EP0231891A2 - Ester sulfonates containing surface-active concentrations and their use - Google Patents

Abstract

The ester sulfonate-containing surfactant concentrates contain (a) one or more surfactants in an amount of 50 to 70% by weight, based on the total weight of the concentrates, from the groups alkali salts of α-sulfonated fatty acid alkyl esters as anionic surfactants and linear aliphatic fatty alcohol polyglycol ethers as nonionic surfactants a ratio of anionic surfactant: nonionic surfactant in the range from 1: 0.3 to 1: 3, (b) one or more saturated and / or unsaturated linear aliphatic carboxylic acids in amounts of 10 to 30% by weight, based on the total weight of the concentrates , and (c) water in amounts of 0 to 10 wt .-%, based on the total weight of the concentrates. The invention also relates to the use of such concentrates in detergents, dishwashing detergents and cleaning agents for household and industrial purposes.

Description

The invention relates to ester sulfonate-containing surfactant concentrates and their use in household and industrial cleaners.

In large-scale industrial processes, α-sulfofatty acid ester salts are formed in the form of aqueous pastes by neutralizing α-sulfofatty acid esters with aqueous alkali metal hydroxide. Fats and / or oils of natural origin, which are obtained by ester cleavage and subsequent esterification with lower alkanols, in particular methanol, or by transesterification of natural triglycerides with lower alkanols, serve as the technical starting material. Depending on the origin of the natural raw material, the resulting fatty acid ester mixtures contain fatty acids of a comparatively wide range of the chain length of the alkyl chains. Fatty acids with 10 to 24 carbon atoms are usually used. Tallow oil or palm oil are preferred as natural raw materials.

The sulfonation of the fatty acid ester mixtures with gaseous SO₃ leads to more or less discoloration ten acidic crude sulfonates, which are bleached and converted into ester sulfonate pastes by neutralization to a pH of about 6 to 7. Such pastes are of increasing practical importance today as surface-active agents or wetting agents for detergents and cleaning agents which can be produced from native raw material sources.

The technical handling of such pastes of alkali salts of α-sulfonated fatty acid alkyl esters (also referred to as "ester sulfonate salts") presents difficulties insofar as such pastes show exceptional concentration / viscosity behavior. Such solutions or suspensions can only be moved and pumped sufficiently well in comparatively low solids concentrations in water, for example up to solids contents of about 35% by weight, without interfering with the course of technical processes. Products which have a viscosity below 10,000 mPas at a temperature of approximately 70 ° C. are generally referred to as “pumpable”. Higher solids contents (from about 40% by weight) in ester sulfonate salt solutions or suspensions lead to a disproportionately high increase in the viscosity, so that the mixtures can no longer be freely moved or pumped. This results in several serious disadvantages: Highly concentrated ester sulfonate salt pastes cannot be neutralized immediately by neutralizing the crude sulfonic acid mixture with aqueous alkali hydroxide solution, since the stirrability and thus the uniform mixing of the components of the neutralization reaction can no longer be guaranteed. In addition, on an industrial scale, it is not possible dissipate the heat of neutralization to the required extent. The resulting increase in the concentrations or the reaction temperature leads to undesired side reactions, including, in particular, an undesirably high formation of disalts of α-sulfofatty acid with ester cleavage. Furthermore, it is to be regarded as a disadvantage that, due to the increase in viscosity, the ester sulfonate pastes obtained can no longer be pumped off or moved via pipelines in large-scale operation. There is a closure of the pipelines and thus a lasting disruption to the operation of the entire system.

In the meantime, numerous solutions have been proposed to improve this situation. DE-OS 33 05 430 proposes the addition of long-chain, optionally substituted alcohols as viscosity regulators. A viscosity reduction below the desired value of 10,000 MPas at 70 ° C. can thus be achieved.

According to the teaching of DE-OS 33 34 517, aqueous slurries of α-sulfofatty acid ester salts which contain an addition of lower alcohol sulfates and lower alcohols should be sufficiently mobile. The compounds mentioned for lowering the viscosity are first introduced into the reaction mixtures in higher concentrations than ultimately required and then removed again by concentration.

The disclosure of DE-OS 31 23 681 is primarily for the preparation of a highly concentrated aqueous solution of an α-sulfofatty acid ester salt, the crude sulfonic acid with caustic alkali solution in the presence neutralize a lower alcohol to a pH of 2.5 to 4 and then bring the pH to the required level in the range of 6 to 7 in a second neutralization step by adding further alkali solution.

The aforementioned proposals of the prior art relate to the usual technical feedstocks (fatty acids) of natural origin with a comparatively wide range of alkyl radicals in the natural fatty acid mixture (C₁₀ to C₂₄). With a narrower range of the chain length of the alkyl radical in the native fatty acids (for example C₁₆ to C₁₈), as occurs, for example, in the splitting of sebum fat or the processing of palm oil, the measures for lowering the viscosity can be significantly reduced. This is the subject of patent application P 34 39 520.2. According to the application, aqueous pastes of ester sulfonate salts which have been prepared on the basis of C₁₆ or C₁₈ fatty acids have solids contents of at least 60% by weight and are still pumpable at 60 ° C, although they are practically free from viscosity regulators. A disadvantage of such ester sulfonate salt pastes, however, is that, according to the aforementioned German patent application P 34 39 520.2, they have comparatively large contents of "disalt", ie of disalts of α-sulfofatty acid, which were formed by cleaving the ester in a strongly alkaline medium . Such salts, the proportion of which can make up to 25% by weight of the technical ester sulfonates, are highly undesirable as a by-product since they significantly impair the rheological properties of the pastes. For high quality ester sulfo natpaste is therefore desirable to have a "disalt" content below 25% by weight.

The object of the invention was to provide alkali salts of α-sulfonated fatty acid alkyl esters in a form which is flowable and pumpable at low temperature, i.e. Alkali salts that have a viscosity below 10,000 mPas. Such ester sulfonate salts should be made available in the highest possible active substance contents, i.e. the surfactant contents in the concentrates should be well above 50%.

It has now surprisingly been found that concentrates of alkali metal salts of α-sulfonated fatty acid alkyl esters are obtained which are flowable and pumpable at low temperature if ester sulfonates are nonionic surfactants and fatty acids and, if appropriate, small amounts of water in amounts such that the content of detergent substances (ester sulfonates + Disalze + nonionic tenside + fatty acids) makes up 90 to 100 wt .-%, adds. The invention relates to ester sulfonate-containing surfactant concentrates which (a) one or more surfactants in an amount of 50 to 70% by weight, based on the total weight of the concentrates, from the groups (α) alkali metal salts of α-sulfonated fatty acid alkyl esters from fatty acids with 16 and / or 18 carbon atoms and alcohols with 1 to 8 carbon atoms in the alkyl radical and (ß) linear aliphatic fatty alcohol polyglycol ethers with 10 to 20 carbon atoms in the alkyl radical of the alcohol and 3 to 15 ethoxy groups in the molecule, the ratio of the surfactant components ( α): (β) is in the range from 1: 0.3 to 1: 3, (b) one or more saturated and / or unsaturated, linear aliphatic Carboxylic acids with 8 to 22 carbon atoms in amounts of 10 to 30% by weight, based on the total weight of the concentrates, and (c) water in amounts of 0 to 10% by weight, based on the total weight of the concentrates . In addition, the surfactant concentrates may contain other constituents, such as, for example (apart from disalting), other minor constituents present in the production of the main constituents, which can constitute up to about 25% by weight. The invention also relates to the use of such concentrates in washing, rinsing and cleaning agents for household and industrial purposes in amounts of 1 to 15% by weight of washing-active substance, based on the total weight of the washing, rinsing and cleaning agents.

The surfactant concentrates containing estersulfonate according to the invention contain one or more surfactants as main component (a). The surfactant component of the concentrates is composed of two groups of surfactants: the concentrates contain anionic surfactants (α) and nonionic surfactants (ß). According to the invention, the alkali salts α-sulfonated fatty acid alkyl esters known per se from the prior art are used as anionic surfactants. Lithium salts, sodium salts, potassium salts or rubidium salts are suitable as such. Because of the optimal availability of the raw materials (sodium hydroxide solution or soda or potassium hydroxide solution or potash), the sodium salts and potassium salts of the α-sulfonated fatty acid alkyl esters are preferred.

The fatty acid alkyl esters come from the group of esters of fatty acids with 16 and / or 18 carbon atoms. Fatty acids of this type are found in workup processes for natural fats and / or oils in large quantities. Thus, the extraction of oleic acid by splitting tallow fat according to the so-called "cross-linking process" or working up palm oil leads to a product that contains fatty acids of chain length C₁₆ and C₁₈ in a ratio of approximately 1: 1. Such fats and / or oils of native origin are therefore particularly well suited as a starting material for the surfactants in the surfactant concentrates according to the invention. However, other sources of fatty acids are also available. So the extraction of the so-called palm stearin from palm oil leads to fatty acid mixtures with a C₁₆: C₁₈ ratio of about 60:40. Also, the fatty acid cuts occurring in the practical process of sebum processing are often in the C number range mentioned. In addition, hardened soybean oil also contains predominantly fatty acids of chain length C₁₆ and C₁₈. In addition to the native sources mentioned, other sources are also conceivable, in particular those which make fatty acids of the chain length mentioned available after chemical conversion, for example curing by upstream hydrogenation steps.

The alkali metal salts of α-sulfonated fatty acid alkyl esters contained as anionic surfactants contain alcohols with 1 to 8 carbon atoms in the alkyl radical as the ester component. As such, methanol, ethanol, propanol, isopropanol, butanol, sec-butanol, isobutanol, tert-butanol and also pentanol, hexanol, heptanol and octanol and their isomers are suitable. Alcohols with 1 to 4 carbon atoms in the alkyl radical are preferred, methanol and ethanol in particular being used with advantage. The fatty acid alkyl esters are formed by transesterification from natural sources available fats and oils or by direct esterification of the previously pure fatty acids.

The introduction of the sulfo group in the α-position takes place according to known methods, primarily by reacting the corresponding fatty acid ester or fatty acid ester mixture with gaseous SO₃. The compounds obtained are processed further by methods known per se, i.e. for example bleached and neutralized.

In addition to the anionic surfactants mentioned, the ester sulfonate-containing surfactant concentrates according to the invention also contain nonionic surfactants from the group of linear, aliphatic fatty alcohol polyglycol ethers. Such fatty alcohol polyglycol ethers are produced in processes known per se by reacting long-chain fatty alcohol with ethylene oxide in the molar ratio desired for the product. The fatty alcohols used have an alkyl chain length of 10 to 20 carbon atoms, preferably 10 to 16 carbon atoms. Undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol or eicosanol are suitable as such fatty alcohols.

The linear aliphatic fatty alcohols mentioned are ethoxylated with ethylene oxide in a molar ratio of 1: 3 to 1:15, so that the average content of ethoxy groups in the molecule of the fatty alcohol polyglycol ether is in the range from 3 to 15 ethoxy groups per molecule. A content of ethoxy groups in the range from 3 to 10 per molecule is preferred.

The surfactants mentioned from the two groups of anionic and nonionic surfactants can be used individually or in mixtures with one another as one of the components of the ester sulfonate-containing surfactant concentrates according to the invention. The ratio of the anionic to the nonionic surfactants (components (α): components (β)) according to the invention is in the range from 1: 0.3 to 1: 3, preferably in the range from 1: 1 to 1: 2.

A total of 50 to 70% by weight of surfactants (ester sulfonates + nonionic surfactants) are present in the concentrates, based on the total weight of the concentrates. Concentrates which contain the surfactants mentioned in an amount of 50 to 60% by weight, based on the total weight of the concentrates, are preferred.

The concentrates according to the invention contain one or more saturated and / or unsaturated, linear aliphatic carboxylic acids as a further component. These are primarily saturated or unsaturated fatty acids with 8 to 22 carbon atoms. Such fatty acids, like the fatty acids mentioned above, can originate from natural sources or have already been modified from them by chemical reaction. The fatty acids in particular come from caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, strearic acid, nonadecanoic acid, arachic acid and behenic acid as saturated fatty acids, palmitoleic acid, oleic acid and erucic acid and unsaturated linoleic acid in unsaturated fatty acid and linoleic acid . Are preferred as Fatty acid component is the oleic acid accessible from sebum fat cleavage as well as palmitic acid, stearic acid and linoleic acid, ie fatty acids with 16 and / or 18 carbon atoms.

The amount of fatty acid in the concentrates according to the invention is in the range from 10 to 30% by weight, based on the total weight of the concentrates, preferably in the range from 15 to 20% by weight. In general, the chain length of the fatty acids added does not have a significant effect on the change in viscosity of the concentrates according to the invention, i.e. in principle, all fatty acids work equally well.

If appropriate, the ester sulfonate-containing surfactant concentrates according to the invention can also contain water. If a water content is provided, this is in the range of 1 to 10% by weight, preferably in the range of 2 to 5% by weight. This means that the concentrates according to the invention are products which, depending on the water content, have a detergent content in the range from 90 to 100% by weight.

The concentrates according to the invention with the specified components can advantageously be used in detergents, dishwashing detergents and cleaning agents for household and industrial purposes. For this purpose, the concentrates are added to customary cleaning liquors in amounts of 1 to 15% by weight of washing-active substance, based on the total weight of the washing, rinsing and cleaning agents. The amount used depends on various parameters such as water hardness, application area, etc.

Surprisingly, it has been found that the detergents and cleaning agents produced using the surfactant concentrates according to the invention show equally good or even better washing results even at a lower content of detergent substance compared to the prior art. It follows that detergent formulations based on alkylbenzenesulfonates with 11% by weight of detergent-active substance give at most equally good, but mostly significantly worse wash results than detergents based on the estersulfonate-containing concentrates proposed by the present invention at low levels of detergent-active substance.

Examples

The invention is illustrated by the following examples.

The powdered technical product Texin® ES 68 was used as the anionic surfactant (component (α)). It contained 69% by weight of tallow fatty acid methyl ester sulfonate sodium salt and 16% by weight of disalt.

The viscosity of the surfactant concentrates was measured in a Höppler viscometer.

example 1 Production of a concentrate containing estersulfonate.

The inventive ester sulfonate-containing surfactant concentrate was produced using the "Texin® ES 68 in powder form" anion surfactant (described above).

48 g of an adduct of 7 moles of ethylene oxide with an oleyl / cetyl alcohol mixture were introduced in a mixture with coconut / palm kernel oil fatty acid in different concentrations (see FIG. 1). 28 g of Texin® ES 68 were introduced into this mixture and completely dissolved at elevated temperature. The solution was further stirred for 1/2 h. Its viscosity at 20 ° C was 1800 mPas.

Example 2 Production of another surfactant concentrate containing estersulfonate directly from the acidic ester sulfonate.

44.5 g of an adduct of 7 moles of ethylene oxide with oleyl / cetyl alcohol and 27.0 g of coconut / plamkern oil fatty acid were introduced and 23.5 g of acidic ester sulfonate were introduced into this mixture and dissolved. 5.0 g of a 50% sodium hydroxide solution were then added dropwise with vigorous stirring. The alkali metal salt of the ester sulfonate formed in this mixture with slight evolution of heat. The viscosity of the mixture was 1650 mPas (20 ° C).

Example 3 Dependence of viscosity on temperature and fatty acid content.

28 parts by weight of Texin® ES 68 in powder form were mixed with 48 parts by weight of an adduct of 7 mol of ethylene oxide and oleyl / cetyl alcohol. 5 to 40 parts by weight (see FIG. 1) of coconut oil / Plamkernöl fatty acid were added to the mixture in portions.

As can be seen from FIG. 1, the value for the viscosity dropped sharply above a fatty acid content of approximately 10 parts. Fatty acid concentrations above 20 parts showed no further reduction in viscosity.

The viscosity behavior as a function of the fatty acid content was also temperature-independent in the measuring range from 20 to 40 ° C.: As can be seen from FIG. 1, comparable reductions in viscosity measured above a fatty acid content of approx. 10 parts.

Adding water to the system described in FIG. 1 resulted in a reduction in viscosity even at a significantly lower fatty acid concentration. As shown in Fig. 2, partially Even at low fatty acid concentrations (5 to 15 parts) a viscosity well below 10,000 mPas can be achieved.

Example 4 Dependence of the viscosity on the type of fatty acid used in the concentrate.

Different types of fatty acids were tested for their effect in the concentrates according to the invention. Fatty acids of different chain lengths and iodine numbers were used in a concentration of 19 parts, based on the total concentrate. The following fatty acids were used:

Coconut / palm kernel oil fatty acid, JZ = 16-22
Coconut fatty acid, JZ = 8-14,
hydrogenated coconut / palm kernel oil fatty acid, JZ <1,
Caprylic / Capric acid, JZ = 0.1-1,
Soybean oil fatty acid, JZ = 120-130,
Olein, JZ =
Lauric acid, JZ <0.1

Other components of the tested concentrates were:

28 parts of Texin® ES 68 in powder form,
48 parts of adduct of 7 moles of ethylene oxide with oleyl / cetyl alcohol,
5 parts water.

It was found that the iodine number and chain length have no significant influence on the viscosity of the concentrates according to the invention.

Example 5 Dependence of the viscosity on the water content.

28 parts by weight of Texin® ES 68 in powder form were mixed with 48 parts by weight of an adduct of 7 moles of ethylene oxide and oleyl / cetyl alcohol and 5 parts by weight or 10 parts by weight or 19 parts by weight of coconut - / Palm kernel oil fatty acid added. Different amounts of water were added to these mixtures. The result can be seen in FIGS. 3 to 5. As was shown in all cases, the viscosity of the water-mixed mixtures went through a minimum, which is about 2.5 to 5 parts by weight of water with a low fatty acid content (see FIG. 3) and decreases with increasing amounts of fatty acids Water content shifts towards (see. Fig. 4 and 5). Consequently, water addition to the estersulfonate-containing concentrates according to the invention is not required at higher fatty acid contents.

Example 6 Washing attempts

Detergents were put together with the surfactant concentrates containing estersulfonate according to the invention and washing tests were carried out in the so-called "launderometer". At washing temperatures of 30 or 60 or 90 ° C and a water hardness of 16 ° d 8.2 g of fabric (two lobes of test fabric and 2 lobes of cotton filler fabric) were washed with 10 steel balls in a launderometer for 15 minutes and then rinsed twice in cold tap water for 2 minutes. The liquor ratio was 1: 12. The degree of whiteness of the dried and ironed lobules was measured (ZEISS-Elrepho) and stated in% remission (R).

Patches made from polyester / cotton (LPBV) or from refined cotton (LBV), each soiled with pigment / skin fat, were used as the test fabric.

• a) = Kokosfettalkohol + 7 Mol Ethylen­oxid
• b) = Oleyl/Cetylalkohol + 7 Mol Ethylenoxid
• c) = Gemisch aus 10 Gew.-% a) + 75 Gew.-% b) + 15 Gew.-% Oleyl­/Cetylalkohol + 70 Mol Ethylenoxid

2 Gew.-% Seife, berechnet als Talgfettsäure
26 Gew.-% Natriumtripolyphosphat
1 Gew.-% Carboxymethylcellulose
5 Gew.-% Natriumwasserglas 1 : 3,35
Natriumsulfat ad 100 Gew.-%

The respective detergents were used in a dosage of 10 g per liter of alkali. The composition of the detergents is shown in the table below.
3 to 8% by weight of anionic surfactant (alkylbenzenesulfonate = ABS; ester sulfonate = ES);
3 to 5% by weight of nonionic surfactant:

• a) = coconut fatty alcohol + 7 moles of ethylene oxide
• b) = oleyl / cetyl alcohol + 7 moles of ethylene oxide
• c) = mixture of 10% by weight a) + 75% by weight b) + 15% by weight oleyl / cetyl alcohol + 70 mol ethylene oxide

2% by weight soap, calculated as tallow fatty acid
26% by weight sodium tripolyphosphate
1% by weight carboxymethyl cellulose
5% by weight sodium water glass 1: 3.35
Sodium sulfate ad 100 wt .-%

The type and amount of the anionic surfactant and the nonionic surfactant used are shown in FIGS. 6 to 11.

As was shown in detail, detergents with the estersulfonate-containing concentrates according to the invention are comparable in terms of washing results to the detergents of the prior art. The contents of the detergent substance can be lower when using the concentrates according to the invention in the detergents without loss of detergency and are, for example, 8% detergent substance (3% ester sulfonate and 5% nonionic surfactant) or 10% detergent substance (5% ester sulfonate and 5% Nonionic surfactant).

Example 7

A mixture of 33 parts by weight of Texin® ES 68 in powder form (corresponding to 23 parts by weight of ester sulfonate), 36 parts by weight of C _{12/18 fatty} alcohol + 10 moles of ethylene oxide, 27 parts by weight of C _8/18 fatty acid and 4 parts by weight of water gave a concentrate with a viscosity of 8500 mPas.

Claims (12)

1. Containing ester sulfonate surfactant concentrates (a) one or more surfactants in an amount of 50 to 70% by weight, based on the total weight of the concentrates, from the groups (α) Alkali metal salts of α-sulfonated fatty acid alkyl esters from fatty acids with 16 and / or 18 C atoms and alcohols with 1 to 8 C atoms in the alkyl radical and (β) linear aliphatic fatty alcohol polyglycol ethers with 10 to 20 carbon atoms in the alkyl radical of the alcohol and 3 to 15 ethoxy groups in the molecule, the ratio of the surfactant components (α): (β) being in the range from 1: 0.3 to 1: 3 . (b) one or more saturated and / or unsaturated linear aliphatic carboxylic acids having 8 to 22 carbon atoms in amounts of 10 to 30% by weight, based on the total weight of the concentrates, and (c) water in amounts of 0 to 10% by weight, based on the total weight of the concentrates. 2. Concentrates according to claim 1, characterized in that they preferably contain sodium or potassium salts of the esters as alkali salts of α-sulfonated fatty acid alkyl esters. 3. Concentrates according to claims 1 and 2, characterized in that they contain sodium and / or potassium salts of α-sulfonated fatty acid methyl esters from fatty acids with 16 and / or 18 carbon atoms. 4. Concentrates according to claims 1 to 3, characterized in that they contain fatty alcohol polyglycol ethers with 10 to 16 carbon atoms in the alkyl radical of the fatty alcohol. 5. Concentrates according to claims 1 to 4, characterized in that they contain fatty alcohol polyglycol ethers with 3 to 10 ethoxy groups in the molecule. 6. Concentrates according to claim 5, characterized in that they contain fatty alcohol polyglycol ethers with 7 ethoxy groups in the molecule. 7. Concentrates according to claims 1 to 6, characterized in that they contain anionic surfactants (α) and nonionic surfactants (ß) in a ratio of 1: 1 to 1: 2. 8. Concentrates according to claims 1 to 7, characterized in that they contain one or more surfactants in an amount of 50 to 60 wt .-%, based on the total weight of the concentrates. 9. Concentrates according to claims 1 to 8, characterized in that they contain one or more saturated linear carboxylic acids with 12 to 18 carbon atoms. 10. Concentrates according to claims 1 to 9, characterized in that they contain one or more saturated fatty acids in amounts of 15 to 20 wt .-%, based on the total weight of the concentrates. 11. Concentrates according to claims 1 to 10, characterized in that they contain water in amounts of 1 to 10, preferably 2 to 5 wt .-%, based on the total weight of the concentrates. 12. Use of concentrates according to Claims 1 to 11 in detergents, dishwashing detergents and cleaning agents for household and industrial purposes in amounts of 1 to 15% detergent-active substance, based on the total weight of the detergents, dishwashing detergents and cleaning agents.

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