JPS63245496A - Alkaline concentrated liquid cleanser - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a concentrated alkaline liquid detergent containing a concentrated aqueous solution of an alkaline builder and a surfactant for use in the industrial cleaning of metal surfaces.

BACKGROUND OF THE INVENTION A variety of formulations are used for industrial aqueous cleaning of hard surfaces. The most important ingredients of these formulations are hirugu and surfactants individually and in combinations of the three.

The properties of these basic mixtures of builders and surfactants are:
In many cases, additional components such as complexing agents or corrosion inhibitors must be added to adapt to the particular operating conditions envisaged.

The pH of the alkaline detergent aqueous solution is about 11-14. They are particularly suitable for difficult cleaning tasks, such as the removal of thick coatings of oils and pigments in the repair industry and for cleaning equipment and containers. Furthermore, products of this type are particularly suitable for precision cleaning of metal surfaces where a metallically clean surface is required. It is applied, for example, in post-hardening cleaning, cleaning of steel strip before annealing and before painting, and for pre-treatment of workpieces in galvanizing plants, phosphating plants, painting and enameling industries. It will be done. Such types of cleaning solutions provide an ultimate cleanliness of the workpiece surface and a high soil dispersion capacity of the bath. In addition to manual cleaning, dipping, brushing, spraying, sonication and electrolysis are used individually or in combination with each other. Typical alkaline detergents are made as powders by mixing 80-100% alkaline builders and 0-20% of various anionic and nonionic surfactants.

The most common inorganic builders are sodium and/or potassium hydroxides, silicates and carbonates, which act as alkalis. Gluconates, alkanolamines, polycarboxylic acids, polyoxycarboxylic acids and phosphonates can optionally be used as complexing agents. The surfactant mixture consists of low and high ethoxylated and propoxylated alkylphenols, fatty acids of various chain lengths, fatty amines of various chain lengths and/or fatty acids or sulfonic acids. These ingredients are contained in alkaline cleaners.
in various combinations at reaction concentrations (E. Usually,
Optimal product composition can only be determined by trial and error using specific samples.

Powdered detergents exhibit a significant tendency to kick up powder and thus can cause problems and endanger the user during application. Other formulations may clump during storage, particularly under pressure when stacking pellets. To intensify the cleaning bath, the solution must be preheated to about 40-50°C, stirred, and the powder added slowly and in portions to the bath. Otherwise, the powder will sink to the bottom upon addition and become mineralized, severely reducing the dissolution rate. Placing a solid formulation in a hot bath may expose the user to the risk of being splashed with hot water. Solid formulations are
Because they are usually hygroscopic, they cannot be dosed automatically without significant expense, which is commercially unacceptable. The choice of surfactants for these detergents is very narrow. For example, nonionic surfactants with terminal 01 (groups) are air oxidized in the presence of solid sodium hydroxide. As a result, the storage stability of the detergent is greatly impaired, and it is especially This is reflected in negative effects such as an increase in the landing point of surfactants, an increase in the optimum cleaning temperature of the cleaning solution, and a worsening of the foaming behavior, such as severe foaming of the solution.
The ability of powders to absorb liquid surfactants is traditionally limited. In order to obtain a free-flowing powder, it is necessary not to exceed a concentration limit that depends on the particle size distribution of the powder.

Most of these difficulties can be avoided with liquid cleaning agents. However, two problems arise in the production of liquid cleaning agents. That is, in most cases, the builder storium compound is at the highest concentration of 100-1509 for a thermodynamically stable solution at ambient temperature (room temperature).
/g. In contrast, if the corresponding potassium compound is used, approximately 5
0097 (1 can be dissolved. However,
In that case, the raw material cost would essentially double. Furthermore, the solubility of the surfactants in these highly salt-concentrated, strongly alkaline solutions is inadequate overall. Typical nonionic surfactants cannot be dissolved at all, and anionic surfactants can dissolve very short non-hydrophobic carbon chains of 6 or fewer carbon atoms. Nonylphenol quinlates, fatty alcohol quinlates, fatty acids and alkylbenzene sulfonates are unsuitable for these detergents.Carboxylic acids with at most about 6 carbon atoms and It is known that sugar interfacial surfactants can be dissolved in high concentrations in builder solutions individually (European Publication Patent No. 1413 087) and in combination. In contrast, long-chain fatty acids and non-ionic surfactants The surfactant cannot be homogeneously incorporated per se. In binary combinations of fatty acid and sugar surfactant or nonionic surfactant and sugar surfactant, the surfactant is also added to the builder solution at a concentration of about 40%. It does not dissolve at ~50%.Also, diluting the combined ingredients to about 30% with water provides a useful solution.

A two-component cleaning agent that does not contain sodium hydroxide itself.
Already proposed. That is, West German Published Patent No. 324
6 080 describes a powdered silicate detergent containing precipitated silica and phosphoric acid. Furthermore, DE 32 46 124 describes diroborate detergents containing halonic acid or borates and phosphoric acid.

Two-component detergents of this type are described by Ch., Rothman [
[Ra.
tio mouth nelle vorbehandlung
durch kon Linuierlichen
Betrieb von EnLi'eLLungsb
aedernl, to Metallo Belle Frey [Metallo
berf Iaeche], Volume 39 (1985),
It is described on pages 41-44.

These types of detergents are suspended in water using dispersants,
If necessary, a complexing agent is then added. The concentration of dissolved salts in the slurry formed is minimal and I) 1-1 is easily adjusted to the acidic range by phosphoric acid, so it is possible that only non-ionic surfactants are dissolved in high concentrations. Anionic surfactants are not very soluble. The slurry is pumped into a clear atom bath and lithium hydroxide is added separately to adjust to the desired 5iOt:Na2O ratio or desired pH value.

The two individual components, the detergent slurry on the one hand, and the sodium hydroxide on the other hand, must be dosed in strictly determined mutual volume ratios. Precipitated silica is
It dissolves in an alkaline medium in a clean bath for a few minutes to form a silicate.

Another means of solving the problem is to prepare the cleaning bath by dissolving the builder and the surfactant separately in water, transferring them, and then introducing them in precisely determined mutual volume ratios. H D High Pluto [1~14D, H
[e1denbruth]
Volbehandlung)
1) ei der
Vorbehandlung vor den
Emaillieren] J, Mitteilungen des Vereis Deutschel Emaillieren 7”
nsDeutscher Email Nachleut
e] e, V,, Volume 31 (1983), 109~
[See page 6. Pilder solutions are prepared using potassium compounds, whereby the concentration of active substance can be approximately 50%. Due to the high raw material costs, this process is quite uneconomical.

It is necessary to use two-component products both from the point of view of storage pores and dosing disadvantages. Furthermore, there is no simple and rapid analytical method for determining the concentrations of both components in the tn cleaning bath towel.

Chemical Abstracts
structs], Volume 100 (1984), 114
Page, abstract [abstract] I 00
Near 0.377k describes an alkaline slurry type dish detergent prepared by making a paste of alkali hydroxide and phosphonate with water. Polyacrylic acid and certain surfactant polymers are required for dispersion.

Besides the high cost of raw materials, the stability of the dispersion and the fact that only certain surfactant copolymers can be used are particularly problematic.

The difficulties, problems and disadvantages of using alkaline powder products, alkaline two-component products or slurries can be avoided by using alkaline homogeneous liquid products containing all the necessary components as a one-component product. can. It has therefore been proposed to use large amounts of solubilizing components such as cumene sulfonate, lignin sulfonate, ethylhexyl sulfonate, phosphoric esters.

The sole function of these hydrophobic substances is to introduce detergent-active anionic and non-ionic surfactants into the salt-rich strongly alkaline Pirgoo solution.

However, they contribute little to the cleaning method.

Another disadvantage is the fact that it considerably increases raw material costs. Although solubilizing substances improve the solubility of surfactants in builder solutions, it is still not possible to use li'f detergents containing builder solutions and with a water content lower than 60%. When diluted by adding water, the water content is 60~
70%, which increases packaging and transportation costs.

Chemical Abstracts, Volume 89 (1978),
p. 79, Abstract 89:91, 432u, states that the use of concentrated alkaline soda products allows 2-6% non-ionic surfactants to be added to the solution without the use of solubilizers.
Can be dissolved.

The disadvantage of this, besides the low alkalinity, is the low active substance concentration of about 30%.

Standard industrial detergents are usually divided into silicate detergents and Phosphe-1 detergents. Powdered silicate detergents based on sodium metasilicate and sodium hydroxide are
Usually formed when dissolving the product in water, Si□t:
It is characterized by the weight ratio or molar ratio of NatO. With corresponding sodium salts and sodium hydroxide, these detergents can be dissolved in water to a maximum concentration of about 1009/C at ambient temperature. In contrast, when using the corresponding potassium salts and potassium hydroxide, solutions with a maximum concentration of about 500 g/Q are obtained.

DE 35 18 672 describes a detergent concentrate containing a nonionic surfactant and a combination of three solubilizers for strongly alkaline detergents. Concentrated detergents for highly alkaline detergents consist of ethoxylated and propoxylated or butquinated fatty alcohols, sugar surfactants, adducts of maleic anhydride with unsaturated fatty acids and branched carboxylic acids. Such detergents are intended in particular for industrial applications, such as the milking and brewing industries.

Objects of the Invention One object of the present invention is therefore to introduce or dissolve surfactants in high concentrations in similarly concentrated aqueous builder solutions.

Another object of the invention is that phosphating, galvanizing,
The object of the present invention is to provide a concentrated cleaning agent for cleaning metal surfaces, in particular steel, non-ferrous metals, copper and zinc, which are to be subjected to finishing treatments such as enameling and painting. Furthermore, the thickeners of the present invention are intended for use in subsequent processing, for example in the intermediate stages of annealing.

DESCRIPTION OF THE INVENTION The above-mentioned objects are achieved by an alkaline concentrated liquid detergent consisting of a concentrated aqueous solution of a hirgu or builder mixture and a specific combination of surfactants.

That is, the present invention provides an alkaline concentrated liquid detergent comprising an aqueous alkaline builder solution and a surfactant, comprising: (a) 50 to 60% by weight of water and at least one alkali metal silicate and/or alkali metal phosphoric acid; Builder or builder mixture aqueous solution containing salt 80-99.7
and (b) 0.3 to 20% by weight of a combination surfactant consisting of an anionic surfactant, a nonionic surfactant and an alkyl glucoside.

In one preferred embodiment of the invention, the concentrated cleaning agent is
The builder mixture contains, in addition to the alkali metal silicate and/or alkali metal phosphate, an alkali metal hydroxide,
It is characterized by also containing an alkali metal gluconate and/or an alkanolamine.

That is, the detergent concentrates of the present invention may contain builders that are each of alkali metal silicates and alkali metal phosphates, or a mixture of the three. Furthermore, in a preferred embodiment of the invention, these builders may be combined with alkali metal hydroxides, alkali metal gluconates and alkanolamines, optionally containing one or more additional builders. In this respect, ('
Builder Mixtures in Aqueous Solutions
in aqueous solution
The builder mixtures described in , l to IO) serve as a reference.

Sodium and/or potassium are preferably used as alkali metals in the present invention. Mixtures of sodium and potassium compounds are preferably used, such that there are more potassium ions than sodium ions; the ratio of potassium to sodium ions is then:
Preferably it is at least 4:1, and may be converted as necessary to increase potassium ions.

The alkali metal silicates as already mentioned in the context of the present invention have a molar ratio of 5iOz to M e t O of 2=1 to 4.
: l (Me is Na and/or K) and is understood to be an aqueous alkali metal silicate solution with a solids content of 28 to 55% by weight. An aqueous sodium silicate solution, i.e. a water glass solution, in particular a molar ratio of 5 ift to NapO of about 3
．． Preference is given to using a water glass solution with a ratio of 4:1 and a total solid gold m of about 38% by weight.

In the present invention, alkali metal phosphates are understood as alkali metal orthophosphates, pyrophosphates and triphosphates (also referred to as tripolyphosphates). However, for the present invention, triphosphates are preferred among these, and potassium triphosphate is particularly preferred.

When such phosphates are used in conjunction with the silicates mentioned above, the silicate component of the aqueous builder solution should normally be predominant, ie the phosphate content should be from 0.1 to 10% by weight based on the aqueous builder solution.

According to the invention, preferred alkali metal hydroxides are sodium hydroxide and/or potassium hydroxide, usually 5
Present as a 0 or 45% by weight aqueous solution.

When the alkali metal silicate solution described above is used in combination with an alkali metal hydroxide, the S of such combination
The specific molar ratio of rO to MetO will be lower. In other words, when alkali metal silicates and alkali metal hydroxides are used simultaneously in the aqueous builder solution, the molar ratio of Si○, to Me, O applies to the sum of the alkali metals. Therefore, the specific combination of alkali metal silicate and alkali metal hydroxide 5i02/Mez
All values of O are based on the ``builder mixture'' described above.
This appears in the example titled "In Equious Solution". The molar ratios of such combinations usually vary over a wide range. However, according to the present invention, S
The molar ratio of i O to M e t O is 0.1 to 1.5;
1 is preferred. Particularly preferred are combinations of aqueous sodium silicate and potassium hydroxide solutions in which the potassium to sodium ratio falls within the range.

Combinations of potassium hydroxide and sodium hydroxide solutions that fall within the range of dual molar ratios can also be used.

Typically, alkali metal silicates and alkali metal hydroxides, such as potassium triphosphate and potassium hydroxide, can also be combined. In this case, the alkali metal hydroxide content of the aqueous builder solution may range from 30 to 50% by weight.

When using an alkali gold FA silicate and a combination of an alkali metal hydrokind and an alkali metal phosphate, the alkali metal silicate content is 1 to 1 based on the builder aqueous solution.
Preferably, it is 0% by weight.

According to the invention, an alkali metal gluconate, in particular sodium or potassium gluconate, is added as an additional builder, preferably based on the aqueous builder solution.
~10% by weight can be used.

Alkanolamines can also be used as additional builders, homogeneously dissolved in the detergent concentrates of the present invention. Usually, alkanolamines have one carbon atom in the alkyl group.
It is understood to be an amine substituted 1 to 3 times with ~4 hydroquine alkyl groups.

In the present invention, it is preferred to use non- and/or tri-ethanolamine, especially in an amount of 0.5 to 3% by weight, based on the aqueous solution.

Another important feature of the invention lies in the above-described combination surfactant consisting of an anionic surfactant, a nonionic surfactant and an alkyl glucoside. This combination of surfactants actually allows such surfactants to be homogeneously dissolved in strongly alkaline aqueous salt-rich solutions.

An alkaline concentrated liquid detergent is prepared using the following combination surfactants of alkyl glucosides, anionic surfactants, and nonionic surfactants.

1. Alkyl gelcond A hydrophobic alkyl group is acetal bonded to a glucose molecule, and the alkyl group is saturated or unsaturated and has 8 carbon atoms.
-14 alkyl polygel condos having 2 to 6 alkyl monoglucoside and/or glucose units.

Examples include C1ff1-C14 alkyl monoglucosides and polygelcondos and octyl/decyl-1
48-glucoside. The last gelconde is preferred for the purposes of the present invention. Depending on the method of application, glucosides are used in amounts ranging from 0.1 to 10% by weight based on the concentrated detergent.

2. Anionic surfactants linear and branched, saturated and unsaturated 08-CI8 carboxylic acids and/or their sodium or potassium salts. aIf is 01-5% by weight based on the concentrated detergent.

Examples of anionic surfactants suitable for the purposes of the present invention include the following:

Linoleic acid, n-hexanecarboxylic acid, isononanoic acid,
Caprylic acid, potassium soft soap (=potassium salt of soybean oil fatty acids) 3. Nonionic surfactants Ethoxylated or propoxylated alcohols, phenols and amines. In particular, fatty alcohols with a chain length of 12 to 18 carbon atoms, oxo alcohols with a chain length of 9 to 15 carbon atoms, nonylphenol and Fatty amines with a chain length of 12 to 18 carbon atoms.

The nonionic surfactant is 0.1 to 0.1 based on the concentrated detergent.
It is used at a concentration of 5% by weight.

Examples of nonionic surfactants include the following.

C+t-C, 6 fatty alcohols ethylated with 4.9 or 14 moles of ethylene oxide, oleyl alcohol ethylated with 2 or 10 moles of ethylene oxide, C8-ethoxylated with 6 moles of ethylene oxide
C12 oxo alcohols, C, -C,5 oxo alcohols ethylated with 7 or 9 moles of ethylene oxide, nonylphenols ethylated with 6 or 12 moles of ethylene oxide, C12-Cl11 fatty amines ethoxylated with 12 moles of ethylene oxide ( Yanoura amine), C I4-C1e fatty amine (tallow amine) etkylated with 12 moles of ethylene oxide.

Corresponding propokylated compounds can also be used.

In one preferred embodiment of the invention, the concentrated cleaning agent is
It is characterized in that the combination surfactant contains the following components in the following amounts, based on the detergent concentrate:

(c) linear and branched, saturated and unsaturated 08-C
0.1 to 5% by weight of an anionic surfactant selected from the group consisting of 18 carboxylic acids and their alkali metal salts and mixtures of these carboxylic acids.

(d) non-ionic selected from the group consisting of C12"-CI8 fatty alcohols, C8-CI5 oxo alcohols, nonylphenols and CIt-CI6 fatty amines, having from 1 to 14 moles of ethylene oxide or propylene oxide, and mixtures thereof; Surfactant 0.1~
5% by weight, and (e) alkyl monoglucosides and/or alkyl polyglucosides having 2 to 6 glucose units and their mixture 0.1
~10% by weight.

The above surfactant combination ratio may be varied within the above range, but the ratio of anionic surfactant to nonionic surfactant to sugar surfactant is 0.5:0.5:
It is preferable to adjust it within the range of 1.0 to 2:3:5.

The invention also covers previous and subsequent finishing treatments such as phosphating, galvanizing, enameling and painting;
Especially in the intermediate process of annealing, the metal surface,
In particular, it relates to concentrated cleaning agents for use in cleaning steel, non-ferrous metals, copper and zinc surfaces.

The concentrated detergent of the present invention can of course be used without being diluted, but it is preferable to prepare an aqueous solution containing 1 to 20% by weight of the concentrated detergent and use it in the above-mentioned cleaning treatment. That is, a preferred cleaning solution contains 10% of the concentrated cleaning agent of the present invention.
~2009/ρ included.

The advantages of the concentrated alkaline liquid detergents of the present invention are, in part, the high active substance content of the builder and the high surfactant concentration. On the other hand, the present invention has made it possible for the first time to provide concentrated alkaline cleaners which exhibit a considerably improved cleaning effect over the products of the state of the art, in particular a cleaning effect on metal surfaces.

The commercially available starting aqueous solutions of the individual builders advantageously used to prepare the detergent concentrates of the invention are considerably cheaper than the corresponding powdered products (since they are of course of the same active substance content, This is balanced against the fact that the potassium compounds preferably used as builders in the present invention are considerably more expensive than the sodium compounds.Therefore, the raw material cost of the builder aqueous solution preferably used in the present invention is based on the active substance wage m. , the same amount as the powdered product.

Nonionic surfactants may be used for cleaning, emulsification and defoaming as required, depending on the degree of alkoxylation.

If the cleaning solution has to meet different requirements, it is possible to use mixtures of nonionic surfactants.

Based on the combination of various surfactants in the cleaning concentrates of the present invention, products suitable for any industrial cleaning application can be obtained. It is thus possible to produce cleaning agents for use in spraying, brushing, dipping and sonication and electrolytic cleaning. By appropriate combinations, it is possible to adjust to a predetermined point, making it possible to produce high-temperature or low-temperature detergents.

In addition to the above-mentioned advantages, the concentrated liquid cleaning agent of the present invention significantly reduces the temperature of the cleaning solution and/or the temperature of the subsequent rinsing step compared to the corresponding powder product, as shown in the application examples below. Be able to do it. In this way, more energy can be saved during cleaning.

In addition to the active ingredients described above, the detergent concentrates of the present invention may of course contain other components typically used in alkaline detergents, such as foam suppressants, corrosion inhibitors, complexing agents, and the like.

The compounds listed below are examples of compounds that are particularly suitable for the purposes of the present invention.

Foam suppressant: aJl; i 0.1 to 5 times (1
Use 1% C14~C+s fatty alcohol (cocoyano alcohol) polyethylene glycol butyl ether,
and 30 moles of ethylene diamine and 60 moles of propylene oxide adduct.

Corrosion inhibitor (for non-ferrous metals): 0.1 based on concentrated detergent
Benztriazole and tolyltriazole used at ~5% by weight.

Complexing agent: polycarboxylic acid, such as polyacrylate, hydroquinethane-141 to diphosphonic acid (1 to IEDr'), used in an amount of 0.1 to 10% by weight based on the Dt thickness detergent.
and aminotris (medylene phosphonic acid) (ATMP
), phosphonic acids and their water-soluble salts, aminopolycarboxylic acids such as edylenoaminetetraacetic acid (EDTA
), nitrilotriacetic acid (NTA) and their water-soluble salts, polyoxycarboxylic acids such as citric acid or its salts.

In the present invention, it is not normally necessary to add such compounds depending on the method of application, but the incorporation of such additives can vary, using the specific amounts needed for the particular case.

The detergent concentrates of the present invention are typically prepared as follows.

First, an aqueous Hirgo solution, for example a water glass solution, and a solution of potassium hydroxide and, if necessary, sodium triphosphate are stirred together at room temperature. Next, the other ingredients, Zunawara surfactant and optional additives, are introduced into the Pilgoo concentrated aqueous solution while stirring. In order to prepare the dilute solution, i.e. the cleaning solution, for use, the concentrated cleaning agent is usually
It is introduced directly into the cleaning bath while stirring. One advantage of the concentrated detergent composition of the present invention is that it does not require dissolution, as is typically the case with powdered products. A dilute solution of the concentrated cleaning agent can be prepared by mixing the concentrated solution with the required amount of water.

[Example] The invention is illustrated by the following examples.

note.

Sodium water glass (40/42X Henkel Command Gesellschaft Auf Dusseldorf)
(manufactured by Akugen [Llenkel KGaA]), molar ratio 5iOt:Na'tO=3.42/1, S +Ot29
, 2% by weight, Na, 08.8% by weight, total solids content 38% by weight.

The indicated molar ratios Sio , :Me2O are based on the total amount of sodium waterglass plus alkali and, if present, potassium hydroxide or sodium hydroxide introduced. This value for silicate-free formulations is 0.

Cleaning liquid concentration note: Potassium soft soap Nisoyura Potassium salt of fatty acids (C78-CI8 fatty acids) Yashiura amine: Unsaturated C12-C18 fatty amine Fatty amine: Unsaturated or saturated CI4-C1g fatty amine Complex palm oil The cold-rolled very fine strips with hole @ liquid were placed in a 559/f2 solution of concentrated cleaning liquid prepared according to Example 3 under cathodic polarization with a current density of IA/dm2 at the temperature of the cleaning and rinsing baths and cleaning. Cleaned and rinsed for varying times. After rinsing, test the strip for water wettability;
After drying, the remaining oil and graphite coverage was determined by the combustion method described in J. Kresse, Metallobcrnaeche, Vol. 37, (1983), pp. 500-503. It was decided by.

The results obtained are shown in Table 1 below.

T? according to West German Published Patent No. 35 18 672? 1. Using a purified acid solution, conduct the test in the same manner as in the application example described in i.

The cleaning solution is as follows: 5 parts sodium hydroxide (100% display) 30 parts water
He had 65 copies in stock.

The concentrated liquid is n-denle glucoside 45 parts C13-C
Adduct of 1fi oxoalcohol with 4 moles of pyrene quinide and 2 moles of ethylene oxide (bulk)
20 parts Oleic acid adduct of maleic anhydride (molar ratio 1:1) 1.5 parts 2-ethylhexanoic acid 135 parts Water
The results obtained using 20 parts of this cleaning solution are shown in Table 2.

The comparative examples show that the cleaning results obtained with one agent according to the state of the art are considerably inferior to the cleaning results obtained with the concentrated cleaning agent of the present invention.

Patent applicant Henkel Kommandit Gesellschaft Auf Akchen

Claims (1)

[Scope of Claims] 1. An alkaline concentrated liquid detergent containing an alkaline builder aqueous solution and a surfactant, comprising (a) water 50-6
(b) an anionic surfactant, a nonionic surfactant and A cleaning agent characterized in that it contains 0.3 to 20% by weight of a combination surfactant consisting of an alkyl glucoside. 2. The builder mixture contains, in addition to the alkali metal silicate and/or alkali metal phosphate, an alkali metal hydroxide,
A cleaning agent according to claim 1, which also contains an alkali metal gluconate and/or an alkanolamine. 3. The cleaning agent according to claim 1 or 2, wherein the alkali metal is sodium and/or preferably potassium. 4. Detergent according to any one of claims 1 to 3, in which the alkali metal is a mixture of potassium and sodium, such that the ratio of potassium to sodium is at least 4:1. 5. The surfactant combination is based on the concentrated detergent: (c) linear, branched, saturated and/or unsaturated C_8~
0.1 to 5% by weight of an anionic surfactant selected from the group consisting of C_1_8 carboxylic acids, their alkali metal salts and mixtures of such carboxylic acids; (d) 1% of ethylene oxide or propylene oxide;
0.1 to 5% by weight of a nonionic surfactant selected from the group consisting of C_1_2 to C_1_8 fatty alcohols, C_8 to C_1_5 oxo alcohols, nonylphenols and C_1_2 to C_1_8 fatty amines, and mixtures thereof, having ~14 moles, and (e) Alkyl monoglucosides in which a linear or branched C_8 to C_1_4 alkyl group is acetal bonded to glucose and/or alkyl polyglucosides having 2 to 6 glucose units and mixtures thereof 0.1 to 1
The cleaning agent according to any one of claims 1 to 4, containing 0% by weight. 6. The ratio of anionic surfactant to nonionic surfactant to sugar surfactant is 0.5:0.5:1.0 to 2:3:5.
The cleaning agent according to any one of claims 1 to 5, which is adjusted to 7. Surface cleaning of metals, especially steel, non-ferrous metals, copper and zinc, before finishing treatments such as phosphating, galvanizing, enameling and painting, and in intermediate steps before subsequent treatments, especially annealing. The cleaning agent according to any one of claims 1 to 6, which is used for. 8. The cleaning agent according to claim 7, which is used as an aqueous solution containing 1 to 20% by weight of the concentrated cleaning agent.