FR2943074A1 - LASER MARKABLE SUBSTRATE AND METHOD FOR MANUFACTURING THE SAME - Google Patents

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 tampering agent producing a visible coloration during an attempt to erase the mark chemically.

Description

The present invention relates to the field of laser-markable substrates, in particular security documents, in particular security papers, and concerns inter alia a substrate giving a colored mark under laser irradiation and the associated manufacturing method.

In the description, paper means any sheet obtained by wet process using a suspension of natural cellulose fibers and / or inorganic, vegetable or organic fibers other than cellulose, which may be synthetic and may contain various fillers and various additives. commonly used in stationery. BACKGROUND In order to include visible marks (or inscriptions) on a substrate, especially marks such as linear or matrix (2D) bar codes, it is known to use laser irradiation marking, for example to using a CO2 laser, a YAG (Yttrium Alumina Garnet) laser or Nd YAG (Neodymium Yttrium Alumina Garnet).

The laser irradiation marking of a standard paper substrate, for example for writing or security printing, leads to obtaining a low-contrast marking, generally yellow or brownish, related to the carbonization of the substrate during marking. . Also, to improve the contrast of the marking by laser irradiation, it is known to incorporate in or apply to the paper or plastic substrates, sensitive laser materials such as mineral fillers, inorganic pigments including conductive pigments and / or pigments with a changing optical effect such as pearl silicates marketed in particular under the name LAZERFLAIR (LS range) by MERCK.

The application US 2006/0090868 discloses a laser-marked fibrous substrate comprising from 1 to 5% of absorbent materials in the form of inorganic platelets based on pearlescent and conductive pigments. However, these sensitive laser materials based on conductive pigments or effect pigments, in particular optically variable or interferential, although substantially improving the contrast of the marking (increase in optical density), do not allow to obtain a dark marking, in particular of black color, required for automatic optical recognition of marks, for example such as bar codes.

In order to provide substrates which under laser irradiation give black-colored marks, coating compositions comprising laser-sensitive materials of different nature have been developed by different companies. For example, the compositions marketed under the trademark PACKMARK by the company DATALASE, PERGAMARK by the company CIBA or CODESTRAM by the company FUJIHUNT are known. These compositions are coated locally on a substrate, in particular a paper, and make it possible to obtain a gray or black marking on the coated substrate after laser irradiation of the coated zone. These compositions comprise, for example, a binder and an oxyanion of a metal with multiple valence, as proposed in the application WO 02/074548. These compositions may also be based on carbohydrate. However, these compositions are expensive to implement, in particular because they must be applied locally to the substrate to be marked by an offline process such as printing. In addition, these compositions are not and can not be adapted to an implementation online, especially during the manufacture of paper, for example for the following reasons: - their formulation has chemical incompatibilities with binders usually used to the manufacture and processing of paper, in particular for the surfacing of paper, for example by size press or pressure film processes, their resistance to high temperatures, for example such as the temperatures used during the manufacture of plastic substrates or by the drying devices commonly used in the field of stationery, is low (this is the case, for example, for compositions based on carbohydrates such as sucrose or sucrose, or for compositions based on encapsulated leuco dyes), they modify the surface properties of the paper, in particular its printability, in particular during the printing offse compositions comprising a high proportion of fillers. Furthermore, the Applicant has observed that it is very easy to erase the markings obtained by laser irradiation on substrates comprising the laser sensitive materials, or locally coated with laser marking sensitive compositions, in particular as described above, in particular with respect to using certain chemicals such as oxidants or strong bases for example. In this way, the substrates comprising these laser sensitive materials or coated with these laser sensitive compositions, and labeled by laser irradiation, do not offer the properties necessary to guard against the attempts of chemical falsification of the laser marking carried out on these substrates. These properties are nevertheless essential for any security application and especially the field of security documents. In particular, it is relatively easy to erase a CO2 laser irradiation marking with chemicals such as sodium hypochlorite (bleach) or sodium hydroxide (sodium hydroxide), among others. Summary There is therefore a need to remedy at least some of the disadvantages mentioned above. In particular, there is a need to provide a laser-markable substrate, that is to say giving a colored mark under laser irradiation, and having an optimized composition to allow an in-line incorporation, in particular on a paper machine, of sensitive materials. laser. There is still a need to obtain a laser-marked substrate having printing properties, especially offset, substantially similar to those of a conventional paper substrate. There is also a need for a laser marker substrate 20 for detecting tampering, particularly chemical, attempts to erase laser markings. The invention aims to meet all or part of these needs. The invention thus has, according to one of its aspects, a laser-marked substrate comprising at least one material capable of forming, under laser irradiation, a colored mark, and at least one tampering agent producing a visible coloration during an attempt to erase the mark chemically, in order to detect said erasure attempt. The mark and / or the coloration may for example be visible, in particular with the naked eye or with the aid of an optical magnification device, under normal (visible light), infrared (IR) and / or ultraviolet light. violet (UV). Thanks to the invention, it is possible to know whether the attempt to erase the mark has taken place, thanks to the presence of a colored product obtained by chemical reaction between the at least one chemical tamper agent present in or on the substrate and chemicals used by fraudsters to try to erase marks made by laser irradiation on the substrate. The tampering agent may for example be incorporated in or on the substrate during its manufacture. It can for example be incorporated: - by impregnation, for example by a size press process, - by surfacing, for example by a press-film process, - by coating according to processes such as air-lay coating, roll coating , curtain coating and coating at the bar, or - by spraying. The tampering agent can be incorporated online or offline. Preferably, it is incorporated in line during the manufacture of the substrate. The tampering agent may for example be incorporated over the entire surface of the substrate or locally, for example in a continuous strip or in a particular pattern. The tampering agent may, for example, make it possible to prevent the chemical erasure of the mark produced by laser irradiation of the substrate, with at least one of the following compounds: an oxidant, a strong or weak base, a strong acid or weak, or - a polar or apolar solvent. The tampering agent may make it possible to prevent chemical erasure of the mark produced by laser irradiation of the substrate with oxidants, for example such as sodium hypochlorite. In this case, the tampering agent may be chosen from the following compounds: - derivatives of manganese, nickel, cobalt or cerium, and in particular their salts, - diamino-diphenyl, its sulphate derivatives or its phosphate derivatives, vanadium derivatives, 4,4'-diaminodinaphthyl (1,1 '), S, N orthophenylene isothiourea, primulin, guanidine derivatives such as diarylguanidine, for example diphenylguanidine, or thiazole derivatives, benzothiazole or aminonaphthothiazole.

The tampering agent may make it possible to prevent the chemical erasure of the mark produced by laser irradiation of the substrate, with strong bases, for example such as sodium hydroxide, and / or weak, for example, such as sodium carbonate. In this case, the tampering agent may be chosen from the following compounds: - derivatives of manganese, nickel, cobalt or cerium, and in particular their salts, - colored indicators such as paranitrophenol, phenolphthalein , pyranine or a derivative of xanthene. The tampering agent may make it possible to prevent the chemical erasure of the mark produced by laser irradiation of the substrate, with strong acids, for example such as sulfuric acid, and / or weak, for example, such as oxalic acid. . In this case, the tampering agent may be chosen from the following compounds: a colored indicator such as a xanthene derivative, ferric ferrocyanide added with ferric chloride, or a thiazole derivative, benzothiazole or aminonaphthothiazole. The tampering agent may make it possible to prevent the chemical erasure of the mark produced by laser irradiation of the substrate, with polar solvents, for example such as ethanol, and / or apolar solvents, for example such as toluene. In this case, the tampering agent may be chosen from the dyes which are insoluble in water but soluble in oils and solvents. These dyes are used in particular for coloring petroleum derivatives.

The substrate may comprise, for example, a single tampering agent which makes it possible to prevent chemical erasure by several erasing products. It may for example comprise manganese sulfate, and preferably manganese chloride, to prevent the erasure of the mark with bases, for example such as soda but also with oxidants such as hypochlorite of sodium, by the appearance in both cases of a brown spot revealing the attempt of erasure.

The substrate may also include several tampering agents to respectively prevent the chemical erasure with several erasing products, including the appearance of revealing stains of each of the erasing products. It may, for example, comprise a thiazole derivative and a xanthene derivative in order to prevent the chemical erasure with oxidants such as sodium hypochlorite, respectively, by the appearance in particular of an orange spot indicative of an attempt to erasure, but also the chemical erasure with bases such as soda, by the appearance in particular of a blue spot revealing an attempt to erase and finally the chemical erasure with acids such as sulfuric acid, by the appearance in particular of a pink spot revealing an attempt of erasure. The invention may allow a user to easily observe any attempt by a chemical to erase the marks made by laser irradiation on the substrate, particularly because of the appearance of a color change on the substrate at the location where the chemical has been applied. The choice of material capable of forming a colored mark under laser irradiation may depend on the contrast that one wishes to obtain and on the irradiation wavelength of the laser used. In particular, the material reacting to CO2 laser marking which emits light in a wavelength between 9 and 11.5 m can be chosen from the following commercial products: MARK IT from ENGELHARD, PACKMARK from DATALASE, FAST MARK from POLYONE, CERMARK from DMC2 or LAZERFLAIR from MERCK. Preferably, the material capable of forming a colored mark under laser irradiation will be chosen from transition metals which induce a change of color by change of oxidation state such as molybdates, tungstates and vanadates, and in particular octamolybdates, heptamolybdates and molybdate amines. Such materials are described in particular in the international application WO 02/074548. The material capable of forming a colored mark under laser irradiation may for example be incorporated in or on the substrate during its manufacture.

It can for example be incorporated: - by impregnation, for example by a size press process, - by surfacing, for example by a press-film process, - by coating according to processes such as air-lay coating, roll coating , the curtain coating and the coating at the bar, or - by spraying. The material can be incorporated online or offline. Preferably, it is incorporated in line during the manufacture of the substrate. Preferably, the material capable of forming the colored mark will be incorporated in the surfacer composition of the substrate, in particular paper. The material may for example be incorporated over the entire surface of the substrate or locally, for example in a continuous strip or in a particular pattern.

The material may be suitable for marking with a CO2 laser and / or a YAG laser, among others. The material may still be suitable for marking by a femtosecond laser. The substrate may also comprise paper mineral fillers such as, for example, kaolin, talc, titanium dioxide, aluminum silicate, alumina hydrate, calcined kaolin, among others. Paper-based mineral fillers can be introduced in bulk into the substrate to increase the opacity and improve the printability, especially offset, of the substrate. The choice of paper mineral fillers used in the substrate can influence the contrast of the marking obtained. In particular, it is preferable to use a mineral filler absorbing in the infrared to improve the contrast obtained during the laser marking. The Applicant has highlighted the fact that, among the usual paper mineral fillers, alumina trihydrate and especially calcined kaolin make it possible to reinforce the contrast of the marking made with the CO2 laser. It is for example possible to use calcined kaolin marketed under the name ANSILEX 93 by the company ENGELHARD.

The substrate may further 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 as a mixture. These surface binders may or may not be accompanied by insolubilizers and surface bonding products to provide better final printability, especially offset, to the substrate.

Preferably, the surface binders may be PVA, in particular highly hydrolysed, for example more than 94%, which offers a high contrast, for example with CO2 laser marking. The substrate may be a plastic substrate.

The substrate may comprise paper fibers. The substrate may be a paper. The substrate may for example be based on cellulosic fibers (in particular cotton fibers) and / or natural organic fibers other than cellulosic and / or synthetic fibers, for example such as polyester or polyamide fibers and / or optionally mineral fibers, for example such as glass fibers. The substrate may comprise one or more impressions, for example made by offset printing, intaglio, laser, inkjet, gravure printing, screen printing and / or flexography, among others. The concentration of material capable of forming a colored mark may be between 0.1 and 10% by dry weight relative to the weight of the substrate, and preferably between 1 and 10%. The concentration of tampering agent reacting during an attempt at chemical erasure of the mark may be included, where appropriate for each tampering 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 faces an amount of material of between 0.1 and 3 g / m 2 by dry weight. The substrate may have a basis weight of between 30 and 200 g / m 2. The substrate may comprise a conventional or security ink, especially fluorescent, phosphorescent, magnetic, photochromic, thermochromic, piezochrome, among others. The substrate may include an authentication and / or identification security element. Among the security elements, some are detectable to the naked eye, in visible light, without the use of a particular device. These security features include, for example, a watermark, colored fibers or boards, printed, metallized or holographic wires, holographic foils, or optically variable impressions. These security elements are called first level.

Other types of security elements are detectable only with a relatively simple device such as a lamp emitting in the ultraviolet or infrared. These security elements comprise, for example, fibers, boards, strips, wires or particles. These security elements may be visible to the naked eye or not, being for example luminescent under a lighting of a Wood lamp emitting in a wavelength of 365 nm. These security elements are said to be second level. Other types of security elements still require for their detection a more sophisticated detection device. These security elements are for example capable of generating a specific signal when they are subjected, simultaneously or not, to one or more external excitation sources. The automatic detection of the signal makes it possible to authenticate, if necessary, the document. These security elements comprise for example tracers in the form of 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 said to be third level. The substrate may comprise at least one first, second and / or third level security element.

The invention further relates, in another of its aspects, the use of a laser marker substrate, as defined above, in a security document and / or a security article. The security document may for example be a means of payment, such as a bank note, a check, a voucher or a restaurant ticket, an identity document such as an identity card or a document such as a visa, a passport or driver's license, a lottery ticket, a ticket, or a ticket to cultural or sporting events. The security article may for example be selected from a security tag, a package, including a packaging for drugs or for food, for cosmetics, perfumes, electronic parts, spare parts, a sheet used in the medical or hospital field, including a paper used to make sterilization packaging, or a paper art.

The invention further relates, in another of its aspects, to a method of manufacturing a laser marker substrate as defined above. The process may comprise the step consisting in introducing, by impregnation, especially in a size press process, or by surfacing, in particular according to a press-film process, during the production of the substrate on a paper machine, the material capable of forming a mark. stained under subsequent laser irradiation. Examples Preliminary remark The substrates described in the following presented examples were labeled with a CO2 laser having the following characteristics: laser of wavelength 10600 nm, beam expander x 2, focal length 125 nm, 127 nm lens, and 3500 mm / s speed. The labeled papers were then evaluated in terms of the contrast of the laser marking by an optical density measurement, as well as in terms of the resistance of the marking to attempts of chemical erasure with acid, sodium hydroxide, sodium hypochlorite , ethanol and toluene.

Formulation 1 (control sample) A laser-markable substrate is made using a conventional paper machine and using the following formulation according to the prior art. Pulpy (Schopper-Riegler 35 ° refining - ° SR) - Long fibers: 60%, - Short fibers: 40%.

Mixer - Mineral feed: 15% by dry weight of calcined kaolin. Headbox - Retention agent: 1.5% by mass relative to the paper production of the cationic starch paper machine, for example based on potato, - Adhesive agent: 3.5% by weight mass of the commercial solution versus paper production of the cationic emulsion paper machine based on rosin. Size press (for 2000 L) - Binder: 200 kg of modified corn starch, - Binder: 20 kg of polyvinyl alcohol (PVA), - Antifoam: 0.35 kg of an aqueous emulsion of a mixture aliphatic hydroxyl compounds, - insolubilizing agent: 3 kg of a commercial solution of modified glyoxal, 10 - material sensitive to laser marking: 250 kg of LAZERFLAIR 800 sold by MERCK. The results show that a yellow-brown contrast is obtained, not black, during the CO2 laser marking of the paper manufactured according to the formulation 1. It is noted that it is easy to erase said laser marking with sodium hypochlorite. 12% chlorine or 5% sodium hydroxide solution. Formulation 2 A laser-markable substrate was made using a conventional paper machine with the same formulation as before but replacing LAZERFLAIR 800 with an ammonium octa-molybdate. The results show that this time we obtain a dark gray contrast during the CO2 laser marking of the paper manufactured according to the formulation 2. It is noted that it is easy to erase said laser marking with hypochlorite of sodium at 12% chlorine or with 5% sodium hydroxide solution. Formulations 3, 4, 5, 6, 7 and 8 A laser-markable substrate is made using a conventional paper machine using the following formulation: Pulp (Schopper-Riegler 35 ° Refiner - ° SR) - Long fibers: 60%, - Short fibers: 40%. Mixer - Mineral fillers: 15% by dry weight. Headbox - Retention agent: 1.5% by mass relative to the paper production of the cationic starch paper machine, for example based on potato, - Adhesive agent: 3.5% by weight mass of the commercial solution versus paper production of the cationic emulsion paper machine based on rosin. Size press (for 2000 L) - Binder: 200 kg of modified corn starch, - Binder: 20 kg of polyvinyl alcohol (PVA), - Antifoam: 0.35 kg of an aqueous emulsion of a mixture aliphatic hydroxyl compounds, - insolubilizing agent: 3 kg of a commercial solution of modified glyoxal, - material sensitive to laser marking: 250 kg of ammonium octamolybdate. Experiments with different types of paper mineral fillers other than kaolin (used in formulation 2) are carried out: rutile titanium dioxide (formulation 3), precipitated calcium carbonate (formulation 4), sodium silicoaluminate (formulation 5), ), aluminum hydroxide (formulation 6), talc (formulation 7) and calcined kaolin (formulation 8). The results of marking tests (measurement of optical density) by CO2 laser irradiation are as follows: Formulation Formulation Formulation Formulation 5 Formulation Formulation Formulation 2 with 3 with 4 with with 6 with 7 with 8 with kaolin silicoaluminate carbonate dioxide hydroxide talc kaolin titanium rutile calcined aluminum sodium calcium precipitated 0.02 0.02 0.03 0.13 0.10 0.08 0.23 The results show that we obtain a better contrast of laser irradiation marking when using calcined kaolin, sodium silicoaluminate or aluminum hydroxide as a paper mineral filler. However, it is then easy to clear the laser mark with sodium hypochlorite 12% chlorine or 5% sodium hydroxide solution. Formulations 9, 10, 11 and 12 Four markable substrates are produced by laser irradiation on a conventional paper machine according to the following common mass formulation (before surfacing): Pulp (35 degree Schopper-Riegler - ° SR) - Long fiber : 60%, - Short fiber: 40%. Mixer - Mineral feed: 15% by dry weight of calcined kaolin. Headbox - Retention agent: 1.5% by mass relative to the paper production of the cationic starch paper machine, for example based on potato, - Adhesive agent: 3.5% by weight mass of the commercial solution versus paper production of the cationic emulsion paper machine based on rosin. The following four size press formulations are then applied in line on the previous fibrous mattress: Size press (for 2000 L) for formulation 9 - Binder: 200 kg of modified corn starch - Antifoam: 0.35 kg of an aqueous emulsion of an aliphatic mixture of hydroxyl compounds, - insolubilizing agent: 3 kg of a modified glyoxal commercial solution, - material sensitive to laser marking: 250 kg of ammonium octamolybdate. Size press (for 2000 L) for the formulation 10 - Binder: 200 kg of modified corn starch, - Binder: 20 kg of polyvinyl alcohol (PVA), - antifoam: 0.35 kg of an aqueous emulsion of an aliphatic mixture of hydroxyl compounds, - insolubilizing agent: 3 kg of a modified glyoxal commercial solution, - material sensitive to laser marking: 250 kg of ammonium octamolybdate. Size press (for 2000 L) for the formulation 11 - Binder: 100 kg of polyvinyl alcohol (PVA), - antifoam: 0.35 kg of an aqueous emulsion of an aliphatic mixture of hydroxyl compounds, - Agent d insolubilization: 3 kg of a commercial solution of modified glyoxal, material sensitive to laser marking: 250 kg of ammonium octamolybdate. Size press (surfacing, for 2000 L) for the formulation 12 - Binder: 100 kg of polyvinyl alcohol (PVA), - antifoam: 0.35 kg of an aqueous emulsion of an aliphatic mixture of hydroxyl compounds, - Agent surface bonding: 50 kg of modified acrylic styrene déricé, - insolubilisation agent: 3 kg of a modified glyoxal commercial solution, - material sensitive to laser marking: 250 kg of ammonium octamolybdate.

It is noted that better results in terms of contrast of the marking by CO2 laser irradiation are obtained on the paper manufactured according to the formulations 11 and 12 when a surface binder in the form of polyvinyl alcohol (PVA) is used. However it is then easy to erase the laser mark with bleach at 12% chlorine or 5% sodium hydroxide solution.

Furthermore, the paper manufactured according to the formulation 12 has a better offset, laser and ink jet printability than that manufactured according to the formulation 11. Formulation 13 A laser-markable paper substrate according to the invention is produced on a paper machine Traditional with the following characteristics: Pulpy (refining at 35 degrees Schopper-Riegler - ° SR) - Long fiber: 60%, - Short fiber: 40%. Mixer - Mineral filler: 15% dry weight of calcined kaolin, - Xanthene tamper (colored indicator): 0.3% by weight of the commercial solution compared to paper production of the paper machine . Headbox - Retention agent: 1.5% by mass relative to the paper production of the cationic starch paper machine, for example based on potato, - Adhesive agent: 3.5% by weight mass of the commercial solution versus paper production of the cationic emulsion paper machine based on rosin.

 Size press (surfacing, for 2000 L) - Binder: 100 kg polyvinyl alcohol (PVA), - antifoam: 0.35 kg of an aqueous emulsion of an aliphatic mixture of hydroxyl compounds, - insolubilization agent: 3 kg of a commercial solution of modified glyoxal, - Material sensitive to laser marking: 250 kg of ammonium octamolybdate, - Tampering agent: 20 kg of manganese chloride. A paper is obtained which has a high contrast, in particular by marking with CO2 laser irradiation. In addition, an attempt to erase the laser mark, for example using sodium hypochlorite at 12 degrees of chlorine or 5% sodium hydroxide solution, results in the appearance of a Brown colored stain that reveals the attempt to falsify the mark on the paper. An attempt to erase the laser mark with acid, such as for example 5% sulfuric acid, causes the appearance of a pink colored stain which also reveals the attempt to falsify the marking. on the substrate. The expression having one is synonymous with having at least one.

Claims (24)

REVENDICATIONS1. Laser-marked substrate, comprising at least one material capable of forming a colored mark under laser irradiation, and at least one tampering agent producing a visible coloration during an attempt to chemically erase the mark. 2. Substrate according to claim 1, the tamper agent being incorporated by impregnation, surfacing, coating or spraying. 3. Substrate according to one of the preceding claims, the tampering agent for preventing the chemical erasure of the mark with at least one of the following compounds: an oxidant, a strong or weak base, an acid strong or weak, - a polar or apolar solvent. 15 4. Substrate according to one of the preceding claims, the tampering agent for preventing the chemical erasure of the mark with oxidants and being chosen from: - derivatives of manganese, nickel, cobalt or cerium, and in particular their salts, - diphenyl-diphenyl, its sulphated derivatives or its phosphate derivatives, vanadium derivatives, 4,4'-diaminodinaphthyl (1,1 '), orthophenylene isothiourea; primulin; guanidine derivatives such as diarylguanidine such as, for example, diphenylguanidine; or thiazole, benzothiazole or aminonaphthothiazole derivatives. 5. Substrate according to one of the preceding claims, the tampering agent for preventing chemical erasure with strong and / or weak bases and being chosen from: - the manganese, nickel, cobalt derivatives or cerium, and in particular their salts, colored indicators such as paranitrophenol, phenolphthalein, pyranine or a xanthene derivative. 6. Substrate according to any one of the preceding claims, the tampering agent for preventing the chemical erasure of the mark with weak and / or strong acids and being chosen from: a colored indicator such as a derivative xanthene, - ferric ferric chloride added with ferric chloride, or - a derivative of thiazole, benzothiazole or aminonaphthothiazole. 7. Substrate according to any one of the preceding claims, the infalesification agent for preventing the chemical erasure with polar and / or apolar solvents and being chosen from water insoluble dyes but soluble in oils and solvents, especially in ethanol and / or toluene. 8. Substrate according to any one of the preceding claims, the tamper agent being a manganese derivative, especially a manganese salt and preferably manganese chloride. A substrate according to any one of the preceding claims, comprising a single tamper preventing chemical erasure by a plurality of erasers. 10. Substrate according to any one of the preceding claims, comprising several tampering agents for preventing respectively the chemical erasure with several erasers. 20 11. Substrate according to any one of the preceding claims, the material capable of forming a colored mark under laser irradiation being incorporated by impregnation, surfacing, coating or spraying. 12. Substrate according to any one of the preceding claims, the material being suitable for marking with a CO2 laser and / or a YAG laser. 25 13. Substrate according to any one of the preceding claims, the material capable of forming a mark being chosen from molybdates, tungstates and vanadates, and in particular octamolybdates, heptamolybdates and molybdate amines. Substrate according to any one of the preceding claims, comprising an infrared absorbing inorganic filler, especially calcined kaolin or alumina trihydrate. 15. Substrate according to any one of the preceding claims, comprising polyvinyl alcohol (PVA), in particular highly hydrolysed, especially more than 94%. 16. The substrate according to any one of the preceding claims, being a paper, especially based on cellulosic fibers. The substrate of any one of claims 1 to 15, being a plastic substrate. 18. Substrate according to any one of the preceding claims, comprising one or more impressions. 10 19. The substrate as claimed in any one of the preceding claims comprising at least one authentication and / or identification security element. 20. Substrate according to any one of the preceding claims, the concentration of material capable of forming a colored mark being between 0.1 and 10% by dry weight relative to the weight of the substrate, preferably between 1 and 10%. 15 21. Substrate according to any one of the preceding claims, the tampering agent concentration being between 0.01 and 5% by dry weight relative to the weight of the substrate. 22. Substrate according to any one of the preceding claims, the substrate comprising on each of its faces an amount of material of between 0.1 and 3 g / m 2 by dry weight. 23. Use of a laser marker substrate according to any one of the preceding claims in a security document and / or security article. 24. A method of manufacturing a laser-marked substrate according to any one of claims 1 to 20, comprising the step of introducing by impregnation, in particular according to a size press process, or by surfacing, in particular according to a film method. press, during the production of the substrate on a paper machine, the material capable of forming a colored mark under laser irradiation.