MXPA96002940A - Solutions or aqueous dispersions decopolimeriza - Google Patents

Abstract

The present invention relates to aqueous solutions or dispersions of copolymers obtained by copolymerization initiated by free radicals of: A1) 40 to 60% by mol of monoolefins with 6 to 40 carbon atoms or alkyl vinyl ethers with 6 to 40 carbon atoms or mixtures thereof of alkyl vinyl ethers with 6 to 40 carbon atoms and up to 50 mol%, based on the total amount of component A1, of monoolefins with 6 to 40 carbon atoms, with B1) 60 to 40 mol% of anhydrides of monoethylenically unsaturated dicarboxylic acids with 4 to 8 carbon atoms or by copolymerization initiated by free radicals of A2) 50 l to 90% by weight of acrylate or alkyl methacrylates with 6 to 40 carbon atoms or vinyl esters of carboxylic acids with 6 to 40 carbon atoms, or mixtures thereof , with B2) 10 to 50% by weight of monoethylenically unsaturated carboxylic acids with 3 to 12 carbon atoms, acid anhydrides mono-ethylenically unsaturated dicarboxylics with 4 to 12 carbon atoms, half-esters or half-amides of monoethylenically unsaturated dicarboxylic acids with 4 to 12 carbon atoms, monoethylenically unsaturated carboxylic acid amides with 3 to 12 carbon atoms, or mixtures thereof, giving copolymers with molar masses from 500 to 30 000, the carboxyl groups present in the aqueous medium being at least partially neutralized and a part of the carboxyl groups being present in the amide form, whose aqueous solutions or dispersions are characterized to contain 0.5 to 40% by weight , with respect to the amount of copolymerized, emulsifying

Description

Solutions or j sμersione;; - Ritualized Liposomes Description The present invention relates to novel solutions or aqueous dispersions of copolymerized. In addition, the invention relates to the use of these solutions or aqueous dispersions for the greasing and filling of hides and skins of furs.

It is known from DE-A 39 26 16"? Ll) to use copolymerizations obtained for copolymerization initiated by free radicals of mono-alcohols with 8 to 40 carbon atoms with anhydrides of ethylenically unsaturated dicarboxylic acids of This is followed by the solvolysis of the anhydride groups of the copolymers and the at least partial neutralization of the carboxyl groups formed in the solvolysis, in an aqueous medium with bases, the copolymerizations of which can be present in the form of aqueous solutions or dispersions, such as products for the hydrophobicization of hides and skins of furs.

It is known from DE-A 39 26 168 (2) to use ripple copolymers obtained by polymerization initiated by free radicals of alkyl vinyl ethers having 8 to 40 carbon atoms or mixtures of alkyl vinyl ethers with 8 to 40 carbon atoms. up to 40 carbon atoms and up to 50 mol% of monoolefins with 8 to 40 carbon atoms and anhydrides of ethylenically unsaturated dicarboxylic acids of 4 to 8 carbon atoms with molar masses of 500 to 2 000, followed by solvolysis of the groups anhydride of the copolymers and at least partial neutralization of the carboxyl groups formed in the solvolysis, in an aqueous medium with bases, the copolymerizations of which may be present in the form of aqueous solutions or dispersions, as products for hydrophobicization of leather and furskins.

From DE-A 39 31 039 (2) it is known to use copolymers, which contain as copolymerized units 50 to 90% by weight of alkyl methacrylates with 8 to 40 carbon atoms and / or vinyl esters of carboxylic acids with 8 to 40 carbon atoms and 10 to 50% by weight of monoethylenically unsaturated carboxylic acids with 3 to 12 carbon atoms, monoethylenically unsaturated dicarboxylic anhydrides with 4 to 12 carbon atoms and / or derivatives of them, and having a molar mass of 500 to 30,000, in at least partially neutralized form in aqueous solution or dispersion, as a means for hydrophobing leather and furriers of fur.

The hydrophobic products for leathers containing the copolymers of publications (1) to (3) are free of additional emulsifiers. These products have, in addition to the hydrophobic action, a certain fatliquoring and retanning effect.

EP-A 372 746 (4) discloses aqueous dispersions of amphiphilic copolymers not soluble in water as auxiliaries for the treatment of tanned leather. These amphiphilic copolymers are composed of a greater proportion of a hydrophobic monomer, for example a long chain alkyl (meth) acrylate, primary alkenes or vinyl esters of long chain alkylcarboxylic acids, and a lower proportion of a monomer hydrophilic, for example, (me) acrylic acid, maleic acid and its anhydrides. These products are used to improve the water resistance of leather. The excipients are used without emulsifier !: additional.

From DE-C 2b 2a-7 ^ (5) it is known to use copolymers from olefins with 10 to 30 carbon atoms and maleic anhydride and which are saponified with bases of alkali metals or amines, for filling and greasing leather and furskins. The hydrolyzed copolymers can still be converted with alkali bisulphite. Since the copolymers are obtained in organic solvents and the latter are not removed, the copolymerized dispersions obtained therefrom contain considerable amounts of organic solvents, for example xylene or dodecylbenzene.

The object of the present invention was to present leather fatliquors with improved properties, and the use of organic solvents must be dispensed with, since these are undesirable from the ecological point of view. These products should, in particular, have a purely greasing and filling action and should not present or only to a negligible degree the hydrophobic effect, which is usually observed in products of this type, since greasing and hydrophobicizing the leather are mainly used for application purposes. different from such finishing products.

Therefore, aqueous solutions or dispersions of copolymers were found, which are obtained by copolymerization initiated by free radicals of A1) 40 to 60% by mol of monoolefins with 6 to 40 carbon atoms or alkyl vinyl ethers with 6 to 40 carbon atoms or mixtures of alkyl vinyl ethers with 6 to 40 carbon atoms and up to 10 mol%, with respect to the total amount of component A1, of monoolefins in?; - < *! • > 40 atoms of 7-Jthono with B1) 60 to 40% by mole of monoethically unsaturated dicarboxylic acid anhydrides with 4 to 8 carbon atoms or by copolymerization initiated by free radicals of A2) 50 to 90% by weight of alkyl aryl or methacrylates with 6 to 40 carbon atoms or vinyl esters of carboxylic acids with 6 to 40 carbon atoms, or mixtures thereof, with B2) 10 to 50% by weight of monoethically unsaturated carboxylic acids with 3 to 12 carbon atoms, anhydrides of monoeunitically unsaturated dicarboxylic acids with 4 to 12 carbon atoms, semi-esters or half-amides of monoethylenically unsaturated dicarboxylic acids with 4 to 12 carbon atoms carbon, amides of monoethylenically unsaturated carboxylic acids with 3 to 12 carbon atoms, or mixtures thereof copolymers with molar masses of 500 to 30 000 are present, the carboxyl groups present in the aqueous medium being at least partially neutralized and a part of the carboxyl groups being present in the amide form, whose aqueous solutions or dispersions are characterized as containing 0. , 5 to 40% by weight, with respect to the amount of co-limerized, of emulsifiers.

The copolymers from the components A1 and B1 or A2 and B2 used herein are known from patents (1) to (3). So, in the present it is not necessary to indicate more details regarding its exact composition, nor examples of monomer components and the way to obtain them, nor is it necessary to explain the solvolysis, neutralization and amidation; this information can be derived from patents (1) to (3).

Particularly suitable monomers A1 are mono-olefins having 8 to 30 carbon atoms, especially olefin with 10 to 24 carbon atoms, and also alkyl vinyl ethers having 8 to 30 carbon atoms, especially alkyl vinyl. ethers with 10 to 24 carbon atoms.

Particularly suitable monomers A- are alkyl (meth) acrylates with 8 to 30 carbon atoms, especially (meth) acrylates with 10 to 24 carbon atoms, as well as vinyl esters of carboxylic acids with 8 to 30 carbon atoms. of carbon, especially carboxylic acids with 10 to 24 carbon atoms.

Suitable monomers B1 or B2 are acrylic acid, methacrylic acid, maleic acid, and especially maleic anhydride.

The molar masses of the described copolymers vary, preferably, from 500 to 20,000, especially from 1,000 to 12,000.

The aqueous solutions or dispersions of the invention contain 0.5 to 40% by weight, preferably 3 to 35% by weight, especially 10 to 30% by weight, based on the amount of copolymerized emulsion. . Suitable emulsifiers are, in principle, all tensio-active compounds of non-ionic, cationic or amphoteric character in aqueous systems. Particularly favorable results are obtained with the representatives of the following groups of emulsifiers: (A) alkoxylated fatty alcohols or oxoalcohols of the general formula I R1 (OX) m (OY) n OH (I) 5 in which R1 means linear or branched alkyl or alkenyl having 6 to 30 carbon atoms, especially 0 alkyl or alkenyl with 8 to 20 carbon atoms, X and Y mean, each independently of the other, ethylene or propylene, and m and n mean, each independently of the other, the numbers 0 to 10, being precise, that the sum of m + n amounts to 2 to 100; with ethoxylated fatty alirohols or oxoalcohols with 5 haeta 90, especially from 15 to 80 ethylene oxide (EO) units, for example isotridecanol with * > .0 (Lutensol® A0 8 and TO 8, products of BASF Aktiengesellschaft, like all other commercial products mentioned) or tallow fatty alcohol with 11, 18, 25, 50 or 80 EO (Lutensol AT 11, AT 18 , AT 25, AT 50 and AT 80 or Siligen® WL); in addition, propoxylated (PO) and ethoxylated fatty alcohols in mixed form or oxoalcohols, eg Cs / Cio-oxoalcohol with 5.5 PO + 8.3 EO (Plurafac® LF 601), C? 3, are well suited. / C15-oxoalcohol with 21 EO + 4 PO (Plurafac LF 401) or C? 3 / Ci5-oxoalcohol with 12 EO + 6 PO (Plurafac LF 600); (b) block copolymers from units of ethylene oxide and propylene oxide with a molar mass of 500 to 15,000, especially 1000 to 10000; an example is a block copolymer from 10% by weight of EO and 90% by weight of PO (Pluronic® RPE 2510); (c) alkoxylated fatty acids of the general formula II O R2_C II (0?) K (OY)] OH (II) in which R2 means linear or branched alkyl or aicytium with 5 .e, 29 carbon atoms, especially alkyl or aikenyl with "up to 19 carmine atoms, X and Y mean, each independently of the other, ethylene or prolylene, and k and 1 mean, each independently of the other, the numbers 0 to 40, being necessary that the sum of k + 1 amounts to 2 to 50; ethoxylated fatty acids with 2 to 50 units of ethylene oxide, for example oleic acid with 5.5 EO (Emulan® A), tallow fatty acid with 3 to 10 £ 0 or castor oil are preferred. 35 to 48 EO; (d) ethoxylated fatty amides of the general formula III OR II R -C-NR3- (C2H40) p-H (III) in which R2 has the meaning indicated above, R3 means hydrogen or the radical of the formula - (C2H40) p-H, and p means a number from 2 to 30; Examples of these amides are the amide dioxide moiioethoxylates, eg with 10 EO (R3-F) (Lutensol FSA 10), or the bi-amides of the amide oxide, eg with twice 5 l. \:?,? '0 GO (k- = (C¿H40) -, •' • '•: (e) alkanolarnides of the fatty acid of the general formula IV OR II R -C NR (CH2) q-OH (IV) where '' > R2 has the meaning indicated above, R4 means hydrogen or the radical of the formula - (CH2) P-OH, and q means a number from 2 to 4, especially 2 or 3; Examples are the mono and diethanolamides of oleic acid,, (Lupritan® HDF); (f) ammonium salts of the fatty acid of saturated or unsaturated fatty acids with 6 to 30 carbon atoms, especially fatty acids with 8 to 20 carbon atoms, with tri-Ci- to C4-alkylamines or with tetra-C cations; - there is Cj-alkylammonium, where the alkyl groups with 1 to 4 carbon atoms in both cases additionally carry hydroxyl groups; Examples are the triethanoiamiha salt of oleic acid (Emulan FM); (g) fatty alcohol phosphates of the general formula V ff Ri-C -P-) R5 (V) OR5 in which R1 has the meaning indicated above and the two radicals R5 mean, each independently of the other, hydrogen or alkyl having 1 to 4 carbon atoms, it being precise that at least one of the radicals R5 does not mean hydrogen; (h) alkyl glucosides having 6 to 30 carbon atoms; Examples are the Cío-hasta C? -monoalkyl glucosides (Lutensol GD 70); (i) alkylphenol alkoxylates of the general formula (VI) R6 -Q, (OX) m- (OY) n-OH wherein R6 means linear or branched alkyl having 1 to 20 carbon atoms, especially alkyl having 4 to 13 carbon atoms, and X, Y, m and n have the meanings indicated above; Of these, alkylphenol ethoxylates with 2 to 60 ethylene oxide units are particulapreferred, eg p-isooctylphenol with 5,7 or 23 EO (Lutensol AP 6) or p-isononylphenol with 4,5, 8, 9, 10, 14, 20 or 58 EO (Emulan PO, Lutensol AP 8, AP 9, AP 10, AP 14, AP 20, Emulate NP 50), (j) 2-mono or dialkyl sulfosuccinate with 5 to 20 carbon atoms; Examples are diisoamyl 2-sulfosuccinate, sodium salt (Lutensit® ABP) and di (2-ethylhexyl) 2-sulfosuccinate, sodium salt (Lutensit ABO); (k) N- (Cg- to C2o_acyl) amino acids with 2 to 6 carbon atoms in the basic amino acid body; of these N- (C9-C2o-acyl) -amino acids are preferred those having 2 to 4 carbon atoms, with the amino group in position opposite to the carboxyl group present in salt form, and that in the amino nitrogen atom they are further substituted by a methyl group; among these, the fatty acid sarcosides of saturated or unsaturated fatty acids with 9 to 20, especially 16 to 18, carbon atoms are especially superior in their action; Suitable salts are the alkali metal salts, espe- cially? of sodium or potassium, ammonium salts or salts of a ~? simple, di or trialkanol amine with 2 to 4 carbon atoms in the radical alkanol, especially mono, di or h, ethanolamine; an especially preferred sarcoc is oleic acid sarcoside or N-oleoylsarcosine (mediallanic acid); in addition, N-stearoyl sarcosine, N-lauroyl sarcosine and N-isononanoyl sarcosine, each in the form of the above-mentioned salts, are especially preferred.

When mixtures are used from the emulsifiers of groups (a) to (k), in some cases even a stronger action can be achieved. Mixtures of this type are, for example, mixtures of emulsifiers (a) and (c), (a) and (h) or (a) and (k) in the weight ratio of each time 5: 95 up to 95: 5, especially 20: 80 to 80: 20.

The emulsifiers can be added to the copolymers at different stages of the process for obtaining the aqueous solutions or dispersions of the invention. The emulsifiers can be added to a fusion of the bristled copolymers, when these have been obtained by polymerization in the absence of solvent, and then carried out the solvolysis, neutralization and / or amidation. Another possibility is to mix the emulsifiers with an aqueous solution of the neutralizing agent, for example alkali metal hydroxide, such as NaOH or KOH, and to add this solution to the copolymers. The emulsifiers can also be added at the end of obtaining aqueous solutions or dispersions of the copolymers subjected to solvolysis, neutralized and / or knotted. Under certain circumstances it is also possible to add the emulsifiers already during the copolymerization of the monomers A1 and B1 or A2 and B2.

The solutions or dispersions of the invention are excellently suited for greasing and filling leather and furskins. No organic solvent is used and no noticeable hydrophobic effect is observed.

The greasing of the leather and the skins is carried out by conventional methods which are known to the expert and which, therefore, do not have to be described in more detail in the present.

In comparison with the greasing with the usual fatliquors, the product can be distributed better by the cross section of the leather. By greasing with, for example, only 2 to 3% by weight of active substance, with respect to the aqueous solution or dispersion, extremely soft leathers are obtained, in comparison with the results obtained with conventional fatliquors used in this quantity. The obtained leather is, therefore, softer, which saves the use of other fatliquors optionally used additionally. Thanks to this effect and to the fact that the polymer is firmly bonded with the tanned fiber, for example to chromium, it is possible to reduce markedly the pollution of the residual water after greasing, that is, the product produces an excellent exhaustion of the greasing bath The sensitivity to hard water and / or chromium (III) salts that are eventually entrained is considerably reduced. It is therefore not necessary to add complexing agents, a factor that is extremely advantageous, since the complexing formers have a disincentive effect, that is, they release the chromium from the chrome-tanned leather and can negatively affect the dyeing.

The oiled leathers with the aqueous solutions or dispersions of copolymerized have very good fastnesses, as well as a good fixation of the auxiliaries in the leather, being thus difficult to extract, for which reason they provide the leather with a good resistance to washing. Examples The following emulsifiers were added to a 25% by weight aqueous dispersion of a copolymerized saponified and 50% neutralized with NaOH from C20 C24 α-olefin and maleic anhydride in the molar ratio of 0.97: 1: 5 (1) tallow fatty alcohol (Cid / Ciß native fatty alcohol) with 25 EO (2) tallow fatty alcohol with 80 EO (3) oleic acid with 5,5 EO (4) isotridecanol with 8 EO 0 (5) oleic acid amide monoethoxylate with 10 EO (6) oleic acid sarcoside "- (7) oleic acid diethanolamide (8) p-isononylphenol with 4.5 EO (9) copolymerized blocks of EO / PO (10% by weight) weight of EO + 90% by weight of PO) 5 (10) C12 / C14 alkyl glucoside (11) 2-di (2-ethexyl) sulfosuccinate, sodium salt (12) oleic acid, triethanolamine salt (13) oxoalcohol C13 / C15 with 21 EO + 4 PO (14) oxocalcohol C13 / C15 with 12 EO + 6 PO 0 The amount of emulsifier in each case was 5.3% by weight, based on the aqueous dispersion.

With these emulsions, de-acidised, chrome-tanned cowhides are used, using 3% by weight of active substance each time. The bladder of the ready leathers was evaluated in comparison with leathers treated with the same copolymerized dispersion without emulsifier, as standard, obtaining the following results: Emulsifier Difference softness (note) (1) 2 (2) 2 (3) 3 (4) 2 (5) 3 (6 ¡3 (7) 3 (8) 3 (9) 2 (10) 2 (11) 2 (12) 1 (13) 2 (14) 2 Evaluation scale for leather softness: from note 1 (hard) to note 10 (very soft) Voucher: Difference softness = softness with emulsifier - softness without emulsifier The leathers obtained were very soft and had a pleasant touch.

Claims (2)

1. indications Solutions or aqueous dispersions of copolymers obtained by co-olisation initiated by free radicals of A1) 40 to 60% by mol of monooiefins with 6 to 40 carbon atoms or alkyl vinyl ethers with 6 to 40 carbon atoms or mixtures of alkyl vinyl ethers with 6 to 40 carbon atoms and up to 50 mol%, with respect to the total amount of component A1, of monoolefins with 6 to 40 carbon atoms, with B1) 60 to 40 mol% of anhydrides of monoethylenically unsaturated dicarboxylic acids with 4 to 8 carbon atoms or by copolymerization initiated by free radicals of A2) 50 to 90% by weight of acrylate or alkyl methacrylates with 6 to 40 carbon atoms or vinyl esters of carboxylic acids with 6 to 40 carbon atoms, or mixtures thereof, with B2) 10 to 50% by weight of monoethylenically unsaturated carboxylic acids with 3 to 12 carbon atoms, anhydrides of monoethylenically unsaturated dicarboxylic acids with 4 to 12 carbon atoms, semi-esters or half-amides of monoethylenically unsaturated dicarboxylic acids with 4 to 12 carbon atoms , amides of carboxylic acids mono- and ionically unsaturated with 3 to 12 carbon atoms, or mixtures thereof copolymerized with molar masses of 500 to 5 30 000, the carboxyl groups present in the aqueous medium being at least partially neutralized and a part of the carboxyl groups being present in the amide form, whose aqueous solutions or dispersions are characterized as containing 0. , 5 to 40% by weight, with respect to the amount of copolymerized, of emulsifiers.
2. 2. Aqueous solutions or dispersions of copolymers according to claim 1, characterized in that they contain emulsifiers of the groups: (a) alkoxylated fatty alcohols or oxoalcohols of the general formula I 2Q 1- (OX) m (OY) n OH (I) ^ in which R1 means linear or branched alkyl or alkenyl with 6 to 30 carbon atoms, X and Y mean, each independently of the other, ethylene or propylene, and 30 m and n mean, each independently of the other, the numbers 0 to 10, being precise, that the sum of m + n ascends to 2 to 100; (b) block copolymers from units of ethylene oxide and propylene oxide with a molar mass of 500 to 15,000; (c) alkoxylated fatty acids of the general formula II OR II R2 c (OX) k (OY)? OH (II) in which R2 means linear or branched alkyl or alkenyl with 5 to 29 carbon atoms, X and Y mean, each independently of the other, ethylene or prolylene, and k and 1 mean, each independently of the other, the numbers 0 to 40, being necessary that the sum of k + 1 amounts to 2 to 50; (d) ethoxylated fatty amides of the general formula III OR II R- C- R3 (C2H40) p-H (III) in which R ^ has the meaning indicated above, R3 means hydrogen or the radical of the formula - (C2H40) p-H, and p means a number from 2 to 30; (e) fatty acid alkanolamides of the general formula IV O R2 c NR4 (CH2) q OH (IV) in which R2 has the meaning indicated above, R4 means hydrogen or the radical of the formula - (CH2) P-OH, and means a number from 2 to 4; (f) ammonium salts of the fatty acid of saturated or unsaturated fatty acids with 6 to 30 carbon atoms with tri-C? - to C4-alkylamines or with tetra- to C-? - to C4-alkylammonium cations, where the groups alkyl with 1 to 4 carbon atoms in both cases additionally carry hydroxyl groups; (g) fatty alcohol phosphates of the general formula V OR5 in which R1 has the meaning indicated above and the two radicals - R5 mean, each independently of the other, hydrogen or alkyl having 1 to 4 carbon atoms, it being precise that at least one of the radicals R5 does not mean hydrogen; (h) alkyl glucosides having 6 to 30 carbon atoms; (i) alkylphenol alkoxylates of the general formula (VI) in which R6 means linear or branched alkyl with 1 to 20 carbon atoms, and X, Y, m and n have the meanings indicated above; (j) 2- mono- or dialkyl sulfosuccinate with 5 to 20 carbon atoms; (k) N- i c- - h yes C2-acyl) amino acids with 2 to 6 carbon atoms in the basic amino acid body. Process for obtaining aqueous solutions or dispersions of copolymers, characterized in that they are polymerized with initiation by free radicals to A1) 40 to 60% by mol of monoolefins with 6 to 40 carbon atoms or alkyl vinyl ethers with 6 to 40 carbon atoms or mixtures of alkyl vinyl ethers with 6 to 40 carbon atoms and up to 50 mol%, with respect to the total amount of component A1, of monoolefins with 6 to 40 carbon atoms, with B1) 60 to 40% by mol of anhydrides of monoethylenically unsaturated dicarboxylic acids with 4 to 8 carbon atoms O well A2) 50 to 90% by weight of alkyl acrylate or ipetacrylates with 6 to 40 carbon atoms or vinyl esters of carboxylic acids with 6 to 40 carbon atoms, or mixtures thereof, with B2) 10 to 50% by weight of monoethylenically unsaturated carboxylic acids with 3 to 12 carbon atoms, anhydrides of monoethylenically unsaturated dicarboxylic acids with 4 to 12 carbon atoms, seraesters or half-amides of monoethylenically unsaturated dicarboxylic acids with 4 to 12 uc- atoms; carbon, amides of carboxylic monoenethically unsaturated emines with 3 to 12 carbon atoms, or mixtures thereof giving copolymers with molar masses of 500 to 30,000, the carboxyl groups present in the aqueous medium are neutralized at least partially, a part of the carboxyl groups is optionally amidated, and an amount of 0.5 to 40% is added to the carboxyl groups. weight, with respect to the amount of copolymerized, of emulsifiers. Procedure for greasing and filling leather and skins, characterized in that aqueous solutions or dispersions of copolymers according to claim 1 or 2 are used for such purposes Summary of the Invention Aqueous solutions or dispersions of copolymers, which are obtained by copolymerization initiated by free radicals of A1) 40 to 60% by mol of monoolefins with 6 to 40 carbon atoms or alkyl vinyl ethers with 6 to 40 carbon atoms or mixtures of alkyl vinyl ethers with 6 to 40 carbon atoms and up to 50 mol%, with respect to the total amount of component A1, of monoolefins with 6 to 40 carbon atoms, with B1) 60 to 40% by mol of anhydrides of monoethylenically unsaturated dicarboxylic acids with 4 to 8 carbon atoms or by copolymerization initiated by free radicals of A2) 50 to 90% by weight of acrylate or alkyl methacrylates with 6 to 40 carbon atoms or vinyl esters of carboxylic acids with 6 to 40 carbon atoms, or mixtures thereof, with B2) 10 to 50% by weight of monoethylenically unsaturated carboxylic acids with 3 to 12 carbon atoms, anhydrides of monoethylenically unsaturated dicarboxylic acids with 4 to 12 carbon atoms, semi-esters or half-amides of monoethylenically unsaturated dicarboxylic acids with 4 to 12 carbon atoms , amides of monoethylenically unsaturated carboxylic acids with 3 to 12 carbon atoms, or mixtures thereof copolymerized with molar masses of 500 to 30 000, the carboxyl groups being present in the aqueous medium at least partially nucleated and a part of the carboxyl groups being present in the amide form, whose solutions or aqueous dispersions are characterized to contain 0.5 up to 40% by weight, with respect to the amount of copolymerized, of emulsifiers. /".- These solutions or aqueous dispersions are suitable for the greasing and filling of hides and skins.