Antistatic PMMA material and preparation method thereof

Abstract

The invention provides an antistatic PMMA (polymethyl methacrylate) material and a preparation method thereof. The antistatic PMMA material comprises the following raw materials in parts by mass: 100 parts of PMMA resin; 5-15 parts of an antistatic agent; 1-5 parts of a lubricant; 0.1 to 1 part of an antioxidant; the antistatic agent comprises a modified silicon dioxide microcapsule, the modified silicon dioxide microcapsule comprises ionic liquid, the surface of the modified silicon dioxide microcapsule is grafted with a polymer chain segment, and the polymer chain segment comprises a methyl methacrylate unit. The antistatic PMMA material can realize stable and lasting antistatic performance on the premise of not influencing transparency, and is especially suitable for application scenes with higher requirements on optical performance and surface resistivity, such as electronic display, optical devices and the like.

Description

Technical Field

[0001] The present application relates to the technical field of functional polymer materials, and in particular to an antistatic PMMA material and a preparation method thereof. Background Art

[0002] Polymethyl methacrylate (PMMA) boasts excellent optical transparency, dimensional stability, and mechanical strength, making it widely used in optical devices, display panels, automotive components, and the electrical and electronic fields. However, as a typical electrical insulating material with high surface resistivity, PMMA is prone to static electricity accumulation in dry environments, leading to dust absorption, device interference, and even electrostatic discharge (ESD). This limits its use in high-end electronic, electrical, and cleanroom applications.

[0003] To improve the antistatic properties of PMMA, several approaches are currently used. First, by adding conductive fillers, such as carbon black, carbon nanotubes, or metal particles, the surface resistivity of the material is reduced by building a conductive network. While this method effectively improves conductivity, it often significantly affects the transparency of the PMMA, and the conductive network is easily broken due to deformation during thermal processing or use, resulting in a decrease in antistatic properties. Alternatively, migrating antistatic agents, such as quaternary ammonium salts and fatty alcohol polyoxyethylene ethers, are added to form a thin conductive layer on the surface to achieve an antistatic effect. However, these antistatic agents suffer from issues such as easy migration, easy scrubbing, and a short service life, making them difficult to meet the antistatic requirements of long-term use. This is especially true under conditions of high temperature or high humidity fluctuations, where the antistatic performance deteriorates significantly. Third, polymeric antistatic agents are introduced. Some techniques attempt to introduce antistatic groups by grafting or block-coating them into the polymer in an effort to improve stability. However, these methods often involve complex preparation, and the antistatic groups lack compatibility with the PMMA matrix, which can lead to uneven dispersion and reduced processing performance.

[0004] In summary, the existing technology lacks a PMMA material solution that can balance long-lasting antistatic performance and optical transparency. Summary of the Invention

[0005] The present application provides an antistatic PMMA material and a preparation method thereof, aiming to solve the problems of existing PMMA materials having insufficient antistatic performance and easy attenuation while maintaining optical transparency.

[0006] In the first aspect, the present application provides an antistatic PMMA material, comprising the following raw materials in parts by mass: 100 parts of PMMA resin; 5 to 15 parts of antistatic agent; 1 to 5 parts of lubricant; 0.1 to 1 part of antioxidant; the antistatic agent comprises modified silica microcapsules, the modified silica microcapsules comprise ionic liquids, the surface of the modified silica microcapsules is grafted with polymer segments, and the polymer segments comprise methyl methacrylate units.

[0007] According to this application, the antistatic PMMA material can achieve stable and long-lasting antistatic performance without affecting transparency, and is particularly suitable for application scenarios such as electronic displays and optical devices that have high requirements for optical performance and surface resistivity.

[0008] Specifically, the modified silica microcapsules form a silica shell structure through in-situ hydrolysis and polycondensation at the oil-water interface, encapsulating the ionic liquid within. This creates a physically stable encapsulation system, effectively preventing the migration, loss, or thermal volatilization of the ionic liquid during processing and long-term use, thereby significantly improving the durability and reliability of the antistatic performance. Furthermore, the ionic liquid itself has high ion mobility and high polarity. Although isolated in the matrix, the encapsulated state can assist in charge dissipation through the local polarity field of the shell, helping to neutralize accumulated static electricity and ensuring that the material maintains excellent antistatic properties even in dry or high-temperature environments.

[0009] The surface of the microcapsules is grafted with polymer chain segments, which include methyl methacrylate units and are highly matched with the PMMA main chain structure. This can significantly improve the compatibility and interfacial bonding between the microcapsules and the PMMA matrix, thereby ensuring that the antistatic agent is evenly dispersed during the melt mixing and injection molding process, reducing microcapsule agglomeration, precipitation or adverse effects on transparency.

[0010] The PMMA resin, as the main component, imparts excellent transparency to the material. The lubricant helps improve processing fluidity and reduce interfacial friction. The antioxidant inhibits thermal oxidative aging during high-temperature injection molding or long-term service, improving the material's operational stability and optical consistency. This optimized combination of components ensures the material maintains excellent optical properties while achieving more stable and durable antistatic properties.

[0011] In summary, this application constructs a modified microcapsule antistatic agent comprising "ionic liquid core + inorganic shell + polymer grafted chain segment", and combines it with a highly transparent PMMA matrix, lubricant and antioxidant system to achieve stable and long-lasting antistatic performance while ensuring high transparency, and has good industrial application prospects.

[0012] In some embodiments, the polymer segment further comprises methacrylic acid units and methoxy polyethylene glycol methacrylate units.

[0013] In some of the above-mentioned embodiments, the carboxyl structure formed by the methacrylic acid (MAA) unit can construct a charge-enriched region on the surface of the microcapsule, which, on the one hand, assists in the charge dissipation of the ionic liquid in the capsule, and on the other hand, forms a confined structure through electrostatic attraction and hydrogen bonding during the release of the ionic liquid, effectively inhibiting its migration and diffusion into the interior of the matrix, thereby delaying the attenuation of the antistatic performance.

[0014] At the same time, the introduction of methoxy polyethylene glycol methacrylate (MPEGMA) units introduces flexible polyether side chains into the polymer chain, enhancing the compatibility and dispersion uniformity between the modified microcapsules and the PMMA matrix, preventing particle agglomeration and degradation of optical properties. This polyether chain is rich in ether oxygen groups, which possess excellent dipole-ion interaction and can form transient interactions with ionic liquid cations, further enhancing their retention and dissipation at the microcapsule interface, thereby improving overall antistatic efficiency and durability.

[0015] In addition, the block structure constructed by the MAA unit and the MPEGMA unit can also adjust the interfacial wettability and processing fluidity through the flexibility of the chain segments, so that the modified microcapsules have better processing adaptability and optical performance retention in the PMMA system, so that the antistatic PMMA material can better balance optical transparency and antistatic durability.

[0016] In some embodiments, the modified silica microcapsules are prepared by the following steps: S1: mixing an ionic liquid, water, a non-polar organic solvent, and an emulsifier, and subjecting the mixture to shear emulsification to obtain a water-in-oil emulsion; S2: adding ethyl orthosilicate to the water-in-oil emulsion to hydrolyze and polycondense the ethyl orthosilicate at the oil-water interface in the emulsion to obtain silica microcapsules; S3: reacting the silica microcapsules with an aminosilane coupling agent to modify the surfaces of the silica microcapsules by amino modification to obtain amino-modified silica microcapsules; S4: reacting the amino-modified silica microcapsules with 4-cyano-4-(phenylthiocarboxymethylthio)valeric acid (CPADB) to cause amidation reaction between the amino groups on the microcapsule surface and the carboxyl groups on the 4-cyano-4-(phenylthiocarboxymethylthio)valeric acid to obtain chain transfer group-modified silica microcapsules; S5: reacting the chain transfer group-modified silica microcapsules with methyl methacrylate, tert-butyl methacrylate, and methoxy polyethylene glycol methacrylate to polymerize and graft the methyl methacrylate, tert-butyl methacrylate, and methoxy polyethylene glycol methacrylate on the surface of the silica microcapsules to obtain polymer chain segment-grafted silica microcapsules; S6: selectively ester-cleaving the polymer chain segment grafted silica microcapsules under the action of trifluoroacetic acid, so that the tert-butyl methacrylate unit in the polymer chain segment ester-cleaves the methacrylic acid unit and isobutylene to obtain modified silica microcapsules.

[0017] In some of the above embodiments, the method uses an oil-in-water emulsion as a microcapsule template system, utilizes the distribution characteristics of the ionic liquid in the internal aqueous phase, and forms a silica shell layer in situ on the micelle surface through the hydrolysis and condensation process of ethyl orthosilicate at the oil-water interface, thereby avoiding the volatilization or thermal degradation of the ionic liquid that may be caused by conventional spray drying and other methods, and achieving efficient and stable physical encapsulation of the ionic liquid.

[0018] Subsequent amino modification provides reactive sites, enabling in-situ graft polymerization on the microcapsule surface, ensuring the directionality, uniformity, and density control of the polymer segments. The introduction of RAFT-type chain transfer groups makes the polymerization process controllable, avoiding the uneven chain lengths and agglomeration problems associated with traditional free radical polymerization, further enhancing the dispersion and interfacial stability of the microcapsules within the PMMA matrix.

[0019] During the graft polymerization stage, MMA monomers were selected to construct a highly compatible chain structure with PMMA, ensuring good compatibility and optical transparency of the modified microcapsules. Methoxypolyethylene glycol methacrylate monomers were used to introduce polyether side chains. Meanwhile, tert-butyl methacrylate (tBA) monomers were introduced to create controlled sites for the subsequent introduction of carboxyl groups. The tBA units were cleaved by trifluoroacetic acid to form MAA structures. This not only introduced carboxyl functional sites into the polymer chain, but also ensured a mild and highly selective cleavage process, preventing degradation of the main chain structure or damage to the microcapsule shell.

[0020] The modified microcapsules prepared by this process not only have stable structure and clear functions, but also can achieve uniform dispersion and long-lasting antistatic properties in PMMA resin.

[0021] In some embodiments, steps S1 and S2 include: 100 parts of ionic liquid are dissolved in 15-25 parts of water to obtain an aqueous phase, 5-10 parts of Span 80 are dissolved in 150-250 parts of n-hexane to obtain an oil phase, the aqueous phase and the oil phase are mixed and shear emulsified at a rate of 8000-12000 r / min for 8-12 minutes to obtain a water-in-oil emulsion; 10 parts of butyl orthosilicate are dissolved in 15-25 parts of ethanol to obtain a butyl orthosilicate solution, and the butyl orthosilicate solution is added dropwise to the water-in-oil emulsion. The pH of the system is adjusted to 9-10 with aqueous ammonia, and the mixture is stirred and reacted at 30-40° C. for 8-12 hours to obtain silica microcapsules.

[0022] In some of the aforementioned embodiments, by employing a "water-in-oil" emulsion system as a template and initiating the hydrolysis and polycondensation of butyl orthosilicate at the oil-water interface of the emulsion, a dense and uniform silica shell is constructed in situ outside the microdroplets containing the ionic liquid, effectively achieving physical encapsulation and chemical isolation of the ionic liquid. Compared to conventional physical adsorption-based encapsulation methods, this structure offers greater structural stability and thermal sealing, effectively preventing the ionic liquid from evaporating or diffusing during processing or service.

[0023] At the same time, the Span 80 used in this method can improve the interfacial tension stability of the water-in-oil emulsion, resulting in a more uniform particle size and a more complete capsule wall, further enhancing the grafting uniformity and dispersion effect during subsequent polymerization modification. Furthermore, the use of ethanol as a cosolvent and ammonia to control the pH value makes the hydrolysis and polycondensation of silica smoother and more controllable, helping to construct a complete and highly transmittant inorganic shell, balancing coating efficiency with interfacial activity for subsequent grafting polymerization.

[0024] In summary, this implementation method achieves an efficient and stable silica microcapsule construction scheme by rationally controlling the raw material ratio, shear rate and interfacial reaction conditions, providing a basic structural support for subsequent functional modification.

[0025] In some embodiments, step S3 includes: 100 parts of the silica microcapsules are dispersed in 400-600 parts of an ethanol aqueous solution, 5-10 parts of 3-aminopropyltriethoxysilane are added, and the mixture is heated at 50-70° C. for 2-4 hours to obtain amino-containing silica microcapsules.

[0026] In some embodiments, step S4 includes: 100 parts of the amino-modified silica microcapsules, 2 to 4 parts of 4-cyano-4-(phenylthiocarboxymethylthio) valeric acid, 1 to 3 parts of N,N'-dicyclohexylcarboximide (DCC) and 0.5 to 1.5 parts of N-hydroxysuccinimide (NHS) are dispersed in 200 to 400 parts of N,N-dimethylformamide, and the mixture is reacted at 20 to 35°C in a nitrogen atmosphere for 10 to 16 hours to obtain chain transfer group-modified silica microcapsules.

[0027] In some of the aforementioned embodiments, in step S4, CPADB is efficiently grafted onto amino sites on the surface of the silica microcapsules via a DCC / NHS condensation system, forming a stable amide bond structure. This effectively anchors the RAFT chain transfer groups required for controlled living polymerization onto the microcapsule surface. This modification strategy prevents the chain transfer groups from migrating or becoming free during subsequent polymerization, which can lead to decreased grafting efficiency and facilitates graft polymerization on the microcapsule surface.

[0028] Furthermore, the DCC / NHS-promoted amidation reaction is mild and highly selective, avoiding damage to the ionic liquid and microcapsule structures caused by high temperatures or strong bases, thereby ensuring the stability and functional integrity of the system. Chain transfer group-modified silica microcapsules enable precise control of the grafting degree and monomer composition during the subsequent polymerization reaction, a key step in constructing structurally uniform and densely grafted polymer segments.

[0029] Therefore, the introduction of RAFT chain transfer groups through the amidation reaction not only ensures the reactivity and grafting uniformity of the modified microcapsules in the subsequent polymerization reaction, but also helps to improve the antistatic performance stability and composite dispersion uniformity of the final antistatic PMMA material.

[0030] In some embodiments, step S5 includes: The chain transfer group-modified silica microcapsules are first reacted with tert-butyl methacrylate to polymerize and graft the tert-butyl methacrylate on the surface of the microcapsules; methoxy polyethylene glycol methacrylate is then added to the system to continue graft polymerization of the methoxy polyethylene glycol methacrylate on the polymer chain segments; and methyl methacrylate is then added to the system to react to continue graft polymerization of the methyl methacrylate on the polymer chain segments, thereby obtaining polymer chain segment-grafted silica microcapsules.

[0031] In some of the above-mentioned embodiments, the polymer chain segments exhibit a spatial configuration design of "internal polarity and external compatibility." Poly(tert-butyl methacrylate) chain segments are grafted internally, and subsequently esterified to form poly(methacrylic acid) chain segments. The PMAA segment has a certain density of carboxyl structures, which can form a weakly confined network through electrostatic interaction and hydrogen bonding, thereby forming a directional adsorption and migration retardation effect on the slowly released ionic liquid in the microcapsule, inhibiting its excessive diffusion into the PMMA matrix, thereby delaying the attenuation of antistatic properties. Flexible polyether side chains are introduced into the middle segment, which have good segment flexibility and polar-dipole synergy, which can not only enhance the wetting and dispersibility of the microcapsules and the matrix, but also help to stabilize the residence state of the ionic liquid at the interface by working together with the PMAA segment. The external PMMA segment structure is the same as the PMMA matrix, with excellent compatibility and refractive index matching, which can significantly improve the dispersibility and interfacial stability of the modified microcapsules without affecting the transparency and mechanical properties of the material.

[0032] Through the sequential construction of the above-mentioned block structure, not only is the hierarchical division of labor and synergistic effect of functional sites (carboxyl, polyether) and structural compatibility (PMMA) achieved, but the modified microcapsules also achieve an effective balance between antistatic and optical properties, giving the final PMMA material long-lasting, stable and uniformly dispersed antistatic properties.

[0033] In some embodiments, step S5 includes: 100 parts of the chain transfer group modified silica microcapsules, 10-20 parts of tert-butyl methacrylate and 0.1-1 parts of azobisisobutyronitrile are dispersed in 400-600 parts of toluene, and the mixture is reacted at 50-70°C under a nitrogen atmosphere for 4-8 hours; after the reaction, 5-10 parts of methoxy polyethylene glycol methacrylate with a number average molecular weight of 300-800 and 0.1-1 parts of azobisisobutyronitrile are added to the system, and the reaction is continued at 50-70°C under a nitrogen atmosphere for 3-5 hours; after the reaction, 25-35 parts of methyl methacrylate and 0.1-1 parts of azobisisobutyronitrile are added to the system, and the reaction is continued at 50-70°C under a nitrogen atmosphere for 6-10 hours to obtain polymer chain segment grafted silica microcapsules.

[0034] In some of the aforementioned embodiments, tBA is chosen rather than directly using methacrylic acid with free carboxyl groups. This is primarily because tBA generates well-structured, sterically hindered hydrophobic ester segments during polymerization. Furthermore, the polarity of tBA and MMA is highly compatible, resulting in enhanced polymerization stability and more predictable reaction control. Furthermore, the tBA ester groups can be selectively cleaved into free carboxyl groups under mild conditions, avoiding the potential side reactions (such as reactions with unreacted amino groups on the microcapsule surface) and disrupted segment arrangement that can occur with direct introduction of highly polar carboxylic acid groups in the initial polymerization phase. This improves the structural integrity and controllability of the microcapsule graft layer. This "protection first, conversion second" approach achieves spatial localization and subsequent release of the carboxyl groups.

[0035] Secondly, the monomer arrangement of the three-step reaction has the purpose of spatial functional gradient design. The poly(tert-butyl methacrylate) chain segment (PtBA) preferentially grafted in the first step can be converted into a carboxyl-containing PMAA chain segment located near the surface of the microcapsule in the subsequent ester cleavage step. Its carboxyl structure is distributed in the area close to the microcapsule, which is conducive to forming a reversible confinement domain with the ionic liquid through electrostatic adsorption and hydrogen bonding when the ionic liquid is slowly released. While cooperating with the ionic liquid to improve the antistatic effect through local charge dissipation, it can also limit the further migration and diffusion of the ionic liquid to the outside, thereby effectively extending the service life of the antistatic agent and slowing down the problem of antistatic performance degradation over time. In the second step reaction, MPEGMA monomers are introduced to construct flexible polyether side chains. The molecular weight is controlled between 300 and 800, taking into account the flexibility of the chain segment and the wettability of the interface. It can form a dipole-ion synergistic stable structure with the ionic liquid, which can cooperate with the PMAA chain segment introduced in the first step to further improve the antistatic effect and antistatic stability. The PMMA segments grafted in the third step are located on the outside of the polymer segments. The PMMA structure obtained by polymerization is highly matched with the PMMA matrix material in terms of chemical composition and refractive index, which can significantly improve the interface compatibility and dispersion stability of the microcapsules in the PMMA system, avoid particle agglomeration and interface reflection, and ensure that the overall optical properties of the material are not affected.

[0036] In summary, this three-step grafting polymerization strategy constructs a polymer chain segment configuration of "inner layer restricted migration and outer layer compatibility" at the molecular level, and uses the spatial distribution gradient to give the antistatic agent microcapsules better ionic liquid release regulation ability and matrix compatibility, thereby making the antistatic PMMA material have better antistatic properties and transparency.

[0037] In some embodiments, step S6 includes: 100 parts of the polymer chain segment grafted silica microcapsules and 150-200 parts of trifluoroacetic acid are dispersed in 800-1200 parts of dichloromethane, and the mixture is reacted at 20-30° C. for 8-12 hours to obtain modified silica microcapsules.

[0038] In some of the aforementioned embodiments, trifluoroacetic acid (TFA) serves as a strongly acidic deprotection agent, effectively cleaving the tBA units in the polymer segments under mild conditions. This reaction primarily proceeds via an acid-catalyzed ester cleavage mechanism: the tert-butyl ester group undergoes dealkylation under the action of TFA, generating methacrylic acid units and releasing isobutylene gas.

[0039] This ester cleavage process is highly selective, acting only on the tBA structure without significantly affecting the polymer backbone or other ester structures, thus avoiding the risk of segment degradation or microcapsule structural damage. Dichloromethane, as an excellent solvent, facilitates full contact, swelling, and dispersion of the components in the reaction system, while maintaining the stability of TFA activity at room temperature, ensuring the cleavage reaction proceeds uniformly at an optimal rate.

[0040] By cleaving the tBA unit ester, a controlled density of carboxyl functional groups is introduced into the polymer chain, creating a stable polar anchoring region. This provides a molecularly confined environment for the ionic liquid and further enhances its retention at the interface. The resulting carboxyl structure possesses strong electrostatic attraction and hydrogen bond donor capabilities, which can non-covalently interact with the slowly released ionic liquid molecules within the capsule, forming a weakly bound state. This synergistic effect with the polyether side chains enhances the stable retention of the ionic liquid in the material and improves the durability of the antistatic properties.

[0041] Therefore, this step achieves the controllable transformation of the functional structure of the microcapsule surface, which can further improve the antistatic properties of the antistatic PMMA material.

[0042] In some embodiments, the PMMA resin has a melt index of 1-5 g / 10 min at 230°C / 3.8 kg. Based on the above embodiments, this melt index range ensures good fluidity and processing stability during melt extrusion granulation and injection molding, facilitating uniform dispersion of the modified microcapsules in the matrix, avoiding uneven dispersion due to excessively high matrix viscosity or structural collapse due to excessively low viscosity, thereby achieving synergistic control of antistatic properties and transparency.

[0043] In some embodiments, the ionic liquid includes at least one of an imidazole ionic liquid and an ammonium salt ionic liquid. Based on the above embodiments, imidazole ionic liquids have excellent charge transfer capabilities and thermal stability, while ammonium salt ionic liquids have higher polarity and moderate viscosity. Both contribute to the formation of ion migration-driven charge dissipation pathways at the microcapsule interface, thereby reducing the rate of static electricity accumulation on the PMMA material surface and enhancing its antistatic effect. For example, in one embodiment of the present application, tributylmethylammonium bis(trifluoromethanesulfonyl)imide is used as the ionic liquid.

[0044] In some embodiments, the lubricant includes at least one of stearic acid, calcium stearate, and dimethyl silicone oil. Based on the above embodiments, this type of lubricant can form a microscale lubricating interface in the PMMA system, reducing friction between the material and the equipment during processing, improving extrusion and injection molding efficiency, and assisting in the formation of low surface energy regions after molding, helping to inhibit the aggregation and migration of microcapsules and enhance the overall material structural stability.

[0045] In some embodiments, the antioxidant includes at least one of antioxidant 1010, antioxidant 1076, and antioxidant 2246. Based on the above embodiments, the antioxidant can effectively inhibit the decomposition, discoloration, or mechanical property degradation of the PMMA matrix due to thermal oxidative aging during high-temperature processing or long-term use. It also helps stabilize the structural integrity of the ionic liquid at high temperatures, preventing its premature degradation or precipitation, thereby ensuring the long-term maintenance of the material's antistatic properties.

[0046] In a second aspect, the present application provides a method for preparing an antistatic PMMA material, comprising: Providing raw materials included in the antistatic PMMA material according to any embodiment of the first aspect; The raw materials are melt-extruded, granulated, and injection-molded to obtain an antistatic PMMA material.

[0047] According to the present application, the preparation method can uniformly disperse modified silica microcapsules with a polymer segment grafted structure in PMMA resin, ensuring their structural stability and uniform dispersion during processing. This method has a simple process flow and the processing temperature is controlled within the traditional PMMA processing window, making it suitable for industrial-scale preparation. The MMA units in the grafted polymer segments have good structural compatibility with the PMMA backbone, helping to maintain the structural integrity of the microcapsules during extrusion and injection molding, preventing leakage or migration of ionic liquids. At the same time, the methacrylic acid units in the polymer segments can further regulate the sustained release rate of the ionic liquid at the microscopic interface, enhancing the long-term stability of the antistatic properties.

[0048] Therefore, this method is not only suitable for the stable processing of the composite structure antistatic agent proposed in this application, but also has good scalability and industrial application value.

[0049] In some embodiments, the method comprises: After mixing all the raw materials evenly, feed them into a twin-screw extruder. The temperature of each zone is controlled at 170-190°C, 190-210°C, 200-220°C, 210-230°C, and 220-240°C, respectively. The screw speed is controlled at 80-120 rpm to fully melt and mix the raw materials. After obtaining a uniform melt, the mixture is extruded through a die, water-cooled, and pelletized to obtain antistatic PMMA masterbatch. The masterbatch is molded in an injection molding machine, the injection temperature is controlled at 220-240° C., the mold temperature is 60-80° C., the holding pressure is 50-70 MPa, and the holding time is 6-12 seconds to obtain an antistatic PMMA material.

[0050] It should be noted that, without affecting the material properties, the process parameters can be appropriately adjusted according to the equipment and product size.

[0051] Compared with the prior art, the present invention has the following advantages: The antistatic PMMA material provided by the present application achieves good antistatic performance while maintaining the original optical transparency and processing performance of the PMMA material by constructing a modified silica microcapsule antistatic agent containing an ionic liquid. Among them, the polymer chain segment containing methyl methacrylate units is grafted onto the surface of the microcapsule, which can effectively enhance the compatibility between the microcapsule and the PMMA matrix and prevent interfacial precipitation and aggregation; the carboxyl structure exposed after ester cleavage, in conjunction with the polyether side chain, helps to further limit the migration of the ionic liquid and improve the long-term stability of the antistatic performance. The overall design combines structural stability, dispersibility and conductive path control, solving the problems of easy migration, easy failure and transparency of the antistatic agent in the existing antistatic PMMA material. The resulting antistatic PMMA material has better antistatic performance and transparency. DETAILED DESCRIPTION

[0052] The various embodiments or implementation schemes in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments.

[0053] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with an embodiment or example is included in at least one embodiment or example of the present application. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0054] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0055] In the description of this specification, unless otherwise specified, "parts" refer to "parts by mass".

[0056] Below, the embodiment of the present application is described. The embodiment described below is exemplary and is only used to explain the present application, and is not to be construed as limiting the present application. Where specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. Reagents or instruments used that do not specify the manufacturer are conventional products that can be obtained commercially.

[0057] PMMA resin, melt index at 230°C / 3.8kg is 3g / 10min; Tributylmethylammonium bis(trifluoromethanesulfonyl)imide, CAS number 405514-94-5; 4-Cyano-4-(phenylthiocarbothioylthio)pentanoic acid, CAS number is 201611-92-9.

[0058] Preparation Example 1 Preparation of modified silica microcapsules: S1: Dissolve 100 parts of tributylmethylammonium bis(trifluoromethanesulfonyl)imide in 20 parts of deionized water to obtain an aqueous phase; add 8 parts of Span 80 to 200 parts of n-hexane and stir to dissolve to obtain an oil phase; slowly add the aqueous phase to the oil phase, and shear emulsify in a high-speed shear emulsifier at 10,000 rpm for 10 minutes to obtain a stable water-in-oil emulsion.

[0059] S2: Dissolve 10 parts of tetraethyl orthosilicate in 20 parts of anhydrous ethanol to prepare a tetraethyl orthosilicate solution; add the solution dropwise to the above-mentioned water-in-oil emulsion at a rate of 1 mL / min while stirring at 500 r / min, and then add ammonia water to adjust the pH of the system to about 9.5; continue stirring at 500 r / min at 35°C for 10 hours to allow the tetraethyl orthosilicate to hydrolyze and condense at the oil-water interface to form SiO2 microcapsules coated with ionic liquid. After the reaction is completed, separate by centrifugation, wash three times with n-hexane, and dry to obtain SiO2 microcapsules.

[0060] S3: Take 100 parts of SiO2 microcapsules and disperse them in 500 parts of 80% ethanol aqueous solution by volume, add 7 parts of 3-aminopropyltriethoxysilane, and heat under reflux at 70°C for 3 hours to complete the amino modification of the microcapsule surface. The product is centrifuged, washed with ethanol twice, and dried to obtain amino silica microcapsules.

[0061] S4: Take 100 parts of amino microcapsules, 3 parts of 4-cyano-4-(phenylthiocarboxymethylthio) pentanoic acid, 2 parts of N,N'-dicyclohexylcarboximide, and 1 part of N-hydroxysuccinimide and disperse them in 300 parts of anhydrous DMF. React at 25°C under nitrogen atmosphere for 12 hours, centrifuge, wash, and dry to obtain chain transfer group-modified silica microcapsules.

[0062] S5: Take 100 parts of chain transfer group modified silica microcapsules and disperse them in 500 parts of anhydrous toluene, add 15 parts of tert-butyl methacrylate and 0.5 parts of azobisisobutyronitrile, and react at 60°C under a nitrogen atmosphere for 6 hours; then add 8 parts of methoxy polyethylene glycol methacrylate with a number average molecular weight of 600 and 0.3 parts of azobisisobutyronitrile, and continue to react at 60°C under a nitrogen atmosphere for 4 hours; then add 30 parts of methyl methacrylate and 0.5 parts of azobisisobutyronitrile, and continue to react at 60°C under a nitrogen atmosphere for 8 hours. Centrifuge, wash, and dry to obtain polymer chain segment grafted silica microcapsules.

[0063] S6: 100 parts of polymer chain segment grafted silica microgels were dispersed in 1000 parts of dichloromethane, 180 parts of trifluoroacetic acid were added, and the mixture was reacted at 25°C for 10 hours. The final modified silica microcapsules A were obtained after centrifugation, washing, and drying.

[0064] Preparation Example 2 Preparation of modified silica microcapsules: The process is substantially the same as that of Preparation Example 1, except that step S5 and step S6 are different, specifically: S5: Take 100 parts of chain transfer group modified silica microcapsules and disperse them in 500 parts of anhydrous toluene, add 15 parts of tert-butyl methacrylate, 8 parts of methoxy polyethylene glycol methacrylate with a number average molecular weight of 600, 30 parts of methyl methacrylate, and 1.3 parts of azobisisobutyronitrile, react at 60°C under a nitrogen atmosphere for 12 hours, centrifuge, wash, and dry to obtain polymer chain segment grafted silica microcapsules.

[0065] S6: 100 parts of polymer chain segment grafted silica microgels were dispersed in 1000 parts of dichloromethane, 180 parts of trifluoroacetic acid were added, and the mixture was reacted at 25°C for 10 hours. The final modified silica microcapsules B were obtained after centrifugation, washing, and drying.

[0066] Preparation Example 3 Preparation of modified silica microcapsules: The process is substantially the same as that of Preparation Example 1, except that step S5 and step S6 are different, specifically: S5: Take 100 parts of chain transfer group modified silica microcapsules and disperse them in 500 parts of anhydrous toluene, add 30 parts of methyl methacrylate and 0.5 parts of azobisisobutyronitrile, and react at 60°C for 8 hours under a nitrogen atmosphere; then add 8 parts of methoxy polyethylene glycol methacrylate with a number average molecular weight of 600 and 0.3 parts of azobisisobutyronitrile, and continue to react at 60°C for 4 hours under a nitrogen atmosphere; then add 15 parts of tert-butyl methacrylate and 0.5 parts of azobisisobutyronitrile, and continue to react at 60°C for 6 hours under a nitrogen atmosphere. Centrifuge, wash, and dry to obtain polymer chain segment grafted silica microcapsules.

[0067] S6: 100 parts of polymer chain segment grafted silica microgels were dispersed in 1000 parts of dichloromethane, 180 parts of trifluoroacetic acid were added, and the mixture was reacted at 25°C for 10 hours. The final modified silica microcapsules C were obtained after centrifugation, washing, and drying.

[0068] Preparation Example 4 Preparation of modified silica microcapsules: The process is substantially the same as that of Preparation Example 1, except that step S5 and step S6 are different, specifically: S5: Take 100 parts of chain transfer group modified silica microcapsules and disperse them in 500 parts of anhydrous toluene, add 8 parts of methoxy polyethylene glycol methacrylate with a number average molecular weight of 600 and 0.3 parts of azobisisobutyronitrile, and continue to react at 60°C under a nitrogen atmosphere for 4 hours; then add 15 parts of tert-butyl methacrylate and 0.5 parts of azobisisobutyronitrile, and continue to react at 60°C under a nitrogen atmosphere for 6 hours; then add 30 parts of methyl methacrylate and 0.5 parts of azobisisobutyronitrile, and react at 60°C under a nitrogen atmosphere for 8 hours. Centrifuge, wash, and dry to obtain polymer chain segment grafted silica microcapsules.

[0069] S6: 100 parts of polymer chain segment grafted silica microgels were dispersed in 1000 parts of dichloromethane, 180 parts of trifluoroacetic acid were added, and the mixture was reacted at 25°C for 10 hours. The final modified silica microcapsules D were obtained after centrifugation, washing, and drying.

[0070] Preparation Example 5 Preparation of modified silica microcapsules: The method is substantially the same as Preparation Example 1, except that step S5 is different and step S6 is not included. Specifically, the method is as follows: S5: Take 100 parts of chain transfer group modified silica microcapsules and disperse them in 500 parts of anhydrous toluene, add 15 parts of methacrylic acid and 0.5 parts of azobisisobutyronitrile, and react at 60°C under a nitrogen atmosphere for 6 hours; then add 8 parts of methoxy polyethylene glycol methacrylate with a number average molecular weight of 600 and 0.3 parts of azobisisobutyronitrile, and continue to react at 60°C under a nitrogen atmosphere for 4 hours; then add 30 parts of methyl methacrylate and 0.5 parts of azobisisobutyronitrile, and continue to react at 60°C under a nitrogen atmosphere for 8 hours. Centrifuge, wash, and dry to obtain polymer chain segment grafted silica microcapsules as modified silica microcapsules E.

[0071] Preparation Example 6 Preparation of modified silica microcapsules: The method is substantially the same as Preparation Example 1, except that step S5 is different and step S6 is not included. Specifically, the method is as follows: S5: 100 parts of chain transfer group-modified silica microcapsules were dispersed in 500 parts of anhydrous toluene, 53 parts of methyl methacrylate and 1.3 parts of azobisisobutyronitrile were added, and the mixture was reacted at 60°C under a nitrogen atmosphere for 12 hours. The mixture was centrifuged, washed, and dried to obtain polymer chain segment-grafted silica microcapsules as modified silica microcapsules F.

[0072] Preparation Example 7 Preparation of modified silica microcapsules: The process is substantially the same as that of Preparation Example 1, except that step S5 and step S6 are different, specifically: S5: Take 100 parts of chain transfer group modified silica microcapsules and disperse them in 500 parts of anhydrous toluene, add 23 parts of tert-butyl methacrylate and 0.8 parts of azobisisobutyronitrile, and react at 60°C under a nitrogen atmosphere for 10 hours; then add 30 parts of methyl methacrylate and 0.5 parts of azobisisobutyronitrile, continue to react at 60°C under a nitrogen atmosphere for 8 hours, centrifuge, wash and dry to obtain polymer chain segment grafted silica microcapsules.

[0073] S6: 100 parts of polymer chain segment grafted silica microgels were dispersed in 1000 parts of dichloromethane, 180 parts of trifluoroacetic acid were added, and the mixture was reacted at 25°C for 10 hours. The final modified silica microcapsules G were obtained after centrifugal separation, washing, and drying.

[0074] Preparation Example 8 Preparation of modified silica microcapsules: The method is substantially the same as Preparation Example 1, except that step S5 is different and step S6 is not included. Specifically, the method is as follows: S5: Take 100 parts of chain transfer group modified silica microcapsules and disperse them in 500 parts of anhydrous toluene, add 23 parts of methoxy polyethylene glycol methacrylate with a number average molecular weight of 600 and 0.8 parts of azobisisobutyronitrile, and react at 60°C under a nitrogen atmosphere for 10 hours; then add 30 parts of methyl methacrylate and 0.5 parts of azobisisobutyronitrile, and continue to react at 60°C under a nitrogen atmosphere for 8 hours. Centrifuge, wash, and dry to obtain polymer chain segment grafted silica microcapsules as modified silica microcapsules H.

[0075] Comparative Preparation Example 1 Preparation of modified silica microcapsules: The method is substantially the same as Preparation Example 1, except that steps S3 to S6 are not included, and the SiO2 microcapsules obtained in step S2 are used as modified silica microcapsules I.

[0076] Comparative Preparation Example 2 Preparation of modified silica microcapsules: The process is substantially the same as that of Preparation Example 1, except that step S5 and step S6 are different, specifically: S5: Take 100 parts of chain transfer group modified silica microcapsules and disperse them in 500 parts of anhydrous toluene, add 45 parts of tert-butyl methacrylate and 1 part of azobisisobutyronitrile, react at 60°C under nitrogen atmosphere for 12 hours, then add 8 parts of methoxy polyethylene glycol methacrylate with a number average molecular weight of 600 and 0.3 parts of azobisisobutyronitrile, continue to react at 60°C under nitrogen atmosphere for 4 hours, centrifuge, wash and dry to obtain polymer chain segment grafted silica microcapsules.

[0077] S6: 100 parts of polymer chain segment grafted silica microgels were dispersed in 1000 parts of dichloromethane, 180 parts of trifluoroacetic acid were added, and the mixture was reacted at 25°C for 10 hours. The final modified silica microcapsules J were obtained after centrifugation, washing, and drying.

[0078] Example 1 Preparation of antistatic PMMA material: Weigh 100 parts of PMMA resin, 10 parts of modified silica microcapsules A, 2 parts of stearic acid, and 0.5 parts of antioxidant 1010, and premix them in a high-speed mixer. The mixture was fed into a twin-screw extruder with the following temperature zones set: first zone 180°C, second zone 200°C, third zone 210°C, fourth zone 220°C, fifth zone 230°C, and screw speed 100 rpm; melt extrusion, water-cooling, stranding, and pelletizing were performed to obtain antistatic PMMA masterbatch; The masterbatch was fed into an injection molding machine for molding, with an injection temperature of 230° C., a mold temperature of 70° C., a holding pressure of 60 MPa, and a holding time of 8 s to obtain an antistatic PMMA material.

[0079] Example 2 Preparation of antistatic PMMA material: The process is substantially the same as Example 1, except that modified silica microcapsules B are used instead of modified silica microcapsules A.

[0080] Example 3 Preparation of antistatic PMMA material: The process is substantially the same as Example 1, except that modified silica microcapsules C are used instead of modified silica microcapsules A.

[0081] Example 4 Preparation of antistatic PMMA material: The process is substantially the same as Example 1, except that modified silica microcapsules D are used instead of modified silica microcapsules A.

[0082] Example 5 Preparation of antistatic PMMA material: The process is substantially the same as Example 1, except that modified silica microcapsules E are used instead of modified silica microcapsules A.

[0083] Example 6 Preparation of antistatic PMMA material: The process is substantially the same as Example 1, except that modified silica microcapsules F are used instead of modified silica microcapsules A.

[0084] Example 7 Preparation of antistatic PMMA material: The process is substantially the same as Example 1, except that modified silica microcapsules G are used instead of modified silica microcapsules A.

[0085] Example 8 Preparation of antistatic PMMA material: The process is substantially the same as Example 1, except that modified silica microcapsules H are used instead of modified silica microcapsules A.

[0086] Comparative Example 1 Preparation of antistatic PMMA material: The process is substantially the same as Example 1, except that modified silica microcapsules I are used instead of modified silica microcapsules A.

[0087] Comparative Example 2 Preparation of antistatic PMMA material: The process is substantially the same as Example 1, except that modified silica microcapsules J are used instead of modified silica microcapsules A.

[0088] Test section The surface resistivity ρ1 (Ω) of the antistatic PMMA materials obtained in each embodiment and comparative example was tested in accordance with GB / T 1410-2006 "Test Method for Volume Resistivity and Surface Resistivity of Solid Insulating Materials" at a test temperature of 23±2°C and a relative humidity of 50%±10%. The antistatic PMMA materials were placed in a constant temperature box at 30±2°C and a relative humidity of 70%±10% for 30 days, and then the surface resistivity ρ2 (Ω) was tested at a temperature of 23±2°C and a relative humidity of 50%±10%. The results are shown in Table 1.

[0089] The light transmittance T (%) of the antistatic PMMA materials obtained in each embodiment and comparative example was tested according to GB / T 2410-2008 "Determination of light transmittance and haze of transparent plastics". The test temperature was 23±2°C and the relative humidity was 50%±10%. The results are shown in Table 1.

[0090] Table 1

[0091] According to Table 1, each example has lower surface resistivity ρ1 and ρ2 than Comparative Examples 1 and 2, while maintaining a high light transmittance T. This indicates that the antistatic PMMA material provided by this application not only achieves long-term stable antistatic performance but also has good optical transparency, making it suitable for applications that are sensitive to static electricity and have high requirements for appearance. This may be due to the fact that in Comparative Example 1, the surface of the microcapsules was not amino-treated and the polymer chain segments were not grafted. This lacks a synergistic interface between the modified silica particles and the PMMA matrix, resulting in the ionic liquid being easily migrated and lost during processing and use. A stable and effective charge dissipation region cannot be formed at the interface, resulting in an extremely high surface resistivity. Furthermore, due to the significant difference in refractive index between the particles and the matrix, the light transmittance is significantly reduced. In Comparative Example 2, although the tert-butyl methacrylate structure in the grafted polymer was subjected to esterification treatment, a certain amount of carboxyl structure was introduced, and polyether side chains were also introduced, which has the potential to construct a weakly polar dissipative region, but no PMMA segment was further introduced. Therefore, the chemical structure of the polymer segment and the PMMA matrix did not match, and the interface compatibility was insufficient, resulting in poor dispersion of the microcapsules in PMMA and weak interface effect, making it difficult to construct a continuous and stable dissipative structure and affecting the light transmittance of the material, so that the antistatic performance and optical performance are significantly lower than those of the embodiments of the present application.

[0092] Examples 1-4 demonstrate that the use of polymer segments with varying grafting sequences and structures significantly influences microcapsule modification. Specifically, grafting hydrophobic tert-butyl ester first and introducing polyether side chains followed by grafting polar methyl methacrylate (Example 1) maintains transparency while creating a polarity gradient. This facilitates the sustained release of ionic liquids at the material interface, forming a stable dissipation zone and achieving a good balance between antistatic performance and light transmittance. In contrast, adjusting the monomer sequence or performing simultaneous polymerization in Examples 2-4 results in a more mixed or offset distribution of polar structures within the segments, resulting in weaker polarity concentration and interfacial synergy. While still exhibiting some antistatic effect, the performance is slightly inferior to that of Example 1, demonstrating that segment structure design significantly influences the construction of the dissipation mechanism.

[0093] According to Examples 1 and 5, the introduction of methacrylic acid units has a significant impact on the performance of antistatic PMMA materials. tBA is used as a grafting monomer. tBA is a hydrophobic monomer with good solubility and reactivity in the toluene system, facilitating uniform grafting. The steric hindrance effect of the ester group facilitates the gradual growth of polymer segments with moderate lengths, controlling the chain length distribution. The carboxyl structure after esterification is distributed near the surface of the microcapsule, which is beneficial for limiting the migration of ionic liquids and improving the durability of the antistatic performance. In contrast, in Example 5, MAA is directly used as a monomer for surface grafting polymerization in toluene. Due to its strong polarity and low solubility in toluene, MAA is prone to local phase separation during the polymerization process, resulting in low grafting efficiency. Polar monomers are prone to self-polymerization or chain termination reactions when polymerized in a non-polar environment, resulting in short and uneven segments. The carboxyl group is directly exposed to the reaction system and may react with other functional groups, which is not conducive to the formation of a regular and controllable PMAA segment structure. Therefore, Example 1 has better antistatic effect and transparency than Example 5.

[0094] According to the comparison between Example 1 and Examples 6 to 8, when the grafted chain segment is composed only of methyl methacrylate (Example 6), the transmittance of the material is the highest, but the surface resistivity changes greatly (ρ2 increases significantly), indicating that the chain segment is too single, which may lead to the construction of the dissipative region being not stable enough and the antistatic performance being not durable enough, which is not conducive to long-term use requirements; further introduction of methacrylic acid units (Example 7) or methoxy polyethylene glycol methacrylate units (Example 8) improves the antistatic effect to a certain extent; when introduced at the same time, the antistatic effect is the best.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An antistatic PMMA material, characterized in that: Including the following raw materials by weight: 100 parts of PMMA resin; 5-15 parts of antistatic agent; 1-5 parts of lubricant; 0.1-1 parts of antioxidant; The antistatic agent comprises modified silica microcapsules, which comprise ionic liquids. Surfaces of the modified silica microcapsules are grafted with polymer segments, which comprise methyl methacrylate units.

2. The antistatic PMMA material according to claim 1, characterized in that: The polymer segment further comprises methacrylic acid units and methoxy polyethylene glycol methacrylate units.

3. The antistatic PMMA material according to claim 2, characterized in that: The modified silica microcapsules are prepared by the following steps: S1: mixing an ionic liquid, water, a non-polar organic solvent, and an emulsifier, and subjecting the mixture to shear emulsification to obtain a water-in-oil emulsion; S2: adding ethyl orthosilicate to the water-in-oil emulsion to hydrolyze and polycondense the ethyl orthosilicate at the oil-water interface in the emulsion to obtain silica microcapsules; S3: reacting the silica microcapsules with an aminosilane coupling agent to modify the surfaces of the silica microcapsules by amino modification to obtain amino-modified silica microcapsules; S4: reacting the amino-modified silica microcapsules with 4-cyano-4-(phenylthioformylthio)pentanoic acid to cause amidation reaction between the amino groups on the microcapsules' surfaces and the carboxyl groups on the 4-cyano-4-(phenylthioformylthio)pentanoic acid to obtain chain transfer group-modified silica microcapsules; S5: reacting the chain transfer group-modified silica microcapsules with methyl methacrylate, tert-butyl methacrylate, and methoxy polyethylene glycol methacrylate to polymerize and graft the methyl methacrylate, tert-butyl methacrylate, and methoxy polyethylene glycol methacrylate on the surface of the silica microcapsules to obtain polymer chain segment-grafted silica microcapsules; S6: selectively ester-cleaving the polymer chain segment grafted silica microcapsules under the action of trifluoroacetic acid, so that the tert-butyl methacrylate unit in the polymer chain segment ester-cleaves the methacrylic acid unit and isobutylene to obtain modified silica microcapsules.

4. The antistatic PMMA material according to claim 3, characterized in that Steps S1 and S2 include: 100 parts of ionic liquid are dissolved in 15-25 parts of water to obtain an aqueous phase, 5-10 parts of Span 80 are dissolved in 150-250 parts of n-hexane to obtain an oil phase, the aqueous phase and the oil phase are mixed and shear emulsified at a rate of 8000-12000 r / min for 8-12 minutes to obtain a water-in-oil emulsion; 10 parts of butyl orthosilicate are dissolved in 15-25 parts of ethanol to obtain a butyl orthosilicate solution, and the butyl orthosilicate solution is added dropwise to the water-in-oil emulsion. The pH of the system is adjusted to 9-10 with aqueous ammonia, and the mixture is stirred and reacted at 30-40° C. for 8-12 hours to obtain silica microcapsules.

5. The antistatic PMMA material according to claim 3, characterized in that: The step S4 comprises: 100 parts of the amino-modified silica microcapsules, 2 to 4 parts of 4-cyano-4-(phenylthiocarboxymethylthio) valeric acid, 1 to 3 parts of N,N'-dicyclohexylcarboximide and 0.5 to 1.5 parts of N-hydroxysuccinimide are dispersed in 200 to 400 parts of N,N-dimethylformamide, and the mixture is reacted under a nitrogen atmosphere at 20 to 35°C for 10 to 16 hours to obtain chain transfer group-modified silica microcapsules.

6. The antistatic PMMA material according to claim 3, characterized in that: The step S5 comprises: The chain transfer group-modified silica microcapsules are first reacted with tert-butyl methacrylate to polymerize and graft the tert-butyl methacrylate on the surface of the microcapsules; methoxy polyethylene glycol methacrylate is then added to the system to continue graft polymerization of the methoxy polyethylene glycol methacrylate on the polymer chain segments; and methyl methacrylate is then added to the system to react to continue graft polymerization of the methyl methacrylate on the polymer chain segments, thereby obtaining polymer chain segment-grafted silica microcapsules.

7. The antistatic PMMA material according to claim 6, characterized in that: The step S5 comprises: 100 parts of the chain transfer group modified silica microcapsules, 10-20 parts of tert-butyl methacrylate and 0.1-1 parts of azobisisobutyronitrile are dispersed in 400-600 parts of toluene, and the mixture is reacted at 50-70°C under a nitrogen atmosphere for 4-8 hours; after the reaction, 5-10 parts of methoxy polyethylene glycol methacrylate with a number average molecular weight of 300-800 and 0.1-1 parts of azobisisobutyronitrile are added to the system, and the reaction is continued at 50-70°C under a nitrogen atmosphere for 3-5 hours; after the reaction, 25-35 parts of methyl methacrylate and 0.1-1 parts of azobisisobutyronitrile are added to the system, and the reaction is continued at 50-70°C under a nitrogen atmosphere for 6-10 hours to obtain polymer chain segment grafted silica microcapsules.

8. The antistatic PMMA material according to claim 3, characterized in that: The step S6 comprises: 100 parts of the polymer chain segment grafted silica microcapsules and 150-200 parts of trifluoroacetic acid are dispersed in 800-1200 parts of dichloromethane, and the mixture is reacted at 20-30° C. for 8-12 hours to obtain modified silica microcapsules.

9. The antistatic PMMA material according to any one of claims 1 to 8, characterized in that: The antistatic PMMA material satisfies at least one of the following conditions: 1) The PMMA resin has a melt index of 1-5 g / 10 min at 230° C. / 3.8 kg; 2) The ionic liquid includes at least one of an imidazole ionic liquid and an ammonium salt ionic liquid; 3) The lubricant includes at least one of stearic acid, calcium stearate, and dimethyl silicone oil; 4) The antioxidant includes at least one of antioxidant 1010, antioxidant 1076, and antioxidant 2246.

10. A method for preparing an antistatic PMMA material, characterized in that: include: Providing raw materials comprising the antistatic PMMA material according to any one of claims 1 to 9; The raw materials are melt-extruded, granulated, and injection-molded to obtain an antistatic PMMA material.

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