High-toughness uniform-color-developing PA12 particle and preparation method thereof
By adjusting the proportions of composite masterbatch, toughening modifier, and functional additives in PA12 particles, a multi-dimensional prevention and control system was established, which solved the problems of surface defects and performance conflicts in PA12 particles, achieving high toughness, color uniformity, and stability, and adapting to the diversified processing needs of new energy vehicles.
Patent Information
- Application Number
- CN202511977225.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-25
- Publication Date
- 2026-02-06
AI Technical Summary
Existing PA12 particle modification methods suffer from surface defects caused by single-function optimization, such as whitening upon bending, color difference, pitting, and black spots. Furthermore, there are performance conflicts between different modification methods, making it difficult to meet the multi-dimensional needs of high-end new energy vehicle scenarios.
By adjusting the proportions of composite masterbatch, toughening modifier, and functional additives, and combining the formulas for improving whitening, color difference, pitting, and black spots during bending, a multi-dimensional prevention and control system is established to ensure the synergistic effect of each component and achieve high toughness and uniform color development.
This approach achieves simultaneous optimization of the surface quality and mechanical properties of PA12 particles in new energy vehicle scenarios, avoiding new defects caused by single adjustments and ensuring uniform appearance and stable core performance.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of PA12 materials, specifically to a high-toughness, color-uniform PA12 particle and its preparation method. Background Technology
[0002] PA12 (polyamide 12), as a high-performance engineering plastic, possesses excellent weather resistance, chemical corrosion resistance, and low-temperature impact toughness, and is widely used in key components such as busbar wrapping in new energy vehicles and insulation layers for high-voltage wiring harnesses. In these applications, the surface quality of PA12 granules after melt molding directly affects the product's appearance consistency, insulation reliability, and service life. Especially in the high-voltage environment of new energy vehicles, surface defects (such as whitening after bending, color difference, pitting, black spots, etc.) may lead to risks such as decreased electrical insulation performance and assembly interference.
[0003] Regarding the aforementioned existing technologies, the inventors discovered that the modification of PA12 particles often employs a single-function optimization strategy: adding POE (polyolefin elastomer) toughening agents improves bending performance, but excessive toughening agents dilute the concentration of masterbatch, leading to color differences; increasing the amount of masterbatch addresses uneven color development, but pigment agglomeration causes surface pitting; adding antioxidants suppresses black spot defects during high-temperature processing, but insufficient compatibility between antioxidants and lubricants leads to new surface precipitates. This single-disease-treating modification approach has significant limitations. Summary of the Invention
[0004] Based on the technical problems existing in the prior art, the present invention provides a high-toughness, uniformly colored PA12 particle and its preparation method.
[0005] In the first aspect, this application discloses a high-toughness, uniformly colored PA12 particle, which adopts the following technical solution: A high-toughness, uniformly colored PA12 particle, comprising the following components by weight: 100 parts PA12 matrix resin, K1 parts composite color masterbatch, and K2 parts toughening modifier; wherein, the weight ratio of K1 and K2 is adjusted by coupling to conform to the following formula (1): η=α·η1+β·η2+γ·η3+δ·η4≥80% Formula (1) η1 is the improvement rate of whitening due to bending, η2 is the improvement rate of color difference, η3 is the improvement rate of pitting, η4 is the improvement rate of black spots; η is the overall defect improvement rate. The functional additives comprise the following substances in parts by weight: Antioxidant 0.2-1.5 parts; 0.15-1.25 parts of silane coupling agent; Lubricant 0.25-1.75 parts; Anti-migration agent 0.1-1.0 parts; Crosslinking agent 0.1-0.5 parts; 0.1-1.0 parts of crosslinking agent.
[0006] Through the above technical solution, this application constructs a core component system and comprehensive performance control framework for high-toughness, uniformly colored PA12 particles. Technically, the particles are defined as consisting of PA12 matrix resin, composite masterbatch, toughening modifier, and functional additives. The functional additives integrate antioxidant, coupling, lubrication, anti-migration, crosslinking, and co-crosslinking functions, overcoming the limitations of traditional additives with single functions. Simultaneously, it proposes to adjust the dosage of three key components through coupling, using a comprehensive defect improvement rate formula to ensure simultaneous improvement of multiple surface defects. This solution solves the problem of new defects caused by single-parameter optimization in traditional PA12 modification, achieving a synergy between high toughness and uniform color development. It can cover the multi-dimensional surface quality requirements of scenarios such as busbar coating in new energy vehicles, ensuring the performance stability of the particles under different processing conditions.
[0007] Furthermore, η1 = 1 - (K2) 基准 / K2)×0.35, K2 基准 =5 parts; K2 = 8 + 0.5 × (T) m -140) Equation (2); Among them, T m The crystallization melting temperature is K2; and when K2 ≥ 10 parts, the amount of crosslinking agent in the functional additive is controlled at 0.1-0.3 parts, and when K2 < 10 parts, the amount of crosslinking agent is 0.3-0.5 parts.
[0008] Through the above technical solution, this application focuses on the precise improvement of bending whitening defects and the appropriate control of crosslinking agent dosage. By establishing a correlation logic between the bending whitening improvement rate and the amount of toughening modifier, the amount of toughening agent is linked to the crystallization melting temperature, enabling dynamic adjustment of bending performance under different temperature conditions. Simultaneously, based on the toughening agent dosage range, a corresponding crosslinking agent dosage range is set to avoid performance conflicts between toughening and crosslinking. This solution solves the problem of balancing toughening and heat resistance in traditional modification methods. It can precisely suppress bending whitening through toughening agents and improve the heat resistance of materials through appropriate crosslinking agent dosage, ensuring that particles possess excellent toughness without mechanical property degradation under high-temperature bending scenarios.
[0009] Furthermore, η2 = 1 - (5 - λ) / 5, λ = 0.25 × K1, where λ is the color correction coefficient (3). When λ ≥ 1.0 parts, the anti-migration agent ≥ 0.5 parts.
[0010] Through the above technical solution, this application establishes a synergistic mechanism for color development control and anti-migration to address color difference defects. Technically, the influence of the dye ratio in the masterbatch on color difference is quantified using a color development correction coefficient, and the color development effect is indirectly controlled by adjusting the amount of masterbatch. Simultaneously, based on the threshold of the color development correction coefficient, a minimum amount of anti-migration agent is set to prevent color difference fluctuations caused by dye migration during processing or use. This solution solves the problem of coexisting color adjustment and migration risks in traditional color development control. It can precisely optimize color difference through the dye ratio and lock dye molecules through the anti-migration agent, ensuring uniform and stable color after particle formation, and preventing color change or migration even after long-term use.
[0011] Furthermore, η3 = 1 - (K1) 颜料占比原 -20% / K1 颜料占比原 ×0.2, where K1 颜料占比原 =35% (4).
[0012] Through the above technical solution, this application constructs an improvement logic for pitting defects from the perspective of pigment dispersion. Technically, based on the original pigment ratio in the composite masterbatch, by setting adjustment rules for the pigment ratio, the risk of pigment agglomeration is reduced at its source, and controlling the pigment ratio can improve its dispersion uniformity in the matrix. This solution overcomes the limitations of traditional pitting improvement that relies solely on processing technology adjustments, optimizing the pigment dispersion state at the material formulation level, avoiding surface roughness caused by pigment agglomeration, improving the surface smoothness of the formed particles, and adapting to the appearance precision requirements of new energy vehicle components.
[0013] Furthermore, η4 = 1 - (ΔT) 原 -15℃) / ΔT 原 ×0.15, ΔT 原 =30℃ (5).
[0014] Through the above technical solution, this application establishes an improvement mechanism related to the processing temperature gradient for black spot defects. The black spot improvement rate is linked to the extrusion temperature gradient, and by setting the adjustment logic of the temperature gradient, the thermal oxidative degradation and carbonization of the material during high-temperature processing are suppressed. This solution solves the problem that traditional black spot improvement relies solely on the regulation of antioxidants. From the perspective of process and material synergy, it reduces carbonization inducements through temperature gradient optimization, and, in conjunction with antioxidant components in functional additives, forms a dual guarantee for black spot prevention and control, reducing the scrap rate during processing and improving the uniformity of particle appearance.
[0015] Furthermore, the crosslinking agent, co-crosslinking agent, and other components in the functional additive synergistically satisfy equation (6): m 抗氧剂 / m 交联剂 ≥3.0 and m 润滑剂 / m助交联剂 ≥0.8 (6); Where m is the weight part of the corresponding component.
[0016] Through the above technical solution, this application constructs a synergistic system of internal components of functional additives, ensuring that crosslinking modification does not conflict with other functions. Technically, threshold ratios are set for the dosage of antioxidants and crosslinking agents, and lubricants and co-crosslinking agents: the former prevents thermal oxidative degradation caused by the crosslinking agent, and the latter prevents a decrease in melt flowability caused by the co-crosslinking agent. This solution solves the problem of "crosslinking efficiency conflicting with the functions of other additives" in traditional crosslinking modification. By controlling the ratios, crosslinking agents, co-crosslinking agents, and other additives work synergistically, ensuring that the crosslinking reaction proceeds fully to improve material performance without affecting antioxidant and lubricating effects, maintaining a balance between particle processing performance and performance in use.
[0017] Furthermore, α is the white refraction weight, β is the color difference weight, γ is the speckle weight, and δ is the black spot weight; α+β+γ+δ=1.
[0018] Through the above technical solution, this application clearly defines the improvement weights for four types of defects: whitening, color difference, pitting, and black spots, with a total weight of 1. The weight values can be adjusted according to the priority of defect improvement in different application scenarios. This solution solves the problem of poor scenario adaptability of traditional fixed formulations. It eliminates the need to redesign formulations for different scenarios; the priority of defect improvement can be optimized simply by adjusting the weight coefficients. This allows the particles to flexibly adapt to the diverse processing needs of the new energy vehicle field, reducing formulation development costs.
[0019] Furthermore, the composite masterbatch comprises the following substances in parts by weight: 1-8 parts of low-viscosity PA12 resin granules; 0.1-2.0 parts of dispersed pigment; Solvent-based dyes: 0.5-2.5 parts; The dispersed coloring pigment is a compound of 68# orange pigment, 192# yellow pigment and titanium dioxide in a weight ratio of (3-8):(1-3):(1-4); The solvent-based dye is a compound of 16# solvent orange and 160:1 fluorescent yellow in a weight ratio of (3-5):1.
[0020] Through the above technical solution, this application refines the component composition and proportioning logic of the composite masterbatch, providing a fundamental guarantee for color uniformity. Technically, low-viscosity PA12 resin is used as the masterbatch carrier to improve the compatibility between the masterbatch and the matrix; through the compounding of pigments and dyes, combined with a specific ratio, the color rendering effect of the dispersed coloring pigment is optimized—pigments ensure hiding power, and dyes enhance transparency. This solution solves the problems of "poor dispersibility and single color" in traditional masterbatches. The low-viscosity carrier promotes uniform dispersion of the masterbatch in the matrix, and the compounding of pigments and dyes achieves precise color control, ensuring uniform color after particle molding, and that the color saturation and stability meet the appearance requirements of new energy vehicle components.
[0021] Furthermore, the toughening modifier includes at least one of maleic anhydride-grafted POE, ethylene-butyl acrylate copolymer, and styrene-maleic anhydride copolymer.
[0022] Through the above technical solution, this application clarifies the selectable types of toughening modifiers, providing flexible space for toughness control. The technical solution lists three types of toughening agents with different performance characteristics: maleic anhydride-grafted POE focuses on high elasticity, ethylene-butyl acrylate copolymer focuses on processing fluidity, and styrene-maleic anhydride copolymer focuses on heat resistance. These can be used individually or in combination depending on the specific requirements for toughness, fluidity, and heat resistance in different scenarios. This solution solves the problem of insufficient performance coverage of traditional single toughening agents, allowing for flexible adjustment of the toughening agent type according to the mechanical requirements of specific application scenarios. This ensures that the particles have an appropriate toughness level under different working conditions without affecting other processing or performance characteristics.
[0023] Secondly, this application provides a method for preparing high-toughness, uniformly colored PA12 particles, using the following technical solution: A method for preparing high-toughness, uniformly colored PA12 particles includes the following preparation steps: PA12 matrix resin and low-viscosity PA12 resin particles were placed in a vacuum drying oven and dried. Next, premix the disperse pigment with the solvent-based dye and lubricant for 3-5 minutes; add the pretreated PA12 matrix resin, low-viscosity PA12 resin particles, toughening modifier, and functional additives (excluding crosslinking agents) to the main hopper of the twin-screw extruder and mix for 5-10 minutes. Then, the crosslinking agent and co-crosslinking agent are added separately to a twin-screw extruder, extruded and granulated, and the granulated PA12 particles are annealed to eliminate the internal stress generated by the crosslinking reaction, so as to prepare high-toughness, uniformly colored PA12 particles.
[0024] Through the above technical solution, this application provides a complete particle preparation process, ensuring the practical implementation of the technical solution. The technical solution employs a phased design for the preparation steps: raw material pretreatment, through drying and premixing, addresses the issues of excessive moisture content leading to air bubbles and uneven pigment dispersion, respectively; in the premixing stage, the crosslinking agent is fed separately from other components to avoid premature reaction; extrusion granulation and annealing ensure sufficient crosslinking and stress elimination, respectively. This solution solves the problems of "large performance fluctuations and poor batch consistency" in traditional preparation processes. Each step is specifically matched to the performance requirements of the preceding claims, ensuring that the final product consistently achieves high toughness, uniform color development, and improvement of multiple defects, with minimal batch-to-batch performance differences, meeting the requirements of industrial production.
[0025] In summary, this application has the following beneficial effects: First, this solution addresses the problem of traditional PA12 modification's "single-disease treatment" approach by employing a formulation coupling control and defect-targeting mechanism. From a formulation design perspective, the dosages of composite masterbatch, toughening modifier, and functional additives are adjusted in tandem through a comprehensive defect improvement rate formula. For four core defects—bending whitening, color difference, pitting, and black spots—a logical correlation is established between the component dosage and process parameters, forming a multi-dimensional prevention and control system. This avoids creating new defects by adjusting a single component and simultaneously optimizes the surface quality and mechanical properties of the granules after molding through the synergistic effect of all components. This ensures that the product meets the stringent requirements of high-end applications such as new energy vehicles in terms of both appearance uniformity and core performance.
[0026] Secondly, this application overcomes the performance conflicts between "toughness and heat resistance," "color development and anti-migration," and "processability and stability" in traditional PA12 modification through meticulous component adaptation and synergistic design of additives. For example, the dynamic matching of the toughening modifier dosage and the crosslinking agent dosage enhances bending toughness through the toughening agent and strengthens heat resistance through the crosslinking agent; the color development correction coefficient is linked to the anti-migration agent dosage, ensuring uniform and bright color while preventing dye migration; and the controlled ratio of functional additives ensures that functions such as anti-oxidation and lubrication are not weakened by the crosslinking reaction. Ultimately, the particles simultaneously possess multi-dimensional properties such as high toughness, uniform color development, heat resistance stability, and anti-migration, adapting to the application requirements under complex working conditions.
[0027] Third, the technical solution of this application forms a complete closed loop from formulation design to preparation process, ensuring the stability and repeatability of industrial production. At the formulation level, the dosage range and synergistic rules of each component are clearly defined, facilitating precise proportioning on the production line. At the preparation method level, the parameters of each step, such as raw material pretreatment, premixing, and extrusion granulation, are standardized, and each step is adapted to the performance requirements of the formulation, avoiding batch differences caused by human operation. At the same time, the quality verification process ensures product compliance through multi-dimensional testing, reducing the production scrap rate. In addition, after granulation, it is compatible with subsequent injection molding, coating, and other processing technologies, eliminating the need for frequent adjustments to processing parameters, thus providing a guarantee for its large-scale application in scenarios such as busbar coating in new energy vehicles. Detailed Implementation
[0028] The present application will be further described in detail below with reference to the embodiments.
[0029] The PA12 matrix resin used in this application is the industrially common L2000 type polyamide 12, whose crystallization melting temperature (Tm) ranges from 145 to 155°C.
[0030] Preparation Example 1 Composite masterbatch 1 Weigh out 68# orange pigment, 192# yellow pigment, and titanium dioxide in a weight ratio of 3:1:1, and put them into a high-speed mixer. Set the mixing speed to 1200 r / min, the mixing temperature to 25℃, and the mixing time to 5 min to collect the dispersed coloring pigment. Then, weigh out 16# solvent orange and 160:1 fluorescent yellow in a weight ratio of 3:1 and stir to prepare a solvent-based coloring dye. Take 1 kg of low-viscosity PA12 resin particles, 0.1 kg of dispersed coloring pigment, and 0.5 kg of solvent-based coloring dye and put them into a twin-screw extruder. Set the temperature gradient as follows: Zone 1 130℃, Zone 2 180℃, Zone 3 210℃, and the die head temperature 215℃. Set the screw speed to 180 r / min and the feeding rate to 5 kg / h. Melt extrusion and pelletizing will produce composite masterbatch 1.
[0031] Preparation Example 2 Composite masterbatch 2 Weigh out 68# orange pigment, 192# yellow pigment, and titanium dioxide in a 5:2:2 weight ratio, add them to a high-speed mixer, set the mixing speed to 1350 r / min, the mixing temperature to 30℃, and the mixing time to 6 min to collect the dispersed coloring pigment; then weigh out 16# solvent orange and 160:1 fluorescent yellow in a 4:1 weight ratio and stir to prepare a solvent-based coloring dye; take 5 kg of low-viscosity PA12 resin granules, 1 kg of dispersed coloring pigment, and 1.5 kg of solvent-based coloring dye and add them to a twin-screw extruder, set the temperature gradient as follows: zone 1 130℃, zone 2 190℃, zone 3 205℃, and die head temperature 220℃, set the screw speed to 200 r / min and the feeding rate to 7 kg / h, melt extrude and pelletize to prepare composite masterbatch 2.
[0032] Preparation Example 3 Composite masterbatch 3 Weigh out 68# orange pigment, 192# yellow pigment, and titanium dioxide in a weight ratio of 8:3:4, and put them into a high-speed mixer. Set the mixing speed to 1500 r / min, the mixing temperature to 35℃, and the mixing time to 8 min to collect the dispersed coloring pigment. Then weigh out 16# solvent orange and 160:1 fluorescent yellow in a weight ratio of 5:1 and stir to prepare a solvent-based coloring dye. Take 8 kg of low-viscosity PA12 resin granules, 2.0 kg of dispersed coloring pigment, and 2.5 kg of solvent-based coloring dye and put them into a twin-screw extruder. Set the temperature gradient as follows: Zone 1 130℃, Zone 2 200℃, Zone 3 220℃, and the die head temperature 225℃. Set the screw speed to 220 r / min and the feeding rate to 8 kg / h. Melt extrusion and pelletizing will produce composite masterbatch 3.
[0033] Preparation Example 4 Functional Additive 1 Functional additive 1 was prepared by mixing 0.9 kg of antioxidant, 0.15 kg of silane coupling agent KH550, 0.5 kg of lubricant, 0.1 kg of anti-migration agent, 0.3 kg of crosslinking agent DCP and 0.6 kg of co-crosslinking agent TAIC.
[0034] Preparation Example 5 Functional Additive 2 Functional additive 2 was prepared by mixing 0.9 kg of antioxidant, 0.7 kg of silane coupling agent KH550, 0.64 kg of lubricant, 0.5 kg of anti-migration agent, 0.3 kg of crosslinking agent DCP and 0.8 kg of co-crosslinking agent TAIC.
[0035] Preparation Example 6 Functional Additive 3 Functional additive 3 was prepared by mixing 0.9 kg of antioxidant, 1.25 kg of silane coupling agent KH550, 0.5 kg of lubricant, 1.0 kg of anti-migration agent, 0.3 kg of crosslinking agent DCP and 0.6 kg of co-crosslinking agent TAIC.
[0036] Preparation Example 7 Functional additive 4 Functional additive 4 was prepared by mixing 1.2 kg of antioxidant, 0.7 kg of silane coupling agent KH550, 0.6 kg of lubricant, 0.8 kg of anti-migration agent, 0.4 kg of crosslinking agent DCP, and 0.5 kg of co-crosslinking agent TAIC. Example 1 This embodiment targets the high-voltage wiring harness covering scenario (prioritizing the suppression of whitening due to bending), and determines the weighting coefficients according to the assignment rules.
[0037] With α=0.6, β=0.1, γ=0.15, and δ=0.15, combined with K1=5.2kg and K2=13kg in Example 1, the overall defect improvement rate η is verified to be ≥80%.
[0038] A high-toughness, uniformly colored PA12 granule comprises 100kg of L2000 type PA12 matrix resin, 5.2kg of composite masterbatch 1, 10.4kg of toughening modifier maleic anhydride grafted POE, 2.6kg of styrene-maleic anhydride copolymer, and 3.4kg of functional additive 1.
[0039] A method for preparing high-toughness, uniformly colored PA12 particles, using the following technical solution: PA12 matrix and composite masterbatch 1 were dried at 80℃ and vacuum degree -0.08MPa for 6h, and pretreated particles were collected. Pretreated granules, toughening agent, and functional additives (excluding crosslinking agent) were added to the main hopper of a twin-screw extruder and mixed at 50°C for 10 min. Crosslinking agent and co-crosslinking agent were added to the side feed hopper. A twin-screw extruder with L / D=40 was used, with the following temperature gradients: Zone 1 130°C, Zone 2 180°C, Zone 3 220°C, Zone 4 225°C, and Die Head 230°C. The screw speed was 120 r / min, and vacuum exhaust was performed at -0.08 MPa. The mixture was then cooled in a 20°C water bath, cut into 2 mm lengths by a roller cutter, and annealed in an 80°C forced-air drying oven for 4 h to obtain a high-toughness, uniformly colored PA12 granule.
[0040] It should be noted that this embodiment is for high-voltage wiring harness wrapping scenarios (prioritizing the suppression of whitening due to bending), and the weighting coefficients are determined according to the assignment rules.
[0041] With α=0.6, β=0.1, γ=0.15, and δ=0.15, combined with K1=5.2kg and K2=13kg in Example 1, the overall defect improvement rate η is verified to be ≥80%.
[0042] Example 2 A high-toughness, uniformly colored PA12 granule comprises 100kg of L2000 type PA12 matrix resin, 6kg of composite masterbatch, 8kg of toughening modifier ethylene-butyl acrylate copolymer, and 3.78kg of functional additives.
[0043] A method for preparing high-toughness, uniformly colored PA12 particles, using the following technical solution: PA12 matrix and composite masterbatch 2 were dried at 80℃ and vacuum degree -0.08MPa for 6h, and pretreated particles were collected. Pretreated granules, toughening agent, and functional additives (excluding crosslinking agent) were added to the main hopper of a twin-screw extruder and mixed at 50°C for 10 min. Crosslinking agent and co-crosslinking agent were added to the side feed hopper. A twin-screw extruder with L / D=40 was used, with the following temperature gradients: Zone 1 130°C, Zone 2 180°C, Zone 3 220°C, Zone 4 225°C, and Die Head 230°C. The screw speed was 120 r / min, and vacuum exhaust was performed at -0.08 MPa. The mixture was then cooled in a 20°C water bath, cut into 2 mm lengths by a roller cutter, and annealed in an 80°C forced-air drying oven for 4 h to obtain a high-toughness, uniformly colored PA12 granule.
[0044] It should be noted that this embodiment is for the scenario of appearance parts (prioritizing color difference control), and the weight coefficient is determined according to the assignment rules.
[0045] With α=0.2, β=0.4, γ=0.2, and δ=0.2, and combined with K1=6kg and K2=8kg in Example 2, the overall defect improvement rate η is verified to be ≥80%.
[0046] Example 3 A high-toughness, uniformly colored PA12 granule comprises 100kg of L2000 type PA12 matrix resin, 8kg of composite masterbatch, 8kg of toughening modifier maleic anhydride grafted POE, and 4kg of functional additives.
[0047] A method for preparing high-toughness, uniformly colored PA12 particles, using the following technical solution: PA12 matrix and composite masterbatch 3 were dried at 80℃ and vacuum degree -0.08MPa for 6h, and pretreated particles were collected. Pretreated granules, toughening agent, and functional additives (excluding crosslinking agent) were added to the main hopper of a twin-screw extruder and mixed at 50°C for 10 min. Crosslinking agent and co-crosslinking agent were added to the side feed hopper. A twin-screw extruder with L / D=40 was used, with the following temperature gradients: Zone 1 130°C, Zone 2 180°C, Zone 3 220°C, Zone 4 225°C, and Die Head 230°C. The screw speed was 120 r / min, and vacuum exhaust was performed at -0.08 MPa. The mixture was then cooled in a 20°C water bath, cut into 2 mm lengths by a roller cutter, and annealed in an 80°C forced-air drying oven for 4 h to obtain a high-toughness, uniformly colored PA12 granule.
[0048] It should be noted that this embodiment is for the scenario of appearance parts (prioritizing color difference control), and the weight coefficient is determined according to the assignment rules.
[0049] With α=0.15, β=0.5, γ=0.2, and δ=0.15, combined with K1=7.35kg and K2=8kg in Example 3, the overall defect improvement rate η is verified to be ≥80%.
[0050] Example 4 A high-toughness, uniformly colored PA12 granule comprises 100kg of L2000 type PA12 matrix resin, 5kg of composite masterbatch, 8kg of toughening modifier maleic anhydride grafted POE, 2kg of SMA, and 4.55kg of functional additives.
[0051] A method for preparing high-toughness, uniformly colored PA12 particles, using the following technical solution: PA12 matrix and composite masterbatch 2 were dried at 80℃ and vacuum degree -0.08MPa for 6h, and pretreated particles were collected. Pretreated granules, toughening agent, and functional additives (excluding crosslinking agent) were added to the main hopper of a twin-screw extruder and mixed at 50°C for 10 min. Crosslinking agent and co-crosslinking agent were added to the side feed hopper. A twin-screw extruder with L / D=40 was used, with the following temperature gradients: Zone 1 130°C, Zone 2 180°C, Zone 3 220°C, Zone 4 225°C, and Die Head 230°C. The screw speed was 120 r / min, and vacuum exhaust was performed at -0.08 MPa. The mixture was then cooled in a 20°C water bath, cut into 2 mm lengths by a roller cutter, and annealed in an 80°C forced-air drying oven for 4 h to obtain a high-toughness, uniformly colored PA12 granule.
[0052] It should be noted that this embodiment is for high-voltage wiring harness wrapping scenarios (prioritizing the suppression of whitening due to bending), and the weighting coefficients are determined according to the assignment rules.
[0053] With α=0.5, β=0.1, γ=0.2, and δ=0.2, combined with K1=5kg and K2=10kg (maleic anhydride grafted POE 8kg + SMA 2kg) in Example 4, the overall defect improvement rate η≥80% was verified.
[0054] Example 5 A high-toughness, uniformly colored PA12 granule comprises 100kg of L2000 type PA12 matrix resin, 8.4kg of composite masterbatch 2, 3.6kg of toughening modifier maleic anhydride grafted POE, 2.4kg of EBA, and 4.2kg of functional additives 4.
[0055] A method for preparing high-toughness, uniformly colored PA12 particles, using the following technical solution: PA12 matrix and composite masterbatch 2 were dried at 80℃ and vacuum degree -0.08MPa for 6h, and pretreated particles were collected. Pretreated granules, toughening agent, and functional additives (excluding crosslinking agent) were added to the main hopper of a twin-screw extruder and mixed at 50°C for 10 min. Crosslinking agent and co-crosslinking agent were added to the side feed hopper. A twin-screw extruder with L / D=40 was used, with the following temperature gradients: Zone 1 130°C, Zone 2 180°C, Zone 3 220°C, Zone 4 225°C, and Die Head 230°C. The screw speed was 120 r / min, and vacuum exhaust was performed at -0.08 MPa. The mixture was then cooled in a 20°C water bath, cut into 2 mm lengths by a roller cutter, and annealed in an 80°C forced-air drying oven for 4 h to obtain a high-toughness, uniformly colored PA12 granule.
[0056] It should be noted that this embodiment is for high-voltage wiring harness wrapping scenarios (prioritizing the suppression of whitening due to bending), and the weighting coefficients are determined according to the assignment rules.
[0057] With α=0.6, β=0.05, γ=0.15, and δ=0.2, combined with K1=8.4kg and K2=3.6kg (maleic anhydride grafted POE 1.8kg + EBA 1.2kg) in Example 5, the overall defect improvement rate η was verified to be ≥80%.
[0058] Performance testing The results are shown in Table 1-5 below: Table 1 Performance Test Table for Example 1
[0059] Table 2 Performance Test Table for Example 2
[0060] Table 3 Performance Test Table for Example 3
[0061] Table 4 Performance Test Table for Example 4
[0062] Table 5 Performance Test Table for Example 5
[0063] Comparing the test results of Examples 1-5 with those in Table 1-5, it can be seen that this solution solves the problem of treating single defects in traditional PA12 modification through formulation coupling control and defect-targeting mechanisms. From the formulation design perspective, the dosages of composite masterbatch, toughening modifier, and functional additives are adjusted in conjunction with a comprehensive defect improvement rate formula. For the four core defects—bending whitening, color difference, pitting, and black spots—a correlation logic is established between the component dosage and process parameters, forming a multi-dimensional prevention and control system. This avoids creating new defects by adjusting a single component and simultaneously optimizes the surface quality and mechanical properties of the formed particles through the synergistic effect of each component, ensuring that the product meets the stringent requirements of high-end scenarios such as new energy vehicles in terms of both appearance uniformity and core performance.
Claims
1. A high-toughness, uniformly colored PA12 particle, characterized in that, Includes the following substances by weight: 100 parts PA12 matrix resin, K1 parts composite color masterbatch, and K2 parts toughening modifier; wherein, the weight ratio of K1 and K2 is adjusted by coupling to conform to the following formula (1): η=α·η1+β·η2+γ·η3+δ·η4≥80% Formula (1) η1 is the improvement rate of whitening during bending, η2 is the improvement rate of color difference, η3 is the improvement rate of pitting, η4 is the improvement rate of black spots; η is the overall defect improvement rate. The assignment rules for α, β, γ, and δ are as follows: When prioritizing the suppression of bending whitening, α=0.4~0.7, β=0.05~0.2, γ=0.1~0.2, δ=0.1~0.2; β+γ+δ≤0.6, and α+β+γ+δ=1; When giving priority to controlling color difference, β=0.3~0.6, α=0.1~0.3, γ=0.1~0.2, δ=0.1~0.2; α+γ+δ≤0.7, and α+β+γ+δ=1; The functional additives comprise the following substances in parts by weight: Antioxidant 0.2-1.5 parts; 0.15-1.25 parts of silane coupling agent; Lubricant 0.25-1.75 parts; Anti-migration agent 0.1-1.0 parts; Crosslinking agent 0.1-0.5 parts; 0.1-1.0 parts of crosslinking agent.
2. The high-toughness, uniformly colored PA12 granules according to claim 1, characterized in that, The η1=1-(K2) 基准 / K2)×0.35, K2 基准 =5 portions; K2 = 8 + 0.5 × (T) m -140) Equation (2); Among them, T m The crystallization melting temperature is K2; and when K2 ≥ 10 parts, the amount of crosslinking agent in the functional additive is controlled at 0.1-0.3 parts, and when K2 < 10 parts, the amount of crosslinking agent is 0.3-0.5 parts.
3. The high-toughness, uniformly colored PA12 granules according to claim 1, characterized in that, The η2 = 1 - (5 - λ) / 5, λ = 0.25 × K1, where λ is the color correction coefficient (3). When λ ≥ 1.0 parts, the anti-migration agent ≥ 0.5 parts.
4. The high-toughness, uniformly colored PA12 granules according to claim 1, characterized in that, The η3 = 1 - (K1) 颜料占比原 -20% / K1 颜料占比原 ×0.2, where K1 颜料占比原 =35% (4).
5. The high-toughness, uniformly colored PA12 granules according to claim 1, characterized in that, The η4 = 1 - (ΔT) 原 -15℃) / ΔT 原 ×0.15, ΔT 原 =30℃ (5).
6. The high-toughness, uniformly colored PA12 granules according to claim 1, characterized in that, The crosslinking agent, co-crosslinking agent, and other components in the functional additive synergistically satisfy equation (6): m 抗氧剂 / m 交联剂 ≥3.0 and m 润滑剂 / m 助交联剂 ≥0.8 (6); Where m is the weight part of the corresponding component.
7. The high-toughness, uniformly colored PA12 granules according to claim 1, characterized in that, α is the white refraction weight, β is the color difference weight, γ is the speckle weight, and δ is the black spot weight; α+β+γ+δ=1.
8. The high-toughness, uniformly colored PA12 granules according to claim 1, characterized in that, The composite masterbatch comprises the following substances in parts by weight: 1-8 parts of low-viscosity PA12 resin granules; 0.1-2.0 parts of dispersed pigment; Solvent-based dyes: 0.5-2.5 parts; The dispersed coloring pigment is a compound of 68# orange pigment, 192# yellow pigment and titanium dioxide in a weight ratio of (3-8):(1-3):(1-4); The solvent-based dye is a compound of 16# solvent orange and 160:1 fluorescent yellow in a weight ratio of (3-5):
1.
9. The high-toughness, uniformly colored PA12 granules according to claim 1, characterized in that, The toughening modifier includes at least one of maleic anhydride-grafted POE, ethylene-butyl acrylate copolymer, and styrene-maleic anhydride copolymer.
10. The method for preparing high-toughness, uniformly colored PA12 particles according to any one of claims 1-9, characterized in that, The preparation steps include the following: PA12 matrix resin and low-viscosity PA12 resin particles were placed in a vacuum drying oven and dried. Next, premix the disperse pigment with the solvent-based dye and lubricant for 3-5 minutes; add the pretreated PA12 matrix resin, low-viscosity PA12 resin particles, toughening modifier, and functional additives (excluding crosslinking agents) to the main hopper of the twin-screw extruder and mix for 5-10 minutes. Then, the crosslinking agent and co-crosslinking agent are added separately to a twin-screw extruder, extruded and granulated, and the granulated PA12 particles are annealed to eliminate the internal stress generated by the crosslinking reaction, so as to prepare high-toughness, uniformly colored PA12 particles.