EP2349733B2 - Id cards with blocked laser engraving writability - Google Patents

Description

The invention relates to layer structures for laser engraved ID cards which have an additional layer which is applied after laser engraving on the card body and the subsequent description of the card by laser engraving and thus falsifying the contained identification information restricts or completely prevented, and a method for Blockage of the laser engraving writability of laser engraving-labeled layer structures.

The description of plastic films by means of laser engraving is an important step in the production of film composites. Such film composites play e.g. a major role for identification documents such as passports, ID cards, ID cards or credit cards. The black and white personalization of cards by laser engraving, i. the application of lettering or illustrations such as black and white photos is well known. In general, the personalization by means of laser engraving is characterized in particular by its high counterfeit security. The image is created inside the card, so that it is not possible to remove the image and create a new image. Separating the cards into their individual layers to access the laser layer is not possible with cards made entirely of polycarbonate.

Plastic cards are typically made by lamination of multiple films. In order to be able to carry out the personalization of the card by means of laser engraving, films equipped with laser-sensitive additives are laminated in their entirety into the outer layers of the multilayer card structure.

After lamination of the card body, the personal data is lasered into the card in the form of textual information and / or image information, i. engraved. Thereafter, the loaded with laser additives film layer but remains active and can also be retrofitted with other data and thus changed content. This possibility opens up the potential of subsequent forgery of identification documents - called ID documents below - by adding data and image information.

WO 2003/055638 discloses an identification document in which security information is introduced into a laser-engravable layer by laser engraving, which is a cover layer, ie the surface of the identification document. Although an additional layer described there serves to protect the printed and possibly also lasered information, this is a protection against mechanical damage by abrasion or scratching.

US 2004/0198858 A1 describes a laser-writable layer structure, which may also contain a laser radiation, ie IR-opaque laminate layer. About the composition of this laminate layer, however, no further information is disclosed.

DE 10 2007 024298 B3 discloses a multi-layer structure for security documents, in which optionally laser-generated luminescent information is introduced into suitable layers and additionally a laser-writable metallization layer and a scratch-resistant coating are provided.

There was therefore a need to block the subsequent loading of such multilayer film composites with information by means of laser engraving or at least severely limit and thus increase the security against forgery of security documents, preferably ID documents.

The object on which the present invention was based was therefore to find multilayer film composites in which the subsequent writability by means of laser engraving is greatly reduced or completely blocked.

This object is achieved in accordance with the invention in that a laser-engraved layered structure is laser-engraved with at least one partial or full-area IR radiation reflecting or absorbing cover layer, wherein the partial or full-surface IR radiation reflecting or absorbing cover layer has at least one IR coating. contains absorbent additive or consists of a multi-layer structure.

In US 2005 / 0259326A1 For example, the use of multilayer optical films that reflect IR light is described in Maps. The IR reflection layers are arranged within the film composite, ie between at least two further polymer layers in the card, in order to enable card recognition by means of reflection of IR radiation. These are so-called VLT (visible light transmissive) cards. The use of IR-reflecting films as cover layers for blocking the laser engraving writability is not described in this application.

The present invention therefore relates to a laser-engraved layered construction comprising at least one thermoplastic layer which can be inscribed by laser engraving and a partial or full-surface IR radiation reflecting or absorbing cover layer, wherein the covering or full-surface IR radiation reflecting or absorbing at least one IR-absorbing Additive contains and wherein it is the IR-absorbing additive in the topcoat to those selected from the classes of azo, azomethine, methine anthraquinone, indanthrone, pyranthrone, flavanthrone, Benzanthron-, Phtalocyanin-, Pervlen , Dioxazine, thioindigo-isoindoline-isoindolinone, quinacridone, pyrrolopyrrole or quinophthalone pigments and metal complexes of azo, azomethine or methine dyes or metal salts of azo compounds. The invention likewise relates to a laser-engraved layered construction comprising at least one thermoplastic layer which can be inscribed by laser engraving and a partial or full-surface IR radiation-reflecting or absorbing cover layer, wherein the partial or full-surface IR radiation reflecting or absorbing cover layer consists of a multi-layer structure which is a multilayer optical interference film.

The inscription of plastic films by laser engraving is referred to in the art and also in the following as laser marking. Accordingly, the term "laser-marked" is to be understood by laser engraving in the following. The process of laser engraving is known in the art and not to be confused with the Printing with laser printers.

Preferably, the laser-engravable equipped thermoplastic layer contains at least one laser-sensitive additive. The laser-sensitive additive can be suitable both for laser engraving lettering from bright to dark background, from dark to light background or even colored lettering. Laser-sensitive additives are preferred for the lettering for laser engraving inscription from dark to light background.

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, for example, in WO-A 2004/50766 and WO-A 2004/50767 described and are commercially available from the Fa. DSM under the trade name Micabs ^®. Further absorbers which are suitable as laser-sensitive additives are carbon black, coated sheet silicates, such as, for example, in US Pat DE-A-195 22 397 described and commercially available under the trade name Lazerflair ^® , 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 such as in WO-A 2006/042714 described.

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 thermoplastic plastic of the thermoplastic layer may preferably be at least one thermoplastic selected from polymers of ethylenically unsaturated monomers and / or polycondensates of bifunctional reactive compounds and / or polyaddition products of bifunctional reactive compounds. For certain applications, it may be advantageous and therefore preferred to use a transparent thermoplastic.

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 (PMMA), poly- or copolymers with styrene such as by way of example and preferably polystyrene (PS) or polystyrene-acrylonitrile (SAN). , thermoplastic polyurethanes, and polyolefins, such as by way of example and preferably polypropylene or polyolefins based on cyclic olefins (eg TOPAS ^® , Hoechst), poly- or copolycondensates of terephthalic acid, such as by way of example and preferably poly- or copolyethylene terephthalate (PET or CoPET), glycol modified PET (PETG), glycol-modified poly- or copolycyclohexanedimethylene terephthalate (PCTG) or poly- or copolybutylene terephthalate (PBT or CoPBT), poly- or copolycondensates of naphthalenedicarboxylic acid, such as by way of example and preferably polyethylene glycol naphthalate (PEN), poly- or copolycondensates t (e) at least one cycloalkyldicarboxylic acid, such as, by way of example and by way of preference, polycyclohexanedimethanolcyclohexanedicarboxylic acid (PCCD), polysulfones (PSU) or mixtures of the abovementioned.

Preferred thermoplastics are polycarbonates or copolycarbonates or blends containing at least one polycarbonate or copolycarbonate. Particular preference is given to blends containing at least one polycarbonate or copolycarbonate and at least one poly- or copolycondensate of terephthalic acid, of naphthalenedicarboxylic acid or of a cycloalkyldicarboxylic acid, preferably of cyclohexanedicarboxylic acid. Very particular preference is given to polycarbonates or copolycarbonates, in particular having average molecular weights M _{w of} from 500 to 100,000, preferably from 10,000 to 80,000, particularly preferably from 15,000 to 40,000, or blends thereof with at least one poly- or copolycondensate of terephthalic acid with medium molecular weight Molecular weights M _w from 10,000 to 200,000, preferably from 26,000 to 120,000.

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 ( Plastics Handbook, Vol. VIII, p. 695 ff, Karl-Hanser-Verlag, Munich 1973 ).

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

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

In addition to ethylene or butane-1,4-glycol radicals, the preferred polyalkylene terephthalates may contain up to 80 mol% of other aliphatic diols having 3 to 12 C atoms or cycloaliphatic diols having 6 to 21 C atoms, eg. B. residues of 1,3-propanediol, 2-ethylpropane-1,3-diol, neopentyl glycol, pentane-diol-1,5, 1,6-hexanediol, cyclohexanedimethanol-1,4, 3-methylpentanediol-2,4, 2-methylpentanediol-2,4, 2,2,4-trimethylpentanediol-1,3 and 2-ethylhexanediol-1,6, 2,2-diethylpropanediol-1,3, hexanediol-2, 5, 1,4-di - ([beta] -hydroxyethoxy) -benzene, 2,2-bis (4-hydroxycyclohexyl) -propane, 2,4-dihydroxy-1,1,3,3-tetramethyl-cyclobutane, 2,2-bis- (3- [beta] -hydroxyethoxyphenyl) -propane and 2,2-bis (4-hydroxypropoxyphenyl) -propane (cf. 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. B. in the DE-OS 19 00 270 and the U.S. Patent 3,692,744 are described to be 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 (for example their dialkyl esters) and ethylene glycol and / or butane-1,4-diol and / or 1,4-cyclohexanedimethanol radicals, 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 at 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 particularly preferred embodiments of the invention, the blend of at least one polycarbonate or copolycarbonate with at least one poly- or copolycondensate of terephthalic acid is a blend of at least one polycarbonate or copolycarbonate with poly- or copolybutylene terephthalate or glycol-modified poly- or copolycyclohexanedimethylene terephthalate. Such a blend of polycarbonate or copolycarbonate with poly- or copolybutylene terephthalate or glycol-modified poly- or copolycyclohexanedimethylene 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 or glycol-modified poly- or Copolycyclohexandimethylenterephthalat, preferably with 1 to 90 wt .-% polycarbonate and 99 to 10 wt .-% polybutylene terephthalate or glycol-modified polycyclohexanedimethylene terephthalate, wherein the proportions add up to 100 wt .-%. Such a blend of polycarbonate or copolycarbonate with poly- or copolybutylene terephthalate or glycol-modified poly- or copolycyclohexanedimethylene terephthalate is particularly preferably one containing 20 to 85% by weight of polycarbonate or copolycarbonate and 80 to 15% by weight of polycarbonate or copolycarbonate. or copolybutylene terephthalate or glycol-modified poly- or copolycyclohexanedimethylene terephthalate, preferably with 20 to 85% by weight of polycarbonate and 80 to 15% by weight of polybutylene terephthalate or glycol-modified polycyclohexanedimethylene terephthalate, the proportions adding to 100% by weight. It is very particularly preferred for such a blend of polycarbonate or copolycarbonate with poly- or copolybutylene terephthalate or glycol-modified poly- or copolycyclohexanedimethylene terephthalate to be such with 35 to 80% by weight of polycarbonate or copolycarbonate and 65 to 20% by weight of polycarbonate. or copolybutylene terephthalate or glycol-modified poly- or copolycyclohexanedimethylene terephthalate, preferably with 35 to 80% by weight of polycarbonate and 65 to 20% by weight of polybutylene terephthalate or glycol-modified polycyclohexanedimethylene terephthalate, the proportions adding to 100% by weight. In very particularly preferred embodiments, these may be blends of polycarbonate and glycol-modified polycyclohexanedimethylene terephthalate in the above-mentioned compositions.

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, let's look at this Quick, "Chemistry and Physics of Polycarbonates", Polymer Reviews, Volume 9, Interscience Publishers, New York, London, Sydney 1964 , on D. Freitag, U. Grigo, PR Müller, H. Nouvertne ', BAYER AG, "Polycarbonates" in Encyclopedia of Polymer Science and Engineering, Volume 11, Second Edition, 1988, pages 648-718 and finally up Dres. U. Grigo, K. Kirchner and PR Müller "Polycarbonates" in Becker / Braun, Plastics Handbook, Volume 3/1, polycarbonates, polyacetals, polyesters, cellulose esters, Carl Hanser Verlag Munich, Vienna 1992, pages 117-299 directed.

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, the one or more optionally substituted aromatic Cores and aliphatic or cycloaliphatic radicals or alkylaryl or heteroatoms may contain as bridge members.

Examples of suitable dihydroxyaryl compounds are: dihydroxybenzenes, dihydroxydiphenyls, bis (hydroxyphenyl) alkanes, bis (hydroxyphenyl) -cycloalkanes, bis (hydroxyphenyl) -aryls, bis (hydroxyphenyl) ethers, bis (hydroxyphenyl) -ketones, Bis (hydroxyphenyl) sulfides, bis (hydroxyphenyl) sulfones, bis (hydroxyphenyl) sulfoxides, 1,1'-bis (hydroxyphenyl) diisopropylbenzenes, and their kemalkylated and nuclear halogenated compounds.

These and other suitable other Dihydroxyarylverbindungen are eg in DE-A 3 832 396 . FR-A 1 561 518 , in H. Schnell, Chemistry and Physics of Polycarbonates, Interscience Publishers, New York 1964, p. 28 ff .; P.102 ff , and in DG Legrand, JT Bendler, Handbook of Polycarbonates Science and Technology, Marcel Dekker New York 2000, pp. 72 et seq , described.

Preferred dihydroxyaryl compounds are, for example, resorcinol, 4,4'-dihydroxydiphenyl, bis (4-hydroxyphenyl) methane, bis (3,5-dimethyl-4-hydroxyphenyl) methane, bis (4-hydroxyphenyl) diphenylmethane , 1, 1-bis (4-hydroxyphenyl) -1-phenyl-ethane, 1,1-bis (4-hydroxyphenyl) -1- (1-naphthyl) -ethane, 1,1-bis (4-hydroxyphenyl) hydroxyphenyl) -1- (2-naphthyl) ethane, 2,2-bis- (4-hydroxyphenyl) -propane, 2,2-bis (3-methyl-4-hydroxyphenyl) -propane, 2,2-bis - (3,5-dimethyl-4-hydroxyphenyl) -propane, 2,2-bis (4-hydroxyphenyl) -1-phenyl-propane, 2,2-bis (4-hydroxyphenyl) -hexafluoro-propane, 2 , 4-bis (4-hydroxyphenyl) -2-methylbutane, 2,4-bis (3,5-dimethyl-4-hydroxyphenyl) -2-methylbutane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis- (3,5-dimethyl-4-hydroxyphenyl) -cylohexane, 1,1-bis (4-hydroxyphenyl) -4-methylcyclohexane, 1,3-bis- [2- (4-hydroxyphenyl) -2-propyl] -benzene, 1,1'-bis (4-hydroxyphenyl) -3-diisopropylbenzene, 1,1'-bis (4-hydroxyphenyl) -4-diisopropylbenzene , 1,3-Bis- [2- (3,5-dimethyl-4-hydroxyphenyl) -2-propyl] -benzene, bis (4-hydro xyphenyl) ether, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, bis (3,5-dimethyl-4-hydroxyphenyl) sulfone and 2,2 ', 3,3' -Tetrahydro-3,3,3 ', 3'-tetramethyl-1,1'-spirobi- [1H-indene] -5,5'-diol or

worin

R¹ und R²

unabhängig voneinander Wasserstoff, Halogen, bevorzugt Chlor oder Brom, C₁-C₈-Alk-yl, C₅-C₆-Cycloalkyl, C₆-C₁₀-Aryl, bevorzugt Phenyl, und C₇-C₁₂-Aralkyl, bevorzugt Phenyl-C₁-C₄-Alkyl, insbesondere Benzyl,

m

eine ganze Zahl von 4 bis 7, bevorzugt 4 oder 5,

R³ und R⁴

für jedes X individuell wählbar, unabhängig voneinander Wasserstoff oder C₁-C₆-Alkyl und

X

Kohlenstoff bedeuten,

mit der Maßgabe, dass an mindestens einem Atom X, R³ und R⁴ gleichzeitig Alkyl bedeuten. Bevorzugt sind in der Formel (Ia) an einem oder zwei Atom(en) X, insbesondere nur an einem Atom X R³ und R⁴ gleichzeitig Alkyl.Dihydroxydiphenylcycloalkanes of the formula (Ia)

wherein

R ¹ and R ²

independently of one another are hydrogen, halogen, preferably chlorine or bromine, C ₁ -C ₈ -alkyl, C ₅ -C ₆ -cycloalkyl, C ₆ -C ₁₀ -aryl, preferably phenyl, and C ₇ -C ₁₂ -aralkyl Phenyl-C ₁ -C ₄ -alkyl, in particular benzyl,

m

an integer from 4 to 7, preferably 4 or 5,

R ³ and R ⁴

individually selectable for each X independently hydrogen or C ₁ -C ₆ alkyl and

X

Mean carbon,

with the proviso that on at least one atom X, R ³ and R ^{4 are} simultaneously alkyl. Are preferred in the formula (Ia) at one or two atom (s) X, in particular only on one atom X, R ³ and R ⁴ are simultaneously alkyl.

Preferred alkyl radical for the radicals R ³ and R ⁴ in formula (Ia) is methyl. The X atoms in alpha position to the diphenyl substituted C atom (C-1) are preferably not dialkyl-substituted, while alkyl disubstitution in beta position to C-1 is preferred.

Particularly preferred dihydroxydiphenylcycloalkanes of the formulas (Ia) are those having 5 and 6 ring C atoms X in the cycloaliphatic radical (m = 4 or 5 in formula (Ia)), for example the diphenols of the formulas (Ia-1) to (Ia) 3d)

A very particularly preferred dihydroxydiphenylcycloalkane of the formula (Ia) is 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane (formula (Ia-1) where R ¹ and R ² are H).

Such polycarbonates can according to the EP-A 359 953 be prepared from Dihydroxydiphenylcycloalkanen of formula (Ia).

Particularly preferred dihydroxyaryl compounds are resorcinol, 4,4'-dihydroxydiphenyl, bis- (4-hydroxyphenyl) -diphenyl-methane, 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, 1,1- Bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1'-bis (4-hydroxyphenyl) -3-diisopropylbenzene and 1,1'-bis (4-hydroxyphenyl) - 4-diisopropyl-benzene.

Very particularly preferred dihydroxyaryl compounds are 4,4'-dihydroxydiphenyl and 2,2-bis (4-hydroxyphenyl) propane.

Both a dihydroxyaryl compound to form homopolycarbonates and various Dihydroxyarylverbindungen be used to form copolycarbonates. It is possible to use both a dihydroxyaryl compound of the formula (I) or (Ia) to form homopolycarbonates and also a plurality of dihydroxyaryl compounds of the formula (I) and / or (Ia) to form copolycarbonates. The various dihydroxyaryl compounds can be linked to one another both statistically and in blocks. In the case of copolycarbonates of dihydroxyaryl compounds of the formula (I) and (Ia), the molar ratio of dihydroxyaryl compounds of the formula (Ia) to the other dihydroxyaryl compounds of the formula (I) which may be used is preferably between 99 mol% (Ia) and 1 mol -% (I) and 2 mol% (Ia) to 98 mol% (I), preferably between 99 mol% (Ia) to 1 mol% (I) and 10 mol% (Ia) to 90 mol% ( I) and in particular between 99 mol% (Ia) to 1 mol% (I) and 30 mol% (Ia) to 70 mol% (I).

An especially preferred copolycarbonate can be prepared by using 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane and 2,2-bis (4-hydroxyphenyl) propane dihydroxyaryl compounds of the formula (Ia) and (I) are prepared.

worin

R, R' und R"

unabhängig voneinander gleich oder verschieden für Wasserstoff, lineares oder verzweigtes C₁-C₃₄-Alkyl, C₇-C₃₄-Alkylaryl oder C₆-C₃₄-Aryl stehen, R weiterhin auch -COO-R'" bedeuten kann, wobei R'" für Wasserstoff, lineares oder verzweigtes C₁-C₃₄-Alkyl, C₇-C₃₄-Alkylaryl oder C₆-C₃₄-Aryl steht.

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

wherein

R, R 'and R "

independently of one another denote hydrogen, linear or branched C ₁ -C ₃₄ -alkyl, C ₇ -C ₃₄ -alkylaryl or C ₆ -C ₃₄ -aryl, R can furthermore also denote -COO-R '", where R 3 '"is hydrogen, linear or branched C ₁ -C ₃₄ alkyl, C ₇ -C ₃₄ alkylaryl or C ₆ -C ₃₄ aryl.

Examples of preferred diaryl carbonates are diphenyl carbonate, methylphenyl phenyl carbonates and di (methylphenyl) carbonates, 4-ethylphenyl phenyl carbonate, di (4-ethylphenyl) carbonate, 4-n-propylphenyl phenyl carbonate, di (4 -n-propylphenyl) carbonate, 4-iso-propylphenyl-phenyl-carbonate, di (4-iso-propylphenyl) -carbonate, 4-n-butylphenyl-phenyl-carbonate, di (4-n-butylphenyl) - carbonate, 4-isobutylphenyl phenyl carbonate, di- (4-isobutylphenyl) carbonate, 4-tert-butylphenyl phenyl carbonate, di- (4-tert-butylphenyl) carbonate, 4-n- Pentylphenyl phenyl carbonate, di (4-n-pentylphenyl) carbonate, 4-n-hexylphenyl phenyl carbonate, di (4-n-hexylphenyl) carbonate, 4-iso-octylphenyl phenyl carbonate, Di- (4-iso-octylphenyl) -carbonate, 4-n-nonylphenyl-phenyl-carbonate, di- (4-n-nonylphenyl) -carbonate, 4-cyclohexylphenyl-phenyl-carbonate, di (4-cyclohexylphenyl) - carbonate, 4- (1-methyl-1-phenylethyl) -phenyl-phenyl-carbonate, di- [4- (1-methyl-1-phenylethyl) -phenyl] -carbonate, biphenyl-4-yl-phenyl-carbonate, di (biphenyl 4-yl) carbonate, 4- (1-naphthyl) phenyl phenyl carbonate, 4- (2-naphthyl) phenyl phenyl carbonate, di- [4- (1-naphthyl) phenyl] - carbonate, di- [4- (2-naphthyl) phenyl] carbonate, 4-phenoxyphenyl phenyl carbonate, di- (4-phenoxyphenyl) carbonate, 3-pentadecylphenyl phenyl carbonate, di (3-pentadecylphenyl) carbonate, 4-trityl phenyl phenyl carbonate, di (4-trityl phenyl) carbonate, methyl salicylate phenyl carbonate, di (methyl salicylate) carbonate, ethyl salicylate phenyl carbonate, di (ethyl salicylate) carbonate, n Propyl salicylate phenyl carbonate, di (n-propyl salicylate) carbonate, iso-propyl salicylate phenyl carbonate, di (iso-propyl salicylate) carbonate, n-butyl salicylate phenyl carbonate, di- (n-butylsalicylate) carbonate, iso-butyl salicylate phenyl carbonate, di- (iso-butylsalicylate) carbonate, tert-butyl salicylate phenyl carbonate, di- (tert-butylsalicylate) carbonate, di (phenyl salicylate) carbonate and di- ( benzyl salicylate) carbonate.

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.

wobei

R^A

für lineares oder verzweigtes C₁-C₃₄-Alkyl, C₇-C₃₄-Alkylaryl, C₆-C₃₄-Aryl oder für -COO-R^D steht, wobei R^D für Wasserstoff, lineares oder verzweigtes C₁-C₃₄-Alkyl, C₇-C₃₄-Alkylaryl oder C₆-C₃₄-Aryl steht, und

R^B, R^C

unabhängig voneinander gleich oder verschieden für Wasserstoff, lineares oder verzweigtes C₁-C₃₄-Alkyl, C₇-C₃₄-Alkylaryl oder C₆-C₃₄-Aryl stehen.

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 (IR),

in which

R ^A

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

R ^B , R ^C

independently of one another are identical or different and represent hydrogen, linear or branched C ₁ -C ₃₄ -alkyl, C ₇ -C ₃₄ -alkylaryl or C ₆ -C ₃₄ -aryl.

Such Monohydroxyarylverbindungen are, for example, 1-, 2- or 3-methylphenol, 2,4-dimethylphenol 4-ethylphenol, 4-n-propylphenol, 4-iso-propylphenol, 4-n-butylphenol, 4-isoButylphenol, 4-tert-butylphenol , 4-n-pentylphenol, 4-n-hexylphenol, 4-iso-octylphenol, 4-n-nonylphenol, 3-pentadecylphenol, 4-cyclohexylphenol, 4- (1-methyl-1-phenylethyl) -phenol, 4-phenylphenol , 4-phenoxyphenol, 4- (1-naphthyl) -phenol, 4- (2-naphthyl) -phenol, 4-tritylphenol, methyl salicylate, ethyl salicylate, n-propyl salicylate, iso-propyl salicylate, n-butyl salicylate, iso-butyl salicylate, tert Butyl salicylate, phenyl salicylate and benzyl salicylate.

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.

Suitable compounds having three or more phenolic hydroxyl groups are, for example, phloroglucinol, 4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) -hepten-2, 4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) -heptane, 1,3,5-tri (4-hydroxyphenyl) -benzene, 1,1,1-tri- (4-hydroxyphenyl) -ethane, tri- (4-hydroxyphenyl) -phenylmethane, 2,2-bis (4,4-bis (4-hydroxyphenyl) cyclohexyl] propane, 2,4-bis (4-hydroxyphenyl-isopropyl) -phenol and tetra (4-hydroxyphenyl) -methane.

Other suitable compounds having three and more functional groups are, for example, 2,4-dihydroxybenzoic acid, trimesic acid (trichloride), cyanuric trichloride and 3,3-bis (3-methyl-4-hydroxyphenyl) -2-oxo-2,3-dihydroindole.

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

The cover layer which reflects or absorbs IR radiation preferably has a transmission for radiation of the wavelength from 800 to 1200 nm, preferably from 850 to 1100 nm, of not greater than 20%, preferably not greater than 15%, particularly preferably not greater than 10% , The cover layer which reflects or absorbs IR radiation preferably furthermore has a transmission for radiation of the wavelength of 400 to 700 nm greater than 60%, preferably greater than 70%. The transmission is determined according to ASTM D 1003.

In one embodiment of the invention, the IR radiation-reflecting or absorbing cover layer contains at least one IR-absorbing additive. According to the invention, organic IR-absorbing additives are suitable here. Suitable organic IR-absorbing additives are compounds which have the highest possible absorption between 700 and 1500 nm (near infrared = NIR). For example, literature-known infrared absorbers are suitable, as they are, for. In M. Matsuoka, Infrared Absorbing Dyes, Plenum Press, New York, 1990 are described in terms of substance class. According to the invention, infrared absorbers from the classes of the azo, azomethine, methine anthraquinone, indanthrone, pyranthrone, flavanthrone, benzanthrone, phthalocyanine, perylene, dioxazine, thioindigo, isoindoline, isoindolinone, quinacridone , Pyrrolopyrrol- or Chinophtalonpigmente and metal complexes of azo, azomethine or methine dyes or metal salts of azo compounds. Of these, phthalocyanines and naphthalocyanines are particularly suitable. Due to the improved solubility in thermoplastics, phthalocyanines and naphthalocyanines with bulky side groups are preferable.

There are no particular limitations on the amount of IR absorbing additives contained in the IR radiation reflecting or absorbing cover layer, as long as the desired absorption of IR radiation and sufficient transparency are ensured. It has proved to be particularly advantageous if the composition of the IR radiation-reflecting or absorbing covering layer contains the IR-absorbing additive (s) in an amount of from 0.0001 to 10% by weight, in particular from 0.001 to 0.05 Wt .-%, based on the total weight of the composition of the IR radiation reflecting or absorbing cover layer contains. Also particularly suitable are mixtures of IR-absorbing additives. The person skilled in the art can achieve an optimization of the absorption in the near infrared range with dyes of different wavelengths of the absorption maxima.

Such IR radiation reflecting or absorbing films or films are known and commercially available.

In a further embodiment of the invention, the cover layer which reflects or absorbs IR radiation is a multi-layer structure which is a multilayer optical interference film, which can preferably be produced by coextrusion of alternating polymer layers. These are preferably layers based on coextruded layers IR radiation-reflecting films with a narrow reflection range due to light interference.

Such multilayer films are preferably composed of a plurality of parallel layers of transparent thermoplastic materials, for which the above-mentioned thermoplastics come into question, each directly juxtaposed layers of different thermoplastic materials whose refractive indices are at least 0.03, more preferably at least 0.06 different from each other. Such a multilayer film preferably contains at least 10 layers.

The individual layers of the multilayer film are preferably very thin with layer thicknesses in the range of about 30 to 500 nm, preferably about 50 to 400 nm, whereby gain interference of light waves reflected at the many interfaces is achieved. Depending on the layer thickness and the refractive index of the thermoplastics, a dominant wavelength band is reflected, while the remaining light is transmitted by the foil.

The amount of reflected light (reflectance) depends on the difference between the two indices of refraction, the ratio of the optical thicknesses of the layers, the number of layers, and the uniformity of the layer thicknesses.

Such multilayer films are known to the person skilled in the art and are described, for example, in US Pat US 3,610,729 . US 3,711,176 . US 4,446,305 . U.S. Patent 4,540,623 . US 5,448,404 . US 5,882,774 . US 6,531,230 . US Patent 6,783,349 . WO-A 99/39224 and WO-A 03/100521

The layer structure according to the invention preferably has at least one layer containing at least one thermoplastic and at least one filler ("filled layer"). As thermoplastics for the above-mentioned in question.

The filler in the filled layers is preferably at least one color pigment and / or at least one other filler for producing a translucency of the filled layers, preferably titanium dioxide, zirconium dioxide, barium sulfate or glass fibers, more preferably titanium dioxide.

The filled layers and the filled films used for their production 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% most preferred embodiments of less than 15%.

The fillers mentioned are preferably used in amounts of from 2 to 45% by weight, more preferably from 5 to 30% by weight, based on the total weight of filler and thermoplastic, of the thermoplastics prior to shaping into the plastic film, which, for example by extrusion or coextrusion added.

The filled layers may have further information in preferred embodiments of the invention. This further information can be obtained, for example, by means of conventional printing techniques, e.g. Ink jet, offset or laser printing, be applied.

The layer structure according to the invention may comprise further additional layers, via which, for example, further information is introduced into the security document, preferably an identification document.

Such further information can be, for example, personalizing portraits or non-personalizing general information, which are contained, for example, in each generic security document, preferably an identification document in the same form.

Such layers can be introduced, for example, from previously by means of conventional printing processes, preferably ink-jet or laser printing, particularly preferably color printing equipped with this information films in the layer structure according to the invention.

Films which can be printed by means of ink-jet printing processes are known to the person skilled in the art and can be, for example, those from at least one of the above-described thermoplastic plastics optionally containing at least one of the fillers described above. In particularly preferred embodiments, for better visibility of the printed information, fillers such as e.g. Titanium dioxide, zirconium dioxide, barium sulfate, etc. used white or translucent colored plastic films.

For films which are to be printed by means of laser printing, in particular by means of color laser printing, plastic films of one of the abovementioned thermoplastics which have a surface resistivity of 10 ⁷ to 10 ¹³ Ω, preferably of 10 ⁸ to 10 ¹² Ω, are particularly suitable. The specific surface resistance in Ω is determined according to DIN IEC 93.

These may preferably be those films in which the thermoplastic resin to achieve the surface resistivity example, an additive selected from tertiary or quaternary, preferably quaternary ammonium or phosphonium salts of a partially or perfluorinated organic acid or quaternary ammonium or Phosphoniumhexafluorophosphaten preferred a partially or perfluorinated alkyl sulfonic acid, preferably a perfluoroalkyl sulfonic acid was added.

• Perfluoroctansulfonsäuretetrapropylammoniumsalz,
• Perfluorbutansulfonsäuretetrapropylammoniumsalz,
• Perfluoroctansulfonsäuretetrabutylammoniumsalz,
• Perfluorbutansulfonsäuretetrabutylammoniumsalz,
• Perfluoroctansulfonsäuretetrapentylammoniumsalz,
• Perfluorbutansulfonsäuretetrapentylammoniumsalz,
• Perfluoroctansulfonsäuretetrahexylammoniumsalz,
• Perfluorbutansulfonsäuretetrahexylammoniumsalz,
• Perfluorbutansulfonsäuretrimethylneopentylammoniumsalz,
• Perfluoroctansulfonsäuretrimethylneopentylammoniumsalz,
• Perfluorbutansulfonsäuredimethyldineopentylammoniumsalz,
• Perfluoroctansulfonsäuredimethyldineopentylammoniumsalz,
• N-Methyl-tripropylammoniumperfluorbutylsulfonat,
• N-Ethyl-tripropylammoniumperfluorbutylsulfonat,
• Tetrapropylammoniumperfluorbutylsulfonat,
• Diisopropyldimethylammoniumperfluorbutylsulfonat,
• Diisopropyldimethylammoniumperfluoroctylsulfonat,
• N-Methyl-tributylammoniumperfluoroctylsulfonat
• Cyclohexyldiethylmethylammoniumperfluoroctylsulfonat,
• Cyclohexyltrimethylammoniumperfluoroctylsulfonat,

sowie die entsprechenden Phosphoniumsalze. Bevorzugt sind die Ammoniumsalze.Preferred suitable quaternary ammonium or phosphonium salts are:

• Perfluoroctansulfonsäuretetrapropylammoniumsalz,
• Perfluorbutansulfonsäuretetrapropylammoniumsalz,
• Perfluoroctansulfonsäuretetrabutylammoniumsalz,
• Perfluorbutansulfonsäuretetrabutylammoniumsalz,
• Perfluoroctansulfonsäuretetrapentylammoniumsalz,
• Perfluorbutansulfonsäuretetrapentylammoniumsalz,
• Perfluoroctansulfonsäuretetrahexylammoniumsalz,
• Perfluorbutansulfonsäuretetrahexylammoniumsalz,
• Perfluorbutansulfonsäuretrimethylneopentylammoniumsalz,
• Perfluoroctansulfonsäuretrimethylneopentylammoniumsalz,
• Perfluorbutansulfonsäuredimethyldineopentylammoniumsalz,
• Perfluoroctansulfonsäuredimethyldineopentylammoniumsalz,
• N-methyl perfluorobutyl sulfonate,
• N-ethyl perfluorobutyl sulfonate,
• Tetrapropylammoniumperfluorbutylsulfonat,
• Diisopropyldimethylammoniumperfluorbutylsulfonat,
• Diisopropyldimethylammoniumperfluoroctylsulfonat,
• N-methyl-tributylammoniumperfluoroctylsulfonat
• Cyclohexyldiethylmethylammoniumperfluoroctylsulfonat,
• Cyclohexyltrimethylammoniumperfluoroctylsulfonat,

and the corresponding phosphonium salts. The ammonium salts are preferred.

It is also possible to use one or more of the abovementioned quaternary ammonium or phosphonium salts, ie also mixtures.

Especially suitable is the perfluorooctanesulfonic acid tetrapropylammonium salt, the perfluorooctanesulfonic acid tetrabutylammonium salt, the perfluorooctanesulfonic acid tetrapentylammonium salt, the perfluorooctanesulfonic acid tetrahexylammonium salt and the perfluorooctanesulfonic acid dimethyldiisopropylammonium salt and the corresponding perfluorobutanesulfonic acid salts.

In a most preferred embodiment, perfluorobutanesulfonic acid dimethyldiisopropylammonium salt (diisopropyldimethylammonium perfluorobutylsulfonate) may be used as an additive.

The salts mentioned are known or can be prepared by known methods. The salts of the sulfonic acids can be prepared, for example, by combining equimolar amounts of the free sulfonic acid with the hydroxy form of the corresponding cation in water at room temperature and concentrating the solution. Other manufacturing methods are described, for example in DE-A 1 966 931 and NL-A 7 802 830 ,

The salts mentioned are preferably added in amounts of from 0.001 to 2% by weight, preferably from 0.1 to 1% by weight, to the thermoplastics prior to shaping into the plastic film, which can be effected, for example, by extrusion or coextrusion.

The layered construction according to the invention may also comprise further additional layers which provide UV protection and / or protection against mechanical damage - such as e.g. Scratch-resistant coatings - etc. have.

• den einzelnen Schichten entsprechende Folien mit Ausnahme der IR-Strahlung reflektierenden oder absorbierenden Deckschicht in einem Folienstapel zusammengelegt und zu einem Schichtverbund laminiert werden,
• anschließend auf den laminierten Schichtverbund die mittels Lasergravur aufzubringenden Daten bzw. Informationen, vorzugsweise personalisierende Daten bzw. Informationen, in den Schichtverbund durch Laserbeschriftung eingebracht werden und
• anschließend mittels Verklebung und/oder Laminieren die IR-Strahlung reflektierenden oder absorbierenden Deckschicht aufgebracht wird.

The layer structure according to the invention can be produced for example in such a way that

• the films corresponding to the individual layers, with the exception of the cover layer which reflects or absorbs IR radiation, are combined in a film stack and laminated to form a layer composite,
• Subsequently, the data to be applied by means of laser engraving or information, preferably personalizing data or information, are introduced into the laminated composite by laser inscription on the laminated layer composite and
• then by gluing and / or laminating the IR radiation reflecting or absorbing cover layer is applied.

The layer structure according to the invention is preferably suitable for increasing the security against forgery of security documents, particularly preferably identification documents. Most preferably, the layer structure according to the invention is suitable for increasing the security against counterfeiting of such identification documents in the form of bonded or laminated laminates in the form of plastic cards, such as e.g. Identity documents, passports, driver's licenses, credit cards, bank cards, access control cards or other identity documents, etc. Preferred identification documents in the context of the present invention are multi-layered sheet-like documents with security features such as chips, photographs, biometric data, etc. These security features can be visible from outside or at least be queriable. Preferably, such an identification document has a size between that of a check card and that of a passport. Such an identification document may also be part of a document of several parts, such as e.g. a plastic identification document in a passport that also contains paper or cardboard parts.

The subject matter of the present invention is therefore furthermore a security document, preferably an identification document containing at least one laser-marked layer structure according to the invention.

The IR radiation-reflecting or absorbing cover layer is fully or partially applied to the layer structure, preferably the security document or identification document after personalization by means of laser engraving in order to prevent the subsequent change of the laser engraved personalizing data and thus to increase the security against counterfeiting.

The invention further provides a method for blocking the laser inscribability of laser-inscribed layer structures, characterized in that a laser-inscribed layer structure containing at least one laser-inscribable thermoplastic layer is provided with a partial or full-surface IR radiation reflecting or absorbing cover layer after laser inscription, wherein the partial or full-surface IR radiation-reflecting cover layer contains at least one IR-absorbing additive and the at least one IR-absorbing additive are those selected from the substance classes of the azo, azomethine, methine-anthraquinone, indanthrone, Pyranthrone, flavanthrone, benzanthrone, phthalocyanine, perylene, dioxazine, thioindigo-isoindoline, isoindolinone, quinacridone, pyrrolopyrrole or quinophthalone pigments and metal complexes of azo, azomethine or methine dyes or metal salts of azo compounds are selected.

By blocking the laser inscribability is to be understood in the context of the invention both a significant reduction in the further laser inscribability and the complete prevention of further laser inscribability

Another object of the invention is a method for blocking inscribability by means of laser engraving of laser engraving inscribed layer structures, characterized in that a laser-engraved layered structure comprising at least one laser-engravable inscribable thermoplastic layer, after inscription by laser engraving with a partial or full-surface IR radiation or reflective absorbing layer is provided and the IR radiation-reflecting or absorbing cover layer after the lettering by means of laser engraving in the form of a multilayer film, which is a multilayer optical interference film is applied to the laser engraved inscribed layer structure by means of an adhesive or by lamination.

This application may be made using an adhesive or by lamination, which may be applied by lamination with both adhesive support and no adhesive.

In the case of application using an adhesive, the use of a latently reactive adhesive is most preferred.

Latent reactive adhesives are known in the art. Preferred latently reactive adhesives are those which have an aqueous dispersion containing a di- or polyisocyanate with a 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 is 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 TMA is carried out analogously to ISO 11359 Part 3 "Determination of the Penetration Temperature". Further preferably, the di- or polyisocyanate is one selected from the group consisting of dimerization products, trimerization products and urea derivatives of TDI (toluene diisocyanate) or IPDI (isophorone diisocyanate). Such latent reactive adhesives are for example in DE-A 10 2007 054 046 described.

By using such latently reactive adhesives, an additional increase in anti-counterfeiting security can be achieved in that no water vapor and / or air can diffuse into the interior beyond the edges of the layer structure and thus can no longer lead to a subsequent delamination. Such layer structures can no longer be separated intact. Accordingly, the cover layer which reflects or absorbs IR radiation can no longer be separated without destroying the entire security document or identification document. Incidentally, the same also applies to a covering layer which is reflective or absorbing by means of lamination.

The use of a film which reflects or absorbs IR radiation to block the laser inscribability of laser-printed layer structures, preferably of security documents, particularly preferably of identification documents, is hitherto unknown and accordingly likewise the subject of the present invention.

The following examples serve to exemplify the invention and are not to be considered as limiting.

Examples Films used for the card layer construction according to the invention Film 1-1: white filled film

It was 100 microns based on polycarbonate Makrolon 3108 ^® of Bayer Material Science AG and titanium dioxide (Kronos® 2230 Fa. Kronos Titan) as a white pigment filler by weight having a composition of 85 wt .-% Makrolon 3108 ^® and 15 is a polycarbonate sheet of thickness. % Titanium dioxide produced at a melt temperature of about 280 ° C by extrusion.

Slide 1-2: white filled foil

A film with the same composition as film 1-1 of thickness 400 μm was produced.

Slide 2: laser-engravable film

There was a polycarbonate film of thickness 50 microns on the basis of the polycarbonate Makrolon 3108 ^®, Bayer MaterialScience AG, and carbon black (lampblack 101 of Messrs. Degussa) having an average Teilchengrö-βe of 95 nm as a laser-sensitive additive at a melt temperature of about 280 ° C by means of Extrusion produced. For this purpose, a compound of 85 wt .-% was polycarbonate Makrolon ^® 3108 and 15 wt .-% of a masterbatch having a composition of 99.004 wt .-% Makrolon 3108 ^® and 0.006 wt .-% (60 ppm) of carbon black used.

Film 3: transparent film

There was prepared 50 microns based on polycarbonate Makrolon ^® 3108 from Bayer MaterialScience AG at a melt temperature of about 280 ° C by means of extrusion, a polycarbonate sheet of thickness.

Slide 4: IR Reflective Film:

A commercially available IR reflection film from 3M (3M Vikuiti® Clear Card IR Filter) was used. It was a transparent, IR-reflective film with less than 20% light transmission in the range between 850 and 1100 nm (determined according to ASTM D 1003).

Example 1: Production of a laser-writable layer structure

1. (1) Folie 3; 50 µm
2. (2) Folie 2; 50 µm
3. (3) Folie 1-1; 100 µm
4. (4) Folie 1-2; 400 µm
5. (5) Folie 1-1; 100 µm
6. (6) Folie 2; 50 µm
7. (7) Folie 3; 50 µm

From the films listed above, a laser-writable layer structure in the form of an ID card was laminated as follows:

1. (1) film 3; 50 μm
2. (2) film 2; 50 μm
3. (3) film 1-1; 100 μm
4. (4) slide 1-2; 400 μm
5. (5) slide 1-1; 100 μm
6. (6) film 2; 50 μm
7. (7) film 3; 50 μm

A symmetric layer structure of the card was chosen to avoid bending the card.

• Vorheizen der Presse auf 170-180°C
• Pressen für 8 Minuten bei einem Druck von 15 N/cm²
• Pressen für 2 Minuten bei einem Druck von 200 N/cm²
• Abkühlen der Presse auf 38°C und öffnen der Presse.

For this purpose, a stack was formed from the films in the above-mentioned order and the lamination was carried out on a lamination press from Bürkle with the following parameters:

• Preheat the press to 170-180 ° C
• Press for 8 minutes at a pressure of 15 N / cm ²
• Press for 2 minutes at a pressure of 200 N / cm ²
• Cool the press to 38 ° C and open the press.

Example 2: Preparation of an adhesive coating on the IR reflection film for subsequent lamination to this ID card

As the IR reflection film, the above-mentioned film 4 was used.

To prepare the adhesive dispersion for the adhesive coating, the following components were used:

A) Polyurethane dispersion:

Polyurethane dispersion having a solids content of about 45% by weight .; Isocyanate-reactive polymer of linear polyurethane chains in water

B) Thickener : Borchi® Gel L 75 N

Non-ionic, liquid, aliphatic polyurethane-based thickener: Viscosity at 23 ° C:> 9,000 mPas; Non-volatile ingredients: 50% by weight.

C) Deactivated polyisocyanate: Dispercoll® BL XP 2514

Suspension of surface-deactivated TDI uretdione (TDI dimer) in water with a solids content of about 40 wt .-%.

For the preparation of the adhesive dispersion, first 700 parts by weight of the polyurethane dispersion A) were added while stirring to 7 parts by weight of the thickener B) in order to increase the viscosity.

Then, with stirring, 100 parts by weight of this thickened dispersion was added with 10 parts by weight of the deactivated polyisocyanate C), so that an aqueous dispersion was obtained.

Subsequently, the IR reflection film was coated with a spiral doctor blade with this adhesive dispersion, wherein the wet layer thickness of the adhesive dispersion was 100 microns, so that a dry film thickness of about 30 microns was obtained. Subsequently, the coated film was dried for 90 minutes at about 35 ° C in a drying oven and was then ready for use in the lamination.

Example 3

The left half of the layer (1) of the ID card prepared in Example 1 was laminated in a second lamination step with the adhesive-coated IR reflective sheet of Example 2.

• Vorheizen der Presse auf 90°C
• Pressen für 8 Minuten bei einem Druck von 15 N/cm²
• Abkühlen der Presse auf 38°C und Öffnen der Presse.

For this purpose, the lamination was carried out on a lamination press of Bürkle with the following parameters:

• Preheat the press to 90 ° C
• Press for 8 minutes at a pressure of 15 N / cm ²
• Cool the press to 38 ° C and open the press.

Example 4

Laser engraving on a Foba laser system was carried out on the ID card from Example 3, which was coated halfway with the IR refection film, with the following parameters: Laser medium: Nd: YAG Wavelength: 1064 nm Power: 40 watts Electricity: 30 A pulse rate: 14 KHz. Feed speed: 200 mm / sec.

• Auf der linken Hälfte der ID-Karte, auf der die IR-Reflektionsfolie auflaminiert war, konnte keine Lasergravur der darunter liegenden laserbeschreibbaren Folienschicht erzielt werden. Auf der rechten Seite konnte kontrastreich die rechte Gesichtshälfte in die laserbeschreibbare Folienschicht eingeschrieben werden, was die grundsätzliche Beschreibbarkeit der Laserschicht nachweist.

In laser engraving, the information was only written on a laser-writable film layer (layer (2)) of the ID card. As information, the full portrait of a woman should be laser engraved into the laser-writeable Be written layer. The result was as follows:

• On the left half of the ID card on which the IR reflection foil was laminated, no laser engraving of the underlying laser writable film layer could be achieved. On the right side, the right half of the face could be inscribed into the laser-writable film layer with high contrast, which proves the fundamental writability of the laser layer.

Thus, the structure according to the invention offers the possibility to prevent the subsequent laser engraving after completion of personalization of an ID card by means of laser engraving by application of an IR radiation reflecting or absorbing cover layer.

Claims (13)

1. Laser gravure inscribed layer structure comprising at least one thermoplastic polymer layer modified so as to be inscribable by means of laser gravure and a top layer which reflects or absorbs IR radiation over part or all of its area, the top layer which reflects or absorbs IR radiation over part or all of its area comprising at least one IR-absorbing additive, and the IR-absorbing additive in the top layer being one selected from the substance classes of the azo, azomethine, methine, anthraquinone, indanthrone, pyranthrone, flavanthrone, benzanthrone, phthalocyanine, perylene, dioxazine, thioindigo, isoindoline, isoindolinone, quinacridone, pyrrolopyrrole or quinophthalone pigments and metal complexes of azo, azomethine or methine dyes or metal salts of azo compounds.
2. Laser gravure inscribed layer structure comprising at least one thermoplastic polymer layer modified so as to be inscribable by means of laser gravure and a top layer which reflects or absorbs IR radiation over part or all of its area, the top layer which reflects or absorbs IR radiation over part or all of its area consisting of a multilayer structure which is a multilayer optical interference film.
3. Laser gravure inscribed layer structure according to Claim 1 or 2, characterized in that the thermoplastic polymer layer modified so as to be inscribable by means of laser gravure comprises at least one laser-sensitive additive.
4. Laser gravure inscribed layer structure according to Claim 3, characterized in that the laser-sensitive additive is carbon black.
5. Laser gravure inscribed layer structure according to at least one of Claims 1 to 4, characterized in that the thermoplastic polymer of the thermoplastic polymer layer modified so as to be laser-inscribable is at least one thermoplastic polymer selected from polymers of ethylenically unsaturated monomers and/or polycondensates of bifunctional reactive compounds, preferably one or more polycarbonate(s) or copolycarbonate(s) based on diphenols, poly- or copolyacrylate(s) and poly- or copolymethacrylate(s), poly- or copolymer(s) with styrene, polyurethane(s), and polyolefin(s), poly- or copolycondensate(s) of terephthalic acid, poly- or copolycondensates of naphthalenedicarboxylic acid, poly- or copolycondensate(s) of at least one cycloalkyl-dicarboxylic acid, polysulphones or mixtures of these, more preferably one or more polycarbonate (s) or copolycarbonate(s) based on diphenols or blends comprising at least one polycarbonate or copolycarbonate.
6. Laser gravure inscribed layer structure according to at least one of Claims 1 to 5, characterized in that the transmission of the top layer which reflects or absorbs IR radiation for radiation of wavelength from 800 to 1200 nm, preferably from 850 to 1100 nm, is not greater than 20%, preferably not greater than 15%, more preferably not greater than 10%, and the transmission for radiation of wavelength from 400 to 700 nm is greater than 60%, preferably greater than 70%.
7. Laser gravure inscribed layer structure according to at least one of Claims 1 to 6, characterized in that the layer structure has at least one layer comprising at least one thermoplastic polymer and at least one filler ("filled layer").
8. Laser gravure inscribed layer structure according to Claim 7, characterized in that the filler is a colour pigment or another filler for generation of translucence of the filled layer, preferably titanium dioxide, zirconium dioxide, barium sulphate or glass fibres.
9. Security document, preferably identification document, comprising at least one laser gravure inscribed layer structure according to at least one of Claims 1 to 8.
10. Process for blocking inscribability by means of laser gravure of laser gravure inscribed layer structures, characterized in that a laser gravure inscribed layer structure comprising at least one thermoplastic polymer layer modified so as to be laser gravure inscribable, after inscription by means of laser gravure, is provided with a top layer which reflects or absorbs IR radiation over part or all of its area, the top layer which reflects or absorbs IR radiation over part or all of its area comprising at least one IR-absorbing additive and the at least one IR-absorbing additive being one selected from the substance classes of the azo, azomethine, methine, anthraquinone, indanthrone, pyranthrone, flavanthrone, benzanthrone, phthalocyanine, perylene, dioxazine, thioindigo, isoindoline, isoindolinone, quinacridone, pyrrolopyrrole or quinophthalone pigments and metal complexes of azo, azomethine or methine dyes or metal salts of azo compounds.
11. Process for blocking inscribability by means of laser gravure of laser gravure inscribed layer structures, characterized in that a laser gravure inscribed layer structure comprising at least one thermoplastic polymer layer modified so as to be laser gravure inscribable, after inscription by means of laser gravure, is provided with a top layer which reflects or absorbs IR radiation over part or all of its area and the top layer which reflects or absorbs IR radiation, after inscription by means of laser gravure, is applied in the form of a multilayer film which is a multilayer optical interference film, to the laser gravure inscribed layer structure by means of an adhesive or by means of lamination.
12. Process according to Claim 11, characterized in that the adhesive is a latently reactive adhesive.
13. Use of a film which reflects or absorbs IR radiation for blocking of inscription by means of laser gravure of laser gravure inscribed layer structures, preferably of security documents, more preferably of identification documents.