NL9401510A - Surfactant composition, surfactant concentrate in liquid form, and aqueous bleaching agent having increased viscosity and cleaning activity - Google Patents

Abstract

The invention relates to a surfactant composition which contains the following essential components in the amounts stated: - 25-75 parts by weight of an alkyl ether carboxylic acid or a salt thereof having the formula R1-O-(CH2-CH2-O)n-CH2-COOM where R1 represents a linear or branched alkyl group having 8-18 carbon atoms, n is a number having a mean value in the range of 0.5-8 and a narrow distribution around said mean, and M represents hydrogen or an alkali metal ion, - 10-50 parts by weight of a fatty acid or a salt thereof having the formula R2-COOM where R2 represents a linear or branched alkyl group which may or may not be saturated and has 8-22 carbon atoms, and M represents hydrogen or an alkali metal ion, and - 10-50 parts by weight of an alkyl ether sulphate and/or an alkylsulphobetaine, the alkyl ether sulphate corresponding to the formula R3-O-(CH2-CH2-O)m-SO3-M+ where R3 represents a linear or branched alkyl group having 8-22 carbon atoms, m is a number having a mean value of 0.5-5, and M represents an alkali metal ion, and the alkylsulphobetaine corresponds to the formula R4-N+(CH3)2-(CH2)3-SO3-M+ where R4 represents a linear or branched alkyl group having 8-22 carbon atoms and M represents an alkali metal ion. The invention also relates to an aqueous surfactant concentrate and to a thickened aqueous bleaching agent which contain a surfactant composition as defined.

Description

Title: Surfactant composition, surfactant concentrate in liquid form and aqueous bleach with increased viscosity and cleaning action.

The invention relates to a surfactant composition, a liquid concentrate based on this composition and an aqueous, optionally perfumed bleaching agent, in which such a composition is present as a thickening agent and optionally as a perfume dissolver.

It is known from GB-B-1 329 086 and from NL-A-7908798 to thicken an aqueous bleach with 1-10% active chlorine with a surfactant, preferably an amine oxide, and a Ce-18 saturated fatty acid.

EP-A-0 274 885 describes mixtures of specific linear and branched amine oxides as thickeners for hypochlorite solutions with 1-15% active chlorine.

EP-A-0 447 261 discloses a perfumed aqueous hypochlorite solution containing a surfactant combination consisting of an alkane sulfonate, an alkyl ether sulfate and a soap. An amine oxide may also be present, but the amount thereof is always less than 50% of the other surfactants. The active chlorine content is between 0.1 and 8%.

The use of ether carboxylic acids to thicken an aqueous chlorine bleach liquid with 1-14% active chlorine is described in GB-A-2 076 010. It also mentions a large number of classes of surfactants, which can also be added if desired, without that further details have been provided.

Finally, EP-A-0 072 600 discloses a class of alkyl ether carboxylic acids, which have a good viscosity-increasing effect on hypochlorite solutions, especially on such solutions with around 10% active chlorine, and which have good biodegradability. These ether carboxylic acids are mainly characterized by their average value of the number of ethylene oxide groups and a narrow distribution around that average value.

The object of the invention is to provide a specific surfactant composition which is suitable for use in various aqueous liquids, in particular bleaching liquids, to increase the viscosity and also to impart moisturizing and cleaning properties to it.

It is further contemplated to provide a surfactant composition of which only a relatively small amount already produces the desired effect and whose components can be considered harmless from an environmental point of view.

A further object of the invention is to provide a surfactant composition which is well compatible with the processing of conventional auxiliaries, such as perfumes and electrolytes.

According to a further object of the invention, an aqueous hypochlorite-based bleaching agent is provided, in particular with a relatively low active chlorine content, which has an increased viscosity and cleaning effect and which is further characterized in that it is a mostly clear bleaching liquid with good phase stability and which maintains a high active chlorine content over the initial active chlorine content for a long time.

The above stated objectives can be achieved according to the invention with or using a surfactant composition containing the following essential components in the indicated amounts: 25-75 wt. parts of an alkyl ether carboxylic acid or a salt thereof of the formula

R1-O- (CH2-CH2-O) n-CH2-C00M

wherein R 1 represents a linear or branched alkyl group of 8-18 carbon atoms, n is a number with an average value in the range of 0.5-8 and a narrow distribution around that average value, and M represents hydrogen or an alkali metal ion, -10 -50 wt. din of a fatty acid or a salt thereof of the formula

R2-C00M

wherein R2 represents a linear or branched saturated or unsaturated alkyl group of 8-22 carbon atoms and M represents hydrogen or an alkali metal ion, and - 10-50 wt. din. of an alkyl ether sulfate and / or an alkyl sulfobetaine, the alkyl ether sulfate corresponding to the formula R 3 -O- (CH 2 -CH 2 -O) m-SO 3 -M + wherein R 3 represents a linear or branched alkyl group of 8-22 carbon atoms, m is a number with an average value of 0.5-5 and M represents an alkali metal ion, and the alkyl sulfobetaine corresponds to the formula

wherein R4 represents a linear or branched alkyl group of 8-22 carbon atoms and M represents an alkali metal ion.

The invention also relates to a stable, easily processable and mostly clear surfactant concentrate in liquid form, which is an aqueous liquid containing 10-40% by weight of the surfactant composition as defined above and containing 0.5-10% by weight of an alkali metal hydroxide .

According to a further embodiment, the invention relates to an aqueous bleach of increased viscosity and cleaning effect, which bleach contains an alkali metal hypochlorite in an amount corresponding to 0.5-8% active chlorine, and in addition at least 0.1% by weight of the surfactant composition as defined above and containing 0.5-5% by weight of an alkali metal hydroxide.

The first component of the present surfactant composition is an alkyl ether carboxylic acid or a salt thereof of the previously indicated formula (for convenience, this component will hereinafter be referred to as ether carboxylic acid). Such compounds are described, inter alia, in EP-A-0 072 600 discussed above. In these compounds, the average number of ethoxy groups is in the range of 0.5-8, in practice usually in the range of 3-5. The narrow distribution of the number of ethoxy groups is essential to achieve the objectives of the invention. Various techniques can be used to realize a narrow distribution when introducing ethoxy groups, which are indicated, for example, in DE-A-4 005 338, US-A-5 057 627 and EP-A-0 361 616 and in a article by A. Behler and U. Ploog in "Fat Sci. Tech" 92f pp. 109-114 (1990). As an example of a suitable ether carboxylic acid for use according to the invention, ΑΚΥΡΟ RLMQ 38 (Chemische Fabrik CHEM-Y GmbH, Germany) can be mentioned.

The ether carboxylic acids are harmless and readily biodegradable compounds which, when used as the sole surfactant, are very capable of thickening a fairly concentrated hypochlorite solution (with at least 10% active chlorine). For thickening hypochlorite solutions with less active chlorine, the present surfactant composition with three essential components is considerably better suited because it provides better phase stability and hypochlorite stability. As the hypochlorite solution has a lower active chlorine content, the amount of ether carboxylic acid relative to the other two essential components is chosen to be lower.

When the present surfactant composition is used, for example in an aqueous hypochlorite bleach with at most 8% active chlorine, the ether carboxylic acid mainly contributes to the phase stability, the increase of the cloud point, the cleaning and wetting effect, the foaming and the dissolution of any perfume used.

The second component is a fatty acid or a salt thereof of the formula shown previously (this component is hereinafter referred to as fatty acid for convenience). Suitable fatty acids are well known and include acids such as lauric, myristic, palmitic, stearic, oleic and partially hydrogenated unsaturated fatty acids, such as partially hydrogenated coconut fatty acid. In particular, this component has a thickening action and contributes to the dissolution of any perfume used when the present surfactant composition is used, for example, in an aqueous hypochlorite bleach as described above.

As the third essential component, an alkyl ether sulfate (hereinafter referred to as ether sulfate) and / or an alkyl sulfobetaine (hereinafter referred to as sulfobetaine) of the formulas shown previously is used in the surfactant composition. Ethyl sulfates such as linear alkyl ether sulfates, for example lauryl ether sulfates, are well known in the surfactant field, for example from EP-A-0 447 261 and GB-A-2 076 010 discussed earlier, and therefore need no further explanation. As an example of an ether sulfate, there can be mentioned a lauryl / myristyl ether sulfate with 2 or 3 EO, which is commercially available under the names CHEMSALAN RLM 70 and CHEMSALAN 30/70 (Chemische Fabrik CHEM-Y GmbH, Germany).

Sulfobetaines for use as the third essential component of the surfactant composition of the invention are also known per se. For more information on this, reference may be made to R. Ohme, D. Ballschuh, H. Seibt in "Tenside Detergents" 22, pp. 180-185 and 235-240 (1991). As an example of a suitable sulfobetaine, stearyl sulfo betaine may be which is commercially available under the trade name RALUFON DS (Raschig AG, Germany).

The third essential component of the present surfactant composition mainly has a thickening action, a cleaning and wetting action, it contributes to the foaming and helps to dissolve any perfume used, for example when that composition is used for thickening a hypochlorite bleach.

The three essential components for forming the sufactant composition can be mixed together in the desired molten ratio, for example at a temperature of 30-50 ° C. The mixture can then be cooled to a semi-solid, more or less pasty state, which can be stored or traded as a finished surfactant composition according to the invention for later processing in a liquid to be thickened. Preferably, the composition is first melted again to facilitate a homogeneous distribution in the liquid to be thickened.

In a particularly suitable embodiment, however, the mixture of the three essential components, which is in the molten state, is diluted with water, adding an alkali metal hydroxide, usually sodium hydroxide, to obtain a concentrated aqueous liquid containing 10-40 wt. % and preferably 20-28% by weight of the surfactant composition also contains 0.5-10% by weight and preferably 0.5-3% by weight alkali metal hydroxide. According to an alternative preparation method, the three essential components can be taken up in water in the desired amounts directly under heating and stirring. The alkali metal hydroxide can then be added before, during or after the introduction of the surfactant components.

Providing the present surfactant composition in the form of a concentrated aqueous liquid as described above has important advantages. Namely, this liquid is a stable, usually clear product, which can easily be incorporated at room temperature into the liquid which it is desired to thicken, for example a hypochlorite solution. Furthermore, a perfume, such as a chlorine-stable perfume, can be included in the concentrated liquid, whereby a clear and phase-stable mixture is often obtained. This can accelerate the subsequent preparation of, for example, a thickened hypochlorite bleach using the present surfactant composition.

The present surfactant composition, preferably used in the above-described form of a concentrated aqueous liquid, is particularly suitable for thickening all kinds of aqueous liquids, especially liquids with an oxidizing or bleaching action, such as a peroxide, a percarbonate and preferably a hypochlorite solution, preferably a hypochlorite solution with 0.5-8% active chlorine. A typical example of such a hypochlorite solution contains 4-6% active chlorine. Although it is in principle possible to add the essential components of the present surfactant composition separately to the aqueous liquid to be thickened and optionally also to add an alkali metal hydroxide, in practice the present surfactant composition is usually started from, preferably in the above-mentioned form of a concentrated aqueous liquid.

Since the main application of the invention is to provide an aqueous hypochlorite bleach with increased viscosity and cleaning performance and containing 0.5-8% active chlorine, this embodiment will be discussed further below.

Such a bleaching agent can be prepared by first adding alkali metal hydroxide to softened or demineralized water and then the present surfactant composition in the form of a concentrated aqueous liquid, optionally already containing a perfume, as discussed previously. If the latter is not the case, but if it is desired to add a perfume, this can be done separately after the surfactant composition has been added. These operations can be performed at room temperature and mixing is continued until a clear product is obtained. The aqueous solution of an alkali metal hypochlorite is then added.

The reason why softened or demineralized water is used is that when lime-containing tap water is used lime soap is formed with the fatty acid present in the surfactant composition, which would increase the viscosity, but would adversely affect the phase stability.

As to the amounts of the various components used and their effects on the aqueous hypochlorite bleach, the following can be noted. An alkali metal hydroxide is added as an alkaline buffer to raise the pH value of the hypochlorite solution to a value usually in the range of 11-14, and maintain this high pH for a long time, at least 3 months. The addition of an alkaline buffer has a thickening and chlorine stabilizing effect, but too much of it has a detrimental effect on the phase stability. The total amount of alkali metal hydroxide in the aqueous bleach, including the alkali metal hydroxide already present in the surfactant composition, is in the range 0.5-5 wt%, preferably in the range 0.5-3 wt%.

The surfactant composition is used in an amount of at least 0.1% by weight and preferably not more than 10% by weight. Usually, the concentration of the surfactant composition is in the range of 0.3-3 wt%, most preferably between 0.5 and 1.5 wt%, optimally around 1 wt%. In practice, this boils down to the fact that in order to set an equal viscosity with a hypochlorite solution containing 4-6% active chlorine, the present harmless surfactant composition is usually less required than the hitherto for the mentioned concentration range of 4-6%. Chlorine commonly used amine oxide compositions are less and less desirable because they are suspected of releasing carcinogens. The low concentration of surfactant composition according to the invention also has a very favorable effect on the hypochlorite stability, because interaction with the surfactants is an important cause of the decrease of the active chlorine content. Finally, when using the present surfactant composition, it appears that a high viscosity as well as a high phase stability or, in other words, a high cloud point can be achieved at the same time.

When a perfume or fragrance is added, a perfume is chosen which is highly resistant to the oxidizing effect of the hypochlorite. Furthermore, care should be taken to ensure that the perfume does not unacceptably harm the phase stability of the aqueous bleach solution, so that a cloudy point would be too low. The incorporation of the perfume into the bleaching solution can sometimes be facilitated by pre-incorporating the perfume into the concentrated aqueous surfactant solution, as discussed previously.

As the hypochlorite solution, which is added as the last component according to the above-described preparation methods for an aqueous hypochlorite bleach, commercially available products such as sodium hypochlorite from AKZO, the Netherlands, with about 150 g / l NaOCl, corresponding to 12, are usually used. 5-13% active chlorine. The amount used is usually about 40% by weight, based on the total final bleach, which corresponds to active chlorine content of about 5% in the final bleach.

Finally, during the preparation of the aqueous hypochlorite bleach or thereafter, small amounts of an electrolyte, such as NaCl, can be added to increase the ionic strength, which has a beneficial effect on the intended thickening. However, it should be taken into account that the alkaline buffer and the alkali metal hypochlorite also already introduce electrolyte, so that, depending on the amounts of the latter components used, more or less or no separate electrolyte will be added.

The aqueous hypochlorite bleach of the invention is a thickened, usually clear, product that also has a cleaning action. Because it is a thickened product, it is very suitable to be used for cleaning vertical, curved or sloping surfaces. The thickened product sticks longer to these surfaces, resulting in a longer reaction time. The product has good stability in all respects, which means that the set viscosity is maintained well, the phase stability is maintained for a long time and the amount of active chlorine decreases only slowly. For clarification, please note that for this type of product it is generally required that the viscosity be within predetermined limits for at least 3 months, that there is also no sagging of components or unacceptable reduction of the components for at least 3 months. cloud point may occur (the phase stability referred to here is usually verified by measuring the cloud point and determining its appearance), and that after 3 months at room temperature, the amount of active hypochlorite is still at least 50% of the initial amount .

The invention will be further elucidated below on the basis of a number of examples.

Examples

The following surfactant components have been used in carrying out the tests described below:

- (A) alkyl ether carboxylic acid: a lauryl / myristyl 3.8 EO

ether carboxylic acid with a narrow distribution of the number of EO groups (ΑΚΥΡΟ RLMQ 38,

Chemical Manufacturers CHEM-Y GmbH, Germany); - (B) fatty acid: a partially hydrogenated coconut fatty acid (fatty acid 1; PRIFAC 5901, Unichema, Germany) resp. a non-hydrogenated coconut fatty acid (fatty acid 2; PRIFAC 7907, Unichema, Germany); - (C) alkyl ether sulfate / alkyl sulfobetaine: - a lauryl / myristyl ether sulfate with 2 or 3 EO groups (CHEMSALAN RLM 70 and CHEMSALAN RLM 30/70, respectively),

Chemical Manufacturers CHEM-Y GmbH, Germany); - a stearyl sulfobetaine (RALUFON DS, Raschig AG, Germany).

All quantities in percent are percent by weight.

Preparation of a surfactant composition

A surfactant composition consisting of 37.1% alkyl ether carboxylic acid, 21.1% fatty acid 2 and 41.8% alkyl 2E0 ether sulfate is prepared by mixing the alkyl ether carboxylic acid and the fatty acid 2 at 40-50 ° C and then adding the alkyl 2E0 ether sulfate add. The mixture is stirred until a homogeneous composition is obtained, which is then allowed to cool to yield a pasty to solid product.

The product obtained can be stored and traded and can be melted at the time of use, adjusted to the desired concentration and alkalinity with water and sodium hydroxide and mixed with aqueous hypochlorite to obtain a thickened hypochlorite bleach.

Preparation of an aqueous surfactant concentrate

An aqueous surfactant concentrate is prepared from the following components in the amounts indicated: 11.1% alkyl ether carboxylic acid; 6.3% fatty acid 2; 12.5% alkyl 2E0 ether sulfate; 5.0% NaOH (50%); and 65.1% demineralized or softened water.

The concentrate is prepared by heating the water to about 45 ° C and then adding the alkyl ether carboxylic acid. A homogeneous cloudy mixture is obtained by stirring. This mixture is further heated to about 50 ° C and then the alkyl 2EO ether sulfate is added. Stirring produces a clear, slightly viscous liquid. The temperature is then brought to about 55 ° C and then the NaOH (50%) is added. By stirring further, a water-thin liquid is obtained first and shortly afterwards a weakly viscous liquid is obtained. It is further heated to 65-70 ° C and then the fatty acid 2, which has been preheated to 35 ° C, is added. Stirring gives a water-thin, clear liquid, which is stirred for another 0.5 hours at 65-70 ° C, after which it is allowed to cool.

The concentrate thus prepared is a thin liquid, clear and stable product which, if desired, can be made more viscous by adding an electrolyte, for example NaCl, and in which perfume or fragrance can be included if desired. The concentrate obtained is highly marketable and can be used by customers as a thickening agent, which also has a cleaning effect, for all kinds of aqueous liquids, in particular aqueous solutions of sodium hypochlorite.

When used in a hypochlorite solution, the aqueous surfactant concentrate is diluted with softened water, then perfume is added if desired, then the required amount of alkali metal hydroxide is introduced and the solution of alkali metal hypochlorite is added as the final component. If necessary, the exact water content is set.

A hypochlorite liquid thus prepared has excellent properties in terms of both viscosity and chlorine and phase stability, as may be seen from the data in the tables below.

Reporting of tests performed and discussion of the results obtained

Using the preparation technique described above, various aqueous surfactant concentrates were made and thickened hypochlorite liquids were again prepared therefrom. The specific components used and the amounts thereof are shown in Tables 1-10 below.

The various properties of interest of the obtained hypochlorite liquids have been investigated and the results are also reported in the tables. The following explanation is provided: - the hypochlorite or chlorine stability is indicated in% relative to the initial chlorine content; - when assessing the appearance, the indications used have the following meanings: Η = clear Ha = hazy T = cloudy G = gel

Table 1 shows the hypochlorite stability and viscosity, which were determined with thickened hypochlorite solutions with different combinations of surfactants (A) and (B) (comparison tests), surfactants (A) and (C) (comparison tests) and surfactants (A), (B) and (C) (tests according to the invention).

It is noteworthy that as soon as a combination of three surfactants according to the invention is used, the hypochlorite stability becomes significantly higher (measured after 3 weeks at a storage temperature of 40 ° C). The viscosities vary widely.

Table 1:

Tables 2-4 show the influence of different ratios of the surfactant combination (A), (B) and (C) on the physical (phase stability and viscosity) and chemical (hypochlorite stability) properties. In case hazy or cloudy is found at 20 ° C, the thickened hypochlorite first appears to clear upon heating and becomes cloudy again above the cloudy point.

label 2 .:

Table 3:

Table 4:

The test results shown in Tables 2-4 show that as less component (A) is used in the surfactant composition, the cloud point decreases, but the viscosity and hypochlorite stability increases. In addition, it appears that variations in the proportions of components (B) and (C), with the amount of component (A) remaining the same, have only a small influence on the cloud point and the hypochlorite stability. A higher content of component (B) to the detriment of component (C) in some cases increases the viscosity and also the thickening effect.

The tests listed in Tables 5-9 used the following surfactant combination: (A) alkyl ether carboxylic acid: 50%; (B) fatty acid 1: 25%; (C) alkyl 2EO

ether sulfate: 25%. The initial chlorine content was 5.2% in the tests shown in Tables 5 and 6 and 4.9% in the tests shown in Table 9. In the tests shown in Tables 7 and 8, the initial chlorine content varying and stated in the tables themselves.

Table 5 shows the effect of the amount of alkali metal hydroxide on the physical and chemical stability of thickened hypochlorite solutions.

Table 5;

It can be noted from Table 5 that the hypochlorite solutions are all clear. An increasing amount of alkali metal hydroxide gives a marked increase in viscosity, but decreases phase stability (falling cloud point). With regard to hypochlorite stability, the following can be noted: - the low pH, which corresponds to a 0.5% alkali metal hydroxide concentration, results in reduced hypochlorite stability; an increasing amount of alkali metal hydroxide results in a greater amount of electrolyte, which slightly decreases the hypochlorite stability; - In the examined thickened hypochlorite solutions, an additional amount of NaOH of approx. 1% additionally gives the most favorable hypochlorite stability.

Table 6 shows the effect of the amount of surfactant combination on the physical and chemical stability of thickened hypochlorite solutions.

Table 6:

It can be noted from Table 6 that the hypochlorite solutions are all clear and have a cloud point above 100 ° C. With an increasing amount of surfactant combination, an increasing viscosity and a decreasing hypochlorite stability is observed. Up to 1% of the surfactant combination, the difference in hypochlorite stability from the blank (without surfactant) is only small (measured after 3 months at 20 ° C).

Table 7 shows the effect of the amount of hypochlorite on the physical stability of thickened hypochlorite solutions.

Table 7:

The results shown in Table 7 show that in the surfactant combination used, an increasing amount of hypochlorite produces an increasing viscosity and a decreasing phase stability. It is further noted that at different hypochlorite concentrations a thickened and phase stable hypochorite solution can be obtained by varying the ratios between the individual surfactants. As a higher hypochlorite content is present, proportionally more alkyl ether carboxylic acid must be used.

Table 8 shows the effect of the amount of electrolyte (NaCl) on the physical stability of thickened hypochlorite solutions.

Table 8:

Table 9 shows the effect of the addition of a chlorine stable perfume on the physical and chemical stability of thickened and perfumed hypochlorite solutions.

Table 9;

Addition of a chlorine stable perfume usually gives an increase in viscosity and usually a decrease in phase stability. However, as more surfactant combination is added, the influence of the perfume on phase stability decreases. Furthermore, the addition of a chlorine stable perfume gives a slight decrease in the hypochlorite stability.

Table 10 juxtaposes the use of a saturated and an unsaturated fatty acid in the present surfactant combination. The initial chlorine content is 5% active chlorine.

Table 10:

* n.a. - not quite

The results shown in table 10 show that when an unsaturated fatty acid (fatty acid 2) is used, a lower viscosity is obtained and the chlorine stability is also slightly decreased.

Claims (8)

Surfactant composition containing the following essential components in the amounts indicated: - 25-75 wt. parts of an alkyl ether carboxylic acid or a salt thereof of the formula R1-O- (CH2-CH2-O) n-CH2-C00M wherein R 1 represents a linear or branched alkyl group having 8-18 carbon atoms, n is a number with an average value in the range of 0.5-8 and a narrow distribution around that average value, and M represents hydrogen or an alkali metal ion, - 10-50 wt. parts of a fatty acid or a salt thereof of the formula R2-C00M wherein R2 represents a linear or branched, saturated or unsaturated alkyl group having 8-22 carbon atoms and M represents hydrogen or an alkali metal ion, and - 10-50 wt. parts. of an alkyl ether sulfate and / or an alkyl sulfobetaine, the alkyl ether sulfate corresponding to the formula R 3 -O- (CH 2 -CH 2 -O) m-SO 3 ~ M + wherein R 3 represents a linear or branched alkyl group of 8-22 carbon atoms, m is a number with an average value of 0.5-5 and M represents an alkali metal ion, and the alkyl sulfobetaine corresponds to the formula

wherein R4 represents a linear or branched alkyl group of 8-22 carbon atoms and M represents an alkali metal ion. Surfactant concentrate in liquid form, characterized in that the concentrate is an aqueous liquid containing 10-40% by weight of the surfactant composition as defined in claim 1 and 0.5-10% by weight of an alkali metal hydroxide. Surfactant concentrate according to claim 2, characterized in that the aqueous liquid contains 20-28% by weight of the surfactant composition and 0.5-3% by weight of alkali metal hydroxide. 4. An aqueous bleach of increased viscosity and cleaning performance, characterized in that the bleach contains an alkali metal hypochlorite in an amount corresponding to 0.5-8% active chlorine, and in addition at least 0.1% by weight of the surfactant composition as defined in claim 1 and contains 0.5-5 wt% of an alkali metal hydroxide. Aqueous bleaching agent according to claim 4, characterized in that the bleaching agent contains at most 10% by weight of the surfactant composition as defined in claim 1. An aqueous bleaching agent according to claim 5, characterized in that the bleaching agent contains alkali metal hypochlorite in an amount corresponding to 4-6% active chlorine, and additionally 0.3-3% by weight of the surfactant composition as defined in claims 1 and 0. 0.5-3 wt.% Alkali metal hydroxide. Aqueous bleaching agent according to claims 4-6, characterized in that the bleaching agent additionally contains an electrolyte to improve the ionic strength. Aqueous bleaching agent according to claims 4-7, characterized in that the bleaching agent additionally contains a perfume.