EP0763139A1

EP0763139A1 - Stuffing agents for leathers and fur-skins

Info

Publication number: EP0763139A1
Application number: EP95920858A
Authority: EP
Inventors: Ramon Segura
Original assignee: Henkel AG and Co KGaA
Current assignee: BASF Personal Care and Nutrition GmbH
Priority date: 1994-05-31
Filing date: 1995-05-22
Publication date: 1997-03-19
Anticipated expiration: 2015-05-22
Also published as: ES2164768T3; WO1995033077A1; EP0763139B1; JPH10501010A; DE4418942A1; PT763139E; DE59509641D1

Abstract

Proposed are new stuffing agents for leathers and fur-skins, containing sulfitation products of unsaturated fatty acid low-alkyl esters as anionic surfactants. The agents lend leathers an improved suppleness and increased hydrophobicity and are characterized by less inclination to form fatty spew as well as an advantageous ecotoxicological tolerability.

Description

Leather and fur oiling agents

Field of the Invention

The invention relates to fatliquoring agents for leather and furs containing selected anionic surfactants and their use for the preparation of the agents.

State of the art

In addition to the tannins, greasing agents are the most important tools to shape the character of leather. The effect of the fatliquoring agents comes about through fiber-insulating lubrication and through hydrophobization.

By covering the leather fibers with a grease film, the mutual friction is reduced and, consequently, the suppleness and stretchability of the fabric are improved. This has positive effects on the tensile strength of the leather, because in a stretchable material, many fibers align in the direction of tension when subjected to tensile stress and then offer greater resistance to tearing than the same fibers within a brittle material. Through the In addition, hydrophobization has tanning effects since it is associated with the displacement of water from the skin.

Vegetable and animal oils, fats and waxes are generally used as leather greasing agents, furthermore the hydrolysis, sulfation, oxidation and hardening products obtained from these substances by chemical conversion and finally mineral greasing agents; in detail:

o Saponifiable fats and oils and natural _W axis and resins belong to the esters. Oils and fats refer to esters of glycerin and fatty acids that are solid or liquid at room temperature. For leather greasing, from the group of animal fats in particular trane, fish oil, beef tallow and cattle claw oil, from the group of vegetable fats castor oil, rape oil and linseed oil are used. In waxes and resins, the fatty acids are esterified with higher molecular weight alcohols instead of glycerin. Examples of waxes are beeswax, Chinese wax, caranuba wax, montan wax and wool fat; The most important resins include rosin, yeast oil and shellac.

o Chemical conversion of vegetable and animal fats results in products that are water-soluble and, in addition, have different emulsifying effects on water-insoluble fats. The sulfated water-soluble oils of various types are known, for example, the tears which have been changed by oxidation and which Degras or Moellon are called, furthermore the be _¬ fen, which arise during the hydrolytic splitting of natural fats, hardened fats and finally free fatty acids such as stearic acid as stoving fats. The mei _¬ most animal and vegetable fats have a ge _¬ knew affinity for leather, which hydrophilic by the introduction or exposure groups still be _¬ is increased considerable.

o are important for leather production on the mine _¬ ral fatliquor. These hydrocarbons are similar to natural fats and oils in some properties, but cannot be saponified. These are fractions from petroleum distillation, which are called mineral oil in liquid form, petroleum jelly in pasty form and paraffin in solid form.

In many cases, however, undesirable stains are formed on the surface of the tanned and greased leather, which are referred to as "fatty spew". Fatty spew is formed mainly on chromgegerb _¬ th leathers for short or prolonged storage as a white, often bloom-the only individual sites or the whole leather surface covered. The rash is reindeer on leakage of solid fats from the leather zurückzufüh _¬. It can be caused by the per se in leather existing natural fat or fatty substances that have been incorporated only in the course of greasing of the leather.

For oiling leather used fat blends tend insbeson _¬ wider then the formation of rash, when much free Contain fatty acids. Free fatty acids generally have a higher melting point than their glycerides. The hydrolytic cleavage of fatty substances during the storage of the leather accordingly increases the risk of fat rashes occurring.

Soaps and licker greases are split in chrome leather, especially in insufficiently deacidified chrome leather, with the release of fatty acids. Sulphated oils and fats have different tendencies to form fat rashes, the tendency to rash generally declines with a longer lifespan [cf. J.In. Soc. eat .Trad.Chem. 47, 379 (1952)].

Fat rashes are more likely to occur the more the leather contains fat substances that tend to form rashes. The amount, composition and position of the fat mixture of natural fat and lickerfat present in the leather are decisive for the extent and the composition of the rash. Loosely structured leather is less prone to rash than leather with a dense fiber structure. Grease rashes are observed more often at low temperatures than at warmer outside temperatures.

The crystalline fatty spew develop holes and small crystals initially formed in the depth, the felting glands channels gradually than larger fatty crystals all the hair hole filling area over the leather upper _¬ addition swell and ver¬ to a dense crystal film in the hair _¬. All fats stearic or palmitic derivatives ent _¬ hold, crystalline fatty spew can cause, with Increasing concentration increases the risk of rash [Ledertechn.Rundsch. 1 (1949)].

In particular, the so-called neutral fats, i.e. substances suitable for leather greasing which do not contain any ionic groups in the molecule, e.g. Fats, waxes and hydrocarbons to form fat rashes. Those neutral fats which represent stearin and / or palmitin derivatives, such as corresponding triglycerides or the free fatty acids, are particularly critical.

Since in the course of leather processing, but after tanning, greasing is required as an almost obligatory operation in order to achieve the desired product properties, it has become common practice to work with special synthetic greasing agents whose tendency to Fat rash formation is low.

A class of fatliquoring agents commonly used in this regard is halogenated compounds such as chlorinated hydrocarbons. However, the increasing ecological and toxicological requirements for agents that get into the environment or with which the consumer comes into contact make this class of substances increasingly unattractive.

Anionic surfactants are usually used for leather greasing. For example, from the European patent EP-B 0247509 (Stockhausen) addition products of sulfuric acid or oleum with unsaturated, alkoxylated and optionally epoxidized fats and oils are known. In addition to reactions with oleum, sulfuric acid or gaseous sulfur Trioxide is also particularly suitable for the hydrophilization of fatty substances by sulfitation, ie the attachment of hydrogen sulfite to unsaturated compounds. In this context, for example, A. Kuenzel on the sulfitation of Dorschtran [Leder 8., 5 (1957)] and M. Mikula on the sulfitation of unsaturated fatty acid butyl esters [Leder, Schuh, Lederwaren ZI. 282 (1986)].

From the German patent application DE-Al 4223704 (Henkel) nonionic lubricants containing oleic acid esters and dialkyl ethers are also known.

However, the use of anionic fatliquoring agents is not without problems. A major disadvantage is that a large number of these agents tend to form fat rashes when used. Furthermore, their biodegradability is not always satisfactory. Sulphated oils are viscous in the area of high active substance contents and can therefore often only be metered with difficulty; after all, their color quality is often unsatisfactory.

The complex object of the invention was therefore to develop new greasing agents for leather and furs based on anionic surfactants, which are characterized by improved ecological and application properties, such as, for example, a more pleasant grip and less tendency towards greasy deposits. Compared to the known sulphated or sulphited fatty substances, the feedstocks should also have better color quality and advantages in handling, in particular with regard to look at the production of liquid, low-viscosity products.

Description of the invention

The invention relates to agents for greasing leather and furs with a content of 1 to 30% by weight of sulfonation products of unsaturated fatty acid lower alkyl esters in the form of their alkali metal, alkaline earth metal, ammonium, alkylammonium, alkanolammonium or glucammonium salts.

Surprisingly that sulfonation products of unsaturated fatty acid alkyl esters according to the invention are not only completely biodegradable, but have proposals in comparison with other known anionic fatliquors a significantly lower tendency to form Fettaus _¬ was found. Moreover, they give leathers also improved Schmalzig- or suppleness, an integrally _¬ take grip and increased water repellency. The sulfation products are also highly concentrated and of low viscosity and can therefore be easily incorporated into liquid, aqueous formulations. In contrast to sulfated ester oils, for example, they are also characterized by an improved color quality. Sulfation products

Sulfation products of unsaturated fatty acid lower alkyl esters are known substances which can be obtained by the relevant methods of preparative organic chemistry.

One method of making them is, for example, to use unsaturated fatty acid lower alkyl esters such as e.g. to implement technical oleic acid esters with gaseous sulfur trioxide and then to neutralize the crude sulfonation product with an aqueous base and at the same time to hydrolyze cyclic intermediates such as sultones [DE-Al 3803912 (Henkel)]. The sulfonation is an electrophilic addition of the SO 3 molecule to the double bond. Mixtures of isomeric hydroxy and alkene sulfonates are formed in the course of neutralization or hydrolysis. An overview of this is provided by A. Behler et al. in C.R. CESIO, elttensidkongress Paris, Vol.II, p.14 (1988).

In a preferred embodiment of the invention, however, the sulfonation products are prepared by adding oleum to the unsaturated esters mentioned. Mixtures of sulfates and sulfonates are obtained.

Sulfation products of unsaturated fatty acid lower alkyl esters of the formula (I) are preferably used,

RiCO-OR ² (I) in which R ^{1 is} an unsaturated acyl radical having 16 to 24 carbon atoms and 1, 2, 3, 4 and / or 5 double bonds and R ^{2 is} a linear or branched alkyl radical having 1 to 8 carbon atoms.

Typical examples are sulfonation products of esters of methanol, ethanol, butanol, octanol and in particular 2-ethylhexanol with palmoleic acid, oleic acid, elaidic acid, petroselic acid, linoleic acid, linolenic acid, elaeostearic acid, gadoleic acid, behenic acid and clupanodonic acid and their technical mixtures in the form of their sodium , Potassium and / or ammonium salts. In addition to the pure unsaturated fatty acids, the sulfonation products can also contain technical fatty acid cuts with a predominantly unsaturated fraction such as rapeseed, sunflower and / or olive oil oleic acid as components. Sulfation products of oleic acid 2-ethylhexyl ester, in particular based on olive oil fatty acid in the form of the sodium salt, are preferably used.

Sulfation

The sulfonation of the unsaturated fatty acid lower alkyl esters can be carried out in the manner known for saturated fatty acid lower alkyl esters [J. Falbe (ed.), "Surfactants in consumer products", Springer Verlag, Berlin-Heidelberg, 1987, p. 61], reactors which work according to the falling film principle, are preferred. Sulfuric acid, oleum, chlorosulfonic acid and gaseous sulfur trioxide are suitable as sulfating agents. The latter is usually diluted with an inert gas, preferably air or nitrogen, and in the form of a Gas mixture which contains the sulfonating agent in a concentration of 1 to 8, in particular 2 to 5,% by volume.

The molar ratio of ester to sulfating agent can be 1: 0.95 3 1: 1.3 and preferably 1: 1.0 to 1: 1.15 in the case of chlorosulfonic acid or sulfur trioxide. If sulfuric acid or oleum is used as the sulfonating agent, it is advantageous to use this in deficit, i.e. for example in a molar ratio of 1: 0.1 to 1: 0.95 and in particular 1: 0.25 to 1: 0.8.

The sulfonation is usually carried out at from 15 to 90 ° C. With regard to the viscosity of the starting materials on the one hand and the color quality of the resulting sulfonation products on the other hand, it has proven to be optimal to carry out the reaction in a temperature range from 20 to 30 ° C.

Neutralization

The acidic sulfonation products obtained during the sulfonation are stirred into aqueous bases, neutralized and adjusted to a pH of 6.5 to 8.5. As bases for the neutralization come alkali metal hydroxides such as sodium, potassium and lithium hydroxide, alkaline earth metal oxides and hydroxides such as magnesium oxide, magnesium hydroxide, calcium oxide and calcium hydroxide, ammonia, mono-, di- and tri-C2-4 ~ alkanolamines, for example mono- , Di- and triethanolamine and primary, secondary or tertiary C 4 alkylamines and glucamines into consideration. The neutralization bases arrive preferably in the form of 5 to 55% by weight aqueous solutions are used, with 5 to 25 percent by weight aqueous Natriumhy _¬ droxidlösungen .-% being preferred.

Bleaching and preservation

The sulfonation may be bleached by the addition of hydrogen peroxide or triumhypochloritlösung Na _¬ in a known manner by neutralization. In this case, be bezo _¬ gene-products to the solid content in the solution of the Sulfierungspro _¬, 0.2 to 2 wt .-% of hydrogen peroxide, calculated as 100% pure substance, or corresponding amounts used sodium hypochlorite. The pH of the solutions can be adjusted using suitable buffering agents, e.g. B. be kept constant with sodium phosphate or citric acid. To stabilize against bacterial _attack , conservation is also recommended, e.g. B. with formaldehyde solution, p-hydroxybenzoate, sorbic acid or other known preservatives.

Cotenside

The sulphonation according to the invention can be used alone, but preferably in admixture with other anionic, nonionic, amphoteric or zwitterionic surfactants, and - limited - and cationic surfactants used _¬ the.

Typical examples of anionic surfactants are alkylbenzene sulfonates, alkane sulfonates, olefin sulfonates, alkyl ether sulfo- nate, glycerol ether, o-methyl ester sulfonates, sulfo fatty acids, alkyl sulfates, fatty alcohol ether sulfates, ether sulfates Glycerin¬, Hydroxymischethersulfate, monoglyceride (ether) - sulfates, fatty acid amide (ether) sulfates, mono- and Dialkylsulfo- succinate, mono- and dialkyl sulfosuccinamates, Sulfotriglyce- ride , Amide soaps, ether carboxylic acids and their salts, fatty acid isethionates, fatty acid sarcosinates, fatty acid taurides, acyl lactylates, alkyl oligoglucoside sulfates and alkyl (ether) phosphates. If the anionic surfactants contain polyglycol ether chains, they can have a conventional, but preferably a narrow, homolog distribution.

Typical examples of nonionic surfactants are fatty alcohol polyglycol ethers, alkylphenol polyglycol ethers, Fettsäurepo- lyglycolester, Fettsäureamidpolygylcolether, Fettaminpoly- glycol ethers, alkoxylated triglycerides, alk (en) yloligoglyko- side, fatty acid-N-alkyl glucamides, polyol fatty acid esters, sugar kerester, sorbitan esters and polysorbates. Provided that contain non-ionic surfactants _¬ polyglycol ether chains, they may have a conventional, but preferably a narrow Ho _¬ mologenverteilung.

Typical examples of amphoteric or zwitterionic surfactants are alkyl betaines, alkyl amido betaines, aminopropionates, amino glycinates, imidazolinium betaines and sulfobetaines.

Typical examples of cationic surfactants with which the anionic sulfonation products are compatible and do not form sparingly soluble salts are esterquats, in particular those which have ethylene oxide units in the molecule. The surfactants mentioned are exclusively known compounds. With regard to the structure and manufacture of these substances, reference is made to relevant reviews, for example J.Falbe (ed.), "Surfactants in Consumer Products", Springer Verlag, Berlin, 1987, pp. 54-124 or J.Falbe (ed.) , "Catalysts, surfactants and mineral oil additives", Thieme _V erlag, Stuttgart, 1978, pp. 123-217.

Fatliquor

In addition to the sulfonation products and other surfactants, the fatliquoring agents can contain other customary auxiliaries and additives. The proportion of the sulfonation products in the agents according to the invention is usually 15 to 90 and preferably 20 to 80% by weight, based on the agents. As a rule, the agents are dosed in such a way that 1 kg of leather or fur (calculated as the shaved weight) accounts for 20 to 1000, preferably 30 to 80 g of the agent.

Industrial applicability

Sulphonation products of unsaturated fatty acid lower alkyl esters, as a component of fatliquoring agents, give leathers and furs an improved lardiness and suppleness, a pleasant feel and increased hydrophobization. A particular advantage lies in the fact that the sulfonation products are also highly concentrated and have a low viscosity and can accordingly be easily incorporated into liquid formulations. In comparison with other known anionic fatliquoring agents, they also show a significantly lower tendency to form fat rashes. When using the agents according to the invention, the colors are brilliant with good levelness.

Another object of the invention therefore relates to the use of the sulfonation products mentioned as anionic surfactants for greasing leather and furs.

Examples

Manufacturing example St.

Preparation of oleic acid 2-ethylhexyl ester sulfonate / sulfate sodium salt. 250 g (0.7 mol) of technical grade oleic acid 2-ethylhexyl ester (based on olive oil fatty acid with an oleic acid content of approx. 70% by weight) were placed in a 1-1-sulphonation reactor with jacket cooling and at a temperature of 31 to 33 ° C 44 g of oleum (20% by weight of SO3) were added in portions. The mixture was subjected to a post-reaction over a period of 90 min at 30 ° C. and then neutralized at about 55 ° C. with the addition of a mixture of 43 g ammonia in 89 g water. The resulting mixture was left overnight, whereupon phase separation occurred. Subsequently, the aqueous, the formed ammonium sulfate-containing phase was separated abge _¬ and discarded. The organic phase was adjusted to a value ei _¬ NEN pH value of 7.5 adjusted. The characteristics of the product are summarized in Table 1:

Table 1 oleic acid 2-ethylhexyl ester sulfonate / sulfate

Anionic surfactant content 42.3% by weight

Unsulphated parts 42.0% by weight

Sodium sulfate 3.8% by weight

Water 11.9% by weight The anionic surfactant content (WAS) as well as the unsulfonated proportions (US) were determined according to the DGF standard methods, Stuttgart 1950-

1984, H-III-10 and G-II-6b determined.

Manufacturing example H2

Production of oleic acid 2-ethylhexyl ester sulfonate sodium salt. 362 g (1 mol) of technical oleic acid 2-ethylhexyl ester (based on olive oil fatty acid) were placed in a 1-1-sulphonation reactor with jacket cooling and reacted at 25 ° C. with 88 g (1.1 mol) of gaseous sulfur trioxide. The sulfur trioxide was expelled from a corresponding amount of 65% oleum by heating, αf was diluted to a concentration of 3% by volume and introduced into the starting product within 15 minutes. After the sulfonation, the acidic reaction mixture was stirred in portions into an aqueous 10% by weight base while maintaining a pH in the range from 7 and neutralized in the process. The characteristics of the product are summarized in Table 2:

Table 2 oleic acid 2-ethylhexyl ester sulfonate

Anionic surfactant content 26.3% by weight Unsulfated parts 3.5% by weight sodium sulfate 1.1% by weight water 69.1% by weight Example 1 ;

Manufacture of sheepskin leather. Wet blue material was first washed and then retanned. The information on the _{amounts used} and the duration of the process steps are summarized in Table 3. All percentages verste _¬ hen is based on the shaved.

Table 3:

Manufacture of sheep clothing leather

Process addition of quantity duration wt.% Min

Wash water (40 ° C) 200 10 new fleets

Water (40 ° C) 100 40 sodium formate 1 sodium bicarbonate 1 acrylate tanning agent 3 rinse off liquor (50 ° C)

Retanning, water (50 ° C) 100 30 dyeing naphthalene condensation test. 2

Dye 3 30 Table 3; Sheepskin Leather Manufacturing (Continued)

Process addition of quantity duration wt.% Min

Lecithin emulsion 3 40 ester sulfonate according to Hl 2 40 sulfited ester oil 3 40

Acrylate tanning agent 2 60

Formic acid 1 15

Rinse off the liquor (50 ° C)

A soft leather with a full, round handle and an even, flowery color was obtained.

Example 2;

Manufacture of furniture leather. Wet blue material was chen gewas _¬ retanned, neutralized, dyed and greased. The details of the amounts used and the duration of the process _steps are summarized in Table 4. All percentages are based on the fold weight. Table 4: Manufacture of furniture leather

Process addition of quantity duration wt.% Min

Wash water (45 ° C) 200 10 new fleets

Retanning water (45 ° C) 100 45 chromium sulfate (33% by weight) 2

Phenol condensation product 2 sodium aluminum silicate 1 rinse off liquor (40 ° C)

Neutralisa water (40 ° C) 100 60 tion sodium bicarbonate 2 new liquors

Color and water (50 ° C) 100 15 fats naphthalene condensation 2 product

ammonia

Dye 45

Lecithin emulsion 2 45 ester sulfonate according to Hl 5 sulfited ester oil 4

SPARE BLADE (RULE 26) Table 4; Manufacture of Furniture Leather (Continued)

Process addition of quantity duration wt.% Min

Formic acid 15

Formic acid 30

Rinse off the liquor (40 ° C)

Cloth-soft, chubby, slightly slimy furniture leather was obtained.

Example 3;

Production of beef suede. Crust leather was paperback and dyed. The information on quantities and duration of Ver _¬ procedural steps are summarized in Table 5 below. Center disclosures All Pro _¬ are based on the shaved.

Table 5; Production of beef suede

Process addition of quantity duration% by weight min

Booklet alkyl sulfate 1 240 ammonia 1 Table 5; Beef Velor Production (Cont'd)

Process addition of quantity duration wt.% Min

Color water (60 ° C) 300 60

Phenol condensation product 2

Ammonia 1

Dye 7

Formic acid 45

Wash ester sulfonate according to Hl 2.5 30 well

It was advertising a silky Velourlederfaser with brilliant Faer _¬ and get beautiful writing effect.

Example 4;

Manufacture of cowhide leather. Wet blue material was gewa _¬ rule, neutralized, washed again and retanned. The details of the amounts used and the duration of the process steps are summarized in Table 6. All percentages verste _¬ hen is based on the shaved. Table 6; Manufacture of cowhide leather

Process addition of quantity duration wt.% Min

Wash water (40 ° C) 200 10 new fleets

Neutralisa water (40 ° C) 100 15 tion of sodium formate 0.5 sodium aluminum silicate 0.5

Wash water (60 ° C) 100 10 new liquor

Retanning water (60 ° C) 100 15 naphthalene condensation product

Dye 1 15

Acrylate tanning agent 2 15

Phenol condensation product 3 30 Table 6:

Cowhide Leather Production (Cont'd)

Process addition of quantity duration wt.% Min

Ester sulfonate ¹ ) 3 45 Ester sulfonate according to Hl 3

Formic acid 0.5 15

1) addition product of 1 mole of SO3 to durcschnittlich ei _¬ NEN trimethylolpropane triölsäureester in the form of the ammonium salt

A very soft leather with good fullness and _uniform , brilliant coloring was obtained.

Comparative Examples VI to V4

Examples 1 to 4 were repeated, but instead of the oleic acid 2-ethylhexyl ester sulfonate salt, a sulfated ester oil from the trade was used. The resulting leather like _¬ sen on a harder grip and less Schmalzigkeit. In addition, an uneven coloring was observed.

Claims

1. Means for greasing leather and furs with a content of 1 to 30 wt .-% sulfonation products of unsaturated fatty acid lower alkyl esters in the form of their alkali metal, alkaline earth metal, ammonium, alkylammonium, alkanolammonium or glucammonium salts.

2. Composition according to claim 1, characterized in that they contain sulfonation products of unsaturated fatty acid lower alkyl esters of the formula (I),

R ¹ CO-OR ² (I)

in which R ^{1 is} an unsaturated acyl radical with 16 to 24 carbon atoms and 1, 2, 3, 4 and / or 5 double bonds and R ^{2 is} a linear or branched alkyl radical with 1 to 8 carbon atoms.

3. Composition according to claim 1, characterized in that they contain sulfonation products of 2-ethylhexyl oleic acid ent.

4. Use of sulfonation products according to claims 1 to 3 as anionic surfactants for the preparation of fatliquoring agents for leather and furs.