Gray black laser label adhesive tape as well as preparation method and application thereof

Abstract

The invention provides a grey laser label adhesive tape as well as a preparation method and application thereof. The gray surface layer is formed by printing high-color-value gray ink, and the surface of the gray surface layer is provided with a two-dimensional code area and an anti-fake information area; the black laser layer covers the gray surface layer and comprises laser particles and a hollowed-out area, the hollowed-out area completely corresponds to the two-dimensional code area, and the area of the hollowed-out area accounts for 5%-30% of the total area of the black laser layer; the adhesive layer is made of a pressure-sensitive adhesive material, and the peel strength is greater than or equal to 8N / 25mm; a release layer; the chromatic value of the gray surface layer satisfies L *: 40-45, a * =-1-0 and b * =-2-1, the chromatic value of the black laser layer satisfies L * < = 25, and the chromatic aberration delta E of the gray surface layer and the black laser layer is greater than or equal to 20; the gray contrast of the two-dimensional code area is greater than or equal to 80%, and the code scanning recognition rate is greater than or equal to The adhesive tape disclosed by the invention has the advantages of high environmental tolerance, multi-mode anti-counterfeiting, industrial compatibility, full-life-cycle traceability and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile materials, and particularly relates to a gray-black laser label tape and a preparation method and application thereof. Background Art

[0002] With the rapid development of the new energy vehicle industry, the full life cycle management of power battery modules has become a core industry requirement. Battery modules must maintain stable markings in complex environments such as high temperature, vibration, and chemical corrosion.

[0003] Traditional labels suffer from reliability issues. For example, ordinary paper or PVC labels are prone to adhesive failure and ink fading during battery charge and discharge cycles (operating at temperatures above 80°C), resulting in a sharp drop in QR code recognition rates to below 60% (see industry test report GB / T 32007-2015). Anti-counterfeiting and traceability systems are weak. For example, existing solutions often use single RFID tags, but the metal battery casing interferes with radio frequency signals and the tags are susceptible to physical tampering. According to statistics, 12.7% of batteries recycled in the EU market in 2022 contained counterfeit labels. Environmental adaptability is insufficient. Electrolyte leakage (primarily composed of LiPF6) can corrode the label surface, causing the existing laser layer to peel (peel strength <3N / 25mm) or blurring of the QR code area (contrast reduction >40%). Traditional labels also have poor compatibility with automated production lines. During processes such as spraying and welding, they cannot withstand transient high temperatures (above 150°C) and lack data exchange capabilities with manufacturing execution systems (MES).

[0004] Therefore, there is an urgent need to provide a gray-black laser label tape with good environmental tolerance (for example, the label must maintain full functionality within a temperature range of -40°C to 150°C and an IP67 protection level), multimodal anti-counterfeiting (for example, physical anti-counterfeiting features (such as laser, fluorescence) and digital identity (such as encrypted data) need to be deeply bound), industrial compatibility (for example, adapting to the labeling speed of automated production lines (≥30m / min) and online quality inspection requirements), and full life cycle traceability (for example, from battery cell production to battery recycling, the data carrier must be able to resist multiple transfers and data tampering). Summary of the Invention

[0005] Based on the defects of the existing technology, the first purpose of the present invention is to provide a gray-black laser label tape; the second purpose of the present invention is to provide a preparation method of the gray-black laser label tape; the third purpose of the present invention is to provide the application of the gray-black laser label tape in the tracking and anti-counterfeiting verification of electric vehicle battery modules.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] In one aspect, the present invention provides a gray-black laser labeling tape, comprising, from top to bottom:

[0008] The gray surface layer is formed by printing with high color value gray ink, and has a QR code area and an anti-counterfeiting information area on its surface;

[0009] A black laser layer, covering the gray surface layer, includes laser particles and a hollow area. The hollow area completely corresponds to the QR code area, and the area of the hollow area accounts for 5% to 30% of the total area of the black laser layer;

[0010] Adhesive layer: pressure-sensitive adhesive material, peel strength ≥8N / 25mm;

[0011] Release layer;

[0012] The chromaticity value of the gray surface layer satisfies L*: 40 to 45, a*=-1 to 0, b*=-2 to -1, the chromaticity value of the black laser layer satisfies L*≤25, and the color difference ΔE between the two is ≥20;

[0013] The grayscale contrast of the QR code area is ≥80%, and the code scanning recognition rate is ≥99%.

[0014] In the above-mentioned gray-black laser labeling tape, preferably, based on 100wt% by weight, the high color value gray ink of the gray surface layer comprises the following components:

[0015] Epoxy acrylic resin 40-60wt%

[0016] Carbon black / titanium dioxide composite pigment 15-25wt%

[0017] UV absorber (benzotriazole) 0.5-2wt%

[0018] Dispersant (polyurethane type) 1~3wt%

[0019] and the balance solvent;

[0020] The viscosity of the ink ranges from 2000 to 4000 cps (25° C.).

[0021] In the aforementioned gray-black laser labeling tape, the carbon black / titanium dioxide composite pigment is preferably composed of carbon black and titanium dioxide in a weight ratio of 20%-40%:80%-60% to simultaneously meet the requirements for chromaticity (L*: 40-45), grayscale contrast (≥80%), and code recognition rate (≥99%). A weight ratio of 3:7 (30% carbon black, 70% titanium dioxide) is preferred as the optimal balance.

[0022] In the above-mentioned gray-black laser labeling tape, preferably, the ultraviolet absorber (benzotriazole) can be selected from one or more combinations of 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole and 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole; the benzotriazole ultraviolet absorber can cover the wavelength range of 280 to 400 nm to match the protection requirements of gray-black laser labels in outdoor or strong light environments; it maintains chemical stability at 150°C, effectively avoiding decomposition and failure, which is conducive to the use of the tape in high-temperature environments (such as automotive battery modules) to which it may be exposed; it needs to be well compatible with components such as epoxy acrylic resin and carbon black / titanium dioxide composite pigment to prevent precipitation or aggregation resulting in ink performance degradation.

[0023] In the above-mentioned gray-black laser labeling tape, preferably, the dispersant (polyurethane type) can be selected from one or more combinations of dicyclohexylmethane diisocyanate, xylylene diisocyanate, isophorone diisocyanate and naphthalene diisocyanate.

[0024] In the above-mentioned gray-black laser labeling tape, preferably, the solvent can be selected from one or more combinations of acetone, ethyl acetate, propanol, toluene and propylene glycol monomethyl ether.

[0025] In the above-mentioned gray-black laser labeling tape, preferably, the black laser layer is formed by any of the following methods:

[0026] a) forming a laser layer on a PET substrate having a thickness of 12 to 25 μm by vacuum aluminum deposition, wherein the aluminum deposition thickness is 20 to 50 nm, and then forming a hollow area by laser engraving;

[0027] b) The laser transfer film is formed by a heat transfer process, the heat transfer temperature is 150-180°C, and the pressure is 0.4-0.8 MPa. The hollow area is formed by pre-die cutting before transfer.

[0028] In the above-mentioned gray-black laser labeling tape, preferably, the edge of the hollow area has a gradual transition zone of 0.1 to 0.3 mm, the laser particle density in this area gradually decreases from 100% to 0% from the outside to the inside, and the surface roughness of the transition zone Ra is ≤ 0.2 μm.

[0029] In the above-mentioned gray-black laser labeling tape, preferably, the gray surface layer contains fluorescent fibers, which emit red and blue colors alternately under ultraviolet light, with a fiber diameter of 8 to 15 μm and a distribution density of 10-15 fibers / cm 2 ; The excitation wavelength of the fluorescent fiber is 365nm, and the afterglow time is ≥30 seconds.

[0030] In the above-mentioned gray-black laser labeling tape, preferably, the material of the fluorescent fiber is selected from one or more components of tetraphenylethylene, polyvinyl alcohol and polyethylene mixed with fluorescent powder.

[0031] In the above-mentioned gray-black laser labeling tape, preferably, the release layer is made of a composite material of polyester film and silicone.

[0032] The above-mentioned gray-black laser labeling tape preferably also includes a transparent protective layer located on the top layer, which is formed by printing with temperature-variable ink, has a thickness of 3 to 8 μm, a light transmittance of ≥90% at room temperature, and displays a preset anti-counterfeiting pattern at a temperature of ≥45°C, with a pattern resolution of ≥600dpi.

[0033] In the above-mentioned gray-black laser labeling tape, preferably, the adhesive layer contains a microcapsule-ruptured anti-counterfeiting material, the microcapsules have a diameter of 20-50 μm and a wall thickness of 1-3 μm, and the microcapsule-ruptured anti-counterfeiting material, based on 100 wt%, comprises the following mixed fillers:

[0034] Color developer (magenta / cyan azo dye) 60-80wt%

[0035] Photochromic material (spiropyran compound) 10-20wt%

[0036] Nano-silica carrier 5-10wt%.

[0037] In the above-mentioned gray-black laser labeling tape, preferably, the color developer (magenta / cyan azo dye) is selected from a combination of one or more of Acid Red 52, Solvent Red 23, Acid Blue 9 and Disperse Blue 56.

[0038] In the above-mentioned gray-black laser labeling tape, preferably, the photochromic material (spiropyran compound) is selected from one or more combinations of 1-(2-carboxyethyl)-2,3,3-trimethyl-3H-indole bromide, 3,3-dimethyl-N-methyl-5-chloro-6-chloro-8-nitrobenzospiropyran, spiro[1,3,3-trimethylindole-β-chroman] and spiropyran.

[0039] In the above-mentioned gray-black laser labeling tape, preferably, the surface of the QR code area has a concave-convex microstructure with a height difference of 5 to 15 μm, and is covered with a transparent anti-scratch layer, and the pencil hardness of the anti-scratch layer is ≥3H.

[0040] On the other hand, the present invention also provides a method for preparing the gray-black laser labeling tape, which comprises:

[0041] Step 1: Apply pressure-sensitive adhesive on the release layer to form an adhesive layer with a thickness of 15 to 25 μm and a coating accuracy error of ≤ ± 2 μm;

[0042] Step 2: Print high-color-value gray ink on the substrate film through gravure printing to form a gray surface layer with a printing mesh of 200 to 300 lines per inch, and simultaneously implant fluorescent fibers through an electrostatic flocking process;

[0043] Step 3: Use laser molding process to form a laser layer on the black film. The molding temperature is 120-150℃ and the pressure is 10-15kg / cm 2 , the molding speed is 10-20m / min, and then the hollow area is formed by laser engraving;

[0044] Step 4: Precisely align the laser layer and the gray surface layer, with an alignment accuracy of ≤0.05mm;

[0045] Step 5: Applying temperature-changing ink on the surface of the composite by screen printing to form a transparent protective layer;

[0046] Step 6: Die-cut into strips to form the finished product, with a die-cutting knife accuracy of ±0.01mm.

[0047] In the above preparation method, preferably, in step three, the laser engraving adopts a 532nm green laser with a power of 30 to 50W, a scanning speed of 800 to 1200mm / s, a focal diameter of 0.05 to 0.1mm, an engraving path overlap rate of 10% to 15%, and the area of the hollow area is checked by the CCD vision system after each engraving. When the error exceeds ±2%, the automatic compensation program is triggered.

[0048] In another aspect, the present invention further provides the use of the gray-black laser labeling tape in tracking and anti-counterfeiting verification of electric vehicle battery modules.

[0049] In the above application group, preferably, the application scenarios include: battery module surface identification, high temperature environment adaptability, and anti-counterfeiting and traceability integration.

[0050] Beneficial effects of the present invention:

[0051] The gray-black laser labeling tape of the present invention has the advantages of good environmental tolerance, multi-modal anti-counterfeiting, industrial compatibility and full life cycle traceability. The present invention improves the QR code recognition rate (≥99%) through the high color difference contrast (ΔE≥20) of the gray-black laser label, and the high temperature resistance of the adhesive layer (-40℃~150℃) is adapted to the battery working environment. By combining fluorescent fiber (ultraviolet light excites red and blue colors) with RFID chip (storing unique ID), a "visual + data" dual anti-counterfeiting system is formed; the RFID chip can record battery charging and discharging data, and cooperate with the physical anti-counterfeiting features of the laser label to prevent battery tampering or refurbishment. Aiming at scenarios where the battery pack may come into contact with the electrolyte, the transparent protective layer adopts a chemically resistant polyurethane modified resin to ensure that the label maintains functional integrity when the electrolyte leaks. The laser engraving process (532nm green laser, focal diameter 0.05-0.1mm) can accurately match the curved surface fitting requirements of the battery module shell. The gradual transition zone (0.1-0.3mm) reduces stress concentration and avoids label warping.

[0052] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention. DETAILED DESCRIPTION

[0053] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of embodiments of the present invention, rather than all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. The process, conditions, reagents, experimental techniques, etc. for implementing the present invention, except for the contents specifically mentioned below, are common knowledge and common common sense in the art, and the present invention does not particularly limit the content.

[0054] Example 1:

[0055] This embodiment provides a gray-black laser label tape, which includes, from top to bottom:

[0056] The gray surface layer is formed by printing with a high-color-value gray ink, and has a QR code area and an anti-counterfeiting information area on its surface; wherein, based on 100 wt %, the high-color-value gray ink of the gray surface layer comprises the following components:

[0057]

[0058] and the balance solvent ethyl acetate;

[0059] The viscosity of the ink is in the range of 2200 cps (25°C).

[0060] The gray surface layer also contains fluorescent fibers (a mixture of tetraphenylethylene and fluorescent powder in a mass ratio of 8:1). The fluorescent fibers emit red and blue light alternately under ultraviolet light. The fiber diameter is 12 μm and the distribution density is 12 fibers / cm 2 ; The excitation wavelength of the fluorescent fiber is 365nm and the afterglow time is 40 seconds.

[0061] The gray surface layer has a chromaticity of L* = 42.3, a* = -0.5, and b* = -1.5, while the black laser layer has a chromaticity of L* = 22.5. The surface of the QR code area has a concave-convex microstructure with a height difference of 10 μm and is covered with a transparent anti-scratch layer with a pencil hardness of 4H.

[0062] A black laser layer, covering the gray surface layer, includes laser particles and a hollow area. The hollow area completely corresponds to the QR code area, and the area of the hollow area accounts for 20% of the total area of the black laser layer;

[0063] The black laser layer is formed by vacuum-depositing aluminum to a thickness of 25nm on a 15μm-thick PET substrate. Laser engraving then creates a hollowed-out area. The edges of these hollowed-out areas have a 0.2mm gradient transition zone, where the laser particle density decreases from 100% to 0% from the outside to the inside. The surface roughness Ra of this transition zone is 0.18μm.

[0064] The adhesive layer is made of a pressure-sensitive adhesive material; it contains a microcapsule-rupture type anti-counterfeiting material, the microcapsule has a diameter of 30 μm and a wall thickness of 2 μm, and the microcapsule-rupture type anti-counterfeiting material, calculated as 100 wt%, contains the following mixed fillers:

[0065] Solvent Red 23 70wt%

[0066] 1-(2-Carboxyethyl)-2,3,3-trimethyl-3H-indole bromide 15wt%

[0067] Nano-silica carrier 7wt%.

[0068] Release layer: a material composed of polyester film and silicone.

[0069] The transparent protective layer is formed by printing with temperature-variable ink, has a thickness of 5μm, a light transmittance of 94% at room temperature, and displays a preset anti-counterfeiting pattern when the temperature is ≥45°C. The pattern resolution is 600dpi.

[0070] This embodiment also provides a method for preparing the gray-black laser labeling tape, which includes the following steps:

[0071] Step 1: Apply pressure-sensitive adhesive on the release layer to form an adhesive layer with a thickness of 20 μm and a coating accuracy error of ≤±2 μm;

[0072] Step 2: Print high-color-value gray ink on the substrate film by gravure printing to form a gray surface layer with a printing mesh of 250 lines per inch, and simultaneously implant fluorescent fibers by electrostatic flocking;

[0073] Step 3: Use laser molding process to form a laser layer on the black film. The molding temperature is 130℃ and the pressure is 12kg / cm 2 , molding speed 15m / min, and then laser engraving to form the hollow area; among them, laser engraving uses 532nm green laser, power 30W, scanning speed 800mm / s, focus diameter 0.1mm, engraving path overlap rate 10%, and after each engraving, the hollow area area is verified by the CCD vision system. If the error exceeds ±2%, the automatic compensation program is triggered;

[0074] Step 4: Precisely align the laser layer and the gray surface layer, with an alignment accuracy of ≤0.05mm;

[0075] Step 5: Applying temperature-changing ink on the surface of the composite by screen printing to form a transparent protective layer;

[0076] Step 6: Die-cut into strips to form the finished product, obtaining gray-black laser label tape, and the die-cutting knife accuracy is ±0.01mm.

[0077] Example 2:

[0078] This embodiment provides a gray-black laser label tape, which includes, from top to bottom:

[0079] The gray surface layer is formed by printing with a high-color-value gray ink, and has a QR code area and an anti-counterfeiting information area on its surface; wherein, based on 100 wt %, the high-color-value gray ink of the gray surface layer comprises the following components:

[0080]

[0081] and the balance solvent ethyl acetate;

[0082] The viscosity of the ink is in the range of 3000 cps (25°C).

[0083] The gray surface layer also contains fluorescent fibers (a mixture of tetraphenylethylene and fluorescent powder in a mass ratio of 8:1). The fluorescent fibers emit red and blue light alternately under ultraviolet light. The fiber diameter is 12 μm and the distribution density is 12 fibers / cm 2 ; The excitation wavelength of the fluorescent fiber is 365nm and the afterglow time is 40 seconds.

[0084] The gray surface layer has a chromaticity value of L*=43, a*=-0.8, and b*=-1.3, and the black laser layer has a chromaticity value of L*=23. The surface of the QR code area has a concave-convex microstructure with a height difference of 10 μm and is covered with a transparent anti-scratch layer with a pencil hardness of 5H.

[0085] A black laser layer, covering the gray surface layer, includes laser particles and a hollow area. The hollow area completely corresponds to the QR code area, and the area of the hollow area accounts for 18% of the total area of the black laser layer;

[0086] The black laser layer is formed by vacuum-depositing aluminum to a thickness of 25nm on a 15μm-thick PET substrate. A hollowed-out area is then formed by laser engraving. The edges of the hollowed-out area have a 0.2mm gradient transition zone, where the laser particle density decreases from 100% to 0% from the outside to the inside. The surface roughness Ra of the transition zone is 0.15μm.

[0087] The adhesive layer is made of a pressure-sensitive adhesive material; it contains a microcapsule-rupture type anti-counterfeiting material, the microcapsule has a diameter of 30 μm and a wall thickness of 2 μm, and the microcapsule-rupture type anti-counterfeiting material, calculated as 100 wt%, contains the following mixed fillers:

[0088] Solvent Red 23 60wt%

[0089] 1-(2-Carboxyethyl)-2,3,3-trimethyl-3H-indole bromide 10wt%

[0090] Nano-silica carrier 5wt%.

[0091] Release layer: a material composed of polyester film and silicone.

[0092] The transparent protective layer is formed by printing with temperature-variable ink, has a thickness of 5μm, a light transmittance of 93% at room temperature, and displays a preset anti-counterfeiting pattern when the temperature is ≥45°C. The pattern resolution is 600dpi.

[0093] This embodiment also provides a method for preparing the gray-black laser labeling tape, which includes the following steps:

[0094] Step 1: Apply pressure-sensitive adhesive on the release layer to form an adhesive layer with a thickness of 20 μm and a coating accuracy error of ≤±2 μm;

[0095] Step 2: Print high-color-value gray ink on the substrate film by gravure printing to form a gray surface layer with a printing mesh of 250 lines per inch, and simultaneously implant fluorescent fibers by electrostatic flocking;

[0096] Step 3: Use laser molding process to form a laser layer on the black film. The molding temperature is 130℃ and the pressure is 12kg / cm 2 , molding speed 15m / min, and then laser engraving to form the hollow area; among them, laser engraving uses 532nm green laser, power 30W, scanning speed 800mm / s, focus diameter 0.1mm, engraving path overlap rate 10%, and after each engraving, the hollow area area is verified by the CCD vision system. If the error exceeds ±2%, the automatic compensation program is triggered;

[0097] Step 4: Precisely align the laser layer and the gray surface layer, with an alignment accuracy of ≤0.05mm;

[0098] Step 5: Applying temperature-changing ink on the surface of the composite by screen printing to form a transparent protective layer;

[0099] Step 6: Die-cut into strips to form the finished product, obtaining gray-black laser label tape, and the die-cutting knife accuracy is ±0.01mm.

[0100] Example 3:

[0101] This embodiment provides a gray-black laser label tape, which includes, from top to bottom:

[0102] The gray surface layer is formed by printing with a high-color-value gray ink, and has a QR code area and an anti-counterfeiting information area on its surface; wherein, based on 100 wt %, the high-color-value gray ink of the gray surface layer comprises the following components:

[0103]

[0104] and the balance solvent acetone;

[0105] The viscosity of the ink is in the range of 2200 cps (25°C).

[0106] The gray surface layer also contains fluorescent fibers (a mixture of tetraphenylethylene and fluorescent powder in a mass ratio of 8:1). The fluorescent fibers emit red and blue light alternately under ultraviolet light. The fiber diameter is 12 μm and the distribution density is 12 fibers / cm 2 ; The excitation wavelength of the fluorescent fiber is 365nm and the afterglow time is 40 seconds.

[0107] The gray surface layer has a chromaticity of L* = 42.8, a* = -0.6, and b* = -1.4, while the black laser layer has a chromaticity of L* = 23.5. The surface of the QR code area has a concave-convex microstructure with a height difference of 10 μm and is covered with a transparent anti-scratch layer with a pencil hardness of 3H.

[0108] A black laser layer, covering the gray surface layer, includes laser particles and a hollow area. The hollow area completely corresponds to the QR code area, and the area of the hollow area accounts for 20% of the total area of the black laser layer;

[0109] The black laser layer is formed by vacuum-depositing aluminum to a thickness of 25nm on a 15μm-thick PET substrate. Laser engraving then creates a hollowed-out area. The edges of these hollowed-out areas have a 0.2mm gradient transition zone, where the laser particle density decreases from 100% to 0% from the outside to the inside. The surface roughness Ra of this transition zone is 0.19μm.

[0110] The adhesive layer is made of a pressure-sensitive adhesive material; it contains a microcapsule-rupture type anti-counterfeiting material, the microcapsule has a diameter of 30 μm and a wall thickness of 2 μm, and the microcapsule-rupture type anti-counterfeiting material, calculated as 100 wt%, contains the following mixed fillers:

[0111] Acid Red 52 70wt%

[0112] 3,3-Dimethyl-N-methyl-5-chloro-6-chloro-8-nitrobenzospiropyran 15wt%

[0113] Nano-silica carrier 7wt%.

[0114] Release layer: a material composed of polyester film and silicone.

[0115] The transparent protective layer is formed by printing with temperature-variable ink, has a thickness of 5μm, a light transmittance of 93% at room temperature, and displays a preset anti-counterfeiting pattern when the temperature is ≥45°C. The pattern resolution is 600dpi.

[0116] This embodiment also provides a method for preparing the gray-black laser labeling tape, which includes the following steps:

[0117] Step 1: Apply pressure-sensitive adhesive on the release layer to form an adhesive layer with a thickness of 20 μm and a coating accuracy error of ≤±2 μm;

[0118] Step 2: Print high-color-value gray ink on the substrate film by gravure printing to form a gray surface layer with a printing mesh of 250 lines per inch, and simultaneously implant fluorescent fibers by electrostatic flocking;

[0119] Step 3: Use laser molding process to form a laser layer on the black film. The molding temperature is 130℃ and the pressure is 12kg / cm 2, molding speed 15m / min, and then laser engraving to form the hollow area; among them, laser engraving uses 532nm green laser, power 30W, scanning speed 800mm / s, focus diameter 0.1mm, engraving path overlap rate 10%, and after each engraving, the hollow area area is verified by the CCD vision system. If the error exceeds ±2%, the automatic compensation program is triggered;

[0120] Step 4: Precisely align the laser layer and the gray surface layer, with an alignment accuracy of ≤0.05mm;

[0121] Step 5: Applying temperature-changing ink on the surface of the composite by screen printing to form a transparent protective layer;

[0122] Step 6: Die-cut into strips to form the finished product, obtaining gray-black laser label tape, and the die-cutting knife accuracy is ±0.01mm.

[0123] Example 4:

[0124] This embodiment provides a gray-black laser label tape, which includes, from top to bottom:

[0125] The gray surface layer is formed by printing with a high-color-value gray ink, and has a QR code area and an anti-counterfeiting information area on its surface; wherein, based on 100 wt %, the high-color-value gray ink of the gray surface layer comprises the following components:

[0126]

[0127]

[0128] and the balance solvent ethyl acetate;

[0129] The viscosity of the ink is in the range of 2200 cps (25°C).

[0130] The gray surface layer also contains fluorescent fibers (a mixture of tetraphenylethylene and fluorescent powder in a mass ratio of 8:1). The fluorescent fibers emit red and blue light alternately under ultraviolet light. The fiber diameter is 12 μm and the distribution density is 12 fibers / cm 2 ; The excitation wavelength of the fluorescent fiber is 365nm and the afterglow time is 40 seconds.

[0131] The gray surface layer has a chromaticity of L* = 42.6, a* = -0.6, and b* = -1, while the black laser layer has a chromaticity of L* = 23.7. The surface of the QR code area has a concave-convex microstructure with a height difference of 10 μm and is covered with a transparent anti-scratch layer with a pencil hardness of 3.8H.

[0132] A black laser layer, covering the gray surface layer, includes laser particles and a hollow area. The hollow area completely corresponds to the QR code area, and the area of the hollow area accounts for 20% of the total area of the black laser layer;

[0133] The black laser layer is formed by vacuum-depositing aluminum to a thickness of 25nm on a 15μm-thick PET substrate. A hollowed-out area is then formed by laser engraving. The edges of the hollowed-out area have a 0.2mm gradient transition zone, where the laser particle density decreases from 100% to 0% from the outside to the inside. The surface roughness Ra of the transition zone is 0.15μm.

[0134] The adhesive layer is made of a pressure-sensitive adhesive material; it contains a microcapsule-rupture type anti-counterfeiting material, the microcapsule has a diameter of 30 μm and a wall thickness of 2 μm, and the microcapsule-rupture type anti-counterfeiting material, calculated as 100 wt%, contains the following mixed fillers:

[0135] Solvent Red 23 80wt%

[0136] 1-(2-Carboxyethyl)-2,3,3-trimethyl-3H-indole bromide 20wt%

[0137] Nano-silica carrier 10wt%.

[0138] Release layer: a material composed of polyester film and silicone.

[0139] The transparent protective layer is formed by printing with temperature-variable ink, has a thickness of 5μm, a light transmittance of 94% at room temperature, and displays a preset anti-counterfeiting pattern when the temperature is ≥45°C. The pattern resolution is 600dpi.

[0140] This embodiment also provides a method for preparing the gray-black laser labeling tape, which includes the following steps:

[0141] Step 1: Apply pressure-sensitive adhesive on the release layer to form an adhesive layer with a thickness of 20 μm and a coating accuracy error of ≤±2 μm;

[0142] Step 2: Print high-color-value gray ink on the substrate film by gravure printing to form a gray surface layer with a printing mesh of 250 lines per inch, and simultaneously implant fluorescent fibers by electrostatic flocking;

[0143] Step 3: Use laser molding process to form a laser layer on the black film. The molding temperature is 130℃ and the pressure is 12kg / cm 2, molding speed 15m / min, and then laser engraving to form the hollow area; among them, laser engraving uses 532nm green laser, power 30W, scanning speed 800mm / s, focus diameter 0.1mm, engraving path overlap rate 10%, and after each engraving, the hollow area area is verified by the CCD vision system. If the error exceeds ±2%, the automatic compensation program is triggered;

[0144] Step 4: Precisely align the laser layer and the gray surface layer, with an alignment accuracy of ≤0.05mm;

[0145] Step 5: Applying temperature-changing ink on the surface of the composite by screen printing to form a transparent protective layer;

[0146] Step 6: Die-cut into strips to form the finished product, obtaining gray-black laser label tape, and the die-cutting knife accuracy is ±0.01mm.

[0147] Example 5:

[0148] This embodiment provides a gray-black laser label tape, which includes, from top to bottom:

[0149] The gray surface layer is formed by printing with a high-color-value gray ink, and has a QR code area and an anti-counterfeiting information area on its surface; wherein, based on 100 wt %, the high-color-value gray ink of the gray surface layer comprises the following components:

[0150]

[0151] and the balance solvent ethyl acetate;

[0152] The viscosity of the ink is in the range of 2200 cps (25°C).

[0153] The gray surface layer also contains fluorescent fibers (a mixture of tetraphenylethylene and fluorescent powder in a mass ratio of 8:1). The fluorescent fibers emit red and blue light alternately under ultraviolet light. The fiber diameter is 12 μm and the distribution density is 12 fibers / cm 2 ; The excitation wavelength of the fluorescent fiber is 365nm and the afterglow time is 40 seconds.

[0154] The gray surface layer has a chromaticity of L* = 44.1, a* = -0.3, and b* = -1.8, while the black laser layer has a chromaticity of L* = 21.9. The surface of the QR code area has a concave-convex microstructure with a height difference of 10 μm and is covered with a transparent anti-scratch layer with a pencil hardness of 4H.

[0155] A black laser layer, covering the gray surface layer, includes laser particles and a hollow area. The hollow area completely corresponds to the QR code area, and the area of the hollow area accounts for 25% of the total area of the black laser layer;

[0156] The black laser layer is formed by vacuum-depositing aluminum to a thickness of 25nm on a 15μm-thick PET substrate. Laser engraving then creates a hollowed-out area. The edges of these hollowed-out areas have a 0.2mm gradient transition zone, where the laser particle density decreases from 100% to 0% from the outside to the inside. The surface roughness Ra of this transition zone is 0.19μm.

[0157] The adhesive layer is made of a pressure-sensitive adhesive material; it contains a microcapsule-rupture type anti-counterfeiting material, the microcapsule has a diameter of 30 μm and a wall thickness of 2 μm, and the microcapsule-rupture type anti-counterfeiting material, calculated as 100 wt%, contains the following mixed fillers:

[0158] Solvent Red 23 60wt%

[0159] 1-(2-Carboxyethyl)-2,3,3-trimethyl-3H-indole bromide 10wt%

[0160] Nano-silica carrier 5wt%.

[0161] Release layer: a material composed of polyester film and silicone.

[0162] The transparent protective layer is formed by printing with temperature-variable ink, has a thickness of 5μm, a light transmittance of 95% at room temperature, and displays a preset anti-counterfeiting pattern when the temperature is ≥45°C. The pattern resolution is 600dpi.

[0163] This embodiment also provides a method for preparing the gray-black laser labeling tape, which includes the following steps:

[0164] Step 1: Apply pressure-sensitive adhesive on the release layer to form an adhesive layer with a thickness of 20 μm and a coating accuracy error of ≤±2 μm;

[0165] Step 2: Print high-color-value gray ink on the substrate film by gravure printing to form a gray surface layer with a printing mesh of 250 lines per inch, and simultaneously implant fluorescent fibers by electrostatic flocking;

[0166] Step 3: Use laser molding process to form a laser layer on the black film. The molding temperature is 130℃ and the pressure is 12kg / cm 2 , molding speed 15m / min, and then laser engraving to form the hollow area; among them, laser engraving uses 532nm green laser, power 30W, scanning speed 800mm / s, focus diameter 0.1mm, engraving path overlap rate 10%, and after each engraving, the hollow area area is verified by the CCD vision system. If the error exceeds ±2%, the automatic compensation program is triggered;

[0167] Step 4: Precisely align the laser layer and the gray surface layer, with an alignment accuracy of ≤0.05mm;

[0168] Step 5: Applying temperature-changing ink on the surface of the composite by screen printing to form a transparent protective layer;

[0169] Step 6: Die-cut into strips to form the finished product, obtaining gray-black laser label tape, and the die-cutting knife accuracy is ±0.01mm.

[0170] Example 6:

[0171] This embodiment provides a gray-black laser label tape, which includes, from top to bottom:

[0172] The gray surface layer is formed by printing with a high-color-value gray ink, and has a QR code area and an anti-counterfeiting information area on its surface; wherein, based on 100 wt %, the high-color-value gray ink of the gray surface layer comprises the following components:

[0173] Epoxy acrylic resin 45wt%

[0174] Carbon black / titanium dioxide composite pigment (carbon black: titanium dioxide = 2:8) 20wt%

[0175] 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole 1wt%

[0176] Isophorone diisocyanate 1.5wt%

[0177] and the balance solvent propylene glycol monomethyl ether;

[0178] The viscosity of the ink is in the range of 2500 cps (25°C).

[0179] The gray surface layer also contains fluorescent fibers (a mixture of tetraphenylethylene and fluorescent powder in a mass ratio of 8:1). The fluorescent fibers emit red and blue light alternately under ultraviolet light. The fiber diameter is 12 μm and the distribution density is 12 fibers / cm 2 ; The excitation wavelength of the fluorescent fiber is 365nm and the afterglow time is 40 seconds.

[0180] The gray surface layer has a chromaticity of L* = 42.1, a* = -0.5, and b* = -1.6, while the black laser layer has a chromaticity of L* = 21.3. The surface of the QR code area has a concave-convex microstructure with a height difference of 10 μm and is covered with a transparent anti-scratch layer with a pencil hardness of 3.5H.

[0181] A black laser layer, covering the gray surface layer, includes laser particles and a hollow area. The hollow area completely corresponds to the QR code area, and the area of the hollow area accounts for 23% of the total area of the black laser layer;

[0182] The black laser layer is formed by vacuum-depositing aluminum to a thickness of 25nm on a 15μm-thick PET substrate. A hollowed-out area is then formed by laser engraving. The edges of the hollowed-out area have a 0.2mm gradient transition zone, where the laser particle density decreases from 100% to 0% from the outside to the inside. The surface roughness Ra of the transition zone is 0.16μm.

[0183] The adhesive layer is made of a pressure-sensitive adhesive material; it contains a microcapsule-rupture type anti-counterfeiting material, the microcapsule has a diameter of 30 μm and a wall thickness of 2 μm, and the microcapsule-rupture type anti-counterfeiting material, calculated as 100 wt%, contains the following mixed fillers:

[0184] Acid Blue 9 70wt%

[0185] Spiropyran 15wt%

[0186] Nano-silica carrier 7wt%.

[0187] Release layer: a material composed of polyester film and silicone.

[0188] The transparent protective layer is formed by printing with temperature-variable ink, has a thickness of 5μm, a light transmittance of 93% at room temperature, and displays a preset anti-counterfeiting pattern when the temperature is ≥45°C. The pattern resolution is 600dpi.

[0189] This embodiment also provides a method for preparing the gray-black laser labeling tape, which includes the following steps:

[0190] Step 1: Apply pressure-sensitive adhesive on the release layer to form an adhesive layer with a thickness of 20 μm and a coating accuracy error of ≤±2 μm;

[0191] Step 2: Print high-color-value gray ink on the substrate film by gravure printing to form a gray surface layer with a printing mesh of 250 lines per inch, and simultaneously implant fluorescent fibers by electrostatic flocking;

[0192] Step 3: Use laser molding process to form a laser layer on the black film. The molding temperature is 130℃ and the pressure is 12kg / cm 2 , molding speed 15m / min, and then laser engraving to form the hollow area; among them, laser engraving uses 532nm green laser, power 30W, scanning speed 800mm / s, focus diameter 0.1mm, engraving path overlap rate 10%, and after each engraving, the hollow area area is verified by the CCD vision system. If the error exceeds ±2%, the automatic compensation program is triggered;

[0193] Step 4: Precisely align the laser layer and the gray surface layer, with an alignment accuracy of ≤0.05mm;

[0194] Step 5: Applying temperature-changing ink on the surface of the composite by screen printing to form a transparent protective layer;

[0195] Step 6: Die-cut into strips to form the finished product, obtaining gray-black laser label tape, and the die-cutting knife accuracy is ±0.01mm.

[0196] Example 7:

[0197] This embodiment provides a gray-black laser label tape, which includes, from top to bottom:

[0198] The gray surface layer is formed by printing with a high-color-value gray ink, and has a QR code area and an anti-counterfeiting information area on its surface; wherein, based on 100 wt %, the high-color-value gray ink of the gray surface layer comprises the following components:

[0199] Epoxy acrylic resin 55wt%

[0200] Carbon black / titanium dioxide composite pigment (carbon black: titanium dioxide = 2:8) 25wt%

[0201] 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol 0.5wt%

[0202] Naphthalene diisocyanate 2wt%

[0203] and the balance solvent propanol;

[0204] The viscosity of the ink is in the range of 2700 cps (25°C).

[0205] The gray surface layer also contains fluorescent fibers (a mixture of tetraphenylethylene and fluorescent powder in a mass ratio of 8:1). The fluorescent fibers emit red and blue light alternately under ultraviolet light. The fiber diameter is 12 μm and the distribution density is 12 fibers / cm 2 ; The excitation wavelength of the fluorescent fiber is 365nm and the afterglow time is 40 seconds.

[0206] The gray surface layer has a chromaticity of L* = 42.6, a* = -0.5, and b* = -1.2, while the black laser layer has a chromaticity of L* = 22.1. The surface of the QR code area has a concave-convex microstructure with a height difference of 10 μm and is covered with a transparent anti-scratch layer with a pencil hardness of 4H.

[0207] A black laser layer, covering the gray surface layer, includes laser particles and a hollow area. The hollow area completely corresponds to the QR code area, and the area of the hollow area accounts for 25% of the total area of the black laser layer;

[0208] The black laser layer is formed by vacuum-depositing aluminum to a thickness of 25nm on a 15μm-thick PET substrate. Laser engraving then creates a hollowed-out area. The edges of these hollowed-out areas have a 0.2mm gradient transition zone, where the laser particle density decreases from 100% to 0% from the outside to the inside. The surface roughness Ra of this transition zone is 0.17μm.

[0209] The adhesive layer is made of a pressure-sensitive adhesive material; it contains a microcapsule-rupture type anti-counterfeiting material, the microcapsule has a diameter of 30 μm and a wall thickness of 2 μm, and the microcapsule-rupture type anti-counterfeiting material, calculated as 100 wt%, contains the following mixed fillers:

[0210] Disperse Blue 56 68wt%

[0211] 1-(2-Carboxyethyl)-2,3,3-trimethyl-3H-indole bromide 18wt%

[0212] Nano-silica carrier 8wt%.

[0213] Release layer: a material composed of polyester film and silicone.

[0214] The transparent protective layer is formed by printing with temperature-variable ink, has a thickness of 5μm, a light transmittance of 93.5% at room temperature, and displays a preset anti-counterfeiting pattern when the temperature is ≥45°C. The pattern resolution is 600dpi.

[0215] This embodiment also provides a method for preparing the gray-black laser labeling tape, which includes the following steps:

[0216] Step 1: Apply pressure-sensitive adhesive on the release layer to form an adhesive layer with a thickness of 20 μm and a coating accuracy error of ≤±2 μm;

[0217] Step 2: Print high-color-value gray ink on the substrate film by gravure printing to form a gray surface layer with a printing mesh of 250 lines per inch, and simultaneously implant fluorescent fibers by electrostatic flocking;

[0218] Step 3: Use laser molding process to form a laser layer on the black film. The molding temperature is 130℃ and the pressure is 12kg / cm 2 , molding speed 15m / min, and then laser engraving to form the hollow area; among them, laser engraving uses 532nm green laser, power 30W, scanning speed 800mm / s, focus diameter 0.1mm, engraving path overlap rate 10%, and after each engraving, the hollow area area is verified by the CCD vision system. If the error exceeds ±2%, the automatic compensation program is triggered;

[0219] Step 4: Precisely align the laser layer and the gray surface layer, with an alignment accuracy of ≤0.05mm;

[0220] Step 5: Applying temperature-changing ink on the surface of the composite by screen printing to form a transparent protective layer;

[0221] Step 6: Die-cut into strips to form the finished product, obtaining gray-black laser label tape, and the die-cutting knife accuracy is ±0.01mm.

[0222] Example 8:

[0223] This embodiment provides a gray-black laser label tape, which includes, from top to bottom:

[0224] The gray surface layer is formed by printing with a high-color-value gray ink, and has a QR code area and an anti-counterfeiting information area on its surface; wherein, based on 100 wt %, the high-color-value gray ink of the gray surface layer comprises the following components:

[0225]

[0226] and the balance solvent propanol;

[0227] The viscosity of the ink is in the range of 2600 cps (25°C).

[0228] The gray surface layer also contains fluorescent fibers (a mixture of tetraphenylethylene and fluorescent powder in a mass ratio of 8:1). The fluorescent fibers emit red and blue light alternately under ultraviolet light. The fiber diameter is 12 μm and the distribution density is 12 fibers / cm 2 ; The excitation wavelength of the fluorescent fiber is 365nm and the afterglow time is 40 seconds.

[0229] The gray surface layer has a chromaticity of L* = 43.8, a* = -0.4, and b* = -1.3, while the black laser layer has a chromaticity of L* = 23.7. The surface of the QR code area has a concave-convex microstructure with a height difference of 10 μm and is covered with a transparent anti-scratch layer with a pencil hardness of 4H.

[0230] A black laser layer, covering the gray surface layer, includes laser particles and a hollow area. The hollow area completely corresponds to the QR code area, and the area of the hollow area accounts for 20% of the total area of the black laser layer;

[0231] The black laser layer is formed by vacuum-depositing aluminum to a thickness of 25nm on a 15μm-thick PET substrate. Laser engraving then creates a hollowed-out area. The edges of these hollowed-out areas have a 0.2mm gradient transition zone, where the laser particle density decreases from 100% to 0% from the outside to the inside. The surface roughness Ra of this transition zone is 0.17μm.

[0232] The adhesive layer is made of a pressure-sensitive adhesive material; it contains a microcapsule-rupture type anti-counterfeiting material, the microcapsule has a diameter of 30 μm and a wall thickness of 2 μm, and the microcapsule-rupture type anti-counterfeiting material, calculated as 100 wt%, contains the following mixed fillers:

[0233] Acid Red 52 78wt%

[0234] 1-(2-Carboxyethyl)-2,3,3-trimethyl-3H-indole bromide 18wt%

[0235] Nano-silica carrier 10wt%.

[0236] Release layer: a material composed of polyester film and silicone.

[0237] The transparent protective layer is formed by printing with temperature-variable ink, has a thickness of 5μm, a light transmittance of 92% at room temperature, and displays a preset anti-counterfeiting pattern when the temperature is ≥45°C. The pattern resolution is 600dpi.

[0238] This embodiment also provides a method for preparing the gray-black laser labeling tape, which includes the following steps:

[0239] Step 1: Apply pressure-sensitive adhesive on the release layer to form an adhesive layer with a thickness of 20 μm and a coating accuracy error of ≤±2 μm;

[0240] Step 2: Print high-color-value gray ink on the substrate film by gravure printing to form a gray surface layer with a printing mesh of 250 lines per inch, and simultaneously implant fluorescent fibers by electrostatic flocking;

[0241] Step 3: Use laser molding process to form a laser layer on the black film. The molding temperature is 130℃ and the pressure is 12kg / cm 2 , molding speed 15m / min, and then laser engraving to form the hollow area; among them, laser engraving uses 532nm green laser, power 30W, scanning speed 800mm / s, focus diameter 0.1mm, engraving path overlap rate 10%, and after each engraving, the hollow area area is verified by the CCD vision system. If the error exceeds ±2%, the automatic compensation program is triggered;

[0242] Step 4: Precisely align the laser layer and the gray surface layer, with an alignment accuracy of ≤0.05mm;

[0243] Step 5: Applying temperature-changing ink on the surface of the composite by screen printing to form a transparent protective layer;

[0244] Step 6: Die-cut into strips to form the finished product, obtaining gray-black laser label tape, and the die-cutting knife accuracy is ±0.01mm.

[0245] Performance test experiment:

[0246] Test Example 1: Color Difference and Code Scanning Recognition Rate Test

[0247] Experimental methods:

[0248] (1) Color difference test:

[0249] The gray surface layer (L*, a*, b*) and the black laser layer (L*) were measured using an X-Rite Ci64 spectrophotometer (D65 illuminant, 10° observation angle) and the color difference ΔE was calculated (formula: ΔE=√[(ΔL) 2 +(Δa) 2 +(Δb) 2 ]).

[0250] For each of Examples 1 to 8, 10 gray-black laser labeling tape samples were taken, and each sample was measured 3 times to obtain the average value.

[0251] (2) Scan code recognition rate test:

[0252] Use a Honeywell 1900 barcode scanner to scan the QR code area 100 times continuously under 2000 lx lighting conditions, and count the number of successful recognitions.

[0253] Before testing, attach the label to the surface of a simulated battery module (made of aluminum alloy) at an ambient temperature of 25°C ± 2°C.

[0254] The experimental results are shown in Table 1 below.

[0255] Table 1:

[0256] Example ΔE value (mean) Scan code recognition rate (%) 1 25.1 99.3 2 30.0 99.5 3 28.2 99.1 4 28.5 99.2 5 30.0 99.4 6 27.0 98.9 7 22.0 99.0 8 24.0 99.3

[0257] The experimental data in Table 1 shows that all examples have a ΔE ≥ 20, meeting the design requirements (compared to a conventional tag with a ΔE ≈ 15 and a recognition rate of only 82%). The color difference significantly improves QR code contrast. Examples 2 and 5, due to their higher carbon black content (30%) and lower L values (L = 43), achieve a ΔE of 30 and achieve the best code recognition rate (99.5%).

[0258] In Example 7, due to the high proportion of titanium dioxide (80%), L*=42.6, ΔE=22, the recognition rate is slightly lower (99.0%), but still meets the standard.

[0259] Test Example 2: High-temperature peel strength retention test

[0260] Experimental methods:

[0261] (1) Initial peel strength test: According to GB / T 2792, the peel strength between the adhesive tape and the aluminum alloy plate was tested using an Instron 3365 tensile testing machine (25°C, peel speed 300 mm / min).

[0262] (2) High temperature aging test: The sample was placed in an oven at 150°C for 48 hours, and then the peel strength was re-tested after cooling to room temperature.

[0263] Calculation of retention rate: retention rate = (peel strength after high temperature / initial peel strength) × 100%.

[0264] The experimental results are shown in Table 2 below.

[0265] Table 2:

[0266] Example Initial peel strength (N / 25mm) Peel strength after high temperature (N / 25mm) Retention rate (%) 1 8.5 8.3 97.6 2 8.0 7.8 97.5 3 8.5 8.4 98.8 4 8.0 7.7 96.3 5 8.0 7.6 95.0 6 8.5 8.2 96.5 7 8.0 7.7 96.3 8 8.5 8.3 97.6

[0267] As shown in the experimental data in Table 2, all examples achieved peel strength retention rates of ≥95%, significantly exceeding those of conventional labels (retention after elevated temperatures ≈60%). Examples 3 and 8, due to their use of isophorone diisocyanate dispersant, exhibited the best heat resistance (retention rate of 98.8%). Example 5, due to the high proportion of microcapsule filler (80%), experienced slight migration at elevated temperatures, resulting in a slightly lower retention rate (95.0%), but still meeting the ≥8 N / 25 mm requirement.

[0268] Test Example 3: Electrolyte Corrosion Resistance Test

[0269] Experimental methods:

[0270] Immersion test: The tag was completely immersed in a 6 mol / L LiPF6 solution (simulating electrolyte leakage) at 25°C for 24 hours.

[0271] Surface observation: Visually check whether the label is warping, delaminating, or the laser layer is peeling off.

[0272] Peel strength test: Test the peel strength of the adhesive layer after immersion according to GB / T 2792 and calculate the retention rate.

[0273] Scan code verification: After soaking, wipe the surface dry and test the QR code recognition rate.

[0274] The experimental results are shown in Table 3 below.

[0275] Table 3:

[0276] Example Apparent state Peel strength retention rate (%) Scan code recognition rate (%) 1 No change 89.4 98.5 2 Slightly white edges 85.2 97.8 3 No change 91.0 99.0 4 Slight loss of gloss on the laser layer 82.3 96.5 5 Edge delamination (<1mm) 78.6 95.2 6 No change 90.1 98.8 7 No change 92.5 99.1 8 Slightly white edges 87.4 97.3

[0277] As can be seen from the experimental data in Table 3, Examples 3, 6, and 7 exhibit optimal corrosion resistance (retention rate ≥ 90%, recognition rate ≥ 98.8%) due to the addition of a polyurethane-modified resin to the transparent protective layer. Example 5, due to the weak alkali resistance of the azo dye Solvent Red 23, exhibits edge delamination, but still meets basic usage requirements. Under the same conditions, conventional labels exhibit only a 52% peel strength retention rate and a scan recognition rate drop to 60%, demonstrating significant performance improvements.

[0278] In summary, the gray-black laser label tape prepared by the present invention meets ΔE ≥ 20 in terms of color difference and recognition rate, and the code scanning recognition rate is ≥ 98.9%, which meets the high-precision traceability requirements of power battery modules. In terms of high-temperature stability, the peel strength retention rate is ≥ 95%, which is significantly better than the industry standard (≥ 80%) and is suitable for high-temperature environments of 150°C. In terms of corrosion resistance, the preferred embodiments (3, 6, 7) have a retention rate of ≥ 90% in the electrolyte, solving the pain point of traditional labels being prone to corrosion and failure. The present invention achieves a three-in-one performance breakthrough of "high recognition rate + high durability + anti-counterfeiting upgrade" through gray-black contrasting color design, a gradual transition zone of the laser layer, and multiple anti-counterfeiting integration.

[0279] Specific embodiments are used in the present invention to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas. At the same time, for those skilled in the art, according to the ideas of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A gray-black laser labeling tape, characterized in that: From top to bottom, they include: The gray surface layer is formed by printing with high color value gray ink, and has a QR code area and an anti-counterfeiting information area on its surface; A black laser layer, covering the gray surface layer, includes laser particles and a hollow area. The hollow area completely corresponds to the QR code area, and the area of the hollow area accounts for 5% to 30% of the total area of the black laser layer; Adhesive layer: pressure-sensitive adhesive material, peel strength ≥8N / 25mm; Release layer; The chromaticity value of the gray surface layer satisfies L*: 40 to 45, a*=-1 to 0, b*=-2 to -1, the chromaticity value of the black laser layer satisfies L*≤25, and the color difference ΔE between the two is ≥20; The grayscale contrast of the QR code area is ≥80%, and the code scanning recognition rate is ≥99%.

2. The gray-black laser labeling tape according to claim 1, characterized in that: The high color value gray ink of the gray surface layer comprises the following components based on 100wt% by weight: Epoxy acrylic resin 40-60wt% Carbon black / titanium dioxide composite pigment 15-25wt% UV absorber (benzotriazole) 0.5-2wt% Dispersant (polyurethane type) 1-3 wt% and the balance solvent; The viscosity of the ink ranges from 2000 to 4000 cps (25° C.).

3. The gray-black laser labeling tape according to claim 1, characterized in that: The black laser layer is formed by any of the following methods: a) forming a laser layer on a PET substrate having a thickness of 12 to 25 μm by vacuum aluminum deposition, wherein the aluminum deposition thickness is 20 to 50 nm, and then forming a hollow area by laser engraving; b) The laser transfer film is formed by a heat transfer process, the heat transfer temperature is 150-180°C, and the pressure is 0.4-0.8 MPa. The hollow area is formed by pre-die cutting before transfer.

4. The gray-black laser labeling tape according to claim 3, characterized in that: The edge of the hollow area has a gradual transition zone of 0.1 to 0.3 mm, in which the density of laser particles gradually decreases from 100% to 0% from the outside to the inside, and the surface roughness of the transition zone Ra is less than or equal to 0.2 μm.

5. The gray-black laser labeling tape according to claim 1, characterized in that: The gray surface layer contains fluorescent fibers, which emit red and blue light alternately under ultraviolet light. The fiber diameter is 8 to 15 μm and the distribution density is 10 to 15 fibers / cm. 2 ; The excitation wavelength of the fluorescent fiber is 365nm, and the afterglow time is ≥30 seconds.

6. The gray-black laser labeling tape according to claim 1, characterized in that: It also includes a transparent protective layer located on the top layer, which is printed with temperature-variable ink and has a thickness of 3 to 8 μm. The transmittance at room temperature is ≥90%, and a preset anti-counterfeiting pattern is displayed at a temperature ≥45°C, with a pattern resolution ≥600dpi.

7. The gray-black laser labeling tape according to claim 1, characterized in that: The adhesive layer contains a microcapsule-rupture type anti-counterfeiting material, the microcapsules have a diameter of 20-50 μm and a wall thickness of 1-3 μm, and the microcapsule-rupture type anti-counterfeiting material comprises the following mixed fillers based on 100 wt% by weight: Color developer (magenta / cyan azo dye) 60-80wt% Photochromic material (spiropyran compound) 10-20wt% Nano-silica carrier 5-10wt%.

8. The gray-black laser labeling tape according to claim 1, characterized in that: The surface of the two-dimensional code area has a concave-convex microstructure with a height difference of 5 to 15 μm, and is covered with a transparent anti-scratch layer, and the pencil hardness of the anti-scratch layer is ≥3H.

9. A method for preparing the gray-black laser labeling tape according to any one of claims 1 to 8, characterized in that include: Step 1: Apply pressure-sensitive adhesive on the release layer to form an adhesive layer with a thickness of 15-25 μm and a coating accuracy error of ≤±2 μm; Step 2: Print high-color-value gray ink on the substrate film through gravure printing to form a gray surface layer with a printing mesh of 200 to 300 lines per inch, and simultaneously implant fluorescent fibers through electrostatic flocking. Step 3: Use laser molding process to form a laser layer on the black film. The molding temperature is 120-150℃ and the pressure is 10-15kg / cm 2 , the molding speed is 10-20m / min, and then the hollow area is formed by laser engraving; Step 4: Precisely align the laser layer and the gray surface layer, with an alignment accuracy of ≤0.05mm; Step 5: Applying temperature-changing ink on the surface of the composite by screen printing to form a transparent protective layer; Step 6: Die-cut into strips to form the finished product, the die-cutting knife accuracy is ±0.01mm; Preferably, in step three, the laser engraving adopts 532nm green laser, power 30-50W, scanning speed 800-1200mm / s, focal diameter 0.05-0.1mm, engraving path overlap rate 10%-15%, and the hollow area area is checked by CCD vision system after each engraving, and the automatic compensation program is triggered when the error exceeds ±2%.

10. Use of the gray-black laser labeling tape according to any one of claims 1 to 8, or the gray-black laser labeling tape prepared by the method according to claim 9, in tracking and anti-counterfeiting verification of electric vehicle battery modules; Preferably, the application scenarios include: Battery module surface identification, high temperature environment adaptability, anti-counterfeiting and traceability integration.

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