Anti-static dust-free cloth and preparation method thereof

Abstract

The invention relates to the technical field of dust-free cloth, in particular to anti-static dust-free cloth and a preparation method thereof. The problems that dust-free cloth accumulates static electricity and is poor in abrasion resistance are solved. Firstly, polyester dust-free cloth is activated through plasma, then the polyester dust-free cloth is immersed in finishing liquid containing conductive liquid, fluorinated nano-silica, hyperbranched polyurethane dispersoid containing dynamic disulfide bonds and vitamin C, and after ultrasonic dipping and two-time dipping and two-time rolling, the polyester dust-free cloth is formed by step heating and curing. According to the invention, a three-dimensional conductive network is constructed through cooperation of multi-dimensional micro-nano materials, the material is endowed with a self-repairing function by utilizing dynamic disulfide bonds, and the anti-static performance and the wear resistance of the dust-free cloth are improved in cooperation with covalent grafting anchoring excited by plasmas.

Description

Technical Field

[0001] This invention relates to the field of cleanroom cloth technology, specifically to an antistatic cleanroom cloth and its preparation method. Background Technology

[0002] Cleanroom wipes are an indispensable wiping consumable in cleanrooms, and their performance directly determines the product yield and production safety. In actual wiping processes, cleanroom wipes face two major technical bottlenecks: First, there's the issue of static electricity buildup. In extremely dry cleanroom environments with high-speed or high-frequency wiping, the intense friction between the lint-free cloth and equipment surfaces easily generates and accumulates high-voltage static electricity. This not only attracts fine dust particles from the air, causing secondary contamination, but electrostatic discharge can also directly damage sensitive microelectronic components, resulting in irreversible damage. Traditional antistatic treatments often use surface coatings with surfactant-based antistatic agents. These agents have poor water resistance and are easily transferred during wiping, leading to a rapid decline in antistatic performance.

[0003] Secondly, there's the issue of abrasion resistance. When wiping rough surfaces or sharp edges, the fibers of cleanroom wipes are prone to breakage, pilling, or even shedding, generating a large number of particles. This not only contradicts the original intention of cleanroom wipes to "not generate dust," but the shed fiber debris can also become a new source of contamination. Existing high-strength cleanroom wipes often achieve this by increasing fabric density or using meltblown technology, but this often sacrifices the fabric's softness, increasing the risk of scratching the surface being wiped.

[0004] Therefore, how to endow cleanroom wipes with durable and efficient antistatic properties and excellent abrasion resistance without damaging their original softness and absorbency through fabric finishing technology has become a technical problem that urgently needs to be solved in the industry.

[0005] Therefore, an antistatic cleanroom cloth and its preparation method are proposed. Summary of the Invention

[0006] The purpose of this invention is to provide an antistatic cleanroom cloth and its preparation method.

[0007] To achieve the above objectives, the present invention provides the following technical solution: Unless otherwise specified, all parts in this invention are parts by weight.

[0008] This invention provides a method for preparing an antistatic cleanroom cloth, the method of which is as follows: Add 15 parts of conductive liquid, 4 parts of fluorinated nano silica, 25 parts of hyperbranched polyurethane dispersion and 1.5-4.0 parts of vitamin C to 55 parts of deionized water, shear and mix at 1000 rpm for 30 min, add 3 parts of blocked isocyanate crosslinking agent (Imprafix 2794) to obtain finishing solution; For polyester cleanroom wipes (made of 100% continuous polyester filament, with a basis weight of 150g / m²) 2 The activated fabric is pretreated with plasma to obtain an activated fabric; the activated fabric is immersed in a finishing solution and ultrasonically rolled to obtain an impregnated fabric; the impregnated fabric is subjected to a second dip and second roll treatment and then cured to obtain a dust-free cloth.

[0009] Preferably, the conductive liquid is prepared as follows: 100 parts of a graphene oxide aqueous dispersion with a concentration of 5 mg / mL are taken, diluted with a 1:1 volume ratio of ethanol / water mixed solvent, the pH is adjusted to 5.0 with glacial acetic acid, and 1.5-3.5 parts of silane coupling agent KH-550 are added. The mixture is reacted at 65℃ and 400 rpm for 4 h to obtain silane-grafted graphene. 5 parts of glycidyltrimethylammonium chloride are added dropwise to the silane-grafted graphene, the temperature is raised to 80℃, and the mixture is refluxed and stirred at 600 rpm for 6 h. After cooling, the mixture is centrifuged and washed to obtain quaternary ammonium salt-grafted silane-modified graphene oxide. 80 parts of quaternary ammonium salt-grafted silane-modified graphene oxide are mixed with 20-32 parts of acidified carbon nanotube aqueous dispersion, and 3 parts of dispersant polyvinylpyrrolidone are added. The mixture is treated at a stirring speed of 800 rpm and an ultrasonic frequency of 25 kHz for 45 min to obtain the conductive liquid.

[0010] The preferred method for preparing fluorinated nano-silica is as follows: 10 parts of nano-silica (average particle size 20 nm) are dispersed in 100 parts of anhydrous ethanol, 3-6 parts of perfluorooctyltrimethoxysilane and 0.5 parts of ammonia are added dropwise, and the mixture is reacted at a constant temperature of 50°C and 500 rpm for 12 h. After centrifugation, the mixture is vacuum dried at 80°C for 8 h. The dried product is then placed in a planetary ball mill and ground continuously at 350 rpm for 2.5 h using zirconia grinding balls (large to small ball mass ratio of 2:1) to obtain fluorinated nano-silica.

[0011] The preferred method for preparing hyperbranched polyurethane dispersion is as follows: 44.4 parts of isophorone diisocyanate, 100 parts of polytetrahydrofuran diol (Mn=1000) and 6 parts of dimethylolpropionic acid are added to a reaction vessel, nitrogen gas is introduced for protection, 0.07 parts of dibutyltin dilaurate catalyst are added, and the reaction is carried out at 75°C and 300 rpm for 2 h; 3-8 parts of 2,2'-dithiodiethanol and 3 parts of pentaerythritol are added, the temperature is raised to 80°C and the reaction is continued for 4 h; the reaction system is cooled to 45°C, 5 parts of triethylamine are slowly added dropwise, and a neutralization reaction is carried out for 30 min; deionized water preheated to the same temperature is slowly added to the neutralized prepolymer at 1500 rpm; as water is introduced, the system undergoes a phase transition, changing from an organic phase to an oil-in-water emulsion, thus obtaining the hyperbranched polyurethane dispersion.

[0012] Preferably, the plasma pretreatment uses oxygen / argon (1:4) as the gas source, with a power of 400-600W and a processing speed of 10 meters / minute.

[0013] Preferably, the ultrasonic impregnation parameters are 40kHz, 300-500W, the liquid temperature is controlled at 40℃, and the impregnation time is 10-20min.

[0014] Preferably, the roller pressure in the two-dip and two-roll process is set to 0.15-0.30 MPa, the fabric running speed is controlled at 6 m / min, and the liquid retention rate of the fabric is controlled at 70% after the two-dip and two-roll process.

[0015] Preferably, the curing and molding process is divided into two stages: the first stage is a pre-baking treatment at 95℃ for 10 minutes, and the second stage is a high-temperature stretching and shaping baking at 140-160℃ for 2-5 minutes.

[0016] In another aspect, the present invention provides an antistatic cleanroom cloth, which is prepared by any of the above-described preparation methods.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention improves antistatic properties by synthesizing quaternary ammonium salt-grafted silanized graphene oxide and constructing a multidimensional network with carbon nanotubes. On the one hand, the quaternary ammonium salt in the quaternary ammonium salt-grafted silanized graphene oxide not only enhances the dispersibility of graphene in an aqueous system, but its own ionic conductivity also forms a "dual ionic-electron conductivity synergy" with the electronic conductivity of graphene, greatly reducing the initial surface resistivity. On the other hand, one-dimensional carbon nanotubes are used as flexible "conductive bridges," interlaced and connected between two-dimensional graphene sheets, forming a robust three-dimensional dual electronic and ionic conductivity channel. This structure endows the conductive network with extremely strong deformation resistance, ensuring that the conductive links remain continuous under complex mechanical stress, eliminating the risk of local accumulation of static charge and discharge breakdown, and achieving long-term antistatic effect.

[0018] 2. This invention innovatively synthesizes hyperbranched polyurethane containing dynamic reversible disulfide bonds as a crosslinking framework and film-forming matrix. The unique three-dimensional spherical molecular structure of hyperbranched polyurethane can form a film on the surface of polyester fibers and fully encapsulate modified materials such as quaternary ammonium salt-grafted silanized graphene oxide. Its high toughness greatly improves the initial abrasion resistance of the coating. At the same time, under the stimulation of micro-heat generated by friction or room temperature environment, the dynamic disulfide bonds can spontaneously undergo dynamic exchange reaction, so that the broken polymer molecular chains can reconnect and crosslink to heal the damage. This dual mechanism of high toughness encapsulation and intrinsic micro-damage self-repair greatly enhances the fatigue resistance of the fiber surface.

[0019] 3. This invention utilizes perfluorinated long carbon chains to modify the core-shell structure of nano-silica, constructing a low-surface-energy micro-nano rough structure on the fabric surface, endowing the cleanroom cloth with excellent self-lubricating properties and wear resistance. Untreated fabrics have a high coefficient of friction when wiped dry. In this invention, fluorinated nano-silica is uniformly distributed in the gaps of the cross-linked network. On the one hand, the extremely low surface energy of the fluoride significantly reduces the frictional resistance at the wiping interface, generating a physical lubrication effect; on the other hand, the hard silica core acts like a microscopic "ball bearing," effectively dispersing and buffering external shear stress, and synergistically protecting the internal polyester fiber skeleton and conductive network from mechanical damage.

[0020] 4. This invention employs a low-temperature plasma pretreatment process under normal pressure to achieve strong chemical anchoring between the antistatic and wear-resistant coating and the polyester fiber substrate. Polyester fibers themselves have high crystallinity and chemical inertness, resulting in poor water resistance and abrasion resistance after conventional physical impregnation. This invention uses a specific ratio of oxygen / argon mixed plasma high-energy particles to bombard the fiber surface, generating a large number of active hydroxyl and carboxyl groups in situ without damaging the fiber's inherent strength. These active groups can undergo grafting reactions with the crosslinked network of hyperbranched polyurethane during subsequent baking, forming stable covalent bonds and completely eliminating coating peeling caused by high-frequency friction and repeated industrial washing.

[0021] 5. This invention deeply integrates ultrasonic cavitation effect, in-situ green reduction of vitamin C, and two-stage temperature-controlled curing process, achieving an overall performance improvement. The strong micro-jets of high-frequency ultrasound force the high-viscosity conductive liquid to deeply penetrate into the interior of the ultrafine fiber capillary bundle, forming an all-round coating; at the same time, during the impregnation of the finishing liquid and the subsequent pre-baking and heating process, as the moisture gradually evaporates, the system concentration increases, and vitamin C environmentally reduces graphene oxide to a highly conductive reduced graphene oxide under heating conditions, avoiding thermal damage to the strength of polyester fibers caused by high temperature or highly toxic reducing agents; subsequently, the high-temperature baking stage triggers the complete network curing of crosslinking agents and disulfide bonds in the system, achieving a perfect unity of excellent film density, high conductivity, and softness without powder shedding. Attached Figure Description

[0022] Figure 1 The figures show the test results of charge surface density in Examples 1-4 and Comparative Examples 1-2 and 7-8 of the present invention. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Please see Figure 1 This invention provides an antistatic cleanroom cloth and its preparation method, the technical solution of which is as follows: Example 1

[0025] Five parts of multi-walled carbon nanotubes (average diameter 15 nm) were placed in 200 parts of mixed acid (concentrated sulfuric acid and concentrated nitric acid in a volume ratio of 3:1). The mixture was refluxed and condensed at 80 °C and stirred at 400 rpm for 4 h. After the reaction was completed, the suspension was slowly poured into 1000 parts of ice-water mixture for dilution and quenching. The mixture was then filtered through a polytetrafluoroethylene microporous membrane with a pore size of 0.22 μm. The filter was repeatedly washed with deionized water until the filtrate was neutral. Finally, the filter cake was freeze-dried in a vacuum freeze dryer at -40 °C for 24 h to obtain acidified carbon nanotube powder. The powder was added to deionized water and ultrasonically dispersed to obtain an acidified carbon nanotube aqueous dispersion with a concentration of 2 mg / mL. 100 parts of a 5 mg / mL aqueous dispersion of graphene oxide were diluted with a 1:1 volume ratio of ethanol / water mixed solvent. The pH was adjusted to 5.0 with glacial acetic acid, and 1.5 parts of silane coupling agent KH-550 were added. The mixture was reacted at 65℃ and 400 rpm for 4 h to obtain silane-grafted graphene. 5 parts of glycidyltrimethylammonium chloride were added dropwise to the silane-grafted graphene, and the mixture was heated to 80℃ and refluxed at 600 rpm for 6 h. After cooling, the mixture was centrifuged and washed until the filtrate was neutral and had a conductivity of less than 50 μS / cm to obtain quaternary ammonium salt-grafted silane-modified graphene oxide. 80 parts of quaternary ammonium salt-grafted silane-modified graphene oxide were mixed with 20 parts of acidified carbon nanotube aqueous dispersion, and 3 parts of polyvinylpyrrolidone dispersant were added. The mixture was treated at 800 rpm and 25 kHz ultrasonic frequency for 45 min to obtain a conductive liquid.

[0026] Ten parts of nano-silica (average particle size of nano-silica is 20 nm) were dispersed in 100 parts of anhydrous ethanol, and 3 parts of perfluorooctyltrimethoxysilane and 0.5 parts of ammonia were added dropwise. The mixture was reacted at 50 °C and 500 rpm for 12 h. After centrifugation, the product was vacuum dried at 80 °C for 8 h. The dried product was then placed in a planetary ball mill and ground continuously at 350 rpm for 2.5 h using zirconia grinding balls (large and small balls in a mass ratio of 2:1) to obtain fluorinated nano-silica.

[0027] 44.4 parts of isophorone diisocyanate, 100 parts of polytetrahydrofuran diol (Mn=1000) and 6 parts of dimethylolpropionic acid were added to a reactor, and nitrogen gas was introduced for protection. 0.07 parts of dibutyltin dilaurate catalyst were added, and the reaction was carried out at 75°C and 300 rpm for 2 h. 3 parts of 2,2'-dithiodiethanol and 3 parts of pentaerythritol were added, and the temperature was raised to 80°C and the reaction was continued for 4 h. The reaction system was cooled to 45°C, and 5 parts of triethylamine were slowly added dropwise for neutralization reaction for 30 min. Deionized water preheated to the same temperature was slowly added to the neutralized prepolymer at 1500 rpm to obtain a hyperbranched polyurethane dispersion.

[0028] 15 parts conductive liquid, 4 parts fluorinated nano silica, 25 parts hyperbranched polyurethane dispersion, and 1.5 parts vitamin C were added to 55 parts deionized water and sheared and mixed at 1000 rpm for 30 min. Then, 3 parts blocked isocyanate crosslinking agent were added to obtain the finishing solution. This solution was then applied to polyester cleanroom fabric (material: 100% continuous polyester filament, basis weight: 150 g / m²). 2 Plasma pretreatment was performed using oxygen / argon (1:4) as the gas source, with a power of 400W and a processing speed of 10 m / min, to obtain activated fabric. The activated fabric was then immersed in a finishing solution at 40 kHz and 300W, with the solution temperature controlled at 40℃, and ultrasonically rolled for 10 min to obtain impregnated fabric. The impregnated fabric was then subjected to a second dip and second nib treatment and cured to obtain a dust-free cloth. In the second dip and second nib treatment, the roller pressure was set to 0.15 MPa, and the fabric running speed was controlled at 6 m / min. After the second dip and second nib treatment, the liquid retention rate of the fabric was controlled at 70%. The curing process consisted of two stages: the first stage was a 95℃ pre-drying treatment for 10 min, and the second stage was a 140℃ high-temperature stretching and setting baking for 2 min.

[0029] Example 2

[0030] The preparation method and parameters were the same as in Example 1, except that the amount of silane coupling agent KH-550 used in the preparation of the conductive liquid was 2.5 parts, and the amount of acidified carbon nanotube aqueous dispersion was 26 parts; the amount of perfluorooctyltrimethoxysilane used in the preparation of fluorinated nano silica was 4.5 parts; the amount of 2,2'-dithiodiethanol used in the preparation of hyperbranched polyurethane dispersion was 5 parts; the amount of vitamin C used was 2.5 parts; the plasma pretreatment power was 500W, the ultrasonic impregnation power was 400W, the time was 15min, the roll pressure in the two-impregnation and two-rolling treatment was set to 0.20MPa, and the second stage of curing and molding was high-temperature stretching and baking at 150℃ for 3min.

[0031] Example 3

[0032] The preparation method and parameters were the same as in Example 1, except that the amount of silane coupling agent KH-550 used in the preparation of the conductive liquid was 3.5 parts, and the amount of acidified carbon nanotube aqueous dispersion was 32 parts; the amount of perfluorooctyltrimethoxysilane used in the preparation of fluorinated nano silica was 6 parts; the amount of 2,2'-dithiodiethanol used in the preparation of hyperbranched polyurethane dispersion was 8 parts; the amount of vitamin C used was 4.0 parts; the plasma pretreatment power was 600W, the ultrasonic impregnation power was 500W, the time was 20min, the roll pressure in the two-impregnation and two-rolling treatment was set to 0.25MPa, and the second stage of curing and molding was high-temperature stretching and baking at 160℃ for 4min.

[0033] Example 4

[0034] The preparation method and parameters were the same as in Example 1, except that the amount of silane coupling agent KH-550 used in the preparation of the conductive liquid was 2.0 parts, and the amount of acidified carbon nanotube aqueous dispersion was 30 parts; the amount of perfluorooctyltrimethoxysilane used in the preparation of fluorinated nano silica was 5 parts; the amount of 2,2'-dithiodiethanol used in the preparation of hyperbranched polyurethane dispersion was 4 parts; the amount of vitamin C used was 3.0 parts; the plasma pretreatment power was 450W, the ultrasonic impregnation power was 350W, the time was 18min, the roll pressure in the two-impregnation and two-rolling treatment was set to 0.30MPa, and the second stage of curing and molding was high-temperature stretching and baking at 145℃ for 5min.

[0035] Comparative Example 1 The preparation method and parameters of Example 1 are the same, except that acidified carbon nanotube aqueous dispersion is not added when preparing the conductive liquid, and only quaternary ammonium salt grafted silanized graphene oxide is used as the single conductive material.

[0036] Comparative Example 2 The preparation method and parameters of Example 1 are the same, except that no quaternary ammonium salt grafted silanized graphene oxide is added when preparing the conductive liquid, and only an acidified carbon nanotube aqueous dispersion is used.

[0037] Comparative Example 3 The preparation method and parameters of Example 1 are the same, except that an equal amount of 1,4-butanediol is used instead of 2,2'-dithiodiethanol when synthesizing hyperbranched polyurethane.

[0038] Comparative Example 4 The preparation method and parameters of Example 1 are the same, except that fluorinated nano-silica is not added to the finishing solution.

[0039] Comparative Example 5 The preparation method and parameters of Example 1 are the same, except that the plasma pretreatment step is omitted and ultrasonic impregnation is performed directly.

[0040] Comparative Example 6 The preparation method and parameters of Example 1 were used, except that ultrasonic impregnation was replaced with conventional room temperature and atmospheric pressure immersion.

[0041] Comparative Example 7 The preparation method and parameters are the same as in Example 1, except that vitamin C is not added to the finishing solution.

[0042] Comparative Example 8 The preparation method and parameters of Example 1 are the same, except that unmodified ordinary graphene oxide is used instead of quaternary ammonium salt-grafted silanized graphene oxide.

[0043] Comparative Example 9 The preparation method and parameters of Example 1 were used, except that the nano-silica (average particle size of 20 nm) was not fluorinated.

[0044] Experiment Example 1: Antistatic Performance Test Antistatic performance was tested according to the standard GB / T 12703; the results are shown in Table 1 and... Figure 1 As shown.

[0045] Table 1. Antistatic performance tests of Examples 1-4 and Comparative Examples 1-2 and 7-8 Group <![CDATA[Surface charge density / μC / m 2 > Surface resistivity / Ω Example 1 1.6 <![CDATA[9.2×10 6 ]]> Example 2 1.1 <![CDATA[4.2×10 6 ]]> Example 3 1.3 <![CDATA[6.0×10 6 ]]> Example 4 1.4 <![CDATA[7.6×10 6 ]]> Comparative Example 1 3.0 <![CDATA[6.5×10 7 ]]> Comparative Example 2 3.7 <![CDATA[1.0×10 8 ]]> Comparative Example 7 6.1 <![CDATA[3.5×10 9 ]]> Comparative Example 8 5.0 <![CDATA[1.8×10 9 ]]> Experiment Example 2: Wear Resistance Test Referring to the ASTM D3884 rotational abrasion method (Taber test), a CS-10 rubber abrasive wheel with a load of 500g was used to record the number of friction cycles when the fabric surface showed obvious pilling, microfiber breakage, or coating peeling; the results are shown in Table 2.

[0046] Table 2. Wear resistance test results of Examples 1-4 and Comparative Examples 3-6 and 8-9 Group Number of friction cycles / times Example 1 1200 Example 2 1280 Example 3 1260 Example 4 1235 Comparative Example 3 650 Comparative Example 4 800 Comparative Example 5 525 Comparative Example 6 830 Comparative Example 8 880 Comparative Example 9 875 As shown in Tables 1-2, in Examples 1-4, this application achieved a nonlinear breakthrough in performance through multidimensional structural design and interfacial chemical reactions. The 1D / 2D (carbon nanotube / modified graphene) hybridization is not a simple stacking, but rather constructs a three-dimensional conductive network of "point-line-surface" that is resistant to tensile strain, solving the problem of easy breakage of conductive links under dynamic wiping; the "physical self-lubrication" provided by fluorinated nano-silica and the "chemical self-repair" provided by the dynamic disulfide bonds of hyperbranched polyurethane form an anti-wear closed loop, avoiding the problem of microcrack propagation; plasma excitation and ultrasonic penetration transform the functional coating from "surface physical coating" to "internal 3D covalent anchoring"; the deep integration of material modification and process field effects improves the antistatic and wear-resistant properties of the cleanroom cloth.

[0047] In Comparative Example 1, only quaternary ammonium salt-grafted silanized graphene oxide was used as the sole conductive material. Without acidified carbon nanotubes, the conductive network was constructed solely from two-dimensional graphene, resulting in a higher conductivity threshold and increased surface resistivity. In Comparative Example 2, only an aqueous dispersion of acidified carbon nanotubes was used to prepare the conductive liquid. Lacking quaternary ammonium salt-grafted graphene oxide, the system lost the synergistic effect of a large two-dimensional electron conduction plane and the ionic conductivity of the quaternary ammonium salt. The linear contact of the carbon nanotubes alone was insufficient to form a complete conductive pathway even at extremely low addition levels, leading to a significant increase in surface resistivity. In Comparative Example 3, after replacing 2,2'-dithiodiethanol with ordinary 1,4-butanediol, the polyurethane network lost its dynamic disulfide bonds. In the Taber friction test, once microcracks formed, they rapidly propagated, causing coating peeling and fiber breakage, significantly reducing the number of wear cycles. In Comparative Example 4, without the addition of fluorinated nano-silica, the cleanroom cloth lacked a low-surface-energy micro-nano rough structure, resulting in extremely high frictional resistance at the wiping interface. Mechanical stress directly acted on the polyurethane coating and substrate, leading to a significant decrease in the number of abrasion cycles. In Comparative Example 5, omitting the plasma pretreatment step, the unactivated polyester fiber surface was chemically inert. The antistatic resin adhered only physically via van der Waals forces. Under mechanical friction, the coating easily peeled off over a large area, causing a sharp drop in the Taber abrasion cycle. In Comparative Example 6, conventional immersion resulted in high-viscosity resin and nanofillers remaining only on the fabric surface, failing to penetrate deep into the fiber capillary bundles. The surface coating was rapidly worn away during friction, exposing the unprotected internal fiber structure. In Comparative Example 7, the lack of the green reducing agent VC prevented graphene oxide from being reduced to a highly conductive reduced graphene oxide state during the medium-temperature pre-baking stage. Its insulating oxygen-containing functional groups blocked electron transport, leading to a significant increase in the surface resistivity of the cleanroom cloth. In Comparative Example 8, unmodified ordinary graphene oxide exhibited poor dispersibility in water and was prone to uncontrolled agglomeration on fabrics, resulting in persistently high surface resistivity. Simultaneously, due to the lack of silane coupling agents and quaternary ammonium salt reactive groups, the graphene sheets could not undergo chemical covalent cross-linking with the polyurethane framework, making them highly susceptible to detachment as free particles during friction. In Comparative Example 9, unfluorinated ordinary nano-silica was used. While it provided microscopic particle support, the lack of extremely low surface energy characteristics of perfluorocarbon chains prevented the generation of a self-lubricating effect. The abundant polar hydroxyl groups on the particle surface actually increased frictional resistance, causing particles to be easily uprooted from the coating during friction, resulting in fewer wear cycles compared to the examples.

[0048] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing an antistatic cleanroom cloth, characterized in that: The preparation method is as follows: The conductive liquid, fluorinated nano-silica, hyperbranched polyurethane dispersion and vitamin C were added to deionized water and sheared and mixed. A blocked isocyanate crosslinking agent was added to obtain the finishing solution. The polyester cleanroom cloth is subjected to plasma pretreatment to obtain activated fabric; the activated fabric is immersed in the finishing solution for ultrasonic padding to obtain impregnated fabric. The impregnated fabric is subjected to a two-dip, two-roll process and then cured to obtain the dust-free cloth.

2. The method for preparing an antistatic cleanroom cloth according to claim 1, characterized in that: The conductive liquid is prepared as follows: Aqueous dispersion of graphene oxide is taken, and silane coupling agent KH-550 is added to react and silane-coated graphene is obtained; glycidyltrimethylammonium chloride is added dropwise to the silane-coated graphene, and the mixture is heated and stirred under reflux. After cooling, it is centrifuged and washed to obtain quaternary ammonium salt-grafted silane-coated graphene oxide; the quaternary ammonium salt-grafted silane-coated graphene oxide is mixed with an acidified carbon nanotube aqueous dispersion, and polyvinylpyrrolidone (PVP) is added as a dispersant. The mixture is then ultrasonically treated to obtain the conductive liquid.

3. The method for preparing an antistatic cleanroom cloth according to claim 1, characterized in that: The preparation method of the fluorinated nano silica is as follows: nano silica is dispersed in anhydrous ethanol, perfluorooctyltrimethoxysilane and ammonia are added dropwise to react, and after the reaction is completed, the mixture is centrifuged, dried and ground to obtain the fluorinated nano silica.

4. The method for preparing an antistatic cleanroom cloth according to claim 1, characterized in that: The hyperbranched polyurethane dispersion is prepared as follows: isophorone diisocyanate, polytetrahydrofuran diol and dimethylolpropionic acid are added to a reaction vessel, and dibutyltin dilaurate is added to react; 2,2'-dithiodiethanol and pentaerythritol are added, and the reaction is continued after heating; after cooling, triethylamine is added to neutralize the reaction, and after the reaction is completed, deionized water is added to obtain the hyperbranched polyurethane dispersion.

5. The method for preparing an antistatic cleanroom cloth according to claim 1, characterized in that: The plasma pretreatment uses a mixture of oxygen and argon as the gas source, with a power of 400-600W.

6. The method for preparing an antistatic cleanroom cloth according to claim 1, characterized in that: The ultrasonic impregnation power is 300-500W, and the impregnation time is 10-20min.

7. The method for preparing an antistatic cleanroom cloth according to claim 1, characterized in that: The roll pressure in the two-dip and two-roll process is set to 0.15-0.30 MPa.

8. The method for preparing an antistatic cleanroom cloth according to claim 1, characterized in that: The curing and molding process is divided into two stages: the first stage is a pre-baking treatment at 95℃ for 10 minutes, and the second stage is a stretching and baking at 140-160℃ for 2-5 minutes.

9. An antistatic cleanroom cloth, characterized in that: The cleanroom cloth is prepared by the preparation method according to any one of claims 1-8.

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