EP1088598A2 - Process for making a polymer film on a metallic substrate, concentrate and treatment solution for this purpose - Google Patents

Abstract

The invention relates to a method for producing a plastic film or plastic-containing film on a metal surface, in which a Treatment liquid, which at the beginning of wetting with the treatment liquid 0.1 to 50% by weight of a non-volatile containing one or more resins film-forming mixture and 99.9 to 50 wt .-% of a water-miscible or / and contains water-soluble solvent and / or water, on the metal surface Forms film, with the volatile portion escaping at least partially, this is characterized in that the treatment liquid at the beginning of wetting with the Treatment liquid has a temperature in the range of 10 to 100 ° C that the metal surface at the beginning of wetting with the treatment liquid at least 20 ° C higher temperature than the treatment liquid and a Has temperature in the range of 30 to 700 ° C and that the film of the treatment serves the metal surface.

The invention also relates to a treatment liquid for producing a Plastic film or plastic-containing film on a metal surface during the wetting of the metal surface with the treatment liquid, the Treatment liquid 0.1 to 50 wt .-% of one or more resins containing non-volatile film-forming mixture and 99.9 to 50 wt .-% of one contains water-miscible or water-soluble solvent and / or water, the is characterized in that the temperature of the treatment liquid in Range of 10 to 100 ° C is that the treatment liquid is adjusted so that its components during the operating time, during the service life and during No or almost no coagulation temperature of the film formation, no or no sediment substantially and are not or not significantly decomposed and that the molecular weight distribution and the viscosity of the treatment liquid in the Do not change the application significantly.

The invention further relates to a concentrate for producing a Treatment liquid, the concentrate after dilution Treatment liquid results.

Description

The invention relates to a method for producing a film from plastic or a plastic-containing material on a metal surface and a concentrate for Production of a treatment liquid and a treatment liquid for the Production of the polymeric film.

Polymer films on metal surfaces are used in a variety of ways. There are also the most diverse large-scale processes for metallic coatings Workpieces or of workpieces with a metallic surface with a polymeric film. Depending on the type of metal surface or workpieces, the Application of a polymeric film can be carried out without difficulty or with considerable disadvantages. Through the appropriate chemical and physical adjustment of the polymer solution or dispersion to be applied can be a polymer layer of the desired thickness can be generated. For example, it is with one Roller application processes such as roll coating are of particular importance Concentration of the plastic-containing treatment solution and the roller pressure of the Application device, the roller speed and the direction of the rollers to match the substrate. It is also comparatively simple the treatment of small or relatively large, rounded workpieces, usually be coated by electro-dipping or spraying.

However, the coating of individual parts is often difficult, especially if they have a larger spatial extension, e.g. Body parts, bumpers, frames, panels, crash barriers. With such The roller application process eliminates substrates. Are spraying especially because of the complex system technology and the high proportion lost treatment liquid (over-spray) uneconomical.

Immersion processes at room temperature without electrical separation are possible with the Disadvantage associated that due to the geometry of the parts different Layer thicknesses are generated and that drops at the drainage points plastic-containing solution or dispersion remain after the subsequent Drying as a thickening are visible. Even after a subsequent one Spray painting, these thickenings are clearly visible. Besides the little Depending on the intended use, the treated parts may have an attractive appearance. also unusable due to lack of accuracy of fit.

DE-A-197 25 780 describes a method for applying plastic or plastic-containing layers on metallic parts at about room temperature and its use as pretreatment of the individual parts for the subsequent Powder coating. A solution or dispersion with a content of 5 up to 50% by weight of an organic polymer in contact with the metallic component brought, the applied solution or dispersion dried, the coated Individual part then with an essentially identical, but highly diluted solution or dispersion brought into contact and finally dried. By the double Dip treatment will make drop-like bumps and larger thickenings avoided. Nevertheless, the layer thickness at the trailing edge is often by a factor of 2 to 3 larger than on the other surfaces of the individual part. However, would only go once would be immersed, the layer thickness at the drain edge would be about 30 to 53 times thicker than on the other surfaces of the item.

On the other hand, in thin-film treatments, classic chromating, for example on aluminum, zinc and their alloys, still offers the best corrosion protection without subsequent painting. So far, it has been a very good and common pretreatment for subsequent painting. Due to the environmental damage and toxicity of chromium-containing solutions, in particular Cr ⁶⁺ ions, intensive efforts have been underway for years to develop cost-effective coating processes that are suitable for series production and which also provide chromate protection equivalent to chromate protection without the use of chromium.

kompatiblen Dispersion und mit Wasser gemischt und das Bad auf eine Temperatur im Bereich von etwa 27 bis 71 °C erhitzt wird und bei denen die zu beschichtenden Teile auf eine Temperatur im Bereich von etwa 104 bis 927°C erhitzt werden. Die sog. kompatible Dispersion enthält entsprechend den Beispielen z.B. Graphit, Aluminium, Titanoxid oder ein schwarzes Pigment, wobei die Gemische mit einer kompatiblen Dispersion entsprechend den Beispielen andeuten, daß es Pigmentdispersionen zum Einfärben von Schutzfilmen sowie zur Verbesserung der Gleitfähigkeit der damit behandelten Substratoberfläche (Gleitlack) sind. Die Beispiele beschreiben jeweils zwei Kunstharze mit einem Pigmentzusatz, jedoch keinen Gehalt an Korrosionsinhibitoren zur Verbesserung der korrosionsschützenden Eigenschaften. Die eingesetzten Kunstharze sind säurefunktionelle physikalisch trocknende Acrylatharze, die gegen alkalische Medien (pH 6 - 14) nicht beständig sind. Aus diesem Grund ist nur ein geringer Korrosionsschutz zu erwarten. Der aus dieser Formulierung resultierende Trockenfilm ist nicht beständig gegen alkalische Flüssigkeiten, die der Weiterverarbeitung der beschichteten Teile dienen, wie z.B. gegen Bohröle, gegen Gleitmittel zur spanabhebenden Verformung oder gegen alkalische Wasserlacke zum Überlackieren.WO 94/10244 describes several compositions for pretreating substrates with polymeric solutions or dispersions and a method for coating substrates with such treatment liquids. This mainly addresses treatment liquids that are applied in the immersion process, in which a polymeric solution or dispersion with a so-called

compatible dispersion and mixed with water and the bath is heated to a temperature in the range of about 27 to 71 ° C and at which the parts to be coated are heated to a temperature in the range of about 104 to 927 ° C. According to the examples, the so-called compatible dispersion contains, for example, graphite, aluminum, titanium oxide or a black pigment, the mixtures with a compatible dispersion according to the examples indicating that there are pigment dispersions for coloring protective films and for improving the lubricity of the substrate surface treated therewith (lubricating lacquer ) are. The examples each describe two synthetic resins with a pigment addition, but no content of corrosion inhibitors to improve the corrosion protection properties. The synthetic resins used are acid-functional, physically drying acrylic resins that are not resistant to alkaline media (pH 6 - 14). For this reason, only a low level of corrosion protection can be expected. The dry film resulting from this formulation is not resistant to alkaline liquids that are used for further processing of the coated parts, such as drilling oils, lubricants for metal-cutting deformation or alkaline water-based paints for painting over.

It was therefore an object of the present invention to provide a method for applying Plastic or plastic-containing layers on substrates with a metallic surface To provide, which avoids the known, especially the aforementioned disadvantages and also at the outlet of the coated substrates with layers Layer thickness can arise with the layer thickness of the other with plastic coated surface areas largely coincides. This method If possible, even without the use of chromate, should lead to results that match those are equivalent to chromating.

The object is achieved with a method for producing a plastic film or a plastic-containing film on a metal surface, in which a Treatment liquid, which at the beginning of wetting with the treatment liquid 0.1 to 50% by weight of a non-volatile containing one or more resins film-forming mixture and 99.9 to 50 wt .-% of a water-miscible or / and contains water-soluble solvent and / or water, on the metal surface Forms film, the volatile portion escapes at least partially, the Treatment liquid at the beginning of wetting with the treatment liquid Has temperature in the range of 10 to 100 ° C, the metal surface to Start wetting with the treatment liquid at a temperature of at least 20 ° C higher temperature than the treatment liquid and a temperature in the range from 30 to 700 ° C and wherein the film of the treatment of the metal surface serves.

The temperature difference between the metal surface and the treatment liquid at the start of wetting with the treatment liquid advantageously at least 25 ° C, preferably at least 32 ° C, particularly preferably at least 45 ° C, very particularly preferably at least 55 ° C. The The temperature of the substrate can also advantageously be at least 70 ° C., at least 100 ° C or in many cases at least 150 ° C above the temperature of the Treatment liquid. The selected temperature difference can vary significantly from the type of heating of the substrates and, if necessary, also of the integration into a Series production depend not only on the chemical and physical Conditions of film formation.

Under the term polymeric film In this application, a film made of plastic or a plastic-containing material should be understood. In the method according to the invention, the treatment of the metal surface means the application of a passivation layer on the surface of a metallic material (alloy or metal), which prevents the corrosion of metal surfaces. The term treatment In the sense of this application, the term is also intended Pretreatment include - unless otherwise stated at the respective text passage, in which a layer that is usually only temporarily protective is applied, which is later overlaid by at least one further protective layer, in particular a lacquer layer. For the purposes of this application, however, this term is not intended to include the formation of an adhesion promoter layer. The term Harden For the purposes of this application, it is intended to encompass both chemical crosslinking and physical curing. The term water miscible is intended in the sense of this application as a generic term of the term water dispersible be understood.

Both the surface of a metallic workpiece and the metal surface (Substrate) made of at least one metal and / or at least one alloy which the metal or alloy reaches to the surface, meant as well as a Workpiece made of any material with a metallic coating is provided and therefore has a metal surface on which in turn a polymeric protective layer is applied. Above all, this can be Substrates with a metal surface on a plastic-containing workpiece, such as a fiber composite material - e.g. for bumpers, covers, body parts - act. This requires comparatively low treatment temperatures.

The substrate can essentially consist of aluminum, iron, copper, magnesium, zinc, Tin and / or at least one of their alloys can be made if necessary additionally metallic, in particular with aluminum, lead, copper, zinc, tin or their Alloys. The metallic coating can in particular by hot dipping, thermal spraying or by physical, chemical or electrodeposition. Preferably that was metallic substrate and others produced by casting or / and rolling.

In many cases it is advantageous if the metal surface is wetted with the film-forming treatment liquid is provided with an adhesion promoter layer - either with an inorganic adhesion promoter layer, in particular with a Phosphate, a silicate or a zirconium and / or titanium-containing Adhesion promoter layer, and / or with an organic adhesion promoter layer, in particular with a phosphonate, polyvinyl butyral cross-linked with acids (more classic Wash primer) or / and containing at least one butyl titanate and / or silane Adhesion promoter layer. A combination of a zirconium and Titanium compound can be selected with a silane. This ensures that the Adhesion of the film is improved and that the damage to the film Infiltration is limited by moisture or aggressive substances. If the Adhesion promoter layer a stronger thermal load on the substrate and afterwards the treatment with the polymeric layer is essentially unaffected in many cases is an inorganic adhesive layer to select. With short-term exposure at temperatures up to 250 ° C can often still be worked with organic bonding agent layers.

1.) Die Temperatur der zu behandelnden Teile wird während des Tauchens nicht zu stark abgekühlt, so daß die verbleibende Restwärme der Teile zur beschleunigten Trocknung des durch das Tauchverfahren applizierten Naßfilmes dient.

2.) Aus höheren Temperaturen der Behandlungsflüssigkeit resultieren bei der Applikation höhere Trockenschichtdicken. Es ist daher bei höheren Temperaturen, wie z.B. im Bereich von 50 bis 80 °C, möglich, mit geringen Konzentrationen (z. B. 0,5 bis 3 Gew.-%) des Trockenrückstandes in der Behandlungsflüssigkeit zu arbeiten und trotzdem ausreichend dicke Filme (z.B. ohne Pigment 0,5 bis 5 µm) zu erzielen. Dagegen ist bei einer Temperatur im Bereich von 20 bis 30 °C für die gleiche Filmdicke eine Konzentration des Trockenrückstandes in der Behandlungsflüssigkeit im Bereich von 8 bis 12 Gew.-% notwendig.

The temperature of the treatment liquid is often at least 18 ° C, but can also be lower at the beginning of work in a cold environment. It can exceed 25 ° C and possibly 35 ° C without having to heat the treatment liquid. It can also be at temperatures of at least 45 ° C, but will only be above 60 ° C in certain applications. The temperature of the substrate can then in particular be at least 60 ° C, possibly at least 90 ° C, possibly also at least 120 ° C; however, the temperature can also be much higher, in particular at least 150 ° C., especially at least 200 ° C. or at least 250 ° C. An elevated temperature of the treatment liquid can offer the following advantages:

1.) The temperature of the parts to be treated is not cooled too much during the dipping, so that the remaining residual heat of the parts serves to accelerate the drying of the wet film applied by the dipping process.

2.) Higher dry layer thicknesses result from higher temperatures of the treatment liquid during application. It is therefore possible, at higher temperatures, for example in the range from 50 to 80 ° C., to work with low concentrations (for example 0.5 to 3% by weight) of the dry residue in the treatment liquid and still have sufficiently thick films (e.g. without pigment 0.5 to 5 µm). In contrast, at a temperature in the range from 20 to 30 ° C., a concentration of the dry residue in the treatment liquid in the range from 8 to 12% by weight is necessary for the same film thickness.

When using the heat from a hot-dip process, a Temperature of the substrate at the start of wetting with the treatment liquid in the range of 200 to 450 ° C for hot-dip galvanizing with zinc or a Zinc alloy and in the range of 200 to 700 ° C for hot dip in a Melt of aluminum or an aluminum alloy such as an alloy Basis AlSi, Galvalume® (55% Al-Zn), Galfan® or Crack-Free-Steel® can be selected. The temperature is preferably at the level as that to be coated Have substrates immediately or shortly after leaving an oven. Here can in particular be a furnace for hardening, annealing or tempering or is a facility for hot dipping. The temperature is below Consideration of the volume of the substrates to be coated, the bath volume, the bath composition and the intended layer thickness advantageously so select that the treatment liquid after wetting and pulling out of the substrate dries at least partially and that the film formed at least partially cures.

The organic polymers, in most cases synthetic resins, are common, however by no means in all cases, with molecular weights on the order of about 800 to about 2000 at room temperature in the solid state and generally good soluble. However, the solubility decreases with increasing molecular weight. Polymers with molecular weights in the range below about 1000 are often inherently liquid. Both groups of substances are sometimes depending on the composition or partly. depending on the Number of neutralizable groups water-miscible and / or water-soluble. The Adding a special organic solvent to the water can increase the solubility of the Increase polymers significantly.

The resin or the resins can be synthetic resins, in particular acrylates, polyesters, Polyurethanes, silicone polyesters, epoxies, phenols, styrenes, resins on the basis Urea-formaldehyde, their mixtures or / and their copolymers, preferably hexamethoxymethylmelamine (HMMM) resins or / and their Mixtures or / and copolymers of several substances of the above Be groups of substances. However, natural resins can also be used.

The resin or the resins can as a solution or dispersion, in particular as Emulsion or suspension present; a solution is preferably used. For deposition of a film according to the invention on a metal surface elevated temperatures are particularly suitable for synthetic resins used in the Treatment liquid is in the form of a solution, e.g. neutralized acid functional acrylic resins with an acid number of at least 50, mostly in Range from 150 to 250.

It is important to ensure that the treatment liquid contains synthetic resins that contain a sufficient number of neutralized or neutralizable groups. Synthetic resins with almost 100% neutralizable or neutralized Groups or better synthetic resins with the addition of neutralizing agents in the Excess are usually readily soluble in water. This can cause coagulation slightly above 40 ° C can be avoided.

1.) Ein langflüchtiges Neutralisationsmittel wie z.B. 2-Amino-2-Methyl-1-Propanol,

2.) ein mittelflüchtiges Neutralisationsmittel wie z.B. 2-Dimethylaminoethanol und

3.) ein kurzflüchtiges Neutralisationsmittel wie z.B. Ammoniak oder Triethylamin.

The neutralization is preferably carried out with neutralizing agents of different volatility, for example with a plurality of amines. This ensures that the resulting films are water-resistant very early on when drying begins. You could use two or three of the following types of neutralizing agents:

1.) A long-volatile neutralizing agent such as 2-amino-2-methyl-1-propanol,

2.) a medium volatile neutralizing agent such as 2-dimethylaminoethanol and

3.) a short-volatile neutralizing agent such as ammonia or triethylamine.

These neutralizing agents can, for example, in a mixing ratio of 1: 1: 1 be used. Such a mixture is at the same time for optimal solubility or Dispersibility of the resins in the treatment liquid and thus optimal Bath stability in the temperature range up to 100 ° C as well as optimal water resistance and weather resistance after drying.

1.) Dispersionen, die der Filmbildung dienen und deswegen ein ungelöstes Harz enthalten, benötigen oftmals Emulgatoren oder/und Schutzkolloide, um das ungelöste Harz in der Flüssigkeit homogen verteilt zu halten. Die Emulgatoren und Schutzkolloide sind jedoch sowohl hydrophob, als auch hydrophil. Sie verbleiben nach dem Verfilmen im trockenen Film und verlieren ihren hydrophilen Charakter nur zum Teil. Aufgrund dieser Substanzen ist die getrocknete Schicht in der Lage verstärkt Wasser aufzunehmen, was jedoch unerwünscht ist. Die erhöhte Wasseraufnahmefähigkeit der Schutzschichten stört, da die korrosionsschützende Wirkung (Witterungsresistenz) dabei wesentlich herabgesetzt wird. Selbstverständlich können Filme, die aus Dispersionen hergestellt wurden, unter Anwesenheit spezieller Reaktionspartner chemisch vernetzt werden, aber aufgrund ihrer besonderen Zusammensetzung ist der Anteil der Vernetzungsmöglichkeiten begrenzt. Die hieraus hergestellten vernetzten Filme sind zwar beständiger gegen Witterungseinflüsse und Chemikalien im Vergleich zu Filmen aus nichtvernetzten Dispersionen, aber sind wesentlich geringer beständig im Vergleich zu dreidimensional vernetzten Filmen, die aus Polymerlösungen hergestellt werden.

2.) Daher können Trockenfilme, die aus Emulgator oder/und Schutzkolloid enthaltenden Dispersionen hergestellt werden, die ein ungelöstes Harz enthalten, bezüglich der Resistenz gegen chemische Medien und Bewitterung von Nachteil sein im Vergleich zu einem Trockenfilm, der aus einer Emulgator- und Schutzkolloid- freien Polymerlösung erzeugt wird. Solche Emulgator- und Schutzkolloid-freien Polymerlösungen gestatten oftmals eine chemische Vernetzung, wobei z.B. Carboxylgruppen enthaltende Harze mit Melaminformaldehyd zu einem dreidimensional vernetzten Polymer reagieren können.

3.) Oft sind die Emulgatoren der Dispersionen, die der Filmbildung dienen und deswegen mindestens ein ungelöstes, in der Flüssigkeit fein verteiltes Harz in Form von Teilchen von meist 90 Vol.-% bis zu etwa 1 µm Größe enthalten, nicht ausreichend temperaturstabil, da sie sich bei der Temperatureinwirkung der heißen Substrate in ihren Eigenschaften verändern, was zu einer irreversiblen Koagulation der Harzteilchen in der Behandlungsflüssigkeit führen kann. Die koagulierten Harzteilchen sind dann oft zu groß, um auf dem Substrat einen geschlossenen Schutzfilm ausbilden zu können, und die Behandlungsflüssigkeit ist dann unbrauchbar.

4.) Ein weiterer Nachteil einer Dispersion, die der Filmbildung dient und deswegen ein ungelöstes Harz enthält, kann darin liegen, daß Harzteilchen mit hohen Molekulargewichten vorliegen und deswegen nach einer Teilverfilmung verursacht durch die hohen Temperaturen der zu behandelnden Teile - insbesondere über 250 °C - von der Behandlungsflüssigkeit nicht mehr aufgenommen werden können und sich an den Wandungen der Tauchbehälter aufbauen oder/und auf der Flüssigkeitsoberfläche schwimmen. Die verfilmten Harzteilchen können prozeßbedingt mechanisch von den Wandungen der Tauchbehälter abgelöst werden und als große Agglomerate ebenfalls auf der Oberfläche der Behandlungsflüssigkeit schwimmen und diese somit verunreinigen. Das kann dazu führen, daß die teilverfilmten Agglomerate in Form von Partikeln, Stippen oder/und Schuppen in dem trocknenden Film eingebunden werden. Die Partikel sind u.U. bis zu 100 oder sogar bis zu 200 µm groß und verursachen dann eine starke Rauhigkeit des Filmes. Derartige Rauhigkeiten müßten wieder aufwendig geglättet werden, bevor eine Lackierung aufgetragen wird.

Aqueous solutions are particularly advantageous for the process according to the invention. They usually do away with the shortcomings that may occur with dispersions. Dispersions can be suitable and used in many cases, but can also cause the disadvantages listed below in certain situations:

1.) Dispersions, which are used for film formation and therefore contain an undissolved resin, often require emulsifiers and / or protective colloids to keep the undissolved resin homogeneously distributed in the liquid. However, the emulsifiers and protective colloids are both hydrophobic and hydrophilic. After filming, they remain in the dry film and only partially lose their hydrophilic character. Because of these substances, the dried layer is able to absorb more water, which is undesirable. The increased water absorption capacity of the protective layers interferes with the fact that the corrosion-protecting effect (weather resistance) is significantly reduced. Of course, films made from dispersions can be chemically crosslinked in the presence of special reactants, but due to their special composition, the proportion of crosslinking possibilities is limited. The crosslinked films produced from them are more resistant to weathering and chemicals than films made from non-crosslinked dispersions, but they are much less resistant compared to three-dimensionally crosslinked films made from polymer solutions.

2.) Therefore, dry films made from dispersions containing emulsifier and / or protective colloid containing an undissolved resin can be disadvantageous in terms of resistance to chemical media and weathering compared to a dry film made from an emulsifier and protective colloid free polymer solution is generated. Such emulsifier and protective colloid-free polymer solutions often permit chemical crosslinking, for example resins containing carboxyl groups can react with melamine formaldehyde to form a three-dimensionally crosslinked polymer.

3.) Often the emulsifiers of the dispersions, which are used for film formation and therefore contain at least one undissolved, finely distributed resin in the liquid in the form of particles of mostly 90% by volume up to about 1 µm in size, are not sufficiently temperature-stable, since their properties change when exposed to the temperature of the hot substrates, which can lead to irreversible coagulation of the resin particles in the treatment liquid. The coagulated resin particles are then often too large to form a closed protective film on the substrate, and the treatment liquid is then unusable.

4.) A further disadvantage of a dispersion which is used for film formation and therefore contains an undissolved resin may be that resin particles with high molecular weights are present and therefore after partial filming caused by the high temperatures of the parts to be treated - in particular above 250 ° C. - Can no longer be absorbed by the treatment liquid and build up on the walls of the immersion tanks and / or float on the liquid surface. Depending on the process, the film-coated resin particles can be mechanically detached from the walls of the immersion containers and, as large agglomerates, can also float on the surface of the treatment liquid and thus contaminate it. This can lead to the partially filmed agglomerates being incorporated in the drying film in the form of particles, specks and / or flakes. The particles may be up to 100 or even up to 200 µm in size and then cause the film to become very rough. Such roughness would have to be smoothed out again in a complex manner before a coating is applied.

Dispersions behave differently with so-called internal emulsifiers. This one No foreign substances are added to dispersions and they behave excellent, since no uncontrolled hydrophilicity effects can occur.

Can be used as a solvent for the organic polymers in the treatment liquid at least one water-miscible and / or water-soluble alcohol, a glycol ether or N-methylpyrrolidone and / or water can be used in the case of Use of a solvent mixture, in particular a mixture of at least a long chain alcohol, e.g. Propylene glycol, an ester alcohol, a glycol ether or / and butanediol with water, preferably only water.

The water used can determine the quality e.g. of city water, well water or Have recycled water. In many cases, however, it is beneficial or for one Series production is advisable to use partially or fully demineralized water quality, to the undesired salting of the treatment liquids by the Limit salt loads in the water used.

The treatment liquid can be at least one volatile and / or non-volatile Additive to adjust defoaming, adhesion, preservation especially against fungal and bacterial attack, neutralization, the Surface wetting, the rheology and / or the course included. The A person skilled in the field of polymers knows when and how much one or several of these additives are used to make stable solutions or dispersions adjust. If in the process of the invention corrosion inhibitors as Pigments and / or in dissolved form are added, e.g. at least one Phosphate, titanate and / or zirconate, in particular dicalcium phosphate, Dimagnesium phosphate, iron III phosphate, modified alkali phosphate, Aluminum triphosphate or at least one zirconium complex compound can improved corrosion protection of the entire layer can be achieved. Also through the Adding an N-ethylmorpholine complex can have the anti-corrosive effect the resins can be increased significantly. This is especially true for the lifespan of the treating components advantageous. Especially for the parts of a substrate, e.g. a body with corners, folds and cavities that differ from the following Spray painting are insufficiently covered, it is particularly advantageous if the parts that were not adequately painted afterwards were high Have corrosion resistance due to the content of corrosion inhibitors in the Movie. It has surprisingly been found that it is with the invention Procedure is possible, even on the areas insufficiently covered with paint Body made of galvanized steel or aluminum alloy to achieve adequate corrosion protection. Furthermore, so-called drying such as e.g. Runner, nose, edge thickening due to the drainage of treatment liquid avoided with the inventive method. It has been shown that the substrates coated according to the invention have an almost constant film thickness over the have entire surface.

The treatment liquid can contain at least one neutralizing agent such as e.g. on Amine, in particular at least one alkanolamine, ammonia and / or sodium hydroxide solution contain.

The pH of the treatment liquid can advantageously be in a range of 1 to 11 are kept, preferably in the range of 4 to 10, particularly preferably in the range from 7 to 9.5.

The polymeric film on the metal surface can be immersed in the substrate the treatment liquid and then applied by drying, the substrate being wetted with the treatment liquid preferably has a temperature in the range of 100 to 200 ° C.

The polymer film can be flooded on the metal surface a surface of the substrate with the treatment liquid, and subsequent Drying are applied, the substrate at the beginning of wetting with the Treatment liquid preferably a temperature in the range of 12 to 150 ° C, in particular at at least 32 ° C, preferably at least 45 ° C.

The polymeric film can be applied to the metal surface by spraying the substrate the treatment liquid and subsequent drying are applied, wherein the substrate at the beginning of the wetting with the treatment liquid advantageously a temperature in the range of 12 to 70 ° C, especially at at least 32 ° C, preferably at least 45 ° C. Spraying can in particular by air or airless atomization.

The polymeric film can be applied to the metal surface by wetting the substrate the treatment liquid by doctoring, spreading or rolling and subsequent drying are applied, the substrate at the beginning of the Wetting with the treatment liquid preferably a temperature in the range from 12 to 70 ° C, especially at least 32 ° C, preferably at least 45 ° C.

Rinsing after application of the polymeric film is not necessary and usually makes no sense, because this means that the deposited film is partially again could be removed.

The method according to the invention is particularly advantageous if the substrate is at a previous temperature treatment such as a glow, anneal, Hot dip coating (such as hot dip galvanizing) or a hardening treatment the temperature required for the coating is brought. This allows at the method according to the invention considerable costs by avoiding a additional heating can be saved.

The substrate is in most cases at the beginning of the wetting with the Treatment liquid a temperature of at least 50 ° C above the Have temperature of the treatment liquid. It is recommended, in particular for hot-dip galvanized general cargo that the substrate to be treated by the Treatment is cooled down or even quenched.

After the deposition of polymeric resin particles, they physically film or / and crosslink in the presence of suitable chemical reactants chemically into a closed, even film. The polymeric film can also by physical filming, i.e. Moving particles together e.g. due to the van der Waals forces when water escapes. The filming is particularly favored when synthetic resins with low Glass transition temperatures are used or if appropriate film formers (e.g. long-chain alcohols) to temporarily soften the polymers become. It is particularly favorable to use solutions containing carboxyl groups To use acrylates in combination with melamine formaldehyde, since then one chemical crosslinking is possible. Networking makes it particularly high chemical resistance and high resistance to weathering.

A film is preferably formed which has a layer thickness after drying from 0.01 to 50 µm, in particular from 0.1 to 20 µm, particularly preferably from 0.5 to 7.5 µm. In many cases, films in the range from 0.6 to 1.8 μm are preferred, in some other cases films in the range from 2.0 to 18 µm.

The residence time of the substrate in the immersion bath is preferably chosen so that the Reactions in the treatment liquid during the wetting of the substrate of the treatment liquid are essentially or completely terminated. On vigorous or certain bubbling of gas bubbles in the area of the contacted Substrates can be seen as an indication of the reactions. The dwell time can be 1 to 120 seconds. In many cases, however, it only becomes 2 to 60 Seconds, advantageously only 3 to 30 seconds, often only 4 to 20 seconds be. As a rule, the thinner or less hot the substrate at the first The contact time with the treatment liquid is shorter become.

Thicker films are produced in the process according to the invention without thicker ones Increase the concentration of the non-volatile components in the treatment liquid especially on thick-walled substrates. Because of their greater heat content thick-walled substrates tend to form thicker films, these Network layers more strongly due to the greater heat supply or can harden. The high temperature or the high heat content of the Treating parts allow the volatile to escape faster Components of the applied wet film and therefore enable faster Concentrate the dry matter contained in the treatment liquid. The latter can help make films faster due to the higher degree of drying can be processed further.

Thicker films can also be made using a higher concentration of the non-volatile Portions in the treatment liquid applied to thin-walled substrates become.

The partially dried polymeric film can be used for the final chemical Crosslinking or physical curing can be thermally treated. For this temperatures in the range from 100 to 400 ° C. are particularly preferred at 120 to 200 ° C, particularly preferably from 140 to 180 ° C. The temperature is here based on the surface temperature of the substrate. The time of thermal aftertreatment can last from 2 seconds to 2.5 hours, preferably 2 minutes to 1 hour, particularly preferably 10 to 30 minutes. The higher the Temperature is selected, the shorter the thermal aftertreatment fail and vice versa. Treatment can include done with IR radiation.

In a preferred process variant, the film to be crosslinked is exposed to UV radiation hardened. This avoids heat and the treatment time is usually a fraction of a second to a few seconds. This however, usually requires a certain composition of the Treatment liquid and the previous complete or almost complete Expulsion of the solvent or solvent mixture.

If a varnish is to be subsequently applied to the film formed, then so the substrate coated with the film is preferably first painted and then the polymers are simultaneously used in the thermal aftertreatment Film and the lacquer applied to it are finally chemically cross-linked or / and physically hardened.

The method according to the invention is also particularly advantageous for workpieces Aluminum alloys, especially for those with an adhesion promoter layer Motor vehicle bodies. If this at a temperature with a polymer Film to be coated after leaving a heat treatment plant Process-related, e.g. at temperatures in the range of 260 to 130 ° C, preferably from 220 to 160 ° C, so that can be coated in the The energy content present in substrates can be used meaningfully without the substrates to have to heat up again. The method according to the invention can therefore be Integrate inexpensively into series production.

In a similar way, the method according to the invention can also be used for hot-dip galvanized Insert workpieces. Here is a formulation of 28 parts by weight acid functional acrylic resins, especially with an acid number of about 135 and with a glass transition temperature of about 28 ° C, from 71 parts by weight acid functional acrylic resins, especially with an acid number of about 215 and with a glass transition temperature of about 95 ° C, and from 1 part by weight of an N-ethylmorpholine complex well proven after using the synthetic resins Ammonia, 2-dimethylaminoethanol and 2-amino-2-methyl-1-propanol in the ratio of 1: 1: 1 were neutralized.

The inventive method offers the possibility that in addition to the Substrate a lacquer layer, a film, a foam or / and an adhesive applied is, the substrate optionally with a further shaped body or with a film is glued.

With the method according to the invention it is also possible to use thicker films to apply, e.g. can have a film thickness in the range of 5 to 25 microns. These films can serve as a single-layer coating. For this, the concentration the treatment liquid increased in order to be able to apply thicker films, preferably to a content of 5 to 25 wt .-% dry matter in the Treatment liquid. It may be desirable to provide color or opaque Components such as pigments or dissolved dyes in the treatment liquid add to a colored or / and colored glaze lacquer layer to train. To a certain extent, effect and metallic paintwork can also be used apply.

In addition to resin (s), the non-volatile, film-forming mixture can contain at least one inorganic additive in dissolved form and / or as a finely divided powder such as a carbonate, chromate, oxide, silicate such as e.g. Layered silicate, containing sulfate. This Additive can be used as a transparent or opaque dye or as a transparent Filler or / and to extend the diffusion path of attacking media in the Dry film to be used on the substrate surface. Here are in particular scale-like particles are an advantage.

Such a single-stage coating can be significantly cheaper are applied as an at least two-stage painting process according to the State of the art. Also, by avoiding over-spray work largely without loss. The drying time of the wet film is significantly reduced. In some cases - such as for galvanized Construction parts for houses, bridges etc. or for traffic safety Facilities, especially traffic lights, lamps and crash barriers - on one physical or / and chemical drying can be transferred so that no additional thermal drying step is required. Therefore, it is one stage applied coating also cheaper than related one-stage applied lacquer coatings according to the prior art.

A film can also be used for decoration and / or special protection against mechanical influences. This is especially for small ones Household appliances such as Toasters and jugs or for machine covers Interesting. Decorative foils such as printed PVC films are state of the art Technology. The films can be self-adhesive or with a separately applied one Glue to be glued.

With a foam that is often applied in a thickness of 5 to 100 mm additional noise shielding and / or thermal insulation e.g. with a Polyurethane foam can be achieved.

With an adhesive layer it is possible to make adhesive connections to other components, especially metal parts. Such connections include For Vehicle bodies, trailers, mobile homes, airplanes can be used. Are next to it also adhesive connections to glass, plastic, wood or other materials possible, e.g. for gluing glass panes.

The object is further achieved with a treatment liquid for producing a Plastic film or plastic-containing film on a metal surface during the wetting of the metal surface with the treatment liquid, the Treatment liquid 0.1 to 50 wt .-% of one or more resins containing non-volatile film-forming mixture and 99.9 to 50 wt .-% of one contains water-miscible or water-soluble solvent and / or water and on a temperature of 10 to 100 ° C is maintained, the treatment liquid is set so that its components during the operating time, during the Service life and at the temperature of film formation not or almost not coagulate, do not sediment or do not sediment significantly and do not or do not do so significantly be decomposed, the molecular weight distribution and the viscosity of the Do not change the treatment liquid significantly during use.

The task is finally solved with a concentrate for the production of a Treatment liquid according to the invention, the concentrate after dilution gives the treatment liquid, the concentrate being 1 to 90% by weight or several resins containing non-volatile film-forming mixture and 99 to 10% by weight of a water-miscible and / or water-soluble solvent or / and Contains water, the concentrate or the treatment liquid being adjusted in this way are that their components during the storage period, during the operating time, during the service life and at the temperature of the film formation not or almost do not coagulate, do not sediment or do not sediment significantly and do not or do not be significantly decomposed and where the molecular weight distribution and Viscosity of the concentrate and treatment liquid during the Storage time and in use do not change significantly.

Working time with the invention Treatment liquid understood, in which hotter parts with the Treatment liquid can be brought into contact to form a polymeric film to train. The stability of the concentrate and the treatment liquid should insofar as it can be ensured that no serious disruption to operations as a result of Instability.

The treatment liquid preferably contains 0.1 to 15% by weight of the non-volatile film-forming mixture and 99.9 to 85 wt .-% one water-miscible and / or water-soluble solvent or / and water. The treatment liquid particularly preferably contains 0.1 to 5% by weight of the non-volatile film-forming mixture and 99.9 to 95 wt .-% of one water-miscible and / or water-soluble solvent or / and water. The preferred content of the non-volatile film-forming mixture in the Treatment liquid can also, depending on the composition of the Treatment liquid and the desired layer vary. In many cases the content of the non-volatile film-forming mixture in the treatment liquid advantageously at least 0.8% by weight or at most 3% by weight, in make cases at least 1 wt .-% or up to 2.5 wt .-%. The content of then at least one solvent in the treatment liquid is at most 99.2% by weight or at least 97% by weight or at most 99% by weight or at most 97.5% by weight.

They are particularly suitable for the passivation of galvanized surfaces Treatment fluids containing non-volatile film-forming Mixtures in the range from 0.5 to 5% by weight, preferably 1 to 3% by weight, and 99.5 have up to 95% by weight of at least one solvent. For pretreatment and Passivation of aluminum-rich surfaces are particularly suitable Treatment fluids containing non-volatile film-forming Mixtures in the range from 0.5 to 5% by weight, preferably 1 to 3% by weight, and 99.5 have up to 95% by weight of at least one solvent. For the colored coating of substrates are particularly suitable treatment liquids that contain of the non-volatile film-forming mixture in the range from 4 to 12% by weight preferably 6 to 10% by weight, and 96 to 88% by weight of at least one solvent exhibit.

The concentrate preferably contains 5 to 80% by weight of one or more resins containing non-volatile film-forming mixture and 95 to 20 wt .-% of one water-miscible and / or water-soluble solvent or / and water, particularly preferably 10 to 70 or 90 to 30% by weight.

The temperature of the treatment liquid is preferably at least 35 ° C, particularly preferably at least 40 ° C, very particularly at 50 to 70 ° C held. However, the preferred temperature ranges may vary depending on the The composition of the treatment liquid and the desired layer vary and also shifted, for example, to temperatures in the range from 75 to 95 ° C his.

Prerequisite for successful continuous use of the invention Treatment fluid is preferably stable for at least a month over at least 6 months, particularly preferably over at least two years, wherein the treatment liquid is supplemented accordingly during this period the working conditions are adjusted: the components of the treatment liquid should be during the operating time, during the service life and at the temperature of the Film formation not or almost not coagulate, not or not significantly sediment and not or not significantly decomposed, and their Molecular weight distribution and viscosity should not be significant in use change. A certain amount of coagulation, decomposition, sedimentation can occur or / and change in molecular weight or viscosity not entirely be excluded because the balance of the treatment liquid by the Immersion of hot parts and through the entry of foreign substances (contamination) can be loaded more heavily.

The treatment liquid advantageously has a viscosity like that of water or only a slightly increased viscosity, as it is difficult to achieve Areas of the parts to be treated, e.g. Bores, threads and cavities reached.

The treatment liquid is preferably obtained by diluting a concentrate made with water and / or a water-containing solvent mixture. If necessary, a defoamer, a leveling agent and / or a Wetting agents are added. When adjusting the treatment liquid is too note that this is sufficiently neutralized. On the share of an organic Solvents can be dispensed with in particular if the The volatility of neutralizing agents are adjusted so that they are sufficient Bath stability is guaranteed at elevated working temperatures.

The crosslinked polymeric dry film according to the invention is usually water-resistant, mechanically resistant, weather-resistant and more flexible than a filmed dry film, e.g. made by physical drying has been. The crosslinked dry film of the invention sometimes also gives one higher gloss than films according to the prior art, which are produced by physical Drying were formed. The films according to the invention are surprising evenly and closed. The cured according to the invention polymeric film shows an optimal barrier effect against weather influences, against e.g. Chemicals used in automobiles such as fuels, oils, battery acids, Brake fluids etc. This high quality film is made with a dry film according to the prior art, which consists of a dispersion by physical drying is normally not achieved.

The method according to the invention has compared to that in the prior art known method for applying a polymeric film the advantage that polymeric film from a treatment liquid applied by immersion that contains only a small concentration of the non-volatile components and is therefore comparatively inexpensive. The immersion process according to the invention has the advantage of getting along without complex plant technology, and still leads to uniformly distributed dry film thicknesses on geometrically simple or complicated parts.

Surprisingly, it was found that the inventive Process is possible to produce pretreatment layers that those of classic chromating e.g. are equivalent on aluminum alloys, however can be achieved without the use of chrome compounds. Sometimes they are protective films according to the invention even the coatings of the classic ones Consider chromating.

This has unexpectedly shown that the addition of an N-ethylmorpholine complex is particularly advantageous. In the production of parts from aluminum or aluminum alloys, especially of assembled and with a Motor vehicle bodies with an adhesion promoter layer can do that The inventive method can be used successfully by the heat of the Tempering or hardening as the starting temperature for the invention Immersion process is used. Here, e.g. Temperatures at the beginning of the Wetting with the treatment liquid in the range of 220 to 160 ° C used become. The method according to the invention for applying the polymeric film is excellently suited to workpieces based on aluminum without further Coating - as with an additional cathodic dip coating - permanently protect. Electrodeposition paint can therefore be saved.

Unexpectedly, it was possible to develop a method that can be used both without Chromium compounds, as well as in some cases without the use of organic Solvents leads to passivation layers, which those of the chromating and Phosphating roughly equivalent, sometimes even in individual properties are superior.

Furthermore, it has proven itself in the pretreatment of hot-dip galvanized workpieces proven advantageous, the inventive method immediately after Use hot dip galvanizing, whereby instead of slow cooling the hot-dip galvanized parts under the influence of air at room temperature by immersion a significant reduction in the treatment liquid according to the invention subsequent cooling time can be achieved.

The invention is basically also for so-called. Endless workpieces such as wires, profiles and metal bands - narrow band, medium band and broad band - suitable.

The substrates coated with a film according to the invention can be used are used for the production of metal sheets, bodies, bumpers, frames, Profiles, guardrail elements, shelf elements, fence elements, radiator elements, Moldings of complicated geometry or small parts. You can in particular are used for pre-assembled bodies and their parts during manufacture of vehicles, trailers, mobile homes or missiles, for covers, Housing, lamps, lights, traffic light elements, glasses frames, screws, nuts, Springs, flanges, furniture such as Garden furniture or furniture elements. Generally the invention is also particularly advantageous for parts with cavities such as divide made of or with pipes and / or profiles that only limit one painting are accessible, in particular window and door frames, car bodies, bicycle frames, Pipe constructions for the protection of electrical lines or of Household appliances such as Pitchers and toasters. The method according to the invention can be used advantageously for parts that may by forming such as Cold-, Cold massive, warm, forming, drawing, pressing, extrusion, etc. or by Casting were molded.

Examples :

The invention is explained below by way of example.

Examples 1 and 2 according to the invention: hot-dip galvanized plates

Sheets were about 100 x 100 mm in size and 2, 3 and 5 thick mm made from a standard hot-dip galvanized steel. The zinc content of the zinc layer was more than 98%. The zinc melt had one when the plates were removed Temperature in the range of 445 to 455 ° C. The plates were removed from the Hot-dip galvanizing bath immersed in the treatment liquid with a time delay. The Treatment liquid had a temperature of about 60 ° C, because the bath in this was kept essentially constant at this temperature. That is how it came about spontaneous cooling of the hot plates. The temperature of the plates e.g. at the Immersion in the treatment liquid was started with a temperature sensor measured on the plate surface. Five plates each were placed under the same Conditions coated. The residence time was 5 to 10 seconds and was so chosen that the reactions in the liquid were almost complete when removed. The non-volatile content in the treatment liquid was 1 in Examples and 2 1.2 and 2.4% by weight, respectively.

The treatment liquid of Example 1 contained the air-drying, transparent one Formulation 1 based on 30% by weight of an acid-functional acrylate resin of pure acrylate and methacrylate and 70% by weight of an acid-functional styrene-acrylate resin. This treatment liquid was for chrome-free preservation of general cargo galvanized surfaces. Additives for the Defoaming, surface wetting and flow adjustment used. Ammonia, 2-dimethylaminoethanol were used to neutralize the acid groups of the resins and 2-amino-2-methyl-1-propanol in a ratio of 1: 1: 1 and Deionized water is used as the solvent. The resin mixture was therefore in Temperature range from 15 to 100 ° C over long process times well soluble in water and was particularly well suited for the treatment of about 400 to 430 ° C Parts that were hot-dip galvanized immediately before. Despite the high temperatures of the immersed parts, the treatment liquid was stable over the long term.

The treatment liquid of Example 2 instead contained 90% by weight of one Formulation 2 based on polyurethane, acrylate and polyester and 10% by weight a melamine-formaldehyde resin. The remaining conditions were as for Example 1 selected. This treatment liquid was for the oven drying, at elevated temperature cross-linking transparent chrome-free pretreatment or / and Treatment of general cargo galvanized surfaces or the surfaces of aluminum or aluminum alloys. The films produced with formulation 2 had to be at temperatures in the range of 140 to 200 ° C for 30 to 10 minutes treated for the final curing of the film. This Treatment liquid was used to treat galvanized surfaces in the Automotive engineering is particularly well suited because it can withstand high temperatures was permanently stable.

After the coating of the respective plates of Examples 1 and 2, the polymer films were checked optically. The layer weight of the polymeric film could only be determined approximately. A layer weight of 1 g / m ² corresponds approximately to a layer thickness of 1 µm. The layer coverage in the range from 0.5 to 5 µm was determined gravimetrically and averaged over 5 values. The layer coverage larger than 5 µm was determined with the aid of a Permascope from Fischer and averaged over 10 values.

Table 1 indicates a strong dependence of the film thickness depending on the Plate thickness and thus from the heat content of the substrates. The films on the 5th mm thick sheets were not only thicker due to the high heat content trained, but also offered a much better corrosion protection than thinner films. All films on the galvanized steel plates were optically perfect: The transparent films were closed. The layer thickness distribution fluctuated only slightly on each plate. There was none on the drain edges substantial thickening of the protective films.

When testing plates of Examples 1 and 2, it was found that all films on the galvanized steel plates were optically flawless: the transparent films were closed. The layer thickness distribution only fluctuated on one plate at a time marginally. There was no significant thickening of the drain edges Protective films. There were only slight differences between the films with the treatment liquids of Examples 1 and 2 were generated.

Comparative examples on hot-dip galvanized steel plates

Hot-dip galvanized and then cooled steel sheets were used for comparative examples 1 to 6. In comparative example 6, the hot-dip galvanized plate was not further coated. The residence time was 5 to 10 seconds and was therefore chosen approximately as in the examples according to the invention, although no bubbling occurred as a sign of a reaction. The residence time also had no significant influence on the formation of the layer thicknesses. The coated panels were air dried. The other working conditions were otherwise the same as in example 1. Experiments on comparative examples 1 to 5 on hot-dip galvanized steel plates: treatment liquid and parts at room temperature (approx. 20 ° C) Comparative example Approach dip Wall-thick diving objects Immersion temperature Substrate temperature before diving Substrate temperature after diving Dry film thickness VB 1 98.8 wt% water 2 mm 20 ° C 20 ° C 20 ° C 0.1 µm 1.1% by weight formulation 1 0.1% by weight additives VB 2 92.5 wt% water 2 mm 20 ° C 20 ° C 20 ° C 1.0 µm 6.9% by weight formulation 1 0.6% by weight additives VB3 87.5 wt% water 2 mm 20 ° C 20 ° C 20 ° C 1.5 µm 11.5% by weight formulation 1 1.0% by weight additives VB 4 94.0 wt% water 2 mm 20 ° C 20 ° C 20 ° C 1.0 µm 6.0 parts by weight Wording 4th VB 5 90.0% by weight water 2 mm 20 ° C 20 ° C 20 ° C 2.1 µm 10.0 parts by weight Wording 4th Qualitative assessment of the layer quality with regard to the white rust formation in Example 1 in comparison to Comparative Examples 1, 2 and 6 on hot-dip galvanized steel plates Example or comparative example Exposure after 4 weeks% white rust on the surface Exposure after 6 months% white rust on the surface Outdoor exposure after 12 months% white rust on the surface DIN 50 017 KK after 360 h% white rust on the surface Trial 1 0 2 10 10 Trial 4 1 20th 40 60 Trial 5 0 0 2 0 Trial 8 1 10 15 5 Trial 17 0 0 0 0 VB 1 100 100 100 100 VB 2 5 20th 40 60 VB 6: substrate untreated 100 100 100 100

In comparison to Examples 1 and 2, Comparative Examples 1 to 5 showed that the immersion treatment of surfaces with a temperature of around 20 ° C in one Treatment liquid of about 20 ° C a thinner by a factor of 7 Dry layer with the same concentration of the non-volatile film-forming components in of the treatment liquid as if the treatment liquid were at 60 ° C warmed and the substrates to be treated previously a temperature in the range of Have 200 to 400 ° C. That means the concentration of the non-volatile film-forming portion in the treatment liquid increased by about a factor of 7 would have to be to achieve similar layer thicknesses at room temperature, what would have a very negative impact on investment costs. Particularly disadvantageous is that at room temperatures on the drain edges and in the area of bores and threads overcoating occurs and the parts due to lack Dimensional accuracy are unusable.

Outdoor weathering tests in an industrial atmosphere and Condensation water constant climate tests according to DIN 50 017 KK. This resulted in due to the strongly fluctuating on a single plate Layer thickness distributions in Comparative Examples 1 and 2 are thinner coated areas insufficient corrosion protection. Comparative Example 1 showed so bad results that the corrosion protection was no better than without the supposedly anti-corrosion coating, as in Comparative Example 6 busy.

The drain edges showed much thicker coatings than the rest Surfaces. In some cases, layer thicknesses of more than 50 µm occurred at the run-off edges.

Example 3 according to the invention: Formulation 2 for aluminum alloys

Parallel tests with the treatment liquid from Example 2 on an aluminum alloy customary in automobile construction led to the same good results as on galvanized plates. For this purpose, the plates were previously passivated from an aluminum alloy frequently used in automobile construction on the basis of Tl / Zr. The plates were heated immediately after the heat treatment during tempering - if necessary with a time delay for slow cooling or for the completeness of the test series a little higher - and immersed at about the specified target temperature (Table 4). A concentration of the non-volatile constituents of the treatment liquid of 2.4% by weight was used. The treatment liquid is particularly suitable for coating parts that have a temperature in the range from 160 to 250 ° C. The remaining working conditions were the same as in Example 2. The results show that the same layer thicknesses can be produced with the same concentrations of chemically very different formulations and with the same immersion bath parameters. The coatings were optically flawless: the layers were closed, the layer thickness distribution was even and there were no significant thickening at the drainage edges.

Example 4 According to the Invention: Film Formation on an Aluminum Alloy and then applied car top coat

For this example, substrates from a common in vehicle construction Aluminum alloy used. The substrates were previously passivated with a Cr-free Coating from at least one Zr / Ti compound. The records were made in Connection to heat treatment during tempering - if necessary with a time delay for slow cooling or for the completeness of the experimental range heated a little higher - and submerged at about the specified target temperature (Table 4). The treatment liquid of Example 4 contained 95% by weight of one Formulation 3 based on polyurethane and acrylate and 5% by weight of one Melamine formaldehyde resin. It was done with a concentration of worked non-volatile components of the treatment liquid of 2.4 wt .-%. The remaining conditions were maintained as in Example 2. This Treatment liquid was for the drying in the oven at elevated temperature, transparent, chrome-free treatment and / or pretreatment of the surfaces of Aluminum or aluminum alloys thought. This treatment liquid was just as well suited as the treatment liquid of Examples 2 and 3. The with Formulation 3 films still had to be produced at temperatures in the range of Aftertreated 140 to 200 ° C for 30 to 10 minutes for final curing become. The quality of the polymeric film was without applied topcoat tested. The coatings were optically perfect: the layers were closed, the layer thickness distribution was even and on the drain edges no significant thickening occurred. After applying the top coat carried out all tests to determine the adhesion Cross-cut method flawless results. The entire shift sequence fulfilled that physical-technical tests of automotive painting.

Example 5 according to the invention: Film formation on an aluminum alloy as Single-layer paint treatment

The plates from a commonly used in the automotive industry Aluminum alloys were water-wetted to remove oil residues and dirt remove. You have not been passivated. The parts became tight to a temperature heated above the temperature at which the parts entered the treatment liquid were immersed (Table 4). The residence time was 5 to 10 seconds and was chosen so that the reactions in the liquid almost end when removed were. The treatment liquid of Example 5 contained 54.7% by weight of one Formulation 4 based on acrylate, methacrylate, styrene and polyester and 30 % By weight of a rutile white pigment, 0.3% by weight of a black carbon black pigment, 9.0 % By weight of silicate and 6.0% by weight of other additives for defoaming, leveling, wetting, neutralization and adjustment of the rheology. It was here with a concentration of the non-volatile components of the treatment liquid of 6 or 10 wt .-% worked to produce thicker colored protective films. The coated panels were then air dried. This Treatment liquid was for air drying, gray, chrome free preservation Various small parts made of steel, galvanized steel, aluminum, cast aluminum, cast zinc or cast iron thought. The treatment liquid was for aluminum castings excellent as it was permanently stable. The coatings were optical flawless: the layers were closed, the layer thickness distribution was uniformly and no significant thickening occurred at the drain edges. The quality of the coating corresponded to the quality level with the usual ones Process applied one-coat spray painting.

Comparison of example 3 with comparative examples 7 to 9: aluminum alloys

Conventional coating processes on aluminum alloy sheets were used for comparative examples 7 to 9. Assessment of the coating quality without subsequent painting with regard to the quality of the corrosion protection on aluminum alloys Example or comparative example Salt spray test according to DIN 50 021 SS:% corroded surface Alternating test according to VDA 621-415:% corroded surface Outdoor exposure according to VDA 621-414:% corroded surface Example 3 after 720 h after 5 rounds after 6 months Trial 27 0% corrosion 0% corrosion 0% corrosion - after 10 rounds - - <5% corrosion - VB 7: yellow chromating after 720 h after 5 rounds after 6 months 0% corrosion 0% corrosion 20% corrosion VB 8: Green chromating after 720 h after 5 rounds after 6 months 0% corrosion <5% corrosion 30% corrosion VB 9: zinc phosphate after 24 h after 5 rounds after 1 month 0% corrosion 40% corrosion 60% corrosion after 168 h - after 6 months 20% corrosion - 100% corrosion

Salt spray tests according to DIN 50 021 SS, alternating tests were carried out on selected samples according to VDA 621-415 and outdoor weathering tests according to VDA 621-414. Here it was found that Example 3, Test 27, in the salt spray test and in the alternate test one compared to the conversion layers of the highest quality conventional ones Procedure (VB 7 and 8) results equivalent to one Zinc phosphate layer, however, superior corrosion resistance. Against that is Coating according to the invention in terms of outdoor exposure far better than that highest quality conventional coatings. It should be noted that only example 3, experiment 27, had previously been passivated with Ti / Zr fluorine, but not that Substrates of comparative examples 7 to 9, since the latter with such Passivation cannot be coated according to the invention. The layer thickness in the area the run-off edge was only slightly larger than in the case of example 3, experiment 27 larger areas.

Claims (27)

Process for producing a plastic film or a plastic film Film on a metal surface, in which a treatment liquid is added Start of wetting with the treatment liquid 0.1 to 50 wt .-% of a one or more resin-containing non-volatile film-forming mixture and 99.9 to 50% by weight of a water-miscible and / or water-soluble Contains solvent and / or water, a film on the metal surface forms, the volatile portion escaping at least partially, thereby characterized in that the treatment liquid at the beginning of wetting with the treatment liquid a temperature in the range of 10 to 100 ° C. has that the metal surface at the beginning of wetting with the Treatment liquid a temperature at least 20 ° C higher than that Treatment liquid and a temperature in the range of 30 to 700 ° C. and that the film is used to treat the metal surface. A method according to claim 1, characterized in that the metal surface before wetting with the film-forming treatment liquid with a Adhesion promoter layer, preferably with a phosphate, a silicate or one Zirconium or / and titanium, a phosphonate and / or a silane-containing Adhesion promoter layer is provided. A method according to claim 1 or 2, characterized in that the resin or the resins are synthetic resins, in particular acrylates, polyesters, Polyurethanes, silicone polyesters, epoxies, phenols, styrenes, resins on the basis Urea-formaldehyde, their mixtures or / and their Copolymers. Method according to one of the preceding claims, characterized in that that the resins as a solution or dispersion, especially as an emulsion or / and suspension are present, preferably as a solution. Method according to one of the preceding claims, characterized in that that the non-volatile, film-forming mixture in addition to resin (s) at least one inorganic additive in dissolved form and / or as a finely divided powder such as e.g. contains a carbonate, chromate, oxide, silicates, sulfate. Method according to one of the preceding claims, characterized in that that as a solvent for the organic polymers at least one water-miscible and / or water-soluble alcohol, a glycol ether or N-methylpyrrolidone or / and water is used in case of use a solvent mixture, in particular a mixture of at least one long chain alcohol such as Propylene glycol, an ester alcohol, a glycol ether or / and butanediol with water, preferably only water. Method according to one of the preceding claims, characterized in that that the treatment liquid at least one volatile or / and non-volatile additive for adjusting the defoaming, the adhesion, the Conservation, neutralization, surface wetting, rheology or / and the course contains. Method according to one of the preceding claims, characterized in that that the treatment liquid has at least one neutralizing agent, e.g. contains an amine, ammonia and / or sodium hydroxide solution, preferably at least two of the neutralizers from the long-volatile group Neutralizing agents such as 2-amino-1-methyl-1-propanol, one medium volatile neutralizing agents such as 2-dimethylaminoethanol and a short volatile neutralizing agent such as Ammonia or Triethylamine. Method according to one of the preceding claims, characterized in that that the pH of the treatment liquid is in a range from 1 to 11 is held. Method according to one of the preceding claims, characterized in that that the film is also formed by physical filming. Method according to one of the preceding claims, characterized in that that the film on the metal surface by immersing the substrate in the Treatment liquid and is applied by subsequent drying, the substrate being wetted with the treatment liquid preferably has a temperature in the range of 100 to 200 ° C. Method according to one of the preceding claims, characterized in that that the film on the metal surface by flooding the substrate with the Treatment liquid and is applied by subsequent drying, the substrate being wetted with the treatment liquid preferably has a temperature in the range of 12 to 150 ° C. Method according to one of the preceding claims, characterized in that that the film on the metal surface by spraying the substrate with the Treatment liquid and is applied by subsequent drying, the substrate being wetted with the treatment liquid preferably has a temperature in the range of 12 to 70 ° C. Method according to one of the preceding claims, characterized in that that the film on the metal surface by wetting the substrate with the Treatment liquid by doctoring, spreading or rolling and is applied by subsequent drying, whereby the substrate Start wetting with the treatment liquid, preferably one Has temperature in the range of 12 to 70 ° C. Method according to one of the preceding claims, characterized in that that the substrate in a previous temperature treatment such as e.g. an annealing, hot dip coating or annealing on the for the Coating required temperature is brought. Method according to one of the preceding claims, characterized in that that the substrate is cooled or quenched more, the Temperature of the substrate preferably at least 80 ° C, especially preferably at least 100 ° C above the temperature of the Treatment liquid is. Method according to one of the preceding claims, characterized in that that a layer thickness of the film after drying from 0.01 to 50 µm, in particular from 0.1 to 20 µm, particularly preferably from 0.5 to 5 µm is trained. Method according to one of the preceding claims, characterized in that that the partially dried film for final chemical crosslinking or physical curing is thermally aftertreated, in particular at temperatures in the range of 100 to 400 ° C and in particular over a Time from 2 seconds to 2.5 hours. Method according to one of claims 1 to 17, characterized in that the film to be crosslinked is cured with UV radiation. Method according to one of claims 1 to 18, characterized in that the substrate is only painted when the thermal aftertreatment for the final chemical cross-linking or physical curing of the film is carried out, which can also serve to harden the paint layer. Method according to one of the preceding claims, characterized in that that aluminum alloy components, especially those with a Motor vehicle bodies provided with an adhesion promoter layer at the temperature a film that is coated after leaving a Heat treatment plant is present, e.g. at temperatures in the range of 260 up to 130 ° C, preferably from 220 to 160 ° C. Method according to one of the preceding claims, characterized in that that corrosion inhibitors are added as pigments and / or in dissolved form like e.g. at least one phosphate, titanate and / or zirconate, in particular dicalcium phosphate, dimagnesium phosphate, iron III phosphate, modified alkali phosphate, aluminum triphosphate or a Zirconium complex compound. Method according to one of the preceding claims, characterized in that that in addition a layer of lacquer, a film, a foam on the substrate or / and an adhesive is applied, the substrate possibly with a another molded body or is glued with a film. Method according to one of the preceding claims, characterized in that that the substrate to be coated is a sheet, a body or a part a body, part of a vehicle, trailer, camper or Missile, a cover, a housing, a lamp, a lamp, a Traffic light element, a piece of furniture or furniture element, an element of a Household appliances, a frame, a profile, a molded part of complicated geometry, a guardrail, radiator or fence element, a bumper, a part or with at least one tube or / and a profile, a window, door or Bicycle frame or a small part such as a screw, nut, flange, Spring or an eyeglass frame. Method according to one of the preceding claims, characterized in that that the substrate was produced by casting or / and rolling and preferably essentially made of aluminum, iron, copper, magnesium, zinc, Tin or their alloys is also metallic, in particular be coated with aluminum, copper, zinc, tin or their alloys can. Treatment liquid for the production of a plastic film or plastic-containing film on a metal surface during wetting the metal surface with the treatment liquid, the Treatment liquid 0.1 to 50 wt .-% of one or more resins containing non-volatile film-forming mixture and 99.9 to 50 wt .-% a water-miscible or water-soluble solvent and / or water contains, characterized in that the temperature of the Treatment liquid in the range of 10 to 100 ° C is that Treatment liquid is adjusted so that its components during the Operating time, during the service life and at the temperature of the film formation do not or hardly coagulate, do not sediment or do not sediment significantly and not or not significantly decomposed and that the Molecular weight distribution and the viscosity of the treatment liquid in the Do not change the application significantly. Concentrate for the production of a treatment liquid according to claim 26, the concentrate, after dilution, gives the treatment liquid, characterized in that the concentrate 1 to 90 wt .-% of a or several resins containing non-volatile film-forming mixture and 99 up to 10% by weight of a water-miscible and / or water-soluble solvent or / and water contains that the concentrate or the treatment liquid are set so that their components during the storage period, during the operating time, during the service life and at the temperature of the Film formation not or almost not coagulate, not or not significantly sediment and not or not significantly decomposed and that the Molecular weight distribution and the viscosity of the concentrate and the Treatment liquid during the storage period and not in use change significantly.