Anti-static light-cured coating and preparation method thereof

Abstract

The application relates to the technical field of photocuring coatings, and mainly relates to an antistatic photocuring coating and a preparation method thereof. The antistatic photocuring coating comprises the following raw materials in parts by weight: polyurethane acrylate: 40-50 parts by weight; active diluent: 20-30 parts by weight; photoinitiator: 1-5 parts by weight; superfine silver powder: 12-17 parts by weight; wetting dispersant: 1-5 parts by weight; leveling agent: 0.1-1 part by weight; defoaming agent: 0.1-1 part by weight; and modified nanosilica: 0.1-2 parts by weight. The application can effectively improve the problems that metal particles are prone to agglomeration and uneven dispersion, the conductive path has good continuity, and the antistatic effect is good.

Description

Technical Field

[0001] This application relates to the field of photocurable coating technology, and mainly to an antistatic photocurable coating and its preparation method. Background Technology

[0002] Antistatic UV-curable coatings, as a functional coating material, have broad application prospects in fields such as electronics, precision instruments, automotive interiors, and aerospace. Vacuum electroplating processes have extremely high requirements for the smoothness, adhesion, and conductivity of the substrate surface. Antistatic coatings not only need to meet these basic requirements, but also need to effectively dissipate static charge, prevent static accumulation from damaging the product, and ensure the stability of the coating during UV curing and subsequent electroplating processes.

[0003] However, existing antistatic UV-curable coatings still face many technical challenges in practical applications. The core of the antistatic function lies in the conductive component, which is usually metal particles (such as silver powder, copper powder, nickel powder, etc.) or conductive carbon materials. The uniformity of dispersion of these conductive particles in polymer matrices such as polyurethane acrylate is the key to determining the stability and reliability of the coating's antistatic performance. Due to the high surface energy of metal particles, they are prone to agglomeration, resulting in uneven dispersion in the coating and discontinuities in the conductive pathways. This leads to fluctuations in the coating's resistivity and low local electrostatic dissipation efficiency.

[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this application is to provide an antistatic photocurable coating and its preparation method.

[0006] The technical solution of this application is as follows: An antistatic UV-curable coating, comprising the following raw materials in parts by weight: Polyurethane acrylate: 40-50 parts by weight; Reactive diluent: 20-30 parts by weight; Photoinitiator: 1-5 parts by weight; Ultrafine silver powder: 12-17 parts by weight; Wetting and dispersing agent: 1-5 parts by weight; Leveling agent: 0.1-1 parts by weight; Defoamer: 0.1-1 parts by weight; Modified nano-silica: 0.1-2 parts by weight.

[0007] Furthermore, the modified nano-silica, by weight, includes the following raw materials: 95-105 parts nano-silica, 850-950 parts solvent, 15-25 parts isocyanate, 0.1-1 parts catalyst, and 45-55 parts polyethylene glycol monomethyl ether.

[0008] Modified nano-silica is introduced into the system at extremely low addition levels. Its surface is dual-modified with isocyanate and polyethylene glycol monomethyl ether. On one hand, physical adsorption and van der Waals forces occur between the inorganic silicon core and the surface of the ultrafine silver powder. On the other hand, the organic PEG segments have good compatibility with the polyurethane acrylate matrix, thus acting as molecular bridges between the silver powder particles and the resin matrix. This bridging effect significantly improves the uniformity of silver powder dispersion in the matrix, effectively avoiding the problem of conductive path breakage caused by agglomeration, resulting in more stable coating resistivity and more uniform electrostatic dissipation efficiency. Simultaneously, the nanoscale size of nano-silica allows it to fill the micro-voids between silver powder particles, further improving the coating's density and benefiting the adhesion performance in subsequent vacuum electroplating processes. The proportions of each component are optimized to ensure antistatic properties without affecting the UV curing speed and the mechanical properties of the coating.

[0009] Furthermore, the molecular weight of polyethylene glycol monomethyl ether is 700-800.

[0010] Furthermore, the isocyanate is isophorone diisocyanate, the catalyst is dibutyltin dilaurate, and the solvent is anhydrous toluene.

[0011] Furthermore, the preparation of modified nano-silica includes the following steps: Nano-silica is dispersed in a solvent to obtain a nano-silica suspension; Under inert gas protection, isocyanate, catalyst and nano silica suspension were mixed at 82-87℃ and reacted for 2-3 hours. Add polyethylene glycol monomethyl ether and continue the reaction at this temperature for 3-5 hours. The reaction product was cooled, centrifuged, washed, and dried to obtain modified nano-silica.

[0012] If polyethylene glycol monomethyl ether (PEG) and isocyanate are added simultaneously, the long-chain flexible structure of PEG forms a spatial barrier on the surface of nano-silica, hindering the direct contact between isocyanate and surface -OH groups, resulting in weak anchoring and low grafting density. However, by first completing the isocyanate anchoring reaction and then grafting PEG, it is ensured that each PEG chain "grows" on the nano-silica surface through stable urethane bonds, rather than through physical adsorption. The modified nano-silica prepared by this process has a uniform surface structure and controllable PEG grafting density, enabling it to stably perform its dual functions as a silver powder dispersant and interfacial bridge in coatings.

[0013] Furthermore, the isocyanate addition time is controlled within 1 hour, and the reaction temperature during the addition process does not exceed 90°C.

[0014] Modified nano-silica does not coat the surface of silver powder to form an insulating shell, but rather acts as nanoscale spacer wedges and molecular bridges, "embedded" in the gaps between ultrafine silver powder particles. Each modified nano-silica particle is in contact with the surfaces of multiple silver powder particles simultaneously (physical adsorption), while its peripheral PEG segments extend into the polyurethane acrylate matrix (compatibility grafting), and the residual -NCO groups form covalent bonds with the resin matrix (chemical anchoring). This effectively blocks the macroscopic aggregation of silver powder while preserving its microscopic conductive connectivity.

[0015] In the preparation of modified nano-silica, the first step involves the carbamate reaction between the -NCO groups of isophorone diisocyanate (IPDI) and the -Si-OH groups on the nano-silica surface, forming a stable covalent bond. The key to this step is the strict control of the amount of IPDI used, ensuring that one end of each IPDI molecule is anchored to the SiO2 surface while the -NCO group at the other end remains exposed. IPDI, rather than nonlinear diisocyanate, is chosen because its alicyclic structure results in a difference in reactivity between the two -NCO groups. The less reactive -NCO preferentially completes surface anchoring, while the more reactive -NCO is reserved for the next reaction, thus achieving precise control of stepwise grafting. Then, polyethylene glycol monomethyl ether with a molecular weight of 700-800 reacts with the -NCO groups on the IPDI through its terminal hydroxyl groups, covalently grafting the PEG flexible segments of the ethoxy repeating unit onto the nano-silica surface. The nano-silica surface forms a three-layer structure from the inside out: the inorganic SiO2 core provides a rigid framework, IPDI residues and their retained -NCO groups act as chemical anchors, and PEG segments constitute a flexible shell compatible with the organic matrix. PEG with a molecular weight of 700-800 forms a dense polymer brush layer on the surface with a thickness of about 2-3 nm. This thickness is precisely within the optimal window for steric hindrance—effectively preventing irreversible aggregation of silver powder particles driven by van der Waals forces, while avoiding reduced grafting density or chain entanglement during UV curing due to excessively long segments.

[0016] The subsequent UV curing process permanently locks this dynamically coupled structure into a stable functional network. Free radicals generated by the photoinitiator initiate the cross-linking and curing of the polyurethane acrylate. During this process, the -NCO groups retained on the surface of the modified nano-silica react with the PUA to form covalent bonds. The modified nano-silica particles are chemically bonded to the resin cross-linking network, becoming structural nodes rather than inert fillers. This constructs a continuous mechanical transmission chain, preventing interface debonding even in the high-temperature or plasma environments of pretreatment before vacuum electroplating.

[0017] Furthermore, the reactive diluent includes one or more of isoborneol acrylate, trimethylolpropane triacrylate, and ethoxylated trimethylolpropane triacrylate.

[0018] This application also provides a method for preparing an antistatic UV-curable coating, comprising the following steps: The base material is obtained by mixing polyurethane acrylate, reactive diluent, wetting and dispersing agent, leveling agent and defoamer; Mix the ultrafine silver powder with the base material at 300-500 rpm. Then, modified nano-silica was added and dispersed at 2400-2600 rpm. Continue adding photoinitiator and stirring until homogeneous to obtain an antistatic photocurable coating.

[0019] Further, after adding a photoinitiator and stirring evenly, the mixture is degassed and filtered to obtain an antistatic photocurable coating.

[0020] During the preparation process, the wetting and dispersing agent reduces the interfacial tension between the silver powder and the resin, forming a preliminary organic protective layer on the surface of each silver powder particle. The silver powder is in a protected but not yet positioned state. Modified nano-silica is then added, and the rotation speed is rapidly increased to 2400-2600 rpm for high-speed dispersion. In a high shear field, the soft aggregates of modified nano-silica are broken down into primary nanoparticles. The PEG segments on their surface are strongly thermodynamically driven due to their high solubility parameters matching those of the polyurethane acrylate matrix, migrating from the high-shear region to the resin phase. Simultaneously, strong van der Waals forces and hydrogen bonds exist between the inorganic core surface of the modified nano-silica and the silver powder surface, driving the modified nano-silica closer to the silver powder surface. Ultimately, the modified nano-silica particles are "stuck" in the gaps between the silver powder particles—the inorganic core achieves physical adsorption towards the silver powder, the PEG segments achieve compatibility grafting towards the resin, and the residual -NCO groups prepare for chemical bonding towards the -OH and -NH- groups in the resin.

[0021] Compared with the prior art, this application has the following beneficial effects: 1. This application uses ultrafine silver powder as the core conductive component, in conjunction with modified nano-silica, to fundamentally solve the industry problem of fluctuations in antistatic performance caused by the agglomeration of conductive fillers. Modified nano-silica is embedded between silver powder particles in extremely low amounts. Its inorganic core is physically adsorbed onto the silver powder surface through van der Waals forces, blocking agglomeration. PEG segments form a steric hindrance layer approximately 2-3 nm thick, kinetically preventing silver powder particles from approaching each other. Residual -NCO groups form covalent bonds with the resin matrix during UV curing, becoming structural nodes. This combination ensures uniform dispersion of silver powder in the matrix, continuous and unbroken conductive pathways, and stable coating resistivity, meeting the stringent requirements of vacuum electroplating processes for antistatic coatings.

[0022] 2. This application achieves simultaneous improvement in mechanical properties while ensuring antistatic functionality through formulation optimization and chemical anchoring mechanisms. Polyurethane acrylate provides the foundation for flexibility and adhesion, while reactive diluents participate in curing and cross-linking to ensure coating density. The modified nano-silica surface reacts with the resin matrix during photocuring, making each nanoparticle a structural node in the cross-linked network rather than an inert filler, constructing a continuous mechanical transfer chain. Even in the thermal cycling and plasma environments of pre-plating treatment, the interface is not easily debonded. The nanoscale size of the nano-silica also fills the micro-voids between the silver powder and the resin, improving coating density and surface smoothness, effectively enhancing mechanical properties. Detailed Implementation

[0023] To facilitate understanding of this application, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of this application.

[0024] This application provides an antistatic UV-curable coating, comprising the following raw materials in parts by weight: Polyurethane acrylate: 40-50 parts by weight; Reactive diluent: 20-30 parts by weight; Photoinitiator: 1-5 parts by weight; Ultrafine silver powder: 12-17 parts by weight; Wetting and dispersing agent: 1-5 parts by weight; Leveling agent: 0.1-1 parts by weight; Defoamer: 0.1-1 parts by weight; Modified nano-silica: 0.1-2 parts by weight.

[0025] The reactive diluent includes one or more of isobornyl acrylate, trimethylolpropane triacrylate, and ethoxylated trimethylolpropane triacrylate.

[0026] Modified nano-silica, by weight, comprises the following raw materials: 95-105 parts nano silica, 850-950 parts solvent, 15-25 parts isocyanate, 0.1-1 parts catalyst, 45-55 parts polyethylene glycol monomethyl ether.

[0027] The preferred solvent is anhydrous toluene.

[0028] The preferred isocyanate is isophorone diisocyanate.

[0029] The catalyst is preferably dibutyltin dilaurate.

[0030] The preparation of modified nano-silica includes the following steps: Step a: Dispersion of nano-silica: Add nano-silica to the solvent and stir at 2400-2600 rpm for 15-45 minutes in a reactor equipped with a high-speed shear stirrer to form a uniform nano-silica suspension.

[0031] Step b: Isocyanate grafting reaction: Under inert gas (nitrogen) protection, the temperature of the reactor is raised to 82-87℃, and isocyanate and catalyst are added to the above nano silica suspension while stirring (400-600 rpm).

[0032] The addition time of isophorone diisocyanate should be controlled within 1 hour.

[0033] After the addition is complete, continue the reaction at 82-87℃ for 2-3 hours. During the addition process, ensure that the reaction temperature does not exceed 90℃.

[0034] Step c: Adding polyether monool: Slowly add polyethylene glycol monomethyl ether (molecular weight 700-800).

[0035] Step d: Incubation reaction: After the addition is completed, continue the reaction at 82-87℃ for 3-5 hours until the characteristic peak of isocyanate (-NCO) detected by infrared spectroscopy (FTIR) basically disappears.

[0036] Step e: Post-treatment: Cool the reaction product to room temperature and separate the solid product by centrifugation. Wash the solid repeatedly with anhydrous toluene. Finally, dry in a vacuum oven at 60-70℃ for 12-24 hours to obtain modified nano-silica.

[0037] This application also provides a method for preparing an antistatic photocurable coating, comprising the following steps: Step 1: Base Material Mixing Stage Step 1a: Accurately weigh the polyurethane acrylate, reactive diluent, wetting and dispersing agent, leveling agent and defoamer, and add them to the mixing tank in sequence.

[0038] Step 1b: Stir at 500-700 rpm for 10-30 minutes at 20-30℃ to ensure that all liquid components are fully mixed and homogeneous to obtain the base material.

[0039] Step 2: Dispersion stage of ultrafine silver powder and modified nano-silica: Step 2a: Add ultrafine silver powder to the above base material while stirring at a speed of 300-500 rpm.

[0040] Step 2b: Add modified nano-silica.

[0041] Step 2c: Increase the stirring speed to 2400-2600 rpm and perform vigorous dispersion for 30-90 minutes. During the dispersion process, control the dispersion temperature at 27±1℃ using jacket cooling.

[0042] Step 3: Reduce the stirring speed to 400 rpm, slowly add the photoinitiator, and continue stirring for 12 minutes until the photoinitiator is completely dissolved and evenly distributed to obtain the coating.

[0043] Step 4: Vacuum degassing and filtration: Step 4a: Transfer the coating to a vacuum degassing device and perform vacuum degassing for 10-25 minutes at a vacuum degree of 0.08MPa±0.015 until no bubbles escape from the coating surface.

[0044] Step 4b: After degassing, the coating is precisely filtered through a 200-300 mesh filter to obtain an antistatic UV-cured coating.

[0045] The present application will be further described below through specific embodiments.

[0046] Example 1 This embodiment discloses an antistatic UV-curable coating, comprising the following raw materials: Polyurethane acrylate: 45kg; Reactive diluent: 25 kg; Photoinitiator: 3 kg (Irgacure 184); Ultrafine silver powder: 15kg; Wetting and dispersing agent: 2.5 kg (BYK-P 104); Leveling agent: 0.3kg (BYK-S3700); Defoamer: 0.2kg (BYK-052); Modified nano-silica: 0.5 kg (average particle size 20 nm).

[0047] The polyurethane acrylate used is from Guangzhou Bahe New Material Technology Co., Ltd., BW 8298.

[0048] The reactive diluent is trimethylolpropane triacrylate.

[0049] The average particle size of the ultrafine silver powder is 3 micrometers.

[0050] The preparation of modified nano-silica includes the following steps: Step a: Dispersion of nano silica: Add 100 kg of nano silica (Aerosil 200) to 900 kg of anhydrous toluene, and stir at 2500 rpm for 30 minutes in a reactor equipped with a high-speed shear stirrer to form a uniform nano silica suspension.

[0051] Step b: Isocyanate grafting reaction: Under nitrogen protection, the temperature of the reactor is raised to 85°C, and 20 kg of isophorone diisocyanate and 0.5 kg of dibutyltin dilaurate are added to the above nano silica suspension while stirring (500 rpm).

[0052] The addition time of isophorone diisocyanate should be controlled within 1 hour.

[0053] After the addition is complete, continue the reaction at 85°C for 2.5 hours. During the addition process, ensure that the reaction temperature does not exceed 90°C.

[0054] Step c: Adding polyether monool: Slowly add 50 kg of polyethylene glycol monomethyl ether (molecular weight 750).

[0055] Step d: Incubation reaction: After the addition is completed, continue the reaction at 85°C for 4 hours until the characteristic peak of isocyanate (-NCO) detected by infrared spectroscopy (FTIR) basically disappears.

[0056] Step e: Post-treatment: The reaction product was cooled to room temperature, and the solid product was separated by centrifugation. The solid was washed four times with anhydrous toluene. Finally, it was dried in a vacuum oven at 60°C for 12 hours to obtain modified nano-silica.

[0057] This embodiment also provides a method for preparing an antistatic photocurable coating, comprising the following steps: Step 1: Base Material Mixing Stage Accurately weigh the polyurethane acrylate, reactive diluent, wetting and dispersing agent, leveling agent and defoamer, and add them to the mixing tank in sequence.

[0058] Stir at 600 rpm for 18 minutes at room temperature (25°C) to ensure that all liquid components are fully mixed and homogeneous to obtain the base material.

[0059] Step 2: Dispersion stage of ultrafine silver powder and modified nano-silica: Step 2a: Add ultrafine silver powder to the above base material while stirring at 400 rpm.

[0060] Step 2b: Add 0.5 kg of modified nano-silica.

[0061] Step 2c: Increase the stirring speed to 2500 rpm and perform vigorous dispersion for 60 minutes. During the dispersion process, control the dispersion temperature at 27±1℃ using jacket cooling.

[0062] The fineness was measured to be 5 micrometers using a scraper fineness gauge.

[0063] Step 3: Reduce the stirring speed to 400 rpm, slowly add the photoinitiator, and continue stirring for 12 minutes until the photoinitiator is completely dissolved and evenly distributed to obtain the coating.

[0064] Step 4: Vacuum degassing and filtration: Step 4a: Transfer the coating to a vacuum degassing device and perform vacuum degassing for 18 minutes at a vacuum level of 0.08 MPa until no bubbles escape from the coating surface.

[0065] Step 4b: After degassing, the coating is precisely filtered through a 250-mesh filter to obtain an antistatic UV-cured coating.

[0066] Performance testing: 1. Surface resistivity: The four-probe method (Keithley 2400 source meter) was used to test the resistivity of solid insulating materials according to GB / T 1410-2006 "Test methods for volume resistivity and surface resistivity of solid insulating materials".

[0067] The coating thickness obtained by antistatic UV-curing coating is controlled at 12 micrometers.

[0068] 2. Adhesion: The cross-cut test was conducted according to GB / T 9286-2021 "Cross-cut test for paint and varnish films". The coating was applied to a PC substrate and then cured.

[0069] 3. Pencil hardness: Tested according to GB / T 6739-2022 "Determination of paint film hardness by pencil method for paints and varnishes".

[0070] 4. Storage stability: Store the antistatic UV-cured coating sample in an environment of 50℃ and 85% humidity for 14 days. After removal, observe the coating layering and the hardness of the bottom sediment.

[0071] Test results: 1. Surface resistivity: 2.6 × 10⁻⁶ 4 Ω / sq.

[0072] 2. Adhesion: Grade 0.

[0073] 3. Pencil hardness: 2H.

[0074] 4. Storage stability: No stratification, no sediment at the bottom, and uniform coating.

[0075] Comparative Example 1 The difference from Example 1 is that the modified nano silica is replaced with commercially available nano silica.

[0076] Test results: 1. Surface resistivity: 5.5 × 10⁻⁶ 5 Ω / sq.

[0077] 2. Adhesion: Level 2.

[0078] 3. Storage stability: There is stratification, with hard sediment at the bottom.

[0079] Commercially available nano-silica has a surface rich in -Si-OH groups, making it hydrophilic and oleophobic. However, it disperses very poorly in PUA resin, failing to separate the silver powder and exhibiting no compatibility with the matrix. This leads to severe agglomeration of the silver powder, significant breakage of the conductive network, and a marked increase in surface resistivity. Although the amount of nano-silica used is relatively low, its poor interfacial compatibility with the organic matrix still affects adhesion. Furthermore, due to the lack of steric hindrance and chemical anchoring, the ultrafine silver powder rapidly settles within 14 days, forming an irreversible hard mass at the bottom, resulting in poor stability.

[0080] Comparative Example 2 The difference from Example 1 is that the preparation of modified nano-silica includes the following steps: Step a: Dispersion of nano silica: Add 100 kg of nano silica (Aerosil 200) to 900 kg of anhydrous toluene, and stir at 2500 rpm for 30 minutes in a reactor equipped with a high-speed shear stirrer to form a uniform nano silica suspension.

[0081] Step b: Isocyanate grafting reaction: Under nitrogen protection, the temperature of the reactor is raised to 85°C, and 20 kg of isophorone diisocyanate and 0.5 kg of dibutyltin dilaurate are added to the above nano silica suspension while stirring (500 rpm).

[0082] The addition time of isophorone diisocyanate should be controlled within 1 hour. During the addition process, ensure that the reaction temperature does not exceed 90°C.

[0083] After the addition is complete, continue the reaction at 85°C for 4 hours.

[0084] Step c: Post-treatment: The reaction product was cooled to room temperature, and the solid product was separated by centrifugation. The solid was washed four times with anhydrous toluene. Finally, it was dried in a vacuum oven at 60°C for 12 hours to obtain modified nano-silica.

[0085] Test results: 1. Surface resistivity: 1.6 × 10⁻⁶ 5 Ω / sq.

[0086] 2. Adhesion: Level 1.

[0087] 3. Storage stability: There is slight stratification, with a small amount of hard sediment at the bottom.

[0088] Comparative Example 2 showed better dispersibility with IPDI anchoring compared to Comparative Example 1, but due to the lack of steric hindrance from polyethylene glycol monomethyl ether, the ultrafine silver powder still exhibited some agglomeration, resulting in an overall increase in surface resistivity. The adhesion showed a decreasing trend compared to Example 1, relying solely on the limited compatibility of the IPDI urethane bonds. IPDI anchoring provided some stability, but due to the lack of steric hindrance from polyethylene glycol monomethyl ether, it still slowly settled during long-term storage.

[0089] Comparative Example 3 The difference from Example 1 is that the preparation of modified nano-silica includes the following steps: Step a: Dispersion of nano silica: Add 100 kg of nano silica (Aerosil 200) to 900 kg of anhydrous toluene, and stir at 2500 rpm for 30 minutes in a reactor equipped with a high-speed shear stirrer to form a uniform nano silica suspension.

[0090] Step b: Under nitrogen protection, the temperature of the reactor is raised to 85°C. While stirring (500 rpm), 50 kg of polyethylene glycol monomethyl ether (molecular weight 750) and 0.5 kg of dibutyltin dilaurate are added to the above nano silica suspension.

[0091] After the addition is complete, continue the reaction at 85°C for 2.5 hours. During the addition process, ensure that the reaction temperature does not exceed 90°C.

[0092] Step c: Slowly add 20 kg of isophorone diisocyanate, controlling the addition time of isophorone diisocyanate to be within 1 hour.

[0093] Step d: Incubation reaction: After the addition is complete, continue the reaction at 85°C for 4 hours.

[0094] Step e: Post-treatment: The reaction product was cooled to room temperature, and the solid product was separated by centrifugation. The solid was washed four times with anhydrous toluene. Finally, it was dried in a vacuum oven at 60°C for 12 hours to obtain modified nano-silica.

[0095] Test results: 1. Surface resistivity: 6.8 × 10⁻⁶ 4 Ω / sq.

[0096] 2. Adhesion: Level 1.

[0097] 3. Storage stability: There is stratification, with a small amount of sediment at the bottom.

[0098] Comparative Example 3 altered the preparation sequence. Because polyethylene glycol monomethyl ether (PEG) first physically adsorbed onto the surface of nano-silica to form a spatial shielding layer, it hindered the contact between isophorone diisocyanate and -Si-OH, resulting in weak anchoring, uneven grafting, and significant consumption of -NCO by PEG. Uneven PEG grafting led to unstable steric hindrance, and the silver powder dispersion was less uniform than in Example 1, with a decreasing trend in surface resistivity. Due to weak anchoring, consumption of -NCO by PEG, and insufficient chemical anchoring function, the interface easily detached, leading to decreased adhesion and poorer storage stability.

[0099] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of this application.

Claims

1. An antistatic UV-curable coating, characterized in that, By weight, the following ingredients are included: Polyurethane acrylate: 40-50 parts by weight; Reactive diluent: 20-30 parts by weight; Photoinitiator: 1-5 parts by weight; Ultrafine silver powder: 12-17 parts by weight; Wetting and dispersing agent: 1-5 parts by weight; Leveling agent: 0.1-1 parts by weight; Defoamer: 0.1-1 parts by weight; Modified nano-silica: 0.1-2 parts by weight.

2. The antistatic photocurable coating according to claim 1, characterized in that, Modified nano silica, by weight, comprises the following raw materials: 95-105 parts nano silica, 850-950 parts solvent, 15-25 parts isocyanate, 0.1-1 parts catalyst, and 45-55 parts polyethylene glycol monomethyl ether.

3. The antistatic photocurable coating according to claim 2, characterized in that, The molecular weight of polyethylene glycol monomethyl ether is 700-800.

4. The antistatic photocurable coating according to claim 2, characterized in that, The isocyanate is isophorone diisocyanate, the catalyst is dibutyltin dilaurate, and the solvent is anhydrous toluene.

5. The antistatic photocurable coating according to claim 2, characterized in that, The preparation of modified nano-silica includes the following steps: Nano-silica is dispersed in a solvent to obtain a nano-silica suspension; Under inert gas protection, isocyanate, catalyst and nano silica suspension were mixed at 82-87℃ and reacted for 2-3 hours. Add polyethylene glycol monomethyl ether and continue the reaction at this temperature for 3-5 hours. The reaction product was cooled, centrifuged, washed, and dried to obtain modified nano-silica.

6. The antistatic photocurable coating according to claim 2, characterized in that, The isocyanate addition time is controlled within 1 hour, and the reaction temperature during the addition process does not exceed 90℃.

7. The antistatic photocurable coating according to claim 1, characterized in that, The reactive diluent includes one or more of isobornyl acrylate, trimethylolpropane triacrylate, and ethoxylated trimethylolpropane triacrylate.

8. A method for preparing an antistatic photocurable coating according to any one of claims 1-7, characterized in that, Includes the following steps: The base material is obtained by mixing polyurethane acrylate, reactive diluent, wetting and dispersing agent, leveling agent and defoamer; Mix the ultrafine silver powder with the base material at 300-500 rpm. Then, modified nano-silica was added and dispersed at 2400-2600 rpm. Continue adding photoinitiator and stirring until homogeneous to obtain an antistatic photocurable coating.

9. The method for preparing the antistatic photocurable coating according to claim 8, characterized in that, After adding a photoinitiator and stirring evenly, the mixture is degassed and filtered to obtain an antistatic photocurable coating.