Polystyrene composite material and preparation method therefor, polystyrene antistatic sheet and carbon nanotube aggregate

Abstract

A polystyrene composite material and a preparation method therefor, a polystyrene antistatic sheet and a carbon nanotube aggregate. The polystyrene composite material comprises the following components in parts by weight: 80-95 parts of polystyrene; 10-20 parts of a styrene-acrylonitrile copolymer; 1-10 parts of a carbon nanotube aggregate; 1-3 parts of a toughening agent; 2-4 parts of a dispersing agent; 0-1 part of an antioxidant; 0-3 parts of a compatibilizer; and 0-3 parts of a surfactant. The carbon nanotube aggregate comprises array carbon nanotubes and winding carbon nanotubes that coat the surfaces of the array carbon nanotubes. By means of the combined action of all the components in the formula of the polystyrene composite material, a system in which carbon nanotube aggregates are uniformly dispersed is formed; therefore, the overall antistatic performance and the surface evenness and cleanliness of the polystyrene composite material are significantly improved, better facilitating the application of the polystyrene composite material to the field of electronic packaging.

Description

Polystyrene composite material and preparation method thereof, polystyrene antistatic sheet and carbon nanotube aggregate Technical Field

[0001] The present application relates to the technical field of electronic packaging materials, and in particular to a polystyrene composite material and a preparation method thereof, a polystyrene antistatic sheet, and a carbon nanotube aggregate. Background Art

[0002] Plastic leather is a semi-finished sheet material used in electronic packaging. This semi-finished sheet can be manufactured into carrier tape through a blister or slicing process. The plastic leather or carrier tape contains a conductive polymer layer. Polystyrene (PS) is commonly used as the base material for this conductive layer, and conductive carbon black, graphite, and carbon fiber can be added as fillers.

[0003] Compared to traditional fillers, high-surface-area carbon nanotubes (CNTs) offer superior mechanical, electrical, and thermal stability properties, significantly improving material performance with just a small addition. However, CNTs are prone to agglomeration due to van der Waals forces, making uniform dispersion difficult within a polystyrene matrix. Consequently, achieving uniform dispersion of CNTs presents significant challenges. Technical issues

[0004] The purpose of the embodiments of the present application is to provide a polystyrene composite material and a preparation method thereof, a polystyrene antistatic sheet and a carbon nanotube aggregate. Technical Solutions

[0005] The technical solution adopted in the embodiment of this application is:

[0006] In a first aspect, a polystyrene composite material is provided, comprising the following components in parts by weight:

[0007] Polystyrene 80-95 parts;

[0008] 10-20 parts of styrene-acrylonitrile copolymer;

[0009] 1-10 parts of carbon nanotube aggregates;

[0010] 1~3 parts of toughening agent;

[0011] 2~4 parts of dispersant;

[0012] Antioxidant 0~1 part;

[0013] Compatibilizer 0~3 parts;

[0014] Surfactant 0-3 parts;

[0015] The carbon nanotube aggregates include arrayed carbon nanotubes and entangled carbon nanotubes coated on the surfaces of the arrayed carbon nanotubes.

[0016] In some embodiments, the bulk density of the carbon nanotube aggregates is 20-35 kg / m 3 and / or,

[0017] The tap density of carbon nanotube aggregates is 40~60kg / m 3 and / or,

[0018] The resistivity of the carbon nanotube aggregate is 60-90 mΩ·cm; and / or,

[0019] The particle size of carbon nanotube aggregates is ≤200 μm.

[0020] In some embodiments, the polystyrene comprises high impact polystyrene; and / or,

[0021] Polystyrene powder ≤3000 mesh; and / or,

[0022] The mass percentage of the styrene component in the styrene-acrylonitrile copolymer is 15% to 50%.

[0023] In some embodiments, the toughening agent includes at least one of butadiene rubber, isoprene rubber, styrene-butadiene-styrene rubber, styrene-isoprene-styrene rubber, acrylonitrile-butadiene rubber, styrene-butadiene rubber, ethylene-propylene rubber, and styrene-ethylene-butadiene-styrene rubber; and / or

[0024] The dispersant includes any one of an anionic wetting dispersant, a cationic wetting dispersant and a controlled free radical type hyperdispersant; and / or,

[0025] The antioxidant includes at least one of antioxidant 1010, antioxidant 168, antioxidant 1076, antioxidant 1330, antioxidant 1035, antioxidant 3144, antioxidant 1024, and antioxidant 126; and / or,

[0026] The compatibilizer includes maleic anhydride grafted polystyrene; and / or,

[0027] The surfactant includes at least one of sodium dodecyl sulfate, sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, sodium tetradecyl sulfate, sodium tetradecyl sulfonate, and sodium tetradecylbenzene sulfonate.

[0028] In a second aspect, a method for preparing a polystyrene composite material is provided, comprising:

[0029] Providing the raw materials of each component of the polystyrene composite material of the first aspect;

[0030] The polystyrene composite material is obtained by melting polystyrene, carbon nanotube aggregates, styrene-acrylonitrile copolymer, toughening agent, dispersant, antioxidant, compatibilizer and surfactant.

[0031] In some embodiments, the melt processing includes twin-screw melt extrusion granulation, and the conditions of the twin-screw melt extrusion granulation include:

[0032] Melting section: 200~210℃; first extrusion section: 215~225℃; first shearing section: 220~230℃; first pressurizing section: 225~235℃; first melt exhaust section: 225~235℃; second extrusion section: 230~240℃; second shearing section: 230~240℃; second pressurizing section: 225~235℃; second melt exhaust section: 220~230℃; die head temperature: 215~235℃; main engine speed 400~1000rpm / min, vacuum degree ≤-0.05MPa.

[0033] In some embodiments, the method for preparing carbon nanotube aggregates comprises:

[0034] placing a first metal catalyst supported by vermiculite in a fluidized bed reactor through which a carbon source gas is passed to perform a first reaction, and then adding a second metal catalyst supported by alumina to the fluidized bed reactor to perform a second reaction to obtain a reaction product;

[0035] The reaction product is treated with acid, and then washed with water and dried to obtain carbon nanotube aggregates.

[0036] In some embodiments, the mass ratio of the first metal catalyst to the second metal catalyst is 1:(2-4); and / or,

[0037] The first metal catalyst and the second metal catalyst independently include at least one of iron, molybdenum, cobalt, nickel, vanadium, chromium, manganese, ruthenium, lead, silver, platinum, and gold.

[0038] In some embodiments, the flow rate of the carbon source gas in the fluidized bed reactor is 400-500 L / min; and / or,

[0039] The temperature of the first reaction is 630-690° C., and the time of the first reaction is 5-10 minutes; and / or,

[0040] The temperature of the second reaction is 630-690° C., and the time of the second reaction is 35-50 minutes.

[0041] In some embodiments, the acid treatment comprises: soaking the reaction product in a concentrated sulfuric acid solution for 15 to 30 minutes.

[0042] In a third aspect, a polystyrene antistatic sheet is provided, comprising the polystyrene composite material provided in the first aspect of the present application or the polystyrene composite material prepared by the preparation method provided in the second aspect of the present application.

[0043] In a fourth aspect, a carbon nanotube aggregate is provided, comprising an array of carbon nanotubes and a entangled carbon nanotube coated on the surface of the array of carbon nanotubes.

[0044] In some embodiments, the bulk density of the carbon nanotube aggregates is 20-35 kg / m 3 and / or

[0045] The tap density of carbon nanotube aggregates is 40~60kg / m 3 and / or,

[0046] The resistivity of the carbon nanotube aggregate is 60-90 mΩ·cm; and / or,

[0047] The particle size of carbon nanotube aggregates is ≤200 μm.

[0048] In some embodiments, carbon nanotube aggregates are prepared by the following steps:

[0049] placing a first metal catalyst supported by vermiculite in a fluidized bed reactor through which a carbon source gas is passed to perform a first reaction, and then adding a second metal catalyst supported by alumina to the fluidized bed reactor to perform a second reaction to obtain a reaction product;

[0050] The reaction product is treated with acid, and then washed with water and dried to obtain carbon nanotube aggregates.

[0051] In some embodiments, the mass ratio of the first metal catalyst to the second metal catalyst is 1:(2-4); and / or,

[0052] The first metal catalyst and the second metal catalyst independently include at least one of iron, molybdenum, cobalt, nickel, vanadium, chromium, manganese, ruthenium, lead, silver, platinum, and gold; and / or,

[0053] The flow rate of the carbon source gas in the fluidized bed reactor is 400-500 L / min; and / or,

[0054] The temperature of the first reaction is 630-690° C., and the time of the first reaction is 5-10 minutes; and / or,

[0055] The temperature of the second reaction is 630-690° C., and the time of the second reaction is 35-50 minutes.

[0056] In some embodiments, the acid treatment comprises: soaking the reaction product in a concentrated sulfuric acid solution for 15 to 30 minutes. Beneficial effects

[0057] The beneficial effects of the polystyrene composite material provided by the embodiment of the present application are as follows: a certain weight portion of carbon nanotube aggregates, styrene-acrylonitrile copolymer, toughening agent, and dispersant are used in the polystyrene composite material; wherein the carbon nanotube aggregates are a coating structure formed by winding carbon nanotube-coated array carbon nanotubes, such carbon nanotube aggregates are not easy to be messy as a whole, are easy to disperse, and are easy to overlap to form a good conductive network, and the styrene-acrylonitrile copolymer improves the compatibility of carbon nanotube aggregates with polystyrene, and can further improve the dispersion performance of carbon nanotube aggregates together with the added dispersant. In addition, the toughening agent can also improve the overall mechanical properties of the polystyrene composite material. Therefore, the polystyrene composite material of the present application forms a system in which carbon nanotube aggregates are uniformly dispersed through the combined action of the various components in the formula, significantly improving the overall antistatic performance and surface smoothness and cleanliness performance of the polystyrene composite material, and can be better applied to the field of electronic packaging.

[0058] The beneficial effect of the method for preparing a polystyrene composite material provided in the embodiments of this application is that, by mixing and melting the various raw material components of the polystyrene composite material, a polystyrene composite material having uniformly dispersed carbon nanotube aggregates is obtained. This preparation method is not only easy to process, but also, due to the synergistic effect of the various components in the polystyrene composite material, the prepared polystyrene composite material has excellent antistatic properties, as well as surface smoothness and cleanliness, and is therefore well-suited for use in the preparation of electronic packaging materials.

[0059] The beneficial effect of the polystyrene antistatic sheet provided in the embodiments of the present application is that: based on the polystyrene antistatic sheet including the polystyrene composite material provided in the first aspect of the present application or the polystyrene composite material prepared by the preparation method provided in the second aspect of the present application, such a polystyrene antistatic sheet has excellent antistatic performance, surface smoothness and cleanliness.

[0060] The carbon nanotube aggregates provided in the embodiments of the present application have the following beneficial effects: The present application has developed a carbon nanotube aggregate having a wrapped carbon nanotube array structure. Such a carbon nanotube aggregate is less likely to be disorganized as a whole, is easily dispersed, and easily overlaps to form a good conductive network. Therefore, such a carbon nanotube aggregate can be used as a filler in a plastic leather substrate such as polystyrene, where it can be evenly dispersed, thereby obtaining an antistatic polystyrene composite material with uniform surface conductivity and good conductivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or exemplary technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0062] FIG1 is a schematic flow chart of a method for preparing a polystyrene composite material according to an embodiment of the present application;

[0063] FIG2 is a scanning electron microscope image of a carbon nanotube aggregate provided in an embodiment of the present application. Modes for Carrying Out the Invention

[0064] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0065] In this application, the term "and / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0066] In this application, "at least one" means one or more, "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items.

[0067] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. Some or all of the steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0068] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0069] The terms "first" and "second" are used solely for descriptive purposes to distinguish objects, such as substances, from one another and should not be understood to indicate or imply relative importance or to implicitly specify the quantity of the technical features being referred to. For example, without departing from the scope of the embodiments of this application, a first XX may also be referred to as a second XX, and similarly, a second XX may also be referred to as a first XX. Thus, features defined as "first" or "second" may explicitly or implicitly include one or more of such features.

[0070] Plastic leather is a semi-finished sheet material used in the field of electronic packaging. The semi-finished sheet material can be made into carrier tape through a blister or slicing process. Carrier tape refers to a packaging product used in the field of electronic packaging. It is used in conjunction with a cover tape to carry and store electronic components such as resistors, capacitors, transistors, diodes, etc. in the holes (also called pockets) of the carrier tape, and the cover tape is sealed on top of the carrier tape to form a closed package to protect the electronic components from contamination and damage during transportation. The plastic leather or carrier tape contains a layer of polymer material as a conductive material layer. Such a conductive material layer includes a top surface and a bottom surface opposite to the top surface. Most companies on the market use polystyrene as the base material of the conductive material layer.

[0071] Currently, polystyrene fillers primarily consist of conductive carbon black, graphite, and carbon fiber. Carbon black is the mainstream filler, and its widespread adoption stems from the relatively low price of conductive carbon black and the wide range of carbon black options available to meet varying conductivity requirements. However, excessive amounts of carbon black can easily compromise the overall performance of the material and can cause decarbonization during use, contaminating embedded components.

[0072] Carbon nanotubes (CNTs) have attracted considerable attention in recent years for their exceptional properties, finding applications in a wide range of fields. CNTs are seamless hollow tubes formed from rolled graphite sheets. Due to quantum confinement of electrons within the CNTs, electrons can only move along the axial direction of the CNTs within the graphite sheets. Consequently, CNTs exhibit unique electrical and thermal properties. Research and testing results indicate that the average electrical conductivity of CNTs can reach 1000–2000 S / m (Siemens per meter), and their thermal conductivity at room temperature (25–27°C) typically reaches 6600 W / mK (Watts per minute per Kelvin). CNTs also possess excellent mechanical properties, such as high strength and modulus. Therefore, combining CNTs with polymers to form CNT / polymer composites can leverage the complementary strengths of both materials, maximizing their respective properties. In carbon nanotube / polymer composites, carbon nanotubes can act as electrical and thermal conductors and reinforcements, thus making carbon nanotube / polymer composites have antistatic properties, thermal conductivity, microwave absorption and electromagnetic shielding properties, and have broad application prospects.

[0073] Under the same conductivity requirements, the amount of carbon nanotubes added to carbon nanotube-modified polystyrene composites can be 1 / 10 to 1 / 8 of that of carbon black. This amount of carbon nanotubes effectively maintains the intrinsic properties of the matrix material while minimizing decarburization. Therefore, high-surface-area carbon nanotubes can significantly improve material performance with only a small addition. However, due to van der Waals forces, carbon nanotubes easily aggregate, resulting in low dispersion within the polystyrene matrix in polystyrene composites.

[0074] To improve the dispersion of carbon nanotubes in polystyrene composites, thereby obtaining antistatic polystyrene composites with a uniform and smooth surface and good conductivity, this application investigated the dispersion properties of carbon nanotubes themselves and simultaneously adjusted the formulation of the polystyrene composite to improve the compatibility of the carbon nanotubes with the polystyrene resin, achieving unexpected results. In view of this, the present application provides the following technical solutions. Polystyrene composite materials

[0075] In a first aspect, an embodiment of the present application provides a polystyrene composite material comprising the following components in parts by weight:

[0076] Polystyrene 80-95 parts;

[0077] 10-20 parts of styrene-acrylonitrile copolymer;

[0078] 1-10 parts of carbon nanotube aggregates;

[0079] 1~3 parts of toughening agent;

[0080] 2~4 parts of dispersant;

[0081] Antioxidant 0~1 part;

[0082] Compatibilizer 0~3 parts;

[0083] Surfactant 0-3 parts;

[0084] The carbon nanotube aggregates include arrayed carbon nanotubes and entangled carbon nanotubes coated on the surfaces of the arrayed carbon nanotubes.

[0085] In the polystyrene composite material formula provided in the embodiment of the present application, the carbon nanotube aggregate is a coating structure formed by winding the carbon nanotube-coated array carbon nanotube. Such carbon nanotube aggregates are not easy to be messy as a whole and are easy to disperse. Moreover, the carbon nanotube aggregates are easy to overlap to form a good conductive network. The styrene-acrylonitrile copolymer improves the compatibility of the carbon nanotube aggregates with polystyrene, and can further improve the dispersion performance of the carbon nanotube aggregates together with the added dispersant. In addition, the toughening agent can also improve the overall mechanical properties of the polystyrene composite material. Therefore, the polystyrene composite material of the present application forms a system in which the carbon nanotube aggregates are evenly dispersed through the combined action of the various components in the formula, which can significantly improve the overall antistatic performance and surface smoothness and cleanliness performance of the polystyrene composite material, and can be better applied to the field of electronic packaging.

[0086] A carbon nanotube aggregate refers to a composite of multiple carbon nanotubes, which can exist in a variety of mixed forms and contain carbon nanotubes of various numbers of layers and diameters. In addition, the carbon nanotube aggregate may contain a small amount of impurities from the carbon nanotube manufacturing process (for example, catalysts, amorphous carbon, and granular carbon), but this does not substantially affect the performance of the carbon nanotube aggregate. The carbon nanotube aggregate provided in the embodiments of the present application is a carbon nanotube aggregate having a coating structure formed by entangled carbon nanotubes in a carbon nanotube-coated array. In the polystyrene composite material, the weight percentage of the carbon nanotube aggregate is 1 to 10 parts, for example, 1 part, 2 parts, 4 parts, 6 parts, 8 parts, 10 parts, etc.

[0087] In some embodiments, the bulk density of the carbon nanotube aggregates formed by the wrapped carbon nanotube array carbon nanotubes of the present invention is 20-35 kg / m 3 For example, it can be 20kg / m 3 , 25kg / m 3 , 28kg / m 3 、30kg / m 3 、32kg / m 3 、35kg / m 3 wait.

[0088] Bulk density refers to the mass per unit volume of a granular or powdered material in its naturally stacked state. In the polystyrene composite materials of the present application, the carbon nanotube aggregates with the aforementioned bulk density exhibit excellent processability, electrical conductivity, and thermal stability. The bulk density can be adjusted within the aforementioned range depending on the intended use.

[0089] In some embodiments, the tap density of the carbon nanotube aggregate formed by the wrapped carbon nanotube array carbon nanotubes of the present invention is 40-60 kg / m 3 ; For example, it can be 40kg / m 3, 45kg / m 3 , 50kg / m 3 , 55kg / m 3 , 58kg / m 3 , 60kg / m 3 wait.

[0090] Tap density refers to the mass of a granular or powdered material in a container, which is then vibrated regularly, divided by the volume of the particles after tapping. The carbon nanotube aggregates in the polystyrene composite materials of the present application examples exhibited a tap density of the aforementioned bulk density, demonstrating their ease of processing and good dispersibility.

[0091] In some embodiments, the resistivity of the carbon nanotube aggregate formed by the wrapped carbon nanotube array carbon nanotubes of the embodiments of the present application is 60-90 mΩ·cm; for example, it can be 60 mΩ·cm, 65 mΩ·cm, 70 mΩ·cm, 75 mΩ·cm, 78 mΩ·cm, 80 mΩ·cm, 85 mΩ·cm, 90 mΩ·cm, etc. Specifically, it can be the resistivity of the carbon nanotube aggregate powder tested at 4 MPa.

[0092] In some embodiments, the particle size of the carbon nanotube aggregates formed by the entangled carbon nanotube-coated array carbon nanotubes in the embodiments of the present application is ≤200 μm. Specifically, the carbon nanotube aggregates can be crushed to a particle size of D by a gas flow milling process. max ≤200μm. Small-sized carbon nanotube aggregates can be better dispersed in polystyrene composites.

[0093] Specifically, before using carbon nanotube aggregates in polystyrene composites, the carbon nanotube aggregates can be pretreated, including pre-dispersing the raw carbon nanotube aggregates to obtain the carbon nanotube aggregates. Pre-dispersing the carbon nanotube aggregates to obtain uniformly dispersed carbon nanotube aggregates can further improve the dispersion of the carbon nanotube aggregates in the polystyrene resin, thereby enhancing the performance of the resulting product. For example, in some specific cases, the pre-dispersion treatment can be performed by ultrasonic dispersion.

[0094] In some embodiments, the carbon nanotubes in the carbon nanotube aggregates may have a diameter of 4 to 25 nm, a length of 1 to 100 μm, an aspect ratio of 5,000 to 10,000:1, and a specific surface area (BET) of 200 to 300 m 2 / g, and further, the ash content of the carbon nanotubes is ≤2%. The carbon nanotube aggregates formed by the carbon nanotubes have better dispersibility and conductivity.

[0095] In some embodiments, the polystyrene in the polystyrene composite material includes high-impact polystyrene (HIPS); the Mw of the polystyrene phase in the high-impact polystyrene is 150,000-300,000 g / mol, and the high-impact polystyrene has good dimensional stability, better impact strength and rigidity.

[0096] In the polystyrene composite material, the weight percentage of polystyrene is 80 to 95 parts, for example, 80, 82, 84, 86, 90, 95, etc. The polystyrene powder has a mesh size of ≤3000. For example, the polystyrene raw material particles are crushed to form a powder with a mesh size of ≤3000. This facilitates the dispersion of the carbon nanotube aggregates in the polystyrene matrix.

[0097] Acrylonitrile-styrene copolymer (AS), also known as AS resin, is a polymer formed by the copolymerization of acrylonitrile and styrene. It exhibits high-temperature resistance, excellent gloss and chemical resistance, as well as superior hardness, rigidity, dimensional stability, and a high load-bearing capacity. The AS copolymer improves the compatibility of carbon nanotube aggregates with polystyrene, further enhancing the dispersion of the carbon nanotube aggregates. In polystyrene composites, the amount of the AS copolymer by weight is 10 to 20 parts, for example, 10, 12, 14, 16, 18, or 20 parts.

[0098] In some embodiments, the weight percentage of the styrene component in the styrene-acrylonitrile copolymer in the polystyrene composite material is 15% to 50%. That is, based on the total weight of the styrene-acrylonitrile copolymer being 100%, the content of the styrene component is 15% to 50%, such as 15%, 18%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, etc. The styrene-acrylonitrile copolymer under these conditions improves the compatibility of the carbon nanotube aggregates with the polystyrene.

[0099] In some embodiments, the toughening agent in the polystyrene composite material includes at least one of butadiene rubber, isoprene rubber, styrene-butadiene-styrene rubber, styrene-isoprene-styrene rubber, acrylonitrile-butadiene rubber, styrene-butadiene rubber, ethylene-propylene rubber, and styrene-ethylene-butadiene-styrene rubber; the above toughening agent can improve the overall toughening properties of the polystyrene composite material.

[0100] In the polystyrene composite material, the weight portion of the toughening agent is 1 to 3 parts, for example, it can be 1 part, 1.2 parts, 1.5 parts, 2 parts, 2.5 parts, 3 parts, etc.

[0101] In some embodiments, the dispersant in the polystyrene composite material includes any one of anionic wetting dispersants, cationic wetting dispersants, and controlled radical hyperdispersants. For example, the dispersant may be anionic wetting dispersants such as sodium oleate, carboxylates, sulfate ester salts, and sulfonates, or cationic wetting dispersants such as amine salts and quaternary ammonium salts. These wetting dispersants can further improve the overall dispersibility of the polystyrene composite material system.

[0102] In the polystyrene composite material, the weight portion of the dispersant is 2 to 4 parts, for example, 2 parts, 2.2 parts, 1.5 parts, 3 parts, 3.5 parts, 4 parts, etc.

[0103] In some embodiments, an antioxidant may be added or not added to the polystyrene composite material as needed. Specifically, when an antioxidant is added, the antioxidant in the polystyrene composite material includes antioxidant 1010 [i.e., pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], antioxidant 168 [i.e., tris[2,4-di-tert-butylphenyl] phosphite], antioxidant 1076 [i.e., β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], antioxidant 1330 [i.e., 1,3,5-trimethyl-2,4,6-(3,5-di-tert-butyl-4-hydroxybenzyl)benzene], antioxidant 1035 [i.e., 2,2'- At least one of thiobis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], antioxidant 3144 [i.e., 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid], antioxidant 1024 [i.e., N,N'-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine], and antioxidant 126 [i.e., bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite]. These antioxidants can improve the overall oxidation resistance of the polystyrene composite material, thereby extending its service life.

[0104] In the polystyrene composite material, the weight portion of the antioxidant is 0-1 part, for example, it can be 0.1 part, 0.2 part, 0.4 part, 0.6 part, 0.8 part, 1 part, etc.

[0105] In some embodiments, a compatibilizer may or may not be added to the polystyrene composite material as needed. Specifically, when a compatibilizer is added, it comprises maleic anhydride-grafted polystyrene, thereby further improving the compatibility between the carbon nanotube aggregates and the polystyrene. The amount of the compatibilizer by weight ranges from 0 to 3 parts, for example, 1 part, 1.2 parts, 1.4 parts, 2 parts, 2.5 parts, 3 parts, etc.

[0106] In some embodiments, a surfactant may or may not be added to the polystyrene composite material as needed. Specifically, when a surfactant is added, the surfactant includes at least one of sodium dodecyl sulfate, sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, sodium tetradecyl sulfate, sodium tetradecyl sulfonate, and sodium tetradecylbenzene sulfonate. This further improves the dispersibility of the carbon nanotube aggregates. The surfactant may be present in an amount of 0 to 3 parts by weight, for example, 1 part, 1.2 parts, 1.4 parts, 2 parts, 2.5 parts, 3 parts, etc. Preparation method of polystyrene composite material

[0107] In a second aspect, a method for preparing a polystyrene composite material is provided, as shown in FIG1 , the preparation method comprising:

[0108] S10: providing raw materials of various components of the polystyrene composite material according to an embodiment of the present application;

[0109] S20: melt-treating the polystyrene, carbon nanotube aggregates, styrene-acrylonitrile copolymer, toughening agent, dispersant, antioxidant, compatibilizer, and surfactant to obtain a polystyrene composite material.

[0110] The beneficial effect of the method for preparing a polystyrene composite material provided in the embodiments of this application is that, by mixing and melting the various raw material components of the polystyrene composite material, a polystyrene composite material having uniformly dispersed carbon nanotube aggregates is obtained. This preparation method is not only easy to process, but also, due to the synergistic effect of the various components in the polystyrene composite material, the prepared polystyrene composite material has excellent antistatic properties, as well as surface smoothness and cleanliness, and is therefore well-suited for use in the preparation of electronic packaging materials.

[0111] In step S10, the components of the polystyrene composite material provided in the embodiment of the present application are weighed. Specifically, when the polystyrene composite material contains an antioxidant, a compatibilizer, and a surfactant, the components of the polystyrene composite material include polystyrene, carbon nanotube aggregates, a toughening agent, a dispersant, an antioxidant, a compatibilizer, and a surfactant. When the polystyrene composite material does not contain an antioxidant, a compatibilizer, and a surfactant, the components of the polystyrene composite material include polystyrene, carbon nanotube aggregates, a toughening agent, and a dispersant. The specific weight parts and types of the above components are described above.

[0112] In some embodiments, the carbon nanotube aggregates provided in step S10 are prepared by a method comprising: placing a first metal catalyst loaded with vermiculite in a fluidized bed reactor through which a carbon source gas is passed to perform a first reaction, and then adding a second metal catalyst loaded with alumina to the fluidized bed reactor to perform a second reaction to obtain a reaction product; and subjecting the reaction product to acid treatment, and then washing and drying the reaction product to obtain carbon nanotube aggregates.

[0113] Carbon nanotube aggregates (CNTs) of varying morphology are prepared using metal catalysts supported on different carriers in a single fluidized bed process. This results in CNT aggregates comprising entangled CNTs in an array of CNTs coated with CNTs. The CNT aggregates exhibit a coated structure, making them less disorganized and easier to disperse. Furthermore, the coated structure facilitates the bonding of the conductive network, making it less prone to breakage and enhancing conductivity. Consequently, the resulting CNT aggregates exhibit excellent dispersibility, form a good conductive path at a relatively low concentration, and exhibit minimal dispersion resistance during processing.

[0114] In some embodiments, the mass ratio of the first metal catalyst to the second metal catalyst is 1:(2-4). The vermiculite-supported first metal catalyst catalyzes the synthesis of arrayed carbon nanotubes, while the alumina-supported second metal catalyst catalyzes the synthesis of entangled carbon nanotubes. The catalytic reaction in a fluidized bed reactor with a mass ratio of the first metal catalyst to the second metal catalyst of 1:(2-4) can effectively coat the arrayed carbon nanotubes with entangled carbon nanotubes.

[0115] Specifically, the first metal catalyst supported on vermiculite can be prepared by a conventional hydrothermal method to obtain a first metal catalyst supported on vermiculite. The second metal catalyst supported on alumina can be prepared by a conventional spherical α-alumina impregnation method to obtain a second metal catalyst supported on alumina. The first metal catalyst and the second metal catalyst independently include at least one of iron, molybdenum, cobalt, nickel, vanadium, chromium, manganese, ruthenium, lead, silver, platinum, and gold; for example, the first metal catalyst can be at least one of iron, molybdenum, cobalt, nickel, vanadium, chromium, manganese, ruthenium, lead, silver, platinum, and gold, and further metals such as nickel, cobalt, and iron can be selected; the second metal catalyst can be at least one of iron, molybdenum, cobalt, nickel, vanadium, chromium, manganese, ruthenium, lead, silver, platinum, and gold, and further metals such as molybdenum, cobalt, and iron can be selected. In the first metal catalyst supported on vermiculite, the first metal catalyst loading amount can be 3-20wt%, and in the second metal catalyst supported on alumina, the second metal catalyst loading amount can be 3-20wt%. This can catalyze the synthesis of arrayed carbon nanotubes and entangled carbon nanotubes respectively.

[0116] In some embodiments, the flow rate of the carbon source gas in the fluidized bed reactor is 400-500 L / min. Such a flow rate allows the carbon source gas to fully contact and react with the vermiculite-supported first metal catalyst and the alumina-supported metal catalyst.

[0117] In some embodiments, the first reaction temperature is 630-690°C for 5-10 minutes, and the second reaction temperature is 630-690°C for 35-50 minutes. Extending the second reaction time allows the surface of the arrayed carbon nanotubes to be fully coated with the entangled carbon nanotubes.

[0118] In some embodiments, the acid treatment includes soaking the reaction product in a concentrated sulfuric acid solution for 15-30 minutes. The concentrated sulfuric acid solution is an aqueous solution containing 70% or greater sulfuric acid by weight. Under these conditions, impurities such as the catalyst in the carbon nanotube aggregates can be effectively cleaned and removed.

[0119] In one specific embodiment, the steps for preparing carbon nanotube aggregates include: first introducing a first metal catalyst supported by vermiculite into a fluidized bed reactor and reacting for 5-10 minutes, then adding a second metal catalyst supported by alumina to continue the reaction; wherein the carbon source gas introduced into the reaction has a flow rate of 400-500 L / min, the inert gas flow rate is 500-550 L / min, the reaction temperature is 630-690°C, and the reaction time, from the entry of the carbon source gas to the final discharge, is approximately 40-60 minutes. After the reaction is completed, the obtained powder is soaked in concentrated sulfuric acid for 15-30 minutes to remove impurities, and then washed with deionized water and dried. In this way, by initially growing array carbon nanotubes and then growing entangled carbon nanotubes to cover the grown array carbon nanotubes, the entangled carbon nanotubes can be coated on the surface of the array carbon nanotubes to form carbon nanotube aggregates, thereby improving the dispersion performance of the carbon nanotube aggregates.

[0120] The inert gas may be at least one of nitrogen, argon and helium. The carbon source gas may be an alkane or an alkene, such as methane, ethane, propane, hexane, ethylene, propylene and the like.

[0121] Step S20: a polystyrene composite material synthesis step.

[0122] In some embodiments, the melt processing includes twin-screw melt extrusion granulation, and the conditions of twin-screw melt extrusion granulation include: melting section: 200~210℃; first extrusion section: 215~225℃; first shearing section: 220~230℃; first pressurization section: 225~235℃; first melt exhaust section: 225~235℃; second extrusion section: 230~240℃; second shearing section: 230~240℃; second pressurization section: 225~235℃; second melt exhaust section: 220~230℃; head temperature: 215~235℃; main engine speed 400~1000rpm / min, vacuum degree ≤-0.05MPa.

[0123] Specifically, the granulation can be performed by melt extrusion in a twin-screw extruder. The twin-screw extruder sequentially comprises a melting section, a first extrusion section, a first shearing section, a first pressurizing section, a first melt-degassing section, a second extrusion section, a second shearing section, a second pressurizing section, a second melt-degassing section, and a die. The raw materials are mixed and pelletized according to the design parameters of the twin-screw extruder.

[0124] Specifically, the raw materials of each component are placed in a high-speed mixer with a rotation speed of 200-400 rpm and mixed for 3-10 minutes, respectively fed from three different loss-in-weight scales, and melt-extruded into granules through a twin-screw extruder at an extrusion temperature of 200-240°C and a main engine speed of 400-1000 rpm / min. Polystyrene antistatic sheet

[0125] In a third aspect, an embodiment of the present application provides a polystyrene antistatic sheet, comprising the polystyrene composite material provided in the first aspect of the embodiment of the present application or the polystyrene composite material prepared by the preparation method provided in the second aspect of the embodiment of the present application.

[0126] The characteristics of the polystyrene composite material provided in the embodiments of the present application enable the polystyrene antistatic sheet containing the characteristics of the polystyrene composite material to have excellent antistatic performance, surface smoothness and cleanliness.

[0127] Specifically, the formula components of the polystyrene composite material are as described above; the raw materials and process parameters in the preparation method of the polystyrene composite material are as described above, and will not be repeated here. carbon nanotube aggregates

[0128] In a fourth aspect, an embodiment of the present application provides a carbon nanotube aggregate, comprising an array of carbon nanotubes and a entangled carbon nanotube coated on the surface of the array of carbon nanotubes.

[0129] In this application, a carbon nanotube aggregate with a wrapped carbon nanotube array structure is developed. This carbon nanotube aggregate is less cluttered, easier to disperse, and more easily connects to form a well-conductive network. Therefore, when used as a filler in a plastic substrate such as polystyrene, this carbon nanotube aggregate can be evenly dispersed, resulting in an antistatic polystyrene composite material with uniform surface conductivity.

[0130] In some embodiments, the bulk density of the carbon nanotube aggregates is 20-35 kg / m 3 Furthermore, the tap density of carbon nanotube aggregates is 40~60kg / m 3 Furthermore, the resistivity of the carbon nanotube aggregate is 60-90 mΩ·cm. Furthermore, the particle size of the carbon nanotube aggregate is ≤200 μm.

[0131] In some embodiments, carbon nanotube aggregates are prepared by the following steps: placing a first metal catalyst supported by vermiculite in a fluidized bed reactor through which a carbon source gas is passed to carry out a first reaction, and then adding a second metal catalyst supported by alumina to the fluidized bed reactor to carry out a second reaction to obtain a reaction product; the reaction product is treated with acid, and then washed with water and dried to obtain carbon nanotube aggregates.

[0132] In some embodiments, the mass ratio of the first metal catalyst to the second metal catalyst is 1:(2-4). Furthermore, the first metal catalyst and the second metal catalyst independently comprise at least one of iron, molybdenum, cobalt, nickel, vanadium, chromium, manganese, ruthenium, lead, silver, platinum, and gold. Furthermore, the flow rate of the carbon source gas in the fluidized bed reactor is 400-500 L / min. The temperature of the first reaction is 630-690°C, and the duration of the first reaction is 5-10 minutes. Furthermore, the temperature of the second reaction is 630-690°C, and the duration of the second reaction is 35-50 minutes. Furthermore, the acid treatment comprises soaking the reaction product in a concentrated sulfuric acid solution for 15-30 minutes.

[0133] In the process of preparing carbon nanotube aggregates, a first metal catalyst supported by vermiculite first undergoes a first reaction, growing shorter array carbon nanotubes on the surface of the first metal catalyst. Then, a second metal catalyst supported by alumina is introduced to carry out a second reaction. During this process, the array carbon nanotubes on the surface of the first metal catalyst continue to grow, while the majority of the second metal catalyst surrounds the first metal catalyst under the influence of the fluidized state. The entangled carbon nanotubes grown on the surface of the second metal catalyst easily surround the array carbon nanotubes on the surface of the first metal catalyst and grow along the growth direction of the array carbon nanotubes, thus forming a carbon nanotube aggregate with array carbon nanotubes inside and entangled carbon nanotubes outside. It is precisely because of this special structure that the overall structure is not easy to be disordered, is easy to disperse, and is easy to overlap to form a good conductive network.

[0134] The carbon nanotube aggregates provided in the embodiments of the present application have the following advantages over conventional wound carbon nanotubes or conventional arrayed carbon nanotubes: the carbon nanotube aggregates in the embodiments of the present application have significantly better dispersion performance than wound carbon nanotubes and are not easy to agglomerate in the substrate; and compared with arrayed carbon nanotubes prepared in a fixed bed, the carbon nanotube aggregates in the embodiments of the present application have a simple process and can be produced in large quantities, greatly reducing production costs.

[0135] The following describes the details in conjunction with specific embodiments. Example 1

[0136] A polystyrene composite material, comprising the following raw material components: 90 parts by weight of high-impact polystyrene; 15 parts by weight of styrene-acrylonitrile copolymer; 3 parts by weight of a toughening agent (butadiene rubber); 5 parts by weight of carbon nanotube aggregates; 3 parts by weight of a dispersant (sodium oleate); and 0.5 parts by weight of an antioxidant (1010).

[0137] The preparation of polystyrene composite materials includes the following steps:

[0138] A vermiculite-supported first metal catalyst (Fe:Co:Ni in a molar ratio of 1:1:0.6, with a total loading of 8 wt%) was introduced into a fluidized bed reactor and reacted for 10 minutes. A second alumina-supported metal catalyst (Fe:Co:Ni in a molar ratio of (5-9):1:0.05, with a total loading of 10 wt%) was then added to continue the reaction. The carbon source gas flow rate was 500 L / min, the inert gas flow rate was 550 L / min, the reaction temperature was 690°C, and the reaction time, from the introduction of the carbon source gas to its final discharge, was approximately 60 minutes. After the reaction, the resulting powder was immersed in concentrated sulfuric acid for 30 minutes to remove impurities, then washed with deionized water and dried to produce carbon nanotube aggregates. The scanning electron micrograph is shown in Figure 2. The carbon nanotube aggregates were then pulverized to a Dmax ≤ 200 μm using a jet milling process.

[0139] The high-impact polystyrene particles are crushed into powders with a size of ≤3000 mesh at a low temperature of less than -190°C.

[0140] The prepared high-impact polystyrene, carbon nanotube aggregates, styrene-acrylonitrile copolymer, toughening agent, and other additives were mixed in a high-speed mixer at 400 rpm for 10 minutes. The materials were then fed from three different loss-in-weight scales and melt-extruded into pellets through a twin-screw extruder at an extrusion temperature of 240°C and a main engine speed of 500 rpm / min. The twin-screw extruder sequentially comprises a melting section, a first extrusion section, a first shearing section, a first pressurizing section, a first melt-degassing section, a second extrusion section, a second shearing section, a second pressurizing section, a second melt-degassing section, and a die. The set process conditions of the twin-screw extruder are as follows: melting section: 210°C; first extrusion section: 225°C; first shearing section: 230°C; first pressurizing section: 235°C; first melt exhaust section: 235°C; second extrusion section: 240°C; second shearing section: 240°C; second pressurizing section: 235°C; second melt exhaust section: 230°C; head temperature: 235°C; main engine speed 1000rpm / min, vacuum degree ≤-0.05MPa. Example 2

[0141] A polystyrene composite material, comprising the following raw material components: 85 parts by weight of high-impact polystyrene; 10 parts by weight of styrene-acrylonitrile copolymer; 2 parts by weight of a toughening agent (butadiene rubber); 6 parts by weight of carbon nanotube aggregates; 2 parts by weight of a dispersant (sodium oleate); and 0.6 parts by weight of an antioxidant (1010).

[0142] The preparation method is the same as that in Example 1. Example 3

[0143] A polystyrene composite material, comprising the following raw material components: 93 parts by weight of high-impact polystyrene; 12 parts by weight of styrene-acrylonitrile copolymer; 2.5 parts by weight of a toughening agent (butadiene rubber); 4 parts by weight of carbon nanotube aggregates; 3 parts by weight of a dispersant (sodium oleate); and 0.3 parts by weight of an antioxidant (1010).

[0144] The preparation method is the same as that in Example 1. Comparative Example 1

[0145] A polystyrene composite material, compared with Example 2, differs in that the carbon nanotube aggregates in the formula are replaced by acidified carbon nanotubes, and the acidified carbon nanotubes are prepared only by a second metal catalyst supported by alumina through a fluidized bed process. Comparative Example 2

[0146] A polystyrene composite material, compared with Example 2, differs in that the carbon nanotube aggregates in the formula are replaced by acidified carbon nanotubes, and the acidified carbon nanotubes are prepared by a fluidized bed process using only a first metal catalyst supported by vermiculite. Performance Testing

[0147] The polystyrene composite materials prepared in Examples 1-3 and Comparative Examples 1 and 2 were melt-extruded to produce 0.2 mm thick sheet samples at an extrusion temperature of 240°C. These sheet samples were tested for surface flatness and surface resistivity. Surface flatness was observed visually; surface resistivity was tested using the DC comparison method. The test equipment and measurement error complied with the requirements of GB / T 3048.5. The results are shown in Table 1.

[0148] Table 1 Performance test

[0149] Test Items Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Surface Flatness Smooth surface without pitting Smooth surface without pitting Smooth surface without pitting With pitting A little rough, no pitting Surface Average Resistivity Ω / Sq.10 5.6 10 4.1 10 6.2 10 6.4 10 5.1 Conductive uniformity measures the conductivity of 20 areas on both sides of the surface, with a value of 10 5.2 ~10 6.0 The conductivity of 20 areas on both sides of the meter is measured, and the value is between 10 3.8 ~10 4.5 The conductivity of 20 areas on both sides of the meter is measured, and the value is between 10 6.0 ~10 6.5The conductivity of 20 areas on both sides of the meter is measured, and the value is between 10 4.1 ~10 8.5 The conductivity of 20 areas on both sides of the meter is measured, and the value is between 10 3.1 ~10 7.0 Changes between

[0150] The above are merely optional embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included within the scope of the claims of the present application.

Claims

1. A polystyrene composite material, wherein: The composition comprises the following components in parts by weight: Polystyrene 80-95 parts; 10-20 parts of styrene-acrylonitrile copolymer; 1-10 parts of carbon nanotube aggregates; 1~3 parts of toughening agent; 2~4 parts of dispersant; Antioxidant 0~1 part; Compatibilizer 0~3 parts; Surfactant 0~3 parts; The carbon nanotube aggregate comprises array carbon nanotubes and entangled carbon nanotubes coated on the surface of the array carbon nanotubes.

2. The polystyrene composite material according to claim 1, wherein: The bulk density of the carbon nanotube aggregates is 20-35 kg / m 3 and / or, The tap density of the carbon nanotube aggregate is 40-60 kg / m 3 and / or, The resistivity of the carbon nanotube aggregate is 60-90 mΩ·cm; and / or, The particle size of the carbon nanotube aggregate is ≤200 μm.

3. The polystyrene composite material according to claim 1, wherein: The polystyrene comprises high impact polystyrene; and / or, The polystyrene powder is ≤3000 mesh; and / or, The mass percentage of the styrene component in the styrene-acrylonitrile copolymer is 15% to 50%.

4. The polystyrene composite material according to claim 1, wherein: The toughening agent includes at least one of butadiene rubber, isoprene rubber, styrene-butadiene-styrene rubber, styrene-isoprene-styrene rubber, acrylonitrile-butadiene rubber, styrene-butadiene rubber, ethylene-propylene rubber, and styrene-ethylene-butadiene-styrene rubber; and / or, The dispersant includes any one of an anionic wetting dispersant, a cationic wetting dispersant and a controlled free radical type hyperdispersant; and / or, The antioxidant includes at least one of antioxidant 1010, antioxidant 168, antioxidant 1076, antioxidant 1330, antioxidant 1035, antioxidant 3144, antioxidant 1024, and antioxidant 126; and / or, The compatibilizer comprises maleic anhydride grafted polystyrene; and / or, The surfactant includes at least one of sodium dodecyl sulfate, sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, sodium tetradecyl sulfate, sodium tetradecyl sulfonate, and sodium tetradecylbenzene sulfonate.

5. A method for preparing a polystyrene composite material, wherein: include: Providing raw materials of various components of the polystyrene composite material according to any one of claims 1 to 4; The polystyrene, the carbon nanotube aggregate, the styrene-acrylonitrile copolymer, the toughening agent, the dispersant, the antioxidant, the compatibilizer and the surfactant are melt-treated to obtain the polystyrene composite material.

6. The preparation method according to claim 5, wherein: The melt processing includes twin-screw melt extrusion granulation, and the conditions of the twin-screw melt extrusion granulation include: Melting section: 200~210℃; first extrusion section: 215~225℃; first shearing section: 220~230℃; first pressurizing section: 225~235℃; first melt exhaust section: 225~235℃; second extrusion section: 230~240℃; second shearing section: 230~240℃; second pressurizing section: 225~235℃; second melt exhaust section: 220~230℃; die head temperature: 215~235℃; main engine speed 400~1000rpm / min, vacuum degree ≤-0.05MPa.

7. The preparation method according to claim 5, wherein: The preparation method of the carbon nanotube aggregate comprises: Placing a first metal catalyst supported by vermiculite in a fluidized bed reactor through which a carbon source gas is passed to perform a first reaction, and then adding a second metal catalyst supported by alumina to the fluidized bed reactor to perform a second reaction to obtain a reaction product; The reaction product is treated with acid, then washed with water and dried to obtain the carbon nanotube aggregate.

8. The preparation method according to claim 7, wherein: The mass ratio of the first metal catalyst to the second metal catalyst is 1:(2-4); and / or, The first metal catalyst and the second metal catalyst independently include at least one of iron, molybdenum, cobalt, nickel, vanadium, chromium, manganese, ruthenium, lead, silver, platinum, and gold.

9. The preparation method according to claim 7, wherein: The flow rate of the carbon source gas in the fluidized bed reactor is 400-500 L / min; and / or, The temperature of the first reaction is 630-690° C., and the time of the first reaction is 5-10 min; and / or, The temperature of the second reaction is 630-690° C., and the time of the second reaction is 35-50 min.

10. A carbon nanotube aggregate, wherein: It comprises an array carbon nanotube and a winding carbon nanotube coated on the surface of the array carbon nanotube.

11. The carbon nanotube aggregate according to claim 10, wherein: The bulk density of the carbon nanotube aggregates is 20-35 kg / m 3 ; and / or The tap density of the carbon nanotube aggregate is 40-60 kg / m 3 and / or, The resistivity of the carbon nanotube aggregate is 60-90 mΩ·cm; and / or, The particle size of the carbon nanotube aggregate is ≤200 μm.

12. The carbon nanotube aggregate according to claim 10, wherein: The carbon nanotube aggregates are prepared by the following steps: Placing a first metal catalyst supported by vermiculite in a fluidized bed reactor through which a carbon source gas is passed to perform a first reaction, and then adding a second metal catalyst supported by alumina to the fluidized bed reactor to perform a second reaction to obtain a reaction product; The reaction product is treated with acid, then washed with water and dried to obtain the carbon nanotube aggregate.

13. The carbon nanotube aggregate according to claim 12, wherein: The mass ratio of the first metal catalyst to the second metal catalyst is 1:(2-4); and / or, The first metal catalyst and the second metal catalyst independently include at least one of iron, molybdenum, cobalt, nickel, vanadium, chromium, manganese, ruthenium, lead, silver, platinum, and gold; and / or, The flow rate of the carbon source gas in the fluidized bed reactor is 400-500 L / min; and / or, The temperature of the first reaction is 630-690° C., and the time of the first reaction is 5-10 min; and / or, The temperature of the second reaction is 630-690° C., and the time of the second reaction is 35-50 min.

14. The carbon nanotube aggregate according to claim 12, wherein: The acid treatment comprises: soaking the reaction product in a concentrated sulfuric acid solution for 15 to 30 minutes.

15. A polystyrene antistatic sheet, wherein: The invention comprises the polystyrene composite material according to any one of claims 1 to 4 or the polystyrene composite material prepared by the preparation method according to any one of claims 5 to 9.

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