Method of immobilizing marking composition on substrate

Abstract

The invention relates to a method for fixing a marking composition on a substrate by laser irradiation, the marking composition comprising at least one colorant, the method comprising the following steps:-depositing (102) the marking composition on at least a portion of the substrate (4); fixing (104) a portion of the marking composition deposited on the substrate by irradiating at least the portion of the marking composition by moving a laser beam, characterized in that the laser beam in contact with the irradiated marking composition has a power density of 32 W / mm2 to 7.7 kW / mm2 and the moving speed of the laser beam is 10 ms-1 to 9.0 ms-1 measured relative to the substrate.

Description

Technical Field

[0001] The present invention generally relates to a method for fixing a marking composition onto a substrate using a laser.

[0002] More specifically, the present invention relates to a method for attaching a marking composition to a fragile substrate, such as, in particular, an organic substrate of plant origin, an organic substrate of animal origin, a substrate of synthetic origin (e.g., including plastics), or a substrate made of cellulose (e.g., cardboard or paper).

[0003] The present invention also relates to a method for fixing a marking composition onto a metal or plastic layer of a substrate. Background Technology

[0004] Hot stamping is known to be used for marking leather substrates. These methods involve pressing a die onto the leather to be marked. While these methods are feasible, they do not allow for the use of pigments. Furthermore, these methods can locally damage the substrate, affecting its properties such as water resistance, hydrophilicity, or hydrophobicity. Finally, these methods do not allow for easy customization of patterns on the substrate.

[0005] Laser marking methods on hard substrates selected from materials such as metals, plastics, ceramics, and glass are also known. These methods are effective but cannot be used on soft or flexible substrates, which can be described as fragile because they are easily scratched or damaged by heat. In fact, in these methods, the characteristics of the laser beam used to irradiate the substrate cause heating exceeding 500°C due to the photo-material interaction between the laser beam and the substrate. This characteristic is suitable for hard substrates (e.g., metals, plastics, ceramics, or glass) but not for more fragile substrates (e.g., leather, textiles, cardboard) because the material heating induced in this method damages these substrates through a thermal engraving phenomenon that causes localized carbonization. This localized carbonization is incompatible with the production of markings in colors other than black and causes significant localized changes in the properties of the substrate, particularly its behavior in water.

[0006] There are also known methods for marking metal layers on substrates. These methods are effective, but they do not achieve very good adhesion between the marking composition and the metal layer. Furthermore, the color obtained on the metal layer is dull, so these methods do not reproduce the color fixed on the metal layer very well. These methods also take longer to implement.

[0007] The object of the present invention is to overcome at least one of the above-mentioned disadvantages in order to provide a fixing method suitable for marking marking compositions on different types of substrates (e.g., fragile, especially organically derived substrates or metal and plastic substrates). Summary of the Invention

[0008] Therefore, the present invention provides a method for fixing a marking composition onto a substrate by laser irradiation, the marking composition comprising at least one colorant, the method comprising the following steps: - Deposit the marking composition on at least a portion of the substrate; - A portion of the marking composition is fixed by moving a laser beam to irradiate at least a portion of the marking composition deposited on a substrate; -Remove the marking composition that was not irradiated during the fixing step.

[0009] According to the present invention, the laser beam in contact with the irradiated marking composition has a strength of 32 W / mm². 2 Up to 7.7 kW / mm 2 The power density, and the laser beam movement speed is 10 mm / s to 9.0 m / s (ms) relative to the substrate. -1 ).

[0010] In the context of this invention, displacement velocity corresponds to the displacement velocity relative to the substrate to be marked or the position of the laser beam on the substrate.

[0011] Power density corresponds to the amount of power passing through each unit of a surface. Therefore, it quantifies the power received on a portion (region) of the surface.

[0012] According to the present invention, colorants of various colors can be fixed onto fragile substrates without altering them, unlike hot stamping techniques. This method is also easy to implement and allows for easier creation of personalized designs.

[0013] It should be noted that, according to the invention, the combination of power density and scanning speed allows for the limitation of the amount of power received per unit area by the substrate during its irradiation. Surprisingly, contrary to expectations, this irradiation limitation does not impede optimal fixation of the marking composition on fragile substrates.

[0014] The removal step allows for the cleaning of substrate portions covered by the marked composition that were not fixed during the fixing step.

[0015] In one implementation, the power density is 60 W / mm². 2 Up to 5 kW / mm 2 The laser beam moves at a speed of 0.1 ms. -1 Up to 9.0 m. s -1 This allows for further limitation of damage to the substrate while maintaining excellent marking performance.

[0016] In this disclosure, a laser beam refers to a beam of light emitted by a laser or laser element. A colorant refers to a reagent comprising at least one pigment or at least one dye or a mixture thereof.

[0017] In one implementation, the power density is 430 W / mm². 2 Up to 1.1 kW / mm 2 The laser beam travels at a speed of 2500 mm / sec to 7000 mm / sec. Therefore, the method according to this disclosure is faster while allowing the same performance to be achieved.

[0018] In one implementation, the power density is 480 W / mm². 2 Up to 1.1 kW / mm 2 The laser beam travels at a speed of 3300 mm / sec to 7000 mm / sec. This characteristic allows for minimizing heating of the substrate and thus minimizing potential damage.

[0019] In one implementation, the power density is 480 W / mm². 2 Up to 550 W / mm 2 The laser beam travels at a speed of 4900 mm / sec to 7000 mm / sec. This characteristic allows for heating of the substrate without any modification to it (no material damage occurs, and the substrate remains intact).

[0020] In a preferred embodiment, the power density is 60 W / mm². 2 Up to 5 kW / mm 2 The laser beam travels at a speed ranging from 0.1 m / s to 9.0 m / s (ms). -1 This characteristic allows for better results while limiting the amount of power received by the substrate.

[0021] In one implementation, the laser beam is moved at a speed of 0.6 m / s to 9.0 m / s.

[0022] This feature further reduces the substrate's exposure to the laser beam, thus limiting the risk of damaging the substrate without affecting the quality of the fixation.

[0023] In one embodiment, the laser beam in contact with the irradiated marking composition has a power of 1 kW / mm². 2 Up to 5 kW / mm 2 The power density.

[0024] This feature allows for very fast scanning speeds, which reduces the method completion time.

[0025] Within the scope of this invention, the displacement of the laser beam relative to the substrate can be performed in any suitable manner, for example by at least one of the following displacements: - The displacement of the laser beam (i.e., laser scanning), -Displacement of the substrate, - A combination of the displacement of the laser beam and the displacement of the substrate.

[0026] In one embodiment, after the removal step, the marking composition covers at least 90% of the irradiated substrate.

[0027] In one embodiment, the surface roughness of the substrate is from 0 micrometers to 2 millimeters.

[0028] Therefore, this method is applicable to different types of substrates, namely smooth substrates or rough substrates.

[0029] In one embodiment, the substrate is planar or curved.

[0030] In one embodiment, the method includes the step of air-drying the marking composition prior to the irradiation step, wherein the drying step preferably lasts for less than 2 minutes.

[0031] In one embodiment, the laser is coupled to a focusing device having a focal length for focusing the laser beam to a focal point. A substrate is then placed at or less than 5 cm from the focal point, preferably less than 1 cm.

[0032] The combination of beam power and velocity characteristics with this focusing makes fixation effective, even on substrates with planar or non-planar shapes. Substrates with non-planar shapes specifically refer to substrates whose surface to be marked is curved or whose surface to be marked has planar and non-planar portions and / or irregular surfaces, such as substrates with uneven areas. Therefore, the method is configured to fix the marking composition to a substrate or a portion of a substrate located at the focal point (e.g., when the substrate or a portion of the substrate used is planar), or to a substrate or a portion of a substrate off-focus (particularly when the substrate or a portion of the substrate is curved, i.e., non-planar).

[0033] Furthermore, working outside the focal point allows for a reduction in laser power density in contact with the substrate. Therefore, these features provide an easy-to-implement solution for attaching colorants to fragile substrates without requiring the surface to be marked to be flattened.

[0034] In one embodiment, the fixation is performed on a face (or surface) of a substrate including a metal layer (referred to as a marking face), and the method includes a step of treating at least one area of ​​the metal layer by laser irradiation prior to the deposition step, and a deposition and fixation step on the treated area of ​​the metal layer.

[0035] In this embodiment, the metal layer can form a markable surface of the substrate.

[0036] In this embodiment, the metal layer may include at least one layer of at least one of the following materials: - Metals, such as pure metals (e.g., zinc, aluminum, copper, gold, silver) or processed metals (e.g., anodized aluminum). - Metal alloys (e.g., brass, steel or stainless steel, ferrous metals, cast zinc (zamak) type alloys (alloys of zinc, aluminum and optional copper)).

[0037] Therefore, according to the method of the present invention, the marking composition can be fixed onto different metal materials.

[0038] In this embodiment, the metal layer may be covered with a protective layer. The protective layer may include at least one of the following elements: anodized layer, paint (e.g., a layer obtained by ink printing, screen printing, or paint coating), galvanizing, metallization, or plasticizing (e.g., epoxy resin type). Hereinafter, when the protective layer includes paint, galvanizing, metallization, or plasticizing, the latter is referred to as painted metal.

[0039] Therefore, when implementing the fixation method on a metal layer, the method according to the invention may include a processing step that allows the surface of the metal layer to be transformed or prepared prior to the deposition and fixation of the marking composition. This step, combined with the properties of the laser used in the fixation step, allows for excellent fixation of the marking composition on the metal layer, and excellent color rendering of the marking composition on the metal layer. Furthermore, the optical properties of the laser also allow for faster implementation of the fixation method on a substrate having a metal layer.

[0040] In this embodiment, the processing step may use a laser that emits a laser beam, and the laser beam used in the processing step and the laser beam used in the fixing step may have at least one of the same properties, which includes at least one of the following: -wavelength; -Power density; -Displacement velocity; - Number of scans (passes).

[0041] This feature allows the same laser to be used in both the processing and fixing steps, which helps to limit the cost of implementing the method according to the invention.

[0042] In this embodiment, the processing step can be performed using a laser with a power density less than or equal to (preferably less than) the power density of the laser used in the fixing step and a laser beam displacement with a velocity relative to the substrate less than or equal to (preferably less than) the displacement velocity of the laser beam used in the fixing step. For example, a power density of 955 W / mm². 2 Up to 1.9kW / mm2 (Preferred value: 955 W / mm) 2 Up to 1.7 kW / mm 2 The displacement speed is from 500 mm / s to 1600 mm / s (preferably from 500 mm / s to 1500 mm / s).

[0043] In this embodiment, the processing steps may include at least one of the following processes: - Anodizing; -Laser ablation; - Laser engraving; -Mechanical ablation.

[0044] In this embodiment, after treatment, the treated area may have a surface of one of the following colors: -White; -grey.

[0045] In this embodiment, particularly when the substrate has a colored anodized aluminum oxide layer, the processing steps allow for at least partial removal of the anodized layer to expose a white or gray aluminum oxide layer.

[0046] Therefore, in this invention, lightening the color of the metal plate improves the adhesion of the colorant to the metal plate.

[0047] In this embodiment, the surface color of the processed area may depend on at least one of the following parameters: -Laser power density; - The displacement velocity of the laser beam; - The number of times the laser beam passes.

[0048] Therefore, the above parameters can be applied to the processing area of ​​the desired color.

[0049] In this embodiment, during the processing step, the laser beam can be configured to irradiate the processing area only once.

[0050] Of course, in one embodiment, the fixing is performed on the surface of the substrate including the metal layer (referred to as the marking surface), and the deposition step can be performed on the marking surface (also referred to as the marking surface). Therefore, in this case, no pretreatment is performed.

[0051] In one embodiment, during the fixing step, the laser is configured to scan the portion of the marking composition n times, where n is greater than or equal to 2.

[0052] This feature allows for limiting damage to the substrate irradiated by the laser beam while obtaining a substrate with the aforementioned advantages.

[0053] In one implementation, n is 2 to 20, preferably 3 to 10.

[0054] In one implementation, the number of scans depends on the properties of the substrate. According to the invention, very good results are obtained when n equals 3.

[0055] According to the present invention, the laser used in the fixing step is either continuous or pulsed.

[0056] In one embodiment, the laser used in the fixing and / or processing steps is a solid-state or gas-based (e.g., CO2) gain medium laser. In this invention, a solid-state laser refers to a laser in which the amplification medium comprises a crystal. For example, a solid-state laser may include a laser diode, a YAG laser, or a fiber laser.

[0057] Therefore, the laser used in the fixing and / or processing steps can be at least one of the following lasers: - A YAG laser that emits a laser beam with a wavelength of 1064 nanometers. - A CO2 laser that emits a laser beam with a wavelength of 10,600 nanometers. - A YAG laser that emits a laser beam with a wavelength of 532 nanometers. - A YAG laser that emits a laser beam with a wavelength of 355 nanometers.

[0058] Alternatively or in combination, the laser used in the fixing and / or processing steps may be a frequency-doubled or third-doubled YAG laser that emits a laser beam with an emission wavelength of 100 nm (UV) to 1 μm (far-infrared) (e.g., 532 nm, 355 nm, or 266 nm).

[0059] Therefore, the method according to the invention is applicable to commonly used and widely commercially available lasers, improving the ease of implementation of the method at a reasonable cost.

[0060] In one implementation, when the laser beam is a YAG laser, the generated laser beam is a pulsed laser beam, and when the laser beam is a CO2 laser, the generated laser beam is a continuous laser beam.

[0061] In one implementation, for example, when the laser beam contacts the substrate, the minimum diameter of the beam is 70 to 120 micrometers.

[0062] In one embodiment, the processing steps can be performed using a CO2 laser that emits a laser beam with an emission wavelength of 10,600 nanometers and a power density of 955 W / mm². 2 Up to 1.277 kW / mm 2The moving speed is 500 mm / s to 900 mm / s.

[0063] In one implementation, the processing steps can be performed using a YAG laser that emits a laser beam with an emission wavelength of 355 nanometers and a power density of 1.0 kW / mm². 2 Up to 1.9 kW / mm 2 (Preferred power: 1.7 kW / mm) 2 The moving speed is 1000 mm / s to 1600 mm / s (preferably 1500 mm / s).

[0064] In one embodiment, the labeling composition comprises: -Aqueous matrix; - At least one colorant in an aqueous matrix.

[0065] Typically, this colorant can be a soluble solution, or a mixture of pigments or a mixture of dissolved dyes.

[0066] In one embodiment, the colorant or marking composition has photochromic and / or thermochromic properties.

[0067] In this disclosure, the term "photochromic element" refers to an element capable of changing color according to the intensity of received light. Therefore, changes in the intensity of received light result in a change in color. Furthermore, the term "thermochromic element" refers to an element capable of changing color according to temperature. Therefore, changes in the temperature of the environment in which the element is located result in a change in color.

[0068] In one embodiment, when the colorant contains at least one pigment, each pigment is in the form of particles with a size of 10 nm to 0.1 mm.

[0069] In one embodiment, the amount of the aqueous matrix in the labeling composition is from 50% to 84% by weight.

[0070] In one embodiment, the amount of colorant in the labeling composition is 16% to 50%.

[0071] In one implementation, the aqueous matrix is ​​a liquid.

[0072] Using this aqueous liquid alkali as a carrier for the colorant and particles constituting the labeling composition provides a solution that improves the ergonomics of implementation and the safety of the method. In fact, the colorant particles are dispersed within the liquid matrix.

[0073] In one embodiment, the aqueous matrix comprises an acrylic adhesive mixed with water and a short-chain alcohol, or with a surfactant.

[0074] This formulation of the marking composition improves both the uniformity and stability of the suspension constituting the marking composition and the fixation of the colorant on the substrate. Therefore, the quality and lifespan of the marking are improved.

[0075] Adhesives are emulsions of water and acrylic or vinyl resins.

[0076] In one embodiment, the aqueous matrix does not contain organic solvents. Therefore, the use of flammable and toxic organic solvents to humans and the environment can be avoided.

[0077] In one embodiment, the aqueous matrix comprises an organic solvent.

[0078] In a variation of this embodiment, the colorant is in the form of particles with a size of 10 to 50 micrometers.

[0079] These properties improve the fixation of colorants during the fixation step. Furthermore, such particle size poses less risk to humans (in the event of inhalation or ingestion).

[0080] In one embodiment, at least one colorant is configured not to change color after a fixed step.

[0081] In one embodiment, the colorant is selected from: - Pigments containing at least one of the following elements: metal oxides, metals, metal alloys, metal alloy oxides; -Inorganic pigments; -Organic pigments; - Pigments containing carbonate minerals; - Sodium aluminosilicate thiosulfate; - Synthetic dyes; -Natural dyes; Or a mixture thereof.

[0082] In one implementation, when the colorant is a pigment, the colorant may be in particulate form.

[0083] In one embodiment, the white inorganic pigment comprises TiO2.

[0084] In one embodiment, the inorganic pigment comprises at least one of the following elements: white inorganic pigment, composite inorganic pigment, and colored natural inorganic pigment.

[0085] In one embodiment, the pigment containing metal oxides may contain synthetic pigments colored with metal oxides.

[0086] In one embodiment, the organic pigment may comprise TiO2 and / or polyoxymethylene-based thermochromic pigment melamine.

[0087] Using colorants based on inorganic materials allows for the achievement of very good color quality. Furthermore, such colorants offer ecological advantages.

[0088] The use of sodium thiosulfate aluminosilicate-based colorants provides non-toxic and inexpensive labeling compositions.

[0089] Carbonate mineral-based colorants are inexpensive and have low toxicity.

[0090] In one embodiment, the metal particles are selected from particles of bronze, gold, silver, copper, aluminum, or mixtures thereof.

[0091] Therefore, the method according to the invention is applicable to precious metals, such as gold and silver or bronze-type alloys, which makes it possible to obtain high-quality and valuable marking objects.

[0092] In addition, these metal particles allow the substrate to be dyed in different colors.

[0093] In one embodiment, the labeling composition comprises at least one metal oxide particle as a colorant (here, a pigment). For example, the particles of the at least one metal oxide are selected from the following transition metal oxides: -Titanium oxide; -Iron oxide; - Tin dioxide.

[0094] These compositions allow for different marking colors.

[0095] In one embodiment, the colorant further comprises particulate silicate, which accounts for 38% to 74% by weight of the colorant composition.

[0096] In one embodiment, the silicate includes mica.

[0097] This type of colorant, especially mica-based colorants, is environmentally friendly and inexpensive. Furthermore, mica particles improve the adhesion of the colorant to the substrate and absorb some of the light beam energy. Therefore, the mica particles limit substrate heating while increasing heat transfer to the colorant particles, which contributes to the quality of the marking.

[0098] In one embodiment, the silicate, preferably mica, is in particulate form having at least one of the following properties: - The particle size is larger than the size of other particles in the colorant composition by k × 10 3 Multiples, where k is an integer from 1 to 9. - Particle size ranges from 3.0 µm to 80 µm.

[0099] In one embodiment, the labeling composition is deposited on a substrate as a layer with a thickness of 10 nanometers to 0.1 millimeters.

[0100] In one embodiment, the substrate includes at least one of the following materials: -Metal; -plastic; - Composite materials; - Organic materials derived from plants; - Organic materials derived from animals; - Materials derived from the synthesis, such as polyurethane; - Cellulose-based materials, such as cardboard or paper; -Woven or nonwoven materials that are at least partially organic in nature.

[0101] For the purposes of this invention, the organic nature of a material corresponds to the fact that at least some of its components or ingredients are produced by living organisms, animals, or plants.

[0102] Therefore, this method is very suitable for fragile substrates, such as leather products made of natural leather, vegetable leather or synthetic leather.

[0103] Furthermore, this method is well-suited for harder substrates, such as glass, composites, metals, and plastics, which are known to be difficult to fix stably in marking compositions for extended periods.

[0104] The present invention also relates to a marking composition intended to be fixed onto a substrate by laser irradiation, comprising: - An aqueous matrix comprising water and a stabilizer, said aqueous matrix being present in the labeling composition in a proportion of 50% to 84% by weight. - At least one colorant, which is in the form of particles suspended in an aqueous matrix, and is present in the labeling composition at a proportion of 16% to 50% by weight.

[0105] Water-based matrix refers to liquid matrix or paste matrix.

[0106] This marking composition is intended to be implemented within the framework of the method of the present invention described above.

[0107] In one embodiment, the marking composition is adapted to be fixed according to the method described above, preferably fixed to a substrate by the method described above.

[0108] Therefore, the marking composition has the property of being able to be fixed onto a fragile substrate by the above method, while exhibiting good adhesion to the substrate.

[0109] The marking composition also has the property of enabling it to be fixed to the metal layer of a substrate by the following methods, while exhibiting good adhesion to the substrate.

[0110] The adhesion of the marking composition to these different substrates is stable over time.

[0111] In one embodiment, the stabilizer includes short-chain alcohols, or acrylic resins and surfactants.

[0112] In one embodiment, the aqueous matrix comprises an organic solvent.

[0113] In one embodiment, each colorant is in particulate form with a size of 10 nm to 0.1 mm.

[0114] In one embodiment, the colorant is selected from: - A pigment that contains at least one of the following elements: metal oxide, metal, metal alloy, or metal alloy oxide; -Inorganic pigments; -Organic pigments; - Pigments containing carbonate minerals; - Sodium thiosulfate aluminosilicate; - Synthetic dyes; -Natural dyes; Or a mixture thereof.

[0115] In one embodiment, the colorant further comprises at least one particulate silicate, preferably mica, in an amount of 38% to 74% by weight in the colorant composition.

[0116] In one embodiment, the silicate, preferably mica, is in particulate form having at least one of the following properties: - The particle size is larger than the size of other particles in the colorant composition by k × 10 3 times, - Particle size ranges from 3.0 µm to 80 µm.

[0117] In one embodiment, each colorant is in particulate form with a size of 10 nm to 0.2 mm, preferably 10 nm to 0.1 mm.

[0118] Of course, the various features, variations and embodiments of the present invention can be combined with each other in various combinations to the extent that they are compatible or not mutually exclusive.

[0119] The present invention also relates to a marking composition comprising at least one colorant and an aqueous matrix. Such a composition is suitable for fixation onto a substrate by the methods described above. Attached Figure Description

[0120] The following description, given with reference to the accompanying drawings as non-limiting embodiments, will make it clear what the invention consists of and how it can be implemented.

[0121] In the attached diagram: Figure 1 This is a schematic diagram of one embodiment of a system for attaching marking composite materials according to the present invention; Figure 2 This is an embodiment of a deposition apparatus included in a system for fixing a marking composition according to the present invention; Figure 3 This is a first embodiment of a fixing and / or processing device included in a system for fixing a marking composition according to the present invention; Figure 4 This is a second embodiment of a fixing and / or processing device included in a system for fixing a marking composition according to the present invention; Figure 5 This is a first embodiment of a method for attaching a marking composition to a substrate according to the present disclosure; Figure 6 This is a front view of a planar substrate irradiated by a fixing device used in a system for fixing marking compositions; and Figure 7 Examples of curved substrates marked with a marking composition using the fixing method (first embodiment or second embodiment) according to the present invention; Figure 8 This is a side view of the substrate according to the present invention; Figure 9 This is a second embodiment of the method of attaching a marking composition to a substrate according to the present disclosure. Detailed Implementation

[0122] system Figure 1 A system S for attaching a marking composition 2 to a substrate 4 is shown. System S includes a control unit 50 and a fixing device 10. Optionally, system S also includes a deposition device 20, a cleaning device 60, and a synchronization device 90. In one embodiment, system S optionally includes a processing device 80.

[0123] like Figure 1 and Figure 3 As shown, the fixing device 10 includes a frame 11, a laser device 30, and a bracket 40. The fixing device 10 is connected to a control unit 50, which is configured to control the fixing device 10.

[0124] The control unit 50 is a computer or any other electronic component capable of executing a series of commands and / or calculations. The control unit 50 typically includes a processor, memory, and various input and output interfaces.

[0125] Due to its input and output interfaces, the control unit 50 is adapted to receive input data, such as adjustment data, the pattern to be generated, the type of substrate used, etc. For this purpose, the control unit 50 is typically connected to a human-machine interface, allowing the user to input data, which will be used by the fixing device 10 to fix the marking composition 2 onto the substrate 4.

[0126] The output data consists of commands sent to different components of system S.

[0127] For the fixed device 10, and particularly for the laser device 30, these commands include, for example, adjustment data of the laser device 30 (e.g., operating mode, power, scanning speed, etc.). For the support 40, these data include, for example, the distance from the laser beam focusing plane.

[0128] like Figure 3 As shown, the frame 11 supports the laser device 30 and the bracket 40.

[0129] In this embodiment, the laser device 30 includes a laser 31 configured to irradiate the marking composition 2 located on the substrate 4, a scanning device 32, and a focusing device 33 including at least one focusing lens 34.

[0130] The laser 31 is configured to emit a monochromatic beam 35 toward the substrate 4 along a propagation direction toward the substrate 4.

[0131] exist Figure 3 In the process, the laser beam 35 enters the scanning device 32, and the scanning device 32 guides the laser beam 35 onto the substrate 4.

[0132] The scanning device 32 is configured to move the laser beam 35 on the surface 3 of the substrate 4 along two directions x and y, transverse to the propagation direction of the laser beam 35. Therefore, laser scanning is performed by the scanning device 32. Typically, the scanning device 32 consists of at least two movable mirrors for guiding the laser beam 35 onto the substrate 4 to perform a spatial scan of the portion of the substrate to be irradiated, defined by input data transmitted to the control unit 50. In this disclosure, the scanning device is typically a high-speed scanning head, such as a galvanometer scanner. Therefore, in this embodiment, the movement of the laser beam 35 is performed by the scanning device 32, which is configured to move the laser beam on the surface 3 of the substrate 4.

[0133] Typically, a two-dimensional (x, y) scan of the substrate is performed by scanning each portion of the substrate surface to be irradiated along an (imaginary) line aligned along the x-axis defined on the substrate, and then by moving the laser beam 35 along another line along the y-axis in a linear manner. Of course, other movement modes can be configured, such as linear scanning along the y-axis followed by movement along the x-axis, to perform a two-dimensional (x, y) scan or a vector scan known to those skilled in the art.

[0134] Here, a portion of the substrate can be scanned.

[0135] In one embodiment, the fixing device 10, particularly the laser, is configured to scan n times on each portion of the surface of the substrate 4 to be irradiated, where n is an integer greater than or equal to 2. Typically, n corresponds to the number of times the laser beam 35 scans the portion of the substrate 4 to be irradiated. As mentioned above, in a variation, n can be equal to 1 when a single scan is performed.

[0136] In an exemplary embodiment, the surface portion of the substrate 4 has a start point and an end point, which define the portion of the substrate 4 to be irradiated. Therefore, the laser beam 35 is configured to first scan the portion of the substrate 4 defined between the start point and the end point. During this first scan (i.e., the first iteration), the laser beam 35 begins to irradiate the portion of the substrate again by performing a second scan of the portion defined between the start point and the end point. The laser beam 35 can perform n scans, where n is preferably equal to 3. Typically, the laser beam 35 can begin at the end point of the first scan and thus scan all points of the portion of the substrate 4 to be irradiated, ending at the start point of the first scan. Of course, other embodiments are also possible. Alternatively, during the second scan, the laser beam 35 can follow a similar path to the first scan. In this case, the laser beam 35 starts from the start point and ends at the end point.

[0137] The laser beam 35 is configured to scan 2 to 40 times, preferably 2 to 20 times, and more preferably 3 to 10 times, at each point on the portion of the substrate 4 to be irradiated (this allows for a better trade-off between energy consumption and marking efficiency). Typically, the number of scans depends on the nature of the laser beam 35, such as its movement speed and power density. This may also depend on the type of laser 31 used, the material of the substrate (as defined below), and particularly the surface 3 of the substrate 4 irradiated by the laser beam 35, etc. For example, as described below, for fragile substrates (e.g., animal leather, vegetable leather, artificial leather), the number of scans n of the laser beam is greater than or equal to 1 (e.g., 5 to 10 times) to fix the marking composition, with a power density of 300 W / mm². 2 Up to 500 W / mm 2The moving speed is 1500 mm / s to 2500 mm / s.

[0138] When more than two scans are programmed, it can be programmed that even scans start from the same starting point, while odd scans start from the same starting point, different from the starting point of even scans (as described above in the case of two scans).

[0139] The movement of the laser beam 35, controlled by the scanning device 32, on the surface of the substrate 4 allows for the generation of multiple patterns, shapes, symbols, designs, and letters on the surface of the substrate 4. Typically, the desired pattern is pre-input into the control unit 50, which then controls the scanning device 32 to generate the desired shape.

[0140] At the output of the scanning device 32, the laser beam 35 is focused onto the substrate 4 by the focusing device 33. Here, the focusing device 33 therefore has a focal length for focusing the laser beam 35 onto a focal point included in the focusing plane.

[0141] The fixing device 10 also includes a positioning device 12, such as one or more positioning pins configured to define a machine reference system. The substrate 4 has a reference system aligned with the machine reference system of the fixing device 10. Therefore, this positioning device allows for precise movement and repositioning of the substrate 4 within the fixing device 10. The positioning device 12 may include one or more positioning pins, supports, brackets, etc. In the illustrated embodiment, the positioning device 12 is located on a support of the fixing device. Of course, such a device can be located in other locations, such as on the chassis 11. The elements of the fixing device 10 are preferably aligned with the machine reference system of the fixing device 10.

[0142] The fixing device 10 may optionally include a processing device 80 configured to process the metal layer of the substrate 4 by laser irradiation. This processing device 80 is used if the substrate 4 has a metal layer on its surface 3 and it is desired to fix the marking composition 2 onto the metal layer.

[0143] Typically, the metal layer requiring this treatment includes at least one of the following materials: metals, such as zinc or aluminum; and treated metals, such as anodized aluminum (a metallic material).

[0144] Of course, the processing device 80 can also be used on metal covered with a protective layer. Typically, the protective layer may include at least one of the following elements: anodized layer, paint, spray paint, galvanizing, metallization, or plasticizing (e.g., epoxy resin type). When the protective layer includes at least one of the following elements: paint, spray paint, galvanizing, metallization, or plasticizing, the metal layer is called painted metal.

[0145] In one embodiment, the processing device 80 and / or the laser 30 may be detachable (removable from the fixing device 10). Thus, in this case, the processing device 80 and / or the laser 30 are aligned with the machine reference frame once inserted into the fixing device 10.

[0146] like Figure 3 As shown, the processing device 80 is similar to the laser device 30. This means that the processing device 80 includes all the elements of the laser device 30 described below and operates in a similar manner.

[0147] In a preferred embodiment, the processing device 80 and the laser device are a single element. Therefore, in this preferred embodiment, the laser device 30 is configured to process the metal layer of the substrate 4 and fix the marking composition 2 to the substrate (here, the metal layer of the substrate 4). Thus, in this configuration, a single laser device 30 performs two functions. Of course, in variations of the device 10, two laser devices 30 may be present, one for processing the metal layer and the other for depositing the marking composition on the metal layer.

[0148] Advantageously, the processing device 80 is configured to scan once on the metal layer region of the substrate 4 to be processed. This laser scan is performed before the marking composition 2 is fixed onto the substrate 4. When processing is performed by the processing device 80, the laser device 30 is configured to fix the marking composition 2 onto the processing area. This means that the laser beam 35 only irradiates the portion of the marking composition 2 located on the processing area of ​​the substrate 4. Typically, the processing area is included (i.e., programmed, defined) in the input data.

[0149] Figure 3 The substrate 4 shown is located on the bracket 40. The bracket is used to hold the substrate 4 in the fixing device 10. Typically, the substrate 4 can be located on a flat bracket 40. In one embodiment, the bracket 40 and the frame 11 are formed as a single piece. In a variation, the bracket 40 is not flat and may have claws fixed to a portion of the substrate to hold the substrate 4.

[0150] like Figure 3 As shown, a distance d separates the surface 3 of the substrate 4 from the focusing device 33. This distance d is defined between a point on the surface 3 of the substrate (located in plane PL1) and a parallel plane PL2 of the focusing device 33. The distance d from the focal plane can be from 0 cm to 5 cm. Therefore, typically, plane PL1 can be located in or parallel to the focusing plane, and at most 5 cm from the focusing plane, while plane PL2 is parallel to the focusing plane.

[0151] In one embodiment, the support 40 is movable. In this case, the support 40 is arranged to move in at least one spatial direction. Figure 3 In the illustrated embodiment, the support 40 is arranged to move the substrate 4 along a z-axis parallel to the propagation direction of the laser beam 35. This arrangement allows the position of the substrate 4 to be adjusted relative to the focal point of the laser beam 35. In this embodiment, the distance d is adjusted by moving the support 40. As described above, the substrate 4 can be offset from the focal plane by 5 cm (depending on the focusing device 33) or positioned within the focal plane (including the focal point).

[0152] The position of the substrate 4 relative to the focal point of the laser beam 35 can be adjusted before or during laser beam 35 emission. Alternatively, in another embodiment, the support 40 can be arranged to move the substrate 4 in three spatial dimensions: x, y, and z. In this case, the movement of the laser beam 35 relative to the substrate 4 can be a combination of the movement of the laser beam 35 via the scanning device 32 and the movement of the substrate 4 caused by the movement of the substrate 4 via the support 40.

[0153] For this purpose, the bracket 40 may be equipped with a motor (not shown), or the position of the bracket 40 may be adjusted by an adjusting ring to position the bracket 40 in the correct position.

[0154] The laser 31 used in the laser device 30 is a continuous laser 31 or a pulsed laser.

[0155] Different types of lasers can be used in system S, such as solid-state lasers or CO2 lasers with amplification media. In this disclosure, the solid-state amplification media includes crystals, such as neodymium-doped yttrium aluminum garnet (Nd-YAG) crystals or neodymium-doped yttrium aluminum garnet (Nd: Y3Al2(AlO4)3) crystals.

[0156] Preferably, the laser used is configured to emit a laser beam 35 at a power of 0.50 W to 30.0 W.

[0157] In the first embodiment, the solid amplification medium of the laser 31 is an Nd-YAG crystal that emits a laser beam with a wavelength of 1,064 nanometers.

[0158] In this embodiment, when the laser beam has 1.9 kW / mm 2 Up to 3.8 kW / mm 2At a power density of [specific value], for example on leather, very good results are obtained. The emitted laser beam 35 pulses at a pulse rate in the range of 1 kHz to 50 kHz. The power of the emitted laser beam used to fix the marking composition 2 onto the substrate 4 is 7.5 W to 15 W. In this embodiment, the laser beam 35 is configured to scan the surface of the substrate 4 at a scanning speed of 3 m / s to 4.5 m / s. In this embodiment, the laser beam 35 typically has a power density of 1.9 W / mm². 2 Up to 3.8 kW / mm 2 The laser power density is in contact with the marking composition irradiated by the laser beam 35.

[0159] In another embodiment, laser 31 is a CO2 laser that emits an infrared laser beam with an emission wavelength of 10,600 nanometers.

[0160] Preferably, the CO2 laser 31 operates in pulsed mode and emits a laser beam with a power of less than or equal to 25 watts (preferably 3 watts to 25 watts). The pulse frequency rate of the laser beam 35 ranges from 1 kHz to 200 kHz, preferably from 1 kHz to 50 kHz. In this embodiment, the power density of the laser beam 35 is 32 W / mm². 2 Up to 7.7 kW / mm 2 60 W / mm is preferred 2 Up to 1.89 kW / mm 2 At that time, very good results were obtained. In this embodiment, the laser beam 35 is configured to have a beam of 10 mm·s. -1 up to 9.0 m‧s -1 The surface of the substrate 4 is preferably scanned at a scanning speed of 0.1 m / s to 9 m / s, and the laser power density is 60 W / mm² when in contact with the marking composition irradiated by the laser beam 35. 2 Up to 5 kW / mm 2 .

[0161] In another embodiment, the solid-state gain medium of laser 31 is a third-harmonic-doped yttrium aluminum garnet crystal, referred to as a Yd:YAG laser, which emits a laser beam with a wavelength of 355 nanometers.

[0162] In this embodiment, when the power density of the laser beam is 32 W / mm² 2 Up to 7.7 kW / mm 2 Preferably, it is 5.0 W / mm 2 Up to 60 W / mm 2Very good results were obtained. The emitted laser beam 35 pulses at a pulse rate in the range of 1 kHz to 50 kHz. The power of the emitted laser beam is 3 W to 8 W, typically 5 W. In this embodiment, the laser beam 35 is configured to scan the substrate surface at a scanning speed of 10 mm / s to 150 mm / s, and the laser power density is typically 60 W / mm² when contacting the marking composition irradiated by the laser beam 35. 2 Up to 5 kW / mm 2 .

[0163] In another embodiment, the laser used is a frequency-doubled YAG laser that emits a laser beam with a wavelength of 532 nanometers.

[0164] In this embodiment, when the power density of the laser beam is 5.0 W / mm² 2 Up to 2 kW / mm 2 Furthermore, very good results were obtained in the fixed step at displacement velocities ranging from 10 mm / s to 2000 mm / s. Typically, for CICP pigments (mica + TiO2 + SnO2 + Fe2O3), at a displacement of 1000 mm / sec and a displacement of 1.27 kW / mm... 2 Very good results were obtained with high power density and 20 scans. The emitted laser beam 35 pulses at a pulse rate ranging from 1 kHz to 50 kHz. The power of the emitted laser beam is 3 watts to 8 watts, typically 7 watts.

[0165] The laser beam 35 has a diameter of 40 micrometers to 120 micrometers, preferably 50 micrometers to 120 micrometers, and contacts the surface 3 of the substrate 4 covered with the marking composition.

[0166] Therefore, the laser beam 35 of system S irradiates the marking composition 2 to fix the marking composition 2 onto the substrate 4.

[0167] In system S, the unirradiated portion of the labeled composition 2 is subsequently removed by cleaning the unirradiated portion.

[0168] In system S, these un-irradiated portions can be manually cleaned using a wipe or sponge moistened with an aqueous composition, or cleaned by a cleaning device 60 controlled by control unit 50. The aqueous solution may contain alcohol, or a combination of water and soap. In another variation, the un-irradiated marking composition 2 can be removed by an adhesive (e.g., with an adhesive roller).

[0169] The cleaning device 60 may include an ultrasonic system configured to emit sound waves to remove portions of the marking composition 2 that have not been irradiated by the laser beam 35. In another embodiment, the cleaning device 60 comprises a movable arm equipped with tools, such as a wet sponge, brush, spray device, or wipe, for removing the marking composition that has not been irradiated by the laser beam 35 using an aqueous solution.

[0170] According to this disclosure, different substrates 4 can be marked by the above-described system S.

[0171] It is worth noting that the marked substrate 4 can be a fragile substrate.

[0172] Typically, fragile substrates include polyurethane, plasticized leather, artificial leather, and animal-derived organic substrates such as leather (smooth and textured). Organic substrates also include plant-derived pressed or dried substrates, such as cardboard, paper, plant-derived imitation leather, and so-called plant skins or plant skins, such as pineapple skin, mango skin, mushroom skin, tomato skin, etc.

[0173] The fixing device 10 can mark other types of substrates. For example, other substrates that can be marked by the fixing device 10 may include metal, plastic, glass, and composite materials. (Use the following description...) Figure 9 To describe these other substrates, which are referred to as hard substrates, in more detail.

[0174] In this disclosure, if the Shore A hardness of the substrate is 10 to 90, preferably 50 to 90, the substrate is referred to as a brittle, soft, or fragile substrate. For substrate 4 with a Shore A hardness of 50 to 90, deposition performance is improved. For a soft substrate, we refer to a substrate configured for mechanical marking by low-intensity actions (less than 10 Newtons), such as by a fingernail.

[0175] Conversely, if the Shore A hardness of substrate 4 is greater than 90, it is referred to as a hard substrate. As mentioned above, these hard substrates may require surface treatment using the fixing device 10.

[0176] In some applications, the substrate may be plastic or include plastic.

[0177] Typically, in this case, the substrate may include at least one of the following plastics: styrene (ABS), polyolefin homopolymer (PP), polyester (PETG), polyamide (PA-6), biodegradable material (PLA), recycled plastic (PA-6 r, PS r, ABS r), acrylic resin (PMMA), polyurethane (PU), or imitation leather.

[0178] When the substrate comprises a metal, the substrate may include at least one of the following: a metal alloy, such as brass (a copper and zinc alloy) or stainless steel (an iron and carbon alloy); a metal, such as zinc or aluminum; a metal with an oxide layer, such as anodized aluminum; or a metal including a protective layer, such as painted metal. Here, the metal may be coated with any of the aforementioned metal layers. The protective layer may include: anodized layer, paint, spray paint, zinc plating, metallization, or plasticizing (e.g., epoxy resin type).

[0179] The substrate used can also have different thicknesses.

[0180] Furthermore, these substrates can be of various shapes. Typically, the substrates used can be flat or curved.

[0181] The substrate according to this disclosure can have a roughness from 0 micrometers to 2 centimeters. The roughness depends on the substrate 4 to be labeled, on which the labeling composition 2 is deposited.

[0182] The fragile substrate marked by method 100 according to the present invention preferably has a Shore A hardness of 50 to 90.

[0183] In this disclosure, the labeling composition 2 comprises: - An aqueous matrix, comprising 50% to 84% by weight in the labeling composition. - At least one colorant, which is in the form of particles suspended in an aqueous matrix, and is present in the labeling composition at a proportion of 16% to 50% by weight.

[0184] Each colorant in the marking composition 2 is in particulate form with a size ranging from 10 nm to 0.1 mm.

[0185] Aqueous matrix is ​​used as an application carrier for labeling composition 2.

[0186] Aqueous matrices contain water and stabilizers.

[0187] Typically, stabilizers contain short-chain water-soluble alcohols or acrylic resins mixed with surfactants.

[0188] When alcohols are used, this aqueous matrix helps reduce the surface tension of the colorant / water matrix. The effect of alcohols is particularly to accelerate the drying of the marking composition on the substrate surface.

[0189] In one embodiment, the aqueous matrix may contain a water-soluble organic solvent. Typically, the organic solvent is selected from acetaldehyde, acetic acid, acetone, acetonitrile, dimethoxyethane, dimethylformamide, dimethyl sulfoxide (DMSO), dioxane, ethanol, ethylamine, ethylene glycol, glycerol, methanol, propanol, propylene glycol, tetrahydrofuran, and triethylene glycol. Of course, other organic solvents may also be used.

[0190] In a preferred embodiment, the aqueous matrix, particularly the stabilizer, does not contain organic solvents.

[0191] For example, when the stabilizer is a water-soluble short-chain alcohol, the short-chain alcohol may contain a C2-C3 matrix or may be methanol.

[0192] When the stabilizer is an acrylic resin and a surfactant, the method of intervening in the fixation of the colorant by mixing the acrylic resin with water.

[0193] In this case, the surfactant can be selected from anionic surfactants, cationic surfactants, nonionic surfactants (e.g., esters), amphoteric surfactants, polymeric surfactants, and bio-derived surfactants belonging to one of the aforementioned categories.

[0194] The surfactant used depends on the colorant used in the labeling composition.

[0195] Colorants can be selected from: - A pigment that contains at least one of the following elements: metal oxide, metal, metal alloy, or metal alloy oxide; -Inorganic pigments; -Organic pigments; - Carbonate mineral pigments; - Sodium thiosulfate aluminosilicate; - Synthetic dyes; -Natural dyes; Alternatively, it can be a mixture of the colorants listed above.

[0196] Typically, when colorants include pigments, the pigments can be in particulate form.

[0197] For example, when a colorant (here, a pigment) contains particles of at least one metal, these particles are selected from bronze, gold, and silver.

[0198] As mentioned above, the colorant can be a mixture of several different pigment particles.

[0199] Therefore, in one embodiment, the colorant further comprises at least one silicate, preferably mica, included in the colorant composition at a ratio of 38% to 74% by weight.

[0200] Typically, when silicates include mica or mica, mica particles can be coated with particles of one or more metal oxides.

[0201] The particles of at least one metal oxide are selected from the following transition metal oxides: -Titanium oxide; -Iron oxide; - Tin dioxide.

[0202] In one embodiment, the colorant or marking composition has photochromic and / or thermochromic properties.

[0203] The following detailed examples describe different colorants used in the marking composition 2 in method 100, which will be described below. In particular, in these examples, the colorant comprises at least one pigment in particulate form.

[0204] Example 1 In this embodiment, the colorant comprises a pigment in particulate form. The particles are bronze particles made of a copper-tin alloy known to those skilled in the art. The particle size of the bronze particles is 10 nanometers to 20 µm. The bronze particles are mixed in an aqueous matrix containing water and short-chain alcohols, but remain insoluble. For example, the bronze particles are present in labeling composition 2 at 16.6 wt%, the isopropanol of the aqueous matrix is ​​present in labeling composition 2 at 16.6 wt%, and the water of the aqueous matrix is ​​present in labeling composition 2 at 66.6 wt%. The composition is then applied to a substrate manually or via a deposition apparatus 20. The color obtained from this labeling composition is typically gold.

[0205] Example 2 In this embodiment, the colorant comprises a pigment containing carbon particles and iron oxide particles (Fe2O3). The carbon particles have a particle size of 10 nanometers to 100 µm. This colorant allows for the production of a black color. The iron oxide particles are mixed in an aqueous matrix containing water and short-chain alcohols, but remain insoluble. For example, the colorant is present in labeling composition 2 at 16.6% by weight, isopropanol of the aqueous matrix is ​​present in labeling composition 2 at 16.6% by weight, and water of the aqueous matrix is ​​present in labeling composition 2 at 66.6% by weight. The composition is then applied to a substrate manually or via a deposition apparatus 20.

[0206] Example 3 In this embodiment, the colorant includes a pigment containing synthetic or natural mica particles, which are combined with precious metal particles selected from gold (here, coating) to obtain a gold / gold color, or selected from silver to obtain a silver color.

[0207] In this embodiment, the mica particles are a thousand times larger than silver or gold particles. Typically, mica particles have a size on the order of micrometers, while gold or silver particles have a size on the order of tens or hundreds of nanometers. The mica particles are present in the colorant composition at a proportion of 80% to 99% by weight. As described above, these particles are mixed with an aqueous matrix.

[0208] For example, the colorant is present in the labeling composition 2 at 16.6% by weight, the isopropanol component of the aqueous matrix is ​​present in the labeling composition 2 at 16.6% by weight, and the water of the aqueous matrix is ​​present in the labeling composition 2 at 66.6% by weight. The composition is then applied to the substrate manually or by means of the deposition apparatus 20.

[0209] Example 4 In this embodiment, the aqueous matrix comprises an acrylic binder and a surfactant. Typically, in this embodiment, the colorant is present in the labeling composition 2 at 30% by weight, the acrylic binder is present in the labeling composition 2 at 64% by weight, and the surfactant is present in the labeling composition 2 at 66.6% by weight. The surfactant may include sodium lauryl sulfoacetate.

[0210] Colorants include pigments containing synthetic mica particles or natural mica particles mixed with metal oxide particles.

[0211] Mica particles are present in the colorant composition at a proportion of 38% to 74% by weight. The remainder of the colorant composition consists of particles of at least one metal oxide. In this embodiment, the size of the mica particles is 3.8 μm to 74 μm.

[0212] Different compositions of colorants can be considered.

[0213] Case 1: The colorant in the marking composition comprises mica particles, titanium dioxide (TiO2) particles, tin dioxide (SnO2) particles, and iron oxide (Fe2O3) particles, each with a particle size of 10 to 60 micrometers. For example, the mica particles are present in the colorant composition at 66% to 74% by weight, the TiO2 particles at 15% to 19% by weight, the Fe2O3 particles at 11% to 15% by weight, and the SnO2 particles at less than 1% by weight. As described above, this colorant is mixed with an aqueous matrix to obtain marking composition 2. According to this embodiment, the marking composition 2 irradiated onto the substrate is gold / gold.

[0214] Case 2: In this embodiment, the colorant of the marking composition includes mica particles, titanium dioxide (TiO2) particles, and iron oxide (Fe2O3) particles, each with a particle size of 10 to 60 micrometers. As described above, the colorant is mixed with an aqueous matrix to obtain marking composition 2. According to this embodiment, the marking composition 2 irradiated onto the substrate is gold / gold.

[0215] Case 3: In this embodiment, the colorant of the marking composition includes mica particles and iron oxide particles (Fe2O3) with a particle size of 5 to 23 micrometers. As described above, the colorant is mixed with an aqueous matrix to obtain marking composition 2. According to this embodiment, the marking composition 2 irradiated onto the substrate is gold / gold.

[0216] Case 4: In this embodiment, the colorant of the marking composition includes mica particles and titanium dioxide (TiO2) particles with a particle size of 10 to 60 micrometers. As described above, the colorant is mixed with an aqueous matrix to obtain marking composition 2. In this embodiment, marking composition 2 irradiated onto the substrate is white.

[0217] Case 5: The colorant in the marking composition comprises mica particles and iron oxide III particles (Fe2O3). As described above, this colorant is mixed with an aqueous matrix to obtain marking composition 2. According to this embodiment, marking composition 2 irradiated onto the substrate is green.

[0218] Case 6: The colorant in the marking composition includes mica particles present in the colorant composition at 69% to 73% by weight and titanium dioxide particles present in the colorant composition at 26% to 30% by weight. As described above, the colorant is mixed with an aqueous matrix to obtain marking composition 2. According to this embodiment, marking composition 2 irradiated onto the substrate is gray.

[0219] Case 7: The colorant in the marking composition comprises mica particles, iron oxide particles, and tin dioxide (SnO2) particles. As described above, this colorant is mixed with an aqueous matrix to obtain marking composition 2. According to this embodiment, marking composition 2 irradiated onto a substrate is yellow.

[0220] Case 8: The colorant in the marking composition comprises mica particles, iron oxide particles, and titanium dioxide (TiO2) particles. As described above, this colorant is mixed with an aqueous matrix to obtain marking composition 2. According to this embodiment, marking composition 2 irradiated onto the substrate is orange.

[0221] Case 9: The colorant in the marking composition includes mica particles, SnO2 particles, and TiO2 particles. As described above, this colorant is mixed with an aqueous matrix to obtain marking composition 2. According to this embodiment, marking composition 2 irradiated onto the substrate is purple.

[0222] Case 10: The colorant in the marking composition includes mica particles, TiO2 particles, and Fe2O3 particles. As described above, this colorant is mixed with an aqueous matrix to obtain marking composition 2. According to this embodiment, marking composition 2 irradiated onto the substrate is black.

[0223] Case 11: The colorant in the marking composition comprises mica particles and Fe2O3 particles. As described above, this colorant is mixed with an aqueous matrix to obtain marking composition 2. According to this embodiment, marking composition 2 irradiated onto the substrate is red.

[0224] Although the colorant in this embodiment is shown to be mixed with an aqueous composition containing an acrylic binder and a surfactant, in alternative embodiments, the colorant may be mixed in an aqueous matrix containing short-chain alcohols, as shown in the preceding embodiments.

[0225] Example 5 In one embodiment, the colorant comprises a pigment containing at least one of the following particles: - Ceramic enamel particles composed of silicon dioxide, - Flux particles -Alumina particles, Or a mixture thereof.

[0226] This colorant is gray. Typically, the colorant accounts for 16.6% by weight in labeling composition 2, the isopropanol of the aqueous matrix accounts for 16.6% by weight in labeling composition 2, and the water of the aqueous matrix accounts for 66.6% by weight in labeling composition 2.

[0227] Example 6 In this embodiment, the colorant comprises a pigment comprising alumina particles coated with titanium dioxide, and also includes tin oxide. In this embodiment, the colorant particles are 5 μm to 60 μm, here 5 μm to 30 μm. This colorant allows for the production of a blue color. The alumina particles are mixed in an aqueous matrix comprising an acrylic binder and a surfactant. For example, the colorant is present in the labeling composition 2 at 30% by weight, and the aqueous matrix is ​​present in the labeling composition at 66% by weight. In this embodiment, the aqueous matrix in the labeling composition 2 contains 60% by weight of the acrylic binder, and the surfactant is present in the labeling composition 2 at 6% by weight. The composition is then applied to a substrate manually or via a deposition apparatus 20.

[0228] In order to perform the marking according to the invention, the marking composition 2 must be deposited on the substrate surface 3 that will be positioned facing the laser beam 35, and this deposition can be performed in various ways.

[0229] In this disclosure, the marking composition 2 can be manually deposited onto the substrate 4, for example using a brush. In this case, the thickness of the deposited marking composition 2 can be less than 1 mm, preferably 0.01 mm to 0.1 mm.

[0230] In one variant, the labeling composition can be automatically deposited using a deposition device 20. For this purpose, the deposition device 20 is controlled by a control unit 50.

[0231] Typically, the deposition apparatus 20 may include a movable arm equipped with tools, such as a brush arranged to deposit the marking composition on the surface 3 of the substrate 4. The deposition of the marking composition 2 is preferably performed linearly on the substrate 4.

[0232] exist Figure 2 In the variant shown, deposition apparatus 20 uses a coating rod based on a known technology known as Rod Coater. For example... Figure 2 As shown, in this embodiment, the deposition apparatus 20 includes a movable cylindrical rod 21 covered with a wire 22 wound around the rod 21, thereby forming a coil. Figure 2 In this configuration, substrate 4 is located on support 40. A portion of the marking composition 2 is deposited, for example by spraying, onto a given location P on surface 3 of substrate 4. Rotation (movement) of rod 21 in direction 6 allows the marking composition 2 to be deposited onto substrate 4 in direction 6.

[0233] The thickness of the marking composition 2 depends on the thickness of the wire 22 used. The moving speed of the rod 21 is controlled by the control unit 50. It typically varies between 2 m / min and 15 m / min.

[0234] In this disclosure, the deposition apparatus 20 is configured such that the thickness of the labeling composition 2 is 10 μm to 20 mm, for example, 10 μm to 100 μm.

[0235] Figure 4 A second embodiment of the fixing device 70 is shown. Only the following description will be provided. Figure 3 The differences.

[0236] In this embodiment, the fixing device 70 includes a frame 11, a laser device 30 including a laser 31 that emits a laser beam 35, a focusing device 33 including a focusing lens 34, and a bracket 40.

[0237] In this embodiment, the fixing device 70 does not include a scanning device.

[0238] Here, the support 40 is a movable support 40, which is configured to move in three spatial directions, x, y, and z, as explained in the previous embodiments. Therefore, in this embodiment, the movement of the laser 35 is implemented by the movement of the substrate 4.

[0239] First, the distance between the substrate 4 and the focusing device 33 is adjusted by moving the support 40 along the z-axis to position the substrate at the required distance from the focal point of the focusing device. This distance can be adjusted before emitting the laser beam 35 or during laser irradiation.

[0240] Then, the laser beam 35 at the output of the focusing device 33 moves on the substrate 4 via a movable support 40, which moves in two spatial directions, x and y. Typically, the movement of the support 40 is linear. The support 40 moves along an (imaginary) line along the x-axis and then along the y-axis to another line, thus achieving relative movement of the laser beam 35 relative to the substrate 4. Through the movement of the support 40 in both dimensions (x, y), the laser beam 35 irradiates the portion of the substrate to be irradiated to obtain the desired pattern.

[0241] For this purpose, the fixing device 70 may include a synchronization device 90 for synchronizing the movement of the substrate 4 relative to the laser beam 35. In this case, the synchronization device 90 is controlled by the control unit 50.

[0242] method Reference Figures 5 to 8 A first embodiment of a method 100 for attaching a marking composition to a substrate is described. The marking composition 2 used is as described above and is suitable for attaching to a substrate by method 100 (or 200, as described below).

[0243] Figure 5 The method shown is by Figure 1 The system S shown is implemented.

[0244] Method 100 includes step 102 of depositing the labeling composition 2 on at least a portion of a substrate 4. In this embodiment, the substrate 4 is granular polyurethane with an average particle size of 35 μm.

[0245] As described above, this deposition on the substrate 4 can be performed manually (e.g., using a brush) or automatically via the deposition apparatus 20 as described above. If the deposition of the marking composition 2 is performed outside the fixtures 10, 70, the substrate 4 is wedged onto the machine reference frame of the fixtures 10, 70, for example, using the positioning device 12 of the fixtures 10, 70.

[0246] When the marking composition 2 is deposited on a substrate, particularly on the surface 3 of the substrate, method 100 may optionally include step 103 of drying the marking composition 2.

[0247] The drying step 103 depends on the labeling composition 2 used.

[0248] Typically, drying step 103 is carried out outdoors. The drying time depends on the materials of the marking composition 2 and the substrate 4. In the given examples, the drying time is less than two minutes.

[0249] Method 100 then includes step 104 of fixing a portion of the marking composition 2 by laser irradiation. The fixing step 104 is performed by… Figure 3 The fixing device 10 shown or Figure 4 The fixing device 70 shown performs the operation, particularly the laser device 30 that emits the laser beam 35 from the fixing devices 10 and 70. For example... Figure 5 As shown, the laser beam 35 irradiates the substrate 4 at a point or position 36. Here, the laser beam 35 has a diameter of 90 μm at the surface 3 of the substrate 4. Then, the laser beam 35 moves on the surface 3 of the substrate 4 to obtain the desired pattern on the surface 3 of the substrate 4.

[0250] As described above, the movement of the laser beam 35 can be achieved using methods such as... Figure 3 The scanning can be performed by the scanning device 32 shown, or by moving the substrate 4 with the aid of a movable support 40, or by a combination of both. The movement of the scanning device 32 and / or the substrate 4 along the x and y axes allows the laser beam 35 to be directed to the desired position on the surface 3 of the substrate 4.

[0251] Here, typically during the fixing step 104, the laser beam 35 in contact with the irradiated marking composition 2 has a strength of 32 W / mm². 2 Up to 7.7 kW / mm 2 60 W / mm is preferred 2 Up to 5 kW / mm 2 The power density, and the movement of the laser beam at a distance of 10 mm·s relative to the substrate. -1 up to 9.0 m‧s -1 0.10 m‧s is preferred -1 up to 9.0 m‧s -1 It proceeds at a certain speed.

[0252] In one implementation, the colorant remains unchanged (before and after laser fixation). However, in a variation, the colorant may include a thermochromic pigment that changes color upon laser irradiation.

[0253] Method 100 may optionally include step 106, which involves removing the marked composition that was not irradiated in fixation step 104.

[0254] Typically, the removal step 106 can be performed manually or by the cleaning device 60 as described above.

[0255] The removal step 106 allows for the removal of portions of the marking composition 2 that were not irradiated by the laser beam 35 in the fixing step 104.

[0256] It can be seen that the result obtained after removing step 106 Figure 5 The substrate 4 shown is marked with gold markings. In this embodiment, nine 3 mm by 3 mm gold patterns 16 have been marked on the substrate 4. In addition to the patterns 16, the substrate 4 has unmarked portions 17. This means that these portions 17 are not irradiated by the laser beam 35 during the fixing step 104.

[0257] The marking composition 2 irradiated by laser beam 35 did not change color (coloration) between deposition step 102 and fixing step 104.

[0258] Figure 7 An embodiment of the substrate 4 obtained after applying method 100 to substrate 4 is shown.

[0259] Figure 6 The substrate 4 shown is grained leather with an average roughness of 35 μm, having two parts. The first part 14 is not covered by the marking composition, and the second part 15 is covered by the marking composition 2 in the deposition step 102. In this embodiment, as described above, in the fixing step 104, the first part 14 and the second part 15 of the substrate 4 are irradiated by a CO2 laser beam (the first and second parts are irradiated with the same laser parameters).

[0260] Here, the laser beam 35 irradiates portions P1, P2, P3 and P4 of the first portion 14 of the substrate 4 and portions P5, P6, P7 and P8 of the second portion 15.

[0261] like Figure 6 As shown, substrate 4 has no markings on portions P1, P2, P3, and P4, while portions P5, P6, P7, and P8 have 18 gold square patterns of 5mm by 5mm marked on surface 3 of substrate 4. In the second part 15, all portions P5, P6, P7, and P8 of substrate 4 are covered with marking composition 2, which is fixed to substrate 4. Therefore, laser beam 35 does not mark or damage the first part 14 of substrate 4, which has been irradiated.

[0262] Typically, the marking composition 2 in portions P5, P6, P7, and P8 covers at least 90 percent of the irradiated portions P5, P6, P7, and P8 of the substrate 4.

[0263] For coverage, we refer to the ratio between the effective marked surfaces (i.e., the stained or colored surfaces, here the surfaces of the marking composition fixed to the substrate 4) on the effective irradiated surface after method 100. In this embodiment, each of portions P5, P6, P7, and P8 corresponds to the effective irradiated surface in the second portion 15 of the substrate 4. Here, for each portion P5, P6, P7, and P8, the effective marked surface is obtained by comparing the effective irradiated surface (here the surfaces of portions P5, P6, P7, and P8) with the proportion of unirradiated substrate in each portion P5, P6, P7, and P8.

[0264] Figure 7 An example of a cylindrical bottle or flask B made of synthetic leather or artificial leather (polyurethane) is shown. Figure 7 As shown, a gold pattern M is marked on the surface 3 of the substrate 4 of box B. The pattern M is marked using the method 100 described above.

[0265] Typically, in method 100, before the fixing step 104, here after or during the drying step 103, the bottle M has already been positioned relative to the focusing device 33.

[0266] The distance d separating the surface of substrate 4 from bottle B and focusing device 33 is adapted to the shape of bottle B. Since method 100 can mark substrates up to 5 cm from the focusing plane, it is not necessary to adapt the distance d during fixing step 104 even if the substrate is curved. In fact, this 5 cm allows the shape and curvature of the substrate to be marked to be encompassed during the fixing step.

[0267] Method 100 is typically used when the substrate, particularly the surface 3 of the substrate 4 that comes into contact with the laser beam 35 during the fixing step, includes at least one of the following elements: - Organic materials derived from plants; - Organic materials derived from animals; -Synthetic materials; - Cellulose materials; -Metallic materials; - Plastic materials; - Composite materials; - A mixture or combination of several of the aforementioned materials.

[0268] Animal organic materials include leather (e.g., leather from mammals such as cows, or leather from vertebrates such as fish or snakes). Plant organic materials include various types of plant leather (e.g., mango peel, pineapple peel, mushroom peel, or mushroom mycelium).

[0269] Plastic materials also include synthetic leather, such as imitation leather.

[0270] Embodiments of implementing method 100 on different substrates will now be described.

[0271] The results given below were obtained using a flat substrate with an average roughness of less than 2 cm, preferably less than 50 mm, and more preferably less than 1 mm. The colorant given is used in the marking composition as described above, i.e., the marking composition contains 50% to 84% by weight of an aqueous matrix (water + short-chain alcohol or acrylic binder mixed with a surfactant) and 16% to 50% by weight of at least one colorant (described below) in the marking composition.

[0272] For example, Table 1 shows an embodiment of implementing method 100 on a substrate having a surface 3 including the fragile material (leather, imitation leather, plant hide) as described above.

[0273] The colorant used includes at least one of the elements mentioned above.

[0274] Table 1

[0275] The lasers used in Table 1 are similar to those described above and are obtained in fixed step 104 by a single scan (n equals 1) or multiple scans (n ​​is greater than or equal to 2) of the laser beam.

[0276] For these results, the power density of the laser beam used was 32 W / mm². 2 Up to 7.7 kW / mm 2 The displacement velocity is 10 mm / sec to 9 m / sec.

[0277] Preferably, while limiting substrate damage, 300W / mm 2 Up to 500W / mm 2 A higher power density, a moving speed of 1500 mm / sec to 2500 mm / sec, and a number of scans greater than 1, preferably 3 to 10, preferably 5 to 10, will result in better marking results.

[0278] Table 2 shows an embodiment of implementing method 100 on a substrate having a surface comprising a (non-fragile) plastic material, wherein the plastic material is irradiated during a fixing step.

[0279] The results given below were obtained using a flat substrate with an average roughness of less than 2.00 cm, preferably less than 0.50 cm, and more preferably less than 1.00 mm.

[0280] The applicable plastic materials (polymers) marked by method 100 include at least one of the following plastics: styrene (ABS), polyolefin homopolymer (PP), polyester (PETG), polyamide (PA-6), biodegradable material (PLA), recycled plastics (PA-6 r, PS r, ABS r), and acrylic resin (PMMA).

[0281] For example, Table 2 shows an embodiment of implementing method 100 on a substrate having a surface including a plastic material marked by method 100.

[0282] Table 2

[0283] The solid-state gain medium lasers described in Table 2 are similar to those described above (devices) and are obtained in fixed step 104 by a single or multiple scans of the laser beam.

[0284] For these results, for example, for at least one scan of the laser beam, the power density of the laser beam used was 32 W / mm². 2 Up to 7.7 kW / mm 2 The displacement velocity ranges from 10 mm / s to 9 m / sec.

[0285] Metallic materials suitable for marking by method 100 include metals covered with a protective layer (e.g., an anodized layer, such as aluminum oxide, or a lacquer layer), and are referred to as painted metals as described above. Different colorants can be used in the marking composition for marking (marking surface 43) of anodized or painted metals in method 100. These colorants include one of the following: organic pigments: white inorganic pigments, colored CICP inorganic pigments, colored synthetic pigments made from metal oxides, colored natural inorganic pigments, synthetic dyes and color-developing dyes, and colorants based on natural dyes, as described in Tables 1 and 2. In this case, the laser used in the fixing step is preferably a CO2 laser with an emission wavelength of 10,600 nm, a power density, and is used at a speed similar to that described above (Table 2).

[0286] Therefore, it should be understood that the substrate may have other materials, such as other material layers that are not processed by method 100 (i.e., the steps of method 100 are not implemented on these layers).

[0287] Now refer to Figure 8 and Figure 9 A second embodiment of the method 200 according to this disclosure is described. Figure 9 The method 200 shown is by Figure 1 The system S shown is an implementation. It will be described and referenced only. Figure 5 , Figure 6 and Figure 7 The differences in method 100 described.

[0288] Figure 8 A side view of a substrate 42 suitable for marking according to method 200 is shown. Of course, as described above, in the embodiments described, Figure 8 The substrate shown can also be marked by method 100.

[0289] The substrate 42 can be of any type. Typically, the substrate 42 used in method 200 includes at least one of the following materials: -Metal; -plastic; -Glass; -ceramics; Stone; -brick; - Composite materials; - Organic materials derived from plants; - Organic materials derived from animals; -Synthetic materials; - Cellulose materials; Or a mixture or combination of several layers of these aforementioned materials.

[0290] Therefore, the substrate 42 may include a fragile material, such as the material listed in method 100, or a material with a higher hardness coefficient (i.e., a Shore A hardness coefficient greater than or equal to 80).

[0291] The substrate 42 has a surface 43, which in this embodiment includes a metal layer 44. Surface 43 is also referred to as a marking surface 43.

[0292] For example, metal layer 44 includes at least one layer of the following materials: -Metal; -Metal alloys; Or a mixture or combination of several layers of these aforementioned materials.

[0293] The substrate 42 may include another layer 41 made of a different material. Figure 9 In the illustrated embodiment, the substrate 42 is made of a single material, here a single 5 mm thick layer of anodized aluminum.

[0294] Figure 8 The substrate 42 shown is placed Figure 3 The fixing device 10 shown or Figure 4In the fixture 70 shown, it is marked by the marking composition 2 through the steps of method 200, which will be described below. For this purpose, the substrate 42 is positioned relative to the machine reference system of the fixtures 10, 70.

[0295] and Figure 5 Unlike method 100, method 200 includes step 202 of treating the metal layer 44 by laser irradiation before deposition step 102.

[0296] Here, typically, processing step 202 is handled by... Figure 3 and Figure 4 The processing device 80 shown is used for execution.

[0297] To improve density and reduce cost, the processing apparatus 80 is similar to the fixing device 30 described above. Typically, processing step 202 is performed by the laser device 30, which emits a laser beam onto the metal layer 44 of the substrate 42. Figure 9 As shown, the laser beam can irradiate or illuminate the surface of the metal layer 44 with a beam diameter of 90 μm.

[0298] In processing step 202, the laser beam can move across the surface of the metal layer 44 via laser scanning, typically using methods such as... Figure 3 The galvanometer head 32 shown can be moved as follows: Figure 4 The substrate 4 is shown. The movement of the laser beam locally causes surface treatment of the metal layer 44, particularly a chemical transformation of the surface of the metal layer 44 or a physical transformation of the metal layer, depending on the substrate. Therefore, the area scanned by the laser beam 35 forms a treated area 45 on the metal layer 44.

[0299] In processing step 202, a single scan of the laser beam on the metal layer 44 allows the processing area 45 to be obtained. Of course, in variations of method 200, the laser beam can scan the metal layer 44 multiple times. However, these additional scans result in additional energy consumption.

[0300] In this embodiment, during processing step 202, the laser beam moves across the surface of the metal layer 44 to form a desired shape pattern. This desired shape may be programmed in the input data or defined by default by the system S. The default shape may be rectangular, square, circular, or elliptical. Figure 9As shown, the processing area 45 is decomposed into circular patterns with a diameter of 5 mm. Of course, other shapes can be obtained depending on the movement of the laser during processing step 202 as described above. Typically, the processing area 45 can have a shape associated with one or more personalized patterns (e.g., logos, names, strings of words, strings of letters, images, etc.). Therefore, the processing area 45 can be decomposed into different separate parts on the surface 43 of the metal layer 44.

[0301] For example, if a CO2 laser emits at 10,600 nm, then the power density can be 955 W / mm². 2 Up to 1.27kW / mm 2 The speed can be from 500 mm / sec to 900 mm / sec.

[0302] For example, if a YAG laser emits at 355 nm, then the power density can be 1 kW / mm². 2 Up to 1.9 kW / mm 2 (Preferred power: 1.7 kW / mm) 2 The speed can be from 1000 mm / s to 1600 mm / s (preferably 1500 mm / s).

[0303] In this embodiment, the processed area 45 (here, a circular pattern) of the metal layer 44 has a surface color that distinguishes it from areas not treated by the laser beam (i.e., areas of the metal layer 44 not irradiated by the laser beam). The processed area 45 advantageously has a white or grayscale color. The color of the processed area 45 depends particularly on the properties of the laser beam, such as the laser beam's movement speed and / or power density. It can also depend on the material of the metal layer 44. Therefore, in method 200, the grayscale level of the processed area 45 can be selected by adjusting the laser irradiation parameters, for example, by adjusting the number of scans and / or power density and / or movement speed.

[0304] Typically, for method 200, when the metal layer 44 (especially the marking surface) is made of anodized aluminum, the processing steps can use 955 W / mm², for example, when using a CO2 laser. 2 Up to 1.27 kW / mm 2 The power density and laser beam movement speed of 500 mm / sec to 900 mm / sec are optimal. These parameters allow for better results in fixing the marked composition while limiting the energy consumption of method 200.

[0305] In method 200, the color of the treated area 45 may affect the fixation properties of the marking composition 2. For example, for anodized aluminum, it is preferable that the treated area 45 remains gray to facilitate adhesion of the marking composition during fixation step 206. Thus, adhesion becomes easier and more stable over time. Furthermore, the color of the colorant in the marking composition is better ultimately presented on the metal layer 44.

[0306] At the end of processing step 202, a processed area 45 is obtained on the surface of the metal layer 44.

[0307] Method 200 then includes a step 204 of depositing the labeled composition 2, which in this embodiment is similar to the deposition step 102 of method 100. Here, specifically, the deposition of the labeled composition 2 is achieved through... Figure 2 The deposition is performed using the shown deposition apparatus 20, or manually (e.g., using a brush). As described above, if deposition requires moving the substrate and repositioning it in the same location, in method 200, the substrate 4 is aligned with the same machine reference frame of the fixing devices 10, 70 via the positioning device 12.

[0308] In deposition step 204, deposition apparatus 20 deposits a layer of marking composition 2 on the treated area 45 of metal layer 44. The marking composition may also cover untreated areas of metal layer 44. If substrate 42 is moved during deposition, the substrate is repositioned in fixtures 10, 70 and aligned with the machine reference system of fixtures 10, 70.

[0309] exist Figure 9 In method 200 shown, the labeling composition 2 comprises an aqueous matrix and at least one colorant as described above. Therefore, the aqueous matrix may comprise an acrylic binder mixed with water and a short-chain alcohol, or with a surfactant.

[0310] Advantageously, the colorant (in particulate form) of the marking composition 2 is adapted to be fixed on the treatment area 45. This colorant comprises silicate particles covered by metal oxide particles or silicate particles covered by at least one noble metal particle. The silicate particles are selected from mica. When the silicate particles contain mica or mica, the colorant used in the marking composition can be the colorant described in Example 3 above (which has a colorant composed of mica particles covered by at least one noble metal particle) or the colorant of Example 4 above (which has a colorant composed of mica particles covered by at least one metal oxide particle).

[0311] In another embodiment, the colorant comprises particles of at least one metal alloy or particles of at least one transition metal. Therefore, the colorant may be similar to the colorant of Example 1, or similar to the colorant of Example 5, or similar to the colorant of Example 6.

[0312] In another variation, the colorant comprises particles of at least one carbonate mineral. Therefore, the colorant can be similar to the colorant in Example 2 described above.

[0313] In another variant, the colorant includes sodium thiosulfate aluminosilicate particles.

[0314] In another embodiment, the colorant comprises a pigment containing particles of at least one inorganic material as described above, such as Cu2(CO3)(OH)2) or particles of mica-TiO2–SnO2–Fe2O3 (Table 1 or Table 2).

[0315] In another variation, the colorant comprises a pigment containing particles of at least one organic material. The organic material may include polyoxymethylene-melamine-based materials.

[0316] In one variation, the colorant or marking composition has photochromic and / or thermochromic properties that are not altered by the steps of method 200, particularly during step 206 of fixing the colorant or during step 208 of removing the colorant.

[0317] When the colorant has photochromic properties, it can be similar to the colorant described in Example 7 below.

[0318] Example 7 In this Example 7, the colorant is a colorant composition comprising: -21.0% to 24.0% of polyoxymethylene melamine particles; -1.3% to 1.8% blue photochromic pigment; - Monomethylstyrene maleic anhydride particles contain: *62.0% to 68.0% mineral oil; *7.5% to 9.5% maleate polymer.

[0319] When the colorant has thermochromic properties, such colorant may be similar to the colorant described in Example 8 below.

[0320] Example 8 In this Example 8, the colorant is a composition of colorants, comprising: -19.0% to 27.2% of polyoxymethylene melamine particles; -5.8% to 7.2% styrene-maleic anhydride monomethyl maleate polymer particles; -2.0% to 4.2% of ODB-II (2′-anilino-6′-(dibutylamino)-3′-methyl-3H-spiro-3-one) particles; -0.3% to 0.7% Black DCF particles; -45.6% to 47.5% ethyl stearate granules; -15.2% to 15.8% methyl palmitate granules.

[0321] Following deposition step 204, method 200 may optionally include drying step 205. Drying step 205 is identical to drying step 103 described in method 100.

[0322] Method 200 includes a step 206 of fixing the marking composition 2 by moving a laser beam 35 on the surface of a substrate covered with the marking composition 2. In this embodiment, the fixing step 206 of method 200 is the same as the fixing step 104 of method 100. Therefore, in fixing step 206, the laser device 30 emits a laser beam 35, which moves along the surface of the metal layer 44 covered by the marking composition 2. Thus, in this step 206, the marking composition 2 is fixed to the treated area 45 of the metal layer 44 by illuminating or irradiating the treated area 45 with the laser beam 35. As described above, the substrate surface irradiated by the laser beam 25 can be located at the focal point or off-center (preferably up to 5 cm).

[0323] Advantageously, in method 200, the laser beam 35 is programmed to move only over the treatment area 45 of the substrate 42 to fix the marking composition to the treatment area. Therefore, in the fixing step 206, the laser beam 35 follows a movement similar to that of the laser beam in treatment step 202. Thus, in the illustrated embodiment, the laser beam 35 emitted in fixing step 206 irradiates only the treatment area 45.

[0324] Preferably, in the fixing step 206, the laser beam 35 irradiates the processing area 45 by performing a first scan over the entire processing area 45, i.e., by irradiating the entire surface of the processing area 45. In this first scan, as in method 100, the power density of the laser beam 35 in contact with the marking composition 2 covering the processing area 45 is 60 W / mm². 2 Up to 5 kW / mm 2 And measured at 0.1 m·s relative to substrate 42. -1 up to 0.9 m‧s -1 Move at a speed.

[0325] After the first scan, the laser beam 35 irradiates the processing area 45 by scanning the entire processing area 45 at least a second time. In this second scan, the laser beam 35 may follow a similar movement to the first scan, that is, starting from the same starting point and ending at the same ending point, or starting from the ending point of the previous scan and returning to the starting point of the previous scan, or following another movement while scanning only the portion of the marked composition 2 that was irradiated in the first scan of the laser beam 35. Furthermore, the irradiation parameters, here the laser beam movement speed and power density, are preferably similar from one scan to the next. Of course, these irradiation parameters can be changed, for example, by programming a higher or lower movement speed than used in the first scan.

[0326] Preferably, the laser beam 35 can scan the processing area 45 2 to 20 times, more preferably 3 to 10 times. In the illustrated embodiment, during the fixing step 104, the laser beam 35 scans the processing area 45 three times.

[0327] If processing step 202 and fixing step 206 are performed by two different and removable devices, then processing step 202 and / or fixing step 206 includes aligning processing device 80 and / or laser device 30 before performing these steps using positioning device 12.

[0328] Method 200 may optionally include step 208, which removes the marked composition 2 that was not irradiated in fixation step 206.

[0329] The removal step 208 can be performed manually or by the cleaning device 60 as described above.

[0330] from Figure 8 As can be seen, the metal layer 44 of the substrate 42 includes color markings only on the processed area 45. Therefore, in this embodiment, a color pattern is obtained on the metal layer 44 after method 200. Other portions of the substrate 42 are not marked (or dyed or colored) by the marking composition 2.

[0331] Therefore, in removal step 208, the unirradiated portions of the marking composition 2 from fixation step 206 and / or the portions of the marking composition irradiated in fixation step 206 but not located on the treatment area 45 of the metal layer 44 are removed. A colored pattern 24 is obtained on the surface of the metal layer 44.

[0332] Therefore, method 200 allows the marking composition 2 to be fixed onto a substrate 42 having a metal layer 44. As mentioned above, the marking composition 2 can be of different types, and various colorants can be used to dye (or color) the metal layer 44 to the desired color.

[0333] Table 3 shows the results of a substrate 42 having a metal layer 44 by implementing the above method 200, the metal layer 44 having areas colored (i.e. marked) by different colors.

[0334] In this embodiment, the fixing step 206 can use an emission wavelength of 355 nm and a power density typically of 32 W / mm². 2 Up to 208 W / mm 2 The laser beam is used for these two steps. The laser beam moves at a speed of 50 mm / s. -1 Up to 500 mm‧s -1 Furthermore, the laser beam scans the surface of the substrate to be marked in a single pass.

[0335] Table 3

[0336] Table 4 shows the results of a substrate 42 having a metal layer 44 by implementing the above method 200, the metal layer 44 having areas colored (i.e. marked) by different colors.

[0337] In this embodiment, the fixing step 206 can use an emission wavelength of 10,600 nm and a power density of 60 W / mm². 2 Up to 5 kW / mm 2 The process involves using a CO2 laser beam. The laser beam moves at a speed of 0.1 ms in both steps. -1 up to 9.0 ms -1 The number of scans by the laser beam ranges from 1 to 20.

[0338] Table 4

[0339] An embodiment of a substrate having a metallic surface marked by method 200 will then be described.

[0340] Suitable metal layers marked by method 200 include at least one of the following materials: pure metals, such as zinc, aluminum, copper, gold, and silver; treated (oxidized) metals, such as anodized aluminum; metal alloys, such as brass or steel or stainless steel (also known as stainless steel), ferrous metals, and cast zinc alloys (alloys of zinc, aluminum, and optionally copper). Of course, in one embodiment, the metal layer may be covered by a protective layer as described above.

[0341] The results given below were obtained using a flat substrate with an average roughness of less than 2.00 cm. The marking compositions used are similar to those used in Tables 1 and 2 above.

[0342] The fixing step is performed using one of the following lasers with a power density of 32 W / mm². 2 Up to 7.7 kW / mm 2 The measurement speed relative to the substrate is 10 mm·s. -1 up to 9.0 m‧s -1 Advantageously, when the processing steps are at 955 W / mm 2 Up to 1.277 kW / mm 2 Power density, 500 mm·s -1 Up to 900 mm‧s -1 Better results were obtained when using a CO2 laser with a moving speed, a scan count of n=1, and an emission wavelength of 10,600 nm.

[0343] Table 5

[0344] The solid-state gain medium lasers described in Table 5 are similar to those lasers (devices) described above, and are obtained by either a single scan of the laser beam in fixed step 206 or multiple scans of the laser beam in fixed step 206.

[0345] Variant This invention is by no means limited to the embodiments described and illustrated, but those skilled in the art will be able to provide any variations based on the invention.

Claims

1. A method for fixing a marking composition (2) onto a substrate (4, 42) by laser irradiation, said marking composition (2) comprising at least one colorant, said method comprising the following steps: - The marking composition (2) is deposited (102, 204) on at least a portion of the substrate (4, 42); -A portion of the marking composition (2) is fixed (104, 206) by irradiating at least a portion of the marking composition deposited on the substrates (4, 42) with a moving laser beam (35). -Removal (106, 208) of the marking composition (2) that was not irradiated during the fixation steps (104, 206). Characterized by the laser beam (35) in contact with the irradiated marking composition (2) having a strength of 32 W / mm². 2 Up to 7.7kW / mm 2 The power density, and the moving speed of the laser beam is 10 mm·s relative to the substrate. -1 up to 9.0 m‧s -1 .

2. The method according to claim 1, characterized in that, The power density is 60 W / mm². 2 Up to 5 kW / mm 2 The laser beam moves at a speed of 0.1 m·s. -1 up to 9.0 m‧s -1 .

3. The method according to claim 1 or 2, characterized in that, The fixing step is performed on the surface of a substrate (3, 43) including a metal layer, the surface of which is hereinafter referred to as the marking surface. The method includes: a treatment step (202) of at least one area of ​​the metal layer (44) by laser irradiation prior to the deposition step (102, 204), and a deposition (204) and fixing (206) step on the treated area (45) of the metal layer (44).

4. The method according to claim 3, characterized in that, The processing step (202) uses a laser that emits a laser beam. The laser beam used in the processing step (202) and the laser beam used in the fixing step (206) have at least one of the same properties, which include at least one of the following elements: -wavelength; -Power density; - Movement speed.

5. The method according to any one of claims 3 to 4, characterized in that, The surface of the processing area (45) has one of the following colors: -White; - Grayscale color.

6. The method according to any one of claims 1 to 5, characterized in that, The substrate (4, 42) includes at least one of the following elements: -Metal; -plastic; - Composite materials; - Organic materials derived from plants; - Organic materials derived from animals; -Synthetic materials; - Cellulose materials; - A mixture or combination of several of the aforementioned materials.

7. The method according to any one of claims 1 to 6, characterized in that, During the fixing steps (104, 206), the laser is configured to scan the portion of the marking composition (2) n times, where n is greater than or equal to 2.

8. The method according to any one of claims 1 to 7, characterized in that, The substrates (4, 42) have a roughness of 0 micrometers to 2 centimeters.

9. The method according to any one of claims 1 to 8, characterized in that, The laser (31) is coupled to a focusing device (33) having a focal length for focusing the laser beam (35) at a focal point, and the substrate (4, 42) is located at the focal point or at a distance of less than or equal to 5 cm from the focal point.

10. The method according to any one of claims 1 to 9, characterized in that, The laser (31) used in the fixing steps (104, 206) includes at least one of the following lasers: - A YAG laser, wherein the YAG laser emits a laser beam with a wavelength of 1064 nanometers. - A CO2 laser, which emits a laser beam with a wavelength of 10600 nanometers. - A frequency-doubled YAG laser that emits a laser beam with a wavelength of 532 nanometers. - A third-harmonic YAG laser that emits a laser beam with a wavelength of 355 nanometers.

11. The method according to claim 10, characterized in that, When the laser beam is a YAG laser, the generated laser beam (31) is a pulsed laser beam (31), and when the laser beam is a CO2 laser, the generated laser beam (31) is a continuous laser beam (31).

12. The method according to any one of claims 1 to 11, characterized in that, The labeling composition (2) comprises: -Water-containing matrix, - At least one colorant in an aqueous matrix.

13. The method according to claim 12, characterized in that, The aqueous matrix comprises an acrylic adhesive containing water and short-chain alcohols, or a mixture of water and surfactants.

14. The method according to any one of claims 12 to 13, characterized in that, The colorant is selected from: - A pigment that contains at least one of the following elements: metal oxide, metal, metal alloy, or metal alloy oxide; -Inorganic pigments; -Organic pigments; - Pigments containing carbonate minerals; - Sodium thiosulfate aluminosilicate; - Synthetic dyes; -Natural dyes; Or a mixture thereof.

15. The method according to claim 14, characterized in that, The colorant also comprises a silicate in particulate form, wherein the silicate content in the colorant composition is from 38% to 74% by weight.

16. The method according to any one of claims 1 to 15, characterized in that, The marking composition (2) fixed on the substrate (4, 42) has a thickness of 10 nanometers to 0.1 millimeters.

17. The method according to any one of claims 1 to 16, characterized in that, When the colorant contains at least one pigment, each pigment is in the form of particles with a size of 10 nm to 0.2 mm.

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