EP4096930A1 - Method for producing markings of different irreversible colours from the same composition - Google Patents

Method for producing markings of different irreversible colours from the same composition

Info

Publication number
EP4096930A1
EP4096930A1 EP21705884.1A EP21705884A EP4096930A1 EP 4096930 A1 EP4096930 A1 EP 4096930A1 EP 21705884 A EP21705884 A EP 21705884A EP 4096930 A1 EP4096930 A1 EP 4096930A1
Authority
EP
European Patent Office
Prior art keywords
marking
support
matrix
color
producing
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.)
Pending
Application number
EP21705884.1A
Other languages
German (de)
French (fr)
Inventor
Jean-François LETARD
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.)
Olikrom
Original Assignee
Olikrom
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 Olikrom filed Critical Olikrom
Publication of EP4096930A1 publication Critical patent/EP4096930A1/en
Pending 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
    • 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
    • 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
    • B41M5/28—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using thermochromic compounds or layers containing liquid crystals, microcapsules, bleachable dyes or heat- decomposable compounds, e.g. gas- liberating
    • 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
    • B41M5/34—Multicolour thermography

Definitions

  • TITLE PROCESS FOR MAKING A MARKING OF DIFFERENT IRREVERSIBLE COLORS FROM THE SAME COMPOSITION
  • the invention relates to a method of producing a marking of different colors from the same composition.
  • markings are widely used whether from inks, paints, varnishes, or directly in the material in the case of plastics in particular to make patterns intended to fight against fraud or in a decorative purpose.
  • a known process consists in degrading the material conferring a base color, by temperature for example so that the organic material turns brown or even blackens.
  • the black associated with this browning is nothing other than a carbonization of said material and the marking produced appears in black compared to the base color.
  • the only color of the marking is therefore black without any possibility of producing different colors and if this were the case, it could only be shades of gray, difficult to control.
  • Another solution for carrying out a color marking according to a given surface graphics consists in providing several layers of different colors superimposed on the same support and in removing the layers necessary to reveal the desired color corresponding to a given layer according to a defined surface graphics.
  • green can be eliminated in order to reveal the red part of the surface graphic and / or the green layer and the red layer can be eliminated to reveal the blue part of the surface graphic.
  • the difficulty consists in being able to remove very thin layers and the work consists of an ablation so that traces of the ablation may remain, the definition remains limited and the duration of such a service is long with an extremely limited quality. .
  • thermochromic pigments absorb infrared radiation, in a well-known manner.
  • thermochromic pigments when subjected to infrared radiation, changes color. This is very interesting for determining at what temperature a product is at a given moment, but the material returns to its initial color as soon as the submission to infrared radiation ceases. Such a process is reversible and therefore does not find application in the field of security.
  • a patent EP 2722367 is known from the prior art which describes a composition of dyes, soluble in methylene chloride and capable of changing color depending on the type of infrared energy emitted, with a maximum absorption at- above llOOnm.
  • This formulation makes it possible to design different compositions capable of generating a color with more or less density.
  • This modular formulation increases the range of colors available.
  • three compositions from the same base are superimposed with a complex process of implementation and all the superimposed layers are treated by three lasers at a given power and at a given frequency to reveal a color. Indeed, only the composition of the layer concerned reacts with the associated laser parameters.
  • PCT / EP2016 / 061069 similarly describes a superposition of layers capable of generating a given color under activation by a laser of a given wavelength.
  • This document does not reiterate this process but wishes to propose a more ecological composition and wishes to use a solvent that is more respectful of the environment, that is to say water, or even 90% water.
  • Document US 4861620 describes a method of changing the colors of the pigments present on the surface of a product by increasing the temperature of the product by means of a laser. This phenomenon is linked to the loss of water molecules contained in thermochromium pigments.
  • the thermochromium pigments used in this method require a high temperature to change color.
  • a high temperature causes the deterioration of the product itself.
  • Document DE 10054803 relates for its part to a process for lightening a plastic surface comprising several layers of materials each comprising a pigment capable of lightening depending on the temperature to which each pigment is exposed. This configuration is very limiting and requires the use of different pigments on several layers of materials.
  • the present invention relates to a color marking in a composition attached to a matrix, that is to say a functionalized coating of the ink, paint or varnish type, to be attached to a support, or to be integrated into the support, by example a functionalized plastic material, excluding any ablation of material constituting said matrix.
  • Such color markings are much more complex to reproduce by fraudsters, are directly visible to the owner, can be recognized without having to you might as well enter indications in natural language.
  • a cardholder's card is recognizable by the colors used, the graphics of the marking, the combination of the colors of the marking which confer a unique identification.
  • the aim is also to allow high-speed marking work, therefore inexpensive, tamper-proof to guarantee safety and impossible to reproduce without knowledge of the marking parameters, of the composition used and of the irreversible color change pigments induced by a thermo- and / or photo-assisted process.
  • the solution according to the present invention consists in using a matrix integrating at least one irreversible photo-induced and / or thermochromium pigment.
  • This at least one photo-induced and / or thermochromium pigment requires an energy intensity to go from a first initial fundamental state to an excited state and then to come to a second stable ground state, by generating a given color. Irreversibility results from the fact that it would take too much energy to bring it back to its first ground state, with its base color. Indeed, the necessary energy level would induce degradation of the matrix which necessarily has limits of resistance to degradation.
  • the solution according to the present invention is aimed at a process consisting in integrating at least one irreversible photo-induced and / or thermochromium compound in a matrix, in subjecting it to an activation energy sufficient to cause it to change state, said energy. to be less than the degradation energy of said matrix.
  • the energy input is produced from a pulsed laser beam and more particularly a fiber laser. More particularly still, the working wavelength of said fiber laser is 1.06 ⁇ m.
  • the power of the fiber laser is 20W to adapt the intensity of the energy emitted according to the desired marking. The power of the laser is lower, for a given frequency, than the degradation energy of the matrix.
  • thermochromium pigment has the property of changing colors depending on the temperature to which it is exposed.
  • a photo-induced pigment has the property of changing colors depending on the light to which it is exposed.
  • the matrix containing the pigment is not exposed to too high a temperature which could degrade it.
  • the matrix is thus subjected to sufficient activation energy to cause the pigment to change state by electronic excitation, but this activation energy remains lower than the degradation energy of the matrix.
  • the pigments developed by the company Olikrom have the photo-induced and / or thermochromic qualities necessary for the present process.
  • FIG. 1 represents a typical graph for a base color, dark blue, this by varying the power on the ordinate and the frequency on the abscissa.
  • FIG. 2 represents a typical graph for a base color, brown, this by varying the power on the ordinate and the frequency on the abscissa.
  • FIG. B represents a typical graph for a basic color, turquoise blue, this by varying the power on the ordinate and the frequency on the abscissa.
  • FIG. 4 represents a typical graph for a basic color, black, this by varying the power on the ordinate and the frequency on the abscissa.
  • the marking method according to the present invention is illustrated with regard to a control which is a support, for example polycarbonate, or having received a layer of the matrix, for example a polyurethane, comprising at least one photo-induced pigment and / or thermochromium, either having been functionalized in the mass with said composition, making it possible to show the variations in power and in frequency.
  • the exemplifying choice implements a support in the form of a credit card on which a checkerboard with the frequency on the x-axis and the power on the y-axis.
  • the material of the support has a known point of degradation of the material, this point being variable depending on the nature of the materials.
  • marking means any inscription, any geometric surface or wireframe shape, produced on the surface of said support or in the support when the material has been functionalized in the mass.
  • the references 1 to 4 show in the checkerboard, the measurement points for each color tested and the markings consist of square pixels of a few tenths of a millimeter each.
  • integrated into a support is understood to mean:
  • thermochromium pigment either the introduction of at least one irreversible photo-induced and / or thermochromium pigment into the support during the manufacture of said support
  • At least one photo-induced and / or thermochromic pigment integrated in a matrix attached in a layer on the surface of said support.
  • the color marking process comprises the succession of the following steps:
  • the matrix comprises a single pigment to obtain a marking of different colors and a single layer of ink.
  • the method consists in emitting an energy beam with a pulsed laser, in particular a fiber laser, even more a fiber laser emitting at the wavelength of 1.06 ⁇ m.
  • the nominal power is 20W.
  • the frequency f expressed in kilohertz KHz, increases by 20kHz for each next pixel of the checkerboard, this for the same percentage of the nominal power.
  • the power is expressed in Watt and goes from 0 to 100%.
  • the maximum power emitted remains below the degradation power of the matrix.
  • the color obtained is defined according to the reference L, a, b, de the CIELAB color space. This repository consists of defining:
  • - b represents the value on a blue / yellow axis.
  • the tests are carried out on a polycarbonate support covered with a layer of the matrix according to the present invention, arranged in the form of pixels, in checkers.
  • the at least one pigment could have been incorporated into the polycarbonate material directly.
  • the matrix incorporates a single irreversible photo-induced and / or thermochromium pigment, the basic color of which, in the visible, is dark blue defined in the table by the parameters L, a, b.
  • L, a, b the basic color of which, in the visible, is dark blue defined in the table by the parameters L, a, b.
  • the second test is carried out on a brown background from a matrix incorporating a single photo-induced pigment and / or irreversible thermochromium of brown color with an L, a, b colorimetry indicated in Table 2 below.
  • Brown gives variations in greens and yellows. Greens appear when the intensity increases, it is the color change from brown to green and the frequency limits the color change from yellow to green. It can be seen that brown is quickly transformed into yellow and green colors. Yellow quickly becomes predominant as the frequency increases.
  • the third test is carried out on a turquoise blue background from a matrix incorporating a photo-induced and / or irreversible thermochromium pigment, turquoise blue with the parameters L, a, b defined in Table 3 below. Turquoise blue is therefore a lighter blue. The impact is important because the colors that appear during variations in power and frequency change from beige to burgundy through light oranges.
  • the fourth test is carried out on a black background with color variations from black to beige, orange, purple and pink.
  • the parameters L, a, b are defined in Table 4 below. [00BB] [Tables 4]
  • the tests were carried out with a single photo-induced pigment and / or thermochromium.
  • the method provides for the introduction of at least one pigment and it is possible to combine two or more photo-induced and / or thermochromic pigments to adjust and obtain an infinity of colors.

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  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Thermal Transfer Or Thermal Recording In General (AREA)
  • Heat Sensitive Colour Forming Recording (AREA)

Abstract

Method for producing, on a medium, markings of different colours from the same composition, according to a given graphic design, characterised in that it consists of the succession of the following steps: - integrating into said medium a matrix comprising at least one irreversible photo induced and/or thermochromic pigment, - emitting an energy beam onto the surface of said medium integrating the matrix comprising the at least one irreversible photo induced and/or thermochromic pigment, with a pulsed laser, according to the graphic design of the markings to be produced on said medium, - varying frequency and power parameters of said energy beam to generate a desired colour in a given region of the graphic design of said markings.

Description

DESCRIPTION DESCRIPTION
TITRE : PROCEDE DE REALISATION D'UN MARQUAGE DE COULEURS DIFFERENTES IRREVERSIBLES A PARTIR D'UNE MÊME COMPOSITION TITLE: PROCESS FOR MAKING A MARKING OF DIFFERENT IRREVERSIBLE COLORS FROM THE SAME COMPOSITION
[0001] L'invention concerne un procédé de réalisation d'un marquage de couleurs différentes à partir d'une même composition. The invention relates to a method of producing a marking of different colors from the same composition.
[0002] On sait que les marquages sont très utilisés que ce soit à partir des encres, des peintures, des vernis, ou directement dans la matière dans le cas des matières plastiques notamment pour réaliser des motifs destinés à lutter contre la fraude ou dans un but décoratif. Un procédé connu consiste à dégrader la matière conférant une couleur de base, par la température par exemple si bien que la matière organique brunit voire noircit. Le noir lié à ce brunissement n'est autre qu'une carbonisation de ladite matière et le marquage réalisé apparaît en noir par rapport à la couleur de base. La seule couleur du marquage est donc le noir sans aucune possibilité de produire des couleurs différentes et si cela était le cas, ce ne pourrait être que des nuances de gris, difficiles à maîtriser. We know that markings are widely used whether from inks, paints, varnishes, or directly in the material in the case of plastics in particular to make patterns intended to fight against fraud or in a decorative purpose. A known process consists in degrading the material conferring a base color, by temperature for example so that the organic material turns brown or even blackens. The black associated with this browning is nothing other than a carbonization of said material and the marking produced appears in black compared to the base color. The only color of the marking is therefore black without any possibility of producing different colors and if this were the case, it could only be shades of gray, difficult to control.
[0003] Une autre solution pour effectuer un marquage de couleur suivant un graphisme surfacique donné, consiste à prévoir plusieurs couches de différentes couleurs superposées sur un même support et à retirer les couches nécessaires pour faire apparaître la couleur recherchée correspondant à une couche donnée suivant un graphisme surfacique défini. Ainsi, on peut prendre l'exemple suivant de couleurs superposées : bleu pour la couche de base, rouge pour la couleur intermédiaire et vert pour la couleur de la couche du dessus. Ainsi, on peut éliminer suivant un premier profil surfacique donné du vert pour faire apparaître la partie rouge du graphisme surfacique et/ou on peut éliminer la couche verte et la couche rouge pour faire apparaître la partie bleue du graphisme surfacique. On obtient ainsi un graphisme surfacique avec trois couleurs. La difficulté consiste à pouvoir éliminer des couches très fines et le travail consiste en une ablation si bien qu'il peut rester des traces de l'ablation, la définition reste limitée et la durée d'une telle prestation est longue avec une qualité extrêmement limitée. Another solution for carrying out a color marking according to a given surface graphics, consists in providing several layers of different colors superimposed on the same support and in removing the layers necessary to reveal the desired color corresponding to a given layer according to a defined surface graphics. Thus, we can take the following example of superimposed colors: blue for the base coat, red for the intermediate color and green for the color of the top coat. Thus, according to a first given surface profile, green can be eliminated in order to reveal the red part of the surface graphic and / or the green layer and the red layer can be eliminated to reveal the blue part of the surface graphic. We thus obtain a surface graphics with three colors. The difficulty consists in being able to remove very thin layers and the work consists of an ablation so that traces of the ablation may remain, the definition remains limited and the duration of such a service is long with an extremely limited quality. .
[0004] L'art antérieur propose également l'intégration de pigments thermo chromes dans la matière. Ces pigments thermo chrome absorbent les rayonnements infrarouges, ceci de façon parfaitement connue. De fait le matériau qui intègre de tels pigments thermo chrome, lorsqu'il est soumis à un rayonnement infrarouge, change de couleur. Ceci est très intéressant pour déterminer à quelle température se trouve un produit à un moment donné mais le matériau retrouve sa couleur initiale dès que la soumission à un rayonnement infrarouge cesse. Un tel procédé est réversible et donc ne trouve pas application dans le domaine de la sécurité. [0004] The prior art also proposes the integration of thermochromic pigments in the material. These thermochromium pigments absorb infrared radiation, in a well-known manner. In fact the material which incorporates such thermochromic pigments, when subjected to infrared radiation, changes color. This is very interesting for determining at what temperature a product is at a given moment, but the material returns to its initial color as soon as the submission to infrared radiation ceases. Such a process is reversible and therefore does not find application in the field of security.
[0005] On connaît de l'art antérieur un brevet EP 2722367 qui décrit une composition de colorants, solubles dans le chlorure de méthylène et susceptibles de changer de couleur suivant le type d'énergie infrarouge émise, avec un maximum d'absorption au-dessus de llOOnm. Cette formulation permet de concevoir des compositions différentes et aptes à générer une couleur avec plus ou moins de densité. Cette formulation modulable permet d'augmenter la gamme de couleurs disponibles. Dans un exemple, trois compositions issues de la même base, sont superposées avec un processus complexe de mise en oeuvre et l'ensemble des couches superposées est traitée par trois lasers à une puissance et à une fréquence données pour faire apparaître une couleur. En effet, seule la composition de la couche concernée réagit avec les paramètres laser associés. [0005] A patent EP 2722367 is known from the prior art which describes a composition of dyes, soluble in methylene chloride and capable of changing color depending on the type of infrared energy emitted, with a maximum absorption at- above llOOnm. This formulation makes it possible to design different compositions capable of generating a color with more or less density. This modular formulation increases the range of colors available. In one example, three compositions from the same base are superimposed with a complex process of implementation and all the superimposed layers are treated by three lasers at a given power and at a given frequency to reveal a color. Indeed, only the composition of the layer concerned reacts with the associated laser parameters.
[0006] Un autre document de l'art antérieur US 4816367 propose des microcapsules contenant des colorants et un révélateur de couleur, sachant que chaque microcapsule est associée à une des trois couleurs fondamentales. L'enveloppe de chacun des trois types de microcapsules, comprend un absorbeur d'énergie, sensible chacun à une longueur d'ondes donnée si bien que lorsque le rayonnement correspond au bleu, seules les microcapsules du bleu réagissent, libérant la couleur bleue tandis que les autres microcapsules de couleur différentes, restent encapsulées. Il est ainsi possible de rapporter une couleur donnée dans une couche comprenant différentes microcapsules de différentes couleurs, suivant un motif donné. Another document of the prior art US 4816367 proposes microcapsules containing dyes and a color developer, knowing that each microcapsule is associated with one of the three fundamental colors. The envelope of each of the three types of microcapsules, includes an energy absorber, each sensitive to a given wavelength so that when the radiation corresponds to blue, only the microcapsules of the blue react, releasing the blue color while the other microcapsules of different colors remain encapsulated. It is thus possible to report a given color in a layer comprising different microcapsules of different colors, according to a given pattern.
[0007] Le PCT/EP2016/061069 décrit de la même façon une superposition de couches susceptible de générer une couleur donnée sous l'activation par un laser d'une longueur d'ondes donnée. Ce document ne réinvente pas ce procédé mais souhaite proposer une composition plus écologique et souhaite recourir à un solvant plus respectueux de l'environnement, c'est à dire de l'eau, voire 90% d'eau. [0008] Le document US 4861620 décrit une méthode de changement de couleurs des pigments présents sur la surface d'un produit par l'augmentation de la température du produit au moyen d'un laser. Ce phénomène est lié à la perte de molécules d'eau contenues dans les pigments thermo chrome. Cependant les pigments thermo chrome utilisés dans cette méthode nécessitent une température élevée pour changer de couleur. Or une température élevée entraîne la détérioration du produit lui-même. En effet le produit exposé à une température trop importante entraîne la formation de bulles sur la surface du produit qui donc se déforme. Un tel produit est inutilisable dans les procédés industriels cités tels que le marquage sur encre, dans une matière plastique, dans un environnement contraint laminé. [0007] PCT / EP2016 / 061069 similarly describes a superposition of layers capable of generating a given color under activation by a laser of a given wavelength. This document does not reinvent this process but wishes to propose a more ecological composition and wishes to use a solvent that is more respectful of the environment, that is to say water, or even 90% water. [0008] Document US 4861620 describes a method of changing the colors of the pigments present on the surface of a product by increasing the temperature of the product by means of a laser. This phenomenon is linked to the loss of water molecules contained in thermochromium pigments. However, the thermochromium pigments used in this method require a high temperature to change color. However, a high temperature causes the deterioration of the product itself. In fact, the product exposed to too high a temperature causes the formation of bubbles on the surface of the product which therefore deforms. Such a product cannot be used in the cited industrial processes such as marking on ink, in a plastic material, in a constrained laminated environment.
[0009] Le document DE 10054803 concerne quant à lui un procédé d'éclaircissement d'une surface plastique comprenant plusieurs couches de matériaux comprenant chacune un pigment apte à s'éclaircir selon la température à laquelle chaque pigment est exposé. Cette configuration est très limitante et nécessite de mettre en oeuvre différents pigments sur plusieurs couches de matériaux. [0009] Document DE 10054803 relates for its part to a process for lightening a plastic surface comprising several layers of materials each comprising a pigment capable of lightening depending on the temperature to which each pigment is exposed. This configuration is very limiting and requires the use of different pigments on several layers of materials.
[0010] La présente invention vise un marquage couleur dans une composition rapportée dans une matrice, c'est-à-dire un revêtement fonctionnalisé du type encre, peinture ou vernis, à rapporter sur un support, ou à intégrer dans le support, par exemple une matière plastique fonctionnalisée, en excluant toute ablation de matière constituant ladite matrice. The present invention relates to a color marking in a composition attached to a matrix, that is to say a functionalized coating of the ink, paint or varnish type, to be attached to a support, or to be integrated into the support, by example a functionalized plastic material, excluding any ablation of material constituting said matrix.
[0011] Il existe une demande du marché pour réaliser des marquages en couleur sur un support, de grande précision, de grande reproductibilité, sans variation des couleurs du marquage au cours du temps, non falsifiables sauf à dégrader la matrice, ceci sur des supports en matériaux divers tels que ceux utilisés pour la fabrication de cartes bancaires, des documents d'identité comme les cartes d'identité, généralement constituées d'une feuille de matière plastique mais aussi sur des céramiques, du verre ou du métal pour de la décoration ou des signatures d'artiste. L'exemple retenu des cartes bancaires est un bon exemple pour soutenir l'intérêt du procédé selon la présente invention car il réunit toutes les problématiques et la présente invention y apporte toutes les solutions. [0011] There is a market demand for making color markings on a support, of great precision, of great reproducibility, without variation of the colors of the marking over time, not falsifiable except to degrade the matrix, this on supports in various materials such as those used for the manufacture of bank cards, identity documents such as identity cards, generally made of a plastic sheet but also on ceramics, glass or metal for decoration or artist signatures. The example of bank cards is a good example to support the interest of the method according to the present invention because it brings together all the problems and the present invention provides all the solutions.
[0012] De tels marquages en couleur sont beaucoup plus complexes à reproduire par des fraudeurs, sont directement visibles par le propriétaire, peuvent être reconnus sans pour autant inscrire des indications en langage naturel. Ainsi, la carte d'un porteur est reconnaissable aux couleurs utilisées, au graphisme du marquage, à la combinaison des couleurs du marquage qui confèrent une identification unique. Le but est aussi de permettre un travail de marquage à grande vitesse, donc peu coûteux, infalsifiable pour garantir la sécurité et impossible à reproduire sans la connaissance des paramètres de marquage, de la composition utilisée et des pigments à changement de couleur irréversibles induit par un processus thermo- et/ou photo-assisté. [0012] Such color markings are much more complex to reproduce by fraudsters, are directly visible to the owner, can be recognized without having to you might as well enter indications in natural language. Thus, a cardholder's card is recognizable by the colors used, the graphics of the marking, the combination of the colors of the marking which confer a unique identification. The aim is also to allow high-speed marking work, therefore inexpensive, tamper-proof to guarantee safety and impossible to reproduce without knowledge of the marking parameters, of the composition used and of the irreversible color change pigments induced by a thermo- and / or photo-assisted process.
[0013] La solution selon la présente invention consiste à utiliser une matrice intégrant au moins un pigment photo induit et/ou thermo chrome, irréversible. Ce au moins un pigment photo-induit et/ou thermo chrome nécessite une intensité énergétique pour passer d'un premier état initial fondamental à un état excité puis à venir à un second état fondamental stable, en générant une couleur donnée. L'irréversibilité résulte du fait qu'il faudrait un niveau d'énergie trop important pour le ramener à son premier état fondamental, avec sa couleur de base. En effet, le niveau énergétique nécessaire induirait une dégradation de la matrice qui présente nécessairement des limites de résistance à la dégradation. La solution selon la présente invention vise un procédé consistant à intégrer au moins un composé photo induit et/ou thermo chrome, irréversible, dans une matrice, à le soumettre à une énergie d'activation suffisante pour le faire changer d'état, ladite énergie devant être inférieure à l'énergie de dégradation de ladite matrice. De façon perfectionnée, l'apport d'énergie est réalisé à partir d'un faisceau laser impulsionnel et plus particulièrement un laser fibré. Plus particulièrement encore, la longueur d'onde de travail dudit laser fibré est 1,06 pm. La puissance du laser fibré est de 20W pour adapter l'intensité de l'énergie émise en fonction du marquage recherché. La puissance du laser est inférieure, pour une fréquence donnée, à l'énergie de dégradation de la matrice. Selon le procédé de la présente invention, il est possible d'obtenir à partir d'un seul pigment photo induit et/ou thermo chrome une série donnée de couleurs, ces couleurs variant dans une palette donnée en fonction des niveaux d'énergie choisis et en fonction de la fréquence. L'association de plusieurs pigments photo induits et/ou thermo chromes permet d'augmenter la palette des résultats colorimétriques. [0014] Ainsi, un pigment thermo chrome a la propriété de changer de couleurs selon la température à laquelle il est exposé. Un pigment photo induit a quant à lui la propriété de changer de couleurs en fonction de la lumière à laquelle il est exposé. Ces deux caractéristiques sont liées lorsque le pigment est exposé à un laser qui induit forcément une augmentation de la température, il s'agit d'un processus thermo-photo-assisté. Cependant pour la présente invention, c'est le caractère photo induit qui domine de manière à ce que la matrice contenant le pigment ne soit pas exposée à une température trop importante qui pourrait la dégrader. La matrice est ainsi soumise à une énergie d'activation suffisante pour faire changer d'état le pigment par excitation électronique mais cette énergie d'activation reste inférieure à l'énergie de dégradation de la matrice. The solution according to the present invention consists in using a matrix integrating at least one irreversible photo-induced and / or thermochromium pigment. This at least one photo-induced and / or thermochromium pigment requires an energy intensity to go from a first initial fundamental state to an excited state and then to come to a second stable ground state, by generating a given color. Irreversibility results from the fact that it would take too much energy to bring it back to its first ground state, with its base color. Indeed, the necessary energy level would induce degradation of the matrix which necessarily has limits of resistance to degradation. The solution according to the present invention is aimed at a process consisting in integrating at least one irreversible photo-induced and / or thermochromium compound in a matrix, in subjecting it to an activation energy sufficient to cause it to change state, said energy. to be less than the degradation energy of said matrix. In an improved manner, the energy input is produced from a pulsed laser beam and more particularly a fiber laser. More particularly still, the working wavelength of said fiber laser is 1.06 µm. The power of the fiber laser is 20W to adapt the intensity of the energy emitted according to the desired marking. The power of the laser is lower, for a given frequency, than the degradation energy of the matrix. According to the process of the present invention, it is possible to obtain from a single photo-induced pigment and / or thermochromium a given series of colors, these colors varying in a given palette as a function of the energy levels chosen and depending on the frequency. The association of several photo-induced and / or thermochromic pigments makes it possible to increase the range of colorimetric results. [0014] Thus, a thermochromium pigment has the property of changing colors depending on the temperature to which it is exposed. A photo-induced pigment has the property of changing colors depending on the light to which it is exposed. These two characteristics are linked when the pigment is exposed to a laser which inevitably induces an increase in temperature, it is a thermo-photo-assisted process. However, for the present invention, it is the photo-induced character which dominates so that the matrix containing the pigment is not exposed to too high a temperature which could degrade it. The matrix is thus subjected to sufficient activation energy to cause the pigment to change state by electronic excitation, but this activation energy remains lower than the degradation energy of the matrix.
[0015] Les pigments développés par la société Olikrom ont les qualités photo induites et/ou thermo chromiques nécessaires au présent procédé. The pigments developed by the company Olikrom have the photo-induced and / or thermochromic qualities necessary for the present process.
[0016] La présente invention est maintenant décrite à l'aide d'exemples uniquement illustratifs et nullement limitatifs de la portée de l'invention, ceci à partir des illustrations jointes, sur lesquelles : The present invention is now described with the aid of examples which are only illustrative and in no way limitative of the scope of the invention, this from the accompanying illustrations, in which:
[0017] [Fig. 1] représente un graphique type pour une couleur de base, bleu foncé, ceci en faisant varier la puissance en ordonnée et la fréquence en abscisse. [0017] [Fig. 1] represents a typical graph for a base color, dark blue, this by varying the power on the ordinate and the frequency on the abscissa.
[0018] [Fig. 2] représente un graphique type pour une couleur de base, marron, ceci en faisant varier la puissance en ordonnée et la fréquence en abscisse. [0018] [Fig. 2] represents a typical graph for a base color, brown, this by varying the power on the ordinate and the frequency on the abscissa.
[0019] [Fig. B] représente un graphique type pour une couleur de base, bleu turquoise, ceci en faisant varier la puissance en ordonnée et la fréquence en abscisse. [0019] [Fig. B] represents a typical graph for a basic color, turquoise blue, this by varying the power on the ordinate and the frequency on the abscissa.
[0020] [Fig. 4] représente un graphique type pour une couleur de base, noire, ceci en faisant varier la puissance en ordonnée et la fréquence en abscisse. [0020] [Fig. 4] represents a typical graph for a basic color, black, this by varying the power on the ordinate and the frequency on the abscissa.
[0021] Le procédé de marquage selon la présente invention est illustré en regard d'un témoin qui est un support, par exemple en polycarbonate, soit ayant reçu une couche de la matrice, par exemple un polyuréthane, comportant au moins un pigment photo induit et/ou thermo chrome, soit ayant été fonctionnalisé dans la masse avec ladite composition, permettant de montrer les variations en puissance et en fréquence. En l'occurrence, le choix exemplifiant met en oeuvre un support en forme de carte de crédit sur lequel est réalisé un damier avec la fréquence en abscisse et la puissance en ordonnée. Le matériau du support présente un point connu de dégradation de la matière, ce point étant variable suivant la nature des matériaux. On entend par marquage, toute inscription, toute forme géométrique surfacique ou filaire, réalisée sur la surface dudit support ou dans le support lorsque le matériau a été fonctionnalisé dans la masse. Sur le témoin représenté au format d'une carte de crédit, les références 1 à 4 montrent dans le damier, les points de mesure pour chaque couleur testée et les marquages consistent en des pixels de forme carrée de quelques dixièmes de millimètres chacun. On entend pour la suite de la description et pour les revendications par "intégrer dans un support" : The marking method according to the present invention is illustrated with regard to a control which is a support, for example polycarbonate, or having received a layer of the matrix, for example a polyurethane, comprising at least one photo-induced pigment and / or thermochromium, either having been functionalized in the mass with said composition, making it possible to show the variations in power and in frequency. In this case, the exemplifying choice implements a support in the form of a credit card on which a checkerboard with the frequency on the x-axis and the power on the y-axis. The material of the support has a known point of degradation of the material, this point being variable depending on the nature of the materials. The term “marking” means any inscription, any geometric surface or wireframe shape, produced on the surface of said support or in the support when the material has been functionalized in the mass. On the witness represented in the format of a credit card, the references 1 to 4 show in the checkerboard, the measurement points for each color tested and the markings consist of square pixels of a few tenths of a millimeter each. For the remainder of the description and for the claims, the term “integrated into a support” is understood to mean:
- soit l'introduction d'au moins un pigment photo induit et/ou thermo chrome, irréversible, dans le support lors de la fabrication dudit support, - either the introduction of at least one irreversible photo-induced and / or thermochromium pigment into the support during the manufacture of said support,
- soit au moins un pigment photo induit et/ou thermo chrome, intégré dans une matrice rapportée en une couche sur la surface dudit support. - Or at least one photo-induced and / or thermochromic pigment, integrated in a matrix attached in a layer on the surface of said support.
[0022] Le procédé de marquage en couleurs, avec un graphisme donné, selon la présente invention, comprend la succession des étapes suivantes : The color marking process, with a given graphic, according to the present invention, comprises the succession of the following steps:
- intégration d'au moins un pigment photo induit et/ou thermo chrome irréversible dans un support - integration of at least one irreversible photo-induced and / or thermochromium pigment in a support
- émission d'un faisceau d'énergie sur ladite matrice, à partir d'un laser impulsionnel, de façon préférentielle de type fibré, selon le graphisme du marquage à réaliser, - emission of an energy beam on said matrix, from a pulsed laser, preferably of the fiber type, according to the design of the marking to be produced,
- variation de la puissance et de la fréquence du faisceau d'énergie pour générer une couleur souhaitée sur une zone donnée du graphisme dudit marquage. variation of the power and frequency of the energy beam to generate a desired color on a given area of the graphics of said marking.
[0023] Selon une forme de réalisation, la matrice comprend un unique pigment pour obtenir un marquage de couleurs différentes et une seule couche d'encre. [0023] According to one embodiment, the matrix comprises a single pigment to obtain a marking of different colors and a single layer of ink.
[0024] Le procédé consiste à émettre un faisceau d'énergie avec un laser impulsionnel, notamment un laser fibré, plus encore un laser fibré émettant à la longueur d'ondes de 1,06 pm. La puissance nominale est de 20W. La fréquence f, exprimée en kilohertz KHz, augmente de 20kHz à chaque pixel suivant du damier, ceci pour un même pourcentage de la puissance nominale. La puissance est exprimée en Watt et passe de 0 à 100%. Sur les différents tests, la puissance maximale émise reste en dessous de la puissance de dégradation de la matrice. La couleur obtenue est définie suivant le référentiel L, a, b, de l'espace chromatique CIELAB. Ce référentiel consiste à définir : The method consists in emitting an energy beam with a pulsed laser, in particular a fiber laser, even more a fiber laser emitting at the wavelength of 1.06 μm. The nominal power is 20W. The frequency f, expressed in kilohertz KHz, increases by 20kHz for each next pixel of the checkerboard, this for the same percentage of the nominal power. The power is expressed in Watt and goes from 0 to 100%. On the various tests, the maximum power emitted remains below the degradation power of the matrix. The color obtained is defined according to the reference L, a, b, de the CIELAB color space. This repository consists of defining:
- L : la clarté sur une échelle de 0 à 100, 100 correspondant au blanc. - L: clarity on a scale of 0 to 100, 100 corresponding to white.
- a : représente la valeur sur un axe vert / rouge. - a: represents the value on a green / red axis.
- b : représente la valeur sur un axe bleu/jaune. - b: represents the value on a blue / yellow axis.
[0025] Les essais sont réalisés sur un support en polycarbonate recouvert d'une couche de la matrice selon la présente invention, disposée sous forme de pixels, en damiers. Le au moins un pigment aurait pu être intégré dans le matériau polycarbonate directement. The tests are carried out on a polycarbonate support covered with a layer of the matrix according to the present invention, arranged in the form of pixels, in checkers. The at least one pigment could have been incorporated into the polycarbonate material directly.
[0026] Dans un premier essai, la matrice intègre un seul pigment photo induit et/ou thermo chrome irréversible dont la couleur de base, dans le visible, est le bleu foncé défini dans le tableau par les paramètres L, a, b. On constate que, lorsque la puissance augmente, la couleur varie d'un rouge foncé à un rose puis à un gris clair et au fur et à mesure que la fréquence augmente, le rouge foncé s'éclaircit et les gris prennent une couleur rose voire rouge. On peut donc obtenir une palette complète des couleurs du rouge foncé au gris clair en passant par les roses. Les résultats sur les points 1 à 4 retenus donnent les valeurs suivantes, exprimées dans le tableau 1. In a first test, the matrix incorporates a single irreversible photo-induced and / or thermochromium pigment, the basic color of which, in the visible, is dark blue defined in the table by the parameters L, a, b. We note that, when the power increases, the color varies from a dark red to a pink then to a light gray and as the frequency increases, the dark red becomes lighter and the grays take on a pink color or even Red. We can therefore obtain a complete palette of colors from dark red to light gray through pinks. The results on points 1 to 4 selected give the following values, expressed in Table 1.
[0027] [Tableaux 1] [0027] [Tables 1]
[0028] Le deuxième essai est réalisé sur fond marron à partir d'une matrice intégrant un seul pigment photo induit et/ou thermo chrome irréversible de couleur marron avec une colorimétrie L, a, b indiquée dans le tableau 2 qui suit. Le marron donne des variations dans les verts et jaunes. Les verts apparaissent lorsque l'intensité augmente, c'est le changement de couleur du marron au vert et la fréquence limite le changement de couleur du jaune au vert. On constate que le marron est rapidement transformé en couleurs jaune et verte. Le jaune devient rapidement prédominant dès que la fréquence augmente. The second test is carried out on a brown background from a matrix incorporating a single photo-induced pigment and / or irreversible thermochromium of brown color with an L, a, b colorimetry indicated in Table 2 below. Brown gives variations in greens and yellows. Greens appear when the intensity increases, it is the color change from brown to green and the frequency limits the color change from yellow to green. It can be seen that brown is quickly transformed into yellow and green colors. Yellow quickly becomes predominant as the frequency increases.
[0029] [Tableaux 2] [0029] [Tables 2]
[0030] Le troisième essai est réalisé sur fond bleu turquoise à partir d'une matrice intégrant un pigment photo induit et/ou thermo chrome irréversible, bleu turquoise avec les paramètres L, a, b définis dans le tableau 3 ci-dessous. Le bleu turquoise est donc un bleu plus clair. L'incidence est importante car les couleurs qui apparaissent lors des variations de puissance et de fréquence passent du beige au bordeaux en passant par des oranges clairs. The third test is carried out on a turquoise blue background from a matrix incorporating a photo-induced and / or irreversible thermochromium pigment, turquoise blue with the parameters L, a, b defined in Table 3 below. Turquoise blue is therefore a lighter blue. The impact is important because the colors that appear during variations in power and frequency change from beige to burgundy through light oranges.
[0031] [Tableaux 3] [0031] [Tables 3]
[0032] Le quatrième essai est réalisé sur fond noir avec des variations de couleurs du noir au beige, orange, violet et rose. Les paramètres L, a, b sont définis dans le tableau 4 ci- dessous. [00BB] [Tableaux 4] The fourth test is carried out on a black background with color variations from black to beige, orange, purple and pink. The parameters L, a, b are defined in Table 4 below. [00BB] [Tables 4]
[0034] Les essais ont été conduits avec un seul pigment photo induit et/ou thermo chrome. Le procédé prévoit l'introduction d'au moins un pigment et il est possible de combiner deux ou plusieurs pigments photo induit et/ou thermo chrome pour ajuster et obtenir une infinité de couleurs. The tests were carried out with a single photo-induced pigment and / or thermochromium. The method provides for the introduction of at least one pigment and it is possible to combine two or more photo-induced and / or thermochromic pigments to adjust and obtain an infinity of colors.
[0035] Les applications sont nombreuses dans le domaine de la sécurité afin de rendre des supports infalsifiables mais les applications peuvent être aussi la décoration d'objets en différents matériaux tels que du verre, des matériaux céramiques. There are many applications in the field of security in order to make media tamper-proof, but the applications can also be the decoration of objects made of different materials such as glass, ceramic materials.

Claims

REVENDICATIONS
[Revendication 1] [Procédé de réalisation, sur un support, d'un marquage de couleurs différentes à partir d'une même composition, selon un graphisme donné, caractérisé en ce qu'il consiste en la succession des étapes suivantes : [Claim 1] [Process for producing, on a support, a marking of different colors from the same composition, according to a given design, characterized in that it consists of the succession of the following steps:
- intégrer dans ledit support une matrice comprenant au moins un pigment photo induit et/ou thermo chrome irréversible, - Integrating into said support a matrix comprising at least one irreversible photo-induced and / or thermochromium pigment,
- émettre un faisceau d'énergie sur la surface dudit support intégrant la matrice comprenant le au moins un pigment photo induit et/ou thermo chrome irréversible, avec un laser impulsionnel, selon le graphisme du marquage à réaliser sur ledit support, - Emitting an energy beam on the surface of said support integrating the matrix comprising the at least one photo-induced pigment and / or irreversible thermochromium, with a pulsed laser, according to the graphics of the marking to be produced on said support,
- variation des paramètres de fréquence et de puissance dudit faisceau d'énergie pour générer une couleur souhaitée sur une zone donnée du graphisme dudit marquage. variation of the frequency and power parameters of said energy beam to generate a desired color on a given area of the graphics of said marking.
[Revendication 2] Procédé de réalisation, sur un support, d'un marquage selon la revendication 1, caractérisé en ce que la matrice comprend un unique pigment pour obtenir un marquage de couleurs différentes et une seule couche d'encre. [Claim 2] A method of producing, on a support, a marking according to claim 1, characterized in that the matrix comprises a single pigment to obtain a marking of different colors and a single layer of ink.
[Revendication B] Procédé de réalisation, sur un support, d'un marquage selon l'une des revendications 1 ou 2, caractérisé en ce que le laser impulsionnel est un laser fibré. [Claim B] A method of producing, on a support, a marking according to one of claims 1 or 2, characterized in that the pulsed laser is a fiber laser.
[Revendication 4] Procédé de réalisation, sur une matrice, d'un marquage selon la revendication 3, caractérisé en ce que le laser fibré travaille à une longueur d'ondes de 1,06 pm. [Claim 4] A method of producing, on a matrix, a marking according to claim 3, characterized in that the fiber laser works at a wavelength of 1.06 µm.
[Revendication 5] Procédé de réalisation, sur un support, d'un marquage selon l'une quelconque des revendications précédentes, caractérisé en ce que la puissance maximale du faisceau d'énergie est inférieure, pour une fréquence donnée, à l'énergie de dégradation du matériau constituant le matériau de la matrice. [Claim 5] A method of producing, on a support, a marking according to any one of the preceding claims, characterized in that the maximum power of the energy beam is less, for a given frequency, than the energy of degradation of the material constituting the matrix material.
[Revendication 6] Procédé de réalisation, sur un support, d'un marquage selon l'une quelconque des revendications 4 ou 5, caractérisé en ce que la puissance du laser fibré est de 20W.1 [Claim 6] A method of producing, on a support, a marking according to any one of claims 4 or 5, characterized in that the power of the fiber laser is 20W.1
EP21705884.1A 2020-01-28 2021-01-28 Method for producing markings of different irreversible colours from the same composition Pending EP4096930A1 (en)

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PCT/EP2021/051999 WO2021152018A1 (en) 2020-01-28 2021-01-28 Method for producing markings of different irreversible colours from the same composition

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DE10054803A1 (en) * 2000-11-04 2002-05-29 Kurz Leonhard Fa Plastics article comprising of or provided with foil e.g. transfer or hot embossing foil useful for decorating e.g. metal or wood, contains 3 or more different colorants, bleached by laser under conditions specific for each
JP4505293B2 (en) * 2004-01-16 2010-07-21 テクノポリマー株式会社 Chromatic colorant for multicolor laser marking, multicolor laser marking composition, molded article containing the same, and laser marking method
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