High-toughness piano black PMMA-ASA alloy resin composition and preparation method thereof

Abstract

The invention relates to the technical field of high polymer material modification, and particularly discloses a high-toughness piano black PMMA-ASA alloy resin composition and a preparation method thereof. The high-toughness piano black PMMA-ASA alloy resin composition is prepared from the following components in parts by weight: 65 to 75 parts of a resin base material, 28 to 32 parts of an impact modifier, 8 to 12 parts of a heat-resistant agent, 0.5 to 2 parts of a compatible tackifier, 1.9 to 2.1 parts of a coloring agent, 0.25 to 0.35 part of an antioxidant, 0.17 to 0.24 part of a lubricating agent and 0.25 to 0.35 part of a weather-resistant agent. The high-toughness piano black PMMA-ASA alloy resin composition provided by the invention overcomes the defect of poor impact resistance of a PMMA-ASA alloy material in related technologies, also obtains good glossiness and blackness while improving the impact strength, and is suitable for being used for producing automobile exterior trimming materials of high-end automobile products.

Description

Technical Field

[0001] The present application relates to the technical field of polymer material modification, and more specifically, to a high-toughness piano black PMMA-ASA alloy resin composition and a preparation method thereof. Background Art

[0002] In order to improve the appearance and sense of luxury, automotive exterior parts usually need a high-gloss effect, which is difficult to achieve through direct injection molding and usually requires spraying. However, the spraying process is not only costly, but also easily pollutes the environment.

[0003] Polymethyl methacrylate (PMMA) resin is commonly known as organic glass. It has excellent optical properties and excellent mechanical properties. It also has the advantages of good weather resistance, high tinting power, and high surface hardness. It has been widely used in the automotive industry. ASA toughening agent usually contains several structural units such as butyl acrylate, styrene, and acrylonitrile. It has excellent mechanical properties, coloring properties, and chemical cracking resistance. Therefore, it is widely used in automotive exterior parts, such as grilles, columns, triangles, etc. The spray-free PMMA-ASA alloy made of these two materials has excellent weather resistance and surface scratch resistance, and is often used to produce automotive exterior parts.

[0004] Regarding the above-mentioned related technologies, the inventors believe that PMMA itself is very brittle, and PMMA has poor compatibility with ASA toughening agent, which makes it difficult for PMMA-ASA alloy to simultaneously have high impact strength, good surface gloss and ideal blackness, and therefore difficult to use in high-end automotive products. Summary of the invention

[0005] In the related art, PMMA-ASA alloy is difficult to have high impact strength, good surface gloss and relatively ideal blackness at the same time, and is difficult to be used in high-end automotive products. In order to improve this defect, the present application provides a high-toughness piano black PMMA-ASA alloy resin composition and a preparation method thereof.

[0006] In a first aspect, the present application provides a high-toughness piano black PMMA-ASA alloy resin composition, which adopts the following technical solution: A high-toughness piano black PMMA-ASA alloy resin composition comprises the following components in parts by weight: 65-75 parts of a resin base material, 28-32 parts of an impact modifier, 0.5-2 parts of a compatible tackifier, 8-12 parts of a heat-resistant agent, 1.9-2.1 parts of a dye, 0.25-0.35 parts of an antioxidant, 0.17-0.24 parts of a lubricant, and 0.25-0.35 parts of a weathering agent; the resin base material comprises a PMMA resin, and the impact modifier comprises a polyvinyl alcohol having an average particle size of 200-300 μm. The impact modifier is composed of 1# particles with an average particle size of 100-250nm and 2# particles with an average particle size of 100-250nm, the weight of the 1# particles accounts for 5-80% of the total weight of the impact modifier; the impact modifier is a core-shell structure composed of a rubber core and a plastic shell, the components of the rubber core include at least one of acrylic rubber, silicone rubber, and butadiene rubber, and the components of the plastic shell are styrene-acrylate copolymer or styrene-acrylonitrile copolymer; the compatible tackifier is styrene-maleic anhydride copolymer.

[0007] By adopting the above technical scheme, the present application uses PMMA resin and an impact modifier with a core-shell structure, and limits the impact modifier to be composed of two core-shell particles with different particle size specifications. The acrylic rubber in the rubber core can make the impact modifier and PMMA resin have good compatibility, and the compounding of 1# particles and 2# particles can produce a synergistic toughening effect, and the compatible tackifier can enhance the bonding force between the components. Therefore, the high-toughness piano black PMMA-ASA alloy resin composition of the present application has good impact resistance. In general, high-toughness alloy resin compositions need to be toughened by rubber particles with larger particle sizes, and to achieve the effect of piano black high gloss, rubber particles with smaller particle sizes are required. The impact modifier selected by the present application is compounded by particles of different particle sizes, and small particle size particles can be used to offset the negative effects of large particle size particles, thereby improving the uniformity and matching of the refractive index of the material. At the same time, since the compatibility between PMMA resin and impact modifier is improved, the high-toughness piano black PMMA-ASA alloy resin composition of the present application achieves good surface gloss and blackness. Since the alloy resin composition of the present application overcomes the defects in the related art, it improves the impact strength and obtains good gloss and blackness, so it is suitable for the production of automotive exterior materials for high-end automotive products.

[0008] Preferably, the PMMA resin has a melt index of 5-20 g / 10 min measured at 230° C. / 3.8 kg.

[0009] By adopting the above technical solution, the present application optimizes the melt index of the PMMA resin, which helps to improve the blackness, glossiness and impact strength of the PMMA-ASA alloy resin composition.

[0010] Preferably, the weight of the rubber core of the 1# particles accounts for 60-90% of the total weight of the 1# particles, and the weight of the rubber core of the 2# particles accounts for 60-85% of the total weight of the 1# particles.

[0011] By adopting the above technical scheme, the present application optimizes the ratio of the rubber core weight of 1# particles and 2# particles in the total weight of the particles, improves the compatibility between the impact modifier and the PMMA resin, and helps to improve the impact strength, blackness and glossiness of the PMMA-ASA alloy resin composition.

[0012] Preferably, the rubber core material of the 1# particles is acrylic rubber, the plastic shell is a gradient copolymer of styrene and methyl methacrylate, the distribution density of the styrene structural units in the gradient copolymer on the inner side of the plastic shell is 100%, and decreases toward the outer side of the plastic shell, the distribution density of the methyl methacrylate structural units in the gradient copolymer on the outer side of the plastic shell is 100%, and decreases toward the inner side of the plastic shell, and the content of styrene structural units in the gradient copolymer is 5-80wt%; the rubber core components of the 2# particles include acrylic rubber, silicone rubber and butadiene rubber, and in the rubber core of the 2# particles, the proportion of silicone rubber is 1-10wt%, the proportion of butadiene rubber is 5-20wt%, and the balance is acrylic rubber.

[0013] By adopting the above technical scheme, the present application further optimizes the composition of 1# particles and 2# particles, reduces the influence of 1# particles on the overall glossiness by the setting of gradient copolymer, and improves the matching degree of refractive index. The present application also uses silicone rubber, cis-1,4-butadiene rubber and acrylate rubber as the rubber core of 2# particles. Silicone rubber has both high bond energy and high flexibility, and has excellent heat resistance, weather resistance and aging resistance, while acrylate rubber has good mechanical properties and processing properties. The cooperation of the two with cis-1,4-butadiene rubber can play a good synergistic toughening effect, further improves the mechanical properties of PMMA-ASA alloy resin composition, and helps to improve the impact strength of PMMA-ASA alloy resin composition.

[0014] Preferably, the silicone rubber content of the rubber core of the 2# particles is 3-12wt%.

[0015] By adopting the above technical solution, the present application optimizes the silicone rubber content of the 2# particle rubber core, which helps to improve the impact strength of the PMMA-ASA alloy resin composition.

[0016] Preferably, the rubber material in the 2# granular rubber core also includes butadiene rubber.

[0017] By adopting the above technical solution, acrylic rubber is a polar rubber, while silicone rubber is a non-polar rubber, and the blending of the two is somewhat difficult. Butadiene rubber can improve the compatibility between acrylic rubber and silicone rubber, which helps to further improve the impact strength of the PMMA-ASA alloy resin composition.

[0018] Preferably, the resin base material further comprises polycarbonate.

[0019] By adopting the above technical solution, polycarbonate can increase the chain entanglement density of PMMA resin, can play a synergistic toughening role with the impact modifier, and is helpful to improve the impact strength of the PMMA-ASA alloy resin composition.

[0020] Preferably, the resin base material further comprises ultra-high molecular weight SAN.

[0021] By adopting the above technical solution, the addition of ultra-high molecular weight SAN helps to improve the impact strength of the PMMA-ASA alloy resin composition.

[0022] Preferably, the resin base material further comprises modified PMMA, and the modified PMMA is prepared according to the following method: (1) mixing reduced graphene oxide, diethylaminoethyl methacrylate and methyl methacrylate, adding an initiator after ultrasonic dispersion to obtain a dispersion, and setting aside; (2) adding light calcium carbonate to water, then adding the dispersion under water bath heating conditions, stirring and heating under nitrogen protection, and adding hydroquinone to continue the reaction. After the reaction is completed, the product is collected, washed and dried to obtain modified PMMA.

[0023] By adopting the above technical solution, the present application further preferably includes modified PMMA as the component of the resin base material. In the modified PMMA, hydrogen bonds can be formed between the hydroxyl groups on the surface of the reduced graphene oxide and the amino groups of diethylaminoethyl methacrylate, thereby weakening the interaction between the reduced graphene oxide layers and improving the compatibility between the reduced graphene oxide and methyl methacrylate. The reduced graphene oxide and diethylaminoethyl methacrylate can act together as physical crosslinking points, and have a synergistic effect with components such as impact modifiers, which helps to fully improve the impact strength of the PMMA-ASA alloy resin composition.

[0024] In a second aspect, the present application provides a method for preparing a high-toughness piano black PMMA-ASA alloy resin composition, using the following technical solution.

[0025] A method for preparing a high-toughness piano black PMMA-ASA alloy resin composition comprises the following steps: (1) mixing a resin base material, an impact modifier, a compatible tackifier, a heat-resistant agent, a colorant, an antioxidant, a lubricant, and a weathering agent to obtain a premix; (2) The premix is ​​fed into a twin-screw extruder through a main feed port, and after melt mixing, it is sequentially extruded, water-cooled, and granulated to obtain a high-toughness piano black PMMA-ASA alloy resin composition; the processing temperature of the extruder is 180-260° C., and the rotation speed of the extruder is 180-600 rpm.

[0026] By adopting the above technical solution, the present application optimizes the preparation process and process conditions, and can achieve the preparation of a high-toughness piano black PMMA-ASA alloy resin composition.

[0027] In summary, this application has the following beneficial effects: 1. The high-toughness piano black PMMA-ASA alloy resin composition of the present application overcomes the defect of poor impact resistance of PMMA-ASA alloy materials in the related art, and while improving the impact strength, it also obtains good glossiness and blackness, and is suitable for the production of automotive exterior materials for high-end automotive products.

[0028] 2. In this application, two particle size ranges of impact modifier particles are preferably selected. Downstream customers can make targeted compounding in different proportions according to specific performance requirements. Because different particle sizes are used for compounding, the toughening agent is more evenly dispersed and the molecular gap is smaller, which not only improves the impact strength, but also increases the freedom of downstream customers in formula design, which can fully meet the needs of different customers.

[0029] 3. This application innovatively introduces a compatible thickener suitable for the impact modifier. Due to its special structure, it not only allows the impact modifier to be dispersed more evenly, but also due to the thickening effect of the maleic anhydride group, the components of the system are tightly bonded together, the molecular gap is reduced, and the impact strength of the PMMA-ASA alloy resin composition is further improved through the synergistic effect between the components. It is also beneficial to the dyeing performance of the material and further enhances the blackness value of the material. DETAILED DESCRIPTION

[0030] The present application is further described in detail below in conjunction with embodiments, preparation examples and comparative examples. The raw materials involved in the present application can all be obtained commercially.

[0031] Preparation example of modified PMMA The following is an explanation using Preparation Example 1.

[0032] Preparation Example 1 In this preparation example, modified PMMA was prepared according to the following method: (1) 0.1 g of reduced graphene oxide, 0.1 g of diethylaminoethyl methacrylate and 10 g of methyl methacrylate were mixed, and 0.315 g of initiator was added after ultrasonic dispersion at 600 W for 2 h to obtain a dispersion solution for later use; (2) Add 3 g of light calcium carbonate to 70 mL of water, and then heat to 50° C. in a water bath, then add the dispersion, stir at a rate of 300 r / min under nitrogen protection, heat to 80° C. and keep warm for 4 h, then add 0.1 g of hydroquinone and continue to react for 30 min. After the reaction is completed, the product is cooled to 20° C., washed with 10 wt% hydrochloric acid, and then filtered to remove impurities. The remaining product is washed with deionized water to neutrality, and then vacuum dried at 60° C. for 24 h to obtain modified PMMA. Example

[0033] Examples 1-5 The following description is given by taking Example 1 as an example.

[0034] Example 1 In this embodiment, the resin base material is PMMA resin, and the melt index of the PMMA resin measured under the conditions of 230°C / 3.8kg is 5g / 10min (referred to as the melt index for short); the impact modifier is composed of 1# particles with an average particle size of 200nm (referred to as the first particle size for short) and 2# particles with an average particle size of 100nm (referred to as the second particle size for short) in a weight ratio of 5:95 (referred to as the particle ratio for short).

[0035] Both 1# particles and 2# particles are core-shell structures composed of a rubber core and a plastic shell. The component of the rubber core of 1# particles is acrylic rubber (AR-100), and the plastic shell is a gradient copolymer of styrene and methyl methacrylate. The distribution density of the styrene structural unit in the gradient copolymer is 100% on the inside of the plastic shell, and decreases toward the outside of the plastic shell. The distribution density of the methyl methacrylate structural unit in the gradient copolymer is 100% on the outside of the plastic shell, and decreases toward the inside of the plastic shell. The content of the styrene structural unit in the gradient copolymer is 5wt% (referred to as the 1# particle shell ratio in Table 1); the weight of the rubber core of 1# particles accounts for 60% of the total weight of 1# particles (referred to as the first rubber core ratio). The plastic shell material of 2# particles is SAN, and the rubber core is composed of acrylic rubber, silicone rubber and butadiene rubber in a weight ratio of 1:5:94 (referred to as the 2# particle core ratio in Table 1), and the weight of the rubber core of 2# particles accounts for 60% of the total weight of 1# particles (referred to as the second rubber core ratio).

[0036] In this embodiment, the heat-resistant agent is of brand MS-NB, provided by Nippon Denki Chemical Co., Ltd.; the antioxidants are of brand 1010 and 168 (mixed in a weight ratio of 1:1), provided by SI group; the lubricant is of brand EBS, provided by Kao Corporation of Japan; the weathering agent is of brand UV-P and 770 (mixed in a weight ratio of 1:2), provided by BASF; the dye is a black masterbatch of brand XP6399D, provided by Shanghai Cabot Chemical; the compatible tackifier is of brand SAG008, and the manufacturer is Jiayirong Polymer (Shanghai) Co., Ltd.

[0037] The present embodiment provides a high-toughness piano black PMMA-ASA alloy resin composition, comprising the following components: 6.5 kg of resin base material, 3.2 kg of impact modifier, 0.05 kg of compatible tackifier, 0.8 kg of heat-resistant agent, 0.19 kg of colorant, 0.025 kg of antioxidant, 0.017 kg of lubricant, and 0.025 kg of weathering agent.

[0038] This embodiment provides a method for preparing a high-toughness piano black PMMA-ASA alloy resin composition, comprising the following steps: (1) adding a resin base material, an impact modifier, a heat resistant agent, a colorant, an antioxidant, a lubricant, and a weathering agent into a high-speed dispersant, and stirring at a speed of 350 rpm for 4 minutes to obtain a premix; (2) The premix is ​​fed into a twin-screw extruder through a main feed port, and after melt mixing, it is extruded, water-cooled, and granulated in sequence to obtain a high-toughness piano black PMMA-ASA alloy resin composition; in this step, the processing temperature of the extruder is 180° C. (referred to as the processing temperature), and the speed of the extruder is 180 rpm (referred to as the extruder speed).

[0039] As shown in Table 1, the differences between Examples 1-5 are mainly in the different amounts of raw materials used and the production and processing parameters.

[0040] Table 1 Raw material dosage and production and processing parameters Example 6 The difference between this embodiment and embodiment 4 is that the rubber core of the 2# particle is blended with acrylic rubber and silicone rubber (MVQ, industrial grade), and the silicone rubber content of the rubber core of the 2# particle is 3 wt%.

[0041] Example 7 The difference between this embodiment and embodiment 6 is that the silicone rubber content of the rubber core of the 2# particle is 8 wt%.

[0042] Example 8 The difference between this embodiment and embodiment 6 is that the silicone rubber content of the rubber core of the 2# particle is 12 wt%.

[0043] Example 9 The difference between this embodiment and embodiment 8 is that the rubber material in the inner core of the 2# granular rubber further includes butadiene rubber (BR9000), and the weight ratio of butadiene rubber to acrylic rubber is 1:10.

[0044] Example 10 The difference between this embodiment and embodiment 9 is that the resin base material is composed of PMMA resin and auxiliary resin in a weight ratio of 5:1, and the auxiliary resin is polycarbonate (2805, Bayer AG, Germany).

[0045] Embodiment 11 The difference between this embodiment and embodiment 10 is that the auxiliary resin further includes ultra-high molecular weight SAN (average molecular weight 1.2 million), and the amount of ultra-high molecular weight SAN is 35% of the weight of the polycarbonate.

[0046] Example 12 The difference between this embodiment and embodiment 11 is that the auxiliary resin further includes the modified PMMA of preparation example 1, and the amount of the modified PMMA is 45% of the weight of the polycarbonate.

[0047] Example 13 The difference between this embodiment and embodiment 12 is that the melt index of the PMMA resin measured at 230° C. / 3.8 kg is 3 g / 10 min.

[0048] Embodiment 14 The difference between this embodiment and embodiment 12 is that the weight of the rubber core of the 1# particle accounts for 40% of the total weight of the 1# particle.

[0049] Embodiment 15 The difference between this embodiment and embodiment 12 is that the weight of the rubber core of the 2# particle accounts for 40% of the total weight of the 2# particle.

[0050] Example 16 The difference between this embodiment and embodiment 12 is that the silicone rubber content of the rubber core of the 2# particle is 1%.

[0051] Comparative Example Comparative Example 1 This comparative example is different from Example 4 in that the impact modifier is entirely composed of 2# particles.

[0052] Comparative Example 2 This comparative example is different from Example 4 in that the impact modifier is entirely composed of 1# particles.

[0053] Comparative Example 3 The difference between this comparative example and Example 4 is that the average particle size of 1# particles is 400 nm.

[0054] Comparative Example 4 The difference between this comparative example and Example 4 is that the average particle size of 2# particles is 500 nm.

[0055] Comparative Example 5 This comparative example is different from Example 4 in that the components of the resin composition do not include a compatible tackifier.

[0056] Performance testing methods The PMMA-ASA alloy resin compositions prepared in the examples and comparative examples were used as test objects. Test specimens were made by injection molding according to the required test size. After being placed at 25° C. and 80% RH for 24 hours, relevant properties were tested.

[0057] The test methods for each performance are: Izod notched impact strength I is tested according to ISO-180; glossiness (20°) is tested according to ISO-2813; blackness L is tested according to SCI, using X-Rite Ci7600 instrument; Izod notched impact strength I at low temperature (-30°C) -30℃ : Tested with reference to ISO-180; the performance index test results of each embodiment and comparative example are shown in Table 2.

[0058] Table 2 Performance index test results It can be seen from the combination of Examples 1-5 and Comparative Examples 1-4 and Table 2 that the impact strength measured in Examples 1-5 is higher than that in Comparative Examples 1-4, indicating that the present application overcomes the defect of poor impact resistance of PMMA-ASA alloy material by the combination of resin base material and impact modifier. While improving the impact strength, Examples 1-5 also obtain good glossiness and blackness, which are more suitable for the production of automotive exterior materials for high-end automotive products. Among Examples 1-5, the room temperature (cantilever beam) impact strength of Example 4 is the highest, the glossiness of Example 5 is the best, and the blackness of Examples 4 and 5 is the most ideal, indicating that the matching of Examples 4-5 is more reasonable and can give full play to the synergistic effect of each component. If the room temperature impact resistance is the main improvement direction, it is most ideal to use Example 4 as the basis.

[0059] It can be seen from Example 4, Comparative Examples 1-2 and Table 2 that when 1# particles and 2# particles are not used in combination, the comprehensive performance of the impact resistance, glossiness and blackness of the alloy resin composition is poor, indicating that the improvement of impact resistance, glossiness and blackness requires the coordinated cooperation of 1# particles and 2# particles.

[0060] It can be seen from Example 4, Comparative Examples 3-4 and Table 2 that when the particle size of 1# particles and 2# particles exceeds the specified range, the comprehensive performance of the impact resistance, glossiness and blackness of the alloy resin composition is poor, indicating that the improvement of impact resistance, glossiness and blackness also depends on the appropriate particle size of the impact modifier.

[0061] It can be seen from Example 4, Comparative Example 5 and Table 2 that when the compatible tackifier is missing in the formulation components, the impact strength of the PMMA-ASA alloy resin composition is low, and the blackness value and glossiness are not ideal.

[0062] Combining Example 4, Examples 6-8 and Table 2, it can be seen that the impact strength, glossiness and blackness measured in Examples 6-8 are better than those in Example 4, indicating that within the silicone rubber content range selected in this application, the impact modifier containing silicone rubber helps to improve the above properties.

[0063] Combining Example 8, Example 9 and Table 2, it can be seen that the impact strength measured in Example 9 is higher than that in Example 8. This is because the addition of butadiene rubber can improve the compatibility between acrylic rubber and silicone rubber, thereby further improving the impact resistance of the PMMA-ASA alloy resin composition.

[0064] Combining Example 9, Example 10 and Table 2, it can be seen that the impact strength measured in Example 10 is higher than that in Example 9. This is because the polycarbonate increases the chain entanglement density of the PMMA resin and can play a synergistic toughening role with the impact modifier, thereby improving the impact strength of the PMMA-ASA alloy resin composition.

[0065] It can be seen from Example 10, Example 11 and Table 2 that the impact strength measured in Example 11 is higher than that in Example 10. This is because the addition of ultra-high molecular weight SAN can improve the impact strength of the PMMA-ASA alloy resin composition.

[0066] It can be seen from Example 11 and Example 12 and Table 2 that the impact strength measured in Example 12 is higher than that in Example 11. This is because the reduced graphene oxide and diethylaminoethyl methacrylate can act together as physical crosslinking points and have a synergistic effect with components such as the impact modifier, thereby helping to fully improve the impact strength of the PMMA-ASA alloy resin composition.

[0067] It can be seen from Example 12, Examples 13-16 and Table 2 that the impact strength measured in Examples 13-16 is lower than that in Example 12, indicating that when the silicone rubber content in the impact modifier is insufficient, the rubber core proportion of the impact modifier is too low, and the melt index of the PMMA resin is small, it is not conducive to fully improving the impact strength of the PMMA-ASA alloy resin composition.

[0068] The above embodiments are merely explanations of the present application and are not limitations of the present application. After reading this specification, those skilled in the art may make modifications to the embodiments of the present application without any creative contribution as needed. However, as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A high-toughness piano black PMMA-ASA alloy resin composition, characterized in that: The invention comprises the following components in parts by weight: 65-75 parts of a resin base material, 28-32 parts of an impact modifier, 0.5-2 parts of a compatible tackifier, 8-12 parts of a heat-resistant agent, 1.9-2.1 parts of a dye, 0.25-0.35 parts of an antioxidant, 0.17-0.24 parts of a lubricant, and 0.25-0.35 parts of a weathering agent; the resin base material comprises PMMA resin, the impact modifier comprises 1# particles with an average particle size of 200-300nm and 2# particles with an average particle size of 100-250nm, and the weight of the 1# particles accounts for 5-80% of the total weight of the impact modifier; the impact modifier is a core-shell structure composed of a rubber core and a plastic shell, the components of the rubber core comprise at least one of acrylic rubber, silicone rubber, and butadiene rubber, and the components of the plastic shell are styrene-acrylate copolymer or styrene-acrylonitrile copolymer; the compatible tackifier is a styrene-maleic anhydride copolymer.

2. The high-toughness piano black PMMA-ASA alloy resin composition according to claim 1, characterized in that: The melt index of the PMMA resin measured at 230° C. / 3.8 kg is 5-20 g / 10 min.

3. The high-toughness piano black PMMA-ASA alloy resin composition according to claim 1, characterized in that: The weight of the rubber core of the 1# particles accounts for 60-90% of the total weight of the 1# particles, and the weight of the rubber core of the 2# particles accounts for 60-85% of the total weight of the 1# particles.

4. The high-toughness piano black PMMA-ASA alloy resin composition according to claim 3, characterized in that: The rubber core material of the 1# particles is acrylic rubber, and the plastic shell is a gradient copolymer of styrene and methyl methacrylate. The distribution density of the styrene structural units in the gradient copolymer on the inner side of the plastic shell is 100%, and decreases toward the outer side of the plastic shell. The distribution density of the methyl methacrylate structural units in the gradient copolymer on the outer side of the plastic shell is 100%, and decreases toward the inner side of the plastic shell. The content of styrene structural units in the gradient copolymer is 5-80wt%; the rubber core components of the 2# particles include acrylic rubber, silicone rubber and butadiene rubber. In the rubber core of the 2# particles, the proportion of silicone rubber is 1-10wt%, the proportion of butadiene rubber is 5-20wt%, and the balance is acrylic rubber.

5. The high-toughness piano black PMMA-ASA alloy resin composition according to claim 4, characterized in that: The silicone rubber content of the rubber core of the 2# particles is 3-12wt%.

6. The high-toughness piano black PMMA-ASA alloy resin composition according to claim 4, characterized in that: The rubber material in the 2# granular rubber core also includes butadiene rubber.

7. The high-toughness piano black PMMA-ASA alloy resin composition according to claim 1, characterized in that: The resin matrix also includes polycarbonate.

8. The high-toughness piano black PMMA-ASA alloy resin composition according to claim 7, characterized in that: The resin base material also includes ultra-high molecular weight SAN.

9. The high-toughness piano black PMMA-ASA alloy resin composition according to claim 7, characterized in that: The components of the resin base material also include modified PMMA, and the modified PMMA is prepared according to the following method: (1) reducing graphene oxide, diethylaminoethyl methacrylate and methyl methacrylate are mixed, and an initiator is added after ultrasonic dispersion to obtain a dispersion for later use; (2) Light calcium carbonate is added to water, and then the dispersion is added under water bath heating conditions, and the mixture is stirred and heated under nitrogen protection, and hydroquinone is added to continue the reaction. After the reaction is completed, the product is collected, washed and dried to obtain modified PMMA.

10. The method for preparing the high-toughness piano black PMMA-ASA alloy resin composition according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) Mixing the resin base material, the impact modifier, the compatible tackifier, the heat resistant agent, the colorant, the antioxidant, the lubricant, and the weathering agent to obtain a premix; (2) The premix is ​​fed into a twin-screw extruder through a main feed port, and after melt mixing, it is extruded, water-cooled, and granulated in sequence to obtain a high-toughness piano black PMMA-ASA alloy resin composition; the processing temperature of the extruder is 180-260° C., and the rotation speed of the extruder is 180-600 rpm.

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