Plastic alloy material for vehicle-mounted cover plate as well as preparation method and application of plastic alloy material

Abstract

The invention relates to the technical field of plastics, in particular to a plastic alloy material for a vehicle-mounted cover plate as well as a preparation method and application of the plastic alloy material. The material is prepared from a polybutylene terephthalate end group reconstruction-hydrolysis-resistant stable master batch, acrylonitrile-styrene-acrylate terpolymer resin, polymethyl methacrylate resin, a secondary interface construction master batch, epoxy functionalized polyhedral oligomeric silsesquioxane and a light stabilizer UV-622. Through the introduction of secondary interface construction master batch, the lauroyl / succinic acid double-grafted beta-cyclodextrin graft and the reaction compatibilizer have a synergistic effect, so that the compatibility and the interface bonding force of the multiphase polymer are effectively improved, and phase separation is inhibited. A sectional feeding reactive extrusion process is adopted for preparation, so that uniform distribution of functional aids is ensured. The material has excellent weather resistance, hydrolysis resistance, mechanical strength and surface durability, and solves the problems of easy yellowing, fogging, surface cracking and the like of the vehicle-mounted cover plate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of plastics, in particular to a plastic alloy material for a vehicle cover plate, a preparation method and application thereof. BACKGROUND

[0002] With the development of intelligent and high-quality interior of the automobile, the vehicle cover plate material needs not only to have excellent mechanical strength and heat resistance, but also to have higher requirements for the durability of the surface appearance. At present, the widely used plastic alloy system mostly uses polybutylene terephthalate (PBT) as the base resin, and uses its good mechanical properties and dimensional stability. However, the PBT resin itself has the problems of easy hydrolysis of terminal carboxyl group and poor ultraviolet aging resistance, and under the conditions of high temperature and high humidity or long-term light exposure, the molecular chain is easily broken, which leads to material surface powdering, gloss reduction and even micro-cracks, seriously affecting the appearance and service life of the cover plate.

[0003] In order to improve the weather resistance of PBT, a common technical means is to blend it with polymers such as acrylonitrile-styrene-acrylate (ASA) or polymethyl methacrylate (PMMA) which have good weather resistance. However, due to the significant difference in polarity and compatibility between PBT and these polymers, simple blending often leads to weak interfacial adhesion, and phase separation easily occurs under external force or environmental stress, forming optical defects and mechanical weak points. In addition, the traditional compatibilizers introduced to improve the interfacial compatibility are mostly non-reactive, which may fail due to migration in the long-term use process, and cannot provide long-term stability for the material.

[0004] On the other hand, in order to improve the ultraviolet resistance of the material, small molecule ultraviolet absorbers and light stabilizers are usually added to the system. However, such small molecule additives are prone to volatilization, migration or exudation during processing and use, not only reducing the long-term protection effect, but also possibly polluting the surrounding parts or affecting the surface texture of the cover plate. Especially under high shear and high temperature processing conditions, the dispersion uniformity and chemical stability of the additives are more difficult to guarantee, leading to local yellowing or haze rising of the material in long-term service.

[0005] In addition, the existing modification technology often focuses on the improvement of a single property, and lacks the system synergy of compatibility, weather resistance, scratch resistance and other requirements. If only the compatibility is improved, the heat deformation resistance of the material may be sacrificed; if the ultraviolet shielding is excessively pursued, the processing flowability of the base resin may be affected or the interface defects may be enlarged. How to construct a stable, firm and functionally integrated interface structure in a multi-component blending system has become a key difficulty in improving the comprehensive performance of the vehicle cover plate. SUMMARY

[0006] Therefore, the present application aims to provide a plastic alloy material for vehicle cover plate, a preparation method and application thereof, so as to solve the problem of yellowing, fogging and surface micro-cracks of the existing plastic alloy for vehicle cover plate under long-term ultraviolet and thermal oxygen environment, resulting in insufficient appearance and optical stability.

[0007] In order to achieve the above purpose, the present application provides a plastic alloy material for vehicle cover plate, which is prepared from 6090 parts by mass of polybutylene terephthalate end group reconstitution-hydrolysis resistant stabilizing master batch, 2000 parts of acrylonitrile-styrene-acrylate terpolymer resin, 2000 parts of polymethyl methacrylate resin, 250-350 parts of secondary interface construction master batch, 35-65 parts of epoxy functionalized cage silsesquioxane, and 15-25 parts of light stabilizer UV-622.

[0008] Preferably, the melt mass flow rate of the acrylonitrile-styrene-acrylate terpolymer resin at 220℃ / 10kg is 25g / 10min.

[0009] Preferably, the melt volume flow rate of the polymethyl methacrylate resin at 230℃ / 3.8kg is 3cm 3 / 10min.

[0010] Preferably, the epoxy functionalized cage silsesquioxane is from Hybrid Plastics Company, item number EP0409.

[0011] Further, the polybutylene terephthalate end group reconstitution-hydrolysis resistant stabilizing master batch is prepared from 6000 parts of polybutylene terephthalate resin, 30-40 parts of epoxy chain extender, 20-30 parts of hydrolysis resistant stabilizer, 12-18 parts of antioxidant 1010, and 12-18 parts of antioxidant 168.

[0012] Preferably, the melt volume flow rate of the polybutylene terephthalate resin at 250℃ / 2.16kg is 50.0cm 3 / 10min.

[0013] Preferably, the epoxy chain extender is from BASF Company, model Joncryl ADR-4400.

[0014] Preferably, the hydrolysis resistant stabilizer is from Germany Rhein Chemie, model Stabaxol P100.

[0015] Further, the preparation steps of the secondary interface construction master batch are as follows:

[0016] (1) the β-cyclodextrin and dodecanoyl chloride are reacted by acyl chloride reaction to obtain lauroylated β-cyclodextrin intermediate; the lauroylated β-cyclodextrin intermediate and succinic anhydride are reacted by ring-opening esterification to obtain lauroyl / succinic acid group double-grafted β-cyclodextrin graft;

[0017] (2) the ethylene-glycidyl methacrylate copolymer and the styrene-acrylonitrile copolymer resin are melt grafted under the initiation of dicumyl peroxide to obtain a reactive compatibilizer master batch;

[0018] (3) the reactive compatibilizer master batch and the triazine ultraviolet absorber UV-1577 are reacted by ring-opening addition grafting to obtain a reactive compatibilizer master batch;

[0019] (4) the reactive compatibilizer master batch and the lauroyl / succinic acid group double-grafted β-cyclodextrin graft are mixed by internal mixing, cooled and granulated to obtain a secondary interface construction master batch.

[0020] Preferably, in the step (1), the mass ratio of the β-cyclodextrin to the dodecanoyl chloride is 90-120:34-46; the mass ratio of the lauroylated β-cyclodextrin intermediate to the succinic anhydride is 95-125:8-12.

[0021] Preferably, in the step (2), the glycidyl methacrylate content of the ethylene-glycidyl methacrylate copolymer is 6wt%, and the melt mass flow rate thereof at 190℃ / 2.16kg is 3g / 10min.

[0022] Preferably, in the step (2), the melt mass flow rate of the styrene-acrylonitrile copolymer resin at 220℃ / 10kg is 26g / 10min.

[0023] Preferably, in the step (2), the mass ratio of the ethylene-glycidyl methacrylate copolymer to the styrene-acrylonitrile copolymer resin is 160-210:70-100.

[0024] Preferably, in the step (2), a co-rotating twin-screw extruder is used for melt grafting, the screw rotation speed is 260rpm-340rpm, the total feeding amount of the main feeding port is 2.5kg / h-3.5kg / h, and the temperature zone temperature is 155℃-165℃, 165℃-175℃, 175℃-185℃, 185℃-195℃, 195℃-205℃ and 195℃-205℃ from the feeding section to the die head in turn, and the vacuum exhaust is started in the middle and rear sections to-0.06±0.01MPa.

[0025] Preferably, in the step (3), the mass ratio of the reactive compatibilizer master batch to the triazine ultraviolet absorber UV-1577 is 220-310:20-30.

[0026] Preferably, in step (4), the mass ratio of the reaction compatibilizer masterbatch to the lauroyl / succinic acid-based double-grafted β-cyclodextrin graft is 240-340:10-20.

[0027] Furthermore, the present invention also provides a method for preparing a plastic alloy material for vehicle cover plates, comprising the following steps:

[0028] (i) Polybutylene terephthalate resin is reacted with epoxy chain extender, hydrolysis stabilizer and antioxidant by extrusion granulation to obtain polybutylene terephthalate end group reconstruction-hydrolysis stabilized masterbatch;

[0029] (ii) A segmented feeding reaction extrusion water-cooled pelletizing method is adopted. Polybutylene terephthalate end-group reconstruction-hydrolysis stabilizing masterbatch and polymethyl methacrylate resin are added at the main feeding port. Acrylonitrile-styrene-acrylate terpolymer resin is added at side feeding port one. Secondary interface construction masterbatch is added at side feeding port two. Premixed epoxy functionalized cage-like silsesquioxane and light stabilizer UV-622 are added at side feeding port three to obtain a plastic alloy material for vehicle cover.

[0030] Preferably, in step (i), the extrusion granulation uses a co-rotating twin-screw extruder with a screw speed of 220-280 rpm, a feed rate of 18-22 kg / h, and temperature zones from the feeding section to the die head of 230-240℃, 235-245℃, 240-250℃, 245-255℃, 245-255℃, and 240-250℃, and vacuum exhaust to -0.06±0.01 MPa in the middle and rear sections.

[0031] Preferably, in step (ii), the segmented feeding reaction extrusion adopts a co-rotating twin-screw extruder: the screw speed is 280-330 rpm, the feed rate is 22-28 kg / h, and the temperature zones from the feeding section to the die head are 225-235℃, 230-240℃, 235-245℃, 240-250℃, 245-255℃, 245-255℃, 240-250℃, and 235-245℃ respectively, and a vacuum exhaust is set to -0.06±0.01 MPa in the 9th temperature zone.

[0032] Preferably, in step (ii), the main feeding port is located in the first temperature zone, the first side feeding port is located in the fourth temperature zone, the second side feeding port is located in the sixth temperature zone, and the third side feeding port is located in the eighth temperature zone.

[0033] Furthermore, the present invention also provides an application of the above-mentioned plastic alloy material in the preparation of vehicle cover plates.

[0034] The beneficial effects of this invention are:

[0035] This invention effectively enhances the compatibility and interfacial bonding between multiphase polymers by introducing a lauroyl / succinic acid-based double-grafted β-cyclodextrin graft. The long lauroyl chain enhances the affinity with non-polar components such as polymethyl methacrylate resin, while the succinic acid group can react with the end groups of polybutylene terephthalate resin to form a chemical anchor, thereby constructing a continuous and stable transition layer at the phase interface. This structure not only suppresses surface haze and gloss loss caused by phase separation, but also significantly improves the dimensional stability and hydrolysis resistance of the material under humid and hot environments.

[0036] By covalently anchoring the triazine UV absorber into the reactive compatibilizer masterbatch, the UV-absorbing functional groups are immobilized and stabilized, preventing the migration and leaching of small molecule additives during processing and use. This design allows the UV absorber to be distributed uniformly in the polymer matrix for a long period of time, especially forming a continuous and effective shielding layer on the material surface, significantly delaying yellowing and molecular chain degradation caused by UV radiation, and improving the material's color retention ability in outdoor or strong light environments.

[0037] A reactive compatibilizer network was formed by a peroxide-initiated melt grafting reaction between ethylene-glycidyl methacrylate copolymer and styrene-acrylonitrile copolymer resin. This network not only effectively bridges the polybutylene terephthalate resin and the acrylonitrile-styrene-acrylate terephthalate copolymer resin, but also further strengthens the interfacial chemical bonding through the chain extension reaction of epoxy groups with the polybutylene terephthalate end groups, thereby improving the overall mechanical strength and impact resistance of the material.

[0038] By employing a segmented feeding process, epoxy-functionalized cage-like silsesquioxanes and light stabilizers are introduced into the later temperature zone of the extrusion process, preventing premature reaction or degradation under high-temperature and high-shear conditions. This operational strategy causes functional additives to be more inclined to distribute in the surface region of the polymer blend, effectively improving the density, hardness, and scratch resistance of the material surface, while maintaining the toughness and flowability of the matrix, achieving a balanced optimization of surface protection and bulk properties.

[0039] The synergistic effect of the above components and processes enables the final plastic alloy material to achieve a comprehensive improvement in weather resistance, mechanical strength and surface durability while maintaining good processability, thus meeting the requirements of appearance maintenance and functional stability of vehicle cover panels under long-term complex use environments. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0041] In this specific embodiment of the invention, β-cyclodextrin is sourced from Shanghai Aladdin Biochemical Technology Co., Ltd., product number C104384; ethylene-glycidyl methacrylate copolymer is sourced from Sumitomo Chemical, model Igetabond BF-2C, with a glycidyl methacrylate content of 6 wt% and a melt flow rate of 3 g / 10 min at 190℃ / 2.16 kg; styrene-acrylonitrile copolymer resin is sourced from Toray Plastics, model TOYOLAC A20C 333, with a melt flow rate of 26 g / 10 min at 220℃ / 10 kg; and polybutylene terephthalate resin is sourced from BASF, model Ultradur B4520 High Speed, with a melt volumetric flow rate of 50.0 cm³ at 250℃ / 2.16 kg. 3 / 10min; Epoxy chain extender from BASF, model Joncryl ADR-4400; Hydrolysis stabilizer from Rhein Chemicals, model Stabaxol P100; Acrylonitrile-styrene-acrylate terpolymer resin from Toray Plastics, model ASA TA50 X02, melt flow rate 25g / 10min at 220℃ / 10kg; Polymethyl methacrylate resin from ROHM, model PLEXIIGLAS 8N, melt volume flow rate 3cm at 230℃ / 3.8kg. 3 / 10min; The epoxy-functionalized cage-like silsesquioxane is from Hybrid Plastics, catalog number EP0409.

[0042] Example 1:

[0043] S1: Weigh 90g of β-cyclodextrin and add it to 750g of anhydrous N,N-dimethylformamide. Stir mechanically at 550rpm for 25min at 25℃ to form a homogeneous slurry. Cool the system to 8℃ and add 28g of triethylamine and 2.8g of 4-dimethylaminopyridine sequentially under nitrogen protection. Then, add 34g of dodecyl chloride dropwise at 8℃, controlling the dropwise addition time to 35min and maintaining the system temperature at 8℃. After the dropwise addition is completed, raise the temperature to 25℃ and continue stirring for 3.5h. After the reaction is completed, slowly pour the reaction solution into 1800g of acetone to precipitate. Filter to obtain the solid and wash it sequentially with 450g of acetone and 450g of deionized water. Finally, dry it at 45℃ and -0.08MPa vacuum for 10h to obtain lauroyl β-cyclodextrin intermediate.

[0044] S2: Weigh 95g of lauroyl β-cyclodextrin intermediate and add it to 650g of anhydrous dimethyl sulfoxide. Stir at 550rpm for 25min at 55℃. Under nitrogen protection, add 8g of succinic anhydride, 2.0g of triethylamine and 0.4g of 4-dimethylaminopyridine, and maintain the reaction at 55℃ for 5h. After the reaction is completed, cool to 25℃ and pour the reaction solution into 1800g of anhydrous ethanol to precipitate. Filter and wash with 900g of deionized water. Then dry at 65℃ and -0.08MPa vacuum for 10h to obtain lauroyl / succinic acid-based double-grafted β-cyclodextrin graft.

[0045] S3: Weigh 160g of ethylene-glycidyl methacrylate copolymer and 70g of styrene-acrylonitrile copolymer resin, pre-dry them separately in a 60℃ hot air oven for 2h, mix them, and add 0.8g of dicumyl peroxide for premixing for 10min; melt graft the above mixture through a conventional co-rotating twin-screw extruder, set the screw speed to 260rpm, the total feed rate at the main feed port to 2.5kg / h, and the temperature zones from the feeding section to the die head to be 155℃, 165℃, 175℃, 185℃, 195℃, and 195℃ respectively, and turn on the vacuum exhaust to -0.05MPa in the middle and rear sections to remove volatiles, extrude water-cooled strands and pellets to obtain reaction compatibilizer masterbatch;

[0046] S4: Weigh 220g of reaction compatibilizer masterbatch and add it to the internal mixer. Under nitrogen protection, set the chamber temperature to 170℃ and the rotor speed to 55rpm. After mixing for 3 minutes, add 20g of triazine UV absorber UV-1577 and continue mixing for 4 minutes. Discharge, cool and granulate to obtain reaction compatibilizer masterbatch.

[0047] S5: Weigh 240g of reaction compatibilizer masterbatch and add it to the internal mixer. Set the chamber temperature to 160℃ and the rotor speed to 55rpm and mix for 3min under nitrogen protection. Then add 10g of lauroyl / succinic acid double-grafted β-cyclodextrin graft and continue mixing for 3min. Discharge, cool and granulate to obtain secondary interface construction masterbatch.

[0048] S6: Weigh 6000g of polybutylene terephthalate resin, dehumidify and dry at 100℃ for 4h, then add 30g of epoxy chain extender, 20g of hydrolysis stabilizer, 12g of antioxidant 1010 and 12g of antioxidant 168. Perform reactive extrusion granulation using a conventional co-rotating twin-screw extruder. Set the screw speed to 220rpm, feed rate to 18kg / h, and temperature zones from the feeding section to the die head to be 230℃, 235℃, 240℃, 245℃, 245℃, and 240℃ respectively. Vacuum exhaust to -0.05MPa in the middle and rear sections to obtain polybutylene terephthalate end-group reconstruction-hydrolysis stabilized masterbatch.

[0049] S7: Weigh 6090g of polybutylene terephthalate end-group reconstruction-hydrolysis-resistant stabilized masterbatch, 2000g of acrylonitrile-styrene-acrylate terpolymer resin, and 2000g of polymethyl methacrylate resin, and dehumidify and dry them at 80℃ for 4 hours for later use. Weigh 250g of secondary interface construction masterbatch, 35g of epoxy functionalized cage-like silsesquioxane, and 15g of light stabilizer UV-622. Use a conventional co-rotating twin-screw extruder for segmented feeding reaction extrusion: simultaneously add 6090g of polybutylene terephthalate end-group reconstruction-hydrolysis-resistant stabilized masterbatch and 2000g of polymethyl methacrylate resin at the main feed port (temperature zone 1), and add the other two at the side feed port (located at temperature zone 4). 2000g of acrylonitrile-styrene-acrylate terpolymer resin was added to the first feed port (zone 6). 250g of secondary interface building masterbatch was added to the second side feed port (located in zone 6). 35g of premixed epoxy functionalized cage-like silsesquioxane and 15g of light stabilizer UV-622 were added to the third side feed port (located in zone 8). The screw speed was set to 280rpm, the feed rate to 22kg / h, and the zone temperatures from the feeding section to the die head were 225℃, 230℃, 235℃, 240℃, 245℃, 245℃, 240℃, and 235℃, respectively. Vacuum exhaust was set to -0.05MPa in zone 9, followed by extrusion and water cooling pelletizing to obtain a plastic alloy material for vehicle cover plates.

[0050] S8. Weigh 3000g of plastic alloy material for vehicle cover plates, dehumidify and dry at 80℃ for 4 hours, and then use conventional injection molding process to form cover plate samples with a thickness of 2mm. Set the barrel temperature from feeding section to nozzle as 230℃, 240℃, 248℃, 248℃, mold temperature 75℃, injection speed 70mm / s, holding pressure 55MPa, holding time 9s, and cooling time 28s. After demolding, place the sample in an environment of 23℃ and 50% relative humidity for 48 hours for conditioning before subsequent testing.

[0051] Example 2:

[0052] S1: Weigh 100g of β-cyclodextrin and add it to 800g of anhydrous N,N-dimethylformamide. Stir mechanically at 600rpm for 30min at 25℃ to form a homogeneous slurry. Cool the system to 5℃ and add 32g of triethylamine and 3.2g of 4-dimethylaminopyridine sequentially under nitrogen protection. Then, add 40g of dodecyl chloride dropwise at 5℃, controlling the dropwise addition time to 30min and maintaining the system temperature at 5℃. After the dropwise addition is completed, raise the temperature to 25℃ and continue stirring for 4h. After the reaction is completed, slowly pour the reaction solution into 2000g of acetone to precipitate. Filter to obtain the solid and wash it sequentially with 500g of acetone and 500g of deionized water. Finally, dry it at 50℃ and -0.08MPa vacuum for 12h to obtain lauroyl β-cyclodextrin intermediate.

[0053] S2: Weigh 110g of lauroyl β-cyclodextrin intermediate and add it to 700g of anhydrous dimethyl sulfoxide. Stir at 600rpm for 30min at 60℃. Under nitrogen protection, add 10g of succinic anhydride, 2.5g of triethylamine and 0.5g of 4-dimethylaminopyridine, and maintain the reaction at 60℃ for 6h. After the reaction is completed, cool to 25℃ and pour the reaction solution into 2000g of anhydrous ethanol to precipitate. Filter and wash with 1000g of deionized water. Then dry at 70℃ and -0.08MPa vacuum for 12h to obtain lauroyl / succinic acid-based double-grafted β-cyclodextrin graft.

[0054] S3: Weigh 180g of ethylene-glycidyl methacrylate copolymer and 80g of styrene-acrylonitrile copolymer resin, pre-dry them separately in a 60℃ hot air oven for 2h, mix them, and add 1g of dicumyl peroxide for 10min of premixing; melt graft the above mixture through a conventional co-rotating twin-screw extruder, set the screw speed to 300rpm, the total feed rate at the main feed port to 3kg / h, and the temperature zones from the feeding section to the die head to be 160℃, 170℃, 180℃, 190℃, 200℃, and 200℃ respectively, and turn on the vacuum exhaust to -0.06MPa in the middle and rear sections to remove volatiles, extrude water-cooled strands and pellets to obtain reactive compatibilizer masterbatch;

[0055] S4: Weigh 261g of reaction compatibilizer masterbatch and add it to the internal mixer. Under nitrogen protection, set the chamber temperature to 175℃ and the rotor speed to 60rpm. After mixing for 3 minutes, add 25g of triazine UV absorber UV-1577 and continue mixing for 5 minutes. Discharge, cool and granulate to obtain reaction compatibilizer masterbatch.

[0056] S5: Weigh 286g of reaction compatibilizer masterbatch and add it to the internal mixer. Set the chamber temperature to 165℃ and the rotor speed to 60rpm and mix for 4min under nitrogen protection. Then add 14g of lauroyl / succinic acid double-grafted β-cyclodextrin graft and continue mixing for 4min. Discharge, cool and granulate to obtain secondary interface construction masterbatch.

[0057] S6: Weigh 6000g of polybutylene terephthalate resin, dehumidify and dry at 100℃ for 4h, then add 35g of epoxy chain extender, 25g of hydrolysis stabilizer, 15g of antioxidant 1010 and 15g of antioxidant 168. Perform reactive extrusion granulation using a conventional co-rotating twin-screw extruder. Set the screw speed to 250rpm, feed rate to 20kg / h, and the temperature zones from the feeding section to the die head to be 235℃, 240℃, 245℃, 250℃, 250℃, and 245℃ respectively. Vacuum exhaust to -0.06MPa in the middle and rear sections to obtain polybutylene terephthalate end-group reconstruction-hydrolysis stabilized masterbatch.

[0058] S7: Weigh 6090g of polybutylene terephthalate end-group reconstruction-hydrolysis-resistant stabilized masterbatch, 2000g of acrylonitrile-styrene-acrylate terpolymer resin, and 2000g of polymethyl methacrylate resin, and dehumidify and dry them at 80℃ for 4 hours for later use. Weigh 300g of secondary interface construction masterbatch, 50g of epoxy functionalized cage-like silsesquioxane, and 20g of light stabilizer UV-622. Use a conventional co-rotating twin-screw extruder for segmented feeding reaction extrusion: simultaneously add 6090g of polybutylene terephthalate end-group reconstruction-hydrolysis-resistant stabilized masterbatch and 2000g of polymethyl methacrylate resin at the main feed port (temperature zone 1), and add the other two at the side feed port (located at temperature zone 4). 2000g of acrylonitrile-styrene-acrylate terpolymer resin was added to the first feed port (zone 6). 300g of secondary interface building masterbatch was added to the second side feed port (located in zone 6). 50g of premixed epoxy functionalized cage-like silsesquioxane and 20g of light stabilizer UV-622 were added to the third side feed port (located in zone 8). The screw speed was set to 300rpm, the feed rate to 25kg / h, and the zone temperatures from the feeding section to the die head were 230℃, 235℃, 240℃, 245℃, 250℃, 250℃, 245℃, and 240℃, respectively. Vacuum exhaust was set to -0.06MPa in zone 9, followed by extrusion and water cooling pelletizing to obtain a plastic alloy material for vehicle cover plates.

[0059] S8. Weigh 3000g of plastic alloy material for vehicle cover plates, dehumidify and dry at 80℃ for 4 hours, and then use conventional injection molding process to form cover plate samples with a thickness of 2mm. Set the barrel temperature from the feeding section to the nozzle as 235℃, 245℃, 250℃, 250℃, mold temperature 80℃, injection speed 80mm / s, holding pressure 60MPa, holding time 10s, and cooling time 25s. After demolding, place the sample in an environment of 23℃ and 50% relative humidity for 48 hours to acclimate for subsequent testing.

[0060] Example 3:

[0061] S1: Weigh 120g of β-cyclodextrin and add it to 850g of anhydrous N,N-dimethylformamide. Stir mechanically at 650rpm for 35min at 25℃ to form a homogeneous slurry. Cool the system to 2℃ and add 38g of triethylamine and 3.8g of 4-dimethylaminopyridine sequentially under nitrogen protection. Then, add 46g of dodecyl chloride dropwise at 2℃, controlling the dropwise addition time to 25min and maintaining the system temperature at 2℃. After the dropwise addition is completed, raise the temperature to 25℃ and continue stirring for 4.5h. After the reaction is completed, slowly pour the reaction solution into 2200g of acetone to precipitate. Filter to obtain the solid and wash it sequentially with 550g of acetone and 550g of deionized water. Finally, dry it at 55℃ and -0.08MPa vacuum for 14h to obtain lauroyl β-cyclodextrin intermediate.

[0062] S2: Weigh 125g of lauroyl β-cyclodextrin intermediate and add it to 750g of anhydrous dimethyl sulfoxide. Stir at 650rpm for 35min at 65℃. Under nitrogen protection, add 12g of succinic anhydride, 3.0g of triethylamine and 0.6g of 4-dimethylaminopyridine, and maintain the reaction at 65℃ for 7h. After the reaction is completed, cool to 25℃ and pour the reaction solution into 2200g of anhydrous ethanol to precipitate. Filter and wash with 1100g of deionized water. Then dry at 75℃ and -0.08MPa vacuum for 14h to obtain lauroyl / succinic acid-based double-grafted β-cyclodextrin graft.

[0063] S3: Weigh 210g of ethylene-glycidyl methacrylate copolymer and 100g of styrene-acrylonitrile copolymer resin, pre-dry them separately in a 60℃ hot air oven for 2h, mix them, and add 1.4g of dicumyl peroxide for 10min of premixing; melt graft the above mixture through a conventional co-rotating twin-screw extruder, set the screw speed to 340rpm, the total feed rate at the main feed port to 3.5kg / h, and the temperature zones from the feeding section to the die head to be 165℃, 175℃, 185℃, 195℃, 205℃, and 205℃ respectively, and turn on the vacuum exhaust to -0.07MPa in the middle and rear sections to remove volatiles, extrude water-cooled strands and pellets to obtain reaction compatibilizer masterbatch;

[0064] S4: Weigh 310g of reaction compatibilizer masterbatch and add it to the internal mixer. Under nitrogen protection, set the chamber temperature to 180℃ and the rotor speed to 65rpm. After mixing for 3 minutes, add 30g of triazine UV absorber UV-1577 and continue mixing for 6 minutes. Discharge, cool and granulate to obtain reaction compatibilizer masterbatch.

[0065] S5: Weigh 340g of reaction compatibilizer masterbatch and add it to the internal mixer. Set the chamber temperature to 170℃ and the rotor speed to 65rpm and mix for 4min under nitrogen protection. Then add 20g of lauroyl / succinic acid double-grafted β-cyclodextrin graft and continue mixing for 5min. Discharge, cool and granulate to obtain secondary interface construction masterbatch.

[0066] S6: Weigh 6000g of polybutylene terephthalate resin, dehumidify and dry it at 100℃ for 4h, then add 40g of epoxy chain extender, 30g of hydrolysis stabilizer, 18g of antioxidant 1010 and 18g of antioxidant 168. Use a conventional co-rotating twin-screw extruder for reactive extrusion granulation. Set the screw speed to 280rpm, the feed rate to 22kg / h, and the temperature zones from the feeding section to the die head to be 240℃, 245℃, 250℃, 255℃, 255℃, and 250℃ respectively. Vacuum exhaust to -0.07MPa in the middle and rear sections to obtain polybutylene terephthalate end-group reconstruction-hydrolysis stabilized masterbatch.

[0067] S7: Weigh 6090g of polybutylene terephthalate end-group reconstruction-hydrolysis-resistant stabilized masterbatch, 2000g of acrylonitrile-styrene-acrylate terpolymer resin, and 2000g of polymethyl methacrylate resin, and dehumidify and dry them at 80℃ for 4 hours for later use. Weigh 350g of secondary interface construction masterbatch, 65g of epoxy functionalized cage-like silsesquioxane, and 25g of light stabilizer UV-622. Use a conventional co-rotating twin-screw extruder for segmented feeding reaction extrusion: simultaneously add 6090g of polybutylene terephthalate end-group reconstruction-hydrolysis-resistant stabilized masterbatch and 2000g of polymethyl methacrylate resin at the main feed port (temperature zone 1), and add the other two at the side feed port (located at temperature zone 4). 2000g of acrylonitrile-styrene-acrylate terpolymer resin was added to the first feed port (zone 6). 350g of secondary interface building masterbatch was added to the second side feed port (located in zone 6). 65g of premixed epoxy functionalized cage-like silsesquioxane and 25g of light stabilizer UV-622 were added to the third side feed port (located in zone 8). The screw speed was set to 330rpm, the feed rate to 28kg / h, and the zone temperatures from the feeding section to the die head were 235℃, 240℃, 245℃, 250℃, 255℃, 255℃, 250℃, and 245℃, respectively. Vacuum exhaust was set to -0.07MPa in zone 9, followed by extrusion and water cooling pelletizing to obtain a plastic alloy material for vehicle cover plates.

[0068] S8. Weigh 3000g of plastic alloy material for vehicle cover plates, dehumidify and dry at 80℃ for 4 hours, and then use conventional injection molding process to form cover plate samples with a thickness of 2mm. Set the barrel temperature from the feeding section to the nozzle as 240℃, 250℃, 255℃, 255℃, mold temperature 85℃, injection speed 90mm / s, holding pressure 65MPa, holding time 12s, and cooling time 22s. After demolding, place the sample in an environment of 23℃ and 50% relative humidity for 48 hours to acclimate for subsequent testing.

[0069] The difference between Comparative Example 1 and Example 2 is that in step S5, 14g of lauroyl / succinic acid double-grafted β-cyclodextrin graft was replaced with 14g of β-cyclodextrin, while the other conditions were the same as in Example 2.

[0070] The difference between Comparative Example 2 and Example 2 is that in step S5, 14g of lauroyl / succinic acid double-grafted β-cyclodextrin graft was replaced with 14g of lauroylated β-cyclodextrin intermediate, and the other conditions were the same as in Example 2.

[0071] The difference between Comparative Example 3 and Example 2 is that step S4, which involves preparing the reaction compatibilizer masterbatch, is omitted. Instead, in step S5, 261g of the reaction compatibilizer masterbatch is used as the matrix and the mixture is stirred at 165°C and 60rpm under nitrogen protection for 4 minutes. At the same time, 25g of triazine UV absorber UV-1577 and 14g of lauroyl / succinic acid double-grafted β-cyclodextrin graft are added and stirred for another 4 minutes. The mixture is then discharged, cooled, and granulated to obtain the secondary interface construction masterbatch. The remaining conditions are the same as in Example 2.

[0072] The difference between Comparative Example 4 and Example 2 is that 1g of dicumyl peroxide was not added for premixing for 10 minutes in step S3, while the other conditions were the same as in Example 2.

[0073] The difference between Comparative Example 5 and Example 2 is that in step S3, 80g of styrene-acrylonitrile copolymer resin was replaced with an equal mass of ethylene-glycidyl methacrylate copolymer (i.e., in step S3, the ethylene-glycidyl methacrylate copolymer was 260g and the styrene-acrylonitrile copolymer resin was 0g), and the other conditions were the same as in Example 2.

[0074] The difference between Comparative Example 6 and Example 2 is that in step S7, instead of adding 50g of premixed epoxy functionalized cage-like silsesquioxane and 20g of light stabilizer UV-622 at the side feed port three (located in the 8th temperature zone), it is added at the main feed port (the 1st temperature zone) simultaneously with the polybutylene terephthalate end-group reconstruction-hydrolysis stabilizing masterbatch and polymethyl methacrylate resin. The other conditions are the same as in Example 2.

[0075] Performance testing:

[0076] Sample preparation: The example samples and comparative sample were prepared into plastic alloy material granules for vehicle cover plates according to their respective steps S7; then, they were all injection molded and conditioned according to step S8. The test specimens required for tensile, bending, impact and heat distortion temperature tests related to the standard specimen size were prepared in accordance with the multi-purpose specimen preparation principle specified in GB / T 17037.1-2019 using the same batch of granules under the same injection molding conditions and conditioned in the standard environment specified in GB / T 2918-2018.

[0077] Differential scanning calorimetry (DSC) characterization: DSC tests were performed on the examples and comparative samples according to GB / T 19466.3-2004. 8 mg of each sample was placed in an aluminum crucible and sealed. A three-stage heating-cooling-heating program was performed under a nitrogen atmosphere (50 mL / min). The program was as follows: heating from 30 °C to 260 °C (10 °C / min) and holding for 3 min to eliminate thermal history; then cooling to 30 °C at 10 °C / min and holding for 3 min; finally, heating back to 260 °C at 10 °C / min. The melting temperature Tm, crystallization temperature Tc, and enthalpy of fusion ΔHm were recorded, and the degree of crystallinity was calculated based on the theoretical enthalpy of fusion.

[0078] Yellow Index and its Variation: The yellow index YI and its variation ΔYI of the 2mm cover plate samples of the examples and comparative examples were determined according to GB / T 39822-2021. A spectrophotometer was used with a light source of D65, a field of view of 10°, and a geometric condition of D / 8 (including specular reflection). The measurement wavelength range was 400-700nm with a wavelength interval of 10nm. YI was measured at three locations for each sample in its initial state, and the average was taken as YI0. Subsequently, the samples in the same batch were subjected to xenon arc aging and constant humidity heat treatment, respectively. After aging or humidity heat treatment, YI was obtained under the same measurement conditions. t , and calculate ΔYI=YI t -YI0;

[0079] Color difference determination: The color of objects was measured according to the method specified in GB / T 3979-2008, and the color difference was calculated based on the standard illuminant and geometric conditions specified in GB / T 3978-2008 and the color difference formula in GB / T 7921-2008. The color difference of the examples and comparative samples was calculated using a spectrophotometer with a light source of D65, a field of view of 10°, and geometric conditions of D / 8 (including specular reflection). The L*, a*, and b* of each sample were measured in the initial state and the average was taken as the reference. After xenon arc aging or constant humidity and heat treatment, L*, a*, and b* were measured again. ΔEab was calculated according to the CIE 1976 (Lab*) color difference formula and used as the evaluation index for appearance stability.

[0080] Xenon arc lamp accelerated aging: The 2mm cover plate samples of the examples and comparative examples were subjected to xenon arc lamp accelerated aging according to GB / T 16422.2-2022. An xenon arc lamp aging chamber equipped with a daylight filter was used, and the irradiance was set to 0.55W / m². 2(340nm), blackboard temperature 63℃, chamber temperature 38℃, relative humidity 50%, spray cycle set to 102min light irradiation and 18min light irradiation with water spray, cumulative aging time 1000h; after aging, the sample was placed in an environment of 23℃ and 50% relative humidity for 24h, and the yellow index was retested and ΔYI was calculated according to GB / T 39822-2021, and ΔEab was calculated according to the CIE 1976 (Lab*) color difference formula;

[0081] Constant humidity and heat aging: The samples of the examples and comparative examples were subjected to constant humidity and heat aging according to GB / T 2423.3-2016 to evaluate hydrolytic stability. The 2mm cover plate samples were placed in a constant temperature and humidity chamber, with the temperature set at 85℃ and the relative humidity at 85%, and exposed continuously for 500h. After the treatment, the samples were placed in an environment of 23℃ and 50% relative humidity for 24h. The yellow index was retested according to GB / T 39822-2021 and ΔYI was calculated. ΔEab was calculated according to the color difference formula of CIE 1976 (Lab*). The tensile strength of the multipurpose samples in the same batch was tested according to GB / T 1040.2-2018 and the strength retention rate was calculated (retention rate = tensile strength after humidity and heat / initial tensile strength × 100%).

[0082] Scratch damage: Scratch damage and scratch visibility were assessed for the examples and comparative samples according to GB / T 44303-2024. A constant load method was used at 23°C with a spherical indenter (end radius 1.0 mm), a load of 10 N, a scratching speed of 100 mm / min, a single scratch length of 50 mm, and 5 parallel scratches were made on each sample with a spacing of 5 mm between adjacent scratches. After scratching, the L*, a*, and b values ​​of the scratch trajectory centerline and the L*, a*, and b* values ​​of the adjacent unscratched areas were measured under the same spectrophotometric conditions (D65, 10°, D / 8 including specular reflection). ΔE*ab was used as the scratch visibility index, and the average value of 5 scratches was taken for each sample.

[0083] Tensile properties: The tensile properties of the examples and comparative samples were determined according to GB / T 1040.2-2018. Multipurpose specimens prepared according to GB / T 17037.1-2019 were used, and the tensile section was taken as the tensile specimen. After conditioning in an environment of 23℃ and 50% relative humidity for 48 hours, the test was carried out. The clamp spacing was 50 mm, and the test speed was 50 mm / min. Five specimens were tested for each sample, and the average value was taken. The tensile strength and elongation at break were recorded.

[0084] Heat distortion temperature: The heat distortion temperature of the sample in Implementation 2 and the comparative example was determined according to GB / T 1634.2-2019. Using 80mm×10mm×4mm test strips, the temperature at which the specified deflection was reached was measured under a loading condition of 1.8MPa and a heating rate of 2℃ / min. Three test strips were tested for each sample and the average value was taken. The test results are shown in Table 1.

[0085] Table 1 Performance Test Results

[0086] Item Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Initial Yellow Index 1.8 1.6 2.0 2.6 2.3 2.1 2.0 2.2 2.4 ΔYI after Xenon Arc Aging 1000 h 1.3 0.9 1.1 2.7 2.1 1.9 1.8 2.2 1.4 ΔΕab after Xenon Arc Aging 1000 h 1.9 1.3 1.5 3.2 2.7 2.9 2.5 2.8 2.1 ΔYI after Constant Hygrothermal 500 h 1.9 1.4 1.7 3.0 2.4 2.1 2.3 2.6 2.2 ΔΕab after Constant Hygrothermal 500 h 2.3 1.6 2.0 3.6 3.1 2.7 2.9 3.3 2.5 Tensile Strength Retention / % after Constant Hygrothermal 500 h 90.2 93.5 92.0 84.3 86.8 91.0 89.5 85.7 88.6 Scratch Visibility ΔΕ*ab 1.6 1.2 1.0 2.9 2.5 2.2 2.4 2.6 2.3 Tensile Strength / MPa 56.2 58.5 59.1 52.4 53.7 56.8 54.1 53.0 55.6 Elongation at Break / % 47.8 45.3 42.5 35.6 38.9 49.2 40.5 37.4 33.1 Heat Distortion Temperature (1.8 MPa) / °C 91.2 93.0 94.4 89.8 90.6 92.2 90.1 89.5 96.0

[0087] Data Analysis:

[0088] As can be seen from the data in Examples 1-3 of Table 1, the plastic alloy material for vehicle cover plates prepared by this invention maintains stability in terms of initial appearance color, color retention after xenon arc aging and constant humid heat, scratch visibility, and comprehensive mechanical and heat resistance properties. This is because the lauroyl / succinic acid-based double-grafted β-cyclodextrin graft enhances the compatibility with polymethyl methacrylate resin and acrylonitrile-styrene-acrylate terpolymer resin through the lauroyl group, and utilizes the succinic acid group to chemically couple with the end groups and epoxy-containing segments of polybutylene terephthalate resin, constructing a continuous interfacial transition layer. The reactive compatibility system formed by the ethylene-glycidyl methacrylate copolymer and the styrene-acrylonitrile copolymer resin enhances interphase bonding and inhibits microcrack initiation. The grafting and immobilization of triazine UV absorber UV-1577 and the synergistic stabilization of light stabilizer UV-622, combined with the contribution of epoxy-functionalized cage-like silsesquioxane to surface densification and scratch resistance, enable the material to maintain high tensile strength and heat distortion temperature while achieving long-term maintenance of appearance durability.

[0089] As can be seen from the data in Table 1 for Example 2 and Comparative Example 1, when only unmodified β-cyclodextrin is used, the changes in yellow index and color difference after xenon arc aging and constant humid heat are greater, the tensile strength retention rate after humid heat decreases, and scratches are more easily observed. This is because β-cyclodextrin is highly hydrophilic and easily absorbs moisture, forming polar enrichment and microporous defects at the interface, promoting water vapor penetration and photo-oxidation. Therefore, it is evident that compatibility needs to be improved through lauroyl groups and reaction anchored through succinic acid groups to achieve synergistic effects.

[0090] As can be seen from the data in Table 1 for Example 2 and Comparative Example 2, when only lauroyl groups are introduced without succinic acid groups for reaction anchoring, the yellow index changes and color differences are still greater after aging and humid heat, and the mechanical retention rate is also reduced. The reason is that lauroyl groups mainly improve dispersion, but the interface is still mainly physically entangled, and the additives and phase boundary structures are easily migrated and relaxed under the action of light, heat, and water vapor.

[0091] As can be seen from the data in Table 1 for Example 2 and Comparative Example 3, when the triazine UV absorber UV-1577 was not pre-grafted and fixed in step S4 but instead added in a blend, the color difference and yellow index changes after xenon arc aging increased, and the visibility of scratches increased, but the elongation at break actually increased. This may be because the unfixed triazine UV absorber UV-1577 migrates more easily and forms microphase separation on the surface, weakening the continuous shielding and amplifying the optical contrast; at the same time, the reduced grafting reaction lowers the interface constraint and increases ductility.

[0092] As can be seen from the data in Table 1 for Example 2 and Comparative Example 4, when dicumyl peroxide is not added in step S3, the tensile strength and retention rate after damp heat decrease, the color difference and yellow index changes after xenon arc aging and constant damp heat increase, and the scratches are more obvious. This is because the absence of dicumyl peroxide makes it difficult for the ethylene-glycidyl methacrylate copolymer and styrene-acrylonitrile copolymer resin to form an effective graft structure. The epoxy groups cannot be directionally enriched at the interface and fully react with the end groups of the polybutylene terephthalate resin, leading to an amplified interfacial channel effect.

[0093] As can be seen from the data in Table 1 for Example 2 and Comparative Example 5, replacing the styrene-acrylonitrile copolymer resin with additional ethylene-glycidyl methacrylate copolymer resulted in decreased tensile strength, elongation at break, and retention after damp heat, while increasing color difference and yellow index changes after aging and damp heat. This is because the styrene-acrylonitrile copolymer resin provides a polar and rigid framework that matches the acrylonitrile-styrene-acrylate terpolymer resin and stabilizes the distribution of the epoxy-reactive phase; its absence leads to interfacial imbalance, making the synergistic effect difficult to manifest.

[0094] As can be seen from the data in Table 1 for Example 2 and Comparative Example 6, when epoxy-functionalized cage-like silsesquioxane and light stabilizer UV-622 are added to the main feedstock in advance, although the heat distortion temperature can increase, the elongation at break decreases, the visibility of scratches increases, and the color retention deteriorates after aging. This may be because a competitive reaction and local microgelation occur under high temperature and high shear in the early stage, increasing the heat modulus but reducing ductility and inducing surface roughness, while simultaneously weakening the sustained effect of the light stabilizer UV-622 on the surface.

[0095] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.

Claims

1. A plastic alloy material for vehicle cover plates, characterized in that, The product is prepared by weight of 6090 parts of polybutylene terephthalate end-group reconstruction-hydrolysis stabilizing masterbatch, 2000 parts of acrylonitrile-styrene-acrylate terpolymer resin, 2000 parts of polymethyl methacrylate resin, 250-350 parts of secondary interface construction masterbatch, 35-65 parts of epoxy functionalized cage-like silsesquioxane and 15-25 parts of light stabilizer UV-622. The polybutylene terephthalate end-group reconstruction-hydrolysis stabilizing masterbatch is prepared by weight of 6000 parts polybutylene terephthalate resin, 30-40 parts epoxy chain extender, 20-30 parts hydrolysis stabilizer, 12-18 parts antioxidant 1010 and 12-18 parts antioxidant 168. The preparation steps of the secondary interface construction masterbatch are as follows: (1) β-Cyclodextrin and dodecyl chloride were reacted by acyl chloride reaction to obtain lauroyl β-cyclodextrin intermediate; then lauroyl β-cyclodextrin intermediate was reacted with succinic anhydride by ring-opening esterification to obtain lauroyl / succinic acid double-grafted β-cyclodextrin graft. (2) Ethylene-glycidyl methacrylate copolymer and styrene-acrylonitrile copolymer resin were melt grafted under the initiation of dicumyl peroxide to obtain reactive compatibilizer masterbatch; (3) The reactive compatibilizer masterbatch was obtained by a ring-opening addition grafting reaction with the triazine UV absorber UV-1577; (4) The reaction compatibilizer masterbatch and lauroyl / succinic acid double-grafted β-cyclodextrin graft are mixed by intensive mixing, cooled and granulated to obtain secondary interface construction masterbatch.

2. The plastic alloy material for vehicle cover plates according to claim 1, characterized in that, In step (1), the mass ratio of β-cyclodextrin to dodecyl chloride is 90-120:34-46; the mass ratio of lauroyl β-cyclodextrin intermediate to succinic anhydride is 95-125:8-12; in step (2), the mass ratio of ethylene-glycidyl methacrylate copolymer to styrene-acrylonitrile copolymer resin is 160-210:70-100; in step (3), the mass ratio of reaction compatibilizer masterbatch to triazine UV absorber UV-1577 is 220-310:20-30; in step (4), the mass ratio of reaction compatibilizer masterbatch to lauroyl / succinic acid double-grafted β-cyclodextrin graft is 240-340:10-20.

3. The plastic alloy material for vehicle cover plates according to claim 1, characterized in that, The acrylonitrile-styrene-acrylate terpolymer resin has a melt mass flow rate of 25 g / 10 min at 220℃ / 10 kg; the polymethyl methacrylate resin has a melt volume flow rate of 3 cm³ at 230℃ / 3.8 kg. 3 / 10min; The epoxy-functionalized cage-like silsesquioxane is from Hybrid Plastics, catalog number EP0409.

4. The plastic alloy material for vehicle cover plates according to claim 1, characterized in that, In step (2), the glycidyl methacrylate content of the ethylene-glycidyl methacrylate copolymer is 6wt%, and the melt flow rate is 3g / 10min at 190℃ / 2.16kg; the melt flow rate of the styrene-acrylonitrile copolymer resin is 26g / 10min at 220℃ / 10kg.

5. The plastic alloy material for vehicle cover plates according to claim 1, characterized in that, In step (2), the melt grafting is performed using a co-rotating twin-screw extruder with a screw speed of 260 rpm to 340 rpm, a total feed rate of 2.5 kg / h to 3.5 kg / h at the main feed port, and temperature zones from the feeding section to the die head of 155℃-165℃, 165℃-175℃, 175℃-185℃, 185℃-195℃, 195℃-205℃, and 195℃-205℃, and vacuum exhaust is activated in the middle and rear sections to -0.06±0.01 MPa.

6. A method for preparing a plastic alloy material for vehicle cover plates according to any one of claims 1-5, characterized in that, Includes the following steps: (i) Polybutylene terephthalate resin is reacted with epoxy chain extender, hydrolysis stabilizer and antioxidant by extrusion granulation to obtain polybutylene terephthalate end group reconstruction-hydrolysis stabilized masterbatch; (ii) A segmented feeding reaction extrusion water-cooled pelletizing method is adopted. Polybutylene terephthalate end-group reconstruction-hydrolysis stabilizing masterbatch and polymethyl methacrylate resin are added at the main feeding port. Acrylonitrile-styrene-acrylate terpolymer resin is added at side feeding port one. Secondary interface construction masterbatch is added at side feeding port two. Premixed epoxy functionalized cage-like silsesquioxane and light stabilizer UV-622 are added at side feeding port three to obtain a plastic alloy material for vehicle cover.

7. The method for preparing the plastic alloy material for vehicle cover plates according to claim 6, characterized in that, In step (i), the extrusion granulation uses a co-rotating twin-screw extruder with a screw speed of 220-280 rpm, a feed rate of 18-22 kg / h, and temperature zones from the feeding section to the die head of 230-240℃, 235-245℃, 240-250℃, 245-255℃, 245-255℃, and 240-250℃, and vacuum exhaust to -0.06±0.01 MPa in the middle and rear sections.

8. The method for preparing the plastic alloy material for vehicle cover plates according to claim 6, characterized in that, In step (ii), the segmented feeding reaction extrusion adopts a co-rotating twin-screw extruder: the screw speed is 280-330 rpm, the feed rate is 22-28 kg / h, and the temperature zones from the feeding section to the die head are 225-235℃, 230-240℃, 235-245℃, 240-250℃, 245-255℃, 245-255℃, 240-250℃, and 235-245℃ respectively, and a vacuum exhaust is set to -0.06±0.01 MPa in the 9th temperature zone.

9. The method for preparing the plastic alloy material for vehicle cover plates according to claim 6, characterized in that, In step (ii), the main feed port is located in the first temperature zone, the first side feed port is located in the fourth temperature zone, the second side feed port is located in the sixth temperature zone, and the third side feed port is located in the eighth temperature zone.

10. The use of a plastic alloy material for vehicle cover plates according to any one of claims 1-5 in the manufacture of vehicle cover plates.