COATING SYSTEM, ITS USE FOR COATING PARTS AND PARTS SO COATED FOR RAIL AND AIR VEHICLES

Abstract

The present invention relates to improved coating agents, based on RMA systems, which crosslink by means of a classical Michael addition. These coating agents comprise at least 15 to 70% by weight of one or more acidic compounds (a), 4 to 40% by weight of one or more vinylogue carbonyl compounds (b), 0.1 to 15% by weight of one or more latent basic catalysts (c), up to 10% by weight of one or more light stabilizers, and up to 20% by weight of one or more open-time extending agents, respectively, relative to the total amount of the coating agent. The invention also relates to coatings and coating systems that can be produced from said agents, in particular primer-clear coat systems, as well as coated parts, notably parts for railway and aircraft, for example, railway cars or aircraft.

Description

[0001] The present invention relates to improved coating materials based on RMA systems, which crosslink using a classical Michael addition. The invention also relates to the coatings and coating systems that can be produced therefrom, as well as coated components, in particular components for rail and air vehicles such as railway carriages or aircraft.

[0002] Coating materials that crosslink in a Michael addition reaction are known. The coatings produced from these exhibit high weathering stability and chemical resistance. The rapid curing of these coating materials is achieved through the use of high catalyst concentrations, although this significantly reduces the processing time or pot life of the coating material.

[0003] Rapid curing is particularly advantageous when coating or painting large components, such as those in aircraft or railway carriages. However, the sheer size of the surfaces means that coating the entire component takes a relatively long time, necessitating long pot lives and long open times for the coating materials used. Pot life, as defined below, is the time between the mixing of all components of a coating material and the point at which the crosslinking reaction in the coating material has progressed to the point where the coating material can no longer be processed. Open time, as defined below, is the time during which a coating film applied to a surface can still be corrected without affecting its flow properties.

[0004] During the application of the coating material, the already coated surfaces must be able to absorb the overspray generated during the painting of adjacent surfaces without causing surface defects, such as poor flow. Overspray, in the following, refers to the material loss of the coating material caused during spray painting. This material loss can be caused by overspray due to an unfavorable orientation of the spray gun relative to the workpiece or in the case of highly perforated workpieces such as grids. Overspray can also occur due to coating material droplets flowing laterally in front of the workpiece surfaces. Overspray absorption is the property of an applied coating material to absorb material from overspray in such a way that the desired smooth surface of the film or layer is maintained.

[0005] After applying the coating material as a film or layer to a substrate surface, rapid drying or curing is desirable for coating. Forced drying at elevated temperatures is generally not feasible for large components, as this would require correspondingly large ovens. Therefore, rapid drying at room temperature is particularly advantageous when coating or painting very large components.

[0006] WO 2013 / 050623 discloses a crosslinkable composition comprising a component with at least two CH-acidic protons in activated methylene or methine groups, a component with at least two activated unsaturated groups and a catalyst system that contains or can generate a basic Michael addition catalyst.

[0007] From EP 2374836 A1, crosslinking binder systems, hereinafter referred to as RMA systems, are known which exhibit a favorable pot life to drying time ratio. The described binder systems show short drying times even at room temperature, despite long pot lives. EP 2374836 A1 is hereby expressly incorporated into this description. A disadvantage of the known RMA systems is that the coatings and materials produced from them do not exhibit the required and usual properties.

[0008] It is therefore an object of the present invention to provide improved coating materials, coatings and coating systems based on RMA systems, which are particularly suitable for coating components of aircraft and rail vehicles.

[0009] This problem is solved by coating materials for producing a coating according to the main claim. Further embodiments are disclosed in the dependent and sub-claims and the description.

[0010] The coating materials according to the invention comprise at least one RMA system which has one or more CH-acidic compounds A, one or more vinylogous carbonyl compounds B and one or more latent basic catalysts C, as well as one or more light stabilizers, one or more pot life extenders and one or more open time extenders.

[0011] In the following, the term "light stabilizer" refers to additives and auxiliaries that protect coatings against the effects of UV light, in particular preventing or at least significantly delaying polymer degradation caused by UV radiation. The term "pot life extender" refers to additives and auxiliaries that, as components of the ready-to-use coating material, delay the curing of the coating material before application. They evaporate during application, so that the curing of the applied coating material is not impaired, and in particular, not prolonged. The term "open time extender" refers to additives and auxiliaries that remain in the coating material even after application and delay its curing for coating.

[0012] The coating materials according to the invention contain at least 15 to 70, preferably 20 to 60, particularly preferably 25 to 55 wt.%, one or more CH-acidic compounds A, selected from compounds of the formula wherein R is hydrogen, an alkyl or aryl group, Y is an alkyl, aralkyl, aryl, alkoxy group or an amino group, and Y' is an alkyl, aralkyl, aryl, alkoxy group or an amino group, 4 to 40, preferably 8 to 35, particularly preferably 10 to 30 wt.%, one or more vinylogous carbonyl compounds B selected from acrylates and maleates, 0.1 to 15, preferably 0.2 to 10, particularly preferably 0.3 to 5 wt.%, one or more latent basic catalysts C, 0.00001 to 10, preferably 0.5 to 5, particularly preferably 1 to 3 wt.%, one or more light stabilizers selected from the group comprising radical scavengers, UV absorbers, quenchers and peroxide decomposers, 0.00001 to 20, preferably 0.01 up to 10, particularly preferably 0.1 to 5 wt.%, one or more open time extenders selected from the group comprising basic NH functional compounds with pKa values ​​between 4 and 14, and, 0.00001 to 20, preferably 0.01 to 15, particularly preferably 0.1 to 10 wt.%.-%, one or more pot life extenders selected from the group containing alcohols with up to 6 carbon atoms and evaporation rates below 35. each in relation to the total quantity of the coating material.

[0013] Furthermore, the coating materials according to the invention can 0 to 70, preferably 0.00001 to 65, particularly preferably 0.00001 to 40 wt.%, pigments; 0 to 25, preferably 0.00001 to 8, particularly preferably 0.00001 to 5 wt.%, dispersing additives; 0 to 60, preferably 0.00001 to 40, particularly preferably 0.00001 to 30 wt.%, functional fillers; and 0 to 50, preferably 0.00001 to 40, particularly preferably 0.00001 to 30 wt.%, aprotic solvents. where the quantities given refer to the total quantity of the coating material.

[0014] According to the invention, compounds A and B are used in an A:B stoichiometric ratio of 0.5:1 to 2:1, preferably of 0.75:1 to 1.6:1, particularly preferably of 0.9:1 to 1.3:1, and most preferably of 0.95:1 to 1.1:1, wherein the amounts of substance are based on the acidic protons of compounds A and on the vinylogous carbonyl groups of compounds B.

[0015] According to the invention, the catalysts C and compounds A are used in a molar ratio C:A of 0.8:1 to 2.5:1, preferably 1.1:1 to 1.9:1, particularly preferably 1.3:1 to 1.7:1, wherein the amounts of substance are based on the cation X +< of the catalyst C and the acidic protons of the compounds A.

[0016] Suitable CH-acidic compounds A according to the invention are malonic acid esters, acetoacetic acid esters, or mixtures thereof. Malonic acid esters with oligomeric and polymeric substituents, for example, based on polyesters, polyurethanes, polyacrylates, epoxy resins, polyamides, or polycarbonates, are particularly preferred. The acetoacetic acid esters used preferably contain oligomeric and polymeric substituents, for example, based on polyalcohols, polyvinyl alcohols, epoxy resins, hydroxy-functional polyethers, polyesters, or polyacrylates. Acetoacetic acid esters with oligomeric and polymeric substituents based on polyesters and / or polyacrylates are particularly preferred.Particularly preferred are compounds selected from the group containing malonic acid esters with oligomeric and polymeric substituents based on polyesters, obtained from the reaction of at least malonic acid, dimethyl malonic ester and / or diethyl malonic ester with hexahydrophthalic acid and / or its anhydride and neopentyl glycol, as well as acetoacetic acid esters with oligomeric and polymeric substituents based on polyesters, obtained from the reaction of at least acetoacetic acid, methyl acetoacetic acid and / or ethyl acetoacetic acid with hexahydrophthalic acid and / or its anhydride and neopentyl glycol.

[0017] Suitable vinylogous carbonyl compounds B according to the invention are, for example, unsaturated acryloyl-functionalized acrylates and / or maleates. Acrylic esters of compounds containing 1 to 20 carbon atoms and at least 2, preferably 2 to 6, hydroxyl groups are preferred according to the invention. Polyesters of maleic acid, fumaric acid, and / or itaconic acid or their anhydrides reacted with di- or polyvalent hydroxyl compounds, which may contain a monovalent hydroxyl or carboxyl compound, are also preferred according to the invention. Resins such as polyesters, polyurethanes, polyethers, and / or alkyd resins containing appropriately activated unsaturated groups, such as urethane acrylates, polyether acrylates, polyfunctional polyacrylates, polyalkyl maleates, and polyacrylates obtained from the reaction of acrylic acid with epoxy resins, are also preferred according to the invention.According to the invention, butanediol diacrylate, hexanediol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate and ditrimethylolpropane tetraacrylate and dipentaerythritol hexaacrylate as well as dipropylene glycol diacrylate and tripropylene glycol diacrylate are particularly preferred.

[0018] Suitable latent basic compounds for catalysts C are, for example, substituted carboxylic acid salts of formula II: wherein R is hydrogen, alkyl or aralkyl (Ar-R) or a polymer, X +< is an alkali or alkaline earth metal cation, in particular lithium, sodium or potassium, or a quaternary ammonium or phosphonium salt of formula (R') 4 Y +<, wherein YY is nitrogen or phosphorus, R' is equal or different from hydrogen, alkyl, aral or aralkyl or a polymer and wherein R and R' can form a ring structure or R and R' can be a polymer.

[0019] According to the invention, R is preferably an alkyl group or an aralkyl group, particularly preferably an alkyl group with 1 to 4 carbon atoms. The carbonate group and the cation X< can also be present on a molecule with the corresponding structure. Furthermore, R' is preferably an alkyl group, particularly preferably an alkyl group with 1 to 4 carbon atoms, and especially preferably with 3 to 4 carbon atoms. According to the invention, ammonium and / or phosphonium carbonates are preferably used.Suitable ammonium carbonates include, for example, tetrahexylammonium methyl carbonate, tetrahexylammonium hydrogen carbonate, tetradecanyltrihexylammonium methyl carbonate, tetradecylammonium methyl carbonate, tetrabutylammonium methyl carbonate, tetrabutylammonium ethyl carbonate, tetrabutylammonium hydrogen carbonate, tetrapropylammonium methyl carbonate, tetrapropylammonium ethyl carbonate, tetrapropylammonium hydrogen carbonate, benzyltrimethylammonium methyl carbonate, trihexylammonium methyl carbonate, and trioctylammonium methyl carbonate. Tetrabutylammonium methyl carbonate, tetrabutylammonium ethyl carbonate, tetrabutylammonium hydrogen carbonate, tetrapropylammonium methyl carbonate, tetrapropylammonium ethyl carbonate, tetrapropylammonium hydrogen carbonate, and mixtures thereof are particularly preferred.

[0020] Suitable light stabilizers include radical scavengers such as sterically hindered aliphatic amines, e.g., based on substituted 2,2,6,6-tetramethylpiperidines; UV absorbers such as 2-hydroxyphenylbenztriazoles, 2-hydroxybenzophenones, 2-hydroxyphenyltriazines, or oxalanilides; as well as quenchers such as organonickel compounds and peroxide decomposers such as thioethers or phosphites. Radical scavengers, for example, sterically hindered aliphatic amines based on substituted 2,2,6,6-tetramethylpiperidines, and / or UV absorbers, for example, 2-hydroxyphenylbenztriazoles, 2-hydroxybenzophenones, 2-hydroxyphenyltriazines, and oxalanilides, are preferred. Substituted 2,2,6,6-tetramethylpiperidines, 2-hydroxyphenyltriazines, 2-hydroxybenzophenones, and mixtures thereof are particularly preferred.

[0021] Suitable pot life extenders are alcohols with up to 6, preferably up to 4, particularly preferably up to 3 carbon atoms, which have an evaporation number below 35, preferably below 20. According to the invention, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol and mixtures thereof can be used.

[0022] Suitable open-time extenders are basic NH-functional compounds with a pKa value between 4 and 14. Succinimides, 1,2,4-triazoles, 1,2,3-benzotriazoles, 5,5-diphenylhydantoins, hydantoins, (RS)-3-ethyl-3-methylpyrrolidine-2,5-dione, and mixtures thereof are preferred. Succinimides, 1,2,4-triazoles, 1,2,3-benzotriazoles, and mixtures thereof are particularly preferred.

[0023] In a further embodiment of the present invention, inorganic and / or organic pigments can be added to the coating materials to produce a color-imparting coating. Further additives, such as dispersing additives and functional fillers, can also be added to improve the required properties of the coating material and / or the coating.

[0024] Inorganic and / or organic pigments can be added to the coating materials according to the invention in amounts up to 70%, preferably 0.00001% to 65%, and particularly preferably 0.00001% to 40% by weight, the amounts of which refer to the total amount of the coating material. Suitable inorganic pigments include, for example, titanium dioxide, iron oxides, chromium oxides, chromium titanates, bismuth vanadate, cobalt blue, and carbon black. Titanium dioxide, iron oxides, and carbon black are preferred inorganic pigments. Suitable organic pigments include, for example, Pigment Yellow 151, Pigment Yellow 213, Pigment Yellow 83, Pigment Orange 67, Pigment Orange 62, Pigment Orange 36, Pigment Red 170, Pigment Violet 19, Pigment Violet 23, Pigment Blue 15:3, Pigment Blue 15:6, and Pigment Green 7. The pigments used most frequently are Pigment Yellow 151, Pigment Orange 67, Pigment Red 170, Pigment Violet 19, Pigment Blue 15:3, and Pigment Green 7.

[0025] In a further embodiment, the coating materials can additionally contain up to 25%, preferably 0.00001 to 8%, and particularly preferably 0.00001 to 5% by weight of dispersing additives, the quantities of which refer to the total amount of the coating material. Suitable dispersing additives are, for example, high-molecular-weight block copolymers with pigment-affine groups, highly branched polyesters, and acrylate-polyester copolymers with pigment-affine groups. High-molecular-weight block copolymers with pigment-affine groups are preferred dispersing additives.

[0026] In a further embodiment, the coating materials can additionally contain up to 60, preferably 0.00001 to 50, particularly preferably 0.00001 to 40 wt.% functional fillers, the quantities of which refer to the total quantity of the coating material. Suitable fillers include carbonates such as chalk, limestone flour, calcite, precipitated calcium carbonate, dolomite, barium carbonate; sulfates such as barite, blanc fixe, calcium sulfate; silicates such as talc, pyrophyllite, chlorite, hornblende, mica, kaolin, wollastonite, slate flour, precipitated calcium silicates, precipitated aluminum silicates, precipitated calcium aluminum silicates, precipitated sodium aluminum silicates; feldspars; mullite; silicas such as quartz, quartzite, cristobalite, diatomaceous earth, silica, precipitated silica, pumice flour, perlite, calcium metasilicates; fibers from melts of glass or basalt; glass flour; glass beads; and slag. Preferred fillers are barium sulfate and / or talc.

[0027] In further embodiments of the invention, the coating materials additionally contain up to 50%, preferably 0.00001 to 40%, and particularly preferably 0.00001 to 30% by weight of aprotic solvents, the quantities referring in each case to the total amount of the coating material. In the following, the term aprotic solvents is understood to mean solvents that do not contain an ionizable proton in the molecule. Suitable aprotic solvents are, for example, aliphatic hydrocarbons, cycloaliphatic hydrocarbons, aromatic hydrocarbons, ketones, esters, ethers, and ether esters, in particular ethyl acetate, butyl acetate, acetone, n-butanone, methyl isobutyl ketone, methoxypropyl acetate, and dimethyl sulfoxide. Preferably used solvents are ethyl acetate, butyl acetate, acetone, n-butanone, methyl isobutyl ketone, methoxypropyl acetate, and mixtures thereof.

[0028] The compounds used as catalysts C according to the invention are latent bases, since the carbonate salt according to formula II is in equilibrium with its dissociation products carbon dioxide and the corresponding hydroxide or alkoxy base. As long as carbon dioxide cannot escape from the system, the equilibrium lies on the side of the carbonate salt. Only when carbon dioxide is removed and thus a sufficient amount of base is present does crosslinking begin via Michael addition. If the coating materials according to the invention are stored in closed containers from which carbon dioxide cannot escape, the coating material can generally be formulated as a single-component system. However, storage stability can be increased if the individual components of the coating material according to the invention are formulated in multi-component systems.For example, a catalyst component containing catalysts C can be mixed with the binder components containing CH-acidic compounds A and vinylogous carbonyl compounds B only shortly before processing.

[0029] According to the invention, the CH-acidic compounds A and the vinylogous carbonyl compounds B, together with the light stabilizers, open time extenders, and pot life extenders, can be contained in a binder component. This binder component can further contain pigments, additional additives, and solvents. The catalysts C, and optionally further solvents and pot life extenders, can be contained in a catalyst component. In a preferred embodiment, the CH-acidic compounds A can be present in a first binder component, the vinylogous carbonyl compounds B in a second binder component, and the catalysts C in a catalyst component. In such a three-component system, the CH-acidic compounds A, together with the open time extenders and light stabilizers, are preferably contained in the first binder component.Optionally, this first binder component may also contain pigments, fillers, and additional additives. The second binder component preferably contains the vinylogous carbonyl compounds B. Furthermore, the second binder component may also contain pigments, fillers, and additional additives. The catalyst component contains the catalysts C. Furthermore, the catalyst component may contain solvents and pot life extenders.

[0030] It is known that the addition of other components commonly used in the production of a coating reduces the storage stability of RMA systems. The coating materials according to the invention, with their specific selection of light stabilizers, open time extenders, pot life extenders, pigments, dispersing additives, functional fillers, and aprotic solvents, exhibit unexpectedly high storage stability compared to previously known coating materials based on RMA systems.

[0031] Furthermore, the properties of coatings made from coating materials based on RMA systems, unlike coatings made from coating materials based on conventional binders such as epoxy resins or polyurethanes, are significantly and negatively affected by the presence of other components in the coating material. Surprisingly, it has been found that the coating materials according to the invention result in coatings that exhibit the properties required for use in components of rail and aircraft, in particular gloss retention, mechanical stability, and light stability.

[0032] In a particularly preferred embodiment, the coating materials according to the invention comprise at least 15 to 70, preferably 20 to 60, particularly preferably 25 to 55 wt.% malonic acid esters with oligomeric and polymeric substituents based on polyesters obtained from the reaction of at least malonic acid, dimethyl malonic ester and / or diethyl malonic ester with hexahydrophthalic acid and / or its anhydride and neopentyl glycol, as well as acetoacetic acid esters with oligomeric and polymeric substituents based on polyesters obtained from the reaction of at least acetoacetic acid, methyl acetoacetic acid and / or ethyl acetoacetic acid with hexahydrophthalic acid and / or its anhydride and neopentyl glycol, as CH-acidic compounds A 4 to 40, preferably 8 to 35, particularly preferably 10 to 30 wt.-% butanediol diacrylate, hexanediol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate and / or dipentaerythritol hexaacrylate as vinylogous carbonyl compounds B, 0.1 to 15, preferably 0.2 to 10, particularly preferably 0.3 to 5 wt.% tetrabutylammonium methyl carbonate, tetrabutylammonium ethyl carbonate, tetrabutylammonium hydrogen carbonate, tetrapropylammonium methyl carbonate, tetrapropylammonium ethyl carbonate, tetrapropylammonium hydrogen carbonate or mixtures thereof as latent basic catalysts C, 0.00001 to 10, preferably 0.5 to 5, particularly preferably 1 to 3 wt.% substituted 2,2,6,6-tetramethylpiperidines, 2-hydroxyphenyltriazines, 2-hydroxybenzophenones or mixtures thereof as light stabilizers, 0.00001 to 20, preferably 0.01 to 10, particularly preferably 0.1 to 5 wt.% succinimides, 1,2,4,-triazoles, 1,2,3,-benzotriazoles or mixtures thereof as open time extenders, 0.00001 to 20, preferably 0.01 to 15, particularly preferably 0.1 to 10 wt.-% methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol or mixtures thereof as pot life extenders, 0 to 50, preferably 0.00001 to 40, particularly preferably 0.00001 to 30 wt% ethyl acetate, butyl acetate, acetone, n-butanone, methyl isobutyl ketone, methoxypropyl acetate or mixtures thereof as aprotic solvents, . where the quantities given refer to the total quantity of the coating material.

[0033] In a further particularly preferred embodiment, the coating materials according to the invention have at least 15 to 70, preferably 20 to 60, particularly preferably 20 to 55 wt.% malonic acid esters with oligomeric and polymeric substituents based on polyesters obtained from the reaction of at least malonic acid, dimethyl malonic ester and / or diethyl malonic ester with hexahydrophthalic acid and / or its anhydride and neopentyl glycol, as well as acetoacetic acid esters with oligomeric and polymeric substituents based on polyesters obtained from the reaction of at least acetoacetic acid, methyl acetoacetic acid and / or ethyl acetoacetic acid with hexahydrophthalic acid and / or its anhydride and neopentyl glycol, as CH-acidic compounds A, 4 to 40, preferably 8 to 35, particularly preferably 10 to 30 wt.-% butanediol diacrylate, hexanediol diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate and / or dipentaerythritol hexaacrylate as vinylogous carbonyl compounds B, 0.1 to 15, preferably 0.2 to 10, particularly preferably 0.3 to 5 wt.% tetrabutylammonium methyl carbonate, tetrabutylammonium ethyl carbonate, tetrabutylammonium hydrogen carbonate, tetrapropylammonium methyl carbonate, tetrapropylammonium ethyl carbonate, tetrapropylammonium hydrogen carbonate or mixtures thereof as vinylogous carbonyl compounds B, 0.00001 to 10, preferably 0.5 to 5, particularly preferably 1 to 3 wt.% substituted 2,2,6,6-tetramethylpiperidines, 2-hydroxyphenyltriazines, 2-hydroxybenzophenones or mixtures thereof as light stabilizers, 0.00001 to 20, preferably 0.01 to 10, particularly preferably 0.1 to 5 wt.% succinimides, 1,2,4,-triazoles, 1,2,3,-benzotriazoles or mixtures thereof as open time extenders, 0.00001 to 20, preferably 0.01 to 15, particularly preferably 0.1 to 10 wt.-% Methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol or mixtures thereof as pot life extenders, 0 to 70, preferably 0.00001 to 65, particularly preferably 0.00001 to 40 wt% titanium dioxide, iron oxides, carbon blacks, Pigment Yellow 151, Pigment Orange 67, Pigment Red 170, Pigment Violet 19, Pigment Blue 15:3, Pigment Green 7 or mixtures thereof as pigments, 0 to 25, preferably 0.00001 to 8, particularly preferably 0.00001 to 5 wt% high molecular weight block copolymers with pigment-affine groups as dispersing additives, 0 to 60, preferably 0.00001 to 40, particularly preferably 0.00001 to 30 wt% barium sulfate and / or talc as functional additives Fillers and 0 to 50, preferably 0.00001 to 40, particularly preferably 0.00001 to 30 wt.% ethyl acetate, butyl acetate, acetone, n-butanone, methyl isobutyl ketone, methoxypropyl acetate or mixtures thereof as aprotic solvents. where the quantities given refer to the total quantity of the coating material.

[0034] The coating materials according to the invention can be used to produce coating systems comprising two or more layers. The coating materials according to the invention can be used to produce at least one layer or coating. In a preferred embodiment, the coating materials are used to produce a two-layer system; they are particularly preferably used to produce a basecoat-clearcoat system. In the following, clearcoats are defined as coating materials and coatings that do not contain colorants. Basecoats are defined as coating materials and coatings that contain colorants such as dyes or pigments. Basecoat-clearcoat systems are also frequently used in aircraft and rail vehicles because they are very weather-resistant, especially with regard to gloss retention.

[0035] The coating materials and coatings according to the invention surprisingly exhibit significantly higher storage stability compared to previously known RMA coating materials and coatings. They also show improved drying behavior. Furthermore, the coatings obtained from the coating materials according to the invention exhibit improved light stability, in particular less yellowing and higher gloss retention.

[0036] The coating materials according to the invention have pot lives greater than or equal to 1 hour, preferably greater than or equal to 2 hours, and particularly preferably between 2 and 4 hours. The pot life is usually determined by measuring the flow time from a flow cup. The end of the pot life is defined as the point in time at which the flow time is twice the initial flow time. The test method is described in detail in the examples below. Furthermore, the coating materials according to the invention exhibit open times of greater than or equal to 15 minutes, preferably greater than 20 minutes, and particularly preferably greater than or equal to 25 minutes. In addition to the long pot lives and open times, the coating materials according to the invention surprisingly exhibit an unusually wide climatic window in which they can be processed without impairment. For example, they can be processed at temperatures up to 45°C and at relative humidity up to 99%.Furthermore, they show a long overspray recording, for example over a period of more than 25 minutes.

[0037] In contrast to conventional polyurethane-based coatings, the coatings according to the invention exhibit significantly shorter drying times. Furthermore, the coatings according to the invention can be masked more quickly; that is, they are sufficiently cured at room temperature within 1 to 4 hours after application to allow, for example, the application of stencils, which can then be removed after the pattern has been painted without damaging the coating. Stencils are typically used to apply colored decorations and patterns to a coating.

[0038] Due to their properties, the coating materials according to the invention are particularly suitable for use in coating large components. They are especially suitable for coating large-area components such as those used, for example, in railway carriage and aircraft construction.

[0039] The present invention also relates to methods for coating components. The methods according to the invention comprise the steps (a) applying the coating material according to the invention to the surface of a substrate and (b) curing the applied coating material for 1 to 12, preferably 1 to 6, particularly preferably 1 to 4 hours at temperatures between 5 to 45, preferably 15 to 40, particularly preferably 20 to 35 °C.

[0040] The coating materials according to the invention have above-average solids contents and, accordingly, contain low proportions of volatile organic substances such as solvents. The solids content is defined as the mass fraction of a coating material that remains as residue after evaporation at 105 °C for 30 minutes. The solids typically consist mainly of binders, non-volatile additives, pigments, and fillers. The solids contents of the coating materials according to the invention are between 65 and 95%, preferably between 70 and 90%, and particularly preferably between 75 and 85% by weight, based on the total weight of the coating material.

[0041] Coating materials with high solids content are typically difficult to process using conventional spraying methods. In contrast, the coating materials according to the invention can be readily applied using high-pressure hydraulic spraying (airless), airless spraying with air assistance (airmix), as well as pneumatic or compressed air spraying. Surprisingly, these application methods also achieve high-quality surfaces. Electrostatically assisted airspray or airmix processes are particularly suitable according to the invention.

[0042] Suitable substrates include metals such as aluminum, aluminum alloys, steels and iron alloys, plastics, and glass and carbon fiber reinforced composites. The component surfaces to be coated may be primed, such as the usual epoxy resin or polyurethane-based primers known to those skilled in the art.

[0043] In the case of coating materials according to the invention, which have several components, all components are mixed before application. The mixing can be carried out manually or mechanically. In a further embodiment, a coating system with at least one additional coating can be produced by applying and curing further coating materials on the first coating.

[0044] In a preferred embodiment of the method according to the invention, a coating system is produced in a two-layer structure. First, a base coat is applied and cured; then a clear coat is applied to this coating and cured. The base coat or clear coat, or both, can be produced from the coating materials according to the invention.

[0045] The coatings according to the invention have a dry film thickness of 20 to 150 µm. Low dry film thicknesses with high opacity are particularly suitable for coating components for the aerospace industry, as this allows for weight savings.

[0046] Since the coating materials according to the invention can be cured at room temperature, they are particularly suitable for coating large components, such as those used in the construction of aircraft and railway carriages. They are especially suitable for coating fuselage sections, wings, radomes, vertical stabilizers, horizontal stabilizers, engine nacelles, winglets and landing flaps, as well as for power units, carriage parts, roofs, doors and landing gear fairings. They are also suitable for coating interior components of rail and aircraft, such as ceiling panels, wall coverings, floor panels, hatch panels and doors. Examples

[0047] The coating materials are manufactured according to paint-related standards known and understood by those skilled in the art. The catalyst solution used in example formulations 1 and 2 is prepared by adding 42.8 g of diethyl carbonate and 26.1 g of isopropanol to a solution of 17.1 g of tetrabutylammonium hydroxide in 14 g of water. Example recipe 1: Clear varnish substance Quantity [wt.%] Binder component Malonate-functional polyester with an acid proton concentration of 5.66 mol / kg based on the solvent-free polyester, 85% in butyl acetate 52 Di-trimethylolpropane tetraacrylate 23 Hexanediol diacrylate 5,5 Bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate 3 Succinimid 1,5 Methyl ethyl ketone 6 catalyst component catalyst solution 6 Isopropanol 3 Example formula 2: Base coat substance Quantity [wt.%] Binder component 1 Malonate-functional polyester with an acid proton concentration of 5.66 mol / kg based on the solvent-free polyester, 85% in butyl acetate 31 titanium dioxide 35 high molecular weight block copolymer with pigment-affine groups 1 Bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate 1 Succinimid 1 Butyl acetate 4, 5 Binder component 2 Ditrimethylolpropane tetraacrylate 14 Hexanediol diacrylate 3 catalyst component catalyst solution 3, 5 Isopropanol 2 Methyl ethyl ketone 4

[0048] To assess the storage stability of the coating materials according to the invention, the pot life and drying time of example formulation 2 were determined. Samples were tested after 1 day of storage at 23 °C, after 28 days of storage at 40 °C, and after 1 year of storage at 20 to 23 °C, and were also used to produce a coating.

[0049] Pot life determination: The pot life is determined using a flow cup test. In this method, a liquid is poured into a cup of defined volume, which has a defined nozzle in its base. The coating material flows out of the nozzle, and the time from the point of exit until the liquid stream stops is measured as the flow time. All preparation and measurements are carried out at a temperature of 23 °C. First, all components of the coating material are mixed, and the flow time of the mixture is immediately measured (start flow time). The measurement is repeated at regular intervals. The end of the pot life is reached when the flow time is twice the start flow time.

[0050] Determining Drying Time: To determine the drying time, a drying time recorder, specifically a drying time measuring device from BYK Gardener, is used. The coating material under investigation is applied evenly to glass strips using a film puller. The glass strips are then placed in a linear recorder. Needles are then placed on the coating and drawn across the drying film at a defined, constant speed. This produces a characteristic drying pattern of the coating, in which the individual time intervals show the different curing stages: open time, baseline, film break, and surface mark. Curing of the coating material begins at the end of the open time, i.e., when the mark etched into the applied film by the needle remains visible. It ends with the surface mark, i.e., when the mark disappears.at the point in time when the needle no longer leaves a visible trace in the applied film.

[0051] To assess the storage stability of the coating material, the properties of coatings produced from differently stored samples of Example Formulation 2 were also investigated. Gloss and elongation at break were determined for this purpose. Samples were taken after 1 day of storage at 23 °C, after 28 days of storage at 40 °C, and after 1 year of storage at 20–23 °C to produce a coating. Example Formulation 2 was applied to primed aluminum plates using a cup gun and cured at room temperature to prepare the test specimens.

[0052] Determination of surface gloss: The gloss of the coating surface is determined as a reflectometer value. The reflectometer value of a sample is defined as the ratio of the luminous fluxes reflected in the mirror direction by the sample surface and a glass surface with a refractive index of 1.567. The measurements are taken using a standard reflectometer at an angle of 60°.

[0053] Determination of elongation at break: The elongation at break is determined by mandrel bending test. For this test, the specimens are bent around a mandrel. The smaller the radius of the mandrel around which the plate can be bent without damaging or breaking the coating, the greater the elongation at break of the coating. The diameter of the mandrel is given as the measured value. Table: Storage stability of example recipe 2 storage 1 day, 24°C 28 days, 40°C 1 year, 20 - 23 °C Potting time 2,5 h 2,5 h 2,5 h Opening hours 59 min 60 min 56 min End of surface track 136 min 132 min 128 min Elongation at break 12 mm 12 mm 12 mm shine 87 88 87

[0054] As the table shows, the coating materials according to the invention exhibit high storage stability. After prolonged storage at elevated temperatures, the coating materials themselves show no deterioration in their processability. The coatings produced from them also show no impairment of their properties.

Claims

1. Coating material for the production of a coating containing at least - 15 to 70 % by weight of at least one CH-acidic compound A selected from compounds of the formula with R being hydrogen, an alkyl group or aryl group, Y being an alkyl group, aralkyl group, aryl group, alkoxy group or an amino group, and with Y' being an alkyl group, aralkyl group, aryl group, alkoxy group or an amino group, - 4 to 40 % by weight of at least one vinylogous carbonyl compound B selected from acrylates and maleates, - 0.1 to 15 % by weight of at least one latent base catalyst C, - 0.00001 to 10 % by weight of at least one light stabilizer selected from the group comprising free-radical scavengers, UV absorbers, quenching agents and peroxide decomposers, - 0.00001 to 20 % by weight of at least one open-time extender selected from the group comprising basic NH functional compounds with a pKa value of between 4 and 14, and, - 0.00001 to 20 % by weight of at least one pot life extender selected from the group comprising alcohols with up to 6 carbon atoms, and showing an evaporation number of below 35. each based on the total quantity of the coating material.

2. Coating material as defined in claim 1, characterized in that it furthermore contains up to 70 % by weight of at least one inorganic and / or organic pigment.

3. Coating material as defined in claim 2, characterized in that the pigments are selected from the group comprising titanium dioxide, iron oxides, chromium oxides, chromium titanates, bismuth vanadate, cobalt blue, carbon blacks, pigment yellow 151, pigment yellow 213, pigment yellow 83, pigment orange 67, pigment orange 62, pigment orange 36, pigment red 170, pigment violet 19, pigment violet 23, pigment blue 15:3, pigment blue 15:6 and pigment green 7.

4. Coating material as defined in one of the preceding claims, characterized in that the catalysts C are substituted carboxylic acid salts of the formula wherein R is hydrogen, an alkyl group or aralkyl group or a polymer group, X+ is an alkali metal cation, an alkaline earth metal cation or a quaternary ammonium salt or phosphonium salt of the formula (R')4Y+, wherein Y is nitrogen or phosphorus, R' is the same or different, is hydrogen, an alkyl group, an aryl group or an aralkyl group or a polymer and wherein R and R' form a ring structure or are a polymer.

5. Coating material as defined in one of the preceding claims, characterized in that the light stabilizers are substituted 2,2,6,6-tetramethylpiperidines, 2-hydroxyphenyl benzotriazoles, 2-hydroxybenzophenones, 2-hydroxyphenyltriazines, oxalanilides, organic nickel compounds, thioethers and / or phosphites.

6. Coating material as defined in one of the preceding claims, characterized in that the coating material contains 0.5 to 5 % by weight, preferably 1 to 3 % by weight, of light stabilizers, based on the total quantity of the coating material.

7. Coating material as defined in one of the preceding claims, characterized in that the pot-life extenders are alcohols with up to 4 carbon atoms.

8. Coating material as defined in one of the preceding claims, characterized in that the coating material contains 0.01 to 15 % by weight, preferably 0.1 to 10 % by weight, of pot-life extenders, based on the total quantity of the coating material.

9. Coating material as defined in one of the preceding claims, characterized in that the open-time extenders are succinimides, 1,2,4,-triazoles, 1,2,3,-benzotriazoles, 5,5-diphenylhydantoins, hydantoins and / or (RS)-3-ethyl-3-methylpyrrolidine-2,5-dione.

10. Coating material as defined in one of the preceding claims, characterized in that the coating material contains 0.01 to 10 % by weight, preferably 0,1 to 5 % by weight, of open-time extenders, based on the total quantity of the coating material.

11. Coating material as defined in one of the preceding claims, characterized in that the coating material furthermore contains up to 25 % by weight of at least one dispersing additive.

12. Coating material as defined in one of the preceding claims, characterized in that the coating material furthermore contains up to 60 % by weight of at least one functional filler.

13. Coating material as defined in one of the preceding claims, characterized in that the coating material furthermore contains up to 50 % by weight of at least one aprotic solvent.

14. Use of the coating material as defined in any one of claims 1 to 13 for the production of at least one coating in a coating system.

15. Use as defined in claim 14, characterized in that at least one base coat is produced from a coating material as defined in any one of claims 2 to 13.

16. Use as defined in claim 14, characterized in that at least one transparent lacquer is produced from a coating material as defined in any one of claims 1 and 4 to 13.

17. Method for coating a component, the method comprising the steps a) applying the coating material as defined in any one of claims 1 to 13 to a substrate and (b) curing the applied layer for a duration of 1 to 12 hours at a temperature of between 5 and 45 °C.

18. Method as defined in claim 17, characterized in that the coating material in step (a) is applied by means of a spraying method.

19. Component coated with at least one coating produced from a coating material as defined in any one of claims 1 to 13.

20. Component as defined in claim 19, characterized in that the component is a rail vehicle component or an aircraft component.