Preparation method of environment-friendly ultraviolet light curing type coloring material

Abstract

This invention relates to the field of coating technology, specifically a method for preparing an environmentally friendly UV-curable coloring material. The invention involves adding polyurethane acrylate, a photoinitiator, hydrophobic silica-coated titanium dioxide, a hydrophobic flame-retardant material, a diluent, a leveling agent, inorganic nano-pigments, and a dispersant, mixing them thoroughly to obtain a UV-curable coating. This UV-curable coating is then applied to the surface of a PET substrate film and cured under UV light to obtain the finished product. The finished product prepared by this invention exhibits excellent hydrophobicity and flame retardancy, thus showing broad application prospects in the field of coating technology.

Description

Technical Field

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

[0002] Photocurable functional films typically use polyethylene terephthalate (PET) film as a support substrate. After coating its surface with a photocurable coating, it is cured by ultraviolet radiation to form a composite material that combines high transparency, excellent adhesion, and specific functions. Due to its high processing efficiency and low energy consumption, this type of material is widely used in automotive glass functional films, building energy-saving window films, and electronic device protective films. However, despite the great potential of photocurable PET functional films in these fields, several key performance limitations remain to be overcome, directly affecting the reliability, durability, and safety of the products: Firstly, insufficient surface hydrophobicity / self-cleaning properties easily lead to decreased visibility and maintenance difficulties. In daily automotive use, rainwater, mud, oil, and other contaminants easily adhere to the outside of car windows. When the outside lacks an effective hydrophobic layer, the contaminants spread evenly to form a water film, severely interfering with the driver's vision at night or in backlight conditions. Simultaneously, the hydrophilic surface causes contaminants to adhere more firmly after drying, making them difficult to wash away naturally by rainwater, increasing the maintenance cost of frequent manual cleaning. Secondly, the inherent flame retardancy of the substrate and coating is extremely poor, posing a serious safety hazard. This defect is particularly prominent and dangerous in electronic device applications. When devices such as mobile phones and laptops catch fire due to battery thermal runaway, short circuits, or other reasons, the protective film and internal insulating film attached to the battery or motherboard may be quickly ignited, transforming from protective components into flame spread channels and additional fuel, accelerating the spread of the fire.

[0003] To overcome the shortcomings of existing technologies, this invention provides a method for preparing environmentally friendly UV-curable coloring materials. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing an environmentally friendly UV-curable coloring material to solve the problems raised in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing an environmentally friendly UV-curable coloring material includes the following steps: Step 1: Mix polycaprolactone diol, toluene diisocyanate, dibutyltin dilaurate, and p-hydroxyanisole. Stir and react under nitrogen atmosphere. Then add hydroxyethyl methacrylate and octafluoropentanol and continue the reaction to obtain polyurethane acrylate. Step 2: A silica coating layer is generated in situ on the surface of titanium dioxide by adding tetraethyl orthosilicate, followed by surface modification by sequentially adding γ-mercaptopropyltrimethoxysilane and perfluorodecyltrimethoxysilane to obtain a hydrophobic silica-coated titanium dioxide material; the surface of silica is modified by adding perfluorodecyltrimethoxysilane and γ-aminopropyltriethoxysilane, followed by grafting an epoxidizing flame retardant to obtain a hydrophobic flame retardant material; Step 3: Mix polyurethane acrylate, photoinitiator, hydrophobic silica-coated titanium dioxide material, hydrophobic flame retardant material, diluent, leveling agent, inorganic nano pigment, and dispersant. After stirring evenly, allow to stand to remove bubbles to obtain a photocurable coating. Apply the photocurable coating to the surface of a PET base film and cure it under ultraviolet light to obtain the finished product.

[0006] In a more optimized manner, in step one, the molar ratio of polycaprolactone diol, toluene diisocyanate, octafluoropentanol, and hydroxyethyl methacrylate is 0.2:(0.43-0.45):0.2:0.2; dibutyltin dilaurate is 0.15-0.20 wt% of the total monomers, and p-hydroxyanisole is 0.15-0.20 wt% of the total monomers; the reaction is stirred at 60-65℃ for 1.5-2.0 h; and the reaction is continued for 2.0-3.0 h.

[0007] In a more optimized manner, the content of each component in the UV-curable coating is as follows (by mass fraction): 4.5-5.0% photoinitiator, 3.5-4.5% hydrophobic silica-coated titanium dioxide material, 2.0-2.5% hydrophobic flame retardant material, 12-15% diluent, 0.5-0.7% leveling agent, 0.3-0.5% inorganic nano-pigment, 0.1-0.2% dispersant, with the balance being polyurethane acrylate; the UV curing time is 50-80 seconds.

[0008] A more optimized preparation process for hydrophobic silicon-coated titanium dioxide materials is as follows: Step 1: Mix tetraethyl orthosilicate and anhydrous ethanol, stir until homogeneous to obtain a tetraethyl orthosilicate solution; mix titanium dioxide powder, polyvinylpyrrolidone, and anhydrous ethanol, disperse evenly by ultrasonication, heat to 35-40℃, add tetraethyl orthosilicate solution and ammonia water dropwise while stirring continuously, continue the reaction for 4.5-5.5 hours after the addition is complete, centrifuge, wash with water, and dry to obtain silicon-coated titanium dioxide material; Step 2: Add the silicon-coated titanium dioxide material to an ethanol aqueous solution, ultrasonically disperse it evenly, adjust the pH to 4-5, then add γ-mercaptopropyltrimethoxysilane, continue ultrasonic dispersion for 10-15 min, then heat to 80-85℃, stir continuously for 1.0-1.5 h, then add perfluorodecyltrimethoxysilane, continue stirring for 4-5 h, after which cool, centrifuge, wash and dry to obtain the hydrophobic silicon-coated titanium dioxide material.

[0009] In a more optimized manner, in step 1, the reaction molar ratio of tetraethyl orthosilicate and titanium dioxide powder is (2.1-2.3):1.

[0010] In a more optimized manner, in step 2, the ethanol-water solution includes anhydrous ethanol and deionized water in a volume ratio of (3-4):1; the reaction mass ratio of silicon-coated titanium dioxide material, γ-mercaptopropyltrimethoxysilane, and perfluorodecyltrimethoxysilane is 10:(0.5-0.6):(1.3-1.5).

[0011] A more optimized preparation process for hydrophobic and flame-retardant materials is as follows: Step S1: Add perfluorodecyltrimethoxysilane and γ-aminopropyltriethoxysilane to anhydrous ethanol, stir evenly, and adjust the pH to 4-5 to obtain a modified solution; mix silica powder and ethanol aqueous solution, ultrasonically disperse evenly, add the modified solution, and stir and react at 65-70℃ for 7-8 hours. After the reaction is completed, filter, wash and dry to obtain the modified silicon material; Step S2: Phenylephrine dichloride and ethyl acetate are stirred and mixed to obtain a phenylphosphrine dichloride solution; under nitrogen atmosphere, eugenol, triethylamine and ethyl acetate are stirred and dissolved at 0-2℃, and then the phenylphosphrine dichloride solution is added dropwise. After standing for 50-70 min, the temperature is raised to 25-30℃ and the reaction is continued for 20-25 h. After the reaction is completed, the mixture is filtered, washed and dried to obtain the modified phosphoryl flame retardant material. Step S3: Mix m-chloroperoxybenzoic acid and ethyl acetate to obtain a reaction solution; mix modified phosphoryl flame retardant material and ethyl acetate, then add the reaction solution dropwise, let stand at 0-2℃ for 50-70 min, then raise the temperature to 25-30℃ and continue the reaction for 20-25 h. After the reaction is completed, wash, rotary evaporate and dry to obtain epoxidized flame retardant. Step S4: Add the modified silicon material to toluene, heat to 45-50℃, then add the epoxidized flame retardant while stirring continuously, and continue stirring for 12-14 hours. After the reaction is completed, centrifuge, wash and dry to obtain the hydrophobic flame retardant material.

[0012] In a more optimized manner, in step S1, the ethanol aqueous solution includes anhydrous ethanol and deionized water in a volume ratio of (3-4):1; the reaction mass ratio of perfluorodecyltrimethoxysilane, γ-aminopropyltriethoxysilane, and silica powder is 1.7:(0.65-0.75):7.7.

[0013] In a more optimized manner, in step S2, the reaction molar ratio of eugenol to phenylphosphodichloro is (2.0-2.1):1; in step S3, the reaction molar ratio of modified phosphoryl flame retardant material to m-chloroperoxybenzoic acid is 5:(16-18).

[0014] In a more optimized manner, in step S3, the reaction mass ratio of modified silicon material to epoxidized flame retardant is 10:(1.5-1.7).

[0015] Ideally, the thickness of the photocurable coating is 6-8 μm, and the thickness of the PET base film is 50-60 μm.

[0016] The beneficial effects of this invention are: The key feature of this invention is that by adding tetraethyl orthosilicate, titanium dioxide powder, ammonia, and anhydrous ethanol, tetraethyl orthosilicate undergoes hydrolysis and condensation under the action of an alkaline catalyst, generating a silica coating layer in situ on the surface of titanium dioxide. The core layer of this silica-coated titanium dioxide material is titanium dioxide. When the coating is exposed to natural light for a long time, the internal titanium dioxide can reduce the direct degradation of the resin by ultraviolet radiation, thereby improving the coating's resistance to ultraviolet aging. Meanwhile, the outer silica coating layer can inhibit the photocatalytic effect of titanium dioxide and simultaneously block moisture and corrosive media. Furthermore, γ-mercaptopropyltrimethoxysilane is added to perform surface epoxidation modification on the silica-coated titanium dioxide material, chemically bonding the terminal thiol groups to the surface of the silica shell. Subsequently, perfluorodecyltrimethoxysilane was added, which condensed with the remaining silanol groups on the material surface to introduce a perfluorocarbon long chain. The mercaptopropyl chain provided a certain degree of hydrophobicity, while the outer perfluorocarbon long chain had extremely low surface energy. Together, they formed a low surface energy composite surface, giving the hydrophobic silicon-coated titanium dioxide material excellent hydrophobicity.

[0017] The key feature of this invention is that mixing perfluorodecyltrimethoxysilane and γ-aminopropyltriethoxysilane in an acidic solution effectively catalyzes the rapid hydrolysis of the methoxy / ethoxy groups of the two silanes, generating the corresponding silanols. The silanol molecules undergo dehydration condensation with the silanol molecules on the surface of silica powder, forming strong Si-O-Si covalent bonds, chemically anchoring the two functional chains to the silica surface. This step yields a modified silicon material with both hydrophobicity and amino reactivity. Eugenol and phenylphosphodichloro are mixed to undergo a substitution reaction, yielding a modified phosphoryl flame retardant material. The modified phosphoryl flame retardant material is then mixed with m-chloroperoxybenzoic acid oxidant, converting the allyl double bonds of the modified phosphoryl flame retardant material into highly reactive epoxy groups, yielding an epoxidative flame retardant. The prepared epoxidative flame retardant is then covalently grafted onto the surface of the modified silicon material, undergoing a ring-opening reaction to obtain a hydrophobic flame retardant material.

[0018] This hydrophobic flame-retardant material uses silica as a rigid framework. Through the synergistic co-condensation of perfluorodecylsilane and γ-aminopropylsilane, an interface with hydrophobic fluorocarbon molecular chains is constructed on its surface, giving the material intrinsic hydrophobicity. Secondly, a eugenol-based bio-based phosphoryl flame retardant was prepared via a substitution reaction, and highly reactive epoxy groups were introduced through an epoxidation reaction. Then, the phosphorus-containing flame retardant was grafted onto the already hydrophobic silica framework via strong covalent bonds, achieving a synergistic improvement in both flame-retardant function and hydrophobicity.

[0019] The invention is characterized by preparing a fluorinated polyurethane acrylate by adding polycaprolactone diol, toluene diisocyanate, dibutyltin dilaurate, p-hydroxyanisole, hydroxyethyl methacrylate, and octafluoropentanol. The polyurethane acrylate, photoinitiator, hydrophobic silica-coated titanium dioxide material, hydrophobic flame retardant material, diluent, leveling agent, inorganic nano-pigment, and dispersant are then mixed uniformly to obtain a photocurable coating. This photocurable coating is applied to the surface of a PET substrate film and photocured to obtain the finished product. This finished product exhibits excellent overall performance. The octafluoropentanol segments introduced into the fluorinated polyurethane acrylate resin provide the coating substrate with inherent hydrophobicity and excellent adhesion. During the subsequent photocuring process, the acrylic double bonds in the photoinitiator resin undergo click chemical crosslinking with the thiol groups grafted onto the surfaces of the hydrophobic silica-coated titanium dioxide and the hydrophobic flame retardant material, firmly anchoring the functional filler in the polymer network in a covalent manner. This step not only significantly improves the dispersion stability of particles in the resin, avoiding light scattering and curing obstacles caused by agglomeration, but also constructs a uniform inorganic-organic hybrid cross-linked network, thereby simultaneously enhancing the hydrophobic durability of the composite coating. Furthermore, the synergistic effect of the silica physical barrier and the chemically bonded phosphorus-nitrogen flame-retardant components effectively improves the flame retardancy of the material. In summary, this finished product exhibits excellent hydrophobicity and flame retardancy, thus possessing broad application prospects in the field of coating technology. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Raw material source: Polyvinylpyrrolidone, model K30; silica powder, specification 15nm; polycaprolactone diol, average molecular weight 530g / mol; diluent, specifically 1,6-hexanediol diacrylate; leveling agent, model BYK-3570; inorganic nano-pigment, specifically carbon black pigment, model Microlith Black 0066K; dispersant, specifically carbon black pigment dispersant, model K-185; photoinitiator, specifically photoinitiator 184.

[0022] Example 1: Step 1: Tetraethyl orthosilicate and anhydrous ethanol were mixed and stirred until homogeneous to obtain a tetraethyl orthosilicate solution; titanium dioxide powder, polyvinylpyrrolidone, and anhydrous ethanol were mixed and ultrasonically dispersed until homogeneous, then heated to 40°C. The tetraethyl orthosilicate solution and ammonia were added dropwise while continuously stirring. After the addition was complete, the reaction continued for 5.5 hours. After the reaction was completed, the mixture was centrifuged, washed with water, and dried to obtain silicon-coated titanium dioxide material; the molar ratio of tetraethyl orthosilicate to titanium dioxide powder was 2.2:1. Step 2: Add the silicon-coated titanium dioxide material to an ethanol-water solution, ultrasonically disperse it evenly, adjust the pH to 4, then add γ-mercaptopropyltrimethoxysilane dropwise, continue ultrasonic dispersion for 15 min, raise the temperature to 85℃, stir continuously for 1.5 h, then add perfluorodecyltrimethoxysilane dropwise, continue stirring for 5 h, after which the reaction is completed, cool, centrifuge, wash, and dry to obtain the hydrophobic silicon-coated titanium dioxide material; the ethanol-water solution includes anhydrous ethanol and deionized water in a volume ratio of 4:1; the reaction mass ratio of silicon-coated titanium dioxide material, γ-mercaptopropyltrimethoxysilane, and perfluorodecyltrimethoxysilane is 10:0.55:1.4; Step 3: Add perfluorodecyltrimethoxysilane and γ-aminopropyltriethoxysilane to anhydrous ethanol, stir until homogeneous, and adjust the pH to 4 to obtain a modified solution; mix silica powder and ethanol aqueous solution, ultrasonically disperse until homogeneous, add the modified solution, and stir at 70℃ for 8 hours. After the reaction is complete, filter, wash, and dry to obtain modified silicon material; the ethanol aqueous solution includes anhydrous ethanol and deionized water in a volume ratio of 4:1; the reaction mass ratio of perfluorodecyltrimethoxysilane, γ-aminopropyltriethoxysilane, and silica powder is 1.7:0.7:7.7; Step 4: Phenylephrine dichloride and ethyl acetate were stirred and mixed to obtain a phenylphosphrine dichloride solution; under nitrogen atmosphere, eugenol, triethylamine, and ethyl acetate were stirred and dissolved at 2°C, and then the phenylphosphrine dichloride solution was added dropwise. After standing for 70 min, the temperature was raised to 30°C and the reaction was continued for 25 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain the modified phosphoryl flame retardant material; the molar ratio of eugenol to phenylphosphrine dichloride was 2.05:1. Step 5: Mix m-chloroperoxybenzoic acid and ethyl acetate to obtain a reaction solution; mix modified phosphoryl flame retardant material and ethyl acetate, then add the reaction solution dropwise, let stand at 2℃ for 70 min, then raise the temperature to 30℃ and continue the reaction for 25 h. After the reaction is completed, wash, rotary evaporate, and dry to obtain an epoxidized flame retardant; the molar ratio of modified phosphoryl flame retardant material to m-chloroperoxybenzoic acid is 5:17. Step 6: Add the modified silicon material to toluene, heat to 50°C, and then add the epoxidized flame retardant while stirring continuously. Continue stirring and react for 14 hours. After the reaction is completed, centrifuge, wash, and dry to obtain the hydrophobic flame retardant material. The mass ratio of the modified silicon material to the epoxidized flame retardant is 10:1.6. Step 7: Polycaprolactone diol, toluene diisocyanate, dibutyltin dilaurate, and p-hydroxyanisole are mixed and reacted at 65°C for 2.0 h under nitrogen atmosphere. Then, hydroxyethyl methacrylate and octafluoropentanol are added, and the reaction is continued for 3.0 h to obtain polyurethane acrylate. The molar ratio of polycaprolactone diol, toluene diisocyanate, octafluoropentanol, and hydroxyethyl methacrylate is 0.2:0.44:0.2:0.2. Dibutyltin dilaurate and p-hydroxyanisole are 0.15 wt% of the total monomers. Step 8: By mass fraction, mix 74.35% polyurethane acrylate, 5% photoinitiator, 4% hydrophobic silica-coated titanium dioxide material, 2.5% hydrophobic flame retardant material, 13% diluent, 0.6% leveling agent, 0.4% inorganic nano pigment, and 0.15% dispersant. After stirring evenly, allow to stand to remove bubbles to obtain a photocurable coating. Apply the photocurable coating to the surface of a PET base film and cure it under ultraviolet light for 80 seconds to obtain the finished product. The coating thickness is 6μm, and the PET base film thickness is 50μm.

[0023] Example 2: Step 1: Tetraethyl orthosilicate and anhydrous ethanol were mixed and stirred until homogeneous to obtain a tetraethyl orthosilicate solution; titanium dioxide powder, polyvinylpyrrolidone, and anhydrous ethanol were mixed and ultrasonically dispersed until homogeneous, then heated to 37°C. The tetraethyl orthosilicate solution and ammonia were added dropwise while continuously stirring. After the addition was complete, the reaction continued for 5 hours. After the reaction was completed, the mixture was centrifuged, washed with water, and dried to obtain silicon-coated titanium dioxide material; the molar ratio of tetraethyl orthosilicate to titanium dioxide powder was 2.2:1. Step 2: Add the silicon-coated titanium dioxide material to an ethanol-water solution, ultrasonically disperse it evenly, adjust the pH to 4, then add γ-mercaptopropyltrimethoxysilane dropwise, continue ultrasonic dispersion for 12 min, raise the temperature to 82℃, stir continuously for 1.3 h, then add perfluorodecyltrimethoxysilane dropwise, continue stirring for 4.5 h, after which the reaction is completed, cool, centrifuge, wash, and dry to obtain the hydrophobic silicon-coated titanium dioxide material; the ethanol-water solution includes anhydrous ethanol and deionized water in a volume ratio of 4:1; the reaction mass ratio of silicon-coated titanium dioxide material, γ-mercaptopropyltrimethoxysilane, and perfluorodecyltrimethoxysilane is 10:0.55:1.4; Step 3: Add perfluorodecyltrimethoxysilane and γ-aminopropyltriethoxysilane to anhydrous ethanol, stir until homogeneous, and adjust the pH to 4 to obtain a modified solution; mix silica powder and ethanol aqueous solution, ultrasonically disperse until homogeneous, add the modified solution, and stir at 67℃ for 7.5 h. After the reaction is complete, filter, wash, and dry to obtain modified silicon material; the ethanol aqueous solution includes anhydrous ethanol and deionized water in a volume ratio of 4:1; the reaction mass ratio of perfluorodecyltrimethoxysilane, γ-aminopropyltriethoxysilane, and silica powder is 1.7:0.7:7.7; Step 4: Phenylephrine dichloride and ethyl acetate were stirred and mixed to obtain a phenylphosphrine dichloride solution; under nitrogen atmosphere, eugenol, triethylamine, and ethyl acetate were stirred and dissolved at 1°C, and then the phenylphosphrine dichloride solution was added dropwise. After standing for 60 min, the temperature was raised to 27°C and the reaction was continued for 22 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain the modified phosphoryl flame retardant material; the molar ratio of eugenol to phenylphosphrine dichloride was 2.05:1. Step 5: Mix m-chloroperoxybenzoic acid and ethyl acetate to obtain a reaction solution; mix modified phosphoryl flame retardant material and ethyl acetate, then add the reaction solution dropwise, let stand at 1℃ for 60 min, then raise the temperature to 27℃ and continue the reaction for 22 h. After the reaction is completed, wash, rotary evaporate, and dry to obtain an epoxidized flame retardant; the molar ratio of modified phosphoryl flame retardant material to m-chloroperoxybenzoic acid is 5:17. Step 6: Add the modified silicon material to toluene, heat to 47°C, and then add the epoxidized flame retardant while stirring continuously. Continue stirring and react for 13 hours. After the reaction is completed, centrifuge, wash, and dry to obtain the hydrophobic flame retardant material. The mass ratio of the modified silicon material to the epoxidized flame retardant is 10:1.6. Step 7: Polycaprolactone diol, toluene diisocyanate, dibutyltin dilaurate, and p-hydroxyanisole were mixed and reacted at 62°C for 1.7 h under nitrogen atmosphere. Then, hydroxyethyl methacrylate and octafluoropentanol were added, and the reaction was continued for 2.5 h to obtain polyurethane acrylate. The molar ratio of polycaprolactone diol, toluene diisocyanate, octafluoropentanol, and hydroxyethyl methacrylate was 0.2:0.44:0.2:0.2. Dibutyltin dilaurate and p-hydroxyanisole were 0.15 wt% of the total monomers. Step 8: By mass fraction, mix 74.35% polyurethane acrylate, 5% photoinitiator, 4% hydrophobic silica-coated titanium dioxide material, 2.5% hydrophobic flame retardant material, 13% diluent, 0.6% leveling agent, 0.4% inorganic nano pigment, and 0.15% dispersant. After stirring evenly, allow to stand to remove bubbles to obtain a UV-curable coating. Apply the UV-curable coating to the surface of a PET base film and cure it under ultraviolet light for 65 seconds to obtain the finished product. The coating thickness is 6μm, and the PET base film thickness is 50μm.

[0024] Example 3: Step 1: Tetraethyl orthosilicate and anhydrous ethanol were mixed and stirred until homogeneous to obtain a tetraethyl orthosilicate solution; titanium dioxide powder, polyvinylpyrrolidone, and anhydrous ethanol were mixed and ultrasonically dispersed until homogeneous, then heated to 35°C. The tetraethyl orthosilicate solution and ammonia were added dropwise while continuously stirring. After the addition was complete, the reaction continued for 4.5 hours. After the reaction was completed, the mixture was centrifuged, washed with water, and dried to obtain silicon-coated titanium dioxide material; the molar ratio of tetraethyl orthosilicate to titanium dioxide powder was 2.2:1. Step 2: Add the silicon-coated titanium dioxide material to an ethanol-water solution, ultrasonically disperse it evenly, adjust the pH to 4, then add γ-mercaptopropyltrimethoxysilane dropwise, continue ultrasonic dispersion for 10 min, raise the temperature to 80℃, stir continuously for 1.0 h, then add perfluorodecyltrimethoxysilane dropwise, continue stirring for 4 h, after which the reaction is completed, cool, centrifuge, wash, and dry to obtain the hydrophobic silicon-coated titanium dioxide material; the ethanol-water solution includes anhydrous ethanol and deionized water in a volume ratio of 4:1; the reaction mass ratio of silicon-coated titanium dioxide material, γ-mercaptopropyltrimethoxysilane, and perfluorodecyltrimethoxysilane is 10:0.55:1.4; Step 3: Add perfluorodecyltrimethoxysilane and γ-aminopropyltriethoxysilane to anhydrous ethanol, stir until homogeneous, and adjust the pH to 4 to obtain a modified solution; mix silica powder and ethanol aqueous solution, ultrasonically disperse until homogeneous, add the modified solution, and stir at 65℃ for 7 hours. After the reaction is complete, filter, wash, and dry to obtain modified silicon material; the ethanol aqueous solution includes anhydrous ethanol and deionized water in a volume ratio of 4:1; the reaction mass ratio of perfluorodecyltrimethoxysilane, γ-aminopropyltriethoxysilane, and silica powder is 1.7:0.7:7.7; Step 4: Phenylephrine dichloride and ethyl acetate were stirred and mixed to obtain a phenylphosphrine dichloride solution; under nitrogen atmosphere, eugenol, triethylamine, and ethyl acetate were stirred and dissolved at 0°C, and then the phenylphosphrine dichloride solution was added dropwise. After standing for 50 min, the temperature was raised to 25°C and the reaction was continued for 20 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain the modified phosphoryl flame retardant material; the molar ratio of eugenol to phenylphosphrine dichloride was 2.05:1. Step 5: Mix m-chloroperoxybenzoic acid and ethyl acetate to obtain a reaction solution; mix modified phosphoryl flame retardant material and ethyl acetate, then add the reaction solution dropwise, let stand at 0℃ for 50 min, then raise the temperature to 25℃ and continue the reaction for 20 h. After the reaction is completed, wash, rotary evaporate, and dry to obtain an epoxidized flame retardant; the molar ratio of modified phosphoryl flame retardant material to m-chloroperoxybenzoic acid is 5:17. Step 6: Add the modified silicon material to toluene, heat to 45°C, and then add the epoxidized flame retardant while stirring continuously. Continue stirring and react for 12 hours. After the reaction is completed, centrifuge, wash, and dry to obtain the hydrophobic flame retardant material. The mass ratio of the modified silicon material to the epoxidized flame retardant is 10:1.6. Step 7: Polycaprolactone diol, toluene diisocyanate, dibutyltin dilaurate, and p-hydroxyanisole are mixed and reacted at 60°C for 1.5 h under nitrogen atmosphere. Then, hydroxyethyl methacrylate and octafluoropentanol are added, and the reaction is continued for 2.0 h to obtain polyurethane acrylate. The molar ratio of polycaprolactone diol, toluene diisocyanate, octafluoropentanol, and hydroxyethyl methacrylate is 0.2:0.44:0.2:0.2. Dibutyltin dilaurate and p-hydroxyanisole are 0.15 wt% of the total monomers. Step 8: By mass fraction, mix 74.35% polyurethane acrylate, 5% photoinitiator, 4% hydrophobic silica-coated titanium dioxide material, 2.5% hydrophobic flame retardant material, 13% diluent, 0.6% leveling agent, 0.4% inorganic nano pigment, and 0.15% dispersant. After stirring evenly, allow to stand to remove bubbles to obtain a photocurable coating. Apply the photocurable coating to the surface of a PET base film and cure it under ultraviolet light for 50 seconds to obtain the finished product. The coating thickness is 6μm, and the PET base film thickness is 50μm.

[0025] Step 1: Add perfluorodecyltrimethoxysilane and γ-aminopropyltriethoxysilane to anhydrous ethanol, stir until homogeneous, and adjust the pH to 4 to obtain a modified solution; mix silica powder and ethanol aqueous solution, ultrasonically disperse until homogeneous, add the modified solution, and stir at 70℃ for 8 hours. After the reaction is complete, filter, wash, and dry to obtain modified silicon material; the ethanol aqueous solution includes anhydrous ethanol and deionized water in a volume ratio of 4:1; the reaction mass ratio of perfluorodecyltrimethoxysilane, γ-aminopropyltriethoxysilane, and silica powder is 1.7:0.7:7.7; Step 2: Phenylephrine dichloride and ethyl acetate were stirred and mixed to obtain a phenylphosphrine dichloride solution; under nitrogen atmosphere, eugenol, triethylamine, and ethyl acetate were stirred and dissolved at 2°C, and then the phenylphosphrine dichloride solution was added dropwise. After standing for 70 min, the temperature was raised to 30°C and the reaction was continued for 25 h. After the reaction was completed, the mixture was filtered, washed, and dried to obtain the modified phosphoryl flame retardant material; the molar ratio of eugenol to phenylphosphrine dichloride was 2.05:1. Step 3: Mix m-chloroperoxybenzoic acid and ethyl acetate to obtain a reaction solution; mix modified phosphoryl flame retardant material and ethyl acetate, then add the reaction solution dropwise, let stand at 2℃ for 70 min, then raise the temperature to 30℃ and continue the reaction for 25 h. After the reaction is completed, wash, rotary evaporate, and dry to obtain an epoxidized flame retardant; the molar ratio of modified phosphoryl flame retardant material to m-chloroperoxybenzoic acid is 5:17. Step 4: Add the modified silicon material to toluene, heat to 50°C, and then add the epoxidized flame retardant while stirring continuously. Continue stirring and react for 14 hours. After the reaction is completed, centrifuge, wash, and dry to obtain the hydrophobic flame retardant material. The mass ratio of the modified silicon material to the epoxidized flame retardant is 10:1.6. Step 5: Polycaprolactone diol, toluene diisocyanate, dibutyltin dilaurate, and p-hydroxyanisole were mixed and reacted at 65°C for 2.0 h under nitrogen atmosphere. Then, hydroxyethyl methacrylate and octafluoropentanol were added, and the reaction was continued for 3.0 h to obtain polyurethane acrylate. The molar ratio of polycaprolactone diol, toluene diisocyanate, octafluoropentanol, and hydroxyethyl methacrylate was 0.2:0.44:0.2:0.2. Dibutyltin dilaurate and p-hydroxyanisole were 0.15 wt% of the total monomers. Step 6: By mass fraction, mix 74.35% polyurethane acrylate, 5% photoinitiator, 2.5% hydrophobic flame retardant material, 17% diluent, 0.6% leveling agent, 0.4% inorganic nano pigment, and 0.15% dispersant. After stirring evenly, allow to stand to remove bubbles to obtain a UV-curable coating. Apply the UV-curable coating to the surface of a PET base film and cure it under ultraviolet light for 80 seconds to obtain the finished product. The coating thickness is 6μm, and the PET base film thickness is 50μm.

[0026] Comparative Example 2: The hydrophobic silica-coated titanium dioxide material and the hydrophobic flame-retardant material were removed, and the rest was the same as in Example 1. The specific steps are as follows: Step 1: Polycaprolactone diol, toluene diisocyanate, dibutyltin dilaurate, and p-hydroxyanisole were mixed and stirred at 65°C for 2.0 h under nitrogen atmosphere. Then, hydroxyethyl methacrylate and octafluoropentanol were added, and the reaction was continued for 3.0 h to obtain polyurethane acrylate. The molar ratio of polycaprolactone diol, toluene diisocyanate, octafluoropentanol, and hydroxyethyl methacrylate was 0.2:0.44:0.2:0.2. Dibutyltin dilaurate was 0.15 wt% of the total monomers, and p-hydroxyanisole was 0.15 wt% of the total monomers. Step 2: By mass fraction, mix 74.35% polyurethane acrylate, 5% photoinitiator, 19.5% diluent, 0.6% leveling agent, 0.4% inorganic nano pigment, and 0.15% dispersant. After stirring evenly, allow to stand to remove bubbles to obtain a UV-curable coating. Apply the UV-curable coating to the surface of a PET base film and cure it under ultraviolet light for 80 seconds to obtain the finished product. The coating thickness is 6μm, and the PET base film thickness is 50μm.

[0027] Contact angle test: A UV-curable coating was applied to the surface of a glass plate and cured under ultraviolet light for 80 seconds to obtain a sample. The hydrophilic and hydrophobic properties of the coating on the sample surface were tested using a contact angle meter, with deionized water as the test liquid.

[0028] Flame retardant performance test: Add the UV-curable coating to the mold and cure to obtain the sample; refer to GB / T 2406.2-2009 "Determination of burning behavior of plastics by oxygen index method - Part 2: Room temperature test" to test the oxygen index of the sample for Type I specimen.

[0029] Adhesion test: A UV-curable coating was applied to the surface of a glass plate and cured under ultraviolet light for 80 seconds to obtain a sample. The adhesion of the coating on the sample surface was tested using a paint film adhesion tester.

[0030] Transmittance test: The UV-Vis absorption spectrum of a 6μm thick thin film sample was measured using a UV-Vis spectrometer. The test wavelength range was 380-760nm in the visible light range. The visible light transmittance of the coating was tested. The results are shown in the table below:

[0031] Conclusion: The samples in Examples 1-3 exhibited stable properties. However, in Comparative Example 1, removing the hydrophobic silica-coated titanium dioxide material significantly reduced the water contact angle, decreased the hydrophobicity of the coating, and also resulted in a certain decrease in the oxygen index. Furthermore, in Comparative Example 2, removing both the hydrophobic silica-coated titanium dioxide material and the hydrophobic flame-retardant material further reduced the water contact angle and significantly decreased the oxygen index, demonstrating that the hydrophobic silica-coated titanium dioxide material and the hydrophobic flame-retardant material significantly improved the flame retardancy and hydrophobicity of the coating. Additionally, the coating exhibited good adhesion, reaching 5B; the visible light transmittance remained stable at around 45%, indicating that the coating possessed good light transmittance.

[0032] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process method article or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process method article or apparatus.

[0033] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing an environmentally friendly UV-curable coloring material, characterized in that: Includes the following steps: Step 1: Mix polycaprolactone diol, toluene diisocyanate, dibutyltin dilaurate, and p-hydroxyanisole. Stir and react under nitrogen atmosphere. Then add hydroxyethyl methacrylate and octafluoropentanol and continue the reaction to obtain polyurethane acrylate. Step 2: A silica coating layer is generated in situ on the surface of titanium dioxide by adding tetraethyl orthosilicate, followed by surface modification by sequentially adding γ-mercaptopropyltrimethoxysilane and perfluorodecyltrimethoxysilane to obtain a hydrophobic silica-coated titanium dioxide material; the surface of silica is modified by adding perfluorodecyltrimethoxysilane and γ-aminopropyltriethoxysilane, followed by grafting an epoxidizing flame retardant to obtain a hydrophobic flame retardant material; Step 3: Mix polyurethane acrylate, photoinitiator, hydrophobic silica-coated titanium dioxide material, hydrophobic flame retardant material, diluent, leveling agent, inorganic nano pigment, and dispersant. After stirring evenly, allow to stand to remove bubbles to obtain a photocurable coating. Apply the photocurable coating to the surface of a PET base film and cure it under ultraviolet light to obtain the finished product.

2. The method for preparing an environmentally friendly UV-curable coloring material according to claim 1, characterized in that: In step one, the molar ratio of polycaprolactone diol, toluene diisocyanate, octafluoropentanol, and hydroxyethyl methacrylate is 0.2:(0.43-0.45):0.2:0.2; dibutyltin dilaurate is 0.15-0.20 wt% of the total monomers, and p-hydroxyanisole is 0.15-0.20 wt% of the total monomers; the reaction is stirred at 60-65℃ for 1.5-2.0 h; and the reaction is continued for 2.0-3.0 h.

3. The preparation method of an environmentally friendly UV-curable coloring material according to claim 1, characterized in that: The components of the UV-curable coating are as follows (by mass fraction): 4.5-5.0% photoinitiator, 3.5-4.5% hydrophobic silica-coated titanium dioxide material, 2.0-2.5% hydrophobic flame retardant material, 12-15% diluent, 0.5-0.7% leveling agent, 0.3-0.5% inorganic nano-pigment, 0.1-0.2% dispersant, with the balance being polyurethane acrylate; the UV curing time is 50-80 seconds.

4. The preparation method of an environmentally friendly UV-curable coloring material according to claim 3, characterized in that: The preparation process of hydrophobic silica-coated titanium dioxide material is as follows: Step 1: Mix tetraethyl orthosilicate and anhydrous ethanol, stir until homogeneous to obtain a tetraethyl orthosilicate solution; mix titanium dioxide powder, polyvinylpyrrolidone, and anhydrous ethanol, disperse evenly by ultrasonication, heat to 35-40℃, add tetraethyl orthosilicate solution and ammonia water dropwise while stirring continuously, continue the reaction for 4.5-5.5 hours after the addition is complete, centrifuge, wash with water, and dry to obtain silicon-coated titanium dioxide material; Step 2: Add the silicon-coated titanium dioxide material to an ethanol aqueous solution, ultrasonically disperse it evenly, adjust the pH to 4-5, then add γ-mercaptopropyltrimethoxysilane, continue ultrasonic dispersion for 10-15 min, then heat to 80-85℃, stir continuously for 1.0-1.5 h, then add perfluorodecyltrimethoxysilane, continue stirring for 4-5 h, after which cool, centrifuge, wash and dry to obtain the hydrophobic silicon-coated titanium dioxide material.

5. The method for preparing an environmentally friendly UV-curable coloring material according to claim 4, characterized in that: In step 1, the molar ratio of tetraethyl orthosilicate to titanium dioxide powder is (2.1-2.3):

1.

6. The method for preparing an environmentally friendly UV-curable coloring material according to claim 4, characterized in that: In step 2, the ethanol aqueous solution includes anhydrous ethanol and deionized water in a volume ratio of (3-4):1; the reaction mass ratio of silicon-coated titanium dioxide material, γ-mercaptopropyltrimethoxysilane, and perfluorodecyltrimethoxysilane is 10:(0.5-0.6):(1.3-1.5).

7. The method for preparing an environmentally friendly UV-curable coloring material according to claim 3, characterized in that: The preparation process of hydrophobic flame-retardant materials is as follows: Step S1: Add perfluorodecyltrimethoxysilane and γ-aminopropyltriethoxysilane to anhydrous ethanol, stir evenly, and adjust the pH to 4-5 to obtain a modified solution; mix silica powder and ethanol aqueous solution, ultrasonically disperse evenly, add the modified solution, and stir and react at 65-70℃ for 7-8 hours. After the reaction is completed, filter, wash and dry to obtain the modified silicon material; Step S2: Mix phenylphosphine dichloride and ethyl acetate to obtain a phenylphosphine dichloride solution; Eugenol, triethylamine, and ethyl acetate were dissolved by stirring at 0-2℃ under nitrogen atmosphere. Then, phenylphosphine dichloride solution was added dropwise. After standing for 50-70 minutes, the temperature was raised to 25-30℃ and the reaction was continued for 20-25 hours. After the reaction was completed, the modified phosphoryl flame retardant material was obtained by filtration, washing, and drying. Step S3: Mix m-chloroperoxybenzoic acid and ethyl acetate to obtain a reaction solution; mix modified phosphoryl flame retardant material and ethyl acetate, then add the reaction solution dropwise, let stand at 0-2℃ for 50-70 min, then raise the temperature to 25-30℃ and continue the reaction for 20-25 h. After the reaction is completed, wash, rotary evaporate and dry to obtain epoxidized flame retardant. Step S4: Add the modified silicon material to toluene, heat to 45-50℃, then add the epoxidized flame retardant while stirring continuously, and continue stirring for 12-14 hours. After the reaction is completed, centrifuge, wash and dry to obtain the hydrophobic flame retardant material.

8. The method for preparing an environmentally friendly UV-curable coloring material according to claim 7, characterized in that: In step S1, the ethanol aqueous solution includes anhydrous ethanol and deionized water in a volume ratio of (3-4):1; the reaction mass ratio of perfluorodecyltrimethoxysilane, γ-aminopropyltriethoxysilane and silica powder is 1.7:(0.65-0.75):7.

7.

9. The method for preparing an environmentally friendly UV-curable coloring material according to claim 7, characterized in that: In step S2, the reaction molar ratio of eugenol and phenylphosphodichloro is (2.0-2.1):1; in step S3, the reaction molar ratio of modified phosphoryl flame retardant material and m-chloroperoxybenzoic acid is 5:(16-18); in step S4, the reaction mass ratio of modified silicon material and epoxidized flame retardant is 10:(1.5-1.7).

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