METHOD FOR TRANSFERRING EMBOSSED STRUCTURES TO COATING COMPOSITIONS UNDER PRETREATMENT OF THE EMBOSSING TOOL USED FOR THIS PURPOSE

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) having at least one embossing die (p1), wherein the embossing die (p1) of the embossing tool (P1) is pretreated with at least one organic solvent and / or at least one reactive diluent before carrying out step (2-i) or before carrying out step (1-ii), and to a use of a correspondingly pretreated embossing tool (P1) having at least one embossing die (p1) for the purpose of such a transfer of an embossed structure. State of the art

[0002] In many applications today, it is common practice in technology to provide workpieces with structures on their surfaces whose structural characteristics are in the micrometer or even nanometer range. Such structures are also referred to as microstructures (structures with characteristics in the micrometer range) or nanostructures (structures with characteristics in the nanometer range). Such structures are used, for example, to influence material surfaces with regard to optical, bionic, and / or haptic properties. Such structures are also referred to as embossed structures.

[0003] A common method is to transfer these structures into a lacquer. The transfer of the structures into the lacquer is often achieved with an embossing process, in which a matrix containing the micro- and / or nanostructures to be formed in a negative form on an embossing or transfer surface is brought into contact with the lacquer and pressed into it. In order to then permanently form and maintain the structures on the surface of the workpiece, the lacquer is typically in situ hardened.

[0004] Particularly in the field of haptics and bionics, microstructures in the range of >40 µm and an aspect ratio of >1 are created. The aspect ratio is the ratio of a structure's height to its diameter. For example, the structural elements of the fine structure of a lotus flower are approximately 10-20 µm high and approximately 10-15 µm wide, and the structural elements of the fine structure of a gecko's foot are approximately 100 µm high and approximately 1 µm wide (cf. E. Arzt et al., PNAS 2003, 100, 10603-10606).

[0005] US 2014 / 110371 A1 discloses a method for transferring an embossed structure using an embossing tool.

[0006] DE 10 2004 012 067 A1 describes a method for producing adhesive elements on a carrier material using plastic materials such as elastomers which have structures in the micrometer range.

[0007] WO 2005 / 047549 A1 describes velour-like, fine-fiber surfaces that can have fine structures in the form of raised areas with a length of 110 µm and a diameter of 3-60 µm. To produce such finely structured velour-like surfaces, a polymer dispersion is applied to a carrier surface with a corresponding negative structure and cured, so that the coating material takes on the fine structure. One disadvantage of this process is that it is a discontinuous process.

[0008] DE10 2007 061 980 A1 discloses a method for producing a microstructure, in which a tool mold in the form of a web-shaped plastic film is provided, the surface of which has an arrangement of elevations and depressions in the shape of the desired microstructure, the depressions are filled with a curable first lacquer, the surface of the plastic film is brought into contact with a layer of a curable second lacquer, the first lacquer in contact with the second lacquer is cured in the depressions of the plastic film together with the layer of the second lacquer and is thereby bonded to the layer of second lacquer and the surface of the plastic film is again removed from the second cured lacquer, so that the cured first lacquer bonded to the second lacquer is pulled out of the depressions of the plastic film.The process is used to produce security elements with micro-optical structures, such as micro-optical moiré magnification arrays. The structure depth of the microstructure, according to DE10 2007 061 980 A1, ranges from 1 to a maximum of 20 µm.

[0009] Continuous processes for transferring embossed structures to coating materials, in which, for example, a roll-to-roll printing press is equipped with an embossing device bearing a negative structure on its surface, and in which this structure is transferred to a coating material, are known in the art, especially in the field of optical film production and security printing (holograms). For an economical process with the highest possible molding accuracy (the most exact replication of the negative structure possible without significant losses), the use of radiation-curable coating materials, in particular, has proven particularly advantageous.Such coating materials allow the liquid coating material used to be at least partially cured while still in contact with the embossing tool, such as an embossing roller, thereby achieving good structural fidelity at high line speeds. Such processes are described, for example, in WO 88 / 09252 A1 and WO 94 / 18609 A1. WO 2009 / 121357 A1 also discloses such a process for producing optical films, in which the coating material is first applied to a carrier film using known application methods and then embossed. A comparable process is also disclosed, for example, in DE 41 32 476 A1.

[0010] A disadvantage of these known methods mentioned above, however, is that, at least in some of them, the coating material is first applied to the embossing tool and then transferred from there to the substrate. This results in limitations of these methods with regard to the desired layer thickness of the coating material, so that embossed structures with a structure depth of >40 µm are only inadequately reproduced. A second disadvantage of these known methods mentioned above is that they are not sufficiently suitable for transferring embossing, particularly in the micrometer range, without reducing the overall reproduction accuracy to an unacceptable extent, especially when embossed structures with a structure depth of >40 µm are to be reproduced.Increasing the pressure with which the embossing tool is pressed onto the coating compound cannot lead to increased molding accuracy, as this often results in the embossing die of the embossing tool becoming clamped / interlocked in the embossed coating, which means that a higher force is required to separate the coated substrate with the corresponding fine structuring from the embossing tool. This, in turn, can lead to at least individual structural elements of this fine structuring being destroyed by tearing or the occurrence of a cohesive fracture during the separation process, particularly if the negative structure within the embossing die is completely filled. This not only results in the embossed structure not being formed correctly, but also in the embossing tool being contaminated, which requires costly cleaning or replacement. In addition, increasing the pressure during the embossing process, i.e.With increased contact pressure, there is a risk that the coating material used will not be sufficiently pressed into the recesses of the embossing die, as the coating material will be displaced at the sides or edges of the substrate being coated. Furthermore, the air remaining in the holes of the embossing die cannot be compressed as desired, so that the impressions often do not correspond to the shape specified by the die, which can lead to undesirable crater formation. Large, trapped air bubbles in particular typically significantly reduce the stability of the embossed structure, resulting in low abrasion resistance even with only slight mechanical stress on the surface.

[0011] There is therefore a need for a method for transferring embossed structures that does not have the aforementioned disadvantages. Task

[0012] An object of the present invention is therefore to provide a method for transferring embossed structures, in particular those with a high aspect ratio, from an embossing tool to coating agents and to substrates comprising such coating agents, - in particular one with which corresponding micro- and / or nanostructures, in particular microstructures, can be transferred, - which enables sufficient molding accuracy during the transfer of the embossed structures so that no modulation depth is lost during embossing, and which in particular enables the production of an embossing die which is as reusable as possible for transferring the embossed structures or can be carried out using such an embossing die.At the same time and in particular, the embossed structures to be transferred should be able to be replicated to the greatest possible extent and transferred as defect-free as possible, in particular without the appearance of craters, and the process should in particular not have any disadvantages caused by undesirable or insufficient properties of the coating agents and coatings used, such as insufficient adhesion. Solution

[0013] This object is achieved by the subject matter claimed in the patent claims and the preferred embodiments of these subject matter described in the following description.

[0014] A first subject of the present invention is therefore a method for transferring an embossed structure using an embossing tool (P1), which comprises at least the steps (1-i) and (2-i) or (1-ii) and (2-ii), namely (1-i) applying a coating agent (B1a) to at least part of a surface of a substrate (F1) to obtain a composite (B1aF1) and (2-i) at least partially embossing the coating agent (B1a) applied at least partially to the surface of the substrate (F1) by means of at least one embossing tool (P1) having at least one embossing die (p1), or (1-ii) applying a coating agent (B1a) to at least part of an at least partially embossed surface of an embossing die (p1) of an embossing tool (P1) and (2-ii) applying a substrate (F1) to at least part of the surface of the coating agent (B1a) applied to the embossing die (p1) to obtain a composite (B1aF1) located on (p1), characterized in thatthat the at least one embossing die (p1) of the embossing tool (P1) is pretreated 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 by step (2-i) and step (1-ii) microstructures are transferred as embossed structures onto the coating agent (B1a), which microstructures have a structure depth of >30 µm.

[0015] A further subject matter of the present invention is a use of an embossing tool (P1) having at least one embossing die (p1) for transferring an embossed structure to at least part of a surface of a coating agent (B1a), characterized in that the at least one embossing die (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 microstructures having a structure depth of >30 µm are preferably transferred to the coating agent (B1a) as the embossed structure.

[0016] It was surprisingly found that the method according to the invention - and in particular the pretreatment to be 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, with very high molding accuracy even at high speed onto the coating material to be embossed, so that no modulation depth is lost during embossing. In particular, it was surprisingly found that the method according to the invention makes it possible to transfer microstructures as embossed structures with structure depths >30 µm, in particular >40 µm and aspect ratios >1, with dimensionally accurate and at high speed from an embossing tool which bears the negative structure of the embossed structure to be transferred on its surface, to a coating material.

[0017] In particular, it has surprisingly been shown that the use of conventional methods known from the prior art for transferring haptic embossed structures in particular only leads to an incomplete impression, i.e. the surface structure on the coating material does not correspond sufficiently to the positive of the negative on the embossing device, since the arrangement and dimension of the individual structural elements of the negative of the embossed structure to be transferred often ensures that the air cannot escape to the sides during the embossing process and thus often remains in the depressions as a spacer between the coating material and the lowest point of the respective structural elements, as a result of which in particular the tips are not reproduced and the individual transferred structural elements have craters.These disadvantages are surprisingly avoided by the method according to the invention, and in particular by the pretreatment to be carried out before performing step (2-i) and step (1-ii). Surprisingly, it has been found that even with a comparatively high structural depth and a comparatively high aspect ratio of the embossed structures to be transferred, precisely those structures can be transferred with high molding accuracy that have individual structural elements that are not connected to one another, but are present at least partially as individual "holes" on the surface of the embossing die of the embossing tool.Although with such an arrangement of the structural elements within the embossing die the air cannot escape to the sides during the embossing process, but instead has to be forced out of the individual structural elements ("holes"), the method according to the invention surprisingly enables a defect-free transfer of the embossed structure, in particular without crater formation. Detailed description

[0018] The term "comprising" within the meaning of the present invention in connection with the coating compositions used according to the invention, such as, for example, the coating composition (B1a), and the process according to the invention and its process steps preferably means "consisting of." For example, with regard to the coating composition (B1a) used according to the invention, in addition to the components contained therein, such as components (a) and / or (b) and / or (c), one or more of the further components optionally contained in the coating composition (B1a) used according to the invention may also be present therein. All components may be present in their preferred embodiments listed below.With regard to the process according to the invention, in addition to steps (1-i) and (2-i) or (1-ii) and (2-ii) and the pretreatment step, this process may comprise further optional process steps such as, for example, steps (3) and (4).

[0019] 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) A first subject matter of the present invention is, as stated above, the method according to the invention for transferring an embossed structure to at least part of a surface of a coating agent (B1a). In Fig. 1 and Fig. 2 Steps (1-i) and (2-i), as well as optionally (3) and optionally (4) of the process according to the invention are illustrated by way of example, as can also be seen from the following description of these figures. The process according to the invention necessarily includes the aforementioned pretreatment.

[0020] Preferably, the process according to the invention is a continuous process.

[0021] The embossed structure is transferred or maintained by at least partially embossing the coating agent (B1a) applied at least partially to the surface of the substrate (F1) according to process step (2-i). Alternatively, transfer by means of process steps (1-ii) and (2-ii) is possible. The term "embossing" refers to the at least partial provision of an embossed structure to the coating agent (B1a), optionally as part of a composite (B1aF1), on at least part of its surface. At least a specific area of ​​the coating agent (B1a) is provided with an embossed structure. Preferably, the entire surface of the coating agent (B1a), optionally as part of the composite (F1B1a), is provided with an embossed structure.

[0022] The embossed structures of the composites (F1B1a) and (F1B1) are preferably each independently based on a recurring and / or regularly arranged pattern. This can be a continuous embossed structure such as a continuous groove structure or a plurality of preferably recurring individual embossed structures. The respective individual embossed structures can preferably in turn be based on a groove structure which has more or less pronounced webs (embossed elevations) by which the embossed height of the embossed structure is defined. Depending on the respective geometry of the webs of a preferably recurring individual embossed structure, a plurality of different, preferably recurring individual embossed structures can result in the top view, such asPreferably serpentine, jagged, hexagonal, diamond-shaped, rhombus-shaped, parallelogram-shaped, honeycomb-shaped, circular, dot-shaped, star-shaped, linen-shaped, net-shaped, polygonal, preferably triangular, quadrangular, particularly preferably rectangular and square, pentagonal, hexagonal, heptagonal and octagonal, wire-shaped, elliptical, oval, and grid-shaped patterns, wherein at least two patterns can also overlap. The webs of the individual embossed structures can also have a curvature, i.e., a convex and / or concave structure.

[0023] The respective embossed structure can be described by its width, such as the width of the ridges (i.e., its structural width), and by the height of the embossing (i.e., its structural height (or structural depth). The structural width, such as the width of the ridges, can have a length of up to one centimeter, but is preferably in a range from 10 nm to 1 mm. The structural height is preferably in a range from 0.1 nm to 1 mm. Preferably, however, the respective embossed structure represents a micro- and / or nanostructure. Microstructures are structures – both in terms of structural width and structural height – with characteristics in the micrometer range. Nanostructures are structures – both in terms of structural width and structural height – with characteristics in the nanometer range. Micro- and nanostructures are structures that have a structural width in the nanometer range and a structural height in the micrometer range, or vice versa.The terms structural height and structural depth are interchangeable.

[0024] The structural width of the respective embossed structure is preferably in a range from 10 nm to 500 µm, particularly preferably in a range from 25 nm to 400 µm, very particularly preferably in a range from 50 nm to 250 µm, in particular in a range from 100 nm to 100 µm. The structural height of the respective embossed structure is preferably in a range from 10 nm to 500 µm, particularly preferably in a range from 25 nm to 400 µm, very particularly preferably in a range from 50 nm to 300 µm, in particular in a range from 100 nm to 200 µm. This applies in each case to both the embossed structure of the composite (F1B1) and the composite (F1B1a).

[0025] The embossed structures transferred by the method according to the invention are very particularly preferably microstructures. The structure width is preferably in a range from 1 µm to 500 µm, particularly preferably in a range from 2 µm to 400 µm, very particularly preferably in a range from 5 µm to 250 µm, in particular in a range from 10 µm to 100 µm. The structure height of the respective embossed structure is preferably in a range from 1 µm to 500 µm, particularly preferably in a range from 2 µm to 400 µm, very particularly preferably in a range from 5 µm to 300 µm, in particular in a range from 10 µm to 200 µm. Particularly preferably, the embossed structures to be transferred have, at least in part, a structure depth (structure height) of >10 µm or >20 µm, very particularly preferably >30 µm or >40 µm, in particular >45 µm or >50 µm. The maximum structure depth is preferably 500 µm or 450 µm or 400 µm or 300 µm or 250 µm.

[0026] The aspect ratio of the embossed structure transferred to the coating agent (B1a) is preferably >1. The term aspect ratio is known to those skilled in the art. The aspect ratio describes the ratio of the height (depth) of a structural element to its lateral extent (width). For example, periodically arranged rectangles with a height of 10 µm and a width of 5 µm have an aspect ratio of 2 (10:5). The larger the value of the aspect ratio, the more difficult it generally is to produce the correspondingly structured surface. The aspect ratio of the embossed structure transferred to the coating agent (B1a) is preferably >2 or >3 or >5 or >10, particularly preferably >15 or >20 or >50. In hierarchical structures, the aspect ratio indicates the aspect ratio of the largest hierarchy level.

[0027] The structure width and structure height of the respective embossed structure are determined by mechanically scanning the surface. The embossed height is measured at at least 10 locations in a line, evenly distributed across the sample's web width. Care must be taken to ensure that the scanning device does not compress the embossed structure. Determining the structure height represents a measurement of the replication accuracy and is performed using atomic force microscopy according to the method described below.

[0028] The process according to the invention enables the process to be carried out at high process speeds, preferably at speeds in the range from 1 to 150 m / min, particularly preferably from 1.5 to 100 m / min, very particularly preferably from 2 to 75 m / min, even more preferably from 3 to 50 m / min, in particular from 5 to 40 m / min, most preferably from 10 to 25 m / min. The process speed preferably refers to the belt speed at which the substrate (F1) coated at least partially with a coating agent (B1a) is moved during the implementation of the process according to the invention or at which the substrate (F1) as such is moved.

[0029] The coating (B1) of the composite (F1B1) or the coating agent (B1a) of the composite (F1Ba1a) and the at least one embossing die (p1) of the embossing tool (P1) preferably have embossed structures that are mirror images of one another. Alternative (i) comprising steps (1-i) and (2-i)

[0030] The process according to the invention according to alternative (i) comprises at least steps (1-i), (2-i) and optionally (3) and optionally (4). Step (1-i)

[0031] Step (1-i) of the method according to the invention provides for applying a coating agent (B1a) to at least part of a surface of a substrate (F1). The substrate (F1) represents a carrier material for the coating agent (B1a) or coating (B1) to be applied thereto.

[0032] 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, in particular selected from the group consisting of polymethyl (meth)acrylates, polybutyl (meth)acrylates, polyethylene terephthalates, polybutylene terephthalates, polyvinylidene fluorides, polyvinyl chlorides, polyesters including polycarbonates and polyvinyl acetate, preferably polyesters such as PBT and PET, polyamides, polyolefins such as polyethylene, polypropylene, polystyrene and polybutadiene, polyacrylonitrile, polyacetal, polyacrylonitrile-ethylene-propylene-diene-styrene copolymers (A-EPDM), polyetherimides, phenolic resins, urea resins, melamine resins, alkyd resins, epoxy resins, polyurethanes including TPU, polyether ketones, polyphenylene sulfides, polyethers, polyvinyl alcohols and mixtures thereof.Particularly preferred substrates or layers located on their surface are polyolefins such as PP (polypropylene), which can be optionally isotactic, syndiotactic or atactic and optionally non-oriented or oriented by uni- or bisaxial stretching, SAN (styrene-acrylonitrile copolymers), PC (polycarbonates), PMMA (polymethyl methacrylates), PBT (poly(butylene terephthalate)), PA (polyamides), ASA (acrylonitrile-styrene-acrylic ester copolymers) and ABS (acrylonitrile-butadiene-styrene copolymers), as well as physical mixtures (blends) thereof. Particular preference is given to PP, SAN, ABS, ASA and blends of ABS or ASA with PA or PBT or PC. Very particular preference is given to PET, PBT, PP, PE and polymethyl methacrylate (PMMA) or impact-modified PMMA. Particularly preferred is a polyester, most preferably PET, as material for the substrate (F1).Alternatively, the substrate (F1) itself—optionally despite a layer of at least one of the aforementioned polymers applied thereto—can be made of another material such as glass, ceramic, metal, paper, and / or fabric. In this case, the substrate (F1) preferably represents a plate and can be used, for example, in a roll-to-plate embossing device.

[0033] The thickness of the substrate (F1) is preferably 2 µm to 5 mm. A layer thickness of 25 to 1,000 µm, in particular 50 to 300 µm, is particularly preferred.

[0034] The substrate (F1) is preferably a film, particularly preferably a film web, most preferably a continuous film web. In this case, the substrate (F1) can preferably be used in a roll-to-roll embossing device.

[0035] The term "endless film" or "endless film web" in the sense of the present invention preferably refers to a film with a length of 100 m to 10 km.

[0036] Preferably, the substrate (F1) is moved during the implementation of step (1-i) (and preferably also during the implementation of steps (2-i), optionally (3) and optionally (4) of the method as well as during the implementation of steps (1-ii), (2-ii), optionally (3) and optionally (4) of the method of alternative (ii)) and is therefore a moving substrate. Preferably, the substrate (F1) is moved during the implementation of steps (1-i) and (2-ii) by means of a transport device such as a conveyor belt. The corresponding device used for the implementation of step (1-i) and also step (2-ii) therefore preferably comprises such a transport device. The corresponding device used for the implementation of step (1-i) further comprises a means for applying the preferably radiation-curable coating agent (B1a) to at least part of a surface of the substrate (F1).The same applies to the corresponding device used to carry out step (2-ii). Step (2-i)

[0037] Step (2-i) of the method according to the invention provides for at least partial embossing of the coating agent (B1a) applied at least partially to the surface of the substrate (F1) by means of at least one embossing tool (P1) having at least one embossing die (p1).

[0038] A conventional printing cylinder can be used as the embossing tool (P1), which bears the negative form of the embossed structure to be embossed into the surface of the composite (F1B1a). This cylinder can be pressed onto the composite (F1B1a) for at least partial embossing. As already mentioned, the at least one embossing die (p1) of the embossing tool (P1) used for at least partial embossing has a "negative structure," i.e., the mirror image of the embossed structure possessed by the composite (F1B1a) obtained after carrying out step (2-i) of the process according to the invention, consisting of a substrate (F1) and the at least partially embossed coating agent (B1a). The embossing tool (P1) is preferably a metallic embossing tool, particularly preferably made of nickel, steel, or copper, whereby copper may, but need not, contain chromium.Accordingly, the embossing die (p1) is preferably metallic, particularly preferably made of nickel, optionally additionally containing phosphorus. Alternatively, soft materials such as polydimethylsiloxanes (PDMS) can also be used to produce (p1).

[0039] Preferably, in step (2-i), the at least one embossing die (p1) is part of a first roller acting as an embossing tool (P1), and the composite (F1B1a) used for the at least partial embossing is guided over a second roller that is opposite the first roller and rotates in the opposite direction. Preferably, the at least partial embossing according to step (2) takes place at the level of the roller gap formed by the two opposing, counter-rotating rollers. Preferably, the embossing die (p1) of the embossing tool (P1) faces the coating agent (B1a) of the composite (F1B1a). The at least partial embossing is preferably achieved by pressing or pressing the embossing die (p1) onto the composite (F1B1a).

[0040] Alternatively, a composite (B2F2) comprising a substrate (F2) and an at least partially embossed and at least partially cured coating (B2) can be used as the embossing die (p1), which will be described in more detail below. In this case, a composite (F1B1aB2F2) is obtained after the at least partial embossing. Preferably, the embossing tool (P1) including the embossing die (p1) is pressed at least partially onto the applied coating agent (B1a) during the implementation of step (2-i).

[0041] Preferably, the embossing die (p1) of the embossing tool (P1) used in step (2-i) is reusable and can be used repeatedly to transfer at least one embossed structure, preferably within the method according to the invention. Preferably, micro- and / or nanostructures are transferred as an embossed structure to the coating agent (B1a) by step (2-i).

[0042] Preferably, the embossing die (p1), thus preferably the composite (F2B2), is a film web (F2) having an at least partially embossed and at least partially cured coating (B2). Particularly preferably, the substrate (F2) is a continuous film web having the at least partially embossed and at least partially cured coating (B2), whereby the composite (F2B2) used as the embossing die (p1) represents a continuous embossing die, particularly when the substrate (F1) is also a continuous film web.

[0043] The at least one embossing die (p1) of the embossing tool (P1) used for the at least partial embossing according to step (2-i) has a "negative structure" ("negative mold") on the mirror image of the embossed structure which the composite (F1B1) obtained after carrying out optional step (4) of the method according to the invention, comprising a substrate (F1) and an at least partially embossed and at least partially cured coating (B1), has.

[0044] The corresponding device used to carry out step (2-i) comprises a means for at least partially embossing the coating agent (B1a) applied at least partially to the surface of the substrate (F1) by means of at least one embossing tool (P1). Furthermore, the device used preferably has a means for pressing (P1) onto the substrate (F1), which is preferably used as a continuous film web, after the preferably radiation-curable coating agent (B1a) has been applied to (F1), which means is preferably located downstream of the means for applying the radiation-curable coating agent (B1a), as seen in the conveying direction of the substrate (F1).

[0045] The at least partial embossing according to step (2-i) of the method according to the invention is carried out by means of an embossing tool (P1). (P1) can preferably be an embossing calender, which preferably comprises an anilox applicator, particularly preferably an anilox roller mill. This calender preferably has rollers arranged one above the other at a specific distance in the vertical direction and rotating in opposite directions, i.e., counter-rotating, or co-rotating, wherein the composite (F1B1a) to be provided with an embossed structure is fed to the rollers and passed through the resulting roller gap, wherein the gap width is variably adjustable. The anilox roller mill preferably comprises a first roller, such as a metallic 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 functions as an embossing roller (printing roller).The anilox rolling mill preferably comprises a second roller (pressure roller or contact roller). The first roller functions as an embossing tool (P1) and contains the negative mold of the embossed structure to be embossed into the surface of the composite (F1B1a). For this purpose, the embossing tool (P1) is preferably provided with a composite (F2B2) as an embossing die (p1), which represents this negative mold. The creation of the negative mold of the structure to be embossed on the embossing tool (P1) is carried out according to the methods known and customary to those skilled in the art, whereby specific methods may be particularly advantageous depending on the structure and materials. This is preferably achieved according to the invention in that the embossing roller functions as an embossing tool (P1) and comprises the composite (F2B2), preferably used as the embossing die (p1), in the form of a coated and at least partially embossed film, preferably a film web, particularly preferably a moving endless film web.The pressure roller moves the composite (F1B1a) to be embossed in the opposite direction. Embossing takes place according to step (2-i) at the point in the roller gap formed by the counter-rotating rollers arranged at a specific distance from one another. The first roller, which guides the embossing die (p1), serves to emboss the composite (F1B1a), which is guided by the second roller opposite this embossing roller, which presses the composite (F1B1a) to be provided with an embossed structure against the first embossing roller. As already explained above, the structures on the embossing roller—i.e., those of the embossing die (p1)—can either have a continuous structure or be designed as an interrupted structure (sequence of individual embossed structures), whereby a combination of both structures is also possible. The respective structures on the embossing roller can have a wide variety of geometric shapes, depending on the intended structure of the composite.If necessary, step (2-i) can be carried out at elevated temperature, e.g., at 30 to 100°C or at least up to 80°C. In this case, the composite to be embossed (F1B1a) first passes through a heating rolling mill, followed, if necessary, by irradiation with infrared light before the actual embossing process described above takes place. After embossing, the then embossed composite (F1B1a) passes through a cooling rolling mill, if necessary for cooling. Alternatively, step (2-i) can also be carried out with cooling: In this case, the composite to be embossed (F1B1a) first passes through a cooling rolling mill before the actual embossing process described above takes place.

[0046] Preferably, the composite (F2B2) used as embossing die (p1) in step (2-i) is a composite of a film web (F2) and a coating (B2) applied thereto and at least partially embossed and at least partially cured.

[0047] Preferably, the composite (F2B2) used as embossing die (p1) in step (2-i) is guided over a first roller acting as embossing tool (P1) during the execution of step (2-i) and the composite (F1B1a) is guided over a second roller which is opposite the first roller and rotates in the opposite direction or in the same direction, preferably in the opposite direction.

[0048] Preferably, the at least partial embossing according to step (2-i) takes place at the level of the roll gap formed by the two opposing rolls rotating in opposite directions or in the same direction, with the at least partially embossed coating (B2) of the composite (B2F2) facing the coating agent (B1a) of the composite (F1B1a). The at least partial embossing is preferably achieved by pressing or pressing the composite (F2B2) onto the composite (F1B1a).

[0049] The composite (F2B2) preferably used as the embossing die (p1) in step (2-i) comprising the substrate (F2) and the at least partially embossed and at least partially cured coating (B2) is hereinafter also referred to as the "master substrate" or "master film." If the substrate (F2) is a film, the corresponding master film is referred to as the "master film." If the substrate (F2) is a film web, the corresponding master film is referred to as the "master film web." The coating (B2) of the master film is hereinafter also referred to as the "at least partially cured master lacquer" or "master lacquer layer," and the coating agent (B2a) used to produce the cured master lacquer is referred to as the "master lacquer." Preferably, no further (lacquer) layer is located between (F2) and (B2) of the composite (F1B1).However, it is possible that between (F2) and (B3) of the composite (F2B2) there is at least one adhesion promoter layer, which in this case is preferably permeable to UV radiation. Optional step (3)

[0050] Step (3) of the method according to the invention provides for at least partial curing of the coating agent (B1a) within the composite (F1B1a) obtained after step (2-i) or step (2-ii), wherein the coating agent (B1a) is in contact with the embossing die (p1) throughout the entire duration of the at least partial curing. After carrying out step (3), a composite (B1F1) comprising the substrate (F1) and the at least partially embossed and at least partially cured coating (B1) is obtained.

[0051] Preferably, steps (2-i) and (3) are carried out simultaneously. The at least partial curing according to step (3) preferably takes place during the execution of step (2-i). in situ.

[0052] The corresponding device used to carry out step (3) therefore preferably comprises at least one radiation source for irradiating the coating agent (B1a) with curing radiation. Since the coating agent (B1a) is preferably a UV-curable coating agent, UV radiation is preferably used as the curing radiation. If the coating agent (B1a) is not radiation-curable, it is preferably chemically curable. In this case, curing according to step (3) takes place thermally, for example by using suitable heat radiators. Combined curing, i.e., thermal curing and curing by means of UV radiation, is of course also possible.

[0053] Suitable radiation sources for radiation curing include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure lamps, fluorescent tubes, pulsed lamps, metal halide lamps (halogen lamps), lasers, LEDs, and electron flash units, which allow radiation curing without a photoinitiator, or excimer lamps. Radiation curing occurs through the exposure to high-energy radiation, i.e., UV radiation or daylight, or through irradiation with high-energy electrons. The radiation dose usually sufficient for crosslinking with UV curing is in the range of 80 to 3,000 mJ / cm². Of course, multiple radiation sources can also be used for curing, e.g., two to four. These can also radiate in different wavelength ranges.

[0054] Preferably, the at least partial curing in step (3) is carried out by irradiation through the substrate (F1). It is advantageous that the permeability of the substrate (F1) for the radiation used is matched to at least one photoinitiator used, which is preferably present in the coating agent (B1a). For example, the material PET as substrate (F1), e.g., a PET film, permeable to radiation with a wavelength below 400 nm. Suitable photoinitiators that generate radicals upon exposure to this radiation include, for example, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphinate, and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide. Therefore, in this case, at least one such photoinitiator is preferably present in the coating composition (B1a). Optional step (4)

[0055] Step (4) of the method according to the invention provides for an optional removal of the composite (F1B1) from the embossing die (p1). This allows a composite (F1B1) consisting of the substrate (F1) and the at least partially embossed and at least partially cured coating (B1) to be obtained. Preferably, step (4) is carried out. Alternative (ii) comprising steps (1-ii) and (2-ii)

[0056] The process according to the invention according to alternative (ii) comprises at least steps (1-ii), (2-ii), and optionally (3) and optionally (4). Steps (3) and (4) have already been described above in connection with alternative (i) and can also be carried out analogously within alternative (ii).

[0057] All preferred embodiments described in connection with alternative (i) are to be applied analogously to alternative (ii). Step (1-ii)

[0058] Step (1-ii) of the method according to the invention provides for applying a coating agent (B1a) to at least part of an at least partially embossed surface of an embossing die (p1) of an embossing tool (P1). As mentioned above, a composite (B2F2) comprising a substrate (F2) and an at least partially embossed and at least partially cured coating (B2) can be used as the embossing die. Step (2-ii)

[0059] Step (2-ii) of the method according to the invention provides for applying a substrate (F1) to at least part of the surface of the coating agent (B1a) applied to the embossing die (p1) to obtain a composite (B1aF1) located on (p1).

[0060] If a composite (B2F2) is used as the embossing matrix (p1) in step (1-ii), then after the application of the coating agent (B1a), preferably to at least part of its at least partially embossed surface, while maintaining the composite (B1aB2F2) during step (2-ii), said composite is guided over a first roller acting as an embossing tool (P1), and the substrate (F1) used within step (2-ii) is guided over a second roller which is opposite the first roller and rotates in the opposite direction or concurrently therewith, preferably in the opposite direction. The at least partial embossing according to step (2-ii) preferably takes place at the level of the roller gap formed by the two opposing rollers rotating in the same direction or in the opposite direction, wherein the coating agent (B1a) of the composite (B1aB2F2) faces the substrate (F1).The at least partial embossing is preferably achieved by pressing or pressing the substrate (F1) onto the composite (B1aB2F2).

[0061] In Fig. 1 is a schematic side view of a device which can be used to carry out steps (1-i) and (2-i) as well as optionally (3) and optionally (4) of the method according to the invention and in which the method according to the invention is illustrated by way of example. Likewise, this device can also be used in a fundamentally analogous manner to carry out steps (1-ii) and (2-ii) as well as (3) and optionally (4) of the method according to the invention. By means of this device, structures such as micro- and / or nanostructures can be transferred, preferably from an embossing die (F2B2, p1) present as a master film, to a substrate (F1) coated with (B1a). This device is therefore also generally referred to as a transfer device and is in Fig. 1provided with the reference symbol (10).

[0062] The transfer device (10) comprises an embossing area (1) in which a printing roller (2) with a roller shell made of quartz glass is arranged. The printing roller (2) is driven to rotate. Next to the printing roller (2) is a radiation source arranged as an illumination unit (3), which generates UV light and can in particular comprise a row of UV LEDs arranged in the longitudinal direction of the printing roller (2). As shown in Fig. 1As shown, the lighting unit (3) can also be arranged inside the printing roller (2). A pressure roller (4) is arranged in the embossing area (1) and is pressed against the printing roller (2). Two film web rolls (6) and (7), which can be driven to rotate by a motor, are arranged in a matrix frame (5) of the transfer device (10). Of course, the film web rolls (6) and (7) can also be mounted and arranged in a manner other than in a matrix frame (5), e.g. in a cabinet-like element or even outside the actual transfer device (10). A master film web (8), which represents a continuous embossing matrix, is rolled up onto the film web rolls (6) and (7), which are shown here as being arranged in the matrix frame. The master film web (8) is provided with a master lacquer layer on a transfer surface, in which master lacquer layer negative forms of micro- and / or nanostructures to be transferred are introduced as a surface relief.The master lacquer layer is at least partially cured, so that the relief-like structures within it are durable. The master foil web (8) represents a composite (F2B2). The master foil web (8) runs from the first foil web roll (6), is fed to the embossing area (1) via various deflection roller systems, and runs, as shown in . Fig. 1can be seen, vertically from above into the area between the printing roller (2) and the pressure roller (4). There, it is guided tightly over a section of the circumference of the printing roller (2), then leaves the printing roller (2) again and is fed, again via deflection roller systems with web tensioners, to the second film roll conveyor (7) and wound up thereon. A film web (9) forming the substrate (F1) to be provided with structures such as micro- and / or nanostructures is fed from a film web roll (11), again here via various deflection roller systems with web tensioners to the embossing area (1), there runs tightly over a circumferential section of the pressure roller (4) and from there into the area where the pressure roller (4) rests on the printing roller (2) or into the area of ​​the roller gap formed between these elements. The film web (9) leaves this area in the illustration according to Fig. 1vertically downwards and is - again guided via deflection roller systems and web tensioners - guided to a film web roll (12) on which it is wound up as a finished, treated product. On its way into the embossing area (1) or towards the nip between the printing roller (2) and the pressure roller (4), the film web (9) is coated with a coating layer on its surface facing the printing roller (2) in the printing area (1) by means of a coating application unit (27) arranged here outside the printing area (1). Thus, according to step (1-i) of the method according to the invention, the coating application unit (27) applies a coating agent (B1a) to the film web (9) used as (F1). In the printing area (1), the film web (9) with its surface provided with the not yet cured coating layer is brought together with the surface of the master film web (8) provided with the master coating layer in order to carry out step (2-i) of the method according to the invention.Before the structures are transferred, the master lacquer layer is wetted with at least one organic solvent and / or at least one reactive thinner using an ultrasonic nozzle. The film web (9) runs over the pressure roller (4), and the master film web (8) runs over the printing roller (2). Both webs, the film web (9) and the master film web (8), face each other with their respective lacquer layers (in the case of the master film web (8), the at least partially cured master lacquer layer corresponding to the coating (B2), and in the case of the film web (9), the uncured lacquer layer corresponding to the coating agent (B1a)). In the area in which the pressure roller (4) is pressed against the printing roller (2), the negative image of the structures to be transferred, such as micro- and / or nanostructures, which is formed in the master lacquer layer (B2), is pressed into the uncured lacquer layer corresponding to the coating agent (B1a), whereby the structures are transferred.At the same time, the illumination unit (2) provides UV illumination, thus at least partially curing the uncured lacquer layer, which corresponds to the coating agent (B1a) of the lacquer layer on the film web (9), as long as this lacquer layer is still in contact with the master lacquer layer (8). Thus, immediately upon transfer of the structures and... in situthe at least partial curing of the lacquer layer is carried out. The irradiation of the film web (9), or of the uncured lacquer layer applied thereto, takes place through the film material (9) when irradiated from the outside onto the printing cylinder (2). Alternatively, the irradiation takes place through the quartz glass material of the outer surface of the printing cylinder (2) and also through the material of the master film web (8) and the master lacquer layer applied thereto. Accordingly, the master film web (8) and master lacquer layer are designed to be permeable to the radiation used, in this case UV light. The outer surface of the printing roller (2) is described here as being made of quartz glass. In principle, however, another material can also be used here, as long as it is permeable to the curing radiation emitted from the interior of the printing roller (2) (which may be something other than UV light).Alternatively, instead of the lighting unit (3) which provides UV illumination, a thermal heat emitter can be used, for example, if the coating agent (B1a) is a non-radiation-curing coating agent. Following the at least partial curing by UV illumination, optional post-exposure is possible, e.g. by means of IR radiation. At the end of this curing process according to optional step (4) of the method according to the invention, the film web (9) and the master film web (8) separate, separating the now structured layer composites (F1B1) and master film (F2B2). The coated film web (9) thus provided with the desired structuring (i.e. the composite (F1B1)) is fed to the film web roll (12) as the finished product and wound up thereon.If the printing roller (2) is illuminated from the outside by means of a lighting unit (3), the coated film web (9) provided with the desired structuring (i.e., the composite (F1B1)) can also be opaque if the arrangement is selected such that the master film web (8) (i.e., the composite (F2B2)) and the film web (9) (i.e., the composite (F1B1)) are interchanged. The coating on the coating application unit (27) according to step (1-i) of the method according to the invention can then be carried out on the master film web (8) without restricting the process.

[0063] In Fig. 2A schematic side view of a device is shown 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 illustrates the method according to the invention by way of example. By means of this device, in particular structures such as micro- and / or nanostructures can be transferred to a substrate (F1) coated with (B1a) by means of a conventional embossing tool (P1), and a composite (F1B1) can be obtained after at least partial curing.

[0064] The Fig. 2The device (30) shown operates according to a transfer principle, in which the desired negative structures are embossed directly from a structured printing cylinder or a printing roller, which here is a master printing cylinder (17), into the not yet cured lacquer layer applied to the master foil web (8b) - corresponding to a composite (F1B1a) - and these are then combined with the structures applied thereon in situby means of a lighting unit (3) to obtain the master film web (8) - corresponding to a composite (F1B1). In this process, the film web (8a) used as substrate (F1) is pulled off a film web roll (18) which contains only the carrier material, i.e. the pure film without applied master lacquer, is guided over various deflection roller systems and web tensioning systems and introduced into an embossing area (1) of the device. There, the film web (8a) runs into an area between a pressure roller (4) and the master printing cylinder (17) and is provided with the not yet cured master lacquer layer (corresponding to the coating agent B1a) in the lacquer application device (27) outside the printing area.In the embossing area (1), in which the master film web (8b) with the not yet cured master lacquer layer runs along a section of the outer surface of the master printing cylinder (17), the micro- and / or nanostructures embossed in the outer surface of the master printing cylinder (17) are introduced and transferred as a negative image into the master lacquer layer of the master film web (8b). Before the structures are transferred, the micro- and / or nanostructures embossed into the outer surface of the printing cylinder (17) are wetted with at least one organic solvent and / or at least one reactive thinner using an ultrasonic nozzle. The master film web (8b) comprising the uncured coating agent (B1a) is then at least partially cured according to optional step (3) of the method according to the invention. in situby irradiation with a lighting unit (3) using UV radiation, e.g., by means of a unit formed from UV LEDs. Subsequently, the master film (8) thus obtained, i.e. the composite (F1B1), is removed from the outer surface of the master printing cylinder (17), and the thus finished master film web (8) is wound onto a film web roll (19). The film web roll (19) then contains the finished master film web (8) with the master lacquer layer applied thereto and the negative images of the micro- and / or nanostructures embossed therein. This film web roll (19) can be removed and then in a transfer device (10) according to Fig. 1 or in another transfer device operating on the same principle as the first film web roll (6). Coating agents (B1a)

[0065] Any type of coating agent can be used as coating agent (B1a) within the process according to the invention. The coating agent (B1a) can be a physically drying, thermally curable, chemically curable, and / or radiation-curable coating agent (B1a). Preferably, the coating agent (B1a) is a chemically curable, thermally curable, and / or radiation-curable coating agent, particularly preferably a radiation-curable coating agent. Accordingly, the at least partial curing according to optional step (3) is preferably carried out by means of radiation curing.

[0066] Physical drying is preferably understood to mean the simple evaporation of solvent(s) to form the coating (B1). Thermal curing preferably involves a curing mechanism that is attributable to a temperature above room temperature (>23°C). This can, for example, be the formation of radicals or ions, preferably radicals from an initiator, which decomposes at the elevated temperatures and thus initiates a radical or ionic polymerization. Examples of such thermally activatable initiators are those that have a half-life at 80°C of less than 100 hours.Chemical curing is preferably understood as the reaction of at least two different and mutually complementary reactive functional groups, for example in the sense of a polycondensation such as a reaction of an -OH group with a -COOH group, or in the sense of a polyaddition (reaction of an NCO group with an -OH or amino group).

[0067] If the coating composition (B1a) is a physically drying, thermally curable, and / or chemically curable coating composition, at least one conventional polymer known to the person skilled in the art is used as a binder for its production. This polymer then preferably has crosslinkable functional groups. Any conventional crosslinkable functional group known to the person skilled in the art is suitable. In particular, the crosslinkable functional groups are selected from the group consisting of hydroxyl groups, amino groups, carboxylic acid groups, isocyanates, polyisocyanates, and epoxides. The polymers are preferably crosslinkable or curable exothermically or endothermically, preferably in a temperature range from -20°C to 250°C, or from 18°C ​​to 200°C.Particularly suitable polymers are at least one polymer selected from the group consisting of polyurethanes, polyethers, polyesters, polyamides, polyureas, polyvinyl chlorides, polystyrenes, polycarbonates, poly(meth)acrylates, epoxy resins, phenol-formaldehyde resins, and melamine-formaldehyde resins. The polymers can, in particular, be OH-functional. In this case, they can be subsumed under the general term "polyols." Such polyols can be, for example, polyacrylate polyols, polyester polyols, polyether polyols, polyurethane polyols, polyurea polyols, polyester polyacrylate polyols, polyester polyurethane polyols, polyurethane polyacrylate polyols, polyurethane-modified alkyd resins, fatty acid-modified polyester polyurethane polyols, and mixtures of the aforementioned polyols. Polyacrylate polyols, polyester polyols, and polyether polyols are preferred.

[0068] At least one polymer can be used which is cured with the participation of isocyanate and / or oligomerized isocyanate groups, very particularly preferably at least one corresponding polyurethane and / or at least one corresponding polyurea (e.g., so-called "polyaspartic binders"). Polyaspartic binders are components which are reacted by reacting amino-functional compounds, in particular secondary amines, with isocyanates. If at least one polyurethane is used, polyurethane-based resins which can be produced by a polyaddition reaction between hydroxyl-containing components such as polyols and at least one polyisocyanate (aromatic and aliphatic isocyanates, di-, tri-, and / or polyisocyanates) are particularly suitable. This typically requires a stoichiometric conversion of the OH groups of the polyols with the NCO groups of the polyisocyanates.However, the stoichiometric ratio to be used can also be varied, since the polyisocyanate can be added to the polyol component in such quantities that "over-crosslinking" or "under-crosslinking" can occur. If epoxy resins, i.e. epoxy-based resins, are used, then preferably those epoxy-based resins produced from glycidyl ethers, which have terminal epoxy groups and hydroxyl groups as functional groups within the molecule, are suitable. These are preferably reaction products of bisphenol A and epichlorohydrin or bisphenol F with epichlorohydrin and mixtures thereof, which are also used in the presence of reactive diluents.Crosslinking of such epoxy-based resins typically occurs through polymerization of the epoxy groups of the epoxy ring, through a polyaddition reaction in the form of addition of other reactive compounds as hardeners in stoichiometric amounts to the epoxy groups, whereby the presence of one active hydrogen equivalent is required per epoxy group (i.e., one H-active equivalent is required for curing per epoxy equivalent), or through polycondensation via the epoxy and hydroxyl groups. Suitable hardeners include, for example, polyamines, particularly (hetero)aliphatic, (hetero)aromatic, and (hetero)cycloaliphatic polyamines, polyamidoamines, polyaminoamides, and polycarboxylic acids and their anhydrides.

[0069] The coating agent (B1a) can be cured by using a radiation source, preferably by using UV radiation. Thus, (B1a) is preferably a UV-curing coating agent.

[0070] Preferably, (B1a) therefore contains unsaturated carbon double bonds, particularly preferably (meth)acrylic groups. This coating composition (B1a) preferably contains at least one urethane (meth)acrylate. When cured with (N)IR and / or UV light, the coating composition (B1a) preferably contains at least one photoinitiator that can be decomposed by light of the incident wavelength into radicals, which in turn can initiate a radical polymerization. When cured with electron beams, however, the presence of such photoinitiators is not required.

[0071] The coating agent (B1a) is preferably a radiation-curable coating agent. The terms "radiation-curable" and "radiation-curing" are interchangeable. The term "radiation curing" preferably refers to a radical polymerization of polymerizable compounds as a result of electromagnetic and / or corpuscular radiation, for example (N)IR light in the wavelength range of λ=>400-1,200 nm, preferably 700-900 nm, and / or UV light in the wavelength range of λ=100 to 400 nm, preferably λ=200 to 400 nm, and particularly preferably λ=250 to 400 nm, and / or electron beams in the range of 150 to 300 keV, and particularly preferably with a radiation dose of at least 80, preferably 80 to 3,000 mJ / cm². Curing is particularly preferably carried out using UV radiation as radiation curing. The coating agent (B1a) can be cured by using a suitable radiation source.Thus, (B1a) is preferably a UV-curing coating agent.

[0072] For curing with (N)IR and / or UV light, the coating composition (B1a) contains at least one photoinitiator as component (a). This photoinitiator can be decomposed by light of the incident wavelength into radicals, which in turn can initiate a radical polymerization. However, when curing with electron beams, the presence of such photoinitiators is not required. Preferably, the coating composition (B1a) contains at least one photoinitiator as component (a), which can be decomposed by light of the incident wavelength into radicals, which in turn can initiate a radical polymerization.

[0073] Photoinitiators such as UV photoinitiators are known to those skilled in the art. Examples include phosphine oxides, benzophenones, α-hydroxyalkylaryl ketones, thioxanthones, anthraquinones, acetophenones, benzoins and benzoin ethers, ketals, imidazoles, or phenylglyoxylic acids, and mixtures thereof.

[0074] Phosphine oxides are, for example, mono- or bisacylphosphine oxides, for example 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl 2,4,6-trimethylbenzoylphenylphosphinate or bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide.Benzophenones are, 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-Hydroxyalkylaryl ketones are, for example, 1-benzoylcyclohexan-1-ol (1-hydroxycyclohexylphenyl ketone), 2-hydroxy-2,2-dimethylacetophenone, (2-hydroxy-2-methyl-1-phenylpropan-1-one), 1-Hydroxyacetophenone, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one or polymer containing 2-hydroxy-2-methyl-1-(4-isopropen-2-ylphenyl)-propan-1-one as copolymerized units.Xanthones and thioxanthones are, for example, 10-thioxanthenone, thioxanthen-9-one, xanthen-9-one, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2,4-dichlorothioxanthone or chloroxanthenone. Anthraquinones are, for example, β-methylanthraquinone, tert-butylanthraquinone, anthraquinonecarboxylic acid esters, benz[de]-anthracen-7-one, benz[a]anthracene-7,12-dione, 2-methylanthrax-quinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloro-anthraquinone or 2-amylanthraquinone.Acetophenone sind beispielsweise Acetophenon, Acetonaphthochinon, Valerophenon, Hexanophenon, α-Phenylbutyrophenon, p-Morpholinopropiophenon, Dibenzosuberon, 4-Morpholinobenzophenon, p-Diacetylbenzol, 4'-Methoxyaceto-phenon, α-Tetralon, 9-Acetylphenanthren, 2-Acetylphenanthren, 3-Acetylphenan-thren, 3-Acetylindol, 9-Fluorenon, 1-Indanon, 1,3,4-Triacetylbenzol, 1-Acetonaphthon, 2-Acetonaphthon, 2,2-Dimethoxy-2-phenylacetophenon, 2,2-Di-ethoxy-2-phenylacetophenon, 1,1-Dichloracetophenon, 1-Hydroxyacetophenon, 2,2-Diethoxyacetophenon, 2-Methyl-1-[4-(methylthio)phenyl] -2-morpholinopropan-1-on, 2,2-Dimethoxy-1,2-diphenylethan-2-on oder 2-Benzyl-2-dimethylamino-1-(4-morpho-linophenyl)-butan-1-on. Benzoine und Benzoinether sind beispielsweise 4-Morpholino-deoxybenzoin, Benzoin, Benzoinisobutylether, Benzointetrahydropyranylether, Benzoinmethylether, Benzoinethylether, Benzoinbutylether, Benzoinisopropylether oder 7-H-Benzoinmethylether.Examples of ketals include acetophenone dimethyl ketal, 2,2-diethoxyacetophenone, and benzil ketals, such as benzil dimethyl ketal. Other photoinitiators that can be used include benzaldehyde, methyl ethyl ketone, 1-naphthaldehyde, triphenylphosphine, tri-o-tolylphosphine, and 2,3-butanedione. Typical mixtures include, for example, 2-hydroxy-2-methyl-1-phenyl-propan-2-one and 1-hydroxy-cyclohexyl-phenyl ketone, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide and 2-hydroxy-2-methyl-1-phenyl-propan-1-one, benzophenone and 1-hydroxy-cyclohexyl-phenyl ketone, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide and 1-hydroxy-cyclohexyl-phenyl ketone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide and 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2,4,6-trimethylbenzophenone and 4-methylbenzophenone or 2,4,6-trimethylbenzophenone and 4-methylbenzophenone and 2,4,6-Trimethylbenzoyldiphenyl phosphine oxide.

[0075] 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. Therefore, at least one such photoinitiator is preferably used as component (a). Commercially available photoinitiators include, for example, the products Irgacure®< 184, Irgacure®< 500, Irgacure®< TPO, Irgacure®< TPO-L, and Lucirin®< TPO, as well as Darocure®< 1173 from BASF SE.

[0076] Coating agent (B1a) preferably contains at least one component (b) that has at least one preferably terminal carbon double bond. This is preferably a (meth)acrylic group. Component (b) preferably has one or two ethylenically unsaturated groups, such as one or two or three or even more (meth)acrylic groups. Two or more different components (b) can also be used.

[0077] Examples of component (b) are mono-, di-, and / or tri-functional (meth)acrylic acid esters such as ethylene glycol di(meth)acrylate, 1,2-propanediol di(meth)acrylate, 1,3-propanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,3-butanediol 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, tricyclodecanedimethanol di(meth)acrylate, Tri-methylolpropane tri(meth)acrylate, ditrimethylolpropane penta- or hexa(meth)acrylate, pentaerythritol tri- or tetra(meth)acrylate, glycerol di- or tri(meth)acrylate, as well as di- and poly(meth)acrylates of sugar alcohols, such as sorbitol, mannitol, diglycerol, threitol, erythritol, adonitol (ribitol), arabitol (lyxitol), xylitol, dulcitol (galactitol), maltitol or isomalt, 2-phenoxyethyl (meth)acrylate, 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, as well as lauryl, stearyl, isodecyl, octyl and decyl (meth)acrylate, esters of α,β-ethylenically unsaturated carboxylic acids, preferably of (meth)acrylic acid with alcohols having 1 to 20 C atoms, preferably optionally hydroxy-substituted alkanols having 1 to 20 C atoms, e.g. (meth)acrylic acid methyl ester, (meth)acrylic acid ethyl ester, (meth)acrylic acid n-butyl ester, (meth)acrylic acid 2-ethylhexyl ester, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate or 4-Hydroxybutyl(meth)acrylate.

[0078] Very particularly preferred components (b) are 1,4-butanediol di(meth)acrylate and 1,6-hexanediol di(meth)acrylate as well as tricyclodecanedimethanol di(meth)acrylate.

[0079] As component (b) additionally or alternatively, at least one polyester, polyether, carbonate, epoxy, poly(meth)acrylate and / or urethane (meth)acrylate, and / or unsaturated polyester resin may be used.

[0080] Urethane (meth)acrylates are obtainable, for example, by reacting polyisocyanates with hydroxyalkyl (meth)acrylates and, if appropriate, chain extenders such as diols, polyols, diamines, polyamines, dithiols, or polythiols. Urethane (meth)acrylates that are dispersible in water without the addition of emulsifiers also contain ionic and / or non-ionic hydrophilic groups, which are introduced into the urethane, for example, by building blocks such as hydroxycarboxylic acids. Such urethane (meth)acrylates essentially contain the following building blocks: (a) at least one organic aliphatic, aromatic or cycloaliphatic di- or polyisocyanate, for example at least one of the polyisocyanates described above for the two-component coating compositions, (b) at least one compound having at least one isocyanate-reactive group, preferably one of the hydroxyl-bearing monomers described above for the polyacrylate polyols, and at least one radically polymerizable unsaturated group and (c) optionally at least one compound having at least two isocyanate-reactive groups, for example one of the polyhydric alcohols described above for the polyesterols.

[0081] The urethane (meth)acrylates preferably have a number-average molecular weight M n of 200 to 20,000, in particular of 500 to 10,000, particularly preferably of 600 to 3,000 g / mol (determined by gel permeation chromatography using tetrahydrofuran and polystyrene as standard). The urethane (meth)acrylates preferably have a content of 1 to 5, particularly preferably of 2 to 4, mol of (meth)acrylic groups per 1,000 g of urethane (meth)acrylate. Commercially available urethane (meth)acrylates that can be used as component (b) are, for example, products of the Laromer® or Desmolux® series, such as Laromer® UA 9033, Laromer® UA 9065, or Desmolux® XP 2738.

[0082] Epoxy (meth)acrylates are obtainable by reacting epoxides with (meth)acrylic acid. Suitable epoxides include, for example, epoxidized olefins, aromatic glycidyl ethers, or aliphatic glycidyl ethers, preferably those of aromatic or aliphatic glycidyl ethers. Epoxidized olefins can be, for example, ethylene oxide, propylene oxide, isobutylene oxide, 1-butene oxide, 2-butene oxide, vinyloxirane, styrene oxide, or epichlorohydrin. Preference is given to ethylene oxide, propylene oxide, isobutylene oxide, vinyloxirane, styrene oxide, or epichlorohydrin, particularly preferably ethylene oxide, propylene oxide, or epichlorohydrin, and 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, e.g.2,5-bis[(2,3-epoxypropoxy)phenyl]octahydro-4,7-methano-5H-indene), tris[4-(2,3-epoxypropoxy)phenyl]methane isomers), phenol-based epoxy novolaks and cresol-based epoxy novolaks. Aliphatic glycidyl ethers are, for example, 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 of hydrogenated bisphenol A (2,2-bis[4-(2,3-epoxypropoxy)cyclohexyl]propane). The epoxy (meth)acrylates preferably have a number-average molecular weight M n of 200 to 20,000, particularly preferably of 200 to 10,000 g / mol and very particularly preferably of 250 to 3,000 g / mol; the content of (meth)acrylic groups is preferably 1 to 5, particularly preferably 2 to 4 per 1.000 g epoxy (meth)acrylate (determined by gel permeation chromatography with polystyrene as standard and tetrahydrofuran as eluent).

[0083] (Meth)acrylated poly(meth)acrylates are the corresponding esters of α,β-ethylenically unsaturated carboxylic acids, preferably (meth)acrylic acid, particularly preferably acrylic acid, with polyacrylate polyols, obtainable by esterification of poly(meth)acrylate polyols with (meth)acrylic acid. The polyacrylate polyols can be, for example, those described above for the two-component coating compositions.

[0084] Carbonate (meth)acrylates are available with various functionalities. The number-average molecular weight M n of the carbonate (meth)acrylates is preferably less than 3,000 g / mol, more preferably less than 1,500 g / mol, and most preferably less than 800 g / mol (determined by gel permeation chromatography using polystyrene as standard, solvent tetrahydrofuran). The carbonate (meth)acrylates are easily obtainable by transesterification of carbonic acid esters with polyhydric, preferably dihydric, alcohols (diols, e.g., hexanediol) and subsequent esterification of the free OH groups with (meth)acrylic acid or transesterification with (meth)acrylic acid esters, as described, for example, in EP 0 092 269 A1. They are also obtainable by reacting phosgene or urea derivatives with polyhydric, e.g., dihydric alcohols.Also conceivable are (meth)acrylates of polycarbonate polyols, such as the reaction product of one of the aforementioned di- or polyols and a carbonic acid ester or a hydroxyl-containing (meth)acrylate. Suitable carbonic acid esters include, for example, ethylene, 1,2-, or 1,3-propylene carbonate, and dimethyl, diethyl, or dibutyl carbonate. Suitable hydroxyl-containing (meth)acrylates include, for example, 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)acrylates are preferably aliphatic carbonate (meth)acrylates.

[0085] Unsaturated polyester resins are preferably composed of the following components: (a1) maleic acid or its derivatives, (a2) at least one cyclic dicarboxylic acid or its derivatives, (a3) ​​at least one aliphatic or cycloaliphatic diol.

[0086] Derivatives are preferably understood as the anhydrides in question in monomeric or polymeric form, mono- or dialkyl esters, preferably mono- or di-C 1 -C 4 -alkyl esters, particularly preferably mono- or dimethyl esters or the corresponding mono- or diethyl esters, furthermore mono- and divinyl esters and mixed esters, preferably mixed esters with different C 1 - C 4 -alkyl components, particularly preferably mixed methyl ethyl esters.

[0087] If (B1a) contains a component (b), this is preferably at least one urethane (meth)acrylate.

[0088] The coating composition (B1a) may further comprise an additive as component (c). The term "additive" is known to the person skilled in the art, for example from the Römpp Lexikon, "Lacke und Druckfarben" (Laquers and Printing Inks), Thieme Verlag, 1998, page 13. Preferably, at least one rheology additive is used as component (c). This term is also known to the person skilled in the art, for example from the Römpp Lexikon, "Lacke und Druckfarben" (Laquers and Printing Inks), Thieme Verlag, 1998, page 497. The terms "rheology additive," "rheological additive," and "rheology aid" are interchangeable. The additive used as component (c) is preferably selected from the group consisting of flow control agents, surface-active agents such as surfactants, wetting and dispersing agents, as well as thickeners, thixotropic agents, plasticizers, slip and antiblocking additives, and mixtures thereof. These terms are also known to the expert, e.g. from the Römpp Lexikon, "Lacke und Druckfarben", Thieme Verlag, 1998.Leveling agents are components that help coatings achieve smooth films by reducing viscosity and / or surface tension. Wetting and dispersing agents are components that reduce surface tension or, more generally, interfacial tension. Slip and antiblocking additives are components that reduce sticking (blocking). Examples of commercially available additives are the products Efka®< SL 3259, Byk®< 377, Tego®< Rad 2500, Tego®< Rad 2800, Byk®< 394, Byk-SILCLEAN 3710, Silixan®< A250, Novec FC 4430, and Novec FC 4432. Preferably, 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, is used as additive (c). Siloxanes are particularly preferred as component (c).Silicone (meth)acrylates are particularly preferred.

[0089] The coating agent (B1a) can contain at least one further component (d) different from components (a) and (b) and (c), such as, for example, fillers, pigments, thermally activatable initiators such as, for example, potassium peroxodisulfate, dibenzoyl peroxide, cyclohexanone peroxide, di-tert-butyl peroxide, azobisisobutyronitrile, cyclohexylsulfonylacetyl peroxide, diisopropyl percarbonate, tert-butyl peroctoate or benzpinacol, di-tert-butyl peroxide, cumene hydroperoxide, dicumyl peroxide, tert-butyl perbenzoate, silylated pinacols, hydroxyl-containing amine N-oxides, such as 2,2,6,6-tetramethylpiperidine-N-oxyl and 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, and organic solvents and stabilizers. However, (B1a) preferably contains no organic solvents. Component (c) can be present in an amount ranging from 0 to 15% by weight, preferably from 0 to 12% by weight, particularly preferably from 0 to 10% by weight.-% in (B1a), each based on the total weight of the coating agent (B1a).

[0090] The coating agent (B1a) preferably contains at least one photoinitiator as component (a) in an amount in a range from 0.01 to 15 wt.%, preferably in a range from 0.1 to 12 wt.%, particularly preferably in a range from 0.5 to 10 wt.%, the at least one component (b) in an amount in a range from 40 to 99 wt.%, preferably in a range from 45 or >45 to 90 wt.%, particularly preferably in a range from 50 or >50 such as 55 to 85 wt.%, very particularly preferably in a range from 55 or 60 to 80 wt.%, the at least one additive as component (c) in an amount in a range from 0.01 to 5 wt.%, preferably in a range from 0.05 to 4.5 wt.%, particularly preferably in a range from 0.1 to 4 wt.%, very particularly preferably in a range from 0.2 or 0.5 to 3 wt.%, in each case based on the total weight of the Coating agent (B1a).

[0091] The solids content of the coating composition (B1a) is preferably ≥80 wt.%, particularly preferably ≥90 wt.%, very particularly preferably ≥95 wt.%, in particular ≥98 or ≥99 wt.%, most preferably 100 wt.%, in each case based on the total weight of the coating composition (B1a). The solids content is determined using the method described below.

[0092] Preferably, the double bond conversion of the at least partially cured coating (B1) obtained from (B1a) is at least 70%, particularly preferably at least 75%, even more preferably at least 80%, very particularly preferably at least 85%, in particular at least 90%. Pretreatment

[0093] The method according to the invention comprises, prior to carrying out step (2-i) and prior to carrying out step (1-ii), pretreatment of 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. This pretreatment 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 carried out by means of at least one nozzle, particularly preferably by means of at least one ultrasonic nozzle. Wetting is preferably carried out by forming a mist, particularly preferably in the form of droplets, which condenses on the embossing die (p1) of the embossing tool (P1) and thereby coats it with a liquid film. Preferably, the embossing die (p1) of the embossing tool (P1) is completely wetted, i.e.The complete embossing die including all structural elevations, especially in the full extent of the structural width and structural depth, is wetted.

[0094] The term "organic solvent" is known to those skilled in the art, for example from Council Directive 1999 / 13 / EC of March 11, 1999 (referred to therein as "solvent"). In principle, any conventional organic solvent known to those skilled in the art can be used in the pretreatment step carried out according to the invention. The term "reactive diluent" is also known to those skilled in the art, for example from Römpp, Lacke und Druckfarben, Thieme Verlag 1998, page 491. Accordingly, the term "reactive diluent" refers to a diluent that becomes a component of the binder used during film formation. For the purposes of the present invention, the term "binder" is again understood, in accordance with DIN EN ISO 4618 (German version, dated March 2007), to preferably refer to the non-volatile components of a coating composition responsible for film formation.Pigments and / or fillers contained therein are not considered binders. In principle, any conventional reactive diluent known to those skilled in the art can be used in the pretreatment step carried out according to the invention.

[0095] Preferably, the at least one organic solvent is selected from the group consisting of mono- and polyhydric alcohols such as corresponding C 1 -C 12 alcohols, for example methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, ethylene glycol, ethyl glycol, propyl glycol, butyl glycol, butyl diglycol, 1,2-propanediol and / or 1,3-propanediol, ethers, for example diethylene glycol dimethyl ether, aliphatic hydrocarbons, aromatic hydrocarbons, for example toluene and / or xylenes, 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. Particularly preferred are mono- and polyhydric alcohols such as corresponding C 1 -C 6 alcohols, very particularly preferred are corresponding C 1 -C 4 alcohols such as ethanol.

[0096] Preferably, the at least one reactive diluent is selected from the group consisting of monofunctional (meth)acrylates, difunctional (meth)acrylates, trifunctional (meth)acrylates and multifunctional such as tetra- and pentafunctional (meth)acrylates, and mixtures thereof.

[0097] Suitable monofunctional (meth)acrylates are, for example, 2-phenoxyethyl (meth)acrylate or higher ethoxylated phenoxy (meth)acrylates, ethyl diglycol (meth) acrylate, ethyl triglycol (meth) acrylate, 4-tert-butylcyclo-hexyl (meth) acrylate, trimethylolpropane formal mono (meth) acrylate, isobornyl (meth) acrylate, Tetrahydrofurfury (meth) acrylate, 2-(2-ethoxyethoxy) ethyl (meth) acrylate, as well as butyl, hexyl, lauryl, stearyl, isodecyl, octyl and decyl (meth) acrylate and 2-ethylhexyl (meth) acrylate.

[0098] Suitable difunctional (meth)acrylates are, for example, ethylene glycol di(meth)acrylate, 1,2-propanediol di(meth)acrylate, 1,3-propanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,3-butanediol 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-cyclohexanediol di(meth)acrylate, 1,2-, 1,3- or 1,4-cyclohexanediol di(meth)acrylate, glycerol di(meth)acrylate, di(meth)acrylates of sugar alcohols, such as sorbitol, Mannitol, diglycerol, threitol, erythritol, adonite (ribitol), arabitol (lyxitol), xylitol, dulcitol (galactitol), maltitol or isomalt.

[0099] Suitable trifunctional (meth)acrylates include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, glycerol triacrylate, and tri(meth)acrylates of sugar alcohols, such as sorbitol, mannitol, diglycerol, threitol, erythritol, adonitol (ribitol), arabitol (lyxitol), xylitol, dulcitol (galactitol), maltitol or isomalt.

[0100] Suitable multifunctional (meth)acrylates include ditrimethylolpropane penta- or hexa(meth)acrylate, pentaerythritol tetra(meth)acrylates, poly(meth)acrylates of sugar alcohols such as sorbitol, mannitol, diglycerol, threitol, erythritol, adonitol (ribitol), arabitol (lyxitol), xylitol, dulcitol (galactitol), maltitol or isomalt. use

[0101] A further subject matter of the present invention is a use of an embossing tool (P1) having at least one embossing die (p1) for transferring an embossed structure to at least part of a surface of a coating agent (B1a), characterized in that the at least one embossing die (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 microstructures having a structure depth of >30 µm are preferably transferred to the coating agent (B1a) as the embossed structure.

[0102] All preferred embodiments described hereinbefore in connection with the method according to the invention are also preferred embodiments with regard to the use according to the invention. Determination methods 1. Determination of the non-volatile fraction

[0103] The non-volatile fraction (solids or solid content) is determined according to DIN EN ISO 3251 (date: June 2008). 1 g of sample is weighed into a previously dried aluminum dish and dried for 60 minutes at 125 °C in a drying cabinet, cooled in a desiccator, and then reweighed. The residue, based on the total amount of sample used, corresponds to the non-volatile fraction. 2. Determination of impression accuracy

[0104] The molding accuracy is determined using a commercially available atomic force microscope (AFM) using a commercially available cantilever. Using AFM, for example, the surface topography of a specific grating structure, such as that of the embossing tool P1 with a depth of, for example, 140 nm and a period of, for example, 430 nm, can be compared with the surface topography of a master foil (B1F1) after embossing. In this case, the embossing tool is intentionally damaged at a specific location to define a reference point. Using this reference point, the same areas of the reference and the replication can be examined and compared with each other. The molding accuracy defines how precisely a specific reference structure can be transferred, for example from the embossing tool P1 to a master foil (B1F1).For example, if the examined area of ​​the embossing tool P1 has a grating structure with a depth of 140 nm, this reference depth is then compared with the corresponding height of the structure determined on the master foil (B1F1). The percentage change, which corresponds to the replication accuracy, is defined as: . Δh = 100 ∗ 1 − h m h r Here, Δh corresponds to the percentage change, hm to the height of the structure of the examined area of ​​the master foil, and hr to the corresponding depth of the structure of the examined area of ​​the embossing tool. This percentage change, i.e., the molding accuracy, is also referred to as 'shrinkage'. The lower the Δh values, the better the molding accuracy. Examples and Comparison examples

[0105] The following examples and comparative examples serve to illustrate the invention, but are not to be construed as limiting.

[0106] Unless otherwise stated, parts are by weight and percentages are by percentage. 1. Raw materials and materials used

[0107] Laromer ®< UA 9033 - aliphatic urethane acrylate from BASF AG Irgacure ®< 500 - commercially available photoinitiator from BASF AG Byk-057 - commercially available defoamer from BYK Chemie GmbH 2. Examples Example 1: Production of a structured film (with microstructure):

[0108] A continuous matrix with the desired positive structure is produced using a roll-to-roll embossing machine with a nickel embossing device that carries the desired negative structure. A transparent PET film web is used as the substrate. This is first unwound from a roll and guided via a system of deflection rollers and a web cleaning system to a coating application unit, where the coating compound is applied by means of Slot-die coatingThis allows for precise control of the amount of paint applied. By controlling the temperature of the Slot coatersthe flow rate per unit of time can be changed in order to additionally influence the paint application pattern. A mixture of 93.7 parts by weight of Laromer ®< UA 9033, 0.7 parts by weight of Byk-057 and 5.6 parts by weight of Irgacure ®< 500 is used as the coating compound. The surface of the film web that is to be provided with the desired embossed structure is guided tautly with contact pressure over a section of the outer surface of the printing roller, which is then coated with the aforementioned coating compound in another section. As the printing roller rotates and the film web is guided over it, the coating compound is applied to the surface of the film web and adheres there. In the same step, images of the negative structures of the printing roller are embossed into the paint layer as a positive structure. The printing roller used as the embossing tool was wetted with ethanol before use.Wetting occurs via an ultrasonic nozzle. This atomization leads to the formation of extremely fine droplets. The solvent mist directed toward the embossing roller condenses on the surface of the structured embossing roller. Since the droplets are significantly smaller than the structures, they can penetrate the "holes" of the structures and completely coat the material of the embossing tool with a liquid film. While the embossing device is still in contact with the coating material, the coating compound is cured by a UV-LED lamp (wavelength 365 nm, intensity 80%) directed from the direction of the uncoated side of the film. The typical output of the UV system used is approximately 1300 mW / cm². At the end of the embossing process, the film, with the cured varnish applied to the surface and containing the microstructures, is peeled off the surface of the printing roller, whereby the structures are released from the negative molds.In this way, a continuous web of film with a structured surface is obtained and then wound up. 3. Investigations of the structured film

[0109] It was found that, thanks to the pretreatment, microstructures, particularly with structure depths >40 µm and aspect ratios >1, can be transferred to the coating material to be embossed with very high replication accuracy, even at high speed, without any loss of modulation depth during embossing. This also applies, and in particular, to structures that have individual structural elements that are not connected to one another, but are present at least partially as individual "holes" on the surface of the embossing die of the embossing tool. Although, with such an arrangement of the structural elements within the embossing die, the air cannot escape to the sides during the embossing process, but instead must be forced out of the individual structural elements ("holes"), the method according to the invention enables defect-free transfer of the embossed structure, in particular without crater formation.Such undesirable crater formation in the form of air bubbles, which can occur without the pretreatment according to the invention, can be seen from the SEM images of the . Fig. 3 and Fig. 4 However, the pretreatment according to the invention prevents such crater formation, as can be seen from the microscope images of the Fig. 5 and Fig. 6 is evident.

Claims

1. A method for transferring an embossed structure using an embossing tool (P1), which comprises at least the steps 1-i and 2-i or 1-ii and 2-ii, specifically 1-i applying a coating composition (B1a) to at least a part of a surface of a substrate (F1), to give a composition (B1aF1), and 2-i 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 die (p1), or 1-ii applying a coating composition (B1a) to at least a part of an at least partially embossed surface of an embossing die (p1) of an embossing tool (P1) and 2-ii applying a substrate (F1) to at least a part of the surface of the coating composition (B1a), applied to the embossing die (p1), to give a composite (B1aF1) on (p1), which comprises pretreating the at least one embossing die (p1) of the embossing tool (P1), before the implementation of step 2-i and before the implementation of step 1-ii, with at least one organic solvent and / or at least one reactive diluent, and, through step 2-i and step 1-ii, transferring microstructures having a structure depth > 30 µm as embossed structure onto the coating composition (B1a).

2. The method according to claim 1, wherein the pretreatment to be carried out before implementation of 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 or 2, wherein the pretreatment to be carried out before implementation of step 2-i and step 1-ii takes place using at least one ultrasonic nozzle.

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

5. The method according to any one of the preceding claims, wherein through step 2-i and step 1-ii microstructures and / or nanostructures are transferred as embossed structure onto the coating composition (B1a).

6. The method according to one of the preceding claims, wherein through step 2-i and step 1-ii microstructures having a structure depth > 40 µm are transferred as embossed structure onto the coating composition (B1a).

7. The method according to any one of the preceding claims, wherein the aspect ratio of the embossed structure transferred by step 2-i and step 1-ii onto the coating composition (B1a) is > 1.

8. The method according to any one of the preceding claims, wherein a coating (B1) obtainable from the coating composition (B1a), and the at least one embossing die (p1) of the embossing tool (P1), have embossed structures which are mirror images of one another.

9. The method according to any one of the preceding claims, which comprises, after implementation of step 2-i and of step 1-ii, at least one further 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 (B1aF1), to give a composite (B1F1) composed of substrate (F1) and of at least partially embossed and at least partially cured coating (B1), where throughout the duration of the at least partial curing the coating composition (B1a) is in contact with the at least one embossing die (p1) of the at least one embossing tool (P1), and optionally comprises a step 4, specifically 4 removing the composite (B1F1) obtained after step 3 from the embossing die (p1) of the embossing tool (P1).

10. The method according to any one of the preceding claims, wherein the coating composition (B1a) is a radiation-curing coating composition.

11. The method according to any one of the preceding claims, wherein the solids content of the coating composition (B1a) is ≥ 90 wt%, based on the total weight of the coating composition (B1a).

12. The method according to any one of the preceding claims, wherein the coating composition (B1a) comprises at least one component (b) which comprises at least one carbon double bond and which is present therein in an amount in a range from 40 to 95 wt%.

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

14. The method according to any one of the preceding claims, wherein the substrate (F1) is a preferably moving film web.

15. The use of an embossing tool (P1) comprising at least one embossing die (p1) for transferring an embossed structure to at least a part of a surface of a coating composition (B1a), wherein the at least one embossing die (p1) of the embossing tool (P1) has been pretreated, before the transfer, with at least one organic solvent and / or at least one reactive diluent, and the embossed structure transferred onto the coating composition (B1a) comprises microstructures having a structure depth > 30 µm.