Antifingerprint coating for automobile touch screen, preparation method and application

Abstract

This invention discloses an anti-fingerprint coating for automotive touchscreens, its preparation method, and its application, relating to the field of industrial coating technology. The coating includes a base layer, an intermediate layer, and a top layer. The base layer is composed of acrylic resin, waterborne epoxy resin, silane coupling agent, nano-silica, defoamer, and deionized water. The intermediate layer is composed of UV-curable resin, reactive diluent, nano-alumina, photoinitiator, leveling agent, and defoamer. The top layer is composed of fluorinated resin, organosilicon resin, hydrophobic nano-silica, solvent, leveling agent, and curing accelerator. The invention is prepared and applied based on these materials. This invention achieves excellent anti-fingerprint capabilities by employing a three-layer structure design and constructing a surface energy gradient structure in the top layer with an inner fluorinated layer and an outer organosilicon layer with nano-texture. The base layer provides strong interfacial bonding, the intermediate layer provides high-hardness scratch-resistant protection, and the surface layer forms a low surface energy and micro-rough structure, achieving a smooth touch and long-lasting stain resistance.

Description

Technical Field

[0001] This invention relates to the field of industrial coatings technology, specifically to an anti-fingerprint coating for automotive touchscreens, its preparation method, and its application. Background Technology

[0002] With the development of intelligent cockpits in the automotive industry, large-size touch displays such as central touchscreens, air conditioning touch panels, and navigation control screens have become the core human-machine interaction windows of vehicles. Under the combined effects of frequent touching, oil stains, environmental temperature changes, and repeated wiping with cleaning agents, vehicle touchscreens are prone to fingerprint residue, oil film contamination, and localized blurring, thus affecting display clarity and touch sensitivity. To improve visual appeal and reduce maintenance frequency, the industry commonly employs anti-fingerprint coating technology, forming a protective film with low surface energy on the touchscreen glass or plastic surface. However, existing anti-fingerprint coating technologies still have significant technical shortcomings.

[0003] Firstly, existing anti-fingerprint coatings mostly rely on a single fluorine-containing material or a single organosilicon material to construct a low surface energy layer, lacking synergistic control over the surface microstructure and surface energy gradient. This means the anti-fingerprint effect relies solely on the material's inherent oleophobic properties, resulting in poor durability. After repeated finger touches and wiping with a damp cloth, the anti-fingerprint ability rapidly declines, easily leading to problems such as difficulty in removing hand oil and surface fogging. Secondly, most traditional coatings employ a single-coat film-forming process, making it difficult to establish a structural gradient within the coating film. This makes it difficult to balance abrasion resistance and anti-fingerprint performance: if the hardness is increased, the feel deteriorates and cracks are easily generated; if flexibility is maintained, scratch resistance is insufficient, making it difficult for the top coating to maintain long-term stability in automotive applications.

[0004] In addition, some existing technologies still have shortcomings in adhesion control, especially on the surfaces of tempered glass, PC or PMMA substrates commonly used in automotive touch panels. Simply relying on resin film formation or physical adsorption methods makes it difficult to achieve long-term stable bonding. After high and low temperature cycles, alcohol wiping, and cleaning agent spraying, the coating is prone to peeling, flaking or cracking, which cannot meet the requirements of the vehicle's overall life cycle. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an anti-fingerprint coating for automotive touchscreens, its preparation method, and its application, thereby resolving the problems mentioned in the background section.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides an anti-fingerprint coating for automotive touchscreens, comprising the following specific components:

[0008] Base coat, intermediate coat, top coat;

[0009] The base coating is composed of acrylic resin, waterborne epoxy resin, silane coupling agent, nano silica, defoamer, and deionized water.

[0010] The intermediate layer is composed of UV-curable resin, reactive diluent, nano-alumina, photoinitiator, leveling agent and defoamer;

[0011] The top coating is composed of fluorinated resin, silicone resin, hydrophobic nano-silica, solvent, leveling agent and curing accelerator.

[0012] To further optimize this technical solution, the base coating comprises the following components in parts by weight:

[0013] 20–40 parts acrylic resin;

[0014] 10–20 parts of waterborne epoxy resin;

[0015] 2–5 parts of silane coupling agent;

[0016] 3–8 parts of nano-silica;

[0017] Defoamer 0.2–0.6 parts;

[0018] 20–35 parts deionized water.

[0019] To further optimize this technical solution, the intermediate layer comprises the following components in parts by weight:

[0020] 25–45 parts of UV-curable resin;

[0021] 10–25 parts of reactive diluent;

[0022] 5–10 parts of nano-alumina;

[0023] 2–6 parts of photoinitiator;

[0024] Leveling agent 0.5–1.5 parts;

[0025] 0.2–0.5 parts of defoamer.

[0026] To further optimize this technical solution, the top coating comprises the following components in parts by weight:

[0027] 5–15 parts of fluorinated resin;

[0028] 10–20 parts of silicone resin;

[0029] 1–3 parts of hydrophobic nano-silica;

[0030] Solvent 30–55 parts;

[0031] Leveling agent 0.2–0.6 parts;

[0032] Curing accelerator 0.5–1 part.

[0033] A method for preparing an anti-fingerprint coating for automotive touchscreens, based on the above-mentioned anti-fingerprint coating for automotive touchscreens, includes the preparation of a base layer, an intermediate layer, and a top layer;

[0034] The preparation of the base coating includes:

[0035] A primer masterbatch was prepared using water-based epoxy resin, deionized water, and acrylic resin.

[0036] A coupling agent-nanoparticle composite dispersion was prepared using nano-silica and silane coupling agent;

[0037] An antifoaming agent is added to the primer stock solution and the coupling agent-nanoparticle composite dispersion to obtain the working solution of the primer layer;

[0038] The preparation of the intermediate layer includes:

[0039] An active diluent is added to the UV-curable resin and stirred to obtain the UV resin base solution;

[0040] An active diluent was added to nano-alumina to perform a two-stage dispersion and surface enrichment treatment of nano-alumina, which was then added to the UV resin base solution.

[0041] After adding a photoinitiator, leveling agent, and defoamer and filtering, the intermediate layer coating is obtained.

[0042] The preparation of the top coating includes:

[0043] Fluorinated resin and organosilicon resin are mixed, and a solvent is added to obtain a fluorinated-organosilicon resin mixture.

[0044] Hydrophobic nano-silica was added to a solvent to prepare a hydrophobic nano-silica sol.

[0045] Hydrophobic nano-silica sol was added to a fluorinated-organic silicone resin mixture, and leveling aids and curing accelerators were added in sequence to obtain the topcoat application solution.

[0046] To further optimize this technical solution, the preparation of the base coating, specifically the preparation of the coupling agent-nanoparticle composite dispersion, includes:

[0047] Add nano-silica to a small amount of deionized water and pre-stir at 600–1000 rpm for 10–15 minutes to initially wet the powder; then use ultrasonic dispersion for 15–30 minutes to prevent the nano-silica from agglomerating significantly.

[0048] Under the premise of stable suspension of nano-silica, silane coupling agent is slowly added dropwise, with the addition time controlled at 10–20 minutes. At the same time, the pH of the system is adjusted to 4.0–5.5, and the mixture is stirred for 40–60 minutes at 25–35℃ to allow the silane coupling agent to undergo hydrolysis and condensation reaction on the surface of nano-silica, forming a coating layer and obtaining a composite dispersion.

[0049] To further optimize this technical solution, the preparation of the intermediate layer involves a two-stage dispersion and surface enrichment treatment of nano-alumina, including:

[0050] Add the active diluent to the nano alumina and disperse it at high speed at 1000–2000 rpm for 20–40 minutes to form a suspension slurry with uniform particle size of nano alumina.

[0051] The nano-alumina slurry was then slowly added to the UV resin base liquid under stirring conditions. After stirring for 20–30 minutes, the system was allowed to stand for 30–90 minutes, allowing the nanoparticles to form a slightly enriched distribution near the liquid surface under the influence of gravity and resin rheological behavior.

[0052] An application of an anti-fingerprint coating for automotive touchscreens, based on the aforementioned anti-fingerprint coating for automotive touchscreens, includes the application of a base coat, an intermediate coat, and a top coat.

[0053] Applications of the primer coating include:

[0054] The working fluid of the base coating is uniformly applied to the surface of the automotive touch screen substrate by spraying, rolling or dipping, and the wet film thickness is controlled at 3–8 μm.

[0055] After coating, a segmented gradient temperature drying process is used to allow the resin system to fully form a film and promote the reaction between the coupling agent and the substrate surface to form a dense and adherent underlayer.

[0056] The applications of the middleware layer include:

[0057] The intermediate layer coating is applied to the surface of the cured base layer by spraying or roller coating, with the wet film thickness controlled at 2–6 μm;

[0058] A two-stage UV curing process is used for pre-curing and full curing to obtain the intermediate layer;

[0059] Topcoat applications include:

[0060] Apply the topcoat liquid to the cured intermediate layer in a clean environment for the first thin coat, and then spray the same surface a second time to complete the two film-forming processes.

[0061] After film formation, bake at 100–140℃ for 15–30 minutes to allow the fluorinated resin and silicone resin to undergo further crosslinking or condensation, thereby obtaining the top coating and completing the application of the coating.

[0062] To further optimize this technical solution, the intermediate layer utilizes a two-stage UV curing process, including:

[0063] The first stage uses a low-energy-density UV light source of 200–400 mJ / cm² for pre-curing for 1–5 seconds, which allows the coating surface to quickly form an initial cross-linked network and lock the gradient distribution of nanoparticles.

[0064] The second stage uses a high-energy-density UV light source of 600–1200 mJ / cm² for complete curing for 5–20 seconds, which allows the entire intermediate layer system to be fully cross-linked, thereby obtaining the intermediate layer.

[0065] Further optimization of this technical solution, in the application of the top coating:

[0066] The first thin coating is applied, with the wet film thickness controlled at 0.5–1.5 μm. After coating, the film is flash-dried at 50–70 °C for 1–3 minutes to form an initial low surface energy thin layer mainly composed of fluorinated resin.

[0067] For the second spraying, the wet film thickness is controlled at 1–3 μm. After spraying, it is dried at 70–90℃ for 5–10 minutes to allow the silicone resin to migrate to the outermost surface under the drive of interfacial tension.

[0068] Compared with the prior art, the present invention provides an anti-fingerprint coating for automotive touchscreens, a preparation method thereof, and its application, which has the following beneficial effects:

[0069] This automotive touchscreen anti-fingerprint coating, its preparation method, and its application utilize a three-layer structure design. The top coating features a surface energy gradient structure consisting of an inner fluorine-containing layer and an outer silicone layer with nano-texture. This not only achieves excellent anti-fingerprint capabilities but also maintains stable performance under prolonged touch, repeated wiping, and temperature variations. The bottom coating provides strong interfacial bonding, the middle layer offers high-hardness scratch-resistant protection, and the surface layer forms a stable low surface energy and micro-roughness structure, resulting in a smooth touch and long-lasting stain resistance. This ensures the touchscreen remains clear, clean, and comfortable to the touch even in the complex automotive environment, significantly improving the human-machine interaction experience and overall vehicle quality. Attached Figure Description

[0070] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0071] Figure 1 This is a schematic diagram illustrating the composition of an anti-fingerprint coating for automotive touchscreens proposed in this invention.

[0072] Figure 2 This is a schematic flowchart of a method for preparing an anti-fingerprint coating for automotive touchscreens proposed in this invention. Detailed Implementation

[0073] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0074] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0075] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it a single embodiment or an embodiment selectively excluded from other embodiments.

[0076] Reference Figure 1 An anti-fingerprint coating for automotive touchscreens comprises the following specific components: a base coat, an intermediate coat, and a top coat.

[0077] The base coating is composed of acrylic resin, waterborne epoxy resin, silane coupling agent, nano silica, defoamer, and deionized water.

[0078] The base coating comprises, by weight, the following components:

[0079] Acrylic resin 20–40 parts; as the main film-forming substance, it can form a uniform film layer with a certain degree of flexibility on the substrate surface, thereby improving the initial adhesion of the overall coating system.

[0080] 10–20 parts of waterborne epoxy resin; it has excellent chemical reactivity and can form a dense gel network at low temperatures, which can form an interface bond with glass or plastic touch screen substrates, further improving the chemical resistance and adhesion of the coating.

[0081] 2–5 parts of silane coupling agent; as an interface bridging material, its hydrolyzed active groups can condense with the hydroxyl groups on the surface of glass or plastic substrates, while the other end combines with the resin system, thereby significantly improving the adhesion of the primer to the touch screen surface.

[0082] 3–8 parts of nano-silica; used to improve the mechanical strength of the substrate, giving the base coating a certain degree of scratch resistance and wear resistance, and preventing the upper coating from peeling off due to substrate wear.

[0083] Defoamer 0.2–0.6 parts; used to suppress bubble formation during mixing and application, ensuring the density and transparency of the coating film.

[0084] 20–35 parts deionized water; used as a dispersion medium and viscosity modifier to give the overall primer system good workability and leveling properties.

[0085] The intermediate layer is composed of UV-curable resin, reactive diluent, nano-alumina, photoinitiator, leveling agent, and defoamer.

[0086] The intermediate layer comprises, by weight, the following components:

[0087] 25–45 parts of UV-curable resin; providing a high-hardness matrix that rapidly cross-links into a film after UV irradiation, forming a high-hardness, wear-resistant protective layer on the touchscreen surface.

[0088] 10–25 parts of reactive diluent; used to adjust the viscosity of the system to make it suitable for spraying or roller coating, and at the same time participates in the cross-linking reaction with the resin during the curing process without causing dilution damage to the film quality.

[0089] 5–10 parts of nano-alumina can significantly improve the scratch resistance of the intermediate layer surface and reduce the minor wear and tear that occurs during touch use.

[0090] Photoinitiator 2–6 parts; decomposes into free radicals or cations under UV light, promoting rapid resin curing, and is an important component for achieving second-level curing of the intermediate layer.

[0091] Leveling agent 0.5–1.5 parts; used to improve the spreading ability of coatings during construction, making the surface smoother and more transparent after UV curing, which helps to improve the display effect.

[0092] Defoamer 0.2–0.5 parts; used to eliminate microbubbles in the coating liquid, ensuring the optical transparency and overall strength of the hardened layer.

[0093] The top coating is composed of fluorinated resin, silicone resin, hydrophobic nano-silica, solvent, leveling agent and curing accelerator.

[0094] The top coating comprises, by weight, the following components:

[0095] 5–15 parts of fluorinated resin; the core anti-fingerprint component, which has extremely low surface energy, making it difficult for finger oils and stains to adhere to the surface, thus giving the touchscreen excellent anti-fingerprint and easy-to-clean properties.

[0096] 10–20 parts of silicone resin; further enhances the lubricity of the coating surface, making the touch feel smoother, while improving stain resistance and watermark resistance.

[0097] 1–3 parts of hydrophobic nano silica; it has a natural micro-nano structure, which can build fine textures on the surface during film formation, and together with fluorinated resin, it forms a hydrophobic and oleophobic effect, making it difficult for fingerprints to adhere and easy to wipe away.

[0098] Solvent 30–55 parts; as the volatile medium of the system, used to adjust viscosity and ensure uniformity during spraying or dipping.

[0099] Leveling agent 0.2–0.6 parts; improves the spreading and film-forming quality of the topcoat, and avoids defects such as pinholes and orange peel.

[0100] Curing accelerator 0.5–1 part; used to accelerate film formation and crosslinking of the resin system, and improve the durability and stability of the top anti-fingerprint film.

[0101] Reference Figure 2 A method for preparing an anti-fingerprint coating for automotive touchscreens, based on the aforementioned anti-fingerprint coating for automotive touchscreens, includes the preparation of a base layer, an intermediate layer, and a top layer.

[0102] The preparation of the base coating includes:

[0103] Aqueous epoxy resin and deionized water are added to a stirred tank equipped with stirring and temperature control. The mixture is stirred at 400–800 rpm for 20–30 minutes at 25–35°C to ensure complete dispersion of the aqueous epoxy resin and the formation of a homogeneous aqueous phase. Acrylic resin is then slowly added under continuous stirring, with the addition time controlled within 10–20 minutes to prevent sudden increases in viscosity in certain areas. Stirring continues for 20–40 minutes to obtain a transparent or slightly milky-white primer masterbatch.

[0104] First, add a small amount of nano-silica (e.g., 10–20% of the total water volume) to deionized water and pre-stir at 600–1000 rpm for 10–15 minutes to initially wet the powder. Then, use ultrasonic dispersion (frequency 20–40 kHz) for 15–30 minutes to prevent the nano-silica from agglomerating significantly.

[0105] Under the premise of stable suspension of nano-silica, silane coupling agent is slowly added dropwise, with the addition time controlled at 10–20 minutes. At the same time, the pH of the system is adjusted to 4.0–5.5 (which can be controlled by a small amount of organic acid or weak acid buffer). Stirring is continued at 25–35℃ for 40–60 minutes to allow the silane coupling agent to undergo hydrolysis and condensation reaction on the surface of nano-silica, forming a coating layer and obtaining a stable coupling agent-nanoparticle composite dispersion, which enhances both adhesion and wear resistance.

[0106] The above coupling agent-nanoparticle composite dispersion was slowly added to the base coat stock solution at 300–600 rpm, with stirring maintained during the addition process to avoid excessively high local concentrations. After thorough mixing, the defoamer was added, and the mixture was stirred for another 10–20 minutes. Subsequently, the system was filtered through a 1–5 μm filter to remove large particles and possible impurities and foam, yielding the working solution for the base coat.

[0107] The preparation of the intermediate layer includes:

[0108] Add the UV-curing resin to a mixing container, control the temperature at 25–35°C, and stir at 300–600 rpm for 10–20 minutes to eliminate internal stress and air bubbles in the resin. Then add the reactive diluent in batches, stirring for 10–15 minutes after each addition, so that the viscosity of the system is gradually adjusted to a suitable range for application (e.g., 100–500 mPa·s) to obtain the UV resin base liquid.

[0109] Take the active diluent in another container and add it to the nano alumina. Disperse it at high speed at 1000–2000 rpm for 20–40 minutes. If necessary, sonicate it for 10–20 minutes to form a suspension slurry with uniform particle size.

[0110] The nano-alumina slurry was then slowly added to the aforementioned UV resin base liquid under stirring conditions. After stirring for 20–30 minutes, the system was allowed to stand for 30–90 minutes, allowing the nanoparticles to form a slightly enriched distribution near the liquid surface under the influence of gravity and resin rheological behavior.

[0111] Under light-protected conditions, add the photoinitiator, leveling agent, and defoamer to the above system and stir for 15–30 minutes until completely dissolved and dispersed. Then filter using a 1–5 μm filter cartridge to remove coarse particles and insoluble matter, obtaining a stable intermediate layer coating.

[0112] The preparation of the top coating includes:

[0113] Add fluorinated resin and silicone resin to a mixing vessel, control the temperature at 20–30°C, and stir at 300–600 rpm for 20–30 minutes to ensure thorough mixing of the two resins in the solvent system. Subsequently, add solvent (alcohol or ester) in batches to adjust the overall solid content and viscosity to suit spraying or dip coating (e.g., viscosity controlled at 20–100 mPa·s) to obtain a fluorinated-silicone resin mixture.

[0114] Hydrophobic nano-silica is added to a solvent and stirred at 800–1500 rpm for 15–30 minutes, with sonication for 10–20 minutes if necessary, to ensure uniform dispersion of the hydrophobic nano-silica and the formation of a relatively stable nano-sol. This nano-sol is then slowly added to a fluorinated-organic silicone resin mixture under stirring, and stirring is continued for 20–30 minutes to allow the nano-hydrophobic particles and the low surface energy resin to co-form a potential microtextured structure.

[0115] Hydrophobic nano-silica sol is added to a fluorinated silicone resin mixture. After the resin mixture and nano-sol are fully combined, a leveling agent is added at a low stirring speed of 300–500 rpm. After adding the leveling agent, stirring continues for 10–15 minutes to ensure complete dissolution and uniform distribution. Subsequently, a curing accelerator is added, and stirring continues for another 10–20 minutes to ensure the system is homogeneous and stable, thus obtaining the topcoat application solution.

[0116] An application of an anti-fingerprint coating for automotive touchscreens, based on the aforementioned anti-fingerprint coating for automotive touchscreens, includes the application of a base coat, an intermediate coat, and a top coat.

[0117] Applications of the primer coating include:

[0118] The working fluid of the base coating is uniformly applied to the surface of the automotive touch screen substrate by spraying, rolling or dipping, and the wet film thickness is controlled at 3–8 μm.

[0119] After coating, a segmented gradient temperature drying process is adopted: first, pre-dry at 50–70℃ for 3–8 minutes to allow moisture and a small amount of low-boiling-point system to slowly evaporate, then raise to 90–110℃ and keep at that temperature for 10–20 minutes to allow the resin system to fully form a film and promote the reaction between the coupling agent and the substrate surface to form a dense and adherent underlayer.

[0120] The applications of the middleware layer include:

[0121] The intermediate layer coating is applied to the surface of the cured base layer by spraying or roller coating, with the wet film thickness controlled at 2–6 μm;

[0122] A two-stage UV curing process is used to perform pre-curing and full curing to obtain the intermediate layer.

[0123] The two-stage UV curing process includes:

[0124] The first stage uses a low-energy-density UV light source of 200–400 mJ / cm² for pre-curing for 1–5 seconds, which allows the coating surface to quickly form an initial cross-linked network, locks the gradient distribution of nanoparticles, and at the same time maintains a certain degree of fluidity inside.

[0125] The second stage uses a high-energy-density UV light source of 600–1200 mJ / cm² for complete curing for 5–20 seconds, which allows the entire intermediate layer system to be fully cross-linked, thereby obtaining the intermediate layer.

[0126] Topcoat applications include:

[0127] Apply the topcoat liquid to the cured intermediate layer in a clean environment for the first thin coat, and then spray the same surface a second time to complete the two film-forming processes.

[0128] The first thin coating is applied, with the wet film thickness controlled at 0.5–1.5 μm. After coating, the film is flash-dried at 50–70 °C for 1–3 minutes to form an initial low surface energy thin layer mainly composed of fluorinated resin, but still retaining a certain surface activity.

[0129] The second coating is applied with a wet film thickness controlled at 1–3 μm. After coating, the film is dried at 70–90℃ for 5–10 minutes, which allows the silicone resin to migrate to the outermost surface under the drive of interfacial tension, forming a surface energy gradient structure of “inner fluorinated resin and outer silicone enrichment”. At the same time, hydrophobic nano-silica forms fine textures on the outermost layer.

[0130] After film formation, bake at 100–140℃ for 15–30 minutes to allow the fluorinated resin and silicone resin to further crosslink or condense, fix the nanotexture structure and stabilize the surface energy. If necessary, a short hot air blowing at 80–100℃ can be added in the early stage of curing to promote the appearance of surface microtexture, thereby obtaining the top coating and completing the application of the coating.

[0131] Example 1:

[0132] Base coat: 20 parts acrylic resin, 10 parts waterborne epoxy resin, 2 parts silane coupling agent, 3 parts nano silica, 0.2 parts defoamer, and 35 parts deionized water.

[0133] Intermediate layer: 25 parts UV-curable resin, 10 parts reactive diluent, 5 parts nano alumina, 2 parts photoinitiator, 0.5 parts leveling agent, and 0.2 parts defoamer.

[0134] Top coating: 5 parts fluorinated resin, 10 parts silicone resin, 1 part hydrophobic nano silica, 55 parts solvent, 0.2 parts leveling agent, and 0.5 parts curing accelerator.

[0135] The preparation of an anti-fingerprint coating for automotive touchscreens includes the preparation of a base coat, an intermediate coat, and a top coat.

[0136] The preparation of the base coating includes:

[0137] Aqueous epoxy resin and deionized water were added to a stirred tank equipped with stirring and temperature control. The mixture was stirred at 800 rpm for 30 minutes at 35°C to ensure complete dispersion of the aqueous epoxy resin and the formation of a homogeneous aqueous phase. Subsequently, acrylic resin was slowly added under continuous stirring, with the addition time controlled within 20 minutes to prevent sudden increases in viscosity in certain areas. Stirring was continued for another 40 minutes to obtain a transparent or slightly milky white primer masterbatch.

[0138] First, add a small amount of deionized water (20% of the total water volume) to the nano-silica and pre-stir at 1000 rpm for 15 minutes to initially wet the powder. Then, use ultrasonic dispersion (frequency 40 kHz) for 30 minutes to prevent the nano-silica from agglomerating significantly.

[0139] Under the premise of stable suspension of nano-silica, silane coupling agent is slowly added dropwise, with the addition time controlled at 20 minutes. At the same time, the pH of the system is adjusted to 4.0, and the mixture is stirred for another 60 minutes at 35°C. This allows the silane coupling agent to undergo hydrolysis and condensation reactions on the surface of nano-silica, forming a coating layer and resulting in a stable coupling agent-nanoparticle composite dispersion, which enhances both adhesion and wear resistance.

[0140] The above-mentioned coupling agent-nanoparticle composite dispersion was slowly added to the base coat stock solution at 600 rpm, while stirring continuously to avoid excessively high local concentrations. After thorough mixing, the defoamer was added, and the mixture was stirred for another 20 minutes. Subsequently, the system was filtered through a 5 μm filter to remove large particles and possible impurities and foam, yielding the working solution for the base coat.

[0141] The preparation of the intermediate layer includes:

[0142] Add the UV-curing resin to a mixing container, control the temperature at 35℃, and stir at 600 rpm for 20 minutes to eliminate internal stress and air bubbles in the resin. Then add the reactive diluent in batches, stirring for 15 minutes after each addition, so that the viscosity of the system is gradually adjusted to a suitable range for application (100–500 mPa·s), thus obtaining the UV resin base liquid.

[0143] Take the active diluent from another container and add it to the nano alumina. Disperse it at high speed at 2000 rpm for 40 minutes, followed by 20 minutes of ultrasonication, so that the nano alumina forms a suspension slurry with uniform particle size.

[0144] The nano-alumina slurry was then slowly added to the aforementioned UV resin base liquid under stirring conditions. After stirring for 30 minutes, the system was allowed to stand for 90 minutes, allowing the nanoparticles to form a slightly enriched distribution near the liquid surface under the influence of gravity and resin rheological behavior.

[0145] Under light-protected conditions, a photoinitiator, leveling agent, and defoamer were added to the above system, and the mixture was stirred for 30 minutes until completely dissolved and dispersed. The mixture was then filtered using a 5μm filter to remove coarse particles and insoluble matter, resulting in a stable intermediate coating layer.

[0146] The preparation of the top coating includes:

[0147] Fluorinated resin and silicone resin were added to a mixing vessel, and the temperature was controlled at 30°C. The mixture was stirred at 600 rpm for 30 minutes to ensure that the two resins were fully mixed in the solvent system. Subsequently, solvent (alcohol) was added in batches to adjust the overall solid content and viscosity to make it suitable for spraying or dip coating (viscosity controlled at 100 mPa·s) to obtain a fluorinated-silicone resin mixture.

[0148] Hydrophobic nano-silica was added to a solvent and stirred at 1500 rpm for 30 minutes, followed by 20 minutes of sonication, to ensure uniform dispersion of the hydrophobic nano-silica and the formation of a relatively stable nano-sol. This nano-sol was then slowly added to a fluorinated-organosilicon resin mixture under stirring, and stirring was continued for another 30 minutes.

[0149] Hydrophobic nano-silica sol was added to a fluorinated silicone resin mixture. After the resin mixture and nano-sol were fully combined, a leveling agent was added at a low stirring speed of 500 rpm. After adding the leveling agent, stirring was continued for 15 minutes to ensure complete dissolution and uniform distribution. Subsequently, a curing accelerator was added, and stirring was continued for another 20 minutes to ensure the system was homogeneous and stable, thus obtaining the topcoat application liquid.

[0150] The application of anti-fingerprint coatings for automotive touchscreens includes the application of base coats, intermediate coats, and top coats.

[0151] Applications of the primer coating include:

[0152] The working fluid of the base coating layer is evenly applied to the surface of the automotive touch screen substrate by spraying, and the wet film thickness is controlled at 3–8 μm.

[0153] After coating, a segmented gradient temperature drying process is adopted: first, pre-dry at 70℃ for 8 minutes to allow moisture and a small amount of low boiling point system to slowly evaporate, then raise to 110℃ and keep warm for 20 minutes to allow the resin system to fully form a film and promote the reaction between the coupling agent and the substrate surface to form a dense adhesion underlayer.

[0154] The applications of the middleware layer include:

[0155] The intermediate layer coating is applied to the surface of the cured base layer by spraying, and the wet film thickness is controlled at 2–6 μm.

[0156] A two-stage UV curing process is used to perform pre-curing and full curing to obtain the intermediate layer.

[0157] The two-stage UV curing process includes:

[0158] The first stage uses a low-energy-density UV light source of 400mJ / cm² for pre-curing for 5 seconds, which allows the coating surface to quickly form an initial cross-linked network, locks the gradient distribution of nanoparticles, and at the same time maintains a certain degree of fluidity inside.

[0159] The second stage uses a high-energy-density UV light source of 1200mJ / cm² for complete curing for 20 seconds, which allows the entire intermediate layer system to be fully cross-linked, thereby obtaining the intermediate layer.

[0160] Topcoat applications include:

[0161] Apply the topcoat liquid to the cured intermediate layer in a clean environment for the first thin coat, and then spray the same surface a second time to complete the two film-forming processes.

[0162] The first thin coating is applied, with the wet film thickness controlled between 0.5 and 1.5 μm. After coating, the film is flash-dried at 70°C for 3 minutes to form an initial low surface energy thin layer mainly composed of fluorinated resin, but still retains a certain surface activity.

[0163] The second coating is applied with a wet film thickness controlled at 1–3 μm. After coating, the film is dried at 90°C for 10 minutes, which allows the silicone resin to migrate to the outermost surface under the drive of interfacial tension, forming a surface energy gradient structure of “inner fluorinated resin and outer silicone enrichment”. At the same time, hydrophobic nano-silica forms fine textures on the outermost layer.

[0164] After film formation, the film is baked at 140℃ for 30 minutes to allow the fluorinated resin and silicone resin to further crosslink or condense, fix the nanotexture structure and stabilize the surface energy. In the early stage of curing, a short-term hot air blowing at 100℃ is added to promote the appearance of surface microtexture, thereby obtaining the top coating and completing the application of the coating.

[0165] Example 2:

[0166] Base coat: 30 parts acrylic resin, 15 parts waterborne epoxy resin, 3.5 parts silane coupling agent, 5 parts nano silica, 0.4 parts defoamer, and 28 parts deionized water.

[0167] Intermediate layer: 35 parts UV-curable resin, 18 parts reactive diluent, 7.5 parts nano alumina, 4 parts photoinitiator, 1.0 part leveling agent, and 0.3 parts defoamer.

[0168] Top coating: 10 parts fluorinated resin, 15 parts silicone resin, 2 parts hydrophobic nano silica, 42 parts solvent, 0.4 parts leveling agent, and 0.8 parts curing accelerator.

[0169] The preparation of an anti-fingerprint coating for automotive touchscreens includes the preparation of a base coat, an intermediate coat, and a top coat.

[0170] The preparation of the base coating includes:

[0171] Aqueous epoxy resin and deionized water were added to a stirred tank equipped with stirring and temperature control. The mixture was stirred at 800 rpm for 30 minutes at 35°C to ensure complete dispersion of the aqueous epoxy resin and the formation of a homogeneous aqueous phase. Subsequently, acrylic resin was slowly added under continuous stirring, with the addition time controlled within 20 minutes to prevent sudden increases in viscosity in certain areas. Stirring was continued for another 40 minutes to obtain a transparent or slightly milky white primer masterbatch.

[0172] First, add a small amount of deionized water (20% of the total water volume) to the nano-silica and pre-stir at 1000 rpm for 15 minutes to initially wet the powder. Then, use ultrasonic dispersion (frequency 40 kHz) for 30 minutes to prevent the nano-silica from agglomerating significantly.

[0173] Under the premise of stable suspension of nano-silica, silane coupling agent is slowly added dropwise, with the addition time controlled at 20 minutes. At the same time, the pH of the system is adjusted to 4.0, and the mixture is stirred for another 60 minutes at 35°C. This allows the silane coupling agent to undergo hydrolysis and condensation reactions on the surface of nano-silica, forming a coating layer and resulting in a stable coupling agent-nanoparticle composite dispersion, which enhances both adhesion and wear resistance.

[0174] The above-mentioned coupling agent-nanoparticle composite dispersion was slowly added to the base coat stock solution at 600 rpm, while stirring continuously to avoid excessively high local concentrations. After thorough mixing, the defoamer was added, and the mixture was stirred for another 20 minutes. Subsequently, the system was filtered through a 5 μm filter to remove large particles and possible impurities and foam, yielding the working solution for the base coat.

[0175] The preparation of the intermediate layer includes:

[0176] Add the UV-curing resin to a mixing container, control the temperature at 35℃, and stir at 600 rpm for 20 minutes to eliminate internal stress and air bubbles in the resin. Then add the reactive diluent in batches, stirring for 15 minutes after each addition, so that the viscosity of the system is gradually adjusted to a suitable range for application (100–500 mPa·s), thus obtaining the UV resin base liquid.

[0177] Take the active diluent from another container and add it to the nano alumina. Disperse it at high speed at 2000 rpm for 40 minutes, followed by 20 minutes of ultrasonication, so that the nano alumina forms a suspension slurry with uniform particle size.

[0178] The nano-alumina slurry was then slowly added to the aforementioned UV resin base liquid under stirring conditions. After stirring for 30 minutes, the system was allowed to stand for 90 minutes, allowing the nanoparticles to form a slightly enriched distribution near the liquid surface under the influence of gravity and resin rheological behavior.

[0179] Under light-protected conditions, a photoinitiator, leveling agent, and defoamer were added to the above system, and the mixture was stirred for 30 minutes until completely dissolved and dispersed. The mixture was then filtered using a 5μm filter to remove coarse particles and insoluble matter, resulting in a stable intermediate coating layer.

[0180] The preparation of the top coating includes:

[0181] Fluorinated resin and silicone resin were added to a mixing vessel, and the temperature was controlled at 30°C. The mixture was stirred at 600 rpm for 30 minutes to ensure that the two resins were fully mixed in the solvent system. Subsequently, solvent (alcohol) was added in batches to adjust the overall solid content and viscosity to make it suitable for spraying or dip coating (viscosity controlled at 100 mPa·s) to obtain a fluorinated-silicone resin mixture.

[0182] Hydrophobic nano-silica was added to a solvent and stirred at 1500 rpm for 30 minutes, followed by 20 minutes of sonication, to ensure uniform dispersion of the hydrophobic nano-silica and the formation of a relatively stable nano-sol. This nano-sol was then slowly added to a fluorinated-organosilicon resin mixture under stirring, and stirring was continued for another 30 minutes.

[0183] Hydrophobic nano-silica sol was added to a fluorinated silicone resin mixture. After the resin mixture and nano-sol were fully combined, a leveling agent was added at a low stirring speed of 500 rpm. After adding the leveling agent, stirring was continued for 15 minutes to ensure complete dissolution and uniform distribution. Subsequently, a curing accelerator was added, and stirring was continued for another 20 minutes to ensure the system was homogeneous and stable, thus obtaining the topcoat application liquid.

[0184] The application of anti-fingerprint coatings for automotive touchscreens includes the application of base coats, intermediate coats, and top coats.

[0185] Applications of the primer coating include:

[0186] The working fluid of the base coating layer is evenly applied to the surface of the automotive touch screen substrate by spraying, and the wet film thickness is controlled at 3–8 μm.

[0187] After coating, a segmented gradient temperature drying process is adopted: first, pre-dry at 70℃ for 8 minutes to allow moisture and a small amount of low boiling point system to slowly evaporate, then raise to 110℃ and keep warm for 20 minutes to allow the resin system to fully form a film and promote the reaction between the coupling agent and the substrate surface to form a dense adhesion underlayer.

[0188] The applications of the middleware layer include:

[0189] The intermediate layer coating is applied to the surface of the cured base layer by spraying, and the wet film thickness is controlled at 2–6 μm.

[0190] A two-stage UV curing process is used to perform pre-curing and full curing to obtain the intermediate layer.

[0191] The two-stage UV curing process includes:

[0192] The first stage uses a low-energy-density UV light source of 400mJ / cm² for pre-curing for 5 seconds, which allows the coating surface to quickly form an initial cross-linked network, locks the gradient distribution of nanoparticles, and at the same time maintains a certain degree of fluidity inside.

[0193] The second stage uses a high-energy-density UV light source of 1200mJ / cm² for complete curing for 20 seconds, which allows the entire intermediate layer system to be fully cross-linked, thereby obtaining the intermediate layer.

[0194] Topcoat applications include:

[0195] Apply the topcoat liquid to the cured intermediate layer in a clean environment for the first thin coat, and then spray the same surface a second time to complete the two film-forming processes.

[0196] The first thin coating is applied, with the wet film thickness controlled between 0.5 and 1.5 μm. After coating, the film is flash-dried at 70°C for 3 minutes to form an initial low surface energy thin layer mainly composed of fluorinated resin, but still retains a certain surface activity.

[0197] The second coating is applied with a wet film thickness controlled at 1–3 μm. After coating, the film is dried at 90°C for 10 minutes, which allows the silicone resin to migrate to the outermost surface under the drive of interfacial tension, forming a surface energy gradient structure of “inner fluorinated resin and outer silicone enrichment”. At the same time, hydrophobic nano-silica forms fine textures on the outermost layer.

[0198] After film formation, the film is baked at 140℃ for 30 minutes to allow the fluorinated resin and silicone resin to further crosslink or condense, fix the nanotexture structure and stabilize the surface energy. In the early stage of curing, a short-term hot air blowing at 100℃ is added to promote the appearance of surface microtexture, thereby obtaining the top coating and completing the application of the coating.

[0199] Example 3:

[0200] Base coat: 40 parts acrylic resin, 20 parts waterborne epoxy resin, 5 parts silane coupling agent, 8 parts nano silica, 0.6 parts defoamer, and 20 parts deionized water.

[0201] Intermediate layer: 45 parts UV-curable resin, 25 parts reactive diluent, 10 parts nano alumina, 6 parts photoinitiator, 1.5 parts leveling agent, and 0.5 parts defoamer.

[0202] Top coating: 15 parts fluorinated resin, 20 parts silicone resin, 3 parts hydrophobic nano silica, 30 parts solvent, 0.6 parts leveling agent, and 1.0 part curing accelerator.

[0203] The preparation of an anti-fingerprint coating for automotive touchscreens includes the preparation of a base coat, an intermediate coat, and a top coat.

[0204] The preparation of the base coating includes:

[0205] Aqueous epoxy resin and deionized water were added to a stirred tank equipped with stirring and temperature control. The mixture was stirred at 800 rpm for 30 minutes at 35°C to ensure complete dispersion of the aqueous epoxy resin and the formation of a homogeneous aqueous phase. Subsequently, acrylic resin was slowly added under continuous stirring, with the addition time controlled within 20 minutes to prevent sudden increases in viscosity in certain areas. Stirring was continued for another 40 minutes to obtain a transparent or slightly milky white primer masterbatch.

[0206] First, add a small amount of deionized water (20% of the total water volume) to the nano-silica and pre-stir at 1000 rpm for 15 minutes to initially wet the powder. Then, use ultrasonic dispersion (frequency 40 kHz) for 30 minutes to prevent the nano-silica from agglomerating significantly.

[0207] Under the premise of stable suspension of nano-silica, silane coupling agent is slowly added dropwise, with the addition time controlled at 20 minutes. At the same time, the pH of the system is adjusted to 4.0, and the mixture is stirred for another 60 minutes at 35°C. This allows the silane coupling agent to undergo hydrolysis and condensation reactions on the surface of nano-silica, forming a coating layer and resulting in a stable coupling agent-nanoparticle composite dispersion, which enhances both adhesion and wear resistance.

[0208] The above-mentioned coupling agent-nanoparticle composite dispersion was slowly added to the base coat stock solution at 600 rpm, while stirring continuously to avoid excessively high local concentrations. After thorough mixing, the defoamer was added, and the mixture was stirred for another 20 minutes. Subsequently, the system was filtered through a 5 μm filter to remove large particles and possible impurities and foam, yielding the working solution for the base coat.

[0209] The preparation of the intermediate layer includes:

[0210] Add the UV-curing resin to a mixing container, control the temperature at 35℃, and stir at 600 rpm for 20 minutes to eliminate internal stress and air bubbles in the resin. Then add the reactive diluent in batches, stirring for 15 minutes after each addition, so that the viscosity of the system is gradually adjusted to a suitable range for application (100–500 mPa·s), thus obtaining the UV resin base liquid.

[0211] Take the active diluent from another container and add it to the nano alumina. Disperse it at high speed at 2000 rpm for 40 minutes, followed by 20 minutes of ultrasonication, so that the nano alumina forms a suspension slurry with uniform particle size.

[0212] The nano-alumina slurry was then slowly added to the aforementioned UV resin base liquid under stirring conditions. After stirring for 30 minutes, the system was allowed to stand for 90 minutes, allowing the nanoparticles to form a slightly enriched distribution near the liquid surface under the influence of gravity and resin rheological behavior.

[0213] Under light-protected conditions, a photoinitiator, leveling agent, and defoamer were added to the above system, and the mixture was stirred for 30 minutes until completely dissolved and dispersed. The mixture was then filtered using a 5μm filter to remove coarse particles and insoluble matter, resulting in a stable intermediate coating layer.

[0214] The preparation of the top coating includes:

[0215] Fluorinated resin and silicone resin were added to a mixing vessel, and the temperature was controlled at 30°C. The mixture was stirred at 600 rpm for 30 minutes to ensure that the two resins were fully mixed in the solvent system. Subsequently, solvent (alcohol) was added in batches to adjust the overall solid content and viscosity to make it suitable for spraying or dip coating (viscosity controlled at 100 mPa·s) to obtain a fluorinated-silicone resin mixture.

[0216] Hydrophobic nano-silica was added to a solvent and stirred at 1500 rpm for 30 minutes, followed by 20 minutes of sonication, to ensure uniform dispersion of the hydrophobic nano-silica and the formation of a relatively stable nano-sol. This nano-sol was then slowly added to a fluorinated-organosilicon resin mixture under stirring, and stirring was continued for another 30 minutes.

[0217] Hydrophobic nano-silica sol was added to a fluorinated silicone resin mixture. After the resin mixture and nano-sol were fully combined, a leveling agent was added at a low stirring speed of 500 rpm. After adding the leveling agent, stirring was continued for 15 minutes to ensure complete dissolution and uniform distribution. Subsequently, a curing accelerator was added, and stirring was continued for another 20 minutes to ensure the system was homogeneous and stable, thus obtaining the topcoat application liquid.

[0218] The application of anti-fingerprint coatings for automotive touchscreens includes the application of base coats, intermediate coats, and top coats.

[0219] Applications of the primer coating include:

[0220] The working fluid of the base coating layer is evenly applied to the surface of the automotive touch screen substrate by spraying, and the wet film thickness is controlled at 3–8 μm.

[0221] After coating, a segmented gradient temperature drying process is adopted: first, pre-dry at 70℃ for 8 minutes to allow moisture and a small amount of low boiling point system to slowly evaporate, then raise to 110℃ and keep warm for 20 minutes to allow the resin system to fully form a film and promote the reaction between the coupling agent and the substrate surface to form a dense adhesion underlayer.

[0222] The applications of the middleware layer include:

[0223] The intermediate layer coating is applied to the surface of the cured base layer by spraying, and the wet film thickness is controlled at 2–6 μm.

[0224] A two-stage UV curing process is used to perform pre-curing and full curing to obtain the intermediate layer.

[0225] The two-stage UV curing process includes:

[0226] The first stage uses a low-energy-density UV light source of 400mJ / cm² for pre-curing for 5 seconds, which allows the coating surface to quickly form an initial cross-linked network, locks the gradient distribution of nanoparticles, and at the same time maintains a certain degree of fluidity inside.

[0227] The second stage uses a high-energy-density UV light source of 1200mJ / cm² for complete curing for 20 seconds, which allows the entire intermediate layer system to be fully cross-linked, thereby obtaining the intermediate layer.

[0228] Topcoat applications include:

[0229] Apply the topcoat liquid to the cured intermediate layer in a clean environment for the first thin coat, and then spray the same surface a second time to complete the two film-forming processes.

[0230] The first thin coating is applied, with the wet film thickness controlled between 0.5 and 1.5 μm. After coating, the film is flash-dried at 70°C for 3 minutes to form an initial low surface energy thin layer mainly composed of fluorinated resin, but still retains a certain surface activity.

[0231] The second coating is applied with a wet film thickness controlled at 1–3 μm. After coating, the film is dried at 90°C for 10 minutes, which allows the silicone resin to migrate to the outermost surface under the drive of interfacial tension, forming a surface energy gradient structure of “inner fluorinated resin and outer silicone enrichment”. At the same time, hydrophobic nano-silica forms fine textures on the outermost layer.

[0232] After film formation, the film is baked at 140℃ for 30 minutes to allow the fluorinated resin and silicone resin to further crosslink or condense, fix the nanotexture structure and stabilize the surface energy. In the early stage of curing, a short-term hot air blowing at 100℃ is added to promote the appearance of surface microtexture, thereby obtaining the top coating and completing the application of the coating.

[0233] Comparative Example 1 (Top coating without hydrophobic nano-silica):

[0234] Base coat: 30 parts acrylic resin, 15 parts waterborne epoxy resin, 3.5 parts silane coupling agent, 5 parts nano silica, 0.4 parts defoamer, and 28 parts deionized water.

[0235] Intermediate layer: 35 parts UV-curable resin, 18 parts reactive diluent, 7.5 parts nano alumina, 4 parts photoinitiator, 1.0 part leveling agent, and 0.3 parts defoamer.

[0236] Top coating: 10 parts fluorinated resin, 16 parts silicone resin, 45 parts solvent, 0.4 parts leveling agent, and 0.8 parts curing accelerator.

[0237] The preparation of an anti-fingerprint coating for automotive touchscreens includes the preparation of a base coat, an intermediate coat, and a top coat.

[0238] The preparation of the base coating includes:

[0239] Aqueous epoxy resin and deionized water were added to a stirred tank equipped with stirring and temperature control. The mixture was stirred at 800 rpm for 30 minutes at 35°C to ensure complete dispersion of the aqueous epoxy resin and the formation of a homogeneous aqueous phase. Subsequently, acrylic resin was slowly added under continuous stirring, with the addition time controlled within 20 minutes to prevent sudden increases in viscosity in certain areas. Stirring was continued for another 40 minutes to obtain a transparent or slightly milky white primer masterbatch.

[0240] First, add a small amount of deionized water (20% of the total water volume) to the nano-silica and pre-stir at 1000 rpm for 15 minutes to initially wet the powder. Then, use ultrasonic dispersion (frequency 40 kHz) for 30 minutes to prevent the nano-silica from agglomerating significantly.

[0241] Under the premise of stable suspension of nano-silica, silane coupling agent is slowly added dropwise, with the addition time controlled at 20 minutes. At the same time, the pH of the system is adjusted to 4.0, and the mixture is stirred for another 60 minutes at 35°C. This allows the silane coupling agent to undergo hydrolysis and condensation reactions on the surface of nano-silica, forming a coating layer and resulting in a stable coupling agent-nanoparticle composite dispersion, which enhances both adhesion and wear resistance.

[0242] The above-mentioned coupling agent-nanoparticle composite dispersion was slowly added to the base coat stock solution at 600 rpm, while stirring continuously to avoid excessively high local concentrations. After thorough mixing, the defoamer was added, and the mixture was stirred for another 20 minutes. Subsequently, the system was filtered through a 5 μm filter to remove large particles and possible impurities and foam, yielding the working solution for the base coat.

[0243] The preparation of the intermediate layer includes:

[0244] Add the UV-curing resin to a mixing container, control the temperature at 35℃, and stir at 600 rpm for 20 minutes to eliminate internal stress and air bubbles in the resin. Then add the reactive diluent in batches, stirring for 15 minutes after each addition, so that the viscosity of the system is gradually adjusted to a suitable range for application (100–500 mPa·s), thus obtaining the UV resin base liquid.

[0245] Take the active diluent from another container and add it to the nano alumina. Disperse it at high speed at 2000 rpm for 40 minutes, followed by 20 minutes of ultrasonication, so that the nano alumina forms a suspension slurry with uniform particle size.

[0246] The nano-alumina slurry was then slowly added to the aforementioned UV resin base liquid under stirring conditions. After stirring for 30 minutes, the system was allowed to stand for 90 minutes, allowing the nanoparticles to form a slightly enriched distribution near the liquid surface under the influence of gravity and resin rheological behavior.

[0247] Under light-protected conditions, a photoinitiator, leveling agent, and defoamer were added to the above system, and the mixture was stirred for 30 minutes until completely dissolved and dispersed. The mixture was then filtered using a 5μm filter to remove coarse particles and insoluble matter, resulting in a stable intermediate coating layer.

[0248] The preparation of the top coating includes:

[0249] Fluorinated resin and silicone resin were added to a mixing vessel, and the temperature was controlled at 30°C. The mixture was stirred at 600 rpm for 30 minutes to ensure that the two resins were fully mixed in the solvent system. Subsequently, solvent (alcohol) was added in batches to adjust the overall solid content and viscosity to make it suitable for spraying or dip coating (viscosity controlled at 100 mPa·s) to obtain a fluorinated-silicone resin mixture.

[0250] A leveling agent is added to a fluorinated silicone resin mixture at a low stirring speed of 500 rpm. After adding the leveling agent, stirring continues for 15 minutes to ensure complete dissolution and uniform distribution. A curing accelerator is then added, followed by stirring for another 20 minutes to obtain the topcoat application solution.

[0251] The application of anti-fingerprint coatings for automotive touchscreens includes the application of base coats, intermediate coats, and top coats.

[0252] Applications of the primer coating include:

[0253] The working fluid of the base coating layer is evenly applied to the surface of the automotive touch screen substrate by spraying, and the wet film thickness is controlled at 3–8 μm.

[0254] After coating, a segmented gradient temperature drying process is adopted: first, pre-dry at 70℃ for 8 minutes to allow moisture and a small amount of low boiling point system to slowly evaporate, then raise to 110℃ and keep warm for 20 minutes to allow the resin system to fully form a film and promote the reaction between the coupling agent and the substrate surface to form a dense adhesion underlayer.

[0255] The applications of the middleware layer include:

[0256] The intermediate layer coating is applied to the surface of the cured base layer by spraying, and the wet film thickness is controlled at 2–6 μm.

[0257] A two-stage UV curing process is used to perform pre-curing and full curing to obtain the intermediate layer.

[0258] The two-stage UV curing process includes:

[0259] The first stage uses a low-energy-density UV light source of 400mJ / cm² for pre-curing for 5 seconds, which allows the coating surface to quickly form an initial cross-linked network, locks the gradient distribution of nanoparticles, and at the same time maintains a certain degree of fluidity inside.

[0260] The second stage uses a high-energy-density UV light source of 1200mJ / cm² for complete curing for 20 seconds, which allows the entire intermediate layer system to be fully cross-linked, thereby obtaining the intermediate layer.

[0261] Topcoat applications include:

[0262] Apply the topcoat liquid to the cured intermediate layer in a clean environment for the first thin coat, and then spray the same surface a second time to complete the two film-forming processes.

[0263] The first thin coating is applied, with the wet film thickness controlled between 0.5 and 1.5 μm. After coating, the film is flash-dried at 70°C for 3 minutes to form an initial low surface energy thin layer mainly composed of fluorinated resin, but still retains a certain surface activity.

[0264] The second coating is applied with a wet film thickness controlled at 1–3 μm. After coating, the film is dried at 90°C for 10 minutes, allowing the silicone resin to migrate to the outermost surface under interfacial tension, forming a surface energy gradient structure of “inner fluorinated resin and outer silicone enrichment”.

[0265] After film formation, bake at 140℃ for 30 minutes to allow the fluorinated resin and silicone resin to further crosslink or condense. In the early stage of curing, add a short-term hot air purging at 100℃ to promote the appearance of surface micro-texture, thereby obtaining the top coating and completing the application of the coating.

[0266] Comparative Example 2 (intermediate layer does not contain nano-alumina):

[0267] Base coat: 30 parts acrylic resin, 15 parts waterborne epoxy resin, 3.5 parts silane coupling agent, 5 parts nano silica, 0.4 parts defoamer, and 28 parts deionized water.

[0268] Intermediate layer: 40 parts UV-curable resin, 20 parts reactive diluent, 4 parts photoinitiator, 1.0 part leveling agent, and 0.3 parts defoamer.

[0269] Top coating: 10 parts fluorinated resin, 15 parts silicone resin, 2 parts hydrophobic nano silica, 42 parts solvent, 0.4 parts leveling agent, and 0.8 parts curing accelerator.

[0270] The preparation of an anti-fingerprint coating for automotive touchscreens includes the preparation of a base coat, an intermediate coat, and a top coat.

[0271] The preparation of the base coating includes:

[0272] Aqueous epoxy resin and deionized water were added to a stirred tank equipped with stirring and temperature control. The mixture was stirred at 800 rpm for 30 minutes at 35°C to ensure complete dispersion of the aqueous epoxy resin and the formation of a homogeneous aqueous phase. Subsequently, acrylic resin was slowly added under continuous stirring, with the addition time controlled within 20 minutes to prevent sudden increases in viscosity in certain areas. Stirring was continued for another 40 minutes to obtain a transparent or slightly milky white primer masterbatch.

[0273] First, add a small amount of deionized water (20% of the total water volume) to the nano-silica and pre-stir at 1000 rpm for 15 minutes to initially wet the powder. Then, use ultrasonic dispersion (frequency 40 kHz) for 30 minutes to prevent the nano-silica from agglomerating significantly.

[0274] Under the premise of stable suspension of nano-silica, silane coupling agent is slowly added dropwise, with the addition time controlled at 20 minutes. At the same time, the pH of the system is adjusted to 4.0, and the mixture is stirred for another 60 minutes at 35°C. This allows the silane coupling agent to undergo hydrolysis and condensation reactions on the surface of nano-silica, forming a coating layer and resulting in a stable coupling agent-nanoparticle composite dispersion, which enhances both adhesion and wear resistance.

[0275] The above-mentioned coupling agent-nanoparticle composite dispersion was slowly added to the base coat stock solution at 600 rpm, while stirring continuously to avoid excessively high local concentrations. After thorough mixing, the defoamer was added, and the mixture was stirred for another 20 minutes. Subsequently, the system was filtered through a 5 μm filter to remove large particles and possible impurities and foam, yielding the working solution for the base coat.

[0276] The preparation of the intermediate layer includes:

[0277] Add the UV-curing resin to a mixing container, control the temperature at 35℃, and stir at 600 rpm for 20 minutes to eliminate internal stress and air bubbles in the resin. Then add the reactive diluent in batches, stirring for 15 minutes after each addition, so that the viscosity of the system is gradually adjusted to a suitable range for application (100–500 mPa·s), thus obtaining the UV resin base liquid.

[0278] Add photoinitiator, leveling agent, and defoamer to the UV resin base solution and stir for 30 minutes until completely dissolved and dispersed. Then filter using a 5μm filter cartridge to remove coarse particles and insoluble matter, obtaining a stable intermediate layer coating.

[0279] The preparation of the top coating includes:

[0280] Fluorinated resin and silicone resin were added to a mixing vessel, and the temperature was controlled at 30°C. The mixture was stirred at 600 rpm for 30 minutes to ensure that the two resins were fully mixed in the solvent system. Subsequently, solvent (alcohol) was added in batches to adjust the overall solid content and viscosity to make it suitable for spraying or dip coating (viscosity controlled at 100 mPa·s) to obtain a fluorinated-silicone resin mixture.

[0281] Hydrophobic nano-silica was added to a solvent and stirred at 1500 rpm for 30 minutes, followed by 20 minutes of sonication, to ensure uniform dispersion of the hydrophobic nano-silica and the formation of a relatively stable nano-sol. This nano-sol was then slowly added to a fluorinated-organosilicon resin mixture under stirring, and stirring was continued for another 30 minutes.

[0282] Hydrophobic nano-silica sol was added to a fluorinated silicone resin mixture. After the resin mixture and nano-sol were fully combined, a leveling agent was added at a low stirring speed of 500 rpm. After adding the leveling agent, stirring was continued for 15 minutes to ensure complete dissolution and uniform distribution. Subsequently, a curing accelerator was added, and stirring was continued for another 20 minutes to ensure the system was homogeneous and stable, thus obtaining the topcoat application liquid.

[0283] The application of anti-fingerprint coatings for automotive touchscreens includes the application of base coats, intermediate coats, and top coats.

[0284] Applications of the primer coating include:

[0285] The working fluid of the base coating layer is evenly applied to the surface of the automotive touch screen substrate by spraying, and the wet film thickness is controlled at 3–8 μm.

[0286] After coating, a segmented gradient temperature drying process is adopted: first, pre-dry at 70℃ for 8 minutes to allow moisture and a small amount of low boiling point system to slowly evaporate, then raise to 110℃ and keep warm for 20 minutes to allow the resin system to fully form a film and promote the reaction between the coupling agent and the substrate surface to form a dense adhesion underlayer.

[0287] The applications of the middleware layer include:

[0288] The intermediate layer coating is applied to the surface of the cured base layer by spraying, and the wet film thickness is controlled at 2–6 μm.

[0289] A two-stage UV curing process is used to perform pre-curing and full curing to obtain the intermediate layer.

[0290] The two-stage UV curing process includes:

[0291] The first stage uses a low-energy-density UV light source of 400mJ / cm² for pre-curing for 5 seconds, which allows the coating surface to quickly form an initial cross-linked network.

[0292] The second stage uses a high-energy-density UV light source of 1200mJ / cm² for complete curing for 20 seconds, which allows the entire intermediate layer system to be fully cross-linked, thereby obtaining the intermediate layer.

[0293] Topcoat applications include:

[0294] Apply the topcoat liquid to the cured intermediate layer in a clean environment for the first thin coat, and then spray the same surface a second time to complete the two film-forming processes.

[0295] The first thin coating is applied, with the wet film thickness controlled between 0.5 and 1.5 μm. After coating, the film is flash-dried at 70°C for 3 minutes to form an initial low surface energy thin layer mainly composed of fluorinated resin, but still retains a certain surface activity.

[0296] The second coating is applied with a wet film thickness controlled at 1–3 μm. After coating, the film is dried at 90°C for 10 minutes, which allows the silicone resin to migrate to the outermost surface under the drive of interfacial tension, forming a surface energy gradient structure of “inner fluorinated resin and outer silicone enrichment”. At the same time, hydrophobic nano-silica forms fine textures on the outermost layer.

[0297] After film formation, the film is baked at 140℃ for 30 minutes to allow the fluorinated resin and silicone resin to further crosslink or condense, fix the nanotexture structure and stabilize the surface energy. In the early stage of curing, a short-term hot air blowing at 100℃ is added to promote the appearance of surface microtexture, thereby obtaining the top coating and completing the application of the coating.

[0298] The samples from Examples 1-3 and Comparative Examples 1-2 were applied to tempered glass touchscreen substrates and tested using the same cleaning and drying pretreatment.

[0299] Key test items include:

[0300] Water contact angle (°): reflects the hydrophobicity of the surface. The higher the value, the better the resistance to water stains and the easier it is to clean.

[0301] Oil contact angle (°, using standard mineral oil): reflects the surface's ability to repel fingerprint grease; the higher the value, the better the anti-fingerprint performance.

[0302] Pencil hardness (according to GB / T 6739): characterizes the surface's resistance to scratches; the higher the grade, the better.

[0303] Cross-cut adhesion test (according to GB / T 9286, grade 0 is best): assesses the adhesion between the coating and the substrate.

[0304] Alcohol resistance (500 rubs with anhydrous ethanol on a cotton cloth): This test examines the resistance to chemical cleaning.

[0305] Steel Wool Friction Test (0000 steel wool, 1000 cycles, 1kg load): To examine wear resistance.

[0306] Fingerprint residue level (1-5, 1 for almost no residue, 5 for severe residue): The degree of residue is observed visually after 10 touches.

[0307] The samples were tested according to the above test items, and the test results are shown in Table 1:

[0308] Table 1

[0309]

[0310] The test results above show that Examples 1-3 exhibit excellent anti-fingerprint, abrasion-resistant, and adhesion properties. Examples 2 and 3, in particular, utilize a combination of fluorinated resin, silicone resin, and hydrophobic nano-silica in the top coating. By adjusting the intermediate and high values ​​of the formulation, the water contact angle is stabilized at a relatively high level of 118–121°, and the oil contact angle at 85–88°. This indicates that the coating surface has good repellency to both water and oil, and the fingerprint residue level can be controlled at 1–2, essentially not affecting the display effect. Combined with the addition of nano-alumina in the intermediate layer, Examples 2 and 3 achieve a pencil hardness of 5H–6H. Coupled with the good adhesion of the bottom coating, the coating shows no significant peeling, cracking, or severe loss of gloss after steel wool friction and alcohol wiping, meeting the reliability requirements of automotive touchscreens under long-term use and frequent cleaning conditions.

[0311] In contrast, Comparative Example 1 omitted the hydrophobic nano-silica in the top coating, relying solely on fluorinated resin and silicone resin to provide low surface energy. While pencil hardness and adhesion were acceptable, the water and oil contact angles decreased significantly, raising the fingerprint residue level to 3-4. Visible fingerprints easily formed after repeated touches, and an oil film remained after wiping, indicating a significant deterioration in anti-fingerprint performance. In Comparative Example 2, the absence of nano-alumina in the intermediate layer resulted in an overall surface hardness decrease to approximately 2H. Visible scratches and haze were more likely to occur after steel wool friction and alcohol wiping. Although the top layer still possessed some anti-fingerprint effect, it was difficult to maintain high appearance quality for extended periods in real-world automotive applications. Overall, the multi-layered structure combining a base coating with enhanced adhesion, an intermediate hardening layer containing nano-alumina, and a top anti-fingerprint layer containing fluorinated / silicone / hydrophobic nano-silica, along with an optimized formulation, achieved a good balance between anti-fingerprint performance, wear resistance, and adhesion reliability, demonstrating significantly superior overall technical performance compared to the comparative examples.

[0312] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An anti-fingerprint coating for automotive touch screens, characterized by, It includes the following specific components: Base coat, intermediate coat, top coat; The base coating is composed of acrylic resin, waterborne epoxy resin, silane coupling agent, nano silica, defoamer, and deionized water. The intermediate layer is composed of UV-curable resin, reactive diluent, nano-alumina, photoinitiator, leveling agent and defoamer; The intermediate layer comprises, by weight, the following parts: 25–45 parts of UV-curable resin; 10–25 parts of reactive diluent; 5–10 parts of nano-alumina; 2–6 parts of photoinitiator; Leveling agent 0.5–1.5 parts; Defoamer 0.2–0.5 parts; The preparation of the intermediate layer includes: An active diluent is added to the UV-curable resin and stirred to obtain the UV resin base solution; An active diluent was added to nano-alumina to perform a two-stage dispersion and surface enrichment treatment of nano-alumina, and then added to the UV resin base solution. After adding a photoinitiator, leveling agent, and defoamer and filtering, the intermediate layer coating is obtained. The process includes a two-stage dispersion and surface enrichment treatment of nano-alumina, comprising: Add the active diluent to the nano alumina and disperse it at high speed at 1000–2000 rpm for 20–40 minutes to form a suspension slurry with uniform particle size of nano alumina. The nano-alumina slurry was then added to the UV resin base liquid under stirring conditions. After stirring for 20–30 minutes, the system was allowed to stand for 30–90 minutes. The top coating is composed of fluorinated resin, silicone resin, hydrophobic nano-silica, solvent, leveling agent and curing accelerator.

2. The anti-fingerprint coating for a car touch screen according to claim 1, characterized in that, The base coating comprises, by weight, the following parts: 20–40 parts acrylic resin; 10–20 parts of waterborne epoxy resin; 2–5 parts of silane coupling agent; 3–8 parts of nano-silica; Defoamer 0.2–0.6 parts; 20–35 parts deionized water.

3. The anti-fingerprint coating for a car touch screen according to claim 1, characterized in that, The top coating comprises, by weight, the following parts: 5–15 parts of fluorinated resin; 10–20 parts of silicone resin; 1–3 parts of hydrophobic nano-silica; Solvent 30–55 parts; Leveling agent 0.2–0.6 parts; Curing accelerator 0.5–1 part.

4. A method for preparing an anti-fingerprint coating for automotive touchscreens, comprising preparing the coating based on any one of claims 1-3, characterized in that, This includes the preparation of the base coat, intermediate coat, and top coat; The preparation of the base coating includes: A primer masterbatch was prepared using water-based epoxy resin, deionized water, and acrylic resin. A coupling agent-nanoparticle composite dispersion was prepared using nano-silica and silane coupling agent; An antifoaming agent is added to the primer stock solution and the coupling agent-nanoparticle composite dispersion to obtain the working solution of the primer layer; The preparation of the top coating includes: Fluorinated resin and organosilicon resin are mixed, and a solvent is added to obtain a fluorinated-organosilicon resin mixture. Hydrophobic nano-silica was added to a solvent to prepare a hydrophobic nano-silica sol. Hydrophobic nano-silica sol was added to a fluorinated-organic silicone resin mixture, and leveling aids and curing accelerators were added in sequence to obtain the topcoat application solution.

5. The method for preparing an anti-fingerprint coating for automotive touchscreens according to claim 4, characterized in that, The preparation of the base coating includes, during the preparation of the coupling agent-nanoparticle composite dispersion: Add nano-silica to deionized water and pre-stir at 600–1000 rpm for 10–15 minutes to initially wet the powder; then use ultrasonic dispersion for 15–30 minutes to prevent the nano-silica from agglomerating significantly. Under the premise of stable suspension of nano-silica, silane coupling agent is slowly added dropwise, with the addition time controlled at 10–20 minutes. At the same time, the pH of the system is adjusted to 4.0–5.5, and the mixture is stirred for 40–60 minutes at 25–35℃ to allow the silane coupling agent to undergo hydrolysis and condensation reaction on the surface of nano-silica, forming a coating layer and obtaining a composite dispersion.

6. An application of an anti-fingerprint coating for automotive touchscreens, based on the anti-fingerprint coating for automotive touchscreens according to any one of claims 1-3, characterized in that, This includes the application of base coat, intermediate coat, and top coat; Applications of the primer coating include: The working fluid of the base coating is uniformly applied to the surface of the automotive touch screen substrate by spraying, rolling or dipping, and the wet film thickness is controlled at 3–8 μm. After coating, a segmented gradient temperature drying process is used to allow the resin system to fully form a film and promote the reaction between the coupling agent and the substrate surface to form a dense and adherent underlayer. The applications of the middleware layer include: The intermediate layer coating is applied to the surface of the cured base layer by spraying or roller coating, with the wet film thickness controlled at 2–6 μm; A two-stage UV curing process is used for pre-curing and full curing to obtain the intermediate layer; Topcoat applications include: Apply the topcoat liquid to the cured intermediate layer in a clean environment for the first thin coat, and then spray the same surface a second time to complete the two film-forming processes. After film formation, bake at 100–140℃ for 15–30 minutes to allow the fluorinated resin and silicone resin to undergo further crosslinking or condensation, thereby obtaining the top coating and completing the application of the coating.

7. The application of the anti-fingerprint coating for automotive touchscreens according to claim 6, characterized in that, In the application of the intermediate layer, a two-stage UV curing process is included: The first stage uses a low-energy-density UV light source of 200–400 mJ / cm² for pre-curing for 1–5 seconds, which allows the coating surface to quickly form an initial cross-linked network and lock the gradient distribution of nanoparticles. The second stage uses a high-energy-density UV light source of 600–1200 mJ / cm² for complete curing for 5–20 seconds, which allows the entire intermediate layer system to be fully cross-linked, thereby obtaining the intermediate layer.

8. The application of the anti-fingerprint coating for automotive touchscreens according to claim 6, characterized in that, In the application of the top coating: The first thin coating is applied, with the wet film thickness controlled at 0.5–1.5 μm. After coating, the film is flash-dried at 50–70 °C for 1–3 minutes to form an initial low surface energy thin layer mainly composed of fluorinated resin. For the second spraying, the wet film thickness is controlled at 1–3 μm. After spraying, it is dried at 70–90℃ for 5–10 minutes to allow the silicone resin to migrate to the outermost surface under the drive of interfacial tension.

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