Black-to-white laser master batch and preparation method thereof

Abstract

The invention is suitable for the technical field of laser marking materials, and provides a black-whitening laser master batch and a preparation method thereof.The black-whitening laser master batch comprises a base material, carbon nanotubes and a lubricant, the base material comprises one or more of polypropylene, polyamide and polycarbonate, the carbon nanotubes are added, and the lubricant is added into the base material to prepare the black-whitening laser master batch. The material can more efficiently absorb laser energy and generate a local heat effect, so that a clear and lasting mark is formed on the surface of the material, the excellent light absorption characteristic and thermal conductivity of the carbon nanotubes can help to disperse and conduct heat in the laser marking process, thermal damage to the material is reduced, and the laser marking quality is improved. The integral structural integrity of the material can be kept in the marking process, and meanwhile the definition and durability of the mark are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser marking materials, and particularly relates to a black-on-white laser masterbatch and a preparation method thereof. Background Art

[0002] Laser marking is a marking method that uses a laser beam with a high energy density to act on a target, causing physical or chemical changes on the surface of the target, thereby obtaining a visible pattern. The high-energy laser beam is focused on the surface of the material, causing the material to quickly vaporize and form pits. As the laser beam moves regularly on the surface of the material while controlling the on-off of the laser, the laser beam processes a specified pattern on the surface of the material.

[0003] The blackness of the material for traditional "black background and white characters" laser marking is not black enough, and the whiteness of the white characters marked by laser is insufficient; in the prior art, some use polypropylene materials as the materials for laser marking. Compared with traditional materials, the blackness and brightness of polypropylene materials are increased, but there are still problems that the white characters marked by laser are not white enough and not clear enough. Summary of the Invention

[0004] The present invention provides a black-on-white laser masterbatch, aiming to solve the above problems.

[0005] The present invention is realized as follows. A black-on-white laser masterbatch includes the following components: a matrix material, carbon nanotubes, and a lubricant. By adding carbon nanotubes, the material can absorb laser energy more efficiently, generate a local thermal effect, thereby forming clear and durable marks on the surface of the material. The excellent light absorption characteristics and thermal conductivity of carbon nanotubes can help disperse and conduct heat during the laser marking process, reduce the thermal damage of the material, contribute to maintaining the overall structural integrity of the material during the marking process, and at the same time improve the clarity and durability of the marks. By adding a lubricant, the fluidity and processing performance of the material are improved, ensuring the uniformity and stability of the masterbatch; The carbon nanotubes are pretreated, and the pretreatment method includes: Performing high-temperature heat treatment on the carbon nanotubes in an inert atmosphere; Ultrasonically treating with a mixed solution of concentrated sulfuric acid and concentrated nitric acid; Introducing ammonia gas into a CVD reactor for nitrogen doping; When preparing the masterbatch, the mixed materials are placed in an electric field for orientation and then extruded into shape.

[0006] Preferably, by weight, the matrix material is 100 parts, the carbon nanotubes are 0.01 - 0.3 parts, and the lubricant is 0.05 parts.

[0007] Preferably, the matrix material includes one or more of polypropylene, polyamide, and polycarbonate.

[0008] Preferably, the lubricant comprises one or more of silicone, silicone oil, pentaerythritol stearate, and ethylene bis-stearamide.

[0009] Preferably, the pretreatment method is as follows: Place the carbon nanotubes in a tube furnace, heat them to 800 - 1000 °C under an inert atmosphere, hold for 1 - 2 h, and then naturally cool to room temperature; Mix concentrated sulfuric acid with a concentration of 98% and concentrated nitric acid with a concentration of 68% in a volume ratio of 2 - 3:1 to obtain a mixed solution. Put the heat-treated carbon nanotubes into the mixed solution, perform ultrasonic treatment at a power of 200 - 400 W for 1 - 2 h, then filter and wash repeatedly with deionized water until the pH value is close to neutral, vacuum dry at 60 - 80 °C for 2 - 3 h, then put them into a CVD reactor, introduce ammonia at 50 - 100 sccm, and react at 600 - 800 °C for 1 - 2 h, and naturally cool to room temperature.

[0010] First, perform high-temperature heat treatment on the carbon nanotubes to remove surface impurities and defects, and improve their purity and crystallinity. Then, oxidize the carbon nanotubes with strong acid to introduce carboxyl groups on their surfaces to improve their dispersibility and compatibility with the polymer matrix. Finally, dope the non-metallic element nitrogen into the carbon nanotubes to adjust their electronic structure and optical properties, thereby improving the effect of laser marking.

[0011] Preferably, the black-on-white laser masterbatch further comprises the following components by weight: 1 - 5 parts of modified quercetin and 5 - 10 parts of modified nano-zirconia.

[0012] Preferably, the preparation method of the modified quercetin is as follows: By weight, dissolve 6 - 10 parts of quercetin in 10 - 15 times the weight of ethanol, add 0.5 - 1.5 parts of 3-aminopropyltriethoxysilane, stir and heat to 50 - 60 °C and react for 40 - 60 min. Then add 1 - 2 parts of styrene, 0.1 - 0.3 parts of azobisisobutyronitrile, and 0.5 - 1 part of nano-titanium dioxide, stir and react at 70 - 80 °C for 2 - 3 h. Filter the reaction mixture through a filter membrane (such as a 0.22 μm microporous filter membrane), wash with ethanol, and vacuum dry at 60 - 80 °C to obtain the modified quercetin.

[0013] Quercetin can effectively absorb laser energy and convert it into heat energy. After absorbing laser energy, it will undergo thermal decomposition to produce gases and carbonized products, thereby forming clear marks on the material surface. The antioxidant property of quercetin can prevent the material from being over-oxidized during the laser marking process, maintaining the clarity and durability of the marks. First, amino groups are introduced onto the surface of quercetin through 3-aminopropyltriethoxysilane to provide reaction sites and reactivity. Then, styrene undergoes a polymerization reaction on the surface of quercetin to form a polymer graft layer, improving the dispersibility and stability of quercetin in the matrix material, enhancing its laser absorption effect, and cooperating with nano-titanium dioxide, which has a high refractive index and photocatalytic properties, to enhance laser absorption and thermal effects.

[0014] Preferably, the preparation method of the modified nano-zirconia is as follows: By weight, disperse 15 - 20 parts of nano-zirconia powder in 80 - 100 parts of ethanol, ultrasonically treat for 30 - 40 min, then add 1 - 5 wt% of silane coupling agent based on the mass of nano-zirconia, stir and react at 55 - 65 °C for 1 - 2 h. Centrifuge the reaction mixture (5000 rpm, 10 min), wash the precipitate with ethanol 3 times, and centrifuge after each washing. Vacuum-dry the washed nano-zirconia at 60 - 80 °C to obtain the modified nano-zirconia.

[0015] Nano-zirconia has a high refractive index, can enhance the absorption and scattering of laser, improve the utilization rate of laser energy, has excellent thermal stability and chemical stability, can withstand high temperatures during the laser marking process, prevent the material from thermal decomposition, and has certain photocatalytic activity to promote the thermal effect and chemical reaction during the laser marking process. Through modification with silane coupling agent, amino groups are introduced onto the surface of zirconia to improve the compatibility of zirconia with quercetin and carbon nanotubes and enhance the synergistic effect.

[0016] The present invention also provides a preparation method of the above black-on-white laser masterbatch, including the following steps: Weigh each raw material according to the ratio; Mix each raw material evenly through a high-speed mixer; Add the evenly mixed materials into a twin-screw extruder for mixing and extrusion to obtain the masterbatch. The processing conditions of the twin-screw extruder are preferably: zone 1 at 160 - 170 °C, zone 2 at 170 - 185 °C, zone 3 at 175 - 185 °C, zone 4 at 180 - 195 °C, zone 5 at 190 - 200 °C, zone 6 at 190 - 205 °C, zone 7 at 200 - 215 °C, zone 8 at 210 - 220 °C, and the screw speed is 300 - 350 r / min. Through twin-screw extrusion, the carbon nanotubes are evenly dispersed in the polymer matrix, which helps the uniform absorption of laser energy on the material surface and produces a consistent and clear marking effect.

[0017] Preferably, before adding to the twin-screw extruder, the uniformly mixed material is first placed in an electric field (electric field strength: 1 - 10 V / μm) and maintained at 80 - 100 °C for 10 - 30 min. By applying the electric field, the carbon nanotubes and modified nano-zirconia are oriented along the electric field direction to form an efficient laser absorption network, significantly improving the utilization rate of laser energy, forming an efficient heat conduction path, quickly transferring the heat generated by the laser, and reducing thermal damage.

[0018] Compared with the prior art, the embodiments of the present application mainly have the following beneficial effects: The black-on-white laser masterbatch provided by the present invention has excellent light absorption characteristics and thermal conductivity by adding carbon nanotubes, can help disperse and conduct heat during the laser marking process, reduce the thermal damage of the material, contribute to maintaining the overall structural integrity of the material during the marking process, and at the same time improve the clarity and durability of the mark.

[0019] The black-on-white laser masterbatch provided by the present invention pre-treats the carbon nanotubes to introduce carboxyl groups to improve their dispersibility and compatibility with the polymer matrix, dopes the non-metallic element nitrogen in the carbon nanotubes to adjust their electronic structure and optical properties, thereby improving the effect of laser marking. By adding modified quercetin, the laser absorption effect is enhanced, which has a high refractive index and photocatalytic properties, enhancing the laser absorption and thermal effect. By adding modified nano-zirconia, the light absorption performance and thermal stability are further enhanced, thereby obtaining a clearer and more durable mark. Description of the Drawings

[0020] Figure 1 is a flowchart of a preparation method of a black-on-white laser masterbatch provided by the present invention.

[0021] Figure 2 is another flowchart of a preparation method of a black-on-white laser masterbatch provided by the present invention. Detailed Embodiments

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used in the description of the present application in this specification are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the description and claims of this application and the above description of the drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the description and claims of this application or the above drawings are used to distinguish different objects and are not used to describe a specific order.

[0023] References to "embodiments" in this document mean that the specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears at various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0024] Embodiment 1 An embodiment of the present invention provides a black-on-white laser masterbatch, which comprises the following components by weight: 100 parts of the matrix material, 0.01 part of carbon nanotubes, and 0.05 part of lubricant. Among them, the matrix material includes one or more of polypropylene, polyamide, and polycarbonate. In this embodiment, the matrix material is T30S, and the lubricant includes one or more of silicone, silicone oil, pentaerythritol stearate, and ethylene bisstearamide. As Figure 1 shown, the preparation method of the black-on-white laser masterbatch comprises the following steps: Weigh each raw material according to the ratio; Mix all the raw materials evenly through a high-speed mixer; Add the evenly mixed materials into a twin-screw extruder for mixing and extrusion to obtain the masterbatch.

[0025] Embodiment 2 An embodiment of the present invention provides a black-on-white laser masterbatch, which comprises the following components by weight: 100 parts of the matrix material, 0.05 part of carbon nanotubes, and 0.05 part of lubricant. Among them, the matrix material includes one or more of polypropylene, polyamide, and polycarbonate. In this embodiment, the matrix material is T30S, and the lubricant includes one or more of silicone, silicone oil, pentaerythritol stearate, and ethylene bisstearamide. As Figure 1 shown, the preparation method of the black-on-white laser masterbatch comprises the following steps: Weigh each raw material according to the ratio; Mix all the raw materials evenly through a high-speed mixer; Add the evenly mixed materials into a twin-screw extruder for mixing and extrusion to obtain the masterbatch.

[0026] Embodiment 3 An embodiment of the present invention provides a black-on-white laser masterbatch, which comprises the following components by weight: 100 parts of the matrix material, 0.1 part of carbon nanotubes, and 0.05 part of lubricant. Among them, the matrix material includes one or more of polypropylene, polyamide, and polycarbonate. In this embodiment, the matrix material is T30S, and the lubricant includes one or more of silicone, silicone oil, pentaerythritol stearate, and ethylene bisstearamide. As Figure 1As shown, the preparation method of the black-on-white laser masterbatch includes the following steps: Weigh each raw material according to the ratio; Mix all the raw materials evenly through a high-speed mixer; Add the evenly mixed materials into a twin-screw extruder for kneading and extrusion to obtain the masterbatch.

[0027] Example 4 The embodiment of the present invention provides a black-on-white laser masterbatch, which includes the following components by weight: 100 parts of the matrix material, 0.3 parts of carbon nanotubes, and 0.05 parts of lubricant. Among them, the matrix material includes one or more of polypropylene, polyamide, and polycarbonate. In this embodiment, the matrix material is T30S, and the lubricant includes one or more of silicone, silicone oil, pentaerythritol stearate, and ethylene bis-stearamide. As Figure 1 shown, the preparation method of the black-on-white laser masterbatch includes the following steps: Weigh each raw material according to the ratio; Mix all the raw materials evenly through a high-speed mixer; Add the evenly mixed materials into a twin-screw extruder for kneading and extrusion to obtain the masterbatch.

[0028] Example 5 (Based on Example 3, the carbon nanotubes are pretreated) The embodiment of the present invention provides a black-on-white laser masterbatch, which includes the following components by weight: 100 parts of the matrix material, 0.1 parts of carbon nanotubes, and 0.05 parts of lubricant. Among them, the matrix material includes one or more of polypropylene, polyamide, and polycarbonate. In this embodiment, the matrix material is T30S, and the lubricant includes one or more of silicone, silicone oil, pentaerythritol stearate, and ethylene bis-stearamide. As Figure 1 shown, the preparation method of the black-on-white laser masterbatch includes the following steps: Weigh each raw material according to the ratio; Mix all the raw materials evenly through a high-speed mixer; Add the evenly mixed materials into a twin-screw extruder for kneading and extrusion to obtain the masterbatch.

[0029] Among them, the carbon nanotubes are pretreated before use, and the pretreatment method is as follows: Put the carbon nanotubes into a tube furnace, heat them to 800 °C under an inert atmosphere, hold for 1 h, and naturally cool to room temperature; Mix concentrated sulfuric acid with a concentration of 98% and concentrated nitric acid with a concentration of 68% evenly in a volume ratio of 2:1 to obtain a mixed solution. Put the heat-treated carbon nanotubes into the mixed solution, ultrasonically treat them at a power of 200 W for 1 h, then filter and wash repeatedly with deionized water until the pH value is close to neutral, vacuum dry at 60 °C for 2 h, then put them into a CVD reactor, introduce ammonia at 50 sccm, react at 600 °C for 1 h, and naturally cool to room temperature.

[0030] Example 6 (Based on Example 3, the carbon nanotubes are pretreated) The embodiment of the present invention provides a black-on-white laser masterbatch, which includes the following components by weight: 100 parts of the matrix material, 0.1 part of carbon nanotubes, and 0.05 part of lubricant. Among them, the matrix material includes one or more of polypropylene, polyamide, and polycarbonate. In this embodiment, the matrix material is T30S, and the lubricant includes one or more of silicone, silicone oil, pentaerythritol stearate, and ethylene bis-stearamide. As Figure 1 shown, the preparation method of the black-on-white laser masterbatch includes the following steps: Weigh each raw material according to the ratio; Mix all the raw materials evenly through a high-speed mixer; Add the evenly mixed materials into a twin-screw extruder, mix and extrude to obtain the masterbatch.

[0031] Among them, the carbon nanotubes are pretreated before use, and the pretreatment method is as follows: Put the carbon nanotubes into a tube furnace, heat them to 900 °C under an inert atmosphere, hold for 1.5 h, and naturally cool to room temperature; Mix concentrated sulfuric acid with a concentration of 98% and concentrated nitric acid with a concentration of 68% evenly in a volume ratio of 2.5:1 to obtain a mixed solution. Put the heat-treated carbon nanotubes into the mixed solution, ultrasonically treat them at a power of 300 W for 1.5 h, then filter and wash repeatedly with deionized water until the pH value is close to neutral, vacuum dry at 70 °C for 2.5 h, then put them into a CVD reactor, introduce ammonia at 75 sccm, react at 700 °C for 1.5 h, and naturally cool to room temperature.

[0032] Example 7 (Based on Example 3, the carbon nanotubes are pretreated) An embodiment of the present invention provides a black-on-white laser masterbatch, which comprises the following components by weight: 100 parts of the matrix material, 0.1 part of carbon nanotubes, and 0.05 part of lubricant. Among them, the matrix material includes one or more of polypropylene, polyamide, and polycarbonate. In this embodiment, the matrix material is T30S. The lubricant includes one or more of silicone, silicone oil, pentaerythritol stearate, and ethylene bisstearamide. As Figure 1 shown, the preparation method of the black-on-white laser masterbatch comprises the following steps: Weigh each raw material according to the ratio; Mix all the raw materials evenly through a high-speed mixer; Add the evenly mixed materials into a twin-screw extruder for kneading and extrusion to obtain the masterbatch.

[0033] Among them, the carbon nanotubes are pretreated before use. The pretreatment method is as follows: Put the carbon nanotubes into a tube furnace, heat them to 1000 °C under an inert atmosphere, keep them for 2 h, and then naturally cool them to room temperature; Mix concentrated sulfuric acid with a concentration of 98% and concentrated nitric acid with a concentration of 68% evenly according to a volume ratio of 3:1 to obtain a mixed solution. Put the heat-treated carbon nanotubes into the mixed solution, perform ultrasonic treatment at a power of 400 W for 2 h, then filter and wash them repeatedly with deionized water until the pH value is close to neutral, vacuum dry them at 80 °C for 3 h, then put them into a CVD reactor, introduce ammonia at 100 sccm, and react at 800 °C for 2 h, and then naturally cool them to room temperature.

[0034] Example 8 (On the basis of Example 6, adding modified quercetin and modified nano-zirconia) An embodiment of the present invention provides a black-on-white laser masterbatch, which comprises the following components by weight: 100 parts of the matrix material, 0.1 part of carbon nanotubes, 0.05 part of lubricant, 1 part of modified quercetin, and 5 parts of modified nano-zirconia. Among them, the matrix material includes one or more of polypropylene, polyamide, and polycarbonate. In this embodiment, the matrix material is T30S. The lubricant includes one or more of silicone, silicone oil, pentaerythritol stearate, and ethylene bisstearamide. As Figure 1 shown, the preparation method of the black-on-white laser masterbatch comprises the following steps: Weigh each raw material according to the ratio; Mix all the raw materials evenly through a high-speed mixer; Add the evenly mixed materials into a twin-screw extruder for kneading and extrusion to obtain the masterbatch.

[0035] Among them, the carbon nanotubes are pretreated before use, and the pretreatment method is as follows: Put the carbon nanotubes into a tube furnace, heat them to 900 °C under an inert atmosphere, keep them for 1.5 h, and naturally cool them to room temperature; Mix concentrated sulfuric acid with a concentration of 98% and concentrated nitric acid with a concentration of 68% evenly in a volume ratio of 2.5:1 to obtain a mixed solution. Put the heat-treated carbon nanotubes into the mixed solution, ultrasonically treat them at a power of 300 W for 1.5 h, then filter and wash them repeatedly with deionized water until the pH value is close to neutral, vacuum dry them at 70 °C for 2.5 h, then put them into a CVD reactor, introduce ammonia at 75 sccm, and react at 700 °C for 1.5 h, and naturally cool them to room temperature.

[0036] In this embodiment, the preparation method of the modified quercetin is as follows: By weight, dissolve 6 parts of quercetin in 10 times the weight of ethanol, add 0.5 part of 3-aminopropyltriethoxysilane, stir and heat to 50 °C and react for 40 min, then add 1 part of styrene, 0.1 part of azobisisobutyronitrile, and 0.5 part of nano-titanium dioxide, stir and react at 70 °C for 2 h, filter the reaction mixture through a filter membrane (such as a microporous filter membrane with a pore size of 0.22 μm), wash it with ethanol, and vacuum dry it at 60 °C to obtain the modified quercetin.

[0037] In a specific implementation, the preparation method of the modified nano-zirconia is as follows: By weight, disperse 15 parts of nano-zirconia powder in 80 parts of ethanol, ultrasonically treat it for 30 min, then add a silane coupling agent accounting for 1 wt% of the mass of nano-zirconia, stir and react at 55 °C for 1 h, centrifuge the reaction mixture (5000 rpm, 10 min), wash the precipitate with ethanol 3 times, centrifuge it after each washing, and vacuum dry the washed nano-zirconia at 60 °C to obtain the modified nano-zirconia.

[0038] Example 9 (on the basis of Example 6, adding modified quercetin and modified nano-zirconia) The embodiment of the present invention provides a black-on-white laser masterbatch, which comprises the following components by weight: 100 parts of the matrix material, 0.1 part of carbon nanotubes, 0.05 part of lubricant, 2 parts of modified quercetin, and 6 parts of modified nano-zirconia. Among them, the matrix material includes one or more of polypropylene, polyamide, and polycarbonate. In this embodiment, the matrix material is T30S, and the lubricant includes one or more of silicone, silicone oil, pentaerythritol stearate, and ethylene bis-stearamide. As Figure 1 shown, the preparation method of the black-on-white laser masterbatch includes the following steps: Weigh each raw material according to the ratio; Mix all the raw materials evenly through a high-speed mixer; Add the uniformly mixed materials into a twin-screw extruder for kneading and extrusion to obtain masterbatch.

[0039] Among them, the carbon nanotubes are pretreated before use, and the pretreatment method is as follows: Put the carbon nanotubes into a tube furnace, heat them to 900 °C under an inert atmosphere, keep them for 1.5 h, and naturally cool them to room temperature; Mix concentrated sulfuric acid with a concentration of 98% and concentrated nitric acid with a concentration of 68% evenly according to a volume ratio of 2.5:1 to obtain a mixed solution. Put the heat-treated carbon nanotubes into the mixed solution, perform ultrasonic treatment at a power of 300 W for 1.5 h, then filter and wash repeatedly with deionized water until the pH value is close to neutral, vacuum dry at 70 °C for 2.5 h, then put them into a CVD reactor, introduce ammonia at 75 sccm, and react at 700 °C for 1.5 h, and naturally cool to room temperature.

[0040] In this embodiment, the preparation method of the modified quercetin is as follows: By weight, dissolve 6 parts of quercetin in 10 times the weight of ethanol, add 0.5 part of 3-aminopropyltriethoxysilane, stir and heat to 50 °C for reaction for 40 min, then add 1 part of styrene, 0.1 part of azobisisobutyronitrile, and 0.5 part of nano-titanium dioxide, stir and react at 70 °C for 2 h, filter the reaction mixture through a filter membrane (such as a microporous filter membrane with a pore size of 0.22 μm), wash with ethanol, and vacuum dry at 60 °C to obtain modified quercetin.

[0041] In a specific implementation, the preparation method of the modified nano-zirconia is as follows: By weight, disperse 15 parts of nano-zirconia powder in 80 parts of ethanol, perform ultrasonic treatment for 30 min, then add a silane coupling agent accounting for 1 wt% of the mass of nano-zirconia, stir and react at 55 °C for 1 h, centrifuge the reaction mixture (5000 rpm, 10 min), wash the precipitate with ethanol 3 times, centrifuge after each washing, and vacuum dry the washed nano-zirconia at 60 °C to obtain modified nano-zirconia.

[0042] Example 10 (on the basis of Example 6, adding modified quercetin and modified nano-zirconia) The embodiment of the present invention provides a black-on-white laser masterbatch, which includes the following components by weight: 100 parts of the matrix material, 0.1 part of carbon nanotubes, 0.05 part of lubricant, 3 parts of modified quercetin, and 7.5 parts of modified nano-zirconia. Among them, the matrix material includes one or more of polypropylene, polyamide, and polycarbonate. In this embodiment, the matrix material is T30S, and the lubricant includes one or more of silicone, silicone oil, pentaerythritol stearate, and ethylene bis-stearamide. As Figure 1 shown, the preparation method of the black-on-white laser masterbatch includes the following steps: Weigh each raw material according to the ratio; Mix each raw material evenly through a high - speed mixer; Add the evenly - mixed material into a twin - screw extruder for mixing and extrusion to obtain masterbatch.

[0043] Among them, the carbon nanotubes are pretreated before use, and the pretreatment method is as follows: Put the carbon nanotubes into a tubular furnace, heat them to 900 °C in an inert atmosphere, keep for 1.5 h, and then cool naturally to room temperature; Mix concentrated sulfuric acid with a concentration of 98% and concentrated nitric acid with a concentration of 68% evenly at a volume ratio of 2.5:1 to obtain a mixed solution. Put the heat - treated carbon nanotubes into the mixed solution, perform ultrasonic treatment at a power of 300 W for 1.5 h, then filter and wash repeatedly with deionized water until the pH value is close to neutral, vacuum - dry at 70 °C for 2.5 h, then put them into a CVD reactor, introduce ammonia at 75 sccm, react at 700 °C for 1.5 h, and cool naturally to room temperature.

[0044] In this embodiment, the preparation method of the modified quercetin is as follows: By weight, dissolve 8 parts of quercetin in 12.5 times the weight of ethanol, add 1 part of 3 - aminopropyltriethoxysilane, stir and heat to 55 °C for reaction for 50 min, then add 1.5 parts of styrene, 0.2 part of azobisisobutyronitrile, and 0.75 part of nano - titanium dioxide, stir and react at 75 °C for 2.5 h. Filter the reaction mixture through a filter membrane (such as a 0.22 - μm microporous filter membrane), wash with ethanol, and then vacuum - dry at 70 °C to obtain modified quercetin.

[0045] In a specific implementation, the preparation method of the modified nano - zirconia is as follows: By weight, disperse 17.5 parts of nano - zirconia powder in 90 parts of ethanol, perform ultrasonic treatment for 35 min, then add a silane coupling agent accounting for 3 wt% of the mass of nano - zirconia, stir and react at 60 °C for 1.5 h. Centrifuge the reaction mixture (5000 rpm, 10 min), wash the precipitate with ethanol 3 times, centrifuge after each washing, and vacuum - dry the washed nano - zirconia at 70 °C to obtain modified nano - zirconia.

[0046] Example 11 (On the basis of Example 6, add modified quercetin and modified nano - zirconia) The embodiment of the present invention provides a black - on - white laser masterbatch, which includes the following components by weight: 100 parts of the matrix material, 0.1 part of carbon nanotubes, 0.05 part of lubricant, 4 parts of modified quercetin, and 9 parts of modified nano - zirconia. Among them, the matrix material includes one or more of polypropylene, polyamide, and polycarbonate. In this embodiment, the matrix material is T30S, and the lubricant includes one or more of silicone, silicone oil, pentaerythritol stearate, and ethylene bis - stearamide, such as Figure 1As shown, the preparation method of the black-on-white laser masterbatch includes the following steps: Weigh each raw material according to the ratio. Mix all the raw materials evenly through a high-speed mixer. Add the evenly mixed materials into a twin-screw extruder for kneading and extrusion to obtain the masterbatch.

[0047] Among them, the carbon nanotubes are pretreated before use, and the pretreatment method is as follows: Put the carbon nanotubes into a tube furnace, heat them to 900 °C in an inert atmosphere, keep them for 1.5 h, and then naturally cool them to room temperature; Mix concentrated sulfuric acid with a concentration of 98% and concentrated nitric acid with a concentration of 68% evenly in a volume ratio of 2.5:1 to obtain a mixed solution. Put the heat-treated carbon nanotubes into the mixed solution, perform ultrasonic treatment at a power of 300 W for 1.5 h, then filter and wash them repeatedly with deionized water until the pH value is close to neutral, vacuum dry them at 70 °C for 2.5 h, and then put them into a CVD reactor, introduce ammonia at 75 sccm, react at 700 °C for 1.5 h, and naturally cool them to room temperature.

[0048] In this example, the preparation method of the modified quercetin is as follows: By weight, dissolve 10 parts of quercetin in 15 times the weight of ethanol, add 1.5 parts of 3-aminopropyltriethoxysilane, stir and heat to 60 °C for reaction for 60 min, then add 2 parts of styrene, 0.3 part of azobisisobutyronitrile, and 1 part of nano-titanium dioxide, stir and react at 80 °C for 3 h. Filter the reaction mixture through a filter membrane (such as a microporous filter membrane with a pore size of 0.22 μm), wash it with ethanol, and then vacuum dry it at 80 °C to obtain the modified quercetin.

[0049] In a specific implementation, the preparation method of the modified nano-zirconia is as follows: By weight, disperse 20 parts of nano-zirconia powder in 100 parts of ethanol, perform ultrasonic treatment for 40 min, then add a silane coupling agent accounting for 5 wt% of the mass of nano-zirconia, stir and react at 65 °C for 2 h. Centrifuge the reaction mixture (5000 rpm, 10 min), wash the precipitate with ethanol 3 times, and centrifuge it after each washing. Vacuum dry the washed nano-zirconia at 80 °C to obtain the modified nano-zirconia.

[0050] Example 12 (On the basis of Example 6, add modified quercetin and modified nano-zirconia) An embodiment of the present invention provides a black-on-white laser masterbatch, which comprises the following components in parts by weight: 100 parts of the matrix material, 0.1 part of carbon nanotubes, 0.05 part of lubricant, 5 parts of modified quercetin, and 10 parts of modified nano-zirconia. Among them, the matrix material includes one or more of polypropylene, polyamide, and polycarbonate. In this embodiment, the matrix material is T30S. The lubricant includes one or more of silicone, silicone oil, pentaerythritol stearate, and ethylene bis-stearamide. As Figure 1 shown, the preparation method of the black-on-white laser masterbatch comprises the following steps: Weigh each raw material according to the ratio; Mix all the raw materials evenly by a high-speed mixer; Add the evenly mixed materials into a twin-screw extruder for mixing and extrusion to obtain the masterbatch.

[0051] Among them, the carbon nanotubes are pretreated before use, and the pretreatment method is as follows: Put the carbon nanotubes into a tube furnace, heat them to 900 °C in an inert atmosphere, keep them for 1.5 h, and then cool them naturally to room temperature; Mix concentrated sulfuric acid with a concentration of 98% and concentrated nitric acid with a concentration of 68% evenly at a volume ratio of 2.5:1 to obtain a mixed solution. Put the heat-treated carbon nanotubes into the mixed solution, perform ultrasonic treatment at a power of 300 W for 1.5 h, then filter and wash them repeatedly with deionized water until the pH value is close to neutral, vacuum dry them at 70 °C for 2.5 h, and then put them into a CVD reactor, introduce ammonia at 75 sccm, and react at 700 °C for 1.5 h, and then cool them naturally to room temperature.

[0052] In this embodiment, the preparation method of the modified quercetin is as follows: By weight, dissolve 10 parts of quercetin in 15 times the weight of ethanol, add 1.5 parts of 3-aminopropyltriethoxysilane, stir and heat to 60 °C for reaction for 60 min, then add 2 parts of styrene, 0.3 part of azobisisobutyronitrile, and 1 part of nano-titanium dioxide, stir and react at 80 °C for 3 h, filter the reaction mixture through a filter membrane (such as a microporous filter membrane with a pore size of 0.22 μm), wash it with ethanol, and then vacuum dry it at 80 °C to obtain the modified quercetin.

[0053] In a specific implementation, the preparation method of the modified nano-zirconia is as follows: By weight, disperse 20 parts of nano-zirconia powder in 100 parts of ethanol, perform ultrasonic treatment for 40 min, then add a silane coupling agent accounting for 5 wt% of the mass of nano-zirconia, stir and react at 65 °C for 2 h, centrifuge the reaction mixture (5000 rpm, 10 min), wash the precipitate with ethanol 3 times, centrifuge and separate after each washing, and vacuum dry the washed nano-zirconia at 80 °C to obtain the modified nano-zirconia.

[0054] Example 13 (Based on Example 10, the uniformly mixed material is subjected to electric field treatment) An embodiment of the present invention provides a black-on-white laser masterbatch, which includes the following components by weight: 100 parts of the matrix material, 0.1 part of carbon nanotubes, 0.05 part of lubricant, 3 parts of modified quercetin, and 7.5 parts of modified nanozirconia. Among them, the matrix material includes one or more of polypropylene, polyamide, and polycarbonate. In this embodiment, the matrix material is T30S. The lubricant includes one or more of silicone, silicone oil, pentaerythritol stearate, and ethylene bisstearamide. As Figure 2 shown, the preparation method of the black-on-white laser masterbatch includes the following steps: Weigh each raw material according to the ratio; Mix all the raw materials evenly through a high-speed mixer; Place the uniformly mixed material in an electric field and keep it at 80 - 100 °C for 10 - 30 min; Add the material after electric field treatment into a twin-screw extruder, mix and extrude it to obtain the masterbatch.

[0055] Among them, the carbon nanotubes are pretreated before use, and the pretreatment method is as follows: Put the carbon nanotubes into a tubular furnace, heat them to 900 °C in an inert atmosphere, keep them for 1.5 h, and then cool them naturally to room temperature; Mix concentrated sulfuric acid with a concentration of 98% and concentrated nitric acid with a concentration of 68% evenly according to a volume ratio of 2.5:1 to obtain a mixed solution. Put the heat-treated carbon nanotubes into the mixed solution, perform ultrasonic treatment at a power of 300 W for 1.5 h, then filter and wash them repeatedly with deionized water until the pH value is close to neutral. Vacuum dry them at 70 °C for 2.5 h, and then put them into a CVD reactor, introduce ammonia at 75 sccm, and react at 700 °C for 1.5 h, and then cool them naturally to room temperature.

[0056] In this embodiment, the preparation method of the modified quercetin is as follows: By weight, dissolve 8 parts of quercetin in 12.5 times the weight of ethanol, add 1 part of 3-aminopropyltriethoxysilane, stir and heat to 55 °C and react for 50 min, then add 1.5 parts of styrene, 0.2 part of azobisisobutyronitrile, and 0.75 part of nano-titanium dioxide, stir and react at 75 °C for 2.5 h. Filter the reaction mixture through a filter membrane (such as a 0.22 μm microporous filter membrane), wash it with ethanol, and then vacuum dry it at 70 °C to obtain the modified quercetin.

[0057] In a specific implementation, the preparation method of the modified nano-zirconia is as follows: by weight, disperse 17.5 parts of nano-zirconia powder in 90 parts of ethanol, ultrasonically treat for 35 min, then add a silane coupling agent accounting for 3 wt% of the mass of nano-zirconia, stir and react at 60 °C for 1.5 h, centrifuge the reaction mixture (5000 rpm, 10 min), wash the precipitate with ethanol 3 times, centrifuge after each washing, and vacuum-dry the washed nano-zirconia at 70 °C to obtain the modified nano-zirconia.

[0058] Comparative Example 1 Only use T30S as the black-on-white laser masterbatch.

[0059] Comparative Example 2: The difference from Example 10 is that the carbon nanotubes are not pretreated.

[0060] Comparative Example 3: The difference from Example 10 is that the modified quercetin is replaced with ordinary quercetin.

[0061] Comparative Example 4: The difference from Example 10 is that the modified nano-zirconia is replaced with ordinary nano-zirconia.

[0062] Comparative Example 5: The difference from Example 10 is that the carbon nanotubes are not pretreated, the modified quercetin is replaced with ordinary quercetin, and the modified nano-zirconia is replaced with ordinary nano-zirconia.

[0063] Performance Test Perform color difference analysis on the black-on-white laser masterbatches of Examples 1-13 and Comparative Examples 1-5 after laser marking. The results are shown in Table 1 below: Table 1 Results of color difference analysis of samples

[0064] It can be seen from the above results that by adding carbon nanotubes, the laser marking effect can be improved. By pretreating the carbon nanotubes, the laser marking effect can be further improved. Further, by adding modified quercetin and modified nano-zirconia, the laser marking effect can be further improved. The pretreated carbon nanotubes, modified quercetin and modified nano have a synergistic effect.

[0065] It should be noted that, for the foregoing embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, certain steps may be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0066] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the protection scope of the invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on these embodiments, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art can still, without conflict, make combinations, additions, deletions or other adjustments to the features in the embodiments of the present invention according to the circumstances without creative efforts, so as to obtain different technical solutions that are essentially not divorced from the concept of the present invention, and these technical solutions also belong to the scope of protection of the present invention.

Claims

1. A black-on-white laser masterbatch, characterized in that: The method comprises the following components: a matrix material, carbon nanotubes, and a lubricant. The carbon nanotubes are pretreated, and the pretreatment method comprises: heat treating carbon nanotubes at high temperature under an inert atmosphere; Ultrasonic treatment with a mixture of concentrated sulfuric acid and concentrated nitric acid; Ammonia gas is introduced into the CVD reactor for nitrogen doping; When preparing the masterbatch, the mixed material is placed in an electric field for directional arrangement and then extruded into shape.

2. The black-on-white laser masterbatch according to claim 1, characterized in that: In parts by weight, the base material comprises 100 parts, the carbon nanotubes 0.01-0.3 parts, and the lubricant 0.05 parts.

3. The black-on-white laser masterbatch according to claim 1, characterized in that: The matrix material includes one or more of polypropylene, polyamide, and polycarbonate.

4. The black-on-white laser masterbatch according to claim 1, characterized in that: The lubricant includes one or more of silicone, silicone oil, pentaerythritol stearate, and ethylene bis stearamide.

5. The black-on-white laser masterbatch according to claim 1, characterized in that: The pretreatment method is specifically as follows: placing carbon nanotubes in a tubular furnace, heating to 800-1000°C in an inert atmosphere, maintaining for 1-2 hours, and naturally cooling to room temperature; mixing 98% concentrated sulfuric acid and 68% concentrated nitric acid at a volume ratio of 2-3:1 to obtain a mixed solution, placing the heat-treated carbon nanotubes in the mixed solution, ultrasonically treating them at a power of 200-400W for 1-2 hours, then filtering, repeatedly washing with deionized water until the pH value is close to neutral, vacuum drying at 60-80°C for 2-3 hours, then placing them in a CVD reactor, introducing ammonia at 50-100sccm, reacting at 600-800°C for 1-2 hours, and naturally cooling to room temperature.

6. The black-on-white laser masterbatch according to claim 5, characterized in that: The invention also comprises the following components in parts by weight: 1-5 parts of modified quercetin and 5-10 parts of modified nano zirconium dioxide.

7. The black-on-white laser masterbatch according to claim 6, characterized in that: The preparation method of the modified quercetin is as follows: by weight, 6-10 parts of quercetin are dissolved in 10-15 times the weight of ethanol, 0.5-1.5 parts of 3-aminopropyltriethoxysilane are added, stirred and heated to 50-60° C. for reaction for 40-60 minutes, then 1-2 parts of styrene, 0.1-0.3 parts of azobisisobutyronitrile, and 0.5-1 parts of nano titanium dioxide are added, stirred and reacted at 70-80° C. for 2-3 hours, the reaction mixture is filtered through a filter membrane, washed with ethanol, and then vacuum dried at 60-80° C. to obtain modified quercetin.

8. The black-on-white laser masterbatch according to claim 6, characterized in that: The preparation method of the modified nano zirconium dioxide is as follows: by weight, 15-20 parts of nano zirconium dioxide powder are dispersed in 80-100 parts of ethanol, ultrasonic treatment is performed for 30-40 minutes, and then 1-5wt% of the mass of the nano zirconium dioxide is added with a silane coupling agent, and the mixture is stirred and reacted at 55-65° C. for 1-2 hours. The mixture after the reaction is centrifuged, and the precipitate is washed with ethanol for 3 times, and centrifuged after each washing. The washed nano zirconium dioxide is vacuum dried at 60-80° C. to obtain the modified nano zirconium dioxide.

9. The method for preparing black-on-white laser masterbatch according to any one of claims 1 to 8, characterized in that: The steps include: Weigh each raw material according to the ratio; Mix all the raw materials evenly in a high-speed mixer; The uniformly mixed materials are added into a twin-screw extruder for mixing and extrusion to obtain master batches.

10. The method for preparing black-on-white laser masterbatch according to claim 9, characterized in that: Before adding into the twin-screw extruder, the mixed materials are placed in an electric field and kept at 80-100℃ for 10-30min.

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