Heat-resistant flame-retardant ABS (acrylonitrile butadiene styrene) and preparation method thereof

Abstract

The invention relates to the technical field of ABS (Acrylonitrile Butadiene Styrene) materials, in particular to heat-resistant flame-retardant ABS and a preparation method thereof. The heat-resistant and flame-retardant ABS is prepared from the following components in parts by weight: 50 to 70 parts of ABS resin, 5 to 18 parts of a main flame retardant, 3 to 8 parts of an auxiliary flame retardant, 5 to 30 parts of a flame-retardant and heat-resistant aid, 0.1 to 0.5 part of an anti-dripping agent, 0.5 to 2 parts of a lubricant and 0.3 to 0.5 part of an antioxidant, the flame-retardant heat-resistant auxiliary agent is subjected to certain modification treatment, so that the flame-retardant heat-resistant auxiliary agent has good compatibility with the ABS resin, the heat resistance and the combustion resistance of the ABS material can be remarkably improved, and meanwhile, the good mechanical property of the material can be kept to a certain extent.

Description

Technical Field

[0001] The present invention relates to the technical field of ABS materials, and in particular to heat-resistant and flame-retardant ABS and a preparation method thereof. Background Art

[0002] ABS is a copolymer of three monomers: acrylonitrile, butadiene, and styrene. Each monomer offers distinct properties: acrylonitrile offers heat and chemical resistance, as well as tensile strength; butadiene offers impact resistance and low-temperature impact resistance; and styrene offers easy processing, high gloss, easy coloring, and high rigidity. ABS is an amorphous material composed of a dispersed phase of a butadiene rubber-based elastomer and a continuous phase of a polystyrene-acrylonitrile (SAN) copolymer resin. The properties of ABS depend primarily on the ratio of the three monomers and the molecular structure of the two phases. This allows for great flexibility in product design, resulting in hundreds of different ABS grades on the market. These grades offer varying properties, such as moderate to high impact resistance, low to high gloss, and high-temperature distortion characteristics. ABS offers exceptional processability, low creep, excellent dimensional stability, and high impact strength. Based on the above excellent properties of ABS, it is widely used in automobiles, home appliances, electronic appliances, office equipment, construction, daily necessities and other fields. However, due to the low oxygen index of ABS and its non-crystalline polymer, ABS has disadvantages such as flammability and poor temperature resistance. Its application in TV casings, hair dryer casings, power strips, etc. requires further improvement in flame retardant heat resistance and other performance.

[0003] Patent document CN104987647A discloses flame-retardant ABS plastic. The flame retardant in this invention is a mixture of aluminum hypophosphite, 10-(2,5-dihydroxyphenyl)-10-hydrogen-9-oxa-10-phosphaphenanthrene-10-oxide, and 2-carboxyethylphenyl hypophosphite in a mass ratio of 1:1:1. This flame-retardant ABS plastic exhibits excellent flame retardancy, a low smoke generation rate, and does not contain halogenated flame retardants, thus preventing secondary pollution.

[0004] However, adding a large amount of flame retardants to ABS materials will cause material performance to deteriorate and costs to increase. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a heat-resistant and flame-retardant ABS and a preparation method thereof, so as to solve the problems of traditional ABS materials such as reduced material performance and easy precipitation of flame retardants due to the addition of flame retardants.

[0006] Based on the above purpose, the present invention provides a heat-resistant and flame-retardant ABS, comprising the following components in parts by weight: 50-70 parts of ABS resin, 5-18 parts of a main flame retardant, 3-8 parts of an auxiliary flame retardant, 5-30 parts of a flame retardant and heat-resistant additive, 0.1-0.5 parts of an anti-dripping agent, 0.5-2 parts of a lubricant, and 0.3-0.5 parts of an antioxidant; The preparation steps of the flame retardant and heat resistant auxiliary agent are as follows: (1) The porous silica powder was dispersed in an ethanol-water mixed solution, the pH value was adjusted to 4 with hydrochloric acid, and ultrasonic dispersion was performed uniformly. KH-570 was added and mixed uniformly. The mixture was stirred at 80°C for 10-12 hours. After the reaction was completed, the solution was centrifuged, washed three times with ethanol, and dried to obtain olefinated silica powder. (2) Alkenylated silica powder, 4-bromostyrene, N-(2,4,6-tribromophenyl)maleimide, maleic anhydride and xylene were mixed and placed in a reactor; heated to 75°C in a water bath under a nitrogen atmosphere, stirred for 30 minutes, and then azobisisobutyronitrile was added, the water bath temperature was maintained at 75-77°C, and the reaction was carried out for 4-5 hours; then ethanol was added for extraction, filtered, and dried to obtain a flame retardant and heat-resistant additive; The usage ratio of ethanol, deionized water, porous silica powder, and KH-570 in step (1) is 120 g:40 g:5-6 g:5-20 mL; The amount ratio of the olefinated silica powder, 4-bromostyrene, N-(2,4,6-tribromophenyl)maleimide, maleic anhydride, xylene, azobisisobutyronitrile, and ethanol in step (2) is 3-5 g: 25-30 g: 60-65 g: 15-20 g: 500-550 g: 0.2-1 g: 400-500 g; The porous silica powder in step (1) has a particle size of 300-400 nm and a specific surface area of 300-400 m 2 / g; Preferably, the particle size of the porous silica powder in step (1) is 300-400nm, and the specific surface area is 300-400m 2 / g.

[0007] Preferably, the ABS resin is composed of a butadiene rubber-based elastomer as a dispersed phase and a polystyrene-acrylonitrile (SAN) copolymer resin as a continuous phase.

[0008] Preferably, the main flame retardant is one or more of tetrabromobisphenol A, decabromodiphenylethane, and 1,2-bis(2,4,6-tribromophenoxy)ethane.

[0009] Preferably, the auxiliary flame retardant is one or more of zinc borate, zinc oxide, organic montmorillonite, and hydrotalcite.

[0010] Preferably, the anti-drip agent is polytetrafluoroethylene.

[0011] More preferably, the anti-drip agent is one or more of FD3150, FD3200, and FD3100.

[0012] Preferably, the antioxidant is one or more of 168, 626, 1010, 1076, and DSTP.

[0013] Preferably, the lubricant is one or more of oleamide, erucamide, pentaerythritol stearamide, and ethylene bisstearamide.

[0014] Furthermore, the present invention also provides a method for preparing heat-resistant and flame-retardant ABS, comprising the following steps: ABS resin, main flame retardant, auxiliary flame retardant, flame retardant and heat-resistant additive, anti-drip agent, lubricant and antioxidant are added into a high-speed mixer according to the raw material ratio, fully mixed and then added into a twin-screw extruder, and extruded and granulated at 190-210°C and a screw speed of 400 rpm to obtain heat-resistant and flame-retardant ABS resin; The beneficial effects of the present invention are as follows: the present invention increases the glass transition temperature of the polymer and improves the heat resistance of the resin by adding a homemade heat-resistant flame retardant additive to the ABS material, thereby improving the heat resistance of ABS and its combustion resistance.

[0015] The present invention grafts porous silicon dioxide into the heat-resistant flame retardant additive, thereby ensuring that the ABS material has excellent flame retardant and heat-resistant properties while also ensuring that the ABS material has good mechanical properties. DETAILED DESCRIPTION

[0016] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to specific embodiments.

[0017] The two elements or properties of the raw materials used in the examples and comparative examples of the present invention are as follows: ABS uses PA-757, from Chi Mei in Taiwan; the main flame retardant is decabromodiphenylethane, from Chongqing Yuanyuanxiang Technology; the auxiliary flame retardant is antimony trioxide, from Shandong Yihong Chemical; 4-bromostyrene, from Shanghai Aladdin Biochemical Technology; N-(2,4,6-tribromophenyl)maleimide, from Hubei Xingyan New Materials; maleic anhydride, from Sigma-Aldrich; the anti-dripping agent is FD3150, from Luju Chemical; the lubricant is EBS, from Kao, Japan; the antioxidant is a combination of 1010 and 168, from Senior; the porous silica powder has a particle size of 300-400 nm and a specific surface area of 300-400 m 2 / g.

[0018] Example 1: A heat-resistant and flame-retardant ABS, the specific preparation method is as follows: (1) Add 120 g of ethanol and 40 g of deionized water to a beaker, weigh 5 g of porous silica powder and disperse it in the ethanol-water mixed solution, adjust the pH value to 4 with hydrochloric acid, and disperse it evenly with ultrasonication. Add 5 mL of KH-570, mix evenly, and stir the mixture at 80 ° C for 10 h. After the reaction is completed, centrifuge the solution, wash it repeatedly with ethanol three times, and dry it in a vacuum drying oven at 100 ° C for 12 h to obtain olefinated silica powder. (2) 3 g of olefinated silica powder, 25 g of 4-bromostyrene, 60 g of N-(2,4,6-tribromophenyl)maleimide, 15 g of maleic anhydride and 500 g of xylene were mixed and placed in a reactor; heated to 75 °C in a water bath under a nitrogen atmosphere and stirred for 30 min, then 0.2 g of azobisisobutyronitrile as an initiator was added, the water bath temperature was kept at 75 °C, and the reaction was continued for 4 h; then 40 g of ethanol was added for extraction and precipitation, filtered, and the precipitate was dried in a vacuum drying oven at 50 °C to obtain a flame retardant and heat-resistant additive; (3) Add 50g ABS resin, 5g decabromodiphenylethane, 3g antimony trioxide, 5g flame retardant and heat-resistant additive, 0.1 anti-dripping agent FD3150, 0.5g lubricant EBS, and 0.3g antioxidant into a high-speed mixer and mix them thoroughly at a speed of 800rpm for 10min. Then, add the mixed materials into a twin-screw extruder and extrude them into granules at 190℃ and a screw speed of 400 rpm to obtain heat-resistant and flame-retardant ABS.

[0019] Example 2: A heat-resistant and flame-retardant ABS, the specific preparation method is as follows: (1) Add 120 g of ethanol and 40 g of deionized water to a beaker, weigh 5.5 g of porous silica powder and disperse it in the ethanol-water mixed solution, adjust the pH value to 4 with hydrochloric acid, and disperse it evenly with ultrasonication. Add 10 mL of KH-570, mix evenly, and stir the mixture at 80 ° C for 11 h. After the reaction is completed, centrifuge the solution, wash it repeatedly with ethanol three times, and dry it in a vacuum drying oven at 100 ° C for 12 h to obtain olefinated silica powder. (2) 4 g of olefinated silica powder, 27 g of 4-bromostyrene, 63 g of N-(2,4,6-tribromophenyl)maleimide, 18 g of maleic anhydride and 550 g of xylene were mixed and placed in a reactor; heated to 75 °C in a water bath under a nitrogen atmosphere and stirred for 30 min, then 0.6 g of azobisisobutyronitrile as an initiator was added, the water bath temperature was maintained at 76 °C, and the reaction was carried out for 4 h; then 450 g of ethanol was added for extraction and precipitation, filtered, and the precipitate was dried in a vacuum drying oven at 50 °C to obtain a flame retardant and heat-resistant additive; (3) Add 60g ABS resin, 12g decabromodiphenylethane, 7g antimony trioxide, 20g flame retardant and heat-resistant additive, 0.3g anti-dripping agent FD3150, 1g lubricant EBS, and 0.4g antioxidant into a high-speed mixer and mix them thoroughly at a speed of 800rpm for 15min. Then, add the mixed materials into a twin-screw extruder and extrude and granulate them at 200℃ and a screw speed of 400 rpm to obtain heat-resistant and flame-retardant ABS.

[0020] Example 3: A heat-resistant and flame-retardant ABS, the specific preparation method is as follows: (1) Add 120 g of ethanol and 40 g of deionized water to a beaker, weigh 5.7 g of porous silica powder and disperse it in the ethanol-water mixed solution, adjust the pH value to 4 with hydrochloric acid, and disperse it evenly with ultrasonication. Add 12 mL of KH-570, mix evenly, and stir the mixture at 80 ° C for 12 h. After the reaction is completed, centrifuge the solution, wash it repeatedly with ethanol three times, and dry it in a vacuum drying oven at 100 ° C for 12 h to obtain olefinated silica powder. (2) 4.5 g of olefinated silica powder, 30 g of 4-bromostyrene, 65 g of N-(2,4,6-tribromophenyl)maleimide, 20 g of maleic anhydride and 550 g of xylene were mixed and placed in a reactor; heated to 75 °C in a water bath under a nitrogen atmosphere and stirred for 30 min, then 0.7 g of azobisisobutyronitrile as an initiator was added, the water bath temperature was maintained at 77 °C, and the reaction was carried out for 5 h; then 500 g of ethanol was added for extraction and precipitation, filtered, and the precipitate was placed in a vacuum drying oven at 50 °C to obtain a flame retardant and heat-resistant additive; (3) Add 65g of ABS resin, 15g of decabromodiphenylethane, 6g of antimony trioxide, 18g of flame retardant and heat-resistant additive, 0.4g of anti-dripping agent FD3150, 1.5g of lubricant EBS, and 0.4g of antioxidant into a high-speed mixer and mix them thoroughly at a speed of 800rpm for 10min. Then, add the mixed materials into a twin-screw extruder and extrude and granulate them at 210℃ and a screw speed of 400 rpm to obtain heat-resistant and flame-retardant ABS.

[0021] Example 4: A heat-resistant and flame-retardant ABS, the specific preparation method is as follows: (1) Add 120 g of ethanol and 40 g of deionized water to a beaker, weigh 6 g of porous silica powder and disperse it in the ethanol-water mixed solution, adjust the pH value to 4 with hydrochloric acid, and disperse it evenly with ultrasonication. Add 20 mL of KH-570, mix evenly, and stir the mixture at 80 ° C for 12 h. After the reaction is completed, centrifuge the solution, wash it repeatedly with ethanol three times, and dry it in a vacuum drying oven at 100 ° C for 12 h to obtain olefinated silica powder. (2) 5 g of olefinated silica powder, 30 g of 4-bromostyrene, 65 g of N-(2,4,6-tribromophenyl)maleimide, 20 g of maleic anhydride and 550 g of xylene were mixed and placed in a reactor; heated in a water bath to 75 °C under a nitrogen atmosphere and stirred for 30 min, then 1 g of azobisisobutyronitrile as an initiator was added, the water bath temperature was maintained at 77 °C, and the reaction was carried out for 5 h; then 500 g of ethanol was added for extraction and precipitation, filtered, and the precipitate was dried in a vacuum drying oven at 50 °C to obtain a flame retardant and heat-resistant additive; (3) Add 70g ABS resin, 18g decabromodiphenylethane, 8g antimony trioxide, 30g flame retardant and heat-resistant additive, 0.5g anti-dripping agent FD3150, 2g lubricant EBS, and 0.5g antioxidant into a high-speed mixer and mix them thoroughly at a speed of 800rpm for 10-20min. Then, add the mixed materials into a twin-screw extruder and extrude them into granules at 210℃ and a screw speed of 400 rpm to obtain heat-resistant and flame-retardant ABS.

[0022] Comparative Example 1: The difference from Example 1 is that the porous silica powder is replaced with silica powder, and the remaining steps remain unchanged. The specific steps are as follows; (1) Add 120 g of ethanol and 40 g of deionized water to a beaker, weigh 5 g of silica powder and disperse it in the ethanol-water mixed solution, adjust the pH value to 4 with hydrochloric acid, and disperse it evenly with ultrasound. Add 5 mL of KH-570, mix evenly, and stir the mixture at 80 ° C for 10 h. After the reaction is completed, centrifuge the solution, wash it repeatedly with ethanol three times, and dry it in a vacuum drying oven at 100 ° C for 12 h to obtain olefinated silica powder. (2) 3 g of olefinated silica powder, 25 g of 4-bromostyrene, 60 g of N-(2,4,6-tribromophenyl)maleimide, 15 g of maleic anhydride and 500 g of xylene were mixed and placed in a reactor; heated to 75 °C in a water bath under a nitrogen atmosphere and stirred for 30 min, then 0.2 g of azobisisobutyronitrile as an initiator was added, the water bath temperature was kept at 75 °C, and the reaction was continued for 4 h; then 40 g of ethanol was added for extraction and precipitation, filtered, and the precipitate was dried in a vacuum drying oven at 50 °C to obtain a flame retardant and heat-resistant additive; (3) Add 50g ABS resin, 5g decabromodiphenylethane, 3g antimony trioxide, 5g flame retardant and heat-resistant additive, 0.1 anti-dripping agent FD3150, 0.5g lubricant EBS, and 0.3g antioxidant into a high-speed mixer and mix them thoroughly at a speed of 800rpm for 10min. Then, add the mixed materials into a twin-screw extruder and extrude them into granules at 190℃ and a screw speed of 400 rpm to obtain heat-resistant and flame-retardant ABS.

[0023] Comparative Example 2: The difference from Example 1 is that porous silica powder is not added, and the other steps remain unchanged. The specific steps are as follows: (1) 25 g of 4-bromostyrene, 60 g of N-(2,4,6-tribromophenyl)maleimide, 15 g of maleic anhydride and 500 g of xylene were mixed and placed in a reactor; heated in a water bath to 75 °C under a nitrogen atmosphere and stirred for 30 min, then 0.2 g of azobisisobutyronitrile as an initiator was added, the water bath temperature was kept at 75 °C, and the reaction was carried out for 4 h; then 40 g of ethanol was added for extraction and precipitation, filtered, and the precipitate was dried in a vacuum drying oven at 50 °C to obtain a flame retardant and heat-resistant additive; (2) Add 50g ABS resin, 5g decabromodiphenylethane, 3g antimony trioxide, 5g flame retardant and heat-resistant additive, 0.1g anti-dripping agent FD3150, 0.5g lubricant EBS, and 0.3g antioxidant into a high-speed mixer and mix them thoroughly at a speed of 800rpm for 10min. Then add the mixed materials into a twin-screw extruder and extrude them into granules at 190℃ and a screw speed of 400 rpm to obtain heat-resistant and flame-retardant ABS.

[0024] Comparative Example 3: The difference from Example 1 is that the porous silica powder is directly added to the raw materials, and the other steps remain unchanged. The specific steps are as follows: (1) Add 120 g of ethanol and 40 g of deionized water to a beaker, weigh 5 g of porous silica powder and disperse it in the ethanol-water mixed solution, adjust the pH value to 4 with hydrochloric acid, and disperse it evenly with ultrasonication. Add 5 mL of KH-570, mix evenly, and stir the mixture at 80 ° C for 10 h. After the reaction is completed, centrifuge the solution, wash it repeatedly with ethanol three times, and dry it in a vacuum drying oven at 100 ° C for 12 h to obtain olefinated silica powder. (2) 25 g of 4-bromostyrene, 60 g of N-(2,4,6-tribromophenyl)maleimide, 15 g of maleic anhydride and 500 g of xylene were mixed and placed in a reactor; heated in a water bath to 75 °C under a nitrogen atmosphere and stirred for 30 min, then 0.2 g of azobisisobutyronitrile as an initiator was added, the water bath temperature was kept at 75 °C, and the reaction was carried out for 4 h; then 40 g of ethanol was added for extraction and precipitation, filtered, and the precipitate was dried in a vacuum drying oven at 50 °C to obtain a flame retardant and heat-resistant additive; (3) Add 50g ABS resin, 5g decabromodiphenylethane, 3g antimony trioxide, 5g flame retardant and heat-resistant additive, 3g olefinated silica powder, 0.1 anti-dripping agent FD3150, 0.5g lubricant EBS, and 0.3g antioxidant into a high-speed mixer and mix them thoroughly at a speed of 800rpm for 10min. Then, add the mixed materials into a twin-screw extruder and extrude and granulate them at 190℃ and a screw speed of 400 rpm to obtain heat-resistant and flame-retardant ABS.

[0025] Comparative Example 4: A heat-resistant and flame-retardant ABS, the specific preparation method is as follows: 50 g of ABS resin, 5 g of decabromodiphenylethane, 3 g of antimony trioxide, 0.1 g of anti-dripping agent FD3150, 0.5 g of lubricant EBS, and 0.3 g of antioxidant were added to a high-speed mixer and fully mixed at a speed of 800 rpm for 10 min. The mixed materials were then added to a twin-screw extruder and extruded into granules at 190° C. and a screw speed of 400 rpm to obtain heat-resistant and flame-retardant ABS.

[0026] Performance Testing Tensile strength: tested according to GB / T 1039-1992; Flexural strength: tested according to ASTM D790; Impact strength: tested according to GB / T 1043-1993; Melt index: tested according to ASTM D1238; Vicat temperature: tested according to ASTM D1525; UL-94: tested using a limiting oxygen index instrument; Table 1 Performance test results <![CDATA[Impact strength (KJ / m 2 )]]> Tensile strength (MPa) Flexural strength (MPa) Melt index (g / 10min) 200℃, 5KG Vicat temperature (℃) UL-94 / 1.5mm Example 1 7.2 48.7 76.8 2.1 103.2 V0 Example 2 6.3 49.1 78.1 1.5 107.5 V0 Example 3 5.5 48.9 78.5 1.3 108.5 V0 Example 4 4.9 48.6 79.1 1.1 110.2 V0 Comparative Example 1 6.8 47.9 74.2 2.5 98.5 V0 Comparative Example 2 8.5 46.3 71.6 3.8 89.7 V0 Comparative Example 3 5.1 45.8 69.4 1.9 95.2 V0 Comparative Example 4 9.1 48.2 73.7 3.1 93.7 V1 From the test data results of Examples 1-4 and the comparative example in Table 1, it can be seen that the introduction of the flame retardant and heat-resistant additive prepared by the present invention can effectively improve the flame retardancy and heat resistance of the material, and at the same time, can also give the ABS material good mechanical properties.

[0027] It can be seen from Example 1 and Comparative Examples 2 and 3 that the present invention improves the flame retardancy and heat resistance of ABS materials by grafting silica into flame retardant and heat-resistant additives. This is mainly because at high temperatures, silica may form a glassy carbon layer with the decomposition products of the copolymer, forming a certain physical barrier effect. At the same time, the olefinated silica can also be better compatible with the matrix resin and dispersed more evenly, without causing much impact on the mechanical properties of the ABS material. In addition, it can be seen from Example 1 and Comparative Example 1 that by replacing the silica powder with porous silica powder, the flame retardancy and heat resistance of the ABS material are better. This may be because the porous silica can fix the brominated flame retardant in the pores through physical adsorption and chemical bonding, and can be slowly released at high temperatures, avoiding the "blow-out effect" caused by concentrated release and the problem of the flame retardant easily slipping and precipitating between polymers. At the same time, the pores can capture the gas and heat generated by the pyrolysis of ABS, reducing the release of corrosive gases.

[0028] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Within the scope of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

Claims

1. A heat-resistant and flame-retardant ABS, characterized in that: The invention comprises the following components in parts by weight: 50-70 parts of ABS resin, 5-18 parts of main flame retardant, 3-8 parts of auxiliary flame retardant, 5-30 parts of flame retardant and heat-resistant auxiliary agent, 0.1-0.5 parts of anti-dripping agent, 0.5-2 parts of lubricant, and 0.3-0.5 parts of antioxidant; The preparation steps of the flame retardant and heat resistant auxiliary agent are as follows: (1) The porous silica powder was dispersed in an ethanol-water mixed solution, the pH was adjusted to 4, and the solution was evenly dispersed by ultrasonication. KH-570 was added and mixed evenly. The mixture was stirred at 80°C for 10-12 hours. After the reaction was completed, the mixture was purified to obtain olefinated silica powder. (2) Mix olefinated silica powder, 4-bromostyrene, N-(2,4,6-tribromophenyl)maleimide, maleic anhydride and xylene, heat to 75°C in a water bath under a nitrogen atmosphere, stir, then add azobisisobutyronitrile, maintain the water bath temperature at 75-77°C, react for 4-5 hours, and purify to obtain a flame retardant and heat-resistant additive; The usage ratio of ethanol, deionized water, porous silica powder, and KH-570 in step (1) is 120 g:40 g:5-6 g:5-20 mL; The amount ratio of the olefinated silica powder, 4-bromostyrene, N-(2,4,6-tribromophenyl)maleimide, maleic anhydride, xylene, azobisisobutyronitrile, and ethanol in step (2) is 3-5 g: 25-30 g: 60-65 g: 15-20 g: 500-550 g: 0.2-1 g: 400-500 g.

2. The heat-resistant and flame-retardant ABS according to claim 1, characterized in that: The porous silica powder in step (1) has a particle size of 300-400 nm and a specific surface area of 300-400 m 2 / g.

3. The heat-resistant and flame-retardant ABS according to claim 1, characterized in that: The ABS resin is composed of a butadiene rubber-based elastomer as a dispersed phase and a polystyrene-acrylonitrile (SAN) copolymer resin as a continuous phase.

4. The heat-resistant and flame-retardant ABS according to claim 1, characterized in that: The main flame retardant is one or more of tetrabromobisphenol A, decabromodiphenylethane, and 1,2-bis(2,4,6-tribromophenoxy)ethane.

5. The heat-resistant and flame-retardant ABS according to claim 1, characterized in that: The auxiliary flame retardant is one or more of zinc borate, zinc oxide, organic montmorillonite and hydrotalcite.

6. The heat-resistant and flame-retardant ABS according to claim 1, characterized in that: The anti-drip agent is polytetrafluoroethylene; preferably, PTFE is one or more of FD3150, FD3200, and FD3100.

7. The heat-resistant and flame-retardant ABS according to claim 1, characterized in that: The antioxidant is one or more of 168, 626, 1010, 1076, and DSTP.

8. The heat-resistant and flame-retardant ABS according to claim 1, characterized in that: The lubricant is one or more of oleamide, erucamide, pentaerythritol stearamide, and ethylene bisstearamide.

9. A method for preparing the heat-resistant and flame-retardant ABS according to any one of claims 1 to 8, characterized in that: The following steps are involved: ABS resin, main flame retardant, auxiliary flame retardant, flame retardant and heat-resistant additive, anti-dripping agent, lubricant and antioxidant are added into a high-speed mixer according to the raw material ratio, and after being fully mixed, they are added into a twin-screw extruder, and extruded and granulated at 190-210° C. and a screw speed of 400 rpm to obtain heat-resistant and flame-retardant ABS resin.