Antistatic composite material as well as preparation method and application thereof

Abstract

The invention provides an antistatic composite material and a preparation method and application thereof.The antistatic composite material is obtained by compounding a base material and a surface coating modified antistatic agent, and the surface coating modified antistatic agent comprises a surface modified conductive agent and a maleic anhydride grafted cycloolefin copolymer coating the surface of the surface modified conductive agent, the surface modified conductive agent is a carbon material modified by a silane coupling agent. The surface modification conductive agent is coated with the maleic anhydride grafted cycloolefin copolymer, a compact barrier layer is formed on the surface of the carbon conductive additive, a metal ion migration path is blocked, and the metal ion precipitation amount is remarkably reduced; the carbon additive can be prevented from being agglomerated, the dispersity is excellent, and the performance of the composite material is improved.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor materials technology, and relates to an antistatic composite material, its preparation method, and its application. Background Technology

[0002] As semiconductor advanced manufacturing processes advance to 5nm and below, the impact of metal ion contamination on wafer surface on device yield increases exponentially—when metal ions (such as Na+)... + K + Fe³ + Cu² + When the amount of metal ion deposited on the wafer surface exceeds 1 ppb, it will cause the threshold voltage of the MOSFET to drift and the leakage current to increase, leading to chip malfunction. Therefore, carriers that directly contact the wafer (such as wafer cassettes and transfer trays) must meet the stringent requirement of metal ion deposition of <1 ppb, and must also possess: anti-static properties and a surface resistivity of 10 Ω·cm. 4 -10 9 Ω / sq, avoiding electrostatic adsorption of airborne particles or breakdown of wafer oxide layer; Mechanical properties: high strength and high modulus, suitable for high-frequency handling and stacking in automated production lines; Chemical resistance: resistant to commonly used semiconductor reagents such as acids and alkalis, without swelling or component migration.

[0003] Currently, the mainstream wafer carrier materials in the industry are antistatic modified materials. The antistatic function is achieved by adding carbon-based additives (graphene, carbon nanotubes, conductive carbon black, etc.), but there are the following insurmountable defects:

[0004] The inherent problem of metal impurities: On the one hand, during the preparation process of carbon-based additives (such as chemical exfoliation of graphene and catalytic growth of carbon nanotubes), metal catalyst residues (such as Fe, Ni, and Co) are easily introduced, and the metal impurity content of conventional products is >100ppm. Even with high-temperature (800-1200℃) annealing or strong acid (aqua regia) immersion purification, the porous structure of carbon materials makes it difficult to completely remove impurities. The metal content after purification is still >1ppm, which makes it easy for metal impurities in carbon-based additives to precipitate. Ultimately, the amount of metal ions precipitated in PC / PP composite materials reaches 10-1000ppb, which cannot meet the requirements of advanced semiconductor processes.

[0005] Poor interfacial compatibility: Carbon materials have an inert surface and weak interfacial bonding with the matrix, making them prone to agglomeration during processing, which leads to a decrease in the mechanical properties of the material. Furthermore, the agglomerates can easily form ion migration channels, further aggravating the precipitation of metal ions. Insufficient barrier performance: It is impossible to effectively block the migration of metal ions from carbon additives to the wafer surface. Even with coating modification (such as PTFE coating), there is still a risk of coating peeling off, and it increases the process cost.

[0006] Therefore, further research on wafer carrier materials is of great significance in this field. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide an antistatic composite material, its preparation method, and its application.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] On one hand, the present invention provides an antistatic composite material, which is obtained by combining a matrix material and a surface-coated modified antistatic agent. The surface-coated modified antistatic agent includes a surface-modified conductive agent and a maleic anhydride grafted cyclic olefin copolymer coated on its surface. The surface-modified conductive agent is a carbon material modified by a silane coupling agent.

[0010] In this invention, a surface-modified conductive agent is coated with a maleic anhydride-grafted cyclic olefin copolymer (COC-g-MAH) to form a dense barrier layer on the surface of the carbon conductive additive, blocking the migration path of metal ions and significantly reducing the amount of metal ions released. This invention can avoid the agglomeration of carbon additives, has excellent dispersibility, and improves the performance of composite materials.

[0011] Preferably, the matrix material is a cyclic olefin copolymer (COC).

[0012] Preferably, the cyclic olefin copolymer has a cyclic olefin content of 50-70% (e.g., 50%, 52%, 54%, 56%, 58%, 60%, 62%, 64%, 66%, or 70%) and a weight-average molecular weight of 10,000-100,000.

[0013] Preferably, the maleic anhydride-grafted cyclic olefin copolymer is obtained by grafting a low molecular weight cyclic olefin copolymer with maleic anhydride.

[0014] Preferably, the weight-average molecular weight of the low molecular weight cyclic olefin copolymer is 2000-10000 (e.g., 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500, 8000, 8500, or 10000). In this invention, if the molecular weight of the cyclic olefin copolymer used is too low, the coating layer is prone to breakage; if it is too high, the flowability is poor, making uniform coating difficult.

[0015] In this invention, the low molecular weight cyclic olefin copolymer is prepared by the lubricant preparation method in patent CN 118546281 A.

[0016] Preferably, the cyclic olefin content in the low molecular weight cyclic olefin copolymer is 20-80 wt% (e.g., 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, or 80 wt%).

[0017] Preferably, the maleic anhydride-grafted cyclic olefin copolymer is prepared by the following method:

[0018] A low molecular weight cyclic olefin copolymer is reacted with maleic anhydride under the initiation of an initiator, and then melt extruded to obtain the maleic anhydride-grafted cyclic olefin copolymer.

[0019] Preferably, the amount of maleic anhydride used is 2%-4% of the mass of the low molecular weight cyclic olefin copolymer (e.g., 2%, 2.5%, 3%, 3.5% or 4%, etc.).

[0020] Preferably, the initiator is selected from any one or a combination of at least two of dicumyl peroxide (DCP), triallyl isocyanurate (TAIC), benzoyl peroxide (BPO), or 2,5-bis(tert-butyl)-2,5-dimethylhexane (DHBP).

[0021] Preferably, the amount of the initiator is 0.2%-0.4% of the mass of the low molecular weight cyclic olefin (e.g., 0.2%, 0.25%, 0.3%, 0.35% or 0.4%, etc.).

[0022] Preferably, the reaction temperature is 80-100℃ (e.g., 80℃, 82℃, 84℃, 86℃, 88℃, 90℃, 92℃, 94℃, 96℃ or 100℃, etc.), and the reaction time is 10-15min (e.g., 10min, 10.5min, 11min, 11.5min, 12min, 12.5min, 13min, 13.5min, 14min or 15min, etc.).

[0023] Preferably, the reaction is carried out under stirring; in this invention, the reaction can be completed in a high-speed mixer.

[0024] Preferably, the melt extrusion is carried out in a twin-screw extruder, the temperature of the melt extrusion is 170-240℃ (e.g., 170℃, 180℃, 190℃, 200℃, 210℃, 220℃, 230℃ or 240℃, etc.), and the screw speed is 100-300 r / min (e.g., 100 r / min, 125 r / min, 150 r / min, 175 r / min, 200 r / min, 225 r / min, 250 r / min, 275 r / min or 300 r / min, etc.).

[0025] Preferably, the melt extrusion is followed by water cooling and pelletizing to obtain a maleic anhydride-grafted cyclic olefin copolymer.

[0026] Preferably, the water temperature for water cooling is 15-30℃ (e.g., 15℃, 16℃, 17℃, 18℃, 19℃, 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃, 28℃ or 30℃, etc.).

[0027] Preferably, the silane coupling agent is selected from aminosilane coupling agents (such as KH550) or vinylsilane coupling agents (such as KH570). The amino (-NH2) or vinyl (-CH=CH2) contained in the molecular structure can be grafted with COC-g-MAH, and the hydroxyl (-Si-OH) can be condensed with the hydroxyl groups on the surface of carbon materials.

[0028] Preferably, the carbon material is selected from any one or a combination of at least two of graphene, multi-walled carbon nanotubes, or conductive carbon black.

[0029] Preferably, the graphene sheet has a diameter of 1-5 μm (e.g., 1 μm, 2 μm, 3 μm, 4 μm or 5 μm) and a thickness of 0.8-1.2 nm (e.g., 0.8 nm, 0.9 nm, 1 nm, 1.1 nm or 1.2 nm).

[0030] Preferably, the multi-walled carbon nanotubes have a diameter of 5-15 nm (e.g., 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm or 15 nm, etc.) and a length of 1-100 μm (e.g., 1 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm or 100 μm, etc.).

[0031] Preferably, the specific surface area of ​​the conductive carbon black is 800-1200 m² / g (e.g., 800 m² / g, 850 m² / g, 900 m² / g, 950 m² / g, 1000 m² / g, 1050 m² / g, 1100 m² / g, 1150 m² / g, or 1200 m² / g, etc.).

[0032] Preferably, the preparation method of the surface-modified conductive agent includes the following steps:

[0033] The silane coupling agent is hydrolyzed, and the resulting aqueous solution is mixed with a carbon material and reacted to obtain the surface-modified conductive agent.

[0034] Preferably, the specific operation of hydrolyzing the silane coupling agent is to add the silane coupling agent to water, adjust the pH to 2-4 (e.g., 2, 2.5, 3, 3.5 or 4), and hydrolyze to obtain a hydrolyzed aqueous solution.

[0035] Preferably, the pH is adjusted using hydrochloric acid or acetic acid.

[0036] In this invention, the hydrolysis is carried out under stirring at a speed of 100-1000 rpm / min (e.g., 100 rpm / min, 200 rpm / min, 300 rpm / min, 400 rpm / min, 500 rpm / min, 600 rpm / min, 700 rpm / min, 800 rpm / min, 900 rpm / min or 1000 rpm / min, etc.).

[0037] Preferably, the hydrolysis temperature is 30-70℃ (e.g., 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃ or 70℃, etc.), and the hydrolysis time is 20-180min (e.g., 20min, 30min, 40min, 50min, 60min, 70min, 80min, 90min, 100min, 110min, 120min, 130min, 140min, 150min or 180min, etc.).

[0038] Preferably, the concentration of the hydrolyzed aqueous solution is 0.8-10 wt% (e.g., 0.8 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, or 10 wt%).

[0039] Preferably, the mass ratio of the hydrolyzed aqueous solution to the carbon material is 1:1 to 3:1 (e.g., 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1, 2:1, 2.2:1, 2.4:1, 2.6:1 or 3:1, etc.).

[0040] Preferably, the reaction temperature between the hydrolyzed aqueous solution and the carbon material is 30-70℃ (e.g., 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃ or 70℃, etc.), and the reaction time is 1-3h (e.g., 1h, 1.5h, 2h, 2.5h or 3h, etc.).

[0041] Preferably, the reaction between the hydrolyzed aqueous solution and the carbon material is carried out under stirring, and the stirring speed is 100-1000 rpm / min (e.g., 100 rpm / min, 200 rpm / min, 300 rpm / min, 400 rpm / min, 500 rpm / min, 600 rpm / min, 700 rpm / min, 800 rpm / min, 900 rpm / min or 1000 rpm / min, etc.).

[0042] Preferably, after the reaction between the hydrolyzed aqueous solution and the carbon material is completed, post-treatment is performed, specifically including: centrifugation, washing, and drying to obtain the surface-modified carbon material.

[0043] Preferably, the centrifugation speed is 8000-10000 r / min (e.g., 8000 r / min, 8250 r / min, 8500 r / min, 8750 r / min, 9000 r / min, 9250 r / min, 9500 r / min, 9750 r / min or 10000 r / min, etc.), and the centrifugation time is 10-30 min (e.g., 10 min, 15 min, 20 min, 25 min or 30 min, etc.).

[0044] In this invention, the number of water washes is 3-5 times (e.g., 3, 4 or 5 times, etc.) to remove unreacted coupling agent.

[0045] Preferably, the drying is carried out in a vacuum drying oven at a temperature of 80-200℃ (e.g., 80℃, 95℃, 110℃, 125℃, 140℃, 155℃, 170℃, 185℃, or 200℃) for a time of 1-6 hours (e.g., 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, or 6 hours).

[0046] Preferably, the coating is achieved by adding maleic anhydride-grafted cyclic olefin copolymer and surface-modified conductive agent to a solvent, adding a reaction promoter to carry out the reaction, and completing the surface coating.

[0047] Preferably, the solvent is toluene.

[0048] Preferably, the reaction promoter is DMAP (4-dimethylaminopyridine).

[0049] Preferably, the mass ratio of the maleic anhydride grafted cyclic olefin copolymer to the surface-modified conductive agent is 25:75-75:25, for example, 25:75, 30:70, 40:60, 50:50, 60:40, 70:30 or 75:25.

[0050] Preferably, the reaction temperature for adding the reaction promoter is 60-80℃ (e.g., 60℃, 65℃, 70℃, 75℃ or 80℃, etc.), and the reaction time is 2-4h (e.g., 2h, 2.5h, 3h, 3.5h or 4h, etc.).

[0051] Preferably, the mass ratio of the surface-coated modified antistatic agent to the matrix is ​​5:95-15:85.

[0052] On the other hand, the present invention provides a method for preparing the antistatic composite material as described above, the method comprising the following steps:

[0053] The surface-coated modified antistatic agent is mixed with the matrix, and then melt-extruded and granulated to obtain the antistatic composite material.

[0054] Preferably, the mixing is carried out under stirring, and in this invention, the mixing is completed using a high-speed mixer.

[0055] Preferably, the mixing temperature is 90-110℃ (e.g., 90℃, 95℃, 100℃, 105℃ or 110℃, etc.), and the mixing time is 15-20min (e.g., 15min, 15.5min, 16min, 16.5min, 17min, 17.5min, 18min, 18.5min, 19min or 20min, etc.).

[0056] Preferably, the melt extrusion is carried out in a twin-screw extruder, the temperature of the melt extrusion is 190-260℃ (e.g., 190℃, 200℃, 210℃, 220℃, 230℃, 240℃, 250℃ or 260℃, etc.), the extruder speed is 100-300 rpm / min (e.g., 100 rpm / min, 125 rpm / min, 150 rpm / min, 175 rpm / min, 200 rpm / min, 225 rpm / min, 250 rpm / min, 275 rpm / min or 300 rpm / min, etc.), and the vacuum degree is >0.09 MPa (for volatile matter removal).

[0057] Preferably, the length-to-diameter ratio of the twin-screw extruder is >40.

[0058] On the other hand, the present invention provides an application of the antistatic composite material as described above in wafer carrier materials.

[0059] Compared with the prior art, the present invention has the following beneficial effects:

[0060] This invention utilizes maleic anhydride-grafted cyclic olefin copolymer (COC-g-MAH) to coat a surface-modified conductive agent, forming a dense barrier layer on the surface of a carbon conductive additive, blocking the migration path of metal ions, and significantly reducing the amount of metal ion precipitation; this invention can avoid the agglomeration of carbon additives, has excellent dispersibility, and improves the performance of composite materials. Detailed Implementation

[0061] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0062] Example 1

[0063] This embodiment provides an antistatic composite material, the preparation method of which includes the following steps:

[0064] Step 1: Add coupling agent KH550 to deionized water (concentration 1%), add acetic acid to pH=4, stir and hydrolyze at 30℃ for 60 min at a stirring speed of 1000 rpm / min to obtain coupling agent hydrolysate;

[0065] Step 2: Carbon nanotubes (CNTs, 10 nm in diameter and 200 μm in length) were added to the coupling agent hydrolysate (mass ratio 1:2), and the mixture was stirred and reacted (reaction time 60 min, temperature 30 °C, stirring speed 1000 rpm / min). The mixture was then centrifuged (speed 8000 r / min, time 30 min), washed three times with deionized water (to remove unreacted coupling agent), and dried in a vacuum drying oven at 200 °C for 2 h to obtain the surface-modified conductive agent.

[0066] Step 3: Add low molecular weight COC (20wt% cyclic olefin content, 2000 Mw weight average), initiator (DCP) and maleic anhydride to a high-speed mixer and mix for 15 min. Add the premix to a twin-screw extruder and extrude at 220°C and 300 r / min to graft maleic anhydride onto the COC molecular chain to obtain COC-g-MAH.

[0067] Step 4: Add COC-g-MAH and surface-modified conductive agent to a 60℃ toluene solution at a mass ratio of 25:75. After stirring and dissolving thoroughly, add DMAP and react for 2 hours. After filtration and washing, the surface-coated modified conductive agent is obtained.

[0068] Step 5: Add the surface-coated conductive agent and COC (manufacturer: Tuoxi Technology, brand name TAMT1410YC) matrix to a high-speed mixer at a mass ratio of 5:95, mix at 100℃ for 20 minutes, add the mixture to a twin-screw extruder, granulate at an extrusion temperature of 190℃ and a screw speed of 150 r / min to obtain the COC antistatic composite material.

[0069] Example 2

[0070] This embodiment provides an antistatic composite material, the preparation method of which includes the following steps:

[0071] Step 1: Add coupling agent KH792 to deionized water (10% concentration), add acetic acid to pH=4, stir and hydrolyze at 30℃ for 60 min at a stirring speed of 1000 rpm / min to obtain coupling agent hydrolysate;

[0072] Step 2: Add graphene (5 μm in diameter, 1 nm in thickness) to the coupling agent hydrolysate (mass ratio 1:1), stir and react (reaction time 60 min, temperature 30 °C, stirring speed 1000 rpm / min), centrifuge (speed 8000 r / min, time 30 min), wash 5 times with deionized water (to remove unreacted coupling agent), and dry in a vacuum drying oven at 200 °C for 2 h to obtain the surface-modified conductive agent;

[0073] Step 3: Add low molecular weight COC (60wt% cyclic olefin content, 5000 Mw weight average), initiator (BPO) and maleic anhydride to a high-speed mixer and mix for 15 min. Add the premix to a twin-screw extruder and extrude at 180℃ and 100 r / min to graft maleic anhydride onto the COC molecular chain to obtain COC-g-MAH.

[0074] Step 4: Add COC-g-MAH and surface-modified conductive agent to a 60℃ toluene solution at a mass ratio of 50:50. After stirring and dissolving thoroughly, add DMAP and react for 2 hours. After filtration and washing, the surface-coated conductive agent is obtained.

[0075] Step 5: Add the surface-coated conductive agent and COC (manufacturer: Tuoxi Technology, brand name TAMT1410YC) matrix to a high-speed mixer at a mass ratio of 10:90, mix at 90℃ for 15 minutes, add the mixture to a twin-screw extruder, granulate at an extrusion temperature of 220℃ and a screw speed of 200r / min to obtain the COC antistatic composite material.

[0076] Example 3

[0077] This embodiment provides an antistatic composite material, the preparation method of which includes the following steps:

[0078] Step 1: Add coupling agent KH570 to deionized water (5% concentration), add hydrochloric acid to pH=2, stir and hydrolyze at 50℃ for 120 min at a stirring speed of 500 rpm / min to obtain coupling agent hydrolysate;

[0079] Step 2: Add conductive carbon black (specific surface area 1000 m² / g) to the coupling agent hydrolysate (mass ratio 1:3), stir and react (reaction time 120 min, temperature 50℃, stirring speed 1000 rpm / min), centrifuge (speed 10000 r / min, time 60 min), wash 3 times with deionized water (to remove unreacted coupling agent), and dry in a vacuum drying oven at 150℃ for 4 h to obtain the surface-modified conductive agent;

[0080] Step 3: Add COC resin (80wt% cyclic olefin content, 8000% weight average molecular weight (Mw)), initiator (bis(2,5-diphenyl)) and maleic anhydride to a high-speed mixer and mix for 15 min. Add the premix to a twin-screw extruder and extrude at 180℃ and 100 r / min to graft maleic anhydride onto the COC molecular chain to obtain COC-g-MAH.

[0081] Step 4: Add COC-g-MAH and surface-modified conductive agent to a 60℃ toluene solution at a mass ratio of 75:25. After stirring and dissolving thoroughly, add DMAP and react for 2 hours. After filtration and washing, the surface-coated conductive agent is obtained.

[0082] Step 5: Add the surface-coated conductive agent and COC (manufacturer: Tuoxi Technology, brand name TAMT1410YC) matrix to a high-speed mixer at a mass ratio of 15:85, mix at 110℃ for 20 minutes, add the mixture to a twin-screw extruder, granulate at an extrusion temperature of 260℃ and a screw speed of 300r / min to obtain the COC antistatic composite material.

[0083] Comparative Example 1

[0084] The only difference from Example 1 is that steps 1 and 2 are omitted, and the conductive agent is used directly without surface modification.

[0085] Comparative Example 2

[0086] The only difference from Example 1 is that PC (manufacturer Sumitomo Chemical, model TE2011-15) is used as the matrix resin in step 5; the other steps are the same.

[0087] Comparative Example 3

[0088] The only difference from Example 1 is that in step 3, the low molecular weight cyclic olefin copolymer is selected with a cyclic olefin content of 20wt% and a weight average molecular weight (Mw) of 20000.

[0089] Comparative Example 4

[0090] The only difference from Example 1 is that in step 3, the low molecular weight cyclic olefin copolymer is selected with a cyclic olefin content of 50wt% and a weight average molecular weight (Mw) of 1000.

[0091] The composite materials prepared in the above embodiments and comparative examples were subjected to performance tests, and the test methods are as follows:

[0092] 1. Metal precipitation content test method (ICP-MS test method, the test elements include: Li, Na, Mg, Al, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Ti, V, Zn, Mo, Ba, W, Sr, Ta, a total of 20 elements).

[0093] Weigh 5g of conductive modified particles, take 60mL of pure water, wash the particles and then discard the pure water. Repeat the washing process 10 times. Then, put the washed particles into 60mL of pure water and soak for 24h. After that, test the total metal concentration n1 of the soaking solution.

[0094] Take another 5g of the corresponding matrix resin particles, treat and soak them in the same way, and test the total metal concentration n2 of the soaking solution.

[0095] The total amount of metal precipitated is n = n1 - n2.

[0096] 2. Tensile strength testing shall be performed in accordance with standard ISO 527.

[0097] 3. Volume resistivity testing shall be performed in accordance with standard GB / T1410-2006.

[0098] Table 1

[0099]

[0100] Comparing the data of Example 1 and Comparative Example 1, the surface modification treatment of the conductive agent effectively improved the mechanical properties and promoted the dispersion of the conductive agent.

[0101] Comparing the data of Example 1 and Comparative Example 2, COC resin has a higher barrier effect than PC, effectively reducing the amount of metal precipitated.

[0102] Comparing the data of Example 1 and Comparative Example 3, it was found that the high molecular weight of COC used for coating the conductive agent surface leads to a reduction in the barrier effect.

[0103] Comparing the data of Example 1 and Comparative Example 4, it was found that the low molecular weight of COC used for coating the conductive agent surface leads to a reduction in the barrier effect and a decrease in mechanical properties.

[0104] The applicant declares that the above embodiments illustrate the antistatic composite material, its preparation method, and its application, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product, addition of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An antistatic composite material, characterized by, The antistatic composite is obtained by compounding a base material and a surface-coated modified antistatic agent, the surface-coated modified antistatic agent comprising a surface-modified conductive agent and a maleic anhydride grafted cycloolefin copolymer coated on the surface of the surface-modified conductive agent, the surface-modified conductive agent being a carbon material modified by a silane coupling agent.

2. The antistatic composite material according to claim 1, characterized in that, The base material is a cycloolefin copolymer. The cycloolefin content of the cycloolefin copolymer is 50-70%, and the weight average molecular weight is 10000-100000.

3. The antistatic composite material according to claim 1, characterized in that, The maleic anhydride grafted cycloolefin copolymer is obtained by grafting reaction of a low molecular weight cycloolefin copolymer and maleic anhydride; the weight average molecular weight of the low molecular weight cycloolefin copolymer is 2000-10000, and the cycloolefin content of the low molecular weight cycloolefin copolymer is 20-80wt%; The maleic anhydride grafted cycloolefin copolymer is prepared by the following preparation method: The low molecular weight cycloolefin copolymer and maleic anhydride are reacted under the initiation of an initiator, and then melt extruded to obtain the maleic anhydride grafted cycloolefin copolymer.

4. The antistatic composite material according to claim 3, characterized in that, The amount of maleic anhydride is 2%-4% of the mass of the low molecular weight cycloolefin copolymer; The initiator is selected from any one or a combination of at least two of dicumyl peroxide, triallyl isocyanurate, benzoyl peroxide or 2,5-bis(tert-butyl)-2,5-dimethylhexane; The amount of initiator is 0.2%-0.4% of the mass of the low molecular weight cycloolefin; The reaction temperature is 80-100℃, and the reaction time is 10-15min; The melt extrusion is carried out in a twin-screw extruder, the temperature of the melt extrusion is 170-240℃, and the screw rotation speed is 100-300r / min; After the melt extrusion, water cooling and granulation are carried out to obtain the maleic anhydride grafted cycloolefin copolymer.

5. The antistatic composite material according to claim 1, characterized in that, The silane coupling agent is selected from an amino silane coupling agent or a vinyl silane coupling agent; The carbon material is selected from any one or a combination of at least two of graphene, multi-walled carbon nanotube or conductive carbon black; The flake diameter of the graphene is 1-5μm, and the thickness is 0.8-1.2nm, the diameter of the multi-walled carbon nanotube is 5-15nm, and the length is 1-100μm, and the specific surface area of the conductive carbon black is 800-1200m² / g; The preparation method of the surface-modified conductive agent comprises the following steps: The surface-modified conductive agent is obtained by mixing and reacting the hydrolyzed aqueous solution with the carbon material; The specific operation of the hydrolysis of the silane coupling agent is to add the silane coupling agent into water, adjust the pH to 2-4, and hydrolyze to obtain the hydrolyzed aqueous solution; The hydrolysis is carried out under stirring, and the stirring speed is 100-1000rpm / min; the temperature of the hydrolysis is 30-70℃, and the hydrolysis time is 20-180min; the concentration of the hydrolyzed aqueous solution is 0.8-10wt%; The mass ratio of the hydrolyzed aqueous solution to the carbon material is 1:1-3:1; The reaction temperature of the hydrolyzed aqueous solution and the carbon material is 30-70℃, and the reaction time is 1-3h; The post-treatment is performed after the reaction of the hydrolyzed aqueous solution with the carbon material, and specifically includes centrifugal separation, water washing, and drying to obtain the surface-modified carbon material; The centrifugal separation is performed at a speed of 8000-10000 r / min for 10-30 min. The drying is performed at a temperature of 80-200℃ for 1-6 h.

6. The antistatic composite material according to claim 1, characterized in that, The coating is achieved by adding the maleic anhydride grafted cycloolefin copolymer and the surface-modified conductive agent into a solvent, and adding a reaction promoter to react; The solvent is toluene; The reaction promoter is 4-dimethylaminopyridine; The mass ratio of the maleic anhydride grafted cycloolefin copolymer to the surface-modified conductive agent is 25:75-75:25; The reaction is performed at a temperature of 60-80℃ for 2-4 h.

7. The antistatic composite material according to claim 1, characterized in that, The mass ratio of the surface-coated modified antistatic agent to the matrix is 5:95-15:

85.

8. The method of producing an antistatic composite material according to any one of claims 1 to 7, characterized in that, The preparation method comprises the following steps: The surface-coated modified antistatic agent is mixed with the matrix, and then melt extrusion and granulation are performed to obtain the antistatic composite material.

9. The preparation method according to claim 8, characterized in that, The mixing is performed under stirring; The mixing is performed at a temperature of 90-110℃ for 15-20 min; The melt extrusion is performed in a twin-screw extruder at a temperature of 190-260℃, an extruder speed of 100-300 rpm / min, and a vacuum degree of >0.09 MPa; The length-diameter ratio of the twin-screw extruder is >40.

10. Use of the antistatic composite material according to any one of claims 1-7 in wafer carrier materials.

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