EP0739425A1

EP0739425A1 - Fatty treatment agent for leather

Info

Publication number: EP0739425A1
Application number: EP95904545A
Authority: EP
Inventors: Rudolf Zauns-Huber; Fredi Wolter; Günter Uphues; Gilbert Schenker
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 1994-01-12
Filing date: 1995-01-03
Publication date: 1996-10-30
Anticipated expiration: 2015-01-03
Also published as: ATE165623T1; WO1995019451A1; US5683611A; BR9506479A; DE4400507A1; ES2115355T3; DE59502052D1; CA2181081A1; EP0739425B1; JPH09507520A

Abstract

Aqueous dispersions containing special aminopropionic acid derivatives and co-oligomers based on fatty crotonates are suitable for the oiling of leather. The leathers thus treated are distinguished by high resistance to washing and cleaning and by impermeability to water.

Description

"Means for greasing leather"

Field of the Invention

The invention relates to agents for greasing leather. The leathers treated with these agents are characterized by good washing and cleaning fastness and good water resistance. The agents according to the invention are aqueous dispersions containing special aminopropionic acid derivatives and co-oligomers based on fat crotonates.

State of the art

The greasing of vegetable and / or mineral-tanned leather or fur skins is an essential process step in the finishing of the ready-to-use material. The shape of the fat distribution in the skin substance and the extent to which the fat components are incorporated in the skin substance influence the properties and the usability of the finished products is crucial. There is extensive specialist knowledge of possible interactions between the fat components on the one hand and the tanned skin substance which contains residual tannins on the other hand. The special structure of the fatliquoring agents - for example the extent of their lipophilic groups and any reactive groups present for reaction with suitable reactive components in the tanned leather - determine, among other things, the durability and effect of the greasing equipment in practical use of the leather and fur products.

An important aspect in practice is the creation of greasy finishing agents which can be bound in the tanned skin substance so reliably that a wash and cleaning resistance of the leather and fur products sufficient for the practical needs is ensured. High-quality leather goods, for example from the clothing industry, are said to be accessible both to water-surfactant laundry and, if appropriate, to chemical cleaning without a significant loss in quality. For special cases, the additional condition of sufficient waterproofness of the finished leather is desired.

In particular, three process principles are known for waterproofing leather or furs:

1. impregnation by storing water-insoluble compounds, for example solid fats, waxes or special polymers,

2. Impregnation by storing water-swellable compounds which form highly viscous emulsions when water is absorbed and clog the interstices of the leather, for example special emulsifiers of the W / O type, 3. Treatment with compounds having a hydrophobic effect, for example aluminum, chromium and / or zirconium complexes, silicone or organic fluorine compounds.

DE 1 669 347 describes the use of water-emulsifiable half-esters of sulfosuccinic acid for greasing leather, but no waterproofing effects have yet been achieved.

EP 193832 relates to a process for the production of waterproof leather or furs using sulfosuccinic acid monoesters in combination with impregnating and / or hydrophobic greasing agents.

DE 37 17 961 describes a process for the preparation of N, N-disubstituted β-aminopropionic acids and their use, inter alia, for the hydrophobization of leather and furs. The preparation of these compounds takes place in two steps in such a way that primary alkylamines are initially attached to acrylic or methacrylic acid and the N-alkylaminopropionic acids formed in the process are mixed with carboxylic acid anhydrides, carboxylic acid chlorides, sulfonic acid chloride, isocyanates, halocarboxylic acids or or methacrylic acids are implemented. If desired, the products can then - at least partially - be neutralized.

Recently, amphiphilic agents have been described for the greasy finishing of in particular mineral-tanned leathers and furs, which represent certain selected co-oligomers of hydrophobic or oleophilic monomers on the one hand and hydrophilic monomer components on the other hand. Amphiphilic agents of this type can be worked into the leather or skins to be finished in the form of aqueous dispersions, emulsions and / or solutions after completion of the main tanning, for example by being rolled in. In the case of mineral-tanned leather or fur skins in particular, they can Amphiphilic agents simultaneously take over the function of retanning. Finally, the amphiphilic agents can be finally fixed with mineral tannins in particular. The more recent patent literature describes auxiliary substances of the type concerned here.

Corresponding agents and their use are described, for example, in EP 372 746, the amphiphilic copolymers being formed from a predominant portion of at least one hydrophobic monomer and a minor portion of at least one copolymerizable hydrophilic monomer. The following are listed as hydrophobic monomers: long-chain alkyl (meth) acrylates, long-chain alkoxy- or alkylphenoxy (polyethylene oxide) - (meth) acrylates, primary alkenes, vinyl esters of long-chain alkylcarboxylic acids and mixtures thereof. The minor proportion of hydrophilic co-monomers are ethylenically unsaturated water-soluble acids or hydrophilic basic comonomers. The molecular weight (weight average) of the copolymers is in the range from 2,000 to 100,000.

EP 412 389 describes the use of copolymers as agents for the hydrophobization of leather and fur skins, which by radical copolymerization of (a) Cβ - ^ - monoolefins with (b) ethylenically unsaturated C4_8-dicarboxylic acid anhydrides in the manner of a sub¬ Punch polymerization at temperatures of 80 to 300 ° C. to give copolymers with molar masses of 500 to 20,000 g / mol, subsequent solvolysis of the anhydride groups of the copolymers and at least partial neutralization of the carboxyl groups formed in the solvolysis in an aqueous medium with bases and which are in the form of aqueous dispersions or solutions.

For the same purpose, EP 418661 describes the use of copolymers containing (a) 50 to 90% by weight of C8-40-alkyl (meth) acrylates, vinyl esters of C8-40-carboxylic acids or mixtures thereof and (b) 10 to 50% by weight of monoethylenically unsaturated C3_.12-CaH-.on acids, monoethylenically unsaturated dicarboxylic acid anhydrides, half-esters or half-amides of monoethylenically unsaturated C4_i2-dicarboxylic acids, amides of C3_i2-monocarboxylic acids or mixtures thereof einpoly erized contain and have molecular weights of 500 to 30,000 g / mol. The copolymers are in at least partially neutralized form in aqueous solution or in aqueous dispersion for the stated purpose.

Investigations by the applicant have shown that comparatively low molar masses can be of decisive importance for the rapid and uniform penetration of fatliquors of this type. Corresponding indirect information for the polymer chemist can also be found in the last three publications mentioned in the description of the production of the copolymer types described therein. The radical copolymerization of the components claimed in each case to (a) and (b) should advantageously be carried out in the presence of chain transfer agents such as mercaptans (EP 372746 A2, page 6, 20/21) or in the presence of regulators such as C 4 aldehydes, allyl alcohol, butene -l-ol-3, formic acid or organic SH-containing compounds are made (EP 418661 AI, column 6, paragraph 2). EP 412389 also recommends using corresponding regulators to obtain sufficiently low molecular weight polymers, see AI, column 4, paragraph 2 there.

The applicant's earlier patent application DE-AP 41 29 244.8 relates to the use of aqueous dispersions of co-oligomers from the free-radically triggered aqueous emulsion copolymerization in the weakly acidic to neutral pH range as amphiphilic agents for greasing and washable finishing of leather and fur skins ; The main components are half esters of maleic acid with oleophilic alcohols and / or their lower alkylene oxide adducts as well as acrylic acid and / or methacrylic acid; in addition can also minor amounts of further hydrophilic and / or oleophilic co-monomers may be contained in the oligomer molecule.

Description of the invention

The object of the present invention was to provide means for the above-described application area, i.e. for the greasing finish of leather.

This object was achieved according to the invention by aqueous dispersions containing special aminopropionic acid derivatives and co-oligomers based on fat crotonates. Fat crotonates are understood to mean esters of crotonic acid (trans-2-butenoic acid) with Cιo-40 "fatty alcohols.

The present invention relates to aqueous dispersions

i) at least one amino propionic acid derivative of the general formula (I)

R ¹ -N-CH ₂ -CHR ³ -Cθ2X (I)

wherein

the radical R is a saturated or unsaturated, straight-chain or branched alkyl or alkoxyalkyl group with 8 to 22 carbon atoms, - The radical R ^{2 is} an alkyl group with 1 to 18 carbon atoms, a saturated or unsaturated carboxyalkyl radical with 3 to 4 carbon atoms, a carboxyphenyl radical or a carboxyl radical

the radical R ^{3 is} hydrogen or a methyl group,

- The radical X is hydrogen, alkali metal, alkaline earth metal, ammonium, alkylamium or alkanolammonium and

- The radical Y is a group -C0-, -SO2-, -CONH or an alkylene group with up to three carbon atoms

mean and

ii) at least one water-dispersible and / or water-emulsifiable co-oligomer (II)

a) fat crotonates and

b) radically copolymerizable, hydrophilic, ethylenically unsaturated acids and / or their anhydrides, which also

c) may contain minor amounts of further copolymerizable comonomers.

In a preferred embodiment, the R 1 radical in the formula for the aminopropionic acid derivatives (I) is a saturated alkyl radical with predominantly 12 to 18 C atoms. In a further preferred embodiment, the radical Y in the formula for the aminopropionic acid derivatives (I) is an alkylene group, in particular a group -CH2-CH2-, and the radical R ^{2 is} a carboxyl group (-CO2H). The teaching according to the invention thus provides a combination of special aminopropionic acid derivatives with co-oligomers based on fat crotonates for the application area of the greasing of leather and fur specified here, their use as main oleophilic components in amphiphilic dressing agents of the type concerned in the prior art not previously described.

The agents according to the invention are particularly suitable for the rapid and penetrating impregnation of leather and / or furs, so that genuine and cleanable leather and fur files are accessible. In addition, the leathers obtained in this way have good water resistance due to the hydrophobizing properties of the agents according to the invention.

With regard to the co-oligomers (II), it is preferred that those fatty crotonate building blocks (a) are preferred which contain C12-24 fatty alcohols as the alcohol component. Straight-chain fatty alcohols or their mixtures are preferred. However, it has been shown that the use of branched-chain fatty alcohols in the fat cronate component (a) can also lead to interesting results in individual cases. For example, by using such branched chain alcohols to a limited extent, the penetrability of the co-oligomer (II) into the fiber structure of the skin material to be treated can be promoted. It is also possible to use corresponding branched alcohols with a shorter carbon number, suitable alcohols having at least 6 carbon atoms, preferably having at least 8 carbon atoms. An important branched-chain alcohol that can be used in connection with the fatty crotonate building blocks (a) is 2-ethylhexanol. However, the amount of branched-chain, in particular shorter, alcohols to be used will always be comparatively small. As a rule, no more than 50% by weight, preferably no more than 30 or no more than 20% by weight, of the alcohols present in (a) residues formed by such branched chain, especially lower alcohols. For practical work - based on the oleophilic fat crotonate (a) - quantitative ratios of at least about 90-95% by weight of the pronounced oleophilic long-chain fatty alcohols, especially in the range Ci2-18 _< ^a ^ ^{s, have} particularly suitable components for training the crotonate ester proved.

The hydrophilic components (b) used in the amphiphilic co-oligomers (II) can correspond to the corresponding building blocks from the co-oligomers of EP 372 746, EP 412389 and EP 418661 cited. In particular, the last-mentioned publication provides detailed information on suitable classes of substances and numerous special representatives.

For the purposes of the present invention, particularly important building blocks (b) for the co-oligomers (II) are ethylenically unsaturated monocarboxylic acids and / or ethylenically unsaturated dicarboxylic acids and / or their anhydrides, each preferably having up to 12 carbon atoms. The dicarboxylic acids can also be present, at least in part, in the form of their partial derivatives with a carboxyl group and a derivatized carboxylic acid group, for example as dicarboxylic acid half esters.

Particularly interesting representatives from the class of monoethylenically unsaturated C3_i2 monocarboxylic acids are, for example, acrylic acid, methacrylic acid and crotonic acid. Particularly suitable building blocks (b) can also be dicarboxylic acids or their derivatives, in particular their anhydrides. Typical representatives are maleic acid, fu aric acid, itaconic acid, glutaconic acid and corresponding anhydrides.

Maleic anhydride is of particular importance. Fatty crotonates (a) and maleic anhydride can be satisfactorily converted into co-olives with or without the use of auxiliary solvents. gomer (II) an easily adjustable low molecular weight implement. It is in particular possible to bring about equal molar amounts of maleic anhydride and fat crotonate with one another so that after solvolysis, in particular hydrolysis of the maleic anhydride building blocks, on the one hand sufficiently high concentrations of carboxyl groups for fixing the oligomers in the skin or respectively Fiber structure are available, but on the other hand also reliably high levels of the oleophilic and thus greasy and water-repellent fat crotonate building block are integrated.

In addition to or instead of these hydrophilic building blocks (b) based on carboxylic acids, other copolymerizable hydrophilic compounds can also be used. Particularly suitable here are ethylenically unsaturated monomers containing sulfonic acid groups. Known representatives of this type are, in particular, corresponding aliphatic and / or aromatic sulfonic acids, such as styrene sulfonic acid, but also compounds such as vinyl sulfonic acid, allylsulfonic acid, methallylsulfonic acid and the like. As already stated, the building block (b) of the co-oligomer (II) can be formed wholly or partly from those sulfoic acid compounds accessible to the copolymerization or co-oligomerization.

Co-oligomers (II) in which the components (a) and (b) are present in ratios of 30 to 90% by weight (a) to 70 to 10% by weight (b) are particularly preferred. % here based on the sum of (a) and (b). Preferred ranges for the mixing ratios are about 35 to 80% by weight (a) to 65 to 20% by weight (b).

In addition to building blocks (a) and (b), the amphiphilic co-oligomers (II) can also contain minor amounts of further copolymerizable comonomers, which are referred to in the above definition as building blocks (c). Any ethylenically unsaturated compounds which are accessible to the co-oligomerization, such as those, can be suitable here are described in the relevant prior art, cf. here, for example, EP 418661 A1, columns 3, 49 to column 4, 27. As a rule, these are comonomers which have neither a pronounced hydrophobizing action nor hydrophilizing groups in the sense of the carboxyl groups or sulfonic acid groups of the components which are also used according to the invention (b) have. If such comonomers (c) are also used in the amphiphilic co-oligomers described according to the invention, their proportion is preferably not more than about 30% by weight and in particular not more than about 15% by weight - the statement by weight. -% - refers to the sum of (a), (b) and (c).

For the purposes of the teaching according to the invention, those co-oligomers (II) are particularly preferred which are free from the optional building blocks (c) according to the above definition, that is to say which are composed exclusively of building blocks (a) and (b). These preferred co-oligomers (II) contain the building blocks (a) and (b) in mixing ratios of about 40 to 70% by weight (a) to 60 to 30% by weight (b); the percentages by weight relate again to the sum of (a) and (b).

The co-oligomers (II) based on the fat crotonates preferably have average molecular weights (molar masses) in the range from about 500 to 30,000 g / mol. Molar masses in the range from approximately 1,000 to 15,000 g / mol can be particularly suitable. It has been shown that within these comparatively broad ranges the lower values - average molecular weights or molecular weights in the range from approximately 1,000 to 4,000 or 5,000 g / mol and expediently in the range from approximately 1,000 to 3,000 g / mol - can be of particular importance .

As indicated, those co-oligomers (II) are preferred in the context of the teaching according to the invention which result from the reaction of fatty crotona and maleic anhydride and whose maleic acid drid building blocks have been converted into the corresponding form with free carboxyl groups by hydrolysis and / or solvolysis with H-active components. Alcohols are particularly suitable for the solvolysis of the maleic anhydride units with H-active components, but also other compounds such as carboxylic acids, reactive hydrogen-containing amino compounds and the like. Such a targeted solvolysis can have a targeted influence on enhancing the greasing or water-repellent properties of the co-oligomers (II). In addition, by using sufficiently long hydrocarbon residues, the ratio of oleophilic to hydrophilic groups can be shifted in the direction of the water-repellent oleophilic elements.

However, access to the co-oligomers (II) is also possible, for example, in the following manner: in a first process step, the free crotonic acid and maleic anhydride are reacted with one another to form the corresponding oligomer compound. Subsequently, with the exclusion of water and rapid discharge of the condensation water, the crotonic acid constituents are esterified with the desired fatty alcohols or fatty alcohol mixtures. The hydrolysis or solvolysis of the anhydride rings is then carried out subsequently.

The agents according to the invention are preferably adjusted to a weakly acidic to weakly alkaline range. To ensure storage stability, it may be expedient to provide forms of supply whose aqueous phase is adjusted to neutral to weakly alkaline pH values by adding inorganic and / or organic bases. All bases described in the relevant prior art are suitable per se for pH regulation. The alkali metal salts, in particular sodium and / or potassium, are particularly preferred. However, ammonium salts or salts of alkanolamines such as diethanolamine are also suitable representatives. Preferred pH Values for storage-stable products can be in the range around pH 7 to 8. In this way it is possible to produce aqueous-pasty masses whose content of components (I) and (II) is, for example, in the range from about 30 to approx .75% by weight. Such pasty masses are to be mixed with water and / or aqueous active substance mixtures of the type described below at any time and put into practical use.

In an important embodiment, the agents according to the invention are used together with selected emulsifiers which, when introduced into mineral-tanned leather and / or furs in particular, cause additional greasing or hydrophobization and can preferably be fixed simultaneously via acidic groups in the tanned leather or fur. An important example of compounds of this type are the water-emulsifiable sulfosuccinic acid half esters mentioned at the outset, which are derived from long-chain fatty alcohols and / or their alkylene oxide adducts. An important example of the class of emulsifiers of the type concerned here are half-esters of Ciss-sulfosuccinic acid. It has been shown that by using such emulsifier-like auxiliary components - which are known per se as finishing agents for leather greasing - advantageous effects can be achieved in the sense of the objective according to the invention. The following are examples of connection types of this type:

Sulfosuccinic acid half-esters of long-chain fatty alcohols with in particular 12 to 24 carbon atoms and / or their alkylene oxide adducts with preferably up to 6 alkylene oxide residues, corresponding sulfosuccinic acid half-esters of fatty acid mono- and / or diglycerides or their alkylene oxide adducts with preferably up to 6 alkylene oxide residues with a further preferred chain length of the fatty acid (s) in the range Ci2-24 _< long-chain sulfofatty acids, in particular corresponding alpha-sulfofatty acids with preferably 12 to 24, in particular 16 to 18 carbon atoms, the hydrocarbon radicals usually being saturated in the case of these alpha-substituted sulfofatty acids, and internal sulfofatty acids of olefinically 1- and / or polyunsaturated carboxylic acids such as oleic acid, linoleic acid, linolenic acid and the like.

The agents according to the invention can also contain greasing agents or hydrophobizing agents in the sense of the mixtures of materials from EP 193832 cited at the beginning. In this embodiment of the invention, therefore, the mixtures according to the invention of components (I) and (II) are combined with impregnating and / or hydrophobic fatliquoring agents, such as sulfosuccinic acid monoester salts with Ci2-24 ~ ^{Fe't'tres'te11} » ^ιn Combination with other impregnating fatliquoring agents, selected in particular from the group of oxidized or oxidized and partially sulfated Ci8-26-K ° - ¹ l ^{en assers'to '} ff ^e or C32_40 ^_ waxes. Other examples of these additional impregnating fatliquoring agents are phosphoric acid mono-Ci2_24 alkyl esters, partial esters of polycarboxylic acids such as citric acid mono-Ci6_24 alkyl esters, partial esters of polyalcohols such as sorbitan, glycerol or pentaerythritol Ci5_24 fatty acid esters.

A particularly suitable class of emulsifier, which can also be used in the context of the teaching according to the invention, are the N-acylamino acids known from the finishing of leathers and furs with fatty substances, in particular fatty acid sarcosides, for example N-oleoyl sarcosine, as used, for example are described in detail as emulsifiers for the introduction of silicone oils into leather and furs in EP-B-0213480. Suitable emulsifiers are, accordingly, salts of amino acids, in particular N- (Cg_20 ^_ acyl), wherein corresponding salts of an amino acid having 2 to 6 carbon atoms, with the acyl radical of a saturated or unge¬ saturated fatty acid having 9 to 20 carbon atoms at the A Nitrogen, which is optionally additionally substituted by methyl, special Importance. Suitable salts of these emulsifiers are in particular alkali, ammonium or alkanolamine salts.

Of the N- (Cg_20-acyl) amino acids, those with 2 to 4 carbon atoms and with the amino group in the alpha position to the carboxyl group are particularly preferred, which are also substituted on the nitrogen atom by a methyl group. Of these, the fatty acid sarcosides of saturated or unsaturated fatty acids having 9 to 20, preferably 16 to 18, carbon atoms have a particularly superior effect. The preferred sarcoside is the oleic acid sarcoside. Furthermore, N-stearoyl sarcosine, N-lauroyl sarcosine and N-isononanoyl sarcosine are particularly suitable, in each case in the form of their alkali metal salts, ammonium salts or the salts of mono-, di- or trialkanolamines, in particular with 2 up to 4 carbon atoms in the alkanol radical.

When such mixtures of valuable substances are used, the amount of components (I) and (II) which are obligatorily contained according to the invention is preferably at least about 35% by weight of the mixture of valuable substances and in particular at least about 50% by weight. However, it may be expedient to provide at least about 70 to 80% by weight of the mixture of valuable substances to be introduced into the leather or fur skins to be finished, based on components (I) and (II).

The agents according to the invention are introduced via their form of supply of the aqueous dispersion or their mixtures with the further components mentioned - in a manner known per se - see in particular also the information given in the publications mentioned above for comparable products. It is therefore only briefly summarized:

The dispersions according to the invention are suitable for the treatment of all customary tanned skins, in particular corresponding material which has been tanned with mineral tanning agents. The tanned Skins are usually deacidified before treatment. They may have been stained before treatment. Coloring can also only be carried out after the treatment according to the invention.

The leather to be impregnated is expediently mixed with the dispersions in an aqueous liquor at pH values of about 4 to 10 and preferably at pH 5 to 8 and at temperatures of about 20 to 60 ° C., preferably 30 to 50 ° C., during a Treatment up to a few hours in several stages if necessary. The treatment takes place, for example, by drumming in a barrel. The amount of the dispersions according to the invention is usually 0.1 to 30% by weight, in particular 1 to 20% by weight, based on the shaved weight of the leather or the wet weight of the fur skins. The liquor length is usually 10 to 1,000%, preferably 30 to 150%, and 50 to 500% for fur skins.

After completion of the treatment with the aqueous liquor, the pH of the treatment liquor is shifted into the slightly acidic range by adding acids. The addition of organic acids, preferably formic acid, is particularly suitable. Preferred pH values are in the range from 3 to 5, preferably in the range from about 3.5 to 4. If desired, a fixation with, in particular, mineral tanning agents can be added, the use of aluminum salts, but also of other polyvalent mineral salts, being used here , for example chrome or zirconium salts can be particularly preferred. Examples

1. Preparation of the compounds to be used according to the invention 1.1 Preparation of the aminopropionic acid derivatives (I)

The aminopropionic acid derivatives (I) can be prepared by methods known per se, e.g. B. by addition of acrylic or methacrylic acid to primary alkylamines and subsequent reaction of the resulting N-alkylaminopropionic acids with carboxylic acid anhydrides, carboxylic acid chlorides, sulfonic acid chlorides, isocyanates, halocarboxylic acids or acrylic or methacrylic acids (compare, for example, the above-cited DE-A-37 17 961).

1.2. Preparation of the (amphiphilic) co-oligomers (II)

The preparation of the co-oligomers (II) to be used according to the invention is described below for four selected examples.

example 1

700 g of a Ciö / is fatty alcohol crotonate (45-55% C; 45-55% Ci8 fatty alcohols), 300 g maleic anhydride and 250 g xylene were weighed in a 3 1 reactor. The reaction mixture was heated to a boiling point of the xylene at a constant bath temperature of 175 ° C. At an internal temperature of 150 ° C., 47.5 g of tert-butyl perbenzoate in 47.5 g of xylene were added dropwise over the course of 2 hours. Due to the onset of polymerization, the internal temperature rose to 164 ° C. After the initiator metering had ended, there was a two-hour post-reaction time at 160 ° C. Then another 2.5 g of tert-butyl perbenzoate in 2.5 g of xylene were added. After a further 2 h reaction time at 160 ° C, the xylene was removed under vacuum (50-200 mbar). After cooling to 80 ° C., 1,500 g of water and 30.6 g of NaOH were added, so that a partially neutralized, stable dispersion was formed.

Residual monomers:

Ciö crotonate: 5.1%

Cjs crotonate: 6.3%

Maleic anhydride: <0.1%

Mo1eku1arqweights:

Mw: 2,100 g / mol

Mn: 1,200 g / mol

Solids content: 40.2% by weight

Example 2

600 g of a Ci6 / i8 fatty alcohol cronate (45-55% CIÖ-; 45-55% cis fatty alcohol). 400 g of maleic anhydride and 176 g of xylene were weighed into a 3 1 reactor. With a constant bath temperature of 160 ° C., the reaction mixture was heated until the xylene boiled. At an internal temperature of 150 ° C., 47.5 g of tert-butyl perbenzoate in 117.8 g of xylene were added dropwise over the course of 2 hours. Due to the onset of polymerization, the internal temperature rose to 169 ° C. After the initiator metering had ended, there was a two-hour post-reaction time at 150 ° C. Then another 2.5 g of tert-butyl perbenzoate in 6.2 g of xylene were added. After a further 2 h reaction time at 150 ° C., the xylene was drawn off under vacuum (50-200 mbar). After cooling to 80 ° C., 2,333 g of water and 54.4 g of NaOH were added, so that a partially neutralized, stable dispersion was formed.

Residual monomers:

Ciδ crotonate: 3.9% cis crotonate: 4.3% maleic anhydride: <0.01%

Molecular weights

Mw: 2,000 g / mol

Mn: 1,350 g / mol

Solids content: 30.1% by weight

Example 3

5,600 g of a Ci6 / i8 fatty alcohol crotonate (45-55% CIÖ; 45-55% cis fatty alcohol), 2,400 g maleic anhydride and 1,800 g xylene were weighed in a 25 1 reactor. With a constant bath temperature of 170 ° C, the reaction mixture was heated until the xylene boiled. 400 g of tert-butyl perbenzoate in 600 g of xylene were added dropwise at an internal temperature of 150 ° C. in the course of 2 hours. The internal temperature was kept at 150 ° C during the reaction. After the initiator metering had ended, there was a two-hour post-reaction time at 150 ° C. A further 80 g of tert-butyl perbenzoate were then added. After a further 2 h reaction time at 150 ° C., the xylene was removed under vacuum (50-200 mbar). After cooling to 80 ° C., 16,000 g of water and 371 g of NaOH were added, so that a partially neutralized, stable dispersion was formed.

Residual monomers:

Ci5 ~ crotonate: 5.6%

Ci8 ~ crotonate: 6.1% maleic anhydride: <0.1%

Molecular weights:

Mw: 2,100 g / mol

Mn: 1,300 g / mol

Solids content: 34.4% by weight

Example 4

172.2 g of crotonic acid, 206.1 g of maleic anhydride and 100 g of xylene were weighed out in a 3 1 reactor. With a constant bath temperature of 175 ° C, the reaction mixture was heated until the xylene boiled. At an internal temperature of 150 ° C., 18 g of tert-butyl perbenzoate in 64 g of xylene were added dropwise over the course of 2 hours. The internal temperature was 150 ° C. during the polymerization. After the initiator metering had ended, there was a two-hour post-reaction time at 150 ° C. A further 1 g of tert-butyl perbenzoate in 4 g of xylene were then added. After a further 2 h reaction time, 515 g of Stenol 1618 (45-55% Ci6>; 45-55% cis fatty alcohol) were added. At an internal temperature of 160 ° C, the polymer was azeotropically esterified with the fatty alcohol within 7 hours. 34.1 g of water were obtained, which corresponds to an esterification conversion of 95%. After the esterification had ended, the xylene was removed in vacuo (50-200 mbar).

After cooling to 80 ° C., 1,340 g of water and 40 g of NaOH were added, so that a partially neutralized, stable dispersion was formed.

Residual monomers:

Stenol 1618: 4.7%

Maleic anhydride: 0.15%

Crotonic acid: 0.05%

Molecular weights:

Mw: 10,600 g / mol

Mn: 1,000 g / mol

Solids content: 40.1% by weight

Claims

New patent claims

1. Means for greasing leather in the form of an aqueous dispersion, characterized in that they contain

i) at least one aminopropionic acid derivative of the general formula (I)

R1-N-CH ₂ -CHR3-CO ₂ X (I)

wherein

the radical R * is a saturated or unsaturated, straight-chain or branched alkyl or alkoxyalkyl group with 8 to 22 carbon atoms,

- The radical R ^{2 is} an alkyl group with 1 to 18 carbon atoms, a saturated or unsaturated carboxyalkyl radical with 3 to 4 carbon atoms, a carboxyphenyl radical or a carboxyl radical

the radical R ^{3 is} hydrogen or a methyl group,

- The radical X is hydrogen, alkali metal, alkaline earth metal, ammonium, alkylammonium or alkanolammonium and

- The radical Y is a group -C0-, -SO2-, -C0NH or an alkylene group with up to three C atoms mean and

ii) at least one water-dispersible and / or water-emulsifiable co-oligomer (II)

a) fat crotonates and

b) free-radically copolymerizable hydrophilic ethylenically unsaturated acids and / or their anhydrides, which also

c) may contain minor amounts of further copolymerizable comonomers.

2. Composition according to claim 1, wherein the radical R of the aminopropionic acid derivatives (I) is a saturated alkyl radical with predominantly 12 to 18 carbon atoms.

3. Composition according to claim 1 or 2, wherein the radical Y of the aminopropionic acid derivative (I) is an alkylene group, in particular a group -CH2-CH2, and the radical R ^{2 is} a carboxyl group (-CO2H).

4. Composition according to one of claims 1 to 3, wherein one uses co-oligomers (II) which contain as building blocks (a) esters or ester mixtures of crotonic acid and C ^^ - fatty alcohols.

5. Composition according to one of claims 1 to 4, wherein co-oligomers (II) are used which, as building blocks (b), ethylenically unsaturated monocarboxylic acids, ethylenically unsaturated dicarboxylic acids and / or their anhydrides, each with preferably up to 12 C-atoms contain, the dicarboxylic acids also at least partly in the form of their partial derivatives with a carboxyl group and a derivatized carboxylic acid group, for example as dicarboxylic acid half esters.

6. Composition according to one of claims 1 to 5, wherein co-oligomers (II) are used which contain at least partially residues of copolymerizable aliphatic and / or aromatic sulfonic acids as building blocks (b), the building blocks (b) also exclusively such sulfonic acids can be formed.

7. Composition according to one of claims 1 to 6, wherein one uses co-oligomers (II) in which the building blocks (a) and (b) in weight ratios - based on the sum of (a) and (b) - from 30 to 90 parts, preferably 35 to 80 parts (a) to 70 to 10 parts, preferably 65 to 20 parts (b), furthermore, if comonomers according to (c) are used, their proportions are preferably not is more than 30% by weight, preferably not more than 15% by weight, based here on the sum of (a), (b) and (c).

8. Composition according to one of claims 1 to 7, wherein one uses co-oligomers (II) from the radical copolymerization of fatty crotonates with acrylic acid, methacrylic acid, maleic anhydride, maleic acid, crotonic acid and / or fumaric acid.

9. Agent according to one of claims 1 to 8, wherein one uses co-oligomers (II), in the production of which no chain transfer agents or molecular weight regulators have been used.

10. Composition according to one of claims 1 to 9, wherein one uses co-oligomers (II) with average molecular weights (molar masses) of 500 to 30,000 g / mol, preferably from about 1,000 to 15,000 g / mol, the use of Low Molecule Co-Oligomers important with molecular weights in the range of about 1,000 to 4,000 g / mol may be particularly preferred.

11. Agent according to one of claims 1 to 10, wherein one uses co-oligomers (II) from fatty crotonate and maleic anhydride, the maleic anhydride portion of which has been converted to maleic acid residue or maleic acid derivative residue by hydrolysis and / or solvolysis with H-active components is.

12. Composition according to one of claims 1 to 11, wherein co-oligomers (II) are used which are produced by co-oligomerization of crotonic acid and maleic anhydride, subsequent esterification of the crotonic acid components with fatty alcohols and, if desired, subsequent hydrolysis or solvolysis of the anhydride rings have been.

13. Agent according to one of claims 1 to 12, wherein the agents have been adjusted to a weakly acidic to weakly alkaline pH range.

14. Composition according to one of claims 1 to 13, wherein the compounds (I) and the co-oligomers (II) are used together with emulsifiers which, when introduced into mineral-tanned leather and / or skins, cause additional greasing and can preferably be fixed simultaneously via acidic groups in the tanned leather or fur.

15. Composition according to one of claims 1 to 14, wherein the compounds (I) and the co-oligomers (II) are fixed therein after their entry into the leather and / or fur skins to be finished by post-treatment with in particular mineral tanning agents.

16. Composition according to one of claims 1 to 15, which additionally contain emulsifiers and / or low-molecular fatliquoring agents for leather dressing, which contain an oleophilic hydrocarbon radical having preferably at least 8 to 10 carbon atoms, optionally together with at least one acid group contained in the molecule and preferably assigned to the following classes:

Sulfosuccinic acid semiesters of long-chain fatty alcohols with in particular 12 to 24 carbon atoms and / or their alkylene oxide adducts with preferably up to 6 alkylene oxide residues,

Half-sulfosuccinic acid esters of fatty acid mono- and / or diglycerides or their alkylene oxide adducts with preferably up to 6 alkylene oxide residues with a preferred chain length of the fatty acid (s) in the range Ci2-24 _*

long chain sulfo fatty acids, especially alpha sulfo fatty acids in the range of Ci2-24 _<

internal sulfonates of olefinically 1- and / or polyunsaturated fatty acids with at least 12, preferably 16 to 24, carbon atoms,

Salts of an amino acid with 2 to 6 C atoms and with the acyl residue of a saturated or unsaturated fatty acid with 9 to 20 C atoms on the amine nitrogen atom, which is optionally additionally substituted by methyl, in particular fatty acid sarcosides.

17. Composition according to one of claims 1 to 16, which additionally contain other impregnating and / or hydrophobicizing leather greasing agents, a preferred mixture of active substances of this type being based on the following components:

Sulfosuccinic Halbester with ^{Ci2-24-f: et} 'tresten in Kombi¬ nation with compounds from the group of oxidized or oxidized and partly sulfonated Ci8-26- ^{Koh1enwassers'} ^to f ^fe' or C32-40 ~ ^Wa CHSE, phosphoric acid mono-Ci2-24 - ^A l '^< yl ^es'ter »partial esters of polycarboxylic acids, such as citric acid mono-Ci8-24 alkyl esters, partial esters of polyalcohols, such as sorbitan, glycerol or pentaerythritol Ci8_24 fatty acid esters.

18. Composition according to one of claims 1 to 17, wherein the buzzer of components (I) and (II) at least about 35 wt .-%, preferably at least the majority of the impregnating and / or hydrophobizing materials in the appropriate Wertstoffge¬ mixtures of constitutes aqueous dispersions.

19. Using mixtures containing

i) at least one aminopropionic acid derivative of the general formula (I)

R! -N-CH2-CHR ³ -C02X (I)

wherein the radical R * is a saturated or unsaturated, straight-chain or branched alkyl or alkoxyalkyl group with 8 to 22 C atoms,

the radical R ^{2 is} an alkyl group with 1 to 18 carbon atoms, a saturated or unsaturated carboxyalkyl radical with 3 to 4 carbon atoms, a carboxyphenyl radical or a carboxyl radical

the radical R ^{3 is} hydrogen or a methyl group,

the radical X is hydrogen, alkali metal, alkaline earth metal, ammonium, alkylammonium or alkanolammonium and

the radical Y is a group -C0-, -SO2-, -CONH or an alkylene group with up to three C atoms

mean and

ii) at least one water-dispersible and / or water-emulsifiable co-oligomer (II)

a) fat crotonates and

c) may contain minor amounts of further copolymerizable comonomers,

for greasing leather.