A high-concentration carbon black PET masterbatch and its preparation method

Abstract

This invention relates to the technical field of PET masterbatch, and particularly to a high-concentration carbon black PET masterbatch and its preparation method. A high-concentration carbon black PET masterbatch comprises the following components by weight: 45-55 parts high-pigment carbon black; 40-50 parts PET carrier resin; 1.5-5.0 parts composite dispersant; 0.3-0.5 parts composite antioxidant; 0.3 parts composite interfacial coupling agent; and 0.5-0.8 parts lubricant. The composite dispersant includes an amino-terminated PET oligomer with a number-average molecular weight of 1000-2000 and an amino value of 20-30 mgKOH / g. This application utilizes the amino-terminated PET oligomer to interact with the active functional groups on the carbon black surface, achieving surface grafting modification of carbon black particles. This forms a molecular chain layer on the carbon black surface with a structure consistent with the matrix resin, fundamentally reducing the interfacial tension between carbon black and the PET matrix, improving the interfacial bonding state between the two phases, and allowing each component to synergistically match the processing and performance requirements of the high-concentration carbon black filling system.

Description

Technical Field

[0001] This invention relates to the technical field of PET masterbatch, and in particular to a high-concentration carbon black PET masterbatch and its preparation method. Background Technology

[0002] With the rapid development of the polyester industry, the application scale of polyester-based plastic products and synthetic fibers in packaging materials, textile industry, engineering products and other fields continues to expand, placing higher demands on the coloring performance and functional stability of polyester materials. Carbon black masterbatch, as a core additive for coloring and functional modification of polyester materials, directly determines the appearance quality, mechanical properties and service durability of the final product due to its concentration, dispersion uniformity and processing stability. High-concentration carbon black masterbatch can significantly reduce the amount of additives added in downstream processing, reduce the impact on the properties of the matrix resin, and simultaneously reduce production and storage costs, becoming a core direction for technological development in the industry.

[0003] Currently, the production and preparation of high-concentration carbon black polyester masterbatch in the industry still faces many insurmountable technical bottlenecks. On the one hand, high-pigment carbon black itself has low surface activity and a large specific surface area, making it extremely prone to forming irreversible agglomerates. Its interfacial compatibility with the polyester matrix is ​​extremely poor. Conventional dispersing agents can only achieve physical coating, and desorption easily occurs during high-temperature processing. This cannot fundamentally solve the dispersion problem of carbon black, resulting in a large number of agglomerates in the finished masterbatch. In downstream applications, this can easily lead to problems such as uneven coloring and large batch-to-batch color differences. In high-requirement scenarios such as spinning, it can also cause production failures such as spinneret blockage and fiber breakage.

[0004] On the other hand, polyester resins are highly susceptible to thermo-oxidative degradation and hydrolysis during high-temperature melt processing, leading to a decrease in the molecular weight and deterioration of the mechanical properties of the matrix resin. The addition of high-concentration carbon black further catalyzes this degradation reaction, making it difficult for existing technologies to simultaneously achieve both strong shear dispersion of carbon black and protection of the polyester matrix's performance. Furthermore, current mixing and cooling processes cannot effectively prevent material stratification and secondary carbon black agglomeration, hindering the continuous, stable, and large-scale production of high-concentration masterbatches. Therefore, developing a high-concentration carbon black polyester masterbatch with high dispersibility, high stability, and excellent processing adaptability, along with its preparation method, has significant industrial value and practical implications. Summary of the Invention

[0005] To overcome the aforementioned deficiencies, this application provides a high-concentration carbon black PET masterbatch and its preparation method.

[0006] A high-concentration carbon black PET masterbatch comprises the following substances in parts by weight:

[0007] 45-55 parts of high-pigment carbon black; 40-50 parts of PET carrier resin; 1.5-5.0 parts of composite dispersant; 0.3-0.5 parts of compound antioxidant; 0.3 parts of composite interface coupling agent; Lubricant 0.5-0.8 parts; The composite dispersant includes amino-terminated PET oligomers, wherein the number average molecular weight of the amino-terminated PET oligomers is 1000-2000 and the amino value is 20-30 mgKOH / g.

[0008] Through the above technical solutions, this application clarifies the basic component composition of high-concentration carbon black PET masterbatch and defines the positioning and function logic of each functional component in the system from a technical perspective. High-pigment carbon black, as the core coloring functional component of the system, provides coloring power and hiding properties for the finished product. PET carrier resin, as the continuous phase matrix, provides dispersion and support space for carbon black particles, while ensuring the compatibility of the masterbatch with the matrix of downstream polyester products. The composite dispersant is the core functional component of the system. The amino-terminated PET oligomer within it can interact with the active functional groups on the carbon black surface to achieve surface grafting modification of the carbon black particles, forming a molecular chain layer on the carbon black surface with a structure consistent with the matrix resin. This fundamentally reduces the interfacial tension between carbon black and the PET matrix, improving the interfacial bonding state between the two phases. The composite antioxidant, composite interfacial coupling agent, and lubricant respectively undertake the functions of thermo-oxidative stabilization, interfacial reinforcement, and processing rheology regulation of the system. Each component synergistically matches the processing and performance requirements of the high-concentration carbon black-filled system.

[0009] Furthermore, the composite dispersant also includes carboxyl-terminated hyperbranched polyester and oxidatively modified EVA wax, wherein the mass ratio of the carboxyl-terminated hyperbranched polyester, the oxidatively modified EVA wax and the amino-terminated PET oligomer is (1.2-1.5):(0.1-0.3):(1.0-1.2).

[0010] Through the above technical solutions, this application clarifies the path to achieve the dispersion function within the system. Terminal carboxyl-terminated hyperbranched polyester possesses multiple terminal functional groups and a three-dimensional spherical molecular structure, allowing it to anchor onto the surface of carbon black particles through multi-point adsorption, forming a thick adsorption layer around the particles. This steric hindrance effect prevents carbon black particles from approaching each other and agglomerating. Oxidized modified EVA wax has excellent lubrication and penetration properties, allowing it to penetrate into the gaps between primary carbon black agglomerates, reducing internal friction between particles and achieving depolymerization of the agglomerates in conjunction with shearing action. Amino-terminated PET oligomers can form an interfacial compatibility layer between the carbon black and the matrix, achieving good compatibility between the modified carbon black and the PET matrix. These three components, through proportioning and matching, form a synergistic effect, achieving stable dispersion of carbon black in the PET matrix from three dimensions: agglomerate depolymerization, particle anchoring, and interfacial compatibility, thus meeting the dispersion requirements of high-concentration carbon black systems.

[0011] Furthermore, the composite interface coupling agent comprises the following substances in parts by weight: 0.15-0.20 parts of epoxy silane coupling agent; 0.1-0.2 parts of monoalkoxy titanate coupling agent; 0-0.8 parts of maleic anhydride-grafted PET.

[0012] Through the above technical solutions, this application clarifies the method for controlling the interfacial properties within the system. The active functional groups of the epoxy silane coupling agent can chemically bond with the polar functional groups on the carbon black surface, and the molecular chains at the other end can form molecular entanglements with the PET matrix, building a molecular-scale interfacial bridge structure between the carbon black and the PET matrix, strengthening the bonding force at the interface between the two phases, and preventing interfacial phase separation. The monoalkoxy titanate coupling agent can interact with the active sites on the carbon black surface, reducing the surface energy and oil absorption value of the carbon black particles, weakening the van der Waals forces between carbon black particles, and inhibiting the formation of soft agglomerates of carbon black. Maleic anhydride grafted onto PET can further improve the compatibility between the filler system and the matrix resin, adjust the melt rheological properties of the system, and improve the stability of the carbon black dispersion state in the matrix, forming a functional complement to the first two types of coupling agents. Furthermore, the composite antioxidant comprises the following substances in parts by weight: 1-5 parts of hindered phenolic primary antioxidant; Phosphite-based antioxidant cofactors: 1-5 parts; 1.5 parts of benzofuranone carbon radical scavenger.

[0013] Through the above technical solutions, this application clarifies the technical path for inhibiting thermo-oxidative degradation within the system. Hindered phenolic primary antioxidants can react with peroxide free radicals within the system to generate stable compounds, terminating the chain reaction of polymer oxidative degradation and achieving long-term thermo-oxidative protection of the PET matrix. Phosphite secondary antioxidants can react with hydroperoxides generated within the system, decomposing unstable hydroperoxides into stable alcohol compounds, blocking the continuous transmission of the oxidation chain reaction, and forming a synergistic effect with the hindered phenolic primary antioxidants to improve antioxidant protection efficiency. Benzofuranone carbon free radical scavengers can rapidly capture carbon free radicals generated within the system in the early stages of polymer melting, blocking the degradation process from the initial stage of the oxidation reaction, precisely inhibiting the rapid degradation behavior of PET in the early stages of high-temperature melting processing. The three types of components work together to achieve degradation protection throughout the entire processing cycle.

[0014] Furthermore, the hindered phenolic primary antioxidant includes any one of antioxidant 1010, antioxidant 1076, and antioxidant 3114; the phosphite secondary antioxidant includes at least one of antioxidant 168, antioxidant 626, and antioxidant P-EPQ; and the benzofuranone carbon radical scavenger includes at least one of antioxidant HP-136 or antioxidant 1790.

[0015] Through the above technical solutions, this application refines the technical compatibility between the antioxidant system and the PET processing system. The listed hindered phenolic primary antioxidants all possess good thermal stability and compatibility with the PET matrix. They do not volatilize or decompose during the high-temperature melt processing of PET, and can stably exert their free radical scavenging effect without migrating into downstream products, making them suitable for the processing and use scenarios of polyester products. The listed phosphite secondary antioxidants all possess excellent hydrolysis resistance and high-temperature stability, remaining stable in the high-temperature and high-humidity environment of PET processing without hydrolytic failure, and continuously exerting their hydroperoxide decomposition effect. The listed benzofuranone carbon free radical scavengers possess extremely high free radical scavenging efficiency and high-temperature activity, and can quickly exert their effect during the short-time high-temperature melting process of twin-screw extrusion, precisely matching the melt processing characteristics of PET and achieving degradation inhibition in the early stages of processing.

[0016] Secondly, this application provides a method for preparing high-concentration carbon black PET masterbatch, employing the following technical solution: A method for preparing high-concentration carbon black PET masterbatch includes the following preparation steps: S1. Raw material pretreatment: After preparing the raw materials according to the mass proportions and drying and activating them, the materials are gradient mixed and pre-dispersed, and the pre-dispersed mixture is collected. S2. Twin-screw melt extrusion compounding: The pre-dispersed mixture is fed into the twin-screw extruder through a closed weight loss feeder. After segmented temperature control, two-stage high shear compounding, and two-stage vacuum devolatilization, it is extruded through a melt pressure stabilizing pump and a multi-stage filtration mechanism to obtain uniform strips. S3. Gradient cooling and drying: The strip is subjected to three-stage gradient cooling and then the surface moisture is dried by air knife. S4. Pelletizing, drying and screening: The dried strips are pelletized, then vacuum dried and screened by step heating to obtain semi-finished color masterbatch. S5. Testing and Vacuum Packaging: The filtration performance of the semi-finished product is tested. After passing the test, the product is cooled in a nitrogen atmosphere and vacuum-packed with nitrogen to obtain the high-concentration masterbatch finished product.

[0017] Through the above technical solutions, this application clarifies the entire process path for preparing high-concentration carbon black PET masterbatch, defining the functional positioning and connection logic of each process from a technical perspective. The raw material pretreatment process removes adsorbed moisture from the raw materials, preventing hydrolytic degradation of PET during subsequent high-temperature processing, and simultaneously activates the carbon black surface, providing a foundation for the subsequent dispersion process. The twin-screw melt extrusion and mixing process matches the melting behavior of PET through segmented temperature control, achieving deep deagglomeration and uniform dispersion of carbon black agglomerates through strong shearing, removing small molecule volatiles and residual moisture through two-stage vacuum devolatilization, and stabilizing the melt flow state and removing impurities through melt pressure stabilization and filtration, ensuring the uniformity of the extruded strips. Subsequent gradient cooling, pelletizing, drying, sieving, and packaging processes sequentially complete the shaping, granulation, performance stabilization, and storage protection of the strips. The entire process is seamlessly connected, ensuring the dispersion performance and quality stability of the finished masterbatch.

[0018] Furthermore, the gradient mixing pre-dispersion treatment includes the following steps: The dried high-pigment carbon black and composite interface coupling agent were added to a high-speed mixer and stirred at 1000 r / min for 2 min. The temperature was then raised to 105℃ to complete the pre-activation of the carbon black surface. Add PET carrier resin and continue high-speed stirring at 1000 rpm for 6 minutes until the material temperature reaches 120°C. Add composite dispersant, composite antioxidant and lubricant, and continue mixing for 2 minutes until the material temperature reaches 145°C and the material is uniformly sandy. Seal and discharge the high-speed mixed material into a low-speed mixer, maintain a slight positive pressure of nitrogen at 0.02-0.05 MPa, control the material temperature at 150-155°C, and stir at 300 rpm for 5-8 minutes.

[0019] Through the above technical solution, this application refines the specific operational steps of the gradient mixing pre-dispersion process at the technical level, clarifying the technical implementation logic of the pre-dispersion process. First, high-pigment carbon black and a composite interface coupling agent are stirred at high speed. Under shear action, the coupling agent molecules can fully contact and adsorb onto the surface of the carbon black particles, achieving pre-activation of the carbon black surface and laying the foundation for subsequent surface modification and dispersion. After adding PET carrier resin, high-speed stirring continues, achieving preliminary uniform mixing of carbon black and carrier resin. Simultaneously, the frictional heating caused by stirring and shearing reaches the optimal operating temperature of the additives. At this point, the composite dispersant, composite antioxidant, and lubricant are added, allowing each functional additive to disperse uniformly and exert its function at the optimal temperature, completing the pre-depolymerization and surface modification of the carbon black agglomerates. Subsequent low-speed, constant-temperature, and pressure mixing can maintain the material temperature while preventing material stratification, isolating oxygen and moisture, ensuring the uniformity and stability of the pre-dispersion mixture, and providing a stable raw material for the subsequent extrusion process.

[0020] Furthermore, the three-stage gradient cooling includes the following steps: First, cool the material strip at a water temperature of 60-70℃ and adjust the water passage length to 35cm; then cool it at a water temperature of 40-50℃ and adjust the water passage length to 40cm; finally, cool it at a water temperature of 25-30℃ and adjust the water passage length to 40cm; after cooling, use an air knife with an air pressure of 0.3-0.5MPa to dry the surface moisture of the material strip.

[0021] Through the above technical solution, this application refines the specific operation steps of the three-stage gradient cooling process at the technical level, clarifying the technical control logic of the strip cooling and shaping process. High-temperature cooling allows the freshly extruded molten strip to cool slowly, avoiding excessive internal stress and increased brittleness caused by conventional rapid cooling processes, thus preventing brittle fracture. It also controls the initial crystallization rate of the PET matrix, preventing excessively rapid crystallization that could repel carbon black particles to the grain boundary region and prevent secondary agglomeration of carbon black. Medium-temperature cooling allows the PET matrix to enter a uniform crystallization stage, controlling the crystallinity of the matrix within a suitable range to ensure a balance between the hardness and toughness of the strip, while maintaining the uniform dispersion of carbon black in the matrix and preventing damage to the dispersed structure during crystallization. Low-temperature cooling finally cools the strip to a suitable temperature range for pelletizing, ensuring stable pelletizing. Subsequent air knife drying thoroughly removes moisture from the strip surface, preventing residual moisture from causing hydrolysis of PET in subsequent processes, while also ensuring the stability of strip conveying during pelletizing.

[0022] In summary, this application has the following beneficial effects: First, this application enables the uniform and stable dispersion of high-pigment carbon black in a polyester matrix, significantly improving the coloring performance and application stability of masterbatches. Through the synergistic effect of the composite dispersion system and the interfacial coupling system, in-situ surface modification of carbon black particles can be achieved, forming a compatible layer on the carbon black surface that matches the structure of the matrix resin. This fundamentally reduces the interfacial tension between carbon black and the polyester matrix, eliminating phase separation problems at the two-phase interface. Simultaneously, it efficiently breaks down primary carbon black agglomerates and inhibits secondary agglomeration of carbon black particles through steric hindrance, allowing carbon black to be uniformly dispersed in the continuous polyester phase at the nanoscale. This effect significantly improves the coloring power and hiding power of the masterbatch, avoiding uneven coloring and batch-to-batch color differences in the finished product. In downstream applications, carbon black agglomerates will not cause clogging of processing equipment, ensuring the consistency of appearance quality and performance of downstream products, and adapting to various high-requirement polyester coloring applications.

[0023] Secondly, this application can protect the performance of the polyester matrix and stabilize the processing rheological properties of the system throughout the entire high-temperature processing. Through a multi-component synergistic composite antioxidant system, degradation inhibition can be achieved from the initial stage of the oxidation reaction to the entire chain transfer process, effectively blocking the thermo-oxidative degradation and hydrolysis reactions of polyester resin during high-temperature melting, and solving the problem of accelerated polyester degradation caused by high-concentration carbon black. Combined with a process design that isolates moisture and oxygen throughout the entire process, it can prevent the polyester molecular chains from breaking, maximizing the preservation of the inherent molecular weight and properties of the polyester matrix, and stabilizing the melt viscosity and flow characteristics of the system. This effect ensures the stability of the melt extrusion process, avoids melt pressure fluctuations and melt fracture problems, and allows the finished masterbatch to maintain stable processing performance, preventing the mechanical properties and long-term durability of downstream products from being affected by matrix performance degradation.

[0024] Third, this application enables continuous and stable production of high-concentration masterbatches, improving batch consistency and downstream process adaptability. Through a gradient mixing and pre-dispersion process, uniform mixing and pre-dispersion of each component can be achieved, avoiding material stratification caused by differences in raw material specific gravity, and providing a uniform and stable raw material base for subsequent melt dispersion. Combined with a gradient cooling process, the crystallization rate and crystallinity of the polyester matrix can be precisely controlled, avoiding uneven internal stress and brittle fracture problems caused by rapid cooling, while preventing carbon black aggregation during crystallization and maintaining the stability of the dispersed structure. The synergistic matching of the entire process enables continuous and stable operation of the production process, resulting in uniform particle size, stable performance, and excellent batch-to-batch consistency. It is adaptable to various downstream polyester processing technologies, has a wide processing window, and can achieve stable application without additional adjustments to downstream production parameters. Detailed Implementation

[0025] The present application will be further described in detail below with reference to the embodiments.

[0026] The raw materials and instruments used in this embodiment are shown below, but are not limited thereto. Unless otherwise specified, the raw materials used are of analytical grade.

[0027] High-pigment carbon black: C611 high-pigment carbon black; Carboxyl-terminated hyperbranched polyester: Wuhan Hyperbranched Resin Technology Co., Ltd.; PET carrier resin: Huaxiyue PET polyester chips JH604; Preparation Example 1 Maleic anhydride-grafted PET: Take 100kg PET, 1.5kg maleic anhydride, 0.08kg dicumyl peroxide and 0.001kg antioxidant 1010, stir and mix them and melt-shear them. Adjust the temperature of the twin-screw extruder to 260℃ in zone 1, 270℃ in zone 2, 280℃ in zone 3 and 280℃ in zone 4 and the screw speed to 200rpm. After extrusion and granulation, vacuum drying can be used to prepare maleic anhydride-grafted PET.

[0028] Preparation Example 2 Composite interface coupling agent 1 0.15 kg of epoxy silane coupling agent KH560 and 0.1 kg of monoalkoxy titanate coupling agent NDZ-101 were mixed to prepare composite interface coupling agent 1.

[0029] Preparation Example 3 Composite interface coupling agent 2 0.17 kg of epoxy silane coupling agent KH560, 0.15 kg of monoalkoxy titanate coupling agent NDZ-101 and 0.4 kg of maleic anhydride-grafted PET were mixed to prepare composite interface coupling agent 2.

[0030] Preparation Example 4 Composite interface coupling agent 3 0.20 kg of epoxy silane coupling agent KH560, 0.2 kg of monoalkoxy titanate coupling agent NDZ-101 and 0.8 kg of maleic anhydride-grafted PET were mixed to prepare composite interface coupling agent 3.

[0031] Preparation Example 5 Compound antioxidant 1 Take 1 kg of antioxidant 1010, 5 kg of antioxidant 168 and 1.5 kg of antioxidant 1790 and stir them together to prepare composite antioxidant 1.

[0032] Preparation Example 6 Compound antioxidant 2 Take 2 kg of antioxidant 1010, 3 kg of antioxidant 168 and 1.5 kg of antioxidant 1790 and stir them together to prepare composite antioxidant 2.

[0033] Preparation Example 7 Compound antioxidant 3 Take 5 kg of antioxidant 1010, 1 kg of antioxidant 168 and 1.5 kg of antioxidant 1790 and stir them together to prepare composite antioxidant 3.

[0034] Preparation Example 8 Composite dispersant 1: Amino-terminated PET oligomers with a number average molecular weight of 1000-2000 and an amino value of 20-30 mg KOH / g. Take 1000g PTA, 365g EG, 0.4g antimony glycolate, and 0.25g TPP. Perform esterification at 240℃ and 0.25MPa. After the water output reaches the standard, release the pressure. Perform polycondensation at 265℃ and 3000Pa for 30min. Collect the oligomer. Take 1000g of the above oligomer and add 34g of 1,6-hexanediamine. React at 205℃ under nitrogen atmosphere for 70min. Perform high vacuum devolatilization for 30min. Dry the discharged material to prepare composite dispersant 1.

[0035] Preparation Example 9 Composite Dispersant 2 Take 1.2 kg of carboxyl-terminated hyperbranched polyester, 0.1 kg of oxidized modified EVA wax and 1.0 kg of composite dispersant 1, stir and mix them to prepare composite dispersant 2.

[0036] Preparation Example 10 Composite dispersant 3 Take 1.3 kg of carboxyl-terminated hyperbranched polyester, 0.2 kg of oxidized modified EVA wax and 1.1 kg of composite dispersant 1, stir and mix them to prepare composite dispersant 3.

[0037] Preparation Example 11 Composite dispersant 4 Take 1.5 kg of carboxyl-terminated hyperbranched polyester, 0.3 kg of oxidized modified EVA wax and 1.2 kg of composite dispersant 1, stir and mix them to prepare composite dispersant 4.

[0038] Example 1 A high-concentration carbon black PET masterbatch comprises the following substances: 45kg high-pigment carbon black, 40kg PET carrier resin, 1.5kg composite dispersant, 0.3kg composite antioxidant, 0.3kg composite interfacial coupling agent, 0.5kg lubricant pentaerythritol stearate; A method for preparing high-concentration carbon black PET masterbatch includes the following preparation steps: S1 Raw Material Pretreatment: Weigh each component according to the formula. Vacuum dry the high-pigment carbon black at 100℃ for 2 hours, and vacuum dry the PET carrier resin at 120℃ for 4 hours until the moisture content is ≤30ppm. Seal and preheat the remaining additives to room temperature. Then perform gradient mixing and pre-dispersion: Add the dried high-pigment carbon black and composite interface coupling agent to a high-speed mixer and stir at 1000r / min for 2 minutes. Raise the temperature to 105℃ to complete the pre-activation of the carbon black surface. Add the PET carrier resin and continue stirring at 1000r / min for 6 minutes until the material temperature reaches 120℃. Add the composite dispersant, composite antioxidant, and lubricant and continue mixing for 2 minutes until the material temperature reaches 145℃. The material is uniformly sandy. Seal and discharge the material into a low-speed mixer, maintain a slight positive pressure of nitrogen (0.03MPa), control the material temperature at 150-155℃, and stir at 300r / min for 6 minutes to obtain the pre-dispersion mixture. S2 Twin-Screw Melt Extrusion Mixing: The pre-dispersed mixture is fed into the twin-screw extruder through a closed, weightless feeder at a rate of 150 kg / h and a main extruder speed of 280 rpm. The barrel temperature control in 11 zones is as follows: Zone 1 190℃, Zone 2 280℃, Zone 3 290℃, Zone 4 290℃, Zone 5 280℃, Zone 6 270℃, Zone 7 250℃, Zone 8 210℃, Zone 9 210℃, Zone 10 210℃, and Zone 11 210℃, with a die head temperature of 250℃. After two-stage high-shear mixing and two-stage vacuum devolatilization, the melt pressure is stabilized by a melt pressure stabilizing pump, and after multi-stage filtration, uniform strips are extruded. S3 Gradient Cooling and Drying: The strip undergoes three-stage gradient cooling: first, water cooling at 65℃ with a water flow length of 35cm; then, water cooling at 45℃ with a water flow length of 40cm; and finally, water cooling at 28℃ with a water flow length of 40cm. After cooling, the surface moisture is dried using an air knife with a wind pressure of 0.4MPa. S4 pelletizing, drying and screening: The material strips are fed into the pelletizer and pelletized at a speed of 100 r / min. After pelletizing, the pellets are pre-crystallized at 120℃ for 1 h, vacuum dried at 145℃ for 2.5 h, and then screened by 20 mesh / 60 mesh ultrasonic sieve to obtain the color masterbatch semi-finished product. S5 Testing and Vacuum Packaging: After the semi-finished product passes the filtration performance test, it is cooled to below 50°C in a nitrogen atmosphere, then vacuum-packed with nitrogen to obtain the finished product.

[0039] Example 2 A high-concentration carbon black PET masterbatch comprises the following substances: 50kg high-pigment carbon black, 45kg PET carrier resin, 3.5kg composite dispersant, 0.4kg composite antioxidant, 0.3kg composite interfacial coupling agent, 0.6kg lubricant pentaerythritol stearate; A method for preparing high-concentration carbon black PET masterbatch includes the following preparation steps: S1 Raw Material Pretreatment: Weigh each component according to the formula. Vacuum dry the high-pigment carbon black at 100℃ for 2 hours, and vacuum dry the PET carrier resin at 120℃ for 4 hours until the moisture content is ≤30ppm. Seal and preheat the remaining additives to room temperature. Then perform gradient mixing and pre-dispersion: Add the dried high-pigment carbon black and composite interface coupling agent to a high-speed mixer and stir at 1000r / min for 2 minutes. Raise the temperature to 105℃ to complete the pre-activation of the carbon black surface. Add the PET carrier resin and continue stirring at 1000r / min for 6 minutes until the material temperature reaches 120℃. Add the composite dispersant, composite antioxidant, and lubricant and continue mixing for 2 minutes until the material temperature reaches 145℃. The material is uniformly sandy. Seal and discharge the material into a low-speed mixer, maintain a slight positive pressure of nitrogen (0.03MPa), control the material temperature at 150-155℃, and stir at 300r / min for 6 minutes to obtain the pre-dispersion mixture. S2 Twin-Screw Melt Extrusion Mixing: The pre-dispersed mixture is fed into the twin-screw extruder through a closed, weightless feeder at a rate of 150 kg / h and a main extruder speed of 280 rpm. The barrel temperature control in 11 zones is as follows: Zone 1 190℃, Zone 2 280℃, Zone 3 290℃, Zone 4 290℃, Zone 5 280℃, Zone 6 270℃, Zone 7 250℃, Zone 8 210℃, Zone 9 210℃, Zone 10 210℃, and Zone 11 210℃, with a die head temperature of 250℃. After two-stage high-shear mixing and two-stage vacuum devolatilization, the melt pressure is stabilized by a melt pressure stabilizing pump, and after multi-stage filtration, uniform strips are extruded. S3 Gradient Cooling and Drying: The strip undergoes three-stage gradient cooling: first, water cooling at 65℃ with a water flow length of 35cm; then, water cooling at 45℃ with a water flow length of 40cm; and finally, water cooling at 28℃ with a water flow length of 40cm. After cooling, the surface moisture is dried using an air knife with a wind pressure of 0.4MPa. S4 pelletizing, drying and screening: The material strips are fed into the pelletizer and pelletized at a speed of 100 r / min. After pelletizing, the pellets are pre-crystallized at 120℃ for 1 h, vacuum dried at 145℃ for 2.5 h, and then screened by 20 mesh / 60 mesh ultrasonic sieve to obtain the color masterbatch semi-finished product. S5 Testing and Vacuum Packaging: After the semi-finished product passes the filtration performance test, it is cooled to below 50°C in a nitrogen atmosphere, then vacuum-packed with nitrogen to obtain the finished product.

[0040] Example 3 A high-concentration carbon black PET masterbatch comprises the following substances: 55kg high-pigment carbon black, 50kg PET carrier resin, 5.0kg composite dispersant, 0.5kg composite antioxidant, 0.3kg composite interfacial coupling agent, 0.8kg lubricant pentaerythritol stearate; A method for preparing high-concentration carbon black PET masterbatch includes the following preparation steps: S1 Raw Material Pretreatment: Weigh each component according to the formula. Vacuum dry the high-pigment carbon black at 100℃ for 2 hours, and vacuum dry the PET carrier resin at 120℃ for 4 hours until the moisture content is ≤30ppm. Seal and preheat the remaining additives to room temperature. Then perform gradient mixing and pre-dispersion: Add the dried high-pigment carbon black and composite interface coupling agent to a high-speed mixer and stir at 1000r / min for 2 minutes. Raise the temperature to 105℃ to complete the pre-activation of the carbon black surface. Add the PET carrier resin and continue stirring at 1000r / min for 6 minutes until the material temperature reaches 120℃. Add the composite dispersant, composite antioxidant, and lubricant and continue mixing for 2 minutes until the material temperature reaches 145℃. The material is uniformly sandy. Seal and discharge the material into a low-speed mixer, maintain a slight positive pressure of nitrogen (0.03MPa), control the material temperature at 150-155℃, and stir at 300r / min for 6 minutes to obtain the pre-dispersion mixture. S2 Twin-Screw Melt Extrusion Mixing: The pre-dispersed mixture is fed into the twin-screw extruder through a closed, weightless feeder at a rate of 150 kg / h and a main extruder speed of 280 rpm. The barrel temperature control in 11 zones is as follows: Zone 1 190℃, Zone 2 280℃, Zone 3 290℃, Zone 4 290℃, Zone 5 280℃, Zone 6 270℃, Zone 7 250℃, Zone 8 210℃, Zone 9 210℃, Zone 10 210℃, and Zone 11 210℃, with a die head temperature of 250℃. After two-stage high-shear mixing and two-stage vacuum devolatilization, the melt pressure is stabilized by a melt pressure stabilizing pump, and after multi-stage filtration, uniform strips are extruded. S3 Gradient Cooling and Drying: The strip undergoes three-stage gradient cooling: first, water cooling at 65℃ with a water flow length of 35cm; then, water cooling at 45℃ with a water flow length of 40cm; and finally, water cooling at 28℃ with a water flow length of 40cm. After cooling, the surface moisture is dried using an air knife with a wind pressure of 0.4MPa. S4 pelletizing, drying and screening: The material strips are fed into the pelletizer and pelletized at a speed of 100 r / min. After pelletizing, the pellets are pre-crystallized at 120℃ for 1 h, vacuum dried at 145℃ for 2.5 h, and then screened by 20 mesh / 60 mesh ultrasonic sieve to obtain the color masterbatch semi-finished product. S5 Testing and Vacuum Packaging: After the semi-finished product passes the filtration performance test, it is cooled to below 50°C in a nitrogen atmosphere, then vacuum-packed with nitrogen to obtain the finished product.

[0041] Example 4 A high-concentration carbon black PET masterbatch comprises the following substances: 50kg high-pigment carbon black, 45kg PET carrier resin, 3.5kg composite dispersant 1, 0.4kg composite antioxidant 2, 0.3kg composite interfacial coupling agent 2, 0.6kg lubricant pentaerythritol stearate; A method for preparing high-concentration carbon black PET masterbatch includes the following preparation steps: S1 Raw Material Pretreatment: Weigh each component according to the formula. Vacuum dry the high-pigment carbon black at 100℃ for 2 hours, and vacuum dry the PET carrier resin at 120℃ for 4 hours until the moisture content is ≤30ppm. Seal and preheat the remaining additives to room temperature. Then perform gradient mixing and pre-dispersion: Add the dried high-pigment carbon black and composite interface coupling agent to a high-speed mixer and stir at 1000r / min for 2 minutes. Raise the temperature to 105℃ to complete the pre-activation of the carbon black surface. Add the PET carrier resin and continue stirring at 1000r / min for 6 minutes until the material temperature reaches 120℃. Add the composite dispersant, composite antioxidant, and lubricant and continue mixing for 2 minutes until the material temperature reaches 145℃. The material is uniformly sandy. Seal and discharge the material into a low-speed mixer, maintain a slight positive pressure of nitrogen (0.03MPa), control the material temperature at 150-155℃, and stir at 300r / min for 6 minutes to obtain the pre-dispersion mixture. S2 Twin-Screw Melt Extrusion Mixing: The pre-dispersed mixture is fed into the twin-screw extruder through a closed, weightless feeder at a rate of 150 kg / h and a main extruder speed of 280 rpm. The barrel temperature control in 11 zones is as follows: Zone 1 190℃, Zone 2 280℃, Zone 3 290℃, Zone 4 290℃, Zone 5 280℃, Zone 6 270℃, Zone 7 250℃, Zone 8 210℃, Zone 9 210℃, Zone 10 210℃, and Zone 11 210℃, with a die head temperature of 250℃. After two-stage high-shear mixing and two-stage vacuum devolatilization, the melt pressure is stabilized by a melt pressure stabilizing pump, and after multi-stage filtration, uniform strips are extruded. S3 Gradient Cooling and Drying: The strip undergoes three-stage gradient cooling: first, water cooling at 65℃ with a water flow length of 35cm; then, water cooling at 45℃ with a water flow length of 40cm; and finally, water cooling at 28℃ with a water flow length of 40cm. After cooling, the surface moisture is dried using an air knife with a wind pressure of 0.4MPa. S4 pelletizing, drying and screening: The material strips are fed into the pelletizer and pelletized at a speed of 100 r / min. After pelletizing, the pellets are pre-crystallized at 120℃ for 1 h, vacuum dried at 145℃ for 2.5 h, and then screened by 20 mesh / 60 mesh ultrasonic sieve to obtain the color masterbatch semi-finished product. S5 Testing and Vacuum Packaging: After the semi-finished product passes the filtration performance test, it is cooled to below 50°C in a nitrogen atmosphere, then vacuum-packed with nitrogen to obtain the finished product.

[0042] Example 5 A high-concentration carbon black PET masterbatch comprises the following substances: 50kg high-pigment carbon black, 45kg PET carrier resin, 3.5kg composite dispersant 1, 0.4kg composite antioxidant 3, 0.3kg composite interfacial coupling agent 3, 0.6kg lubricant pentaerythritol stearate; A method for preparing high-concentration carbon black PET masterbatch includes the following preparation steps: S1 Raw Material Pretreatment: Weigh each component according to the formula. Vacuum dry the high-pigment carbon black at 100℃ for 2 hours, and vacuum dry the PET carrier resin at 120℃ for 4 hours until the moisture content is ≤30ppm. Seal and preheat the remaining additives to room temperature. Then perform gradient mixing and pre-dispersion: Add the dried high-pigment carbon black and composite interface coupling agent to a high-speed mixer and stir at 1000r / min for 2 minutes. Raise the temperature to 105℃ to complete the pre-activation of the carbon black surface. Add the PET carrier resin and continue stirring at 1000r / min for 6 minutes until the material temperature reaches 120℃. Add the composite dispersant, composite antioxidant, and lubricant and continue mixing for 2 minutes until the material temperature reaches 145℃. The material is uniformly sandy. Seal and discharge the material into a low-speed mixer, maintain a slight positive pressure of nitrogen (0.03MPa), control the material temperature at 150-155℃, and stir at 300r / min for 6 minutes to obtain the pre-dispersion mixture. S2 Twin-Screw Melt Extrusion Mixing: The pre-dispersed mixture is fed into the twin-screw extruder through a closed, weightless feeder at a rate of 150 kg / h and a main extruder speed of 280 rpm. The barrel temperature control in 11 zones is as follows: Zone 1 190℃, Zone 2 280℃, Zone 3 290℃, Zone 4 290℃, Zone 5 280℃, Zone 6 270℃, Zone 7 250℃, Zone 8 210℃, Zone 9 210℃, Zone 10 210℃, and Zone 11 210℃, with a die head temperature of 250℃. After two-stage high-shear mixing and two-stage vacuum devolatilization, the melt pressure is stabilized by a melt pressure stabilizing pump, and after multi-stage filtration, uniform strips are extruded. S3 Gradient Cooling and Drying: The strip undergoes three-stage gradient cooling: first, water cooling at 65℃ with a water flow length of 35cm; then, water cooling at 45℃ with a water flow length of 40cm; and finally, water cooling at 28℃ with a water flow length of 40cm. After cooling, the surface moisture is dried using an air knife with a wind pressure of 0.4MPa. S4 pelletizing, drying and screening: The material strips are fed into the pelletizer and pelletized at a speed of 100 r / min. After pelletizing, the pellets are pre-crystallized at 120℃ for 1 h, vacuum dried at 145℃ for 2.5 h, and then screened by 20 mesh / 60 mesh ultrasonic sieve to obtain the color masterbatch semi-finished product. S5 Testing and Vacuum Packaging: After the semi-finished product passes the filtration performance test, it is cooled to below 50°C in a nitrogen atmosphere, then vacuum-packed with nitrogen to obtain the finished product.

[0043] Example 6 A high-concentration carbon black PET masterbatch comprises the following substances: 50kg high-pigment carbon black, 45kg PET carrier resin, 3.5kg composite dispersant 2, 0.4kg composite antioxidant 2, 0.3kg composite interface coupling agent 2, 0.6kg lubricant pentaerythritol stearate; A method for preparing high-concentration carbon black PET masterbatch includes the following preparation steps: S1 Raw Material Pretreatment: Weigh each component according to the formula. Vacuum dry the high-pigment carbon black at 100℃ for 2 hours, and vacuum dry the PET carrier resin at 120℃ for 4 hours until the moisture content is ≤30ppm. Seal and preheat the remaining additives to room temperature. Then perform gradient mixing and pre-dispersion: Add the dried high-pigment carbon black and composite interface coupling agent to a high-speed mixer and stir at 1000r / min for 2 minutes. Raise the temperature to 105℃ to complete the pre-activation of the carbon black surface. Add the PET carrier resin and continue stirring at 1000r / min for 6 minutes until the material temperature reaches 120℃. Add the composite dispersant, composite antioxidant, and lubricant and continue mixing for 2 minutes until the material temperature reaches 145℃. The material is uniformly sandy. Seal and discharge the material into a low-speed mixer, maintain a slight positive pressure of nitrogen (0.03MPa), control the material temperature at 150-155℃, and stir at 300r / min for 6 minutes to obtain the pre-dispersion mixture. S2 Twin-Screw Melt Extrusion Mixing: The pre-dispersed mixture is fed into the twin-screw extruder through a closed, weightless feeder at a rate of 150 kg / h and a main extruder speed of 280 rpm. The barrel temperature control in 11 zones is as follows: Zone 1 190℃, Zone 2 280℃, Zone 3 290℃, Zone 4 290℃, Zone 5 280℃, Zone 6 270℃, Zone 7 250℃, Zone 8 210℃, Zone 9 210℃, Zone 10 210℃, and Zone 11 210℃, with a die head temperature of 250℃. After two-stage high-shear mixing and two-stage vacuum devolatilization, the melt pressure is stabilized by a melt pressure stabilizing pump, and after multi-stage filtration, uniform strips are extruded. S3 Gradient Cooling and Drying: The strip undergoes three-stage gradient cooling: first, water cooling at 65℃ with a water flow length of 35cm; then, water cooling at 45℃ with a water flow length of 40cm; and finally, water cooling at 28℃ with a water flow length of 40cm. After cooling, the surface moisture is dried using an air knife with a wind pressure of 0.4MPa. S4 pelletizing, drying and screening: The material strips are fed into the pelletizer and pelletized at a speed of 100 r / min. After pelletizing, the pellets are pre-crystallized at 120℃ for 1 h, vacuum dried at 145℃ for 2.5 h, and then screened by 20 mesh / 60 mesh ultrasonic sieve to obtain the color masterbatch semi-finished product. S5 Testing and Vacuum Packaging: After the semi-finished product passes the filtration performance test, it is cooled to below 50°C in a nitrogen atmosphere, then vacuum-packed with nitrogen to obtain the finished product.

[0044] Example 7 A high-concentration carbon black PET masterbatch comprises the following substances: 50kg high-pigment carbon black, 45kg PET carrier resin, 3.5kg composite dispersant, 0.4kg composite antioxidant, 0.3kg composite interfacial coupling agent, and 0.6kg pentaerythritol stearate lubricant; A method for preparing high-concentration carbon black PET masterbatch includes the following preparation steps: S1 Raw Material Pretreatment: Weigh each component according to the formula. Vacuum dry the high-pigment carbon black at 100℃ for 2 hours, and vacuum dry the PET carrier resin at 120℃ for 4 hours until the moisture content is ≤30ppm. Seal and preheat the remaining additives to room temperature. Then perform gradient mixing and pre-dispersion: Add the dried high-pigment carbon black and composite interface coupling agent to a high-speed mixer and stir at 1000r / min for 2 minutes. Raise the temperature to 105℃ to complete the pre-activation of the carbon black surface. Add the PET carrier resin and continue stirring at 1000r / min for 6 minutes until the material temperature reaches 120℃. Add the composite dispersant, composite antioxidant, and lubricant and continue mixing for 2 minutes until the material temperature reaches 145℃. The material is uniformly sandy. Seal and discharge the material into a low-speed mixer, maintain a slight positive pressure of nitrogen (0.03MPa), control the material temperature at 150-155℃, and stir at 300r / min for 6 minutes to obtain the pre-dispersion mixture. S2 Twin-Screw Melt Extrusion Mixing: The pre-dispersed mixture is fed into the twin-screw extruder through a closed, weightless feeder at a rate of 150 kg / h and a main extruder speed of 280 rpm. The barrel temperature control in 11 zones is as follows: Zone 1 190℃, Zone 2 280℃, Zone 3 290℃, Zone 4 290℃, Zone 5 280℃, Zone 6 270℃, Zone 7 250℃, Zone 8 210℃, Zone 9 210℃, Zone 10 210℃, and Zone 11 210℃, with a die head temperature of 250℃. After two-stage high-shear mixing and two-stage vacuum devolatilization, the melt pressure is stabilized by a melt pressure stabilizing pump, and after multi-stage filtration, uniform strips are extruded. S3 Gradient Cooling and Drying: The strip undergoes three-stage gradient cooling: first, water cooling at 65℃ with a water flow length of 35cm; then, water cooling at 45℃ with a water flow length of 40cm; and finally, water cooling at 28℃ with a water flow length of 40cm. After cooling, the surface moisture is dried using an air knife with a wind pressure of 0.4MPa. S4 pelletizing, drying and screening: The material strips are fed into the pelletizer and pelletized at a speed of 100 r / min. After pelletizing, the pellets are pre-crystallized at 120℃ for 1 h, vacuum dried at 145℃ for 2.5 h, and then screened by 20 mesh / 60 mesh ultrasonic sieve to obtain the color masterbatch semi-finished product. S5 Testing and Vacuum Packaging: After the semi-finished product passes the filtration performance test, it is cooled to below 50°C in a nitrogen atmosphere, then vacuum-packed with nitrogen to obtain the finished product.

[0045] Example 9 A high-concentration carbon black PET masterbatch comprises the following substances: 50kg high-pigment carbon black, 45kg PET carrier resin, 3.5kg composite dispersant 4, 0.4kg composite antioxidant 2, 0.3kg composite interface coupling agent 2, 0.6kg lubricant pentaerythritol stearate; A method for preparing high-concentration carbon black PET masterbatch includes the following preparation steps: S1 Raw Material Pretreatment: Weigh each component according to the formula. Vacuum dry the high-pigment carbon black at 100℃ for 2 hours, and vacuum dry the PET carrier resin at 120℃ for 4 hours until the moisture content is ≤30ppm. Seal and preheat the remaining additives to room temperature. Then perform gradient mixing and pre-dispersion: Add the dried high-pigment carbon black and composite interface coupling agent to a high-speed mixer and stir at 1000r / min for 2 minutes. Raise the temperature to 105℃ to complete the pre-activation of the carbon black surface. Add the PET carrier resin and continue stirring at 1000r / min for 6 minutes until the material temperature reaches 120℃. Add the composite dispersant, composite antioxidant, and lubricant and continue mixing for 2 minutes until the material temperature reaches 145℃. The material is uniformly sandy. Seal and discharge the material into a low-speed mixer, maintain a slight positive pressure of nitrogen (0.03MPa), control the material temperature at 150-155℃, and stir at 300r / min for 6 minutes to obtain the pre-dispersion mixture. S2 Twin-Screw Melt Extrusion Mixing: The pre-dispersed mixture is fed into the twin-screw extruder through a closed, weightless feeder at a rate of 150 kg / h and a main extruder speed of 280 rpm. The barrel temperature control in 11 zones is as follows: Zone 1 190℃, Zone 2 280℃, Zone 3 290℃, Zone 4 290℃, Zone 5 280℃, Zone 6 270℃, Zone 7 250℃, Zone 8 210℃, Zone 9 210℃, Zone 10 210℃, and Zone 11 210℃, with a die head temperature of 250℃. After two-stage high-shear mixing and two-stage vacuum devolatilization, the melt pressure is stabilized by a melt pressure stabilizing pump, and after multi-stage filtration, uniform strips are extruded. S3 Gradient Cooling and Drying: The strip undergoes three-stage gradient cooling: first, water cooling at 65℃ with a water flow length of 35cm; then, water cooling at 45℃ with a water flow length of 40cm; and finally, water cooling at 28℃ with a water flow length of 40cm. After cooling, the surface moisture is dried using an air knife with a wind pressure of 0.4MPa. S4 pelletizing, drying and screening: The material strips are fed into the pelletizer and pelletized at a speed of 100 r / min. After pelletizing, the pellets are pre-crystallized at 120℃ for 1 h, vacuum dried at 145℃ for 2.5 h, and then screened by 20 mesh / 60 mesh ultrasonic sieve to obtain the color masterbatch semi-finished product. S5 Testing and Vacuum Packaging: After the semi-finished product passes the filtration performance test, it is cooled to below 50°C in a nitrogen atmosphere, then vacuum-packed with nitrogen to obtain the finished product.

[0046] Performance testing The high-concentration carbon black PET masterbatches prepared in Examples 1-8 were subjected to performance testing. Carbon black dispersion grade: Test standard: GB / T 18251-2000 "Determination of pigment or carbon black dispersion in polyolefin pipes, fittings and compoundings".

[0047] Melt mass flow rate: Test standard: GB / T 3682.1-2018 "Plastics - Determination of melt mass flow rate (MFR) and melt volumetric flow rate (MVR) of thermoplastics - Part 1: Standard methods". The test results are shown in Table 1 below: Table 1 Performance Test Table

[0048] Based on the technical solutions of Examples 1-5, 6, and 7-8, this application clarifies the basic component composition of high-concentration carbon black PET masterbatch and defines the positioning and function logic of each functional component within the system from a technical perspective. High-pigment carbon black, as the core coloring functional component of the system, provides coloring power and hiding power for the finished product. PET carrier resin, as the continuous phase matrix, provides dispersion and support space for carbon black particles while ensuring the compatibility of the masterbatch with the matrix of downstream polyester products. The composite dispersant is the core functional component of the system. The amino-terminated PET oligomer within it can interact with the active functional groups on the carbon black surface to achieve surface grafting modification of the carbon black particles, forming a molecular chain layer on the carbon black surface consistent with the matrix resin structure. This fundamentally reduces the interfacial tension between carbon black and the PET matrix, improving the interfacial bonding state between the two phases. The composite antioxidant, composite interfacial coupling agent, and lubricant respectively undertake the functions of thermo-oxidative stabilization, interfacial reinforcement, and processing rheology adjustment. Each component synergistically matches the processing and performance requirements of the high-concentration carbon black-filled system.

[0049] Meanwhile, this application also utilizes the multi-terminal functional groups and three-dimensional spherical molecular structure of end-carboxyl hyperbranched polyester, which can be anchored to the surface of carbon black particles through multi-point adsorption, forming a thick adsorption layer around the particles. This steric hindrance effect prevents the carbon black particles from agglomerating. Oxidized modified EVA wax possesses excellent lubrication and penetration properties, allowing it to penetrate into the gaps between the original carbon black agglomerates, reducing the internal friction between particles and achieving depolymerization of the agglomerates through shearing action. Amino-terminated PET oligomers can form an interfacial compatibility layer between the carbon black and the matrix, achieving good compatibility between the modified carbon black and the PET matrix. These three components, through proportioning and matching, form a synergistic effect, achieving stable dispersion of carbon black in the PET matrix from three dimensions: agglomerate depolymerization, particle anchoring, and interfacial compatibility, thus meeting the dispersion requirements of high-concentration carbon black systems.

[0050] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

[0051] All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art. In case of conflict, the definitions in this specification shall prevail.

[0052] When this specification uses the prefixes “known to those skilled in the art,” “prior art,” or similar terms to derive materials, substances, methods, steps, apparatus, or components, the objects derived from such prefixes cover those commonly used in the art at the time of this application, but also include those that are not currently commonly used but will become generally recognized in the art as suitable for similar purposes.

[0053] In the context of this specification, except where expressly stated otherwise, any matters or issues not mentioned shall apply directly to those known in the art without any modification.

Claims

1. A high-concentration carbon black PET masterbatch, characterized in that, Includes the following substances by weight: 45-55 parts of high-pigment carbon black; 40-50 parts of PET carrier resin; 1.5-5.0 parts of composite dispersant; 0.3-0.5 parts of compound antioxidant; 0.3 parts of composite interface coupling agent; Lubricant 0.5-0.8 parts; The composite dispersant includes amino-terminated PET oligomers, wherein the number average molecular weight of the amino-terminated PET oligomers is 1000-2000 and the amino value is 20-30 mgKOH / g.

2. The high-concentration carbon black PET masterbatch according to claim 1, characterized in that, The composite dispersant also includes carboxyl-terminated hyperbranched polyester and oxidatively modified EVA wax, wherein the mass ratio of the carboxyl-terminated hyperbranched polyester, the oxidatively modified EVA wax and the amino-terminated PET oligomer is (1.2-1.5):(0.1-0.3):(1.0-1.2).

3. The high-concentration carbon black PET masterbatch according to claim 1, characterized in that, The composite interfacial coupling agent comprises the following substances in parts by weight: 0.15-0.20 parts of epoxy silane coupling agent; 0.1-0.2 parts of monoalkoxy titanate coupling agent; 0-0.8 parts of maleic anhydride-grafted PET.

4. The high-concentration carbon black PET masterbatch according to claim 1, characterized in that, The composite antioxidant comprises the following substances in parts by weight: 1-5 parts of hindered phenolic primary antioxidant; Phosphite-based antioxidant cofactors: 1-5 parts; 1.5 parts of benzofuranone carbon radical scavenger.

5. The high-concentration carbon black PET masterbatch according to claim 4, characterized in that, The hindered phenolic primary antioxidant includes any one of antioxidant 1010, antioxidant 1076, and antioxidant 3114; the phosphite secondary antioxidant includes at least one of antioxidant 168, antioxidant 626, and antioxidant P-EPQ; and the benzofuranone carbon radical scavenger includes at least one of antioxidant HP-136 or antioxidant 1790.

6. A method for preparing high-concentration carbon black PET masterbatch according to any one of claims 1-5, characterized in that, The preparation steps include the following: S1. Raw material pretreatment: After preparing the raw materials according to the mass proportions and drying and activating them, the materials are gradient mixed and pre-dispersed, and the pre-dispersed mixture is collected. S2. Twin-screw melt extrusion compounding: The pre-dispersed mixture is fed into the twin-screw extruder through a closed weight loss feeder. After segmented temperature control, two-stage high shear compounding, and two-stage vacuum devolatilization, it is extruded through a melt pressure stabilizing pump and a multi-stage filtration mechanism to obtain uniform strips. S3. Gradient cooling and drying: The strip is subjected to three-stage gradient cooling and then the surface moisture is dried by air knife. S4. Pelletizing, drying and screening: The dried strips are pelletized, then vacuum dried and screened by step heating to obtain semi-finished color masterbatch. S5. Testing and Vacuum Packaging: The filtration performance of the semi-finished product is tested. After passing the test, the product is cooled in a nitrogen atmosphere and vacuum-packed with nitrogen to obtain the high-concentration masterbatch finished product.

7. The method for preparing high-concentration carbon black PET masterbatch according to claim 6, characterized in that, The gradient mixing and pre-dispersion treatment includes the following steps: The dried high-pigment carbon black and composite interface coupling agent were added to a high-speed mixer and stirred at 1000 r / min for 2 min. The temperature was then raised to 105℃ to complete the pre-activation of the carbon black surface. Add PET carrier resin and continue high-speed stirring at 1000 rpm for 6 minutes until the material temperature reaches 120°C. Add composite dispersant, composite antioxidant and lubricant, and continue mixing for 2 minutes until the material temperature reaches 145°C and the material is uniformly sandy. Seal and discharge the high-speed mixed material into a low-speed mixer, maintain a slight positive pressure of nitrogen at 0.02-0.05 MPa, control the material temperature at 150-155°C, and stir at 300 rpm for 5-8 minutes.

8. The method for preparing high-concentration carbon black PET masterbatch according to claim 6, characterized in that, The three-stage gradient cooling includes the following steps: First, cool the material strip at a water temperature of 60-70℃ and adjust the water passage length to 35cm; then cool it at a water temperature of 40-50℃ and adjust the water passage length to 40cm; finally, cool it at a water temperature of 25-30℃ and adjust the water passage length to 40cm; after cooling, use an air knife with an air pressure of 0.3-0.5MPa to dry the surface moisture of the material strip.

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