US20120103545A1 - Laser-markable substrate, and associated manufacturing method - Google Patents

Laser-markable substrate, and associated manufacturing method Download PDF

Info

Publication number
US20120103545A1
US20120103545A1 US13/256,108 US201013256108A US2012103545A1 US 20120103545 A1 US20120103545 A1 US 20120103545A1 US 201013256108 A US201013256108 A US 201013256108A US 2012103545 A1 US2012103545 A1 US 2012103545A1
Authority
US
United States
Prior art keywords
substrate
laser
antitampering
agent
mark
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US13/256,108
Inventor
Sandrine Rancien
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ArjoWiggins Security SAS
Original Assignee
ArjoWiggins Security SAS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ArjoWiggins Security SAS filed Critical ArjoWiggins Security SAS
Assigned to ARJOWIGGINS SECURITY reassignment ARJOWIGGINS SECURITY ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: RANCIEN, SANDRINE
Publication of US20120103545A1 publication Critical patent/US20120103545A1/en
Abandoned legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
    • B41M3/00—Printing processes to produce particular kinds of printed work, e.g. patterns
    • B41M3/14—Security printing
    • B41M3/142—Security printing using chemical colour-formers or chemical reactions, e.g. leuco-dye/acid, photochromes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
    • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
    • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
    • D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
    • D21H21/40—Agents facilitating proof of genuineness or preventing fraudulent alteration, e.g. for security paper
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
    • D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
    • D21H21/40—Agents facilitating proof of genuineness or preventing fraudulent alteration, e.g. for security paper
    • D21H21/44—Latent security elements, i.e. detectable or becoming apparent only by use of special verification or tampering devices or methods
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
    • D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
    • D21H21/40—Agents facilitating proof of genuineness or preventing fraudulent alteration, e.g. for security paper
    • D21H21/44—Latent security elements, i.e. detectable or becoming apparent only by use of special verification or tampering devices or methods
    • D21H21/46—Elements suited for chemical verification or impeding chemical tampering, e.g. by use of eradicators
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
    • D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
    • D21H21/40—Agents facilitating proof of genuineness or preventing fraudulent alteration, e.g. for security paper
    • D21H21/44—Latent security elements, i.e. detectable or becoming apparent only by use of special verification or tampering devices or methods
    • D21H21/48—Elements suited for physical verification, e.g. by irradiation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
    • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
    • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
    • B41M5/267—Marking of plastic artifacts, e.g. with laser

Definitions

  • the present invention relates to the field of laser-markable substrates, especially to security documents, in particular to security paper, and inter alia relates to a substrate yielding a colored mark under laser irradiation and the associated manufacturing method.
  • paper is understood to mean any sheet obtained by wet processing using a suspension of natural cellulose fibers and/or mineral fibers and/or plant or organic fibers other than cellulose fibers, optionally synthetic fibers, possibly containing various fillers and various additives commonly used in papermaking.
  • laser marking for example marking with an infrared laser, especially a CO 2 laser, a YAG (yttrium aluminum garnet) laser or else an Nd:YAG (neodymium-doped yttrium aluminum garnet) laser.
  • an infrared laser especially a CO 2 laser, a YAG (yttrium aluminum garnet) laser or else an Nd:YAG (neodymium-doped yttrium aluminum garnet) laser.
  • the laser marking of a standard paper substrate leads to low-contrast marks, generally having a yellow or brownish color, associated with the carbonization of the substrate during marking.
  • laser-sensitive materials such as mineral fillers, inorganic pigments including conductive pigments and/or variable optical-effect pigments such as pearl-luster silicates sold especially under the name Lazerflair® (LS range) by Merck.
  • Patent application US 2006/0090868 describes a fibrous laser-markable substrate comprising 1 to 5% absorbent materials in the form of inorganic platelets based on pearl-luster conductive pigments.
  • laser-sensitive materials based on conductive pigments, or especially variable-optical-effect or interference-effect pigments substantially improve the contrast of the marking (increasing the optical density), they do not enable the dark marking, especially the black marking, required for automatic optical recognition of marks, for example such as barcodes.
  • compositions comprising laser-sensitive materials of different nature have been developed by various companies.
  • compositions sold by Datalase under the trade name Packmark®, by Ciba under the trade name Pergamark® or else by Fujifilm Hunt Chemicals under the trade name Codestream® are known. These compositions are coated locally onto a substrate, especially a paper, and make it possible to obtain a gray or black marking on the coated substrate after laser irradiation of the coated region.
  • These compositions comprise for example a binder and an oxyanion of a multivalent metal, such as that provided in patent application WO 02/074548.
  • These compositions may also be carbohydrate-based.
  • compositions are costly to implement, especially because they must be locally applied to the substrate to be marked using an off-line method such as printing. Furthermore, these compositions are not and cannot be adapted to an on-line implementation, especially during manufacture of the paper, for example for the following reasons:
  • Patent application DE 102 32 786 describes a laser-markable material that makes it possible to obtain a marking in relief that provides a tactile effect.
  • Patent applications WO 99/16625, WO 98/48398, EP 0 308 904 and FR 2 496 936 provide in particular tamper-resistant substrates comprising laser-markable materials.
  • the markings created on said substrates are supposed to be tamper-resistant, in particular mechanically and chemically indelible.
  • a laser-markable substrate i.e. a substrate yielding a colored mark under laser irradiation, having a composition that is optimized so as to enable on-line incorporation, in particular in a paper machine, of laser-sensitive materials.
  • the invention aims to meet all or some of these needs.
  • One subject of the invention is thus a laser-markable substrate comprising at least one material able under laser irradiation to form a colored mark, and at least one antitampering agent producing a visible coloration, especially an irreversible visible coloration, when an attempt is made to chemically remove the mark, making it possible to detect said removal attempt.
  • the mark and/or the coloration may for example be visible, especially to the naked eye or using an optical magnifying device, whether under normal (visible), infrared (IR) and/or ultraviolet (UV) light.
  • the mark and/or the coloration may for example form a spot or blotch, characters, for example such as an ideogram or alphanumeric signs, a symbol, an image, an acronym, a word or a code.
  • the antitampering agent may for example be incorporated into or on the substrate during its manufacture.
  • the substrate for example by mixing it into the fibrous suspension in the case of a paper substrate or into the plastic material intended to be extruded or injection-molded in the case of a plastic substrate;
  • the antitampering agent may be incorporated on-line or off-line. Preferably it is incorporated on-line during manufacture of the substrate.
  • the antitampering agent may for example be incorporated over the entire area of the substrate or locally, for example in a continuous band or in a particular pattern.
  • the antitampering agent may for example make it possible to prevent chemical removal of the mark, produced by laser irradiation of the substrate, using at least one of the following compounds:
  • the antitampering agent may make it possible to prevent chemical removal of the mark, produced by laser irradiation of the substrate, using oxidizing agents, for example such as sodium hypochlorite.
  • oxidizing agents for example such as sodium hypochlorite.
  • the antitampering agent may be chosen from the following compounds:
  • the antitampering agent may make it possible to prevent chemical removal of the mark, produced by laser irradiation of the substrate, using strong bases, for example such as caustic soda, and/or weak bases such as for example sodium carbonate.
  • strong bases for example such as caustic soda, and/or weak bases such as for example sodium carbonate.
  • weak bases such as for example sodium carbonate.
  • the antitampering agent may be chosen from the following compounds:
  • colored indicators such as para-nitrophenol, phenolphthalein, pyranine or a xanthene derivative.
  • the antitampering agent may make it possible to prevent chemical removal of the mark, produced by laser irradiation of the substrate, using strong acids, for example such as sulfuric acid, and/or weak acids such as for example oxalic acid.
  • strong acids for example such as sulfuric acid, and/or weak acids such as for example oxalic acid.
  • the antitampering agent may be chosen from the following compounds:
  • the antitampering agent may make it possible to prevent chemical removal of the mark, produced by laser irradiation of the substrate, using polar solvents, for example such as ethanol, and/or nonpolar solvents such as for example toluene.
  • polar solvents for example such as ethanol
  • nonpolar solvents such as for example toluene
  • the antitampering agent may be chosen from dyes that are insoluble in water but soluble in oils and solvents. These dyes are especially used in the dyeing of petroleum derivatives.
  • the antitampering agent may be compatible with the adhesives used for labels, protective films or stamps.
  • the antitampering agent of said substrate is compatible with the adhesive of said adhesive substrate.
  • the antitampering agent is compatible with the adhesive of a label, a protective film, especially protecting the information-containing pages of a passport, or a stamp intended to make contact with or be applied to the substrate.
  • certain adhesives used may react with certain antitampering agents. These may be in particular certain antitampering agents that make it possible to prevent chemical removal using a nonpolar solvent.
  • a person skilled in the art may therefore find it necessary to select one or more antitampering agents so as to avoid an undesired reaction with said adhesive of a label, a protective film or a stamp intended to make contact with or be applied to said substrate, and in particular it may be necessary to avoid certain antitampering agents that make it possible to prevent chemical removal using a nonpolar solvent.
  • the substrate may for example comprise a single antitampering agent making it possible to prevent chemical removal using a plurality of removal products. It may for example comprise manganese sulfate, and preferably manganese chloride, so as to make it possible to prevent removal of the mark using bases, for example such as caustic soda, but also oxidizing agents such as sodium hypochlorite, and in both cases the appearance of a brown spot or blotch indicates the attempted removal.
  • bases for example such as caustic soda, but also oxidizing agents such as sodium hypochlorite, and in both cases the appearance of a brown spot or blotch indicates the attempted removal.
  • the substrate may also comprise a plurality of antitampering agents making it possible to prevent, respectively, chemical removal using a plurality of removal products, especially causing colors to appear indicative of each removal product.
  • It may for example comprise a thiazole derivative and a xanthene derivative so as to make it possible to prevent, respectively, chemical removal using oxidizing agents such as sodium hypochlorite, via the appearance especially of an orange spot or blotch indicative of a removal attempt, but also chemical removal using bases such as caustic soda, via the appearance especially of a blue spot or blotch indicative of a removal attempt, and finally chemical removal using acids such as sulfuric acid, via the appearance especially of a pink spot or blotch indicative of a removal attempt.
  • the invention may make it possible for a user to easily notice any attempt, using a chemical, to remove marks produced by laser irradiation on the substrate, especially by causing a color change to appear on the substrate in the location where the chemical was applied.
  • the choice of material able to form a colored mark under laser irradiation may depend on the contrast required and the wavelength of the laser irradiation used.
  • the commercially available product Micabs from Merck is a material that reacts to a marking laser that emits light at a wavelength between 100 nm and 11.5 ⁇ m.
  • a material that reacts to infrared marking lasers, especially CO 2 marking lasers, emitting light at a wavelength between 9 and 11.5 ⁇ m may in particular be chosen from the following commercially available products: Mark-it® from Engelhard, Packmark® from Datalase, Fast Mark® from Polyone, CerMark® from DMC2 or Lazerflair® from Merck.
  • the material able to form a colored mark under laser irradiation may furthermore cause a relief to be formed, especially by swelling under the effect of said laser irradiation.
  • the laser used to create a mark may be:
  • the material able to form a colored mark under laser irradiation will be chosen from derivatives of mica, or else from transition metals that provide a color change via a change of oxidation state, such as molybdates, tungstates and vanadates, and in particular octamolybdates, heptamolybdates and amine molybdates.
  • transition metals that provide a color change via a change of oxidation state
  • Such materials are especially described in international patent application WO 02/074548.
  • the material able to form a colored mark under laser irradiation may for example be incorporated into or on the substrate during its manufacture.
  • the material may be incorporated on-line or off-line. Preferably it is incorporated on-line during manufacture of the substrate.
  • the material able to form the colored mark will be incorporated into the facing composition of the substrate, especially a paper substrate.
  • the material may for example be incorporated over the entire area of the substrate or locally, for example in a continuous band or in a particular pattern. If required, said continuous band or said particular pattern may especially be respectively superposed on or covered by said continuous band or said particular pattern in which the antitampering agent has been incorporated into the substrate.
  • the material may be able to be marked by a laser such as those described above, especially a UV laser or an infrared laser, in particular a CO 2 and/or a YAG laser, inter alia.
  • a laser such as those described above, especially a UV laser or an infrared laser, in particular a CO 2 and/or a YAG laser, inter alia.
  • the material may also be able to be marked by a femtosecond laser.
  • the laser-markable material and the antitampering agent may be mixed into a single composition, especially into an ink, a lacquer or varnish, a coating composition, a facing composition, or an impregnating composition. Said composition may be incorporated using the methods described above, over the entire area of the substrate or locally, for example in a continuous band or in a particular pattern.
  • the substrate may also comprise mineral paper fillers such as for example kaolin, talc, titanium dioxide, aluminum silicate, alumina hydrate, calcined kaolin, inter alia.
  • the mineral paper fillers may be introduced into the thickness of the substrate so as to increase the opacity and improve the printability, especially the offset printability, of the substrate.
  • the choice of the mineral paper fillers used in the substrate may also influence the contrast of the marking obtained.
  • a mineral filler that is absorbent in the infrared so as to improve the contrast obtained by the laser marking.
  • alumina trihydrate and above all calcined kaolin increase the contrast of the marking produced, in particular using a CO 2 laser. It is for example possible to use calcined kaolin sold under the trade name Ansilex 93® by Engelhard.
  • the substrate may also comprise surface binders.
  • the presence of certain surface binders may also make it possible to improve the contrast.
  • the surface binders may be chosen for example from polyvinyl alcohol (PVA), starch or a latex, alone or in a mixture. These surface binders may be accompanied or not accompanied by insolubilizers and surface bonding products so as to provide the substrate with better final printability, especially offset printability.
  • PVA polyvinyl alcohol
  • starch starch
  • latex latex
  • the surface binders may be formed of PVA, especially highly hydrolyzed PVA, for example more than 94% hydrolyzed, thereby providing a high contrast, for example to markings made using a CO 2 laser.
  • the substrate may be a plastic substrate.
  • the substrate may be made of paper.
  • the substrate may for example be based on cellulose fibers (in particular cotton fibers) and/or natural organic fibers other than cellulose fibers and/or synthetic fibers, for example such as polyester fibers or polyamide fibers and/or optionally mineral fibers, for example such as glass fibers.
  • cellulose fibers in particular cotton fibers
  • natural organic fibers other than cellulose fibers and/or synthetic fibers
  • polyester fibers or polyamide fibers for example such as polyester fibers or polyamide fibers
  • optionally mineral fibers for example such as glass fibers.
  • the substrate may comprise one or more prints, for example produced by offset printing, intaglio printing, laser printing, inkjet printing, photogravure, screen printing and/or flexography, inter alia.
  • the concentration of material able to form a colored mark may lie between 0.1 and 10% by dry weight relative to the weight of the substrate, and preferably between 1 and 10%.
  • the concentration of the antitampering agent that reacts during an attempt to chemically remove the mark may lie, if necessary for each antitampering agent used, between 0.01 and 5% by dry weight relative to the weight of the substrate.
  • the substrate may comprise on each of its sides an amount of laser-sensitive material lying between 0.1 and 3 g/m 2 by dry weight.
  • the substrate may have a grammage lying between 30 and 200 g/m 2 .
  • the substrate may comprise a conventional ink or a security ink, especially fluorescent, phosphorescent, magnetic, photochromic, thermochromic or piezochromic ink, inter alia.
  • the substrate may comprise an authenticating and/or identifying security element.
  • Certain security elements can be detected with the naked eye, in visible light, without using a particular apparatus.
  • These security elements comprise for example a watermark, colored fibers or platelets, printed, metallized or holographic threads, holographic foils, or variable-optical-effect prints.
  • These security elements are called first-level security elements.
  • security element can only be detected using a relatively simple apparatus such as a lamp emitting in the ultraviolet or infrared.
  • These security elements for example comprise fibers, platelets, strips, threads or particles.
  • These security elements may or may not be visible to the naked eye, being for example luminescent under a Wood's lamp emitting at a wavelength of 365 nm.
  • These security elements are called second-level security elements.
  • Detection of yet further types of security element requires more sophisticated detection apparatus.
  • These security elements are for example capable of generating a specific signal when they are subjected, whether simultaneously or not, to one or more external sources of excitation.
  • the automatic detection of the signal makes it possible to authenticate, if required, the document.
  • These security elements for example comprise tracers that take the form of an active material, particles or fibers, capable of generating a specific signal when these tracers are subjected to optronic, electrical, magnetic or electromagnetic excitation.
  • These security elements are called third-level security elements.
  • the substrate may comprise at least one first-, second- and/or third-level security element.
  • Another subject of the invention is the use of a laser-markable substrate, as defined above, in a security document and/or a security article.
  • the security document may for example be a payment means, such as a banknote, a check, a purchase order or a meal ticket, an identity document such as an identity card or an official document such as a visa, a passport or driver's license, a lottery ticket, a travel ticket or else a ticket for entry to cultural or sporting events.
  • a payment means such as a banknote, a check, a purchase order or a meal ticket
  • an identity document such as an identity card or an official document such as a visa, a passport or driver's license, a lottery ticket, a travel ticket or else a ticket for entry to cultural or sporting events.
  • the security article may for example be chosen from a security label, packaging, especially packaging for medicinal products, foodstuffs, cosmetics, perfumes, electronic parts or spare parts, a sheet used in the field of medicine or in hospitals, especially paper used to produce sterile packaging, or else a type of paper used for art.
  • Yet another subject of the invention is a method for manufacturing a laser-markable substrate such as defined above.
  • the method may comprise a step consisting of introducing, by impregnation, especially using a size press method, or by facing, especially using a film press method, during manufacture of the substrate in a paper machine, the material able to form a colored mark under subsequent laser irradiation.
  • the marked papers were then evaluated in terms of the contrast of the laser marking using an optical-density measurement and in terms of the ability of the marking to withstand chemical removal attempts using acid, caustic soda, sodium hypochlorite, ethanol and toluene.
  • a laser-markable substrate was manufactured using a conventional paper machine and using the following formulation in accordance with the prior art.
  • a laser-markable substrate was manufactured, using a conventional paper machine, with the same formulation as above but replacing the Lazerflair® 800 with ammonium octamolybdate.
  • a laser-markable substrate was manufactured, using a conventional paper machine, with the following formulation:
  • Tests were carried out using various mineral paper fillers other than kaolin (used in formulation 2): rutile titanium dioxide (formulation 3), precipitated calcium carbonate (formulation 4), sodium aluminosilicate (formulation 5), aluminum hydroxide (formulation 6), talc (formulation 7) and calcined kaolin (formulation 8).
  • Formulation 4 Formulation 3 with with rutile precipitated Formulation 5
  • Formulation 2 titanium calcium with sodium with kaolin dioxide carbonate aluminosilicate 0.02 0.02 0.03 0.13
  • Formulation 6 Formulation 8 with aluminum
  • Formulation 7 with calcined hydroxide with talc kaolin 0.10 0.08 0.23
  • the paper manufactured according to formulation 12 had a better offset, laser and inkjet printability than that manufactured according to formulation 11.
  • a laser-markable paper substrate was manufactured according to the invention using a conventional paper machine with the following properties:
  • an attempt to remove the laser marking for example using sodium hypochlorite (12% chlorine) or a 5% sodium hydroxide solution, led to a brown colored spot or blotch appearing, indicating that an attempt had been made to tamper with the marking on the paper.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Paper (AREA)
  • Laser Beam Processing (AREA)
  • Thermal Transfer Or Thermal Recording In General (AREA)

Abstract

The present invention relates to a laser-markable substrate, comprising at least one material capable of forming a colored mark under laser irradiation and at least one tamper-proof agent producing an irreversible visible coloration when an attempt is made to chemically erase the mark.

Description

  • The present invention relates to the field of laser-markable substrates, especially to security documents, in particular to security paper, and inter alia relates to a substrate yielding a colored mark under laser irradiation and the associated manufacturing method.
  • In the description, the term “paper” is understood to mean any sheet obtained by wet processing using a suspension of natural cellulose fibers and/or mineral fibers and/or plant or organic fibers other than cellulose fibers, optionally synthetic fibers, possibly containing various fillers and various additives commonly used in papermaking.
    • BACKGROUND
  • In order to produce visible marks (or inscriptions) on a substrate, especially marks such as linear or matrix (2D) barcodes, it is known to use laser marking, for example marking with an infrared laser, especially a CO2 laser, a YAG (yttrium aluminum garnet) laser or else an Nd:YAG (neodymium-doped yttrium aluminum garnet) laser.
  • The laser marking of a standard paper substrate, for example for printing writing on, or of a security paper, leads to low-contrast marks, generally having a yellow or brownish color, associated with the carbonization of the substrate during marking.
  • Thus, to improve the contrast of the laser marking, it is known to incorporated into or apply onto paper or plastic substrates laser-sensitive materials such as mineral fillers, inorganic pigments including conductive pigments and/or variable optical-effect pigments such as pearl-luster silicates sold especially under the name Lazerflair® (LS range) by Merck.
  • Patent application US 2006/0090868 describes a fibrous laser-markable substrate comprising 1 to 5% absorbent materials in the form of inorganic platelets based on pearl-luster conductive pigments.
  • However, although these laser-sensitive materials based on conductive pigments, or especially variable-optical-effect or interference-effect pigments, substantially improve the contrast of the marking (increasing the optical density), they do not enable the dark marking, especially the black marking, required for automatic optical recognition of marks, for example such as barcodes.
  • In order to provide substrates that, under laser irradiation, yield black marks, coating compositions comprising laser-sensitive materials of different nature have been developed by various companies. For example, compositions sold by Datalase under the trade name Packmark®, by Ciba under the trade name Pergamark® or else by Fujifilm Hunt Chemicals under the trade name Codestream®, are known. These compositions are coated locally onto a substrate, especially a paper, and make it possible to obtain a gray or black marking on the coated substrate after laser irradiation of the coated region. These compositions comprise for example a binder and an oxyanion of a multivalent metal, such as that provided in patent application WO 02/074548. These compositions may also be carbohydrate-based.
  • However, these compositions are costly to implement, especially because they must be locally applied to the substrate to be marked using an off-line method such as printing. Furthermore, these compositions are not and cannot be adapted to an on-line implementation, especially during manufacture of the paper, for example for the following reasons:
      • their formulations are chemically incompatible with the binders usually used in the manufacture and conversion of paper, especially for the facing of the paper, for example using size press or film press methods;
      • their ability to withstand high temperatures, for example the temperatures used during the manufacture of plastic substrates or in the drying devices commonly used in the papermaking field, is poor (this is the case for example of laser-sensitive compositions based on carbohydrates such as saccharose or sucrose, or based on encapsulated leuco dyes); and
      • they modify the properties of the surface of the paper, especially its printability, for example offset printability; this is the case of compositions comprising a high proportion of fillers.
  • Patent application DE 102 32 786 describes a laser-markable material that makes it possible to obtain a marking in relief that provides a tactile effect.
  • One of the main advantages of the laser marking disclosed in the prior-art documents is its ability to resist tampering, whether mechanical or chemical. Patent applications WO 99/16625, WO 98/48398, EP 0 308 904 and FR 2 496 936 provide in particular tamper-resistant substrates comprising laser-markable materials. In particular, due to bonding, during irradiation (marking), between the laser-markable material and the substrate, and during anchoring of the laser-markable material in the substrate, the markings created on said substrates are supposed to be tamper-resistant, in particular mechanically and chemically indelible.
  • The applicant has however observed that it is possible to chemically remove the markings obtained by laser irradiation on substrates comprising laser-sensitive materials, or coated locally with compositions sensitive to laser marking, in particular such as described above, especially using certain chemicals or solvents such as oxidizing agents or strong bases for example. Thus, substrates comprising these laser-sensitive materials or coated with these laser-sensitive compositions, and marked by laser irradiation, do not have the properties required to thwart attempts to chemically tamper with the laser marking on these substrates. These properties are however vital to any security application, and especially in the field of security documents.
  • In particular it is relatively easy to remove a laser marking with chemicals such as sodium hypochlorite (bleach) or sodium hydroxide (caustic soda), inter alia.
    • SUMMARY
  • There is consequently a need to obviate at least some of the aforementioned drawbacks.
  • There is in particular a need to provide a laser-markable substrate, i.e. a substrate yielding a colored mark under laser irradiation, having a composition that is optimized so as to enable on-line incorporation, in particular in a paper machine, of laser-sensitive materials.
  • There is furthermore a need to obtain a laser-markable substrate having printing properties, especially offset printing properties, substantially analogous to those of a traditional paper substrate.
  • In view of the applicant's observations described above, and despite the teachings of the prior art, there is also a need to obtain a laser-markable substrate that makes it possible to detect any attempt to tamper with it, in particular chemically, by attempting to remove the laser markings.
  • The invention aims to meet all or some of these needs.
  • One subject of the invention, according to one of its aspects, is thus a laser-markable substrate comprising at least one material able under laser irradiation to form a colored mark, and at least one antitampering agent producing a visible coloration, especially an irreversible visible coloration, when an attempt is made to chemically remove the mark, making it possible to detect said removal attempt.
  • The term “irreversible” is intended to mean “permanent”, i.e. said coloration cannot be removed and does not disappear with time.
  • The mark and/or the coloration may for example be visible, especially to the naked eye or using an optical magnifying device, whether under normal (visible), infrared (IR) and/or ultraviolet (UV) light.
  • The mark and/or the coloration may for example form a spot or blotch, characters, for example such as an ideogram or alphanumeric signs, a symbol, an image, an acronym, a word or a code.
  • By virtue of the invention it is possible to ascertain whether there has been an attempt to remove the mark by dint of the presence of a colored product obtained by chemical reaction between said at least one anti-chemical-tampering agent, present in or on the substrate, and the chemicals used by the fraudsters in their attempt to remove the marks produced beforehand, by laser irradiation on the substrate. Said colored product forms a spot or blotch on the substrate.
  • The antitampering agent may for example be incorporated into or on the substrate during its manufacture.
  • It may for example be incorporated:
  • into the thickness of the substrate, for example by mixing it into the fibrous suspension in the case of a paper substrate or into the plastic material intended to be extruded or injection-molded in the case of a plastic substrate;
  • by impregnation, for example using a size press method;
  • by facing, for example using a film press method;
  • by coating, using a method such as air knife coating, roll coating, curtain coating, or bar coating; or else
  • by spraying.
  • The antitampering agent may be incorporated on-line or off-line. Preferably it is incorporated on-line during manufacture of the substrate.
  • The antitampering agent may for example be incorporated over the entire area of the substrate or locally, for example in a continuous band or in a particular pattern.
  • The antitampering agent may for example make it possible to prevent chemical removal of the mark, produced by laser irradiation of the substrate, using at least one of the following compounds:
      • an oxidizing agent;
      • a strong or weak base;
      • a strong or weak acid; or
      • a polar or nonpolar solvent.
  • The antitampering agent may make it possible to prevent chemical removal of the mark, produced by laser irradiation of the substrate, using oxidizing agents, for example such as sodium hypochlorite. In this case the antitampering agent may be chosen from the following compounds:
      • derivatives of manganese, nickel, cobalt or cerium and in particular their salts;
      • pp-diaminodiphenyl, its sulfate derivatives or its phosphate derivatives;
      • vanadium derivatives;
      • 4,4′-diaminodinaphthyl (1,1′);
      • S,N-orthophenylene isothiourea;
      • primuline;
      • guanidine derivatives such as diarylguanidine derivatives, such as for example diphenylguanidine; or
      • derivatives of thiazole, benzothiazole or aminonaphthothiazole.
  • The antitampering agent may make it possible to prevent chemical removal of the mark, produced by laser irradiation of the substrate, using strong bases, for example such as caustic soda, and/or weak bases such as for example sodium carbonate. In this case the antitampering agent may be chosen from the following compounds:
  • derivatives of manganese, nickel, cobalt or cerium and especially their salts;
  • colored indicators such as para-nitrophenol, phenolphthalein, pyranine or a xanthene derivative.
  • The antitampering agent may make it possible to prevent chemical removal of the mark, produced by laser irradiation of the substrate, using strong acids, for example such as sulfuric acid, and/or weak acids such as for example oxalic acid. In this case the antitampering agent may be chosen from the following compounds:
      • a colored indicator such as a xanthene derivative;
      • ferric chloride added to potassium ferrocyanide; or
      • a thiazole derivative, benzothiazole or aminonaphthothiazole.
  • The antitampering agent may make it possible to prevent chemical removal of the mark, produced by laser irradiation of the substrate, using polar solvents, for example such as ethanol, and/or nonpolar solvents such as for example toluene. In this case the antitampering agent may be chosen from dyes that are insoluble in water but soluble in oils and solvents. These dyes are especially used in the dyeing of petroleum derivatives.
  • The antitampering agent may be compatible with the adhesives used for labels, protective films or stamps.
  • In particular, if the substrate is an adhesive substrate, the antitampering agent of said substrate is compatible with the adhesive of said adhesive substrate.
  • According to another particular case, the antitampering agent is compatible with the adhesive of a label, a protective film, especially protecting the information-containing pages of a passport, or a stamp intended to make contact with or be applied to the substrate. This is because certain adhesives used may react with certain antitampering agents. These may be in particular certain antitampering agents that make it possible to prevent chemical removal using a nonpolar solvent. A person skilled in the art may therefore find it necessary to select one or more antitampering agents so as to avoid an undesired reaction with said adhesive of a label, a protective film or a stamp intended to make contact with or be applied to said substrate, and in particular it may be necessary to avoid certain antitampering agents that make it possible to prevent chemical removal using a nonpolar solvent.
  • The substrate may for example comprise a single antitampering agent making it possible to prevent chemical removal using a plurality of removal products. It may for example comprise manganese sulfate, and preferably manganese chloride, so as to make it possible to prevent removal of the mark using bases, for example such as caustic soda, but also oxidizing agents such as sodium hypochlorite, and in both cases the appearance of a brown spot or blotch indicates the attempted removal.
  • The substrate may also comprise a plurality of antitampering agents making it possible to prevent, respectively, chemical removal using a plurality of removal products, especially causing colors to appear indicative of each removal product. It may for example comprise a thiazole derivative and a xanthene derivative so as to make it possible to prevent, respectively, chemical removal using oxidizing agents such as sodium hypochlorite, via the appearance especially of an orange spot or blotch indicative of a removal attempt, but also chemical removal using bases such as caustic soda, via the appearance especially of a blue spot or blotch indicative of a removal attempt, and finally chemical removal using acids such as sulfuric acid, via the appearance especially of a pink spot or blotch indicative of a removal attempt.
  • The invention may make it possible for a user to easily notice any attempt, using a chemical, to remove marks produced by laser irradiation on the substrate, especially by causing a color change to appear on the substrate in the location where the chemical was applied.
  • The choice of material able to form a colored mark under laser irradiation may depend on the contrast required and the wavelength of the laser irradiation used. In particular, the commercially available product Micabs from Merck is a material that reacts to a marking laser that emits light at a wavelength between 100 nm and 11.5 μm. A material that reacts to infrared marking lasers, especially CO2 marking lasers, emitting light at a wavelength between 9 and 11.5 μm, may in particular be chosen from the following commercially available products: Mark-it® from Engelhard, Packmark® from Datalase, Fast Mark® from Polyone, CerMark® from DMC2 or Lazerflair® from Merck.
  • The material able to form a colored mark under laser irradiation may furthermore cause a relief to be formed, especially by swelling under the effect of said laser irradiation.
  • The laser used to create a mark may be:
      • a gas laser, especially a neutral atomic laser, for example a helium/cadmium laser emitting in the UV/visible at a wavelength of 442 nm, an ionized atomic laser or a molecular laser, for example a nitrogen (N2) laser emitting in the UV at a wavelength of 337 nm or a CO2 laser emitting at a wavelength lying between 9 and 11.5 μm;
      • a solid-state laser, for example a ruby laser, a neodymium-doped glass laser, an alexandrite laser or a YAG laser, optionally a rare-earth-doped YAG laser;
      • a liquid laser (or a dye laser), for example emitting in the UV at a wavelength lying between 100 and 350 nm or for example a laser pumped by an X2 YAG laser or by an N2 laser; or
      • a semiconductor laser, for example a gallium arsenide laser.
  • Preferably, the material able to form a colored mark under laser irradiation will be chosen from derivatives of mica, or else from transition metals that provide a color change via a change of oxidation state, such as molybdates, tungstates and vanadates, and in particular octamolybdates, heptamolybdates and amine molybdates. Such materials are especially described in international patent application WO 02/074548.
  • The material able to form a colored mark under laser irradiation may for example be incorporated into or on the substrate during its manufacture.
  • It may for example be incorporated:
      • into the thickness of the substrate, for example by mixing it into the fibrous suspension in the case of a paper substrate or into the plastic material intended to be extruded or injection-molded in the case of a plastic substrate;
      • by impregnation, for example using a size press method;
      • by facing, for example using a film press method;
      • by coating, using a method such as air knife coating, roll coating, curtain coating, or bar coating; or else
      • by spraying.
  • The material may be incorporated on-line or off-line. Preferably it is incorporated on-line during manufacture of the substrate.
  • Preferably, the material able to form the colored mark will be incorporated into the facing composition of the substrate, especially a paper substrate.
  • The material may for example be incorporated over the entire area of the substrate or locally, for example in a continuous band or in a particular pattern. If required, said continuous band or said particular pattern may especially be respectively superposed on or covered by said continuous band or said particular pattern in which the antitampering agent has been incorporated into the substrate.
  • The material may be able to be marked by a laser such as those described above, especially a UV laser or an infrared laser, in particular a CO2 and/or a YAG laser, inter alia. The material may also be able to be marked by a femtosecond laser.
  • The laser-markable material and the antitampering agent may be mixed into a single composition, especially into an ink, a lacquer or varnish, a coating composition, a facing composition, or an impregnating composition. Said composition may be incorporated using the methods described above, over the entire area of the substrate or locally, for example in a continuous band or in a particular pattern.
  • The substrate may also comprise mineral paper fillers such as for example kaolin, talc, titanium dioxide, aluminum silicate, alumina hydrate, calcined kaolin, inter alia. The mineral paper fillers may be introduced into the thickness of the substrate so as to increase the opacity and improve the printability, especially the offset printability, of the substrate.
  • The choice of the mineral paper fillers used in the substrate may also influence the contrast of the marking obtained.
  • In particular, it is preferable to use a mineral filler that is absorbent in the infrared so as to improve the contrast obtained by the laser marking. The applicant has demonstrated that, of the commonly used mineral paper fillers, alumina trihydrate and above all calcined kaolin increase the contrast of the marking produced, in particular using a CO2 laser. It is for example possible to use calcined kaolin sold under the trade name Ansilex 93® by Engelhard.
  • The substrate may also comprise surface binders. The presence of certain surface binders may also make it possible to improve the contrast.
  • The surface binders may be chosen for example from polyvinyl alcohol (PVA), starch or a latex, alone or in a mixture. These surface binders may be accompanied or not accompanied by insolubilizers and surface bonding products so as to provide the substrate with better final printability, especially offset printability.
  • Preferably, the surface binders may be formed of PVA, especially highly hydrolyzed PVA, for example more than 94% hydrolyzed, thereby providing a high contrast, for example to markings made using a CO2 laser.
  • The substrate may be a plastic substrate.
  • The substrate may be made of paper.
  • The substrate may for example be based on cellulose fibers (in particular cotton fibers) and/or natural organic fibers other than cellulose fibers and/or synthetic fibers, for example such as polyester fibers or polyamide fibers and/or optionally mineral fibers, for example such as glass fibers.
  • The substrate may comprise one or more prints, for example produced by offset printing, intaglio printing, laser printing, inkjet printing, photogravure, screen printing and/or flexography, inter alia.
  • The concentration of material able to form a colored mark may lie between 0.1 and 10% by dry weight relative to the weight of the substrate, and preferably between 1 and 10%.
  • The concentration of the antitampering agent that reacts during an attempt to chemically remove the mark may lie, if necessary for each antitampering agent used, between 0.01 and 5% by dry weight relative to the weight of the substrate.
  • The substrate may comprise on each of its sides an amount of laser-sensitive material lying between 0.1 and 3 g/m2 by dry weight.
  • The substrate may have a grammage lying between 30 and 200 g/m2.
  • The substrate may comprise a conventional ink or a security ink, especially fluorescent, phosphorescent, magnetic, photochromic, thermochromic or piezochromic ink, inter alia.
  • The substrate may comprise an authenticating and/or identifying security element.
  • Certain security elements can be detected with the naked eye, in visible light, without using a particular apparatus. These security elements comprise for example a watermark, colored fibers or platelets, printed, metallized or holographic threads, holographic foils, or variable-optical-effect prints.
  • These security elements are called first-level security elements.
  • Other types of security element can only be detected using a relatively simple apparatus such as a lamp emitting in the ultraviolet or infrared. These security elements for example comprise fibers, platelets, strips, threads or particles. These security elements may or may not be visible to the naked eye, being for example luminescent under a Wood's lamp emitting at a wavelength of 365 nm.
  • These security elements are called second-level security elements.
  • Detection of yet further types of security element requires more sophisticated detection apparatus. These security elements are for example capable of generating a specific signal when they are subjected, whether simultaneously or not, to one or more external sources of excitation. The automatic detection of the signal makes it possible to authenticate, if required, the document.
  • These security elements for example comprise tracers that take the form of an active material, particles or fibers, capable of generating a specific signal when these tracers are subjected to optronic, electrical, magnetic or electromagnetic excitation.
  • These security elements are called third-level security elements.
  • The substrate may comprise at least one first-, second- and/or third-level security element.
  • Another subject of the invention, according to another of its aspects, is the use of a laser-markable substrate, as defined above, in a security document and/or a security article.
  • The security document may for example be a payment means, such as a banknote, a check, a purchase order or a meal ticket, an identity document such as an identity card or an official document such as a visa, a passport or driver's license, a lottery ticket, a travel ticket or else a ticket for entry to cultural or sporting events.
  • The security article may for example be chosen from a security label, packaging, especially packaging for medicinal products, foodstuffs, cosmetics, perfumes, electronic parts or spare parts, a sheet used in the field of medicine or in hospitals, especially paper used to produce sterile packaging, or else a type of paper used for art.
  • Yet another subject of the invention, according to another of its aspects, is a method for manufacturing a laser-markable substrate such as defined above.
  • The method may comprise a step consisting of introducing, by impregnation, especially using a size press method, or by facing, especially using a film press method, during manufacture of the substrate in a paper machine, the material able to form a colored mark under subsequent laser irradiation.
    • EXAMPLES Preliminary remark
  • The substrates described in the following examples were marked with a CO2 laser having the following properties:
      • laser wavelength 10600 nm;
  • ×2 beam expander (beam size increased by a factor of two);
      • focal distance 125 nm;
      • 127 nm lens; and
      • speed of 3500 mm/s.
  • The marked papers were then evaluated in terms of the contrast of the laser marking using an optical-density measurement and in terms of the ability of the marking to withstand chemical removal attempts using acid, caustic soda, sodium hypochlorite, ethanol and toluene.
    • Formulation 1 (Reference Sample)
  • A laser-markable substrate was manufactured using a conventional paper machine and using the following formulation in accordance with the prior art.
  • Pulper (refining to 35 degrees Schopper-Riegler (°SR))
      • long fibers: 60%; and
      • short fibers: 40%.
    Mixer
      • mineral filler: 15% by dry weight of calcined kaolin.
    Head Box
      • retention agent: 1.5% by weight, relative to the weight of the paper produced in the paper machine, of cationic starch, for example based on potatoes; and
      • bonding agent: 3.5% by weight, relative to the weight of the paper produced in the paper machine, of a commercially available solution of rosin-based cationic emulsion.
    Size Press (Facing, for 2000 L)
      • binder: 200 kg of modified maize starch;
      • binder: 20 kg of polyvinyl alcohol (PVA);
      • antifoam: 0.35 kg of an aqueous emulsion of an aliphatic mixture of hydroxylated compounds;
      • insolublizing agent: 3 kg of a commercially available modified-glyoxal solution; and
      • laser-sensitive material: 250 kg of Lazerflair® 800 sold by Merck.
  • The results showed that a yellow-brown contrast and not a black contrast was obtained by CO2 laser marking of the paper manufactured according to formulation 1. It was observed that it was easy to remove said laser marking using sodium hypochlorite (12% chlorine) or a 5% sodium hydroxide solution.
    • Formulation 2
  • A laser-markable substrate was manufactured, using a conventional paper machine, with the same formulation as above but replacing the Lazerflair® 800 with ammonium octamolybdate.
  • The results showed that this time a gray-black contrast was obtained by CO2 laser marking of the paper manufactured according to formulation 2. It was noted that it was easy to remove said laser marking using sodium hypochlorite (12% chlorine) or using a 5% sodium hydroxide solution.
    • Formulations 3, 4, 5, 6, 7 and 8
  • A laser-markable substrate was manufactured, using a conventional paper machine, with the following formulation:
    • Pulper (Refining to 35 Degrees Schopper-Riegler (°SR))
      • long fibers: 60%; and
      • short fibers: 40%.
    Mixer
      • mineral fillers: 15% by dry weight.
    Head Box
      • retention agent: 1.5% by weight, relative to the weight of the paper produced in the paper machine, of cationic starch, for example based on potatoes; and
      • bonding agent: 3.5% by weight, relative to the weight of the paper produced in the paper machine, of a commercially available solution of rosin-based cationic emulsion.
    Size Press (Facing, for 2000 L)
      • binder: 200 kg of modified maize starch;
      • binder: 20 kg of polyvinyl alcohol (PVA);
      • antifoam: 0.35 kg of an aqueous emulsion of an aliphatic mixture of hydroxylated compounds;
      • insolublizing agent: 3 kg of a commercially available modified-glyoxal solution; and
      • laser-sensitive material: 250 kg of ammonium octamolybdate.
  • Tests were carried out using various mineral paper fillers other than kaolin (used in formulation 2): rutile titanium dioxide (formulation 3), precipitated calcium carbonate (formulation 4), sodium aluminosilicate (formulation 5), aluminum hydroxide (formulation 6), talc (formulation 7) and calcined kaolin (formulation 8).
  • The results of the CO2-laser-marking tests (measurement of the optical density) were the following:
  •
    Formulation 4
    Formulation 3 with
    with rutile precipitated Formulation 5
    Formulation 2 titanium calcium with sodium
    with kaolin dioxide carbonate aluminosilicate
    0.02 0.02 0.03 0.13
    Formulation 6 Formulation 8
    with aluminum Formulation 7 with calcined
    hydroxide with talc kaolin
    0.10 0.08 0.23
  • The results showed that a higher contrast was obtained for the laser marking when calcined kaolin, sodium aluminosilicate or aluminum hydroxide were used as the mineral paper filler.
  • However, it was then easy to remove the laser mark using sodium hypochlorite (12% chlorine) or a 5% sodium hydroxide solution.
    • Formulations 9, 10, 11 and 12
  • Four laser-markable substrates were manufactured, using a conventional paper machine, with the bulk formulation (before facing) as follows:
    • Pulper (Refining to 35 Degrees Schopper-Riegler (°SR))
      • long fibers: 60%; and
      • short fibers: 40%.
    Mixer
      • mineral filler: 15% by dry weight of calcined kaolin.
    Head Box
      • retention agent: 1.5% by weight, relative to the weight of the paper produced in the paper machine, of cationic starch, for example based on potatoes; and
      • bonding agent: 3.5% by weight, relative to the weight of the paper produced in the paper machine, of a commercially available solution of rosin-based cationic emulsion.
  • Next, on-line, on the above fibrous mat, the four following size press formulations are applied respectively:
    • Size Press (Facing, for 2000 L) for Formulation 9
      • binder: 200 kg of modified maize starch;
      • antifoam: 0.35 kg of an aqueous emulsion of an aliphatic mixture of hydroxylated compounds;
      • insolublizing agent: 3 kg of a commercially available modified-glyoxal solution; and
      • laser-sensitive material: 250 kg of ammonium octamolybdate.
    Size Press (Facing, for 2000 L) for Formulation 10
      • binder: 200 kg of modified maize starch;
      • binder: 20 kg of polyvinyl alcohol (PVA);
      • antifoam: 0.35 kg of an aqueous emulsion of an aliphatic mixture of hydroxylated compounds;
      • insolublizing agent: 3 kg of a commercially available modified-glyoxal solution; and
      • laser-sensitive material: 250 kg of ammonium octamolybdate.
    Size Press (Facing, for 2000 L) for Formulation 11
      • binder: 100 kg of polyvinyl alcohol (PVA);
      • antifoam: 0.35 kg of an aqueous emulsion of an aliphatic mixture of hydroxylated compounds;
      • insolublizing agent: 3 kg of a commercially available modified-glyoxal solution; and
      • laser-sensitive material: 250 kg of ammonium octamolybdate.
    Size Press (Facing, for 2000 L) for Formulation 12
      • binder: 100 kg of polyvinyl alcohol (PVA);
      • antifoam: 0.35 kg of an aqueous emulsion of an aliphatic mixture of hydroxylated compounds;
      • surface bonding agent: 50 kg of a modified acrylic styrene derivative;
      • insolublizing agent: 3 kg of a commercially available modified-glyoxal solution; and
      • laser-sensitive material: 250 kg of ammonium octamolybdate.
  • Better results were obtained in terms of the contrast of the CO2 laser marking on the paper manufactured according to formulations 11 and 12 when a surface binder in the form of polyvinyl alcohol (PVA) was used.
  • However, it was then easy to remove the laser mark using bleach (12% chlorine) or a 5% sodium hydroxide solution.
  • Moreover, the paper manufactured according to formulation 12 had a better offset, laser and inkjet printability than that manufactured according to formulation 11.
    • Formulation 13
  • A laser-markable paper substrate was manufactured according to the invention using a conventional paper machine with the following properties:
    • Pulper (Refining to 35 Degrees Schopper-Riegler (°SR))
      • long fibers: 60%; and
      • short fibers: 40%.
    Mixer
      • mineral filler: 15% by dry weight of calcined kaolin; and
      • antitampering agent based on xanthene (colored indicator): 0.3% by weight of the commercially available solution relative to the weight of the paper produced in the paper machine.
    Head Box
      • retention agent: 1.5% by weight, relative to the weight of the paper produced in the paper machine, of cationic starch, for example based on potatoes; and
      • bonding agent: 3.5% by weight, relative to the weight of the paper produced in the paper machine, of the commercially available solution of rosin-based cationic emulsion.
    Size Press (Facing, for 2000 L)
      • binder: 100 kg of polyvinyl alcohol (PVA);
      • antifoam: 0.35 kg of an aqueous emulsion of an aliphatic mixture of hydroxylated compounds;
      • insolublizing agent: 3 kg of a commercially available modified-glyoxal solution;
      • laser-sensitive material: 250 kg of ammonium octamolybdate; and
      • antitampering agent: 20 kg of manganese chloride.
  • A paper having a high contrast, especially to CO2 laser markings, was obtained. In addition an attempt to remove the laser marking, for example using sodium hypochlorite (12% chlorine) or a 5% sodium hydroxide solution, led to a brown colored spot or blotch appearing, indicating that an attempt had been made to tamper with the marking on the paper. An attempt to remove the laser marking using an acid, such as for example 5% sulfuric acid solution, led to the appearance of a pink colored spot or blotch that also indicated an attempt had been made to tamper with the marking on the substrate.
  • The expression “comprising a” is intended to be synonymous with “comprising at least one”.

Claims (21)

1. A laser-markable substrate, comprising:
at least one material able to form a colored mark under laser irradiation; and
at least one antitampering agent producing an irreversible visible coloration when an attempt is made to chemically remove the colored mark.
2. The substrate as claimed in claim 1, the antitampering agent being incorporated into the thickness of the substrate by impregnation, facing, coating or spraying.
3. The substrate as claimed claim 1, the antitampering agent making it possible to prevent chemical removal of the mark containing at least one of the following compounds:
an oxidizing agent;
a strong or weak base;
a strong or weak acid; or
a polar or nonpolar solvent.
4. The substrate as claimed in claim 1, the antitampering agent making it possible to prevent chemical removal of the mark using oxidizing agents and being chosen from:
derivatives of manganese, nickel, cobalt or cerium;
pp-diaminodiphenyl, its sulfate derivatives or its phosphate derivatives;
vanadium derivatives;
4,4′-diaminodinaphthyl (1,1′);
S,N-orthophenylene isothiourea;
primuline;
guanidine derivatives; or
derivatives of thiazole, benzothiazole or aminonaphthothiazole.
5. The substrate as claimed in claim 1, the antitampering agent making it possible to prevent chemical removal using strong and/or weak bases and being chosen from:
derivatives of manganese, nickel, cobalt or cerium;
colored indicators.
6. The substrate as claimed in claim 1, the antitampering agent making it possible to prevent chemical removal of the mark using weak and/or strong acids and being chosen from:
a colored indicator;
ferric chloride added to potassium ferrocyanide; or
a thiazole derivative, benzothiazole or aminonaphthothiazole.
7. The substrate as claimed in claim 1, the antitampering agent making it possible to prevent chemical removal with polar and/or nonpolar solvents and being chosen from dyes that are insoluble in water but soluble in oils and solvents.
8. The substrate as claimed in claim 1, the antitampering agent being a manganese derivative.
9. The substrate as claimed in claim 1, the at least one material able to form a colored mark under laser irradiation being incorporated into the thickness of the substrate by impregnation, facing, coating or spraying.
10. The substrate as claimed in claim 1, the at least one material being able to be marked by a UV laser or by an infrared laser, in particular a CO2 laser and/or a YAG laser.
11. The substrate as claimed in claim 1, said colored mark having a relief.
12. The substrate as claimed in claim 1, the at least one material able to form a mark being chosen from derivatives of mica, molybdates, tungstates and vanadates.
13. The substrate as claimed in claim 1, further comprising a mineral filler absorbent in the infrared.
14. The substrate as claimed in claim 1, further comprising polyvinyl alcohol (PVA).
15. The substrate as claimed in claim 1, wherein the substrate is based on cellulose fibers.
16. The substrate as claimed in claim 1, wherein the substrate is a plastic substrate.
17. The substrate as claimed in claim 1, further comprising at least one authenticating and/or identifying security element.
18. The substrate as claimed in claim 1, wherein the concentration of material able to form a colored mark lying between 0.1 and 10% by dry weight relative to the weight of the substrate.
19. The substrate as claimed in claim 1, wherein the concentration of the at least one antitampering agent lying between 0.01 and 5% by dry weight relative to the weight of the substrate.
20. A security document and/or a security article, comprising:
a laser-markable substrate, comprising:
at least one material able to form a colored mark under laser irradiation, and
at least one antitampering agent producing an irreversible visible coloration when an attempt is made to chemically remove the colored mark.
21. A method of manufacturing a laser-markable substrate as claimed in claim 1, comprising:
introducing into the thickness of the substrate, by impregnation or by facing during manufacture of the substrate in a paper machine, material of the substrate able to form a colored mark under laser irradiation.
US13/256,108 2009-03-13 2010-03-15 Laser-markable substrate, and associated manufacturing method Abandoned US20120103545A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR0951612A FR2943074B1 (en) 2009-03-13 2009-03-13 LASER MARKABLE SUBSTRATE AND METHOD FOR MANUFACTURING THE SAME
FR0951612 2009-03-13
PCT/IB2010/051110 WO2010103499A1 (en) 2009-03-13 2010-03-15 Laser-markable substrate, and associated manufacturing method

Publications (1)

Publication Number Publication Date
US20120103545A1 true US20120103545A1 (en) 2012-05-03

Family

ID=40886197

Family Applications (1)

Application Number Title Priority Date Filing Date
US13/256,108 Abandoned US20120103545A1 (en) 2009-03-13 2010-03-15 Laser-markable substrate, and associated manufacturing method

Country Status (8)

Country Link
US (1) US20120103545A1 (en)
EP (1) EP2406084A1 (en)
BR (1) BRPI1009820A2 (en)
CA (1) CA2754867A1 (en)
FR (1) FR2943074B1 (en)
MX (1) MX2011009553A (en)
RU (1) RU2011137051A (en)
WO (1) WO2010103499A1 (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014180885A1 (en) 2013-05-10 2014-11-13 Fábrica Nacional De Moneda Y Timbre - Real Casa De La Moneda Method of providing a security document with a security feature, and security document
US20140370247A1 (en) * 2012-03-01 2014-12-18 Ferro Corporation Laser Absorbing Compounds
US20150001179A1 (en) * 2012-02-03 2015-01-01 Sandvik Surface Solutions Division Of Sandvik Materials Technology Deutschland Gmbh Method for producing etchable structures using a laser having a wavelength in the infrared range
WO2015040053A1 (en) * 2013-09-18 2015-03-26 Bundesdruckerei Gmbh Activatable value or security product, method of activation and method for producing a value or security product
US9776210B2 (en) 2012-03-01 2017-10-03 Ferro Corporation Laser absorbing compounds
EP3225376A1 (en) * 2016-03-30 2017-10-04 Wirthwein AG Plastic moulded part with black or grey uv marking, method for producing a mark on the plastic moulded part and in-mould film
EP3225375A1 (en) * 2016-03-30 2017-10-04 Wirthwein AG Plastic moulded part with coloured uv marking, method for producing a mark on the plastic moulded part and in-mould film with photochrome pigments
DE102019006029A1 (en) * 2019-08-27 2021-03-04 Veridos Gmbh Book-like identification document

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2943074B1 (en) * 2009-03-13 2011-05-20 Arjowiggins Security LASER MARKABLE SUBSTRATE AND METHOD FOR MANUFACTURING THE SAME
CN102168391A (en) * 2011-02-17 2011-08-31 无锡侨颂特种纸有限公司 Method for manufacturing chemical anti-counterfeiting paper
FR2992256A1 (en) * 2012-06-26 2013-12-27 Arjowiggins Security ELEMENT IN LASER ENGRAVABLE SHEET.

Citations (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2233279A (en) * 1989-06-01 1991-01-09 Aussedat Rey Sa Forgery-proof security paper
US5123999A (en) * 1989-08-07 1992-06-23 Aussedat-Rey Forgery-proof security paper and aqueous or organic composition especially useful for rendering paper forgery-proof
US5156717A (en) * 1988-12-07 1992-10-20 Aussedat-Rey Non-fluorescent forgery-proof safety paper and document obtained
WO2002057548A1 (en) * 2001-01-22 2002-07-25 Arjo Wiggins Security Sas Paper comprising bodies which comprise at least one biochemical marker
US6630055B1 (en) * 1997-09-15 2003-10-07 Arjo Wiggins Papiers Couches Coated paper including a pseudo-watermark, and a method of manufacture
EP1661729A2 (en) * 2004-11-30 2006-05-31 MERCK PATENT GmbH Laser marking of valuable documents
US20070204755A1 (en) * 2004-03-24 2007-09-06 Kba-Giori S.S.A. Process and Apparatus for Providing Identity Marks on Security Documents
DE102006021961A1 (en) * 2006-05-10 2007-11-15 Giesecke & Devrient Gmbh Safety element with laser marking
US20080122217A1 (en) * 2003-05-26 2008-05-29 Sandrine Rancien Security Document and Method for the Production Thereof
US20090315316A1 (en) * 2006-07-25 2009-12-24 Ovd Kinegram Ag Method of generating a laser mark in a security document, and security document of this kind
WO2010007287A1 (en) * 2008-06-24 2010-01-21 Arjowiggins Security Structure comprising a watermark or pseudo-watermark and integrated microcircuit device
WO2010018346A2 (en) * 2008-08-12 2010-02-18 Arjowiggins Security Integrale Solutions E-document comprising electromagnetic disturbance element
US20100071609A1 (en) * 2006-10-12 2010-03-25 Arjowiggins Security film comprising a fibrous substrate
EP2174796A1 (en) * 2008-10-07 2010-04-14 European Central Bank Laser-marked document showing a fixed colour in a surrounding with a colour shift effect
EP2174797A1 (en) * 2008-10-07 2010-04-14 European Central Bank Laser-marked document showing a colour-shift effect
WO2010103499A1 (en) * 2009-03-13 2010-09-16 Arjowiggins Security Laser-markable substrate, and associated manufacturing method
WO2010116343A2 (en) * 2009-04-10 2010-10-14 Arjowiggins Security Sectional documents comprising a structure equipped with a watermark or pseudo-watermark and associated process
US20120021194A1 (en) * 2010-06-21 2012-01-26 James Hardie Technology Limited Method for Marking a Substrate
US20120164419A1 (en) * 2009-02-23 2012-06-28 Japan Coloring Co., Ltd. Multilayer laser-markable sheet for electronic passport and electronic passport

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2365656A1 (en) * 1976-05-25 1978-04-21 Arjomari Prioux SECURITY PAPER
DE3048736C2 (en) 1980-12-23 1982-09-30 GAO Gesellschaft für Automation und Organisation mbH, 8000 München Identity card and process for its production
DE3100295A1 (en) * 1981-01-08 1982-08-05 Bayer Ag, 5090 Leverkusen USE OF 7-HYDROXY-CUMARINE COMPOUNDS FOR IMPREGNATING PAPER
FR2620146B1 (en) * 1987-09-03 1991-10-04 Arjomari Prioux MEANS, PAPER AND SECURITY DOCUMENT AGAINST CHEMICAL FALSIFICATION AND COUNTERFEITING
DE3731853A1 (en) 1987-09-22 1989-03-30 Gao Ges Automation Org MULTI-LAYER ID CARD USED AS A PRINT AND METHOD FOR THE PRODUCTION THEREOF
FR2671566B1 (en) * 1991-01-11 1993-04-09 Arjomari Europ SAFETY DOCUMENT INFALSIFIABLE BY A CHEMICAL AGENT.
DE19704478A1 (en) * 1997-02-06 1998-08-13 Merck Patent Gmbh Laser-markable papers and cardboard
FR2762425B1 (en) 1997-04-18 1999-06-04 Chevillot Sa INFALSIFIABLE, INDELEBILE AND CONTRAST MARKING OF OBJECTS AND PARTICULARLY LABELS
US6075223A (en) 1997-09-08 2000-06-13 Thermark, Llc High contrast surface marking
GB2339784A (en) * 1998-07-21 2000-02-09 Courtaulds Chemicals Plastics film; identifying goods
DE19842867C2 (en) * 1998-09-19 2000-08-03 Mitsubishi Hitec Paper Flensbu Heat-sensitive recording material and a method for checking authenticity
JP3913680B2 (en) * 2001-03-16 2007-05-09 データレイズ・リミテッド Composition for laser marking
DE10232786A1 (en) 2002-07-18 2004-02-12 Giesecke & Devrient Gmbh Security document, valuable document or bank note on security paper, has security marking sensed by touch, in form of laser-generated relief structure
DE102004038542A1 (en) * 2004-08-06 2006-02-23 Giesecke & Devrient Gmbh Data carrier with security element and method for its production
DE102006008247A1 (en) * 2006-02-22 2007-08-23 Giesecke & Devrient Gmbh Laser-marked safety features for protecting valuable objects, has laser-marked marking substance with core-covering-particles, and one of the material of the core and covering absorbs the radiation of the marking laser

Patent Citations (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5156717A (en) * 1988-12-07 1992-10-20 Aussedat-Rey Non-fluorescent forgery-proof safety paper and document obtained
GB2233279A (en) * 1989-06-01 1991-01-09 Aussedat Rey Sa Forgery-proof security paper
US5123999A (en) * 1989-08-07 1992-06-23 Aussedat-Rey Forgery-proof security paper and aqueous or organic composition especially useful for rendering paper forgery-proof
US6630055B1 (en) * 1997-09-15 2003-10-07 Arjo Wiggins Papiers Couches Coated paper including a pseudo-watermark, and a method of manufacture
US7235289B2 (en) * 2001-01-22 2007-06-26 Arjowiggins Security Paper including bodies carrying at least one biochemical marker
WO2002057548A1 (en) * 2001-01-22 2002-07-25 Arjo Wiggins Security Sas Paper comprising bodies which comprise at least one biochemical marker
US20080122217A1 (en) * 2003-05-26 2008-05-29 Sandrine Rancien Security Document and Method for the Production Thereof
US8117964B2 (en) * 2004-03-24 2012-02-21 KBA—Giori S.A. Process and apparatus for providing identity marks on security documents
US20070204755A1 (en) * 2004-03-24 2007-09-06 Kba-Giori S.S.A. Process and Apparatus for Providing Identity Marks on Security Documents
EP1661729A2 (en) * 2004-11-30 2006-05-31 MERCK PATENT GmbH Laser marking of valuable documents
DE102006021961A1 (en) * 2006-05-10 2007-11-15 Giesecke & Devrient Gmbh Safety element with laser marking
US20090315316A1 (en) * 2006-07-25 2009-12-24 Ovd Kinegram Ag Method of generating a laser mark in a security document, and security document of this kind
US8298753B2 (en) * 2006-07-25 2012-10-30 Ovd Kinegram Ag Method of generating a laser mark in a security document, and security document of this kind
US20100071609A1 (en) * 2006-10-12 2010-03-25 Arjowiggins Security film comprising a fibrous substrate
US8376409B2 (en) * 2006-10-12 2013-02-19 Arjowiggins Security Security sheet comprising a fibrous substrate
WO2010007287A1 (en) * 2008-06-24 2010-01-21 Arjowiggins Security Structure comprising a watermark or pseudo-watermark and integrated microcircuit device
WO2010018346A2 (en) * 2008-08-12 2010-02-18 Arjowiggins Security Integrale Solutions E-document comprising electromagnetic disturbance element
EP2174797A1 (en) * 2008-10-07 2010-04-14 European Central Bank Laser-marked document showing a colour-shift effect
EP2174796A1 (en) * 2008-10-07 2010-04-14 European Central Bank Laser-marked document showing a fixed colour in a surrounding with a colour shift effect
US20120164419A1 (en) * 2009-02-23 2012-06-28 Japan Coloring Co., Ltd. Multilayer laser-markable sheet for electronic passport and electronic passport
FR2943074A1 (en) * 2009-03-13 2010-09-17 Arjowiggins Security LASER MARKABLE SUBSTRATE AND METHOD FOR MANUFACTURING THE SAME
WO2010103499A1 (en) * 2009-03-13 2010-09-16 Arjowiggins Security Laser-markable substrate, and associated manufacturing method
WO2010116343A2 (en) * 2009-04-10 2010-10-14 Arjowiggins Security Sectional documents comprising a structure equipped with a watermark or pseudo-watermark and associated process
US20120021194A1 (en) * 2010-06-21 2012-01-26 James Hardie Technology Limited Method for Marking a Substrate

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150001179A1 (en) * 2012-02-03 2015-01-01 Sandvik Surface Solutions Division Of Sandvik Materials Technology Deutschland Gmbh Method for producing etchable structures using a laser having a wavelength in the infrared range
US20140370247A1 (en) * 2012-03-01 2014-12-18 Ferro Corporation Laser Absorbing Compounds
US9321130B2 (en) * 2012-03-01 2016-04-26 Ferro Corporation Laser absorbing compounds
US9776210B2 (en) 2012-03-01 2017-10-03 Ferro Corporation Laser absorbing compounds
WO2014180885A1 (en) 2013-05-10 2014-11-13 Fábrica Nacional De Moneda Y Timbre - Real Casa De La Moneda Method of providing a security document with a security feature, and security document
KR20160028407A (en) * 2013-05-10 2016-03-11 파브리카 나씨오날 데 모네다 이 띰브레-레알 까사 데 라 모네다 Method of providing a security document with a security feature, and security document
US9938667B2 (en) 2013-05-10 2018-04-10 Fábrica Nacional de Moneda y Timbre-Real Casa de la Moneda Method of providing a security document with a security feature, and security document
KR102218657B1 (en) 2013-05-10 2021-02-23 파브리카 나씨오날 데 모네다 이 띰브레-레알 까사 데 라 모네다 Method of providing a security document with a security feature, and security document
WO2015040053A1 (en) * 2013-09-18 2015-03-26 Bundesdruckerei Gmbh Activatable value or security product, method of activation and method for producing a value or security product
EP3225376A1 (en) * 2016-03-30 2017-10-04 Wirthwein AG Plastic moulded part with black or grey uv marking, method for producing a mark on the plastic moulded part and in-mould film
EP3225375A1 (en) * 2016-03-30 2017-10-04 Wirthwein AG Plastic moulded part with coloured uv marking, method for producing a mark on the plastic moulded part and in-mould film with photochrome pigments
DE102019006029A1 (en) * 2019-08-27 2021-03-04 Veridos Gmbh Book-like identification document

Also Published As

Publication number Publication date
FR2943074B1 (en) 2011-05-20
RU2011137051A (en) 2013-04-20
FR2943074A1 (en) 2010-09-17
WO2010103499A1 (en) 2010-09-16
EP2406084A1 (en) 2012-01-18
CA2754867A1 (en) 2010-09-16
BRPI1009820A2 (en) 2016-03-15
MX2011009553A (en) 2011-10-12

Similar Documents

Publication Publication Date Title
US20120103545A1 (en) Laser-markable substrate, and associated manufacturing method
EP2331751B1 (en) Laser imageable paper
US7897212B2 (en) Method of marking material, marked and verification of genuineness of a product
US6483576B1 (en) Counterfeit detection system
BR112019024513A2 (en) METHOD TO PRODUCE WATER INSOLUBLE QUANTUM POINT PATTERNS
BRPI0719827B1 (en) security sheet, security tape made of paper, security document, article to be authenticated, and processes for manufacturing a security sheet and authentication of a security sheet.
JP2009134528A (en) Ic label for forgery prevention
CA2474110A1 (en) Process for blending of ink used in counterfeit detection systems
SA521430912B1 (en) Security inks and machine readable security features
US20150290958A1 (en) Secure card customisable by thermal transfer printing
US20050116465A1 (en) Packaging with embedded security measures
JP7006016B2 (en) Personal authentication medium
JP2004526597A (en) Thermal recording paper and its use
JP7314643B2 (en) Method for producing threaded printed matter and anti-counterfeit paper, and roll film printed matter and anti-counterfeit paper
CN202694676U (en) Invisible anti-counterfeiting label
JP6194565B2 (en) Information recording medium and reading method thereof
WO2015036808A1 (en) Security carrier for thermal printing
US9731541B2 (en) Label, adhesive label, and printed product
JP2011149107A (en) Falsification-preventing paper
JP7447400B2 (en) Anti-counterfeiting media
RU2819116C2 (en) Protective paints and machine-readable security features
JP2003293287A (en) Coated sheet
JPH02245399A (en) Forgery discriminating paper
ITMI941546A1 (en) PROCEDURE FOR THE ANTI-COUNTERFEIT PROTECTION OF DOCUMENTS MADE ON PAPER SUPPORTS OR OTHER OPPORTUNITIES
JPH03230996A (en) Forgery judging paper

Legal Events

Date Code Title Description
AS Assignment

Owner name: ARJOWIGGINS SECURITY, FRANCE

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:RANCIEN, SANDRINE;REEL/FRAME:027574/0905

Effective date: 20120113

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION