Preparation method of antistatic flame-retardant ABS material

Abstract

The invention relates to the technical field of high polymer material modification, and discloses a preparation method of an antistatic flame-retardant ABS (acrylonitrile butadiene styrene) material, which comprises the steps of raw material preparation, premixed main material preparation, melt extrusion and post-treatment. The raw materials comprise ABS (Acrylonitrile Butadiene Styrene) resin, melamine polyphosphate, a polyether ester amide block copolymer, a modified antistatic carrier and the like; wherein the modified antistatic carrier is powder prepared from zinc borate, fumed silica and a silane coupling agent adsorbing a liquid zwitterionic antistatic agent. During extrusion, the premixed main material is added from a main feeding port, and the polyether ester amide block copolymer is added from a side feeding port at the middle-rear section of the screw. According to the invention, the problem of processing slip caused by a liquid assistant is solved through a carrier technology, and the flame retardant property is improved by utilizing the synergistic effect of zinc borate and the flame retardant; the step-by-step feeding process reduces the shearing action on polyether ester amide, and is beneficial to construction of a conductive network. The obtained material has good flame retardant grade, antistatic durability and mechanical strength.

Description

Technical Field

[0001] This invention relates to the field of polymer material modification technology, specifically to a method for preparing an antistatic and flame-retardant ABS material. Background Technology

[0002] Acrylonitrile-butadiene-styrene copolymer (ABS) is widely used in electronics, automotive interiors, and office equipment due to its excellent impact strength, processing fluidity, and surface gloss. However, ABS resin not only has a low limiting oxygen index and is easily flammable, but also has a high surface resistivity, making it prone to accumulating static charge during use. This can lead to dust adsorption, affect the operation of electronic components, and even cause electrical fires. Therefore, endowing ABS materials with flame-retardant and antistatic properties is essential for expanding their application range.

[0003] Currently, industrial processes typically involve compounding ABS with antistatic agents and flame retardants. Common low-molecular-weight antistatic agents (including quaternary ammonium salts and betaine amphoteric surfactants) are mostly liquid or low-melting-point waxy substances. During twin-screw extrusion, directly adding liquid additives can form a lubricating film on the resin particles and screw surface, reducing the coefficient of friction and leading to screw slippage, unstable material transport, and significant fluctuations in the main motor current, hindering continuous and stable industrial production. Furthermore, small-molecule antistatic agents primarily rely on migration to the material surface to absorb moisture and conduct electricity. This physical migration mechanism makes the antistatic effect highly susceptible to environmental humidity and easily lost through wiping or washing, lacking long-term effectiveness.

[0004] To address durability issues, polyether ester amide (PEEA) polymeric permanent antistatic agents are increasingly being adopted. This material functions by constructing a continuous, interconnected conductive phase structure within the matrix resin. However, to achieve V-0 flame retardancy standards, formulations typically require a high proportion of flame-retardant powders (including phosphorus-nitrogen-based flame retardants), necessitating strong shear forces from the extruder to ensure uniform filler dispersion. PEEA molecular chains are flexible and sensitive to thermal shear. When subjected to strong shear and prolonged high-temperature melt mixing with flame retardants, they are prone to thermomechanical degradation or shear dispersion into isolated micro-regions, leading to disruption of the conductive network. To compensate for this disruption, a significant increase in PEEA dosage is usually required, not only increasing costs but also severely impairing the rigidity and heat resistance of ABS materials.

[0005] Therefore, how to solve the problems of slippage and easy loss in the processing of liquid additives while avoiding the damage to the conductive network of polymeric antistatic agents by high-shear processes, and prepare ABS materials that combine flame retardancy, durable antistatic properties and mechanical properties, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a method for preparing antistatic and flame-retardant ABS materials, which solves the problems faced by existing antistatic and flame-retardant ABS materials when adding liquid antistatic agents, such as unstable extrusion processing, easy surface precipitation failure, and difficulty in simultaneously achieving long-lasting antistatic properties, flame retardancy, and mechanical properties.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] This invention provides a method for preparing antistatic and flame-retardant ABS material, comprising the following steps:

[0009] Raw material preparation: The raw materials include ABS resin, melamine polyphosphate, polyether ester amide block copolymer, modified antistatic carrier, maleic anhydride grafted ABS, and additives; the modified antistatic carrier is a powder prepared from components including zinc borate, fumed silica, silane coupling agent and liquid zwitterionic antistatic agent;

[0010] Preparation of premixed main material: The raw materials other than the polyether ester amide block copolymer are put into a mixer and mixed evenly to obtain the premixed main material;

[0011] Melt extrusion: Melt extrusion is performed using a co-rotating twin-screw extruder. The premixed main material is added through the main feed port, and the polyether ester amide block copolymer is added through the side feed port located in the middle and rear section of the screw of the co-rotating twin-screw extruder.

[0012] Post-processing: The extruded melt is cooled, pelletized, and dried to obtain the antistatic and flame-retardant ABS material.

[0013] By adopting the above technical solution, this invention resolves the contradiction between adding liquid additives and protecting the polymer conductive network through a combination of carrier adsorption technology and stepwise feeding process.

[0014] By utilizing the high specific surface area of ​​fumed silica and the layered structure of zinc borate as a framework, liquid zwitterionic antistatic agents are fixed within the pores of the powder through physical adsorption, avoiding screw slippage and subsequent precipitation problems caused by direct addition of liquid additives. At the same time, the glassy substance formed by zinc borate during combustion, together with the char layer and gas produced by melamine polyphosphate, generates a synergistic flame-retardant effect of boron, phosphorus, and nitrogen, enhancing the density of the char layer.

[0015] The side-feeding process introduces polyether ester amide block copolymer into the melt, subjecting it to a shorter thermal history and weaker shearing action. This preserves the molecular chain integrity of the polyether ester amide and promotes the formation of a continuous conductive network in the ABS matrix, thereby reducing the surface resistivity of the material at a lower addition level.

[0016] The small-molecule antistatic agent released by the carrier acts on the surface of the material, while the conductive network constructed by the polyether ester amide acts inside the material. The combination of the two achieves dual charge dissipation on both the surface and the volume.

[0017] Preferably, in the step of preparing the raw materials, the raw materials are composed of the following components by weight: ABS resin: 60.0-65.0 parts; melamine polyphosphate: 15.0-20.0 parts; polyether ester amide block copolymer: 10.0-15.0 parts; modified antistatic carrier: 4.8-5.1 parts; maleic anhydride-grafted ABS: 1.0-2.0 parts; antioxidant: 0.5-0.7 parts; silane coupling agent: 0.3-0.5 parts. By adopting the above technical solution, the proportions of each component ensure V-0 flame retardant performance, while the maleic anhydride-grafted ABS improves the interfacial bonding between the inorganic filler and the resin matrix, balancing the impact strength of the material.

[0018] Preferably, in the step of preparing the raw materials, the modified antistatic carrier is prepared from raw materials comprising the following parts by weight: zinc borate: 2.5-3.0 parts; fumed silica: 0.25-0.5 parts; molten dodecyl dimethyl betaine: 1.5-2.0 parts; silane coupling agent: 0.05-0.08 parts. By adopting the above technical solution, the inorganic powder combination at this ratio can completely adsorb molten dodecyl dimethyl betaine without overflow, while ensuring the modification coverage of the inorganic surface by the silane coupling agent.

[0019] Preferably, in the step of preparing raw materials, the process of preparing the modified antistatic carrier includes the following steps: weighing zinc borate and fumed silica into a high-speed mixer equipped with a heating device and heating to 85-95°C; after the material temperature reaches 85-95°C, a silane coupling agent is sprayed in atomized form under low-speed stirring at 350-500 rpm, and the temperature is maintained for mixing for 3-5 minutes; the speed is increased to 800-1000 rpm, and preheated to a molten state dodecyl dimethyl betaine is uniformly added dropwise into the high-speed mixer; after the addition is completed, the speed is increased to 1600-2000 rpm for high-speed shear mixing for 10-15 minutes; the material is discharged into a cold mixer and cooled to 30-40°C before being discharged to obtain the modified antistatic carrier powder. By adopting the above technical solution, the carrier function was constructed in stages: the first stage uses high temperature and coupling agent treatment to reduce the surface polarity of inorganic powder and remove adsorbed water; the second stage uses the low viscosity of molten dodecyl dimethyl betaine to penetrate into the pores of the powder; the third stage uses high-speed shearing to break up agglomerated particles and uses the cooling process to make the antistatic agent undergo phase change and solidify in the pores, thereby being physically locked.

[0020] Preferably, in the step of adding dodecyl dimethyl betaine, the preheating temperature of dodecyl dimethyl betaine is 55-65°C, and the dropping rate is controlled at 60-100 ml / min. By adopting the above technical solution, the preheating temperature is slightly higher than the melting point to ensure fluidity, and the dropping rate is controlled to prevent powder agglomeration caused by excessive local liquid.

[0021] Preferably, in the melt extrusion step, the side feed port is located at position 22D-26D of the co-rotating twin-screw extruder; the screw speed of the co-rotating twin-screw extruder is set to 100-140 rpm. By adopting the above technical solution, the side feed position avoids the high-shear zone of the solid conveying section, and with a suitable screw speed, it ensures uniform material dispersion while reducing the mechanical shear degradation of the polyether ester amide molecular chains.

[0022] Preferably, in the melt extrusion step, the temperature of each zone of the co-rotating twin-screw extruder is set as follows: Zone 1 100-120℃, Zones 2 to 4 190-210℃, Zone 5 200-210℃, Zones 6 to 8 210-230℃, Zone 9 220-230℃, and the die head 225-230℃. By adopting the above technical solution, the stepped temperature distribution ensures that the components are mixed at a suitable viscosity and prevents the flame retardant from decomposing due to localized high temperatures.

[0023] Preferably, in the melt extrusion step, the vacuum level in the vacuum exhaust zone of the co-rotating twin-screw extruder is controlled between -0.08 MPa and -0.1 MPa. By adopting the above technical solution, volatiles and reaction byproducts in the melt are effectively removed, reducing internal porosity of the product and improving material density.

[0024] Preferably, in the raw material preparation step, the ABS resin is pre-dried under vacuum at 75-85°C for 3-5 hours, and the polyether ester amide block copolymer is pre-dried under vacuum at 65-75°C for 5-7 hours. By adopting the above technical solution, the moisture content of the raw materials is reduced, preventing hydrolysis reactions during high-temperature processing that could lead to a decrease in molecular weight.

[0025] Preferably, in the step of preparing the raw materials, the antioxidant is a mixture of antioxidant 1010 and antioxidant 168, and the mixing weight ratio of antioxidant 1010 to antioxidant 168 is 1:1.8 to 1:2.2. By adopting the above technical solution, hindered phenolic antioxidants and phosphite antioxidants are combined in a specific ratio to capture free radicals and decompose peroxides, respectively, thereby synergistically improving the thermal processing stability and aging resistance of the material.

[0026] In summary, this application includes at least one of the following beneficial technical effects:

[0027] 1. This invention utilizes modified carrier technology to solve the problem of unstable processing of liquid additives and improve antistatic durability. By using zinc borate and fumed silica as porous adsorption carriers, combined with surface modification of silane coupling agents, the liquid zwitterionic antistatic agent is solidified into a solid powder with good flowability. This effectively eliminates extruder screw slippage and main machine current fluctuations caused by direct addition of liquid additives, ensuring the stability of the production process. Simultaneously, the physical adsorption and chemical coupling effects of the carrier limit the migration rate of small-molecule antistatic agents, inhibiting their excessive loss to the material surface, allowing the material to maintain a low surface resistivity even after water washing.

[0028] 2. The step-feeding process employed in this invention effectively protects the polymer's conductive network and improves antistatic efficiency. The polyether ester amide block copolymer is added through a side feed port in the middle to rear section of the screw, avoiding the high-shear and long-heat-history regions of the solid conveying section and the initial melting stage, thus reducing the mechanical degradation of the molecular chains. Compared to the main feed mixing method, this process helps the polyether ester amide maintain the integrity of its phase structure within the ABS matrix and construct continuous conductive pathways, thereby significantly reducing the surface resistivity of the material at the same addition amount and achieving a long-lasting antistatic effect.

[0029] 3. The multifunctional carrier in this invention achieves a balance between flame retardant synergy and mechanical properties. Zinc borate in the carrier component not only serves as a carrier for the liquid antistatic agent but also acts as a flame retardant synergist, forming a synergistic flame retardant system with melamine polyphosphate. During combustion, it promotes the formation of a dense, expanded char layer, enabling the material to meet the UL-94V-0 flame retardant standard. Compared to solutions using inert carriers such as calcium carbonate, this functionalized carrier avoids the loss of flame retardant performance due to the introduction of inactive fillers. Combined with the interfacial compatibilization effect of maleic anhydride-grafted ABS, it effectively reduces the negative impact of high filler content on the material's impact strength. Detailed Implementation

[0030] Preparation Examples 1-4:

[0031] Preparation Example 1:

[0032] This preparation example provides a modified antistatic carrier, the raw material components of which include:

[0033] Zinc borate: 2.8 parts;

[0034] Fumed silica: 0.35 parts;

[0035] Molten dodecyl dimethyl betaine (BS-12): 1.75 parts;

[0036] Silane coupling agent KH-550: 0.06 parts.

[0037] The preparation method of this modified antistatic carrier includes the following steps:

[0038] The weighed zinc borate and fumed silica were put into a high-speed mixer equipped with a heating jacket and a liquid spraying device. The heating was started and the temperature was set to 90°C.

[0039] After the material temperature reaches 90℃, set the stirring paddle speed to 400rpm for low-speed stirring. At the same time, spray the silane coupling agent KH-550 evenly in the form of atomization through the nozzle. Maintain low-speed mixing for 4 minutes to complete the initial activation of the inorganic powder surface.

[0040] Maintain the temperature inside the mixer at 90℃, increase the speed to 900 rpm, and uniformly add solid dodecyl dimethyl betaine, which has been preheated to 60℃ and is in a transparent anhydrous molten liquid state, into the mixer through a liquid feed pump at a flow rate of 80 ml / min.

[0041] After the addition is complete, the rotation speed is increased to 1800 rpm, and high-speed shear mixing is continued for 12 minutes to use shear force and heat energy to promote the penetration of liquid antistatic agent into the pores of powder.

[0042] The material is fed into a cold mixer and cooled to below 40°C before being discharged, resulting in a modified antistatic carrier powder with free flow properties.

[0043] Preparation Example 2:

[0044] This preparation example provides a modified antistatic carrier, the raw material components of which include:

[0045] Zinc borate: 3.0 parts;

[0046] Fumed silica: 0.25 parts;

[0047] Molten dodecyl dimethyl betaine (BS-12): 1.5 parts;

[0048] Silane coupling agent KH-550: 0.05 parts.

[0049] The preparation method of this modified antistatic carrier includes the following steps:

[0050] Weigh out zinc borate and fumed silica and put them into a high-speed mixer with a heating jacket. Start the heating and set the temperature to 85°C.

[0051] Once the material temperature reaches 85℃, set the stirring paddle speed to 350rpm for low-speed stirring, and simultaneously spray the silane coupling agent KH-550 evenly in the form of atomization, and maintain low-speed mixing for 3 minutes.

[0052] Maintain the temperature inside the mixer at 85℃, increase the rotation speed to 800 rpm, and uniformly add dodecyl dimethyl betaine, which has been preheated to 60℃ and is in a molten liquid state, into the mixer through a liquid feed pump at a flow rate of 60 ml / min;

[0053] After the addition is complete, increase the rotation speed to 1600 rpm and continue high-speed shear mixing for 10 minutes;

[0054] The material is fed into a cold mixer and cooled to below 40°C before being discharged to obtain modified antistatic carrier powder.

[0055] Preparation Example 3:

[0056] This preparation example provides a modified antistatic carrier, the raw material components of which include:

[0057] Zinc borate: 2.5 parts;

[0058] Fumed silica: 0.5 parts;

[0059] Molten dodecyl dimethyl betaine (BS-12): 2.0 parts;

[0060] Silane coupling agent KH-550: 0.08 parts.

[0061] The preparation method of this modified antistatic carrier includes the following steps:

[0062] Weigh out zinc borate and fumed silica and put them into a high-speed mixer with a heating jacket. Start the heating and set the temperature to 95°C.

[0063] Once the material temperature reaches 95℃, set the stirring speed to 500rpm for low-speed stirring, and simultaneously spray the silane coupling agent KH-550 evenly in the form of atomization, and maintain low-speed mixing for 5 minutes.

[0064] Maintain the temperature inside the mixer at 95℃, increase the rotation speed to 1000 rpm, and uniformly add dodecyl dimethyl betaine, which has been preheated to 60℃ and is in a molten liquid state, into the mixer through a liquid feed pump at a flow rate of 100 ml / min;

[0065] After the addition is complete, increase the rotation speed to 2000 rpm and continue high-speed shear mixing for 15 minutes to ensure that the high proportion of liquid is fully adsorbed;

[0066] The material is fed into a cold mixer and cooled to below 40°C before being discharged to obtain modified antistatic carrier powder.

[0067] Preparation Example 4:

[0068] This preparation example provides a reference sample without added oil-absorbing agent, the raw material components of which include:

[0069] Zinc borate: 2.8 parts;

[0070] Molten dodecyl dimethyl betaine (BS-12): 1.75 parts;

[0071] Silane coupling agent KH-550: 0.06 parts.

[0072] The method for preparing the reference sample includes the following steps:

[0073] Add the weighed zinc borate into a high-speed mixer with a heating jacket (without adding fumed silica), start the heating, and set the temperature to 90℃;

[0074] Once the material temperature reaches 90℃, set the stirring paddle speed to 400rpm for low-speed stirring, and simultaneously spray the silane coupling agent KH-550 evenly in atomized form, maintaining low-speed mixing for 4 minutes.

[0075] Maintain the temperature inside the mixer at 90℃, increase the rotation speed to 900 rpm, and uniformly add dodecyl dimethyl betaine, which has been preheated to 60℃ and is in a molten liquid state, into the mixer through a liquid feed pump at a flow rate of 80 ml / min;

[0076] After the addition is complete, increase the rotation speed to 1800 rpm and continue high-speed shear mixing for 12 minutes;

[0077] The material is discharged into a cold mixer for cooling. Due to the lack of highly oil-absorbing components, the resulting product is a viscous, agglomerated mixture of reference samples.

[0078] Examples 1-4:

[0079] Example 1:

[0080] This embodiment provides a method for preparing an antistatic and flame-retardant ABS material, the raw material components of which, by weight, include:

[0081] ABS resin: 63.0 parts;

[0082] Melamine polyphosphate (MPP): 18.0 parts;

[0083] Polyether ester amide block copolymer (PEEA): 12.0 parts;

[0084] Preparation Example 1: 4.96 parts;

[0085] Maleic anhydride-grafted ABS (ABS-g-MAH): 1.5 parts;

[0086] Antioxidant 1010: 0.2 parts;

[0087] Antioxidant 168: 0.4 parts;

[0088] Silane coupling agent KH-550: 0.4 parts.

[0089] The preparation method of this antistatic and flame-retardant ABS material includes the following steps:

[0090] ABS resin was vacuum dried at 80°C for 4 hours, and polyether ester amide was vacuum dried at 70°C for 6 hours.

[0091] The dried ABS resin, melamine polyphosphate, maleic anhydride-grafted ABS, antioxidant, silane coupling agent KH-550, and the modified antistatic carrier prepared in Preparation Example 1 were put into a low-speed mixer and mixed at room temperature for 5 minutes to obtain a uniformly dispersed premixed main material.

[0092] A co-rotating twin-screw extruder with a length-to-diameter ratio (L / D) of 44:1 was used. The premixed main material was added to the main feed port, and the polyether ester amide was added to the side feed port located at screw 24D.

[0093] The extruder screw speed is set to 120 rpm, the vacuum degree of the vacuum exhaust zone is -0.09 MPa, and the temperature of each zone is set as follows: Zone 1 110℃, Zones 2 to 4 200-210℃, Zone 5 (side feed port) 205℃, Zones 6 to 8 220-230℃, Zone 9 225℃, and the die head 230℃.

[0094] The extruded melt strip is cooled by circulating water, dried by a fan, granulated, and dried at 80°C for 4 hours to obtain the finished product.

[0095] Example 2:

[0096] This embodiment provides a method for preparing an antistatic and flame-retardant ABS material, the raw material components of which, by weight, include:

[0097] ABS resin: 60.0 parts;

[0098] Melamine polyphosphate (MPP): 20.0 parts;

[0099] Polyether ester amide block copolymer (PEEA): 10.0 parts;

[0100] Preparation Example 2: 4.8 parts of the modified antistatic carrier;

[0101] Maleic anhydride-grafted ABS (ABS-g-MAH): 2.0 parts;

[0102] Antioxidant 1010: 0.2 parts;

[0103] Antioxidant 168: 0.4 parts;

[0104] Silane coupling agent KH-550: 0.5 parts.

[0105] The preparation method of this antistatic and flame-retardant ABS material includes the following steps:

[0106] The raw material pretreatment process is the same as in Example 1;

[0107] A premixed main material was prepared by mixing ABS resin, MPP, ABS-g-MAH, antioxidant and the modified antistatic carrier obtained in Preparation Example 2.

[0108] Using a co-rotating twin-screw extruder, premixed main feed material is added to the main feed, and PEEA is added to the side feed.

[0109] Considering the increased content of flame retardant powder, the process parameters were adjusted as follows: the screw speed was set to 140 rpm to enhance shear dispersion, the vacuum degree was -0.1 MPa, and the temperature of each zone was set as follows: Zone 1 120℃, Zones 2 to 4 210℃, Zone 5 210℃, Zones 6 to 8 230℃, Zone 9 230℃, and the die head 230℃.

[0110] The subsequent cooling, pelletizing and drying steps are the same as in Example 1.

[0111] Example 3:

[0112] This embodiment provides a method for preparing an antistatic and flame-retardant ABS material, the raw material components of which, by weight, include:

[0113] ABS resin: 65.0 parts;

[0114] Melamine polyphosphate (MPP): 15.0 parts;

[0115] Polyether ester amide block copolymer (PEEA): 15.0 parts;

[0116] Preparation Example 3: 5.08 parts of the modified antistatic carrier;

[0117] Maleic anhydride-grafted ABS (ABS-g-MAH): 1.0 part;

[0118] Antioxidant 1010: 0.2 parts;

[0119] Antioxidant 168: 0.4 parts;

[0120] Silane coupling agent KH-550: 0.3 parts.

[0121] The preparation method of this antistatic and flame-retardant ABS material includes the following steps:

[0122] The raw material pretreatment process is the same as in Example 1;

[0123] A premixed main material was prepared by mixing ABS resin, MPP, ABS-g-MAH, antioxidant and the modified antistatic carrier obtained in Preparation Example 3.

[0124] Using a co-rotating twin-screw extruder, premixed main feed material is added to the main feed, and PEEA is added to the side feed.

[0125] Considering the high resin matrix content, the process parameters were adjusted as follows: the screw speed was set to 100 rpm to protect the PEEA phase structure, the vacuum degree was -0.08 MPa, and the temperatures of each zone were set as follows: Zone 1 100℃, Zones 2 to 4 190-200℃, Zone 5 200℃, Zones 6 to 8 210-220℃, Zone 9 220℃, and the die head 225℃.

[0126] The subsequent cooling, pelletizing and drying steps are the same as in Example 1.

[0127] Example 4:

[0128] This embodiment provides a method for preparing an antistatic and flame-retardant ABS material. The raw material components are exactly the same as those in Example 1 by weight (using the modified antistatic carrier of Preparation Example 1 and 0.4 parts of silane coupling agent KH-550). The process parameters are adjusted to a screw speed of 130 rpm, and the rest are the same as in Example 1.

[0129] The preparation method of this antistatic and flame-retardant ABS material includes the following steps:

[0130] The raw material pretreatment process is the same as in Example 1;

[0131] The main ingredient mixing process is the same as in Example 1;

[0132] A co-rotating twin-screw extruder was used, employing the same feeding method as in Example 1;

[0133] Change the extrusion temperature profile and speed: set the screw speed to 130 rpm, and set the temperature of each zone as follows: Zone 1 115℃, Zones 2 to 4 205℃, Zone 5 205℃, Zones 6 to 8 225℃, Zone 9 220℃, and the die head 225℃.

[0134] The subsequent cooling, pelletizing and drying steps are the same as in Example 1.

[0135] Comparative Examples 1-5:

[0136] Comparative Example 1:

[0137] The difference from Example 1 is that the pre-preparation of the modified antistatic carrier is not performed (i.e., the steps of Preparation Example 1 are not performed).

[0138] Comparative Example 2:

[0139] Compared with Example 1, the difference is that the modified antistatic carrier used was replaced with the reference sample obtained in Preparation Example 4 (i.e., no fumed silica was added during the preparation process), and the rest of the formulation and process were the same as in Example 1.

[0140] Comparative Example 3:

[0141] The difference from Example 1 is that dodecyl dimethyl betaine (BS-12) was not added when preparing the modified antistatic carrier.

[0142] The specific operation is as follows: the carrier raw materials include only 2.8 parts of zinc borate, 0.35 parts of fumed silica and 0.06 parts of silane coupling agent KH-550, which are added after being processed according to the process of preparation example 1, and the rest are the same as in example 1.

[0143] Comparative Example 4:

[0144] The difference from Example 1 is that zinc borate was replaced with an equal weight of inert filler (calcium carbonate) in the preparation of the modified antistatic carrier; otherwise, it was the same as in Example 1. That is, calcium carbonate was used to adsorb the liquid antistatic agent, thereby stripping the chemical functional properties of zinc borate.

[0145] Comparative Example 5:

[0146] The difference compared to Example 1 is that the method of adding polyether ester amide (PEEA) is changed.

[0147] The specific operation is as follows: side feeding is cancelled, and polyether ester amide (12.0 parts) is added to the mixer along with other main materials and modified carriers in the mixing process of preparing premixed main materials, and all of it is added to the extruder through the main feed port. All other process parameters are the same as in Example 1.

[0148] Test Examples 1-2:

[0149] Test Example 1:

[0150] Process feasibility and processing stability testing

[0151] This test case aims to verify the industrial operational feasibility and processing stability of each embodiment and comparative example in actual preparation. The test focuses on the impact of introducing a high proportion of liquid components on the morphology of the mixture, feeding accuracy, and extruder operating status.

[0152] Experimental steps:

[0153] The preparation processes of Examples 1-4 and Comparative Examples 1-5 were monitored throughout the entire process. First, after the main material premixing step was completed, the mixer discharge valve was opened, and the physical morphology and flow state of the material were directly recorded. Then, the premix was added to a loss-in-weight metering feeder, with a feed rate set to 50 kg / h, and ran continuously for 15 minutes. Whether bridging or interruption of material feeding occurred on the feeder screw was recorded. After the extruder process conditions stabilized for 30 minutes, the main extruder current data and die head melt pressure data were continuously recorded for 20 minutes using a data acquisition system, and the fluctuation range was calculated. Finally, the surface quality of the melt strip exiting the die head was observed, and whether there were any broken strips, foaming, or uneven diameter phenomena was recorded.

[0154] Test results:

[0155] The test data is summarized in Table 1.

[0156] Table 1: Data on Processing Stability and Process Parameter Monitoring of Each Component

[0157] Group Physical form of premix Feeding status description Host current fluctuation range (%) Melt pressure fluctuation range (%) Strip appearance quality Example 1 Dry powder with good flowability Continuous stability 2.34 1.12 Smooth surface and uniform output Example 2 Dry powder, micro dust Continuous stability 2.87 1.45 The surface is smooth, with occasional slight roughness. Example 3 Dry powder with good flowability Continuous stability 2.15 1.08 Smooth surface and uniform output Example 4 Dry powder with good flowability Continuous stability 2.41 1.26 Smooth surface and uniform output Comparative Example 1 Moisture not only sticks to the walls but also clumps together. Frequent bridge construction makes material unloading difficult. 18.65 12.4 Rough surface, large diameter fluctuation Comparative Example 2 Thick paste / clump Unable to feed -- -- Unable to squeeze out Comparative Example 3 Dry powder with excellent flowability Continuous stability 1.98 0.95 Smooth surface Comparative Example 4 Dry powder with moderate flowability Relatively stable 3.12 1.58 Smooth surface Comparative Example 5 Dry powder with good flowability Continuous stability 2.2 1.15 Smooth surface

[0158] Note: "--" indicates that the material could not enter the extruder due to its condition, and no valid data was obtained.

[0159] Results analysis:

[0160] Based on the data in Table 1 and the analysis of the extrusion process, in Comparative Example 2, without the addition of fumed silica, the liquid antistatic agent mixed with zinc borate formed viscous agglomerates, causing the material to lose its fluidity and preventing it from being fed into the extruder. This indicates that in a high liquid-to-solid ratio system, a single inorganic powder cannot bear excessive liquid; therefore, it is necessary to introduce porous materials with high oil absorption values ​​in conjunction with a shearing process to achieve dry powdering.

[0161] Comparative Example 1 uses a direct mixing process, where the liquid antistatic agent is free on the surface of the resin particles, acting as an external lubricant in the extruder's feeding and compression sections, resulting in a reduction in the friction coefficient between the screw and the material. Data shows that the main motor current fluctuation reached 18.65%, accompanied by melt pressure fluctuations, indicating periodic screw slippage, leading to unstable conveying and uneven strip size. Examples 1-4 utilize carrier technology to adsorb the liquid component into the pores of the solid particles, avoiding direct contact between the liquid and the screw surface, ensuring normal solid friction and shearing processes, controlling the current fluctuation within 3%, and achieving stable processing.

[0162] Although Comparative Example 5 showed similar processing stability data to the Example, it changed the way PEEA was added. Subsequent performance tests revealed that its stability was achieved at the expense of the PEEA phase structure. The Example scheme, while employing a side-feeding process to protect the conductive network, did not compromise processing stability due to the introduction of a liquid antistatic agent.

[0163] Test Example 2:

[0164] Experimental steps:

[0165] The granules obtained from the above extrusion granulation were injection molded into standard test strips on an injection molding machine. The injection temperature was set at 210℃-230℃, and the mold temperature was 60℃. A vertical burning test was performed on 1.6mm thick samples according to UL-94 standards, recording the afterburning time and dripping. Surface resistivity was measured according to ASTM D257 standards using a three-electrode method (concentric electrodes) at 23℃ and 50% relative humidity. The samples were then immersed in deionized water for ultrasonic cleaning for 60 minutes, dried, and conditioned for 24 hours before water-resistant surface resistivity was tested to characterize antistatic durability. The notched impact strength of the cantilever beam was tested at 23℃ according to ISO 180 standards.

[0166] Test results:

[0167] The specific test data is summarized in Table 2.

[0168] Table 2: Summary of Performance Test Results of Flame-Retardant and Antistatic ABS Composite Materials

[0169] Group UL-94 flame retardant rating (1.6mm) Total residual combustion time ( , ) Initial surface resistivity ( ) Surface resistivity after water washing ) Notched impact strength ( ) Example 1 V-0 18.5 <![CDATA[2.4×10 9 ]]> <![CDATA[8.1×10 9 ]]> 12.4 Example 2 V-0 8.2 <![CDATA[6.5×10 9 ]]> <![CDATA[1.2×10 10 ]]> 10.8 Example 3 V-1 36.4 <![CDATA[8.2×10 8 ]]> <![CDATA[4.5×10 9 ]]> 14.1 Example 4 V-0 21.3 <![CDATA[3.1×10 9 ]]> <![CDATA[9.5×10 9 ]]> 11.9 Comparative Example 1 V-2 45.6 <![CDATA[1.8×10 9 ]]> <![CDATA[6.4×10 11 ]]> 8.3 Comparative Example 2 -- -- -- -- -- Comparative Example 3 V-0 19.1 <![CDATA[4.5×10 11 ]]> <![CDATA[2.2×10 11 ]]> 12.6 Comparative Example 4 NC (No rating) >100 (burned out) <![CDATA[5.2×10 9 ]]> <![CDATA[3.8×10 12 ]]> 11.2 Comparative Example 5 V-0 17.8 <![CDATA[6.2×10 11 ]]> <![CDATA[5.8×10 11 ]]> 9.5

[0170] Note: "--" indicates that Comparative Example 2 could not be sampled due to processing failure and there is no data; Comparative Example 1 showed that dripping cotton ignited.

[0171] Results analysis:

[0172] The test results in Table 2 show that the present invention has advantages in constructing an antistatic network and maintaining material properties.

[0173] Regarding the construction of the antistatic network, the surface resistivity of Example 1 reaches 10. 9 The level was significantly lower than that of Comparative Example 3 (without small molecule antistatic agent) at 10. 11 and 10% of Comparative Example 5 (PEEA main feed) 11 This indicates that zwitterionic small molecules act as bridges between the conductive polymer phases in the system, reducing the interfacial barrier; it also confirms the necessity of the side-feeding process for preserving the PEEA conductive network structure, as the high-shear process of the main feed disrupts the continuous conductive network.

[0174] Regarding durability, the resistivity change of Example 1 after washing was less than one order of magnitude, while the resistivity of Comparative Example 1 (direct mixing) and Comparative Example 4 (calcium carbonate carrier) rebounded to 10 after washing. 11 -1012 Data demonstrates that the composite carrier of zinc borate and fumed silica, through physical confinement and chemical adsorption, creates an anchoring effect on small-molecule antistatic agents, inhibiting their excessive migration and loss to the surface.

[0175] Regarding mechanical and flame-retardant properties, the combustion test failure of Comparative Example 4 confirmed the synergistic char-forming effect of zinc borate in the MPP system. Mechanically, the notched impact strength of Example 1 was superior to that of Comparative Example 1, indicating that pre-adsorbing the liquid additive into a solid powder before redispersing reduced stress concentration points in the matrix and mitigated the negative impact of antistatic agent addition on the matrix's mechanical properties.

Claims

1. A method for preparing an antistatic and flame-retardant ABS material, characterized in that, Includes the following steps: Raw material preparation: The raw materials include ABS resin, melamine polyphosphate, polyether ester amide block copolymer, modified antistatic carrier, maleic anhydride grafted ABS, and additives; the modified antistatic carrier is a powder prepared from components including zinc borate, fumed silica, silane coupling agent and liquid zwitterionic antistatic agent; Preparation of premixed main material: The raw materials other than the polyether ester amide block copolymer are put into a mixer and mixed evenly to obtain the premixed main material; Melt extrusion: Melt extrusion is performed using a co-rotating twin-screw extruder. The premixed main material is added through the main feed port, and the polyether ester amide block copolymer is added through the side feed port located in the middle and rear section of the screw of the co-rotating twin-screw extruder. Post-processing: The extruded melt is cooled, pelletized, and dried to obtain the antistatic and flame-retardant ABS material.

2. The method for preparing an antistatic and flame-retardant ABS material according to claim 1, characterized in that, In the step of preparing the raw materials, the raw materials consist of the following components by weight: ABS resin: 60.0-65.0 parts; Melamine polyphosphate: 15.0-20.0 parts; Polyether ester amide block copolymer: 10.0-15.0 parts; Modified antistatic carrier: 4.8-5.1 parts; Maleic anhydride-grafted ABS: 1.0-2.0 parts; Antioxidant: 0.5-0.7 parts; Silane coupling agent: 0.3-0.5 parts.

3. The method for preparing an antistatic and flame-retardant ABS material according to claim 1, characterized in that, In the step of preparing the raw materials, the modified antistatic carrier is prepared from raw materials comprising the following parts by weight: Zinc borate: 2.5-3.0 parts; Fumed silica: 0.25-0.5 parts; Molten dodecyl dimethyl betaine: 1.5-2.0 parts; Silane coupling agent: 0.05-0.08 parts.

4. The method for preparing an antistatic and flame-retardant ABS material according to claim 3, characterized in that, In the step of preparing raw materials, the process of preparing the modified antistatic carrier includes the following steps: The weighed zinc borate and the fumed silica are put into a high-speed mixer equipped with a heating device and heated to 85-95°C. After the material temperature reaches 85-95℃, the silane coupling agent is sprayed in atomized form under low-speed stirring conditions of 350-500rpm, and the mixture is kept at the temperature for 3-5 minutes. Increase the rotation speed to 800-1000 rpm and uniformly drop the preheated molten dodecyl dimethyl betaine into the high-speed mixer; After the addition is complete, increase the rotation speed to 1600-2000 rpm for high-speed shear mixing for 10-15 minutes; The material is discharged into a cold mixer and cooled to 30-40°C to obtain the modified antistatic carrier powder.

5. The method for preparing an antistatic and flame-retardant ABS material according to claim 4, characterized in that, In the step of adding the dodecyl dimethyl betaine, the preheating temperature of the dodecyl dimethyl betaine is 55-65℃, and the dropping rate is controlled at 60-100ml / min.

6. The method for preparing an antistatic and flame-retardant ABS material according to claim 1, characterized in that, In the melt extrusion step, the side feed port is located at position 22D-26D of the co-rotating twin-screw extruder; the screw speed of the co-rotating twin-screw extruder is set to 100-140 rpm.

7. The method for preparing an antistatic and flame-retardant ABS material according to claim 6, characterized in that, In the melt extrusion step, the temperature of each zone of the co-rotating twin-screw extruder is set as follows: Zone 1 100-120℃, Zones 2 to 4 190-210℃, Zone 5 200-210℃, Zones 6 to 8 210-230℃, Zone 9 220-230℃, and the die head 225-230℃.

8. The method for preparing an antistatic and flame-retardant ABS material according to claim 1, characterized in that, In the melt extrusion step, the vacuum level in the vacuum exhaust zone of the co-rotating twin-screw extruder is controlled between -0.08 MPa and -0.1 MPa.

9. The method for preparing an antistatic and flame-retardant ABS material according to claim 1, characterized in that, In the step of preparing raw materials, the ABS resin is pre-dried under vacuum at 75-85°C for 3-5 hours, and the polyether ester amide block copolymer is pre-dried under vacuum at 65-75°C for 5-7 hours.

10. The method for preparing an antistatic and flame-retardant ABS material according to claim 2, characterized in that, In the step of preparing raw materials, the antioxidant is a mixture of antioxidant 1010 and antioxidant 168, and the mixing weight ratio of antioxidant 1010 to antioxidant 168 is 1:1.8 to 1:2.2.