KR20020049053A - Coating agent and a method for coating the surface of a substrate - Google Patents

Abstract

The present invention relates to a coating agent for coating the surface of a substrate in the form of a foil which is provided with an upper cover layer, a middle chromophore layer and a lower carrier layer. According to the invention, the lower carrier layer is a free-flowing, hardenable adhesive and levelling layer for gluing the foil onto the surface of the substrate and for covering irregularities in the surface of the substrate. A flexible, hardenable cover layer is provided. The present invention also relates to a method for coating the surface of a substrate using such a coating agent.

Description

COATING AGENT AND A METHOD FOR COATING THE SURFACE OF A SUBSTRATE}

Such coatings are known. These are used for the coating of the product surface, in particular as a substitute for enamel.

Aqueous enameling the substrate after first leveling the substrate surface with a filler is disadvantageous in terms of time, labor and cost. For example, automotive parts with a composition base of iron or aluminum or composite fibers should be first leveled after the anticorrosion layer is applied. During this process, a homogenizing filler is added one or more times, and an intermediate grinding operation must be performed after each filling process. And the surface planarized in this way must be coated with an enamel base layer and a top layer thereon. Non-uniformities associated with the manufacturing process resulting from the joint, such as weld points, grinding points or rivets, cannot be automatically leveled. This process is sensitive to external factors, especially dust, resulting in the release of solvent. Therefore, process steps must be performed in an isolated facility.

EP 0 352 298B1 discloses automobile body flanking and a method of making the same. This automotive body flanking is made of plastic and coated with a film consisting of a support layer, a colored layer and a transparent enamel layer. The laminate is heated, preformed and then inserted into an injection mold to produce final automotive body flanking.

U. S. Patent No. 5,021, 278A describes a thermoformable laminate comprising a support layer, a paint layer and a protective clearcoat layer. The laminate is heated, preformed and then molded onto the substrate.

EP 0 615840A1 relates to a coating film in the form of a laminate in which a coating film for a metal container for beverages is sequentially formed from below with an adhesive layer, a coloring layer, a polyester layer and an upper layer. The film is drawn with the adhesive layer and applied on a flat metal sheet and then shaped into a can.

The addition of these known films and films to metal or fiber composition substrates is complex and not suitable for all cases because the films must be melted onto the substrate since there is usually no adhesive layer. Moreover, known films lack flexibility and must be preformed to be applied on a substrate.

German patent application DE 197 01 594A1 discloses a method for producing a profile strip, in particular for producing an edge strip for use in the furniture industry. German patent application DE 38 17 479A1 discloses a multilayer surface film. Since this is intended as a protective layer application for the smooth surface, there is no mention of labeling that homogenizes the unevenness in the substrate to be coated.

The present invention relates, for example, to a coating for coating a body of a motor vehicle, a body of a motor vehicle or a part thereof, in particular a substrate surface of a railway vehicle body, into a film form having an upper cover layer, an intermediate coloring layer and a lower hardened support layer. The invention also relates to a method of coating a substrate surface with such a coating.

Embodiments of the present invention are described in more detail with reference to the following drawings,

1 is a schematic structural diagram of a coating agent according to the present invention;

2 is a schematic diagram of a coating agent and a substrate before coating;

3 is a schematic of the coating final compound and substrate after coating.

It is therefore an object of the present invention to provide a coating method of the type described above, which shortens the coating and processing time, is less susceptible to the external environment, minimizes the emission and can omit additional surface finishing processes.

The solution to this problem consists of a coating having the features of claim 1 and a method of using the coating. According to the present invention, the lower support layer is a free flowing, curable adhesive and homogenizing layer that is capable of bonding the film to the surface of the substrate and stacking irregularities in the substrate surface, and is provided with a curable flexible upper cover layer.

Therefore, due to the free-flowing lower adhesive and homogenizing layer, the colored decorative coating is applied and at the same time, non-uniformities in the surface of the substrate are laminated, and the coating after applying the coating has a high resistance to external influences and stress due to the cover layer, and then cures. You go through the process.

The bottom adhesion between the substrate surface and the colored layer and the reaction time of the homogenizing layer do not play an absolute role. This can be rough in seconds, minutes, hours or days. However, this is a secondary priority because the substrate or surface can be adequately protected because the substrate is already in its final stage, and no further processing steps are required, so even with longer reaction times, production delays It does not occur

There is no undesired release since the liquid substance does not have to be treated throughout the whole operation. The process according to the invention can be carried out on the same substrate in parallel with other process steps, for example building a motor vehicle or other structure of a railroad car, since it is not affected by inflow factors, in particular dust. . Only one coating step is necessary. No preforming of the coating is necessary. Apart from the overall coating time, there is no waiting time for drying or reaction of the coating material.

The dependent claims of the present invention disclose useful results. Homogenization of the non-uniformities in the substrate surface due to the lower adhesion and homogenization layer is easy when the layer has a thickness of at least 0.15 mm, particularly preferably at least 1 mm, because it completely fills the depressions in the surface This is because there is enough free flowing material to form a plane. Thereby, the lower adhesion and homogenization layer has the desired viscosity consistency, particularly preferred thixotropic. This layer is sufficiently viscous and does not flow out of the coating and has sufficient free flow to even out unevenness in the substrate surface.

The thixotropic layers are usually not viscous and liquefied under load, i.e., when a coating agent is applied to the substrate, so that the non-uniformity can be excellently homogenized particularly well.

The bottom adhesive and homogenization layer can be designed to cover the entire surface or to cover a point or line. The lower layer need not be added to the intermediate colored layer in succession. Applying an adhesive spot or strip is enough to save material.

The lower adhesive and homogenizing layer is preferably based on a multicrosslinkable, thermally crosslinkable, wetcrosslinkable or photocrosslinkable polymer, as well as multicomponent materials based on epoxy, polyurethane, or acid curing binders. Particularly suitable are polyurethanes or mixture bases of multiple polyurethanes. The bottom adhesive and homogenization layer can also be produced, for example, from partially crosslinked pressure reactive adhesives. These are already pressure sensitive adhesives that are crosslinked (ie by electron beam curing or UV curing), but have sufficient adhesion and viscosity retention to ensure substrate adhesion of the coating and homogenization of non-uniformities on the substrate surface. Internal crosslinking is advantageous to achieve improved cohesion in adhesion, as a result of which it is possible to achieve a higher layer of the adhesive layer without falling off the coating, for example. However, the lower adhesive and homogenizing layer may also be constituted by a foamed adhesive surface, a foamed adhesive spot or a foamed adhesive strip. Effervescent performs a homogenization function.

The top cover layer preferably consists of a thermoplastic matrix, which is fully cured by heating or UV light radiation or electron beams or visible light. Curing of the protective layer, preferably the transparent top cover layer, takes place only after the film has been added to the final component. The top cover layer is preferably a transparent crosslinkable enamel layer, in particular a thermally crosslinkable or photocrosslinkable enamel layer which can provide reliable curability to sufficiently protect the coating result from external influences.

Under the adhesion and homogenization layer of the coating according to the invention and / or above the top cover layer, a protective layer may be added to protect the outer layers of the coating from breakage during storage and transport, in the case of the top cover layer to the substrate. Added at the time of authorization. The lower protective layer here is preferably a paper film, and / or the upper protective layer is preferably a polyester film or a polyolefin film, in particular a polypropylene film.

In the method according to the invention using the coating according to the invention, it can be applied to the substrate by a rolling or doctor method. Preferably a coating having a flexible top cover layer of a crosslinkable polymer, in particular a thermal crosslinkable or photocrosslinkable polymer, is used, which is thermally crosslinked or photocrosslinked after the coating is applied to the substrate.

When using a coating with a wet-cured bottom adhesive and homogenizing layer, the substrate surface is covered with a liquid, preferably water or sprayed on it, before the coating is added. However, when using a coating with a thermally cured bottom adhesive and homogenizing layer, the resulting composition of the substrate and coating may be heated to cure the adhesive and homogenizing layer. In this case, by applying the coating agent to the substrate by heating the resultant of the composition (by heat or radiation depending on the nature of the upper cover layer), a coating agent having a flexible top cover layer which can be thermally crosslinked is used, It is preferable to crosslink the top cover layer at the same time.

In order to protect the top cover layer from damage, it is desirable to use a coating with a top protective layer, which is only removed after the coating is applied to the substrate.

The coating agent according to the invention can be applied to a substrate having a non-uniformity of 0.5 mm or more and / or a substrate with a corrosion protection layer, depending on the thickness of the lower adhesive and homogenizing layer.

The coatings according to the invention are suitable for metallic or reinforced fibrous material substrates, for example body parts of motor vehicles, motor vehicles or components thereof, in particular body bodies of railway vehicles.

1 schematically shows a cross section of a coating (1) embodiment according to the invention. The coating 1 consists of at least three functional layers, namely an upper cover layer 2, an intermediate coloring layer and a lower adhesive and homogenizing layer 4. The top cover layer 2 is flexible and can be cured to form a rigid protective layer, preferably a clear clear enamel layer. The mesocolored layer is preferably formed by colored thermoplastics, in particular colored polyurethanes which never require further curing. The layer thickness should be about 20-100um. This choice is determined by the compatibility and adhesion to the adhesion and homogenization layer or top cover layer, and the mechanical and thermal properties and compatibility with the colorants and pigments that color the plastic. The bottom adhesive and homogenization layer consists of a pressure sensitive adhesive, a hot melt adhesive, a single composition system or a suitable adhesive such as a light activatable adhesive or a foamed adhesive web, or an adhesive tape. The approximate function of the adhesion and homogenization layer 4 can be said to transfer the mechanical properties of fillers in conventional automotive enamels. The choice of such materials is made based on the mechanical and thermal properties as well as the fusion and adhesion to the colored layer or substrate material and may be a material available on the market. In particular, moisture crosslinking or thermal crosslinking or multicomponent polyurethane or epoxy systems are suitable. The layer thickness should be at least 150 μm. Particularly preferred is a layer thickness of at least 500 μm, in particular at least 1 mm.

Further, a protective film 5 of layer thickness of about 100 mu m, preferably made of polyester, may be provided to protect the upper protective layer 2 from damage during storage, transportation and application of the coating agent 1 on the substrate. Can be. Since it is a rigid elastic material that serves as a surface homogenization layer in applying techniques such as rollers and doctors, no rolling or grinding marks remain in the film. The protective film can be removed from the top cover layer 2 after the coating 1 has been applied to the substrate.

Finally, a temporary protective layer 6 may be provided on the lower adhesive and homogenizing layer 4 to protect the adhesive compound. This protective layer is removed before applying the coating 1 to the substrate.

Specifically, the following materials can be used for layers 2, 3, and 4:

As the thermoplastic component of the colored layer 3, polymethyl methacrylate (PMMA), polybutyl methacrylate (PBMA), polyurethane (PUR), polyethylene terephthalate (PETP), polybutylene terephthalate (PBTP), Polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), polyester (PES), polyolefin (PE, PP), polyamide (PA), polycarbonate (PC), acrylonitrile-butadiene-styrene polymer ( ABS), acryl-styrene-acrylonitrile copolymer (ASA), and acrylonitrile-ethylene-propylene-diene-triene copolymer (A-EPDM) can be used, and halogen-free polymers are preferred. As pigments and colorants, organic and inorganic colorants, organic, inorganic or metal pigments, mica effect pigments, interference pigments, pearlized pigments and liquid crystal polymers can be used.

As the material of the upper cover layer 2 in the transparent form, a radiation-cured clear enamel layer, in particular a polymerizable binder or a mixture of a thermoplastic material and a polymerizable binder may be used, wherein the binder is a free radical process. It can be polymerized by a free radical process or a cationic process or both. Depending on the reaction mechanism an appropriate curing catalyst (photoinitiator) is applied to the material.

Radical polymerizable binders are usually mono or poly-ethylene unsaturated compounds. Of particular importance are unsaturated polybinders because they are involved in the crosslinking of reaction systems to form insoluble products. Radical polymerizable aliphatic urethane acrylates, polyether acrylates, polyester acrylates, epoxy acrylates or acrylated isocyanurates or mixtures of two or more of these family compounds are used.

Examples of monounsaturated compounds include methacrylates, acrylates, acrylic acid derivatives (methyl, ethyl, butyl, isooctyl and hydroxyethyl as well as vinyl and allyl compounds such as vinyl acetate, vinyl stearate and allyl acetate). Acrylate, hydroxyethyl methacrylate, ethyl or methyl methacrylate).

Examples of polyunsaturated compounds include (meth) acrylates and butadiene or isoprene copolymers of polyvinyl alcohol, as well as ethylene glycol diacrylates, diethylene glycol dimethacrylates, triethylene glycol diacrylates, butanediol-1,4- Diacrylate, butanediol-1,3-dimethacrylate, neopentyl glycol diacrylate, trimethylolpropane di (meth) acrylate, trimethylolethane di (meth) acrylate, glycerol diacrylate and triacrylate , Pentaerythritol diacrylate, triacrylate, tetraacrylate or methacrylate, dipentaerythritol tetraacrylate, pentaacrylate, hexaacrylate and -methacrylate, diacrylate and 1,4- Cyclohexanediol, 1,4-dimethylol cyclohexane, polyethylene glycol or oligo Such as dimethacrylates, silicone-modified acrylates and methacrylates of esters or oligoretanes, diacrylates, triacrylates and tetraacrylates and methacrylates of tris (2-hydroxyethyl) isocyanurate Acrylates and methacrylates of polyols.

Unsaturated binders can be used as mixtures as well as independent materials.

Examples of the photoinitiator include benzoin, benzyl, benzopinone, benzoin alkylene ether, esters of phenyl glyoxylic acid, α-trichloroacetopinone, α-diethoxy-acetopinone, α-hydroxyacetopinone and benzyldimethyl. Ketal, methylbenzoyl formate, 1-benzoylcyclohexanone, α-amino-acetopinone, D, L-campokinone, 2,2-diethoxyacetopinone, N-dimethylethanolamine, 4-benzoyl-4'- Methyldiphenyl sulfide, isopropyldioxanthone, ethyl-4-dimethylaminobenzoate, N-methyldiethanolamine, 1-hydroxyl cyclohexylphenyl ketone, bis (2,4,6-trimethyl benzoyl) -phosphine Oxide, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1, 2-hydroxy-2-methyl-1-phenyl-propane-1, bis (2,6-dime Oxybenzoyl) -2,4,4-trimethylphenylphosphine oxide, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one, [2-hydroxy-2-methyl-1- [4- (1-methyl ratio Yl) phenyl] propanone, 2,4,6-trimethyl-benzoylphenylphosphonic acid ethyl ester, diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide.

Photoinitiators can be added to the binder as independent compositions or mixtures.

Pressure sensitive adhesives can be used as the adhesive, in which case a thermal post-cure system can be used. The polymer applied to the intermediate colored layer 3 as a non-curable high viscosity liquid has some degree of adhesion (tackiness) and is bonded to the substrate surface by pressure welding. The thermal post-cure system is then crosslinked with each other. Process temperatures are usually between 10 ° C and 40 ° C.

Moreover, reactive heat-melt adhesives can be used, which arise due to cooling and partial crystallization of the backbone polymer. By adding other reaction components the system can be adapted for wet crosslinking or thermal crosslinking. Among wet cure single component systems, polyurethane systems are preferred. The curing reaction is initiated only by adding sufficient moisture. Moisture is provided by applying moisture to the substrate surface prior to applying the coating 1. Relative humidity of 40% should be maintained during the process.

Moisture, preferably water, can be microencapsulated in order to achieve sufficient and complete curing of the thick layer. Capsules are destroyed by applying a coating to the substrate, thus releasing the moist component. The encapsulant material remains as a filler in the adhesion and homogenization layer 4. Microencapsulated adhesives are present, for example, in epoxy resins, acrylates, polyesters and polyurethanes.

In the case of a thermoset monocomponent system, the coating is activated by temperature. The hardener is previously blocked or present as a solid component in the resin.

Finally, a single component system can be envisioned where the reaction components are present in microencapsulated form in the resin. During application of the coating agent 1 the capsule is broken and the reaction components are released to initiate the curing reaction.

Alternatively, two- or three-component systems based on polyurethane or epoxy systems can also be used. In this case, the second and / or third component (curing agent and activating component) may be microencapsulated or present in the applied layer by a separable protecting group, which may be heat treated at room temperature, or light (UV light). Or visible light) or moisture. During this process, the reaction components are released from the microencapsulation or the protective group is cleaved. Both microencapsulated and cleavable protective groups can remain in the layer. The other possibility is to provide a hardener or active ingredient to the non-crosslinked system in a non-reactive molecular state, which is exposed to temperature, humidity, UV light or visible light and then changes to a reaction state due to internal or intermolecular rearrangement. Thus, the adhesion and curing of the homogenization layer 4 are brought about.

The activating or curing agent component may be precoated as a contact reaction partner on either of the surfaces to be bonded into the homogenization of the film composition and into the adhesive layer, which results in curing of the composition in situ or on the inside. It is possible to spray all of the components onto the adhesive and homogenization layer immediately before applying the film and to apply the film directly, or to provide individual components (active agents or curing agents) on the substrate surface to be bonded. A thin film may be used to add a curing agent or active material, where the film is in the form of a curing agent film or an activator film, or may be applied in a moist state.

Particularly preferred is a photo-crosslinkable adhesive, since it is medium to high in adhesive strength, elastic and rapidly precured. Final intensity (dark reaction) is only achieved after hours or days. Photoinitiators decompose into compounds which will be exposed to radiation, preferably light, to initiate polymerization. This process continues after the end of the exposure and even in the unexposed areas (dark reaction).

The adhesion and homogenization layer may also be in the form of a foamed adhesive web, adhesive tape or adhesive spot. In this case, the adhesive surface and the core of the adhesive tape form the same adhesive polymer unit. The polymer is present as both a pure viscoelastic adhesive and an adhesive tape in the foam closed cell structure. Because of the viscoelastic nature, the polymer can flow into the roughness of the surface to increase the active surface area and the peeling resistance. In addition, materials such as those generally used in the form of films can be added to the coating 1 and the individual layers in each layer. These adducts are, for example, stabilizers (antioxidants, UV absorbers, HALS), metal deactivators, thio synergists, processing aids, flow control aids, thixo Thixotropy and antifoaming agents, further fillers, fibers, varnishes, antistatic agents, plasticizers and flame retardants may be added.

The material for the curable top cover layer 2 of the thermoplastic and the binder can be obtained in a known manner by extrusion. The thermoplastic material is melted in the extruder. The binder, curing agent and optional additives are mixed and added to the molten thermoplastic material in the molding machine. This yields a reactive mixture and is obtained in the form of granules, powders or films.

The ratio of the binder, the hardener and the adduct and the thermoplastic material is from 1: 1 to 1: 5, but particularly preferably 1: 3.

The upper cover layer 2 is extruded together with the intermediate colored layer 3 and the lower adhesive and homogenizing layer 4 in one operation to form a multilayer film. A reactive radiation-curable mixture of thermoplastics, binders, hardeners and optional adducts may be held in a transparent film at a layer thickness of 15-100 um, for example cured with UV light.

The polymerization is preferably initiated in the transparent layer by UV emitters such as low, medium or high pressure mercury lamps, xenon lamps, argon lamps, metal halide lamps, flash emission lamps, laser beams or electron beams (electron beam curing). do. The wavelength for UV / VIS light curing is preferably 200-600 um.

The film result sublayer may also be coated independently with an adhesive, in which case an adhesive spot or adhesive strip may also be applied. Foamed adhesive webs, adhesive strips or adhesive spots may also be applied independently.

The following example discloses a detailed example of how this method is performed. In this example, unless otherwise indicated, parts refer to parts by weight and percentages refer to parts by weight.

Example 1

The next mixing provided a photo active mixture;

material % Ebecryl 40 23 Alkoxylated PETIA (UCB) Ebecryl IRR 264 41-45.2 Triacylates of Tris (2-hydroxyethyl) isocyanurate (UCB) Ebecryl 1290 11 Fatty UR-Ac (UCB) Ebecryl 5129 11 Fatty UR-Ac (UCB) Ebecryl 350 5 Silicone Dialkylate (UCB) Tinuvin 952 One HALS additive (Ciba SC) Tinuvin 400 One UV absorbers (Ciba SC) Irgacure 184 6 Photoinitiator (Ciba SC) Lucirin TPO One Photoinitiator (BASF)

This mixture was metered into a melt of polymethyl methacrylate Lucryl G55 or Lucryl G87e (BASF) under a continuous process:

material Part Lucryl G55 3 Mixture Example 1 One

Curing condition: UV light 2 * 2-3m / min; 120 W / cm

In this example, Lucryl 55 PMMA was chosen as the thermoplastic for the colored layer because it is the same as the thermoplastic component of the clear top layer, and therefore has the best adhesion and adaptability. In addition, the pigments and colorants can be easily integrated into the melt at about 220 ° C.

Further, in this example a metallic pigment (Eckart's aluminum flake PCR 501, which is a Sio ₂ coated powdered non-leaving pigment with a particle distribution size of 10-60um) or metallic luster pigment (inde Merck's Iriodin ^ⓡ mica flakes, coated mica, which is a screen a powder to α-Fe ₂ O ₃ having a particle size distribution of 10-60um.)

Example 2

material % Ebecryl 2000 43 Fatty UR-Ac (UCB) Ebecryl IRR 264 25.5 Aliphatic Triacrylate (UCB) of UR-Ac in HDDA Lucirin TPO-L 0.5 Photoinitiator (BASF) CGI 184 3 Photoinitiator (Ciba SC) Tinuvin 292 2 HALS additive (Ciba SC) Tinuvin 400 2 UV Absorber (Ciba SC) SR 9003 7 Propoxylated Neopentyl Glycol Diacrylate (Cray Vaaley) Ebecryl 350 2 Silicone Diacrylate (UCB) CN 965 10 Fatty UR-Ac (Cray Valley) SR 344 5 Polyethylene Glycol Diacrylate (Cray Valley)

This mixture was metered into a melt of thermoplastic polyurethane KU-1-8602 or KU-2-8602 (Bayer) in a continuous process.

material part KU-2-8602 3 Mixture Example 2 One

UV light curing conditions: 2 * 2-4m / min; 120 W / cm

2 and 3 show the action of the adhesion and homogenization layer 4 when applying the coating 1 to the substrate 10. The coating 1 can be applied on a surface 11 with a roughly prepared surface having a non-uniformity of at least 0.5 mm and a temporary corrosion protection layer coated with, for example, a two-component EP metal based coat of Lankwitzer Lackfabrik [Lankwitz Enamel Factory]. Can be. After cutting the coating (1) and removing the protective film (6) from the lower adhesive and homogenizing layer (4), the coating (1) is made of metal substrates by rollers and / or selectively operated wide area doctor blades. 10 may be tightly pressed against the surface 11. The free flowing adhesive component of the lower adhesive and homogenizing layer 4 is distributed onto the nonuniformities 12 in the surface 11 of the substrate 10. The rigid protective film 5 supports the uniform and even distribution of the adhesive component on the surface. After the desired leveling operation is achieved, the protective film 5 can be removed from the top cover layer 2. The top cover layer 2 is then cured by spinning or heating to reach the final state of corrosion resistance. Thus, the substrate 10 surface 11 is finish coated. The reaction time of the adhesive compound may take several hours or even several days, but since the surface 11 is already in its final state and adequately protected from external influences, the substrate 10 can be continuously processed without requiring waiting time, which is not a problem. Do not.

In the case of the wet-curing adhesive and homogenizing layer 4, the surface 11 of the substrate 10 is sprayed with water before the coating agent 1 is applied so that a thin water film is covered.

If a heat-crosslinking system such as a polyurethane system is used as the adhesion and homogenization layer 4 and the reaction temperature is preferably about 50 ° C.-70 ° C., the required thermal threshold is that of the heat cured top cover layer 2. In the case of the top cover layer 2 which is photo-crosslinkable by heating, the case is reached by applying the coating agent 1 by heating and then heating the whole layer composition. Studies show that sufficient heating for a depth of about 2 mm is achieved by process control of 2 * 2-3 m / min, 120 W / cm.

The present invention provides, for example, a coating agent and a coating method for coating an automobile body, a body portion of a motor vehicle or a part thereof, in particular a substrate surface of a railway vehicle body, into a film shape having an upper cover layer, an intermediate coloring layer and a lower hardened support layer. Industrial availability is self-explanatory in that sense.

Claims (24)

A coating agent in the form of a film for coating a surface of a substrate having an upper cover layer, an intermediate coloring layer and a lower hardenable adhesive layer, The bottom curable adhesive layer is a free flowing adhesion and homogenization layer for bonding a film to the surface of a substrate and for depositing non-uniformities within the substrate surface, wherein the coating is provided with a flexible curable top cover layer. The method of claim 1, And wherein the lower adhesive and homogenizing layer has a layer thickness of at least 0.150 mm, preferably at least 1 mm. The method according to claim 1 or 2, Wherein the bottom adhesive and homogenization layer has viscous consistency. The method of claim 3, The lower adhesive and homogenizing layer has a thixotropic profile. The method according to any one of claims 1 to 4, And the lower adhesive and homogenizing layer is designed to form spots, lines or entire areas. The method according to any one of claims 1 to 5, Wherein the bottom adhesive and homogenizing layer is produced based on a multi-component material based on a heat-crosslinking, wet-crosslinking or photo-crosslinking polymer or epoxy cured, urethane cured or acid cured binder. The method of claim 6, The adhesive and homogenizing layer comprises a microcapsule containing moisture, preferably water. The method according to any one of claims 1 to 7, The lower adhesive and homogenizing layer is produced based on polyurethane or a mixture of multiple polyurethanes. The method according to any one of claims 1 to 8, The bottom adhesive and homogenization layer is produced based on a partially crosslinked pressure-reactive adhesive. The method according to any one of claims 1 to 8, The bottom adhesive and homogenization layer is a coating comprising a foamed adhesive web, a foamed adhesive spot, or a foamed adhesive strip. The method according to any one of claims 1 to 10, The top cover layer is a coating, characterized in that a clear lacquer layer capable of crosslinking, in particular heat-crosslinking or photo-crosslinking. The method according to any one of claims 1 to 11, And a removable protective layer is applied below the adhesive and homogenizing layer and / or over the top cover layer. The method according to any one of claims 1 to 12, The lower protective layer is a paper film and / or the upper protective layer is a polyester film or a polyolefin film, in particular a polypropylene film. A method for coating the surface of a substrate with a film having an upper cover layer, an intermediate coloring layer and a lower support layer, wherein the coating agent according to any one of claims 1 to 13 is used. The method of claim 14, The coating is applied to the surface of the substrate by a rolling and / or doctor method. The method according to any one of claims 14 to 15, Coatings having a flexible top cover layer, which is a crosslinkable, in particular heat-crosslinkable or photo-crosslinkable polymer, are used, wherein the top cover layer is thermally crosslinked or photo-crosslinked after the coating is applied to the substrate. How to feature. The method according to any one of claims 14 to 16, When using a coating with a wet-cured bottom adhesive and homogenizing layer, the surface of the substrate is covered with a liquid, preferably water, before applying the coating. The method of claim 17, Moisture, preferably water, is introduced in the form of microcapsules provided in the adhesion and homogenization layer. The method according to any one of claims 14 to 18, When using a coating having a heat-curing bottom adhesive and homogenizing layer, the substrate composition and the coating are heated. The method of claim 19, A coating having a flexible top cover layer of a heat-crosslinkable polymer is used, wherein the heat-curing bottom adhesive and homogenizing layer and the top cover layer are simultaneously crosslinked by applying the coating to the substrate and then heating the entire composition. How to. The method according to any one of claims 14 to 20, And a coating having a top protective layer removed after the coating is applied to the substrate. The method according to any one of claims 14 to 21, A coating is applied to a substrate having a non-uniformity of 0.5 mm or less and / or having a corrosion protection layer. The method according to any one of claims 14 to 22, The coating is applied to a metal substrate or a fiber reinforced material substrate. The coating of any one of claims 1 to 13 or the method of any of claims 14 to 23 is used to coat a body part of an automobile body or a motor vehicle or to coat a part, in particular a vehicle body of a railway vehicle. Characterized by using the method.