Layer structure with engraved pattern as visible security element

Abstract

The invention relates to a layer structure, preferably a security sheet in a cover, particularly preferably a security sheet in a cover for an identity document or a security document, comprising at least a) a first radiation-embossable layer a) comprising at least one polymeric material; and b) at least one further layer b) comprising at least one polymeric material, preferably a thermoplastic elastomer, preferably a thermoplastic polyurethane, having a hardness of > 40 Shore A according to DIN ISO 7619-1-2012-2 to < 95 Shore D according to DIN ISO 7619-1-2012-2; wherein the further layer b) partially covers the first layer a) to form an overlapping area, and wherein a contiguous embossed pattern partially extends in the overlapping area, preferably in the further layer b), and partially extends in the part of the layer a) outside the overlapping area, to a method for its production and to a laminate comprising such a layer structure and to the use of the layer structure in a security document.

Description

[0001] The present invention relates to a layer structure having an engraved pattern extending over the overlapping area of ​​layer a) and other layers b).

[0002] Plastic-based security documents and / or valuable documents, particularly identity documents such as ID cards, are now preferably manufactured as multilayer composites by lamination under high temperature and pressure without the use of adhesive layers to prevent subsequent separation of the layer structure for replacement of identity features. Before or during the lamination process, the corresponding security features are incorporated into these multilayer composites, and these features must therefore be configured to withstand the lamination process parameters without damage. Furthermore, the security features must not introduce any weaknesses into the multilayer composite that would allow the composite to be reopened without damage. Of particular interest are security features that can be incorporated after the lamination process or into the finished document and that are easily identifiable in the event of forgery. Ideally, the security features should still be able to be linked to the document holder's data or otherwise personalize or tamper with.

[0003] Security features in secure and / or valuable files are typically categorized into three security levels:

[0004] -1 level safety features are those that can be perceived purely by the naked eye without the use of any additional aids.

[0005] Level -2 security features are those that require an aid (such as a magnifying glass, filter, reader, etc.) to become visible.

[0006] -3 safety features are those that can only be identified in a laboratory setting through legal proceedings.

[0007] Generally, analysis is accompanied by at least partial damage to the document. Therefore, the need for Level 1 security features increases, which can be quickly perceived, preferably by visual or tactile means, preferably containing the document holder's personal data, and can be quickly identified on its own with little or no aids in the event of forgery. These security features are also referred to below as personalized security features.

[0008] In the case of documents made of polymeric materials such as plastics, especially polycarbonate, the most important personalized security feature is the document holder's photograph. This is because it can be incorporated into the document, for example, as a black and white photograph, after a blank document has been laser-engraved. To improve the anti-counterfeiting properties of laser-engraved photographs, methods have been developed that enable laser engraving of color photographs, as described in European patent application EP 3613602 A1. In addition to color laser engraving, this method also allows for the provision of partially structured photographs to make them easier to distinguish from forgeries. Thus, for example, more intense laser radiation can be used to engrave certain areas of the photograph, thereby creating additional structure. However, with considerable effort, forgers can also create structures on photographs, for example, by applying a transparent varnish.

[0009] A popular security feature on polycarbonate identification documents is a transparent window. Improved security in anti-counterfeiting involves disrupting the transparency of this window during an attempt to forge it. This disruption occurs, for example, when a transparent film is affixed to the document, or when the document is mechanically disassembled. In some cases, the document holder's photograph or other personally identifiable information is laser-engraved into the transparent window to make forgery more difficult. A variation of this is described in WO 2014 / 151377A2.

[0010] In the production of travel passport booklets, especially those with data sheets in the form of security tables (e.g., made of polycarbonate), there is a need for anti-counterfeiting connections between the data sheets and the passport booklet or the passport booklet cover (i.e., the rest of the travel passport).

[0011] The discovery that the data sheet (also known as the security form) is a reliable link between the passport photo and the passport book (especially the anti-counterfeiting link) is complex and expensive from a manufacturing technology perspective.

[0012] Therefore, there is a need to further improve the methods for reliably linking data sheets in travel passports, such as by laser engraving or welding, to prevent forgery, or to make at least some parts of the security documents as resistant to forgery as possible.

[0013] Therefore, the object of the present invention is to provide a layer structure having improved anti-counterfeiting elements, particularly anti-counterfeiting engraved patterns, and to provide anti-counterfeiting security documents manufactured therefrom. In particular, the object of the present invention is to provide an anti-counterfeiting hinge, i.e., an anti-counterfeiting connection between a data sheet (e.g., in the form of a security form) and a passport flap of a travel passport. A further object is to provide a method for producing an anti-counterfeiting layer structure, and an anti-counterfeiting security document produced by said method.

[0014] At least one of these objectives is unexpectedly achieved through the first subject matter of the invention, which relates to a layered structure, preferably a hinge, more preferably a hinge formed between a security form and a cover, such as a hinge formed by a splice, and most preferably a hinge formed between a security form and a cover of an identity document or security document (e.g., a travel passport), comprising at least:

[0015] a) A first radiation-sculpable layer a), comprising at least one polymer material; and

[0016] b) at least one other layer b) comprising at least one polymeric material, preferably a thermoplastic elastomer, preferably a thermoplastic polyurethane, having a hardness of ≥40 Shore A to ≤95 Shore D, preferably ≥45 Shore A to ≤90 Shore D, more preferably ≥50 Shore A to ≤85 Shore D, and particularly preferably ≥55 Shore A to ≤80 Shore D, wherein the Shore hardness is determined according to DIN ISO 7619-1-2012-2;

[0017] The other layer b) partially covers the first layer a) to form an overlapping area, and the coherent engraving pattern extends partially in the overlapping area, preferably in the other layer b), most preferably only in the other layer b), and partially in portions of layer a) outside the overlapping area.

[0018] The layer structure can be any layer structure that a person skilled in the art would choose as a layer structure, especially as a hinge, more preferably as a hinge between a security form and a cover, for example as a flap, and most preferably as a hinge between a security form and a cover for identification or security documents. A hinge is preferably understood to refer to a connection, especially a flexible connection, between two or more parts constituting an identification or security document (e.g., a travel passport or birth certificate). If it is a hinge between a security form and a cover, then layer b) represents a flap, and layer a) represents the security form.

[0019] By means of a continuous engraving pattern introduced, for example by laser engraving, the connection between the data sheet of the first layer a) and the passport book can be configured in a personalized and counterfeit-proof manner in the overlapping areas and in the areas adjacent to the first layer a) of the overlapping areas, for example by splices of the other layers b). For example, the engraving pattern can be equipped with the personal data of the passport book holder.

[0020] In one possible design of a travel passport where data pages can be linked to other pages in the passport book, such as in EP 2433810, the connection of these pages can be personalized by introducing a coherent engraving pattern, for example, containing the passport holder's personal data. This is equally feasible in the case of attached visa forms or other passport book entries.

[0021] The layer structure is preferably formed as a hinge. More preferably, it is formed as a hinge in the form of a flap between a security form and a cover. Specifically, it is the cover of an identity document or security document such as a travel passport or birth certificate. However, the following discussion only refers to layer structures that can be configured as hinges or hinges between security forms and covers. Therefore, all the properties and components of the layer structure mentioned below also apply to hinges or hinges between security forms and covers.

[0022] According to the present invention, a security form refers to a portion of a secure document containing personal data, such as in a travel passport or personal identification document. Such a security form is referred to as a data page and is preferably attached to the cover of the identification or security document via a splice. The splice is preferably sewn and / or glued to the cover.

[0023] The layer structure preferably has a flat dimension. The area of ​​the layer structure is preferably 1 cm². 2 Up to 1m 2 Within the range, further optimization is within 5cm. 2 up to 0.8m 2 Within a range, more preferably within 10cm 2 up to 0.5m 2 Within the range, the optimal selection is within 50cm. 2 up to 0.1m 2 The thickness of the layer structure is preferably in the range of 0.1 cm to 5 cm, more preferably in the range of 0.2 cm to 2 cm, and most preferably in the range of 0.5 cm to 1 cm.

[0024] The first layer a) can be any radiation-etchable layer comprising a polymer material. The first layer a) is preferably made of a transparent radiation-etchable polymer material. The first layer a) is preferably transparent and clear. According to the invention, "transparent" means that the layer is at least partially transparent to light in the wavelength range of 400 nm to 700 nm. The first layer a), and more preferably the other layers b), are preferably composed of a polymer material having a radiation transmittance (also called transmittance) of ≥10% to ≤99.95%, preferably ≥30% to ≤95%, more preferably ≥40% to ≤93% for selected radiation in the wavelength range of 400 to 700 nm, as determined by UV-VIS-NIR-MIR as described in the Method section.

[0025] The layer structure, especially the first layer a), is preferably clear before laser treatment. In the context of this application, "clear" means that the layer structure or the first layer a) has a haze of ≤20%, preferably ≤15%, more preferably ≤10%, and particularly preferably ≤5%, as measured according to standard ASTM D1003:2013.

[0026] If the layer structure is formed in the form of a hinge, particularly a hinge in the form of a preferred flap between the security form and the cover, then the first layer a) forms the security form and the other layers b) form the flap.

[0027] The first layer a), and especially the other layers b), may consist of a single membrane or a composite of at least two membranes.

[0028] The polymer material of the first layer a) may be the same as that of the other layers b). Alternatively, the polymer material of the first layer a) may be different from that of the other layers b). The material of the first layer a) may be harder or softer than the materials of the other layers b), wherein preferably the material of the first layer a) is harder than the materials of the other layers b). The polymer material of the first layer a) has an elastic modulus preferably in the range of 1500 MPa to 2500 MPa, more preferably in the range of 1700 MPa to 2200 MPa. The polymer material of the other layers b) preferably has an elastic modulus in the range of 10 MPa to 150 MPa, more preferably in the range of 20 MPa to 130 MPa.

[0029] At least one of the films of the first layer a) or the other layers b) preferably comprises at least one polymer material selected from polycarbonate, copolycarbonate, polyester, copolyester, or a mixture of at least two of them. The first layer a) and especially the other layers b) may comprise or be composed of thermoplastic materials, particularly thermoplastic elastomers.

[0030] The polycarbonate or copolycarbonate may be any polycarbonate or copolycarbonate that a person skilled in the art would choose to produce the first layer a) or the other layers b), but more preferably the first layer a) of the layer composite. A particularly suitable polycarbonate preferably included in layer a), and preferably also included in layer b), is preferably one having an M of at least 10,000 g / mol, preferably 20,000 g / mol to 300,000 g / mol. w High molecular weight thermoplastic aromatic polycarbonate comprising a bifunctional carbonate structural unit of formula (I), defined by gel permeation chromatography at 23 °C in tetrahydrofuran relative to a polystyrene standard, with weight-average molecular weight determined by pre-calibrated method.

[0031]

[0032] in

[0033] R 1 and R 2Independently, they are hydrogen or halogen, preferably chlorine or bromine, C1-C8-alkyl, C5-C6-cycloalkyl, or C6-C... 10 -Aryl, preferably phenyl, and C7-C 12 -Aryl group, preferably phenyl-C1-C4-alkyl group, especially benzyl group

[0034] m is between 4 and 7, preferably an integer of 4 or 5.

[0035] R 3 and R 4 Each X can be selected individually, and each can be hydrogen or C1-C6-alkyl independently of the others.

[0036] X is carbon.

[0037] The premise is that R is on at least one atom X. 3 and R 4 It is also an alkyl group.

[0038] Particularly suitable thermoplastic polymers or thermoplastic plastics are selected from one or more polycarbonates or copolycarbonates based on bisphenol, such as those described above; one or more polyacrylates or copolyacrylates and one or more polymethacrylates or copolymethacrylates, such as and preferably polymethyl methacrylate or poly(meth)acrylate (PMMA); one or more polymers or copolymers containing styrene, such as and preferably polystyrene (PS), acrylonitrile-butadiene-styrene (ABS) or polystyrene-acrylonitrile (SAN); one or more thermoplastic polyurethanes; and one or more polyolefins, such as and preferably polypropylene-type or cycloolefin-based polyolefins (e.g. Hoechst), one or more condensation polymers or cocondensation polymers of terephthalic acid, such as and preferably polyethylene terephthalate or copolyethylene terephthalate (PET or CoPET), glycol-modified PET (PETG), glycol-modified polycyclohexanedimethyl terephthalate or copolycyclohexanedimethyl terephthalate (PCTG), or polybutylene terephthalate or copolybutylene terephthalate (PBT or CoPBT), polyamide (PA), one or more condensation polymers or cocondensation polymers of naphthalene, such as and preferably polyethylene naphthalate (PEN), one or more condensation polymers or cocondensation polymers of at least one cycloalkyl dicarboxylic acid, such as and preferably polycyclohexanedimethylcyclohexanedicarboxylic acid (PCCD), polysulfone (PSU), a mixture of at least two of the above, or a blend of at least two of the above.

[0039] Thermoplastic elastomers are materials in which an elastomeric phase is physically incorporated or chemically integrated into a thermoplastically processable polymer. They are distinguished from polymer blends in which the elastomeric phase is physically incorporated and from block copolymers in which the elastomeric phase is a component of the polymer backbone. Due to the structure of thermoplastic elastomers, hard and soft regions exist adjacent to each other. Here, the hard regions form a crystalline network structure or continuous phase, the gaps of which are filled by elastomeric segments. Because of this structure, these materials exhibit rubber-like properties.

[0040] The thermoplastic elastomer is preferably selected from thermoplastic copolyamide (TPE-A), especially polyether block amide, thermoplastic polyurethane (TPE-U), thermoplastic polyester elastomer (TPE-E), styrene block copolymer (TPE-S), TPE-V-vulcanized (crosslinked) PP / EPDM blends, or mixtures of at least two of them.

[0041] Thermoplastic copolyamide (TPE-A) can be any copolyamide that a person skilled in the art would choose for the layered structure, particularly polyether block amide (PEBA). Preferred polyether block amides are, for example, those composed of polymer chains formed from repeating units conforming to formula (II).

[0042]

[0043] in

[0044] A is a polyamide chain formed by losing the carboxyl end groups of a polyamide with two carboxyl end groups.

[0045] B is a polyepoxide diol chain formed by losing the OH end groups of a polyepoxide diol, and

[0046] n is the number of units forming the polymer chain. The end group is preferably an OH group or a compound group that terminates the polymerization.

[0047] Dicarboxylic acid polyamides with terminal carboxyl groups are obtained in known ways, such as by polycondensation of one or more lactams and / or one or more amino acids, and by polycondensation of dicarboxylic acids with diamines, in each case in the presence of an excess of an organic dicarboxylic acid, preferably with terminal carboxyl groups. These carboxylic acids become part of the polyamide chain during the polycondensation process, particularly by addition to the end of the chain, thereby obtaining polyamides with μ-dicarboxylic acid functional groups. The dicarboxylic acid also acts as a chain terminator, and is therefore used in excess.

[0048] Polyamides can be obtained from lactams and / or amino acids having hydrocarbon chains consisting of 4 to 14 carbon atoms, such as caprolactam, heptanolactam, dodecylolactam, undecylolactam, decanolactam, 11-aminoundecanoic acid, or 12-aminododecanoic acid.

[0049] Examples of polyamides formed by the condensation polymerization of dicarboxylic acids and diamines may include condensation products of hexamethylenediamine with adipic acid, azelaic acid, sebacic acid and 1,12-dodecanoic acid, as well as condensation products of azelaic acid with azelaic acid.

[0050] Dicarboxylic acids that can be considered for use in the synthesis of polyamides, i.e., those used to fix carboxyl groups to each end of the polyamide chain and to act as chain terminators, include those having 4 to 20 carbon atoms, particularly alkyl diacids such as succinic acid, adipic acid, octanoic acid, azelaic acid, sebacic acid, undecanoic acid, or dodecanoic acid, as well as alicyclic or aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, or cyclohexane-1,4-dicarboxylic acid.

[0051] Polyalkylene glycols with terminal OH groups are unbranched or branched and have alkylene groups containing at least two carbon atoms. In particular, these are polyethylene glycol, polypropylene glycol, and polyoxytetramethylene glycol and their copolymers.

[0052] The average molecular weight of these OH-terminated polyepoxide diols can vary over a wide range; advantageously, it ranges from 100 g / mol to 6000 g / mol, particularly from 200 g / mol to 3000 g / mol.

[0053] Based on the total weight of the polyepoxide diol and dicarboxylic acid polyamide used to produce the PEBA polymer, the weight percentage of the polyepoxide diol is preferably from 5% to 85% by weight, more preferably from 10% to 50% by weight.

[0054] The methods used to synthesize this PEBA polymer are known from FR-PS 7418913, DE-OS 2802989, DE-OS2837687, DE-OS2523991, EP-A 095893, DE-OS 2712987 and DE-OS2716004.

[0055] Preferred and suitable are those PEBA polymers that have a random structure, the opposite of those mentioned above. To manufacture these polymers, a mixture of the following components is prepared.

[0056] 1. A compound selected from one or more aminocarboxylic acids or lactams having at least 10 carbon atoms that forms a polyamide.

[0057] 2. α,ω-dihydroxypolyepoxyalkylene glycol,

[0058] 3. At least one organic dicarboxylic acid,

[0059] In a 1:(2+3) weight ratio of 30:70 to 98:2 (where hydroxyl and carbonyl groups are present in equivalent amounts in (2+3)), in the presence of 2% to 30% by weight of water based on the polyamide-forming compound of group 1, the mixture is heated to a temperature of 23°C to 30°C under autogenous pressure, and then further treated at 250°C to 280°C under standard pressure or reduced pressure after removing the water and excluding oxygen. Such a preferred PEBA polymer is described, for example, in DE-OS2712987.

[0060] Preferred PEBA polymers may be obtained, for example, from Atochem under the trade name PEBAX. 5010 5020 5030 5040 5070 was acquired from Arkema (Germany), Vestamid from Hüls AG, Grilamid from EMS-Chemie, and Kellaflex from DSM.

[0061] Polyether block amides may also contain additives commonly used in polymers or plastics. Examples of common additives include pigments, stabilizers, flow aids, lubricants, and mold release agents.

[0062] Examples of thermoplastic copolyamides that may be mentioned include those from Arkema (Germany). 5010 5020 5030 5040 Products like 5070. Below are examples of thermoplastic polyurethane.

[0063] Thermoplastic polyester elastomer (TPE-E) can be any polyester elastomer that a person skilled in the art would choose for the layer structure; the polyester elastomer is preferably a copolyester. Suitable copolyesters (segmented polyester elastomers) are formed, for example, from a large number of repeating short-chain ester units and long-chain ester units linked by ester bonds, wherein the short-chain ester units account for 15% to 65% by weight of the copolyester and have formula (III-a):

[0064]

[0065] in

[0066] R is a divalent dicarboxylic acid group with a molecular weight of ≤350 g / mol.

[0067] D is a divalent organic diol group with a molecular weight of ≤250 g / mol;

[0068] Long-chain ester units comprise 35% to 85% by weight of the copolyester, according to formula III-b

[0069]

[0070] in

[0071] R is a divalent dicarboxylic acid group with a molecular weight of ≤350 g / mol.

[0072] G is a divalent long-chain diol group with an average molecular weight of 350 g / mol to 6000 g / mol.

[0073] Preferred copolyesters can be prepared by copolymerizing a) one or more dicarboxylic acids, b) one or more linear long-chain diols and c) one or more low molecular weight diols.

[0074] The dicarboxylic acid used for producing copolyesters is preferably an aromatic acid having 8 to 16 carbon atoms, especially phthalic acid, such as phthalic acid, terephthalic acid and isophthalic acid.

[0075] The low molecular weight diols used to form the short-chain ester units of the copolyester are preferably acyclic, alicyclic, and aromatic dihydroxy compounds. Preferred diols have 2 to 15 carbon atoms, such as ethylene glycol, propylene glycol, tetramethylene glycol, isobutylene glycol, pentamethylene glycol, 2,2-dimethyltrimethylene glycol, hexamethylene glycol and decamethylene glycol, dihydroxycyclohexane, cyclohexanediol, resorcinol, hydroquinone, etc. Bisphenols used for this purpose include bis(p-hydroxy)biphenyl, bis(p-hydroxyphenyl)methane, bis(p-hydroxyphenyl)ethane, and bis(p-hydroxyphenyl)propane.

[0076] The long-chain diols used for the production of copolyesters preferably have a molecular weight of 600 g / mol to 3000 g / mol. These include poly(alkylene ether) glycols, wherein the alkylene groups have 2 to 9 carbon atoms. Diol esters of poly(epoxyalkylene) dicarboxylic acids or polyester diols can also be used as long-chain diols.

[0077] Long-chain diols also include polyformaldehyde obtained by reacting formaldehyde with a diol. Polysulfide diols are also suitable. Polybutadiene glycol and polyisoprene glycol, their copolymers, and the saturated hydrogenation products of these materials are satisfactory long-chain polymeric diols. Methods for synthesizing such copolyesters are known from DE-OS2239271, DE-OS2213128, DE-OS2449343, and US-A 3023192.

[0078] The polymeric material of the first layer a) or the polymeric material of the other layers b), especially thermoplastic elastomers, preferably also contains additives conventionally used in plastics. Examples of conventional additives are lubricants, such as fatty acid esters, their metal soaps, fatty acid amides and silicone compounds, anti-blocking agents, inhibitors, hydrolysis stabilizers, light stabilizers, heat stabilizers and discoloration stabilizers, flame retardants, dyes, pigments, inorganic or organic fillers and reinforcing agents. Reinforcing agents are especially fiber-reinforcing materials, such as inorganic fibers prepared according to existing techniques and which may also be sized. Further details regarding the aforementioned auxiliaries and additives can be found in specialized literature, such as J.H. Saunders, K. C. Frisch: "High Polymers", Vol. XVI, Polyurethane, Parts 1 and 2, Interscience Publishers 1962 and 1964, R. H. Müller (editor): Taschenbuch der Kunststoff-Additive, 3rd edition, Hanser Verlag, München 1989 or DE-A 2901774.

[0079] Radiation-engravable polymer materials are preferably color-changeable via laser in the presence of dye. According to the invention, "color-changeable via laser" means that in the polymer material of the first layer a), coloring with dye can be achieved by means of laser input with an energy input of ≥1 watt of continuous radiation or ≥5 watt of pulsed radiation, resulting in a color that is visible to the naked eye. For the pulsed radiation, a pulse frequency in the range of 0.5 kHz to 1000 kHz is preferred, more preferably 5 kHz to 100 kHz, and even more preferably 15 kHz to 50 kHz is used. In this manner and type, the engraved pattern on the first layer a) can also be configured to be colored. A method for introducing colored engraved patterns is described in EP 3613602A1.

[0080] In the context of this invention, a radiation-engravable first layer a) refers to a layer comprising a material that interacts with light in a wavelength range of ≥0.1 μm to ≤1000 μm, preferably ≥1.0 μm to ≤50 μm, more preferably ≥1.0 μm to ≤2.5 μm, such that irradiation with light having sufficient energy within that wavelength range results in a color change. This color change can be produced by a radiation-sensitive material present in the first layer a) that changes color due to irradiation within the aforementioned wavelength range, or by contacting the first layer a) with a colorant that penetrates into the first layer a) when irradiated within the aforementioned wavelength range, thus causing a color change in the first layer a).

[0081] Preferably, the layer structure in the first layer a) comprises at least one additive that has maximum absorption in the wavelength range of the focused nonionized electromagnetic radiation used. Alternatively, the first layer a) can be coated with at least one additive in the form of a coating composition that has maximum absorption in the wavelength range of the focused nonionized electromagnetic radiation. Details of the additives are given later in conjunction with other embodiments.

[0082] The first layer a) preferably has at least one of the following properties, more preferably all of them:

[0083] (E1) For the selected radiation, particularly in the wavelength range of 950 nm to 1200 nm, preferably in the wavelength range of 1000 nm to 1150 nm, it has a radiation transmittance of ≥2% to ≤99.95%, preferably ≥4% to ≤90%, more preferably ≥5% to ≤85%, which is determined by UV-VIS-NIR-MIR as described in the Methods section;

[0084] (E2) The thickness is in the range of 0.01 mm to 20 mm, more preferably in the range of 0.02 mm to 10 mm, even more preferably in the range of 0.05 mm to 5 mm, and even more preferably in the range of 0.1 mm to 1 mm.

[0085] Preferably, the first layer a) has a performance combination selected from (E1); (E2); (E1) and (E2).

[0086] The thickness of layer a) can be achieved by laminating a single film of the corresponding thickness or by laminating multiple films.

[0087] The other layers b) preferably have at least one, more preferably at least two, and particularly preferably have all of the following properties:

[0088] (B1) For the selected radiation, it has a radiation permeability of ≥2% to ≤99.95%, preferably ≥4% to ≤90%, more preferably ≥5% to ≤85%, which is determined by UV-VIS-NIR-MIR as described in the Methods section;

[0089] (B2) The thickness is in the range of 0.05 mm to 10 mm, particularly preferably in the range of 0.1 mm to 2 mm, very particularly preferably in the range of 0.15 mm to 1 mm, and more preferably in the range of 0.2 mm to 0.8 mm;

[0090] (B3) For each selected radiation, the transmittance (also known as radiation transmittance) of light in the wavelength range of 950 nm to 1200 nm is in the range of ≥0% to ≤50%, preferably ≥1% to ≤40%, more preferably ≥5% to ≤30%, and most preferably ≥7% to ≤20%, which is determined by UV-VIS-NIR-MIR as described in the Methods section.

[0091] (B4) Contains an IR absorber having ≤20% light transmittance in the wavelength range of 950nm to 1200nm.

[0092] Preferably, the other layer b) has a combination of properties selected from (B1); (B2); (B3); (B4); (B1) and (B2); (B1) and (B3); (B1) and (B4); (B2) and (B3); (B2) and (B4); (B3) and (B4); (B1) and (B2) and (B3); (B1) and (B2) and (B4); (B1) and (B3) and (B4); (B2) and (B3) and (B4); (B1) and (B2) and (B3) and (B4). Preferred IR absorbers for achieving properties (B3) or (B4) are described below.

[0093] The layered structure preferably has at least one, more preferably at least two, and more preferably all of the following properties:

[0094] (S1) For the selected radiation, it has a radiation permeability of ≥2% to ≤99.95%, preferably ≥4% to ≤90%, more preferably ≥5% to ≤85%, which is determined by UV-VIS-NIR-MIR as described in the Methods section;

[0095] (S2) at 1cm 2 Up to 1m 2 Further optimization of 5cm 2 up to 0.8m 2 10cm is preferred 2 up to 0.5m 2 The optimal size is 50cm. 2 up to 0.1m 2 The area within the range;

[0096] (S3) The thickness is in the range of 0.1 mm to 2 cm, particularly preferably in the range of 0.2 mm to 1.5 cm, very particularly preferably in the range of 0.5 mm to 1 cm, and even more preferably in the range of 1 mm to 0.5 cm;

[0097] (S4) exactly one first layer a) and other layers b).

[0098] Preferably, the layer structure has a performance combination selected from (S1); (S2); (S3); (S4); (S1) and (S2); (S1) and (S3); (S1) and (S4); (S2) and (S3); (S2) and (S4); (S3) and (S4); (S1) and (S2) and (S3); (S1) and (S2) and (S4); (S1) and (S3) and (S4); (S1) and (S3) and (S4); (S2) and (S3) and (S4); (S1) and (S2) and (S3) and (S4).

[0099] According to the invention, the other layer b) partially covers the first layer a) to form an overlapping region. A step can be formed from the other layer b) to the first layer a). A continuous engraved pattern extends partially on layer a) outside the overlapping region. This portion of the engraved pattern is hereinafter referred to as the first portion of the engraved pattern. Another portion of the continuous engraved pattern located in the overlapping region is hereinafter referred to as the additional portion of the engraved pattern. This additional portion of the engraved pattern is preferably introduced only into the other layer b). If a step is formed, the step preferably has a dimension corresponding to ±10% of the thickness of the other layer b). The step preferably has a dimension in the range of 1 μm to 1000 μm, more preferably in the range of 2 μm to 500 μm, and particularly preferably in the range of 10 μm to 100 μm.

[0100] The overlapping region is a region of a layered structure, wherein a portion of the region of the first layer a) is covered by a portion of the region of the other layer b). The overlapping region preferably extends over the area of ​​the first layer a) in the range of 1% to 90% of the area on one side based on the first layer a), more preferably 2% to 80%, particularly preferably 3% to 70%, very particularly preferably 4% to 60%, and more preferably 5% to 30%. The other layer b) preferably covers the first layer a) across its entire size. Preferably, the other layer b) covers the first layer a) in the range of 10% to 90% of the area on one side based on the first layer b), more preferably 20% to 80%, particularly preferably 30% to 70%, and most preferably 40% to 60%. The other layer b) preferably extends beyond the first layer a) outside the overlapping region, particularly in the range of 20% to 60% of the area on one side based on the first layer a).

[0101] The overlapping region preferably extends over the entire length of the other layers b), and more preferably also over the entire length of the first layer a). The overlapping region preferably has a length of 1 mm to 1000 mm, more preferably 2 mm to 500 mm, particularly preferably 5 mm to 200 mm, and most preferably 10 mm to 100 mm. Alternatively, the overlapping region preferably has a length of 0.1 mm to 1000 mm, more preferably 1 mm to 500 mm, particularly preferably 5 mm to 200 mm, and most preferably 10 mm to 100 mm.

[0102] The engraved patterns located in the overlapping region at least in a portion of the other layers b) and in a portion of the first layer a) outside the overlapping region can be various engraved patterns that a person skilled in the art would choose for the purpose. The engraved patterns are preferably laser-engraved patterns.

[0103] The engraved pattern preferably has a width in the overlapping region, preferably for both the first portion of the engraved pattern and the other portion of the engraved pattern, within the range of 0.005 mm to 5 mm, more preferably within the range of 0.01 mm to 1 mm, and even more preferably within the range of 0.02 mm to 0.1 mm. The engraved pattern located in the portion of the layer structure consisting only of the first layer a), i.e., the first portion of the engraved pattern, preferably has a width in the range of 0.005 mm to 5 mm, more preferably within the range of 0.01 mm to 1 mm, and even more preferably within the range of 0.02 mm to 0.1 mm. The engraved pattern preferably extends along the entire length of the overlapping region. The engraved pattern preferably extends along the 0.1 cm of the layer structure. 2 Up to 100cm 2 1cm is preferred 2 Up to 80cm 2 The optimal size is 5cm. 2 Up to 50cm 2 It extends over the area within the range.

[0104] Depending on the configuration of the overlapping region, it terminates at least at one location within the overlapping region, preferably on both sides, or preferably on all sides, in a step that can have a maximum thickness dimension of the other layer b). However, the two layers, i.e., the first layer a) and the other layer b), can also be joined to each other such that no step is formed in the transition from the overlapping region to the first layer a) outside the overlapping region, but instead a smooth transition from the first layer a) to the other layer b) is ensured within the overlapping region. In particular, without steps, the coherent engraved pattern appears smooth.

[0105] The first layer a) extends beyond the overlapping region at least at one location. The engraved pattern extends from the other layers b) within the overlapping region, optionally crossing the step, and preferably continuously further into the first layer a). In the context of this invention, coherence or continuity means that at least a portion of the engraved pattern on at least the other layers b) located in the overlapping region smoothly transitions into the portion of the engraved pattern extending beyond the overlapping region on the first layer a). The smooth transition of the engraved pattern from the overlapping region to the first layer a) outside the overlapping region preferably occurs without offset between the two regions. This means that no offset is perceptible to the naked eye in the engraved pattern.

[0106] The engraved pattern portion on the other layer b) located within the overlapping area, based on the size of the overlapping area of ​​the first layer a) adjacent to the overlapping area, at least partially covers the other layer b) within a range of 0.1 mm to 1 cm, more preferably within a range of 0.2 mm to 0.5 cm, and particularly preferably within a range of 0.5 mm to 0.1 cm. Based on the distance on the first layer a) relative to the overlapping area, the engraved pattern portion on the first layer a) located outside the overlapping area preferably has a range of 0.1 mm to 1 cm, more preferably within a range of 0.2 mm to 0.5 cm, and particularly preferably within a range of 0.5 mm to 0.1 cm.

[0107] The continuous engraved pattern is preferably formed in the form of text or numbers with one or more symbols, or a combination thereof. The continuous engraved pattern is preferably configured in the form of personal data selected from name, date of birth, travel passport number, and other personal data, or a combination of at least two of them. In addition to the engraved pattern that spans the steps from the overlapping area to the first layer a), there are also additional engraved patterns on the other layers b) or the first layer a).

[0108] The overlapping region can take on various shapes or configurations that a person skilled in the art would choose for this purpose. The overlapping region preferably has a shape selected from circles, ellipses, squares, rectangles, irregular polygons, regular polygons, or combinations of at least two of these. The overlapping region is preferably rectangular.

[0109] The overlapping area is preferably disposed on the first layer a) such that it is adjacent to or surrounded by the first layer a) to a degree of ≥20%, more preferably ≥50%, particularly preferably ≥80%, and most preferably 100%.

[0110] Due to the different structures of the layer structures in the overlapping region and the different structures in portions of the layer structure formed solely by the first layer a), the engraved patterns in the overlapping region can take a different shape than the engraved patterns on the first layer a) outside the overlapping region. The engraved patterns in the overlapping region can be introduced only into the other layers b), or into both a portion of the first layer a) and a portion of the other layers b). Preferably, the engraved patterns in the overlapping region are introduced only into a portion of the other layers b).

[0111] The engraved pattern in the overlapping region preferably has a different form than the engraved pattern on the first layer a). The different form is preferably selected from different colors, different thicknesses, and different intensities, or a combination of at least two of these. The color of the engraved pattern is preferably white or off-white in the overlapping region and black in the region on the first layer a) outside the overlapping region.

[0112] The engraved patterns in the layer structure of the first layer (a) outside the overlapping region preferably have at least one, preferably at least two, and more preferably all of the following properties:

[0113] Ga)1. A depth in the range of 10% to 100%, more preferably 20% to 95%, particularly preferably 30% to 90%, and most preferably 50% to 80% based on the thickness of the first layer a);

[0114] Ga)2. The depth is in the range of 0.001 mm to 2 mm, more preferably in the range of 0.002 mm to 1.5 mm, most preferably in the range of 0.005 mm to 1 mm, and even more preferably in the range of 0.005 mm to 0.5 mm;

[0115] Ga)3. A portion of the first layer a) outside the overlapping area is engraved with a pattern whose color is different from the portion of the engraved pattern in the adjacent other layers b).

[0116] Preferably, the engraved pattern in the layer structure in the region of the first layer a) outside the overlapping region has a combination of properties selected from Ga)1; Ga)2; Ga)3; Ga)1 and Ga)2; Ga)1 and Ga)3; Ga)2 and Ga)3; Ga)1 and Ga)2 and Ga)3.

[0117] Preferably, the engraved pattern in the first layer a) outside the overlapping area is lighter in color than the engraved pattern in layer b), more precisely, by at least 2 units in the L value, as measured according to Cielalab DIN 5033-3:1992-07.

[0118] The engraved patterns in the layered structure of the overlapping region preferably have at least one, preferably at least two, more preferably at least three in various arbitrary combinations, and more preferably all of the following properties:

[0119] Gb)1. A depth in the range of 10% to 100%, more preferably 20% to 95%, particularly preferably 30% to 90%, and most preferably 50% to 80% based on the thickness of the other layers b);

[0120] Gb)2. A depth in the range of 5% to 100%, more preferably 10% to 95%, particularly preferably 30% to 90%, and most preferably 50% to 80% based on the thickness of the layer structure;

[0121] Gb)3. A depth in the range of 0 to 80%, more preferably 10 to 70%, more preferably 20 to 60%, and most preferably 30 to 50% based on the thickness of the first layer a);

[0122] Gb)4. A depth in the range of 0.001 mm to 1 mm, more preferably in the range of 0.002 mm to 0.5 mm, even more preferably in the range of 0.005 mm to 0.01 mm, and even more preferably in the range of 1 mm to 0.5 cm.

[0123] Preferably, the engraved pattern in the layer structure in the overlapping region has a combination of properties selected from Gb)1.; Gb)2.; Gb)3.; Gb)4.; Gb)1. and Gb)2.; Gb)1. and Gb)3.; Gb)1. and Gb)4.; Gb)2. and Gb)3.; Gb)2. and Gb)4.; Gb)3. and Gb)4.; Gb)1. and Gb)2. and Gb)3.; Gb)2. and Gb)3. and Gb)4.; Gb)1. and Gb)2. and Gb)3. and Gb)4.

[0124] In addition to the first layer a) and the at least one other layer b), the layer structure may include at least one other layer c). The first layer a) is preferably directly adjacent to one of the other layers b). The other layers b) and c) are preferably symmetrically located on either side of adjacent first layers a) and other layers b) in the layer structure. The other layer c) differs from the other layers b) in at least one material composition.

[0125] The at least one other layer b) may consist of a single membrane or a composite of at least two membranes. Preferably, at least one, most preferably at least two, or all of the membranes contain at least one thermoplastic elastomer. The membrane in layer b) containing the thermoplastic elastomer is preferably the outermost membrane in the layer structure.

[0126] The thermoplastic elastomer is preferably selected from thermoplastic copolyamides (TPE-A), particularly polyether block amides, thermoplastic polyurethanes (TPE-U), thermoplastic polyester elastomers (TPE-E), styrene block copolymers (TPE-S), TPE-V-vulcanized (crosslinked) PP / EPDM blends, or mixtures of at least two of these. Preferred thermoplastic elastomers have been described above in conjunction with the first layer a). All statements relating to these thermoplastic elastomers also apply particularly to the other layers b) and optionally to the at least one other layer c). The polymer materials and other components of layers a) and b) are preferably different, but they can also be the same. Thus, in a preferred embodiment, layer a) in the selection of polymer materials can be the same as layer b). However, layers a) and b) preferably have different thicknesses. Therefore, it is preferred that the other layer b) is configured to be thinner than layer a). This is because the other layer b) should be configured to be particularly flexible so that, for example, in the form of a splice, it can be sewn together with the cover on the one hand and on the other hand, together with the cover, it can also form at least a portion of the cover's curvature without tearing or preventing the cover from being intentionally bent or otherwise damaged. As described above, the first layer a) can be formed as a secure form attached to the cover of an identity document or security document by a splice layer b).

[0127] Copolyesters may also contain additives conventionally used in polymers or plastics. Examples of conventional additives are lubricants, such as fatty acid esters, their metal soaps, fatty acid amides and silicone compounds, anti-blocking agents, inhibitors, hydrolysis stabilizers, light stabilizers, heat stabilizers and colorfastness stabilizers, flame retardants, dyes, pigments, inorganic or organic fillers, and reinforcing agents. Reinforcing agents are especially fiber-reinforcing materials, such as inorganic fibers prepared according to existing techniques and which may also be sized. Further details on the aforementioned auxiliaries and additives can be found in specialized literature, such as J.H. Saunders, K.C. Frisch: "High Polymers", Vol. XVI, Polyurethane, Parts 1 and 2, Interscience Publishers 1962 and 1964, R. H. Müller (editor): Taschenbuch der Kunststoff-Additive, 3rd edition, Hanser Verlag, München 1989 or DE-A 2901774.

[0128] Thermoplastic styrene block copolymers (TPE-S) can be any of the styrene block copolymers that a person skilled in the art would choose for the layer structure. A preferred styrene-butene block copolymer consists of a polyethylene-butene rubber intermediate block and polystyrene end blocks chemically coupled at both ends. The polystyrene content is less than 30%. The polystyrene end blocks are uniformly distributed as spherical polystyrene domains within the ethylene rubber matrix. Methods for synthesizing suitable styrene block copolymers are known, for example, from US-P 3485787, 4006116, and 4039629.

[0129] Styrene block copolymers may also contain additives commonly used in polymers or plastics. Examples of common additives include pigments, stabilizers, flow aids, lubricants, and mold release agents.

[0130] Examples of styrene block copolymers (TPE-S) are Elastron G from Elastron (Turkey), such as Elastron G100 and G101; Elastron D, such as Elastron D100 and D101; and Kraton from Kraton Polymers (USA). TM D SIBS, Septon from Kuraray (Japan) TM Especially Septon TM Q1250 or Septon TM V9461, from Ineos Styrolution Group GmbH (Germany) 2G66, from Kraiburg TPE (Germany) K and from PCW GmbH (Germany)

[0131] TPE-S. Other suitable styrene-butene block copolymers are available, for example, under the trade names `Kraton G` and `Elexar` from Shell Chemie GmbH.

[0132] Thermoplastic vulcanized (crosslinked) PP / EPDM compounds can be any PP / EPDM compound that a person skilled in the art would choose for the layer structure. Examples of PP / EPDM compounds are Santoprene (from Exxon Mobil) or... (From DSM)

[0133] This contributes to the material properties and low-temperature flexibility of TPU. Depending on the organic diisocyanate used, TPU-E, or simply TPU, can have aliphatic or aromatic characteristics. TPU typically has a block or segmental structure. The distinction is essentially between hard and soft segments. Hard segments are formed from an organic diisocyanate used for the reaction and a short-chain compound having an average molecular weight of 60 g / mol to 500 g / mol and containing 2 to 3 hydroxyl, amino, thiol, or carboxyl groups, preferably a compound having 2 hydroxyl, amino, thiol, or carboxyl groups, and more preferably a diol. Soft segments are formed from an organic diisocyanate used for the reaction and a long-chain compound having an average molecular weight of ≥500 g / mol and ≤5000 g / mol and containing 2 to 3 hydroxyl, amino, thiol, or carboxyl groups, preferably a compound having 2 hydroxyl, amino, thiol, or carboxyl groups, and more preferably a diol.

[0134] Hard segments contribute strength and upper limit of operating temperature to the performance of TPU; soft segments contribute elastic properties.

[0135] For both hard and soft segments, the organic diisocyanate used can be aromatic, aliphatic, aryliphatic, heterocyclic, and alicyclic diisocyanates or mixtures of these diisocyanates (see HOUBEN-WEYL "Methoden derorganischen Chemie", Vol. E20 "Makromolekulare Stoffe", Georg Thieme Verlag, Stuttgart, New York 1987, pp. 1587-1593 or Justus Liebigs Annalen der Chemie, 562, pp. 75-136).

[0136] Specific examples include: aliphatic diisocyanates such as hexamethylene diisocyanate (HDI), alicyclic diisocyanates such as isophorone diisocyanate (IPDI), cyclohexane 1,4-diisocyanate, 1-methylcyclohexane 2,4-diisocyanate and 1-methylcyclohexane 2,6-diisocyanate and mixtures of their corresponding isomers, dicyclohexylmethane 4,4'-diisocyanate, dicyclohexylmethane 2,4'-diisocyanate and dicyclohexylmethane 2,2'-diisocyanate and mixtures of their corresponding isomers, and aromatic diisocyanates such as toluene 2, 4-Diisocyanate, a mixture of toluene 2,4-diisocyanate and toluene 2,6-diisocyanate, diphenylmethane 4,4'-diisocyanate, diphenylmethane 2,4'-diisocyanate and diphenylmethane 2,2'-diisocyanate, a mixture of diphenylmethane 2,4'-diisocyanate and diphenylmethane 4,4'-diisocyanate, carbamate-modified liquid diphenylmethane 4,4'-diisocyanate and diphenylmethane 2,4'-diisocyanate, 4,4'-diisocyanate oxy-1,2-diphenylethane and naphthalene 1,5-diisocyanate. Hexamethylene 1,6-diisocyanate, isophorone diisocyanate, dicyclohexylmethane 4,4'-diisocyanate, and mixtures of diphenylmethane diisocyanate isomers having a content of >96% by weight of diphenylmethane 4,4'-diisocyanate, especially diphenylmethane 4,4'-diisocyanate and naphthalene 1,5-diisocyanate, are preferred. These diisocyanates can be used alone or in mixtures with each other. They can also be used with up to 15% by weight (based on the total amount of diisocyanates) of polyisocyanates, such as triphenylmethane 4,4',4”-triisocyanate or polyphenylmethylene polyisocyanate. The most preferred organic diisocyanates are, for example, diphenylmethane 4,4'-diisocyanate, hydrogenated diphenylmethane 4,4'-diisocyanate, toluene 2,4-diisocyanate, and hexamethylene diisocyanate.

[0137] Preferred short-chain diols having a molecular weight of 60 g / mol to 500 g / mol are preferably aliphatic diols having 2 to 14 carbon atoms, such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, and dipropylene glycol. However, diesters of terephthalic acid with diols having 2 to 4 carbon atoms, such as bis(ethylene glycol) terephthalate or bis(but-1,4-diol) terephthalate, hydroxyalkylene ethers of hydroquinone, such as 1,4-bis(β-hydroxyethyl)hydroquinone, ethoxylated bisphenols, such as 1,4-bis(β-hydroxyethyl)bisphenol A, (cyclic) aliphatic diamines, such as isophorone diamine, ethylenediamine, propylene-1,2-diamine, propylene-1,3-diamine, N-methylpropylene-1,3-diamine, N,N'-dimethylethylenediamine, and aromatic diamines, such as toluene-2,4-diamine, toluene-2,6-diamine, 3,5-diethyltoluene-2,4-diamine or 3,5-diethyltoluene-2,6-diamine, or primary mono-, di-, tri-, or tetraalkyl-substituted 4,4'-diaminodiphenylmethane, are also suitable. Ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, 1,4-bis(β-hydroxyethyl)hydroquinone, or 1,4-bis(β-hydroxyethyl)bisphenol A are particularly preferred. Mixtures of the compounds mentioned above may also be used. Additionally, a small amount of triol may be added.

[0138] Long-chain compounds having a number average molecular weight of ≥500 and ≤5000, containing 2 to 3 hydroxyl, amino, thiol, or carboxyl groups, preferably compounds having 2 hydroxyl, amino, thiol, or carboxyl groups, are preferred. Diols can be divided into two main categories: polyether glycols and polyester glycols. Polyether glycols are based on, for example, polytetrahydrofuran, polyethylene oxide, and polypropylene oxide, and mixtures thereof. Polyester glycols are typically based on adipates, such as 1,4-butanediol adipate and 1,6-hexanediol adipate, and caprolactone. Cocondensations are also possible.

[0139] In the preparation of TPU, catalysts known and conventional in the art can be used. These can be tertiary amines, such as triethylamine, dimethylcyclohexylamine, N-methylmorpholine, N,N'-dimethylpiperazine, 2-(dimethylaminoethoxy)ethanol, diazabicyclo[2.2.2]octane, etc., and especially organometallic compounds, such as titanates, iron compounds or tin compounds, such as tin diacetate, tin dioctanoate, tin dilaurate, or dialkyltin salts of aliphatic carboxylic acids, such as dibutyltin diacetate or dibutyltin dilaurate, etc. Preferred catalysts are organometallic compounds, especially titanates, iron compounds and tin compounds. The total amount of catalyst in the TPU is preferably about 0% to 5% by weight, more preferably 0.1% to 2% by weight, based on the total amount of TPU.

[0140] In addition, TPU may contain up to ≤20% by weight of auxiliaries and additives based on the total amount of TPU. Common auxiliaries and additives include pigments, dyes, flame retardants, stabilizers to resist aging and weathering effects, plasticizers, lubricants and release agents, antifungal and antibacterial agents, and fillers and mixtures thereof.

[0141] Examples of additives include lubricants such as fatty acid esters, their metal soaps, fatty acid amides, fatty acid ester amides, and silicone compounds; anti-blocking agents, inhibitors, hydrolysis stabilizers, light stabilizers, heat stabilizers, and colorfastness stabilizers; flame retardants; dyes; pigments; inorganic and / or organic fillers, such as polycarbonates; and plasticizers and reinforcing agents. Reinforcing agents are particularly important for fiber-reinforcing materials, such as inorganic fibers produced according to existing technology and which may also be sized. Further details on the aforementioned auxiliaries and additives can be found in specialized literature, such as J.H. Saunders and K. C. Frisch's monograph "High Polymers," Volume XVI, Polyurethane, Parts 1 and 2, Interscience Publishers 1962 and 1964, R. and Taschenbuch für Kunststoff-Additive by H. Müller (Hanser Verlag München 1990) or DE-A 2901774.

[0142] Suitable TPUs include those marketed under the name Desmopan. TM Elastollan TM Pellethane TM Estane TM Morthane TM Elasthane TM Or Texin TM Obtained in the market.

[0143] The TPU of at least one outer layer a) that can be preferably used according to the invention can be prepared continuously by a so-called extrusion process, such as in a multi-screw extruder, or by a so-called belt process. The TPU described above, optionally together with the aforementioned auxiliaries and additives, can be added simultaneously, i.e., in a one-step process, or sequentially, i.e., by a prepolymer process. The prepolymer process is particularly preferred. The prepolymer can be initially loaded in batches or continuously prepared in a section of the extruder or in a separate upstream prepolymer unit, such as a static mixing reactor, for example, a Sulzer mixer.

[0144] The at least one other layer b) is preferably in the form of a single-layer or multi-layer TPU film, and can be made by melting preferred or according to the invention TPU particles in a melt extruder and extruding them through a die to obtain a film with a thickness of ≥20μm to ≤1000μm, preferably ≥50μm to ≤800μm, more preferably ≥100μm to ≤450μm.

[0145] The at least one other layer b) can be prepared by melt extrusion, blow extrusion and / or cast extrusion methods known to those skilled in the art. For this purpose, the corresponding TPU particles of each layer are melted in a melt extruder and extruded through a die to obtain a film of the corresponding layer thickness.

[0146] The material of the at least one other layer b), especially when it is the outer layer, is preferably translucent or transparent; the material of the at least one other layer b) is more preferably transparent.

[0147] A preferred feature of the layered structure is that the color, grain, and tactile properties of the outer layers can be individually achieved. Furthermore, the laminated layered structure preferably possesses not only high adhesive strength but also excellent mechanical stability in terms of tear resistance and abrasion resistance. These properties are maintained even for several years. Additionally, the layered structure exhibits a self-closing function after lamination and folding.

[0148] Furthermore, the layered structure can preferably emit an odor, such as a leather scent, by adding fragrance to the other layers b). The other layers b) preferably contain fragrance, such as LEATHERWOODY from Drom or SUEDERALIFF from Ventos, in an amount ranging from 0.1% to 1% by weight, preferably from 0.2% to 0.8% by weight, and more preferably from 0.3% to 0.7% by weight, based on the total weight of the other layers b).

[0149] In a preferred embodiment of the layer structure, the first layer a), and preferably the other layer b), comprises at least one additive having maximum absorption in the wavelength range of the focused nonionized electromagnetic radiation used to produce the engraved pattern, or wherein the first layer a), and preferably the other layer b), is coated with at least one additive in the form of a coating composition having maximum absorption in the wavelength range of the focused nonionized electromagnetic radiation used.

[0150] Suitable additives generally include all laser-sensitive additives, so-called laser marking additives, i.e., additives made from absorbers in the wavelength range of radiation (C) used to produce engraved patterns. The additives preferably contain at least one or more organic and / or inorganic IR absorbers, preferably inorganic IR absorbers. Such additives and their use in molding compounds are described, for example, in WO-A 2004 / 50766 and WO-A2004 / 5067, and are available from DSM under the name Micros. TM The brand name is available in the market.

[0151] The first layer a) or preferably the other layer b), and optionally further comprising other layers c), preferably contains an IR absorber in an amount of ≥0.5% to ≤10% by weight, preferably ≥0.6% to ≤7% by weight, more preferably ≥0.7% to ≤5% by weight, and most preferably ≥0.75% to ≤2% by weight, based on the total amount of the respective layers a), b), or c). The other layer b) preferably contains an IR absorber in an amount of ≥0.5% by weight to ≤8% by weight, more preferably ≥0.6% by weight to ≤6% by weight, based on the total amount of the other layers b).

[0152] Suitable organic IR absorbers are, for example, compounds that have the highest possible absorption (near-infrared = NIR) between 700 nm and 2500 nm. Suitable infrared absorbers include, for example, those known from the literature, as described according to the substance category, for example in M. Matsuoka, Infrared Absorbing Dyes, Plenum Press, New York, 1990. Particularly suitable are infrared absorbers from the following substance categories: azo, azomethyl, methenylene, anthraquinone, indanone, pyranone, flavinthrone, benzanthrone, phthalocyanine, perylene, dioxazine, indigoferazone, isoindoline, isoindolineone, quinacridone, pyrrolopyrrole or quinophthalone pigments, and metal complexes or metal salts of azo compounds of azo, azomethyl, or methenylene dyes. Among these, phthalocyanine and naphthylphthalocyanine are particularly suitable. Due to their improved solubility in thermoplastics, phthalocyanine and naphthylphthalocyanine with bulky side groups are preferred.

[0153] Suitable inorganic IR absorbers are, for example, mixed oxides of metals, such as phosphorus-containing tin-copper mixed oxides as described in WO-A2006 / 042714, those derived from borides and / or tungstates and mixtures thereof, preferably at least one or more IR absorbers derived from borides and / or tungstates and mixtures thereof, more preferably at least one or more IR absorbers derived from tungstates.

[0154] Suitable inorganic IR absorbers derived from borides are, for example, MxBy type compounds (M = La, Ce, Pr, Nd, Tb, Dy, Ho, Y, Sm, Eu, Er, Tm, Yb, Lu, Sr, Ti, Zr, Hf, V, Ta, Cr, Mo, W, and Ca; x and y are integers from 1 to 6), among which suitable ones are lanthanum hexaboride (LaB6), praseodymium boride (PrB6), neodymium boride (NdB6), cerium boride (CeB6), terbium boride (TbB6), dysprosium boride (DyB6), holmium boride (HoB6), and boron. Yttrium (YB6), samarium boride (SmB6), europium boride (EuB6), erbium boride (ErB6), thulium boride (TmB6), ytterbium boride (YbB6), lutetium boride (LuB6), strontium boride (SrB6), calcium boride (CaB6), titanium boride (TiB2), zirconium boride (ZrB2), hafnium boride (HfB2), vanadium boride (VB2), tantalum boride (TaB2), chromium carbide (CrB and CrB2), molybdenum boride (MoB2, Mo2B5 and MoB), tungsten boride (W2B5), or combinations of these borides.

[0155] Suitable inorganic IR absorbers from tungstates also include, for example, those from the WyOz type (W = tungsten, O = oxygen; z / y = 2.20 to 2.99) and / or MxWyOz (M = H, He, alkali metals, alkaline earth metals, metals from rare earth metals, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si). Those tungsten compounds containing the elements Ge, Sn, Pb, Sb, B, F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, and Bi (x / y = 0.001-1000; z / y = 2.2 to 3.0), wherein the element as M is preferably H, Cs, Rb, K, Tl, In, Ba, Li, Ca, Sr, Fe, and Sn, with Cs being particularly preferred. Ba is especially preferred. 0.33 WO3, Tl 0.33 WO3, K 0.33 WO3, Rb 0.33 WO3, Cs 0.33 WO3, Na 0.33 WO3, Na 0.75 WO3 and its mixtures. In a particular embodiment of the invention, Cs 0.33 The sole use of WO3 as an inorganic IR absorber is highly preferred. A Cs / W ratio of 0.20 to 0.25 is also preferred.

[0156] In inorganic IR absorbers, tungstates are preferred over borides due to their low intrinsic color, especially on layers, preferably on layer a), which have a radiation transmittance of ≥10% to ≤99%, preferably ≥30% to ≤95%, more preferably ≥40% to ≤93% for the selected radiation, said radiation transmittance being determined by UV-VIS-NIR-MIR as described in the Methods section.

[0157] To prepare such tungstates, tungsten trioxide, tungsten dioxide, tungsten oxide hydrate, tungsten hexachloride, ammonium tungstate, or tungstic acid, and optionally other salts containing element M (e.g., cesium carbonate), are mixed in a specific stoichiometric ratio such that the molar ratio of the components is given by the formula MxWyOz. The mixture is then treated in a reducing atmosphere (e.g., an argon-hydrogen atmosphere) at a temperature of 100°C to 850°C, and finally heat-treated in an inert gas atmosphere at a temperature of 550°C to 1200°C to obtain the powder. To prepare the inorganic IR absorber nanoparticles of the present invention, the IR absorber can be mixed with a dispersant described below and other organic solvents (e.g., toluene, benzene, or similar aromatic hydrocarbons) and milled in a suitable milling machine (e.g., a ball mill), wherein zirconium oxide (e.g., having a diameter of 0.3 mm) is added to produce the desired particle size distribution. Nanoparticles in dispersion form are obtained. After milling, additional dispersants may optionally be added. The solvent is removed under elevated temperature and reduced pressure. Nanoparticles with an average size of less than 200 nm are preferred, and those with an average size of less than 100 nm are more preferred. The size of the particles can be determined by means of transmission electron microscopy (TEM). Such measurements of IR absorber nanoparticles are described, for example, in Adachi et al., J. Am. Ceram. Soc. 2008, 91, 2897-2902.

[0158] The production of the tungstate is described in more detail, for example, in EP-A 1801815, and it is commercially available, for example, from Sumitomo MetalMining Co., Ltd. (Japan) under the name YMDS 874.

[0159] For example, for its use in a layered structure having at least one first layer (a) comprising a transparent polymer, particularly a transparent thermoplastic, having a radiation transmittance of ≥10% to ≤99%, preferably ≥30% to ≤95%, more preferably ≥40% to ≤93% for selected radiation (as determined by UV-VIS-NIR-MIR as described in the Methods section), the particles thus obtained are dispersed in an organic matrix, such as in an acrylate, and optionally ground in a mill using a suitable auxiliary agent (e.g., zirconium dioxide) and optionally an organic solvent (e.g., toluene, benzene, or similar hydrocarbons) as described above.

[0160] Suitable polymer-based dispersants, especially those with high transmittance, include polyacrylates, polyurethanes, polyethers, polyesters or polyester polyurethanes and their derivatives.

[0161] Preferred dispersants are polymers based on polyacrylates, polyethers, and polyesters, with particularly preferred dispersants of high thermal stability being polyacrylates (e.g., polymethyl methacrylate) and polyesters. Mixtures of these polymers or acrylate-based copolymers may also be used. Such dispersants and methods for producing tungstate dispersions are described, for example, in JP 2008214596 and Adachi et al., J. Am. Ceram. Soc. 2007, 904059-4061. Suitable dispersants are commercially available.

[0162] Particularly suitable are polyacrylate-based dispersants. Such suitable dispersants are available, for example, from Ciba Specialty Chemicals under the trade name EFKATM, such as EFKATM 4500 and EFKATM 4530. Polyester-containing dispersants are equally suitable. For example, they are available from Avecia under the trade name SolsperseTM, such as SolsperseTM 22000, 24000SC, 26000, and 27000. Polyether-containing dispersants are also known, for example, from Kusumoto Chemicals under the trade names DisparlonTM DA234 and DA325. Polyurethane-based systems are also suitable. Polyurethane-based systems are available from Ciba Specialty Chemicals under the trade names EFKATM 4046 and EFKATM 4047. TexaphorTM P60 and P63 are corresponding trade names from Cognis.

[0163] The additive preferably comprises at least one or more organic and / or inorganic IR absorbers. The additive is preferably introduced into the polymer material in the first layer a) or the other layers b) and c) (if present) via a dispersant (e.g., an organic solvent). The amount of IR absorber in the dispersant can be from 0.2% to 50% by weight, preferably from 1.0% to 40.0% by weight, more preferably from 5.0% to 35% by weight, and most preferably from 10% to 30% by weight, based on the dispersion of the inorganic IR absorber used in various cases. In addition to the pure IR absorber and the dispersant, the overall composition of the ready-to-use IR absorber formulation may also contain additional auxiliaries such as zirconium dioxide, and residual solvents such as toluene, benzene, or similar aromatic hydrocarbons. The IR absorber is preferably used in solid form.

[0164] In layered polymer compositions, there are no limitations on the amount of inorganic IR absorbers, more preferably those derived from tungstates. Typically, the inorganic IR absorbers, especially tungstates (calculated as the solids content of the inorganic IR absorber), can be used in the total polymer composition of each layer, such as layer a) or layer b), in an amount of ≥0.5 wt% to ≤10 wt%, preferably ≥0.6 wt% to ≤2 wt%, more preferably ≥0.7 wt% to ≤1.5 wt%. The other layer b) preferably contains inorganic IR absorbers in an amount of ≥0.5 wt% to ≤10 wt%, preferably ≥0.6 wt% to ≤7 wt%, more preferably ≥0.7 wt% to ≤5 wt%, and most preferably ≥0.75 wt% to ≤2 wt%, based on the total amount of the other layer b).

[0165] In this context, "solid content of inorganic IR absorber," especially tungstate, refers to an inorganic IR absorber, especially tungstate, as a pure substance rather than as a dispersion, suspension or other formulation containing the pure substance. Unless otherwise expressly stated, the content of IR absorber as an additive, especially tungstate, as described below always refers to this solid content.

[0166] Preferably, in addition to tungstate, other IR absorbers may be optionally used as IR absorbers, wherein their proportion in such mixtures is always lower than that of the aforementioned tungstate. In the case of mixtures, it is preferable to contain two to five (inclusive) types, particularly preferably a composition of two or three different IR absorbers. The additional IR absorbers are preferably selected from borides and tin oxides, especially LaB6 or antimony-doped tin oxide or indium tin oxide.

[0167] In a preferred embodiment of the layer structure, the engraved pattern portion on the other layer b) differs from the engraved pattern portion on the first layer a) in terms of color or structure, especially in terms of color.

[0168] The engraved pattern portion on the other layer b) is preferably different in color from the engraved pattern portion on the first layer a). More preferably, the engraved pattern portion on the other layer b), i.e., the additional engraved pattern, has a color selected from white, black, red, yellow, blue, or a mixture of at least two of these colors. Preferably, the engraved pattern portion on the first layer a), i.e., the first engraved pattern, has a gray or black color. However, the first engraved pattern can also be colored, preferably blue, yellow, or red. The engraved pattern portion on the other layer b) is preferably white or translucent milky white, hereinafter also referred to as opaque. Preferably, this white or translucent milky white covers all structures beneath the engraved pattern, i.e., including colored or black structures.

[0169] The structural difference between the engraved pattern portion on the other layer b) and the engraved pattern portion on the first layer a) is preferably selected from the engraved pattern width, engraved pattern depth, engraved pattern sharpness, or a combination of at least two of these. The engraved pattern on the first layer a) is preferably narrower than the engraved pattern on the other layers b). The difference in width between the engraved pattern on the first layer a) and the engraved pattern on the layer b) is in the range of 1% to 100% based on the width of the engraved pattern on the first layer a), more preferably in the range of 2% to 80%, particularly preferably in the range of 5% to 50%, and most preferably in the range of 10% to 40%.

[0170] In a preferred embodiment of the layer structure, only the continuous etched pattern portion on the first layer a) is introduced with colored or black characters, preferably black characters. Most preferably, only the continuous etched pattern portion on the first layer a) is black, including various levels of black brightness, i.e., including all shades of gray from light gray to black.

[0171] In a preferred embodiment of the layered structure, the etched pattern portion extending into the other layer (b) in the overlapping region, i.e., the additional etched pattern, is characterized by a colorless altered structure of the polymer material. The altered structure preferably has a cloudy or milky white appearance. The region of the layered structure containing the altered structure, particularly the etched pattern in the other layer (b), has a haze of ≥20%, preferably ≥50%, more preferably ≥80%, as measured using a BYK Gardner Haze Gard Plus instrument according to standard ASTM D1003:2013. The formation of this colorless altered structure (hereinafter also referred to as a cloudy etched pattern) in the other layer (b) is found to be due to the incorporation of air in the radiatively heated locations of the polymer material, which refracts natural incident light differently than the locations of the other layer (b) in the un-etched areas.

[0172] In a preferred embodiment of the layer structure, the other layer b) has a thickness at the location where the structure is altered by ≥0.001 mm, more preferably ≥0.005 mm, and especially preferably ≥0.01 mm, compared to the location where the structure is not altered.

[0173] In a preferred embodiment of the layered structure, the first layer a) is joined to the other layer b) at least at the etched pattern location in the overlapping region via a bonding area. The bonding area is understood to refer to a portion of the layered structure created by fusing the materials of the first layer a) and the other layer b) through an etched pattern. Through the etched pattern, preferably laser-engraved, in the overlapping region, the materials of the first layer a) and the other layer b) are joined or welded to each other in the region of the bonding area such that they cannot separate from each other without tearing the bonding area. Through welding, the material of the first layer a) is at least partially fused to the material of the other layer b) in the region where they are in contact, and thus remains inseparable from each other.

[0174] In a preferred embodiment of the layer structure, when removing the other layer b) from the first layer a), the continuous engraved pattern is separated at least in the overlapping region. The first layer a) and the other layer b) are joined to each other in the overlapping region of the joint area, at least at the location where the engraved pattern exists, such that, according to standard DIN 11339:2010-06, they can only be separated from each other with a force of at least 1 N / cm at a peel angle of 90°. When attempting to separate the two layers a) and b) from each other, the continuous engraved pattern in the region of the overlapping area and the partial engraved pattern on the first layer a) located in the overlapping region are also separated. During the separation in the overlapping region of layers a) and b), the partial engraved pattern, i.e., the first partial engraved pattern, separates from the other partial engraved pattern, such that only the first partial engraved pattern remains on the first layer a), and the other partial engraved pattern remains on the other layer b). It is impossible to reasonably join the removed portion of the first layer a) containing the first portion of the engraved pattern with the other layer b) containing a portion of the engraved pattern that is different from the original other layer b) to obtain a reasonably joined engraved pattern. Therefore, it is impossible to separate the security form of a travel passport represented by the first layer a) from the cover at such a predetermined breakage location between the first layer a) and the other layer b) to join it with a different cover via a different other layer b). Conversely, the removed portion of the engraved pattern on the other layer b) cannot reasonably join with a different first portion of the engraved pattern of a different first layer a) to produce a meaningful engraved pattern. This prevents the forgery of security documents such as travel passports, which are typically forged by swapping portions of the cover or security form. During the separation, at least one of the layers, i.e., the first layer a) or the other layer b) or the entire engraved pattern, is also destroyed.

[0175] When separating the two layers a) and b) in the overlapping area, especially in the joining area, particularly by removing the other layer b) from the first layer a), it is preferable to alter the structure of the engraved pattern so that the engraved pattern cannot rejoin to achieve its original structure, i.e., its original appearance before the removal of the other layer b) from the first layer a). This means that after removing the other layer b) from the first layer a), the engraved pattern no longer extends continuously or coherently. Preferably, when removing the other layer b) from the first layer a), the engraved pattern on the first layer a) not located in the overlapping area remains intact. Integrity specifically means that the shape, depth, width, sharpness, and color remain unchanged compared to their state before the removal of the other layer b).

[0176] In a preferred embodiment of the layer structure, the engraved pattern portion located in the overlapping region is readable only on the other layers (b). The engraved pattern preferably extends only into the other layers (b) in the overlapping region. The engraved pattern preferably extends into the other layers (b) to a degree ≤99% based on the thickness of the other layers (b), more preferably ≤90%, more preferably ≤80%, particularly preferably ≤70%, and most preferably ≤50%. The engraved pattern, i.e., the additional portion of the engraved pattern, preferably does not extend into the first layer (a) of the overlapping region. If the engraved pattern is to extend into the first layer (a) of the overlapping region, then the additional portion of the engraved pattern preferably has a different color than the first layer (a) outside the overlapping region.

[0177] In a preferred embodiment of the layer structure, the first layer a) comprises at least one dye and / or at least one pigment. The layer structure or the first layer a) preferably further comprises a printing layer applied over the entire area and / or a portion thereof.

[0178] The layer structure or the first layer a) preferably contains pigments with a concentration of 5 ppm to 1000 ppm, more preferably 10 ppm to 800 ppm, and especially preferably 15 ppm to 500 ppm.

[0179] Preferably, the first layer a) comprises at least one thermoplastic and / or at least one black pigment, preferably carbon black.

[0180] In a preferred embodiment of the layer structure, the other layer b) has a thickness in the range of ≥20 μm to ≤1000 μm, preferably ≥50 μm to ≤800 μm, and more preferably ≥100 μm to ≤450 μm. The first layer a) preferably has a thickness in the range of ≥20 μm to ≤1000 μm, preferably ≥50 μm to ≤800 μm, and more preferably ≥100 μm to ≤450 μm. Preferably, all layers a), b) and c) have a thickness in the range of ≥20 μm to ≤1000 μm, preferably ≥50 μm to ≤800 μm, and more preferably ≥100 μm to ≤450 μm.

[0181] In a preferred embodiment of the layered structure, the other layer b) comprises at least one thermoplastic polyurethane. Examples of preferred polyurethanes have been mentioned above in conjunction with available TPUs. More preferably, the polyurethane is prepared from the following components: a linear polyol, especially a diol, such as polyester glycol, polyether glycol, or polycarbonate glycol; and an organic diisocyanate, especially an aliphatic diisocyanate, preferably HDI or IPDI; and a short-chain (typically bifunctional) alcohol (chain extender). Examples of bifunctional alcohols have been described above in conjunction with the description of TPUs and should be used particularly preferably herein.

[0182] Another subject of the present invention relates to a method for producing a layered structure having a bonding region, comprising at least the following steps:

[0183] I) Provide a first layer a) comprising at least one laser-engravable material;

[0184] II) Cover the first layer a) at least partially with at least a portion of another layer b) comprising at least one polymer material, preferably thermoplastic polyurethane, to form an overlapping area of ​​the other layer b) on the first layer a).

[0185] III) Producing engraved patterns, preferably laser-engraved patterns, in the layer structure, wherein a portion of the engraved pattern (also referred to as the first portion of the engraved pattern) is located on a portion of the first layer a) not covered by layer b), and another portion of the engraved pattern (also referred to as the additional portion of the engraved pattern) is located on at least a portion of layer b) and optionally on a portion of the first layer a) covered by the other layer b), to form a bonding area.

[0186] The two layers a) and b) are inseparably bonded to each other in the bonding area.

[0187] The first layer a) can be formed from various radiation-engravable materials, especially laser-engravable materials. In the context of this invention, a radiation-engravable first layer a) refers to a layer comprising a material that interacts with light in a wavelength range of ≥0.1 μm to ≤1000 μm, preferably ≥1.0 μm to ≤50 μm, more preferably ≥1.0 μm to ≤2.5 μm, thereby causing a color change when irradiated with light of sufficient energy within that wavelength range. This color change can be produced in various ways:

[0188] S1. A radiation-sensitive material located in the first layer a) whose color is altered by radiation within the aforementioned wavelength range, or

[0189] S2. This is achieved by the following method: the first layer a) comes into contact with a colorant, which, when irradiated within the aforementioned wavelength range, penetrates into the first layer a) and thus causes a color change in the first layer a).

[0190] S3. Carbonization of the polymer material in the first layer a) itself.

[0191] In variant S1, an IR absorber, as described above for the layered structure of the present invention, can be used, for example. Carbon black can be used as a substitute or supplement to the IR absorber. Carbon black is preferred. Preferably, the amount of carbon black is in the range of 0.1% to 10% by weight based on the total mass of the first layer a), more preferably in the range of 0.2% to 8% by weight, particularly preferably in the range of 0.5% to 6% by weight, and most preferably in the range of 1% to 5% by weight.

[0192] When a colored engraved pattern is required on or in the first layer a), it is preferable to implement variation S2 in addition to one of steps S1 and S3.

[0193] Carbonization constitutes a structural change in the polymer through the energy input of laser radiation. To produce black or gray laser-engraved patterns, it is preferable to adjust the grayscale of the engraved pattern on layer a) by changing the frequency of the laser beam used. At low frequencies, the pulse duration is long enough, in the case of organic materials, to enable carbonization in the layer, constituting variant S3. This results in a dark-colored engraved pattern. This occurs at frequencies below 30 kHz, using a laser with a rated power of 60 watts. At frequencies above 30 kHz, the pulse duration is particularly short. This makes the structural change in the material visible and perceptible, while in the case of organic materials, only limited carbonization exists. This means the engraved pattern has a gray to white appearance. Laser engraving is preferably performed using a laser emitting at wavelengths between 950 nm and 1500 nm, preferably at a wavelength of 1064 nm. Diode lasers are preferred. With diode lasers, particularly short pulse durations can be achieved to produce high energy peaks. Therefore, particularly distinct and light-colored partial engraving patterns can be produced in the other layers b), which are preferably presented as dark-colored partial engraving patterns in the portions of the adjacent first layer a) that do not belong to the overlapping area.

[0194] The polymer material of the first layer a) or the other layers b) is preferably selected from materials used in the layers as described in connection with the layer structure of the invention. To avoid repetition, reference is made below to the foregoing description of the polymer material in relation to the preferred embodiments, materials, amounts, composition, and additives as described in connection with the layer structure of the invention, and these descriptions are also used herein.

[0195] The engraved pattern is preferably prepared in step III) by irradiating the layer structure with focused non-ionic electromagnetic radiation. The irradiation in step III) is preferably achieved by laser radiation having a wavelength in the range of ≥0.1μm to ≤1000μm, preferably ≥1.0μm to ≤50μm, and more preferably ≥1.0μm to ≤2.5μm.

[0196] If irradiation is achieved via laser, it can be performed in continuous wave (CW) laser operation, particularly for engraving patterns on pixel or grayscale files. Pulsed laser radiation is particularly preferred for irradiating the layered structure or for vector or rasterized images. A pulse frequency of 0.5 kHz to 1000 kHz is preferred; a pulse frequency of 5 kHz to 100 kHz is more preferred, and a pulse frequency of 15 kHz to 50 kHz is particularly preferred.

[0197] By varying the power of the laser beam used for irradiation in step III), the intensity of the coloring at the laser-received location can be influenced according to the requirements of the desired application. As already mentioned, the higher the laser output used, the more intense the black coloring at the laser-received location in the first layer a).

[0198] In step III), the radiation used to create the engraved pattern produces the engraved pattern or the additional engraved pattern at least in the overlapping region of the other layers b). The engraved pattern produced in the other layers b) appears as a light-colored engraved pattern. This light-colored engraving occurs due to structural changes in the polymer material in the other layers b). In a variation to prevent a portion of the first layer a) below the other layers b) from being engraved in the overlapping region, the other layers b) contain an IR absorber. This IR absorber has been described above in conjunction with the layer structure of the invention, and the preferred amount used for this purpose has also been described. The selection and amount of the IR absorber also apply to the method described herein. By using the IR absorber, the energy input from the radiation source can be kept as low as possible to obtain the altered structure of the polymer material that produces the appearance of the engraved pattern. Since the IR absorber absorbs a portion of the energy of the incident radiation and converts it into heat (which then has the effect of causing the altered structure of the polymer material to occur, resulting in a colorless, turbid engraved pattern), almost no radiation reaches the first layer a) below the other layers b) in the overlapping region. The hazy engraved pattern in the other layers (b) is believed to be due to air incorporation in the radiatively heated polymer material, which refracts natural incident light differently than in the unengraved areas. The areas containing the altered layer structure, particularly the engraved pattern in the other layers (b), have a haze of ≥20%, preferably ≥50%, more preferably ≥80%, as measured using a BYK Gardner Haze Gard Plus instrument according to standard ASTM D1003:2013.

[0199] To achieve at least one continuously engraved patterned area between the overlapping region and the region formed solely by the first layer a), a laser is continuously guided from the region where only the first layer a) exists to the overlapping region on the other layers b), or vice versa. Thus, a first portion of the engraved pattern, preferably black, is formed on the first layer a) outside the overlapping region. Furthermore, another portion of the engraved pattern is formed on layer b), preferably having a cloudy or milky white appearance. Here, a bonding area is formed in the overlapping region at the location along which the laser is guided. As described above for the layer structure, the two layers a) and b) are inseparably bonded to each other in the bonding area. "Inseparable" means that when attempting to separate the two layers a) and b) from each other, the continuously engraved pattern in the region of the overlapping region separates, resulting in a partial engraved pattern located in the overlapping region on the first layer a). Since layers a) and b) separate in the region of the engraved pattern, each of the two portions containing a portion of the engraved pattern cannot be reasonably bonded to the other portion containing a different engraved pattern. Therefore, it is impossible to separate the security form of a travel passport from the cover at such a predetermined damaged location between the first layer a) and the other layers b) to join it with another security form, as is typically done in an attempt to forge it. Such separation would also damage at least one of layers a) and b), or the entire engraved pattern. Preferably, one of the two materials in both layers a) and b) is also at least partially damaged, making it no longer possible to join layers a) and b) to provide a layered structure with an intact engraved pattern.

[0200] Preferably, an NdYAG laser (neodymium-doped yttrium aluminum garnet laser) is used in the method for generating the engraved pattern in step III). For color laser engraving of layered structures, laser types suitable for engraving and welding of plastic parts, such as layered structures, can also be used. For example, a CO2 laser can also be used. Lasers emitting at wavelengths in the range of 950 nm to 1500 nm are preferred, and preferably at a wavelength of 1064 nm. Diode lasers are preferred. With diode lasers, particularly short pulse durations can be achieved, which allows for the generation of high energy peaks. Therefore, particularly well-defined and light-colored partial engraving patterns can be produced in the other layers b), which preferably appear as dark-colored partial engraving patterns in the adjacent first layer a) in portions not belonging to the overlapping area.

[0201] In step III), the two stacked layers a) and b) can be irradiated from the following side of the layer structure, where radiation first reaches the first layer a), or alternatively from the other side, i.e., from the following side, where radiation first reaches the other layer b). In a preferred embodiment of the method, the stacked layers a) and b) from step II) are irradiated in step III), preferably from the other layer b), where radiation first reaches the other layer b). During irradiation in step III), irradiation can be selectively chosen such that the additional portion of the engraved pattern exists only in the other layer b), or at least partially in the first layer a) below the other layer b). If irradiation is alternately applied from the first side a) and from the other side b) at least once in the overlapping region, alternating black and cloudy areas are obtained in the overlapping region. In this way, it is preferable to introduce a pattern into the engraved pattern in the overlapping region, which can present alternating segments of white and black.

[0202] In a preferred embodiment of the method, at least the first layer a), and preferably the other layers b), comprise a thermoplastic selected from polymers of olefinically unsaturated monomers, condensation polymers of bifunctional reactive compounds, and addition polymers of bifunctional reactive compounds, or combinations of at least two of these. Examples and preferred thermoplastics have been described in conjunction with the layer structures of the invention and are equally effective and applicable to the thermoplastics.

[0203] To avoid repetition, reference is made below to the above statements regarding the preferred embodiments, materials, amounts, composition, and additives as described in conjunction with the layered structure of the present invention.

[0204] Another subject of the invention relates to a laminate including the layered structure of the invention. The laminate preferably has exactly one first layer a) and another layer b), including the aforementioned overlapping area of ​​the two layers a) and b) and an engraved pattern, as described in connection with the layered structure of the invention. In addition to the two layers a) and b) of the layered structure, the laminate may also include at least one other layer c). The at least one other layer c) preferably comprises a polymer material. More preferably, the polymer material of the at least one other layer c) is selected from the materials described for the first layer a) and the materials described for the other layer b).

[0205] Another subject of the invention relates to the use of the layered structure or laminate of the invention for the production of security documents comprising security forms, preferably security forms in multi-layered covers, and more preferably security forms for covers of security and identification documents. All embodiments, materials, amounts, compositions, and additives described in connection with the layered structure of the invention are also applicable herein.

[0206] Another subject of the present invention relates to a method for producing multilayer laminates, the method comprising at least the following steps:

[0207] i) Provides the layer structure of the present invention;

[0208] ii) at a temperature of ≥80°C to ≤220°C, preferably at a temperature of ≥100°C to ≤200°C, more preferably at a temperature of ≥110°C to ≤190°C, and at a temperature of ≥2 N / cm 2 Up to ≤500N / cm 2 The pressure is preferably ≥10 N / cm. 2 Up to ≤400N / cm 2 The pressure is more preferably ≥20 N / cm 2 Up to ≤300N / cm 2 The lamination under pressure comes from the layer structure of step i), preferably using engraved laminate lamination, more preferably using engraved laminate lamination including an anti-stick coating;

[0209] iii) Optionally fold the layer structure, preferably along the centerline of the layer structure, so that the layer structure and the laminate are folded symmetrically;

[0210] iv) Optionally, after step iii), the layer structure is pressed along the centerline, preferably between two rollers, drums and / or plates, the pressing being carried out for 2 to 20 seconds, preferably 2 to 10 seconds, more preferably 2 to 5 seconds, at a temperature ≥0.5°C to ≤150°C above the softening temperature of the outermost layer.

[0211] v) Optionally remove the laminate comprising the layered structure from the press.

[0212] The provision in step i) can be any of the layer structures that a person skilled in the art would choose for this purpose.

[0213] A high-gloss laminate is used for lamination in step ii); thus, the laminate obtains a high-gloss surface on both sides and therefore has a glass-clear appearance.

[0214] To avoid repetition, reference is made to the above description regarding the implementation schemes and preferred scope of each layer of the layered structure.

[0215] In another embodiment of the method of the present invention, as described above, the layer structure can be engraved with black, white or colored engraving patterns by laser radiation at other locations on the layer structure or laminate before and / or after lamination.

[0216] method

[0217] Transmittance / Radiative Transmittance: To measure radiative transmittance, also known as transmittance [%), a method occurring in the UV-VIS-NIR-MIR spectral range is used. The Jasco (V-670) (Japan) UV-VIS-NIR spectrometer is used for the spectral range of ~2600 nm to 200 nm. Unless otherwise specified, the standard procedure selected here has the following settings: UV / VIS bandwidth 1.0 nm; NIR bandwidth 4.0 nm; scan rate 400 nm / min; core 340 nm; grating / detector 850 nm.

[0218] For the spectral range of ~2500nm to 28000nm (wavenumber: 350cm⁻¹) -1 Up to 4000cm -1 Using Nicolet from Thermo Fisher Scientific Inc., USA TM iS TM 10FT-IR type FTIR spectrometer.

[0219] Results in the wavelength range of 200nm to 2700nm Figure 5 This is shown in the diagram because this is the spectral range in which the engraved pattern will later be introduced into the layer structure at 1064 nm using a diode laser. The following settings were used for the Jasco (V-670) spectrometer:

[0220] Measurement duration: 95.36s Conversion points: 16384 Phase correction: Mertz Resolution: 4.000 <![CDATA[Laser wave number: 15798.7 cm -1 > Background scan count: 64 Zero fill: 0 Peak position in the interferogram: 8192 Background zoomed in: 2.0 Number of measurement points: 16672 Change of identity: NB Strong Number of sample scans: 64

[0221] Spectrometer Description

[0222] Spectrometer: Nicoleti S10 Beam splitter: KBr Aperture: Open Light source: IR Laser interval: 1.0000 Sample magnification: 8.0 Detector: DTGSKBr ADC position: 24 High-pass filter: 20.0000 Smart accessories: 016-01776 Mirror speed: 0.4747 Low-pass filter: 11000.0000 Example

[0223] Example 1)

[0224] Production of high-concentration IR masterbatch

[0225] The masterbatch for producing the other layers (b) of TPU film is compounded using a conventional twin-screw compounding extruder at a TPU processing temperature of 175°C to 200°C.

[0226] The masterbatch having the following composition is blended and then granulated:

[0227] -92.5% by weight thermoplastic polyurethane, from BASF's Elastolan TM 1185A

[0228] -7.5% by weight of YMDS 874IR absorbent (cesium tungsten oxide in toluene) from Sumitomo.

[0229] Example 2)

[0230] Producing TPU-based a) type film type as other layers b)

[0231] By using the example from Example 1 ) The masterbatch granules and TPU granules are mixed at the following concentrations to produce TPU films:

[0232] -10% by weight of masterbatch

[0233] -90% by weight thermoplastic polyurethane, from BASF's Elastolan TM 1185A

[0234] Films are produced to a thickness of 200 μm using blown film extrusion equipment. Alternatively, films can be produced by melting the mixture in a melt extruder and extruding it through a die, with thicknesses ranging from 20 μm to 800 μm. The transmittance value of this other layer b) is in Figure 5 and 6 As shown in the image.

[0235] Example 3)

[0236] Producing TPU-based type b) film as other layers b)

[0237] TPU films are produced by mixing masterbatch granules with TPU granules at the following concentrations:

[0238] -20% by weight of masterbatch

[0239] -80% by weight thermoplastic polyurethane, from BASF's Elastolan TM 1185A

[0240] Films are produced to a thickness of 200 μm using blown film extrusion equipment. Alternatively, films can be produced by melting the mixture in a melt extruder and extruding it through a die, with thicknesses ranging from 20 μm to 800 μm. The transmittance value of this other layer b) is in Figure 5 and 6 As shown in the image.

[0241] Example 4)

[0242] The membrane from Example 2) or Example 3) is covered and joined on the first layer a) of a travel passport data page made of polycarbonate by vibration welding.

[0243] The travel passport data page corresponding to the first layer a) of the layered structure of the present invention is produced from a polycarbonate film from Covestro. The data page or security form is produced with the following structure: 100 μm ID6-2000000; 100μm ID6-2750061; 200μm ID4-4010207; 200μm ID4-4010207; 100μm ID6-2750061; 100μm ID6-2000000.

[0244] The film was formed under pressure and heat to produce a monolithic composite with a total thickness of 800 μm. Lamination was performed on a Bürkle 50 / 100 press. First, lamination was performed in a hot press at 190°C and 60 N / cm. 2 The membrane was pressed under pressure for 6 minutes; the pressure was eventually increased to 200 N / cm. 2 Hold for another 60 seconds. Then, heat the laminate at 200 N / cm². 2 The laminate is cooled to 35°C under pressure and then removed from the press. It is then cut to passport-sized dimensions, approximately 92mm x 125mm. Next, another layer (b) in the form of a TPU film from Example 2 or 3 is placed onto one of the 125mm long sides of the laminate. The overlap between the TPU film (other layer b) and the polycarbonate laminate (first layer a) has a width of 6mm. The materials of the first layer a) and the other layer b) are joined by thermal pulse welding on a WISG type instrument from Heinz Schirmacher GmbH to produce the layer structure of the present invention. Welding is performed for 4 seconds at a pressure of 2 bar and a temperature of 140°C. A subsequent cooling time of 20 seconds follows.

[0245] Example 5)

[0246] The film from Example 2) or Example 3) is laminated and bonded onto a travel passport data page made of polycarbonate in the form of the first layer a). The travel passport data page is made of polycarbonate film from Covestro.

[0247] Data pages or security tables are produced in the following layer structure: 100μm ID6-2000000; 100μm ID6-2750061; 200μm ID4-4010207; 200μm ID4-4010207; 100μm ID6-2750061; 100μm ID6-2000000.

[0248] The film was formed under pressure and heat to produce a monolithic composite with a total thickness of 800 μm. Lamination was performed on a Bürkle 50 / 100 press. First, lamination was performed in a hot press at 190°C and 60 N / cm. 2 The membrane was pressed under pressure for 6 minutes; the pressure was eventually increased to 200 N / cm. 2 Hold for another 60 seconds. Then, heat the laminate at 200 N / cm². 2 The laminate is cooled to 35°C under pressure and then removed from the press. The laminate is then cut to passport-sized dimensions, approximately 92mm x 125mm. Next, another layer (b) in the form of a TPU film from Example 2 or 3 is placed onto one of the 125mm long sides of the laminate. The overlap between the TPU film (other layer b) and the polycarbonate laminate (first layer a) has a width of 6mm. The materials of the first layer a) and the other layers b) are bonded by lamination on a Bürkle 50 / 100 press to produce the layer structure of the present invention. First, the materials are heated in a hot press at 160°C and 30 N / cm. 2 Pressed under pressure for 60 seconds. Then, the material was subjected to 50 N / cm² pressure. 2 The laminate is cooled to 35°C under pressure and then removed from the press. For lamination, a laminate with an anti-stick coating is used to prevent the TPU film from adhering to the laminate. A laminate from 4-Plate with an anti-stick coating from Plascotec is used.

[0249] Example 6)

[0250] The joint area is obtained by introducing engraved patterns to seal the joint location.

[0251] The bonding materials from Examples 4) and 5) are sealed at the joint edges by laser engraving, the bonding materials being prepared using other layers b) in the form of a TPU film from Example 3). In cases where the bonding materials of the other layers b) of TPU and the first layer a) of PC separate, re-bonding in a precise manner and type is virtually impossible. Therefore, attempts to forge travel passports can be easily identified. For this purpose, the TPU-PC composite is placed on a workpiece carrier of a laser engraving device. A Foba D84S laser engraving device is used. Laser engraving is performed using a current of 30 amps and a frequency of 8 kHz at a movement speed of 100 mm / s. Figure 1 and2 As shown, both letters and numbers are engraved. Here, the engraving is parallel to and above the joint edge of the PC to TPU, such that the upper half of the letters and numbers in the TPU are engraved in the overlapping area (another part of the engraved pattern), and the lower half in the PC is outside the overlapping area (a first part of the engraved pattern). Here, the engraved pattern is two-tone. In the TPU portion (the other part of the engraved pattern), it appears as a white raised engraved pattern. The engraved pattern in the PC portion outside the overlapping area (the first part of the engraved pattern) appears as a black raised engraved pattern.

[0252] In experiments using tools and heating of other layers in the form of a TPU film (b), it was possible to remove it from the first layer (a) in the form of a PC data page. However, this damaged the engraved letters and numbers. Figure 3 As shown, after removing the other layers (b) of the TPU film from the first layer (a) in the form of a PC layer, the engraved patterns in the other layers (b) of the TPU portion are no longer visible in the underlying PC film. Depending on the amount of IR absorber chosen, additional engraved patterns can be introduced into the overlapping region only into the other layers (b), or into the underlying first layer (a), at the same laser power. Preferably, the additional engraved patterns exist only on the other layers (b).

[0253] Example 7)

[0254] The joint area is obtained by introducing engraved patterns to seal the joint location.

[0255] The layer structure of the present invention is obtained by sealing the bonding materials from Examples 4) and 5) at the bonding edges using laser engraving, wherein the bonding materials are prepared using other layers b) in the form of a TPU film from Example 2). Therefore, in cases where the bonding materials of the other layers b) of TPU and the first layer a) of PC separate, it is virtually impossible to re-bond them in a precise manner and type. Thus, attempts to forge travel passports can be easily identified. For this purpose, the TPU-PC composite is placed on a workpiece carrier of a laser engraving device.

[0256] The Foba D84S laser engraving system was used, with its laser operating at a wavelength of 1064 nm. Laser engraving was achieved using a 30-ampere current and an 8 kHz frequency at a travel speed of 100 mm / s. Figure 1 and 2As shown, letters are engraved. Here, the engraving is parallel to and above the joint edge of the PC to TPU, and is such that the upper half of the letters and numbers are engraved into the TPU in the overlapping area (another part of the engraving pattern) and the lower half in the PC is outside the overlapping area (a first part of the engraving pattern). Here, the engraving pattern appears as a black raised engraving pattern in both the TPU and PC parts.

[0257] In experiments using tools and heating the TPU film, it can be removed from the PC data page. After removing the TPU film, the engraved pattern in the TPU portion is also visible in the PC film below. Therefore, counterfeiting is almost entirely ruled out.

[0258] Example 8)

[0259] Producing TPU-based film type b) with alternative UV absorbers as other layers b)

[0260] Using thermoplastic polyurethane, Elastolan from BASF TM 1185A produces TPU films with a thickness of 200 μm on a blown film extrusion machine. Alternatively, films can be produced by melting thermoplastic polyurethane in a melt extruder and extruding it through a die to a thickness of 20 μm to 800 μm. The film is then coated with a transparent infrared-absorbing liquid by brushing and dried in air. The infrared-absorbing liquid used is LD920C from Clearweld, which contains organic IR-absorbing dyes. Alternatively, the LD920C infrared-absorbing liquid from Clearweld can also be introduced directly into the thermoplastic polyurethane before extrusion.

[0261] Example 9)

[0262] The membrane from Example 8) is covered and bonded onto the first layer a) of a travel passport data page made of polycarbonate by vibration welding.

[0263] The travel passport data page corresponding to the first layer a) of the layered structure of the present invention is produced from a polycarbonate film from Covestro. The data page or security form is produced with the following structure: 100 μm ID6-2000000; 100μm ID6-2750061; 200μm ID4-4010207; 200μm ID4-4010207; 100μm ID6-2750061; 100μm ID6-2000000.

[0264] The film was formed under pressure and heat to produce a monolithic composite with a total thickness of 800 μm. Lamination was performed on a Bürkle 50 / 100 press. First, lamination was performed in a hot press at 190°C and 60 N / cm. 2 The membrane was pressed under pressure for 6 minutes; the pressure was eventually increased to 200 N / cm. 2 Hold for another 60 seconds. Then, heat the laminate at 200 N / cm². 2 The laminate was cooled to 35°C under pressure and then removed from the press. It was then cut to passport-sized dimensions, approximately 92mm x 125mm. Next, another layer (b) in the form of a TPU film from Example 8 was placed onto one of the 125mm long sides of the laminate. The overlap between the TPU film (other layer b) and the polycarbonate laminate (first layer a) was 6mm wide. The materials of the first layer a) and the other layer b) were joined by thermal pulse welding on a WISG type instrument from Heinz Schirmacher GmbH to produce the layer structure of the present invention. Welding was performed for 4 seconds at a pressure of 2 bar and a temperature of 140°C. A subsequent cooling time of 20 seconds followed.

[0265] Example 10)

[0266] The joint area is obtained by introducing engraved patterns to seal the joint location.

[0267] The bonding materials from Examples 8) and 9) are sealed at the joint edges by laser engraving, the bonding materials being produced using other layers b) in the form of a TPU film from Example 8). Therefore, in cases where the bonding materials of the other layers b) of TPU and the first layer a) of PC separate, it is virtually impossible to re-bond them in a precise manner and type. Thus, attempts to forge travel passports can be easily identified. For this purpose, the TPU-PC composite is placed on a workpiece carrier of a laser engraving device. A Trumpf 3130 laser engraving device is used, with its laser operating at a wavelength of 1064 nm. Laser engraving is performed using 80% power and a frequency of 12 kHz at a movement speed of 400 mm / s. Figure 6As shown, both letters and numbers are engraved. Here, the engraving is parallel to and above the bonding edge of the PC to TPU, such that the upper half of the letters and numbers in the TPU are engraved in the overlapping area (another part of the engraved pattern), and the lower half in the PC is outside the overlapping area (a first part of the engraved pattern). Here, the engraved pattern has a two-tone appearance. In the TPU portion (the other part of the engraved pattern), it appears as a white raised engraved pattern. The engraved pattern in the PC portion outside the overlapping area (the first part of the engraved pattern) appears as a black raised engraved pattern.

[0268] Attached Figure

[0269] Figure 1 Preferred embodiments of the layer structure and its manufacturing method are described in sections 4 to 4, and should not be interpreted in a restrictive manner. The accompanying drawings illustrate:

[0270] Figure 1 A layered view in the form of a travel passport, having a personalized engraved pattern that is black on the first layer a) and milky white to white on the other layers b) in the overlapping area;

[0271] Figure 2 Travel passport form Figure 1 A close-up view of a security file, which has a personalized engraved pattern that is black (first part of the engraved pattern) on the first layer a) and cloudy or white (other part of the engraved pattern) on the other layers b) in the overlapping area.

[0272] Figure 3 The layer structure of the present invention, wherein the personalized engraved pattern cannot be separated without damage;

[0273] Figure 4a : A schematic diagram of a method for producing the layer structure of the present invention having a bonding region;

[0274] Figure 4b : A schematic diagram of a method for producing a multilayer laminate including the layer structure of the present invention;

[0275] Figure 5 A graph showing the transmittance values ​​of two other layers b) from Examples 2) and 3) with different proportions of IR absorbers in the wavelength range of 200 nm to 2700 nm.

[0276] Figure 6 The layer structure 10 of the present invention is in the form of a travel passport, which represents a security document.

[0277] Figure 1A layer structure 10 of the present invention, in the form of a travel passport, is shown, representing a security document. The layer structure 10 is produced according to Example 7. The layer structure 10 includes at least one first layer a) 14 composed of polycarbonate and another layer b) 12 composed of thermoplastic polyurethane. The other layer b) 12 overlaps with the first layer a) 14 in an overlapping region 17. Furthermore, a plurality of coherent engraved patterns 13 are present in the layer structure 10, each consisting of a white or nearly transparent portion 16 and a black portion 18. The white portion of the engraved pattern 16 is located in the overlapping region 17, and the black portion of the engraved pattern 18 is located only on the first layer a) 14. The two portions 16 and 18 of the engraved pattern are joined together by a bonding region, wherein the black portion of the engraved pattern, i.e., the first portion of the engraved pattern 18, directly touches the cloudy or white portion of the engraved pattern, i.e., the other portion of the engraved pattern 16.

[0278] Figure 2 yes Figure 1 An enlarged view of the middle part of the layer structure 10. The overlapping area 17 and the engraved pattern 13 are clearly visible, along with the white portion of the engraved pattern 16 on other layers b) 12 and the black portion of the engraved pattern 18 on the first layer a) 14.

[0279] Figure 3 The preparation according to Example 6 is shown. Figure 2 The illustration shows an attempt to forge the layer structure of the present invention. It is evident that the continuous engraving pattern 13 cannot be separated in a manner that allows for the reconstruction of the engraving pattern 13 or its reading on one of the layers (layer a) 14 or (layer b) 12). Therefore, it is impossible to separate the other layer b) 12 from the first layer a) 14 without damage. From the remaining portion of the engraving pattern 18, it is impossible, or only very difficult, to infer the information contained in the continuous engraving pattern 13 prior to the separation of the other layers b) 12.

[0280] Figure 4a A schematic diagram of a method for producing the layer structure 10 having a bonding region is shown. In step I) 20, the first layer a) is provided. In step II) 22, the first layer a) is at least partially covered by the other layers b) and laminated together by lamination on a Bürkle 50 / 100 press. Here, the materials of the first layer a) and the other layers b) are pressed at least in the overlapping region at 160°C and 30 N / cm for 60 seconds on the aforementioned press. Subsequently, the materials are pressed at 50 N / cm... 2The laminate is then cooled to a temperature of 35°C under pressure. The laminate is then removed from the press. For lamination, a laminate with an anti-stick coating is used to prevent the TPU film from adhering to the laminate. A laminate from 4-Plate is used, which has an anti-stick coating from Plascotec. In step III)24, an engraved pattern is created in the overlapping area of ​​layers a) and b) by laser to form a bonding area, and an engraved pattern is also created in the portion of the first layer a) not covered by the other layers b).

[0281] Figure 4b A schematic diagram of a method for producing a multilayer laminate is shown. In step i) 30, the layer structure 10 of the present invention is provided. In step ii) 32, as described above... Figure 4a The aforementioned temperature of 180°C and 100 N / cm in a commercial press 2 The laminate from step i) 30 is laminated under pressure. In optional step iii) 34, the laminate from step ii) 32 is folded along a line extending along the middle of the laminate 10. In optional step iv) 36, the laminate from step iii) 34 is pressed between two rollers at a temperature of 250°C for 5 seconds. Subsequently, the laminate is removed from the press in step v) 38.

[0282] exist Figure 5 The transmittance values ​​of the other layers b) from Examples 2) and 3) in the wavelength range of 200 nm to 2700 nm are plotted, as measured by the test methods described above. Unexpectedly, the transmittance at a wavelength of 1064 nm, where the engraved pattern 13 is introduced into the layer structure 10, does not decrease linearly, but rather decreases significantly more severely. Therefore, when the IR absorber concentration is doubled, from 0.75 wt% in Example 2) to 1.5 wt% in Example 3), the transmittance does not decrease by half but by one-third, i.e., from 45% to 15%.

[0283] Figure 6A layer structure 10 of the present invention, in the form of a travel passport, is shown, representing a security document. Layer structure 10 is produced according to embodiment 10. Layer structure 10 includes at least one first layer a) 14 composed of polycarbonate and other layers b) 12 composed of thermoplastic polyurethane. The first layer a) 14 overlaps with other layers b) 12 in an overlapping region 17. Furthermore, there are multiple coherent engraved patterns 13, at least partially composed of white or nearly transparent portions 16 and black portions 18, partially on the first layer a) 14 and partially on the other layers b) 12. The white portions of the engraved pattern 16 are located on the other layers b) 12, and the black portions of the engraved pattern 18 are located in the overlapping region 17 on the first layer a) 14. The two portions 16 and 18 of the engraved pattern are joined to each other by a bonding region, wherein the black portion of the engraved pattern, i.e., the first portion of the engraved pattern 18, directly touches the cloudy or white portion of the engraved pattern, i.e., the other portion of the engraved pattern 16.

Claims

1. Layer structure comprising at least a) a first radiation-engravable layer a) comprising at least one polymeric material; and b) at least one further layer b) comprising at least one polymeric material having a hardness of > 40 Shore A according to DIN ISO 7619-1-2012-2 to < 95 Shore D according to DIN ISO 7619-1-2012-2; wherein the further layer b) partially covers the first radiation-engravable layer a) to form an overlapping area, and wherein a coherent engraving motif extends partially in the further layer b) and partially in the part of the first radiation-engravable layer a) outside the overlapping area, wherein the further layer b) comprises an IR absorber having a light transmission of < 20% in the wavelength range of 950 nm to 1200 nm, wherein the part of the engraving motif extending within the overlapping area and introduced into the further layer b) is characterized by a colorless altered structure of the polymeric material.

2. Layer structure according to claim 1, wherein the first radiation-engravable layer a) comprises at least one additive having a maximum absorption in the wavelength range of the focused non-ionized electromagnetic radiation used to produce the engraving motif.

3. Layer structure according to any of the preceding claims, wherein the further layer b) comprises the IR absorber in an amount of > 0.5 wt.-% to < 10 wt.-% based on the total amount of layer b).

4. Layer structure according to any of claims 1 to 2, wherein the part of the engraving motif on the further layer b) differs in color or structure from the part of the engraving motif on the first radiation-engravable layer a).

5. Layer structure according to any of claims 1 to 2, wherein only the part of the coherent engraving motif introduced on the first radiation-engravable layer a) has colored or black characters.

6. Layer structure according to any of claims 1 to 2, wherein upon removal of the further layer b) from the first radiation-engravable layer a) the coherent engraving motif is separated at least in the overlapping area.

7. Layer structure according to any of claims 1 to 2, wherein the part of the engraving motif located in the overlapping area is only readable on the further layer b).

8. Layer structure according to any of claims 1 to 2, wherein the polymeric material of the first radiation-engravable layer a) comprises a thermoplastic selected from the group consisting of polymers of ethylenically unsaturated monomers and / or polycondensates of difunctional reactive compounds and / or polyaddition products of difunctional reactive compounds.

9. Layer structure according to any of claims 1 to 2, wherein the first radiation-engravable layer a) comprises at least one dye and / or at least one pigment.

10. Layer structure according to any of claims 1 to 2, wherein the further layer b) comprises at least one thermoplastic polyurethane.

11. Layer structure according to claim 1, wherein the layer structure is a hinge.

12. Layer structure according to claim 1, wherein the layer structure is a hinge formed between a security sheet and a cover.

13. Layer structure according to claim 1, wherein the layer structure is a hinge formed between a security sheet and a cover by a tab.

14. Layer structure according to claim 1, wherein the layer structure is a hinge formed between a security sheet and a cover of a security document.

15. Layer structure according to claim 1, wherein the further layer b) comprises at least one thermoplastic elastomer.

16. Layer structure according to claim 1, wherein the first radiation- engraveable layer a) is coated with at least one additive in the form of a coating composition having a maximum absorption in the wavelength range of the focused non-ionized electromagnetic radiation used.

17. Layer structure according to claim 1, wherein the first radiation- engraveable layer a) and the further layer b) comprise at least one additive having a maximum absorption in the wavelength range of the focused non-ionized electromagnetic radiation used for producing the engraved pattern.

18. Layer structure according to claim 1, wherein the first radiation- engraveable layer a) and the further layer b) are coated with at least one additive in the form of a coating composition having a maximum absorption in the wavelength range of the focused non-ionized electromagnetic radiation used.

19. Layer structure according to claim 3, wherein the further layer b) comprises the IR-absorber in an amount of > 0.6 wt.-% to < 7 wt.-% based on the total amount of layer b).

20. Layer structure according to claim 3, wherein the further layer b) comprises the IR-absorber in an amount of > 0.7 wt.-% to < 5 wt.-% based on the total amount of layer b).

21. Layer structure according to claim 3, wherein the further layer b) comprises the IR-absorber in an amount of > 0.75 wt.-% to < 2 wt.-% based on the total amount of layer b).

22. Method for producing a layer structure having a joint area, comprising at least the following steps: I) providing a first radiation-engraveable layer a) comprising at least one laser-engravable material; II) at least partially covering the first radiation-engraveable layer a) with at least a portion of a further layer b) comprising at least one polymeric material to form an overlapping area of the further layer b) on the first radiation-engraveable layer a); III) producing an engraved pattern in the layer structure, wherein one portion of the engraved pattern is located on a portion of the first radiation-engraveable layer a) not covered by the layer b) and another portion of the engraved pattern is located at least on a portion of the layer b) and optionally on a portion of the first radiation-engraveable layer a) covered by the further layer b) to form a joint area, wherein the two layers a) and b) are inseparably joined to each other in the joint area, wherein the further layer b) comprises an IR-absorber having a light transmission of < 20% in the wavelength range of 950 nm to 1200 nm, wherein the engraved pattern portion extending within the overlap region and introduced into the further layer b) is characterized by a colorless modification of the polymeric material.

23. The method according to claim 22, wherein the further layer b) comprises at least one thermoplastic polyurethane.

24. The method according to claim 22, wherein the engraved pattern is a laser engraved pattern.

25. Laminate comprising the layer structure according to any one of claims 1 to 21.

26. Use of the layer structure according to any one of claims 1 to 21 or of the layer structure produced by the method according to any one of claims 22 to 24 or of the laminate according to claim 25 for the production of a security document.

27. The use according to claim 26 for the production of a security sheet in a multi-layer cover.

28. The use according to claim 26 for the production of a security sheet in a cover for security and identity documents.

29. Method for the production of a multi-layer laminate comprising at least the following steps: i) providing a layer structure according to any one of claims 1 to 21 or produced by the method according to any one of claims 22 to 24; ii) laminating the layer structure from step i) at a temperature of > 80 °C to < 220 °C and a pressure of > 2 N / cm2to < 500 N / cm2; iii) optionally folding the layer structure along a center line of the layer structure such that the layer structure and laminate are folded symmetrically; iv) optionally pressing the layer structure along the center line after step iii) at a temperature of > 0.5 °C to < 150 °C above the softening temperature of the outermost layer for a time of 2 to 20 seconds; v) optionally removing the laminate comprising the layer structure from the press.

30. The method according to claim 29, wherein the lamination in step ii) is laminated using an engraved laminating plate.

31. The method according to claim 29, wherein the lamination in step ii) is laminated using an engraved laminating plate comprising a release coating.

32. The method according to claim 29, wherein the layer structure is pressed between two rollers and / or plates in step iv).

33. The method according to claim 29, wherein the pressing in step iv) is at a temperature of > 1 °C to < 50 °C above the softening temperature of the outermost layer for a time of 2 to 10 seconds.

34. The method according to claim 29, wherein the pressing in step iv) is at a temperature of > 1 °C to < 20 °C above the softening temperature of the outermost layer for a time of 2 to 5 seconds.

Images