UV protective film for outdoor use

Abstract

A process for manufacturing a UV protective film comprises the following steps: - Providing a base film made of polyvinyl chloride, polyacrylate or polyolefin, which has a printed design and / or coloring of the base film, - Application of an abrasion-resistant polyurethane-based melt coating above the base layer, and - Application of a lacquer and / or a polymer protective layer above the abrasion-resistant melt coating, wherein the abrasion-resistant polyurethane-based melt coating and / or the lacquer and / or an applied intermediate layer of a polyurethane-based reactive melt compound is embossed by application using a pair of rollers with a structured roller.

Description

[0001] The present invention relates to UV protection films for outdoor use, especially for coating building elements such as floor coverings, in particular decking, which are intended for outdoor use.

[0002] A key trend in recent years has been high-quality outdoor building elements. More and more people are transforming patios, balconies, and outdoor seating areas into additional "living space." This includes not only appropriate furniture but also comfortable flooring, privacy screens, fences, planters, and much more. While the look of natural stone and wood is widely preferred, there is a demand for easier-care surfaces.

[0003] These requirements can be met using plastics. In addition to the use of solid plastic, and more recently also so-called WPC (wood plastic composite) materials, the coating of substrates has long been known. This has also been very successful for elements such as walls or fences. However, in floor coverings, the resistance has so far been insufficient and / or other defects have arisen. For example, the laminating films familiar from furniture and floor panels for indoor use have the problem that decorative papers fade due to the lack of UV protection of the top layer(s), and the surface is often too smooth, meaning that the slip resistance required for outdoor flooring is not achieved.

[0004] For indoor use, DE 10 2012 022 461 A1 proposes a coating material for which a pressure-, temperature-, and dimensionally stable print substrate is laminated in a belt press with a wear layer comprising an inner, transparent, corundum-containing layer in contact with the print substrate and an outer layer comprising at least one plastic layer. The outer surface can be embossed during or after lamination. Such coating materials are not suitable for outdoor use without modification.

[0005] The task therefore remains to provide easy-care and durable surfaces with the desired appearance for outdoor areas.

[0006] According to the unpublished application PCT / EP 2021 / 078028, printed base films made of PVC, polyacrylate, or polyolefin, which are coated with an abrasion-resistant polyurethane-based hot-melt coating and varnished, offer effective UV protection and thus achieve the necessary durability of the printed design. Slip resistance is ensured by embossing in combination with the abrasion-resistant PUR hot-melt coating. In a preferred variant, the embossing is particularly easily achieved by an embossed intermediate layer beneath the PUR hot-melt coating. The films are manufactured according to PCT / EP 2021 / 078028 by applying a polyurethane-based hot-melt coating to a base film made of PVC, polyacrylate, or polyolefin that has been printed and / or colored with a design, and applying a varnish and / or a polymer protective layer over the hot-melt coating, with a layer being embossed beneath the varnish.However, embossing represents an additional step that involves considerable effort. EP 3 288 688 B1 also describes the process of producing structured surfaces by embossing a moisture-curing, polyurethane-based reactive hot melt compound previously applied to a substrate.

[0007] Surprisingly, it has now been found that the desired structuring is also possible by applying the hot-melt coating and / or varnish using a structured roller instead of embossing. This makes production much easier. The above problem is solved by a process for producing UV protection films, in which a base film made of PVC, polyacrylate or polyolefin, which is printed with a design and / or colored, is provided, optionally an intermediate layer made of a reactive hot-melt mass based on polyurethane is applied above the base film, above the base film or if necessary.A layer of a polyurethane-based abrasion-resistant melt coating is applied above the intermediate layer, and a varnish and / or a polymer protective layer is applied over it. The abrasion-resistant polyurethane-based melt coating, the intermediate layer, or the varnish, or two of them, or all three, is applied by a pair of rollers with a textured roller and provided with a texture by the textured roller. This object is also achieved by a UV protection film comprising: - a base film made of PVC, polyacrylate or polyolefin, - a printed design and / or coloring of the base film, - a smooth intermediate layer of a first melt coating based on polyurethane - a layer of an abrasion-resistant, second melt coating based on polyurethane, and - a varnish and / or a polymer protective layer.

[0008] The UV protection films according to the invention have a structure of at least four layers. Additional layers are possible, e.g., a primer on the underside of the base film. The layers of the UV protection film can each consist of several independent layers. For example, thick layers can be obtained by repeatedly applying the material by knife coating, or a base film can be produced by coextrusion. The layers can be identical or different in composition.

[0009] In the context of the present invention, bottom, below, underside, etc., refers to the surface of a layer that faces the substrate or is closer to it. Top, above, and top side refer to a layer facing away from or further away from the substrate; the uppermost surface of the UV protection film forms the wear surface of the component.

[0010] A printable base film is intended as the lower layer. This must ensure sufficient adhesion to the substrate during lamination, while also providing the necessary mechanical properties for the UV protective film during production and processing.

[0011] Suitable materials for the base film are PVC (polyvinyl chloride), polyacrylates, and polyolefins. These exhibit good UV stability, either on their own or with known additives. They are also very resistant to hydrolysis and thermolysis.

[0012] Bonding to the substrate is typically achieved via adhesive lamination, e.g., using a polyurethane hot-melt adhesive, reactive polyolefin hot-melt adhesive, or reactive silane-terminated hot-melt adhesive. To optimize adhesion, the base film can be primed on the underside. For example, a primer based on vinyl chloride-vinyl acetate copolymer is well suited for PVC, polyacrylate, and PVC-polyacrylate films. A two-component polyurethane primer, among others, is suitable for polyolefin films. Alternatively or additionally, the base film can be subjected to plasma irradiation, corona treatment, or other surface treatments.

[0013] A PVC base film preferably contains, in addition to polyvinyl chloride, a stabilizer, processing aids, UV absorbers, an antistatic agent, and pigments. Modifiers, especially polyacrylate, and epoxidized soybean oil are also preferably included. Tin has proven particularly useful as a stabilizer; BaZn and CaZn are also suitable. Tin is preferably used in combination with phosphite as a co-stabilizer. Examples of processing aids include polymeric flow aids, e.g., based on MMA, BA, or styrene. PVC films with polymer plasticizers and copolymers—particularly based on vinyl chloride and acrylates—can also be used.

[0014] The PVC content is typically between 70% and 85% by weight. The plasticizer content is typically up to 30% by weight, but can be fully or partially replaced by suitable raw material supplements or alternative raw materials such as copolymers. Recycled material can be a component in the formulation. The amount can be set at up to 20% by weight, with up to 5% being preferred. The material used can be from the same or a slightly modified formulation.

[0015] Polyacrylate base films can preferably be made of methyl methacrylate (MMA), butyl acrylate (BA), and / or ethyl acrylate (EA). In particular, copolymers of two, particularly preferably all three, of the mentioned monomers are used. The base film also typically contains one or more UV absorbers, e.g., based on benzotriazole, antioxidants such as phenolic antioxidants, light stabilizers, preferably HALS, and pigments. Furthermore, polyacrylate-based processing aids may be included.

[0016] Polyolefin base films can preferably be made of polyethylene, polypropylene, or olefin copolymers. Olefins here refer to hydrocarbons with at least one aliphatic CC double bond, i.e., linear and cyclic alkenes that may bear hydrocarbon substituents. Substituents with other groups, such as acid and ester groups, are not included. The films may contain fillers, e.g., chalk, and the usual additives. For example, the polyolefin base film can contain, for every 100 parts by weight of polyolefin or polyolefin alloy, preferably propylene homopolymer or high-density polyethylene (HDPE), 25 to 120 parts by weight of a finely divided mineral filler or mineral filler mixture, preferably calcium carbonate, alkaline earth oxides, microtalc, kaolin, silicates, magnesium aluminum oxy- or hydroxy-carbonates and / or silicates and / or silica gel with an average grain diameter of less than 10 µm, preferably from 0.05 to 5 µm.According to another embodiment, the polyolefin base film contains 100 parts by weight of polyolefin or polyolefin alloy, preferably propylene homopolymer or HDPE, 5 to 40 parts by weight (based on 100 parts by weight of polyolefin), preferably 10 to 30 parts by weight, of at least one finely divided organic filler or combinations of these weight amounts of organic fillers with 0 to 30 parts by weight, preferably 5 to 25 parts by weight, of at least one finely divided mineral inorganic filler or filler mixture. In a further preferred embodiment, the base film contains 50 to 80% by weight of polypropylene, preferably light-stabilized, 5 to 20% by weight of HDPE, preferably light-stabilized, 1 to 5% by weight of antioxidants, 1 to 5% by weight of processing aids, and 5 to 15% by weight of antiblocking additives, as well as optionally coloring additives.

[0017] The thickness of the base film is normally from 80 to 250 µm, preferably from 100 to 200 µm and particularly preferably from 120 to 160 µm. However, thinner base films, e.g. down to 40 µm and below, or thicker base films, e.g. up to 300 µm, 450 µm, 500 µm or more, may also be appropriate in individual cases. The base film is generally produced by calendering, but can also be extruded. Extrusion includes all processes, namely blown film, cast film and cast film extrusion. Cast film extrusion is preferred. The melt is distributed over a slot die and cooled by a cooling roll / chill roll. Single-screw and multi-screw extruders and variations thereof are conceivable as tools. Production is preferably carried out using a single-screw extruder. The base film can be stretched uni- or bidirectionally.This provides greater dimensional stability at temperatures during the application of the hot-melt coating. Furthermore, the risk of microcracks in the hot-melt coating is minimized when coating substrates with the UV protection film according to the invention.

[0018] By stretching, the extensibility of the base film adapts to that of the melt coating, ie it becomes similarly low.

[0019] The desired design is printed onto the base film, unless the base film is dyed for solid colors. The base film can be dyed throughout, or in the case of multi-layer base films, the top layer can be dyed throughout. This is preferred for solid-colored designs. A base color can also be provided for printing by a dyed-through base film or the top layer of the base film. The design can be printed using any known method. Particularly suitable are gravure printing, particularly with solvent inks, and digital printing. Wood decor, natural stone and fantasy patterns are just as possible as designs as solid colors. The printing ink is applied to the base film using a series of printing rollers, for example. In digital printing, both single-pass and multi-pass print heads can be used for the design. The printed images are often composed of several printing inks and are characterized by their light stability.In addition to solvent-based printing inks, water-based inks are also conceivable.

[0020] The pigments used to color the base film or its top layer and to create solid colors can be organic or inorganic and reflect or transmit the IR component in sunlight.

[0021] One or two polyurethane-based melt coatings are applied above the print. For the purposes of the present invention, a polyurethane-based melt coating, also referred to as a PUR melt coating or melt coating for short, refers to a reactive melt compound, as described, for example, in WO 2006 / 056472 A1, WO 2012 / 084823 A1, WO 2006 / 106143 A1, or US Pat. No. 8,153,265 B2. The reactive melt compound can react and cure, for example, due to ambient humidity, but also through irradiation with, for example, UV light. It can be a one- or two-component compound. It is important that the compound is transparent so that the color or print remains visible through the melt coating.

[0022] Preferably, one-component reactive hot melt compounds containing a polyurethane prepolymer that cure with humidity are used. Upon heating, the prepolymer chains liquefy into an applicable liquid, which cures to form a polyurethane layer upon exposure to moisture.

[0023] To increase abrasion resistance, the reactive melt of the abrasion-resistant second melt coating contains particles of appropriate hardness. Particles used as abrasives are preferred, such as corundum, zirconium, silicon carbide, boron nitride, diamond, or glass particles. Corundum and glass particles are particularly preferred due to their cost-effectiveness.

[0024] This second PUR hot-melt coating layer typically has a thickness of 10 to 150 µm, preferably 20 to 120 µm, and especially 30 to 100 µm. It can be applied in a conventional manner by brushing, knife coating, roller application, etc.

[0025] According to the invention, the abrasion-resistant, second melt coating is preferably applied using a pair of rollers, one of which is structured. Alternatively, the first melt coating and / or the varnish can be structured accordingly. For structuring with a pair of rollers, a ceramic-coated roller with the desired structure, e.g. a wood pore structure or tile joints, is preferably used. It is expedient to regularly clean the structured roller in a special bath of solvent mixtures or using high-pressure nozzles, dry ice irradiation and / or laser evaporation so that the application depth is maintained. The rollers are preferably replaced to reduce downtimes. Dry ice cleaning or laser evaporation could also be integrated into the machine, but with downtime.

[0026] Beneath the abrasion-resistant, second PUR hot-melt coating, an optional intermediate layer (which, in the film according to the invention, is smooth) is arranged. This intermediate layer is also formed from a polyurethane-based reactive hot-melt compound, but contains no or significantly less filler than the PUR hot-melt coating. The intermediate layer must also be transparent. The intermediate layer makes it particularly easy to obtain the entire PUR hot-melt coating bubble-free and thus highly transparent. Without a low-filler or filler-free intermediate layer, gas bubbles can be introduced during the application of the PUR hot-melt coating, impairing transparency.

[0027] The process according to the invention is also suitable for producing UV protective films with an embossed or structured intermediate layer. If the intermediate layer and / or the varnish is structured, it is not necessary to apply the abrasion-resistant second melt coating with a textured roller. In such a case, the textured varnish, or in particular the textured intermediate layer, ensures sufficient roughness and thus slip resistance. Therefore, with a textured intermediate layer, the abrasion-resistant second melt coating is preferably applied without structuring. This layer (and, if applicable, the varnish) retains the structure of the intermediate layer and does not fill the recesses.

[0028] The thickness of the intermediate layer depends on the desired embossing depth or depth of the structuring and the thickness of the abrasion-resistant second PUR melt coating layer and is generally from 10 to 100 µm, preferably from 20 to 80 µm, particularly preferably from 30 to 60 µm.

[0029] The intermediate layer can be applied in the same way as the PUR hot melt coating, whereby the same or different processes can be used for coating a UV protection film. It is applied using a pair of rollers, one of which is textured provided that neither the PUR hot melt coating above the intermediate layer nor the varnish is to be textured or no varnish is used. In a preferred embodiment, the intermediate layer is applied using a slot die, with or without a roller bar, and the PUR hot melt coating layer is applied using a textured roller application. Advantageously, the same reactive hot melt compound is used for the intermediate layer as for the PUR hot melt coating, but without particles. It is also possible to use a different reactive hot melt compound, e.g. a radiation-curable compound for the intermediate layer and a moisture-curing compound for the hot melt coating.The interlayer can also be provided as a film, e.g., an embossed film. The interlayer significantly improves UV protection because it contains few or no particles. Without the interlayer, particles in the PUR hot-melt coating could reach the base film, allowing light to pass directly onto the printed design.

[0030] If no embossed or structured intermediate layer made of a polyurethane-based reactive melt compound is provided, but rather a smooth intermediate layer, either the varnish or, preferably, the PUR melt coating layer is structured. According to the invention, the structuring of the varnish and / or the intermediate layer and / or the PUR melt coating is carried out using the pair of rollers through which the varnish or layer is applied. It is also possible to create a deep and / or coarse structure in the PUR melt coating layer or the intermediate layer by roller application and to additionally provide the varnish with a fine or finer structure. This fine(er) structure can be introduced by roller application of the varnish or by another known method. As is also known, the embossed pattern or structuring can be coordinated with and correspond with the print design.It is common for embossing / structuring to follow the grain of the printed wood structure or, in the case of a tile look, to simulate joints.

[0031] Typical embossing depths or structuring depths range from 5 to 30 µm, preferably from 10 to 20 µm. This, in combination with the particles in the PUR melt coating layer, ensures sufficient slip resistance. Slip resistance values ​​of at least R10 to R12 according to DIN 51130 or ASR A1.5 / 1.2 are typically achieved, preferably at least R11. However, if the design warrants it, the embossing depths or structuring depths can also be significantly deeper, e.g., 60 µm or more.

[0032] The upper layer is formed by a transparent varnish and / or a removable polymer protective layer. The UV protective film has a very rough surface due to the structuring of the intermediate layer and / or the abrasion-resistant, second PUR hot-melt coating layer. This is also desired to achieve high slip resistance when wet. However, a very rough and very hard, abrasion-resistant surface has the disadvantage that the pressure rollers of wrapping or coating systems wear out very quickly, and the process becomes unstable. This results in complaints due to defective coating. Therefore, the surface of the protective film produced according to the invention or according to the invention is formed by the varnish or the polymer protective layer. The application of a varnish or a polymer protective layer is also necessary to be able to immediately wind up the film with the PUR hot-melt coating.Otherwise, the film roll will block, as it usually takes some time for the applied hot-melt coatings to cure to a blocking-resistant finish. If the polymer protective layer does not develop excessive adhesion to the PUR hot-melt compound, the lacquer layer can be omitted; the material can be wound through the protective layer. An additional advantage of the protective layer is that it protects the surface of the component against scratches, for example, from the slip-resistant PUR hot-melt coating of other components. The lacquer remains part of the protective film according to the invention; the polymer protective layer is removed after the component has been manufactured or directly before or after its laying / installation.

[0033] Acrylic and polyurethane coatings are preferred, especially radiation-curable coatings. The coating is preferably crosslinked using UV or LED lamps. This can be done using a single or multiple sources. The energy output is, for example, 30 W to 200 W, preferably 50 W to 180 W, and especially 90 W to 150 W.

[0034] The varnish is conveniently applied by roller application or spray application and, if necessary, cured by irradiation. As already mentioned, the varnish can be the only structure on the UV protection film and is then applied using a pair of rollers, one of which provides the desired structure. Varnish layer thicknesses of 1 to 50 µm, preferably 3 to 15 µm, particularly preferably 5 to 10 µm, have proven successful. If the varnish contains the structure, correspondingly thicker varnish layers are selected to allow the desired depth of structuring, e.g. 60 µm or more. The varnish not only improves UV protection, but also provides an anti-blocking effect, so that the UV protection film can be wound up and, above all, unwound without problems. The varnish normally has a low gloss level of 4 to 20 gloss points, preferably up to 15 gloss points, according to ISO 2813. The measurement is carried out using a goniophometer.The measuring angle can be 20°, 35°, 60° (preferred) and 80° or 85°.

[0035] The polymer protective layer is preferably a melt compound made of polyethylene (PE, preferably HDPE) or PE (preferably LDPE blended with linear low-density polyethylene, LLDPE) and ethylene-vinyl acetate (EVA). EVA typically has a vinyl acetate content in the range of 15 to 25 wt.%. The polymer protective layer can contain additives such as thermal stabilizers, HALS, UV stabilizers, and optionally fillers. In a preferred embodiment, no additives are included or only UV stabilizers are present in a smaller than usual amount.

[0036] By selecting the correct weight ratio of PE to EVA, the polymer protective layer material exhibits the desired adhesion to the PUR hot melt layer or the paint. The adhesion should be sufficient to prevent the polymer protective layer from detaching significantly until component production is complete. It must be low enough to allow the protective layer to be peeled off. The mixing ratios depend on the desired surface roughness and, if applicable, also on the desired adhesion to the paint. The PE:EVA mixing ratio, based on the mass, can range from 1:5 to 5:1, preferably from 1:1 to 3:1, depending on the desired adhesion. Adhesion can also be influenced by blending different PEs. For example, adding LLDPE leads to increased adhesion and simultaneously improved tear resistance, which facilitates peeling.Other melting compounds that build up the desired adhesion with the PUR melt coating layer or the paint are also possible, e.g. compounds that are known as protection for PVC-laminated sheets.

[0037] The polymer protective layer can be applied to the rough surface after the PUR hot melt coating or after painting using a cast coating process, a doctor blade coating process, or a roller coating process. The casting process into a cooled roller gap is preferred. In this process, the hot melt runs into the valleys, mitigating the abrasive effect. The side facing the sheathing pressure rollers is predominantly smooth.

[0038] The application quantity depends on the structure of the anti-slip PUR melt coating and is from 20 g / m 2 up to 200 g / m 2 , preferably 100 g / m 2 and 150 g / m 2 .

[0039] The total thickness of the UV protection film without polymer protective layer is usually from 50 to 1000 µm, preferably from 100 to 750 µm and particularly preferably from 150 to 550 µm.

[0040] The UV protection film obtained or according to the invention preferably has at least one of the following properties: - Scratch resistance ≥ 3 N, preferably ≥ 4 N, according to DIN 15186, or at least class A3 according to DIN EN 16094:2012-04 and B3 according to DIN CEN / TS 16611:2014, and / or - Abrasion and wear resistance ≥ 3,000 revolutions, preferably ≥ 4,000 revolutions according to DIN EN 13329 or ≥ 8,000 revolutions, preferably 10,000 revolutions according to EN 14354:2017-11, and / or - Weather resistance with at least 10,000, preferably at least 15,000, test hours according to EN 513 (Method 1 (M)) and a minimum colour stability of grey scale 3, assessed according to EN 20105-A02 and / or - Slip resistance reaches at least class R10, which according to DIN 51130:2014 corresponds to a minimum slope of 10°, preferably R11.

[0041] Suitable substrates include wood, metal, plastic, and composite materials, preferably WPC and fiber composites. Substrates made of stone, concrete, and screed are also possible, particularly with base films with a higher thickness of 500 µm to 2 mm. The substrate provides the necessary mechanical properties for the construction element. Coating with the UV protection film not only creates the desired visual design, but also protects the substrate from the elements. Plastics do not age due to UV light, metals do not corrode, and wood stays dry and is also protected from UV light. The surface is easy to clean and thus retains its visual appeal for much longer and with much less effort.

[0042] Typical building elements include floorboards and slabs for terraces, balconies, paths, etc., panels, fence posts and elements, privacy screens, and planters. According to the invention, floor coverings are of particular interest, as they place high demands on slip resistance, become soiled particularly quickly, and are subject to high UV and mechanical stress. Previous products often failed to meet slip resistance requirements, deteriorated too quickly in appearance due to UV light, and / or were unable to withstand mechanical stress. Delamination, especially at corners and edges, was common.

[0043] In contrast, the components produced with the resulting UV protection film or the UV protection film according to the invention offer improved UV protection, especially with the presence of the intermediate layer, and do not require any compromises in terms of slip resistance. Mechanical strength is also improved, as the described measures ensure optimal adhesion of the base film to the substrate and the film layers to each other.

[0044] For example, the paper-based Elesgo film is well-known for outdoor use. This film consists of a printed paper film impregnated with acrylate, coated with a thick acrylic lacquer containing corundum. The uppermost structure is created by a texture-imparting film, which only achieves slip resistance in the range of R10. This is a low value for safe walking in wet conditions. Plastic-based versions of this film with improved internal strength have the same negative slip properties due to the identical coating manufacturing technology. The process is demonstrated at https: / / laminate.de / index.php / de / technologie2 / prozess.

[0045] HPL compact boards are also known, which are produced from melamine or phenolic resin-impregnated paper. Many of these products have low lightfastness due to the printing process. The slip resistance of these products is achieved using press plates, which reduces the effectiveness of the corundum sprinkled into the top paper layer. While this achieves good abrasion resistance, the slip resistance is rather low, as the press plates would otherwise wear out quickly due to the process.

[0046] With the exception of the UV protection films disclosed in PCT / EP2021 / 078028, the current state of the art does not provide high-quality designs for horizontal outdoor applications such as those achieved with this invention. Existing systems fail to meet these high standards after just a few years. Known defects include layer separation, cracking, fading, and color changes due to the use of unsuitable UV protection layers, difficult processing due to excessive stiffness, increased water absorption and resulting swelling, and poor adhesion to the substrate.

[0047] Furthermore, the UV protection films according to the invention are very well suited for the decorative design of swimming pool covers (so-called roller shutter systems). Previously known plastic films have often failed due to their lack of weather resistance. For plastic films with a transparent polyacrylate layer as weather protection, clouding due to water absorption is a problem. In contrast, the UV protection films according to the invention offer good stability in chlorinated (and also saline) swimming pool water and the necessary weather resistance. The known roller shutter-like covers are suitable as a substrate, provided that the cover must be buoyant. Thus, segments made of wood, plastic, and composite materials are preferred, with hollow segments made of plastic, composite materials, and metal being particularly preferred.

[0048] Embodiments of the process for producing the UV protection film according to PCT / EP2021 / 078028 are described in Fig. 1 to 7. Two embodiments of the method according to the present invention are shown in the Fig. 8 and Fig. 9. For identical process sequences, identical reference numerals are used for the devices shown in the figures. In all of the illustrated processes, a base film 1 is produced in a manner known per se (not shown), e.g. by calendering. This base film 1 is printed in an equally known manner (unless it is a colored film for single-color components) and, if necessary, provided with a primer 5 on the underside (underside means facing the substrate) and / or irradiated. The base film 1 is usually rolled up and stored. In the next step, the printed (or colored) base film 1 is unrolled and a reactive melt is applied to the base film 1 or the print D.

[0049] In the Fig. 1, Fig. 2, Fig. 4, Fig. 6, Fig. 8 and Fig. In the embodiments shown in Figure 9, an intermediate layer 2 without particles is first applied by means of a slot nozzle a. In the embodiments according to PCT / EP2021 / 078028 in Fig. 1, Fig. 2, Fig. 4 and Fig. 6 the intermediate layer 2 on the base film 1 is embossed with a pair of rollers b, b'.

[0050] In all figures, an abrasion-resistant melt coating based on polyurethane with particles is applied as a second or third layer 3 by means of rollers c, c'. In the process according to the invention in Fig. 8, this is done with a pair of rollers, one of which is structured (c"), so that the structuring of the PUR hot-melt coating occurs directly during application of the layer. Separate embossing is not necessary and is preferably not performed. The heated PUR hot-melt coating 3 cures after application through contact with atmospheric moisture. Alternatively, radiation curing can be provided for radiation-curing reactive hot-melt compounds.

[0051] Then in Fig. 1, Fig. 2, Fig. 4, Fig. 6, Fig. 8 and Fig. 9 the lacquer 4, here a UV-curing acrylate lacquer, is applied by roller application through the rollers d, d'. In the embodiment according to the invention in Fig. 9, one of the rollers d'' is structured, so that the structuring of the film occurs directly during the application of the varnish. The varnish 4 is cured by UV radiation from the radiation source e. The varnish is cured, for example, by UV lamps, LED radiators; an excimer laser or excimer UV radiator is optionally used in addition to achieve a matting finish and improved scratch resistance of the surface.

[0052] According to Fig. 2, Fig. 8 and Fig. 9 a polymer protective layer 6 is poured onto the paint, according to Fig. 4 and according to Fig. 6 rolled up. In Fig. 3, the polymer protective layer 6 is poured directly onto the PUR melt coating 3, in Fig. 5 and in Fig. 7 rolled up.

[0053] The finished UV protection film is wound up and is ready for coating substrates after the melt coating(s) have cured. It includes Fig. 1, Fig. 2, Fig. 4, Fig. 6, Fig. 8 and Fig. 9 an intermediate layer 2 and a varnish 4, as well as in the Fig. 2 to 9 a polymer protective layer 6. Fig. 3, Fig. 5 and Fig. 7 the varnish 4 and the intermediate layer 2 are missing, Fig. 1 a polymer protective layer 6.

[0054] The Fig. 10a and Fig. 10b schematically shows the layers of a first preferred UV protection film separated and combined. Here, it can be seen how the embossing of the intermediate layer 2 determines the surface structure of the UV protection film. The PUR melt coating 3 and the varnish 4 follow the structure of the intermediate layer 2.

[0055] The Fig. 11a and Fig. 11b schematically shows the layers of a second preferred UV protection film separated and combined. Here, it can be seen how the embossing of the intermediate layer 2 determines the surface structure of the UV protection film. The PUR melt coating 3, varnish 4, and polymer protection layer 6 follow the structure of the intermediate layer 2.

[0056] The Fig. 12a and Fig. 12b schematically shows the layers of a third preferred UV protection film separated and combined. Here, it can be seen how the embossing of the intermediate layer 2 determines the surface structure of the UV protection film. The PUR melt coating 3 and the polymer protection layer 6 follow the structure of the intermediate layer 2.

[0057] The invention also relates to all combinations of preferred embodiments, provided they are not mutually exclusive. The terms "about" or "approx." in conjunction with a numerical value mean that values ​​that are at least 10% higher or lower, or 5% higher or lower, and in any case 1% higher or lower are included. Unless otherwise stated or the context dictates otherwise, percentages refer to the weight, or in case of doubt, to the total weight of the mixture. List of reference symbols 1 base film 2 Intermediate layer 3 PUR melt coating based on polyurethane 4 varnish 5 primers 6 Polymer protective layer D pressure a slot nozzle with or without roller bar b, b' embossing roller pair c, c' Roller application of PUR hot melt coating, c, c'' with structured roller c'' d, d' roller application of varnish, d, d'' with textured roller d'' a radiation source f Pouring (direct extrusion) polymer protective layer g Squeegee application of polymer protective layer h Roller application of polymer protective layer

Claims

[1] A method for producing a UV protective film comprising the steps: - Providing a base film made of polyvinyl chloride, polyacrylate or polyolefin having a printed design and / or coloring of the base film, - Applying an abrasion-resistant polyurethane-based melt coating over the base layer, and - applying a varnish and / or a polymer protective layer above the abrasion-resistant hot-melt coating, wherein the abrasion-resistant polyurethane-based hot-melt coating and / or the varnish and / or an applied intermediate layer of a polyurethane-based reactive hot-melt compound is embossed by application by a pair of rollers with a textured roller. [2] Method according to claim 1, characterized bythat above the base film and below the abrasion-resistant polyurethane-based melt coating, an embossed intermediate layer comprising a polyurethane-based reactive melt compound is applied, which contains no or fewer particles than the abrasion-resistant polyurethane-based melt coating. [3] Method according to claim 2, characterized by that the reactive melt mass is applied in such an amount that the thickness of the intermediate layer is from 10 to 100 µm, preferably from 20 to 80 µm, particularly preferably 30 to 60 µm. [4] Method according to one of claims 1 to 3, characterized by that a primer has been applied to the underside of the base film and / or that the underside of the base film has been subjected to plasma radiation or corona treatment. [5] Method according to one of claims 1 to 4, characterized bythat the base film is provided with a thickness of 40 to 450 µm, preferably 80 to 250 µm, preferably 100 to 200 µm and particularly preferably 120 to 160 µm. [6] Method according to one of claims 1 to 5, characterized by that the abrasion-resistant melt coating contains particles selected from, among others, glass particles, particles used as abrasives and mixtures thereof, preferably corundum. [7] Method according to one of claims 1 to 6, characterized by that the abrasion-resistant melt coating is applied in such an amount that it has a thickness of 10 to 150 µm, preferably 20 to 120 µm and in particular 30 to 100 µm. [8] Method according to one of claims 1 to 7, characterized by that the varnish is an acrylate varnish or a polyurethane varnish, preferably a radiation-curable acrylate or polyurethane varnish. [9] Method according to one of claims 1 to 8, characterized by that the varnish is applied in such an amount that it has a thickness of 1 to 50 µm, preferably 3 to 15 µm, particularly preferably 5 to 10 µm. [10] Method according to one of claims 1 to 9, characterized by that the polymer protective layer is made of polyethylene or of a mixture of polyethylene and ethylene vinyl acetate, preferably in a weight ratio of 1:5 to 5:1, and / or in an amount of 20 to 200 g / m 2 is applied. [11] Method according to one of claims 1 to 10, characterized by that the base film was printed using gravure printing, in particular with solvent inks, or digital printing. [12] Method according to one of claims 1 to 11, characterized by that the abrasion-resistant melt coating is applied by brushing, doctoring or roller application, preferably by roller application wherein one of the rollers is structured. [13] Method according to one of claims 1 to 12, characterized by that the intermediate layer of reactive melt is introduced under the abrasion-resistant melt coating, preferably with a slot die. [14] Method according to one of claims 1 to 13, characterized by that an embossed pattern is matched to the printed design. [15] Method according to one of claims 1 to 14, characterized by that the embossing depths achieved with the structured roller are from 5 to 30 µm, preferably from 10 to 20 µm. [16] Method according to one of claims 1 to 15, characterized by that the varnish is cured by radiation and / or the polymer protective layer is applied by pouring, doctoring or roller application. [17] Process for the production of coated components, characterized by that a UV protective film produced according to one of claims 1 to 16 is laminated with a substrate. [18] Method according to claim 17, characterized by that the UV protection film is laminated to the substrate by heat lamination or adhesive lamination, e.g. using polyurethane hot melt adhesive or reactive polyolefin hot melt or reactive silane terminated hot melt. [19] Method according to claim 17 or 18, characterized by that the substrate is made of wood, metal, plastic or composite material, in particular WPC or fiber composite material. [20] Method according to one of claims 17 to 19, characterized by that the building element is selected from floorboards and panels, panels, fence posts and elements, privacy screens, swimming pool covers and planters. [21] UV protective film comprehensive - a base film made of PVC, polyacrylate or polyolefin, - a printed design and / or coloring of the base film, - a smooth intermediate layer comprising a first polyurethane-based melt coating - a layer comprising an abrasion-resistant, second melt coating based on polyurethane, - a lacquer and / or a polymer protective layer, wherein the abrasion-resistant, second melt coating and / or the lacquer is structured. [22] UV protective film according to claim 21, characterized by that the first melt coating contains no or fewer particles than the abrasion-resistant, second melt coating. [23] UV protective film according to claim 21 or 22, characterized by that it can be produced by a process according to one of claims 1 to 20.

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