WO1995002714A1

WO1995002714A1 - Agents for the cleaning and passivation of metal surfaces

Info

Publication number: WO1995002714A1
Application number: PCT/EP1994/002226
Authority: WO
Inventors: Jürgen Geke; Horst-Dieter Speckmann; Bernd Stedry; Andreas Arnold
Original assignee: Henkel Kommanditgesellschaft Auf Aktien
Priority date: 1993-07-16
Filing date: 1994-07-07
Publication date: 1995-01-26
Also published as: DE4323909A1

Abstract

The invention concerns agents intended for the cleaning and passivation of metal surfaces, the agents being made up of two base formulations A and B which are used together in the agent. Formulation A consists of an oil-in-water emulsion containing an oil, at least one emulsifier and water, and formulation B consists of an aqueous solution of water-soluble salts of carboxylic acids with a corrosion-inhibiting action. The characteristics in use of the overall system, in particular the pH, the foaming behaviour and the ability to protect against corrosion, can be controlled by varying the corrosion-protection additive. It is also possible to produce oil-in-water emulsions with a particularly long shelf life.

Description

Means for cleaning and passivating metal surfaces

The invention relates to agents for cleaning and passivating metal surfaces, in particular iron and steel surfaces, consisting of two base formulations A and B, which are used together to apply the agents. The basic formulation A consists of an 0 / W (oil-in-water) emulsion which contains an oil component, at least one emulsifier component and water, and the basic formulation B consists of an aqueous solution which is more water-soluble Salts of carboxylic acids which are effective as corrosion inhibitors. The invention further relates to the use of such agents.

Detergents, in particular so-called "neutral cleaners", ie neutral to weakly alkaline cleaners, are generally used for surface cleaning of metals before the surface coating or the shaping of metallic workpieces. The aim here is the residue-free removal of adhering dirt, grease and other residues. Passivation agents, in particular corrosion protection emulsions, are used for the temporary protection of metallic workpieces from atmospheric influences which cause corrosion. They contain essentially non-polar or polar oils, emulsifiers, corrosion inhibitors and water. Their effect is based on the adsorption of inhibitor molecules on the metal surface and the formation of a protective film from emulsion components, which acts as a diffusion barrier for atmospheric oxygen as well as water works. Th. Forster et al. report in "Surface Surface", 1989, No. 4, pp. 8 to 12, about the mode of action and investigative methods of rust protection emulsions. Commercial systems are based on oil concentrates that contain emulsifiers and corrosion inhibitors - but no water. This means that the emulsifiers and corrosion inhibitors used must be oil-soluble. For the production of water-diluted O / W emulsions from such oil concentrates, which are then used after dilution with water, this also means that such systems must be self-emitting.

It is known that oil-in-water emulsions which have been prepared and stabilized with non-ionic emulsifiers undergo phase inversion when heated, ie that at higher temperatures the outer, aqueous phase can become the inner phase. This process is usually reversible, ie the original emulsion type regresses when it cools down. It is also known that the position of the phase inversion temperature (PIT) is dependent on many factors, for example the type and phase volume of the oil component, the hydrophilicity and structure of the emulsifier or the composition of the emulsifier system, for example compare K. Shinoda and H. Kunieda in "Encyclopedia of Emulsion Technology", Vol. I, ed. P. Becher 1983 (M. Decker, NY), pp. 337 to 367. Furthermore, it is known that emulsions containing at or little are produced below the phase inversion temperature, are distinguished by a particularly fine particle size and stability, while those which are produced above the phase inversion temperature are less finely divided (see S. Friberg, C. Solans, "J. Colloid Interface Sei." , 66, pp. 367 to 368 (1978)). F. Schambil, F. Jost and MJ Schwuger report in "Progress in Colloid & Polymer Science" 73, (1987), pp. 37 to 47, about the properties of cosmetic emulsions, the fatty alcohols and fatty alcohols. Alcohol polyglycol ethers contain and also describe that emulsions which have been produced above the phase inversion temperature have a low viscosity and high storage stability. DE-A-3819193 describes a process for producing stable, low-viscosity O / W emulsions of polar oil components.

DE-A-39 33 137 describes a process for producing low-viscosity O / W rust protection emulsions, using a mixture containing an oil component, water, at least one emulsifier component and a corrosion inhibitor at a temperature ¬ door, in which all components of the mixture are in liquid form, emulsifies and the emulsion formed is heated to a temperature within or above the phase inversion temperature range of the emulsion or the mixture emulsifies at a temperature within or above the phase inversion temperature range, then the emulsion cools to a temperature below this temperature range and optionally diluted with water. Free carboxylic acids are used as corrosion inhibitors, which can optionally also be neutralized after the emulsion formation. However, such emulsions have proven to be relatively unstable - both in the acidic and in the alkaline pH range - since they tend to separate phases. In practice, the storage stability of such emulsions is therefore insufficient. In addition, such rust protection emulsions also have further disadvantages when used in a form diluted with water. These are inadequate corrosion protection of the treated metal surfaces and a relatively strong foam development, particularly when used in the spraying process.

In the case of the commercially available one-component mixtures, the technical properties are practically exclusively above the changes in the overall system are adjustable, since no individual metering of the components is carried out. The reason for this is the complex emulsion system, which makes targeted analysis as a basis for the metering of the used components difficult. However, since, for example, the pH, the foaming behavior and the corrosion protection in the baths vary over the course of the period of use, it is a serious disadvantage to add all the components of the compositions, even if only individual components of the compositions in the form of a one-component composition Need to be supplemented.

In contrast, it was the object of the present invention to provide means for cleaning and passivating metal surfaces which do not have the disadvantages of known corrosion protection agents and in particular the known O / W rust protection emulsions. The object of the invention was therefore to develop agents which, on the one hand - can be mixed with water to form the customary, dilute aqueous application emulsions - in comparison to purely oil-based corrosion protection agents - and which on the other hand - in comparison to the known 0 / W rust protection emulsions - have a sufficiently good storage stability. In addition, these new agents should ensure excellent corrosion protection of the treated metal surfaces - even against the onset of atmospheric corrosion - in particular when used in the spraying process they should not cause any foam problems and should enable optimal conditions with regard to replenishing the corrosion inhibitor component.

In view of this task, it has now been found that the performance properties of agents for cleaning and passivating metallic surfaces can be adjusted in a particularly simple manner by using corrosion inhibitors separately during use. It was found, that with the aid of a two-component system, in which the corrosion inhibitor component is a separate component, the pH, the foam behavior and the corrosion protection of the entire system can be specifically adjusted and thus controlled via the corrosion protection additive. In addition, it is possible with the aid of the present invention to produce corrosion-inhibitor-free O / W emulsions which are distinguished by a particularly high storage stability. The corrosion inhibitor component to be used is then metered in to the desired extent immediately before or during the use of the cleaning and passivating agents.

The invention thus relates in a first embodiment to an agent for cleaning and passivating metal surfaces consisting of two base formulations A and B, which are used together to apply the agent, characterized in that the base formulation A consists of an O / W emulsion consists of the following components:

(a) 10 to 60% by weight of an oil component,

(b) 1 to 20% by weight of an emulsifier component consisting of at least one adduct of 2 to 20 moles of ethylene oxide with saturated or unsaturated fatty alcohols having 6 to 22 carbon atoms,

(c) 0 to 15% by weight of a co-emulsifier component selected from fatty alcohols, alkoxylated fatty alcohols,

Fetta1koho1-po1yethy1englyko1-mixed ethers and fatty acid esters,

(d) balance: water up to 100% by weight, and the basic formulation B consists of an aqueous solution which contains water-soluble salts of carboxylic acids in amounts of 1% by weight up to the limit of the water-solubility of the salts, the carboxylic acids being selected are made

(e) saturated or unsaturated, straight chain or branched aliphatic monocarboxylic acids with 6 to 22

Carbon atoms,

(f) saturated or unsaturated, straight-chain or branched aliphatic dicarboxylic acids having 6 to 22 carbon atoms,

(g) substituted or unsubstituted benzene mono- and benzoic dicarboxylic acids,

(h) substituted or unsubstituted

Arylsulfonylaminocarboxylic acids, (i) substituted or unsubstituted benzoylalanines, (k) alkylbenzoylacrylic acids, and the salt-forming cations are selected from alkali metals, ammonium, amines and acanolamines.

For the purposes of the invention, it is preferred that the base formulation A consists of an O / W emulsion which contains the following components:

(a) 20 to 50% by weight of oil component,

(b) 2 to 10% by weight of emulsifier component,

(c) 0.1 to 5% by weight of co-emulsifier component,

(d) balance: water up to 100% by weight.

According to the invention it is further preferred that the base formulation A the components (a), (b) and (c) in a weight ratio of (a): (b + c) in the range of 1: (0.04 to 0, 75), in particular in the range from 1: (0.1 to 0.3).

On the one hand, it is essential to select suitable carboxylic acids that are able to act as corrosion inhibitors. On the other hand, the selection of suitable emulsifiers is important, which emulsions are stable at the application stage with the corrosion inhibitors mentioned and the oil components form and, on the other hand, do not further impair the effectiveness of the corrosion inhibitors on the substrate surface under atmospheric corrosion conditions by re-emulsification.

For the individual components of the cleaning and passivating agents according to the invention. The following applies in particular to metallic surfaces:

Oils of different polarity, for example paraffin oils or mineral oils, can be used as oil component (a) of the basic formulation A. So-called ester oils, i.e. Fatty acid glycerides can be used as an oil component. The use of polyolefins, polyalkylene glycols and glycol ethers is also possible. Dialkyl ethers with a chain length of about 8 to 24 carbon atoms per alkyl radical can also be used as mineral oil substitutes. The use of this class of compounds has recently been known in particular from the field of drilling fluid. For the purposes of the invention, paraffin oils and / or mineral oils and / or fatty acid glycerides and / or dialkyl ethers are preferably used as oil component (a) of the basic formulation A.

As emulsifier component (b) of the basic formulation A, addition products of 2 to 20 moles of ethylene oxide with saturated or unsaturated fatty alcohols with 6 to 22 C atoms are suitable. Fatty alcohols suitable for this purpose are native and / or synthetic fatty alcohols, such as hexanol, octanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol (cetyl alcohol), hepatadecanol, octadecanol (stearyl alcohol), nonadecanol, eicosanol, Heneicosanol, Docosanol (behenyl alcohol) and the corresponding unsaturated fatty alcohols. Technically produced adducts of ethylene oxide with such fatty alcohols or fatty alcohol Mixtures usually represent mixtures of polyglycol ethers of the starting fatty alcohols, the average degree of oxyethylation of which corresponds to the amount of ethylene oxide added. For the purposes of the invention, addition products of 4 to 16 moles of ethylene oxide with saturated or unsaturated fatty alcohols having 12 to 18 carbon atoms are preferably used as emulsifier component (b). The following are used in particular: Addition products of 12 mol ethylene oxide onto fatty alcohol mixtures with 16 to 18 carbon atoms.

For the agent according to the invention, it has also proven to be advantageous to use a coemulsifier component (c) in addition to the emulsifier component (b). Because of its hydrophilicity, the co-emulsifier may not itself be suitable for the production of emulsions; together with the previously defined emulsifier components, however, particularly stable and finely divided emulsions of the oil components can be produced. According to the invention, suitable co-emulsifiers are, in particular, saturated or unsaturated fatty alcohols having 12 to 22 carbon atoms. The fatty alcohols which are suitable here are mentioned in detail in the above list of fatty alcohols. Mixtures of such fatty alcohols, as are obtained in the industrial hydrogenation of vegetable and animal fatty acids having 12 to 22 carbon atoms or the corresponding fatty acid methyl esters, are also suitable. Fatty alcohols with 16 to 18 carbon atoms, for example a mixture of cetyl alcohol and stearyl alcohol in a weight ratio of 1: 1, are particularly preferred as co-emulsifiers. Fatty acid esters, fatty alcohol / polyethylene glycol mixed ether and alkoxylated fatty alcohols are used.

Fatty alcohol polyethylene glycol ethers, for example hydroxy misethers, which can be used as co-emulsifiers, are, for example, reacted with fatty alcohol polyglycol ethers α-01efinepoxiden obtained. Their production is described for example in DE-A-37 23 354. Fatty alcohol polyglycol ethers are known in the art in particular as nonionic surfactants. They are produced by reacting fatty alcohols with 12 to 22 carbon atoms and 0, 1 or 2 double bonds in the carbon chain structure in the presence of alkoxylation catalysts with ethylene and / or propylene oxide. Products with so-called "narrow homolog distribution" are known, for example, from J.Am.Oil.Chem.Soc. 63, 691 (1986). Of these, ethoxylated saturated fatty alcohols with 12 to 22 carbon atoms, in particular with 12 to 18 carbon atoms, and 1 to 5 moles of ethylene oxide per mole of fatty alcohol are preferably used as co-emulsifier component (c). For the purposes of the invention, it is further preferred to use glycerol partial esters of saturated or unsaturated fatty acids having 12 to 22 carbon atoms as co-emulsifier component (c). Of these, glycerol monoesters of saturated or unsaturated fatty acids with 16 to 18 carbon atoms are used in particular.

The water-soluble salts of carboxylic acids of the basic formulation B used as a corrosion inhibitor component can have a different structure.

For the purposes of the invention, saturated or unsaturated, straight-chain or branched monocarboxylic acids having 6 to 22 carbon atoms are particularly suitable. These include native or synthetic fatty acids, for example hexanoic acid (caproic acid), heptanoic acid (enanthic acid), octanoic acid (caprylic acid), nonanoic acid, decanoic acid (capric acid), undecanoic acid, dodecanoic acid (lauric acid), tridecanoic acid, tetradecanoic acid (myristic acid), Pentadecanoic acid, hexadecanoic acid (palmitic acid), heptadecanoic acid, octadecanoic acid (stearic acid), nonadecanoic acid, arachic acid, heneicosanoic acid and behenic acid. In the same way, salts of corresponding branched or unbranched saturated carboxylic acids as corrosion inhibitors in the sense of the invention. According to the invention, preference is given here to using salts of saturated, straight-chain or branched aliphatic monocarboxylic acids having 6 to 9 carbon atoms, in particular of oenanthic acid or caprylic acid, as the corrosion inhibitor component (s).

Also suitable as corrosion inhibitor component (f) are water-soluble salts of saturated or unsaturated, straight-chain or branched aliphatic dicarboxylic acids having 6 to 22 carbon atoms. Salts of saturated, straight-chain α, -dicarboxylic acids having 6 to 10 C atoms are preferred according to the invention. These include adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid. Of these, the water-soluble salts of adipic acid and sebacic acid are used in particular.

The water-soluble salts of benzene mono- and benzenedicarboxylic acids to be used as corrosion inhibitor component (g) in the context of the invention can optionally have substituents on the benzene radical selected from alkyl radicals having 1 to 3 carbon atoms, nitro, amino, methoxy and sulfonic acid groups , exhibit. Of these, the salts of benzoic acid, 3-nitrobenzoic acid, 4-aminobenzoic acid, phthalic acid, isophthalic acid and terephthalic acid are to be mentioned in particular.

However, the aromatic carboxylic acids to be used according to the invention also include those in which the carboxyl groups are not bonded directly to the benzene nucleus. In this sense, the corrosion inhibitor component according to the invention is: (h) Water-soluble salts of substituted or unsubstituted arylsulfonylaminocarboxylic acids, as described, for example, in DE-B-1298672 and DE-A-3330223. Such benzenesulfonyl inocarboxylic acids can, for example be substituted on the benzene nucleus with a Cι_5 alkyl group and / or on the N atom with a Cι_3 alkyl group. According to the invention, preference is given to benzenesulfonyl-N-methylaminocaproic acid, (i) water-soluble salts of substituted or unsubstituted benzoylalanines, as described, for example, in DE-A-34 16 120 and DE-A-35 21 116. Such benzoylalaines can be substituted, for example, on the benzene nucleus with a C 6 alkyl group and / or on the N atom with a C 1 alkyl group or a C 4 hydroxyalkylene group. Of these, 3- (p-methyl-benzoyl) -N- (l, l-dimethylethanol) -alanine is preferred according to the invention, (k) water-soluble salts of alkylbenzoylacrylic acids, as described, for example, in DE-A-36 00 401 can be described. Such alkylbenzoylacrylic acids can be substituted, for example, on the benzene nucleus with a Cβ-is-alkyl group. Of these, 3- (p-dodecylbenzoyl) acrylic acid is preferred according to the invention.

The salt-forming cations of the salts of these carboxylic acids, which form the basic formulation B in aqueous solution, are selected according to the invention from alkali metals, ammonium, amines and alkanolamines. Of these, the alkali metal salts, in particular the sodium or potassium salts, are preferably used as salts of carboxylic acids in the context of the invention, the use of the corresponding potassium salts being particularly preferred in view of their better water solubility. Amine or alkanolamine salts, for example corresponding monoethanol or triethanolamine salts, can also be used, if desired. However, since such compounds are now classified as toxicologically unsafe, their use in the context of the invention is generally of little interest. According to a preferred embodiment of the present invention, the basic formulation B consists of an aqueous solution which contains salts of the carboxylic acids mentioned in amounts of 2 to 25% by weight.

The base formulation A, which consists of an O / W emulsion of the components (a) to (d) described above, can be prepared in various ways. For example, these components can be mixed and emulsified in the usual way. According to the invention, however, a procedure is preferred in which the phase inversion temperature (PIT) of the emulsion is taken into account, as is described, for example, in DE-A-3819193 and DE-A-3933137 already cited above. In the case of an emulsion of the oil component, the emulsifier component and water, if appropriate with the addition of a coemulsifier component, the phase inversion temperature of this emulsion is first determined by taking a sample of the emulsion prepared in the customary manner using a Conductivity meter heated and determined the temperature at which the conductivity decreases sharply. The specific conductivity of the oil-in-water emulsion initially present usually decreases within a temperature range of 2 to 8 ° C. from initially over 1 mS / cm when changing to an inverted emulsion to values below 0.1 mS / cm. This temperature range is referred to as the phase inversion temperature range.

Now that the phase inversion temperature range for a particular composition of an emulsion is known, the process for the preparation of the basic formulation A can either be carried out in such a way that the emulsion initially prepared as usual, which contains all the components essential to the invention, is switched off ¬ taking the corrosion inhibitor component - contains, subsequently heated to a temperature which is within or above the Phase inversion temperature range. A further possibility for production consists in that a temperature which is within or above the phase inversion temperature range is already selected for the emulsion formation. As a rule, one proceeds in the manner described last; ie all components of basic formulation A essential to the invention for a particular emulsion are mixed, this mixture is heated to a temperature above the phase inversion temperature range and the mixture is emulsified by intensive stirring. The emulsion formed is then allowed to cool to a temperature below the phase inversion temperature range or the emulsion is cooled to a corresponding temperature. In this way, emulsion concentrates are obtained, which can optionally be diluted with water. The O / W emulsion concentrates thus produced of the basic formulation A according to the invention are notable for excellent storage stability. In addition, they can be mixed with the base formulations B according to the invention, both in concentrated form and in water-diluted form, without difficulty, which likewise results in O / W emulsions.

To prepare the base formulation B, which according to the invention consists of an aqueous solution of water-soluble salts of the carboxylic acids discussed in detail above, the procedure is generally such that the carboxylic acid selected in each case, or else a plurality thereof, is mixed with an aqueous solution of those selected for salt formation Base neutralized. The aqueous alkali, preferably in a stoichiometric excess, in particular an aqueous potassium hydroxide solution, is preferably initially introduced and the carboxylic acid is added. It may be advantageous to heat the mixture obtained while stirring. A further embodiment of the present invention relates to the use of the agents according to the invention for cleaning and passivating metal surfaces, the basic formulation A and the basic formulation B being mixed with one another to form an O / W emulsion, optionally diluted with water, and the resulting formulation Emulsion is used to treat the metal surfaces by dipping and / or spraying. Iron or steel surfaces are particularly suitable as metal surfaces.

Furthermore, it is preferred according to the invention to use the emulsion obtained by mixing the base formulations in a form diluted with water for the treatment of the metal surfaces - in particular by spraying. Such application emulsions diluted with water preferably have concentrations in the range from 0.5 to 50% by weight, based on the base formulations A and B, the weight ratio from A to B in the range from 20: 1 to 0.5: 1, in particular in the range from 10: 1 to 1: 1. The pH values of the application emulsions are generally in the range from greater than 7 to 13, with pH values in the range from 8 to 9.5 being preferred.

Both the emulsion concentrates obtained by mixing the base formulations and the 0 / W emulsions diluted with water ensure very good corrosion protection for metal surfaces made of iron and steel.

In comparison to emulsions produced below the phase inversion temperature, the basic formulations A produced by the phase inversion process are particularly finely divided and low-viscosity and therefore pourable and pumpable. This makes the basic formulations A and B particularly easy to mix guaranteed. Since these concentrates are oil-in-water systems after mixing and the oil phase is very finely divided, they can be easily diluted with water. It is furthermore advantageous that such application emulsions - depending on the choice of the carbonic acid salt used as the corrosion inhibitor in the base formulation B - can also be used without problems in the spraying process for treating metal surfaces. In particular, the salts of short-chain monocarboxylic acids, ie those with 6 to 9 carbon atoms, do not cause any foam problems. The use of the agents according to the invention also makes it possible, if necessary, to meter only one of the two base formulations separately into an application emulsion, in order to counteract a depletion of the application emulsion, for example the corrosion inhibitor component according to base formulation B, caused by the application.

For the purposes of the invention, it is further preferred that additives are added to the application emulsions, if desired in individual cases, these additives preferably being selected from cationic and / or nonionic surfactants, builder substances, non-ferrous metal corrosion inhibitors, microbicides, solubilizers, pH regulators and foam inhibitors . Possible builder substances here are, for example: water-soluble alkali metal borates, silicates, phosphates and / or polyphosphates, preferably in the form of the sodium and / or potassium salts; Hydroxycarboxylic acids and / or polycarboxylic acids and their water-soluble salts, in particular their sodium and / or potassium salts, for example citric acid, tartaric acid, gluconic acid, sugar acid, nitrilotriacetic acid, carboxyl group-containing oxidation products of polygluconsans, as described in DE-A-41 34914, as well as acrylic acid homopolymers and copolymers containing carboxyl groups based on acrylic acid with maleic acid or based on maleic acid with methyl vinyl ether, as described by BASF AG under the name SOKALAN ^ brands are sold; also phosphonic acids and phosphonocarboxylic acids, for example l-hydroxyethane-l, l-diphosphonic acid, aminotris (methylenephosphonic acid), 2-phosphonobutane-l, 2,4-tricarboxylic acid and their water-soluble salts, preferably their sodium and / or Potassium salts. Examples of other suitable additives are also: as non-ferrous metal corrosion inhibitors: mercaptobenzotriazole, tolyltriazole or benzotriazole; as microbicides glutaraldehyde or hexahydrotriazines; and as further cleaning components, in particular nonionic surfactants. Additives of this type may also require the use of suitable foam inhibitors, in particular when used in the spraying process at lower temperatures. End group-capped fatty alcohol polyglycol ethers, optionally ethoxylated dialkyl carbonic acid esters or propoxylated fatty acids are suitable as such. Such compounds are sufficiently known to the person skilled in the art from the relevant literature. In this way it is possible to adjust or adapt the agents according to the invention in the form of their application emulsions to the problems and cleaning tasks present in the individual application.

Examples

The formulations given below were prepared using various commercial products, the composition and origin of which are characterized in more detail here:

Mineral oil Pionier ^R 4556: mineral oil (naphthenic) from the company

Hansen & Rosenthal, Hamburg

Eumulgin ^R Bl: adduct of approx. 12 mol

Ethylene oxide on cetyl / stearyl alcohol (mixture of cetyl and stearyl alcohol in a weight ratio of approx. 1: 1), company Henkel KGaA, Düsseldorf

Rilanit ^R GMO: monoglycerol ester of

Oleic acid / palmitic acid / stearic acid (Henkel KGaA)

Basic formulations. Recipes and production

example 1

Basic formulation A:

45% by weight of Pionier ^R 4556 mineral oil

4.4% by weight of Emulgin ^R Bl

0.6% by weight rilanite ^ GMO

50% by weight water (fully desalinated)

The ingredients specified above were mixed together, the mixture was heated to 95 ° C. and emulsified by vigorous stirring. The phase inversion temperature range of this emulsion, which was previously determined as described above, was 88 to 92 ° C. The emulsion obtained was then cooled.

Example 2 Basic formulation B1:

20% by weight tall oil fatty acid 6.4% by weight potassium hydroxide (45% by weight) 73.6% by weight water (fully desalinated)

Basic formulation B2:

20% by weight caprylic acid

20% by weight potassium hydroxide (45% by weight)

60% by weight water (fully desalinated)

Basic formulation B3:

19% by weight of enanthic acid

18% by weight potassium hydroxide (45% by weight)

63% water (fully desalinated)

To prepare the base formulations B, the potassium hydroxide solution diluted with water was initially introduced and the acid specified above was introduced into this aqueous solution. Each of these mixtures was heated (60 ° C.) with stirring until the acids had completely dissolved. Example 3

Application emulsion, foaming behavior

To prepare the application emulsions used in this test, the base formulation A according to Example 1 was first diluted to an concentration of 40 g / 1 with an aqueous salt solution containing 126 mg / 1 chloride and 71 mg / 1 calcium ions. The total hardness of the salt solution was 10 ° d. The respective base formulations B according to Example 2 were each mixed with the diluted base formulation A in concentrations which are given in Table 1 below and emulsified with stirring.

A laboratory spraying unit with a circulating water volume of 10 l was available for carrying out the foam tests. The respective application emulsions were each added to the circulating water and sprayed at a constant spray pressure of 3 bar and a constant temperature of 65 ° C. The foam development was checked after 120 minutes. The foam height determined in each case is defined as the height of the foam (in cm) above the liquid level in the initial state. Table 1 shows the results obtained.

Table 1

Basic formulation B Bl B2 B3 Additional amount in% by weight related Look at basic formulation A in cm

10% foams over 3.5 2

20% II 3.0 30% II 2.0 40% 50% 60% 70% 80% 90% 100%

In these tests, which were carried out with the addition of water hardness, it was found that the application emulsion with tall oil fatty acid according to the basic formulation B1 caused too much foaming - in comparison to the short-chain fatty acids according to the basic formulations B2 and B3. The use of such an application emulsion in the spray process is therefore not sensible; In contrast, such an application emulsion can certainly be used in the dipping process, since the tall oil fatty acid has a self-emulsifying effect and thus supports the removal of greases from the treated metal surfaces. Example 4

Application emulsion, corrosion tests

To prepare the application emulsion used in this test, the base formulation A according to Example 1 was first concentrated to a concentration of 40 g / 1 with an aqueous salt solution containing 215 mg / 1 chloride, 51 mg / 1 sulfate, 121 mg / 1 calcium ions and 13 mg / 1 magnesium ions, diluted. The total hardness of the salt solution was 20 ° d. The respective base formulations B according to Example 2 were mixed with the diluted base formulation A in the concentrations given below and emulsified with stirring:

- Bl: 20 g / 1,

- B2: 12 g / 1,

- B3: 14 g / 1.

The corrosion-inhibiting effectiveness of the application emulsions thus obtained was tested on steel sheets (quality: St 1405) in the so-called plate climate test. The test sheets were first degreased twice with acetone, cleaned with a mildly alkaline cleaner, rinsed several times with deionized water, then rinsed with alcohol and blown dry. The test sheets prepared in this way were then immersed in the respective application emulsion for 5 minutes at 70 ° C. After removing the test sheets from the respective application emulsion, the sheets were dried at room temperature for 3 hours and then stored in a climate box at room temperature and at a relative humidity of 65 or 76%. The tests were terminated after 25 days, since there were no signs of corrosion on the steel sheets either at a humidity of 65% or at 76%. Comparative example

Anti-rust emulsion according to DE-A-3933137

An O / W rust protection emulsion according to Example 1.1 of DE-A-39 33137 (formulation A) was prepared. Composition: 40% by weight of mineral oil Pionier ^R 4556 8% by weight of Eumulgin ^R Bl

6% by weight stearic acid / palmitic acid (ratio 1: 1) 46% by weight water

Part of the emulsion obtained was neutralized with an aqueous NaOH solution after the elution formation. Both the non-neutralized and the neutralized emulsion concentrate were each diluted with deionized water to a concentration of 40 g / 1 and used in this form for the following corrosion test (analogous to Example 4): Both the non-neutralized were used for this as well as the neutralized application emulsion (concentration: 40 g / 1 in an aqueous salt solution analogous to Example 4). Result: The test sheets already showed signs of corrosion (rust) when immersed in the respective emulsions. As a result, these tests were discontinued.

Claims

1) Means for cleaning and passivating metal surfaces consisting of two basic formulations A and B, which are used together for the use of the agent, characterized in that

- The basic formulation A consists of an O / W emulsion which contains the following components:

(a) 10 to 60% by weight of an oil component,

(c) 0 to 15% by weight of a co-emulsifier component, selected from fatty alcohols, alkoxylated fatty alcohols, fatty alcohol-polyethylene glycol mixed ethers and fatty acid esters,

(d) balance: water up to 100% by weight, and

- The basic formulation B consists of an aqueous solution which contains water-soluble salts of carboxylic acids in amounts of 1% by weight up to the limit of the water-solubility of the salts, the carboxylic acids being selected from

(e) saturated or unsaturated, straight-chain or branched aliphatic monocarboxylic acids with 6 to

22 carbon atoms,

(g) substituted or unsubstituted benzene mono- and benzenedicarboxylic acids,

(h) substituted or unsubstituted arylsulfo ny1aminocarboxylic acids, (i) substituted or unsubstituted benzoylalanines, (k) alkylbenzoylacrylic acids, and the salt-forming cations are selected from alkali metals, ammonium, amines and acanolamines.

2) Agent according to claim 1, characterized in that the basic formulation A contains as oil component (a) paraffin oil and / or mineral oil and / or fatty acid glycerides and / or dialkyl ether.

3) Agent according to claim 1, characterized in that the base formation A as emulsifier component (b) contains at least one adduct of 4 to 16 moles of ethylene oxide with saturated or unsaturated fatty alcohols with 12 to 18 carbon atoms.

4) Agent according to claim 1, characterized in that the base formulation A as coemulsifier component (c) at least one saturated or unsaturated fatty alcohol having 12 to 22 carbon atoms, preferably 16 to 18 carbon atoms, and / or at least one ethoxylated saturated fatty alcohol with 12 to 22 carbon atoms, preferably 12 to 18 carbon atoms, and 1 to 5 moles of ethylene oxide per mole of fatty alcohol and / or at least one glycerol partial ester of fatty acids with 12 to 22 carbon atoms, preferably contains a glycerol monoester of saturated or unsaturated fatty acids with 16 to 18 carbon atoms.

5) Agent according to one or more of claims 1 to 4, characterized in that the base formulation A consists of an O / W emulsion which contains the following components:

(a) 20 to 50% by weight of an oil component,

(b) 2 to 10% by weight of an emulsifier component, (c) 0.1 to 5% by weight of a co-emulsifier component,

(d) Remainder: water up to 100% by weight.

6) Agent according to one or more of claims 1 to 5, characterized in that the base formulation A, the components (a), (b) and (c) in a weight ratio of (a): (b + c) in the range of 1 : (0.04 to 0.75), in particular from 1: (0.1 to 0.3).

7) Agent according to claim 1, characterized in that the basic formulation B contains salts of carboxylic acids, alkali metal salts, in particular potassium salts, of carboxylic acids, which are selected from:

(e) saturated, straight-chain or branched monocarboxylic acids with 6 to 9 carbon atoms,

(f) saturated, straight-chain α, -dicarboxylic acids with 6 to 10 C atoms,

(g) benzoic acid, 3-nitrobenzoic acid, the positionally isomeric phthalic acids,

(h) benzenesulfonyl-N-methylaminocaproic acid,

(i) 3- (p-methylbenzoyl) -N- (l, l-dimethylethanol) alanine,

(k) 3- (p-Dodecy1benzoy1) acrylic acid.

8) Agent according to claims 1 or 7, characterized in that the base formulation B consists of an aqueous solution which contains salts of carboxylic acids in amounts of 2 to 25 wt .-%.

9) Use of agents according to one or more of claims 1 to 8 for cleaning and passivating metal surfaces, preferably iron and steel surfaces, the base formulation A and the base formulation B being mixed with one another to form an O / W emulsion, these possibly diluted with water, and the emulsion obtained, preferably in a form diluted with water, is used for the treatment of the metal surfaces in the dipping and / or spraying process.

10) Use according to claim 9, characterized in that one uses a water-diluted application emulsion with a concentration in the range of 0.5 to 50 wt .-%, based on the sum of the basic formulations A and B, the weight ratio from A to B is in the range from 20: 1 to 0.5: 1, preferably from 10: 1 to 1: 1.

11) Use according to claims 9 or 10, characterized in that the application emulsion has pH values in the range from greater than 7 to 13, preferably from 8 to 9.5.

12) Use according to one or more of claims 9 to 11, characterized in that application emulsions are used, the additional additives selected from cationic and / or nonionic surfactants, builder substances, non-ferrous metal corrosion inhibitors, microbicides, solubilizers, pH regulators and Foam inhibitors included.