Method for transferring embossed structures to coating compositions by pre-treatment of embossing tools for transfer

Abstract

The present invention relates to a method for transferring an embossed structure, comprising at least steps (1‑i) and (2‑i) or (1‑ii) and (2‑ii), wherein steps (1‑i) and (2‑i) or (1‑ii) and (2‑ii) are carried out using an embossing tool (P1) comprising at least one embossing punch (p1), wherein the embossing punch (p1) of the embossing tool (P1) is pretreated with at least one organic solvent and / or at least one reactive diluent before implementing step (2‑i) or before implementing step (1‑ii), and also relates to the use of the correspondingly pretreated embossing tool (P1) comprising at least one embossing punch (p1) for transferring an embossed structure in this manner.

Description

[0001] The present invention relates to a method for transferring an embossed structure, which comprises at least steps (1-i) and (2-i) or (1-ii) and (2-ii), wherein steps (1-i) and (2-i) or (1-ii) and (2-ii) are carried out using an embossing tool (P1) comprising at least one embossing punch (p1), wherein the embossing punch (p1) of the embossing tool (P1) is pretreated with at least one organic solvent and / or at least one reactive diluent before implementing step (2-i) or before implementing step (1-ii), and also relates to the use of the correspondingly pretreated embossing tool (P1) comprising at least one embossing punch (p1) for transferring an embossed structure in this manner. Prior art

[0002] In many applications within the industry, workpieces are now often provided with structures on their surface, whose structural features are in the micrometer range or even in the nanometer range. Such structures are also referred to as microstructures (structures with features in the micrometer range) or nanostructures (structures with features in the nanometer range). Such structures are used, for example, to influence the optical, biomimetic and / or tactile qualities of the material surface. This type of structure is also referred to as embossing or embossed structure.

[0003] A common method here is to transfer these structures into the coating. The transfer of the structures into the coating is usually achieved here by an embossing operation, in which a die, which contains the microstructures and / or nanostructures to be formed in negative form on the embossing surface or transfer surface, is brought into contact with the coating and impressed into the coating. The coating is then usually cured in situ in order to permanently form and maintain these structures on the workpiece surface.

[0004] In particular, in the field of haptics and bionics, microstructures are generated here, especially in the range of >40 μm, with an aspect ratio >1. The aspect ratio refers to the ratio of the height of the structure to its diameter. The structural elements of the fine structure of a lotus are, for example, about 10-20 μm high and about 10-15 μm wide, and the structural elements of the fine structure of a gecko's foot are about 100 μm high and about 1 μm wide (see E. Arzt et al., PNAS 2003, 100, 10603-10606).

[0005] DE 10 2004 012 067 A1 describes a method for producing adhesive elements with micrometer-scale structures on a carrier material using a plastic material such as an elastomer.

[0006] WO 2005 / 047549 A1 describes a velvet-type fine fiber surface which can have a fine structure in the form of protrusions with a length of 110 μm and a diameter of 3-60 μm. In order to produce such a finely structured velvet-like surface, a polymer dispersion is applied to a support surface having a corresponding negative structure and cured, so that the coating exhibits a fine structure. One of the disadvantages of this method is that it involves a discontinuous operation.

[0007] DE 10 2007 061 980 A1 discloses a method for producing a microstructure by providing a molding tool in the form of a polymer film in the form of a web, the surface of the film carrying an arrangement of protrusions and recesses in the form of the desired microstructure and filling the recesses with a first curable coating, contacting the surface of the polymer film with a layer of a second curable coating, curing the first coating in contact with the second coating in the recesses of the polymer film together with the layer of the second coating, and simultaneously bonding it to the layer of the second coating, and removing the surface of the polymer film from the second cured coating to pull the cured first coating bonded to the second coating from the recesses of the polymer film. The method is used to produce a security element with a micro-optical structure, such as a micro-optical Moiré enlargement arrangement. The structure depth of the microstructure according to DE 10 2007 061 980 A1 is in the range of 1 to a maximum of 20 μm.

[0008] Continuous methods for transferring embossed structures to coatings are known in the prior art, especially in the field of production of optical films and in the field of security printing (holograms), where, for example, roll-to-roll printing presses are equipped with embossing devices with negative structures on their surfaces, and where such structures are transferred to coatings. For economical operation with extremely high high-pressure printing accuracy (extremely accurate replication of the negative structure without severe losses), it has been found that the use of coatings, especially radiation-curable materials, is particularly advantageous. With such coatings, the liquid coating used is likely to be at least partially cured while still in contact with an embossing tool, such as an embossing roller, so that high structural accuracy is achieved at high belt speeds. Methods of this type are described in, for example, WO 88 / 09252A1 and WO 94 / 18609A1. Methods of this type for generating optical films are also disclosed in WO 2009 / 121357A1, where the coating is first applied to a carrier film via a known application method and then embossed. Similar methods are also described in, for example, DE 41 32 476A1.

[0009] However, the disadvantage of these known aforementioned methods is firstly that, at least in some of these methods, the coating is first applied to the embossing tool and then transferred from there to the substrate. This imposes restrictions on these methods in terms of the required layer thickness of the coating, which means that embossed structures with a structure depth of >40 μm cannot be fully embossed. Another disadvantage of these known aforementioned methods is that they are also not able to transfer embossing, especially in the micrometer range, without being accompanied by an overall reduction in the embossing accuracy to an unacceptable degree, which is the case in particular when embossing structures with a structure depth of >40 μm are intended to be embossed. An increase in the pressure of the embossing tool used on the coating does not bring about an increased embossing accuracy, because it is often accompanied by the embossing die of the embossing tool getting stuck / locked in the embossing coating, which means that higher forces are required to separate the coated substrate with such a fine structure from the embossing tool. This in turn can lead to damage to at least individual structural elements of this fine structure during the separation process due to tearing and / or cohesive rupture, especially when the negative structure in the embossing die is completely filled. As a result, not only is the embossed structure not correctly embossed, but the embossing tool is also contaminated, necessitating expensive and inconvenient cleaning or replacement. Furthermore, if the pressure during the embossing operation is increased, i.e. if the applied pressing pressure is increased, there is a risk that the coating used is not sufficiently pressed into the recesses of the embossing die, since the coating is displaced laterally or at the edges of the substrate coated therewith. Furthermore, the air remaining in the pores of the embossing die cannot be compressed to any great extent, so that the embossing often does not conform to the form determined by the die, with the result that unwanted shrinkage cavities may be present. In particular, due to large enclosed air bubbles, the stability of the embossed structure is generally much poorer, so that the wear resistance of the surface in the face of even low mechanical loads is low.

[0010] There is therefore a need for a method of transferring an embossing mechanism which does not suffer from the above mentioned disadvantages.

[0011] question

[0012] The problem addressed by the present invention is therefore to provide a method for transferring embossed structures, in particular embossed structures with a high aspect ratio, from an embossing tool to a coating composition and to a substrate provided with such a coating composition, more particularly enabling the transfer of corresponding microstructures and / or nanostructures, in particular microstructures, achieving sufficient embossing precision in the transfer of the embossed structures so that the embossing is not accompanied by any loss of modulation depth and in particular enabling the production of largely reusable embossing dies for transferring the embossed structures and / or a method of this type that can be carried out using embossing dies of this type. At the same time, and in particular, the embossed structures to be transferred can be reproduced to a very high degree and as free of defects as possible, more particularly without the occurrence of craters, without any disadvantages resulting in particular from undesirable or insufficient properties on the part of the coating material and the coating composition used, such as insufficient adhesion.

[0013] Solution

[0014] This problem is solved by the subject matter claimed in the claims and by preferred embodiments of this subject matter described in the following description.

[0015] A first subject of the invention is therefore a method for transferring an embossed structure using an embossing tool (P1), comprising at least steps (1-i) and (2-i) or (1-ii) and (2-ii), in particular

[0016] (1-i) applying the coating composition (B1a) to at least a portion of the surface of the substrate (F1) to produce a composite material (B1aF1), and

[0017] (2-i) at least partially embossing the coating composition (B1a) at least partially applied to the surface of the substrate (F1) by means of at least one embossing tool (P1) comprising at least one embossing punch (p1),

[0018] or

[0019] (1-ii) applying the coating composition (B1a) to at least a portion of at least a portion of the embossing surface of the embossing punch (p1) of the embossing tool (P1), and

[0020] (2-ii) applying a substrate (F1) to at least a portion of the surface of the coating composition (B1a) applied to the embossing die (p1) to produce a composite material (B1aF1) on (p1),

[0021] It comprises pretreating the at least one embossing punch (p1) of the embossing tool (P1) with at least one organic solvent and / or at least one reactive diluent before carrying out step (2-i) and before carrying out step (1-ii), and preferably transferring a microstructure with a structure depth of >30 μm as an embossing structure to the coating composition (B1a) through steps (2-i) and (1-ii).

[0022] Another subject matter of the present invention is the use of an embossing tool (P1) comprising at least one embossing punch (p1) for transferring an embossed structure to at least a portion of the surface of a coating composition (B1a), wherein the at least one embossing punch (p1) of the embossing tool (P1) has been pretreated with at least one organic solvent and / or at least one reactive diluent before the transfer, and the embossed structure transferred to the coating composition (B1a) preferably comprises a microstructure with a structure depth of >30 μm.

[0023] It has surprisingly been found that the process according to the invention - in particular the pretreatment carried out before carrying out step (2-i) and before carrying out step (1-ii) - makes it possible to transfer embossed structures, in particular microstructures, to the coating composition to be embossed with extremely high pressure printing accuracy even at high speeds, so that there is no loss of modulation depth during the embossing process. In this context, it has been found, in particular, surprisingly, that the process according to the invention makes it possible to transfer microstructures as embossed structures with a structure depth of >30 μm, more particularly >40 μm and an aspect ratio of >1 in precise form and at high speeds from an embossing tool with a negative structure of the embossed structure to be transferred on its surface to the coating.

[0024] More particularly, it has surprisingly been shown that the transfer of embossed structures, in particular tactile embossed structures, using conventional methods known from the prior art only results in an incomplete embossing, meaning that the surface structure on the coating does not fully correspond to the positive structure of the negative structure on the embossing device, since the arrangement and size of the individual structural elements of the negative structure of the embossed structure to be transferred ensures that during the embossing operation air cannot escape from the sides and that air therefore often remains in the recesses as spacers between the coating and the lowest point of the respective structural element, with the result that in particular the peaks are not molded and the transferred individual structural elements have shrinkage cavities. These disadvantages are surprisingly avoided by the method according to the invention, in particular by the pretreatment carried out before the implementation of step (2-i) and before the implementation of step (1-ii). In this regard, it has surprisingly been shown in particular that even if the embossed structures to be transferred have a high structural depth and a high aspect ratio, it is possible to accurately transfer these structures with high embossing accuracy, which have individual structural elements that are not connected to each other but are at least partially present in the form of individual "holes" on the surface of the embossing die of the embossing tool. Despite the fact that with such an arrangement of the structural elements within the embossing die, air cannot escape laterally during the embossing operation but must be removed from the individual structural elements ("holes"), the method according to the invention surprisingly achieves a defect-free transfer of the embossed structure, in particular without shrinkage cavities.

[0025] Details

[0026] In the present invention, the term "comprising" with respect to the coating composition used according to the invention, for example the coating composition (B1a), and with respect to the method according to the invention and the method steps therein preferably has the meaning of "consisting of". Here, for example with respect to the coating composition (B1a) used according to the invention, it is possible that the composition not only comprises the components contained therein, such as components (a) and / or (b) and / or (c), but also comprises one or more additional components specified below and optionally present in the coating composition (B1a) used according to the invention. The individual components may be present in their preferred embodiments specified below. With respect to the method according to the invention, this method may not only comprise steps (1-i) and (2-i) or (1-ii) and (2-ii) and a pretreatment step, but also comprise additional optional method steps, for example steps (3) and (4).

[0027] The method according to the invention for transferring an embossed structure, comprising at least steps (1-i) and (2-i) or (1-ii) and (2-ii) and optionally (3) and optionally (4)

[0028] A first subject of the present invention is a process according to the invention for transferring an embossed structure onto at least a part of the surface of a coating composition (B1a), as described above. Figure 1 and Figure 2 An exemplary illustration of steps (1-i) and (2-i) and optionally (3) and optionally (4) of the method of the present invention is provided, which is also apparent from the following description of these figures. The method of the present invention necessarily comprises the above-mentioned pretreatment.

[0029] The process of the present invention is preferably a continuous process.

[0030] The embossed structure is transferred / obtained in method step (2-i) by at least partial embossing of the coating composition (B1a) at least partially applied to the surface of the substrate (F1). Another possibility is the transfer by means of method steps (1-ii) and (2-ii). The term "embossing" means that the coating composition (B1a), optionally as part of the composite material (B1aF1), is at least partially provided with an embossed structure on at least a part of its surface. In this case, at least a certain area of ​​the coating composition (B1a) is provided with the embossed structure. Preferably, the entire surface of the coating composition (B1a), optionally as part of the composite material (F1B1a), is provided with the embossed structure.

[0031] The embossed structures of the composite materials (F1B1a) and (F1B1) are preferably and in each case independently of one another based on a repetitive and / or regularly arranged pattern. The structure can in each case be a continuous embossed structure, such as a continuous groove structure or a plurality of preferably repetitive individual embossed structures. The individual individual embossed structures can in this case in turn preferably be based on a groove structure with more or less pronounced ridges (embossed protrusions) to define the embossed height of the embossed structure. Depending on the respective geometry of the ridges of the preferably repetitive individual embossed structures, a plan view may show a plurality of preferably repetitive individual embossed structures, each different, for example preferably serpentine, zigzag, hexagonal, rhombus, rhombus, parallelogram, honeycomb, circle, dot, star, rope, net, polygonal, preferably triangular, quadrilateral, more preferably rectangular and square, pentagonal, hexagonal, heptagonal and octagonal, linear, elliptical, oval and dotted patterns, it is also possible for at least two patterns to be superimposed on one another. The ridges of the individual embossed structures may also have a curvature, i.e. a convex and / or concave structure.

[0032] The individual embossed structures can be described by their width, such as the width of the ridges, in other words by their structure width, and by the height of the embossing, in other words by its structure width (or structure depth). The structure width, such as the width of the ridges, can be up to 1 cm long, but preferably lies in the range of 10 nm to 1 mm. The structure height is preferably in the range of 0.1 nm to 1 mm. However, preferably, the individual embossed structures represent microstructures and / or nanostructures. Microstructures are structures that have features in the micrometer range both in terms of structure width and structure height. Nanostructures are structures that have features in the nanometer range both in terms of structure width and structure height. Microstructures and nanostructures are structures that have structure widths in the nanometer range and structure heights in the micrometer range, and vice versa. The terms "structure height" and "structure depth" are interchangeable here.

[0033] The structure width of the individual embossed structures is preferably in the range of 10 nm to 500 μm, more preferably in the range of 25 nm to 400 μm, very preferably in the range of 50 nm to 250 μm, more particularly in the range of 100 nm to 100 μm. The structure height of the individual embossed structures is preferably in the range of 10 nm to 500 μm, more preferably in the range of 25 nm to 400 μm, very preferably in the range of 50 nm to 300 μm, more particularly in the range of 100 nm to 200 μm. This applies to the embossed structures of composite material (F1B1) and composite material (F1B1a).

[0034] The embossed structures transferred by means of the method according to the invention are very preferably microstructures. The structure width is preferably in the range of 1 μm to 500 μm, more preferably in the range of 2 μm to 400 μm, very preferably in the range of 5 μm to 250 μm, more particularly in the range of 10 μm to 100 μm. The structure height of the individual embossed structures is preferably in the range of 1 μm to 500 μm, more preferably in the range of 2 μm to 400 μm, very preferably in the range of 5 μm to 300 μm, more particularly in the range of 10 μm to 200 μm. Particularly preferably, the embossed structures to be transferred at least partially have a structure depth (structure height) of >10 μm or >20 μm, very preferably >30 μm or >40 μm, more particularly >45 μm or >50 μm. The maximum structure depth is preferably in each case 500 μm or 450 μm or 400 μm or 300 μm or 250 μm.

[0035] The aspect ratio of the embossed structure transferred to the coating composition (B1a) is preferably >1. The term "aspect ratio" is known to the skilled person. The aspect ratio describes the ratio of the height (depth) of a structural element to its lateral extent (width). For example, a periodically arranged rectangle with a height of 10 μm and a width of 5 μm has an aspect ratio of 2 (10:5). The larger the value of the aspect ratio, the more difficult it is to produce a corresponding structured surface. The aspect ratio of the embossed structure transferred to the coating composition (B1a) is preferably >2 or >3 or >5 or >10, more preferably >15 or >20 or >50. In the case of a hierarchical structure, the aspect ratio indicates the aspect ratio of the largest hierarchical stage.

[0036] The structure width and structure height of the individual embossed structures are determined here by mechanical scanning of the surface. In this case, the embossing height is measured at no less than 10 points on a line evenly distributed over the width of the sample, taking care to ensure that the scanning device does not compress the embossed structure. The determination of the structure height represents a determination of the embossing accuracy and is carried out with the aid of atomic force microscopy according to the technique described below.

[0037] The process of the invention can be carried out at high operating speeds, preferably at speeds of 1 to 150 m / min, more preferably 1.5 to 100 m / min, very preferably 2 to 75 m / min, even more preferably 3 to 50 m / min, more particularly 5 to 40 m / min, most preferably 10 to 25 m / min. The operating speed here preferably refers to the belt speed at which the substrate (F1) at least partially coated with the coating composition (B1a) moves during the implementation of the process of the invention or the substrate (F1) itself moves.

[0038] The coating (B1) of the composite material (F1B1), and the coating composition (B1a) of the composite material (F1Ba1a), and the at least one embossing punch (p1) of the embossing tool (P1), preferably have embossing structures that are mirror images of each other.

[0039] Alternative (i) including steps (1-i) and (2-i)

[0040] The process of the invention according to alternative (i) comprises at least steps (1-i), (2-i) and optionally (3) and optionally (4).

[0041] Step (1-i)

[0042] Step (1-i) of the method of the invention provides for applying the coating composition (B1a) to at least a portion of the surface of a substrate (F1). The substrate (F1) represents the carrier material of the coating composition (B1a) to be applied thereto or the coating (B1) to be applied thereto.

[0043] The substrate (F1) or, if a coated substrate is used, the layer located on the surface of the substrate (F1), preferably consists of at least one thermoplastic polymer, more particularly selected from polymethyl (meth)acrylate, polybutyl (meth)acrylate, polyethylene terephthalate, polybutylene terephthalate, polyvinylidene fluoride, polyvinyl chloride, polyesters, including polycarbonates and polyvinyl acetates, preferably polyesters such as PBT and PET, polyamides, polyolefins such as polyethylene, polypropylene, polystyrene, and also polybutadiene, polyacrylonitrile, polyacetal, polyacrylonitrile-ethylene-propylene-diene-styrene copolymer (A-EPDM), polyetherimides, phenolic resins, urea resins, melamine resins, alkyd resins, epoxy resins, polyurethanes, including TPU, polyetherketones, polyphenylene sulfides, polyethers, polyvinyl alcohol and mixtures thereof. Particularly preferred substrates or layers on their surfaces are polyolefins, such as PP (polypropylene), which may alternatively be isotactic, syndiotactic or atactic and may alternatively be unoriented or oriented by uniaxial or biaxial stretching, SAN (styrene-acrylonitrile copolymer), PC (polycarbonate), PMMA (polymethyl methacrylate), PBT (poly(butylene terephthalate), PA (polyamide), ASA (acrylonitrile-styrene-acrylate copolymer) and ABS (acrylonitrile-butadiene-styrene copolymer), and physical mixtures (blends) thereof. Particularly preferred are PP, SA N, ABS, ASA and blends of ABS or ASA with PA or PBT or PC. Very particularly preferred are PET, PBT, PP, PE and polymethyl methacrylate (PMMA) or impact-modified PMMA. Particularly preferred is the use of polyester, most preferably PET, as substrate (F1). Alternatively, the substrate (F1) itself - optionally although a layer of at least one of the above-mentioned polymers is applied thereto - can be made of different materials, such as glass, ceramic, metal, paper and / or fabric. In this case, the substrate (F1) is preferably a plate and can be used, for example, for roll-to-plate embossing devices.

[0044] The thickness of the substrate (F1) is preferably from 2 μm to 5 mm. Particular preference is given to layer thicknesses of from 25 to 1000 μm, more particularly from 50 to 300 μm.

[0045] The substrate (F1) is preferably a film, more preferably a film web, very preferably a continuous film web. In this case the substrate (F1) can preferably be used in a roll-to-roll embossing device.

[0046] The term "continuous film" or "continuous film roll" in the sense of the present invention preferably refers to a film having a length of 100 m to 10 km.

[0047] When carrying out step (1-i) (preferably also when carrying out steps (2-i), optionally (3) and optionally (4) of the method, and also when carrying out steps (1-ii), (2-ii), optionally (3) and optionally (4) of the method of alternative (ii), the substrate (F1) is preferably moved and is therefore a moving substrate. During the implementation of steps (1-i) and (2-ii), the substrate (F1) is preferably moved by means of a conveying device, such as a conveyor belt. The corresponding device for carrying out steps (1-i) and step (2-ii) therefore preferably comprises such a conveying device. The corresponding device for carrying out step (1-i) further comprises a tool for applying the preferably radiation-curable coating composition (B1a) to at least a portion of the surface of the substrate (F1). With regard to the corresponding device for carrying out step (2-ii), similar comments apply.

[0048] Step (2-i)

[0049] Step (2-i) of the process according to the invention provides for at least partially embossing the coating composition (B1a) applied at least partially to the surface of the substrate (F1) by means of at least one embossing tool (P1) comprising at least one embossing punch (p1).

[0050] The embossing tool (P1) used can be a conventional printing cylinder with a negative form of the embossing structure to be embossed into the surface of the composite material (F1B1a). Such a cylinder can be pressed onto the composite material (F1B1a) to at least partially emboss. As already mentioned, the at least one embossing die (p1) of the embossing tool (P1) for at least partial embossing has a "negative structure", in other words, a mirror image of the embossing structure possessed by the composite material (F1B1a) of the substrate (F1) and the at least partially embossed coating composition (B1a), which is obtained after implementing step (2-i) of the method according to the invention. The embossing tool (P1) is preferably a metal embossing tool, more preferably made of nickel, steel or copper, in which case the copper may - but does not need to - contain a chromium component. Correspondingly, the embossing die (p1) is preferably metallic, more preferably made of nickel, optionally additionally containing a phosphorus component. Alternatively, it is also possible to use a soft material, such as polydimethylsiloxane (PDMS) to manufacture (p1).

[0051] In step (2-i), the at least one embossing punch (p1) is preferably part of a first roller acting as an embossing tool (P1) and guides the composite material (F1B1a) for at least partial embossing via a second roller opposite the first roller and rotating in the opposite direction. The at least partial embossing according to step (2) is preferably carried out at the level of a roll nip formed by two opposite counter-rotating rollers. Preferably in this case, the embossing punch (p1) of the embossing tool (P1) faces the coating composition (B1a) of the composite material (F1B1a). Preferably, the at least partial embossing is achieved by pressing the embossing punch (p1) onto the composite material (F1B1a).

[0052] The embossing punch (p1) used may alternatively be a composite material (B2F2) consisting of a substrate (F2) and an at least partially embossed and at least partially cured coating (B2), as will be described in more detail below. In this case, a composite material (F1B1aB2F2) is obtained after at least partial embossing. During the implementation of step (2-i), the embossing tool (P1) comprising the embossing punch (p1) is preferably at least partially pressed onto the applied coating composition (B1a).

[0053] The embossing punch (p1) of the embossing tool (P1) used in step (2-i) is preferably reusable and can be used repeatedly to transfer at least one embossed structure, preferably within the process of the invention. Step (2-i) preferably transfers the microstructure and / or nanostructure as embossed structure to the coating composition (B1a).

[0054] The embossing die (p1), i.e. preferably in the case of a composite material (F2B2), preferably comprises a film roll (F2) with an at least partially embossed and at least partially cured coating (B2). The substrate (F2) is particularly preferably a continuous film roll comprising an at least partially embossed and at least partially cured coating (B2), so that the composite material (F2B2) used as the embossing die (p1) is a continuous embossing die, especially when the substrate (F1) is also a continuous film roll.

[0055] The at least one embossing punch (p1) of the embossing tool (P1) for at least partial embossing according to step (2-i) has a mirror image "negative structure" ("negative shape") of the embossing structure possessed by the composite material (F1B1), the composite material (F1B1) being obtained after implementing the optional step (4) of the method according to the present invention and consisting of a substrate (F1) and a coating (B1) that is at least partially embossed and at least partially cured.

[0056] The corresponding apparatus for carrying out step (2-i) comprises a device for at least partially embossing the coating composition (B1a) applied at least partially to the surface of the substrate (F1) by means of at least one embossing tool (P1). In addition, the apparatus used preferably has a device for pressing (P1) onto the substrate (F1) preferably used as a continuous film roll after the preferably radiation-curable coating composition (B1a) has been applied to (F1), and this device is preferably arranged downstream of the device for applying the radiation-curable coating composition (B1a) as seen in the conveying direction of the substrate (F1).

[0057] At least part of the embossing of step (2-i) of the method according to the invention is carried out with the aid of an embossing tool (P1). (P1) may preferably be an embossing calender, which preferably comprises a grid applying mechanism, more preferably a grid roller mechanism. Such a calender has rollers which rotate in opposite directions or in the same direction and are preferably arranged one above the other at a specified spacing in the height direction, to which the composite material (F1B1a) to be provided with an embossed structure is fed and passes through a formed roller nip, the nip width of which is variably adjustable. The grid roller mechanism preferably comprises a first roller, such as a metal roller, for example a steel roller or a nickel roller, or a quartz-based roller, or a roller coated with at least one plastic. The first roller serves as an embossing roller (press roll). The grid roller mechanism preferably comprises a second roller (pressure applying roller or pressing roll). The first roller serves as an embossing tool (P1) and contains the negative form of the embossed structure to be embossed into the surface of the composite material (F1B1a). For this purpose, the embossing tool (P1) is preferably equipped with a composite material (F2B2) as an embossing die (p1) presenting such a negative shape. The negative shape of the structure to be embossed is produced on the embossing tool (P1) according to conventional methods known to the skilled person; depending on the structure and the material, specific methods may be particularly advantageous. This is preferably achieved according to the invention by an embossing roller acting as the embossing tool (P1) and by a coated and at least partially embossed film, preferably a film roll, more preferably a continuous film roll (which is preferably moving) in the form of a composite material (F2B2) preferably used as an embossing die (p1). The composite material (F1B1a) to be embossed is moved in opposite directions by means of pressure-applying rollers. In the roller nip formed by counter-rotating rollers arranged at a specified spacing from each other, embossing is carried out according to step (2-i). A first roller guiding the embossing die (p1) is used here to emboss the composite material (F1B1a), which is guided by a second roller opposite to this embossing roller and presses the composite material (F1B1a) against the first embossing roller to provide the embossed structure. As already observed above, the structure on the embossing roller - i.e. the structure of the embossing die (p1) - can have a continuous structure or can be designed as an interrupted structure (a series of individual embossing structures), in which case a combination of the two structures is also possible. Depending on the intended structure of the composite material, the respective structure on the embossing roller can have any of a very diverse range of geometries. If necessary, step (2-i) can be carried out at elevated temperature, for example at 30 to 100° C. or at least to 80° C. In this case, the composite material (F1B1a) to be embossed first passes through a heating roller mechanism, possibly thereafter irradiated with infrared rays, and then the actual embossing operation described above is carried out. After embossing, the composite material (F1B1a) thus embossed optionally passes through a cooling roller mechanism for cooling. Alternatively, step (2-i) can also be carried out under cooling: in this case, the composite material (F1B1a) to be embossed first passes through a cooling roller mechanism and then the actual embossing operation described above is carried out.

[0058] The composite material (F2B2) used as embossing punch (p1) in step (2-i) is preferably a composite material of a film roll (F2) and a coating (B2) applied thereto and at least partially embossed and at least partially cured.

[0059] During the implementation of step (2-i), the composite material (F2B2) used as the embossing die (p1) in step (2-i) is preferably guided via a first roller acting as an embossing tool (P1), and the composite material (F1B1a) is guided via a second roller opposite to the first roller and rotating in the opposite direction to it or rotating in the same direction as it, preferably rotating in the opposite direction.

[0060] The at least partial embossing according to step (2-i) is preferably carried out at the level of the roller nip formed by two oppositely rotating rollers in the opposite or same direction, and the at least partially embossed coating (B2) of the composite material (B2F2) faces the coating composition (B1a) of the composite material (F1B1a). Preferably, the at least partial embossing is achieved by pressing the composite material (F2B2) onto the composite material (F1B1a).

[0061] The composite material (F2B2) which is preferably used as the embossing punch (p1) in step (2-i) and consists of a substrate (F2) and an at least partially embossed and at least partially cured coating (B2) is also referred to below as a "master substrate" or "master film element". When the substrate (F2) is a film, the corresponding master film element is referred to as a "master film". When the substrate (F2) is a film roll, the corresponding master film element is referred to as a "master film roll". The coating (B2) of the master film element is also referred to below as an "at least partially cured master coating" or "master coating", and the coating composition (B2a) used to produce the cured master coating is referred to as a "master coating". Preferably, there are no other (coating) layers between (F2) and (B2) in the composite material (F1B1). However, it is possible that at least one adhesion promoter layer is present between (F2) and (B3) of the composite material (F2B2), which layer is preferably transparent to ultraviolet radiation in this case.

[0062] Optional step (3)

[0063] Step (3) of the process of the invention provides for at least partial curing of the coating composition (B1a) in the composite material (F1B1a) obtained after step (2-i) or step (2-ii); throughout the duration of said at least partial curing, the coating composition (B1a) is in contact with the embossing die (p1). After carrying out step (3), a composite material (B1F1) consisting of a substrate (F1) and an at least partially embossed and at least partially cured coating (B1) is obtained.

[0064] Steps (2-i) and (3) are preferably carried out simultaneously. In this case, the at least partial curing according to step (3) is preferably carried out in situ during the implementation of step (2-i).

[0065] The corresponding device for implementing step (3) therefore preferably comprises at least one radiation source for irradiating the coating composition (B1a) with curing radiation. Since the coating composition (B1a) is preferably a UV-curable coating composition, the curing radiation used is preferably UV radiation. If the coating composition (B1a) is not radiation-curable, it is preferably chemically curable. In this case, the curing according to step (3) is carried out thermally, for example by means of a suitable thermal radiation source. Combination curing is of course also possible, i.e. thermal curing and curing by means of UV radiation.

[0066] Examples of suitable radiation sources for radiation curing are low-pressure, medium-pressure and high-pressure mercury lamps, as well as fluorescent tubes, pulsed lamps, metal halide lamps (halogen lamps), lasers, LEDs, and electronic flash devices so that it is possible to achieve radiation curing without photoinitiators, or excimer lamps. Radiation curing is carried out by exposure to high-energy radiation, i.e. UV radiation or sunlight, or by bombardment with high-energy electrons. In the case of UV curing, radiation doses that are usually sufficient for crosslinking are in the range of 80 to 3000 mJ / cm 2 It will be appreciated that multiple radiation sources may also be used for curing, for example 2 to 4. These radiation sources may also each emit in a different wavelength range.

[0067] The at least partial curing in step (3) is preferably carried out by irradiation through the substrate (F1). In this case, it is advantageous to adjust the permeability of the substrate (F1) to the radiation used according to the at least one photoinitiator used, which is preferably present in the coating composition (B1a). Thus, for example, PET as a material for the substrate (F1), and thus, for example, a PET film, is permeable to radiation with a wavelength below 400 nm. Photoinitiators which generate free radicals under such radiation include, for example, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphinate and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide. In this case, therefore, at least one such photoinitiator is preferably present in the coating composition (B1a).

[0068] Optional step (4)

[0069] Step (4) of the method of the invention provides for the optional removal of the composite material (F1B1) from the embossing die (p1). Accordingly, it is possible to obtain a composite material (F1B1) consisting of a substrate (F1) and an at least partially embossed and at least partially cured coating (B1). Step (4) is preferably implemented.

[0070] Alternative (ii) comprising steps (1-ii) and (2-ii)

[0071] The method of the present invention comprises at least steps (1-ii), (2-ii) and optionally (3) and optionally (4) according to alternative (ii). Steps (3) and (4) have been described above in connection with alternative (i) and can also be carried out similarly in alternative (ii).

[0072] All preferred embodiments described in connection with alternative (i) are analogously applicable to alternative (ii).

[0073] Step (1-ii)

[0074] Step (1-ii) of the method of the invention proposes applying the coating composition (B1a) to at least a portion of the at least partially embossed surface of the embossing punch (p1) of the embossing tool (P1). As mentioned above, the embossing punch used in this case can be a composite material (B2F2) consisting of a substrate (F2) and an at least partially embossed and at least partially cured coating (B2).

[0075] Step (2-ii)

[0076] Step (2-ii) of the method of the invention provides for applying a substrate (F1) to at least a portion of the surface of a coating composition (B1a) applied to an embossing die (p1) to produce a composite material (B1aF1) located on (p1).

[0077] If a composite material (B2F2) is used as embossing die (p1) in step (1-ii), this composite material, after preferably applying the coating composition (B1a) to at least a part of its at least partially embossed surface to produce the composite material (B1aB2F2), is guided during the implementation of step (2-ii) via a first roller acting as embossing tool (P1), and the substrate (F1) used in step (2-ii) is guided via a second roller opposite the first roller and rotating in the same direction or in the opposite direction to the first roller, preferably in the opposite direction. The at least partial embossing according to step (2-ii) is preferably carried out at the level of the roller nip formed by two opposite rollers rotating in the same direction or in the opposite direction, with the coating composition (B1a) of the composite material (B1aB2F2) facing the substrate (F1). In this case, the at least partial embossing is preferably achieved by applying pressure or pressing the substrate (F1) onto the composite material (B1aB2F2).

[0078] Figure 1A schematic side view of an apparatus which can be used to implement steps (1-i) and (2-i) and optionally (3) and optionally (4) of the method according to the invention and for exemplifying the method according to the invention is shown. This apparatus can also be used in a substantially similar manner to implement steps (1-ii) and (2-ii) and (3) and optionally (4) of the method according to the invention. With the aid of this apparatus, it is possible to transfer structures, such as microstructures and / or nanostructures, preferably from an embossing die (F2B2, p1) present as a master film element to a substrate (F1) coated with (B1a). This apparatus is therefore also generally referred to as a transfer apparatus and is referred to in Figure 1 It is given the reference numeral (10).

[0079] The core of the transfer device (10) is an embossing zone (1), in which a press roll (2) is arranged as a roll sleeve made of fused silica. The press roll (2) is driven in rotation. Next to the press roll (2) a radiation source in the form of an illumination unit (3) is arranged, which generates UV light and can in particular comprise a row of UV-LEDs arranged in the longitudinal direction of the press roll (2). Figure 1 As shown in, the lighting unit (3) can also be arranged inside the pressure roller (2). A pressure-applying roller (4) is arranged in the embossing area (1) in a manner pressed against the pressure roller (2). In the die frame (5) of the transfer device (10), two film web rollers (film web rollers) (6) and (7) are arranged, which can be driven to rotate by a motor. Of course, the film web rollers (6) and (7) can also be installed and arranged in a manner other than in the die frame (5), for example in a cabinet element or outside the actual transfer device (10). A master film web (8) representing a continuous embossing die is wound onto the film webs (6) and (7), which are shown here as being arranged in the die frame. The master film web (8) carries a master coating on the transfer surface, in which a negative form of the microstructure and / or nanostructure to be transferred is present as a surface relief. The master coating is at least partially cured, so that the relief-like structure therein is stable. The master film web (8) constitutes a composite material (F2B2). The master film roll (8) is unwound from the first film roll (6), supplied to the embossing area (1) via various deflection roller systems and - as Figure 1As can be seen in the figure - vertically from above it enters the area between the pressure roller (2) and the pressure-applying roller (4). In this area it is guided in tension to a section of the outer circumference of the pressure roller (2), then leaves the pressure roller (2) again and is supplied to the second film roll (7) again via a deflection roller system with web tensioners and is wound onto it. The film roll (9) constituting the substrate (F1) to be provided with a structure, such as a microstructure and / or nanostructure - is supplied - starting from the film roll (11), here also passing through various deflection roller systems with web tensioners, to the embossing zone (1), where it is tensioned over a section of the outer circumference of the pressure-applying roller (4) and from here enters the contact area of ​​the pressure-applying roller (4) on the pressure roller (2) or into the roller pressure zone formed between these two elements. The film roll (9) is supplied according to Figure 1In the illustration of FIG. 1 , the film roll (9) leaves this area vertically downward and is guided - again via a deflection roller system and a web tensioner - to a film roll (12) on which it is wound as a completely processed product. During its entry into the embossing zone (1) or into the roller nip between the pressure roller (2) and the pressure-applying roller (4), the film roll (9) is provided with a coating on its surface facing the pressure roller (2) in the nip zone (1) by means of a coating application unit (27) which is arranged outside the nip zone (1) in this case. The coating application unit (27) thus applies the coating composition (B1a) to the film roll (9) used as (F1) according to step (1-i) of the method according to the invention. In the nip zone (1), the film roll (9) then meets, with its surface with the uncured coating, the surface of the master film roll (8) with the master coating, in order to carry out step (2-i) of the method according to the invention. Before the transfer of the structure, the master coating is moistened with at least one organic solvent and / or at least one reactive diluent by means of an ultrasonic nozzle. In this case, the film roll (9) runs past the pressure-applying roller (4) and the master film roll (8) runs past the pressure roller (2). The two webs, the film roll (9) and the master film roll (8), face each other with their respective coatings (in the case of the master film roll (8), an at least partially cured master coating corresponding to the coating (B2); in the case of the film roll (9), an uncured coating corresponding to the coating composition (B1a)). In the region where the pressure-applying roller (4) is pressed against the pressure roller (2), the structure to be transferred, such as the negative image of the microstructure and / or nanostructure (this negative image is formed in the master coating (B2)), is pressed into the uncured coating corresponding to the coating composition (B1a), and the structure is thereby transferred. At the same time, by means of the lighting unit (2), UV irradiation and thus at least partial curing of the uncured coating (which corresponds to the coating composition (B1a) of the coating on the film roll (9) takes place, as long as this coating is still in contact with the master coating (8). Thus, at least partial curing of the coating takes place directly during the structure transfer and in situ. Here, the irradiation of the film roll (9) or the uncured coating applied thereto is achieved through the film material (9) when irradiating from the outside onto the press cylinder (2). Alternatively, the irradiation is carried out through the fused silica material of the outer surface of the press cylinder (2) and also through the material of the master film roll (8) and the master coating applied thereto. Accordingly, the master film roll (8) and the master coating are designed to be transparent to the radiation used, in this case UV light. The outer surface of the press cylinder (2) is described here as consisting of fused silica. However, any other material is also suitable in principle here, as long as it is transparent to the curing radiation emitted from the inside of the press cylinder (2) (which may not be UV light). Alternatively, instead of the lighting unit (3) supplying UV radiation, it is also possible, for example, to use a thermal emitter if the coating composition (B1a) is a non-radiation-curing coating composition.One possibility after at least partial curing by UV irradiation is an optional post-exposure, for example by means of infrared radiation. At the end of this curing operation of optional step (4) of the method according to the invention, the film roll (9) and the master film roll (8) are separated from each other with the separation of the now structured layer composite material (F1B1) and the master film element (F2B2). The coated film roll (9) with the desired structuring (i.e. the composite material (F1B1)) is thus supplied as a finished product to the film reel (12) and wound thereon. If the pressure roller (2) is illuminated from the outside by means of the lighting unit (3), the coated film roll (9) with the desired structuring (i.e. the composite material (F1B1)) can also be opaque - if this arrangement is selected to exchange the master film roll (8) (i.e. the composite material (F2B2)) and the film roll (9) (i.e. the composite material (F1B1)). The coating according to step (1-i) of the method according to the invention on the coating application unit (27) can then not be limited to the operation on the master film roll (8).

[0080] Figure 2 A schematic side view of an apparatus which can be used to carry out steps (1-i) and (2-i) and optionally (3) and optionally (4) of the method according to the invention and which serves to illustrate the method according to the invention by way of example. With the aid of such an apparatus, it is particularly possible to transfer structures, such as microstructures and / or nanostructures, onto a substrate (F1) coated with (B1a) with the aid of a conventional embossing tool (P1) and, after at least partial curing, to obtain a composite material (F1B1).

[0081] Figure 2The device (30) shown in the figure operates according to the transfer principle, wherein the desired negative structure is embossed directly from a structured press cylinder or roller (which in this case is a master roller (17)) into a not yet cured coating (corresponding to the composite material (F1B1a)) applied to a master film roll (8b), and this coating is then at least partially cured with the structure applied thereto, in situ with the aid of an illumination unit (3) to produce a master film roll (8) - corresponding to the composite material (F1B1). In this method, a film roll (8a) serving as a substrate (F1) is withdrawn from a film roll (18), which contains only carrier material, in other words, a pure film without an applied master coating, and is guided via various deflection roller systems and web tensioning systems and introduced into the embossing zone (1) of the device. Here, the film roll (8a) enters the area between the pressure application roller (4) and the master roller (17) and is provided with an not yet cured master coating (corresponding to the coating composition B1a) in a coating application device (27) outside the embossing zone. In the embossing zone (1), in which the master film roll (8b) with the master coating which has not yet been cured is guided along a section of the outer surface of the master roller (17), the microstructures and / or nanostructures embossed into the outer surface of the master roller (17) are introduced as a negative image into the master coating of the master film roll (8b) and transferred. Before the structures are transferred, the microstructures and / or nanostructures embossed into the outer surface of the roller (17) are moistened with at least one organic solvent and / or at least one reactive diluent by means of an ultrasonic nozzle. The master film roll (8b) with the uncured coating composition (B1a) is then at least partially cured according to the optional step (3) of the method according to the invention. The curing is carried out in situ by irradiation with an illumination unit (3) by means of ultraviolet radiation, for example by means of a unit formed by UV-LEDs. The resulting master film (8), in other words the composite material (F1B1), is then removed from the outer surface of the master roller (17), and the master film roll (8) thus completed is wound onto a film reel (19). The film roll (19) then contains the finished master film roll (8) with the master coating applied thereto and the negative image of the microstructures and / or nanostructures embossed therein. This film roll (19) can be removed and then used as a Figure 1 The first film roll (6) is a transfer device (10) of the present invention or another transfer device operating on the same principle.

[0082] Coating composition (B1a)

[0083] Any kind of coating composition can be used as coating composition (B1a) in the method of the present invention. The coating composition (B1a) can be a physically drying, heat-curable, chemically curable and / or radiation-curable coating composition (B1a). The coating composition (B1a) is preferably a chemically curable, heat-curable and / or radiation-curable coating composition, more preferably a radiation-curable coating composition. Accordingly, the at least partial curing according to optional step (3) is preferably carried out by means of radiation curing.

[0084] Physical drying here preferably means simple evaporation of the solvent to form the coating (B1). Thermal curing here preferably requires a curing mechanism attributable to temperatures above room temperature (>23° C.). This can be, for example, the formation of free radicals or ions, preferably free radicals from initiators that decompose at elevated temperatures, thus initiating free radical polymerization or ionic polymerization. Examples of such thermally activatable initiators are those whose half-life at 80° C. is less than 100 hours. Chemical curing preferably involves the reaction of at least two different and complementary reactive functional groups, for example in the form of polycondensation, such as the reaction of OH groups with COOH groups, or in the form of polyaddition (reaction of NCO groups with OH or amino groups).

[0085] If the coating composition (B1a) is a physically drying, heat-curable and / or chemically curable coating composition, it is prepared using at least one conventional polymer known to the skilled person as a binder. Such a binder therefore preferably has crosslinkable functional groups. Any conventional crosslinkable functional groups known to the skilled person are suitable in this regard. More particularly, the crosslinkable functional groups are selected from hydroxyl groups, amino groups, carboxylic acid groups, isocyanates, polyisocyanates and epoxy groups. The polymer is preferably exothermic or endothermic curable or crosslinkable, preferably in a temperature range of -20°C to 250°C, or 18°C ​​to 200°C. Particularly suitable as a polymer is at least one polymer selected from polyurethanes, polyethers, polyesters, polyamides, polyureas, polyvinyl chlorides, polystyrenes, polycarbonates, poly(meth)acrylates, epoxy resins, phenol-formaldehyde resins, melamine-formaldehyde resins. The polymer can be OH-functional in particular here. In this case, they can be classified under the general term "polyols". Such polyol can be for example polyacrylate polyol, polyester polyol, polyether polyol, polyurethane polyol, polyurea polyol, polyester-polyacrylate polyol, polyester-polyurethane polyol, polyurethane-polyacrylate polyol, polyurethane-modified alkyd resin, fatty acid-modified polyester-polyurethane polyol and the mixture of specified polyol. Preferred are polyacrylate polyol, polyester polyol and polyether polyol.

[0086] In this context, it is possible to use at least one polymer that cures with the participation of isocyanate and / or oligoisocyanate groups, very preferably at least one corresponding polyurethane and / or at least one corresponding polyurea (e.g. so-called "polyaspartic acid adhesives"). Polyaspartic acid adhesives are components that are converted by reaction of amino-functional compounds, especially secondary amines, with isocyanates. If at least one polyurethane is used, suitable are in particular polyurethane-based resins that can be prepared by polyaddition reactions between hydroxyl-containing components, such as polyols and at least one polyisocyanate (aromatic and aliphatic isocyanates, di-, tri- and / or polyisocyanates). This usually requires a stoichiometric conversion of the OH groups of the polyols with the NCO groups of the polyisocyanates. However, the stoichiometric ratio used can also be varied, since polyisocyanates can be added to the polyol component in amounts that lead to "overcrosslinking" or "undercrosslinking". If epoxy resins, i.e. epoxy-based resins, are used, suitable are preferably epoxy-based resins prepared from glycidyl ethers having terminal epoxy groups and hydroxyl groups as functional groups in the molecule. These are preferably reaction products of bisphenol A and epichlorohydrin or bisphenol F and epichlorohydrin and mixtures thereof, which are also used in the presence of reactive diluents. Curing or crosslinking of such epoxy resins is conventionally achieved by polymerization of the epoxy groups of the epoxy rings, by polyaddition reactions in the form of addition reactions of stoichiometric amounts of other reactive compounds as hardeners to the epoxy groups (in this case, the presence of one active hydrogen equivalent per epoxy group is correspondingly required (i.e. one H active equivalent is required per epoxy equivalent for curing)) or by polycondensation via epoxy groups and hydroxyl groups. Examples of suitable hardeners are polyamines, in particular (hetero)aliphatic, (hetero)aromatic and (hetero)alicyclic polyamines, polyamidoamines, polyaminoamides, and also polycarboxylic acids and their anhydrides.

[0087] The coating composition (B1a) can be cured by using a radiation source, preferably UV radiation. (B1a) is therefore preferably a UV radiation-curable coating composition.

[0088] (B1a) therefore preferably contains unsaturated carbon double bonds, more preferably (meth)acrylic acid groups. Such coating compositions (B1a) preferably contain at least one urethane (meth)acrylate. In the case of curing with (N)IR and / or UV light, the coating composition (B1a) preferably comprises at least one photoinitiator which can be decomposed into free radicals by light of the irradiated wavelength, which free radicals can subsequently initiate free radical polymerization. In the case of curing with electron radiation, in contrast, the presence of such a photoinitiator is not necessary.

[0089] The coating composition (B1a) is preferably a radiation-curable coating composition. The terms "radiation-curable" and "radiation-curable" are interchangeable herein. The term "radiation-curing" preferably refers to the use of electromagnetic radiation and / or participating radiation, for example (N)IR light in the wavelength range of λ=>400-1200nm, preferably 700-900nm, and / or UV light in the wavelength range of λ=100 to 400nm, preferably λ=200 to 400nm, more preferably λ=250 to 400nm, and / or in the range of 150 to 300keV, more preferably with at least 80, preferably 80 to 3000mJ / cm 2 The free radical polymerization of the polymerizable compound can be carried out by electron radiation with a radiation dose of 10000 Å. As radiation curing, it is particularly preferred to use ultraviolet radiation for curing. The coating composition (B1a) can be cured using a suitable radiation source. Therefore, (B1a) is preferably a UV radiation curable coating composition.

[0090] For curing with (N)IR and / or UV light, the coating composition (B1a) comprises as component (a) at least one photoinitiator. Such a photoinitiator can be decomposed by light of the radiation wavelength into free radicals, which in turn can initiate free radical polymerization. In contrast, in the case of curing with electron radiation, the presence of such a photoinitiator is not necessary. The coating composition (B1a) preferably comprises as component (a) at least one photoinitiator, which can be decomposed by light of the radiation wavelength into free radicals, which in turn can initiate free radical polymerization.

[0091] Photoinitiators, such as UV photoinitiators are known to the skilled person. Examples of those that come into consideration include phosphine oxides, benzophenones, α-hydroxyalkyl aryl ketones, thioxanthones, anthraquinones, acetophenones, benzoin and benzoin ethers, ketals, imidazoles or phenylglyoxylic acid and mixtures thereof.

[0092] The phosphine oxide is, for example, a monoacyl or bisacyl phosphine oxide, for example 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphinate or bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide. The benzophenone is, for example, benzophenone, 4-aminobenzophenone, 4,4'-bis(dimethylamino)benzophenone, 4-phenylbenzophenone, 4-chlorobenzophenone, Michler's ketone, o-methoxybenzophenone, 2,4,6-trimethylbenzophenone, 4-methylbenzophenone, 2,4-dimethylbenzophenone, 4-isopropylbenzophenone, 2-chlorobenzophenone, 2,2'-dichlorobenzophenone, 4-methoxybenzophenone, 4-propoxybenzophenone or 4-butoxybenzophenone. , α-Hydroxy-alkylaryl ketones are, for example, 1-benzoylcyclohexan-1-one (1-hydroxycyclohexyl phenyl ketone), 2-hydroxy-2, 2-dimethylacetophenone, (2-hydroxy-2-methyl-1-phenyl-propan-1-one), 1-hydroxyacetophenone, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one or polymers which contain two hydroxy-2-methyl-1-(4-isopropen-2-ylphenyl)propan-1-ones in copolymerized form. Xanthone and thioxanthone are, for example, 10-thioxanthone, thioxanth-9-one, xanth-9-one, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2,4-dichlorothioxanthone or chloroxanthone; anthraquinone is, for example, β-methylanthraquinone, tert-butylanthraquinone, anthraquinone carboxylate, benz[de]anthraquinone-7-one, benz[a]anthraquinone-7,12-dione, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone or 2-amylanthraquinone. Acetophenones are, for example, acetophenone, acetylnaphthoquinone, valerophenone, hexanophenone, α-phenylbutyrophenone, p-morpholinopropiophenone, dibenzosuberone, 4-morpholinobenzophenone, p-diacetylbenzene, 4′-methoxyacetophenone, α-tetralone, 9-acetylphenanthrene, 2-acetylphenanthrene, 3-acetylphenanthrene, 3-acetylindole, 9-fluorenone, 1-indanone, 1,3,4-triacetylbenzene, 1-acetonaphthone, 2-acetonaphthone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxyacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1-[4-(methylthio)phenyl]2-morpholinopropan-1-one, 2,2-dimethoxy-1,2-diphenylethan-2-one or 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one. Benzoin and benzoin ethers are, for example, 4-morpholino-deoxybenzoin, benzoin, benzoin isobutyl ether, benzoin tetrahydropyranyl ether, benzoin methyl ether, benzoin ethyl ether, benzoin butyl ether, benzoin isopropyl ether or 7H-benzoin methyl ether.Ketals are, for example, acetophenone dimethyl ketal, 2,2-diethoxyacetophenone or benzil ketal, such as benzil dimethyl ketal. Examples of photoinitiators that may also be used are benzaldehyde, methyl ethyl ketone, 1-naphthaldehyde, triphenylphosphine, tri-o-tolylphosphine, or 2,3-butanedione. Typical mixtures contain, for example, 2-hydroxy-2-methyl-1-phenylpropan-2-one and 1-hydroxycyclohexyl phenyl ketone, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide and 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzophenone and 1-hydroxycyclohexyl phenyl ketone, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide and 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide and 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2,4,6-trimethylbenzophenone and 4-methylbenzophenone, or 2,4,6-trimethylbenzophenone and 4-methylbenzophenone and 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

[0093] Preferred among these photoinitiators are 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphinate, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, benzophenone, 1-benzoylcyclohexan-1-ol, 2-hydroxy-2,2-dimethylacetophenone and 2,2-dimethoxy-2-phenylacetophenone. Preferably, therefore, at least one such photoinitiator is used as component (a). Examples of commercially available photoinitiators are the products PANOL® from BASF SE. 184. 500, TPO, TPO-L and TPO and 1173.

[0094] The coating composition (B1a) preferably comprises at least one component (b) which contains at least one, preferably terminal, carbon double bond. This is preferably a (meth)acrylic acid group. Component (b) preferably contains one or two ethylenically unsaturated groups, for example one or two or three or more (meth)acrylic acid groups. It is also possible to use two or more different components (b).

[0095] Examples of component (b) are mono-, di- and / or trifunctional (meth)acrylates, such as ethylene glycol di(meth)acrylate, 1,2-propylene glycol di(meth)acrylate, 1,3-propylene glycol di(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,1-, 1,1-butylene glycol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,1-butylene glycol di(meth)acrylate, 1,1-butylene glycol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,1-butylene glycol di(meth)acrylate, 1,1-butylene glycol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,1-butylene glycol di(meth)acrylate, 1,3 ... 2-, 1,3- and 1,4-cyclohexanedimethanol di(meth)acrylate, 1,2-, 1,3- or 1,4-cyclohexanediol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane penta- or hexa(meth)acrylate, pentaerythritol tri- or tetra(meth)acrylate, glycerol di- or tri(meth)acrylate and sugar alcohols such as sorbitol, mannitol, diglycerol, threitol, erythritol, adonitol (ribitol), arabitol di- and poly(meth)acrylates of (lyxitol), xylitol, dulcitol (galactitol), maltitol or isomalt, 2-phenoxyethyl (meth)acrylate, ethyl diglycol (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, trimethylolpropane methylal mono(meth)acrylate, isobornyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, and dodecyl (meth)acrylate, octadecyl (meth)acrylate Alkyl esters, isodecyl (meth)acrylate, octyl (meth)acrylate and decyl (meth)acrylate, esters of α,β-ethylenically unsaturated carboxylic acids, preferably (meth)acrylic acid, with alcohols having 1 to 20 carbon atoms, preferably optionally hydroxy-substituted alkanols having 1 to 20 carbon atoms, for example methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate or 4-hydroxybutyl (meth)acrylate.

[0096] Particularly preferred components (b) are 1,4-butanediol di(meth)acrylate and 1,6-hexanediol di(meth)acrylate, and also tricyclodecane dimethanol di(meth)acrylate.

[0097] As component (b), it is also possible, additionally or alternatively, to use at least one polyester, polyether, carbonate, epoxide, poly(meth)acrylate and / or urethane(meth)acrylate, and / or unsaturated polyester resin.

[0098] Urethane (meth) acrylates are obtainable, for example, by reacting polyisocyanates with hydroxyalkyl (meth) acrylates and optionally chain extenders, such as diols, polyols, diamines, polyamines or dithiols or polythiols. Urethane (meth) acrylates, which are dispersible in water without the addition of emulsifiers, additionally contain ionic and / or nonionic hydrophilic groups, which are introduced into the urethane by means of constituents, such as hydroxycarboxylic acids. Urethane (meth) acrylates of this type essentially contain the following as constituents:

[0099] (a) at least one organic aliphatic, aromatic or cycloaliphatic di- or polyisocyanate, for example at least one polyisocyanate as described above for the two-component coating material,

[0100] (b) at least one compound having at least one isocyanate-reactive group, preferably one of the hydroxyl-containing monomers described above for the polyacrylate polyol, and having at least one free-radically polymerizable unsaturated group, and

[0101] (c) optionally at least one compound having at least two isocyanate-reactive groups, for example one of the polyols described above for the polyesterols.

[0102] The urethane (meth)acrylate preferably has a number average molar weight M of 200 to 20 000, in particular 500 to 10 000, more preferably 600 to 3000 g / mol. n (determined by gel permeation chromatography using tetrahydrofuran and polystyrene standards). The urethane (meth)acrylate preferably has a (meth)acrylic acid group content of 1 to 5, more preferably 2 to 4 mol / 1,000 g of urethane (meth)acrylate. Examples of commercially available urethane (meth)acrylates that can be used as component (b) are or Series of products, such as UA 9033, UA 9065 or XP 2738.

[0103] Epoxy (meth) acrylates can be obtained by reacting epoxides with (meth) acrylic acid. Examples of suitable epoxides include epoxidized olefins, aromatic glycidyl ethers or aliphatic glycidyl ethers, preferably those of aromatic or aliphatic glycidyl ethers. Examples of possible epoxidized olefins include ethylene oxide, propylene oxide, isobutylene oxide, 1-butene oxide, 2-butene oxide, vinyl ethylene oxide, styrene oxide or epichlorohydrin, preferably ethylene oxide, propylene oxide, isobutylene oxide, vinyl ethylene oxide, styrene oxide or epichlorohydrin, particularly preferably ethylene oxide, propylene oxide or epichlorohydrin, very particularly preferably ethylene oxide and epichlorohydrin. Aromatic glycidyl ethers are, for example, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol B diglycidyl ether, bisphenol S diglycidyl ether, hydroquinone diglycidyl ether, alkylation products of phenol / dicyclopentadiene, for example 2,5-bis[(2,3-epoxypropoxy)phenyl]octahydro-4,7-methylene-5H-indene, tris[4-(2,3-epoxypropoxy)phenyl]methane isomers, phenolic epoxy novolac resins and cresol epoxy novolac resins. Examples of aliphatic glycidyl ethers are 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, 1,1,2,2-tetrakis[4-(2,3-epoxypropoxy)phenyl]ethane, diglycidyl ether of polypropylene glycol (α,ω-bis(2,3-epoxypropoxy)poly(oxypropylene)) and diglycidyl ether of hydrogenated bisphenol A (2,2-bis[4-(2,3-epoxypropoxy)cyclohexyl]propane). The epoxy(meth)acrylate preferably has a number average molar weight M of 200 to 20 000, more preferably 200 to 10 000 g / mol, very preferably 250 to 3000 g / mol. n The amount of (meth)acrylic acid groups is preferably 1 to 5, more preferably 2 to 4 per 1000 g of epoxy (meth)acrylate (determined by gel permeation chromatography using polystyrene as standard and tetrahydrofuran as eluent).

[0104] (Meth)acrylated poly(meth)acrylates are the corresponding esters of α,β-ethylenically unsaturated carboxylic acids, preferably (meth)acrylic acid, more preferably acrylic acid, and polyacrylate polyols obtainable by esterification of poly(meth)acrylate polyols with (meth)acrylic acid. The polyacrylate polyols may, for example, be those described above for the two-component coatings.

[0105] Carbonate (meth)acrylates are available in various functionalities. The number average molecular weight M of carbonate (meth)acrylates is nPreferably less than 3000 g / mol, more preferably less than 1500 g / mol, more preferably less than 800 g / mol (determined by gel permeation chromatography with polystyrene as standard; solvent: tetrahydrofuran). Carbonate (meth) acrylates are easily obtained by transesterification of carbonates with polyols, preferably diols (diols, for example hexanediol) and subsequent esterification of free OH groups with (meth) acrylic acid or by transesterification with (meth) acrylates as described, for example, in EP 0 092 269 A1. They can also be obtained by reacting phosgene, urea derivatives with polyols, for example diols. Also contemplated are (meth) acrylates of polycarbonate polyols, such as reaction products of one of the diols or polyols mentioned and carbonates, as well as hydroxyl-containing (meth) acrylates. Examples of suitable carbonates include ethylene carbonate, 1,2- or 1,3-propylene carbonate, dimethyl carbonate, diethyl carbonate or dibutyl carbonate. Examples of suitable hydroxyl-containing (meth)acrylates are 2-hydroxyethyl (meth)acrylate, 2- or 3-hydroxypropyl (meth)acrylate, 1,4-butanediol mono(meth)acrylate, neopentyl glycol mono(meth)acrylate, glycerol mono- and di(meth)acrylate, trimethylolpropane mono- and di(meth)acrylate and pentaerythritol mono-, di- and tri(meth)acrylate. The carbonate (meth)acrylate is preferably an aliphatic carbonate (meth)acrylate.

[0106] Unsaturated polyester resin is preferably synthesized from the following components:

[0107] (a1) maleic acid or its derivatives,

[0108] (a2) at least one cyclic dicarboxylic acid or a derivative thereof,

[0109] (a3) at least one aliphatic or alicyclic diol.

[0110] Derivatives are preferably

[0111] - the corresponding anhydrides in monomeric or polymeric form,

[0112] - a mono- or di-alkyl ester, preferably a mono- or di-C1-C4-alkyl ester, more preferably a mono- or di-methyl ester or the corresponding mono- or di-ethyl ester,

[0113] - mono- and divinyl esters, and

[0114] - mixed esters, preferably mixed esters with different C1-C4-alkyl components, more preferably mixed methyl ethyl esters.

[0115] If (B1a) comprises a component (b), this component is preferably at least one urethane (meth)acrylate.

[0116] The coating component (B1a) may further comprise additives as component (c). The term "additives" is used by the skilled person from e.g. Lexikon, "Lacke und Druckfarben", Thieme Verlag, 1998, page 13. Preferably used as component (c) is at least one rheological additive. This term is also used by the skilled worker from, for example Lexikon, "Lacke und Druckfarben", Thieme Verlag, 1998, p. 497. The terms "rheological additives" and "rheological adjuvants" are interchangeable. The additives used as component (c) are preferably selected from flow control agents, surface-active agents such as surfactants, wetting agents and dispersants, and thickeners, thixotropic agents, plasticizers and lubricating and antiblocking additives, and mixtures thereof. These terms are likewise familiar to the skilled person from, for example, Lexikon, "Lacke und Druckfarben", Thieme Verlag, 1998. Flow control agents are components which help the coating composition to flow into a smooth film by reducing the viscosity and / or the surface tension. Wetting agents and dispersants are components which reduce the surface tension or generally the interfacial tension. Lubricating and antiblocking additives are components which reduce adhesion (blocking). Examples of commercially available additives are the products SL 3259, 377, Rad 2500, Rad 2800, 394, Byk-SILCLEAN 3710, A250, Novec FC 4430 and Novec FC 4432. Preferred as additive (c) are at least one poly(meth)acrylate and / or at least one siloxane, such as at least one oligosiloxane and / or polysiloxane, and / or at least one fluorine-containing polymer, such as a fluorine-containing, preferably aliphatic polyester. Particularly preferred are siloxanes as component (c). Particularly preferred are silicone (meth)acrylates.

[0117] The coating composition (B1a) may comprise at least one additional component (d) different from components (a) and (b) and (c), for example fillers, pigments, heat-activatable initiators, for example potassium peroxodisulfate, dibenzoyl peroxide, cyclohexanone peroxide, di-tert-butyl peroxide, azobisisobutyronitrile, cyclohexylsulfonylacetyl peroxide, diisopropyl percarbonate, tert-butyl peroctoate or benzopinacol, di-tert-butyl peroxide, cumene hydroperoxide, diisopropyl peroxide, tert-butyl perbenzoate, silylated pinacol, hydroxyl-containing amine N-oxides, for example 2,2,6,6-tetramethylpiperidine-N-oxyl and 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, and organic solvents and stabilizers. Preferably, however, no organic solvent is present in (B1a). Component (c) may be present in (B1a) in an amount in the range from 0 to 15% by weight, preferably in the range from 0 to 12% by weight, more preferably in the range from 0 to 10% by weight, in each case based on the total weight of the coating composition (B1a).

[0118] The coating composition (B1a) preferably comprises

[0119] at least one photoinitiator as component (a) in an amount in the range of 0.01 to 15 wt. %, preferably in the range of 0.1 to 12 wt. %, more preferably in the range of 0.5 to 10 wt. %,

[0120] the at least one component (b) in an amount in the range of 40 to 99 wt. %, preferably in the range of 45 or >45 to 90 wt. %, more preferably in the range of 50 or >50, such as in the range of 55 to 85 wt. %, very preferably in the range of 55 or 60 to 80 wt. %,

[0121] The at least one additive as component (c) in an amount in the range of 0.01 to 5 wt. %, preferably in the range of 0.05 to 4.5 wt. %, more preferably in the range of 0.1 to 4 wt. %, very preferably in the range of 0.2 or 0.5 to 3 wt. %

[0122] In each case based on the total weight of the coating composition (B1a).

[0123] The solids content of the coating composition (B1a) is preferably ≥80% by weight, more preferably ≥90% by weight, very preferably ≥95% by weight, more particularly ≥98 or ≥99% by weight, most preferably 100% by weight, in each case based on the total weight of the coating composition (B1a). The solids content is determined here by means of the method described below.

[0124] The at least partially cured coating (B1) obtained from (B1a) preferably has a double bond conversion of at least 70%, more preferably at least 75%, even more preferably at least 80%, very preferably at least 85%, more particularly at least 90%.

[0125] Preprocessing

[0126] The method of the present invention comprises - before carrying out step (2-i) and before carrying out step (1-ii) - pre-treating the at least one embossing die (p1) of the embossing tool (P1) with at least one organic solvent and / or at least one reactive diluent. The pre-treatment preferably comprises wetting (spraying) the at least one embossing die (p1) with at least one organic solvent and / or at least one reactive diluent. Wetting is preferably achieved with the aid of at least one nozzle, more preferably with the aid of at least one ultrasonic nozzle. Wetting is preferably carried out by forming a mist, more preferably in the form of droplets, which condense on the embossing die (p1) of the embossing tool (P1) and thereby cover it with a liquid film. It is preferred to completely wet the embossing die (p1) of the embossing tool (P1), i.e., to wet the entire embossing die, including all structural protrusions, especially over the entire range of structural width and structural depth.

[0127] The term "organic solvent" is known to the skilled person, for example, from Council Directive 1999 / 13 / EC of 11 March 1999 (referred to therein as solvent). In the pretreatment step carried out according to the invention, it is in principle possible to use any customary organic solvent known to the skilled person. The term "reactive diluent" is likewise known to the skilled person, for example from Lacke und Druckfarben, Thieme Verlag, 1998, page 491. Accordingly, the term "reactive diluent" refers to a diluent that becomes part of the binder used during film formation. The term "binder" in the sense of the present invention preferably refers to the non-volatile matter of the coating composition responsible for film formation according to DIN EN ISO 4618 (German version, date: March 2007). Pigments and / or fillers contained therein are not included in the concept of binders. In principle, any conventional reactive diluent known to the technician can be used in the pretreatment step carried out in the present invention.

[0128] The at least one organic solvent is preferably selected from monohydric alcohols and polyhydric alcohols, such as the corresponding C1-C 12Alcohols, for example methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, ethylene glycol, ethyl glycol, propyl glycol, butyl glycol, butyl diglycol, 1,2-propylene glycol and / or 1,3-propylene glycol, ethers, for example diethylene glycol dimethyl ether, aliphatic hydrocarbons, aromatic hydrocarbons, for example toluene and / or xylene, ketones, for example acetone, N-methylpyrrolidone, N-ethylpyrrolidone, methyl isobutyl ketone, isophorone, cyclohexanone and / or methyl ethyl ketone, esters, for example methoxypropyl acetate, ethyl acetate and / or butyl acetate, amides, for example dimethylformamide and mixtures thereof. Particular preference is given to monohydric and polyhydric alcohols, for example the corresponding C1-C6 alcohols; particular preference is given to the corresponding C1-C4 alcohols, for example ethanol.

[0129] The at least one reactive diluent is preferably selected from the group consisting of monofunctional (meth)acrylates, difunctional (meth)acrylates, trifunctional (meth)acrylates and polyfunctional, such as tetrafunctional and pentafunctional (meth)acrylates, and mixtures thereof.

[0130] Suitable monofunctional (meth)acrylates are, for example, 2-phenoxyethyl (meth)acrylate or more highly ethoxylated phenoxy (meth)acrylates, ethyl diglycol (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, trimethylolpropane formal mono(meth)acrylate, isobornyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate and also butyl (meth)acrylate, hexyl (meth)acrylate, dodecyl (meth)acrylate, octadecyl (meth)acrylate, isodecyl (meth)acrylate, octyl (meth)acrylate and decyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate.

[0131] Suitable difunctional (meth)acrylates are, for example, ethylene glycol di(meth)acrylate, 1,2-propylene glycol di(meth)acrylate, 1,3-propylene glycol di(meth)acrylate, 1,4-butylene glycol di(meth)acrylate, 1,3-butylene glycol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate. , 1,1-, 1,2-, 1,3- and 1,4-cyclohexanedimethanol di(meth)acrylate, 1,2-, 1,3- or 1,4-cyclohexanediol di(meth)acrylate, glycerol di(meth)acrylate, sugar alcohols such as sorbitol, mannitol, diglycerol, threitol, erythritol, adonitol (ribitol), lyxitol, xylitol, dulcitol (galactitol), maltitol or isomalt di(meth)acrylate.

[0132] Suitable trifunctional (meth)acrylates are, for example, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, glycerol triacrylate, and also tri(meth)acrylates of sugar alcohols, for example sorbitol, mannitol, diglycerol, threitol, erythritol, adonitol (ribitol), lyxitol, xylitol, dulcitol (galactitol), maltitol or isomalt.

[0133] Suitable polyfunctional (meth)acrylates are, for example, ditrimethylolpropane penta- or hexa(meth)acrylate, pentaerythritol tetra(meth)acrylate, and poly(meth)acrylates of sugar alcohols, for example sorbitol, mannitol, diglycerol, threitol, erythritol, adonitol (ribitol), arabitol (lyxitol), xylitol, dulcitol (galactitol), maltitol or isomalt.

[0134] use

[0135] Another subject matter of the present invention is the use of an embossing tool (P1) comprising at least one embossing punch (p1) for transferring an embossed structure to at least a portion of the surface of a coating composition (B1a), wherein the at least one embossing punch (p1) of the embossing tool (P1) has been pretreated with at least one organic solvent and / or at least one reactive diluent before the transfer, and the embossed structure transferred to the coating composition (B1a) preferably comprises a microstructure with a structure depth of >30 μm.

[0136] All preferred embodiments described above in connection with the process according to the invention are also preferred embodiments with regard to the use according to the invention.

[0137] Determination method

[0138] 1. Determination of non-volatile matter

[0139] The non-volatile matter (solids content) is determined in accordance with DIN EN ISO 3251 (date: June 2008). This determination is carried out by weighing 1 g of sample into a pre-dried aluminum pan and drying in a drying oven at 125° C. for 60 minutes, followed by cooling in a desiccator and then reweighing. The residue relative to the total amount of sample used corresponds to the non-volatile matter.

[0140] 2. Determining the stamping accuracy

[0141] The embossing accuracy is determined with the aid of a commercially available atomic force microscope (AFM) and using a commercially available cantilever. With the aid of the AFM, it is possible to compare, for example, the surface topography of a specified lattice structure, such as the lattice structure of the embossing tool P1, with a depth of, for example, 140 nm and a period of, for example, 430 nm, with the surface topography of the master film (B1F1) after embossing. In this case, the embossing tool is deliberately damaged at specific locations in order to define reference points. With the aid of such reference points, it is possible to investigate and compare identical areas of the reference object and the replica with one another. The embossing accuracy defines how accurately a specific reference structure can be transferred, for example from the embossing tool P1 to the master film (B1F1). If, for example, the investigated area of ​​the embossing tool P1 exhibits a lattice structure with a depth of 140 nm, this reference depth is compared with the corresponding height of this structure measured on the master film (B1F1). The percentage change, which corresponds here to the embossing accuracy, is defined as

[0142]

[0143] Δh here corresponds to the percentage change, h m corresponds to the height of the structure in the studied area of ​​the master film, and h r The corresponding depth of the structure corresponds to the investigated area of ​​the embossing tool. This percentage change, in other words the embossing accuracy, is also called "contraction". The smaller the value of Δh, the better the embossing accuracy.

[0144] Examples of the present invention and comparative examples

[0145] The following examples of the present invention and comparative examples are used to illustrate the present invention, but should not be construed as imposing any limitation.

[0146] Unless otherwise indicated, amounts in parts are parts by weight and amounts in % are % by weight in each case.

[0147] 1. Base compounds and materials used

[0148] UA 9033 - Aliphatic urethane acrylate from BASF AG

[0149] 500 - Commercially available photoinitiator from BASF AG

[0150] Byk-057 - Commercial defoamer from BYK Chemie GmbH

[0151] 2. Example

[0152] Embodiment 1 of the present invention: the manufacture of structured film (having microstructure):

[0153] A continuous die with the desired positive structure is made using a roll-to-roll embossing machine with a nickel embossing device with the desired negative structure. A transparent PET film is used as a substrate for this purpose. This film roll is first unwound from a reel and passed through a deflection roller system and a web cleaner to a coating application unit, where the coating is applied through a slot die coating. This enables precise control of the amount of coating applied. By temperature control of the slot coater, it is possible to vary the flow rate per unit time to exert additional influence on the image of the applied coating. The coating used is 93.7 parts by weight UA 9033, 0.7 parts by weight of Byk-057 and 5.6 parts by weight 500. The surface of the film roll to be applied with the desired embossed structure is tensioned and guided under applied pressure through a segment of the outer surface of the pressure roller, another segment of the pressure roller carrying the above-mentioned coating. As the pressure roller rotates and guides the film roll on it, the coating is applied to the surface of the film roll and adheres to it. In the same step, the image of the negative structure of the pressure roller is then also embossed into the coating as a positive structure. The pressure roller used as an embossing tool is moistened with ethanol before use. Wetting is performed via an ultrasonic nozzle. Atomization results in the formation of extremely fine droplets. The solvent mist directed in the direction of the embossing roller condenses on the surface of the structured embossing roller. Since the droplets are much smaller than the structure, they are able to penetrate the "holes" in the structure and provide complete coverage of the liquid film for the material of the embossing tool. While the embossing device is still in contact with the coating, the coating is cured from the direction of the uncoated side of the film with the help of a UV-LED lamp (wavelength 365nm, intensity 80%). The typical power of the UV unit used is about 1300mW / cm 2 At the end of the embossing operation, the film with the coating applied to the surface, exhibiting the microstructures and solidified, is removed from the surface of the embossing roller, these structures then being separated from the negative form. In this way a continuous web of film with a structured surface is obtained, which is then wound up.

[0154] 3. Investigation into structured membranes

[0155] It has been found that, due to the pretreatment carried out, microstructures, in particular structures with a structure depth of >40 μm and an aspect ratio of >1, can be transferred to the coating composition to be embossed with extremely high pressure printing accuracy even at high speeds, without any loss of modulation depth during the embossing process. The same is true for structures whose individual structural elements are not connected to one another but are at least partially present in the form of individual “holes” on the surface of the embossing die of the embossing tool. Although, in the case of such an arrangement of the structural elements in the embossing die, air cannot escape laterally during the embossing operation, but must be removed from the individual structural elements (“holes”), the method according to the invention enables a defect-free transfer of the embossed structure, in particular without shrinkage cavities. Such unwanted shrinkage cavities in the form of bubbles that can occur without the pretreatment according to the invention are not necessarily transferred to the coating composition to be embossed. Figure 3 and 4 In contrast, by means of the pretreatment of the present invention, e.g. Figure 5 and Figure 6 Avoid such shrinkage cavities as is evident in the micrographs.

Claims

1. A method for transferring an embossed structure using an embossing tool (P1), comprising at least steps (1-i) and (2-i) or (1-ii) and (2-ii), in particular (1-i) applying the coating composition (B1a) to at least a portion of the surface of the substrate (F1) to produce a composite material (B1aF1), and (2-i) at least partially embossing the coating composition (B1a) at least partially applied to the surface of the substrate (F1) by means of at least one embossing tool (P1) comprising at least one embossing punch (p1), or (1-ii) applying the coating composition (B1a) to at least a portion of at least a portion of the embossing surface of the embossing punch (p1) of the embossing tool (P1), and (2-ii) applying a substrate (F1) to at least a portion of the surface of the coating composition (B1a) applied to the embossing die (p1) to produce a composite material (B1aF1) on (p1), It comprises pretreating the at least one embossing punch (p1) of the embossing tool (P1) with at least one organic solvent and / or at least one reactive diluent before carrying out step (2-i) and before carrying out step (1-ii), and transferring a microstructure having a structure depth of >30 μm as an embossing structure to the coating composition (B1a) by steps (2-i) and (1-ii), The at least one organic solvent used for the pretreatment is selected from monohydric alcohols and polyhydric alcohols C1-C 12 The at least one reactive diluent used for the pretreatment is selected from the group consisting of monofunctional, difunctional, trifunctional and multifunctional (meth)acrylates and mixtures thereof.

2. The method according to claim 1, wherein the pretreatment carried out before implementing step (2-i) and step (1-ii) comprises wetting the at least one embossing die (p1) with at least one organic solvent and / or at least one reactive diluent.

3. The method according to claim 1, wherein the pretreatment performed before implementing step (2-i) and step (1-ii) is performed using at least one ultrasonic nozzle.

4. The method according to claim 2, wherein the pretreatment performed before implementing step (2-i) and step (1-ii) is performed using at least one ultrasonic nozzle.

5. The method according to any one of claims 1 to 4, wherein the at least one organic solvent used for the pretreatment is selected from C1-C4 alcohols, and the at least one reactive diluent used for the pretreatment is selected from monofunctional, difunctional, trifunctional and multifunctional (meth)acrylates and mixtures thereof.

6. The method according to any one of claims 1 to 4, wherein the microstructure and / or nanostructure is transferred as an embossed structure to the coating composition (B1a) by step (2-i) and step (1-ii).

7. The method according to claim 5, wherein the microstructure and / or nanostructure is transferred as an embossed structure to the coating composition (B1a) by step (2-i) and step (1-ii).

8. The method according to any one of claims 1 to 4, wherein a microstructure having a structure depth of >40 μm is transferred as an embossed structure to the coating composition (B1a) by steps (2-i) and (1-ii).

9. The method according to claim 7, wherein a microstructure having a structure depth of >40 μm is transferred as an embossed structure to the coating composition (B1a) by steps (2-i) and (1-ii).

10. The method according to any one of claims 1 to 4, wherein the embossed structure transferred to the coating composition (B1a) by step (2-i) and step (1-ii) has an aspect ratio >1.

11. The method according to claim 9, wherein the embossed structure transferred to the coating composition (B1a) by step (2-i) and step (1-ii) has an aspect ratio >1.

12. The method according to any one of claims 1 to 4, wherein the coating (B1) obtainable from the coating composition (B1a) and the at least one embossing punch (p1) of the embossing tool (P1) have an embossed structure, wherein the structure of the at least one embossing punch (p1) is the negative structure of the embossed structure of the coating (B1).

13. The method according to claim 11, wherein the coating (B1) obtainable from the coating composition (B1a) and the at least one embossing punch (p1) of the embossing tool (P1) have an embossed structure, wherein the structure of the at least one embossing punch (p1) is the negative structure of the embossed structure of the coating (B1).

14. The method according to any one of claims 1 to 4, comprising, after implementing step (2-i) and step (1-ii), at least one additional step (3), specifically (3) at least partially curing the at least partially embossed coating composition (B1a) obtained after step (2-i) or step (2-ii) within the composite material (B1aF1) to produce a composite material (B1F1) consisting of a substrate (F1) and an at least partially embossed and at least partially cured coating (B1), wherein the coating composition (B1a) is in contact with the at least one embossing die (p1) of the at least one embossing tool (P1) throughout the duration of the at least partial curing.

15. The method according to claim 14, comprising step (4), specifically: (4) Removing the composite material (B1F1) obtained after step (3) from the embossing punch (p1) of the embossing tool (P1).

16. The method according to claim 13, comprising, after carrying out step (2-i) and step (1-ii), at least one additional step (3), specifically (3) at least partially curing the at least partially embossed coating composition (B1a) obtained after step (2-i) or step (2-ii) within the composite material (B1aF1) to produce a composite material (B1F1) consisting of a substrate (F1) and an at least partially embossed and at least partially cured coating (B1), wherein the coating composition (B1a) is in contact with the at least one embossing die (p1) of the at least one embossing tool (P1) throughout the duration of the at least partial curing.

17. The process according to any one of claims 1 to 4, wherein the coating composition (B1a) is a radiation-curable coating composition.

18. The method according to claim 16, wherein the coating composition (B1a) is a radiation-curable coating composition.

19. The method according to any one of claims 1 to 4, wherein the solids content of the coating composition (B1a) is ≥ 90 wt. %, based on the total weight of the coating composition (B1a). 20 . The method according to claim 18 , wherein the solids content of the coating composition (B1a) is ≥ 90 wt %, based on the total weight of the coating composition (B1a).

21. The method according to any one of claims 1 to 4, wherein the coating composition (B1a) comprises at least one component (b) which comprises at least one carbon double bond and is present therein in an amount of 40 to 95% by weight.

22. The method according to claim 20, wherein the coating composition (B1a) comprises at least one component (b) which comprises at least one carbon double bond and is present therein in an amount of 40 to 95% by weight.

23. The method according to any one of claims 1 to 4, wherein the coating composition (B1a) comprises as component (b) at least one monofunctional, difunctional, trifunctional and / or polyfunctional (meth)acrylate.

24. The method according to claim 22, wherein the coating composition (B1a) comprises as component (b) at least one monofunctional, difunctional, trifunctional and / or polyfunctional (meth)acrylate.

25. The method according to any one of claims 1 to 4, wherein the substrate (F1) is a moving film roll.

26. The method according to claim 24, wherein the substrate (F1) is a moving film roll.

27. Use of an embossing tool (P1) comprising at least one embossing punch (p1) for transferring an embossed structure onto at least a portion of the surface of a coating composition (B1a), wherein the at least one embossing punch (p1) of the embossing tool (P1) has been pretreated with at least one organic solvent and / or at least one reactive diluent before the transfer, and the embossed structure transferred to the coating composition (B1a) comprises a microstructure with a structure depth of >30 μm, wherein the at least one organic solvent used for the pretreatment is selected from monohydric alcohols and polyhydric alcohols C1-C 12 The at least one reactive diluent used for the pretreatment is selected from the group consisting of monofunctional, difunctional, trifunctional and multifunctional (meth)acrylates and mixtures thereof.

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