Antistatic ABS plastic and preparation method thereof

Abstract

The invention belongs to the technical field of polymer plastics, and particularly relates to an antistatic ABS (Acrylonitrile Butadiene Styrene) plastic and a preparation method thereof. The antistatic ABS plastic is prepared from the following components in parts by mass: 80-95 parts of ABS resin, 15-25 parts of a composite antistatic agent, 0.2-0.5 part of an antioxidant and 0.5-1 part of a lubricant, the composite antistatic agent is composite particles with modified carbon black as a core and a quaternary ammonium salt antistatic agent as a shell. The preparation method is controllable in process and suitable for industrialization, and the prepared antistatic ABS plastic is low in surface resistivity, high in strength and resistant to migration.

Description

Technical Field

[0001] This invention belongs to the field of polymer plastics technology, specifically relating to an antistatic ABS plastic and its preparation method. Background Technology

[0002] Acrylonitrile-butadiene-styrene copolymer (ABS) is a thermoplastic engineering plastic with excellent comprehensive properties. It combines the chemical resistance of acrylonitrile, the rigidity and processing fluidity of styrene, and the high toughness of butadiene, making it suitable for applications in electronics, office equipment, and automotive manufacturing. Due to its low electrical conductivity and high surface resistivity (up to 10⁻⁶ Ω·cm), ABS is widely used in these applications. 14 -10 16 Ω, when used, easily accumulates static charge on the surface, leading to a series of problems. Therefore, antistatic modification of ABS resin to prepare antistatic ABS plastics with both excellent mechanical properties and antistatic properties has become a key technological direction for expanding its application fields.

[0003] Currently, antistatic modification methods for ABS resin are mainly divided into two categories: external antistatic treatment and internal additive antistatic modification. Among them, the internal additive method has become the mainstream technology for industrial production due to its simple process and long-lasting effect. However, it still has many problems: small molecule antistatic agents such as ethoxyamine and quaternary ammonium salt surfactants migrate to the ABS surface and adsorb moisture in the air to form a conductive water film to dissipate static electricity. They are low in cost and require small amounts, but the antistatic effect is short-lived and unstable. The antistatic agents are easily lost due to wiping, washing, evaporation, etc., which leads to a rapid increase in surface resistivity. Inorganic antistatic agents, represented by graphene and carbon nanotubes, can provide permanent and efficient antistatic properties, but require high amounts to build an effective conductive network. They have poor compatibility with the ABS matrix and are prone to causing a decline in mechanical properties.

[0004] Chinese patent application CN104559028A discloses an antistatic ABS material and its preparation method. This antistatic ABS material is composed of the following components in parts by weight: 75-84 parts ABS resin, 15-20 parts polymethyl methacrylate, 8-12 parts paraffin oil, 3-7 parts dibutyl azelaate, 0.5-1 parts antistatic agent, and 0.05-1.5 parts titanium dioxide. This technical solution mainly uses a compound system of ethylene glycol lauramide and clay to improve the antistatic properties of the ABS material. However, simple physical mixing easily leads to agglomeration of both components, becoming a weak point in mechanical properties. Furthermore, clay has no conductive function and only serves as a carrier, resulting in low antistatic efficiency. Additionally, a large amount of plasticizer in the formulation easily migrates to the surface, exacerbating the loss of the antistatic agent and further shortening the antistatic lifespan.

[0005] Therefore, it is of great significance to develop an antistatic ABS material with high antistatic efficiency and minimal impact on the mechanical properties of the matrix. Summary of the Invention

[0006] Existing antistatic ABS plastics have a poor balance between antistatic efficiency and mechanical properties; in order to solve this problem, the present invention provides an antistatic ABS plastic and its preparation method.

[0007] To achieve the objectives of this invention, the following technical solution is adopted:

[0008] In a first aspect, the present invention provides an antistatic ABS plastic, comprising the following components in parts by weight: 80-95 parts ABS resin, 15-25 parts composite antistatic agent, 0.2-0.5 parts antioxidant, and 0.5-1 part lubricant; The composite antistatic agent is a composite particle with modified carbon black as the core and quaternary ammonium salt antistatic agent as the shell.

[0009] By adopting the above technical solution, this formulation system uses ABS resin as the main component, synergistically adding a core-shell structured composite antistatic agent, and supplementing with a small amount of antioxidant and lubricant. This imparts excellent and durable antistatic properties to ABS plastic while maximizing the preservation of the mechanical properties of the matrix resin. The composite antistatic agent uses conductive carbon black as the core and a compatible quaternary ammonium salt polymer as the shell. Through the core-shell structure design of the composite antistatic agent, the problems of uneven dispersion and interface defects caused by direct addition of carbon black are solved. The carbon black core can construct a continuous conductive network, and the quaternary ammonium salt shell provides surface antistatic function, achieving a synergistic effect of enhanced conductivity and antistatic properties.

[0010] Preferably, the preparation method of the composite antistatic agent includes the following steps: (1) Mix carbon black, silane coupling agent, anhydrous ethanol and water, and ball mill for 5-6 hours to obtain modified carbon black dispersion; (2) Mix (3-acrylamidopropyl)trimethylammonium chloride, Tween-80, NaHCO3, water and modified carbon black dispersion evenly to obtain an aqueous phase liquid; mix styrene, hydroxyethyl acrylate and Span-80 evenly to obtain an oil phase liquid; add the oil phase liquid dropwise to the aqueous phase liquid and mix evenly to obtain a preemulsion; (3) Mix part of the pre-emulsion with part of the initiator aqueous solution evenly and carry out a first reaction. Add the remaining pre-emulsion and the remaining initiator aqueous solution and carry out a second reaction. Cool, adjust the pH to 6-7, precipitate, filter, wash, and dry to obtain a composite antistatic agent.

[0011] By adopting the above technical solution, a core-shell structured quaternary ammonium salt antistatic agent is prepared by emulsion polymerization. In step (1), the carbon black surface is modified and dispersed by ball milling and silane coupling agent. In step (2), a stable oil-water two-phase system is constructed and a pre-emulsion is formed. In step (3), a portion of the pre-emulsion and an initiator are first used to form seed latex particles, and then the remaining raw materials are added so that they preferentially polymerize and grow on the surface of the existing seed particles to ensure uniform coating of the shell layer. The overall process is highly controllable and can stably prepare a composite antistatic agent with good dispersibility and excellent antistatic properties.

[0012] Preferably, in step (1), the mass ratio of carbon black, silane coupling agent, anhydrous ethanol and water is 1:(0.25-0.5):(8-10):(2-3).

[0013] By adopting the above technical solution, this ratio can ensure that the silane coupling agent is fully wetted and grafted onto the carbon black surface, effectively improving the hydrophilicity and dispersion stability of the carbon black.

[0014] Preferably, the mass ratio of (3-acrylamidopropyl)trimethylammonium chloride, styrene and hydroxyethyl acrylate is 6:(4-5):(1-2).

[0015] By adopting the above technical solution, this ratio can achieve a hydrophilic-hydrophobic balance: (3-acrylamidopropyl)trimethylammonium chloride provides sufficient antistatic functional groups, styrene enhances compatibility with ABS resin, and the hydroxyl groups of hydroxyethyl acrylate enhance the interfacial bonding force between the shell, carbon black core, and ABS matrix. The three work together to ensure that the antistatic agent has excellent antistatic properties, compatibility, and migration resistance.

[0016] Preferably, in step (2), the mass ratio of (3-acrylamidopropyl)trimethylammonium chloride, Tween-80, NaHCO3, water and modified carbon black dispersion is 1:(0.08-0.1):(0.004-0.005):(1-1.2):(0.9-1).

[0017] By adopting the above technical solutions, the amount of Tween-80 can effectively reduce the surface tension of the aqueous phase, stabilize the modified carbon black dispersion, and assist in the construction of an oil-water interface film; the amount of NaHCO3 can maintain a weakly alkaline environment in the system and prevent the initiator from decomposing prematurely; the proportion of the modified carbon black dispersion ensures that the carbon black is uniformly dispersed in the aqueous phase.

[0018] Preferably, in step (2), Span-80 accounts for 3%-3.3% of the total mass of (3-acrylamidopropyl)trimethylammonium chloride, styrene and hydroxyethyl acrylate.

[0019] By adopting the above technical solution, Span-80 and Tween-80 form a composite emulsion system. This ratio can ensure that the oil phase droplets are uniformly dispersed in the aqueous phase to form a stable pre-emulsion, avoid oil phase agglomeration leading to uneven polymerization, and improve the regularity of the core-shell structure.

[0020] Preferably, in step (3), the initiator is ammonium persulfate or potassium persulfate; the mass of the initiator is 1%-2% of the total mass of (3-acrylamidopropyl)trimethylammonium chloride, styrene and hydroxyethyl acrylate; the initiator aqueous solution is prepared by mixing the initiator and water at a mass ratio of 1:(8-10).

[0021] By adopting the above technical solution, under the specified dosage and ratio of initiator, the polymerization reaction can proceed smoothly, avoiding explosive polymerization or incomplete polymerization.

[0022] Preferably, in step (3), the temperature of the first reaction is 78-80℃ and the time of the first reaction is 30-40min; the steps of the second reaction are as follows: after reacting at 78-82℃ for 1-2h, the temperature is raised to 84-87℃ and reacted for 0.5-1h.

[0023] By adopting the above technical solution, the temperature and time of the first reaction can form stable active polymerization seeds, control the initial polymerization rate to avoid explosive polymerization, and at the same time, allow polymer chains to be initially grafted onto the surface of the carbon black core to construct a core-shell structure prototype. The segmented temperature design of the second reaction allows the monomer to continue to polymerize and thicken the shell layer at a lower temperature, and then the temperature is increased to promote the complete polymerization of the residual monomer, improve the monomer conversion rate and shell crosslinking degree, and ensure the stability of the antistatic agent performance.

[0024] Secondly, the present invention provides a method for preparing the above-mentioned antistatic ABS plastic, comprising the following steps: ABS resin, composite antistatic agent, antioxidant and lubricant are mixed evenly, melted, extruded, granulated and injection molded to obtain antistatic ABS plastic.

[0025] By adopting the above technical solutions, the overall process meets the needs of large-scale production, the steps are simple and controllable, and the finished antistatic ABS plastic has consistent performance.

[0026] Preferably, the extrusion temperature is 170-210℃ and the injection molding temperature is 190-220℃.

[0027] By adopting the above technical solutions, an extrusion temperature of 170-210℃ can ensure that the ABS resin is fully melted and plasticized, while avoiding excessive temperature that could lead to ABS degradation or deactivation of the composite antistatic agent; an injection molding temperature of 190-220℃ can ensure that the molten material has good fluidity, while ensuring that the product has excellent mechanical properties after cooling and solidification.

[0028] In summary, the beneficial effects of this invention are: (1) The present invention prepares a composite antistatic agent of carbon black-quaternary ammonium salt polymer, which can achieve synergistic effect of electronic conductivity and ionic conductivity; the chemically bonded core-shell structure and good compatibility with the matrix avoid the migration and precipitation problems of traditional small molecule or unmodified antistatic agents, and ensure the long-term stability of ABS resin performance. (2) The quaternary ammonium salt polymer contains styrene segments that are compatible with ABS resin, which avoids the mechanical properties from being reduced due to phase separation; the uniform dispersion and good interfacial bonding enable ABS resin to maintain high strength and other mechanical properties. (3) The present invention controls the proportion of each component and process parameters to balance antistatic properties, mechanical properties and processing properties; the preparation method is controllable and suitable for industrialization; the obtained antistatic ABS plastic has low surface resistivity and excellent migration resistance. Attached Figure Description

[0029] Figure 1 SEM image of the composite antistatic agent prepared in Example 1; Figure 2 TEM image of the composite antistatic agent prepared in Example 1. Detailed Implementation

[0030] The present invention will be further described below with reference to specific embodiments.

[0031] Unless otherwise specified, the experimental methods used in the following examples and comparative examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples and comparative examples are commercially available.

[0032] In the following examples and comparative examples, the antioxidant was prepared by mixing antioxidant 1010 and antioxidant 168 in a ratio of 1.5:1; the lubricant was ethylene bis-stearamide.

[0033] Preparation Example 1 The preparation method of the composite antistatic agent in this example includes the following specific steps: (1) Add 100g carbon black, 35g silane coupling agent KH570, 900g anhydrous ethanol and 400g water to a ball mill and ball mill for 6h to obtain modified carbon black dispersion. (2) Add 300g (3-acrylamidopropyl)trimethylammonium chloride, 28g Tween-80, 1.3g NaHCO3, 360g water and 280g modified carbon black dispersion to a beaker, stir for 20min to obtain an aqueous phase; add 200g styrene, 80g hydroxyethyl acrylate and 18.6g Span-80 to another beaker, stir for 30min to obtain an oil phase; slowly add the oil phase to the aqueous phase in a homogenizer at 10000rpm; after the addition is complete, shear for 15min to obtain a preemulsion; (3) Mix 8.7g of ammonium persulfate with 87g of water and stir for 10min to obtain an initiator aqueous solution; transfer 1 / 5 of the pre-emulsion to a four-necked flask, heat to 79°C in a water bath, add 1 / 3 of the initiator aqueous solution, and react for 40min; at the same time, slowly add the remaining 4 / 5 of the pre-emulsion and the remaining 2 / 3 of the initiator aqueous solution respectively; after the addition is complete, react at 79°C for 2h, then raise the temperature to 85°C and react for 0.5h; cool the reaction system to below 40°C, adjust the pH to 7, and add it to acetone under stirring to precipitate, filter, wash 3 times with anhydrous ethanol, and dry to obtain a composite antistatic agent.

[0034] SEM images of the composite antistatic agent are shown below. Figure 1 TEM images of the composite antistatic agent are shown below. Figure 2 ; Figure 1 Combination Figure 2 It can be seen that the composite antistatic agent presents as well-dispersed, uniformly sized spherical particles with particle diameters mainly distributed in the range of 150nm-250nm; each particle consists of a dark modified carbon black core and a uniformly thick, light-colored quaternary ammonium salt polymer shell.

[0035] Preparation Example 2 The preparation method of the composite antistatic agent in this example includes the following specific steps: (1) Add 100g carbon black, 50g silane coupling agent KH570, 1000g anhydrous ethanol and 300g water to a ball mill and ball mill for 6h to obtain modified carbon black dispersion. (2) Add 300g (3-acrylamidopropyl)trimethylammonium chloride, 30g Tween-80, 1.2g NaHCO3, 320g water and 270g modified carbon black dispersion to a beaker, stir for 20min to obtain an aqueous phase; add 240g styrene, 100g hydroxyethyl acrylate and 19.2g Span-80 to another beaker, stir for 30min to obtain an oil phase; slowly add the oil phase to the aqueous phase in a homogenizer at 10000rpm; after the addition is complete, shear for 15min to obtain a preemulsion; (3) Mix 6.4g of ammonium persulfate with 64g of water and stir for 10min to obtain an initiator aqueous solution; transfer 1 / 5 of the pre-emulsion to a four-necked flask, heat to 78°C in a water bath, add 1 / 3 of the initiator aqueous solution, and react for 40min; at the same time, slowly add the remaining 4 / 5 of the pre-emulsion and the remaining 2 / 3 of the initiator aqueous solution respectively; after the addition is complete, react at 80°C for 1.5h, then raise the temperature to 85°C and react for 1h; cool the reaction system to below 40°C, adjust the pH to 7, and add it to acetone under stirring to precipitate, filter, wash 3 times with anhydrous ethanol, and dry to obtain a composite antistatic agent.

[0036] Preparation Example 3 The preparation method of the composite antistatic agent in this example includes the following specific steps: (1) Add 100g carbon black, 25g silane coupling agent KH570, 850g anhydrous ethanol and 200g water to a ball mill and ball mill for 5h to obtain modified carbon black dispersion. (2) Add 300g (3-acrylamidopropyl)trimethylammonium chloride, 29g Tween-80, 1.5g NaHCO3, 360g water and 300g modified carbon black dispersion to a beaker, stir for 20min to obtain an aqueous phase; add 220g styrene, 50g hydroxyethyl acrylate and 18.8g Span-80 to another beaker, stir for 30min to obtain an oil phase; slowly add the oil phase to the aqueous phase in a homogenizer at 10000rpm; after the addition is complete, shear for 15min to obtain a preemulsion; (3) Mix 11.4g of ammonium persulfate with 92g of water and stir for 10min to obtain an initiator aqueous solution; transfer 1 / 5 of the pre-emulsion to a four-necked flask, heat to 78℃ in a water bath, add 1 / 3 of the initiator aqueous solution, and react for 30min; at the same time, slowly add the remaining 4 / 5 of the pre-emulsion and the remaining 2 / 3 of the initiator aqueous solution respectively; after the addition is complete, react at 79℃ for 1h, then raise the temperature to 87℃ and react for 0.5h; cool the reaction system to below 40℃, adjust the pH to 6, and add it to acetone under stirring to precipitate, filter, wash 3 times with anhydrous ethanol, and dry to obtain a composite antistatic agent.

[0037] Preparation Example 4 The preparation method of the composite antistatic agent in this example includes the following specific steps: (1) Add 100g carbon black, 40g silane coupling agent KH570, 800g anhydrous ethanol and 250g water to a ball mill and ball mill for 5h to obtain modified carbon black dispersion. (2) Add 300g (3-acrylamidopropyl)trimethylammonium chloride, 25g Tween-80, 1.2g NaHCO3, 340g water and 290g modified carbon black dispersion to a beaker, stir for 20min to obtain an aqueous phase; add 250g styrene, 70g hydroxyethyl acrylate and 19.3g Span-80 to another beaker, stir for 30min to obtain an oil phase; slowly add the oil phase to the aqueous phase in a homogenizer at 10000rpm; after the addition is complete, shear for 15min to obtain a preemulsion; (3) Mix 6.2g of potassium persulfate with 10g of water and stir for 10min to obtain an initiator aqueous solution; transfer 1 / 5 of the pre-emulsion to a four-necked flask, heat to 78℃ in a water bath, add 1 / 3 of the initiator aqueous solution, and react for 30min; at the same time, slowly add the remaining 4 / 5 of the pre-emulsion and the remaining 2 / 3 of the initiator aqueous solution respectively; after the addition is complete, react at 78℃ for 1.5h, then raise the temperature to 84℃ and react for 1h; cool the reaction system to below 40℃, adjust the pH to 6, and add it to acetone under stirring to precipitate, filter, wash 3 times with anhydrous ethanol, and dry to obtain a composite antistatic agent.

[0038] Preparation Example 5 The preparation method of the composite antistatic agent in this example includes the following specific steps: (1) Add 100g carbon black, 45g silane coupling agent KH570, 900g anhydrous ethanol and 300g water to a ball mill and ball mill for 6h to obtain modified carbon black dispersion. (2) Add 300g (3-acrylamidopropyl)trimethylammonium chloride, 24g Tween-80, 1.2g NaHCO3, 300g water and 280g modified carbon black dispersion to a beaker, stir for 20min to obtain an aqueous phase; add 210g styrene, 90g hydroxyethyl acrylate and 18g Span-80 to another beaker, stir for 30min to obtain an oil phase; slowly add the oil phase to the aqueous phase in a homogenizer at 10000rpm; after the addition is complete, shear for 15min to obtain a preemulsion; (3) Mix 7.2g of potassium persulfate with 65g of water and stir for 10min to obtain an initiator aqueous solution; transfer 1 / 5 of the pre-emulsion to a four-necked flask, heat to 80℃ in a water bath, add 1 / 3 of the initiator aqueous solution, and react for 40min; at the same time, slowly add the remaining 4 / 5 of the pre-emulsion and the remaining 2 / 3 of the initiator aqueous solution respectively; after the addition is complete, react at 82℃ for 2h, then raise the temperature to 87℃ and react for 0.5h; cool the reaction system to below 40℃, adjust the pH to 7, and add it to acetone under stirring to precipitate, filter, wash 3 times with anhydrous ethanol, and dry to obtain a composite antistatic agent.

[0039] Example 1 An antistatic ABS plastic according to this embodiment is composed of the following components in parts by weight: 88 parts of ABS resin, 20 parts of the composite antistatic agent prepared in Preparation Example 1, 0.5 parts of antioxidant, and 0.8 parts of lubricant.

[0040] The specific steps of the preparation method of antistatic ABS plastic in this embodiment are as follows: ABS resin, composite antistatic agent, antioxidant, and lubricant were added to a high-speed mixer and mixed at 800 rpm for 10 minutes at room temperature. The mixture was then transferred to a twin-screw extruder, melted, extruded, granulated, and injection molded to obtain antistatic ABS plastic. The six extrusion temperatures were 170℃, 190℃, 190℃, 200℃, 200℃, and 210℃, and the three injection molding temperatures were 190℃, 200℃, and 210℃.

[0041] Example 2 An antistatic ABS plastic according to this embodiment is composed of the following components in parts by weight: 85 parts of ABS resin, 18 parts of the composite antistatic agent prepared in Preparation Example 1, 0.3 parts of antioxidant, and 0.6 parts of lubricant.

[0042] The specific steps of the preparation method of antistatic ABS plastic in this embodiment are as follows: ABS resin, composite antistatic agent, antioxidant, and lubricant were added to a high-speed mixer and mixed at 800 rpm for 10 minutes at room temperature. The mixture was then transferred to a twin-screw extruder, melted, extruded, granulated, and injection molded to obtain antistatic ABS plastic. The six extrusion temperatures were 170℃, 180℃, 180℃, 200℃, 200℃, and 210℃, and the three injection molding temperatures were 200℃, 210℃, and 220℃, respectively.

[0043] Example 3 An antistatic ABS plastic according to this embodiment is composed of the following components in parts by weight: 95 parts of ABS resin, 15 parts of the composite antistatic agent prepared in Preparation Example 3, 0.5 parts of antioxidant, and 1 part of lubricant.

[0044] The specific steps of the preparation method of antistatic ABS plastic in this embodiment are as follows: ABS resin, composite antistatic agent, antioxidant, and lubricant were added to a high-speed mixer and mixed at 800 rpm for 10 minutes at room temperature. The mixture was then transferred to a twin-screw extruder, melted, extruded, granulated, and injection molded to obtain antistatic ABS plastic. The six extrusion temperatures were 170℃, 180℃, 190℃, 200℃, 210℃, and 200℃, respectively, and the three injection molding temperatures were 200℃, 210℃, and 215℃, respectively.

[0045] Example 4 An antistatic ABS plastic according to this embodiment is composed of the following components in parts by weight: 92 parts of ABS resin, 22 parts of the composite antistatic agent prepared in Preparation Example 3, 0.2 parts of antioxidant, and 0.5 parts of lubricant.

[0046] The specific steps of the preparation method of antistatic ABS plastic in this embodiment are as follows: ABS resin, composite antistatic agent, antioxidant, and lubricant were added to a high-speed mixer and mixed at 800 rpm for 10 minutes at room temperature. The mixture was then transferred to a twin-screw extruder, melted, extruded, granulated, and injection molded to obtain antistatic ABS plastic. The six extrusion temperatures were 165℃, 190℃, 195℃, 195℃, 210℃, and 210℃, respectively, and the three injection molding temperatures were 195℃, 205℃, and 220℃, respectively.

[0047] Example 5 An antistatic ABS plastic according to this embodiment is composed of the following components in parts by weight: 80 parts of ABS resin, 25 parts of the composite antistatic agent prepared in Preparation Example 4, 0.4 parts of antioxidant, and 0.9 parts of lubricant.

[0048] The specific steps of the preparation method of antistatic ABS plastic in this embodiment are as follows: ABS resin, composite antistatic agent, antioxidant, and lubricant were added to a high-speed mixer and mixed at 800 rpm for 10 minutes at room temperature. The mixture was then transferred to a twin-screw extruder, melted, extruded, granulated, and injection molded to obtain antistatic ABS plastic. The six extrusion temperatures were 165℃, 180℃, 180℃, 195℃, 210℃, and 200℃, and the three injection molding temperatures were 195℃, 200℃, and 205℃, respectively.

[0049] Example 6 The antistatic ABS plastic of this embodiment is basically the same as that of Embodiment 1, except that the amount of ABS resin used is 90 parts.

[0050] Example 7 The antistatic ABS plastic of this embodiment is basically the same as that of Example 1, except that the amount of composite antistatic agent used is 25 parts.

[0051] Comparative Example 1 This comparative example of an antistatic ABS plastic is basically the same as that in Example 1, except that an equal amount of carbon black is used instead of the composite antistatic agent.

[0052] Comparative Example 2 This comparative example of an antistatic ABS plastic is basically the same as that in Example 1, except that the composite antistatic agent added in this comparative example does not contain carbon black.

[0053] Comparative Example 3 The antistatic ABS plastic in this comparative example is basically the same as that in Example 1, except that the mass ratio of (3-acrylamidopropyl)trimethylammonium chloride to styrene in the composite antistatic agent of this comparative example is 6:1.

[0054] Comparative Example 4 The difference between this comparative example and the previous example is that the amount of composite antistatic agent used is 8 parts.

[0055] The antistatic ABS plastics prepared in Examples 1-7 and Comparative Examples 1-4 were subjected to relevant performance tests, and the test results are shown in Table 1 below.

[0056] Surface resistivity was tested according to GB / T 1410-2006 "Test Methods for Volume Resistivity and Surface Resistivity of Materials". A 100mm×100mm square sample with a thickness of 2mm was clamped between the electrodes, and the voltage was selected as 500V. Tensile properties were tested according to GB / T 1040-2006 "Determination of Tensile Properties of Plastics"; The bending properties were tested according to GB / T 9341-2008 "Determination of bending properties of plastics".

[0057] Table 1 Test Results

[0058] As shown in Table 1: Comparing Comparative Example 1 with Example 1, it can be seen that although Comparative Example 1 uses only carbon black and has a lower surface resistivity, the tensile / bending strength is reduced and the mechanical properties are significantly deteriorated due to the severe agglomeration of carbon black in the ABS matrix.

[0059] Comparing Comparative Example 2 with Example 1, it can be seen that Comparative Example 2 has insufficient antistatic properties, lacks a carbon black conductive network, and relies solely on the surface migration of quaternary ammonium salt, resulting in a weak effect.

[0060] Comparing Comparative Example 3 with Example 1, it can be seen that insufficient styrene easily leads to poor hydrophobicity of the shell, decreased compatibility with the ABS matrix, uneven migration of quaternary ammonium salts, and a significant reduction in mechanical properties.

[0061] Comparing Comparative Example 4 with Example 1, it can be seen that when the amount of composite antistatic agent added is too small, an effective conductive network cannot be formed in the matrix, resulting in a significant increase in surface resistivity and failure to meet the antistatic performance standard.

[0062] The surface resistivity of the antistatic ABS plastic obtained by this invention is basically stable at 1.0 × 10⁻⁶. 8 -2.0×10 8 Ω, tensile strength is maintained at 38-45MPa, flexural strength is maintained at 58-66MPa, and antistatic properties and mechanical properties are well balanced.

[0063] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. Antistatic ABS plastic, characterized in that, It consists of the following components in parts by mass: 80-95 parts ABS resin, 15-25 parts composite antistatic agent, 0.2-0.5 parts antioxidant, and 0.5-1 part lubricant; The composite antistatic agent is a composite particle with modified carbon black as the core and quaternary ammonium salt antistatic agent as the shell.

2. The antistatic ABS plastic according to claim 1, characterized in that, The preparation method of the composite antistatic agent includes the following steps: (1) Mix carbon black, silane coupling agent, anhydrous ethanol and water, and ball mill for 5-6 hours to obtain modified carbon black dispersion; (2) Mix (3-acrylamidopropyl)trimethylammonium chloride, Tween-80, NaHCO3, water and modified carbon black dispersion evenly to obtain an aqueous phase liquid; mix styrene, hydroxyethyl acrylate and Span-80 evenly to obtain an oil phase liquid; add the oil phase liquid dropwise to the aqueous phase liquid and mix evenly to obtain a preemulsion; (3) Mix part of the pre-emulsion with part of the initiator aqueous solution evenly and carry out a first reaction. Add the remaining pre-emulsion and the remaining initiator aqueous solution and carry out a second reaction. Cool, adjust the pH to 6-7, precipitate, filter, wash, and dry to obtain a composite antistatic agent.

3. The antistatic ABS plastic according to claim 2, characterized in that, In step (1), the mass ratio of carbon black, silane coupling agent, anhydrous ethanol and water is 1:(0.25-0.5):(8-10):(2-3).

4. The antistatic ABS plastic according to claim 2, characterized in that, The mass ratio of (3-acrylamidopropyl)trimethylammonium chloride, styrene and hydroxyethyl acrylate is 6:(4-5):(1-2).

5. The antistatic ABS plastic according to claim 2, characterized in that, In step (2), the mass ratio of (3-acrylamidopropyl)trimethylammonium chloride, Tween-80, NaHCO3, water and modified carbon black dispersion is 1:(0.08-0.1):(0.004-0.005):(1-1.2):(0.9-1).

6. The antistatic ABS plastic according to claim 2, characterized in that, In step (2), Span-80 accounts for 3%-3.3% of the total mass of (3-acrylamidopropyl)trimethylammonium chloride, styrene and hydroxyethyl acrylate.

7. The antistatic ABS plastic according to claim 2, characterized in that, In step (3), the initiator is ammonium persulfate or potassium persulfate; the mass of the initiator is 1%-2% of the total mass of (3-acrylamidopropyl)trimethylammonium chloride, styrene and hydroxyethyl acrylate; the initiator aqueous solution is prepared by mixing the initiator and water at a mass ratio of 1:(8-10).

8. The antistatic ABS plastic according to claim 2, characterized in that, In step (3), the temperature of the first reaction is 78-80℃ and the time of the first reaction is 30-40min; the steps of the second reaction are as follows: after reacting at 78-82℃ for 1-2h, the temperature is raised to 84-87℃ and reacted for 0.5-1h.

9. The method for preparing antistatic ABS plastic according to any one of claims 1-8, characterized in that, Includes the following steps: ABS resin, composite antistatic agent, antioxidant and lubricant are mixed evenly, melted, extruded, granulated and injection molded to obtain antistatic ABS plastic.

10. The method for preparing antistatic ABS plastic according to claim 9, characterized in that, The extrusion temperature is 170-210℃, and the injection molding temperature is 190-220℃.

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