EP1531012B1 - Supplementary corrosion protection for pieces of organic pre-coated metal sheets - Google Patents

Abstract

The method is for the manufacture of a lacquered component containing metal parts of galvanized steel. All the metal parts during the carrying out of the manufacturing stages consist exclusively of sheets of galvanized steel which bear a coating on a base of organic polymers, whereby in a treatment stage a passivating layer is created on the sections of the metal surface which are not covered by the coating on the base of organic polymers. The metal component may be the body of a motor vehicle, a domestic appliance, or a piece of furniture. An independent claim is included for a lacquered component containing parts of galvanized steel produced by the aforesaid method.

Description

The invention relates to a corrosion protection method for use in the production of painted metallic components from organically pre-coated metal sheets. In this case, places of uncoated metal, which inevitably arise during cutting, forming and joining the precoated metal sheets, provided with a corrosion protection layer, which also serves as a primer for the subsequent painting.

Components assembled from metal sheets such as vehicle bodies, housings of household appliances or metallic pieces of furniture can be assembled from metal sheets which do not yet have a permanent corrosion-protective coating. In a multi-stage process sequence, a permanent corrosion-protective coating can be produced consisting of a conversion layer and a coating layer after assembly of the metallic components. A well-known example of this is the process sequence phosphating and painting, as is common, for example, in the automotive industry. In this case, the actual phosphating is only one step in a treatment sequence, which generally includes, in addition to cleaning and rinsing stages, activation before phosphating, the actual phosphating and often post-passivation after phosphating. Thereafter, join several paint on. The pre-treatment before painting therefore requires several treatment steps, which in turn make a correspondingly extensive and thus costly pretreatment plant required. In addition, during phosphating heavy metal-containing waste, which must be disposed of costly.

Apart from phosphating, other methods for producing a so-called conversion layer are known, which protect the underlying metal from corrosion and which constitutes a primer for a subsequent coating layer. Here, a "conversion layer" is understood to mean a layer on a metal surface which is formed by "conversion treatment" under the action of a "conversion solution" and which both Contains elements of the metal surface as well as from the conversion solution. Typical examples are phosphate layers or chromate layers. Apart from phosphating and chromating processes, further conversion treatment methods are known, for example with conversion solutions based on complex fluorides of boron, silicon, titanium or zirconium. Most of these complex fluorides are used together with organic polymers. Examples of such conversion treatments are in DE-A-101 31 723 and the literature cited there. However, none of these alternative methods has been able to displace the phosphating pretreatment before painting in the automotive industry.

In principle, it would be economically and ecologically more favorable to produce metallic components from material already pre-coated by the manufacturer of the metal strips and only to clean and paint after assembly. Waste associated with the pretreatment would then be centralized by the manufacturers of the metal strips and not widely dispersed by the downstream converters of the metal strips. Accordingly, pre-coated metal strips are already offered on the market. On the one hand, these can be pre-phosphated, ie they can carry a phosphate layer but no further coating based on organic polymers. In the automotive and household appliance industry, metal strips are increasingly being processed which are already provided with a corrosion protection layer by the manufacturer of the strips. Such materials are known, for example, under the names Granocoat ^R , Durasteel ^R , Bonazinc ^R and Durazinc ^R. They carry a thin organic coating over a conversion layer, for example a chromating or phosphating layer. The organic coating consists of polymer systems such as epoxy or polyurethane resins, polyamides and polyacrylates. Solid additives such as silicic acids, zinc dust and soot improve the corrosion protection and, due to their electrical conductivity, allow the metal parts coated with layers of about 0.3 to about 10 μm, preferably up to about 5 μm, to be electrically welded and electrolytically painted. The coating of the substrate materials is generally carried out in a two-stage process, in which first the inorganic conversion layer is produced and subsequently the organic polymer film is applied in a second treatment stage. More information can be found here DE-A-100 22 075 and the literature cited therein.

Thus metal sheets provided in the band method with a coating based on organic polymers are already partially used in the construction of vehicle bodies, household appliances and furnishing articles. In the automotive industry, the strictest requirements with regard to corrosion protection and adhesion of a subsequently applied Paints, since vehicles are exposed to the strongest corrosion stresses. At present, no vehicle bodies are produced exclusively from organically pre-coated metal sheets. Rather, this material is possibly installed together with non-pre-coated sheets to the vehicle bodies. The assembled bodies therefore currently undergo the usual pretreatment process before painting, ie they are subjected to the complex process sequence of phosphating.

In principle, the phosphating process could be replaced by a less expensive pretreatment process if the vehicle bodies were produced exclusively from organically precoated metal substrate. For this purpose, however, the problem must be solved that inevitably arise in the assembly of bodies made of organically pre-coated metal sheets in places where the organic precoating is damaged or completely missing. This is the case, for example, at cut edges, at weld points and at cut points.

From the Offenlegungsschrifit US 20031150524 One skilled in the art will deviate from doctrine for anticorrosive treatment of components composed of painted metal parts of galvanized steel, wherein there may be areas of the metal surface of the galvanized steel that are not covered by a coating based on organic polymers. The composite component is according to the US 2003/150524 contacted with a chromium-free acidic aqueous composition which produces on the free metal surfaces of the device a passivation layer which is not a crystalline zinc phosphate layer. The US 2003/150524 is restricted exclusively to the corrosion-protective treatment of components whose free, uncoated metallic surface must consist of at least 90% non-ferrous metals, in particular zinc.

For reasons of better corrosion protection, such organically precoated metal substrates are frequently used in vehicle construction, in which serves as a metal substrate electrolytically galvanized or hot-dip galvanized steel. In the case of such organically coated metal substrates, however, the sites mentioned with a damaged organic layer are particularly difficult to treat, since they differ from the usual metal surfaces in terms of their electrochemical potentials and their chemical reactivity. In such damaged areas are usually both shares of the steel substrate (ie iron) and the zinc coating bare. In this case, a high local area ratio of steel (iron) to zinc may be present, for example a ratio of> 9: 1. This is particularly the case with cut edges, which represent a cross section through the coated steel substrate. The corrosion conditions deviate from the other conditions on the homogeneous surface at these boundary areas, which combine zinc and iron. Depending on the local ratio of zinc to iron at the exposed metal sites, a different electrochemical potential arises between the potentials of zinc and iron. Furthermore, when machining the bodies grounded areas that have special conditions and thus special electrochemical potentials. Because the grinding process creates an activated interface of steel (iron) with finely divided reactive zinc.

The object of the invention is to provide, as part of a process for the production of painted metallic components which are composed of metal sheets pre-coated with organic polymers, a simpler method than phosphating which can be used to produce corrosion protection and lacquer adhesion at the damaged areas discussed The present invention relates in a first aspect to a "claim 1".

All metal parts of the component should accordingly consist of organically pre-coated galvanized steel. In addition to these metal parts, however, the component may still contain plastic components, as may be the case for example in the automotive industry. For example, to produce a vehicle body, the metallic components made of organically pre-coated galvanized steel can be assembled with plastic parts.

The term "galvanized steel" includes hot dip galvanized steels and electrolytically galvanized steels. Furthermore, alloy-galvanized steels are included, in which the coating For example, may consist of a zinc-nickel alloy or a zinc-aluminum alloy. The steels may be tempered to form an iron-zinc alloy at the interface between steel and zinc.

The joining of the sheets to the component in step a) can be carried out by the usual methods known in the art, for example by gluing, flanging, riveting, flanging and / or welding, in particular by arc welding. In addition to the cutting and / or punching in sub-step a) joining by welding due to the associated damage to the coating based on organic polymers to more locations on the component arise that are not covered by the coating based on organic polymers. These are also passivated in sub-step c), as well as bare metal areas that result from grinding.

The process according to the invention is particularly suitable for the production of components with organically precoated metal sheets which have a coating based on organic polymers with a thickness in the range from 1 to 10 μm, the coating containing electrically conductive particles in addition to the organic polymers. Due to these characteristics of the organic coating, the components can be joined together by arc welding. Examples of such coatings are in DE-A-197 48 764 . DE-A-199 51 113 . DE-A-100 22 075 and in the literature cited therein. As mentioned in the introduction, metal strips with such coatings are commercially available under different trade names.

The passivation layer produced in sub-step c) should thus not represent a conventional zinc phosphate layer since, according to the present task, a process sequence which is shorter than that of zinc phosphating and thus more economical is to be used. A zinc phosphate layer does not form if the treatment solution does not concurrently contain at least 0.3 g / l zinc ion and at least 3 g / l phosphate ion (as phosphoric acid or any protolysis step thereof).

In sub-step c), the assembled component can be brought into contact in different ways with the acidic aqueous treatment solution, for example by immersion in the treatment solution or by spraying with the treatment solution. After this step you can rinse with water, but you do not have to. Ie. the method can be used as a "rinse" or "no-rinse" method.

In this case, the treatment according to sub-step c) does not represent a post-passivation of a preceding major conversion layer formation, but it is the only treatment step after the assembly of the components which produces a passivation layer on the bare metal sites.

In particular, the method sequence according to the invention can be used in the manufacture of vehicle bodies, household appliances, pieces of furniture, or in each case a part thereof.

The aqueous treatment solution in sub-step c) preferably has a pH of at least 2, in particular of at least 2.5, to at most 5, in particular to at most 4. At lower pH values, there is an increasing danger of an excessive pickling attack and damage to the Coating based on organic polymers. At pH values above 5, the pickling attack is increasingly too weak, so that only an insufficient passivation layer is formed. Of course, the transitions in practice are fluent.

In step c) chromium-free acidic aqueous treatment solutions can be used, which are known in the art for the large-scale treatment of uncoated metal parts or metal strips. Preferably, a treatment solution is used, the total of at least 0.01 g / l, preferably at least 0.025 g / l, and up to 10 g / l, preferably up to 1 g / l, in particular to 0.5 g / l Ti- and or Zr and / or Si ions and at least one such amount of fluoride contains that the atomic ratio of Ti to F and / or Zr to F and / or Si to F in the range of 1: 1 to 1: 6, and which additionally contains at least 0.005 g / l, preferably at least 0.01 g / l, and up to 20 g / l, preferably up to 1 g / l of organic polymers. The Ti, Zr and / or Si ions mentioned may be mentioned completely in the form of Hexafluorokomplexen such as the hexafluoroacids or their water in said concentration range salts such as the sodium salts. In this case, the atomic ratio is 1: 6. However, it is also possible to use complex compounds in which less than six fluoride ions in each case are connected to the central elements Ti, Zr or Si. These can form themselves in the treatment solution if hexafluoro complexes of at least one of the central elements Ti, Zr or Si and also at least one further compound of one of these central elements are added to it. As such further compounds are, for example, nitrates, carbonates, hydroxides and / or oxides thereof or another of the three mentioned central elements into consideration. For example, the treatment solution may be hexafluorozirconates and (preferably colloidal) silica (SiO ₂ ) or their reaction products. Unreacted silica may be suspended in the treatment solution. Such a treatment solution can also be obtained by using hydrofluoric acid or its (optionally acidic) salts together with those compounds of Ti, Zr and / or Si which can form fluorocomplexes herewith. Examples are the already mentioned nitrates, carbonates, hydroxides and / or oxides. Preferably, such an amount of Ti, Zr and / or Si is used as the central metal and such an amount of fluoride that the atomic ratio of central metal to fluoride is less than or equal to 1 to 2, in particular less than or equal to 1 to 3. The atomic ratio may also become less than 1 to 6 when the treating solution contains more fluoride, for example in the form of hydrofluoric acid or its salts, than is stoichiometrically required to form the hexafluorocomplexes of the central metals Ti, Zr and / or Si. For example, the atomic ratio may become as small as 1 to 12 or 1:18, or even less, by employing a corresponding excess of fluoride, ie, two or three times or even more times what is necessary to complete formation of the hexafluoro complexes.

1. a) Polyacrylsaüre oder deren Homopolymere,
2. b) Hexafluorozirkonsäure,
3. c) 0,17 bis 0,3 g/l Fluorwasserstoffsäure und
4. d) bis zu 0,6 g/l Hexafluorotitansäure,

gemäß EP-B-8 942 eine Behandlungslösung, enthaltend

1. a) Polyacrylsäure oder eines Esters davon und
2. b) mindestens einer der Verbindungen H₂ZrF₆, H₂TiF₆ und H₂SiF₆, wobei der pH-Wert der Lösung unterhalb von 3,5 liegt,
   (weitere Polymere, die in ähnlichen Behandlungsbädern eingesetzt werden können, sind in WO 02/20652 aufgeführt),

gemäß US-A-4 992 116 eine Behandlungslösung mit pH-Werten zwischen etwa 2,5 und 5, die mindestens drei Komponenten enthält:

1. a) Phosphationen im Konzentrationsbereich zwischen 1,1x10^-5 bis 5,3x10^-3 mol/l, entsprechend 1 bis 500 mg/l,
2. b) mindestens eine Fluorosäure eines Elements der Gruppe Zr, Ti, und Si und
3. c) eine Polyphenolverbindung, erhältlich durch Umsetzung von Poly(vinylphenol) mit Aldehyden und organischen Aminen,

gemäß WO 92/07973 eine Behandlungslösung, die als wesentliche Komponenten in saurer wäßriger Lösung H₂ZrF₆ und ein 3-(N-C_1-4alkyl-N-2-hydroxyethylaminomethyl)-4-hydroxystyrol-Polymer enthält.In this case, treatment solutions can be used which contain known combinations of ingredients in the prior art, for example according to US-A-5 129 967 a treatment solution containing at least the following components in water:

1. a) polyacrylic acid or its homopolymers,
2. b) hexafluorozirconic acid,
3. c) 0.17 to 0.3 g / l hydrofluoric acid and
4. d) up to 0.6 g / l hexafluorotitanic acid,

according to EP-B-8 942 a treatment solution containing

1. a) polyacrylic acid or an ester thereof and
2. b) at least one of the compounds H ₂ ZrF ₆ , H ₂ TiF ₆ and H ₂ SiF ₆ , the pH of the solution being below 3.5,
   (Further polymers which can be used in similar treatment baths are in WO 02/20652 listed)

according to US-A-4 992 116 a treatment solution with pH values between about 2.5 and 5, containing at least three components:

1. a) phosphate ions in the concentration range between 1.1 × 10 ^-5 to 5.3 × 10 ^-3 mol / l, corresponding to 1 to 500 mg / l,
2. b) at least one fluoro acid of an element of the group Zr, Ti, and Si and
3. c) a polyphenol compound obtainable by reacting poly (vinylphenol) with aldehydes and organic amines,

according to WO 92/07973 a treating solution containing as essential components in acidic aqueous solution H ₂ ZrF ₆ and a 3- (NC _1-4 alkyl-N-2-hydroxyethylaminomethyl) -4-hydroxystyrene polymer.

However, preferred are those treatment solutions in which the organic polymers are selected from homopolymers and copolymers of vinylpyrrolidone. Such treatment solutions are described in DE-A-100 05 113 and DE-A-101 31 723 , If, accordingly, a treatment solution containing copolymers of vinylpyrrolidone is used in the process according to the invention, these copolymers can contain one or more other monomers besides vinylpyrrolidone. They may therefore be present, for example, as copolymers of 2 components or as copolymers of 3 components (= terpolymers). Furthermore, mixtures of homo- and two-component copolymers, homopolymers and terpolymers or two-component copolymers and terpolymers can be used.

Suitable homopolymers or copolymers of vinylpyrrolidone are, for example, the polymers or polymers listed in Table 1 of the monomers mentioned there. Copolymers of vinylpyrrolidone with monomers having caprolactam or imidazole groups are particularly preferred. <u> Table 1 </ u>: Examples of Homopolymers or Copolymers of Vinylpyrolidone description Trade name or manufacturer Vinyl pyrrolidone, homopolymer Luviskol ^R , BASF / ISP Vinylpyrrolidone / vinyl acetate Luviskol ^R , BASF / ISP Vinylpyrrolidone / vinyl caprolactam Luvitec ^R , BASF VinylpyrrolidonNinylimidazol Luvitec ^R , BASF Vinylpyrrolidone / vinylimidazolium Luvitec, BASF Vinylpyrrolidone / Na methacrylate Luvite C ^R , BASF Vinylpyrrolidone / olefins ISP ^R , Antaron Vinylpyrrolidone / dimethylaminoethyl ISP ^R Vinylpyrrolidone / dimethylaminopropylmethacrylamide ISP ^R , Styleze Vinyl pyrrolidone / dimethylaminoethyl methacrylate ammonium salt ISP ^R , Gafquat VinylpyrrolidonNinylcaprolactam / dimethylaminoethyl ISP ^R Vinylpyrrolidone / methacrylamidopropyltrimethylammonium chloride ISP ^R , Gafquat VinylpyrrolidonNinylcaprolactam / dimethylaminoethyl ISP ^R , Advantage Vinylpyrrolidone / styrene ISP ^R , Antara

The preferred treatment solutions described above preferably have a temperature in the range from 20 to 45 ° C, in particular from 30 to 40 ° C. This treatment solution is preferably contacted with the cleaned assembled member for a period of time in the range of 1 to 5 minutes, more preferably 2 to 3 minutes.

By definition, the treatment solutions to be used should be free of chromium. It is further preferred that the acidic aqueous treatment solution except metals of the 4th subgroup of the periodic table (for example in the form of complex fluorides of Ti and / or Zr) contains no other subgroup metals ("transition metals"). As a result, the treatment of wastewater is simplified.

In sub-step e), the metallic component pretreated in sub-step c), with or without intermediate rinsing as sub-step d), can be coated with a lacquer customary for the intended use. For example, it may be selected from a dip paint, an electrodeposition paint or a powder paint.

In a second aspect, the present invention relates to a painted component comprising galvanized steel metal parts obtainable by the method described above. As explained above, this is understood to mean that all metal parts of the component consist of organically precoated galvanized steel. In addition to these metal parts, however, the component may still contain plastic components, as may be the case for example in the automotive industry.

By the method according to the invention can be obtained painted metallic components such as vehicle bodies, household appliances, furniture or in each case parts thereof, which meet all current requirements for appearance, corrosion resistance and paint adhesion. The exclusive use of organically pre-coated raw material can significantly shorten the required chemical treatment for the component manufacturer. This brings economic and environmental advantages for the manufacturer of the components, since a less expensive pretreatment plant is sufficient and there are less wastewater contaminated with chemicals.

applications Example 1: Conversion treatment of molded parts (Material: Electrogalvanized with Granocoat ^® ZE coating)

(Referred to in the Examples, "Granocoat ^®" products are coating systems for galvanized steel on the basis of organic polymers and conductive pigments, as they are explained in detail in the foregoing description. These products are described in patent applications DE-A-100 22 075 (Granocoat ^® ZE) and DE-A-100 22 075 Described (Granocoat ^® S).)

Process sequence (immersion application):

1. Cleaning: Ridoline ^® 1570 2%; Ridosol ^® 1237, 0.3%; 5 minutes; 55 ° C Second Kitchen sink: completely desalinated water Third Conversion treatment: 180 seconds; 30 ° C; pH 3.8; Bath composition: H ₂ ZrF ₆ acid (45%; corresponding to 150 mg / l Zr) Luvitec VPI 55 K18P ^® (BASF, Ludwigshafen, Germany.), A vinylpyrrolidone-vinylimidazole copolymer according to (CAS No. 172890-92-5). a solids content of 40 mg / l polymer 4th Kitchen sink: completely desalinated water 5th Dry: Compressed air, then 50 ° C for 10 minutes

Test: SAE J 2334 test 80 rounds Comparative Example 1: zinc phosphating of molded parts (material: Electrolytically galvanized with Granocoat ^® coating ZE) Process sequence (immersion application):

1. Cleaning: Ridoline ^® 1570 2%; Ridosol ^® 1237, 0.3%; 5 minutes; 55 ° C Second Kitchen sink: completely desalinated water Third Activation: according to the prior art 4th zinc phosphate: according to the prior art 5th Kitchen sink: completely desalinated water 6th Dry: Compressed air, then 50 ° C for 10 minutes

Test: SAE J 2334 test 80 rounds Example 2: Conversion treatment of molded parts (material: electrolytically galvanized with Granocoat ^® S coating) Process sequence (immersion application):

1. Cleaning: Ridoline ^® 1570 2%; Ridosol ^® 1237, 0.3%; 5 minutes; 55 ° C Second Kitchen sink: completely desalinated water Third Conversion treatment: 180 seconds; 30 ° C; pH 3.8; Bath composition: H ₂ ZrF ₆ acid (45%, corresponding to 150 mg / l Zr) Luvitec VPI 55 K18P ^® (Fa. BASF) corresponding to a solids content of 40 mg / l Polymer 4th Kitchen sink: completely desalinated water 5th Dry: Compressed air, then 50 ° C for 10 minutes

Test: SAE J 2334 test 80 rounds Comparative Example 2 Zinc phosphating of molded parts (material: Electrolytically galvanized with Granocoat ^® S coating) Process sequence (immersion application):

1. Cleaning: Ridoline ^® 1570 2%; Ridosol ^® 1237, 0.3%; 5 minutes; 55 ° C Second Kitchen sink: completely desalinated water Third Activation: according to the prior art 4th zinc phosphate: according to the prior art 5th Kitchen sink: completely desalinated water 6th Dry: Compressed air, then 50 ° C for 10 minutes

Test: SAE J 2334 test 80 rounds Example 3: Conversion treatment of molded parts (Material: Hot dip galvanized steel with Granocoat ^® ZE coating) Process sequence (immersion application):

1. Cleaning: Ridoline ^® 1570 2%; Ridosol ^® 1237, 0.3%; 5 minutes; 55 ° C Second Kitchen sink: completely desalinated water Third Conversion treatment: 180 seconds; 30 ° C; pH 3.8; Bath composition: H ₂ ZrF ₆ acid (45%, corresponding to 150 mg / l Zr) Luvitec VPI 55 K18P ^® (Fa. BASF) corresponding to a solids content of 40 mg / l Polymer 4. sink: completely desalinated water 5. Drying: Compressed air, then 50 ° C for 10 minutes

Test: SAE J 2334 test 80 rounds Comparative Example 3: zinc phosphating of molded parts (material: fire galvanized steel with Granocoat ^® coating ZE) Process sequence (immersion application):

1. Cleaning: Ridoline 1570, 2%; Ridosol 1237, 0.3%; 5 minutes; 55 ° C Second Kitchen sink: completely desalinated water Third Activation: according to the prior art 4th zinc phosphate: according to the prior art 5th Kitchen sink: completely desalinated water 6th Dry: Compressed air, then 50 ° C for 10 minutes

Test: SAE J 2334 test 80 rounds Results of the examples

example 1 Comparative Example 1 Example 2 Comparative Example 2 Example 3 Comparative Example 3 Corrosion on edges □ □ ○ ○ ○ X Corrosion in the flange area ○ ○ ○ ○ ○ X Corrosion in formed area ○ X X X □ □ ○ No corrosion products present
□ few points of corrosion
X red rust products available

The test results show that with the shorter process sequence according to the invention at least the same results as with a zinc phosphating. The results according to the method of the invention tend to be even better than those achieved with zinc phosphating.

Claims (11)

1. A method for manufacturing a lacquered component containing metal parts in galvanized steel, wherein

   a) sheets in galvanized steel, which bear a coating based on organic polymers, are cut and/or punched and/or deformed and the thereby obtained metal parts are assembled for manufacturing the component, regions of the metal surface of the galvanized steel being formed which are not covered by the coating based on organic polymers and which have a surface ratio of steel to zinc which is greater than 9:1;

   b) the assembled component is cleaned,

   c) the cleaned assembled component is brought into contact with an aqueous chromium-free acid treatment solution, which produces on the regions of the metal surface formed in partial step a), which are not covered by the coating based on organic polymers, a passivation layer which does not represent a zinc phosphate layer,

   d) if desired, but not mandatorily, the component treated in partial step c) is rinsed one or several times with water and

   e) is coated with a lacquer coating,

   wherein all the metal parts of the component during the execution of the partial steps b) to e) exclusively consist of the sheets in galvanized steel, which bear a coating based on organic polymers, and wherein the partial step c) is the only treatment step after the partial step a), which produces a passivation layer on the regions of the metal surface formed in partial step a), which are not covered by the coating based on organic polymers.
2. The method according to claim 1, characterized in that as for the metal component, this is a vehicle body, a household appliance, a piece of furniture, or respectively a portion thereof.
3. The method according to one or both of claims 1 and 2, characterized in that the coating based on organic polymers has a thickness in the range from 1 to 10 µm and in addition to the organic polymers, contains electrically conducting particles.
4. The method according to one or more of claims 1 to 3, characterized in that the aqueous acid treatment solution in partial step c) has a pH value in the range from at least 2, preferably at least 2.5 to at most 5, preferably to at most 4.
5. The method according to one or more of claims 1 to 4, characterized in that the aqueous acid treatment solution all in all contains at least 0.01 g/L, preferably at least 0.025 g/L, and up to 10 g/L, preferably up to 1 g/L, in particular up to 0.5 g/L of Ti and/or Zr and/or Si ions as well as at least an amount of fluoride such that the atomic ratio of Ti to F and/or Zr to F and/or Si to F lies in the range from 1:1 to 1:6, and the treatment solution further contains at least 0.005 g/L, preferably at least 0.01 g/L, and up to 20 g/L, preferably up to 1 g/L of organic polymers.
6. The method according to claim 5, characterized in that the organic polymers are selected from homo- and co-polymers of vinylpyrrolidone.
7. The method according to one or more of claims 4 to 6, characterized in that the aqueous acid treatment solution with a temperature in the range from 20 to 45°C, preferably from 30 to 40°C is brought into contact with the cleaned assembled component for a period of time in the range from 1 to 5 minutes, preferably 2 to 3 minutes.
8. The method according to one or more of claims 1 to 7, characterized in that the aqueous acid treatment solution does not contain any other sub-group metals (transition metals) except for those of the fourth subgroup of the periodic system.
9. The method according to one or more of claims 1 to 8, characterized in that in partial step e), the metal component is coated with a lacquer which is selected from dipping lacquer, electro-dipping lacquer, or powder lacquer.
10. A lacquered component containing galvanized steel metal parts, which may be obtained in accordance with method according to one or more of claims 1 to 9.
11. The use of a aqueous acid treatment solution containing at least 0.01 g/L and up to 10 g/L of Ti and/or Zr and/or Si ions as well as at least an amount of fluoride such that the atomic ratio of Ti to F and/or Zr to F and/or Si to F lies in the range from 1:1 to 1:6, and which further contains at least 0.005 g/L, and up to 1 g/L of organic polymers for a method for manufacturing a lacquered component containing metal parts in galvanized steel, wherein

    a) sheets in galvanized steel, which bear a coating based on organic polymers, are cut and/or punched and/or deformed and the thereby obtained metal parts are assembled for manufacturing the component, regions of the metal surface of the galvanized steel being formed which are not covered by the coating based on organic polymers and which have a surface ratio of steel to zinc which is greater than 9:1;

    b) the assembled component is cleaned,

    c) the cleaned assembled component is brought into contact with an aqueous chromium-free acid treatment solution, which produces on the regions of the metal surface formed in partial step a), which are not covered by the coating based on organic polymers, a passivation layer which does not represent a zinc phosphate layer,

    d) if desired, but not mandatorily, the component treated in partial step c) is rinsed one or several times with water and

    e) is coated with a lacquer coating,

    wherein all the metal parts of the component during the execution of the partial steps b) to e) exclusively consist of the sheets in galvanized steel, which bear a coating based on organic polymers, and wherein the partial step c) is the only treatment step after the partial step a), which produces a passivation layer on the regions of the metal surface formed in partial step a), which are not covered by the coating based on organic polymers.