WO1993019210A1 - Process for stuffing, fulling and waterproofing leathers and pelts - Google Patents

Abstract

A process is disclosed for stuffing, fulling and waterproofing leathers and pelts by using en-adducts of maleic acid anhydride to either unsaturated fatty acids containing 12-24 C atoms, their C1-C20 alkyl ester or C2-C20 alkenyl esters, triglycerides, amides, mono- or di-(C2-C4 alkanol) amides, mono- or dipolyetehr amides or polyether esters; or by using en-adducts derivatized partially or completely by conversion into amides or esters with amines or alcohols.

Description

Process for greasing, filling and waterproofing leather and fur

description

The present invention relates to an improved process for greasing, filling and waterproofing leather and furs, and to an improved greasing agent for leather ri3 furs.

To control the mechanical properties of leather such as softness, flexibility or suppleness, mostly aqueous fat emulsions (licker) are used, which are generally based on petrochemically produced or natural oils and fats. These are made water-emulsifiable by partial sulphonation or with the help of emulsifiers or solubilizers.

Incomplete drainage of the liquor, relatively easy extraction by solvent or water, the occurrence of migration phenomena and unsatisfactory authenticity profiles turn out to be disadvantages of this class of fatliquoring agents.

For example, DE-A 39 09 614 (1) relates to a process for greasing and waterproofing leather and furskins using sulfonated compounds of succinic acid with unsaturated fatty acids or their esters, amides or alkanolamides, for example a reaction product of oleic acid or of an oleic acid derivative with maleic anhydride in the presence of a radical initiator which was then sulfonated with sulfuric acid.

From US-A 3,656,881 (2) it is known that alkenyl-substituted saturated dibasic acids such as iso-octa-decenylsuccinic acid are suitable for softening leather. Organic solvents are also used as solubilizers to achieve sufficient solubility or emulsifiability. Since these are generally not bound by the leather, there are ecological burdens, in particular the waste water from residual liquors and the air from evaporation during the drying process. The object of the invention was therefore to provide an improved agent for greasing, filling and waterproofing leather and furs, which no longer has the disadvantages of the prior art.

Accordingly, a process for greasing, filling and waterproofing leather and furs has been found, which is characterized in that for this purpose ene adducts of maleic anhydride with unsaturated fatty acids having 12 to 24 carbon atoms, their carbon atoms to carbon atoms Alkyl or C ₂ - to C __- alkenyl esters, their triglycerides, their amides, their mono- or di (C ₂ - to C ₄ -alkanol) amides, their mono- or dipolyether amides or their polyether esters or partially or completely En-adducts derivatized by reaction with amines or alcohols to form amides or esters.

The ene adducts mentioned are known in principle from (1) and DE-C 27 54 831 (3). In (1) they are mentioned as intermediates in the manufacture of the sulfonated leather greasing agents claimed there, without being recommended as auxiliaries for leather treatment. In (3) they are claimed as solubilizers for nonionic surfactants in alkaline aqueous solution.

The ene adducts are prepared in a known manner by thermal addition of maleic anhydride to unsaturated fatty acids or their derivatives, about 0.4 to 2 mol, preferably 0.7 to 1 mol, per mole of unsaturated fatty acid, regardless of its double bond number Maleic anhydride is added. The addition can be carried out, for example, in boiling toluene or in bulk at 100 to 200 ° C., preferably in the presence of catalytic amounts of iodine. The unsaturated fatty acids have 12 to 24, preferably 14 to 18 C atoms and one or more olefinic double bonds. Not more than one mole of maleic anhydride is preferably added to each double bond, although this would certainly be possible since the double bond of the fatty acid is not saturated during the addition, but that of the maleic anhydride. An example of unsaturated fatty acids is oleic acid (cis-9,10-octadecenoic acid), furthermore the trans-isomeric elaidic acid, laurolein- (9,10-eicosen-), eruca- (13,14-docosen) -) and the Selacholein- (15,16-Hexadecen-) acid called. As an games for suitable fatty acids with 2 and more olefinic double bonds are mainly linoleic (9,10-12,13-octadecadiene) and linolenic (9,10-12,13-15,16-octadecatriene) acid call.

It is also possible to use the designated esters of the unsaturated fatty acids mentioned, e.g. Methyl, ethyl, propyl, butyl, 2-ethylhexyl, decyl, dodecyl, tetradecyl, hexadecyl, stearyl, hexadecenyl, oleyl, linolyl or linolenyl esters.

In addition to the designated monoesters, the triglycerides of unsaturated fatty acids, i.e. primarily natural fats and in particular oils, can also contain the predominant proportions, i.e. more than 50 mol%, preferably more than

75 mol%, based on the total fatty acids present in the mixture, containing the aforementioned unsaturated fatty acids as esters. For example, linseed oil, olive oil, castor oil, peanut oil, sesame oil, corn oil, sunflower oil, soybean oil, poppy seed oil, cottonseed oil, hemp oil and palm oil as well as the various animal fats and especially oils such as fish oil, whale oil and sperm oil are suitable. In addition to glycerides, the latter also contains considerable proportions of esters with wax alcohols, including unsaturated alcohols.

Particularly suitable fatty acid amides are the compounds which are unsubstituted on amide nitrogen.

In particular, the N-mono- or N, N-diethanolamides or -isopropanolamides can be used as mono- or di- (C ₂ ~ to C ₄ -alkanol) amides.

Suitable mono- or dipolyetheramides are, for example, compounds substituted on amide nitrogen by polyoxyethylene groups with a respective degree of ethoxylation of 1 to 30, in particular 2 to 20.

Suitable polyether esters are, for example, unsaturated fatty acids reacted with 1 to 30 mol, in particular 2 to 20 mol, of ethylene oxide. The amide or ester derivatives are prepared in a known manner by. Addition of the amine or alcohol to the ene adduct containing anhydride groups at temperatures between 20 and 200 ° C., preferably between 50 and 150 ° C. A catalyst, for example p-toluenesulfonic acid, can be used for the addition. Preferably, no more than one mole of amine or alcohol is used per mole of anhydride group. The addition can take place, for example, in toluene or in bulk, preferably in the same reaction medium as in the preparation of the ene adduct. So as alcohols such as methyl, ethyl, propyl, butyl, 2-ethyl Ethιexyl, decyl, dodecyl, tetradecyl, hexadecyl, stearyl, oleyl alcohol or alkoxylated fat or oxo alcohols or carbohydrates such as eg glucose can be used. Straight-chain or branched C ₁ -C 20 -alkanols, in particular C ₄ -C ₈ -alkanols, and Ca 2 -C 20 -alkanols reacted with 2 to 20 mol ethylene oxide and / or propylene oxide per mol alkanol are preferred. Amines which can be used are, for example, mono- or di-N-alkylamines such as n-butylamine, 2-ethylhexylamine, morpholine, piperidine or tallow fatty amine or amino acids such as sarcosine, taurine or iminodiacetic acid or amino alcohols such as iminodiethanol or hydroxyethylamine. Saturated or unsaturated secondary or in particular primary aliphatic amines having a total of 1 to 30, in particular 4 to 18, carbon atoms are preferred.

In a preferred embodiment, the ene adducts of maleic anhydride to unsaturated fatty acids having 14 to 18 carbon atoms, their C_ ₄ - to C_a-alkenyl esters or triglycerides thereof, but in particular on oleic acid, oleic acid oleyl ester or a triglyceride as to more Contains 50 mol% of unsaturated fatty acids with 14 to 18 carbon atoms, based on the total fatty acids present in the mixture, as an ester, or partially or completely by reaction with aliphatic amines with a total of 1 to 30 carbon atoms or with C_ to C ₂ o-alkanols or ene adducts derivatized with alkoxylated alcohols to form amides or esters,

When dissolved in an aqueous alkaline medium, the anhydride groups still present in the attached maleic anhydride hydrolyze to carboxylate groups, which together with the original carboxyl groups which are also still in salt form Groups of unsaturated fatty acids ensure the solubility of the products to be used according to the invention.

With the ene adducts described, it is possible to produce very soft leather without the addition of conventional licker. This advantage is reflected in simple and short application formulations.

In addition to improving the mechanical properties, such as tear resistance, these ene adducts cause a significant increase in the authenticity profile of the leather.

The lightfastness and the heat yellowing resistance of such leathers are influenced very positively. In addition to the. The quantitative fixation of the liquor means that the leather is well fixed, making it highly resistant to being extractable with solvent or water. This leads to so-called washable leathers, i.e. Leather that does not lose its properties such as softness, strength and suppleness after washing, in contrast to leather that has been greased with conventional leathers.

In addition to the softening effect, the products described also have a hydrophobic effect, i.e. Leather and furs treated with them become water-repellent and only absorb small amounts of water.

Another advantage of the aqueous emulsions of the ene adducts to be used according to the invention is that they contain no additional emulsifiers. It is known that leather and furs which have been treated with products containing emulsifiers have to undergo complex processes after treatment with these agents, e.g. an aftertreatment with polyvalent metal salts are subjected to in order to render the emulsifiers in the leather or in the fur skins ineffective, which cause a negative effect on the hydrophobizing effect of these products.

The present invention also relates to fatliquoring, filling and waterproofing agents for leather and furs, which contain the described ene adducts of maleic anhydride with unsaturated fatty acids or their derivatives. The leather treatment compositions according to the invention are suitable for the treatment of all customary tanned hides. The tanned hides are usually deacidified before the treatment. They may have been stained before treatment. However, coloring can also only be carried out after the treatment according to the invention.

The tanned skins are expediently mixed with the aqueous emulsions of the ene adducts in an aqueous liquor, which can be obtained by diluting the emulsions with water, at pH values from 4 to 10, preferably from 5 to 8, and temperatures from 20 to 60 ° C, preferably 30 to 50 ° C, treated for a period of 0.1 to 5 hours, in particular 0.5 to 2 hours. This treatment is carried out, for example, by walking in a company. The amount of emulsion required, based on the shaved weight of the leather or the wet weight of the fur skins, is 0.1 to 30% by weight, preferably 1 to 20% by weight.

The fleet length, i.e. the percentage weight ratio of the treatment liquor to the goods, based on the fold weight of the leather or the wet weight of the fur file, is usually 10 to 1000%, preferably 30 to 150% for leather and 50 to 500% for fur files.

After treatment with the aqueous liquor described above, the pH of the treatment liquor is adjusted by adding acids, preferably organic acids, e.g. Formic acid, adjusted to a pH of 3 to 5, preferably 3.5 to 4.

If conventional retanning agents are also used in the finishing process of the leather and the fur file, treatment with the aqueous emulsion of the ene adducts can take place before or after the retanning step. Examples

Unless stated otherwise, the percentages in the examples are percentages by weight.

Preparation of the aqueous ene adduct emulsions

example 1

240 g of oleic acid (hydrogenation iodine number 90.1) and 108 g of maleic anhydride were heated together at 200 ° C. for 4.5 hours in a nitrogen atmosphere. Then unreacted maleic anhydride (26 g) was distilled off in a water jet vacuum. 320 g of product were obtained.

To 57 g of the oleic acid-ene adduct, 12 g of 50% NaOH in 172 g of water was added to obtain a 25% brown emulsion.

Example 2

Analogously to Example 1, 348 g of ester oil (hydrogenation iodine number 112.6) were reacted with 166 g of maleic anhydride. 13 g of unreacted maleic anhydride and 535 g of product were obtained.

To prepare an emulsion, 24 g of 50% NaOH in 295 g of water were added to 97 g of ene adduct.

Example 3

Analogously to Example 1, 375 g of Kapellan oil (hydrogenation iodine number 122) were reacted with 176 g of maleic anhydride. 10 g of unreacted maleic anhydride and 540 g of product were obtained.

To prepare an emulsion, 92 g of ene adduct were dissolved in 24 g of 50% NaOH in 279 g of water. Example 4

Analogously to Example 1, 266 g of oleic acid oleyl ester (hydrogenation number 95.5) were reacted with 127 g of maleic anhydride. 20 g of unreacted maleic anhydride and 365 g of product were obtained.

To prepare an emulsion, 66 g of ene adduct was dissolved in 75 g of 50% NaOH in 197 g of water.

Example 5

6.2 g of n-butylamine were added to 114 g of the Kapellanöl-En adduct from Example 3 at 70 to 80 ° C. After three hours at 80 ° C., 120 g of product were obtained.

To prepare an emulsion, 100 g of product were added to 300 g of water and 16 g of 50% sodium hydroxide solution.

Example 6

33.2 g of n-tallow fatty amine were added to 88 g of the Kapellanöl-En adduct from Example 3 at 70 to 80 ° C. After three hours at 80 ° C., 121 g of product were obtained.

To prepare an emulsion, 100 g of product were added to 300 g of water and 10.5 g of 50% sodium hydroxide solution.

Example 7

0.6 g of p-toluenesulfonic acid was added to 107 g of the adduct of kapellan oil from Example 3 at 70 to 80 ° C. 14.1 g of isobutanol were added at 120 to 130 ° C. After three hours at 130 ° C., 119 g of product were obtained.

To prepare an emulsion, 100 g of product were added to 300 g of water and 10 g of 50% sodium hydroxide solution.

Example 8

0.6 g of p-toluenesulfonic acid were added to 40.5 g of the adduct of kapellan oil from Example 3 at 70 to 80 ° C. At 120 to 130 ° C, 81.6 g of a commercially available mixture C_ ₂ - to Cis-alkanols which had been reacted with ethylene oxide and propylene oxide (together about 9 mol per mol of alkanol) were added. After three hours at 130 ° C., 122 g of product were obtained.

To prepare an emulsion, 100 g of product were added to 300 g of water and 3.5 g of 50% sodium hydroxide solution.

Application in leather production

Example 9

Chrome-tanned cowhide with a fold thickness of 1.8 mm, which had been deacidified to a pH of 5.0, was drummed with 15% active substance of the emulsion from Example 1, based on the fold weight, in a tanning drum at 40 ° C. for 2 hours . The total fleet length was 150%. The leather was then dyed with 1% by weight of a customary anionic aniline dye. Then it was adjusted to a pH of 3.8 with formic acid. Finally, washing, mechanical stretching and drying were carried out.

The leather obtained was very soft, supple, well filled and evenly colored.

Example 10

Chrome-tanned cowhide with a fold thickness of 1.8 mm, which had been deacidified to a pH value of 5.0 and dyed with 0.7% by weight of a conventional anionic aniline dye, was used with 20% active substance of the emulsion from example 2, based on fold weight, tumbled for 1.5 hours at 40 ° C in the tanning drum. Following this treatment, the leather was brought to a pH of 3.6 with formic acid and finished as usual.

The leather thus obtained was very soft and easy to grip.

Example 11

Chrome-tanned cowhide with a fold thickness of 1.8 mm, which has been deacidified to a pH of 5.0 and dyed with 0.7% by weight of a conventional anionic aniline dye was drummed with 15% active substance of the emulsion from Example 3, based on fold weight, for 30 minutes at 40 ° C. in the tanning drum and then treated with 3% of a conventional synthetic tanning agent for one hour. Then the leather was brought to a pH of 3.6 with formic acid and finished as usual.

The leather thus obtained felt pleasantly soft and easy to grip.

Example 12

The emulsion from Example 4 was used analogously to the procedure given in Example 9.

The leather thus obtained showed soft and round grip properties.

Example 13

The emulsion from Example 5 was used analogously to the procedure given in Example 9.

The leather thus obtained was soft and pleasant to the touch.

Example 14

The emulsion from Example 6 was used analogously to the procedure given in Example 9.

The leather obtained was soft with a slightly slimy feel. No water penetration occurred in the penetrometer within 12 hours at 10% compression.

Example 15

The emulsion from Example 7 was used analogously to the procedure given in Example 9.

The leather thus obtained was pleasantly soft and easy to grip. Example 16

The emulsion from Example 8 was used analogously to the procedure given in Example 9.

The leather obtained has a pleasantly soft feel and an even color.

Claims

Claims 1. A process for greasing, filling and hydrophobicizing leather and furs, characterized in that for this purpose, adducts of maleic anhydride with unsaturated fatty acids having 12 to 24 carbon atoms, their C_ to C ₂₀ alkyl, or C ₂ - to C_o-alkenyl esters, their Trigl ceride, their amides, their mono- or di (C ₂ - to C -alkanol) amides, their mono- or dipolyether amides or their polyether esters or partially or completely by reaction with Amines or alcohols used to form amides or esters derivatized ene adducts. 2. A process for greasing, filling and waterproofing leather and furs according to claim 1, characterized in that for this purpose ene adducts of maleic anhydride with unsaturated fatty acids having 14 to 18 carbon atoms, the C- ₁₄ - to C_ ₈ - Alkenyl esters or their triglycerides or partially or completely derivatized by reaction with aliphatic amines with a total of 1 to 30 carbon atoms or with C ₁ -C 20 -alkanols or with alkoxylated alcohols to give amides or esters. 3. Process for greasing, filling and hydrophobizing leather and furs according to claim 1, characterized in that for this purpose ene adducts of maleic anhydride with oleic acid, oleic acid oleic ester or triglyceride, which is more than 50 mol% unsaturated fatty acids with 14 to Contains 18 carbon atoms, based on the total fatty acids present in the mixture, as the ester. 4. Use of ene adducts of maleic anhydride with unsaturated fatty acids or their derivatives according to claim 1 as fatliquoring, filling and hydrophobicizing agents for leather and furs. 5. Lubricants, fillers and water repellents for leather and furs, containing ene adducts of maleic anhydride with unsaturated fatty acids or their derivatives according to claim 1.