A method for producing an ultraviolet-cured antistatic coating

Abstract

The application discloses a preparation method of an ultraviolet curing antistatic coating and relates to the technical field of antistatic coatings. In the application, hydrochloric acid doped polyaniline is used as a core material, 1-butyl-3-methyl imidazole bistrifluoromethanesulfonylimide ionic liquid is introduced as a dopant, and the carrier mobility of the polyaniline is significantly improved. Urea-formaldehyde resin is used as a wall material to coat the surface of the polyaniline to form microcapsules. The microcapsules release polyaniline and ionic liquid compounds after being broken to fill the crack gap. Secondly, 3,3'-dihydroxy diphenyl disulfide and acryloyl chloride are used as raw materials to generate a disulfide bond diacrylate monomer through an esterification reaction. The monomer, tetra(3-mercaptopropionic acid) pentaerythritol ester crosslinking agent and epoxy vinyl ester resin form a three-dimensional crosslinking network. The mercapto groups in the crosslinking agent and the acrylate groups of the disulfide bond diacrylate monomer undergo a click reaction to realize the topological structure reorganization of the molecular chain. The coating prepared by the application has the effect of long-acting antistatic.

Description

Technical Field

[0001] This invention relates to the field of antistatic coating technology, specifically to a method for preparing a UV-curable antistatic coating. Background Technology

[0002] UV-cured antistatic coatings are functional coatings that cure rapidly under ultraviolet light. They are widely used in electronic device screens, optical lenses, and precision instruments. Their core function lies in introducing conductive materials or ionic additives to form a conductive network structure, thereby reducing surface resistance and preventing static electricity accumulation. Traditional antistatic coating technologies mainly rely on dispersing conductive polymers, nano-metal particles, or carbon-based materials (such as carbon nanotubes and graphene) in a resin matrix, utilizing their conductive properties to dissipate static electricity.

[0003] However, with frequent physical friction, chemical corrosion, or environmental stress during use, micro-cracks or localized damage easily occur on the coating surface, leading to the breakage of the conductive network or the loss of active ingredients, resulting in a significant decrease in antistatic performance. This problem is particularly prominent in scenarios requiring repeated bending or contact, such as flexible displays and wearable devices. In existing technologies, although increasing the coating thickness or optimizing the dispersion of conductive fillers can temporarily improve wear resistance, it is difficult to fundamentally solve the functional degradation caused by structural damage after long-term use, and excessively thick coatings may affect light transmittance and flexibility. Therefore, developing UV-curable antistatic coatings with self-healing properties has become an important research direction. These coatings, by introducing dynamic reversible chemical bonds (such as hydrogen bonds and disulfide bonds) or encapsulating slow-release antistatic agents in microcapsule structures, can automatically fill cracks and rebuild conductive pathways when the coating is damaged, triggered by light, heat, or ambient humidity, thereby restoring antistatic performance. Systems based on dynamic urethane bonds can achieve molecular recombination through chain segment movement at room temperature, while microcapsules loaded with ionic liquids can release conductive components at the damaged site, forming localized conductive patches. This type of self-healing technology not only extends the service life of the coating but also reduces maintenance costs, providing a new path for the development of highly durable antistatic materials. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing an ultraviolet-cured antistatic coating to solve the problems existing in the prior art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for preparing a UV-curable antistatic coating, comprising the following preparation steps:

[0006] (1) Mix urea and formaldehyde solution with a molar ratio of urea to formaldehyde of 1:1.8, add triethanolamine dropwise until pH=8.5, react at 70℃ for 3h to generate prepolymer; disperse the composite powder in a 5% polyvinyl alcohol solution, add urea-formaldehyde prepolymer, emulsify at high speed to form a water-in-oil emulsion; adjust pH, solidify, centrifuge, wash, and dry to obtain microcapsules with a particle size of 30μm;

[0007] (2) 3,3'-dihydroxydiphenyl disulfide reacts with acryloyl chloride to generate disulfide diacrylate monomer; disulfide diacrylate monomer, pentaerythritol tetrakis(3-mercaptopropionic acid) crosslinking agent, and epoxy vinyl ester resin are mixed in proportion and added to ethyl acetate, and photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone is added. The mixture is heated and stirred evenly to obtain a coating prepolymer; finally, microcapsules, carbon nanotubes, and graphene are added to the coating prepolymer, and finally 1% of tetraethylene glycol dithiol by total mass is added. The mixture is stirred evenly to obtain a mixed coating liquid, and after coating and curing, a UV-cured antistatic coating is obtained.

[0008] Furthermore, the method for preparing the composite powder in step (1) is as follows: polyaniline and ionic liquid are added to anhydrous ethanol, the mass ratio of polyaniline, ionic liquid and anhydrous ethanol is 10:2-4:30, heated in a constant temperature water bath at 60℃, stirred evenly, and then ultrasonically dispersed to form a uniform slurry; the slurry is poured into a mold, placed in an ultra-low temperature freezer to freeze first, and then transferred to a freeze dryer for vacuum freeze drying for 24 hours; the freeze-dried composite is ground with a ball mill and passed through a 200-mesh sieve to obtain micron-sized composite powder.

[0009] Furthermore, the mass ratio of the polyaniline, ionic liquid, and anhydrous ethanol is 10:2-4:30.

[0010] Furthermore, the ionic liquid is a 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt ionic liquid.

[0011] Furthermore, in step (1), the mass ratio of composite powder, prepolymer and polyvinyl alcohol solution is 3-5:8:25.

[0012] Furthermore, in step (2), carbon nanotubes and graphene account for 3% and 2% of the mass of the coating prepolymer, respectively.

[0013] Further, the preparation method of the disulfide bond diacrylate monomer in step (2) is as follows: 5 parts of 3,3'-dihydroxydiphenyl disulfide are dissolved in 30 parts of tetrahydrofuran, 4 parts of triethylamine are added, 0.3 parts of cuprous chloride and 2% by mass of 1-alkyl-3-methylimidazolium ionic liquid are added, and the temperature is raised to 80°C under nitrogen protection; acryloyl chloride is slowly added dropwise, the molar ratio of acryloyl chloride to 4'-dithiodibenzoic acid is 2.2:1, and the reaction is carried out for 6 hours and then cooled to room temperature; byproducts are removed by filtration and rotary evaporation is performed to obtain the disulfide bond diacrylate monomer.

[0014] Furthermore, in step (2), the preferred mass ratio of disulfide diacrylate monomer, pentaerythritol tetrakis(3-mercaptopropionic acid) ester, epoxy vinyl ester resin, photoinitiator, and ethyl acetate is 4:2-3:3-4:0.3:25.

[0015] Furthermore, in step (2), the microcapsules account for 10-14% of the mass of the coating prepolymer.

[0016] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0017] This invention utilizes dynamic disulfide bonds and conductive microcapsules to achieve self-repair of conductive pathways and healing of microcracks through a synergistic mechanism, thereby achieving the antistatic effect of the coating.

[0018] First, using polyaniline as the conductive core material, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt ionic liquid is introduced as a dopant. Its high ionic conductivity and π-π interaction with the polyaniline molecular chains significantly improve the carrier mobility of polyaniline. Urea-formaldehyde resin is used as the wall material, forming microcapsules on the polyaniline surface. The wall material has a dense and brittle cross-linked structure. When the coating is subjected to external force wear or scratches, the local stress exceeds the fracture strength of the urea-formaldehyde resin. After the microcapsules rupture, the polyaniline-ionic liquid complex is released, filling the crack gaps. The ionic liquid, with its high fluidity, spreads rapidly and rebridges the remaining conductive network, while the rigid molecular chains of polyaniline rebuild the conductive pathway through π-electron delocalization, allowing the surface resistance of the coating to recover rapidly.

[0019] Secondly, using 3,3'-dihydroxydiphenyl disulfide and acryloyl chloride as raw materials, a disulfide-bonded diacrylate monomer is generated through esterification. The two acrylate groups in this monomer are linked by flexible disulfide bonds, endowing the material with dynamic exchange capabilities. This monomer is then used with pentaerythritol tetrakis(3-mercaptopropionic acid) crosslinking agent and epoxy vinyl ester resin as raw materials to prepare an antistatic coating. The three are copolymerized under UV light initiation. The thiol groups in the crosslinking agent undergo a click reaction with the acrylate groups of the disulfide-bonded diacrylate, while the dynamic disulfide bonds are uniformly distributed in the system. When microcracks occur, the thiol-disulfide bonds inside the coating dynamically break and recombine, achieving topological restructuring of the molecular chains. The coating rapidly cures under UV irradiation to form a dense film. When the conductive network on the surface is damaged due to long-term use, the active repair of the microcapsules and the passive healing of the dynamic bonds provide dual protection. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] To more clearly illustrate the method provided by the present invention, the following embodiments are provided for detailed explanation. The testing methods for various indicators of the preparation method of the UV-curable antistatic coating in the following embodiments are as follows:

[0022] Antistatic properties: The surface resistivity of the examples and comparative examples was measured using a surface resistivity meter;

[0023] Antistatic properties after friction: The surface resistivity of the examples and comparative examples was measured again after rubbing them back and forth 10 times with a steel wool ball weighing 2.5 pounds; the average value was taken after 5 tests.

[0024] Antistatic properties after bending: The examples and comparative examples were removed, bent 270° 10 times, and the surface resistivity was measured; the average value was taken after 5 tests.

[0025] Example 1; (1) 8 parts of aniline monomer were slowly added dropwise to 20 parts of hydrochloric acid aqueous solution at a rate of 1 drop / 10s. The concentration of hydrochloric acid aqueous solution was 2 mol / L. The mixture was stirred for 30 min in an ice-water bath at 5℃ at a stirring speed of 60 rpm to form an aniline hydrochloride solution. Ammonium persulfate was dissolved in deionized water to prepare an ammonium sulfate aqueous solution with a concentration of 25 wt%. The ammonium persulfate aqueous solution was added dropwise to the aniline hydrochloride solution. The molar ratio of aniline to ammonium persulfate was 1:0.8. The mixture was stirred continuously at room temperature for 8 h at a stirring speed of 60 rpm. After the reaction was completed, the solid was filtered and washed three times with deionized water. The solid was then vacuum dried at 0.085 MPa and 60℃ for 8 h to obtain polyaniline.

[0026] (2) Polyaniline and 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt ionic liquid were added to anhydrous ethanol. The mass ratio of polyaniline, ionic liquid and anhydrous ethanol was 10:2:30. The mixture was heated in a constant temperature water bath at 60℃ and mechanically stirred at 500 rpm for 1 h. Then, it was ultrasonically dispersed for 20 min at an ultrasonic power of 300 W and a frequency of 40 kHz to form a uniform slurry. The slurry was poured into a mold and placed in an ultra-low temperature freezer at -80℃ for 12 h. After freezing, it was transferred to a freeze dryer for vacuum freeze drying at a vacuum degree of 0.085 MPa and a temperature of -30℃ for 24 h. The freeze-dried composite was then ground in a ball mill at a speed of 200 rpm for 2 h. After the grinding was completed, it was passed through a 200-mesh sieve to obtain micron-sized composite powder. Finally, urea and formaldehyde solution were mixed at a molar ratio of 1:1.8, and triethanolamine was added dropwise until the pH reached 8.5. The mixture was reacted at 70°C for 3 hours to generate a prepolymer. The composite powder was dispersed in a 5% polyvinyl alcohol solution, and the urea-formaldehyde prepolymer was added. The mixture was emulsified at 800 rpm for 30 minutes to form a water-in-oil emulsion, wherein the mass ratio of the composite powder, prepolymer, and polyvinyl alcohol solution was 3:8:25. A 10% dilute hydrochloric acid aqueous solution was added dropwise to adjust the pH to 3, and the mixture was then cured at 55°C for 4 hours. After the reaction, the mixture was centrifuged at 3000 rpm for 10 minutes. The solid obtained was washed three times with deionized water and then vacuum dried at 0.085 MPa and 40°C for 12 hours to obtain microcapsules with a particle size of 30 μm.

[0027] (3) Dissolve 5 parts of 3,3'-dihydroxydiphenyl disulfide in 30 parts of tetrahydrofuran, add 4 parts of triethylamine, add 0.3 parts of cuprous chloride and 2% by mass of 1-alkyl-3-methylimidazolium ionic liquid, and heat to 80°C under nitrogen protection; slowly add acryloyl chloride, the molar ratio of acryloyl chloride to 3,3'-dihydroxydiphenyl disulfide is 2.2:1, react for 6 h and then cool to room temperature; filter to remove byproducts, and rotary evaporate at 60 rpm until the solvent is completely removed, at 50°C and a vacuum of 0.04 MPa to obtain disulfide diacrylate monomer; combine disulfide diacrylate monomer, pentaerythritol tetrakis(3-mercaptopropionic acid) crosslinking agent, and DERAKANE Epoxy vinyl ester resin 411-350 was mixed with ethyl acetate in a certain proportion, and photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone was added. The mixture was stirred at 50°C and 240 rpm for 60 min. The mass ratio of disulfide diacrylate monomer, pentaerythritol tetrakis(3-mercaptopropionic acid), epoxy vinyl ester resin, photoinitiator, and ethyl acetate was 4:2:3:0.3:25 to obtain a coating prepolymer. Microcapsules, carbon nanotubes, and graphene were then added to the coating prepolymer, with microcapsules accounting for 10% of the prepolymer's mass, and carbon nanotubes and graphene accounting for 3% and 2% respectively. Finally, 1% tetraethylene glycol dithiol was added, and the mixture was stirred at 240 rpm for 1 h to obtain a mixed coating liquid. This mixed coating liquid was then uniformly coated onto the substrate surface to a thickness of 150 μm. A wavelength of 365 nm and an intensity of 50 mW / cm were used. 2 A high-pressure mercury lamp is used, 20cm away from the substrate, for 3 minutes to form a UV-cured antistatic coating.

[0028] Example 2; (1) 10 parts of aniline monomer were slowly added dropwise to 20 parts of hydrochloric acid aqueous solution at a rate of 1 drop / 10s. The concentration of the hydrochloric acid aqueous solution was 2 mol / L. The mixture was stirred for 30 min in an ice-water bath at 2.5℃ at a stirring speed of 60 rpm to form an aniline hydrochloride solution. Ammonium persulfate was dissolved in deionized water to prepare an ammonium sulfate aqueous solution with a concentration of 25 wt%. The ammonium persulfate aqueous solution was added dropwise to the aniline hydrochloride solution. The molar ratio of aniline to ammonium persulfate was 1:0.8. The mixture was stirred continuously at room temperature for 10 h at a stirring speed of 60 rpm. After the reaction was completed, the solid was filtered and washed three times with deionized water. The solid was then vacuum dried at 0.085 MPa and 60℃ for 8 h to obtain polyaniline.

[0029] (2) Polyaniline and 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt ionic liquid were added to anhydrous ethanol. The mass ratio of polyaniline, ionic liquid and anhydrous ethanol was 10:3:30. The mixture was heated in a constant temperature water bath at 60℃ and mechanically stirred at 500 rpm for 1.5 h. Then, it was ultrasonically dispersed for 25 min at an ultrasonic power of 300 W and a frequency of 40 kHz to form a uniform slurry. The slurry was poured into a mold and placed in an ultra-low temperature freezer at -80℃ for 12 h. After freezing, it was transferred to a freeze dryer for vacuum freeze drying at a vacuum degree of 0.085 MPa and a temperature of -40℃ for 24 h. The freeze-dried composite was then ground in a ball mill at a speed of 200 rpm for 2 h. After the grinding was completed, it was passed through a 200-mesh sieve to obtain micron-sized composite powder. Finally, urea and formaldehyde solution were mixed at a molar ratio of 1:1.8, and triethanolamine was added dropwise until the pH reached 8.5. The mixture was reacted at 70°C for 3 hours to generate a prepolymer. The composite powder was dispersed in a 5% polyvinyl alcohol solution, and the urea-formaldehyde prepolymer was added. The mixture was emulsified at 900 rpm for 30 minutes to form a water-in-oil emulsion, wherein the mass ratio of the composite powder, prepolymer, and polyvinyl alcohol solution was 4:8:25. A 10% dilute hydrochloric acid aqueous solution was added dropwise to adjust the pH to 2.5, and the mixture was then cured at 55°C for 4 hours. After the reaction, the mixture was centrifuged at 3000 rpm for 10 minutes. The solid obtained was washed three times with deionized water and then vacuum dried at 0.085 MPa and 40°C for 12 hours to obtain microcapsules with a particle size of 30 μm.

[0030] (3) Dissolve 5 parts of 3,3'-dihydroxydiphenyl disulfide in 30 parts of tetrahydrofuran, add 4 parts of triethylamine, add 0.3 parts of cuprous chloride and 2% by mass of 1-alkyl-3-methylimidazolium ionic liquid, and heat to 80°C under nitrogen protection; slowly add acryloyl chloride, the molar ratio of acryloyl chloride to 3,3'-dihydroxydiphenyl disulfide is 2.2:1, react for 6 h and then cool to room temperature; filter to remove byproducts, and rotary evaporate at 60 rpm until the solvent is completely removed, at a temperature of 55°C and a vacuum degree of 0.04 MPa to obtain disulfide diacrylate monomer; combine disulfide diacrylate monomer, pentaerythritol tetrakis(3-mercaptopropionic acid) crosslinking agent, and DERAKANE Epoxy vinyl ester resin 411-350 was mixed with ethyl acetate in a certain proportion, and photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone was added. The mixture was stirred at 50°C and 240 rpm for 90 min. The mass ratio of disulfide diacrylate monomer, pentaerythritol tetrakis(3-mercaptopropionic acid), epoxy vinyl ester resin, photoinitiator, and ethyl acetate was 4:2.5:3.5:0.3:25 to obtain a coating prepolymer. Microcapsules, carbon nanotubes, and graphene were then added to the coating prepolymer, with microcapsules accounting for 12% of the prepolymer's mass, and carbon nanotubes and graphene accounting for 3% and 2% respectively. Finally, 1% tetraethylene glycol dithiol was added, and the mixture was stirred at 240 rpm for 1 h to obtain a mixed coating liquid. This mixed coating liquid was then uniformly coated onto the substrate surface to a thickness of 150 μm. A wavelength of 365 nm and an intensity of 50 mW / cm were used. 2 A high-pressure mercury lamp is used, 20cm away from the substrate, for 3 minutes to form a UV-cured antistatic coating.

[0031] Example 3; (1) 12 parts of aniline monomer were slowly added dropwise to 20 parts of hydrochloric acid aqueous solution at a rate of 1 drop / 10s. The concentration of the hydrochloric acid aqueous solution was 2 mol / L. The mixture was stirred for 30 min in an ice-water bath at 0℃ at a stirring speed of 60 rpm to form an aniline hydrochloride solution. Ammonium persulfate was dissolved in deionized water to prepare an ammonium sulfate aqueous solution with a concentration of 25 wt%. The ammonium persulfate aqueous solution was added dropwise to the aniline hydrochloride solution. The molar ratio of aniline to ammonium persulfate was 1:0.8. The mixture was stirred continuously at room temperature for 12 h at a stirring speed of 60 rpm. After the reaction was completed, the solid was filtered and washed three times with deionized water. The solid was then vacuum dried at 0.085 MPa and 60℃ for 8 h to obtain polyaniline.

[0032] (2) Polyaniline and 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt ionic liquid were added to anhydrous ethanol. The mass ratio of polyaniline, ionic liquid and anhydrous ethanol was 10:4:30. The mixture was heated in a constant temperature water bath at 60℃ and mechanically stirred at 500 rpm for 2 hours. Then, it was ultrasonically dispersed for 30 minutes at an ultrasonic power of 300 W and a frequency of 40 kHz to form a uniform slurry. The slurry was poured into a mold and placed in an ultra-low temperature freezer at -80℃ for 12 hours. After freezing, it was transferred to a freeze dryer for vacuum freeze drying at a vacuum degree of 0.085 MPa and a temperature of -50℃ for 24 hours. The freeze-dried composite was then ground in a ball mill at a speed of 200 rpm for 2 hours. After the grinding was completed, it was passed through a 200-mesh sieve to obtain micron-sized composite powder. Urea and formaldehyde solutions were mixed at a molar ratio of 1:1.8, and triethanolamine was added dropwise until the pH reached 8.5. The mixture was reacted at 70°C for 3 hours to generate a prepolymer. The composite powder was dispersed in a 5% polyvinyl alcohol solution, and the urea-formaldehyde prepolymer was added. The mixture was emulsified at 1000 rpm for 30 minutes to form a water-in-oil emulsion, wherein the mass ratio of the composite powder, prepolymer, and polyvinyl alcohol solution was 5:8:25. The pH was adjusted to 2 by adding a 10% dilute hydrochloric acid aqueous solution, and then the mixture was cured at 55°C for 4 hours. After the reaction, the mixture was centrifuged at 3000 rpm for 10 minutes. The solid obtained was washed three times with deionized water and then vacuum dried at 0.085 MPa and 40°C for 12 hours to obtain microcapsules with a particle size of 30 μm.

[0033] (3) Dissolve 5 parts of 3,3'-dihydroxydiphenyl disulfide in 30 parts of tetrahydrofuran, add 4 parts of triethylamine, add 0.3 parts of cuprous chloride and 2% by mass of 1-alkyl-3-methylimidazolium ionic liquid, and heat to 80°C under nitrogen protection; slowly add acryloyl chloride, the molar ratio of acryloyl chloride to 3,3'-dihydroxydiphenyl disulfide is 2.2:1, react for 6 h and then cool to room temperature; filter to remove byproducts, and rotary evaporate at 60 rpm until the solvent is completely removed, the temperature is 60°C and the vacuum degree is 0.04 MPa to obtain the disulfide diacrylate monomer; combine the disulfide diacrylate monomer, pentaerythritol tetrakis(3-mercaptopropionic acid) crosslinking agent, and DERAKANE Epoxy vinyl ester resin 411-350 was mixed with ethyl acetate in a certain proportion, and photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone was added. The mixture was stirred at 50°C and 240 rpm for 120 min. The mass ratio of disulfide diacrylate monomer, pentaerythritol tetrakis(3-mercaptopropionic acid), epoxy vinyl ester resin, photoinitiator, and ethyl acetate was 4:3:4:0.3:25 to obtain a coating prepolymer. Microcapsules, carbon nanotubes, and graphene were then added to the coating prepolymer, with microcapsules accounting for 14% of the prepolymer's mass, and carbon nanotubes and graphene accounting for 3% and 2% respectively. Finally, 1% tetraethylene glycol dithiol was added, and the mixture was stirred at 240 rpm for 1 h to obtain a mixed coating liquid. This mixed coating liquid was then uniformly coated onto the substrate surface to a thickness of 150 μm. A wavelength of 365 nm and an intensity of 50 mW / cm were used. 2 A high-pressure mercury lamp is used, 20cm away from the substrate, for 3 minutes to form a UV-cured antistatic coating.

[0034] Comparative Example 1; The difference between Comparative Example 1 and Example 2 lies in the difference in steps (1) and (2). Steps (1) and (2) are changed to: (1) 10 parts of aniline monomer are added to 20 parts of deionized water and stirred for 30 min at a stirring speed of 60 rpm to form an aniline solution; ammonium persulfate is dissolved in deionized water to prepare an ammonium sulfate aqueous solution with a concentration of 25 wt%; the ammonium persulfate aqueous solution is added dropwise to the aniline salt solution, with a molar ratio of aniline to ammonium persulfate of 1:0.8, and the reaction is continuously stirred at room temperature for 10 h at a stirring speed of 60 rpm; after the reaction is completed, the solid is filtered and washed three times with deionized water, and then vacuum dried at 0.085 MPa and 60 °C for 8 h to obtain polyaniline;

[0035] (2) Polyaniline and 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt ionic liquid were added to anhydrous ethanol. The mass ratio of polyaniline, ionic liquid and anhydrous ethanol was 10:3:30. The mixture was heated in a constant temperature water bath at 60℃ and mechanically stirred at 500 rpm for 1.5 h. Then, it was ultrasonically dispersed for 25 min at an ultrasonic power of 300 W and a frequency of 40 kHz to form a uniform slurry. The slurry was poured into a mold and placed in an ultra-low temperature freezer at -80℃ for 12 h. After freezing, it was transferred to a freeze dryer for vacuum freeze drying at a vacuum degree of 0.085 MPa and a temperature of -40℃ for 24 h. The freeze-dried composite was ground in a ball mill at a speed of 200 rpm for 2 h. After the grinding was completed, it was passed through a 200-mesh sieve to obtain micron-sized composite powder. Urea was added to the mixture. The urea-formaldehyde mixture was mixed with formaldehyde solution at a molar ratio of 1:1.8. Triethanolamine was added dropwise until the pH reached 8.5, and the mixture was reacted at 70°C for 3 hours to generate a prepolymer. The composite powder was dispersed in a 5% polyvinyl alcohol solution, and the urea-formaldehyde prepolymer was added. The mixture was emulsified at 900 rpm for 30 minutes to form a water-in-oil emulsion, wherein the mass ratio of the composite powder, prepolymer, and polyvinyl alcohol solution was 4:8:25. A 10% dilute hydrochloric acid aqueous solution was added dropwise to adjust the pH to 2.5, and the mixture was then cured at 55°C for 4 hours. After the reaction, the mixture was centrifuged at 3000 rpm for 10 minutes. The solid obtained was washed three times with deionized water and then vacuum dried at 0.085 MPa and 40°C for 12 hours to obtain microcapsules with a particle size of 30 μm. The remaining steps were the same as in Example 2.

[0036] Comparative Example 2; The difference between Comparative Example 2 and Example 2 lies in step (2). Step (3) is changed as follows: Polyaniline is added to anhydrous ethanol at a mass ratio of 10:30. The mixture is heated in a constant temperature water bath at 60°C and mechanically stirred at 500 rpm for 1.5 h. Then, it is ultrasonically dispersed for 25 min at a power of 300 W and a frequency of 40 kHz to form a uniform slurry. The slurry is poured into a mold and placed in an ultra-low temperature freezer at -80°C for 12 h. After freezing, it is transferred to a freeze dryer for vacuum freeze-drying at a vacuum degree of 0.085 MPa and a temperature of -40°C for 24 h. The freeze-dried composite is ground in a ball mill at a speed of 200 rpm for 2 h. After the grinding is completed, it is passed through a 200-mesh sieve to obtain micron-sized powder. Urea and formaldehyde solution were mixed at a molar ratio of 1:1.8. Triethanolamine was added dropwise until the pH reached 8.5, and the mixture was reacted at 70°C for 3 hours to generate a prepolymer. The composite powder was dispersed in a 5% polyvinyl alcohol solution, and the urea-formaldehyde prepolymer was added. The mixture was emulsified at 900 rpm for 30 minutes to form a water-in-oil emulsion, wherein the mass ratio of powder, prepolymer, and polyvinyl alcohol solution was 4:8:25. A 10% dilute hydrochloric acid aqueous solution was added dropwise to adjust the pH to 2.5, and the mixture was then cured at 55°C for 4 hours. After the reaction, the mixture was centrifuged at 3000 rpm for 10 minutes. The solid obtained was washed three times with deionized water and then vacuum dried at 0.085 MPa and 40°C for 12 hours to obtain microcapsules with a particle size of 30 μm. The remaining steps were the same as in Example 2.

[0037] Comparative Example 3; The difference between Comparative Example 3 and Example 2 lies in the difference in steps (2) and (3). Steps (2) and (3) are changed as follows: (2) Polyaniline and 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt ionic liquid are added to anhydrous ethanol. The mass ratio of polyaniline, ionic liquid and anhydrous ethanol is 10:3:30. The mixture is heated in a constant temperature water bath at 60°C and mechanically stirred at 500 rpm for 1.5 h. Then, it is ultrasonically dispersed for 25 min. The ultrasonic power is 300 W and the frequency is 40 kHz to form a uniform slurry. The slurry is poured into a mold and placed in an ultra-low temperature freezer at -80°C for 12 h. After freezing, it is transferred to a freeze dryer for vacuum freeze drying. The vacuum degree is 0.085 MPa and the temperature is -40°C for 24 h. The freeze-dried composite is ground with a ball mill at a speed of 200 rpm for 2 h. After the grinding is completed, it is passed through a 200-mesh sieve to obtain micron-sized composite powder.

[0038] (3) Dissolve 5 parts of 3,3'-dihydroxydiphenyl disulfide in 30 parts of tetrahydrofuran, add 4 parts of triethylamine, add 0.3 parts of cuprous chloride and 2% by mass of 1-alkyl-3-methylimidazolium ionic liquid, and heat to 80°C under nitrogen protection; slowly add acryloyl chloride, the molar ratio of acryloyl chloride to 3,3'-dihydroxydiphenyl disulfide is 2.2:1, react for 6 h and then cool to room temperature; filter to remove byproducts, and rotary evaporate at 60 rpm until the solvent is completely removed, at a temperature of 55°C and a vacuum degree of 0.04 MPa to obtain disulfide diacrylate monomer; combine disulfide diacrylate monomer, pentaerythritol tetrakis(3-mercaptopropionic acid) crosslinking agent, and DERAKANE Epoxy vinyl ester resin 411-350 was mixed with ethyl acetate in a certain proportion, and photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone was added. The mixture was stirred at 50°C and 240 rpm for 90 min. The mass ratio of disulfide diacrylate monomer, pentaerythritol tetrakis(3-mercaptopropionic acid), epoxy vinyl ester resin, photoinitiator, and ethyl acetate was 4:2.5:3.5:0.3:25 to obtain a coating prepolymer. Finally, composite powder, carbon nanotubes, and graphene were added to the coating prepolymer. The microcapsules accounted for 14% of the coating prepolymer's mass, and the carbon nanotubes and graphene accounted for 3% and 2% of the coating prepolymer's mass, respectively. Finally, 1% of tetraethylene glycol dithiol was added, and the mixture was stirred at 240 rpm for 1 h to obtain a mixed coating liquid. The mixed coating liquid was then uniformly coated onto the substrate surface to a thickness of 150 μm. A wavelength of 365 nm and an intensity of 50 mW / cm were used. 2 A high-pressure mercury lamp is used, 20 cm away from the substrate, for 3 minutes to form a UV-cured antistatic coating; the remaining steps are the same as in Example 2.

[0039] Comparative Example 4; The difference between Comparative Example 4 and Example 2 is that step (1) is omitted, and step (2) is changed to: adding 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt ionic liquid to anhydrous ethanol, with a mass ratio of ionic liquid to anhydrous ethanol of 1:10, heating in a constant temperature water bath at 60°C, mechanically stirring at 500 rpm for 1.5 h, followed by ultrasonic dispersion for 25 min, with an ultrasonic power of 300 W and a frequency of 40 kHz, to form a uniform slurry; pouring the slurry into a mold, placing it in an ultra-low temperature freezer at -80°C for 12 h, and then transferring it to a freeze dryer for vacuum freeze drying at a vacuum degree of 0.085 MPa and a temperature of -40°C for 24 h; grinding the freeze-dried composite with a ball mill at a grinding speed of 200 rpm for 2 h, and then passing it through a 200-mesh sieve to obtain Urea and formaldehyde solutions were mixed at a molar ratio of 1:1.8, and triethanolamine was added dropwise until the pH reached 8.5. The mixture was reacted at 70°C for 3 hours to generate a prepolymer. The composite powder was dispersed in a 5% polyvinyl alcohol solution, and the urea-formaldehyde prepolymer was added. The mixture was emulsified at 900 rpm for 30 minutes to form a water-in-oil emulsion, wherein the mass ratio of powder, prepolymer, and polyvinyl alcohol solution was 4:8:25. A 10% dilute hydrochloric acid aqueous solution was added dropwise to adjust the pH to 2.5, and the mixture was then cured at 55°C for 4 hours. After the reaction, the mixture was centrifuged at 3000 rpm for 10 minutes. The solid obtained was washed three times with deionized water and then vacuum dried at 0.085 MPa and 40°C for 12 hours to obtain microcapsules with a particle size of 30 μm. The remaining steps were the same as in Example 2.

[0040] Comparative Example 5; The difference between Comparative Example 5 and Example 2 lies in step (3), which is changed to: adding acrylate monomer, pentaerythritol tetrakis(3-mercaptopropionic acid) crosslinking agent, and DERAKANE. Epoxy vinyl ester resin 411-350 was mixed with ethyl acetate in a certain proportion, and photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone was added. The mixture was stirred at 50°C and 240 rpm for 90 min. The mass ratio of acrylate monomer, pentaerythritol tetrakis(3-mercaptopropionic acid), epoxy vinyl ester resin, photoinitiator, and ethyl acetate was 4:2.5:3.5:0.3:25 to obtain a coating prepolymer. Microcapsules, carbon nanotubes, and graphene were then added to the coating prepolymer, with microcapsules accounting for 14% of the prepolymer's mass, and carbon nanotubes and graphene accounting for 3% and 2% respectively. Finally, 1% of tetraethylene glycol dithiol was added, and the mixture was stirred at 240 rpm for 1 h to obtain a mixed coating liquid. This mixed coating liquid was then uniformly coated onto the substrate surface to a thickness of 150 μm. A wavelength of 365 nm and an intensity of 50 mW / cm were used. 2 A high-pressure mercury lamp is used, 20 cm away from the substrate, for 3 minutes to form a UV-cured antistatic coating; the remaining steps are the same as in Example 2.

[0041] Example of effect

[0042] Table 1 below shows the performance analysis results of the preparation method of the UV-curable antistatic coating of Examples 1 to 3 and Comparative Examples 1 to 5 of the present invention.

[0043] Table 1

[0044]

[0045] A comparison of the experimental data on surface resistivity between the examples and comparative examples reveals that the present invention uses hydrochloric acid-doped polyaniline as the conductive core material. By introducing 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt ionic liquid as a dopant, its high ionic conductivity and π-π interaction with the polyaniline molecular chains significantly improve the carrier mobility of polyaniline. Urea-formaldehyde resin is used as the wall material to coat the surface of polyaniline to form microcapsules. The wall material has a dense and brittle cross-linked structure. When the coating is subjected to external force wear or scratches, the local stress exceeds the fracture strength of the urea-formaldehyde resin. After the microcapsules rupture, the polyaniline and ionic liquid complex is released and fills the crack gaps. The ionic liquid spreads rapidly due to its high fluidity and rebridges with the remaining conductive network, while the rigid molecular chains of polyaniline rebuild the conductive pathway through π electron delocalization, so that the surface resistance of the coating is quickly restored. This invention uses 3,3'-dihydroxydiphenyl disulfide and acryloyl chloride as raw materials to generate a disulfide-bonded diacrylate monomer through esterification. The two acrylate groups in the monomer are connected by flexible disulfide bonds, endowing the material with dynamic exchange capacity. An antistatic coating is prepared using this monomer, a pentaerythritol tetrakis(3-mercaptopropionic acid) crosslinking agent, and an epoxy vinyl ester resin as raw materials. These three materials are copolymerized under UV light to form a three-dimensional crosslinked network. The thiol groups in the crosslinking agent undergo click reactions with the acrylate groups of the disulfide-bonded diacrylate, while the dynamic disulfide bonds are uniformly distributed in the system. When microcracks occur, the thiol-disulfide bonds inside the coating dynamically break and recombine, achieving topological restructuring of the molecular chains. The coating rapidly cures under UV light to form a dense film. When the conductive network on the surface is damaged due to long-term use, the active repair of the microcapsules and the passive healing of the dynamic bonds provide dual protection.

[0046] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No markings in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for preparing a UV-curable antistatic coating, characterized in that, The preparation steps include the following: (1) Mix urea and formaldehyde solution, with a molar ratio of urea to formaldehyde of 1:1.8, add triethanolamine dropwise until pH=8.5, and react at 70℃ for 3h to generate prepolymer; The composite powder was dispersed in a 5% polyvinyl alcohol solution, and urea-formaldehyde prepolymer was added. The mixture was then emulsified at high speed to form a water-in-oil emulsion. After pH adjustment, the emulsion was cured, centrifuged, washed, and dried to obtain microcapsules with a particle size of 30 μm. The composite powder was prepared as follows: polyaniline and an ionic liquid were added to anhydrous ethanol, with a mass ratio of polyaniline, ionic liquid, and anhydrous ethanol of 10:2-4:

30. The mixture was heated in a constant temperature water bath at 60°C, stirred until homogeneous, and then ultrasonically dispersed to form a uniform slurry. The slurry was poured into a mold, placed in an ultra-low temperature freezer for initial freezing, and then transferred to a freeze dryer for vacuum freeze-drying for 24 hours. The freeze-dried composite was ground using a ball mill and passed through a 200-mesh sieve to obtain micron-sized composite powder. The ionic liquid was 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt ionic liquid. (2) 3,3'-dihydroxydiphenyl disulfide reacts with acryloyl chloride to generate disulfide diacrylate monomer; disulfide diacrylate monomer, pentaerythritol tetrakis(3-mercaptopropionic acid) crosslinking agent, and epoxy vinyl ester resin are mixed in proportion and added to ethyl acetate, and photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone is added. The mixture is heated and stirred evenly to obtain a coating prepolymer; finally, microcapsules, carbon nanotubes, and graphene are added to the coating prepolymer, and finally 1% of tetraethylene glycol dithiol by total mass is added. The mixture is stirred evenly to obtain a mixed coating liquid, and after coating and curing, a UV-cured antistatic coating is obtained.

2. The method for preparing a UV-curable antistatic coating according to claim 1, characterized in that, In step (1), the mass ratio of composite powder, prepolymer and polyvinyl alcohol solution is 3-5:8:

25.

3. The method for preparing a UV-curable antistatic coating according to claim 1, characterized in that, In step (2), carbon nanotubes and graphene account for 3% and 2% of the mass of the coating prepolymer, respectively.

4. The method for preparing a UV-curable antistatic coating according to claim 1, characterized in that, The preparation method of the disulfide bond diacrylate monomer in step (2) is as follows: 5 parts of 3,3'-dihydroxydiphenyl disulfide are dissolved in 30 parts of tetrahydrofuran, 4 parts of triethylamine are added, 0.3 parts of cuprous chloride and 2% by mass of 1-alkyl-3-methylimidazolium ionic liquid are added, and the temperature is raised to 80°C under nitrogen protection; acryloyl chloride is slowly added dropwise, the molar ratio of acryloyl chloride to 3,3'-dihydroxydiphenyl disulfide is 2.2:1, and the reaction is carried out for 6 hours and then cooled to room temperature; byproducts are removed by filtration and rotary evaporation is performed to obtain the disulfide bond diacrylate monomer.

5. The method for preparing a UV-curable antistatic coating according to claim 1, characterized in that, In step (2), the mass ratio of disulfide diacrylate monomer, pentaerythritol tetrakis(3-mercaptopropionic acid) ester, epoxy vinyl ester resin, photoinitiator, and ethyl acetate is 4:2-3:3-4:0.3:

25.

6. The method for preparing a UV-curable antistatic coating according to claim 1, characterized in that, In step (2), the microcapsules account for 10-14% of the mass of the coating prepolymer.

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