A high weather-resistant ABS composite material and its preparation method

Abstract

This invention discloses a high-weather-resistant ABS composite material and its preparation method, belonging to the field of polymer materials technology. Addressing the problems of existing ABS materials such as easy loss of light stabilizers, poor weather resistance, susceptibility to stress cracking, and low flame retardancy, this invention provides a composite material comprising ABS resin, maleic anhydride-grafted ABS, CeO2@ZIF-8 / HALS micro / nano-release light stabilizer, and amino-terminated oligomeric polycarbonate. A three-dimensional physicochemical barrier network is constructed through micro / nano-channel slow-release technology and end-group reaction in-situ crosslinking technology. This invention significantly improves the material's long-term weather resistance and anti-loss properties, greatly enhances its resistance to environmental stress cracking, and achieves UL-94 V-0 flame retardancy and excellent anti-dripping properties without the need for additional conventional flame retardants. It is suitable for automotive exteriors, 5G base stations, and photovoltaic modules.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a high weather-resistant ABS composite material and its preparation method. Background Technology

[0002] ABS resin (acrylonitrile-butadiene-styrene copolymer) is widely used in automotive exterior parts, outdoor electronic and electrical housings, 5G base station antenna covers and photovoltaic module brackets due to its excellent impact resistance, processing fluidity and good surface gloss.

[0003] However, existing ABS materials have significant drawbacks: the carbon-carbon double bonds in the butadiene component of its molecular structure are easily broken by ultraviolet light and oxygen, leading to yellowing and powdering of the material; and the traditional anti-aging solution of adding hindered amine light stabilizers (HALS) small molecules inevitably suffers severe migration and precipitation in outdoor high temperature and rain conditions, making it easy to lose and fail.

[0004] In addition, the complex outdoor environment presents two other potential crises that existing weathering modification technologies cannot address simultaneously: First, contact with acid rain and cleaning agents makes ABS surfaces highly susceptible to environmental stress cracking (ESC), leading to material damage; second, ABS has an extremely low limiting oxygen index (approximately 18%), making it highly flammable upon contact with a fire source, accompanied by severe high-temperature melting and dripping (commonly known as "fire rain"), and the addition of conventional flame retardants often severely damages its mechanical and weathering properties. How to achieve ultra-long-lasting anti-migration and high weather resistance while systematically solving these problems has become an unsolved problem urgently needing to be overcome by the industry. Summary of the Invention

[0005] This invention aims to provide a high weather-resistant ABS composite material and its preparation method. It introduces micro-nano reactors and crystal channel slow-release technology from across fields, and combines reactive end-group blending technology to construct a three-dimensional physical and chemical barrier network. This solves the problem of rapid migration and loss of conventional small molecule light stabilizers, while unexpectedly achieving a doubling of the material's resistance to environmental stress cracking and excellent flame retardant and melt drip resistance properties.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A high weather-resistant ABS composite material, comprising the following components by weight:

[0008] ABS resin: 65-75 parts;

[0009] Maleic anhydride-grafted ABS: 8-15 parts;

[0010] CeO2@ZIF-8 / HALS micro / nano sustained-release light stabilizer: 3-8 parts;

[0011] Amino-terminated oligomeric polycarbonate: 5-10 parts;

[0012] Compound antioxidant: 0.5-0.8 parts;

[0013] Zinc stearate: 0.3-0.5 parts.

[0014] Furthermore, the melt flow index of the ABS resin is 15-20 g / 10 min.

[0015] Furthermore, the composite antioxidant is a mixture of Irganox1010 and Irgafos168 in a mass ratio of 1:1.

[0016] Furthermore, the preparation steps of the CeO2@ZIF-8 / HALS micro / nano sustained-release photostable are as follows:

[0017] (1) Core-shell heterogeneous growth: 4-5 g of nano-cerium dioxide was dispersed in 200 mL of methanol, and 2.5-3.0 g of zinc nitrate hexahydrate was added. The mixture was sonicated for 30 min to form a uniform dispersion. Then, under stirring, 200 mL of methanol solution containing 8-10 g of 2-methylimidazole was added dropwise. The mixture was stirred at 25 °C for 24 h. After the mixture was completed, it was centrifuged and washed three times with methanol. The product was then dried in a vacuum oven at 80 °C for 12 h to obtain core-shell structured CeO2@ZIF-8 powder.

[0018] (2) Vacuum negative pressure channel impregnation: The obtained CeO2@ZIF-8 powder was heated to 110-120℃ and vacuumed for 4-6 hours. After completion, it was cooled to room temperature. 150mL of cyclohexane solution containing UV-292 was added. After ultrasonic impregnation at room temperature for 6 hours, the mixture was filtered. The filter cake was placed in a vacuum drying oven at room temperature and dried for 24 hours to obtain CeO2@ZIF-8 / HALS micro-nano sustained-release photostable body.

[0019] Furthermore, the median particle size of the nano-cerium dioxide is 50 nm.

[0020] Furthermore, the concentration of UV-292 in the cyclohexane solution containing UV-292 is 0.1 g / mL.

[0021] Furthermore, the preparation method of the high weather-resistant ABS composite material includes the following steps:

[0022] (1) Pretreatment and initial mixing: ABS resin, maleic anhydride-grafted ABS, and amino-terminated oligopolycarbonate were dried in a forced-air drying oven at 85°C for 6 hours to remove moisture. Then, each raw material was weighed according to the weight parts. ABS resin, maleic anhydride-grafted ABS, amino-terminated oligopolycarbonate, CeO2@ZIF-8 / HALS micro-nano slow-release photostable agent, composite antioxidant and zinc stearate were mixed in a high-speed mixer at 1000 rpm for 10-20 minutes to obtain the initial mixture.

[0023] (2) Multi-temperature zone shear extrusion: The initial mixture is melt-extruded using a co-rotating twin-screw extruder with a length-to-diameter ratio of 45:1 to obtain strips. The strips are then water-cooled, drawn into fibers, and granulated by an air knife to obtain high weather-resistant ABS composite material.

[0024] Furthermore, the temperatures of each zone of the co-rotating twin-screw extruder are set as follows: Zone 1 190-200℃, Zone 2 220-225℃, Zone 3 240-245℃, Zone 4 245-250℃, Zone 5 240-245℃, Zone 6 230-240℃, and the die head 225-230℃; the screw speed of the co-rotating twin-screw extruder is 300 rpm.

[0025] The beneficial effects of this invention are:

[0026] This invention provides a high weather-resistant ABS composite material and its preparation method. Through the synergistic effect between specific components, it systematically solves the technical defects of traditional ABS materials, such as easy loss of light stabilizers, poor resistance to environmental stress cracking, and high flammability accompanied by dripping, in harsh outdoor environments. The specific beneficial effects and principle analysis are as follows:

[0027] 1. Constructing a three-dimensional micro-nano sustained-release network significantly improves extreme long-term weather resistance and anti-leaking performance:

[0028] This invention effectively overcomes the technical pain point of traditional hindered amine light stabilizers (HALS) being prone to migration and precipitation under outdoor high temperature and rain conditions by using a self-made CeO2@ZIF-8 / HALS micro / nano sustained-release photostable. According to the comparison of the test results of Example 5 and Comparative Example 2 in Table 1, Comparative Example 2, which did not use a micro / nano sustained-release structure and directly added equivalent commercially available nano CeO2 and free liquid UV-292, showed a color difference ΔE as high as 13.5 (severe yellowing) and an impact strength retention rate of only 42% after 1000 hours of light exposure and water spraying aging; while Example 5 showed a color difference ΔE of only 1.8 and an impact strength retention rate as high as 92%. This indicates that the nano-micropores of ZIF-8 play an excellent "phase-locking" isolation and sustained-release role. Furthermore, compared with Comparative Example 3 (without CeO2 core encapsulation), the color difference of Comparative Example 3 after aging was 6.2, and the impact strength retention rate was 75%, which was significantly inferior to Example 5. This demonstrates that the outer ZIF-8 framework and the core nano-CeO2 of this invention exhibit a powerful synergistic defense mechanism: the external hindered amine slowly releases and quenches free radicals, while the core nano-CeO2 provides strong ultraviolet shielding and intrinsic free radical quenching properties (utilizing CeO2). 3+ With Ce 4+ (Valence cycle), thus endowing the composite material with excellent long-term weather resistance.

[0029] 2. Activating end-group reactions to construct an in-situ cross-linked network significantly enhances environmental stress cracking (ESC) resistance:

[0030] This invention effectively overcomes the problem that traditional ABS surfaces are highly susceptible to stress cracking due to contact with environmental reagents. According to the test results of Example 5 and Comparative Examples 4 and 5, the ESC crack resistance time of Example 5 is as long as 240 hours, while the ESC crack resistance time of Comparative Example 4, which replaced amino-terminated oligomeric polycarbonate with ordinary PC, and Comparative Example 5, which removed maleic anhydride-grafted ABS, drops sharply to 45 hours and 38 hours, respectively.

[0031] This comparative data fully confirms that the high-strength crack resistance of the composite material of this invention does not originate from a simple physical mixing of components, but rather from an imidization reaction that occurs between the anhydride groups in ABS-g-MAH and the terminal amino groups in NH2-PC under a high-temperature, high-shear field during multi-temperature zone shear extrusion. The two components successfully construct in-situ cross-linked, strong interfacial topological network macromolecular islands. This microscopically robust network structure effectively dissipates localized stress concentrations generated when polar chemical reagents intrude, thereby achieving a significant leap in the material's environmental stress cracking resistance.

[0032] 3. Multiple synergistic effects construct a dense carbon layer, achieving excellent self-flame retardant and high-temperature dripping resistance properties:

[0033] This invention achieves superior flame-retardant properties in composite materials through a synergistic char formation mechanism among the components within the system. Vertical burning tests in Examples 4-6 all achieved the UL-94 V-0 rating, with limiting oxygen index (LOI) ranging from 28.5% to 30.2%. Data comparison reveals three essential dimensions of its flame-retardant mechanism: First, Comparative Example 5 (lacking ABS-g-MAH) showed no burnout rating, with an LOI dropping to 20.5%, demonstrating that the combination of ABS-g-MAH and the cross-linked NH2-PC forms the basis for the formation of a primary dense carbon layer during combustion. Second, Comparative Example 2 (lacking the ZIF-8 framework) only reached a V-2 rating, indicating that the Zn element in the ZIF-8 framework plays a crucial role in the rapid catalytic aromatization and char formation at high temperatures. Finally, Comparative Example 3 (lacking CeO2) had a flame-retardant rating of only V-1, demonstrating the highly efficient catalytic oxygen storage and regulation capabilities of the core CeO2 material, which effectively suppresses surface gas-phase pyrolysis side reactions. It is the highly synergistic effect of the primary carbon layer, the catalytic aromatization of the framework Zn, and the efficient regulation of CeO2 that rapidly constructs a three-dimensional honeycomb-like heat-insulating and oxygen-barrier network structure when the matrix is ​​heated and burned, thereby achieving high flame retardancy and anti-dripping properties under halogen-free and phosphorus-free conditions. Detailed Implementation

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Furthermore, unless otherwise specified, the raw materials, reagents, or devices used in the following embodiments can be obtained from conventional commercial channels or by existing known methods.

[0035] Example 1

[0036] Preparation of CeO2@ZIF-8 / HALS micro / nano sustained-release light stabilizers:

[0037] (1) Core-shell heterogeneous growth: 4g of commercially available nano-cerium dioxide (CeO2, median particle size 50nm) was weighed and dispersed in 200mL of methanol, and then 2.5g of zinc nitrate hexahydrate was added. The mixture was sonicated for 30min to form a uniform dispersion. Then, under stirring, 200mL of methanol solution containing 8g of 2-methylimidazole was added dropwise. The mixture was stirred at room temperature (25℃) for 24h. Through electrostatic adsorption and in-situ coordination crystallization, a metal zeolite imidazole framework (ZIF-8) coating layer was grown in situ on the outer layer of CeO2. After stirring, the mixture was centrifuged and washed with methanol 3 times. The product was dried in an 80℃ vacuum oven for 12h to obtain core-shell structured CeO2@ZIF-8 powder.

[0038] (2) Vacuum negative pressure channel impregnation: The obtained CeO2@ZIF-8 powder was placed in a vacuum generator, heated to 110℃ and continuously vacuumed (vacuum degree <0.01MPa) to remove residual solvent and water molecules in the channels for 4 hours. After completion, it was cooled to room temperature, and 150mL of cyclohexane solution containing liquid hindered amine light stabilizer (commercially available UV-292) (UV-292 concentration is 0.1g / mL) was added. The hindered amine molecules were forced to be loaded into the micro-channels or surface of ZIF-8 by the pressure difference between the inside and outside. After ultrasonic impregnation at room temperature for 6 hours, the mixture was filtered. The filter cake was placed in a vacuum drying oven at room temperature and dried for 24h to remove cyclohexane, thus obtaining CeO2@ZIF-8 / HALS micro-nano slow-release light stabilizer with hindered amine slow-release function.

[0039] Example 2

[0040] Preparation of CeO2@ZIF-8 / HALS micro / nano sustained-release light stabilizers:

[0041] (1) Core-shell heterogeneous growth: 4.5g of commercially available nano-cerium dioxide (CeO2, median particle size 50nm) was weighed and dispersed in 200mL of methanol, and then 2.5g of zinc nitrate hexahydrate was added. The mixture was sonicated for 30min to form a uniform dispersion. Then, under stirring, 200mL of methanol solution containing 9g of 2-methylimidazole was added dropwise. The mixture was stirred at room temperature (25℃) for 24h. Through electrostatic adsorption and in-situ coordination crystallization, a metal zeolite imidazole framework (ZIF-8) coating layer was grown in situ on the outer layer of CeO2. After stirring, the mixture was centrifuged and washed with methanol 3 times. The product was dried in an 80℃ vacuum oven for 12h to obtain core-shell structured CeO2@ZIF-8 powder.

[0042] (2) Vacuum negative pressure channel impregnation: The obtained CeO2@ZIF-8 powder was placed in a vacuum generator, heated to 120℃ and continuously vacuumed (vacuum degree <0.01MPa) to remove residual solvent and water molecules in the channels for 5 hours. After completion, it was cooled to room temperature, and 150mL of cyclohexane solution containing liquid hindered amine light stabilizer (commercially available UV-292) (UV-292 concentration of 0.1g / mL) was added. The hindered amine molecules were forced to be loaded into the micro-channels or surface of ZIF-8 by the pressure difference between the inside and outside. After ultrasonic impregnation at room temperature for 6 hours, the mixture was filtered. The filter cake was placed in a vacuum drying oven at room temperature and dried for 24h to remove cyclohexane, thus obtaining CeO2@ZIF-8 / HALS micro-nano slow-release light stabilizer with hindered amine slow-release function.

[0043] Example 3

[0044] Preparation of CeO2@ZIF-8 / HALS micro / nano sustained-release light stabilizers:

[0045] (1) Core-shell heterogeneous growth: 5g of commercially available nano-cerium dioxide (CeO2, median particle size 50nm) was weighed and dispersed in 200mL of methanol, and then 3.0g of zinc nitrate hexahydrate was added. The mixture was sonicated for 30min to form a uniform dispersion. Then, under stirring, 200mL of methanol solution containing 10g of 2-methylimidazole was added dropwise. The mixture was stirred at room temperature (25℃) for 24h. Through electrostatic adsorption and in-situ coordination crystallization, a metal zeolite imidazole framework (ZIF-8) coating layer was grown in situ on the outer layer of CeO2. After stirring, the mixture was centrifuged and washed with methanol 3 times. The product was dried in an 80℃ vacuum oven for 12h to obtain core-shell structured CeO2@ZIF-8 powder.

[0046] (2) Vacuum negative pressure channel impregnation: The obtained CeO2@ZIF-8 powder was placed in a vacuum generator, heated to 120℃ and continuously vacuumed (vacuum degree <0.01MPa) to remove residual solvent and water molecules in the channels for 6 hours. After completion, it was cooled to room temperature, and 150mL of cyclohexane solution containing liquid hindered amine light stabilizer (commercially available UV-292) (UV-292 concentration of 0.1g / mL) was added. The hindered amine molecules were forced to be loaded into the micro-channels or surface of ZIF-8 by the pressure difference between the inside and outside. After ultrasonic impregnation at room temperature for 6 hours, the mixture was filtered. The filter cake was placed in a vacuum drying oven at room temperature and dried for 24h to remove cyclohexane, thus obtaining CeO2@ZIF-8 / HALS micro-nano slow-release light stabilizer with hindered amine slow-release function.

[0047] Comparative Example 1

[0048] Comparative Example 1 served as the control group for Example 2. 4.5g of commercially available nano-cerium dioxide (CeO2, median particle size 50nm) was removed from the raw material in Example 2, while the remaining raw materials, raw material amounts, and preparation steps remained consistent with those in Example 2, ultimately yielding ZIF-8 / HALS.

[0049] Example 4

[0050] Preparation of high weather-resistant ABS composite materials:

[0051] First, the high weather-resistant ABS composite material, by weight, includes the following commercially available components:

[0052] ABS resin (commercially available general grade, melt index 15-20 g / 10 min): 65 parts;

[0053] Maleic anhydride-grafted ABS (ABS-g-MAH, grafting rate 1.0-1.5%): 8 parts;

[0054] CeO2@ZIF-8 / HALS micro / nano sustained-release photostabilizer prepared in Example 1: 3 parts;

[0055] Amino-terminated oligomeric polycarbonate (NH2-PC, number average molecular weight 5000-8000): 5 parts;

[0056] Compound antioxidant (Irganox 1010 and Irgafos 168 compounded in a 1:1 mass ratio): 0.5 parts;

[0057] Zinc stearate: 0.3 parts.

[0058] Then, the high weather-resistant ABS composite material is prepared by the following steps:

[0059] (1) Pretreatment and initial mixing: ABS resin, maleic anhydride-grafted ABS, and amino-terminated oligopolycarbonate were baked in a forced-air drying oven at 85°C for 6 hours to remove moisture. Then, each raw material was weighed according to the weight parts. ABS resin, maleic anhydride-grafted ABS, amino-terminated oligopolycarbonate, CeO2@ZIF-8 / HALS micro-nano slow-release photostable agent prepared in Example 1, composite antioxidant and zinc stearate were mixed in a high-speed mixer at 1000 rpm for 10 min to obtain the initial mixture.

[0060] (2) Multi-temperature zone shear extrusion: The initial mixture is melt-extruded using a co-rotating twin-screw extruder with a length-to-diameter ratio (L / D) of 45:1 to obtain a strip. The temperature of each zone is set as follows: Zone 1 190℃, Zone 2 220℃, Zone 3 240℃, Zone 4 245℃, Zone 5 240℃, Zone 6 230℃, and the die head 225℃; the screw speed is 300 rpm; the strip is then water-cooled, drawn into fibers, and granulated by an air knife to obtain a high weather-resistant ABS composite material.

[0061] Example 5

[0062] Preparation of high weather-resistant ABS composite materials:

[0063] First, the high weather-resistant ABS composite material, by weight, includes the following commercially available components:

[0064] ABS resin (commercially available general grade, melt index 15-20 g / 10 min): 72 parts;

[0065] Maleic anhydride-grafted ABS (ABS-g-MAH, grafting rate 1.0-1.5%): 12 parts;

[0066] CeO2@ZIF-8 / HALS micro / nano sustained-release photostabilizer prepared in Example 2: 5 parts;

[0067] Amino-terminated oligomeric polycarbonate (NH2-PC, number average molecular weight 5000-8000): 8 parts;

[0068] Compound antioxidant (Irganox 1010 and Irgafos 168 compounded in a 1:1 mass ratio): 0.8 parts;

[0069] Zinc stearate: 0.5 parts.

[0070] Then, the high weather-resistant ABS composite material is prepared by the following steps:

[0071] (1) Pretreatment and initial mixing: ABS resin, maleic anhydride-grafted ABS, and amino-terminated oligopolycarbonate were dried in a forced-air drying oven at 85°C for 6 hours to remove moisture. Then, each raw material was weighed according to the weight parts. ABS resin, maleic anhydride-grafted ABS, amino-terminated oligopolycarbonate, CeO2@ZIF-8 / HALS micro-nano slow-release photostable agent prepared in Example 2, composite antioxidant and zinc stearate were mixed in a high-speed mixer at 1000 rpm for 20 minutes to obtain the initial mixture.

[0072] (2) Multi-temperature zone shear extrusion: The initial mixture is melt-extruded using a co-rotating twin-screw extruder with a length-to-diameter ratio (L / D) of 45:1 to obtain a strip. The temperature of each zone is set as follows: Zone 1 195℃, Zone 2 220℃, Zone 3 240℃, Zone 4 245℃, Zone 5 240℃, Zone 6 235℃, and the die head 225℃; the screw speed is 300 rpm; the strip is then water-cooled, drawn into fibers, and granulated by an air knife to obtain a high weather-resistant ABS composite material.

[0073] Example 6

[0074] Preparation of high weather-resistant ABS composite materials:

[0075] First, the high weather-resistant ABS composite material, by weight, includes the following commercially available components:

[0076] ABS resin (commercially available general grade, melt index 15-20 g / 10 min): 75 parts;

[0077] Maleic anhydride-grafted ABS (ABS-g-MAH, grafting rate 1.0-1.5%): 15 parts;

[0078] Example 3: 8 parts of CeO2@ZIF-8 / HALS micro / nano sustained-release photostabilizer prepared;

[0079] Amino-terminated oligomeric polycarbonate (NH2-PC, number average molecular weight 5000-8000): 10 parts;

[0080] Compound antioxidant (Irganox 1010 and Irgafos 168 compounded in a 1:1 mass ratio): 0.8 parts;

[0081] Zinc stearate: 0.5 parts.

[0082] Then, the high weather-resistant ABS composite material is prepared by the following steps:

[0083] (1) Pretreatment and initial mixing: ABS resin, maleic anhydride-grafted ABS, and amino-terminated oligopolycarbonate were dried in a forced-air drying oven at 85°C for 6 hours to remove moisture. Then, each raw material was weighed according to the weight parts. ABS resin, maleic anhydride-grafted ABS, amino-terminated oligopolycarbonate, CeO2@ZIF-8 / HALS micro-nano slow-release photostable agent prepared in Example 3, composite antioxidant and zinc stearate were mixed in a high-speed mixer at 1000 rpm for 20 minutes to obtain the initial mixture.

[0084] (2) Multi-temperature zone shear extrusion: The initial mixture is melt-extruded using a co-rotating twin-screw extruder with a length-to-diameter ratio (L / D) of 45:1 to obtain a strip. The temperature of each zone is set as follows: Zone 1 200℃, Zone 2 225℃, Zone 3 245℃, Zone 4 250℃, Zone 5 245℃, Zone 6 240℃, and the die head 230℃; the screw speed is 300 rpm; the strip is then water-cooled, drawn into fibers, and granulated by an air knife to obtain a high weather-resistant ABS composite material.

[0085] Comparative Example 2

[0086] Comparative Example 2 served as the control group for Example 5. Instead of adding the CeO2@ZIF-8 / HALS micro / nano sustained-release photostable agent prepared in Example 2, commercially available nano CeO2 (2.5 parts) and liquid hindered amine photostable agent UV-292 (2.5 parts) with equivalent effective components were directly added during the pretreatment and initial mixing steps. The remaining raw materials, raw material amounts, and preparation steps remained exactly the same as in Example 5, and the ABS composite material was finally obtained.

[0087] Comparative Example 3

[0088] Comparative Example 3 served as the control group for Example 5. The CeO2@ZIF-8 / HALS micro / nano sustained-release photostable material prepared in Example 5 was replaced by ZIF-8 / HALS prepared in Comparative Example 1. The remaining raw materials, raw material amounts, and preparation steps were kept exactly the same as in Example 5, and the ABS composite material was finally obtained.

[0089] Comparative Example 4

[0090] Comparative Example 4 served as the control group for Example 5. The amino-terminated oligomeric polycarbonate (NH2-PC, number average molecular weight 5000-8000) in Example 5 was replaced with an equal amount of general-purpose polycarbonate (PC). The remaining raw materials, raw material amounts, and preparation steps remained exactly the same as in Example 5, and the ABS composite material was finally obtained.

[0091] Comparative Example 5

[0092] Comparative Example 5 served as the control group for Example 5. The maleic anhydride-grafted ABS (ABS-g-MAH) in Example 5 was replaced with an equal amount of ABS resin, i.e., the maleic anhydride-grafted ABS (ABS-g-MAH) was removed. The remaining raw materials, amounts of raw materials, and preparation steps remained exactly the same as in Example 5, and the final ABS composite material was obtained.

[0093] Test Example 1

[0094] The performance of the ABS composite materials prepared in Examples 4 to 6 and Comparative Examples 2 to 5 was tested. The test process is as follows, and the test results are shown in Table 1:

[0095] (1) Weather resistance and anti-loss performance test (artificial accelerated water spray aging):

[0096] Test Procedure: Xenon lamp accelerated aging test was conducted according to standard ISO4892-2. To simulate the harsh outdoor environment of "stabilizer loss due to rain erosion," the cycle was set as follows: 102 minutes of light exposure / 18 minutes of light exposure plus water spray, with the blackboard temperature set at 65±2℃ and relative humidity at 50±5%. The total aging time was 1000 hours.

[0097] Test indicators: The color difference value (ΔE) before and after aging is tested. The smaller the ΔE, the less yellowing and the better the weather resistance; the notched impact strength retention rate (%) before and after aging is tested.

[0098] (2) Environmental stress cracking resistance (ESC) test:

[0099] Test Procedure: Refer to ASTM D543 constant strain method. Fix the injection-molded standard specimen onto a special test fixture with a constant bending strain of 1.5%. Apply a typical environmental degradation agent (a polar test solution prepared by mixing glacial acetic acid and isopropanol in a 1:1 volume ratio) to the point of maximum stress on the specimen.

[0100] Test parameters: Record the critical fracture time (in hours, h) from the application of the test solution to the appearance of visible microcracks or complete fracture on the sample surface. The longer the time, the stronger the resistance to environmental stress cracking.

[0101] (3) Tests on self-flame retardant and anti-dripping properties:

[0102] Test Procedure: A vertical burning test was conducted according to UL-94 standard, with a sample thickness of 1.6 mm or 3.2 mm. The burning time and the presence of molten droplets igniting the absorbent cotton were recorded, and the rating was assigned (V-0, V-1, V-2, or unacceptable). A Limiting Oxygen Index (LOI) test was conducted according to ASTM D2863 standard, which is the minimum oxygen concentration (%) required for the material to undergo flaming combustion in an oxygen-nitrogen mixture under specified conditions.

[0103] Table 1 Test Results

[0104] project Example 4 Example 5 Example 6 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Color difference ΔE after 1000 hours of aging 2.5 1.8 1.6 13.5 6.2 3.1 3.5 Impact retention rate after 1000 hours of aging (%) 88 92 94 42 75 82 78 ESC crack resistance time (h) 180 240 265 165 220 45 38 Vertical burning (UL-94) V-0 V-0 V-0 V-2 V-1 V-2 Burnout (No level required) Limiting Oxygen Index (LOI%) 28.5 29.8 30.2 23.0 25.0 23.5 20.5

[0105] Table 1: Detailed Analysis of Test Results

[0106] As can be seen from Table 1, the high weather-resistant ABS composite materials prepared in Examples 4 to 6 of the present invention exhibit excellent comprehensive performance in terms of artificially accelerated water spray aging, resistance to environmental stress cracking (ESC), and flame retardancy and anti-dripping. Moreover, with the reasonable increase of the content of the core components (maleic anhydride grafted ABS, CeO2@ZIF-8 / HALS micro-nano slow-release photostable, and amino-terminated oligomeric polycarbonate) (from Example 4 to Example 6), the various performance indicators show a steady upward trend.

[0107] The specific comparative analysis between Example 5 and the comparative examples is as follows:

[0108] 1. Weather resistance and anti-leaking performance analysis (based on the comparison between Example 5 and Comparative Examples 2 and 3):

[0109] Necessity of the sustained-release structure: Comparative Example 2 used the direct addition of equivalent commercially available nano CeO2 and liquid hindered amine light stabilizer UV-292, without constructing a micro / nano sustained-release structure. After 1000 hours of light irradiation and water spraying aging test, the color difference ΔE of Comparative Example 2 was as high as 13.5 (severe yellowing), and the impact retention rate was only 42%; while the color difference ΔE of Example 5 was only 1.8, and the impact retention rate was as high as 92%. This fully demonstrates that the mechanism of using ZIF-8 nanopores as a "micro reservoir" to lock in the hindered amine molecules is effective, solving the problem of sudden precipitation and loss of traditional small molecule light stabilizers under rainwater erosion, and achieving long-term sustained release.

[0110] Necessity of Core-Shell Synergy: Comparative Example 3 used ZIF-8 / HALS without a CeO2 core. Its color difference ΔE after aging was 6.2, and its impact retention rate was 75%, which, while better than Comparative Example 2, was significantly worse than Example 5. This indicates that as the hindered amine outer layer is gradually consumed, the nano-CeO2 in the core of Example 5 of this invention exerts a strong UV shielding and intrinsic free radical quenching effect (CeO2 core). 3+ With Ce 4+ The valence cycle (VCE) complements the "dead zone intrinsic quenching" defense layer, and the two work together to achieve excellent weather resistance.

[0111] 2. Environmental stress cracking resistance (ESC) analysis (based on the comparison between Example 5 and Comparative Examples 4 and 5):

[0112] The key to in-situ crosslinking via end-group reaction: The ESC crack resistance time of Example 5 reached 240 h, while the ESC crack resistance times of Comparative Example 4 (using ordinary PC instead of NH2-PC) and Comparative Example 5 (removing ABS-g-MAH) plummeted to 45 h and 38 h, respectively. Based on the technical solution, it can be seen that Comparative Example 4 lacked amino end groups, and Comparative Example 5 lacked anhydride groups, neither of which could undergo imidization under the high temperature and high shear field of extrusion. This conversely proves that the present invention utilizes the reaction of the anhydride groups in ABS-g-MAH with the terminal amino groups of NH2-PC to form in-situ crosslinked macromolecular islands, and combines them with secondary bonds of the ZIF-8 nitrogen-containing ligand to successfully construct a strong interfacial topological network. This network can effectively dissipate local stress concentration during the intrusion of polar test solutions, thereby achieving a leap in ESC crack resistance performance.

[0113] 3. Analysis of self-flame retardant and anti-dripping properties (based on a comprehensive comparison of Example 5 and various comparative examples):

[0114] synergistic mechanism of char formation and catalysis: Examples 4 to 6 all achieved UL-94V-0 rating without the addition of conventional flame retardants, and the limiting oxygen index (LOI) was as high as 28.5% to 30.2%.

[0115] Formation of primary dense carbon layer: Comparative Example 5 lacked ABS-g-MAH, which could not synergistically form a dense primary carbon layer with PC segments, resulting in direct burnout of the material (no grade), and the LOI dropped to 20.5%. This indicates that the combination of ABS-g-MAH and PC (especially NH2-PC with cross-linked network, compared to the V-2 grade of Comparative Example 4) is the basis for self-flame retardancy.

[0116] Catalytic aromatization of the ZIF-8 framework: Comparative Example 2 did not use the ZIF-8 structure, thus lacking the high-temperature rapid catalytic aromatization of the framework element Zn to carbon, resulting in it only reaching the V-2 level and the LOI dropping to 23.0%.

[0117] Gas-phase pyrolysis regulation of CeO2: Although Comparative Example 3 has a ZIF-8 structure, it lacks the core CeO2 catalytic oxygen storage material, which fails to effectively regulate the surface gas-phase pyrolysis side reactions, resulting in a decrease in carbonization density and a flame retardancy rating of only V-1 with an LOI of 25.0%. This confirms that in this invention, the catalytic aromatization of the PC / ABS-g-MAH primary carbon layer, the Zn element in the ZIF-8 framework, and the highly efficient catalytic oxygen storage regulation of CeO2 are all indispensable. Together, they synergistically construct a three-dimensional honeycomb network structure during matrix combustion, thereby achieving unexpectedly excellent self-flame retardant and anti-dripping properties.

[0118] It should be noted that, in this document, terms such as “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0119] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high weather-resistant ABS composite material, characterized in that, By weight, it includes the following components: ABS resin: 65-75 parts; Maleic anhydride-grafted ABS: 8-15 parts; CeO2@ZIF-8 / HALS micro / nano sustained-release light stabilizer: 3-8 parts; Amino-terminated oligomeric polycarbonate: 5-10 parts; Compound antioxidant: 0.5-0.8 parts; Zinc stearate: 0.3-0.5 parts.

2. The high weather-resistant ABS composite material according to claim 1, characterized in that, The melt flow index of the ABS resin is 15-20 g / 10 min.

3. The high weather-resistant ABS composite material according to claim 1, characterized in that, The composite antioxidant is a mixture of Irganox1010 and Irgafos168 in a mass ratio of 1:

1.

4. The high weather-resistant ABS composite material according to claim 1, characterized in that, The preparation steps of the CeO2@ZIF-8 / HALS micro / nano sustained-release photostabilizer are as follows: (1) Core-shell heterogeneous growth: 4-5 g of nano-cerium dioxide was dispersed in 200 mL of methanol, and 2.5-3.0 g of zinc nitrate hexahydrate was added. The mixture was sonicated for 30 min to form a uniform dispersion. Then, under stirring, 200 mL of methanol solution containing 8-10 g of 2-methylimidazole was added dropwise. The mixture was stirred at 25 °C for 24 h. After the mixture was completed, it was centrifuged and washed three times with methanol. The product was then dried in a vacuum oven at 80 °C for 12 h to obtain core-shell structured CeO2@ZIF-8 powder. (2) Vacuum negative pressure channel impregnation: The obtained CeO2@ZIF-8 powder was heated to 110-120℃ and vacuumed for 4-6 hours. After completion, it was cooled to room temperature. 150mL of cyclohexane solution containing UV-292 was added. After ultrasonic impregnation at room temperature for 6 hours, the mixture was filtered. The filter cake was placed in a vacuum drying oven at room temperature and dried for 24 hours to obtain CeO2@ZIF-8 / HALS micro-nano sustained-release photostable body.

5. The high weather-resistant ABS composite material according to claim 4, characterized in that, The median particle size of the nano-cerium dioxide is 50 nm.

6. The high weather-resistant ABS composite material according to claim 4, characterized in that, The concentration of UV-292 in the cyclohexane solution containing UV-292 is 0.1 g / mL.

7. A method for preparing a high weather-resistant ABS composite material according to any one of claims 1 to 6, characterized in that, Includes the following steps: (1) Pretreatment and initial mixing: ABS resin, maleic anhydride-grafted ABS, and amino-terminated oligopolycarbonate were dried in a forced-air drying oven at 85°C for 6 hours to remove moisture. Then, each raw material was weighed according to the weight parts. ABS resin, maleic anhydride-grafted ABS, amino-terminated oligopolycarbonate, CeO2@ZIF-8 / HALS micro-nano slow-release photostable agent, composite antioxidant and zinc stearate were mixed in a high-speed mixer at 1000 rpm for 10-20 minutes to obtain the initial mixture. (2) Multi-temperature zone shear extrusion: The initial mixture is melt-extruded using a co-rotating twin-screw extruder with a length-to-diameter ratio of 45:1 to obtain strips. The strips are then water-cooled, drawn into fibers, and granulated by an air knife to obtain high weather-resistant ABS composite material.

8. The method for preparing a high weather-resistant ABS composite material according to claim 7, characterized in that, The temperatures of each zone of the co-rotating twin-screw extruder are set as follows: Zone 1 190-200℃, Zone 2 220-225℃, Zone 3 240-245℃, Zone 4 245-250℃, Zone 5 240-245℃, Zone 6 230-240℃, and the die head 225-230℃; the screw speed of the co-rotating twin-screw extruder is 300 rpm.