EP0964935B1 - Use of sulphation products of alkylene glycol diesters - Google Patents

Description

Field of the Invention

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

State of the art

In addition to the tannins, greasing agents are the most important tools to improve the character of leather shape. The effect of the greasing agents comes from a fiber-insulating lubrication and a Hydrophobization. By covering the leather fibers with a grease film the mutual Reduces friction and consequently improves the suppleness and stretchability of the fabric. This has positive effects on the tear resistance of the leather, because in a stretchy material many fibers align themselves in the direction of tension when subjected to tensile stress and then set to this Tear greater resistance to the same fibers within a brittle one Material. Through the hydrophobing, tanning effects are also achieved, since they are with a displacement of water from the skin.

• Die verseifbaren Fette und Öle sowie die natürlichen Wachse und Harze gehören zu den Estern. Unter Ölen und Fetten werden dabei vom Lederfachmann Ester aus Glycerin und Fettsäuren bezeichnet, die bei Raumtemperatur fest bzw, flüssig sind. Zur Lederfettung werden dabei aus der Gruppe der tierischen Fette insbesondere Trane, Fischöl, Rindertalg und Rinderklauenöl, aus der Gruppe der pflanzlichen Fette Rizinusöl, Rüböl und Leinöl herangezogen. In Wachsen und Harzen sind die Fettsäuren statt mit Glycerin mit hähermolekularen Alkoholen verestert. Beispiele für Wachse sind Bienenwachs, chinesisches Wachs, Caranubawachs, Montanwachs und Wollfett; zu den wichtigsten Harzen zählen Kolophonium, Juchtenöl und Schellack.
• Durch chemische Umwandlung pflanzlicher und tierischer Fette erhält man Produkte, die wasserlöslich sind und die darüber hinaus in unterschiedlichem Maße emulgierend auf wasserunlösliche Fettstoffe wirken. Bekannt sind etwa die sulfierten wasserlöslichen Öle verschiedenster Art, die durch Oxidation veränderten Trane, die als Dégras oder Moellon bezeichnet werden, ferner die Seifen, die bei der hydrolytischen Spaltung natürlicher Fette entstehen, gehärtete Fette sowie schließlich freie Fettsäuren wie Stearinsäure als Einbrennfette. Die meisten tierischen und pflanzlichen Fette weisen eine gewisse Affinität zur Ledersubstanz auf, die durch die Einführung oder Freilegung hydrophiler Gruppen noch beträchtlich gesteigert wird.
• Wichtig für die Lederherstellung sind weiter die mineralischen Fettungsmittel. Diese Kohlenwasserstoffe sind den natürlichen Fetten und Ölen in manchen Eigenschaften ähnlich, lassen sich jedoch nicht verseifen. Es handelt sich um Fraktionen der Erdöldestillation, die in flüssiger Form Mineralöl, in pastöser Form Vaseline und in fester Form Paraffin genannt werden.

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:

• The saponifiable fats and oils as well as the natural waxes and resins are among the esters. Oils and fats are termed esters of glycerin and fatty acids by the leather specialist, which are solid or liquid at room temperature. For leather greasing, from the group of animal fats in particular trane, fish oil, beef tallow and beef 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.
• The chemical conversion of vegetable and animal fats gives products that are water-soluble and, in addition, have different emulsifying effects on water-insoluble fats. For example, the sulfated water-soluble oils of various types are known, the tears modified by oxidation, which are referred to as dégras or moellon, the soaps which are formed during the hydrolytic splitting of natural fats, hardened fats and finally free fatty acids such as stearic acid as stoving fats. Most animal and vegetable fats have a certain affinity for the leather substance, which is considerably increased by the introduction or exposure of hydrophilic groups.
• Mineral greasing agents are also important for leather production. 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, the surface of the tanned and greased leather forms over the course of the Time unwanted spots called "fatty spew". fatty spew occur primarily on chrome-tanned leather after shorter or longer storage than white, often a veil-like covering that only covers individual areas or the entire leather surface. The rash is due to the release of solid fatty substances from the leather. He can through that natural fat present in the leather itself or caused by fatty substances that only occur in the course of greasing the leather has been incorporated. Fat mixtures used for greasing leather tend to have a particular tendency then to form a day when they contain a lot of free fatty acids. Show free fatty acids generally have a higher melting point than their glycerides. The hydrolytic cleavage of Fatty substances when storing the leather increases the risk of fat rashes.

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 show a different tendency to form fat rashes, the tendency to rash generally decreases with a longer lifespan [cf. J.lnt.Soc.Leath.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 location of the fat mixture of natural fat and lickerfat present in the leather are decisive for the extent and 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 fat rashes develop in the hair holes and gland canals, initially forming small crystals in the depth, which gradually fill the entire hair hole as larger fat crystals, swell out over the leather surface and matted into a dense crystal film. All fats that contain stearin or palmitin derivatives can cause crystalline fat rashes, the risk of rash increases with increasing concentration [ Ledertechn.Rundsch. 1 (1949) ]. In particular, the so-called neutral fats, ie substances suitable for leather greasing that do not contain any ionic groups in the molecule, eg fats, waxes and hydrocarbons, tend 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 step in order to achieve the desired product properties, it has become common practice to work with special synthetic greasing agents whose tendency to form a fat rash is low is. One class of fatliquor 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, European patent specification EP-B 0247509 (Stockhausen) discloses the addition products of sulfuric acid or oleum to unsaturated, alkoxylated and optionally epoxidized fats and oils. In addition to reactions with oleum, sulfuric acid or gaseous sulfur trioxide, sulfitation, ie the addition of hydrogen sulfite to unsaturated compounds, is particularly suitable for the hydrophilization of fatty substances. In this context, for example, A. Kuenzel reports on the sulfitation of Dorschtran [ Leder 8 , 5 (1957) ] and M. Mikula on the suifitation of unsaturated butyl fatty acid esters [ Leder, Schuh, Lederwaren 21 , 282 (1986) ]. German patent application DE-A1 4223704 (Henkel) also discloses nonionic lubricants containing oleic acid esters and dialkyl ethers. DE-A1 44 18 942 (Henkel) also relates to fatliquors containing sulfonated oleic acid esters.

However, the use of anionic fatliquoring agents is not without problems. An essential one The disadvantage is that a large number of these agents in use for the formation of Fat rashes tend to. Furthermore, their biodegradability is not always satisfactory. Sulphated oils are viscous in the area of high active substance contents and therefore can often only be dosing with difficulty; after all, their color quality is often unsatisfactory.

The complex object of the invention was therefore to find new greasing agents for leather and Develop furs based on anionic surfactants, which are characterized by improved ecological and application technology Properties such as more comfortable grip and less tendency to Mark out fat deposits. The feedstocks should also be compared to the known sulfated ones or sulfited fatty substances a better color quality and advantages in handling, especially in With regard to the production of liquid, low-viscosity products.

Description of the invention

The invention relates to the use of sulfation products of alkylene glycol diesters of the formula (I) R ¹ CO-O (CH ₂ ) _n O-OCR ¹ in which R ¹ CO stands for an unsaturated acyl radical with 16 to 22 carbon atoms and n for numbers from 2 to 4, in the form of their alkali metal, alkaline earth metal, ammonium, alkylammonium, alkanolammonium or glucammonium salts for the preparation of leather greasing agents and furs.

Surprisingly, it was found that the sulfation products of the alkylene glycol diesters according to the invention not only have excellent ecological properties, but in comparison with other known anionic fatliquoring agents have a significantly lower tendency to form Have fat rashes. In addition, they also give leathers an improved Schmalzig or. Suppleness, a pleasant grip and increased hydrophobicity. The sulfation products are also highly concentrated and low-viscosity and can therefore be easily dissolved in liquid, Incorporate aqueous formulations. In contrast to sulfated ester oils, they stand out additionally characterized by improved color quality while being different from sulfonated oleic acid esters are fully biodegradable even under anaerobic conditions.

sulfation

Sulfation products of alkylene glycol diesters are known substances, which according to the relevant methods of preparative organic chemistry can be obtained. Usually one starts from their production of alkylene glycols, preferably ethylene or propylene glycol, which are first esterified with unsaturated fatty acids, then the diesters with Sulfated acid or oleum sulfated and neutralized with aqueous bases. Typical examples are Diesters of ethylene glycol, propylene glycol and / or butylene glycol with oleic acid, elaidic acid, petroselinic acid, Linoleic acid, linolenic acid, ricinoleic acid, gadoleic acid and / or erucic acid and their technical blends. Due to the manufacturing process, the diesters can still have a monoester content below of 15% by weight. Sulfation products of propylene glycol dioleate are preferred used in the form of the ammonium, sodium or potassium salt.

sulfation

The sulfation 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 according to Working the falling film principle. are preferred. Sulfuric acid or preferably oleum are suitable as sulfonating agents. The molar ratio of ester to sulfating agent can be 1: 0.1 to 1: 0.95 and in particular 1: 0.25 to 1: 0.8. The sulfation is usually carried out at from 15 to 90.degree. 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, bleaching and preservation

The acidic sulfation products obtained in the sulfation 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-C _2-4 -alkanolamines, for example mono-, Di- and triethanolamine as well as primary, secondary or tertiary C _1-4 -alkylamines and glucamines into consideration. The neutralization bases are preferably used in the form of 5 to 55% by weight aqueous solutions, 5 to 25% by weight aqueous sodium hydroxide solutions being preferred. After neutralization, the sulfation products can be bleached in a manner known per se by adding hydrogen peroxide or sodium hypochlorite solution. Based on the solids content in the solution of the sulfation products, 0.2 to 2% by weight of hydrogen peroxide, calculated as a 100% substance, or corresponding amounts of sodium hypochlorite are used. 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.

cosurfactants

The sulfonation products according to the invention can be used alone, but preferably in a mixture with other anionic, nonionic, amphoteric or zwitterionic surfactants and - to a limited extent - also cationic surfactants. Typical examples of anionic surfactants are alkylbenzenesulfonates, alkanesulfonates, olefin sulfonates, alkyl ether sulfonates, glycerol ether, α-methyl ester sulfonates, sulfofatty acids, alkyl sulfates, fatty alcohol ether sulfates, Glycerol ether, Hydroxymischethersulfate, monoglyceride (ether) sulfates, fatty acid amide (ether) sulfates, mono- and dialkyl sulfosuccinates, mono- and Dialkylsulfosuccinamates, sulfotriglycerides, amide soaps, ether carboxylic acids and their Saize, 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, homogeneous distribution. Typical examples of nonionic surfactants are fatty alcohol polyglycol ethers, alkylphenol polyglycol ethers, fatty acid polyglycotesters, fatty acid amide polyglycol ethers, fatty amine polyglycol ethers, alkoxylated triglycerides, alk (en) yl oligoglycosides, fatty acid N-alkylglucamides, polyol fatty acid orbital esters, sugar esters. If the nonionic surfactants contain polyglycol ether chains, they can have a conventional, but preferably a narrow, homolog distribution. Typical examples of amphoteric or zwitterionic surfactants are alkyl betaines, alkyl amido betaines, aminopropionates, aminoglycinates, imidazolinium betaines and sulfobetaines. Typical examples of cationic surfactants with which the anionic sulfonation products are compatible and do not form poorly soluble salts are ester quats, especially 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, Tenside und Mineralöladditive ", Thieme Verlag, Stuttgart, 1978, pp . 123-217 .

fatliquors

In addition to the sulfation products and other surfactants, the fatliquoring agents can be other common ones Auxiliaries and additives included. The proportion of sulfation products is usually 15 to 90 and preferably 20 to 80% by weight of the agents according to the invention on the means. As a rule, the agents are dosed so that for 1 kg of leather or fur (calculated as Fold weight) 20 to 1000, preferably 30 to 80 g of the agent are eliminated.

Examples

Production of propylene glycol diol sulfate sodium salt . 420 g (0.7 mol) of technical-grade propylene glycol dioleate were placed in a 1-liter sulfonation reactor with jacket cooling, and 44 g of oleum (20% by weight of SO ₃ ) were added in portions at a temperature of from 31 to 33 ° C. 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. The aqueous phase containing the ammonium sulfate formed was then separated off and discarded. The organic value phase was adjusted to a pH of 7.5. The product contained 42.3% by weight of anionic surfactant, 42.0% by weight of unsulfated parts, 3.8% by weight of sodium suifate and ad 100% by weight of water. The anionic surfactant content (WAS) and the unsulfated content (US) were determined according to the DGF standard methods, Stuttgart 1950-1984, H-III-10 and G-II-6b.

Example 1:

Manufacture of sheep clothing leather . Wet blue material was first washed and then retanned. The details of the amounts used and the duration of the process steps are summarized in Table 1. All percentages are based on the fold weight. Manufacture of sheep's clothing leather (quantities as% by weight) process adding Quantity [%] Duration [min] To wash Water (40 ° C) 200 10 preparation Water (40 ° C) 100 40 sodium 1 sodium 1 Acrylatgerbstoff
Rinse the liquor (50 ° C) 3 To wash Water (50 ° C) 100 30 To dye Naphthalinkondensationsprodukt 2 30 dye 3 fats lecithin emulsion 3 40 Propylenglycoldioleatsulfat 2 40 Sulphited ester oil 3 40 tan Acrylatgerbstoff 2 60 aftercare formic acid
Rinse the liquor (50 ° C) 1 15

Example 2:

Manufacture of furniture leather . Wet blue material was washed, retanned, neutralized, dyed and greased in accordance with the information in Table 2. Soft, plump, slightly slimy furniture leather was obtained. Manufacture of furniture leather (quantities as% by weight) process adding Quantity [%] Duration [min] To wash Water (45 ° C)
New fleet 200 10 retanning Water (45 ° C) 100 45 Chromium sulfate (33% by weight) 2 Phenol condensation product 2 sodium aluminum silicate
Rinse the liquor (45 ° C) 1 Neutralization Water (40 ° C) 100 60 sodium 2 preparation Water (50 ° C) 100 15 Naphthalinkondensationsprodukt 2 ammonia 1 To dye dye 3 45 fats lecithin emulsion 2 45 Propylenglycoldioleatsulfat 5 Sulphated ester oil 4 aftercare formic acid
Rinse the liquor (40 ° C) 2 30

Example 3:

Production of beef suede. Crust leather was paperback and dyed; the results are summarized in Table 3. A silky suede fiber with brilliant coloring and a beautiful writing effect was obtained. Manufacture of beef velor (quantities as% by weight) process adding Quantity [%] Duration [min] Broaching Laurylsuffat 1 240 ammonia 1 To dye Water (60 ° C) 300 60 Phenol condensation product 2 ammonia 1 dye 7 pretreat formic acid 4 45 fats Propylene glycol diol sulfate water (60 ° C) 3 30

Claims (2)

1. The use of sulfation products of alkylene glycol diesters corresponding to formula (I): R¹CO-O(CH₂)_nO-OCR¹ in which R¹CO is an unsaturated acyl group containing 16 to 22 carbon atoms and n is a number of 2 to 4,
   in the form of their alkali metal, alkaline earth metal, ammonium, alkyl ammonium, alkanolammonium or glucammonium sats for the production of compositions for oiling leathers and pelts.
2. The use claimed in claim 1, characterized in that sulfation products derived from propylene glycol diacetate are used.