Heat-resistant anti-aging ABS composite plastic and preparation method thereof

Abstract

The invention discloses heat-resistant and anti-aging ABS (acrylonitrile butadiene styrene) composite plastic and a preparation method thereof, belongs to the technical field of ABS composite plastic processing, and aims to solve the technical problem that the heat resistance and the aging resistance of an ABS composite material in the prior art need to be further improved. The preparation method comprises the following steps: adding ABS resin, methyl methacrylate and an initiator into a high-speed mixer at the temperature of 200-220 DEG C, and mixing for 5-10 minutes to obtain modified ABS resin, by preparing the modified ABS resin and an anti-aging agent and modifying N-phenylmaleimide, the heat resistance and the aging resistance of the ABS composite plastic are improved, and the service life of the ABS composite plastic is prolonged. Meanwhile, the mechanical property of the material is also retained.

Description

Technical Field

[0001] The present invention relates to the technical field of ABS composite plastic processing, and particularly relates to a heat-resistant and anti-aging ABS composite plastic and a preparation method thereof. Background Art

[0002] ABS is a common two-phase and three-component polymer material, a thermoplastic plastic between general-purpose plastics and engineering plastics. It consists of a dispersed phase of polybutadiene rubber and a continuous phase of polystyrene-acrylonitrile. The rubber dispersed phase is bonded to the molecular chains of the SAN continuous phase through a graft polymerization mechanism, generating a necessary interfacial fusion with the matrix resin, thereby dispersing the rubber molecules into the SAN resin. Acrylonitrile, butadiene, and styrene monomers endow ABS with heat resistance, chemical stability, impact resistance, easy molding processing, and surface glossiness. Therefore, ABS is widely used in fields such as electromechanical products, the automotive industry, textiles, appliances, and building materials, becoming an indispensable and important material in human social life.

[0003] However, the butadiene rubber phase in ABS is rich in double bonds and is prone to free radical chain reactions under ultraviolet irradiation, resulting in molecular chain breakage and the formation of chromogenic groups, that is, the surface of the material turns yellow. In a high-temperature environment, styrene and acrylonitrile in ABS are easily oxidized and degraded, the brittleness of the material increases, and the notched impact strength decreases. If exposed to the outdoor environment for a long time, ABS components are prone to cracks and powdering, and it is affected by the environment and undergoes aging to varying degrees;

[0004] Moreover, processes such as crushing, extrusion granulation, and injection in the production process will further accelerate its aging process. The rubber phase that provides toughness to ABS has a more obvious aging degree due to its specific structure, so the decrease in the toughness of ABS is usually relatively large. Therefore, in most cases, ABS must be modified.

[0005] In the prior art, usually ultraviolet absorbers and light stabilizers are added to ABS, but the effects are not ideal. The industry is turning to solve the heat-resistant and anti-aging performance of ABS composite plastics. Through the blending modification of materials, its heat-resistant and anti-aging performance has been improved, and the original mechanical properties have also been retained. Summary of the Invention

[0006] The purpose of the present invention is to provide a heat-resistant and anti-aging ABS composite plastic and a preparation method thereof, which are used to solve the technical problems of poor heat resistance, poor anti-aging ability, and the need to further improve the mechanical properties of ABS composite plastics in the prior art.

[0007] The purpose of the present invention can be achieved through the following technical solutions: A preparation method of a heat-resistant and anti-aging ABS composite plastic, comprising the following steps:

[0008] S1. Add ABS resin, methyl methacrylate, and initiator into a high-speed mixer at a temperature of 200 - 220 °C, and mix for 5 - 10 minutes to obtain modified ABS resin;

[0009] S2. Add the modified ABS resin, anti-aging agent, antioxidant, heat-resistant modifier, processing aid, and initiator into a twin-screw extruder, melt and extrude, and pelletize to obtain an ABS mixture;

[0010] S3. Add the modified ABS mixture into a mold, set the temperature at 120 - 130 °C, the pressure at 15 - 30 MPa, perform heat preservation and pressure holding treatment for 60 min, and discharge to obtain ABS composite plastic.

[0011] Furthermore, in step S1, the weight ratio of ABS resin, methyl methacrylate, and initiator is 20:3:0.12, and the initiator is dibenzoyl peroxide; in step S2, the weight ratio of the modified ABS resin, anti-aging agent, antioxidant, heat-resistant modifier, processing aid, and initiator is 80:1.1:0.3:15:0.2:0.5, the initiator is dibenzoyl peroxide, the processing aid is composed of dibutylhydroxytoluene and calcium stearate in a weight ratio of 1:3, and the temperature of the twin-screw extruder is set as follows: the T1 zone is 100 - 130 °C, the T2 - T5 zones are 190 - 205 °C, and the T6 - T12 zones are 205 - 210 °C.

[0012] Furthermore, the processing method of the anti-aging agent in step S2 is as follows: Put UV-3853, toluene, and initiator into a four-necked flask, heat up to 80 - 100 °C under N 2 protection, react for 40 min, add styrene and α-methylstyrene into the flask, keep the reaction for 6 - 8 hours, and perform post-treatment to obtain the anti-aging agent.

[0013] The reaction mechanism for synthesizing the anti-aging agent is as follows:

[0014] In the free radical copolymerization reaction, the initiator decomposes to generate free radicals, which attack the double bond of the monomer to form free radical intermediates; styrene or α-methylstyrene attacks the double bond of another monomer to form an alternating copolymer, and two free radicals couple and terminate to form a stable copolymer chain; under the action of the initiator, the benzene ring or hydroxyl group of UV-3853 initiates a free radical reaction and undergoes a grafting reaction with the copolymer chain to obtain the anti-aging agent.

[0015] Furthermore, the dosage ratio of the UV-3853, toluene, initiator, styrene, and α-methylstyrene is 0.4 g:30 mL:0.2 g:15 g:5 g, and the initiator is azobisisobutyronitrile; the post-treatment includes: after the reaction is completed, distill off the low-boiling substances under reduced pressure to obtain the anti-aging agent.

[0016] Further, in step S2, the antioxidant is composed of a primary antioxidant and a secondary antioxidant compounded at a weight ratio of 1:1. The primary antioxidant is pentaerythritol tetrakis [β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], and the secondary antioxidant is tris(2,4-di-tert-butylphenyl) phosphite.

[0017] Further, the heat-resistant modifier in step 2 is prepared by the following steps:

[0018] A1. Ultrasonically disperse nano-SiO 2 and KH-550 coupling agent in an ethanol solution for 60 min at a temperature of 35-45 °C, and perform post-treatment to obtain pretreated nano-SiO 2 ;

[0019] A2. Add N-phenylmaleimide and toluene to a three-necked flask under nitrogen protection and stir. Add azobisisobutyronitrile, raise the temperature of the three-necked flask to 60-80 °C, add pretreated nano-SiO 2 , react for 6-8 hours, and perform post-treatment to obtain the heat-resistant modifier.

[0020] The synergistic reaction mechanism of N-phenylmaleimide and nano-SiO2 is as follows:

[0021] In the pretreatment of nano-SiO2, the surface of SiO2 is modified with a silane coupling agent to introduce amino groups. Under the action of an initiator, the double bond of N-phenylmaleimide is activated, and ring-opening polymerization occurs to generate a poly(maleimide) prepolymer. Add the pretreated nano-SiO2 to the poly(maleimide) prepolymer to promote the covalent bonding of amino groups and imide groups to obtain the heat-resistant modifier.

[0022] Further, in step A1, the dosage ratio of nano-SiO 2 , KH-550 coupling agent, and ethanol solution is 100 g: 0.5-1 g: 600-1000 mL. The particle size of nano-SiO 2 is 20-50 nm, and the concentration of the ethanol solution is 70%; the post-treatment includes: after the reaction is completed, dry at 80 °C under vacuum for 6 hours to obtain pretreated nano-SiO 2 ; in step A2, the dosage ratio of N-phenylmaleimide, nano-SiO 2 and toluene is 15-20 g: 3-5 g: 115 mL; the weight ratio of N-phenylmaleimide to azobisisobutyronitrile is 20: 0.1; the post-treatment includes: after the reaction is completed, maintain at 60-80 °C, evacuate to a negative pressure of 0.1 MPa, and distill off the excess toluene under reduced pressure to obtain the heat-resistant modifier.

[0023] This application also provides a heat-resistant and anti-aging ABS composite plastic, which is prepared by using the preparation method of the heat-resistant and anti-aging ABS composite plastic.

[0024] The present invention has the following beneficial effects:

[0025] 1. In the present invention, methyl methacrylate is added to the ABS resin for modification in the mixed system. The methyl methacrylate dispersed phase can hinder the aggregation of the ABS rubber phase, reduce stress concentration, and improve the notched impact strength. Its rigid benzene ring structure increases the surface hardness of the material and reduces scratches. The physical dispersion and chemical modification of the melt mixing of methyl methacrylate and ABS achieve complementary performance, significantly improving the toughness and weather resistance of ABS, and reducing costs at the same time.

[0026] 2. In the present invention, an anti-aging agent is prepared by reacting the functional monomer UV-3853 with styrene and α-methylstyrene. UV-3853 has a strong absorption peak in the ultraviolet light region of 300-400 nm. It absorbs the ultraviolet energy through the conjugated structure in the molecule and converts it into harmless heat energy for release, avoiding the breakage of polymer chains or photo-oxidation reactions caused by ultraviolet rays. After absorbing light energy, it jumps from the ground state to the excited state, and through intramolecular vibrational relaxation and energy transfer with surrounding groups, significantly reducing the degradation, discoloration, and embrittlement of the material surface caused by ultraviolet irradiation; and under the synergistic effect of styrene and α-methylstyrene, the rigid structure of the styrene copolymer and the cured crosslinked network of UV-3853 synergistically enhance the rigidity of the material, improving the tensile strength of the material. When under the action of an appropriate amount of initiator, the crosslinking density is moderate, avoiding brittle fracture and retaining its impact performance.

[0027] 3. In the present invention, through the synergistic effect of N-phenylmaleimide and nano-SiO2 in terms of physics and chemistry, the rigid chain segment of N-phenylmaleimide and the physical filling of SiO2 synergistically restrict the movement of the chain segment, increasing the heat distortion temperature. SiO2 forms a weak interaction with the imide ring of N-phenylmaleimide through a coupling agent, reducing interfacial stress concentration, delaying crack propagation, and improving dispersion stability; the high thermal conductivity of SiO2 accelerates heat transfer, reduces local temperature rise, reduces the oxidation reaction rate, and delays oxidative degradation. Moreover, the nano-scale dispersion of SiO2 can hinder the local aggregation of the N-phenylmaleimide molecular chain, maintaining a uniform dispersion state and avoiding performance deterioration caused by phase separation. Detailed implementation mode

[0028] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0029] In this application, the ABS resin is selected from Wuhan Jiyesheng Chemical Co., Ltd., with a CAS number of 9003-56-9, an elastic modulus value of 2 GPa, and a melting temperature of 217-237 °C.

[0030] In this application, pentaerythritol tetrakis [β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] is selected from Hebei Kuoyou Chemical Technology Co., Ltd., with a CAS of 6683-19-8 and a melting point of 110.0-125.0 °C.

[0031] In this application, tris(2,4-di-tert-butylphenyl) phosphite has a CAS number of 31570-04-4 and a boiling point of 609.8 ± 55.0 °C.

[0032] Example 1

[0033] This example provides a method for preparing a heat-resistant and anti-aging ABS composite plastic, which includes the following steps:

[0034] S1. Prepare an anti-aging agent

[0035] Weigh and add: 2 g of UV-3853, 150 mL of toluene, and 1 g of azobisisobutyronitrile into a four-necked flask under nitrogen protection and stir. After the reaction temperature rises to 80 °C, add 75 g of styrene and 25 g of α-methylstyrene to the reaction system, keep the temperature for reaction for 6 hours. After the reaction is completed, distill off the low-boiling substances under reduced pressure to obtain the anti-aging agent.

[0036] S2. Prepare pretreated nano-SiO 2

[0037] Weigh and add: nano-SiO 2 100 g and 0.5 g of KH-550 coupling agent into a glass beaker, add 600 mL of ethanol solution, set the temperature to 35 °C, perform ultrasonic dispersion for 60 min, stir at intervals, and pour the modified nano-SiO 2 slurry into a stainless-steel tray covered with breathable filter paper. After quenching the particles with liquid nitrogen and crushing them, place them in a vacuum drying oven at 80 °C to dry to constant weight to obtain pretreated nano-SiO 2 .

[0038] S3. Prepare a heat-resistant modifier

[0039] Weigh and add: 15 g of N-phenylmaleimide and 115 mL of toluene into a three-necked flask under nitrogen protection and stir. Add 0.075 g of azobisisobutyronitrile, raise the temperature of the three-necked flask to 60 °C, and add 2 3 g of pretreated nano-SiO, react for 6 hours. After the reaction is completed, keep the temperature at 60 °C, pump to a negative pressure of 0.1 MPa, and distill off the excess toluene under reduced pressure to obtain the heat-resistant modifier.

[0040] S4. Preparation of Modified ABS Resin Mixture

[0041] Weigh: Add 100 g of ABS resin, 15 g of methyl methacrylate, and 0.6 g of dibenzoyl peroxide into a high-speed mixer at a temperature of 200 °C, and mix for 5 minutes to obtain modified ABS resin.

[0042] S5. Add 80 g of modified ABS resin, 1.1 g of anti-aging agent, 0.3 g of antioxidant, 15 g of heat-resistant modifier, 0.2 g of processing aid, and 0.5 g of initiator into a twin-screw extruder, melt extrude, and pelletize to obtain an ABS mixture.

[0043] S6. Add the modified ABS mixture into a mold, set the temperature at 120 °C, the pressure at 15 MPa, carry out heat preservation and pressure holding treatment for 60 min, and discharge to obtain ABS composite plastic.

[0044] Example 2

[0045] This example provides a preparation method of heat-resistant and anti-aging ABS composite plastic, including the following steps:

[0046] S1. Preparation of Anti-aging Agent

[0047] Weigh: Add 2 g of UV-3853, 150 mL of toluene, and 1 g of azobisisobutyronitrile into a four-necked flask under nitrogen protection and stir. After the reaction temperature rises to 90 °C, add 75 g of styrene and 25 g of α-methylstyrene into the reaction system, keep the temperature for reaction for 7 hours. After the reaction is completed, distill off the low-boiling substances under reduced pressure to obtain the anti-aging agent.

[0048] S2. Preparation of Pretreated Nano-SiO 2

[0049] Weigh: 2 Add 100 g of nano-SiO 2 and 0.75 g of KH-550 coupling agent into a glass beaker, add 800 mL of ethanol solution, set the temperature at 40 °C, carry out ultrasonic dispersion for 60 min, stir at intervals, pour the modified nano-SiO 2 slurry into a stainless-steel tray covered with breathable filter paper, quench and crush the particles with liquid nitrogen, and then place them in a vacuum drying oven at 80 °C to dry to constant weight to obtain pretreated nano-SiO

[0050] S3. Preparation of Heat-resistant Modifier

[0051] Weigh: Add 15 g of N-phenylmaleimide and 115 mL of toluene into a three-necked flask under nitrogen protection and stir, add 0.075 g of azobisisobutyronitrile, raise the temperature of the three-necked flask to 70 °C, and add pretreated nano-SiO 2React at 4g for 6 hours. After the reaction is completed, maintain at 70°C and evacuate to a negative pressure of 0.1 MPa to distill off the excess toluene under reduced pressure to obtain the heat-resistant modifier.

[0052] S4. Prepare the modified ABS resin mixture

[0053] Weigh and add: 100 g of ABS resin, 15 g of methyl methacrylate, and 0.6 g of benzoyl peroxide to a high-speed mixer at 210°C and mix for 7 minutes to obtain the modified ABS resin.

[0054] S5. Add 80 g of the modified ABS resin, 1.1 g of antioxidant, 0.3 g of antioxidant, 15 g of heat-resistant modifier, 0.2 g of processing aid, and 0.5 g of initiator to a twin-screw extruder, melt and extrude, and pelletize to obtain the ABS mixture.

[0055] S6. Add the modified ABS mixture to a mold, set the temperature at 125°C, the pressure at 17 MPa, perform heat and pressure retention treatment for 60 min, and discharge to obtain the ABS composite plastic.

[0056] Example 3

[0057] This example provides a method for preparing a heat-resistant and anti-aging ABS composite plastic, including the following steps:

[0058] S1. Prepare the antioxidant

[0059] Weigh and add: 2 g of UV-3853, 150 mL of toluene, and 1 g of azobisisobutyronitrile to a four-necked flask under nitrogen protection and stir. After the reaction temperature rises to 70°C, add 75 g of styrene and 25 g of α-methylstyrene to the reaction system, keep the temperature for reaction for 8 hours. After the reaction is completed, distill off the low-boiling substances under reduced pressure to obtain the antioxidant.

[0060] S2. Prepare the pretreated nano-SiO 2

[0061] Weigh and add: nano-SiO 2 100 g and 1 g of KH-550 coupling agent to a glass beaker, add 1000 mL of ethanol solution, set the temperature at 45°C, perform ultrasonic dispersion for 60 min, stir at intervals, and pour the modified nano-SiO 2 slurry into a stainless-steel tray covered with breathable filter paper, quench and crush the particles with liquid nitrogen, and place them in a vacuum drying oven at 80°C to dry to constant weight to obtain the pretreated nano-SiO 2 .

[0062] S3. Prepare the heat-resistant modifier

[0063] Weigh: 15 g of N-phenylmaleimide and 115 mL of toluene were added to a three-necked flask under nitrogen protection and stirred. 0.075 g of azobisisobutyronitrile was added. The temperature of the three-necked flask was raised to 80 °C, and 5 g of pretreated nano-SiO 2 was added. The reaction was carried out for 6 hours. After the reaction was completed, the temperature was maintained at 80 °C, and the negative pressure was pumped to 0.1 MPa. The excess toluene was removed by vacuum distillation to obtain a heat-resistant modifier.

[0064] S4. Preparation of modified ABS resin mixture

[0065] Weigh: 100 g of ABS resin, 15 g of methyl methacrylate, and 0.6 g of benzoyl peroxide were added to a high-speed mixer at 200 °C and mixed for 5 minutes to obtain a modified ABS resin.

[0066] S5. 80 g of the modified ABS resin, 1.1 g of anti-aging agent, 0.3 g of antioxidant, 15 g of heat-resistant modifier, 0.2 g of processing aid, and 0.5 g of initiator were added to a twin-screw extruder, melted and extruded, and pelletized to obtain an ABS mixture.

[0067] S6. The modified ABS mixture was added to a mold, the temperature was set at 130 °C, the pressure was 20 MPa, and the heat preservation and pressure holding treatment was carried out for 60 min, and then the product was discharged to obtain an ABS composite plastic.

[0068] Comparative Example 1

[0069] The difference between this comparative example and Example 3 is that step S1 was cancelled, and UV-3853 in step S1 was used to replace the anti-aging agent in step S1.

[0070] Comparative Example 2

[0071] The difference between this comparative example and Example 3 is that step S3 was cancelled, and N-phenylmaleimide in step S3 was used to replace the heat-resistant modifier in step S3.

[0072] Comparative Example 3

[0073] The difference between this comparative example and Example 3 is that methyl methacrylate was not added in step S4.

[0074] Performance test:

[0075] Referring to the standard GB / T 22411-2008 "Test Method for Anti-aging of Plastic Woven Packaging for Dangerous Goods", the heat resistance and anti-aging performance of the ABS composite plastics prepared in Examples 1-3 and Comparative Examples 1-3 were measured;

[0076] The impact resistance of the ABS composite plastics prepared in Examples 1-3 and Comparative Examples 1-3 was determined with reference to the standard GB / T 40440-2021 "Requirements and Test Methods for Extruded Sheets of Impact-Modified Acrylonitrile-Styrene Copolymers (ABS, AEPDS, and ASA) for Plastics".

[0077] The tensile properties of the ABS composite plastics prepared in Examples 1-3 and Comparative Examples 1-3 were determined with reference to the standard GB / T 1040.1-2018 "Plastics - Determination of Tensile Properties - Part 1: General Principles". The specific test results are shown in Table 1 below:

[0078] Table 1 - Data Sheet for Performance Detection of Specimens

[0079]

[0080] Data Analysis:

[0081] By comparing and analyzing the data in Table 1 above, the heat distortion temperature of the ABS composite plastics prepared in this invention reached 151.6 HDT, the tensile strength reached 61.2 MPa, the notched impact strength reached 14.1 kJ / m 2 , the UV transmittance reached 4.2 UVB, and the QUV 3000h yellowing index ΔYI reached 1.3. All the test data of the examples were better than those of the comparative examples. Therefore, in this invention, the ABS resin was grafted with methyl methacrylate, which improved the heat resistance of the material and also increased the tensile strength and impact strength. Under the synergistic effect of styrene and α-methylstyrene, the rigid structure of the styrene copolymer and the UV-3853 cured crosslinking network synergistically enhanced the rigidity of the material and improved the tensile strength of the material. The thermal stability of the material was improved by the synergistic effect of N-phenylmaleimide and nano-SiO2 in terms of physics and chemistry.

[0082] Compared with the example, the heat resistance and UV resistance of the anti-aging agent in the example were significantly better than the effect of UV-3853, and the tensile strength and impact strength were also improved;

[0083] Compared with the example, the rigid chain segment of N-phenylmaleimide and the physical filling of SiO2 synergistically restricted the segment motion, improving the heat resistance and tensile properties of the material;

[0084] Compared with the example, the methyl methacrylate dispersed phase hindered the aggregation of the ABS rubber phase, reduced stress concentration, and thus improved the notched impact strength and anti-aging performance.

[0085] The above content is only an example and illustration of the structure of the present invention. Those skilled in the art of this technology can make various modifications, supplements, or use similar methods to replace the specific embodiments described, as long as they do not deviate from the structure of the invention or exceed the scope defined by this claims, it shall fall within the protection scope of the present invention.

[0086] In the description of this specification, the descriptions referring to terms such as "an embodiment", "example", "specific example", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0087] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not elaborate all the details, nor do they limit the invention to only the specific implementation manners. Obviously, according to the content of this specification, many modifications and changes can be made. This specification selects and specifically describes these embodiments in order to better explain the principle and practical application of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A method for preparing heat-resistant and aging-resistant ABS composite plastic, characterized in that: The following steps are involved: S1. Add ABS resin, methyl methacrylate and initiator into a high-speed mixer at a temperature of 200-220° C. and mix for 5-10 minutes to obtain modified ABS resin; S2, adding modified ABS resin, anti-aging agent, antioxidant, heat-resistant modifier, processing aid and initiator into a twin-screw extruder, melt-extrude, and pelletize to obtain an ABS mixture; S3. Add the modified ABS mixture into the mold, set the temperature to 120-130°C and the pressure to 15-30MPa, keep the temperature and pressure for 60 minutes, and discharge the material to obtain ABS composite plastic.

2. The method for preparing a heat-resistant and aging-resistant ABS composite plastic according to claim 1, characterized in that: In step S1, the weight ratio of ABS resin, methyl methacrylate and initiator is 20:3:0.12, wherein the initiator is dibenzoyl peroxide; in step S2, the weight ratio of modified ABS resin, anti-aging agent, antioxidant, heat-resistant modifier, processing aid and initiator is 80: 1.1:0.3.:15:0.2:0.5, wherein the initiator is dicumyl peroxide, the processing aid is composed of butylated hydroxytoluene and calcium stearate in a weight ratio of 1:3, and the temperature of the twin-screw extruder is set to 100-130°C for T1 zone, 190-205°C for T2-T5 zone, and 205-210°C for T6-T12 zone.

3. The method for preparing a heat-resistant and aging-resistant ABS composite plastic according to claim 1, characterized in that: The processing method of the anti-aging agent in step S2 is: UV-3853, toluene, and initiator are placed in a four-necked flask, heated to 80-100°C under N2 protection, reacted for 40 minutes, styrene and α-methylstyrene were added to the flask, kept warm for 6-8 hours, and post-treated to obtain the anti-aging agent.

4. The method for preparing a heat-resistant and aging-resistant ABS composite plastic according to claim 3, characterized in that: The dosage ratio of UV-3853, toluene, initiator, styrene and α-methylstyrene is 0.4g:30mL:0.2g:15g:5g, and the initiator is azobisisobutyronitrile; the post-treatment comprises: after the reaction is completed, distilling off low boiling points under reduced pressure to obtain an anti-aging agent.

5. The method for preparing a heat-resistant and aging-resistant ABS composite plastic according to claim 1, characterized in that: In step S2, the antioxidant is composed of a primary antioxidant and a secondary antioxidant in a weight ratio of 1:1, the primary antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and the secondary antioxidant is tris(2,4-di-tert-butylphenyl)phosphite.

6. The method for preparing a heat-resistant and aging-resistant ABS composite plastic according to claim 1, characterized in that: In step S2, the heat-resistant modifier is processed by the following steps: A1, ultrasonically disperse nano-SiO2 and KH-550 coupling agent in ethanol solution for 60 min at a temperature of 35-45°C, and post-treat to obtain pre-treated nano-SiO2; A2, add N-phenylmaleimide and toluene into a three-necked flask protected by nitrogen, stir, add azobisisobutyronitrile, raise the temperature of the three-necked flask to 60-80°C, add pretreated nano-SiO 2， The reaction is carried out for 6-8 hours, and then post-processing is performed to obtain a heat-resistant modifier.

7. The method for preparing a heat-resistant and aging-resistant ABS composite plastic according to claim 6, characterized in that: In step A1, the dosage ratio of nano-SiO2, KH-550 coupling agent and ethanol solution is 100g:0.5-1g:600-1000mL, the particle size of nano-SiO2 is 20-50nm, and the ethanol solution is composed of ethanol, water and sodium hydroxide in a ratio of 70mL:30mL:3g; the post-treatment includes: after the reaction is completed, filtering, washing the filter cake with purified water until it is neutral and then drying, transferring the filter cake to a drying oven at a temperature of 80°C, and vacuum drying. The pretreated nano-SiO2 is dried to a constant weight to obtain pretreated nano-SiO2; in step A2, the amount ratio of N-phenylmaleimide, pretreated nano-SiO2 and toluene is 15-20g:3-5g:115mL; the weight ratio of N-phenylmaleimide to azobisisobutyronitrile is 20:0.1; the post-treatment comprises: after the reaction is completed, maintaining 60-80°C, pumping negative pressure to a negative pressure of 0.1MPa, and removing excess toluene under reduced pressure to obtain a heat-resistant modifier.

8. A heat-resistant and anti-aging ABS composite plastic, characterized in that: The heat-resistant and aging-resistant ABS composite plastic is prepared by the method for preparing the heat-resistant and aging-resistant ABS composite plastic as described in any one of claims 1 to 7.

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