EP0247509B1 - Process for the manufacture of natural fat or oil derivatives, being liquid or having cold-flowing properties at room temperature, and their use - Google Patents

Description

The invention relates to a process for the preparation of derivatives of natural fats and oils which are liquid or flowable at room temperature and their use for leather greasing.

Natural fats and oils of vegetable and animal origin serve primarily for human nutrition. However, ever larger quantities are used as renewable raw materials in a wide variety of areas of industry. The technological usability of these products depends on the properties of the fats and oils. These in turn are mainly determined by their composition and molecular structure. Natural fats and oils essentially consist of triglycerides (neutral fats) and - to a lesser extent - phosphorus lipids and free fatty acids. The properties of this group of substances - this applies in particular to neutral fats - is determined by the type of fatty acids bound to the glycerol molecule in terms of chain length (short, medium and long chain), their degree of saturation and conformation (saturated, mono- or polyunsaturated, cis -, trans arrangement) and determined by the arrangement and amount per glycerol molecule.

Overall, this means that the structure of the building blocks of natural fats and oils ultimately determines their technological usability to a large extent and very often limits them if no changes are made to the molecule (Can) because cost reasons speak against it or because the desired modification is practically impossible to produce by conventional chemical means.

Previous techniques have shown that natural fats and oils have to be subjected to specific cleaning steps or separations into solid and liquid phases or hardening. The desired "fat chemicals" ultimately arise from the cleavage or reaction products of natural oils and fats: fatty acids, glycerin and fatty acid methyl esters - the actual oleochemical raw materials - and the fatty alcohols and fatty amines that are important because of their importance for various derivatives.

Since the molecular structure of natural fats and oils is determined by their origin, fats and oils as such are practically no usable "fat chemicals", "tailor-made" fats and oils must be produced through technical processes. The processes required for this are characterized by high energy consumption and high investment costs. In addition, they are often not very specific (risk of isomerization of the fatty acids, production of mixtures instead of uniform products, etc.).

• Für die technologische Verarbeitbarkeit von Fetten ist es wichtig, daß diese in fließfähiger Form vorliegen. Tierkörperfette, deren Einsatz für die Herstellung von Lederfettungsmitteln wünschenswert wäre, sind fest. Um diese einer Nutzung zugänglich zu machen, müssen sie verflüssigt werden. Dies kann geschehen, indem eine Fraktionierung durchgeführt wird. Dieses Verfahren ist aber aufwendig, mit hohem Energieverbrauch verbunden und auch relativ teuer.
• Auf der Suche nach möglichst billigen, in großer Menge zur Verfügung stehenden Ersatzfetten steht deren technologischen Eignung die Tatsache entgegen, daß es sich hierbei meist um Fette in fester Form handelt, die wiederum erst durch geeignete Maßnahmen verflüssigt werden müssen.
• Fette und Öle mit einer hohen Viskosität erlauben nur eine oberflächliche Fettung von Leder, so daß die Gefahr der Fettfleckigkeit auf dem so behandelten Leder gegeben ist. Ein qualitativ hochwertiges Leder muß duch Fett niedrigerer Viskosität gefettet werden, was wiederum die Einstellung einer bestimmten Viskosität erfordert.
• Für die technologische Weiterverarbeitung von Fetten für Lederfettungsmittel ist es häufig erforderlich, daß Doppelbindungen in den Fettsäuremolekülen vorhanden sind (z.B. zur Durchführung der Sulfonierung). Ausgangsprodukte solcher Art stehen bisher nur in den natürlichen Ölen, die zudem relativ teuer sind, zur Verfügung.
• Auf der anderen Seite sind mehrfach ungesättigte, d.h. entsprechend dünnflüssige Öle für die Lederfettung unerwünscht, weil hier aufgrund des hohen Gehaltes an ungesättigten Doppelbindungen die Gefahr der Verharzung besteht.

Examples from the leather auxiliaries industry should therefore be used to clarify that only with a certain composition of the fatliquor is it technologically usable taking into account specific requirements:

• For the technological processability of fats it is important that they are in a flowable form. Animal body fats, the use of which would be desirable for the production of leather greasing agents, are solid. In order to make them accessible for use, they must be liquefied. This can be done by performing a fractionation. However, this process is complex, involves high energy consumption and is also relatively expensive.
• In search of the cheapest possible replacement fats available in large quantities, their technological suitability is countered by the fact that these are mostly solid fats, which in turn have to be liquefied by suitable measures.
• Fats and oils with a high viscosity allow only a superficial greasing of leather, so that there is a risk of greasy stains on the leather treated in this way. A high quality leather must be greased with grease of lower viscosity, which in turn requires the setting of a certain viscosity.
• For the technological further processing of fats for leather greasing agents, it is often necessary for double bonds to be present in the fatty acid molecules (for example for carrying out the sulfonation). Source products of this type have so far only been available in natural oils, which are also relatively expensive.
• On the other hand, there are polyunsaturated, ie correspondingly low viscosity oils for leather greasing undesirable because there is a risk of resinification due to the high content of unsaturated double bonds.

For many decades, the liquid product sperm oil from the above for technical reasons the means of choice for the leather processing industry. Sperm oil gives the finished leather exceptional suppleness and has always been used to produce leather of the highest quality. In addition, the properties of low-quality leather could be improved by treatment with sperm oil so that it also met high quality standards.

As a result of efforts to protect sperm whale, the supplier of sperm oil, from extinction, the use of sperm oil in Europe was discontinued. In addition to lard oil (the liquid phase of lard), synthetically produced triolein was used as an exchange product for sperm oil, especially in the leather industry. Lubrication is usually carried out in O / W emulsions with the help of licker oils.

Licker oils are self-emulsifying products that consist of a neutral oil and an emulsifier. Depending on its charge character, there are anionic, cationic, amphoteric and nonionic fatliquoring agents. A distinction is often made between synthetic and native lickers, with the distinction between the two becoming more and more blurred. The majority of the emulsifier is either generated in neutral oil by, for example, partial sulfonation, or mixed into it as a separate component.

Sulfonated and sulfited native oils and fats contain α-sulfo fatty acids and hydroxysulfonates. Synthetic lickers contain alkane, α-olefin, dialkylbenzene and chloroparaffinsulfonates as well as long-chain fatty alcohol sulfonates, phosphoric acid, citric acid and alkyl succinic acid esters.

The emulsifying, mostly polar parts of a fatliquor are bound by the leather mainly in the form of ion bonds or by the formation of stable metal complexes in a non-extractable and non-migrable form.

The emulsified components are bound by van der Waals forces via polar groups. The emulsifying components influence the binding of the emulsified insofar as they are responsible for their distribution in the leather and exert an anchor effect through intermolecular forces.

• 1. Weichheit
• 2. Mechanische Eigenschaften wie Reißfestigkeit, Weiterreißfestigkeit, Dehnung, Narbenelastizität usw.
• 3. Fülle, Narbenfestigkeiten und Griffeigenschaften
• 4. Eigenschaften der Lederoberfläche für die nachfolgenden Finish-Prozesse

Greasing is a quality-determining process in the production of leather. This statement applies particularly to very soft types of leather. The following properties of the leather are decisively influenced by the greasing:

• 1. Softness
• 2. Mechanical properties such as tear resistance, Tear resistance, stretch, scar elasticity, etc.
• 3. Fullness, scar strength and grip properties
• 4. Properties of the leather surface for the subsequent finishing processes

It is known that softness is primarily due to separation of the fiber bundles and fibrils during drying. Accordingly, an essential criterion for the softening properties of a fatliquor is its ability to change the surface of the fibers and fibrils in such a way that no sticking occurs during drying. This property is very significantly influenced by the emulsifying proportions of the fatliquor. For the elastic properties, such as tensile strength, elongation, scar elasticity, etc., the lubricating effect of the emulsified parts of a fat licker plays a decisive role. The fibers "coated with the lubricant" have greater lubricity and, at the same time, reduced internal friction.

It can be assumed that a pronounced spreading capacity of the emulsified components has a decisive influence on their lubricating effect. As an explanation, it should be pointed out that spreading capacity means the property of a substance to spread in a monomolecular layer on the surface of a solid or liquid substance. The bigger that Spreading capacity, the lower the amount of substance required. Unfortunately, there are still no results of studies on the influence of the different spreading capacity of the emulsified parts of a fatliquor on the fatlip effect. One reason for this is the complex and complex measurement technology. In addition, the emulsifying parts of a fat liquor can strongly influence the spreading capacity of the emulsified parts.

The practitioner is familiar with the fact that the amount and type of greasing agent influence the fullness, grain strength and feel of the leather. As far as the filling effect is concerned, their assessment is almost always based on subjective observations. In special cases, however, the fullness can be determined objectively by measuring the increase in the thickness of the leather.

For thin types of leather up to a maximum thickness of approx. 1.2 mm - for large cattle hides - the filling effect of greasing agents is particularly evident. With the right choice of products and, if necessary, increased use, it is possible to reduce the otherwise necessary amount of retanning material or even to do without retanning altogether.

Achieving good scar strength is often a difficult problem to solve with soft leather types over 1.2 mm thick. The main reason for a "loose scar" is the different histological structure of the scar layer - papillary layer - on the one hand and reticular layer on the other.

Very often, however, the "loose scar" is caused by the wrong one Selection of the lubricant or an unsuitable lubrication technology causes. In order to avoid this leather defect, which affects quality, it is important to strive for a fat distribution over the leather cross section, which ensures that the mechanical properties, in particular the softness of the scars and reticular layer, are approximately the same in the critical border area of the two layers.

Finally, the "grip" of the leather also depends on the type, amount and properties of the fatliquor used. It cannot be measured objectively and is also difficult to define. In any case, the softness and firmness are only part of what the expert understands by this term. There are e.g. a "round" grip or "fixed" grip, and only specialists are able to give a handle on a leather correctly.

The physical properties of the leather surface for the subsequent finishing are decisively influenced by the structure of the fatliquor used. This applies above all to the absorbency of the leather surface, which is so important in modern dressing methods. It has already been mentioned that the usual licker lubricants consist of an emulsifying and an emulsified component. The emulsifying components are primarily responsible for the behavior of the leather surface for the subsequent processes. They determine the hydrophilic or hydrophobic character of the leather. Their ionic behavior also affects the electrical charge on the surface.

The reaction of fish oil with ethylene oxide condensates and subsequent sulfonation is known from IN-A-146 476.

It is an object of the invention, using fat raw materials, such as animal body fats, as starting materials, which are available in large quantities and are therefore inexpensive to contain solid or solid portions, as starting materials, in an energy-saving manner to convert these starting materials into derivatives which, in addition to the greasy and simultaneously emulsifying effect, and have high spreading capacity and are therefore particularly suitable as leather greasing agents.

This object is achieved by the method according to claim 1.
The oxalkylation is a reaction known per se. The mechanism of the oxyalkylation of a triglyceride which is practically free of active, ie reactive towards alkylene oxides, hydrogen atoms is discussed in "Tenside 3" (1966, volume 2, page 37). DE-AS 12 70 542 describes the reaction of fats which are solid and liquid at room temperature with alkylene oxides with the aim of changing the surface-active properties of the fats such that detergents, defoamers, emulsifiers etc. are formed.

Surprisingly, with the vegetable and / or animal fats used according to the invention which contain solid or solid portions at room temperature, the fatty nature of the oxyalkylation products is not only retained, but the application properties of these products as leather auxiliaries are even improved even more if the fats reacted with alkylene oxide are improved sulfited or sulfonated by known processes. The so obtained Products show at least the same greasing properties as products based on fats that are liquid at room temperature, such as claw oil or lard oil.
Due to the alkoxylation preceding the sulfonation, fatliquoring agents are obtained according to the invention, which deliver completely uniform emulsions with great yield, which are superior to the conventional fatliquoring agents with added emulsifier (the term "sulfonation" is understood here as a common generic term for the introduction of sulfate groups and sulfonic acid groups, which either by treatment with concentrated sulfuric acid or by oxidizing sulfitation into the fat molecule).
The fats which can be used according to the invention as starting materials basically include all triglycerides and their mixtures with free fatty acids, mono- and / or diglycerides. Of particular practical importance is the conversion of fats or oils that are solid at room temperature and have a cloud point above that of the Lard oil.

The following Table 1 shows the composition, determined by gas chromatography, of 2 examples of fats (fat 1 and fat 2) to be used according to the invention in comparison to lard oil:

It is not absolutely necessary to use fats of a certain origin, but e.g. Use fat 1 and 2 from Tab. 1 as a mixture. Or, for example, mixtures of bone fat and rind fat can be used.

The fats that can be used can also be partially broken down, so that free fatty acid is also present in addition to mono- and diglycerides. The acid number of the Fats are not critical, as oxyalkylation experiments with the addition of free fatty acids have shown.

The oxyalkylation can be carried out in the presence of small amounts of water, such as those found in natural fats, or introduced by means of an aqueous catalyst solution.

Ethylene oxide, propylene oxide, butylene oxide, styrene oxide, 1,2-epoxy butadiene and 1,2-epoxy cyclohexene are used as 1,2-epoxides. If more than one epoxy is used, these can be reacted with the fats both in succession and as a mixture. Propylene oxide is preferred for the oxyalkylation.

Basic compounds such as sodium and potassium hydroxide in solid form or as an aqueous solution, sodium methylate or the alkali metal salts of fatty acids are used as catalysts for the reaction of the alkylene oxides with the fats, potassium hydroxide being preferred.

The reaction is carried out using a known method at elevated temperature. In order to achieve a rapid reaction of the alkylene oxides, a reaction temperature in the range from 150 to 170 ° C, e.g. of 160 ° C proved to be useful.

Depending on the consistency of the fats, 5 to 100% by weight of alkylene oxide, preferably 10 to 25% by weight of alkylene oxide, based on the amount of fat, are added.
The alkoxylation is advantageously carried out at normal pressure up to 10 bar.

If the alkoxylation with several 1,2-epoxides carried out, the epoxides can either be reacted in succession with the starting fats, or the reaction can be carried out with a mixture of the epoxides. If more than one 1,2-epoxide is used, propylene oxide and ethylene oxide are preferably used.

Following the alkoxylation, the oxyalkylated fats are sulfonated using methods known per se. The sulfonation can be carried out with concentrated sulfuric acid at room temperature to slightly elevated temperature (from approx. 30 ° C) for a few hours. The amount of concentrated sulfuric acid is advantageously 15 to 35, preferably 20 to 30% by weight, based on the oxyalkylation product. Alternatively, sulfonic acid groups can be introduced by treatment with sodium disulfite in the presence of atmospheric oxygen. Following the sulfation or sulfitation, the product obtained is expediently adjusted to a pH near the neutral point (e.g. pH 6.5) with aqueous alkali. For the sulfonation, the alkoxylated fats obtained in the first process step can contain hydrocarbons and / or further unsaturated fats or fat components such as e.g. Olein can be mixed.

The sulfonation can be carried out immediately after the oxyalkylation, the oxyalkylation products need not be isolated. According to a further embodiment of the invention, the oxyalkylated fats are epoxidized before the sulfonation. This can be done in a known manner, for example with hydrogen peroxide in the presence of formic acid respectively.
The sulphation is preferably carried out with an SO₃ / air mixture with a content of up to 8 vol .-% SO₃ at temperatures of 20 to 50 ° C.

The oxyalkylation products are advantageously freed from volatile constituents (for example by distillation, if appropriate in vacuo).
The great advantage of the process according to the invention is that low-quality, dark-colored fats can be used, which are normally characterized by an increased proportion of free fatty acids, for example 5 to 15%. Nevertheless, you get relatively light-colored, low-odor products.

Example 1:

2000 g bone fat with the characteristic data: acid number (SZ) = 27; Iodine number (JZ) = 54; Saponification number (VZ) = 198; Solidification point (EP.) = 25 ° C are mixed in a temperature-controlled stirred autoclave with 20 g of 45% potassium hydroxide solution and carefully flushed with nitrogen. After heating to 160 ° C., 354 g of propylene oxide are added in portions so that the reactor temperature can be kept in the range from 155 to 165 ° C. and the pressure of 4 bar is not exceeded. Each time the epoxy is added, the reaction is waited for - as can be seen from the drop in pressure to normal pressure. The time required for the gradual addition of the monomer is 1.5 hours. Thereafter, the mixture is left to react at 160 ° C. for 30 minutes and the reaction mixture is stripped to remove volatile constituents. After neutralization at approx. 40 ° C with Concentrated sulfuric acid produces an oil that is slightly cloudy at 20 ° C and solidifies at around 11 ° C. JZ = 48.7.

Example 2:

2000 g dark brown animal fat of inferior quality with the characteristics: SZ = 10; JZ = 55; VZ = 197; EP. = 23 ° C are mixed with 40 g of 30% sodium methylate solution in a temperature-controlled stirred autoclave and freed of oxygen and volatile components by alternately evacuating to approx. 20 mbar and venting with nitrogen while heating to 120 ° C. At an internal reactor temperature of 160 ° C., 354 g of propylene oxide are metered in, as described in Example 1. After neutralizing the reaction mixture with concentrated acetic acid, an opal oil is obtained which solidifies at approx. 12 ° C.

Example 3:

A beef tallow with the characteristic data: SZ = 2.0; JZ = 45; VZ = 198; EP. = 34 ° C is as described in Example 1, but reacted with 25 wt .-% propylene oxide. After neutralization with p-toluenesulfonic acid, cloudy oil is obtained at 20 ° C.

Example 4:

2000 g of animal body fat with the characteristic data: water content = 0.58%; Solidification point = 23 ° C; SZ = 10; VZ = 197; Iodine number = 54.6 is reacted as in Example 1 with 354 g of propylene oxide. After completion of the reaction - recognizable by the constant pressure in the reactor - Are at 155 to 160 ° C and a max. Reaction pressure of 4 bar 176 g of ethylene oxide were metered in in portions. After the reaction has ended, volatile constituents are removed by applying a reduced pressure of approximately 20 mbar, the reaction product is cooled to approximately 40 ° C. and neutralized with sulfuric acid.

Example 5:

The animal body fat as in Example 4 is reacted as in Example 4 with propylene oxide and ethylene oxide, but with the measure that the alkylene oxides are metered into the reactor in portions and not as a mixture. After working up, an oil which is slightly cloudy at 20 ° C. is obtained.

Example 6:

2000 g of the fat used in Example 1 are placed in a pressure reactor and mixed with 20 g of 45% potassium hydroxide solution. During the heating process, the purge is carefully flushed with pure nitrogen. At a temperature of 160 ° C, 354 g of ethylene oxide are added in portions so that the reaction temperature can be maintained and a pressure of max. 6 bar is not exceeded. After the epoxide has reacted, the mixture is cooled and adjusted to pH = 5 with sulfuric acid. A yellow, cloudy oil is obtained.

Example 7:

1000 g of the reaction product from Example 1 are sulfonated at about 30 ° C. with 300 g of concentrated sulfuric acid for 5 hours. After neutralization with 30% sodium hydroxide solution to pH = 6.5, the salt water is separated off and a liquid, red-brown, clear sulfonate is obtained. Organ. born SO₃ = 5.1%.

Chromium-tanned, retanned with vegetable, synthetic and resin tanning, colored shoe upper leather with a fold thickness of approx. 2 mm from cowhides are licked at 50 ° C for 45 minutes with 100% liquor and 7% of the product obtained (based on fold weight). The Leather is dried and finished in the usual way. You get very soft leather with a high degree of grain and color uniformity.

Example 8:

A mixture of 700 g of reaction product from Example 2 and 300 g of a hydrocarbon mixture of chain length C₁₀ to C₃₀ is oxidized at 90 to 120 ° C with air until the iodine number decrease is 22 and the SZ has increased by 16. The oxidate is sulfited at 70 to 80 ° C by adding 9% sodium disulfite and then adjusted to pH 6.5 with ammonia. An oil which is opal at 20 ° C. is obtained.

Chromium-tanned, retanned with anionic polymer tanning agent, colored cowhides, fold thickness 0.8 to 1.0 mm, are licked at 50 ° C. in 150% liquor for 60 minutes with 10% of the product obtained (based on fold weight). After drying and finishing in practice, you get very soft, supple clothing and furniture leather with very little mill grain and high light resistance.

Example 9:

A mixture of 700 g of reaction product from Example 2 and 300 g of a hydrocarbon mixture of chain length C₁₀ to C₃₀ with a SZ = 3 and a JZ = 56.1 is obtained by known methods (see Houben-Weyl, Vol. 14/2, P. 548) epoxidized with hydrogen peroxide in the presence of formic acid. After the aqueous phase has been separated off, the washed and dried sample shows the following characteristic numbers: SZ = 5.0; JZ = 14.5; Epoxy oxygen = 1.1%. The sulfation is carried out by carefully entering 100 g of concentrated sulfuric acid at max. 30 ° C within 2 hours. For the purpose of post-reaction, the mixture is stirred for a further hour at 30 ° C and then adjusted to pH 5.5 with 30% sodium hydroxide solution. After washing with 1000 g of 20% sodium chloride solution, a yellow, emulsifiable oil is obtained, the pH of which is adjusted to 6.5 to 7.0 to improve the storage stability.

White or colored chrome-tanned nappa leather from sheepskins are retanned with synthetic and / or polymer and / or resin tanning agents and leaked at 50 ° C. for 60 minutes with 200% liquor and 12% of the product obtained (based on the shaved weight). After the usual completion, soft nappa leather with a round handle, good speed, low loose grain and high light resistance is obtained.

Comparative example 1:

560 g of the bone fat used in Example 1 with the solidification point of 25 ° C are mixed according to Example 4 with 240 g of a hydrocarbon mixture of chain length C₁₀ to C₃₀ and 200 g of olefin and sulfonated. The sulfonate obtained after working up is inhomogeneous and not suitable for the production of liquid products that can be used as leather greasing agents.

Examples 10-12

The starting material is one at room temperature cloudy, dark brown fish oil with strong sediment and typically unpleasant smell of oil and the following characteristics are used:
SC: 21.7; JZ: 161; VZ: 184
Clear point: not clear up to 100 ° C.

This product is reacted according to Example 1, so that the end product contains 5, 10 and 15% by weight of propoxy groups:

Examples 13-18

800 g (750 g) of propoxylated fish oil from Examples 10 to 12 are placed in a temperature-controlled sulfonation flask equipped with an anchor stirrer and dropping funnel. 160 g (225 g) of 97% strength sulfuric acid are added dropwise from the dropping funnel in 5 hours at a temperature of 32 ° C. with vigorous stirring. For post-reaction, one is left at 32 ° C stir for another hour. By adding 30% sodium hydroxide solution, the temperature rising to about 70 ° C., the pH of the resulting emulsion is adjusted to 6.8. The emulsion is separated into crude sulfonate and salt water by allowing the emulsion to stand at approx. 70 ° C. The aqueous phase is discarded and the sulfonate is adjusted to pH 8.3 with 45% sodium hydroxide solution:

Odor assessment of the products from Examples 13-18:

Hardly noticeable smell with a 20% H₂SO₄ offer
Traniger smell with 30% H₂SO₄ offer not detectable

Example 19

With 10% by weight (based on shaved weight) of a clear mixture of 50% by weight sulfonate from Example 18, 35% by weight white oil, 2% emulsifier and 13% by weight water is a chrome-tanned, with an anionic polymeric tanning agent retanned upper leather licked at 50 ° C in 150% liquor for 1 hour. After drying and finishing, you get very soft, supple furniture leather with a perfect smell.

Comparative Example 2

Geruchsbeurteilung:

deutlich tranig

The fish oil used in Examples 10 to 12 is sulfated and worked up with 97% sulfuric acid without prior reaction with propylene oxide according to Examples 13 to 18: Offer of 97% H₂SO₄ (% by weight) organ. born SO₃ (wt .-%) Water content (% by weight) Appearance at 20 ° C 20th 4.3 20.3 cloudy oil 30th 4.9 19.9 dto

Odor assessment:

clearly oily

The mixture according to Example 19 does not give a clear leather greasing agent.

Claims (16)

1. A process for the production of derivatives of natural fats and oils being liquid or flowable at room temperature, respectively, whereby that fats that are solid at room temperature or contain solid fractions, mixtures of these with free fatty acids,mono- and/or diglycerides are oxalkylated at elevated temperatures in the presence of basic catalysts with at least one 1,2-expoxide, and the obtained reaction products are sulphonated, optionally after epoxydation, in a manner known per se.
2. A process according to claim 1, characterized in that the oxalkylation is carried out at temperatures in the range from 150 to 170, preferably 155 to 165°C.
3. A process according to any one of claims 1 or 2, characterized in that 5 to 100%-wt of 1,2-epoxide, preferably 10 to 25%-wt of 1,2-epoxide, relative to the quantity of fat used are added.
4. A process according to any one of claims 1 to 3, characterized in that ethylen oxide, propylene oxide, butylene oxide, styrene oxide, 1,2-epoxy butadiene and/or 1,2-epoxy cyclohexene are used as 1,2-epoxides.
5. A process according to any one of claims 1 to 4, characterized in that the oxalkylation is carried out in the presence of sodium hydroxide, potassium hydroxide, sodium methylate or alkaline salts of fatty acids.
6. A process according to any one of claims 1 to 5, characterized in that during oxalkylation with more than one epoxide, the epoxides are reacted one after the other or in admixture with the fats.
7. A process according to any one of claims 1 to 6, characterized in that th oxalkylation is carried out with propylene oxide and/or ethylene oxide.
8. A process according to any one of claims 1 to 7, characterized in that the oxalkylation products, optionally in mixture with hydrocarbons and/or unsaturated fatty acids, are sulphonated with concentrated sulfuric acid or sodium disulfite and atmospheric oxygene in a manner known per se, and the obtained reaction products are neutralized.
9. A process according to any one of claims 1 to 8, characterized in that the oxalkylation products are epoxidized prior to sulphonation.
10. A process according to any one of claims 1 to 9, characterized in that solid fats or oils with a turbidity point above the turbidity point of lard oil are used as starting materials.
11. A process according to any one of claims 1 to 10, characterized in that the oxalkylation is carried out at pressures from 1 bar to 10 bar.
12. A process according to any one of claims 1 to 11, characterized in that the sulphonation is carried out with concentrated sulfuric acid in quantities of 15 to 35, preferably 20 to 30%-wt, relative to the amount of oxalkylation product.
13. A process according to any one of claims 1 to 11 , characterized in that the sulphonation is carried out with an SO₃/air mixture having a content of up to 6%-vol SO₃ in a temperature range of 20 to 50°C.
14. Liquid or flowable derivatives of natural fats and oils, obtainable by reaction of fats or fats comprising solid fractions, respectively, mixtures of these with free fatty acids, mono- and/or diglycerides at elevated temperatures in the presence of basic catalysts having at least one 1,2-epoxide, and optionally epoxidization of the oxalkylation products obtained and subsequent sulphonation, optionally in admixture with hydrocarbons and/or unsaturated fatty acids with concentrated sulfuric acid or sodium disulfite and atmospheric oxygene and neutralization of the products obtained.
15. A process for the fatting and fatliquoring of leather, especially for fatliquoring, characterized in that the leather is treated with a product as claimed in claim 14.
16. A process according to claim 15, characterized in that the fatliquoring is carried out in aqueous float with 3 to 15%-wt of fat liquors and greases, relative to the shaved weight of the leather to be fatliquored.