TAMPERPROOF SECURITY DOCUMENT AND PROCESS FOR PREPARING TAMPERPROOF SECURITY DOCUMENTS

FIELD OF THE INVENTION

The invention relates to a process for preparing security documents secured against alteration and tampering.

BACKGROUND OF THE INVENTION

Security documents according to the present invention are bank notes, cheque forms, shares, certificates, postage stamps, air tickets, labels for product protection, identity documents, passports and the like. Bank notes are normally manufactured from so-called security papers consisting of cotton fibers and have special security features, such as a security thread at least partly incorporated into the paper, and a watermark. The period of circulation of a bank note depends on how much it is stressed. Certain denominations are preferably used in financial transactions and thus have a shorter period of circulation due to the greater wear and tear due to environmental influences. The main cause for a restricted period of circulation of bank notes is seen to be early soiling. Since bank note paper is very porous, it has a large surface area or high surface roughness. Even if the resulting projections and cavities are in orders of magnitude which cannot be resolved by the human eye, they offer ideal conditions for dirt deposits in comparison with a smooth surface.

WO 98/15418A discloses a security document, such as a banknote, comprising a single flexible sheet formed from a substrate bearing indicia, said sheet having a first portion of transparent plastics material, and a security device provided at a second position of the sheet spaced laterally from the transparent first portion, wherein the transparent first portion includes self-verification means to verify or inspect the security device when the sheet is bent, folded or twisted to bring the first and second portions into register with one another. However, in this case the usual and time-tested security elements such as portrait watermark and windowed security thread must be forgone, as well as the special properties such as sound and feel of bank note paper. Also, the steel gravure printing usual in the bank note sector, which serves as an additional tactile authenticity mark due to the relief arising from the inking, leads

only to a flat, hardly noticeable relief on plastic substrates. Moreover, pure plastic bank notes are very sensitive to heat, so that plastic substrates have a strong tendency to shrink particularly in countries with unfavorable climatic conditions. In particular with regard to falsification security, plastic bank notes have the decisive disadvantage that the substrate is readily available and can be procured by anyone.

WO 96/28610A discloses a method for producing security paper which includes a security feature, which method comprises forming paper in a wet state, which paper incorporates one or more security features, applying to the paper a sizing agent, thereafter applying to one or both sides of the sized paper a coating comprising an unpigmented polyurethane which may optionally comprise a functional additive provided that the presence of the functional additive does not increase the opacity of the paper by more than 1%, thereafter drying the paper, said coating composition being such as to provide a film, when cast on a glass surface, having a Konig hardness of from 15 to 130 seconds, and also passing the water resistance test as defined by the following steps: a) the total formulation to be used m the coating is cast on a glass plate so as to produce a film with a dry weight of 80g/m ² ; b) the film is initially dried at 23°C. Once it is tack free it is dried for an additional hour at 80 'C; c) the film is weighed before being wetted and tested for tensile strength, Young's Modulus and is visually checked for any change m its transparency; d) a sample of the film is boiled m water containing 10g/L Na ₂ CO ₃ for 30 mins; e) the film is then rinsed in cold water and the steps b) to c) are then repeated; wherein when the film is dried and re-weighed the film meets the following criteria: i) the wet tensile strength and Young's Modulus of the boiled film is not less than 90% of the initial film wet tensile strength and Young's Modulus; ii) the film shows no perceptible loss of transparency, and in) the dried weight of the film is not less than 98% of the original weight. This reduces the soiling problem, but cannot increase the mechanical stability of a substrate. Multilayer substrates comprising a film core coated on both sides with paper plies have also been proposed. The strength of this laminate is increased m comparison with a pure paper substrate, but the soiling problem with the exterior paper layers is not solved. So as not to excessively increase the total thickness of such bank notes, the paper plies must moreover be designed very thin, so that the usual security features such as security thread or watermark can no longer be optimally incorporated.

US 2007/0017647A1 discloses a security paper for producing value documents, exemplified by bank notes, passports or identification documents, comprising a flat substrate provided at least partly with a dirt-repellent protective layer for extending the life time and fitness for circulation, wherein the protective layer comprises at least two lacquer layers, a first lower one of said lacquer layers being formed by a physically drying lacquer layer applied to the substrate which makes contact with the substrate therebelow and closes its pores, and a second upper one of said lacquer layers protecting the substrate from physical and chemical influences. US 2007/0017647A1 discloses that the first lower lacquer layer is preferably elastic, is preferably formed by a water-based dispersion lacquer layer, preferably comprises a polyurethane, and is preferably based on a water-based dispersion of aliphatic polyester polyurethanes or styrene-acrylic polyurethanes . One skilled in the art would understand the term "physically drying lacquer" not defined in US 2007/0017647A1 to mean a lacquer drying or hardening to form a tight film at room temperature or on slight heating by evaporation of solvent or suspension medium, the degree of polymerization and/or molar mass of the binders remaining unchanged during this process e.g. coalescence of binder particles.

Identification cards and documents, such as driving licenses, national or government identification cards, bank cards, credit cards, controlled access cards and smart cards, carry certain items of information which relate to the identity of the bearer. Examples of such information or variable data include name, address, date of birth, signature and photo of the bearer. The ID cards or documents may in addition carry invariant data, i.e., data common to a large number of cards, for example the name of an employer, the name of the issuing authority and the name of a country.

A typical national passport is personalized by ink-jet-printing a citizen' s biographical and biometric information onto the data page of a blank passport consisting of a back and front cover and pages of security paper with security printing. The ink-jet-ink is partly absorbed in the security paper and any attempt to remove the ink will also destroy the surface of the page. However the information can be overwritten. After printing a transparent (possibly optically variable) foil is laminated on top of the data page as a whole or locally over the top of the image of the citizen. The thinness of the foil and its binding to the biographical data makes forgery/alteration difficult. However, under certain

circumstances the laminate foil can be integrally removed making it possible to alter the biographic data.

Identity theft is considered by many governments to be the fastest growing crime. Consequently efforts to improve the security of security documents and in particular ID-documents are presently being made to prevent forgery and alteration.

Therefore, it is highly desirable to be able to manufacture security documents secured against alteration using a simple manufacturing method. However, the application of soiling resistant and/or protective outermost layers as liquid compositions to paper- based security documents is accompanied by staining of the paper- base due to penetration through the porous paper base (so-called strike-through) , which can be observed on the reverse side of the document as greasy areas corresponding to the area to which the composition is applied together with changes in the information being protected e.g. leaching of print and image comprising the information. There is therefore a need for a means of providing soiling resistant and/or protective outermost layers as liquid compositions in which an outermost layer is produced without such disadvantages.

ASPECTS OF THE INVENTION

It is an aspect of the present invention to provide a simple method for manufacturing a secure ID document without changes in the information content of the information being protected or staining of the paper-base.

It is a further aspect of the present invention to provide ID documents, which are difficult to falsify and are tamperproof against changes in the information content of the information being protected or staining of the paper-base.

Further objects of the invention will become apparent from the description hereinafter.

SUMMARY OF THE INVENTION

It has been surprisingly found that the application of particular aqueous primer compositions comprising an ionic fluorinated surfactant { fluorosurfactant) and a polymerizable substance to a paper-based security document drying to a transparent layer prior to the application of a protective crosslinkable liquid composition to the paper-based security document crosslinking to a

glossy transparent layer is able to delay strike-through of the protective crosslinkable liquid composition sufficiently long to enable a crosslinkable composition to be applied and crosslinked without significant penetration into the security paper and moreover that the resulting protective layers are solvent-resistant i.e. survived the crosscut adhesion test after 24 hours immersion in acetone. Improved tamper-proofing is thereby realized. Furthermore, the layers realized with the primer and crosslinkable compositions are totally transparent and the gloss of the image being protected is substantially unchanged or increased by the coating, although deeper in colour, as would be expected with a transparent coating. No significant dulling or matting of the image is observed with the primer composition of the present invention. Aspects of the present invention have been realized by a process for preparing a tamperproof security document comprising in order the steps of a) providing a security document comprising security paper having at least one image on at least one outermost surface of the security paper; b) applying by printing, coating or other application process an aqueous primer composition on at least one of the outermost surfaces of the security paper over the at least one image thereby forming a primer coating on at least the at least one image; c) drying said primer coating; d) optionally curing said primer composition; e) applying by printing, coating or other application process a crosslinkable composition over said primer coating; and f) curing said printed or coated crosslinkable composition, wherein the primer composition comprises at least one ionic fluorinated surfactant and at least one polymerizable substance selected from the group consisting of polyester acrylates, polyester methacrylates, polyurethanes and urea-based monomers. Aspects of the present invention have also been realized by a process for preparing a tamperproof security document comprising in order the steps of a) applying by printing, coating or other application process an aqueous primer composition on at least one of the outermost surfaces of a security paper to provide a primer print or primer layer; b) drying said primer print or primer layer; c) optionally curing said primer print or primer layer; d) providing at least one image over said dried and optionally cured primer print or primer layer; e) applying by printing, coating or other application process a crosslinkable composition over the at least one image; and f) curing said printed or coated crosslinkable composition, wherein said primer composition comprises at least one ionic fluorinated surfactant and at least one polymerizable substance selected from

the group consisting of polyester acrylates, polyester methacrylates, polyurethanes and urea-based monomers.

Aspects of the present invention have also been realized by a print comprising a security paper carrying a printed image on at least one side thereof, wherein said at least one printed image is provided with a primer composition comprising at least one ionic fluorinated surfactant and at least one polymerizable substance selected from the group consisting of polyester acrylates, polyester methacrylates, polyurethanes and urea-based monomers. Aspects of the present invention have also been realized by a security document comprising the above-described print.

Aspects of the present invention have also been realized by the use of a primer composition comprising at least one ionic fluorinated surfactant and at least one polymerizable substance selected from the group consisting of polyester acrylates, polyester methacrylates, polyurethanes and urea-based monomers for preventing the penetration of crosslinkable composition into security papers.

Further advantages and embodiments of the present invention will become apparent from the following description.

DETAILED DESCRIPTION OF THE INVENTION

Definitions

The term "abherent agent", as used in disclosing the present invention means a substance that prevents adhesion of a material, either to itself or to other materials.

The term "printing", as used in disclosing the present invention, means application by a conventional impact or non-impact printing process including but not restricted to ink-jet printing, intaglio printing, screen printing, flexographic printing, offset printing, stamp printing, gravure printing and xerographic printing. The term "security document", as used in disclosing the present invention, means bank notes, cheque forms, shares, certificates, postage stamps, air tickets, labels for product protection, identity documents and the like.

The term ^identity document", as used in disclosing the present invention, means a document bearing identifying data about the product or the individual whose name appears thereon. ID documents include credit cards, bank cards, phone cards, passports, driving licences, network access cards, employee badges, debit cards, security cards, visas, immigration documentation, national ID cards,

citizenship cards, social security cards, security badges, certificates, identification cards or documents, voter registration cards, police ID cards, border crossing cards, legal instruments, security clearance badges and cards, gun permits, gift certificates or cards, membership cards and badges. The terms "document," "card," "badge" and "documentation" are used interchangeably throughout this patent application.

The term "security paper", as used in disclosing the present invention, means a paper used in a security document. The term "image", as used in disclosing the present invention means any way of representing information, such as pictures, logos, photographs, barcodes and text. The image may also comprise some form of a "security pattern", such as small dots, thin lines, holograms, microprint and Moire inducing patterns which may be produced using fluorescent inks, phosphorescent inks, pearlescent inks or other optically variable inks, such as metameric inks.

The term "ink", as used in disclosing the present invention, means a liquid which can be printed using conventional printing techniques and is not confined to liquids containing at least one colorant.

The term "vinyl-monomer", as used in disclosing the present invention, means a substance comprising a single vinyl group capable of chain polymerization.

The term "polyvinyl-monomer", as used in disclosing the present invention, means a substance comprising a more than one vinyl group capable of chain polymerization e.g. a divinyl-monomer with two vinyl groups, a trivinyl-monomer with three vinyl groups, a tetravinyl-monomer with four vinyl groups.

The term "substantially non-printable abhesive surface", as used in disclosing the present invention, means a surface which does not lend itself to efficient deposition of an ink by a conventional printing technique and/or to deposits of ink with substantially no adhesion to the abhesive surface.

The term "substantially non-laminatable abhesive surface", as used in disclosing the present invention, means a surface which does not lend itself to efficient lamination and/or to laminates with substantially no adhesion to the abhesive surface.

The term "porous pigment", as used in disclosing the present invention, means a pigment with detectable pores detectable using techniques such as porosimetry i.e. contains pores in an open

(unfilled) state. These pores can be micropores defined by IUPAC as pores sizes < 2 nm, mesopores defined by IUPAC as pore sizes of 2 to

50 nm or macropores defined by IUPAC as pore sizes greater than 50 nm. Porous pigments often have very high specific surface areas (BET) e.g. 100 to greater than 1500 m ² /g associated with particle sizes greater than 1 μm and have measurable pore volumes e.g. 1.2mL/g for SYLOID™ W300. Examples of porous pigments are silica gels such as SIPERNAT™ 570, SIPERNAT™ 700 and SIPERNAT™ 220 from Degussa and SYLOID™ W300 from W. R. Grace.

A "layer or foil exclusive of porous pigment", as used in disclosing the present invention, means a layer or foil which does not contain porous pigment particles i.e. porous particles containing pores in an open (unfilled) state and does not include a layer or foil containing porous pigment, whose pores have been filled e.g. with a curable liquid.

The term "UV" as used in disclosing the present invention is an abbreviation for ultraviolet radiation.

The term "ultraviolet radiation" as used in disclosing the present invention means electromagnetic radiation in the wavelength range of 100 to 400 nm.

The term "actinic radiation" as used in disclosing the present invention means electromagnetic radiation capable of initiating photochemical reactions.

The term "thermal initiator" as used in disclosing the present invention means an initiator which generates initiating species upon exposure to heat. The term "functional group" as used in disclosing the present invention means an atom or group of atoms, acting as a unit, that has replaced a hydrogen atom in a hydrocarbon molecule and whose presence imparts characteristic properties to this molecule. The term "polyfunctional" means more than one functional group. The term "dispersion", as used in disclosing the present invention, means an intimate mixture of at least two substances, one of which, called the dispersed solid phase or colloid, is uniformly distributed in a finely divided state through the second substance, called the dispersion medium. The term "wt%" is used in disclosing the present invention as an abbreviation for % by weight.

The term "substituted" as used in disclosing this present invention means that one or more of the carbon atoms and/or that a hydrogen atom of one or more of carbon atoms in an aliphatic group, an aromatic group or an alicyclic hydrocarbon group, are replaced by an oxygen atom, a nitrogen atom, a halogen atom, a silicon atom, a sulphur atom, a phosphorous atom, selenium atom or a tellurium atom.

Such substituents include hydroxyl groups, ether groups, carboxylic acid groups, ester groups, amide groups and amine groups.

Process for preparing a tamperproof ID document

Aspects of the present invention have been realized by a process for preparing a tamperproof security document comprising in order the steps of a) providing a security document comprising security paper having at least one image on at least one outermost surface of the security paper; b) applying by printing, coating or other application process an aqueous primer composition on at least one of the outermost surfaces of the security paper over the at least one image thereby forming a primer coating on at least the at least one image; c) drying said primer coating; d) optionally curing said primer composition; e) applying by printing, coating or other application process a crosslinkable composition over said primer coating; and f) curing said printed or coated crosslinkable composition, wherein the primer composition comprises at least one ionic fluorinated surfactant and at least one polymerizable substance selected from the group consisting of polyester acrylates, polyester methacrylates, polyurethane- and urea-based monomers.

According to a first embodiment of the process, according to the present invention, the cured crosslinkable composition is an abhesive layer. According to a second embodiment of the process, according to the present invention, the process comprises the further steps of g) applying by printing, coating or other application process an abhesive crosslinkable composition over the cured crosslinkable composition; and h) curing the abhesive crosslinkable composition, which is preferably applied by a printing process and particularly preferably by an ink-jet printing process.

According to a third embodiment of the process, according to the present invention, the crosslinkable composition is printed or coated according to a second image, thereby increasing the problems for the potential forger. The second image may comprise some form of a "security pattern", such as small dots, thin lines, holograms, microprint and Moire inducing patterns which may be produced using fluorescent inks, phosphorescent inks, pearlescent inks or other optically variable inks, such as metameric inks. According to a fourth embodiment of the process, according to the present invention, the crosslinkable composition is printed or coated according to a second image and an abhesive crosslinkable

composition is printed or coated on the second image according to a third image, thereby increasing the problems for the potential forger still further.

The crosslinkable composition can be a dispersion or a solution with the dispersion medium or solvent being aqueous or non-aqueous and if non-aqueous it can be inert or react in the crosslinking process. If inert the dispersion medium or solvent will usually be evaporated.

According to a fifth embodiment of the process, according to the present invention, the image on at least one side of the security paper is applied by ink-jet printing.

According to a sixth embodiment of the process, according to the present invention, the primer composition is applied patternwise . According to a seventh embodiment of the process, according to the present invention, the primer composition is printed using ink- jet printing.

According to an eighth embodiment of the process, according to the present invention, the primer composition is cured by UV- radiation.

According to a ninth embodiment of the process, according to the present invention, the crosslinkable composition is printed using ink-jet printing.

According to a tenth embodiment of the process, according to the present invention, the crosslinkable composition is applied patternwise .

According to an eleventh embodiment of the process, according to the present invention, the crosslinkable composition is cured by UV-radiation . According to a twelfth embodiment of the process, according to the present invention, the crosslinkable composition is an abhesive crosslinkable composition, which is printed using ink-jet printing. According to a thirteenth embodiment of the process, according to the present invention, the crosslinkable composition is an abhesive crosslinkable composition, which is cured by UV-radiation . According to a fourteenth embodiment of the process, according to the present invention, the process comprises the further steps of g) applying by printing, coating or other application process an abhesive crosslinkable composition over the cured crosslinkable composition; and h) UV-curing the printed or coated abhesive crosslinkable composition.

According to a fifteenth embodiment of the process, according to the present invention, at least one of the primer compositions and the crosslinkable composition is printed using ink-jet printing or if an abrasive crosslinkable composition is also applied at least one of the primer compositions, the crosslinkable composition and the abrasive crosslinkable composition is printed using ink-jet printing.

The image or parts of the image can be provided by any suitable imaging method or combination of imaging methods. Invariant data may be applied by any impact printing technique, such as offset printing, flexographic printing, gravure, screen-printing, ink-jet printing and xerographic printing. For variable data a non-impact printing technique is preferably used, ink-jet printing is the preferred choice since additional security features can be included in the ink-jet inks.

Security paper

The security paper used in different types of security document varies with document type. They are generally based on non-wood fibres such as abaca, cotton, flax, hemp or sisal, although synthetic paper is used for some identity documents, student cards and labels. Compositions used include:

Security paper is generally rag paper, always wood-free, watermarked and chemically impregnated. It is very reactive and strong. Security papers carry identification marks which help to prevent counterfeiting e.g. dyes and watermarks. Security paper is also specially treated to prevent erasure, alteration or duplication of any writing or printing on its surface.

ArjoWiggins Security S. A. S. produces different security papers for use in security documents:

JETGUARD™ is used for the pages of passports, visas and identity cards .

Primer composition

The primer composition used m the process, according to the present invention, comprises at least one ionic fluorinated surfactant and at least one polymeπzable substance selected from the group consisting of polyester acrylates, polyester methacrylates, polyurethane- and urea-based monomers.

The choice of carriers for ingredients of the primer composition e.g. for the at least one polymerizable substance and the at least one ionic fluorosurfactant and/or any diluent used must take into account its effect upon the paper and or image to which the primer composition is to be applied. Alcohols, for example, may lead to colour bleeding or other information degrading effects e.g.

the ethanol in AMFS06 and AFS12 and isopropanol in AFS26, AFS36, AFS38, AFS39, CFS05 and AMFS04.

Ionic fluorosurfactant for primer composition

The surfactant used in the primer composition used in the process, according to the present invention, is an ionic fluorosurfactant . Suitable ionic fluorosurfactants can be identified by their ability when applied as an aqueous solution or dispersion to the paper-based security document of at least delaying the penetration of subsequently applied crosslinkable composition though the paper-base of the security document concerned i.e. to delay so-called "strike-through" of the crosslinkable composition. The ionic fluorinated surfactant, although it delays the penetration of the crosslinkable composition into the security paper, is of itself unusable due to the resulting poor adhesion between the cured crosslinkable composition and the security paper.

The polymerizable-substance containing primer composition must contain sufficient surfactant to prevent strike-through of the crosslinkable composition in the security paper prior to the cross- linking of the subsequently applied crosslinkable composition but no so much that adhesion of the resulting protective layer is not solvent-resistant i.e. cannot survive the crosscut adhesion test after 24 hours immersion in acetone. According to a sixteenth embodiment of the process, according to the present invention, the ionic fluorinated surfactant comprises a perfluorinated group, with a CF ₃ (CF ₂ ) _n - group wherein n is at least 3 being preferred and a CF ₃ (CF ₂ ) _n - group wherein n is at least 5 being particularly preferred. According to a seventeenth embodiment of the process, according to the present invention, the ionic fluorinated surfactant is an anionic, a cationic or amphoteric fluorinated surfactant.

According to an eighteenth embodiment of the process, according to the present invention, the ionic fluorinated surfactant is an anionic fluorosurfactant, with anionic fluorosurfactants with sulphonate, sulphate, phosphate or carboxylate groups being preferred .

Suitable anionic fluorinated surfactants include:

Suitable cationic fluorinated surfactants are:

Suitable amphoteric fluorinated surfactants are:

Polymerizable substance for primer composition

The at least one polymerizable substance selected from the group consisting of polyester acrylates, polyester methacrylates, polyurethane- and urea-based monomers used in the primer composition used m the process, according to the present invention, of itself, fails to delay the penetration of the crosslmkable composition into the security paper. However, surprisingly m combination with a sufficient concentration of an ionic fluorinated surfactant, unusable of itself due to the resulting poor adhesion between the cured crosslmkable composition and the security paper, a synergetic effect is realized m which the strike though of the crosslmkable composition is sufficiently delayed and solvent-resistance is

realized between the cured crosslmkable composition and the security paper.

According to a nineteenth embodiment of the process, according to the present invention, the polymeπzable polyurethane is selected from the group consisting of polyether urethanes, polyester urethanes, aliphatic polyurethanes, aromatic polyurethanes, urethane acrylates, urethane methacrylates, urethane/acrylic hybrids and urethane methacrylic hybrids.

The polymeπzable substance is preferably capable of co- polymerizing with the crosslmkable composition and possesses elasticity.

Suitable polymeπzable substances (PS) are given in the table below:

Information above the solids concentration, particle size, viscosity and possible co-solvent in these polymeπzable substances (PS) is given m the table below:

In general the larger the particle size of the polymeπzable substance the better the penetration prevention properties of the primer comprising the polymeπzable substance. However, rhis cannot solely be regarded as due to a purely physical blocking of the pores m the security paper, since poly (tetrafluoroethylene) particles with specific surface areas of 1.5 to 10 m ² /g (i.e. particle sizes m the range of (ca. 0.6 to 4 μm) different particle sizes were not found to possess penetration prevention properties [EXPERIMENT 25] .

UV-photoinitiators for primer composition or crosslmkable composition

According to a twentieth embodiment of the process, according to the present invention, the primer composition further comprises a UV-initiator .

According to a twenty-first embodiment of the process, according to the present invention, the crosslmkable composition comprises at least one initiator.

According to a twenty-second embodiment of the process, according to the present invention, the crosslinkable composition comprises at least one UV-initiator .

According to a twenty-third embodiment of the process, according to the present invention, the abhesive crosslinkable composition comprises at least one initiator.

According to a twenty-fourth embodiment of the process, according to the present invention, the abhesive crosslinkable composition comprises at least one UV-initiator. According to a twenty-fifth embodiment of the process, according to the present invention, the primer composition further comprises at least one UV-initiator selected from the group consisting of: benzoin, benzoin ethers, benzil, benzil ketal derivatives, α-dialkoxyacetophenones, α-hydroxy-alkyl-phenones, α- amino-alkyl-phenones, acyl-phosphine oxides, benzophenone, benzophenone derivatives, xanthones, amines, benzanthrone (BZA), thioxanthone derivatives, thioxanthone, thiotitanoces amines and Michler's Ketone derivatives 4 , 4' -bis (diethylamino) benzophenone (BEABP) . According to a twenty-sixth embodiment of the process, according to the present invention, the crosslinkable composition comprises at least one UV-initiator selected from the group consisting of: benzoin, benzoin ethers, benzil, benzil ketal derivatives, α-dialkoxyacetophenones, α-hydroxy-alkyl-phenones, α- amino-alkyl-phenones, acyl-phosphine oxides, benzophenone, benzophenone derivatives, xanthones, amines, benzanthrone (BZA), thioxanthone derivatives, thioxanthone, thiotitanoces amines and Michler's Ketone derivatives 4 , 4' -bis (diethylamino) benzophenone (BEABP) . According to a twenty-seventh embodiment of the process, according to the present invention, the abhesive crosslinkable composition comprises at least one UV-initiator selected from the group consisting of: benzoin, benzoin ethers, benzil, benzil ketal derivatives, α-dialkoxyacetophenones, α-hydroxy-alkyl-phenones, α- amino-alkyl-phenones, acyl-phosphine oxides, benzophenone, benzophenone derivatives, xanthones, amines, benzanthrone (BZA), thioxanthone derivatives, thioxanthone, thiotitanoces amines and Michler's Ketone derivatives 4 , 4' -bis (diethylamino) benzophenone (BEABP) . UV-photoinitiators suitable for use in the primer, crosslinkable and abhesive crosslinkable compositions of the present invention have to be compatible with a water-containing hydrophilic

environment and to have a UV-light absorption compatible with the UV- light source used. Moreover, UV-photoinitiators suitable for use m the compositions of the present invention preferably do not evaporate, sublime, decompose or substantially lose their activity in other ways upon subjection to a short drying/heating step e.g. upon heating for 3 minutes at 130°C.

According to a twenty-eighth embodiment of the process, according to the present invention, the at least one UV- photoinitiator used in at least one of the primer composition, the crosslinkable composition and the abhesive crosslmkable composition has a half-life of greater than 3 minutes when heated to 130°C.

Suitable UV-photoinitiators include both low molecular weight compounds and oligomers, such as the ESACURE® range of photoinitiators produced by Lamberti Spa. Furthermore, suitable UV- photoinitiators also include cationic and free radical UV- photoimtiators .

UV-photoinitiators suitable for use in the compositions of the present invention include:

Crosslinkable composition

According to a twenty-ninth embodiment of the process, according to the present invention, the crosslinkable composition comprises at least one initiator, at least one vmyl-monomer and at least one polyvinyl-monomer .

According to a thirtieth embodiment of the process, according to the present invention, the crosslinkable composition further comprises at least one surfactant.

According to a thirty-first embodiment of the process, according to the present invention, the crosslinkable composition further comprises at least one organic solvent.

According to a thirty-second embodiment of the process, according to the present invention, the at least one polyvinyl monomer is a divinyl monomer.

According to a thirty-third embodiment of the process, according to the present invention, the at least one vinyl-monomer is an acrylate or methacrylate .

According to a thirty-fourth embodiment of the process, according to the present invention, the at least one polyvinyl- monomer is a poly-acrylate monomer or a poly-methacrylate monomer.

According to a thirty-fifth embodiment of the process, according to the present invention, the crosslinkable composition comprises a combination of monomers, oligomers and/or prepolymers. The monomers, oligomers and/or prepolymers may possess different degrees of functionality, and a mixture including combinations of mono-, di-, tri- and higher functionality monomers, oligomers and/or prepolymers may be used.

The curable compound (s) used in the curable liquid for the method for preparing a tamperproof ID document according to the present invention can be any monomer and/or oligomer found in Polymer Handbook, Vol. 1 & 2, 4th edition. Edited by J. BRANDRUP, et al. Wiley-Interscience, 1999.

Suitable examples of monomers include: acrylic acid, meth- acrylic acid, maleic acid (or their salts), maleic anhydride; alkyl- (meth) acrylates (linear, branched and cycloalkyl) such as methyl- (meth) acrylate, n-butyl (meth) acrylate, tert-butyl (meth) acrylate, cyclohexyl (meth) acrylate and 2-ethylhexyl (meth) acrylate; aryl(meth)- acrylates such as benzyl (meth) acrylate and phenyl (meth) -acrylate; hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) -acrylate and hydroxypropyl (meth) acrylate; (meth) acrylates with other types of functionalities (e.g. oxirane, amino, polyethylene oxide, phosphate- substituted) such as glycidyl (meth) acrylate, dimethylaminoethyl- (meth) acrylate, methoxypolyethyleneglycol (meth) acrylate and tri- propyleneglycol (meth) acrylate phosphate; allyl derivatives such as allyl glycidyl ether; styrenics such as styrene, 4-methyl-styrene, 4-hydroxystyrene, and 4-acetoxystyrene; (meth) acrylonitrile; (meth)- acrylamides (including N-mono and N, N-disubstituted) such as

N-benzyl (meth) acrylamide; maleimides such as N-phenyl maleimide, N-benzyl maleimide and N-ethyl maleimide; vinyl derivatives such as vinylcaprolactam, vinylpyrrolidone, vinylimidazole, vinylnaphthalene and vinyl halides; vinylethers such as vinylmethyl ether; and vinylesters of carboxylic acids such as vinylacetate and vinylbutyrate .

Preferred monomers and oligomers are selected from 1,6-hexane- diol acrylate, alkoxylated aliphatic diacrylates, alkoxylated hexanediol diacrylate, alkoxylated neopentyl glycol diacrylate, di- ethylene glycol diacrylate, dipropyleneglycol diacrylate, ethoxy- lated(lθ) bisphenol A diacrylate, neopentyl glycol diacrylate, tri- ethylene glycol diacrylate, tripropylene glycol diacrylate, 2(2-

ethoxyethoxy) ethyl acrylate, isobornyl methacrylate, isobornyl acrylate, isodecyl acrylate, lauryl acrylate, tetrahydrofurfuryl acrylate, tridecyl acrylate, tridecyl methacrylate, ditπmethylol- propane tetraacrylate, dipentaerythπtol tetraacrylate, pentaeryth- πtol tetraacrylate, ethoxylated ( 15) trimethylolpropane triacrylate, dipentaerythritol triacrylate, tπmethylol-propane triacrylate, trimethylolpropane trimethacrylate, aliphatic urethane acrylates, amine modified polyether acrylate oligomers, aromatic urethane acrylates, epoxy acrylates and polyester acrylate oligomers. Suitable crosslinkable compositions (CC) include:

Suitable vinyl-monomers (VM) include:

Suitable polyvmyl-monomers (PVM) include:

Surfactants for crosslinkable composition

According to a thirty-sixth embodiment of the process, according to the present invention, the crosslinkable composition comprises at least one surfactant.

The surfactant (s) may be anionic, cationic, non-ionic, or zwitter-ionic and are usually added in a total quantity below 20 wt% based on the total curable liquid weight and particularly in a total below 10 wt% based on the total weight of the curable liquid. Suitable nonionic surfactants include:

Surfactant no. 01 = ZONYL® FSN, a 40% by weight solution of F (CF ₂ CF ₂ ) i_ 9CH ₂ CH ₂ O(CH ₂ CH ₂ O) _x H in a 50% by weight solution of isopropanol in water where x = 0 to about 25, from DuPont;

Surfactant no. 02 = ZONYL® FSN 100: F (CF ₂ CF ₂ ) i_ ₉ CH ₂ CH ₂ O (CH ₂ CH ₂ O) _X H where x = 0 to about 25, from DuPont;

Surfactant no. 03 = ZONYL® FS300, a 40% by weight aqueous solution of a fluorinated surfactant, from DuPont;

Surfactant no. 04 = ZONYL® FSO, a 50% by weight solution of F (CF ₂ CF ₂ ) _x _ 7CH ₂ CH ₂ O (CH ₂ CH ₂ O) _y H where y = 0 to ca . 15 in a 50% by wt . solution of ethylene glycol in water, from DuPont;

Surfactant no. 05 = ZONYL® FSO 100, a mixture of ethoxylated non- ionic fluoro-surfactant with the formula: F (CF ₂ CF ₂ ) ₁ -7CH ₂ CH ₂ O (CH ₂ CH ₂ O) ₇ H where y = 0 to ca . 15, from DuPont;

Surfactant no. 06 = TEGOGLIDE® 410, a polysiloxane-polymer copolymer surfactant, from Goldschmidt;

Surfactant no. 07 = TEGOWET®, a polysiloxane-polyester copolymer surfactant, from Goldschmidt;

Surfactant no. = FLUORAD® FC431: CF ₃ (CF ₂ )7SO ₂ (C ₂ H5)N-CH ₂ CO-(OCH ₂ CH ₂ ) _n OH from 3M;

Surfactant no. 09 = FLUORAD® FC126, a mixture of the ammonium salts of perfluorocarboxylic acids, from 3M;

Surfactant no. 10 = Polyoxyethylene-10-lauryl ether

A particularly preferred non-ionic surfactant is ZONYL® FSO 100. Suitable anionic surfactants include:

Surfactant no. 11 = ZONYL® 7950, a fluorinated surfactant, from

DuPont;

Surfactant no. 12 = ZONYL® FSA, 25% by weight solution of

F (CF ₂ CF ₂ ) _! - ₉ CH ₂ CH ₂ SCH ₂ CH ₂ COOLi in a 50% by weight solution of isopropanol in water, from DuPont;

Surfactant no. 13 = ZONYL® FSE, a 14% by weight solution of

[F (CF ₂ CF ₂ ) ₁ - ₇ CH ₂ CH ₂ O] _x P (O) (ONH ₄ ) _y where x = 1 or 2 ; y = 2 or 1; and x + y = 3 in a 70% by wt solution of ethylene glycol in water, from DuPont;

Surfactant no. 14 = ZONYL® FSJ, a 40% by weight solution of a blend of

F (CF ₂ CF ₂ ) _! -7CH ₂ CH ₂ O] _x P (O) (ONH ₄ ) _y where x = 1 or 2; y = 2 or 1; and x + y = 3 with a hydrocarbon

surfactant in 25% by weight solution of isopropanol in water, from DuPont;

Surfactant no. 15 = ZONYL® FSP, a 35% by weight solution of

[F(CF ₂ CF ₂ ) _I - _V CH ₂ CH ₂ O] _x P(O) (ONH ₄ ) _y where x = 1 or 2; y = 2 or 1 and x + y = 3 in 69.2% by weight solution of isopropanol in water, from DuPont;

Surfactant no. 16 = ZONYL® UR: [F (CF ₂ CF ₂ ) ₁ -7CH ₂ CH ₂ O] _X P (0) (OH) _y where x =

1 or 2; y = 2 or 1 and x + y = 3, from DuPont;

Surfactant no. 17 = ZONYL® TBS: a 33% by weight solution of F (CF ₂ CF ₂ ) ₃ _

_J3 CH ₂ CH ₂ SO ₃ H in a 4.5% by weight solution of acetic acid in water, from DuPont;

Surfactant no. 18 = Ammonium salt of perfluoro-octanoic acid;

Dispersion medium or solvent in crosslinkable composition

The dispersion medium or solvent in the crosslinkable composition may comprise monomers and/or oligomers and/or water and/or organic solvents, such as alcohols, fluorinated solvents and dipolar aprotic solvents.

However, the curable liquids preferably do not comprise an evaporable component, but, sometimes, it can be advantageous to incorporate an extremely small amount of an organic solvent in such inks to improve adhesion to the surface of the ink-receiver after UV curing. In this case, the added solvent can be any amount in the range that does not cause problems of solvent resistance and VOC, and preferably 0.1-5.0 wt%, and particularly preferably 0.1-3.0 wt%, each based on the total weight of the curable liquid.

Suitable organic solvents include alcohol, aromatic hydrocarbons, ketones, esters, aliphatic hydrocarbons, higher fatty acids, carbitols, cellosolves, higher fatty acid esters. Suitable alcohols include, methanol, ethanol, propanol and 1-butanol, 1- pentanol, 2-butanol, t.-butanol. Suitable aromatic hydrocarbons include toluene, and xylene. Suitable ketones include methyl ethyl ketone, methyl isobutyl ketone, 2, 4-pentanedione and hexafluoroacetone . Also glycol, glycolethers, N-methylpyrrolidone, N, N-dimethylacetamid, N, N-dimethylformamid may be used.

Fluorescent or phosphorescent compounds

According to a thirty-seventh embodiment of the process, according to the present invention, at least one of the primer composition, the crosslinkable composition and, if applicable, the

abhesive crosslinkable composition further comprises at least one luminescent entity e.g. a bead, fibre, particle or dye comprises at least one fluorescent compound or at least one phosphorescent compound to introduce additional security features. Luminescent beads and fibres are usually too large to be jettable. Examples of suitable UV-fluorescent and phosphorescent compounds include Tinopal™ grades such as Tinopal™ SFD, Uvitex™ grades such as Uvitex™ NFW and UVITEX™ OB from CIBA-GEIGY SPECIALTY CHEMICALS; LUMILUX™ luminescent pigments from HONEYWELL; KEYFLUOR™ dyes and pigments from KEYSTONE; Leukophor™ grades from CLARIANT; Blancophor™ grades such as Blancophor™ REU and Blancophor™ BSU from BAYER; and fluorescent dyes from SYNTHEGEN.

According to a thirty-eighth embodiment of the process, according to the present invention, at least one of the primer composition, the crosslinkable composition and, if applicable, the abhesive crosslinkable composition further comprises at least one fluorescent compound in a concentration of 0.1 to 20 wt% based on the total weight of the composition applicable, with 1 to 10 wt% being preferred.

Biocides

According to a thirty-ninth embodiment of the process, according to the present invention, the crosslinkable composition further comprises at least one biocide.

Suitable biocides for the curable liquid used in the method for preparing a tamperproof ID document according to the present invention include sodium dehydroacetate, 2-phenoxyethanol, sodium benzoate, sodium pyridinethion-1-oxide, ethyl p-hydroxybenzoate and 1 , 2-benzisothiazolin-3-one and salts thereof. A preferred biocide for the curable liquid is Proxel™ GXL available from ZENECA COLOURS.

A biocide is preferably added in an amount of 0.001 to 3 wt.%, more preferably 0.01 to 1.00 wt . %, each based on the curable liquid.

Abhesive crosslinkable composition

According to a fortieth embodiment of the process, according to the present invention, the crosslinkable composition is abhesive or the crosslinkable composition is printed or coated with an abhesive crosslinkable composition, wherein the abhesive crosslinkable composition further comprises at least one initiator, at least one

vinyl -monomer, at least one polyvmyl-monomer and at least one abherent agent.

Suitable abhesive crosslmkable compositions include "SCOTCHGARD®" Phototool Protector from 3M, which is a solvent-free, low-viscosity solution with the following composition:

3- (trimethoxysilyl) propyl glycidyl ether is the polymerizable abherent agent. This solution is mk-jettable, has a viscosity at 25°C of 11.4 mPa . s and a surface tension of 23.6 mN/m.

Abherent agents

The abherent agent used in the abhesive crosslmkable composition used in the process, according to the present invention, causes the outermost layer to have a difflcult-to-wet surface. This surface preferably has a surface energy of less than 28 mJ/m ² .

The abherent agent must be present in the cured outermost layer produced with the abhesive crosslmkable composition m a polymeric form otherwise it can be easily removed by wiping and using a strong organic solvent such as toluene or a chlorinated solvent. Low molecular weight fluorosurfactants are not suitable abherent agents m the present invention.

A single abherent agent or a mixture of abherent agents may be used as long as the abhesive properties of the outermost layer are obtained.

The abherent agent may be present m the abhesive crosslmkable composition as a polymerizable compound or as a polymeric abherent agent or a combination of both. Preferably the abherent agent is a silicone-modified or a fluormated polymerizable compound. The abherent agent is preferably exclusive of epoxysilanes modified with oxyalkylene ether groups.

According to a forty-first embodiment of the process, according to the present invention, the crosslmkable composition is abhesive or the crosslmkable composition is printed or coated with an

abhesive crosslinkable composition, wherein the abhesive crosslinkable composition further comprises at least one abherent agent selected from the group consisting of fluorinated (meth) acrylates and fluorinated ethylenes. According to a forty-second embodiment of the process, according to the present invention, the crosslinkable composition is abhesive or the crosslinkable composition is printed or coated with an abhesive crosslinkable composition, wherein the abhesive crosslinkable composition further comprises at least one polymeric abherent agent selected from the group consisting of a polytetrafluoroethylene, copolymers of fluorinated ethylene, polymers of fluorinated (meth) acrylates, copolymers of fluorinated (meth) acrylates, perfluoro (alkyl vinyl ether) s and polyvinylidene fluoride . According to a forty-third embodiment of the process, according to the present invention, the crosslinkable composition is abhesive or the crosslinkable composition is printed or coated with an abhesive crosslinkable composition, wherein the abhesive crosslinkable composition further comprises at least one polymeric abherent agent selected from the group consisting of polymers of fluorinated (meth) acrylates and copolymers of fluorinated (meth) acrylates , wherein the fluorinated (meth) acrylate is selected from the group consisting of 2, 2 , 2-trifluoroethyl-α-fluoroacrylate (TFEFA), 2,2,2-trifluoroethyl-methacrylate (TFEMA), 2,2,3,3- tetrafluoropropyl-α-fluoroacrylate (TFPFA), 2,2,3,3- tetrafluoropropyl-methacrylate (TFPMA) , 2,2,3,3, 3-pentafluoropropyl- α-fluoroacrylate (PFPFA) , 2,2,3,3, 3-pentafluoro-propyl-methacrylate (PFPMA), IH, lH-perfluoro-n-octyl acrylate, IH, lH-perfluoro-n-decyl acrylate, IH, lH-perfluoro-n-octyl methacrylate, IH, lH-perfluoro-n- decyl methacrylate, IH, IH, 6H, 6H-perfluoro-1, 6-hexanediol diacrylate, IH, IH, 6H, 6H-perfluoro-1, 6-hexanediol dimethacrylate, 2-(N- butylperfluorooctane-sulfonamido) -ethyl acrylate, 2- (N-ethyl perfluorooctanesulfonamido) ethyl acrylate, 2- (N-ethyl perfluoro- octanesulfonamido) ethyl methacrylate, C ₈ F ₁₇ CH ₂ CH ₂ OCH ₂ CH ₂ -OOC-CH=CH ₂ and C ₈ F ₁₇ CH ₂ CH ₂ OCH ₂ CH ₂ -OOC-C (CH ₃ ) =CH ₂ .

According to a forty-fourth embodiment of the process, according to the present invention, the crosslinkable composition is abhesive or the crosslinkable composition is printed or coated with an abhesive crosslinkable composition, wherein the abhesive crosslinkable composition further comprises an abherent agent selected from the group consisting of silicone-modified (meth) acrylates and epoxy-functional silane compounds, the epoxy-

functional silane compound being preferably selected from the group consisting of γ-glycidoxypropyl trimethoxysilane, γ-glycidoxypropyl triethoxysilane, β-glycidoxyethyl trimethoxysilane, γ- (3, 4-epoxy- cyclohexyl) propyl trimethoxysilane and β- (3, 4-epoxycyclohexyl) ethyl trimethoxysilane.

According to a forty-fifth embodiment of the process, according to the present invention, the crosslinkable composition is abhesive or the crosslinkable composition is printed or coated with an abhesive crosslinkable composition, wherein the abhesive crosslinkable composition further comprises a polymeric abherent agent selected from the group consisting of polymers of dimethylsiloxane acrylate, copolymers of dimethylsiloxane acrylate, dimethyl siloxane modified polyethers, polymers of silicone-modified (meth) acrylates, copolymers of silicone-modified (meth) acrylates, dimethyl siloxane modified polyesters, silicone glycol copolymers, polymers of epoxy-functional silane compounds and copolymers of epoxy-functional silane compounds, the epoxy-functional silane compound being selected from the group consisting of γ-glycidoxypropyl trimethoxysilane, γ-glycidoxypropyl triethoxysilane, β- glycidoxyethyl trimethoxysilane, γ- (3, 4-epoxycyclohexyl) propyl trimethoxysilane and β- (3, 4-epoxycyclohexyl) ethyl trimethoxysilane.

Abherent agents suitable as polymerizable compound constitute preferably from 20 to 99.6%, more preferably 24 to 90%, and most preferably 30 to 80% by weight of the total composition of the abhesive crosslinkable composition.

Abherent agents suitable as a polymerizable compound include silicone-modified (meth) acrylates, fluorinated (meth) acrylates, fluorinated ethylenes and epoxy-functional silane compounds.

Preferred silicone-modified acrylates include Ebecryl™ 350 (silicon diacrylate) and Ebecryl™ 1360 (silicon hexaacrylate) from UCB, Belgium; Actilane™ 800 (silicon acrylate) from AKZO-NOBEL NV; and CN990™ (siliconized urethane acrylate oligomer) from SARTOMER. Illustrative examples of suitable epoxy-silanes include γ- glycidoxypropyl trimethoxysilane, γ-glycidoxypropyl triethoxysilane, β-glycidoxyethyl trimethoxysilane, (- (3, 4-epoxycyclohexyl) propyl trimethoxysilane, β- (3, 4-epoxycyclohexyl) ethyl trimethoxysilane, and the like. The most preferred epoxy-silane compound is (- glycidoxypropyl trimethoxysilane .

Examples of suitable epoxy-silanes include (metha) acryl- oxyalkylalkoxysilanes such as (- (meth) acryloxypropyltrimethoxy- silane, (- (meth) acryloxypropyltriethoxysilane and (- (meth) acryloxy- propyl-triisopropoxysilane; (meth) acryloxyalkylalkoxyalkyl si lanes

such as (- (meth) acryloxypropylmethyldimethoxysilane and (-(meth)- acryl-oxypropylmethyldiethoxysilane; vinyltrimethoxysi lane, vinyltri-ethoxysilane, vinyltriisopropoxysilane, aryltriethoxy- silane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane and vinyltris (2-methoxyethoxy) silane .

The abherent agent present in the cured layer produced with the abhesive crosslinkable composition may be selected from the group consisting of polymers of dimethylsiloxane; copolymers of dimethylsiloxane; dimethyl siloxane-modified polyethers; dimethyl siloxane modified polyesters; silicone glycol copolymers; polymers of fluorinated ethylene such as polytetra-fluoroethylene, polyvinylfluoride and polyvinylidene fluoride (PVDF) ; copolymers of fluorinated ethylene such as a fluorinated ethylene/propylene copolymers and ethylene/tetrafluoroethylene copolymers; polymers of fluorinated (meth) acrylates; copolymers of fluorinated (meth) acrylates; and perfluoro (alkyl vinyl ether) s.

Curing means

According to a forty-sixth embodiment of the process, according to the present invention, at least one of the primer composition, the crosslinkable composition and if applicable the abhesive crosslinkable composition is cured by exposure to actinic radiation, by thermal curing and/or by electron beam curing. A preferred means of radiation curing is ultraviolet radiation. Preferably the curing is performed by an overall exposure to actinic radiation, by overall thermal curing and/or by overall electron beam curing.

The curing means may be arranged in combination with the print head of the ink-jet printer, travelling therewith so that the curable liquid is exposed to curing radiation very shortly after being jetted.

In such an arrangement it can be difficult to provide a sufficiently small radiation source connected to and travelling with the print head. Therefore, a static fixed radiation source may be employed, e.g. a source of curing UV radiation, connected to the radiation source by means of flexible radiation conductive means such as a fibre optic bundle or an internally reflective flexible tube .

Alternatively, the actinic radiation may be supplied from a fixed source to the radiation head by an arrangement of mirrors including a mirror upon the radiation head.

The source of radiation arranged not to move with the print head, may also be an elongated radiation source extending transversely across the ink-receiver surface to be cured and adjacent the transverse path of the print head so that the subsequent rows of images formed by the print head are passed, stepwise or continually, beneath that radiation source.

Any ultraviolet light source may be employed as a radiation source, such as, a high or low pressure mercury lamp, a cold cathode tube, a black light, an ultraviolet LED, an ultraviolet laser, and a flash light, if part of the emitted light can be absorbed by the photo-initiator or photo-initiator system. The preferred source is one exhibiting a relatively long wavelength UV-contribution having a dominant wavelength of 300-400 nm. Specifically, a UV-A light source is preferred due to the reduced light scattering therewith resulting in more efficient interior curing.

UV radiation is generally classed as UV-A, UV-B, and UV-C as follows :

• UV-A: 400 nm to 320 nm

• UV-B: 320 nm to 290 nm • UV-C: 290 nm to 100 nm.

According to a forty-seventh embodiment of the process, according to the present invention, at least one of the printed or coated primer composition, crosslinkable composition and, if applicable, abhesive crosslinkable composition is cured consecutively or simultaneously using two light sources of different wavelengths or illuminance. For example, the first UV source can be selected to be rich in UV-C, in particular in the range of 260 nm- 200 nm. The second UV source can then be rich in UV-A, e.g. a gallium-doped lamp, or a different lamp high in both UV-A and UV-B. The use of two UV sources has been found to be advantageous e.g. a fast curing speed.

For facilitating curing, the ink-jet printer often includes one or more oxygen depletion units. The oxygen depletion units place a blanket of nitrogen or other relatively inert gas (e.g. CO ₂ ), with adjustable position and adjustable inert gas concentration, in order to reduce the oxygen concentration in the curing environment. Residual oxygen levels are usually maintained as low as 200 ppm, but are generally in the range of 200 ppm to 1200 ppm.

Thermal curing can be performed image-wise by use of a thermal head, a heat stylus, hot stamping, a laser beam, etc. If a laser beam is used, then preferably an infrared laser is used in

combination with an infrared absorbing substance in the curable liquid .

Printing means

According to a forty-eighth embodiment of the process, according to the present invention, at least one of the primer composition, the crosslinkable composition and if applicable the abhesive crosslinkable composition is printed by a conventional printing process including but not restricted to ink-jet printing, intaglio printing, screen printing, flexographic printing, offset printing, stamp printing and gravure printing. In the case of ink- jet printing the curable liquid is jetted by one or more printing heads ejecting small droplets of liquid in a controlled manner through nozzles onto an ink-receiver surface, which is moving relative to the printing head(s) .

A preferred printing head for the ink-jet printing system according to the present invention is a piezoelectric head. Piezoelectric ink-jet printing is based on the movement of a piezoelectric ceramic transducer when a voltage is applied thereto. The application of a voltage changes the shape of the piezoelectric ceramic transducer in the printing head creating a void, which is then filled with ink. When the voltage is again removed, the ceramic expands to its original shape, ejecting a drop of ink from the print head. However the method for preparing a tamperproof ID document according to the present invention is not restricted to piezoelectric ink-jet printing. Other ink-jet printing heads can be used and include various types, such as a continuous type and thermal, electrostatic and acoustic drop on demand type. At high printing speeds, the liquid must be ejected readily from the printing heads, which puts a number of constraints on the physical properties of the ink, e.g. a low viscosity at the jetting temperature, which may vary from 25°C to 110°C, a surface energy such that the printing head nozzle can form the necessary small droplets, a homogenous liquid capable of rapid conversion to a dry printed area.

The viscosity of the curable liquid used in the ink-jet printing method according to the present invention is preferably lower than 30 mPa.s, more preferably lower than 15 mPa.s, and most preferably between 2 and 10 mPas at a shear rate of 100 s ^"1 and a jetting temperature between 10 and 55°C.

The ink-jet printing head normally scans back and forth in a transversal direction across the moving ink-receiver surface. Often the ink-jet print head does not print on the way back. Bidirectional printing is preferred for obtaining a high areal throughput. Particularly preferred, is printing in a "single pass printing process", which can be performed by using page wide ink-jet printing heads or multiple staggered ink-jet printing heads which cover the entire width of the ink-receiver surface. In a single pass printing process the ink-jet printing heads usually remain stationary and the ink-receiver surface is transported under the ink-jet printing heads.

Print

Aspects of the present invention are realized by a print comprising a security paper carrying a printed image on at least one side thereof, wherein said at least one printed image is provided with a primer composition comprising at least one ionic fluorinated surfactant and at least one polymerizable substance selected from the group consisting of polyester acrylates, polyester methacrylates, polyurethanes and urea-based monomers.

According to a first embodiment of the print, according to the present invention, the primer composition is provided between the security paper and the printed image. According to a second embodiment of the print, according to the present invention, the primer composition is provided over the printed image.

According to a third embodiment of the print, according to the present invention, the primer composition is curable. According to a fourth embodiment of the print, according to the present invention, the primer composition is cured.

According to a fifth embodiment of the print, according to the present invention, the primer composition is provided with a coating of a crosslinkable composition. According to a sixth embodiment of the print, according to the present invention, the crosslinkable composition is cured.

According to a seventh embodiment of the print, according to the present invention, the crosslinkable composition is abhesive.

According to an eighth embodiment of the print, according to the present invention, the primer composition is provided with a coating of a crosslinkable composition, which is itself provided with an abhesive crosslinkable composition.

According to a ninth embodiment of the print, according to the present invention, the primer composition is provided with a coating of a crosslinkable composition, which is itself provided with a cured abhesive crosslinkable composition. According to a tenth embodiment of the print, according to the present invention, the primer composition is provided with a coating of an abhesive crosslinkable composition or is provided with a coating of a crosslinkable composition, which is itself provided with an abhesive crosslinkable composition, wherein the abhesive crosslinkable composition further comprises at least one abherent agent selected from the group consisting of fluorinated (meth) acrylates and fluorinated ethylenes.

According to an eleventh embodiment of the print, according to the present invention, the primer composition is provided with a coating of an abhesive crosslinkable composition or is provided with a coating of a crosslinkable composition, which is itself provided with an abhesive crosslinkable composition, wherein the abhesive crosslinkable composition further comprises at least one polymeric abherent agent selected from the group consisting of a polytetrafluoro-ethylene, copolymers of fluorinated ethylene, polymers of fluorinated (meth) acrylates, copolymers of fluorinated (meth) acrylates, perfluoro (alkyl vinyl ether) s and polyvinylidene fluoride, the fluorinated (meth) acrylate being preferably selected from the group consisting of 2 , 2 , 2-trifluoroethyl-α-fluoroacrylate (TFEFA), 2, 2, 2-trifluoroethyl-methacrylate (TFEMA) , 2,2,3,3- tetrafluoropropyl-α-fluoroacrylate (TFPFA), 2,2,3,3- tetrafluoropropyl-methacrylate (TFPMA) , 2,2,3,3, 3-pentafluoropropyl- α-fluoroacrylate (PFPFA) , 2,2,3,3, 3-pentafluoropropyl-methacrylate (PFPMA), IH, lH-perfluoro-n-octyl acrylate, IH, lH-perfluoro-n-decyl acrylate, IH, lH-perfluoro-n-octyl methacrylate, IH, lH-perfluoro-n- decyl methacrylate, IH, IH, 6H, 6H-perfluoro-1 , 6-hexanediol diacrylate, IH, IH, 6H, 6H-perfluoro-1, 6-hexanediol dimethacrylate, 2- (N- butylperfluorooctanesulfonamido) ethyl acrylate, 2- (N-ethyl perfluorooctanesulfonamido) ethyl acrylate, 2- (N-ethyl perfluorooctanesulfonamido) ethyl methacrylate, C ₈ F ₁₇ CH ₂ CH ₂ OCH ₂ CH ₂ -OOC- CH=CH ₂ and C ₈ F ₁₇ CH ₂ CH ₂ OCH ₂ CH ₂ -OOC-C (CH ₃ ) =CH ₂ .

According to a twelfth embodiment of the print, according to the present invention, the primer composition is provided with a coating of an abhesive crosslinkable composition or is provided with a coating of a crosslinkable composition, which is itself provided with an abhesive crosslinkable composition, wherein the abhesive crosslinkable composition further comprises an abherent agent

selected from the group consisting of silicone-modified (meth) acrylates and epoxy-functional silane compounds, the epoxy- functional silane compound being preferably selected from the group consisting of γ-glycidoxypropyl trimethoxysilane, γ-glycidoxypropyl triethoxysilane, β-glycidoxyethyl trimethoxysilane, γ- ( 3, 4-epoxy- cyclohexyl) propyl trimethoxysilane and β- (3, 4-epoxycyclohexyl ) ethyl trimethoxysilane .

According to a thirteenth embodiment of the print, according to the present invention, the primer composition is provided with a coating of an abhesive crosslinkable composition or is provided with a coating of a crosslinkable composition, which is itself provided with an abhesive crosslinkable composition, wherein the abhesive crosslinkable composition further comprises a polymeric abherent agent selected from the group consisting of polymers of dimethylsiloxane acrylate, copolymers of dimethylsiloxane acrylate, dimethyl siloxane modified polyethers, polymers of silicone-modified (meth) acrylates, copolymers of silicone-modified (meth) acrylates, dimethyl siloxane modified polyesters, silicone glycol copolymers, polymers of epoxy-functional silane compounds and copolymers of epoxy-functional silane compounds, the epoxy-functional silane compound being preferably selected from the group consisting of γ- glycidoxypropyl trimethoxysilane, γ-glycidoxypropyl triethoxysilane, β-glycidoxyethyl trimethoxysilane, γ- ( 3 , 4-epoxycyclohexyl ) propyl trimethoxysilane and β- (3, 4-epoxycyclohexyl) ethyl trimethoxysilane. According to a fourteenth embodiment of the print, according to the present invention, the primer composition further comprises at least one luminescent entity.

According to a fifteenth embodiment of the print, according to the present invention, the primer composition is provided with a coating of a crosslinkable composition, which further comprises at least one luminescent entity.

According to a sixteenth embodiment of the print, according to the present invention, the primer composition is provided with a coating of an abhesive crosslinkable composition or is provided with a coating of a crosslinkable composition, which is itself provided with an abhesive crosslinkable composition, wherein the abhesive crosslinkable composition further comprises at least one luminescent entity.

Security documents

According to a first embodiment of the security document, according to the present invention, the surface of the outermost crosslmked or abhesive crosslmked composition has a surface energy of less than 28 mJ/m ² .

Applications

The security documents with improved tamper-proofmg realized with the process, according to the present invention, can be used for a wide variety of security applications including, but not limited to, bank notes, cheque forms, shares, certificates, postage stamps, air tickets, labels for product protection and identity documents ₌

The invention is illustrated hereinafter by way of COMPARATIVE EXAMPLES and INVENTION EXAMPLES without however being limited thereto. The percentages and ratios given in these examples are by weight unless otherwise indicated.

Papers used in the EXAMPLES:

The following nonionic fluorosurfactants were used in the comparative examples:

The following materials not disclosed above were used:

• Perenol™ S Konz., a solventless polysiloxane block copolymer surfactant from COGNIS.

Photocurable compositions:

PCC 01 (jettable with a Xaar UPH ink-jet printing head) :

SCOTCHGARD from 3M (sprayable and jettable with a Xaar UPH ink-jet printing head) with the composition:

Measurement methods used:

1. Adhesion:

The adhesion of a layer to the other layer or to the support was tested by using the cross-cut test pressing a 5 cm piece of Scotch Magic™ Tape 810 from 3M onto the sample and pulling it off with moderate force according to ASTM D3359-97 Test Method B. The test result was evaluated as:

A good adhesion of all layers to the security paper is required.

2. Solvent resistance:

Solvent resistance was evaluated by immersing the coated security paper m acetone for 24 hours at room temperature and then evaluating the adhesion as described above. The test result was evaluated as :

3. Gloss measurements:

Gloss was measured using a REFO 60 Reflektometer from Dr Lange which has a polished black glass tile for calibration purposes, the reflectometer being adjusted to 95 upon calibration with the polished black glass tile. The REFO 60 Reflectometer measures gloss using a beam of white light at an incident angle of 60 "according to DIN 67530 and ISO 2813.

EXAMPLES 1 to 17

EXAMPLES 1 to 17 report the evaluation of the penetration- prevention properties of different fluorosurfactants with different papers for the crosslmkable composition PCC 01 and for the abhesive crosslmkable composition: "SCOTCHGARD®" .

The fluorosurfactants used are given in Table 1 below. Different papers were coated with the surfactant solution, the surfactant solution was then dried in a drying cupboard for 1 minute at 60°C and finally the thereby coated papers were overcoated with a barcoater with the appropriate crosslmkable composition to a liquid thickness of 10 μm and then immediately UV-cured m a DRSE-120 conveyor from Fusion UV Systems Ltd with a VPS/1600 UV lamp (speed 20 m/mm, 50% UV power setting giving over a width of 20 cm and a length in the transport direction of 0.8 cm: a UV-A intensity of 1.176 W/cm2, a UVB intensity of 0.466 W/cm2 and a UVC intensity of 0.067 W/) . The UV-cuπng process was completed m less than 1 second. The results are summarized in Table 1 below:

Table 1:

These experiments show that with ionic fluorosurfactants such as AFS35 (Zonyl®FS610) , CFS06 (Zonyl®FSD), AFS36 (Zonyl®FSA) strike- through is not observed, although the adhesion of the crosslmked crosslmkable composition determined as described above was poor i.e. the adhesion with the security paper was poor. The other ionic fluorosurfactants AFS34 (Zonyl®FS62 ) , AFS41 (ZonylOTBS), AMFS06 (Zonyl®FS500) , AFS39 (Zonyl®FSP) and AFS29 (Zonyl®1033D) were not pursued further because of bleeding of the mk-jet images or the background security printing. It is clear, however, that none of the nonionic fluorosurfactants exhibited penetration-prevention properties .

EXAMPLE 18

In EXAMPLE 18 primer compositions comprising PSOl LAROMER®PE55WN) , a polymeπzable latex which of itself does not exhibit penetration-prevention properties, are described with different fluorosurfactants at a concentration of 2% by weight and a particular anionic fluorosurfactant, AFS35 (Zonyl®FS610 ) at different concentrations. Paper 1 was first barcoater-coated with the primer compositions of SAMPLES 1 to 33 given in Table 2 to a wet layer thickness of lOμm.

Table 2:

The primer composition coatings of Samples 1 to 33 were then dried in a drying cupboard for 1 minute at 60 ⁰ C, whereas the layers prepared with the compositions of Samples 2, 3, 7, 19, 23, 24, 26, 27 and 30-32 were evaluated both after drying and after drying and subsequent UV-exposure, whereas layers prepared with the compositions of Samples 1, 4-6, 8-18, 20-22, 25, 28, 29 and 33 were only evaluated after UV-exposure. UV-curing was carried out immediately after drying in a DRSE-120 conveyor from Fusion UV Systems Ltd with a VPS/1600 UV lamp (speed 20 m/min, 50% UV power setting giving over a width of 20 cm and a length in the transport direction of 0.8 cm: a UV-A intensity of 1.176 W/cm ² , a UVB intensity of 0.466 W/cm ² and a UVC intensity of 0.067 W/cm ² ) . The UV-curing process was completed in less than 1 second. Finally the primer composition coating was overcoated with a barcoater with the abhesive crosslinkable composition "SCOTCHGARD®" to a liquid thickness of lOμm and then immediately UV-cured in a DRSE-120 conveyor from Fusion UV Systems Ltd with a VPS/1600 UV lamp (speed 20 m/min, 50% UV power setting giving over a width of 20 cm and a length in the transport direction of 0.8 cm: a UV-A intensity of 1.176 W/cm ² , a UVB intensity of 0.466 W/cm ² and a UVC intensity of 0.067 W/cm ² ) . The UV-curing process was completed in less than 1 second. The adhesion and solvent resistance of the thereby

realized abhesive protective layers were determined as described above and the results given in Table 3.

Table 3:

* normal/white areas ** poor SCOTCHGARrøspreadmg

# poor primer composition spreading ## poor coating quality

The results of SAMPLES 1 to 33 show that a primer composition combining a polymeπzable latex with no penetration prevention properties with ionic fluorosurfactants with penetration prevention properties not only realizes a penetration preventing primer layer, but also a layer exhibiting good adhesion and solvent resistant properties after coating and UV-hardening with a UV-polymerizable composition. Furthermore, combination of a polymeπzable latex with no penetration prevention properties with nonionic fluorosurfactants with no penetration prevention properties resulted in layers with no penetration prevention properties.

Moreover, the spreading of the primer composition, the adhesion and the solvent resistance were acceptable for AFS35-concentrations between 1 and 2 wt% .

The influence of coating the primer of sample 8 to a wet layer thickness of lOμm upon Paper no. 02 (with coloured ink-jet printed images) with drying at 6O ⁰ C for 1 minute was investigated with a MacBeth RD918-SB densitometer with different filters in reflection on different parts of the ink-jet image with and without coating with the composition of SAMPLE 8 and the results are given m Table 4 below:

Table 4:

EXAMPLE 19 [Experiment 37]

In EXAMPLE 19 the influence of the wet layer thickness upon the strike-through of "SCOTCHGARD®" and the adhesion and solvent resistance of the UV-cured SCOTCHGARD®-protective layer was investigated for the primer composition of SAMPLE 8 of EXAMPLE 18 with Papers 3 and 4 both for non-UV-cured primer layers and primer layers UV-cured as described m EXAMPLE 18. Wet layer thicknesses of 4 to 30 μm were realized by barcoater-coatmg on both Papers 3 and 4 followed by drying and optional UV-cuπng as described for EXAMPLE 18. The thereby coated papers were overcoated with a barcoater with the abhesive crosslmkable composition "SCOTCHGARD®" to a liquid thickness of lOμm and then immediately UV-cured m a DRSE-120 conveyor from Fusion UV Systems Ltd with a VPS/1600 UV lamp (speed 20 m/mm, 50% UV power setting giving over a width of 20 cm and a length in the transport direction of 0.8 cm: a UV-A intensity of 1.176 W/cm ² , a UVB intensity of 0.466 W/cm ² and a UVC intensity of 0.067 W/cm ² ) . The UV-curmg process was completed in less than 1 second. The adhesion and solvent resistance of the thereby realized abhesive protective layers were determined as described above and the results given m Table 5. In a parallel experiment the strike- through time of the crosslmkable composition disclosed in Table 1 with the different primer compositions was evaluated by jetting a droplet of this crosslmkable composition on top of the previously dried and exposed primer compositions. The results of these experiments are also given m Table 5.

Table 5:

The results in Table 5 show that for the standard wet layer thickness of 10 μm the primer layer does not have to be UV-cured prior to the deposition of the crosslinkable composition in order to realize acceptable adhesion and solvent resistance of the UV-cured crosslinkable composition. However, it is also clear from these results that UV-curing of the primer composition significantly increases the strike-through time on Paper 3. These results also show that the primer composition is also effective with papers with much higher porosity than Paper 3, such as Paper 4.

EXAMPLE 20

In EXAMPLE 20 the influence of the wet layer thickness upon the strike-through of "PCC 01" was investigated with Paper 1 for the primer composition given in Table 6 below.

Table 6:

Wet layer thicknesses of 10, 20 and 50 μm were realized by barcoater-coating on Paper 1 followed by drying for 1 minute at 60°. The time between drying and barcoater-overcoating to a liquid thickness of lOμm with the crosslinkable composition "PCC 01" was not critical to the outcome of the experiment, but was typically 60 minutes. The time between overcoating with "PCC 01" and UV-curing in a DRSE-120 conveyor from Fusion UV Systems Ltd with a VPS/1600 UV lamp (speed 20 m/min, 50% UV power setting giving over a width of 20 cm and a length in the transport direction of 0.8 cm: a UV-A intensity of 1.176 W/cm ² , a UVB intensity of 0.466 W/cm ² and a UVC intensity of 0.067 W/cm ² ) was critical and was 10s. The UV-curing process was completed in less than 1 second.

The strike-through was evaluated on the samples by comparing the gloss of the paper coated with primer with that of the primer further coated with UV-hardened PCC 01 using a REFO 60 Reflectometer, since a UV-hardened PCC 01 layer is glossy the higher

the difference in gloss between the coated UV-hardened PCC 01 layer and the uncoated primer layer the lower the strike-through. The optical density of the backside of the paper coated with a primer layer measured m reflection with a MacBeth TR924 densitometer with a visible filter opposite to an area of applied UV-hardened PCC 01 and that without applied UV-hardened PCC 01 were compared with the optical density of Paper 1 of 0.20. The results for the different layer configurations are given in Table 7 below:

Table 7:

The degree of strike-though can be evaluated by the increase in gloss of the frontside of the UV-hardened PCC 01-coatmg and by a decrease in the OD of the backside opposite the UV-hardened PCC-01 coating. Reference values for the gloss in the event of no penetration prevention and total penetration protection can be obtained by applying a 10 μm thick wet coating of "PCC 01" to Paper 1 and to 60-65 μm thick glossy Scotch 309 transparent tape affixed to Paper 1 were found to be 4 and 64 respectively. It should be noted that a certain penetration is necessary to obtain good adhesion and hence the optimum gloss value will be significantly lower than 64.

Clearly the degree of strike-through decreased as the thickness of the primer layer increased with the highest gloss corresponding to the lowest degree of strike-through and the lowest increase m OD

on the backside being observed with SAMPLES 6 and 11 with theoretical primer layer thicknesses of 5.42 and 13.05 respectively.

EXAMPLE 21

In EXAMPLE 21 describes experiments in which the application of the ionic fluorosurfactant AFS35 and the polymerizable latex PSOl [LAROMER®PE55WN] in separate coatings is compared with a coating composition in which both components are combined. The compositions for the different coatings dispersions/solutions used in these experiments are given in Table 8 below:

Table

Compositions 1 and 3 and 2 and 3 were successively barcoater-coated on paper 1 at wet thicknesses of lOμm and then dried for 1 minute at 6O ⁰ C in a drying cupboard. Composition 4 was coated on paper 1 at a wet layer thickness of lOμm and then dried for 1 minute at 60°C in a drying cupboard. The coated papers were evaluated both after drying and after drying and subseguent UV-exposure. UV-curing was carried out immediately after drying in a DRSE-120 conveyor from Fusion UV Systems Ltd with a VPS/1600 UV lamp (speed 20 m/min, 50% UV power setting giving over a width of 20 cm and a length in the transport direction of 0.8 cm: a UV-A intensity of 1.176 W/cm ² , a UVB intensity of 0.466 W/cm ² and a UVC intensity of 0.067 W/cm ² ) . The UV-curing process was completed in less than 1 second.

Finally the primer composition coating was overcoated with a barcoater with the abhesive crosslinkable composition "SCOTCHGARD®" to a liquid thickness of lOμm and then immediately UV-cured in a DRSE-120 conveyor from Fusion UV Systems Ltd with a VPS/1600 UV lamp (speed 20 m/min, 50% UV power setting giving over a width of 20 cm and a length in the transport direction of 0.8 cm: a UV-A intensity of 1.176 W/cm ² , a UVB intensity of 0.466 W/cm ² and a UVC intensity of 0.067 W/cm ² ) . The UV-curing process was completed in less than 1 second. The adhesion and solvent resistance of the thereby

realized abhesive protective layers were determined as described above and the results given in Table 9.

Table 9:

The results in Table 9 show that a primer layer without strike- though and with adhesion after curing is only possible by applying an ionic fluorosurfactant and a polymerizable latex m the same composition .

EXAMPLES 22 to 32

In EXAMPLES 22 to 32 primer compositions of PSOl (LAROMER PE55WN) with alternative surfactants were investigated with Paper 1 A standard primer composition was used with the composition given below in Table 10 below;

Table 10:

The surfactants used in EXAMPLES 22 to 32 together with the supplier, type and structure are given in Table 11. The 11 surfactants screened represent all the main classes of surfactants excluding fluorosurfactants .

Table 11:

Paper 1 was barcoater-coated with the primer composition of Table 10 to a wet layer thickness of 10μm with 11 different surfactants, the coatings dried for 1 minute at 60 ⁰ C and part of the coated paper was exposed in a DRSE-120 conveyor from Fusion UV Systems Ltd with a VPS/1600 UV lamp (speed 20 m/mm, 50% UV power setting giving over a width of 20 cm and a length in the transport direction of 0.8 cm: a UV-A intensity of 1.176 W/cm ² , a UVB intensity of 0.466 W/cm ² and a UVC intensity of 0.067 W/cm ² ) giving EXAMPLES 22 to 32 m two variants.

The primer composition coated areas on the Paper 1 samples were then overcoated with a barcoater with the abhesive crosslmkable composition "SCOTCHGARD®" to a liquid thickness of lOμm and then immediately UV-cured in a DRSE-120 conveyor from Fusion UV Systems Ltd with a VPS/1600 UV lamp (speed 20 m/mm, 50% UV power setting giving over a width of 20 cm and a length m the transport direction of 0.8 cm: a UV-A intensity of 1.176 W/cm ² , a UVB intensity of 0.466 W/cm ² and a UVC intensity of 0.067 W/cm ² ) . The UV-curing process was completed in less than 1 second. The strike-through of EXAMPLES 22 to 32 was evaluated both primer layers exposed to UV-irradiation and non-exposed to UV-radiation and the strike through time determined. The results together with an evaluation of the spreading of the primer coatings are given m Table 12.

Table 12 :

The results m Table 12 show that primer compositions with PSOl (Laromer®PEWN55) with surfactants other than ionic fluorosurfactants were unable to prevent penetration by the UV-hardenable composition "SCOTCHGARD".

EXAMPLES 33 and 34

In EXAMPLE 33 and 34 SAMPLES 1 and 8 of EXAMPLE 18 were repeated with PS02 (Laromer PE 22WN) instead of PSOl (Laromer PE 55WN) with Paper 1. After barcoater-coatmg the primer compositions to a wet layer thickness of lOμm on Paper 1, the coatings were dried m a drying cupboard for 1 minute at 60 ⁰ C and then immediately UV- cured m a DRSE-120 conveyor from Fusion UV Systems Ltd with a VPS/1600 UV lamp (speed 20 m/mm, 50% UV power setting giving over a width of 20 cm and a length m the transport direction of 0.8 cm: a UV-A intensity of 1.176 W/cm ² , a UVB intensity of 0.466 W/cm ² and a UVC intensity of 0.067 W/cm ² ) . The UV-curmg process was completed in less than 1 second.

Finally the primer composition coating was overcoated with a barcoater with the abhesive crosslinkable composition "SCOTCHGARD®" to a liquid thickness of lOμm and then immediately UV-cured m a DRSE-120 conveyor from Fusion UV Systems Ltd with a VPS/1600 UV lamp (speed 20 m/mm, 50% UV power setting giving over a width of 20 cm and a length in the transport direction of 0.8 cm: a UV-A intensity of 1.176 W/cm ² , a UVB intensity of 0.466 W/cm ² and a UVC intensity of

0.067 W/cm ² ) . The UV-curing process was completed m less than 1 second. The adhesion and solvent resistance of the thereby realized abhesive protective layers were determined as described above and the results given in Table 13. In a parallel experiment the strike-through time of "SCOTCHGARD®" with the different primer compositions was evaluated by jetting a droplet of "SCOTCHGARD®" on top of the previously dried and exposed primer compositions. The results of these experiments are also given in Table 13.

Table 13:

The spreading of the primer composition, the adhesion and the solvent resistance were acceptable at a AFS35-concentration of 2 wt% .

EXAMPLE 35

In EXAMPLE 35 describes an evaluation of the use of PS03 (SUPERFLEX®E4000) with and without AFS35 with Paper 1 in primer compositions to prevent strike-through of UV-polymerizable compositions. The compositions used in this evaluation are given in Table 14 below.

Table 14:

After barcoater-coating the primer compositions to a wet layer thickness of lOμm on Paper 1, the coatings were dried in a drying cupboard for 1 minute at 60 °C and then immediately UV-cured in a DRSE-120 conveyor from Fusion UV Systems Ltd with a VPS/1600 UV lamp (speed 20 m/min, 100% UV power setting giving over a width of 20 cm and a length in the transport direction of 0.8 cm: a UV-A intensity of 4.310 W/cm ² , a UVB intensity of 1.071 W/cm ² and a UVC intensity of 0.120 W/cm ² ) . The UV-curing process was completed in less than 1 second.

The primer composition coating was then overcoated with a barcoater with the abhesive crosslinkable composition "SCOTCHGARD®" to a liquid thickness of lOμm and then immediately UV-cured in a DRSE-120 conveyor from Fusion UV Systems Ltd with a VPS/1600 UV lamp (speed 20 m/min, 50% UV power setting giving over a width of 20 cm and a length in the transport direction of 0.8 cm: a UV-A intensity of 4.310 W/cm ² , a UVB intensity of 1.071 W/cm ² and a UVC intensity of 0.120 W/cm ² ) . The UV-curing process was completed in less than 1 second. The adhesion and solvent resistance of the thereby realized abhesive protective layers were determined as described above and the results given in Table 14.

The competition between coalescence and Paper 1 penetration was clearly shifted to Paper 1 penetration by diluting the Superflex E4000 dispersion and adding 2 wt% Zonyl FS610 to realize acceptable spreading of the primer composition, acceptable spreading of "SCOTCHGARD®" on the cured primer composition, acceptable adhesion and acceptable solvent resistance with concentrations of the PS03 of 2 to 31 wt% in association with 2 wt% AFS35.

EXAMPLE 36 to

In EXAMPLES 36 to 81 primer compositions with the alternative polymerizable substances PS04 to PS12 (for further information see "Polymerizable substance" section) were evaluated in the

compositions given m Table 15 i.e. with and without 2wt% AFS35 (Zonyl FS610) and with Paper 1.

Table 15:

The primer compositions were barcoater-coated to a wet thickness of 10 μm and the layers dried in a drying cupboard for 1 minute at 60 ⁰ C and then immediately UV-cured m a DRSE-120 conveyor from Fusion UV Systems Ltd with a VPS/1600 UV lamp (speed 20 m/min, 100% UV power setting giving over a width of 20 cm and a length in the transport direction of 0.8 cm: a UV-A intensity of 4.310 W/cm ² , a UVB intensity of 1.071 W/cm ² and a UVC intensity of 0.120 W/cm ² ) . The UV-curing process was completed m less than 1 second.

The primer composition coating was then overcoated with a barcoater with the abhesive crosslmkable composition "SCOTCHGARD®" to a liquid thickness of lOμm and then immediately UV-cured in a DRSE-120 conveyor from Fusion UV Systems Ltd with a VPS/1600 UV lamp (speed 20 m/mm, 50% UV power setting giving over a width of 20 cm and a length in the transport direction of 0.8 cm: a UV-A intensity of 4.310 W/cm ² , a UVB intensity of 1.071 W/cm ² and a UVC intensity of 0.120 W/cm ² ) . The UV-curing process was completed m less than 1 second.

The adhesion and solvent resistance of the thereby realized abhesive protective layers were determined as described above and the results given m Table 16. In a parallel experiment the strike- through time of the photocurable composition PCC 01 with the different primer compositions was evaluated by jetting a droplet of PCC 01 on top of the previously dried and exposed primer

compositions and without a primer composition, The results of these experiments are also given m Table 16.

Table 16:

EXAMPLE PS nr ComposAFS strike- AdhesSolvent nr ition nr. 35 through ion resistance

36 (INV) Plex 6852-0 PS04 1 (50%) yes no ok ok

37 (COMP) Plex 6852-0 PS04 2 (50%) no yes

38 (INV) Plex 6852-0 PS04 9 (10%) yes no ok 10 (10%) yes no ok ok

39 (INV) Ucecoat DW5460 PS05 1 (40%) yes no ok ok

40 (COMP) Ucecoat DW5460 PS05 2 (40%) no yes

41 (COMP) Ucecoat DW5460 PS05 2 (40%) no no sprayed

42 (INV) Ucecoat DW5568# PS06 1 (42%) yes no ok ok

43 (COMP) Ucecoat DW5568 PS06 2 (42%) no no ok not ok

44 (COMP) Ucecoat DW5568 PS06 2 (42%) no no sprayed

45 (COMP) Ucecoat DW7770# PS07 1 (35%) yes m some not ok areas

46 (COMP) Ucecoat DW7770 PS07 2 (35%) no yes -

47 (COMP) Ucecoat DW7770 PS07 2 (35%) no no sprayed

48 (COMP) Ucecoat DW7770# PS07 9(C ₂ H ₅ OH) yes no ok ok (7%)

49 (COMP) Ucecoat DW7770# PS07 10 (C ₂ H ₅ OH) no no ok ok (7%)

50 (COMP) Ucecoat DW7770# PS07 11 (C ₂ H ₅ OH) yes almost ok ok (3.5%) all over

51 (INV) Ucecoat DW7772# PS08 1 (40%) yes no ok not ok

52 (COMP) Ucecoat DW7772 PS08 2 (40%) no no ok not ok

53 (INV) Ucecoat DW7772# PS08 3 (30%) yes no ok not ok

54 (INV) Ucecoat DW7772# PS08 5(20%) yes no ok not ok

55 (INV) Ucecoat DW7772# PS08 7 (10%) yes in some ok not ok areas

56 (INV) Ucecoat DW7772# PS08 9 (8%) yes yes Ucecoat DW7772# PS08 9 (8%) yes no ok not ok

57 (COMP) Ucecoat DW7772# PS08 10 (8%) no yes

58 (COMP) Actilane 650# PS09 1 (40%) yes

59 (COMP) Actilane 650 PS09 2 (40%) no no ok no ok

60 (INV) Actilane 650# 9(8%) yes almost all over

61 (COMP) Actilane 650# PS09 10(8%) no yes

62 (INV) Cytec HA630# PSlO 1 (30%) yes no ok not ok

63 (COMP) Cytec HA630 PSlO 2 (30%) no no ok not ok

primer applied by mk-jet # plus 7wt% Initiator 16

For the polymeπzable substances PS04, PS05, PS07 to PSlO, PS13 and PS15 strike-through was observed in the absence of AFS35. Moreover, is the case of PS06 there was a clear reduction of solvent resistance m the absence of AFS35. However, m the cases of PSIl and PS12 no differentiation in primer behaviour was found between primer compositions containing AFS35 and primer compositions not containing AFS35. With the compositions evaluated with PS08 to PSIl no acceptable solvent resistance was observed, although this is simply a case of finding the optimum concentrations of polymeπzable substance and ionic fluorosurfactant . Therefore, primers comprising polymerizable substances such as (poly) urethanes (e.g. PS05 to PS12), urea-based monomers (e.g. PS04), acrylates (e.g. PS13 and PS15) in combination with an ionic fluorosurfactant such as AFS35 substantially prevent penetration by UV-hardenable compositions, thereby enabling local protection of personalization information without the risk of delamination.

EXAMPLE 82

In EXAMPLE 82 primer compositions with the polymerizable substances PSOl, PS14, PS16 and PS17 (for further information see "Polymerizable substance" section) were evaluated with Paper 1 in the compositions with different concentrations of AFS35 (Zonyl® FS610) and polymerizable substance given in Table 17 below.

Table 17:

The compositions were barcoater-coated at a wet layer thickness of 20 and 50 μm on Paper 1 followed by drying for 1 minute at 60°. The time between drying and barcoater overcoating to a liquid thickness of lOμm with the crosslinkable composition "PCC 01" was not critical to the outcome of the experiment, but was typically 60 minutes. The time between overcoating with "PCC 01" and UV-curing in a DRSE-120 conveyor from Fusion UV Systems Ltd with a VPS/1600 UV lamp (speed 20 m/min, 50% UV power setting giving over a width of 20 cm and a length in the transport direction of 0.8 cm: a UV-A intensity of 1.176 W/cm ² , a UVB intensity of 0.466 W/cm ² and a UVC intensity of 0.067 W/cm ² ) was critical and was 10s. The UV-curing process was completed in less than 1 second.

The strike-through was evaluated on the samples by comparing the gloss of the paper coated with primer with that of the primer further coated with UV-hardened PCC 01 using a REFO 60 Reflectometer . Since a UV-hardened PCC 01 layer is glossy the higher the difference in gloss between the coated UV-hardened PCC 01 layer and the uncoated primer layer the lower the strike-through. The optical density of the backside of the paper coated with a primer layer measured in reflection with a MacBeth TR924 densitometer with a visible filter opposite to an area of applied UV-hardened PCC 01 and that without applied UV-hardened PCC 01 were compared with the

optical density of Paper 1 of 0.20. The results for the different layer configurations are given in Table 18 below:

Table 18:

The degree of strike-though can be evaluated by the increase in gloss of the frontside of the UV-hardened PCC 01-coatmg and by a decrease in the OD of the backside opposite the UV-hardened PCC-01 coating. Reference values for the gloss m the event of no penetration prevention and total penetration protection can be obtained by applying a 10 μm thick wet coating of "PCC 01" to Paper 1 and to 60 to 65 μm thick glossy Scotch 309 transparent tape affixed to Paper 1 were found to be 4 and 64 respectively. It should be noted that a certain penetration is necessary to obtain good adhesion and hence the optimum gloss value will be significantly lower than 64.

Clearly with the exception of PS17 there was total strike- through m the absence of AFS35. With PS17 at a concentration of 24 wt % and a theoretical dry layer thickness of 5.31 μm was sufficient in the absence of AFS35 to avoid substantial strike-through, as seen from the high gloss observed and the low increase in OD expressed as (D on the backside, but total avoidance of strike-through required 2 wt% AFS35. Furthermore, in the case of FS 14 an AFS35-concentration of 4 wt% was necessary to avoid substantial strike-through, whereas for FSOl, FS16 and FS17 an AFS35-concentration of 2 wt% was sufficient to avoid stπke- through.

Clearly the degree of strike-through decreased as the thickness of the primer layer increased with the highest gloss corresponding to the lowest degree of strike-through and the lowest increase m OD on the backside being observed with SAMPLES 6 and 11 with 5 theoretical primer layer thicknesses of 5.42 and 13.05 respectively.

Therefore, primers comprising polymeπzable substances such as acrylates (e.g. PSOl) and (poly) urethanes (e.g. PS14, PS16 and PS17) in combination with an ionic fluorosurfactant such as AFS35 substantially prevent penetration by UV-hardenable compositions, io thereby enabling local protection of personalization information without the risk of delammation.

EXAMPLE 83

15 In EXAMPLE 83 primer compositions with the polymerizable substances PSOl, PSIl and PS12 (for further information see "Polymerizable substance" section) were evaluated with Paper 1 in the compositions given m Table 17 below with and without 2wt% of AFS35 (Zonyl®FS610 ) and with the polymerizable substance at a solids

20 concentration of ca. 9.5 wt% .

Table 19:

The compositions were barcoater-coated at a wet layer thickness of 25 50 μm on Paper 1 followed by drying for 1 minute at 60°. The time between drying and barcoater overcoating to a liquid thickness of lOμm with the crosslmkable composition "PCC 01" was not critical to the outcome of the experiment, but was typically 60 minutes. The time between overcoating with "PCC 01" and UV-cunng m a DRSE-120 30 conveyor from Fusion UV Systems Ltd with a VPS/1600 UV lamp (speed 20 m/mm, 50% UV power setting giving over a width of 20 cm and a length in the transport direction of 0.8 cm: a UV-A intensity of 1.176 W/cm ² , a UVB intensity of 0.466 W/cm ² and a UVC intensity of 0.067 W/cm ² ) was critical and was 10s. The UV-cunng process was 35 completed in less than 1 second.

The strike-through was evaluated on the samples by comparing the gloss of the paper coated with primer with that of the primer further coated with UV-hardened PCC 01 using a REFO 60 Reflectometer Since a UV-hardened PCC 01 layer is glossy the higher the difference in gloss between the coated UV-hardened PCC 01 layer and the uncoated primer layer the lower the strike-through. The optical density of the backside of the paper coated with a primer layer measured m reflection with a MacBeth TR924 densitometer with a visible filter opposite to an area of applied UV-hardened PCC 01 and that without applied UV-hardened PCC 01 were compared with the optical density of Paper 1 of 0.20. The results for the different layer configurations are given in Table 20 below:

Table 20:

The degree of strike-though can be evaluated by the increase m gloss of the frontside of the UV-hardened PCC 01-coatmg and by a decrease in the (OD of the backside opposite the UV-hardened PCC-01 coating. Reference values for the gloss in the event of no penetration prevention and total penetration protection can be obtained by applying a 10 μm thick wet coating of "PCC 01" to Paper 1 and to 60 to 65 μm thick glossy Scotch 309 transparent tape affixed to Paper 1 were found to be 4 and 64 respectively. It should be noted that a certain penetration is necessary to obtain good adhesion and hence the optimum gloss value will be significantly lower than 64.

The OD was lower and hence the strike through was lower for compositions with 2wt% of AFS35 than for compositions with the same latexes without AFS35. However, total strike-through was observed in the absence of AFS35 in the case of PSOl, whereas in the cases of PSlI and PS12 only partial strike-through was observed judging from the gloss values of 36.3 and 40.4 respectively. Moreover, whereas the degree of strike-through was much lower for compositions with

AFS35 in the case of PS12 (Witcobond 315-40), this was not the case for PSIl (Witcobond 233-22) .

Having described in detail preferred embodiments of the current invention, it will now be apparent to those skilled in the art that numerous modifications can be made therein without departing from the scope of the invention as defined in the following claims.

All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

The use of the terms "a" and "an" and "the" and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Of course, variations of those preferred embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.