Color master batch with high tinting strength and preparation method thereof

Abstract

The invention relates to the field of coloring agents, in particular to a high-tinting-strength color master batch and a preparation method thereof. The high-tinting-strength color master batch is prepared from carrier resin, a coloring agent, a dispersion composition, a heat stabilizer, an ultraviolet light absorber and the like, the high-tinting-strength effect of the high-tinting-strength color master batch can be effectively guaranteed, the problem of uneven dispersion caused by secondary agglomeration of a pigment system can be avoided, and on the other hand, by enhancing the performance of the color master batch, the high-tinting-strength color master batch can be obtained. The heat stability, water resistance, corrosion resistance and the like of the master batch are further improved, the compatibility of the master batch with a plastic system can be greatly improved, and the compatibility problems of layering, segregation, agglomeration and the like are avoided, so that the comprehensive use requirements of the existing industry on the master batch are met, and the master batch has wide application potential.

Description

Technical Field

[0001] The present application relates to the field of colorants, and more specifically to a high-tinting-strength masterbatch and a preparation method thereof. Background Art

[0002] Masterbatch, also known as color seed or pigment preparation, is a new type of colorant specifically designed for polymer materials. It consists of three basic components: pigment or dye, carrier, and dispersant, with additives sometimes added to provide specific functionality. This composite material uniformly carries an exceptional amount of pigment within the resin, forming a polymer complex. This gives the masterbatch high tinting strength and enables excellent color dispersion in plastic products.

[0003] In the production of plastic products, masterbatches are widely used because they can ensure color consistency and stability while simplifying the production process. The emergence of masterbatches has greatly improved the color expression of plastic products and also reduced production costs because it allows manufacturers to use less pigment to achieve the desired coloring effect.

[0004] In recent years, my country's masterbatch industry has experienced rapid development, with not only annual increases in production but also continuous improvements in technology. However, despite these remarkable achievements, the domestic masterbatch industry still faces numerous challenges. For example, most companies are small in scale, their production processes are immature, and product quality varies. In particular, the supply of high-end products is insufficient, and many high-performance masterbatches still rely on imports.

[0005] Although existing domestic technologies have improved the coloring performance of masterbatches to a certain extent, there are still the following bottlenecks when achieving high tinting strength. For example: the contradiction between colorant dispersibility and concentration. To improve tinting strength, the amount of pigment added needs to be increased, but at high concentrations, the pigment is prone to secondary agglomeration, resulting in uneven dispersion and color spots or stripes on the surface of the product; insufficient thermal stability. Some organic pigments are easily degraded or undergo crystal transformation during high-temperature processing, resulting in hue shift; and the compatibility between the carrier and the substrate is limited. The polarity difference between engineering plastics and general plastics is large, which further leads to a significant decrease in the waterproof and corrosion resistance properties of the masterbatch after addition. Summary of the Invention

[0006] Therefore, to effectively address the above-mentioned existing problems, the present application provides a high-tinting-strength masterbatch and a method for preparing the same. The masterbatch product ultimately produced by the present application not only effectively maintains its own high tinting strength, but also prevents secondary agglomeration of the pigment system, which can lead to uneven dispersion. Furthermore, by enhancing the performance of the masterbatch, its thermal stability, waterproofness, and corrosion resistance are further improved. Furthermore, its compatibility with plastic systems is significantly enhanced, avoiding compatibility issues such as delamination, segregation, and agglomeration. Thus, the present application meets the comprehensive use requirements of masterbatches in existing industries and has broad application potential.

[0007] The high tinting strength masterbatch, calculated by mass, comprises the following raw materials: 40-55 parts of carrier resin, 30-40 parts of colorant, 8-15 parts of dispersion composition, 1-2 parts of heat stabilizer, 0.3-0.8 parts of ultraviolet absorber, 1.5-3 parts of coupling agent, 4-8 parts of filler, 1.2-2.5 parts of flow aid, and 0.6-1 part of antibacterial agent.

[0008] As a preferred embodiment, the carrier resin is a modified polyethylene resin.

[0009] As a preferred embodiment, the preparation method of the modified polyethylene resin specifically includes the following steps: S1: adding low-density polyethylene, hydroxyethyl acrylate, tetrafluoropropylene and acrylonitrile to a high-speed mixer, mixing at a speed of 800-850 rpm for 10-15 minutes, then adding benzoyl peroxide and an antioxidant, and continuing mixing for 8-12 minutes to obtain a mixture; S2: adding the mixture to a twin-screw extruder, setting four sections in the range of 170-205°C, and finally extruding at a die head temperature of 200°C, a screw speed of 150-160 rpm, and a residence time of 3-4 minutes; S3: cooling in a water tank after extrusion, granulating with a pelletizer, and vacuum drying at 70-75°C for 5-6 hours to obtain the product.

[0010] As a preferred embodiment, the four zones are zone one at 170°C, zone two at 180°C, zone three at 195°C and zone four at 205°C.

[0011] As a preferred embodiment, the aspect ratio of the twin-screw extruder is (38-40):1.

[0012] As a preferred embodiment, the mass ratio of the low-density polyethylene to hydroxyethyl acrylate, tetrafluoropropylene and acrylonitrile is (70-80): (8-12): (6-9): (8-12).

[0013] As a more preferred embodiment, the mass ratio of the low-density polyethylene to hydroxyethyl acrylate, tetrafluoropropylene and acrylonitrile is 75.5:9.5:8:9.

[0014] As a preferred embodiment, the antioxidant is Irganox 1330.

[0015] By using this modified polyethylene carrier resin as the primary raw material for masterbatches, the masterbatch product's tinting strength, thermal stability, water resistance, and corrosion resistance can be effectively improved. Most importantly, its compatibility is significantly enhanced. In particular, the hydroxyl groups within the modified resin can form hydrogen bonds or covalent bonds with polar plastics, enhancing interfacial bonding and preventing the interface from acting as a barrier for corrosion and moisture intrusion. This ensures compatibility with polar materials while also guaranteeing heat resistance, water resistance, and corrosion resistance.

[0016] Furthermore, the fluorinated side chains in the modified carrier resin can form aggregated segments on the resin surface. Their excellent low surface energy significantly enhances the molecular chain adhesion between the modified carrier resin and the non-polar system, effectively avoiding phase separation during application. Furthermore, the hydroxyl groups and fluorinated long chains in the modified carrier resin can form hydrogen bonds with the surface of the pigment particles, preventing agglomeration. Furthermore, by interacting with the rigid cyano groups, they form a barrier around the pigment particles, regulating steric hindrance and thereby inhibiting subsequent reaggregation of the pigment particles. Together, they work with the dispersing composition to reduce shear viscosity and promote uniform distribution of the pigment particles.

[0017] Finally, the fluorine-containing segments and cyanide groups in the modified carrier particles can form a dense fluorocarbon layer, increase the penetration resistance of water molecules and corrosive media, and inhibit the swelling effect of ester and hydrocarbon solvents, thereby obtaining good waterproof and corrosion-resistant properties. In addition, the strength and density of the internal cross-linked three-dimensional network structure of the modified carrier resin can be improved, thereby reducing the diffusion path of water molecules and corrosive media in the system and inhibiting high-temperature oxidation chain breakage, thereby comprehensively improving various properties such as heat resistance.

[0018] As a preferred embodiment, the mass ratio of the carrier resin, the colorant and the dispersion composition is (42-50): (32-39): (9-14).

[0019] As a more preferred embodiment, the mass ratio of the carrier resin, the colorant and the dispersion composition is (44-48): (35-38): (10-12).

[0020] As a preferred embodiment, the colorant is at least one of phthalocyanine blue, azo condensation red, isoindolinone yellow, carbon black, quinacridone violet and solvent orange.

[0021] As a preferred embodiment, the dispersion composition is a composition of polyethylene wax, zinc stearate and polypropylene grafted with maleic anhydride.

[0022] As a preferred embodiment, the mass ratio of the polyethylene wax, zinc stearate and polypropylene grafted maleic anhydride is (5-9): (2-3): (4-6).

[0023] As a more preferred embodiment, the mass ratio of the polyethylene wax, zinc stearate and polypropylene grafted maleic anhydride is (6-8): (2-2.5): (4.5-5.2).

[0024] By compounding and adding the dispersing composition, the melt viscosity can be reduced through non-polar short-chain molecules in the carrier resin system of the present application to form a "micro-region lubrication layer", which reduces the friction and agglomeration between the pigment particles, while forming a certain steric hindrance on the surface of the pigment particles to prevent the particles from re-aggregating. Furthermore, the active groups undergo esterification / amidation reactions with the hydroxyl or amino groups on the surface of the pigment to form covalent bond anchoring, forming a stable connection structure, and greatly improving the dispersibility and dispersion stability of the pigment particles.

[0025] On the other hand, the combined action of the compounded dispersing composition can also help improve the wettability of pigment particles in the carrier resin, reduce internal stress concentration, and form internal van der Waals forces and particle ion clusters, greatly enhancing the interfacial bonding effect, and obtaining a lubrication-anchoring-shielding joint action mechanism, thereby achieving efficient dispersion and stability of the masterbatch, thereby enhancing its coloring effect, heat resistance, waterproofness and other comprehensive properties.

[0026] As a more preferred embodiment, the heat stabilizer is a combination of distearyl thiodipropionate and organotin.

[0027] As a preferred embodiment, the mass ratio of the distearyl thiodipropionate to the organotin is (1.3-1.6): (2-2.2).

[0028] As a more preferred embodiment, the mass ratio of the distearyl thiodipropionate to the organotin is 1.5:2.1.

[0029] As a preferred embodiment, the ultraviolet absorber is at least one of benzophenones, benzotriazoles and phenyl salicylate.

[0030] As a more preferred embodiment, the ultraviolet absorber is benzophenone.

[0031] As a preferred embodiment, the coupling agent is at least one of an aluminum-titanium composite coupling agent, a titanate coupling agent, a phosphate coupling agent and a polyester coupling agent.

[0032] As a more preferred embodiment, the coupling agent is an aluminum-titanium composite coupling agent or a titanate coupling agent.

[0033] As a more preferred embodiment, the filler is a combination of silicon dioxide, hydrotalcite and zirconium phosphate.

[0034] As a preferred embodiment, the mass ratio of the silicon dioxide, hydrotalcite and zirconium phosphate is (0.8-1.2): (2-2.5): (0.3-0.5).

[0035] As a preferred embodiment, the average particle size of the silicon dioxide is 25 to 50 nm.

[0036] As a preferred embodiment, the average particle size of the hydrotalcite is 1 to 1.2 μm.

[0037] As a preferred embodiment, the flow aid is at least one of oleamide, oxidized polyethylene wax, glycerol monostearate, ethylene bisstearamide and dimethyl silicone oil.

[0038] As a more preferred embodiment, the flow aid is a composition of oleamide and glycerol monostearate.

[0039] As a preferred embodiment, the mass ratio of oleamide to glycerol monostearate is (4-5): (1-1.4).

[0040] As a more preferred embodiment, the mass ratio of oleamide to glycerol monostearate is (4.2-4.5): (1.1-1.2).

[0041] As a preferred embodiment, the antibacterial agent is zinc oxide or a quaternary ammonium salt.

[0042] As a more preferred embodiment, the antibacterial agent is zinc oxide.

[0043] The present application further provides a method for preparing the above-mentioned high-tinting-power masterbatch, which specifically comprises the following steps: S1: adding the modified carrier resin, the colorant and the dispersed composition into a high-speed mixer and mixing them at a speed of 600-800 rpm and a temperature of 50-55° C. for 15-20 minutes, then adding the remaining raw materials, and continuing to mix them at a speed of 1000-1400 rpm and a temperature of 60-65° C. for 10-15 minutes to obtain a premix; S2: extruding the premix using a co-rotating twin-screw extruder, separating The section temperature is controlled as 170-175°C for zone 1, 180-185°C for zone 2, 195-200°C for zone 3, 210-215°C for zone 4, 205-210°C for zone 5, and 200-205°C for the die head. The screw speed is 180-220rpm, the vacuum degassing pressure is -0.09-0.08MPa, the extruded material strips are cooled in a water trough, and granulated by a pelletizer. After granulation, the granules are treated in a hot air drying oven at 70-75°C for 5-6h to ensure that the final moisture content of the granules is ≤0.06%. The process is completed.

[0044] As a preferred embodiment, the aspect ratio of the co-rotating twin-screw extruder is (40-45):1.

[0045] As a preferred embodiment, the pelletizing size of the pelletizer is 2-3 mm×2-3 mm.

[0046] This application has the following beneficial effects:

[0047] 1. The high-tinting-strength masterbatch provided in this application can not only effectively ensure its own high tinting-strength effect, but also avoid the secondary agglomeration of the pigment system, which leads to the problem of uneven dispersion. On the other hand, by enhancing the performance of the masterbatch, its thermal stability, waterproofness and corrosion resistance are further improved, and its compatibility with the plastic system can be greatly improved, avoiding compatibility problems such as stratification, segregation and agglomeration, thereby meeting the comprehensive use needs of the existing industry for masterbatch and having broad application potential.

[0048] 2. The high-tinting-power masterbatch provided in this application, in which the modified polyethylene carrier resin added as the carrier resin can achieve the effects of enhancing the interfacial bonding force, preventing the agglomeration of pigment particles, and increasing the medium penetration resistance through the combined action of the hydroxyl groups and fluorine-containing side chain segments contained therein, thereby improving the overall tinting power, heat resistance, waterproof and corrosion resistance of the masterbatch.

[0049] 3. The high-tinting-power masterbatch provided in this application, the combined action of the added compound dispersing composition can also help improve the wettability of the pigment particles in the carrier resin, reduce the internal stress concentration phenomenon, and form internal van der Waals forces and particle ion clusters, greatly enhancing the interfacial bonding effect, and obtaining a lubrication-anchoring-shielding joint action mechanism, thereby achieving efficient dispersion and stability of the masterbatch, thereby enhancing its comprehensive properties such as coloring effect, heat resistance and waterproofness. DETAILED DESCRIPTION

[0050] In the specific implementation manner, specific implementation cases will be used to more intuitively display and illustrate the contents of the invention content of this application.

[0051] Example 1

[0052] The raw materials of the high tinting strength masterbatch, calculated by mass, are: 45.5 parts of carrier resin, 36.8 parts of colorant, 11.6 parts of dispersion composition, 1.2 parts of heat stabilizer, 0.5 parts of ultraviolet absorber, 1.9 parts of coupling agent, 6.4 parts of filler, 1.8 parts of flow aid, and 0.8 parts of antibacterial agent.

[0053] The carrier resin is a modified polyethylene resin, and its preparation method is calculated by mass and specifically includes the following steps: S1: adding 75.5 parts of low-density polyethylene and 9.5 parts of hydroxyethyl acrylate, 8 parts of tetrafluoropropylene and 9 parts of acrylonitrile to a high-speed mixer, mixing at a high speed of 800 rpm for 15 minutes, then adding 0.4 parts of benzoyl peroxide and 0.5 parts of antioxidant Irganox 1330, and continuing to mix for 10 minutes to obtain a mixture; S2: adding the mixture to a twin-screw extruder (with a length-to-diameter ratio of 40:1), setting four sections, zone one at 170°C, zone two at 180°C, zone three at 195°C and zone four at 205°C, and finally extruding at a die head temperature of 200°C, a screw speed of 160 rpm, and a residence time of 3.5 minutes; S3: cooling in a water tank after extrusion, granulating with a pelletizer, and vacuum drying at 75°C for 6 hours, and the mixture is obtained after completion.

[0054] The low-density polyethylene is the 2426H model product provided by Sinopec.

[0055] The colorant is phthalocyanine blue.

[0056] The dispersion composition is a composition of polyethylene wax, zinc stearate and polypropylene grafted maleic anhydride, with a mass ratio of 7.2:2.3:5.

[0057] Polyethylene wax was purchased from AC-6 model product sold by Honeywell Company in the United States; polypropylene grafted maleic anhydride was purchased from 50E739 model product sold by DuPont Company in the United States.

[0058] The heat stabilizer is a composition of distearyl thiodipropionate and dibutyltin dilaurate, with a mass ratio of 1.5:2.1.

[0059] The ultraviolet absorber is benzophenone UV-531.

[0060] The coupling agent is an aluminum-titanium composite coupling agent, purchased from Jessica Chemical Co., Ltd. in Hangzhou, China, and sold as HY-133.

[0061] The filler is a composition of silicon dioxide, hydrotalcite and zirconium phosphate, with a mass ratio of 1:2.1:0.4.

[0062] The average particle size of silica was 30 nm, and the average particle size of hydrotalcite was 1.1 μm.

[0063] The flow aid is a composition of oleamide and glycerol monostearate, with a mass ratio of 4.3:1.2.

[0064] The antibacterial agent is zinc oxide with an average particle size of 25 nm.

[0065] The preparation method of a high-tinting-strength masterbatch specifically includes the following steps: S1: adding a modified carrier resin, a colorant and a dispersed composition to a high-speed mixer and mixing them at a speed of 800 rpm and a temperature of 55°C for 15 minutes, then adding the remaining raw materials and continuing to mix them at a speed of 1200 rpm and a temperature of 65°C for 12 minutes to obtain a premix; S2: extruding the premix using a co-rotating twin-screw extruder, controlling the segmented temperatures to 175°C in zone one, 185°C in zone two, 200°C in zone three, 215°C in zone four, 210°C in zone five and 205°C at the die head, a screw speed of 200 rpm, a vacuum degassing pressure of -0.09 MPa, cooling the extruded material strips in a water tank, granulating them with a pelletizer, and treating the particles in a 70°C hot air drying oven for 6 hours after granulation to ensure that the final moisture content of the particles is ≤0.06%. The method is completed.

[0066] The length-to-diameter ratio of the co-rotating twin-screw extruder is 44:1; the pelletizing size of the pelletizer is 2.5 mm×2.5 mm.

[0067] Example 2

[0068] The only difference between this embodiment and Example 1 is that the raw materials of the high tinting strength masterbatch, calculated by mass, are: 42.5 parts of carrier resin, 33.5 parts of colorant, 9.6 parts of dispersion composition, 1.1 parts of heat stabilizer, 0.3 parts of ultraviolet absorber, 1.6 parts of coupling agent, 5.2 parts of filler, 1.6 parts of flow aid, and 0.6 parts of antibacterial agent.

[0069] The dispersion composition is a composition of polyethylene wax, zinc stearate and polypropylene grafted maleic anhydride, with a mass ratio of 9:2:4.

[0070] The heat stabilizer is a composition of distearyl thiodipropionate and dibutyltin dilaurate, with a mass ratio of 1.3:2.2.

[0071] The filler is a composition of silicon dioxide, hydrotalcite and zirconium phosphate, with a mass ratio of 0.8:2.5:0.5.

[0072] The flow aid is a composition of oleamide and glycerol monostearate, with a mass ratio of 5:1.

[0073] Example 3

[0074] The only difference between this embodiment and Example 1 is that the raw materials of the high tinting strength masterbatch, calculated by mass, are: 50 parts of carrier resin, 38 parts of colorant, 13.2 parts of dispersion composition, 1.6 parts of heat stabilizer, 0.4 parts of ultraviolet absorber, 2.1 parts of coupling agent, 6.1 parts of filler, 2.2 parts of flow aid, and 0.7 parts of antibacterial agent.

[0075] The dispersion composition is a composition of polyethylene wax, zinc stearate and polypropylene grafted maleic anhydride, with a mass ratio of 6.2:3:5.5.

[0076] The heat stabilizer is a composition of distearyl thiodipropionate and dibutyltin dilaurate, with a mass ratio of 1.6:2.

[0077] The filler is a composition of silicon dioxide, hydrotalcite and zirconium phosphate, with a mass ratio of 1.2:2.2:0.3.

[0078] The flow aid is a composition of oleamide and glycerol monostearate, with a mass ratio of 4:1.3.

[0079] Comparative Example 1

[0080] The only difference between this comparative example and Example 1 is that the raw materials of the high tinting strength masterbatch, calculated by mass, are: 35.5 parts of carrier resin, 38 parts of colorant, 11.6 parts of dispersion composition, 1.2 parts of heat stabilizer, 0.5 parts of ultraviolet absorber, 1.9 parts of coupling agent, 6.4 parts of filler, 1.8 parts of flow aid, and 0.8 parts of antibacterial agent.

[0081] Comparative Example 2

[0082] The only difference between this comparative example and Example 1 is that the raw materials of the high tinting strength masterbatch, calculated by mass, are: 42.5 parts of carrier resin, 38.5 parts of colorant, 3.5 parts of dispersion composition, 1.2 parts of heat stabilizer, 0.5 parts of ultraviolet absorber, 1.9 parts of coupling agent, 6.4 parts of filler, 1.8 parts of flow aid, and 0.8 parts of antibacterial agent.

[0083] Comparative Example 3

[0084] The only difference between this comparative example and Example 1 is that the dispersion composition is a composition of polyethylene wax, zinc stearate and polypropylene grafted maleic anhydride, with a mass ratio of 2:4:6.

[0085] Comparative Example 4

[0086] The only difference between this comparative example and Example 1 is that the dispersion composition is a composition of polyethylene wax, zinc stearate and polypropylene grafted maleic anhydride, with a mass ratio of 10:1:1.5.

[0087] Comparative Example 5

[0088] The only difference between this comparative example and Example 1 is that the carrier resin is a modified polyethylene resin, and its preparation method, calculated by mass, specifically comprises the following steps: S1: adding 90 parts of low-density polyethylene, 5.5 parts of hydroxyethyl acrylate, 4 parts of tetrafluoropropylene and 5 parts of acrylonitrile to a high-speed mixer, and mixing at a high speed of 800 rpm for 15 minutes, then adding 0.4 parts of benzoyl peroxide and 0.5 parts of antioxidant Irganox 1330, and continuing mixing for 10 minutes to obtain a mixture; S2: adding the mixture to a twin-screw extruder (with a length-to-diameter ratio of 40:1), setting four zones: zone one at 170°C, zone two at 180°C, zone three at 195°C and zone four at 205°C, and finally extruding at a die head temperature of 200°C, a screw speed of 160 rpm, and a residence time of 3.5 minutes; S3: cooling in a water tank after extrusion, granulating with a pelletizer, and vacuum drying at 75°C for 6 hours to obtain the product.

[0089] Comparative Example 6

[0090] The only difference between this comparative example and Example 1 is that the carrier resin is a modified polyethylene resin, and its preparation method, calculated by mass, specifically comprises the following steps: S1: 55.5 parts of low-density polyethylene, 12.5 parts of hydroxyethyl acrylate, 2 parts of tetrafluoropropylene and 15 parts of acrylonitrile are added to a high-speed mixer, and mixed at a high speed of 800 rpm for 15 minutes, followed by adding 0.4 parts of benzoyl peroxide and 0.5 parts of antioxidant Irganox 1330, and continuing mixing for 10 minutes to obtain a mixture; S2: the mixture is added to a twin-screw extruder (with an aspect ratio of 40:1), set to four sections: zone one at 170°C, zone two at 180°C, zone three at 195°C and zone four at 205°C, and finally extruded at a die head temperature of 200°C, a screw speed of 160 rpm, and a residence time of 3.5 minutes; S3: after extrusion, cooled in a water tank, granulated with a pelletizer, and vacuum dried at 75°C for 6 hours to obtain the product.

[0091] Performance evaluation

[0092] 1. The tinting strength of the masterbatches prepared in the examples and comparative examples was tested with reference to ISO 787-25:2019. The test conditions were as follows: the test samples were the masterbatches prepared in the examples and comparative examples, mixed with polypropylene resin at a content of 1 wt%, and the reference samples were phthalocyanine blue masterbatches sold by Suzhou Hannuo Materials Technology Co., Ltd., which were also mixed with polypropylene resin at a content of 1 wt%. After that, 50 mm × 50 mm × 2 mm standard color plates were prepared by injection molding machines, and 5-point tests were performed with a spectrophotometer. The corresponding K / S value was calculated after taking the average value. The test sample and the reference sample were compared and measured to obtain the relative tinting strength RTS. The results were averaged over 10 tests and recorded in Table 1.

[0093] 2. The masterbatches prepared in the examples and comparative examples were subjected to heat resistance tests with reference to ISO 4577:2019. The test conditions were as follows: the injection molded sheet (50 mm × 50 mm × 2 mm, the preparation method was consistent with the method in performance evaluation 1) after the masterbatch was colored, with uniform thickness, was placed in a forced ventilation oven, treated at 280 ° C for 30 min, taken out and cooled to room temperature, and the ΔE value before and after the heat resistance test was measured with a spectrophotometer. The results were averaged over 10 tests and recorded in Table 1.

[0094] 3. The masterbatches prepared in the examples and comparative examples were tested for water resistance with reference to ASTM D570-98. The test conditions were as follows: drying in an oven at 50±3°C for 24 hours until the mass change was ≤0.1% (constant weight), cooling to a desiccator (room temperature, humidity ≤50% RH), and then weighing the initial dry weight using an analytical balance with an accuracy of 0.1 mg. The masterbatches were immersed in deionized water at 23±1°C for 48 hours. After the immersion test, the surface moisture was quickly absorbed with lint-free filter paper (≤30 seconds), and the wet weight was immediately measured and the water absorption rate was calculated. The results were averaged over 10 tests and reported in Table 1.

[0095] 4. The masterbatches prepared in the Examples and Comparative Examples were subjected to corrosion resistance tests with reference to ASTM D543-21. The ΔE values and weight changes after immersion in n-heptane at 40° C. for 72 hours were obtained. The average values of 10 tests were reported in Table 1.

[0096] Table 1 Performance evaluation results

[0097]

[0098] Judging from the final performance test results of the Examples and Comparative Examples, Comparative Examples 1 to 6 achieved worse performance results than the Examples. Example 1, through the combined effect of the modified carrier resin prepared using the optimal technical solution and the specific compounded dispersing composition, achieved the best synergistic effect, achieving enhanced interfacial bonding, preventing pigment particle agglomeration, and improving medium penetration resistance in the masterbatch system, thereby overall improving the masterbatch's tinting strength, heat resistance, and water and corrosion resistance.

Claims

1. A high tinting strength masterbatch, characterized by: The raw materials are as follows, by mass: 40-55 parts of carrier resin, 30-40 parts of colorant, 8-15 parts of dispersion composition, 1-2 parts of heat stabilizer, 0.3-0.8 parts of ultraviolet absorber, 1.5-3 parts of coupling agent, 4-8 parts of filler, 1.2-2.5 parts of flow aid, and 0.6-1 part of antibacterial agent; The carrier resin is a modified polyethylene resin, and the preparation method thereof specifically comprises the following steps: S1: adding low-density polyethylene, hydroxyethyl acrylate, tetrafluoropropylene and acrylonitrile to a high-speed mixer, mixing at a speed of 800-850 rpm for 10-15 minutes, then adding benzoyl peroxide and an antioxidant, and continuing mixing for 8-12 minutes to obtain a mixture; S2: adding the mixture to a twin-screw extruder, setting four sections within a temperature range of 170-205°C, and finally extruding at a die head temperature of 200°C, a screw speed of 150-160 rpm, and a residence time of 3-4 minutes; S3: cooling in a water tank after extrusion, pelletizing with a pelletizer, and vacuum drying at 70-75°C for 5-6 hours to obtain the mixture; The dispersion composition is a composition of polyethylene wax, zinc stearate and polypropylene grafted maleic anhydride, with a mass ratio of (5-9): (2-3): (4-6).

2. The high tinting strength masterbatch according to claim 1, characterized in that: The colorant is at least one of phthalocyanine blue, azo condensation red, isoindolinone yellow, carbon black, quinacridone violet and solvent orange.

3. The high tinting strength masterbatch according to claim 2, characterized in that: The mass ratio of the carrier resin, the colorant and the dispersion composition is (42-50): (32-39): (9-14).

4. The high tinting strength masterbatch according to claim 3, characterized in that: The mass ratio of the low-density polyethylene to hydroxyethyl acrylate, tetrafluoropropylene and acrylonitrile is (70-80): (8-12): (6-9): (8-12).

5. The high tinting strength masterbatch according to claim 4, characterized in that: The heat stabilizer is a composition of distearyl thiodipropionate and organic tin, with a mass ratio of (1.3-1.6): (2-2.2).

6. The high tinting strength masterbatch according to claim 5, characterized in that: The ultraviolet absorber is at least one of benzophenones, benzotriazoles and phenyl salicylate.

7. The high tinting strength masterbatch according to claim 6, characterized in that: The coupling agent is at least one of an aluminum-titanium composite coupling agent, a titanate coupling agent, a phosphate coupling agent and a polyester coupling agent.

8. The high tinting strength masterbatch according to claim 7, characterized in that: The filler is a composition of silicon dioxide, hydrotalcite and zirconium phosphate, with a mass ratio of (0.8-1.2): (2-2.5): (0.3-0.5).

9. The high tinting strength masterbatch according to claim 8, characterized in that: The flow aid is at least one of oleamide, oxidized polyethylene wax, glycerol monostearate, ethylene bisstearamide and dimethyl silicone oil; and the antibacterial agent is zinc oxide or quaternary ammonium salt.

10. A method for preparing a high-tinting-strength masterbatch according to any one of claims 1 to 9, characterized in that: The specific steps include: S1: Add the modified carrier resin, colorant and dispersing composition into a high-speed mixer and mix them at a speed of 600-800 rpm and a temperature of 50-55° C. for 15-20 minutes. Then add the remaining raw materials and continue mixing at a speed of 1000-1400 rpm and a temperature of 60-65° C. for 10-15 minutes to obtain a premix; S2: The premix is extruded using a co-rotating twin-screw extruder. The segmented temperature is controlled at 170-175°C in zone 1, 180-185°C in zone 2, 195-200°C in zone 3, 210-215°C in zone 4, 205-210°C in zone 5, and 200-205°C at the die head. The screw speed is 180-220 rpm, and the vacuum degassing pressure is -0.09-0.08 MPa. After extrusion, the material strips are cooled in a water trough and granulated with a pelletizer. After granulation, the granules are treated in a hot air drying oven at 70-75°C for 5-6 hours to ensure that the final moisture content of the granules is ≤0.06%.

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