WO2012049160A1

WO2012049160A1 - Security document and/or document of value containing an electromechanical transducer

Info

Publication number: WO2012049160A1
Application number: PCT/EP2011/067703
Authority: WO
Inventors: Georgios Tziovaras; Elisa Picasso; Mehmet-Cengiz Yesildag; Werner Jenninger
Original assignee: Bayer Materialscience Ag
Priority date: 2010-10-14
Filing date: 2011-10-11
Publication date: 2012-04-19
Also published as: EP2441589A1; EP2627519A1

Abstract

The present invention relates to a security document and/or document of value comprising an electromechanical transducer as a novel security element, to a method for producing the same, and to the use of such an electromechanical transducer as a security element in security documents and/or documents of value.

Description

Security and / or value document containing an electromechanical transducer

The present invention relates to a security and / or value document with an electromechanical transducer as a novel security element, a method for its production and the use of such an electromechanical transducer as a security element in security and / or value documents.

In the market of security and / or value documents, in particular identification documents (ID documents) there is a need for continuous improvement of the security features used and development of new security features to always be one step ahead of potential counterfeiters. The security features should be designed so that a counterfeit is technically difficult and purely visually as easy to identify.

Plastic-based security and / or value documents, in particular identification documents, such as e.g. ID cards are now produced as multilayer composites by means of lamination. In these multilayer composites before or during the lamination process, the appropriate security features are introduced, which must therefore be designed so that they withstand the laminating process parameters nondestructive. In addition, no weaknesses in the multi-layer composite must be introduced by the security features, which would enable a non-destructive subsequent opening of the composite again.

Security features in security and / or value documents are usually divided into three security levels:

Tier 1 security features are those that are purely visually perceptible without the use of additional resources.

Level 2 security features are those that require aids (such as a magnifying glass, an optical filter, a reader, etc.) to become visible.

Level 3 security features are those that can only be identified in a laboratory by forensic procedures. As a rule, at least partial destruction of the document is accompanied by the analysis.

While Level 1 security features can be perceived quickly, they are disadvantageous in that sufficiently complex counterfeits can result with limited effort.

Level 3 security features can only be counterfeited at extremely high cost, but their identification can usually be at least partially destroyed Document can not be avoided. Accordingly, the focus is on the improvement of Level 2 security features.

The object underlying the present invention, therefore, was to find a novel security feature to improve the security against forgery of security and / or value documents.

Electromechanical converters convert electrical energy into mechanical energy and vice versa. They are described in the literature as part of sensors, actuators and generators (see, for example, US-A 2004/0263028 and EP-A 2,182,559).

So far, however, neither the suitability nor the use of such electromechanical transducers as a security feature in a safety and / or value document has been described in the literature.

Surprisingly, it has now been found that electromechanical transducers containing two electrodes and a layer arranged therebetween with at least one elastomer or a polymeric piezoelectric material are suitable as a security feature for improving the security against forgery of security and / or value documents.

Such electromechanical transducers can be used as a safety feature, on the one hand, in order to prevent the introduction of electrical energy, e.g. On the other hand, they offer the possibility of electrical energy by introducing mechanical energy, for example, by simply bending the security and / or value document or pressing an invisible button, by means of a "reading device" generate, which makes a hidden information, for example in the form of an EL, OLED or PLED-based arrangement, visible.

The subject of the present invention is accordingly a security and / or value document, characterized in that it comprises at least one electromechanical transducer comprising at least two electrodes and at least one polymer layer arranged between the electrodes, wherein the polymer layer comprises at least one elastomer or one polymeric piezoelectric Contains material.

The elastomer (s) of the polymer layer are so-called electroactive polymers. Electroactive polymers are deflected when activated by electrical energy. Such an electroactive polymer acts as an insulating dielectric between two electrodes and may be deflected upon application of a voltage difference between the two electrodes. In preferred embodiments, the elastomers used in the invention may be those which are pre-stressed. The pre-stress of a electroactive polymer may be described in one or more directions as the change in dimension in this direction after pre-stress relative to the dimension in that direction prior to pre-stressing. The pre-stress may include elastic deformation of the electroactive polymer, and may be generated, for example, by stretching the electroactive polymer under tension and fixing it to one or more of the edges while tensioned. The pre-stress improves the conversion between electrical and mechanical energy. On the one hand, pre-stress can improve the dielectric strength of the electroactive polymer, allowing for greater deflection and thus providing greater mechanical work when electrical energy is converted into mechanical energy. On the other hand, the pre-stress may result in more charge being applied to the electrodes, resulting in more generated electrical energy per cycle of deflection.

Suitable elastomers which can be used according to the invention are all substantially insulating polymers or rubbers (or a combination thereof) which deform in response to an electrostatic force or whose deformation leads to a change in the electric field. Elastomers which can be used according to the invention are preferably silicone elastomers, acrylate elastomers, polyurethanes, thermoplastic elastomers, copolymers comprising polyvinylidene fluoride (PVDF), pressure-sensitive adhesives, fluoroelastomers, polymers comprising silicone and acrylate components, and mixtures of these. For example, polymers comprising silicone and acrylate components may include, for example, copolymers including silicone and acrylate components, polymer blends comprising a silicone elastomer, and an acrylate elastomer. Particularly preferred elastomers are polyurethane elastomer, silicone elastomer, acrylate elastomers and / or polymers comprising silicone and acrylate components. Very particularly preferred elastomers are silicone elastomers.

An example of a suitable silicone elastomer is Dow Corning ^® HS3 (Dow Corning, Wilmington, Delaware) is supplied. An example of a suitable fluoro-silicone is Dow ^Corning® 730 (Dow Corning, Wilmington, Delaware). Another suitable silicone elastomer is NuSil CF19-2186 (NuSil Technology Carpenteria, CA).

A suitable example of a thermoplastic elastomer is styrene-butadiene-styrene (SBS) block copolymer.

Suitable examples of acrylate elastomers are, for example, those from the 4900 VHB acrylate series (3 M Corp., St. Paul, MN). Suitable acrylate elastomers can be prepared from any monoethylenically unsaturated monomer (or combination of monomers) which is homopolymerizable to form a polymer having a glass transition temperature of at most about 0 ° C. Preferred monoethylenically unsaturated monomers include isooctyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, dodecyl acrylate, hexyl acrylate, isononyl acrylate, isooctyl methacrylate and 2-ethylhexyl methacrylate. Any of the monomers may also contain one or more halogens, such as fluorine. Preferably, the acrylate elastomer is one comprising mixtures of aliphatic acrylates, especially containing at least one branched acrylate, which are photocured during fabrication. The elasticity of the acrylate elastomer results from a combination of branched aliphatic groups and the crosslinking between the acrylate polymer chains.

Suitable polyurethane elastomers can be prepared by reacting a polyisocyanate A) and / or a polyisocyanate prepolymer B) with at least one difunctional or polyfunctional isocyanate-reactive compound C) in the presence of a catalyst D) which is customary in polyurethane chemistry.

Suitable polyisocyanates A) are, for example, 1,4-butylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 2,2,4 and / or 2,4,4-trimethylhexamethylene diisocyanate, the isomeric bis (4, 4'-isocyanatocyclohexyl) methanes or mixtures thereof of any isomer content, 1,4-cyclohexylene diisocyanate, 4-isocyanatomethyl-1,9-octane diisocyanate (nonane triisocyanate), 1,4-phenylene diisocyanate, 2,4- and / or 2,6-toluene diisocyanate, 1,5-naphthylene diisocyanate, 2,2'- and / or 2,4'- and / or 4,4'-diphenylmethane diisocyanate, 1,3- and / or 1,4-bis (2-isocyanato-prop-2 -yl) -benzene (TMXDI), 1,3-bis (isocyanatomethyl) benzene (XDI), alkyl 2,6-diisocyanatohexanoate (lysine diisocyanates) having alkyl groups of 1 to 8 carbon atoms and mixtures thereof. Furthermore, uretdione, isocyanurate, biuret, iminooxadiazinedione or oxadiazinetrione-containing compounds based on the diisocyanates mentioned are suitable building blocks of component A).

Component A) may preferably be a polyisocyanate or a polyisocyanate mixture having an average NCO functionality of 2 to 4 with exclusively aliphatically or cycloaliphatically bonded isocyanate groups. Preference is given to polyisocyanates or polyisocyanate mixtures of the abovementioned type with uretdione, isocyanurate, biuret, iminooxadiazinedione or oxadiazinetrione structure and mixtures thereof and an average NCO functionality of the mixture of from 2 to 4, preferably from 2 to 2.6 and more preferably from 2 to 2.4.

The polyisocyanate prepolymers which can be used as component B) can be obtained by reacting one or more diisocyanates with one or more hydroxy-functional, in particular polymeric, polyols, if appropriate with addition of catalysts and auxiliaries and additives. In addition, it is additionally possible to use components for chain extension, such as, for example, with primary and / or secondary amino groups (NH ₂ and / or NH-functional components) for the formation of the polyisocyanate prepolymer. The polyisocyanate prepolymer as component B) may preferably be obtainable from the reaction of polymeric polyols and aliphatic diisocyanates. Hydroxy-functional, polymeric polyols for the conversion to the polyisocyanate prepolymer B) may be, for example, polyester polyols, polyacrylate polyols, polyurethane polyols, polycarbonate polyols, polyetherpolyols, polyesterpolyacrylate polyols, polyurethane polyacrylate polyols, polyurethane polyester polyols, polyurethane polyether polyols, polyurethane polycarbonate polyols and / or polyester polycarbonate polyols. These can be used to prepare the polyisocyanate prepolymer individually or in any mixtures with each other.

Suitable polyester polyols for the preparation of the polyisocyanate prepolymers B) may be polycondensates of di- and optionally tri- and tetraols and di- and optionally tri- and tetracarboxylic acids or hydroxycarboxylic acids or lactones. Instead of the free polycarboxylic acids, it is also possible to use the corresponding polycarboxylic acid anhydrides or corresponding polycarboxylic acid esters of lower alcohols for the preparation of the polyesters.

Examples of suitable diols are ethylene glycol, butylene glycol, diethylene glycol, triethylene glycol, polyalkylene glycols such as polyethylene glycol, furthermore 1,2-propanediol, 1,3-propanediol, butanediol (1,3), butanediol (1,4), hexanediol (1,6) and isomers, neopentyl glycol or hydroxypivalic acid neopentyl glycol esters or mixtures thereof, with hexanediol (1,6) and isomers, butanediol (1,4), neopentyl glycol and neopentyl glycol hydroxypivalate being preferred. In addition, it is also possible to use polyols such as trimethylolpropane, glycerol, erythritol, pentaerythritol, trimethylolbenzene or trishydroxyethyl isocyanurate or mixtures thereof.

Aliphatic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexanedicarboxylic acid, adipic acid, azelaic acid, sebacic acid, glutaric acid, tetrachlorophthalic acid, maleic acid, fumaric acid, itaconic acid, malonic acid, suberic acid, Methyl succinic acid, 3,3-diethylglutaric acid and / or 2,2-dimethyl succinic acid are used. The acid source used may also be the corresponding anhydrides.

If the mean functionality of the polyol to be esterified is> 2, monocarboxylic acids, such as benzoic acid and hexanecarboxylic acid may additionally be used.

Preferred acids are aliphatic or aromatic acids of the abovementioned type. Particular preference is given to adipic acid, isophthalic acid and phthalic acid.

Hydroxycarboxylic acids which can be used as reactants in the preparation of a hydroxyl-terminated polyester polyol are, for example, hydroxycaproic acid, hydroxybutyric acid, hydroxydecanoic acid or hydroxystearic acid or mixtures thereof. Suitable lactones are caprolactone, butyrolactone or homologs or mixtures thereof. Preference is given to caprolactone. Likewise, for the preparation of the polyisocyanate prepolymers B) hydroxyl-containing polycarbonates, for example polycarbonate, preferably polycarbonate, can be used. For example, they may have a number average molecular weight M _{n of} from 400 g / mol to 8000 g / mol, preferably from 600 g / mol to 3000 g / mol. The se can be obtained by reaction of carbonic acid derivatives, such as diphenyl carbonate, dimethyl carbonate or phosgene, with polyols, preferably diols.

Examples of suitable diols are ethylene glycol, 1,2- and 1,3-propanediol, 1,3- and 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, neopentyl glycol, 1,4-bishydroxymethylcyclohexane, 2 Methyl-1,3-propanediol, 2,2,4-trimethylpentanediol-1,3-dipropylene glycol, polypropylene glycols, dibutylene glycol, polybutylene glycols, bisphenol A or lactone-modified diols of the type mentioned above or mixtures thereof.

The diol component then preferably contains from 40% by weight to 100% by weight of hexanediol, preferably 1,6-hexanediol and / or hexanediol derivatives. Such hexanediol derivatives are based on hexanediol and may have ester or ether groups in addition to terminal OH groups. Such derivatives are obtainable, for example, by reaction of hexanediol with excess caprolactone or by etherification of hexanediol with itself to give di- or trihexylenglycol. The amount of these and other components are chosen such that the sum does not exceed 100% by weight, in particular 100% by weight.

Hydroxyl-containing polycarbonates, especially polycarbonate polyols, are preferably linearly constructed.

Likewise, polyether polyols can be used to prepare the polyisocyanate prepolymers B). For example, polytetramethylene glycol polyethers as obtainable by polymerization of tetrahydrofuran by means of cationic ring opening are suitable. Also suitable polyether polyols may be the addition products of styrene oxide, ethylene oxide, propylene oxide, butylene oxide and / or epichlorohydrin to di- or polyfunctional starter molecules. Examples of suitable starter molecules which may be used are water, butyldiglycol, glycerol, diethylene glycol, trimethylolpropane, propylene glycol, sorbitol, ethylenediamine, triethanolamine, or 1,4-butanediol or mixtures thereof.

Preferred components for the preparation of the polyisocyanate prepolymers B) are polypropylene glycol, polytetramethylene glycol polyethers and polycarbonate polyols or mixtures thereof, with polypropylene glycol being particularly preferred.

In this case, polymeric polyols having a number average molecular weight M _n of 400 g / mol to 8000 g / mol, preferably from 400 g / mol to 6000 g / mol and particularly preferably from 600 g / mol to 3000 g / mol can be used. These preferably have an OH functionality of from 1.5 to 6, particularly preferably from 1.8 to 3, very particularly preferably from 1.9 to 2.1.

In addition to the stated polymeric polyols, short-chain polyols can also be used in the preparation of the polyisocyanate prepolymers B). For example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,3-butylene glycol, cyclohexanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol, neopentylglycol .

Hydroquinone dihydroxyethyl ether, bisphenol A (2,2-bis (4-hydroxyphenyl) propane), hydrogenated bisphenol A (2,2-bis (4-hydroxycyclohexyl) propane), trimethylolpropane, trimethylolethane, glycerol or pentaerythritol, or a mixture thereof.

Also suitable are ester diols of the stated molecular weight range, such as α-hydroxybutyl-ε-hydroxycaproic acid ester, ro-hydroxyhexyl-γ-hydroxybutyric acid ester, adipic acid (β-hydroxyethyl) ester or terephthalic acid bis (β-hydroxyethyl) ester.

Furthermore, it is also possible to use monofunctional isocyanate-reactive hydroxyl-containing compounds for the preparation of the polyisocyanate prepolymers B). Examples of such monofunctional compounds are ethanol, n-butanol, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether,

Tripropylene glycol monobutyl ether, 2-ethylhexanol, 1-octanol, 1-dodecanol or 1-hexadecanol or mixtures thereof.

To prepare the polyisocyanate prepolymers B), it is possible to react diisocyanates with the polyols at a ratio of the isocyanate groups to hydroxyl groups (NCO / OH ratio) of 2: 1 to 20: 1, for example 8: 1. In this case, urethane and / or allophanate structures can be formed. A proportion of unreacted polyisocyanates can then be separated off. For this purpose, for example, a thin-film distillation can be used, with residual monomer low products with residual monomer contents of, for example, <1 weight percent, preferably <0.5 weight percent, particularly preferably <0, 1 weight percent, are obtained. The reaction temperature may be from 20 ° C to 120 ° C, preferably from 60 ° C to 100 ° C, amount. Optionally, stabilizers such as benzoyl chloride, isophthaloyl chloride, dibutyl phosphate, 3-chloropropionic acid or methyl tosylate may be added during the preparation.

Furthermore, NH ₂ - and / or NH-functional components can be used in addition to the chain extension in the preparation of the polyisocyanate prepolymers B).

Suitable components for chain extension are organic di- or polyamines. For example, ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,6- Diaminohexane, isophoronediamine, isomer mixtures of 2,2,4- and 2,4,4-trimethylhexamethylenediamine, 2-methylpentamethylenediamine, diethylenetriamine,

Diaminodicyclohexylmethan or dimethylethylenediamine or mixtures thereof.

In addition, it is also possible to use compounds which, in addition to a primary amino group, also have secondary amino groups or, in addition to an amino group (primary or secondary), OH groups, for the preparation of the polyisocyanate prepolymers B). Examples of these are primary / secondary amines, such as diethanolamine, 3-amino-1-methylaminopropane, 3-amino-1-ethylaminopropane, 3-amino-1-cyclohexylaminopropane, 3-amino-1-methylaminobutane, alkanolamines, such as N-aminoethylethanolamine, ethanolamine , 3-aminopropanol, neopentanolamine. For chain termination are usually amines having an isocyanate-reactive group such as methylamine, ethylamine, propylamine, butylamine, octylamine, laurylamine, stearylamine, isononyloxypropylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, N-methylaminopropylamine, diethyl (methyl) aminopropylamine, morpholine, piperidine, or suitable substituted derivatives thereof, amide amines from diprimary amines and monocarboxylic acids, monoketim of diprimary amines, primary / tertiary amines, such as N, N-dimethylaminopropylamine.

The polyisocyanate prepolymers or mixtures thereof used as component B) may preferably have an average NCO functionality of 1.8 to 5, particularly preferably 2 to 3.5 and very particularly preferably 2 to 3.

Component C) is a compound having at least two isocyanate-reactive functional groups. For example, component C) may be a polyamine or a polyol having at least two isocyanate-reactive hydroxy groups.

As component C) it is possible to use hydroxy-functional, in particular polymeric, polyols, for example polyether polyols or polyester polyols. Suitable polyols have already been described above in connection with the preparation of the prepolymer B), so that reference is made to avoid repetition thereof.

It is preferred that component C) is a polymer having 2 to 4 hydroxy groups per molecule, most preferably a polypropylene glycol having 2 to 3 hydroxy groups per molecule.

It is favorable if the polymeric polyols C) have a particularly narrow molecular weight distribution, that is to say a polydispersity (PD = Mw / Mn) of 1.0 to 1.5. For example, polyether polyols preferably have a polydispersity of 1.0 to 1.5 and an OH functionality of greater than 1.9, and particularly preferably greater than or equal to 1.95. Such polyether polyols can be prepared in a manner known per se by alkoxylation of suitable starter molecules, in particular using double metal cyanide catalysts (DMC catalysis). This method is described for example in the patent US 5, 158, 922 and the published patent EP 0 654 302 AI.

The reaction mixture for the polyurethane can be obtained by mixing components A) and / or B) and C). The ratio of isocyanate-reactive hydroxy groups to free isocyanate groups is preferably from 1: 1.5 to 1.5: 1, more preferably from 1: 1.02 to 1: 0.95.

Preferably, at least one of components A), B) or C) has a functionality of> 2.0, preferably> 2.5 preferably> 3.0 to introduce branching or crosslinking into the polymer element. The term "functionality" in component A) and B) refers to the average number of NCO groups per molecule and in component C) to the average number of OH--, NH or NH ₂ groups per molecule. This branching or crosslinking brings about better mechanical properties and better elastomeric properties, in particular also better elongation properties, which is advantageous when using the dielectric elastomers in security and / or value documents according to the invention.

The polyurethane polymer obtained may preferably have a maximum stress of> 0.2 MPa, in particular from 0.4 MPa to 50 MPa, and a maximum elongation of> 100%, in particular of> 120%. In addition, the polyurethane in the elongation range of 50% to 200%, a tension of 0, 1 MPa to 1 MPa, for example from 0, 1 MPa to 0.8 MPa, in particular from 0, 1 MPa to 0.3 MPa, have (determination according to ASTM D 412). Further, the polyurethane may have a Young's modulus at an elongation of 100% from 0.1 MPa to 10 MPa, for example from 1 MPa to 8 MPa (determined according to ASTM D 412).

Preferably, the polyurethane polymer obtained is a dielectric elastomer having a volume resistivity according to ASTM D 257 of> 10 ¹² to <10 ¹⁷ ohm cm. It is also possible that the polyurethane polymer has a dielectric constant according to ASTM 150-98 of> 5 and a dielectric breakdown field strength according to ASTM 149-97a of> 100 V / μιη. Basically, a maximum dielectric constant and a maximum dielectric breakdown field strength are desired in order to optimize the serviceability of the polymer.

The elastomers may contain one or more additives to enhance various properties. Examples of such additives are crosslinkers, thickeners, solvents, thixotropic agents, stabilizers, antioxidants, preferably nonvolatile antioxidants, light stabilizers, emulsifiers, surfactants, adhesives, plasticizers, water repellents, pigments, fillers and leveling agents. In particular for polyurethane elastomers, these additives are added to the reaction mixture for the preparation of the polyurethane in addition to the components A), B), C) and D). Preferred solvents are methoxypropyl acetate and ethoxypropyl acetate. Preferred flow control agents are polyacrylates, in particular amine resin-modified acrylic copolymers.

Preferably, the additives improve the ability of the elastomer to convert between mechanical energy and electrical energy. In general, the additives may improve any polymer property or parameter related to the ability of the parameter to convert between mechanical energy and electrical energy, such as e.g. dielectric breakdown strength, maximum stress, dielectric constant, modulus of elasticity, properties associated with viscoelastic behavior, properties associated with creep, response time, and activation voltage.

For example, fillers can regulate the dielectric constant of the polymer element. Preferably, the reaction mixture comprises fillers to increase the dielectric constants, such as fillers with a high dielectric constant. Examples of these are ceramic fillers, in particular barium titanate, titanium dioxide and piezoelectric ceramics such as quartz or lead zirconium titanate, as well as organic fillers, in particular those having a high electrical polarizability, for example phthalocyanines. In addition, a high dielectric constant can also be achieved by introducing electrically conductive fillers below the percolation threshold. Examples include carbon black, graphite, single-walled or multi-walled carbon nanotubes, graphenes, electrically conductive polymers such as polythiophenes, polyanilines or polypyrroles, or mixtures thereof. In this context, in particular those types of carbon are of interest, which have a surface passivation and therefore at low concentrations below the percolation threshold, although the dielectric constant increase and still do not lead to an increase in the conductivity of the polymer.

For example, the addition of a plasticizer may improve the functioning of the electromechanical transducer by reducing the modulus of elasticity of the elastomer and / or increasing the dielectric breakdown strength of the elastomer. Examples of Suitable Plasticizers include High Molecular Weight Hydrocarbon Oils, High Molecular Weight Hydrocarbon Fats, Pentalyne® H, Piccovar® AP Hydrocarbon Resins, Admex® 760, Plastolein® 9720, Silicone Oils, Silicone Greases, Floral® 105, Silicone elastomers, nonionic surfactants, and the like. Combinations of these materials may also be used.

The use of silicone elastomers as elastomers has the advantage of a higher temperature resistance of the elastomer layer, so that the function of the electromechanical transducer is not impaired or destroyed even at higher laminating temperatures. Thereby can using silicone elastomers, the layer structures can be produced at higher lamination temperatures, and an alternative production method using additional adhesive layers can be dispensed with. By avoiding adhesive layers when using plastic layers of comparable basis, it is possible to produce by lamination in the laminated laminate a subsequently no longer separable monolithic layer composite, which is in terms of security against forgery of security and / or value documents advantage.

It should be noted that the terms "a" and "an" in the context of the present invention and in particular with the components A), B) and C) are not used as number words, but as an indefinite article, unless the context clearly different Statement results.

The polymeric piezoelectric materials may be, for example, fluorinated polymers, e.g. PVDF (polyvinylidene fluoride) or copolymers with VDF, e.g. the VDF / TrFE copolymers (vinylidene fluoride-trifluoroethylene copolymers), or so-called ferroelectrets. Preferred polymeric piezoelectric materials are ferroelectrets. Ferroelectrets are described, for example, in Physics Today, February 2004, 37-43 or ChemPhysChem, 2005, 6, 1014-1025.

Ferroelectrets are polymer materials with a void structure that can store electrical charges for long periods of time. The previously known ferroelectrets have a cellular cavity structure and are formed either as foamed polymer films or as multilayer systems of polymer films or polymer fabrics. If electrical charges are distributed according to their polarity on the different surfaces of the cavities, each charged cavity represents an electric dipole. If the cavities are deformed, this causes a change in the dipole size and leads to a flow of current between external electrodes. The ferroelectrets can exhibit a piezoelectric activity comparable to that of other piezoelectrics.

The use of ferroelectrets in the polymer layer arranged between the electrodes is advantageous because ferroelectrets can be firmly bound into the multilayer composite. Due to the surface constancy of ferroelectrets to the function of the electromechanical transducer, ferroelectret-based layers do not require a planar, ie lateral expansion, but can fulfill the desired function solely on account of thickness reduction or thickness expansion, which due to the small layer thickness and therefore flexibility of the further plastic layers above and / or below the electromechanical transducer in the multilayer structure according to the invention is always given. As a result, in the production of the multi-layer structures according to the invention, attention is not paid to clearances for surface expansion become. Also advantageous is the high sensitivity of ferroelectrets over many other piezoelectrics.

Materials suitable for ferroelectrets include polymers selected from the group consisting of polycarbonate or copolycarbonates, perfluorinated or partially fluorinated polymers, and co-polymers, such as e.g. Polytetrafluoroethylene (PTFE), perfluoroethylene-propylene copolymer (FEP), perfluoroalkoxy polymers (PFA), polyesters, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide, polyetherimide, polyether, polymethyl (meth) acrylate, cyclo-olefin polymers, cyclo Olefin copolymers (COC) and / or polyolefins, such as Polypropylene. With these materials, good to very good piezo activities can be achieved. Preferred materials suitable for ferroelectrets are those which contain at least one polycarbonate or copolycarbonate, in particular at least one polycarbonate or copolycarbonate based on diphenols. In question come as such poly- or copolycarbonates mentioned below for the thermoplastic materials for the plastic layers.

The use of polycarbonate or copolycarbonate as a material for ferroelectrics offers the possibility, if the further plastic layers in the multilayer structure according to the invention also contain at least one polycarbonate or copolycarbonate, to produce a monolithic layer composite during lamination. Such a monolithic layer composite offers special protection against subsequent, non-destructive separation of the layer composite.

Such piezoelectric behavior can be found, for example, in closed cell foams, such as e.g. foamed, closed-pore polypropylene (PP) are observed. In order to achieve piezoelectricity, such a polymer foam is charged in a high electric field. As a result, electrical breakdowns take place within the pores, which generate macrodipoles and polarize the material macroscopically. Such polypropylene ferroelectrets may have a piezoelectric coefficient of several hundred picocoulombs per Newton.

However, it is also possible, instead of the random closed pores of different sizes in the case of closed-cell foams, to introduce the cavities specifically into the polymers, for example by means of structured films or metal meshes as masks.

It is also possible to use multilayer systems composed of a plurality of films stacked one on top of the other. Gerhard et al. For example, (2007 Annual Report on Electrical Insulation and Dielectric Phenomena, pages 453 to 456) describes a three-layer ferroelectret in which a polytetrafluoroethylene film provided with a plurality of uniform continuous recesses by mechanical or laser-based drilling is sandwiched between two uniform fluoroethylene propylene films , Further suitable multi-layer ferrules and their preparation are described, for example, in WO 2010/066348 A2. Further processes for the production of ferroelectrets are known to the person skilled in the art and are described, for example, in US Pat. No. 4,654,546, in Voronina et al. Applied Physics A: Materials Science & Processing 90, 615-618 (2008), "Physical foaming of fluorinated ethylene-propylene (FEP) copolymers in supercritical carbon dioxide: single film fluoropolymer piezoelectrets" and other references. An advantageously simple production method for tubular-shaped ferroelectrons of homogeneous size and structure has been described by RAP Altafim et al., Journal of Applied Physics, 106, 014106 (2009). In the process described there, a sandwich arrangement of two FEP films (FEP: perfluoroethylene-propylene copolymer) and a PTFE masking film inserted between them is first provided. The formed film stack is laminated, the FEP films are bonded together, and subsequently the mask film is removed to release the voids.

According to the invention, the electromechanical transducer can also contain more than two electrodes and in each case a polymer layer arranged therebetween containing at least one elastomer or a polymeric piezoelectric material. Such stack structures may offer the advantage, for example, of enhancing haptic feedback due to the greater mechanical forces that can be generated therewith.

The thickness of the polymer layer containing the elastomer (s) or polymeric piezoelectric material (s) may preferably be in the range of 1 μιη to 150 μιη, with thicknesses below 100 μιη, e.g. between 20 and 100 μιη are preferred for use in particularly thin security and / or value documents.

For certain applications, it may be advantageous and preferred that the polymer layer between the electrodes contains at least one elastomer. However, for certain applications it may again be advantageous and preferred for the polymer layer between the electrodes to contain at least one polymeric piezoelectric material.

The electrode materials may be conductive materials known to those skilled in the art. For this example, metals, metal alloys, conductive oligo- or polymers, such as polythiophenes, polyanilines, polypyrroles, conductive oxides, such as mixed oxides such as ITO, or filled with conductive polymers in question. Suitable fillers for polymers filled with conductive fillers are, for example, metals, conductive carbon-based materials such as carbon black, carbon nanotubes (CNTs), graphenes or conductive oligo- or polymers. The filler content of the polymers is above the percolation threshold, which is characterized in that the conductive fillers form continuous electrically conductive paths. Preferably, the filled with conductive fillers polymers are elastomers. For particularly preferred applications in which the elasticity of the entire electromechanical transducer of interest is preferably suitable Electrode materials are, for example, elastic electrode materials, such as, for example, conductive oligomers or polymers or polymers filled with conductive fillers.

The basic structure and the production of electromechanical transducers is known to the person skilled in the art and described for example in US-A 2004/0263028 or EP-A 2,182,559.

The thickness of the electromechanical transducer as a whole may preferably be in the range of 10 μιη and 200 μιη, wherein thicknesses below 150 μιη, such. between 30 and 120 μιη are preferred for use in particularly thin security and / or value documents.

The electromechanical converter may preferably be located in the security and / or value document according to the invention between at least two thermoplastic resin layers.

The electromechanical converter may preferably be located between at least two filled thermoplastic resin layers in the security and / or value document according to the invention. The filled thermoplastic resin layers can each independently of one another preferably be a translucent, white, black or colored layer filled with fillers. The filled thermoplastic synthetic layers are particularly preferably independent of each other of translucent or white filled layers. Suitable fillers are preferably such translucent or white-colored filled plastic layers preferably contain titanium dioxide, zirconium dioxide, barium sulfate or glass fibers as pigments and / or fillers. Other suitable filled thermoplastic plastic layers those from Teslin ^® in question.

The filled thermoplastic polymer layers are preferably those with a transmission in the visible wavelength range from 380 nm to 780 nm of less than 50%, preferably less than 35%, particularly preferably less than 25%, in very particularly preferred embodiments less than 15 %.

In preferred embodiments of the present invention, the security and / or valuable document may contain at least one further plastic layer which contains laser-sensitive additives, wherein these plastic layer (s) are not located between the optionally filled thermoplastic layers.

As laser-sensitive additives are for example so-called laser marking additives in question, ie those from an absorber in the wavelength range of the laser to be used, preferably in the wavelength range of ND: YAG lasers (neodymium-doped yttrium-aluminum garnet laser). Such laser marking additives and their use in molding compositions are described for example in WO-A 2004/50766 and WO 2004/50767 and are commercially available from the Fa. D SM under the brand name Micabs ^®. Further absorbers which are suitable as laser-sensitive additives are carbon black, coated phyllosilicates as described, for example, in DE-A-195 22 397 and US Pat the brand name Lazerflair ^® commercially available, antimony doped tin oxide such as. in US 6,693,657 and commercially available under the brand name Mark-it ™ and phosphorus-containing tin-copper mixed oxides as described for example in WO-A 2006/042714. It is preferred if the particle size of the laser-sensitive additive is in the range of 100 nm to 10 μm, and particularly advantageous if it is in the range of 500 nm to 2 μm. A most preferred laser-sensitive additive is carbon black.

The security and / or value document according to the invention may comprise one or more further additional layer (s), preferably plastic layers, in particular preferably thermoplastic synthetic layers, via which, for example, further information is introduced into the security or value document, preferably identification document. Such information may be obtained, for example, by means of at least one method selected from printing methods such as e.g. Screen, ink-jet, offset or laser printing processes, etc., or engraving processes, e.g. Laser engraving, or coating methods such as e.g. Doctoring, dipping, etc., optionally with the aid of masking, etc., to one or more ingredients used in the preparation of the document, e.g. Foils have been applied. The information may be of a decorative or individualizing nature, e.g. Show names, addresses, photos etc. The plastic layer (s) providing the information are preferably not located between the optionally present filled layers. The information is preferably located on the respective outward-facing side of the layer (s).

The multilayer structure according to the invention may comprise one or more additional additional layer (s), preferably plastic layers, which are e.g. serve the protection of the security and / or value document. This may be e.g. scratch resistant, antistatic and / or IR reflective finished layers.

The layers according to the invention, preferably plastic layers, in particular preferably thermoplastic synthetic layers, preferably each have a thickness of from 20 μm to 850 μm, it being possible for the individual plastic layers to have the same or different layer thicknesses. For the optionally present filled thermoplastic polymer layers, layer thicknesses of 50 μm to 600 μm are particularly preferred.

Preferably, the security and / or value document according to the invention is an identification document, preferably an ID card, such as an ID card. an identity card, passport, driving license, bank card, credit card, insurance card, other identity card etc ..

The thermoplastic resin layers contained in the multilayer structure according to the invention preferably contain at least one thermoplastic. As thermoplastics for the plastic layers are independently thermoplastics selected from polymers of ethylenically unsaturated monomers and / or polycondensates of bifunctional reactive compounds in question. For certain applications, it may be advantageous to use a transparent thermoplastic. In particularly preferred embodiments, said plastic layers may comprise at least one thermoplastic plastic selected from the aforementioned groups.

Particularly suitable thermoplastics are polycarbonates or copolycarbonates based on diphenols, poly- or copolyacrylates and poly- or co-polyethacrylates such as, by way of example and by way of preference, polymethyl methacrylate, poly- or copolymers with styrene such as, by way of example and preferably, transparent polystyrene or polystyrene-acrylonitrile (SAN), transparent thermoplastic polyurethanes, and polyolefins, such as for example and preferably transparent polypropylene types, or polyolefins based on cyclic olefins (for example, TOPAS ^®, Hoechst) or polyolefin based materials such as Teslin ^®, poly- or copolycondensates of terephthalic acid, such as for example and preferably poly- or copolyethylene terephthalate (PET or CoPET), glycol-modified PET (PETG) or poly- or copolybutylene terephthalate (PBT or CoPBT) or mixtures of the foregoing.

Very particularly preferred are polycarbonates or copolycarbonates, in particular having average molecular weights M _w from 500 to 100,000, preferably 10,000 to 80,000, particularly preferably 15,000 to 40,000 or blends containing at least one such polycarbonate or copolycarbonate. Preference is also given to blends of the abovementioned polycarbonates or copolycarbonates with at least one poly- or copolycondensate of terephthalic acid, in particular at least one such poly- or copolycondensate of terephthalic acid having average molecular weights M _{w of} from 10,000 to 200,000, preferably from 26,000 to 120,000. In particularly preferred

Embodiments of the invention, the blend is a blend of polycarbonate or copolycarbonate with poly- or copolybutylene terephthalate. Such a blend of polycarbonate or copolycarbonate with poly- or copolybutylene terephthalate may preferably be one having from 1 to 90% by weight of polycarbonate or copolycarbonate and from 99 to 10% by weight of poly- or copolybutylene terephthalate, preferably from 1 to 90% by weight % Polycarbonate and 99 to 10 wt .-% polybutylene terephthalate, wherein the proportions add up to 100 wt .-%. Such a blend of polycarbonate or copolycarbonate with poly- or copolybutylene terephthalate is particularly preferably one with 20 to 85% by weight of polycarbonate or copolycarbonate and 80 to 15% by weight of poly- or copolybutylene terephthalate, preferably with 20 to 85 Wt .-% polycarbonate and 80 to 15 wt .-% polybutylene terephthalate, wherein the proportions add up to 100 wt .-%. With very particular preference, such a blend of polycarbonate or copolycarbonate with polybutylene glycol or copolybutylene terephthalate can be mixed with one having 35 to 80% by weight of polycarbonate or copolybutylene terephthalate. % Polycarbonate or copolycarbonate and 65 to 20 wt .-% of poly or Copolybutylenterephthalat, preferably with 35 to 80 wt .-% polycarbonate and 65 to 20 wt .-% polybutylene terephthalate act, wherein the proportions add up to 100 wt .-%.

Particularly suitable polycarbonates or copolycarbonates in preferred embodiments are aromatic polycarbonates or copolycarbonates.

The polycarbonates or copolycarbonates may be linear or branched in a known manner.

The preparation of these polycarbonates can be carried out in a known manner from diphenols, carbonic acid derivatives, optionally chain terminators and optionally branching agents. Details of the production of polycarbonates have been laid down in many patents for about 40 years. By way of example only Fast, "Chemistry and Physics of Polycarbonates", Polymer Reviews, Volume 9, Interscience Publishers, New York, London, Sydney 1964, D. Freitag, U. Grigo, PR Müller, H. Nouvertne, BAYER AG, "Polycarbonates" in Encyclopaedia of Polymer Science and Engineering, Volume 11, Second Edition, 1988, pages 648-718 and finally to Dres. U. Grigo, K. Kirchner and PR Müller "Polycarbonates" in Becker / Braun, Kunststoff Manual, Volume 3/1, polycarbonates, polyacetals, polyesters, cellulose esters, Carl Hanser Verlag Munich, Vienna 1992, pages 117-299 referenced.

Suitable diphenols may be, for example, dihydroxyaryl compounds of the general formula (I)

HO-Z-OH (I)

wherein Z is an aromatic radical having 6 to 34 carbon atoms, which may contain one or more optionally substituted aromatic nuclei and aliphatic or cycloaliphatic radicals or alkylaryl or heteroatoms as bridge members.

Particularly preferred dihydroxyaryl compounds are resorcinol, 4,4'-dihydroxydiphenyl, bis (4-hydroxyphenyl) -diphenylmethane, 1, 1-bis (4-hydroxyphenyl) -1-phenyl-ethane, bis (4-hydroxyphenyl) - 1 - (1-naphthyl) -ethane, bis- (4-hydroxyphenyl) -1- (2-naphthyl) -ethane, 2,2-bis (4-hydroxyphenyl) -propane, 2,2-bis (3 , 5-dimethyl-4-hydroxyphenyl) -propane, 1, 1-bis (4-hydroxyphenyl) -cyclohexane, 1, 1-bis (3,5-dimethyl-4-hydroxyphenyl) -cyclohexane, 1, l- Bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1'-bis (4-hydroxyphenyl) -3-diisopropylbenzene and 1, 1'-bis (4-hydroxyphenyl) - 4-diisopropyl-benzene.

Very particularly preferred dihydroxyaryl compounds are 4,4'-dihydroxydiphenyl, 2,2-bis (4-hydroxyphenyl) propane and 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane. I i

A most preferred copolycarbonate can be prepared using 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane and 2,2-bis (4-hydroxyphenyl) -propane.

Suitable carbonic acid derivatives may be, for example, diaryl carbonates of the general formula (II)

wherein

R, R 'and R "are each, independently of one another or different, hydrogen, linear or branched C ₁ -C ₃₄ -alkyl, C ₇ -C ₃ -alkylaryl or C ₆ -C ₃ -aryl, R furthermore also -COO-R" may mean, where R "is hydrogen, linear or branched C ₃ - alkyl, C ₇ -C ₃₄ alkylaryl or C ₆ -C ₃ -aryl.

Particularly preferred diaryl compounds are diphenyl carbonate, 4-tert-butylphenyl phenyl carbonate, di (4-tert-butylphenyl) carbonate, biphenyl-4-yl phenyl carbonate, di (biphenyl-4-yl) carbonate, 4- (1-methyl-1-phenylethyl) -phenyl-phenyl carbonate, di- [4- (1-methyl-1-phenylethyl) -phenyl] -carbonate and di (methyl salicylate) carbonate.

Very particular preference is given to diphenyl carbonate.

Both a diaryl carbonate and various diaryl carbonates can be used.

In addition, for example, one or more monohydroxyaryl compound (s) may be used as a chain terminator for controlling or changing the end groups, which was not used to prepare the diaryl carbonate (s) used. These may be those of the general formula (III),

in which R ^{A is} linear or branched C ₁ -C ₃ -alkyl, C ₇ -C ₃ -alkylaryl, C ₆ -C ₃ -aryl or -COO-R ^D , where R ^{D is} hydrogen, linear or branched C ₁ -C ₃ -Alkyl, C ₇ -C ₃₄ -alkylaryl or C ₆ -C ₃ -aryl, and

R ^B , R ^c are each, independently of one another or different, hydrogen, linear or branched C ₁ -C ₃ -alkyl, C ₇ -C ₃ -alkylaryl or C ₆ -C ₃ -aryl.

Preference is given to 4-tert-butylphenol, 4-iso-octylphenol and 3-pentadecylphenol.

Suitable branching agents may be compounds having three or more functional groups, preferably those having three or more hydroxyl groups.

Preferred branching agents are 3,3-bis (3-methyl-4-hydroxyphenyl) -2-oxo-2,3-dihydroindole and 1,1,1-tri (4-hydroxyphenyl) ethane.

Suitable poly- or copolycondensates of terephthalic acid in preferred embodiments of the invention are polyalkylene terephthalates. Suitable polyalkylene terephthalates are, for example, reaction products of aromatic dicarboxylic acids or their reactive derivatives (for example dimethyl esters or anhydrides) and aliphatic, cycloaliphatic or araliphatic diols and mixtures of these reaction products.

Preferred polyalkylene terephthalates can be prepared from terephthalic acid (or its reactive derivatives) and aliphatic or cycloaliphatic diols having 2 to 10 carbon atoms by known methods (Kunststoff-Handbuch, Vol. VIII, p. 695 ff, Karl-Hanser Verlag, Munich 1973 ).

Preferred polyalkylene terephthalates contain at least 80 mole%, preferably 90 mole% terephthalic acid residues, based on the dicarboxylic acid component, and at least 80 mole%, preferably at least 90 mole% ethylene glycol and / or butane-1,4-residues, based on the diol component.

In addition to terephthalic acid residues, the preferred polyalkylene terephthalates may contain up to 20 mol% of residues of other aromatic dicarboxylic acids having 8 to 14 carbon atoms or aliphatic dicarboxylic acids having 4 to 12 carbon atoms, for example residues of phthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid , 4,4'-diphenyldicarboxylic acid, succinic, adipic, sebacic, azelaic, cyclohexanediacetic.

The preferred polyalkylene terephthalates, in addition to ethylene or butanediol-l, 4-glycol radicals up to 20 mol% of other aliphatic diols having 3 to 12 carbon atoms or cycloaliphatic diols having 6 to 21 carbon atoms, for. B. residues of 1,3-propanediol, 2-ethylpropanediol-1, 3, neopentyl glycol, Pentanediol-1,5, hexanediol-1,6, cyclohexane-dimethanol-1,4, 3-methylpentanediol-2,4, 2-methylpentanediol-2,4, 2,2,4-trimethylpentanediol-1,3 and 2-ethylhexanediol-1,2,6,2,2-diethylpropanediol-1,3, hexanediol-2,5,1,4-di- ([beta] -hydroxyethoxy) -benzene, 2,2-bis- (4-hydroxycyclohexyl ) -propane, 2,4-dihydroxy-l, 1,3,3-tetramethylcyclobutane, 2,2-bis- (3- [beta] -hydroxyethoxyphenyl) -propane and 2,2-bis- (4-hydroxypropoxyphenyl ) -propane (see DE-OS 24 07 674, 24 07 776, 27 15 932).

The polyalkylene can be prepared by incorporation of relatively small amounts of trihydric or trihydric alcohols or 3- or 4-basic carboxylic acids, as z. For example, in DE-OS 19 00 270 and US Patent 3,692,744 are branched. Examples of preferred branching agents are trimesic acid, trimellitic acid, trimethylolethane and -propane and pentaerythritol.

Preferably, not more than 1 mol% of the branching agent, based on the acid component, is used.

Particularly preferred are polyalkylene terephthalates which have been prepared solely from terephthalic acid and its reactive derivatives (eg their dialkyl esters) and ethylene glycol and / or butane-1,4-diol, and mixtures of these polyalkylene terephthalates.

Preferred polyalkylene terephthalates are also copolyesters which are prepared from at least two of the abovementioned acid components and / or from mindest least two of the abovementioned alcohol components, particularly preferred copolyesters are poly (ethylene glycol / butanediol-1, 4) terephthalates.

The polyalkylene terephthalates preferably used as a component preferably have an intrinsic viscosity of about 0.4 to 1.5 dl / g, preferably 0.5 to 1.3 dl / g, each measured in phenol / o-dichlorobenzene (1: 1 wt Parts) at 25 ° C.

In a particularly preferred embodiment of the present invention, the optional translucent plastic layers, and any additional thermoplastic layers present at least one polycarbonate or copolycarbonate.

The multilayer structure can have a monolithic layer composite in the regions in which the plastic layers are in direct contact with one another. Such a monolithic layer composite offers special protection against subsequent, non-destructive separation of the layer composite. In the case that the plastics of the individual plastic layers are identical or similar plastics or. Plastic mixtures is, in particular for the case of a monolithic layer composite, are to be understood by individual layers, the parts of the layer composite, which were contributed in the production of multi-layer composite of various components, for example, different films, the composite layer.

It may be advantageous for an intermediate layer formed of an adhesive to be present on at least one side, preferably on both sides of the electromechanical transducer, between the electromechanical transducer and the nearest thermoplastic layer. Such an intermediate layer can protect the electromechanical transducer against destruction, in particular at elevated lamination temperatures in the production of the security and / or value document.

The security and / or value document according to the invention may preferably contain electrical connections for contacting the electromechanical converter and / or at least one induction coil and / or at least one inverter and / or at least one voltage converter. Preferably, these components are - if any - between the same thermoplastic layers of plastic as the electromechanical transducer. Electrical connections for contacting are in particular present in such embodiments of the invention, in which the electromechanical transducer is to provide a tactile feedback when applied to a power supplier, such as a reader. At least one inverter and electrical connections for contacting are in particular special present in such embodiments of the invention, in which the electromechanical transducer by mechanical stress, eg bending the security and / or value document or pressing one or more hidden keys, electrical energy to supply an internal consumption, such as an EL device to provide an OLED structure and / or a PLED structure, by the illumination of which, if necessary hidden information can be made visible. At least one voltage converter and electrical connections for contacting are present in particular in those embodiments of the invention in which different voltages must be converted into each other, for example, alternating current into direct current. Voltage transformers may also be capable of converting low AC voltages to high DC voltages. At least one induction coil and electrical connections for contacting are present in particular in such embodiments of the invention, the contactless, ie. without contact to external voltage devices, to be operated. The security and / or value document according to the invention may also contain one or more other voltage suppliers, such as batteries, which would preferably also be located between the same thermoplastic layers of plastic as the electromechanical transducer. Accordingly, the security and / or value document according to the invention can, in preferred embodiments, contain an EL arrangement, an OLED structure and / or a PLED structure.

The present invention furthermore relates to a method for producing a security and / or value document according to the invention, characterized in that

(a) at least one electromechanical transducer is applied to a thermoplastic film,

(b) applying another thermoplastic resin film to the side of the thermoplastic resin film of step (a) on which the one or more electromechanical transducer (s) is located,

(c) laying one or more further thermoplastic films on or under the film stack of step (b),

(d) the film stack obtained in step (c) is subsequently laminated.

Particularly preferably, the translucent plastic layers, and all additionally present transparent plastic layers contain at least one polycarbonate or copolycarbonate, preferably at least one polycarbonate.

To protect the electromechanical transducer, at least one of the thermoplastic resin films used in steps (a) and (b) may be provided with an adhesive layer on the side facing the electromechanical transducer, or between at least one of those used in steps (a) and (b) thermoplastic plastic films and the electromechanical transducer a film of an adhesive material are placed. Both of the thermoplastic resin films used in steps (a) and (b) may be provided with an adhesive layer on the side facing the electromechanical transducer, or between both the thermoplastic resin films used in steps (a) and (b) and the electromechanical transducer in each case a film of an adhesive material are placed.

As adhesive films, for example, those of thermoplastic polyurethane or EVA (ethylene vinyl acetate) are suitable. For adhesive coatings, for example, those based on polyurethane or acrylate adhesives are suitable. Such adhesives are known to the person skilled in the art.

In the case of using adhesive-coated thermoplastic resin films, it is most preferred to use a latent-reactive adhesive. Latent reactive adhesives are known in the art. Preferred latently reactive adhesives are those which have a aqueous dispersion containing a di- or polyisocyanate with melting or softening temperature of> 30 ° C and an isocyanate-reactive polymer. Preferably, such an aqueous dispersion has a viscosity of at least 2000 mPas. Further preferably, the isocyanate-reactive polymer in this dispersion is a polyurethane, which are composed of crystallizing polymer chains which, when measured by means of thermomechanical analysis (TMA) at temperatures below + 110 ° C, preferably at temperatures below + 90 ° C. , partially or completely recrystallize. The measurement by means of TMA is carried out analogously to ISO 11359 Part 3 "Determination of the Penetration Temperature." It is further preferable that the diisocyanate or polyisocyanate is one selected from the group consisting of dimerization products, trimerization products and urea derivatives of TDI (tolylene diisocyanate Such latently reactive adhesives are described, for example, in DE-A 10 2007 054 046. By using such latently reactive adhesives, an additional increase in the security against forgery of the security and / or value document can be achieved by virtue of the fact that over the edges of the layer structure can no longer diffuse water vapor and / or air into the interior and thus can no longer lead to a subsequent delamination Such layer structures can no longer be separated indestructively.

Additionally or alternatively, the thermoplastic resin film used in step (b) and / or at least one of the adhesive layers and / or at least one of the adhesive films may have recesses at the locations where the electromechanical transducer is located. This can for example serve to protect the electromechanical transducer or allow the electromechanical transducer sufficient mobility in the horizontal and / or vertical direction. In this case, the recesses are preferably selected such that the electromechanical converter in the security and / or value document according to the invention is not completely enclosed by thermoplastic material and / or adhesive. Particularly preferred in the security and / or value document according to the invention between the electromechanical transducer and the thermoplastic material and / or adhesive such a r Ab stood that the electromechanical transducer can extend at least in one direction, preferably in more than one direction.

In a preferred embodiment, the production can be carried out such that between the two thermoplastic films from step (a) and (b), a further thermoplastic film, optionally with recesses at the one or more places on which the one or more electromechanical transducers is placed, wherein the thermoplastic material of the film has a Vicat softening temperature B / 50 _(int i _SCh ENSC _h ic _ht) which is less than the Vicat softening point B / 50 of the plastic compositions in step (a) and (b ) used thermoplastic films. Subsequently, it would then be laminated in a two-stage lamination process, with the first lamination step at a temperature above the Vicat _Softening temperature B / 50 ₍ _{Zwi SChe} nschicht ₎ and below the Vicat softening temperature B / 50 of the plastic compositions of the _{thermoplastic} films used in step (a) and (b), and the second lamination step at a temperature above the Vicat softening temperature B / 50 of the plastic compositions of the thermoplastic films used in step (a) and (b) is performed. In such a method, at the lower Vicat softening temperature B / 50 ₍ _intermediate layer _), initially only this layer would soften, and the electromechanical converter and optionally further electronic components (EL device, OLED, PLED, inverter, contacts and / or Induction coil etc.) enclose before at the higher laminating temperature of the entire plastic composite of the stacked films would be softened and interconnected. As a result, both the electromechanical converter and the electronic components can be additionally protected against destruction and loss of function. Such a method is described, for example, in WO-A 2010/091796.

Also in this method, the recesses are preferably selected such that the electromechanical transducer in the security and / or value document according to the invention is not completely enclosed by thermoplastic material and / or adhesive. Particularly preferably, in the security and / or value document according to the invention between the electromechanical transducer and the thermoplastic material and / or adhesive such a distance that the electromechanical transducer can expand at least in one direction, preferably in more than one direction.

The Vicat softening temperature B / 50 of a thermoplastic in the context of the invention is the Vicat softening temperature B / 50 according to ISO 306 (50 N, 50 ° C./h).

The present invention furthermore relates to the use of an electromechanical transducer which comprises at least two electrodes and at least one polymer layer arranged between the electrodes, the polymer layer containing at least one elastomer or at least one polymeric piezoelectric material as security feature in a security and / or value document.

Claims

claims

A security and / or value document, characterized in that it comprises at least one electromechanical transducer comprising at least two electrodes and at least one polymer layer arranged between the electrodes, the polymer layer containing at least one elastomer or at least one polymeric piezoelectric material.

2. Security and / or value document according to claim 1, characterized in that the elastomer or elastomers comprise at least one polyurethane elastomer, silicone elastomer, acrylate elastomer and / or silicone and acrylate components Elastomer, preferably is a silicone elastomer.

The security and / or value document according to claim 1, characterized in that the polymeric piezoelectric material (s) is a fluorinated polymer or a ferroelectret, preferably a ferroelectret.

4. Security and / or value document according to at least one of claims 1 to 3, characterized in that the material of the electrodes is selected from the group comprising metals, metal alloys, conductive oligo- or polymers, conductive oxides and / or filled with conductive fillers polymers.

5. Security and / or value document according to at least one of claims 1 to 4, characterized in that it is an identification document, preferably an ID card.

6. Security and / or value document according to at least one of claims 1 to 5, characterized in that the electromechanical transducer between at least two thermoplastic resin layers, preferably between at least two filled thermoplastic resin layers.

7. Security and / or value document according to at least one of claims 1 to 6, characterized in that it is the one or more polymeric piezoelectric material (s) is a ferroelectret of a material containing at least one polycarbonate or copolycarbonate.

8. security and / or document of value according to claim 7, characterized in that it is the filled thermoplastic resin layers independently of each other is a translucent, white, black or colored filled with fillers layer.

9. Security and / or value document according to at least one of claims 1 to 8, characterized in that there are electrical connections for contacting the electromechanical Converter and / or at least one induction coil and / or at least one inverter and / or at least one voltage converter contains.

10. Security and / or value document according to at least one of claims 1 to 9, characterized in that it contains an EL device, an OLED structure and / or a PLED structure.

11. Security and / or value document according to at least one of claims 1 to 10, characterized in that there is at least on one side, preferably on both sides of the electromechanical transducer between the electromechanical transducer and the nearest thermoplastic layer of plastic, an intermediate layer formed from an adhesive ,

12. A method for producing a security and / or value document according to at least one of claims 1 to 11, characterized in that

(d) the film stack obtained in step (c) is subsequently laminated.

13. The method according to claim 12, characterized in that at least one of the thermoplastic films used in step (a) and (b) are provided on the side facing the electromechanical transducer side with an adhesive layer or between the in step (a) and ( b) applied thermoplastic plastic films and the electromechanical transducer at least one film of an adhesive material is placed.

14. The method according to claim 12 or 13, characterized in that the used in step (b) thermoplastic film and / or at least one of the adhesive layers and / or at least one of the adhesive films at the locations where the electromechanical transducer is located, recesses ,

Use of an electromechanical transducer comprising at least two electrodes and at least one polymer layer arranged between the electrodes, wherein the Polymer layer contains at least one elastomer or at least one polymeric piezoelectric material, as a security feature in a security and / or valuable document.