Silicon-based substituted polystyrene microspheres as well as preparation method and application thereof

Abstract

The invention relates to the technical field of electronic gas purification, in particular to a silicon-based substituted polystyrene microsphere and a preparation method and application thereof, and the silicon-based substituted polystyrene microsphere comprises a crosslinked polystyrene skeleton; the cross-linked polystyrene skeleton is chemically grafted with a silicon group, and the silicon group is connected with a Si-Cl bond or a Si-Br bond. The silicon-based substituted polystyrene microspheres prepared by adopting an in-situ synthesis method are micron-sized highly-crosslinked solids, are stable in structure and are resistant to acid and alkali, and high-content Si-Cl bonds or Si-Br bonds are introduced into the silicon-based substituted polystyrene microspheres, so that the silicon-based substituted polystyrene microspheres react with water, an excellent water removal effect is achieved, new impurities are not generated, and the method is suitable for industrial production. Separation from electron gas is easy, and energy consumption is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic gas purification, and in particular to silicon-substituted polystyrene microspheres, a preparation method and application thereof. Background Art

[0002] In semiconductor manufacturing and the microelectronics industry, high-purity hydrogen chloride (HCl) and hydrogen bromide (HBr) gases are widely used in silicon wafer etching processes. However, these electronic gases are highly hygroscopic. The presence of trace amounts of water can cause corrosion in metal pipes, leading to frequent equipment replacements. Furthermore, corrosion products can contaminate the manufacturing process, severely impacting product yield and stability. Therefore, deep water removal technology for electronic gases has become a critical step in ensuring process reliability.

[0003] At present, the main methods for removing water from electronic gases include physical adsorption, chemical methods and distillation methods. The physical adsorption method uses adsorbents such as silica gel and molecular sieves. Although it is easy to operate and has no secondary pollution, its efficiency in removing trace water is limited and it is difficult to meet the demand for high-purity gas. The chemical method achieves deep water removal through irreversible reactions between small molecule compounds (such as SiCl4, SiBr4, SOCl2, etc.) and water, but excess water removal agents need to be removed through additional separation processes (such as distillation or adsorption), which significantly increases energy consumption and process complexity. In addition, small molecule water removal agents are prone to remain in the gas to form new impurities, posing a risk of secondary pollution to the process.

[0004] Polystyrene microspheres are often used as functional polymer carrier materials due to their chemical stability, acid and alkali resistance, and ease of functionalization. Existing polystyrene microsphere functionalization technologies mainly include in-situ synthesis and post-substitution methods. The post-substitution method introduces functional groups through a benzene ring substitution reaction, but suffers from problems such as uneven distribution of functional groups and difficulty in precisely controlling their content. In contrast, the in-situ synthesis method, by pre-synthesizing functionalized monomers and then polymerizing them, can more precisely control the position and content of functional groups. However, the application of polystyrene microspheres for electronic gas water removal has not been reported in the prior art.

[0005] Therefore, there is an urgent need to develop a new type of water removal material and method that can not only overcome the defects of small molecule water removal agents such as difficulty in separation and high energy consumption, but also achieve efficient removal of trace water in electronic gases while avoiding the introduction of additional impurities. Summary of the Invention

[0006] This invention aims to overcome the main drawbacks of existing small molecule chemical dewatering agents, namely, difficulty in separation, the need for additional process steps, and increased energy consumption. Physical adsorption, while simple, has limited purification capabilities and cannot meet the demand for high-purity electronic gases. Silicon-substituted polystyrene microspheres, their preparation method, and their application are provided to overcome these shortcomings.

[0007] To achieve the above-mentioned purpose, the present invention is implemented through the following technical solutions: In a first aspect, the present invention first provides a silicon-substituted polystyrene microsphere comprising a cross-linked polystyrene skeleton; A silicon-based group is chemically grafted onto the cross-linked polystyrene skeleton, and the silicon-based group is connected with a Si-Cl bond or a Si-Br bond.

[0008] In the semiconductor and microelectronics industries, high-purity HCl and HBr gases are key raw materials for silicon wafer etching processes. However, their strong water absorption leads to the presence of trace amounts of water, which can cause problems such as corrosion of metal pipes, frequent equipment replacement, and contamination of the process by corrosion products. In the prior art, the dehydration of electronic gases mainly relies on small molecule compounds (such as SiCl4, SiBr4) to remove water through chemical reactions. Although this type of method can achieve deep water removal, it is difficult to separate the excess small molecule dehydrating agent from the gas, and additional processes such as distillation or adsorption are required, which significantly increases energy consumption and process complexity. In addition, residual small molecule compounds may become new impurities, posing a threat to process stability. Although physical adsorption methods (such as molecular sieves and silica gel) are simple to operate and have no secondary pollution, their efficiency in removing trace amounts of water is insufficient, making it difficult to meet the demand for high-purity gases. This series of technical bottlenecks has prompted researchers to explore new dehydration materials that can not only efficiently remove trace amounts of water, but also do not require complex separation processes.

[0009] Polystyrene microspheres are often used as functional polymer carrier materials due to their chemical stability, acid and alkali resistance, and ease of functionalization. Existing functionalization technologies for polystyrene microspheres are mainly divided into in-situ synthesis and post-substitution methods. The post-substitution method introduces functional groups through a benzene ring substitution reaction, but there are problems such as uneven distribution of functional groups and difficulty in accurately controlling the content. The in-situ synthesis method can more accurately control the position and content of functional groups by pre-synthesizing functionalized monomers and then polymerizing them. However, the existing technology has not yet combined in-situ synthesized polystyrene microspheres with silicon-based functionalization, especially by introducing Si-Cl or Si-Br bonds to achieve the application of electronic gas dehydration. Although traditional small molecule dehydrating agents can react efficiently with water, their liquid or gaseous properties make separation difficult. Polymer materials are easier to separate from gases due to their solid-state properties. However, how to introduce active groups that can react with water into the polymer skeleton and ensure their stability and reaction efficiency has become a key point for technological breakthroughs.

[0010] Based on the above problems, the present invention proposes a silicon-substituted polystyrene microsphere, the core innovation of which is to chemically graft silicon-based groups containing Si-Cl bonds or Si-Br bonds on the cross-linked polystyrene skeleton through an in-situ synthesis method. In the specific technical scheme, divinylbenzene and hydrogen-containing halogenated silanes (such as HSiCl3, MeHSiBr2) are used as raw materials, and a hydrosilylation reaction is carried out under the action of a Custer catalyst to generate silicon-substituted styrene monomers, which are then formed into highly cross-linked silicon-substituted polystyrene microspheres through precipitation polymerization. This method ensures that the silicon-based functional groups (Si-Cl / Si-Br) are uniformly distributed in the microspheres and the content is controllable by precisely controlling the monomer ratio and reaction conditions. The cross-linked structure of the microspheres not only enhances the chemical stability, but also fixes the active sites on the cross-linked polystyrene skeleton through silicon ethylene groups (Si-CH2-CH2-), thereby avoiding the problem of free small molecule dehydrating agents. In the application phase, the microspheres are filled into a drying device and water-containing HCl or HBr gas is introduced. The Si-Cl / Si-Br bonds in the microspheres react with water to generate silanol (Si-OH) and HCl / HBr, thereby reducing the water content in the gas from 2×10 -4 %~1×10 -3 % down to 1×10 -5 %~1×10 -4 %. Since the microspheres are solid powders with controllable particle size (0.5 to 3 microns), they can be efficiently separated from the gas through simple filtration or sedimentation, without the need for additional purification processes, significantly reducing energy consumption.

[0011] Compared with the prior art, the creativity of the present invention is reflected in the following aspects: First, the silicon-based functional groups (Si-Cl / Si-Br) are directly introduced into the polystyrene skeleton through an in-situ synthesis method, which solves the problem of uneven functionalization of the post-substituted judges and avoids the defect of difficult separation of small molecule dehydrating agents. Secondly, the cross-linked polystyrene skeleton gives the microspheres excellent acid and alkali resistance and structural stability, so that they can still maintain the reaction efficiency of the active sites in a highly corrosive gas environment. In addition, the solid-state characteristics and controllable particle size design of the microspheres not only simplify the separation process, but also improve the operability and scale potential of the dehydration process. Although polymer materials are occasionally used as dehydration carriers in the prior art, they are mostly limited to physical adsorption or non-specific reactions. The present invention realizes directional dehydration reaction through chemical bonding, which has the dual advantages of deep dehydration and efficient separation. This technical solution has broken through the limitations of traditional thinking from material design to application scenarios, and provides a solution that is both innovative and practical for the field of electronic gas purification.

[0012] Preferably, the cross-linked polystyrene backbone is chemically grafted with silicon-based groups via -CH2CH2 bonds.

[0013] Preferably, the silicon-based group structure is as follows: Wherein, X is Cl or Br; When X is Cl, R1, R2 are CH3 or Cl; When X is Br, R1 and R2 are CH3 or Br.

[0014] In a second aspect, the present invention further provides a method for preparing the silicon-substituted polystyrene microspheres, comprising the following steps: (1) under the protection of an inert gas, reacting divinylbenzene with a hydrogen-containing halosilane in the presence of a hydrosilylation catalyst to generate a reaction product containing a silicon-substituted styrene monomer; (2) dissolving the reaction product generated in step (1) in an organic solvent, adding a stabilizer and an initiator, and performing precipitation polymerization to obtain the silicon-substituted polystyrene microspheres.

[0015] The preparation method proposed in the present invention systematically solves the main problem of small molecule chemical dehydrators in the prior art, which is the difficulty in separation and the need for additional process steps, by innovatively combining the hydrosilylation reaction with the precipitation polymerization process. Specifically, under the protection of inert gas, divinylbenzene and hydrogen-containing halogenated silanes (such as HSiCl3, MeHSiBr2) are used as raw materials to generate silicon-substituted styrene monomers through the hydrosilylation reaction. In this step, the efficient catalytic effect of the Custer catalyst (such as a platinum complex) ensures the precise addition of the Si-H bond to the vinyl group to generate a stable silicon-substituted styrene monomer (such as Cl3Si-CH2-CH2-C6H4-CH=CH2), and by regulating the molar ratio of divinylbenzene to hydrogen-containing halogenated silane (1.1:1 to 2:1), it not only avoids side reactions caused by the imbalance of the monomer ratio (such as the generation of disilicon-substituted products), but also optimizes the cross-linking degree and functional group density of the microspheres. Subsequently, in the precipitation polymerization stage, the silicon-substituted styrene monomer is dissolved in a polar solvent such as acetonitrile, polyvinyl pyrrolidone (PVP) is added as a stabilizer and azobisisobutyronitrile (AIBN) as an initiator. By precisely matching the temperature control (65°C to 80°C) and the reaction time (8h to 12h), the gradual polymerization of the monomer and the self-assembly growth of the microspheres are achieved. In this process, PVP inhibits the aggregation of microspheres through steric hindrance, while AIBN triggers a free radical chain reaction, prompting the monomer to form a highly cross-linked polystyrene skeleton in the solvent. At the same time, the silicon-based functional groups (Si-Cl / Si-Br) are firmly grafted onto the skeleton through chemical bonds, forming evenly distributed active sites.

[0016] Compared with the existing technology, the creativity of this preparation method is reflected in the following aspects: First, the synergistic effect of the silylation reaction and precipitation polymerization breaks through the limitations of the traditional functionalization process. The traditional in situ synthesis method requires the pre-synthesis of functionalized monomers, but the synthesis of silicon-based monomers often leads to insufficient purity due to side reactions (such as Si-H bond self-condensation). The present invention directly generates high-purity monomers through one-step silylation, avoiding the complexity of multi-step purification. Secondly, the design of the precipitation polymerization process cleverly combines the effects of solvent selection (such as acetonitrile) and stabilizer (PVP) to ensure that the microspheres form a uniform particle size distribution (0.5 to 3 microns) and a highly cross-linked structure during the growth process, thereby giving the microspheres excellent mechanical strength and corrosion resistance. In addition, by regulating the polymerization temperature and time, the stable immobilization of functional groups in the microspheres is achieved, avoiding the defects of small molecule dehydrating agents that are easy to volatilize or fall off. The silicon-substituted polystyrene microspheres finally obtained can not only efficiently react with water through Si-Cl / Si-Br bonds (reducing the water volume content from 2×10 -4 % down to 1×10 -5 %), and its solid-state powder properties simplify the separation process to filtration or sedimentation, eliminating the need for additional energy. This technical solution optimizes the entire process, from monomer synthesis to microsphere formation. This not only addresses the industry's pain point of difficult separation of small molecule dehydrating agents, but also addresses the application shortcoming of low functionalization efficiency of polymer materials, providing an innovative and efficient and cost-effective approach for electronic gas purification.

[0017] Preferably, the reaction formula for preparing the silicon-substituted styrene monomer in step (1) is as follows: In the formula, X=Cl or Br; when X=Cl, R1, R2 are CH3 or Cl; when X=Br, R1, R2 are CH3 or Br.

[0018] Preferably, the reaction schematic diagram for preparing silicon-substituted polystyrene microspheres in step (2) is: Wherein, X=Cl or Br; when X=Cl, R1 and R2 are CH3 or Cl; when X=Br, R1 and R2 are CH3 or Br. n and m are positive integers.

[0019] Preferably, the water removal reaction mechanism of silicon-substituted polystyrene microspheres is as follows: Wherein, X=Cl or Br; when X=Cl, R1 and R2 are CH3 or Cl; when X=Br, R1 and R2 are CH3 or Br. n and m are positive integers.

[0020] Preferably, the hydrogen-containing halosilane is selected from any one or more combinations of trichlorosilane, methyldichlorosilane, dimethylchlorosilane, tribromosilane, methyldibromosilane and dimethylbromosilane.

[0021] Preferably, the molar ratio of divinylbenzene to hydrogen-containing halosilane is 1.1 to 2:1.

[0022] The molar number of divinylbenzene is lower than the molar number of Si-H, generating disilyl-substituted styrene and reducing the yield of microspheres; the molar number of divinylbenzene is greater than the molar number of hydrogen-containing halogen silane, which can increase the crosslinking degree of microspheres and increase the strength of microspheres; too much divinylbenzene reduces the content of Si-Cl bonds or Si-Br bonds in the microspheres.

[0023] Preferably, the hydrosilylation catalyst is a Custer catalyst, which is a complex of chloroplatinic acid and divinyltetramethyldisiloxane and is a highly efficient catalyst for hydrosilylation. Common Custer catalysts contain platinum in a mass content of 0.1%, 0.3%, 0.5%, etc.

[0024] Preferably, the amount of Custer catalyst used (calculated as platinum mass content) is 0.001% to 0.005% of the total mass of divinylbenzene and hydrogen-containing halosilane.

[0025] The hydrosilylation reaction can be carried out at room temperature or by heating. The higher the temperature, the faster the reaction rate. Considering the low boiling point and high volatility of hydrogen-containing halogenated silanes and the thermal polymerization of divinylbenzene, the present invention is preferably carried out at room temperature. The progress of the reaction can be tracked by nuclear magnetic hydrogen spectrum. The Si-H of the hydrogen-containing halogenated silane has a strong absorption at a chemical shift of 3.90 ppm. When the absorption peak of the reaction system disappears at this point, it indicates that the reaction of the hydrogen-containing halogenated silane is complete. The reaction can also be tracked by infrared spectroscopy. The Si-H bond of the hydrogen-containing halogenated silane has a strong absorption at a chemical shift of 3.90 ppm. When the absorption peak of the reaction system disappears at this point, it indicates that the reaction of the hydrogen-containing halogenated silane is complete. -1 There is strong absorption at this point. When the absorption peak of the reaction system disappears at this point, it indicates that the hydrogen-containing halosilane has completely reacted.

[0026] Silicon-substituted styrene monomers, under the action of an initiator, can undergo precipitation polymerization in a suitable organic solvent to form polystyrene microspheres that precipitate out of the system. Prior to polymerization, the silicon-substituted styrene monomer is dissolved in the organic solvent. As the monomer polymerizes and the degree of polymerization reaches a certain value, the silicon-substituted polystyrene phase separates from the organic solvent and precipitates out of the system.

[0027] Preferably, the temperature of the precipitation polymerization reaction is 65° C. to 80° C., and the reaction time is 8 h to 12 h; the organic solvent is acetonitrile, the stabilizer is polyvinyl pyrrolidone, and the initiator is azobisisobutyronitrile.

[0028] Polyvinylpyrrolidone (PVP) is a nonionic polymer with a backbone composed of alternating hydrophilic pyrrolidone rings and hydrophobic methylene chains. During precipitation polymerization, the pyrrolidone rings of PVP adsorb onto the surface of silicon-substituted polystyrene microspheres through hydrogen bonding or van der Waals forces, while the hydrophobic chains extend outward into the organic solvent (such as acetonitrile). This adsorption behavior forms a dynamic "protective film" that prevents direct contact between microspheres through steric hindrance, effectively inhibiting agglomeration.

[0029] In addition, in polar organic solvents such as acetonitrile, the hydrophilic pyrrolidone ring of PVP forms a solvation layer with the polar molecules of the solvent, while the hydrophobic chain segments are compatible with the hydrophobic surface of the polystyrene skeleton. This "amphiphilicity" enables PVP to bridge the interface between the solvent and the microspheres, reducing the interfacial tension and thus promoting the uniform dispersion of the monomers. At the same time, PVP regulates the charge distribution on the surface of the microspheres through dynamic adsorption-desorption equilibrium, preventing particle aggregation due to electrostatic effects. This mechanism is particularly important in the initial stage of precipitation polymerization. When the monomers gradually polymerize and form microspheres, the stabilizing effect of PVP ensures that the nucleation and growth process of the microspheres are controllable, avoiding abnormal aggregation caused by excessive local concentrations.

[0030] In a third aspect, the present invention also provides an application of the silicon-substituted polystyrene microspheres in reducing the moisture content of electronic gas, comprising the following steps: filling the silicon-substituted polystyrene microspheres into a drying device, introducing aqueous hydrogen chloride or hydrogen bromide gas into the drying device, so that the hydrogen chloride or hydrogen bromide gas contacts the silicon-substituted polystyrene microspheres, and reacts with moisture through the Si-Cl bond or Si-Br bond in the microspheres, thereby reducing the moisture in the hydrogen chloride or hydrogen bromide gas.

[0031] Preferably, the water removal reaction mechanism of silicon-substituted polystyrene microspheres is as follows: Wherein, X=Cl or Br; when X=Cl, R1 and R2 are CH3 or Cl; when X=Br, R1 and R2 are CH3 or Br. n and m are positive integers.

[0032] Preferably, the drying device is made of stainless steel, the temperature of the drying device is controlled at -10°C to 10°C, the temperature of the hydrogen chloride or hydrogen bromide gas introduced is -20°C to 20°C, and the gas flow rate is 0.5L / min to 2.0L / min.

[0033] Preferably, the initial water volume content in the hydrogen chloride or hydrogen bromide gas is 2×10 -4 %~1×10 -3 %; after dehydration, the volume content of water is 1.0×10 -5 %~1×10 -4 %.

[0034] Therefore, the present invention has the following beneficial effects: (1) The present invention adopts an in-situ synthesis method to prepare silicon-substituted polystyrene microspheres. This method can efficiently introduce a high content of Si-Cl bonds or Si-Br bonds. Compared with the post-substitution method, the water removal effect is more stable and controllable; (2) The silicon-substituted polystyrene microspheres of the present invention are highly cross-linked solid powders with stable structure and acid and alkali resistance. Compared with small molecule dehydrating agents such as SiCl4, they are simpler and more efficient to separate from gases, without the need for additional purification processes, and effectively reduce energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 H NMR spectrum of divinylbenzene before reaction with trichlorosilane.

[0036] Figure 2 H NMR spectrum of the reaction of divinylbenzene with trichlorosilane.

[0037] Figure 3 Infrared spectrum of trichlorosilylethyl substituted polystyrene microspheres.

[0038] Figure 4 Scanning electron micrograph of trichlorosilylethyl-substituted polystyrene microspheres. DETAILED DESCRIPTION

[0039] The present invention will be further described below with reference to specific embodiments. Those skilled in the art will be able to implement the present invention based on these descriptions. Furthermore, the embodiments of the present invention described below generally represent only a portion of the present invention, rather than all of the embodiments. Therefore, all other embodiments derived by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0040] Example 1 Under nitrogen, 100g of divinylbenzene, 86g of HSiCl3, and 1.9g of Custer's catalyst (0.3% platinum by weight) were added to a reaction flask, stirred, and allowed to react at room temperature for 6 hours. H-NMR spectroscopy revealed the disappearance of the Si-H absorption peak, indicating complete reaction of the HSiCl3. 900g of anhydrous CH3CN, 0.9g of PVP, and 2.7g of AIBN were added, the temperature was raised to 80°C, and the reaction was stirred for 12 hours. Filtered, the solid was washed with anhydrous CH3CN to remove any remaining CH3CN, yielding 130g of trichlorosilylethyl-substituted polystyrene microspheres.

[0041] Under the protection of high-purity nitrogen, 130 g of trichlorosilylethyl substituted polystyrene microspheres prepared above were placed in a dry 250 mL 316L stainless steel drying tower, and water with a volume content of 5.0 × 10 -4 %, the temperature was -10℃, the flow rate of HCl gas was 1.0L / min, and the drying tower temperature was kept at 0℃. After 30 minutes, the trace moisture gas analyzer detected that the volume content of water in the HCl gas at the outlet of the drying tower was 4.5×10 -5 %.

[0042] Figure 1 This is the H NMR spectrum before the reaction of divinylbenzene and HSiCl3. Figure 2 This is the H NMR spectrum after 6 h of reaction at room temperature. Figure 2 In the figure, the chemical shifts at 7.28, 7.22, 7.14, 6.97, and 6.87 ppm are -C6H4- absorption peaks, 6.61, 6.56, 6.52, 5.64, 5.60, 5.56, 5.13, 5.10, and 5.07 ppm are CH2=CH- absorption peaks, and 2.20 and 2.15 ppm are -CH2- absorption peaks. Figure 1 and Figure 2 It can be seen that after the reaction, the Si-H absorption peak at the chemical shift of 3.87 to 3.93 ppm disappears, and the -CH2- absorption peak at the chemical shift of 2.15 to 2.20 ppm increases, indicating that divinylbenzene and HSiCl3 react completely to form trichlorosilylethyl substituted styrene, whose structural formula can be expressed as: Cl3SiCH2CH2C6H4CH=CH2.

[0043] The infrared spectrum of trichlorosilylethyl substituted polystyrene microspheres is as follows Figure 3 As shown. 2971.51 and 2925.31cm in the figure -1 It is the stretching vibration absorption peak of the carbon-hydrogen bond in the methylene group, 1602.18 cm -1 It is the stretching vibration absorption peak of C=C in the benzene ring, 1485.20, 1442.77cm -1 It is the absorption peak of carbon-hydrogen bond bending vibration in methylene, 1256.34 cm -1 It is the absorption peak of symmetric deformation vibration of silyl methylene, 948.91, 706.78cm -1 It is the deformation vibration absorption peak of silicon-carbon bond, 793.71cm -1 It is the absorption peak of carbon-hydrogen stretching vibration in benzene ring. Infrared spectrum results show that the structure of prepared trichlorosilylethyl substituted polystyrene microspheres is in line with expectations, and the structural formula can be expressed as (Cl3SiCH2CH2C6H4CHCH2) n (CH2CHC6H4CHCH2) m (n, m are positive integers).

[0044] Scanning electron microscopy of trichlorosilylethyl substituted polystyrene microspheres Figure 4 As shown in the figure, it is spherical in shape, with a complete structure and no damage. Figure 4 200 microspheres were randomly selected and the particle size of the microspheres was measured using nano-image measurement software. The results are shown in Table 1.

[0045] Table 1 Particle size statistics of trichlorosilylethyl substituted polystyrene microspheres The results in Table 1 show that the particle size distribution range is mainly 0.9-1.8 μm, accounting for 97%, of which the microspheres with a particle size of 1.2-1.5 μm account for 49%. After calculation, the average particle size of the prepared microspheres is 1.25 μm.

[0046] Example 2 Under nitrogen, 120g of divinylbenzene, 96g of MeHSiBr2, and 0.8g of Custer's catalyst (0.3% platinum by weight) were added to a reaction flask, stirred, and allowed to react at room temperature for 10 hours. H-NMR spectroscopy revealed the disappearance of the Si-H absorption peak, indicating complete reaction of the MeHSiBr2. 600g of anhydrous CH3CN, 1.8g of PVP, and 0.9g of AIBN were added, the temperature was raised to 75°C, and the reaction was stirred for 10 hours. Filtering was performed, and the solid was washed with anhydrous CH3CN to remove any residual CH3CN, yielding 162g of dibromomethylsilylethyl-substituted polystyrene microspheres.

[0047] Under the protection of high-purity nitrogen, 162 g of dibromomethylsilylethyl substituted polystyrene microspheres prepared above were placed in a dry 250 mL 316L stainless steel drying tower, and water with a volume content of 1.0 × 10 -3 %, the temperature is -20℃, the flow rate of HBr gas is 2.0L / min, and the temperature of the drying tower is maintained at -10℃. After 30 minutes, the trace moisture gas analyzer detected that the volume content of water in the HBr gas at the outlet of the drying tower was 9.8×10 -5 %.

[0048] The H NMR spectrum data after the reaction of divinylbenzene and MeHSiBr2 are: 7.25, 7.21, 7.18, 7.04, 6.88, 6.61, 6.55, 6.45, 5.61, 5.55, 5.47, 5.05, 5.02, 2.16, 2.19, 0.05 ppm.

[0049] Infrared data of dibromomethylsilylethyl substituted polystyrene microspheres: 3045.58, 2987.61, 1610.87, 1462.42, 1431.26, 1261.75, 1256.84, 973.35, 792.84, 707.63cm -1 .

[0050] Scanning electron micrograph of dibromomethylsilylethyl-substituted polystyrene microspheres: Spherical in appearance, intact in structure, and free of damage. 200 microspheres were randomly selected from the image and measured using nano-image measurement software. The particle size distribution was primarily in the 1.5-2.4 μm range, representing 93% of the total. The average particle size was calculated to be 1.98 μm.

[0051] The structural formula of the dibromomethylsilylethyl substituted polystyrene microspheres prepared above can be expressed as: (Br2MeSiCH2CH2C6H4CHCH2) n (CH2CHC6H4CHCH2) m (n, m are positive integers).

[0052] Example 3 Under nitrogen, 53g of divinylbenzene, 42g of MeHSiCl2, and 1.5g of Custer's catalyst (0.3% platinum by weight) were added to a reaction flask, stirred, and allowed to react at room temperature for 5 hours. H-NMR spectroscopy revealed the disappearance of the Si-H absorption peak, indicating complete reaction of the MeHSiCl2. 660g of anhydrous CH3CN, 1.1g of PVP, and 0.8g of AIBN were added, the temperature was raised to 68°C, and the reaction was stirred for 11 hours. Filtered, the solid was washed with anhydrous CH3CN to remove residual CH3CN, and 60g of dichloromethylsilylethyl-substituted polystyrene microspheres were obtained.

[0053] Under the protection of high-purity nitrogen, 60 g of dichloromethylsilylethyl substituted polystyrene microspheres prepared above were placed in a dry 100 mL 316L stainless steel drying tower, and water with a volume content of 2.0 × 10 -4 %, temperature, -5°C, flow rate of 0.5L / min HCl gas, maintain the drying tower temperature at -5°C. After 30 minutes, the trace moisture gas analyzer detected that the volume content of water in the HCl gas at the outlet of the drying tower was 1.0×10 -5 %.

[0054] The H NMR spectrum data after the reaction of divinylbenzene with MeHSiCl2 are: 7.27, 7.20, 7.16, 6.97, 6.85, 6.54, 6.51, 6.47, 5.57, 5.53, 5.51, 5.06, 5.03, 2.15, 2.17, 0.02 ppm.

[0055] Infrared data of dichloromethylsilylethyl substituted polystyrene microspheres: 3021.65, 2975.62, 1600.35, 1472.18, 1429.56, 1265.72, 1259.71, 958.31, 795.79, 705.21cm -1 .

[0056] Scanning electron micrograph of dichloromethylsilylethyl-substituted polystyrene microspheres: Spherical in appearance, intact in structure, and free of damage. 200 microspheres were randomly selected from the image and measured using nano-image measurement software. The particle size distribution was primarily in the 1.2-2.1 μm range, representing 95% of the total. The average particle size was calculated to be 1.75 μm.

[0057] The structural formula of the dichloromethylsilylethyl substituted polystyrene microspheres prepared above can be expressed as: (Cl2MeSiCH2CH2C6H4CHCH2) n (CH2CHC6H4CHCH2) m (n, m are positive integers).

[0058] Example 4 Under nitrogen, 72g of divinylbenzene, 100g of HSiBr3, and 1.3g of Custer's catalyst (0.3% platinum by weight) were added to a reaction flask, stirred, and allowed to react at room temperature for 9 hours. H-NMR spectroscopy revealed the disappearance of the Si-H absorption peak, indicating complete HSiBr3 reaction. 600g of anhydrous CH3CN, 1.3g of PVP, and 1.0g of AIBN were added, and the temperature was raised to 70°C, with stirring for 9 hours. The solid was filtered and washed with anhydrous CH3CN to remove any residual CH3CN, yielding 127g of tribromosilylethyl-substituted polystyrene microspheres.

[0059] Under the protection of high-purity nitrogen, 127 g of tribromosilylethyl substituted polystyrene microspheres prepared above were placed in a dry 250 mL 316L stainless steel drying tower, and water with a volume content of 7.8 × 10 -4 %, temperature 0℃, HBr gas flow rate 1.8L / min, and the drying tower temperature was maintained at 0℃. After 30 minutes, the trace moisture gas analyzer detected that the water volume content of the HCl gas at the upper outlet of the drying tower was 3.4×10 -5 %.

[0060] The H NMR spectrum data after the reaction of divinylbenzene and HSiBr3 are: 7.31, 7.24, 7.19, 7.05, 6.96, 6.58, 6.56, 5.62, 5.59, 5.13, 5.08, 2.18, 2.15 ppm.

[0061] Infrared data of tribromosilylethyl substituted polystyrene microspheres: 3009.47, 2980.31, 1604.56, 1463.14, 1442.47, 1253.67, 955.62, 798.31, 698.93 cm -1 .

[0062] Scanning electron micrograph of tribromosilylethyl-substituted polystyrene microspheres: Spherical in appearance, intact in structure, and free of damage. 200 microspheres were randomly selected from the image and measured using nano-image measurement software. The particle size distribution was primarily in the 1.8-2.7 μm range, representing 91% of the total. The average particle size was calculated to be 2.19 μm.

[0063] The structural formula of the tribromosilylethyl substituted polystyrene microspheres prepared above can be expressed as: (Br3SiCH2CH2C6H4CHCH2) n (CH2CHC6H4CHCH2) m (n, m are positive integers).

[0064] Example 5 Under nitrogen, 79g of divinylbenzene, 29g of Me2HSiCl, and 1.4g of Custer's catalyst (0.3% platinum by weight) were added to a reaction flask, stirred, and allowed to react at room temperature for 7 hours. H-NMR spectroscopy revealed the disappearance of the Si-H absorption peak, indicating complete reaction of the Me2HSiCl. 600g of anhydrous CH3CN, 1.6g of PVP, and 0.6g of AIBN were added, and the temperature was raised to 75°C, with stirring for 11 hours. The solid was filtered and washed with anhydrous CH3CN to remove any residual CH3CN, yielding 65g of chlorodimethylsilylethyl-substituted polystyrene microspheres.

[0065] Under the protection of high-purity nitrogen, 65 g of the prepared chlorodimethylsilylethyl substituted polystyrene microspheres were placed in a dry 100 mL 316L stainless steel drying tower, and a water volume content of 3.6 × 10 -4 %, temperature 10℃, flow rate 1.5L / min of HCl gas, and maintain the drying tower temperature at 5℃. After 30 minutes, the trace moisture gas analyzer detected that the volume content of water in the HCl gas at the outlet of the drying tower was 7.2×10 -5 %.

[0066] The H NMR spectrum data after the reaction of divinylbenzene and Me2HSiCl are: 7.31, 7.27, 7.20, 7.05, 6.68, 6.65, 6.63, 5.76, 5.73, 5.24, 5.16, 2.27, 2.25, 0.06 ppm.

[0067] Infrared data of chlorodimethylsilylethyl substituted polystyrene microspheres: 3016.54, 2957.36, 1601.96, 1445.28, 1437.57, 1265.68, 1255.93, 957.68, 796.38, 695.90cm -1 .

[0068] Scanning electron micrograph of chlorodimethylsilylethyl-substituted polystyrene microspheres: Spherical in appearance, intact in structure, and free of damage. 200 microspheres were randomly selected from the image and measured using nano-image measurement software. The particle size distribution was primarily in the 1.5-2.4 μm range, accounting for 96% of the total. The average particle size was calculated to be 1.93 μm.

[0069] The structural formula of the chlorodimethylsilylethyl substituted polystyrene microspheres prepared above can be expressed as: (ClMe2SiCH2CH2C6H4CHCH2) n (CH2CHC6H4CHCH2) m (n, m are positive integers).

[0070] Example 6 Under nitrogen, 108g of divinylbenzene, 83g of Me2HSiBr, and 2.0g of Custer's catalyst (0.3% platinum by weight) were added to a reaction flask, stirred, and allowed to react at room temperature for 11 hours. H-NMR spectroscopy revealed the disappearance of the Si-H absorption peak, indicating complete reaction of the Me2HSiBr. 600g of anhydrous CH3CN, 0.7g of PVP, and 1.5g of AIBN were added, the temperature was raised to 65°C, and the reaction was stirred for 8 hours. Filtering was performed, and the solid was washed with anhydrous CH3CN to remove any residual CH3CN, yielding 76g of bromodimethylsilylethyl-substituted polystyrene microspheres.

[0071] Under the protection of high-purity nitrogen, 76 g of bromodimethylsilylethyl substituted polystyrene microspheres prepared above were placed in a dry 100 mL 316L stainless steel drying tower, and water with a volume content of 6.5×10 -4 %, the temperature was 20℃, the flow rate of HBr gas was 0.8L / min, and the drying tower temperature was maintained at 10℃. After 30 minutes, the trace moisture gas analyzer detected that the volume content of water in the HBr gas at the outlet of the drying tower was 5.4×10 -5 %.

[0072] The H NMR spectrum data after the reaction of divinylbenzene and Me2HSiBr are: 7.24, 7.16, 7.07, 7.02, 6.55, 6.49, 6.45, 5.57, 5.52, 5.05, 5.02, 2.20, 2.16, 0.05 ppm.

[0073] Infrared data of bromodimethylsilylethyl substituted polystyrene microspheres: 3009.69, 2960.58, 1600.47, 1451.36, 1429.21, 1261.69, 1256.91, 955.63, 794.82, 687.30cm -1 .

[0074] Scanning electron micrograph of bromodimethylsilylethyl-substituted polystyrene microspheres: Spherical in appearance, intact in structure, and free of damage. 200 microspheres were randomly selected from the image and measured using nano-image measurement software. The particle size distribution was primarily in the 1.2-2.1 μm range, accounting for 93%. The average particle size was calculated to be 1.58 μm.

[0075] The structural formula of the bromodimethylsilylethyl substituted polystyrene microspheres prepared above can be expressed as: (BrMe2SiCH2CH2C6H4CHCH2) n (CH2CHC6H4CHCH2) m (n, m are positive integers).

[0076] Comparative Example 1 Polydivinylbenzene microspheres without silicon substitution are used as HCl gas dehydrating agent.

[0077] Under nitrogen, 100 g of divinylbenzene, 900 g of anhydrous CH3CN, 0.9 g of PVP, and 2.7 g of AIBN were added to the reaction flask, heated to 80°C, and stirred for 12 h. The mixture was filtered and the solid was washed with anhydrous CH3CN to remove the remaining CH3CN, yielding 75 g of polydivinylbenzene microspheres. Under high-purity nitrogen, the 75 g of polydivinylbenzene microspheres prepared above were placed in a dry 250 mL 316 L stainless steel drying tower. A water content of 5.0 × 10 -4 %, the temperature was -10℃, the flow rate of HCl gas was 1.0L / min, and the drying tower temperature was kept at 0℃. After 30 minutes, the trace moisture gas analyzer detected that the volume content of water in the HCl gas at the outlet of the drying tower was 4.2×10 -4 %.

[0078] Comparative Example 1 shows that due to their large specific surface area, polydivinylbenzene microspheres have a certain water adsorption capacity, which can reduce the moisture content in HCl gas. Compared with Example 1, since polydivinylbenzene microspheres do not contain Si-Cl bonds, their ability to remove water from HCl gas is poor, resulting in lower water removal efficiency.

[0079] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

Claims

1. A silicon-substituted polystyrene microsphere, characterized in that: including a cross-linked polystyrene backbone; The cross-linked polystyrene skeleton is chemically grafted with silicon groups; The silicon-based group is connected with a Si-Cl bond or a Si-Br bond.

2. The silicon-substituted polystyrene microspheres according to claim 1, characterized in that: The silicon-based group structure is as follows: Wherein, X is Cl or Br; When X is Cl, R1, R2 are CH3 or Cl; When X is Br, R1 and R2 are CH3 or Br.

3. A method for preparing the silicon-substituted polystyrene microspheres according to claim 1 or 2, characterized in that: The following steps are involved: (1) under the protection of an inert gas, reacting divinylbenzene with a hydrogen-containing halosilane in the presence of a hydrosilylation catalyst to generate a reaction product containing a silicon-substituted styrene monomer; (2) dissolving the reaction product generated in step (1) in an organic solvent, adding a stabilizer and an initiator, and performing precipitation polymerization to obtain the silicon-substituted polystyrene microspheres.

4. The preparation method according to claim 3, characterized in that The hydrogen-containing halosilane is selected from any one or more combinations of trichlorosilane, methyldichlorosilane, dimethylchlorosilane, tribromosilane, methyldibromosilane, and dimethylbromosilane.

5. The preparation method according to claim 3 or 4, characterized in that The molar ratio of divinylbenzene to hydrogen-containing halosilane is 1.1 to 2:

1.

6. The preparation method according to claim 3, characterized in that The hydrosilylation catalyst is a Custer catalyst, and its usage is 0.001% to 0.005% of the total mass of divinylbenzene and hydrogen-containing halosilane based on the mass of platinum.

7. The preparation method according to claim 3, characterized in that The temperature of the precipitation polymerization reaction is 65° C. to 80° C., and the reaction time is 8 h to 12 h. The organic solvent is acetonitrile, the stabilizer is polyvinyl pyrrolidone, and the initiator is azobisisobutyronitrile.

8. Use of the silicon-substituted polystyrene microspheres according to claim 1 or 2 in reducing the moisture content of electronic gas, characterized in that: The following steps are involved: The silicon-substituted polystyrene microspheres are filled into a drying device, and aqueous hydrogen chloride or hydrogen bromide gas is introduced into the drying device, so that the hydrogen chloride or hydrogen bromide gas contacts the silicon-substituted polystyrene microspheres and reacts with moisture through Si-Cl bonds or Si-Br bonds in the microspheres, thereby reducing the moisture in the hydrogen chloride or hydrogen bromide gas.

9. The use according to claim 8, characterized in that The drying device is made of stainless steel, the temperature of the drying device is controlled at -10°C to 10°C, the temperature of the hydrogen chloride or hydrogen bromide gas introduced is -20°C to 20°C, and the gas flow rate is 0.5L / min to 2.0L / min.

10. The use according to claim 9, characterized in that The initial water volume content in the hydrogen chloride or hydrogen bromide gas is 2×10 -4 %~1×10 -3 %; The water volume content after dehydration is 1.0×10 -5 %~1×10 -4 %.

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