a process for imparting water repeilency to leather and fur skins, wherein leather or fur skin is treated, before, during or after the retanning, with one or more formulations comprising from 1 to 30% by weight, based on the fomiulation, of a mixture of polysiloxanes comprising
from 10 to 90% by weight, based on the mixture, of one or more carboxyl-containing polysiloxanes,
from 90 to 10% by weight, based on the mixture, of one or more carboxyl-free polysiloxanes
and from 3 to 25% by weight, based on the formulation, of at least one emulsifier.
EP 0 213 480 B discloses a process for imparting water repeilency to leather and fur skins, in which an aqueous emulsion of a silicone oil or an anhydrous mixture of a silicone oil and an alkanolamine salt of an amino acid is allowed to act on leather or skins before, during or after the retanning. Examples of polysiloxanes are: dimethylpolysiloxane in which 3% of the methyl groups have been replaced by mercaptopropyl (examples 1 to 7), dimethylpolysiloxane having a viscosity from 80 to 110 mPas, phenylmethylpolysiloxanes having a viscosity from 85 to 120 mPas and dimethylpolysiloxanes having on average from 2 to 10 carboxyl groups per molecule. The performance characteristics of such water repellent formulations can however still be improved. Furthermore, the leathers produced with the aid of the polysiloxanes disclosed can in some cases also be improved with regard to performance characteristics,
WO 95/22627 discloses a process for imparting water repeilency to leather and fur skins using carboxyl-containing polysiloxanes in aqueous emulsion, in which polysiloxanes which are branched in a comb-like manner and may have the formula A are used:
COOH
I
A I
The structural units may, for example, be randomly distributed. The variables are defined as follows:

R are identical or different and, independently of one another, are hydrogen, hydroxy!,
C1-C4-alkyl, phenyl, CrC4-alkoxy, amino, mono- or di-C1-C4-amino, chlorine or fluorine,
it also being possible in each case for a radical R to be the group Z-A-COOH at the
chain ends;
A is a linear or branched C5-C25-alkylene group and
Z is a direct bond, an oxygen atom or an amino, carbonyl, amido or ester group.
On average, preferably from 2.5 to 15 carboxyl groups are present per molecule (page 4, line 17).
Leather and fur skin treated with the aid of such comb-like polysiloxanes generally have very good water repellency.
WO 98/04748 discloses a process for retanning leathers produced using polymeric tanning agents and, if required, aldehyde tanning agents, which leathers are treated with polymer tanning agents and with comb-like polysiloxanes of the fomriula A defined above.
EP-A1 087 021 discloses that leather treatment compositions comprising a combination of polysiloxanes substituted by carboxyl or carboxyiic anhydride groups at the α,-position, the carboxyl groups of the polysiloxane being present in neutralized form, with certain amphiphilic polymers, an emulsifier and an oil or wax are suitable as leather treatment compositions. With the aid of the combination products disclosed, full and soft leathers which were readily washable were produced.
However, it is observed that leather and fur skin obtained according to the publications cited above have in many cases a dyeing with an undesirably low degree of levelness. Moreover, the high price of the polysiloxanes branched in a comb-like manner is to be regarded as disadvantageous.
It is an object of the present invention to provide a process for the production of leather and fur skins which does not have the abovementioned disadvantages. It is furthermore an object of the present invention to provide leather having advantageous performance characteristics.
It is moreover an object of the present invention to provide novel formulations having advantageous performance characteristics.
We have found that this object is achieved by the process defined at the outset. According to the invention, leather is treated with a formulation before, during or after the retanning.

At least one formulation used in the novel process comprises from 1 to 30, preferably from 5 to 20, particularly preferably from 7 to 12.5, % by weight, based on the weight of the formulation, of a mixture of two or more polysiloxanes.
From 10 to 90% by weight, based on the mixture, of the polysiloxanes comprised in at least one formulation are carboxyl-containing polysiloxanes.
In an embodiment, carboxyl-containing polysiloxanes are those which contain the structural elements of the formulae I and II and optionally structural elements III a and/or III b.
The structural elements defined above are each arranged in such a way that Si-O-Si-0 chains are formed. Formation of Si-Si groups is theoretically possible but plays a minor role in most cases.
In the formulae I, II, III a and III b, the variables are defined as follows:
R"* are identical or different and, independently of one another, are
hydrogen,
hydroxyl,
Ci-C4-alkyl, such as methyl, ethyl, n-propyl, isopropyl. n-butyl, isobutyl, sec-butyl and
tert-butyl; in particular methyl;
C6-Ci4-aryl, for example phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl. 2-anthryl. 9-anthryl,
1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl and 9-phenanthryl,
preferably phenyl, 1-naphthyl and 2-naphthyl, particularly preferably phenyl;
C1-C4-alkoxy, such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy,
sec-butoxy and tert-butoxy;
amino,
mono-C1-C4-alkylamino, for example -NHCH3. -NHC2H5. -NH(CH2)2CH3,
-NH(CH2)3CH3. -NH.CH(CH3)2. NHC(CH3)3;
dl-C1-C4-alkylamino. -N(CH3)2. -N(C2H5)2. -N(CH3)(C2H5). -N[(CH2)2CH3]2,
-N(CH3)CH(CH3)2. or Z1-A1-COOH.
In a preferred embodiment of the present invention, all R1 are identical and are each
methyl.
In another preferred embodiment, the structural elements I are identical in each case,
in I in each case one R1 being methyl and the other R1 being phenyl.

In an embodiment of the present invention, the structural elements of the fomiula III a are selected from the following groups: Si(CH3)3, Si(CH3)2C6H5, Si(CH3)20H, Si(CH3)C6H50H.
A' are identical or different and are linear or branched C5-C25-alkylene, unsubstituted or
substituted by one or more C1-C4-alkyl or phenyl, for example
.(CH2)5.. -(CH2)6-. -(CH2)r, -(CH2)8-. -(CHzV. -(CH2)io-, -(CH2)ir. -(082)12-. -(CH2)i3-. -(CH2)i4-.
-CH(CH3)-CH2-CH2-CH2-CH(CH3)-,-C(CH3)2-CH2-CH2-CH2-CH(CH3)-;
-CH(C6H5)-CH2-CH2-CH2-CH(CH3)-; preferably -(CH2)8-. -(082)9-, -(CH2)io-, -(CH2)ir,
-(CH2)irI
it being possible for C5-C25-alkylene to be interrupted by 1 to 8 oxygen atoms not
directly bonded to one another.
Z1 is
a direct bond,
oxygen
an amino group of the formula -NR2-
a carbonyl group,
an amido group of the formula -NR^-CO- or -CO-NR^- or
an ester group of the formula CO-0 or 0-CO;
R2 are identical or different and, independently of one another, are selected from
hydrogen,
C1-C4-alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and
tert-butyl.
Polysiloxanes which comprise the structural elements of the formulae I, II and optionally Ilia and/or III b may be linear or have a cyclic or branched structure. Branched polysiloxanes which comprise the structural elements I, II and optionally III a and/or III b generally additionally comprise structural elements, for example of the formula IV a or IV b

in which the variables are defined as above. Cyclic straight-chain polysiloxanes which comprise the structural elements of the formula I or II usually comprise no structural elements of the formulae III a and III b.
The structural elements 1,11 and optionally IV a and IV b can be distributed alternately, biockwise and preferably randomly in carboxyl-containing polysiloxane molecules.
In an embodiment of the present invention, carboxyl-comprising polysiloxanes contain from 1 to 50, preferably from 2 to 25, particulariy preferably from 2.5 to 15, carboxyl groups per molecule.
Usually, the molecular weight Mw of the carboxyl-containing polysiloxanes used according to the invention and having the structural elements I, II, optionally III a. III b, IV a and IV b is from 5 000 to 150 000, preferably from 10 000 to 100 000, g/mol.
The molecular weight determination can be carried out by methods known to a person skilled in the art, for example by light scattering methods or viscosity determinations.
In an embodiment of the present invention, all or at least a certain proportion, for example a third or a half, of the carboxyl groups in the carboxyl-containing polysiloxanes are neutralized. For example, basic salts, such as hydroxides or carbonates of the alkali metals, for example Na or K, are suitable for the neutralization. Ammonia, alkylamines, such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine and ethylenediamine, and alkanolamines, such as ethanolamine, diethanolamine, triethanolamine. N-methylethanolamine, N-methyl-diethanolamine or N-(n-butyl)diethanolamine, are furthermore suitable.
The mixtures used according to the invention comprise, for example, from 10 to 90, preferably from 40 to 60, particulariy preferably about 50. % by weight, of carboxyl-containing polysiloxane.
The mixtures used according to the invention furthermore comprise polysiloxanes which comprise no carboxyl groups. Such polysiloxanes generally comprise structural units of the above-defined formulae I. optionally III a. Ill b and IV a, the variables being defined as above, but R1 is not Z1-A1-COOH. Carboxyl-free polysiloxanes used according to the invention are preferably composed of structural elements of the above-defined formulae I, optionally III a. III b and IV a.
Particulariy preferably used carboxyl-free polysiloxanes are poly(dimethyl)siloxanes

Carboxyl-free polysiloxanes which comprise the structural elements of the fomnulae I and optionally III a, ill b and IV a may have a linear or cyclic or branched structure. Branched carboxyl-free polysiloxanes which comprise the structural elements I and optionally III a and/or III b generally additionally comprise structural elements, for example of the formula IV a. Cyclic straight-chain carboxyl-free polysiloxanes which comprise the structural elements of the formula I usually comprise no structural elements of the formulae III a and III b.
In a preferred embodiment of the present invention, all R1 in carboxyl-free polysiloxanes are identical and are each methyl.
In another preferred embodiment, the structural elements I in carboxyl-free polysiloxanes are in each case identical, in I in each case one R1 being methyl and the other R1 being phenyl.
In an embodiment of the present invention, the structural elements of the formula III a in carboxyl-free polysiloxanes are selected from the following groups: Si(CH3)3. Si(CH3)2C6H5. Si(CH3)20H. Si(CH3)C6H50H.
Usually, the molecular weight Mw of the carboxyl-free polysiloxanes used according to the invention and having the structural elements 1,11, optionally III a. Ill b and IV a is from 500 to 150 000, preferably up to 10 000, g/mol.
In a preferred embodiment of the present invention, carboxyl-containing and carboxyl-free polysiloxanes are chosen so that the molecular weight of the carboxyl-containing polysiloxane is higher than the molecular weight of the carboxyl-free polysiloxane.
The mixtures used according to the invention comprise, for example, from 10 to 90, preferably from 40 to 60, particulariy preferably about 50, % by weight of carboxyl-free polysiloxane.
The formulations used according to the invention comprise one or more emulsifiers. For example, from 3 to 25, preferably from 5 to 20, particulariy preferably from 8 to 18, % by weight, based on the formulation, of one or more emulsifiers are.
In principle, all compounds which are surface-active in aqueous systems and may be nonionic, anionic, cationic or zwitterionic can be used as emulsifiers.

Particularly suitable emulsifiers are N-acylated amino acid derivatives, for example of the formula V

in which the variables are defined as follows:
R1 is hydrogen,
C1-C4-alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl, in particular methyl;
C6-C14-aryl, for example phenyl, 1-naphthyl. 2-naphthyl, 1-anthryl. 2-anthryl, 9-anthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl. 4-phenanthryl and 9-phenanthryl, preferably phenyl, 1-naphthyl and 2-naphthyl, particulariy preferably phenyl;
R1 is C1-C4-alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl; in particular methyl;
The group CO-R1 is usually derived from saturated or unsaturated fatty acids. Saturated fatty acids are to be understood as meaning carboxylic acids which have Cg-C2o-alkyl and may be linear or branched, substituted or unsubstituted. R1 may be, for example, n-nonyl, n-decyl, n-dodecyl, n-tetradecyl, n-pentadecyl, n-octadecyl or n-eicosyl.
CO-R® may be derived from an unsaturated fatty acid of 9 to 20 carbon atoms and one having up to 5 C-C double bonds, it being possible for the C-C double bonds to be, for example, isolated or allylic, for example the acyl radical of linoleic acid, of linolenic acid and very particulariy preferably of oleic acid.
In an embodiment of the present invention, all or at least a certain proportion, for example a third or a half, of the carboxyl groups are neutralized in N-acylated amino acid derivatives used as emulsifiers. For example, basic salts such as hydroxides or carbonates of the alkali metals, for example, Na or K, are suitable for neutralization. Ammonia, alkylamines, such as methylamine, dimethylamine. trimethylamine, ethyl-amine, diethylamine, triethylamine and ethylenediamine, and particularly preferably alkanolamines, such as ethanolamine, diethanolamine, triethanolamine, N-methyl-ethanolamine, N-methyldiethanolamine or N-(n-butyl)diethanolamine, are furthermore

suitable for the neutralization.
Typical examples of compounds of the fomnula V are N-oleylsarcosine, N-stearyl-sarcosine, N*lauroylsarcosine and N-isononanoylsarcosine and the respective ethanolammonium salts, diethanolammonium salts and N-methyldiethanolammonium salts.
In an embodiment of the present invention, sulfur-containing emulsifier is used.
Sulfur-containing emulsifiers which may be used are in principle all sulfur-containing compounds which are surface-active in aqueous systems and may be nonionic, anionic, cationic or zwitterionic.
Particularly suitable compounds are those of the formula VI

in which the variables are defined as follows:
R1 and R1 are identical or preferably different and are selected from hydrogen,
C1-Cao-alkyl. branched or straight-chain, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl. sec-pentyl, neopentyl. 1,2-dimethylpropyl. isoamyl. n-hexyl, isohexyl. sec-hexyl. n-heptyl. isoheptyl, n-octyl, n-nonyl. n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetra-decyl, n-hexadecyl, n-octadecyl and n-eicosyl, preferably p-branched radicals of the fomiula VI a

(CH2CH20)x-O-R or [CH(CH3)CH20)x-O-R, where x is an integer in the range from 1 to 20,
C6-C14-aryl. for example phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl,

9-anthryl, 1-phenanthryl, 2-phenanthryl. 3-phenanthryl, 4-phenanthryl and 9-phenanthryl. preferably phenyl, 1-naphthyl and 2-naphthyl, particularly preferably phenyl;
R® is selected from C1-C4-alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl,
isobutyl, sec-butyl and tert-butyl and in particular hydrogen;
R® and R1° are identical or preferably different and are selected from C1-C27-alkyl, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, sec-pentyl, neopentyl, 1,2-dimethylpropyl. isoamyl, n-hexyl, isohexyl, sec-hexyl, n-heptyl. isoheptyl. n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl. n-tridecyl. n-tetradecyl, n-hexadecyl, n-octadecyl, n-eicosyl;
the sum of the carbon atoms of R1 and R"'° being not more than 30.
R1 preferably has two carbon atoms more than R1°; for example, the
combinations
R® = n-undecyl and R1° = n-nonyl.
R® = n-dodecyl and R1° = n-decyl.
R® = n-tridecyl and R1° = n-undecyl.
R® = n-tetradecyl and R1° = n-dodecyl.
R® = n-pentadecyl and R'° = n-tridecyl,
are preferred,
R""** is selected from C1-C4-alkyl such as methyl, ethyl, n-propyl. isopropyl. n-butyl. isobutyl. sec-butyl, tert-butyl. phenyl, ortho-tolyl, meta-tolyl and para-tolyl and in particular hydrogen.
In a prefen-ed embodiment of the present invention, exactly one of the radicals R1 and R1 is hydrogen and the other radical is selected from C1-C20-alkyl.
In a particularly preferred embodiment of the present invention, a mixture of a plurality of sulfur-containing compounds is chosen, for example of the formula VI, \Arhich may differ, for example, in that, in the first compound of the formula VI, R® is hydrogen and R1 is selected from C1-C20-alkyI and. in the second one. R® is hydrogen and R1 is selected from C1-C20-alkyl.

In an embodiment of the present invention, all or at least a certain proportion, for example a third or a half, of the sulfonyl groups in sulfur-containing compounds used as emulsifiers are neutralized. For example, basic salts, such as hydroxides or carbonates, of the alkali metals, such as, for example. Na or K, are suitable for the neutralization. Ammonia, alkylamines, such as, for example, methylamine, dimethyl-amine, trimethylamine, ethylamine, diethylamine, triethylamine or ethylenediamine, and very particularly alkanolamines, such as, for example, ethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N-methyldiethanolamine or N-(n-butyl)-diethanolamine, are furthemiore suitable for the neutralization.
The preparation of compounds of the formula VI is known per se and is described in WO 01/68584. It is effected, for example, by mono- or diesterification of dicarboxylic anhydrides of the general fonnula VII

with corresponding alcohols, which need not be present in pure form, followed by a reaction with disulfite.
Instead of pure sulfur-containing compounds, for example sulfur-containing compounds of the formula V, it is possible to use mixtures of different sulfur-containing compounds. For example, it is possible to use, for the esterification, the mixture known as oxo oil 135 or 0X0 thick oil 135 (WO 01/68584).
In an embodiment of the present invention, formulations used in the process according to the invention may comprise up to 40% by weight, preferably up to 20% by weight, based on the fonnulation, of at least one alcohol of the fomiula VIII

where, in formula VIII, the variables R1 and R1° are defined as above.
In an embodiment of the present invention, formulations used in the process according to the invention may comprise up to 50% by weight, preferably up to 30% by weight,

based on the formulation, of at least one compound of the formula VIII.
In a preferred embodiment of the present invention, formulations used in the process according to the invention may comprise up to 40% by weight, particularly preferably up to 20% by weight, of mixtures which comprise at least one alcohol of the general formula VIII; oxo oil 135 and oxo oil 13 may be mentioned by way of example of such mixtures.
The formulation or the formulations used according to the invention is or are preferably aqueous.
In an embodiment of the present invention, at least one formulation used according to the invention comprises at least one further hydrophobic compound. At least one further hydrophobic compound is a carbon-based compound, for example natural or synthetic wax, natural or synthetic oil or natural or synthetic fat.
Examples of natural waxes are beeswax, cork wax, montan waxes and Camauba wax.
Examples of synthetic waxes are polyethylene waxes or ethylene copolymer waxes, as obtainable, for example, by free radical polymerization of ethylene or free radical copolymerization of ethylene with, for example, (meth)acrylic acid or by Ziegler-Natta catalysis. Polyisobutylene waxes may furthermore be mentioned. Paraffin mixtures may also be mentioned; these are to be understood as meaning mixtures of hydrocarbons which have 12 or more carbon atoms and usually have a melting point of from 25 to 45'*C. Such paraffin mixtures can be obtained, for example, in refineries or crackers and are known to a person skilled in the art as paraffin slack wax and sasol waxes. Montan ester waxes are a further example of synthetic waxes.
Examples of natural oils are triglycerides which are liquid at room temperature, for example fish oil, neatsfoot oil, olive oil, cotton seed oil, castor oil, sunflower oil and peanut oil.
Examples of synthetic oils are white oil, liquid paraffin, functionalized parafTins, such as chlorinated or sulfochlorinated paraffins, and polyalkylene glycols, such as polyethylene glycol.
Examples of natural fats are natural triglycerides which are solid at room temperature, such as lanolin, shellac wax and mixtures thereof.
In a prefen"ed embodiment of the present invention, the further hydrophobic compound

is at least one natural triglyceride.
In a further preferred embodiment, a combination of at least one natural triglyceride which is solid or liquid at room temperature and a paraffin mixture having a melting point of from 25 to 40oC is used. The ratio is not critical per se, and weight ratios of natural triglyceride to paraffin mixture of from 10 :1 to 1 :10 are suitable.
According to the invention, from about 10 to 70, preferably from 20 to 40, % by weight, based on the formulation, of one or more further hydrophobic compounds can be used.
For canying out the novel process, leather or fur skin is treated in a liquor, before, during or after the retanning, with the formulations used according to the invention. The novel treatment can be carried out once or repeatedly. The leathers to be treated may have been produced by any desired method, for example by mineral tanning, in particular chrome tanning, or by polymer tanning, tanning v^th syntans, resin tanning, tanning with vegetable tanning agents or tanning with combinations of the abovementioned tanning agents.
In an embodiment of the novel process, at least one novel formulation is added in one or more portions to the leather to be treated or to the skins to be treated. This addition can be effected in an aqueous liquor. Preferably, the liquor length may be from 50 to 2 000, preferably from 100 to 400, % by weight, based on the shaved weight of the leathers or the wet weight of the fur skin.
In an embodiment of the novel process, the components carboxyl-containing polysiloxane, carboxyl-free polysiloxane and emulsifier are added separately to the leather and/or leather and liquor and the novel formulation is prepared in situ.
The novel process is carried out in general by drumming the leather to be treated or the fur skin to be treated in suitable vessels, for example in barrels, in particular in rotatable barrels having intemals. Other methods known to a person skilled in the art are also possible for thorough mixing.
Temperatures of from 20 to 65'oC, preferably from 30 to 60oC, can be chosen as the temperature for the novel process.
The pressure conditions of the novel process are in general not critical. Atmospheric pressure (1 atm) is preferably employed, but it is also possible to employ reduced pressure, for example from 0.5 to 0.99 atm, or superatmospheric pressure, for example from 1.01 to 2 atm.

A pH of from 4 to 8, preferably from 4.5 to 8, can be established as the pH at the beginning of the novel treatment. At the end of the novel treatment, the pH can be reduced by adding an acid, for example fonnic acid, to a pH of from 3 to 5.
The novel treatment is generally complete after a time of from 20 minutes to 24 hours, preferably from 30 minutes to 12 hours. If the treatment is earned out repeatedly, the term novel treatment steps is used in the context of the present invention.
The amount of the formulation used according to the invention may be from 0.1 to 20, in particular from 0.5 to 15, % by weight, based on the shaved weight of the leathers to be treated or the wet weight of the skins to be treated.
During the novel treatment, conventional leather dyes can be added to the liquor. Suitable examples are acidic, substantive or basic aniline dyes, which can be used in amounts customary in tanning.
If it is desired to carry out the novel treatment during the retanning, any desired tanning agents customary in the tannery can, for example mineral tanning agents, in particular chrome tanning agents, or polymer tanning agents, syntans, resin tanning agents, vegetable tanning agents or combinations of the abovementioned tanning agents.
During the novel treatment, organic solvents, for example alcohols, can be added. However, the procedure is preferably carried out without addition of organic solvents.
The novel treatment can be supplemented by an aftertreatment with tanning agents customary in the tannery, for example mineral tanning agents, in particular chrome tanning agents, or with polymer tanning agents, syntans, resin tanning agents, vegetable tanning agents or combinations of the abovementioned tanning agents.
After the novel treatment, the leathers obtained or fur skins obtained according to the invention can be worked up in the manner customary in tanning.
The present invention furthermore relates to leathers produced by the novel process. Said leathers have very good performance characteristics, for example very good water repellency, very good handle and outstandingly level dyeing.
The present invention furthemiore relates to the use of the novel leathers for the production of articles of clothing, for example jackets, coats, shoes and in particular boots. The present invention furthermore relates to the use of the novel leather for the

production of pieces of furniture and furniture parts, for example leather sofas, leather armchairs, arm rests for chairs, arm chairs or sofes or benches. The present invention furthermore relates to the use of the novel leathers for the production of automotive parts, for example automobile seats, parts of dashboards and interior trim parts, for example in car doors.
The present invention furthermore relates to fur skins treated by the novel process.
The present invention furthermore relates to formulations comprising
from 1 to 20% by weight, based on the formulation, of a mixture of polysiloxanes, comprising
from 10 to 90% by weight, based on the mixture, of one or more carboxyl-containing
polysiloxanes,
from 90 to 10% by weight, based on the mixture, of one or more carboxyl-free
polysiloxanes,
and from 3 to 25. preferably from 5 to 20, particularly preferably from 8 to 18, % by weight, based on the formulation, of at least one emulsifier.
In an embodiment of the present invention, the novel formulations are formulations wherein the carboxyl-containing polysiloxanes are those polysiloxanes which comprise the structural elements of the formulae I, II and optionally III a and III b.
The structural elements of the fomiulae I, II, III a and III b are defined as above.
The carboxyl-containing polysiloxanes comprised in the novel formulations may furthermore comprise structural elements of the formulae IV a and IV b.
In an embodiment of the present invention, the carboxyl-free polysiloxanes comprised in the novel formulations are those polysiloxanes which generally comprise structural elements of the above-defined formulae I and optionally III a. Ill b and IV a, the variables being defined as above. Preferred carboxyl-free polysiloxanes comprised in the novel formulation are composed of structural elements of the above-defined formulae I comprise and optionally III a, III b and/or IV a.
In principle, all compounds which are surface-active in aqueous systems and may be nonionic, anionic, cationic or zwitterionic may be mentioned as emuisifiers in the novel formulations.

Particularty suitable emulsifiers are N-acylated amino acid derivatives, for example of the formula V, in which the variables are defined as above.
Other suitable emulsifiers are sulfur-containing emulsifiers.
In principle, all sulfur-containing compounds which are surface-active in aqueous systems and may be nonionic, anionic, cationic or zwitterionic may be mentioned as sulfur-containing emulsifiers in the formulations according to the invention.
Particulariy suitable emulsifiers are sulfur-containing compounds, for example of the fonmula VI, in which the variables are defined as above.
In an embodiment of the present invention, the novel formulations are those formulations which comprise from 10 to 70% by weight, based on the formulation, of at least one further hydrophobic compound.
In an embodiment of the present invention, further hydrophobic compounds are a combination of at least one natural triglyceride which is solid or liquid at room temperature and a paraffin mixture.
The novel fomiulations may have a pH of 7 or more. Preferably, they have a pH of from 7 to not more than 10.
The novel formulations can preferably be aqueous formulations having a solids content of up to 50% by weight, based on the total fonmulation.
The novel formulations have a very good shelf life. Moreover, the novel formulations are excellent for use in the novel process.
The present invention furthermore relates to a process for the preparation of the novel formulations, also refermed to below as novel preparation process. The novel preparation process can be carried out in general by mixing together the components carboxyl-free polysiloxane, carboxyl-containing polysiloxane and one or more emulsifiers and, if required, a hydrophobic compound or hydrophobic compounds. The sequence of the addition of the individual components is not critical. This can be effected, for example, by simple stirring of the components, for example using a mixer or an Ultra-Turrax stirrer. In some cases, further homogenization is effected, for example by means of a slot homogenizer. Novel formulations having a particulariy good shelf life are obtained if further homogenization is carried out

The examples which follow illustrate the invention.
1. Preparation of novel formulations 1.1 to 1.4 from carboxyl-containing
polysiloxane, carboxyl-free polysiloxane, emulsifier and hydrophobic substances
The components mentioned below and shown in table 1 were stinted in a beaker at room temperature.
Carboxyl-containing polysiloxane PS 1: all R1 are CH3, A2 is -(CH2)10- and Z1 is a single bond, kinematic viscosity v 500 - 850 mm2/s. determined at room temperature, molecular weight Mn: 10 000 g/mol, on statistical average 127 structural elements I and 2 or 3 structural elements 11 per molecule, structural elements II are randomly distributed.
Carboxyl-free polysiloxane PS 2: all R"* are CH3, kinematic viscosity v 350 mm^/s, determined at room temperature, molecular weight Mn: 7 500 g/mol.
Emulsifier: N-oleylsarcosine as sodium salt, commercially available from BASF Aktiengesellschaft.
Natural triglyceride: lipoderm oil, a neatsfoot oil.
Synthetic oil: 36/38 paraffin slack wax, commercially available from Shell and from TotalFina.
The novel formulations 1.1 to 1.4 and, for comparative experiments, the formulations V 1.5 and V 1.6 were prepared. The composition of the formulations is shown in table 1.
For quality control of the emulsions thus obtained, 10 ml were taken and made up to 100 ml with water. Emulsions having a good shelf life fomned overnight.

Example 2: Treatment of leather
Example 2.1 Treatment of leather with the novel fonnulations 1.1
The following general method was employed.
The data in % by weight are based in each case on the shaved weight, unless stated othenvise. In all operations, the barriell was rotated about 10 times per minute, unless stated otherwise.
In a rotatable 501 barrel having internals. 100% by weight of water, 3% by weight of sodium formate and 1% by weight of MgO were added to 2.5 kg of chrome-tanned cattle leather (wet blue) having a shaved thickness of 2.5 mm. After 15 minutes, 0.6% by weight of NaHCOs was added and deacidification was effected at 35'C over a period of 150 minutes so that a pH of 4.8 resulted.
3% by weight of the following substance having the following characteristic data were
then added to the leather
30% strength by weight aqueous polymer solution partly neutralized with NaOH;
homopolymer of methacrylic acid, Mp of about 10 000; Fikentscher K value: 12,
viscosity of the 30% strength by weight solution: 65 mPas (DIN EN ISO 3219, 23X),
pH5.1.
Stirring was carried out for a further 30 minutes.
In the first treatment step, 2% by weight of formulation 1.1 was added and dmmming was canied out for a further 30 minutes. 3% by weight of the vegetable tanning agent mimosa extract and 2% by weight of the leather dye Luganil® Black NT, commercially available from BASF Aktiengesellschaft, were then added in the course of 10 minutes. Moreover, 2% by weight of the resin tanning agent Relugan® D, commercially available

from BASF Aktiengesellschaft, 3% by weight of the vegetable tanning agent Chestnut® and 3% by weight of the syntan Basyntan SL®, commercially available from BASF Aktiengesellschaft, were added. The treatment was continued over a period of one hour.
In the second treatment step, a further 7.5% by weight of formulation 1.1 were added and drumming was continued at a pH of 4.7 for 12 hours.
100% by weight of water at about 70**C were then added so that a temperature of SO'^C resulted, and a pH of 3.6 was established by adding formic acid a little at a time over a period of 80 minutes.
The liquor was discharged and the leather was washed with twice 200% by weight of water at 40'C. 100% by weight of water was then added to the top and the top dye was canied out at 40'oC with a mixture of 0.2% by weight of Leather Black VM and 0.3% by weight of the leather dye Luganil® Black AS, commercially available from BASF Aktiengesellschaft, and 0.2% by weight of fonnic acid at a pH of 3.6. Thereafter, the liquor was discharged, 100% by weight of water was added and treatment was effected with 3% by weight of chromium(lll) sulfate at a pH of 3.5.
Finally, washing was carried out twice with water, drying was effected and working up was effected in a manner customary in tanning. The novel leather 3.1 was obtained.
The properties of the leathers obtained are shown in table 2.
Example 2.2
Example 1 was repeated except that formulation 1.2 was used in each case instead of 1.1 in the first and in the second treatment step. The novel leather 3.2 was obtained.
Example 2.3
Example 1 v^s repeated except that formulation 1.3 was used in each case instead of 1.1 in the first and in the second treatment step. The novel leather 3.3 was obtained.
Example 2.4
Example 1 was repeated except that formulation 1.4 was used in each case instead of 1.1 in the first and in the second treatment step. The novel leather 3.4 was obtained.

Comparative example V 2.5
Example 1 was repeated except that fomiulation 1.5 was used in each case instead of 1.1 in the first and in the second treatment step. The comparative leather sample V 3.5 was obtained.
Comparative example V 2.6
Example 1 was repeated except that formulation 1.6 was used in each case instead of 1.1 in the first and in the second treatment step. The comparative leather sample V 3.6 was obtained.
Table 2: Properties of the novel leathers and of the leathers obtained in the comparative experiments

The Maeser measurements were carried out using a Maeser tester according to ASTM D 2099, in each case as double determinations. The static water absorption was carried out at 15% compression and stated in % by weight, based on the finished leather. The dyeing was assessed by visual inspection by a team of testers. The evaluations were effected using ratings: 1 (very good) to 6 (inadequate).
4. Preparation of sulfur-containing emulsifiers
4.1. Preparation of the sulfur-containing E 4.1
115 g (0.3 mol) of the branched alcohol of the fonnula VIII. 1

were initially taken, in the absence of moisture, in a 1000 ml three-necked flask equipped with stirrer, internal thermometer and reflux condenser and were heated to 100oC in an oil bath. 29.4 g (0.3 mol) of maleic anhydride were then introduced with stimng, and the mixture thus obtainable was stin-ed for 5 hours at 100X.
The monoester thus obtainable was cooled to 40**C and stin-ed into 210 ml of water and partially neutralized by adding 17 g (0.21 mol) of 50% by weight aqueous NaOH, and the mixture obtained was heated to 80oC. Thereafter, 28.5 g of sodium disulfite were added with stining, and the mixture was further stirred over a period of 6 hours at 80**C. Cooling to 40oC was then effected.
4.2. Preparation of the sulfur-containing emulsifier E 4.2
The procedure was as above but, instead of 115 g of the branched alcohol VIII.1., 148.9 g (0.3 equivalent, calculated from the OH number) of oxo thick oil 135 were used.
5. Preparation of formulation 5.1 according to the invention using carboxyl-containing polysiloxane, carboxyl-free polysiloxane, sulfur-containing sulfur-containing emulsifier E 4.1 and hydrophobic substances
The components according to Table 1 which are mentioned below were stirred in a beaker at room temperature using a mixer.
Carboxyl-containing polysiloxane "PS 1": all R1 = CH3. A1: -(CH2)10-. Z1: single bond, kinematic viscosity v in the range 500 - 850 mm^/s, determined at room temperature, molecular weight Mn: 10 000 g/mol, on statistical average 127 structural element I and 2 or 3 stoictural elements II per molecule, structural elements II randomly distributed.
Carboxyl-free polysiloxane "PS 2": all R"* = CH3, kinematic viscosity v of 350 mm^/s, determined at room temperature, molecular weight Mn: 7500 g/mol.
Emulsifier E 4.1.
Natural triglyceride: lipoderm oil, a neatsfoot oil.

Synthetic oil: slack wax 36/38, commercially available from Shell and from Total-Fina.
The mixture thus obtainable was then homogenized with the aid of an SHL 105 gap homogenizer from Brau and Luebbe, a pressure of 150 bar and a temperature of 50X being chosen.
Formulation 5.1 according to the invention was obtained.
An analogous procedure was adopted for the preparation of formulations 5.2 and 5.3 according to the invention and of comparative formulations V 5.4 and V 5.5 except that in each case compositions according to Table 3 were chosen. The composition of the formulations is shown in Table 3.
For quality control of the emulsions thus obtained, in each case 10 ml were taken and made to 100 ml with water. Emulsions which were storage-stable overnight resulted.
Table 3

For example 5.6, example 5.1 was repeated, but with 25 g of sulfur-containing emulsifier E 4.2 instead of E 4.1.
Example 6: treatment of leather
Example 6.1 Treatment of leather with formulation 5.1 according to the invention
The following general recipe was followed.
The data in % by weight are based in each case on the shaved weight, unless stated
otherwise. In all operations, the ban-el was rotated 10 times per minute, unless stated
otherwise.
In a rotatable 501 barrel having intemals, 100% by weight of water. 3% by weight of sodium formate and 1% by weight of MgO were added to 2.5 kg of chrome-tanned

cattle leather (wet blue) having a shaved thickness of 2.5 mm. After 15 minutes, 0.6% by weight of NaHCOs was added and deacidification was effected at 35X over a period of 150 minutes so that a pH of 4.8 resulted.
3% by weight of polymer having the following characteristic data were then added: 30% strength by weight aqueous polymer solution partially neutralized with NaOH; homopolymer of methacrylic acid, Mn about 10 000, Fikentscher K value: 12, viscosity of 30% strength by weight solution: 65 mPas (DIN EN ISO 3219, 23X), pH 5.1.
Tanning was carried out for a further 30 minutes.
In the first treatment step, 10% by weight of formulation 5.1 was added and drumming was canied out for a further 30 minutes. 3% by weight of the vegetable tanning agent mimosa extract and 2% by weight of the leather tanning agent Luganil® Black NT, commercially available from BASF Aktiengesellschaft, were then added in the course of 10 minutes. Moreover, 2% by weight of the resin tanning agent ReluganCg) D. commercially available from BASF Aktiengesellschaft, 3% by weight of the vegetable tanning agent Chestnut® and 3% by weight of the sulfone tanning agent from EP-B 0 459 168, example K1, were added. The treatment was continued over a period of one hour.
In the second treatment step a further 7.5% by weight of formulation 5.1 were added and drumming was continued at a pH of 4.7 for 12 hours.
100% by weight of water at about 70^ were then added so that a temperature of 50*C resulted, and a pH of 3.6 was established by adding formic acid a little at a time over a period of 80 minutes.
The liquor was discharged and the leather was washed twice with 200% by weight of water at 40'C. 100% by weight of water was then added to the top and the top dyeing was carried out at 40'C with a mixture of 0.2% by weight of Leather Black VM and 0.3% by weight of the leather dye Luganil® Black AS, commercially available from BASF Aktiengesellschaft, and 0.2% by weight of formic acid at a pH of 3.6. Thereafter, the liquor was discharged, 100% by weight of water was added and treatment was effected with 3% by weight of chromium(lll) sulfate at a pH of 3.5.
Finally, washing was canied out twice with water, drying was effected and working up was effected in a manner customary in tanning. The leather 6.1 according to the invention was obtained.

The properties of the leathers obtained are shown in Table 4.
Examples 6.2 and 6.5 and comparative examples V 6.3 and V 6.4
Example 6.1 was repeated, except that formulations 5.2 and 5.3, V 5.4 and 5.5 were used in each case instead of 5.1 in the first and in the second treatment step. Leathers 6.2 and 6.3 and comparative leather samples V 6.4 and V 6.5 were obtained.
Table 4: Properties of the leathers according to the invention and of the comparative leather samples obtained in the comparative experiments

We claim:-
1. A process for imparting water repellency to leather and fur skins, wherein leather
or fur skin is treated, before, during or after the retanning, with one or more
formulations comprising from 1 to 30% by weight, based on the formulation, of a
mixture of polysiloxanes comprising
from 10 to 90% by weight, based on the mixture, of one or more carboxyl-containing polysiloxanes,
from 90 to 10% by weight, based on the mixture, of one or more carboxyl-free polysiloxanes,
and from 3 to 25% by weight, based on the formulation, of at least one emulsifier.
2. A process according to claim 1, wherein the carboxyl-containing polysiloxanes
are polysiloxanes which comprise structural elements of the formulae I, II and
optionally III a and III b

where the variables are defined as follows:
R1 are identical or different and, independently of one another, are hydrogen,
hydroxy!, C1-C14alkyl, C6-C14-aryl, C1-C4-alkoxy, amino, mono-C1-C4-alkylamino,
di-CrC4-alkylamino or Z1-A1-COOH;
A1 are identical or different and are linear or branched C5-C25-alkylene and
Z1 is a direct bond, oxygen or an amino, carbonyl, amido or ester group.
3. A process according to claim 1 or 2, wherein the formulation comprises from 10 to 70% by weight, based on the formulation, of at least one further hydrophobic compound.
4. A process according to any of the preceding claims, wherein at least one

emulsifier is an N-acylated amino acid.
5. A process according to any of claims 1 to 3, wherein at least one emulsifier is a sulfur-containing emulsifier.
6. A process according to claim 5, wherein at least one sulfur-containing emulsifier comprises one or more compounds of the general formula VI

where the variables are defined as follows
R6 and R7 are identical or different and are selected from
hydrogen, C1-C30-alkyl and C6-C14-aryl,
R8 is CrC4-alkyl or hydrogen.
7. A process according to any of the preceding claims, wherein the further hydrophobic compound is a combination of at least one natural triglyceride solid or liquid at room temperature and a paraffin mixture.
8. A process according to any of the preceding claims, wherein the treatment is carried out at a pH of from 4 to 9.
9. A process according to any of the preceding claims, wherein the treatment is carried out at from 20 to 65°C.
10. A leather produced by a process according to any of claims 1 to 9.
11. The use of a leather according to claim 10 for the production of articles of clothing, pieces of furniture or automotive parts.
12. A fur skin produced according to any of claims 1 to 9.
13. A formulation comprising

from 1 to 20% by weight, based on the formulation, of a mixture of polysildxanes comprising
from 10 to 90% by weight, based on the mixture, of one or more carboxyl-
containing polysiioxanes,
from 90 to 10% by weight, based on the mixture, of one or more carboxyl-free
polysiioxanes,
and from 3 to 25% by weight, based on the formulation, of at least one emulsifier.
14. A formulation according to claim 12, wherein the carboxyl-containing
polysiioxanes are polysiioxanes which comprise structural elements of the
formulae i, II and optionally III a and III b.
15. A formulation according to claim 13 or 14, which comprises from 10 to 70% by
weight based on the formulation, of at least one further hydrophobic compound.
16. A formulation according to any of claims 13 to 15, wherein further hydrophobic
compounds are a combination of at least one natural triglyceride solid or liquid at
room temperature and a paraffin mixture.
17. A process for the preparation of a formulation according to any of claims 13 to 16
by mixing the components carboxyl-free polysiloxane, carboxyl-containing
polysiloxane and one or more emulsifiers.

Documents:

2270-CHENP-2005 ABSTRACT.pdf

2270-CHENP-2005 CLAIMS GRANTED.pdf

2270-CHENP-2005 CORRESPONDENCE OTHERS.pdf

2270-CHENP-2005 CORRESPONDENCE PO.pdf

2270-CHENP-2005 FORM 1.pdf

2270-CHENP-2005 FORM 2.pdf

2270-CHENP-2005 FORM 3.pdf

2270-CHENP-2005 PCT.pdf

2270-CHENP-2005 PETITIONS.pdf

2270-CHENP-2005 POWER OF ATTORNEY.pdf

2270-chenp-2005-abstract.pdf

2270-chenp-2005-claims.pdf

2270-chenp-2005-correspondnece-others.pdf

2270-chenp-2005-correspondnece-po.pdf

2270-chenp-2005-description(complete).pdf

2270-chenp-2005-form 1.pdf

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Patent Number

229310

Indian Patent Application Number

2270/CHENP/2005

PG Journal Number

12/2009

Publication Date

20-Mar-2009

Grant Date

16-Feb-2009

Date of Filing

15-Sep-2005

Name of Patentee

BASF AKTIENGESELLSCHAFT

Applicant Address

D-67056, LUDWIGSHAFEN,

Inventors:

#	Inventor's Name	Inventor's Address
1	LUNKWITZ, RALPH	BERGSTEINSTRASSE 2, 67434 NEUSTADT,
2	DANISCH ,PETER	AN DER MITTAGSWEIDE 123, 67056 LUDWIGSHAFEN,
3	RADLER, THORSTEN,	GEORGE-BUCHNER-STRASSE 31, 67061 LUDWIGSHAFEN,
4	JANSON, WERNER	IM NONNENGARTEN 49, 67098 BAD DURKHEIM,
5	STATTLER, FRIEDRICH	BERGSTRASSE 3, 55234 MONZERNHEIM,

PCT International Classification Number

C14C9/02

PCT International Application Number

PCT/EP04/00706

PCT International Filing date

2004-01-28

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	103 32 991.9	2003-07-18	Germany
2	103 06 748.5	2003-02-17	Germany