Preparation method and application of anti-blue-light eye-protection car window film

Abstract

The invention discloses a preparation method and application of an anti-blue-light eye-protecting car window film, relates to the technical field of optical thin films, and discloses a window film which can effectively cut off harmful short-wave blue light with the wavelength range of 415-455nm. According to the invention, a multi-layer coating structure is constructed by utilizing alternate deposition of a high-refractive-index material titanium dioxide and a low-refractive-index material silicon dioxide. The optical thickness of the coating film meets the Bragg reflection condition, reflection of the wavelength of 435 nm can be enhanced, and the effect of preventing blue light is achieved. According to the invention, tannic acid is adopted to prepare silicon dioxide, and tannic acid can be used as a pore-forming agent, so that the prepared silicon dioxide has a larger surface area and can be grafted with more octadecylamine. Secondly, tannic acid and gallic acid are used for modifying silicon dioxide, tannic acid and gallic acid can cooperate with octadecylamine to conduct hydrophobic modification on silicon dioxide, and the hydrophobic performance of the car window film is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of optical thin films, and specifically to a preparation method and application of a blue light-blocking and eye-protecting window film. Background Art

[0002] Blue light, especially short-wave blue light with a wavelength range of 415 nm - 455 nm, due to its high-energy characteristics, can cause various harms to the eyes. Short-wave blue light can penetrate the cornea and lens of the eye and reach the retina, triggering an excessive production of free radicals in retinal pigment epithelial cells, leading to cellular oxidative stress and death. Prolonged exposure to blue light can also cause irreversible retinal degeneration. Long-term exposure to blue light may accelerate the oxidation of the lens, accelerate the oxidative damage of the lens and cornea, and induce or exacerbate cataracts. Short-wave blue light is prone to scattering in the human eye, resulting in blurred vision and reduced contrast, thus increasing the eye burden. When people are driving or using electronic products, the strong and stimulating short-wave blue light will scatter in the human eye, causing visual blurring and dizziness. Blue light radiation may also interfere with the secretion of the tear film, leading to dry eyes.

[0003] Window films are widely used in automobiles, ships, and building glass. With the rapid development of the economy, the frequency and duration of people's use of automobiles are increasing, and the time that the human eye is exposed to various lights is getting longer. Especially when driving at night, a large amount of short-wave blue light contained in various dazzling LED strong lights in the environment will cause a stinging and dizzy feeling in the short term, resulting in driving fatigue and affecting driving safety. Long-term exposure will cause various eye injuries.

[0004] To solve the above problems, the present invention provides a preparation method and application of a blue light-blocking and eye-protecting window film. Summary of the Invention

[0005] The purpose of the present invention is to provide a preparation method of a blue light-blocking and eye-protecting window film to solve the problems raised in the prior art.

[0006] A preparation method of a blue light-blocking and eye-protecting window film includes the following steps: Step 1: Take a PET film, clean and dry it to obtain a pretreated PET film; Step 2: Perform a coating treatment on the pretreated PET film. First deposit a high-refractive-index film on the surface of the pretreated PET film, and then alternately deposit a low-refractive-index film and a high-refractive-index film to obtain a blue light-blocking and eye-protecting window film; The low-refractive-index film is any one of a silicon dioxide layer and a magnesium fluoride layer; the high-refractive-index film is any one of a titanium dioxide layer, a zirconium dioxide layer, and a silicon nitride layer.

[0007] Preferably, the combination of the low-refractive-index film and the high-refractive-index film is one deposition cycle, and the number of cycles is 1 - 6 times.

[0008] Preferably, the refractive index of the silica layer is 1.45 - 1.47, and the thickness is 74 - 75 nm; the refractive index of the titanium dioxide layer is 2.4 - 2.55, and the thickness is 44 - 45 nm.

[0009] Preferably, the refractive index of the PET film is 1.64 - 1.65, and the visible light transmittance is 90 - 92%.

[0010] Preferably, a hardening layer coating is also coated on the PET surface on the other side of the coating of the anti - blue - light and eye - protecting window film, and its preparation method includes the following steps: S1: Take the PET film, clean and dry it to obtain the pretreated PET film; S2: Perform coating treatment on the pretreated PET film, and sequentially deposit a low - refractive - index film and a high - refractive - index film on the surface of the pretreated PET film; S3: Take hydrophobic modified acrylic resin, hydrophobic modified silica, and photoinitiator, stir evenly to obtain the hardening layer coating; coat the hardening layer coating on the surface of the PET film after coating treatment, and cure it to obtain the anti - blue - light and eye - protecting window film.

[0011] Preferably, the hardening layer coating is composed of the following components, by mass: 90 - 100 parts of hydrophobic modified acrylic resin, 18 - 22 parts of hydrophobic modified silica, and 0.1 - 1 part of photoinitiator.

[0012] Preferably, the preparation method of the hydrophobic modified silica is as follows: Take porous silica and deionized water, disperse them by ultrasonic wave, dropwise add sodium hydroxide, adjust the pH value to 8.5 - 9, add tris(hydroxymethyl)aminomethane, stir for 1 - 2 h, add octadecylamine ethanol solution, stir for 7 - 10 h, wash, filter, and dry to obtain hydrophobic modified silica; The preparation method of the porous silica is as follows: Take tetraethyl orthosilicate, methanol, and ammonia water, stir for 120 - 130 min, dropwise add hydrochloric acid, adjust the pH value to 5.0 - 5.5, add tannic acid and gallic acid, stir for 3 - 4 h, then adjust the pH of the solution to 7.5 - 8.0 with ammonia water, filter, and dry to obtain porous silica.

[0013] Preferably, the preparation method of the hydrophobic modified acrylic resin includes the following steps: Step A: Take diphenylsilanediol, 3 - glycidoxypropyl dimethoxymethylsilane, and barium hydroxide, mix them evenly, introduce nitrogen, heat up to 80 - 85 °C, react for 6 - 7 h, and vacuum dry at 60 - 65 °C for 4 - 5 h to obtain epoxy - based polysiloxane; Step B: Take xylene, heat it up to 90 - 95°C, add epoxy group polysiloxane, add azodiisobutyronitrile, react for 30 - 40 min, dropwise add a mixture of methyl methacrylate, butyl acrylate, styrene, methacrylic acid, and hydroxypropyl acrylate, add azodiisobutyronitrile, react for 3 - 4 h, heat it up to 100 - 105°C, dropwise add azodiisobutyronitrile, add epoxy group polysiloxane, and react for 2 - 3 h to obtain a hydrophobic modified acrylic resin.

[0014] A window film prepared by a preparation method of an anti - blue - light and eye - protecting window film.

[0015] An application of a window film in automobile, ship, and building glass.

[0016] To achieve the above - mentioned purpose, the present invention provides the following technical solutions: Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The present patent invents a window film which can effectively cut off harmful short - wave blue light with a wavelength range of 415 nm - 455 nm. The present invention constructs a multi - layer coating structure by alternately depositing a high - refractive - index material titanium dioxide and a low - refractive - index material silicon dioxide. The optical thickness of the coating satisfies the Bragg reflection condition, which can strengthen the reflection of the 435 nm wavelength and play a role in anti - blue light.

[0017] 2. The present invention uses tannic acid to prepare silicon dioxide. Tannic acid can be used as a pore - forming agent, making the prepared silicon dioxide have a larger surface area and can graft more octadecylamine. Secondly, since the present invention uses tannic acid and gallic acid to modify silicon dioxide, tannic acid and gallic acid can cooperate with octadecylamine to hydrophobically modify silicon dioxide, enhancing the hydrophobic property of the window film.

[0018] 3. The present invention uses epoxy group polysiloxane to hydrophobically modify acrylic resin. Epoxy group polysiloxane has excellent hydrophobicity, and a large number of epoxy groups are introduced into its outer molecular chain, making the prepared hydrophobic modified acrylic resin contain epoxy groups, enhancing the dispersibility of hydrophobic modified silicon dioxide in the acrylic resin matrix, and thus further enhancing the hydrophobic property of the window film. Specific embodiments

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0020] In all the examples and comparative examples of the present invention: PET: refractive index is 1.65, transmittance at 435 nm is 90%, visible light transmittance is 90%, and it can be purchased from Nan Ya Plastics Corporation in Taiwan, model: BH215; silica: refractive index is 1.45; titanium dioxide: refractive index is 2.4.

[0021] Example 1 (TiO 2 / SiO 2 / TiO 2 / PET): A preparation method of a blue light blocking and eye protection window film, comprising the following steps: Step 1: Take a PET film, clean and dry it to obtain a pretreated PET film; Step 2: Perform coating treatment on the pretreated PET film, and sequentially deposit a high refractive index film, a low refractive index film, and a high refractive index film on the surface of the pretreated PET film to obtain a blue light blocking and eye protection window film; adopt a single-period coating structure, the high refractive index material is titanium dioxide and the thickness of this layer is: λ / 4nH = 435 / (4*2.4) = 45 nm, thickness bandwidth ±10%; the low refractive index material is silica and the thickness of this layer is: λ / 4nH = 435 / (4*1.45) = 75 nm, thickness bandwidth ±10%.

[0022] Example 2 (TiO 2 / SiO 2 / TiO 2 / SiO 2 / TiO 2 / PET): Adopt a double-period coating structure, and the rest is the same as in Example 1: Step 1: Take a PET film, clean and dry it to obtain a pretreated PET film; Step 2: Perform coating treatment on the pretreated PET film, and sequentially deposit a high refractive index film, a low refractive index film, a high refractive index film, a low refractive index film, and a high refractive index film on the surface of the pretreated PET film to obtain a blue light blocking and eye protection window film; adopt a double-period coating structure, the high refractive index material is titanium dioxide and the thickness of this layer is 45 nm, thickness bandwidth ±10%; the low refractive index material is silica and the thickness of this layer is 75 nm, thickness bandwidth ±10%.

[0023] Example 3: Adopt a triple-period coating structure, and the rest is the same as in Example 1.

[0024] Example 4: Adopt a quadruple-period coating structure, and the rest is the same as in Example 1.

[0025] Example 5: Adopt a quintuple-period coating structure, and the rest is the same as in Example 1.

[0026] Example 6: Adopt a sextuple-period coating structure, and the rest is the same as in Example 1.

[0027] Example 7 (Ag / PET): Using Ag as the coating material with a coating thickness of 5 nm, it includes the following steps: Step 1: Take a PET film, clean and dry it to obtain a pretreated PET film; Step 2: Perform coating on the pretreated PET film, deposit Ag on the surface of the pretreated PET film with a coating thickness of 5 nm to obtain an anti-blue light and eye-protecting window film.

[0028] Example 8: Using Ag as the coating material with a coating thickness of 10 nm, and the rest is the same as Example 12.

[0029] Example 9: Using Ag as the coating material with a coating thickness of 15 nm, and the rest is the same as Example 12.

[0030] Example 10: Using Ag as the coating material with a coating thickness of 20 nm, and the rest is the same as Example 12.

[0031] Example 11 (TiO 2 / SiO 2 / TiO 2 / Ag / PET): Using Ag as the coating material with a coating thickness of 5 nm, and then deposit a single-period coating structure on the silver layer: it includes the following steps: Step 1: Take a PET film, clean and dry it to obtain a pretreated PET film; Step 2: Perform coating on the pretreated PET film, deposit Ag on the surface of the pretreated PET film with a coating thickness of 5 nm; then use a single-period coating structure to sequentially deposit a titanium dioxide layer with a thickness of 45 nm, a silicon dioxide layer with a thickness of 75 nm, and a titanium dioxide layer with a thickness of 45 nm to obtain an anti-blue light and eye-protecting window film.

[0032] Example 12: Using Ag as the coating material with a coating thickness of 10 nm, and then deposit a single-period coating structure on the silver layer, and the rest is the same as Example 16.

[0033] Example 13: A preparation method of an anti-blue light and eye-protecting window film, including the following steps: Step 1: Take a hydrophobic modified acrylic resin, hydrophobic modified silica, and photoinitiator 1-hydroxycyclohexyl phenyl ketone, stir evenly to obtain a hardening layer coating; coat the hardening layer coating on the other side of the coated and treated PET film prepared in Example 6 and cure it. The thickness of the hardening layer is 5 μm to obtain an anti-blue light and eye-protecting window film; The hardening layer coating is composed of the following components, by mass: 95 parts of hydrophobic modified acrylic resin, 20 parts of hydrophobic modified silica, and 0.5 part of photoinitiator 1-hydroxycyclohexyl phenyl ketone; The preparation method of the hydrophobically modified silica comprises the following steps: S1: Take 10mL of ethyl orthosilicate, 40mL of methanol, and 15mL of 0.02mol / L ammonia water, stir for 125min, add 0.1mol / L hydrochloric acid to adjust the pH value to 5.2, add 0.5g of tannic acid and 0.2g of gallic acid, stir for 3.5h, then adjust the pH value of the solution to 7.8 with 28% ammonia water, filter and dry to obtain porous silica; S2: Take 2 g of porous silica and 100 mL of deionized water, disperse by ultrasonication, add 0.1% sodium hydroxide by mass, adjust the pH value to 8.8, add 0.5 g of tris(hydroxymethyl)aminomethane, stir for 1.5 h, add 80 g of 2% octadecylamine ethanol solution by mass, stir for 8 h, wash, and obtain hydrophobically modified silica; The preparation method of the hydrophobically modified acrylic resin comprises the following steps: Step A: Take 10g of diphenylsilanediol, 12g of 3-glycidyloxypropyldimethoxymethylsilane, and 0.04g of barium hydroxide, mix them evenly, introduce nitrogen, heat to 82°C, react for 6.5h, and vacuum dry at 62°C for 4.5h to obtain epoxy polysiloxane; Step B: Take 65g of xylene, heat it to 92°C, add 5g of epoxy polysiloxane, add 0.5g of azobisisobutyronitrile, react for 35min, add dropwise a mixture of 11g of methyl methacrylate, 35g of butyl acrylate, 30g of styrene, 1.3g of methacrylic acid, and 21g of hydroxypropyl acrylate, add 1g of azobisisobutyronitrile, react for 3.5h, heat it to 102°C, add dropwise 0.5g of azobisisobutyronitrile, add 5g of epoxy polysiloxane, react for 2.5h to obtain a hydrophobically modified acrylic resin.

[0034] Embodiment 14: A method for preparing a blue light-blocking eye-protecting vehicle window film, comprising the following steps: Step 1: Take a hydrophobically modified acrylic resin, hydrophobically modified silica, and a photoinitiator 1-hydroxycyclohexyl phenyl ketone, stir them evenly, and obtain a hardened layer coating; apply the hardened layer coating to the surface of the PET film after the coating treatment prepared in Example 6, and cure it. The thickness of the hardened layer is 5 μm, and an anti-blue light eye protection car window film is obtained; The hardening layer coating is composed of the following components, calculated by weight: 90 parts of hydrophobically modified acrylic resin, 18 parts of hydrophobically modified silica, and 0.1 parts of photoinitiator 1-hydroxycyclohexyl phenyl ketone; The preparation method of the hydrophobically modified silica comprises the following steps: S1: Take 10 mL of tetraethyl orthosilicate, 40 mL of methanol, and 15 mL of ammonia water with a concentration of 0.02 mol / L, stir for 120 min, add hydrochloric acid with a concentration of 0.1 mol / L dropwise to adjust the pH value to 5.0, add 0.5 g of tannic acid and 0.2 g of gallic acid, stir for 3 h, then adjust the pH of the solution to 7.5 with 28% ammonia water by mass fraction, filter and dry to obtain porous silica; S2: Take 2 g of porous silica and 100 mL of deionized water, disperse ultrasonically, add sodium hydroxide with a mass fraction of 0.1% dropwise to adjust the pH value to 8.5, add 0.5 g of tris(hydroxymethyl)aminomethane, stir for 1 h, add 80 g of octadecylamine ethanol solution with a mass fraction of 2%, stir for 7 h, wash to obtain hydrophobically modified silica; The preparation method of the hydrophobically modified acrylic resin includes the following steps: Step A: Take 10 g of diphenylsilanediol, 12 g of 3-glycidoxypropyl dimethoxymethylsilane, and 0.04 g of barium hydroxide, mix evenly, introduce nitrogen, heat up to 80 °C, react for 6 h, and vacuum dry at 60 °C for 4 h to obtain epoxy polyorganosiloxane; Step B: Take 65 g of xylene, heat up to 90 °C, add 5 g of epoxy polyorganosiloxane, add 0.5 g of azobisisobutyronitrile, react for 30 min, dropwise add a mixture of 11 g of methyl methacrylate, 35 g of butyl acrylate, 30 g of styrene, 1.3 g of methacrylic acid, and 21 g of hydroxypropyl acrylate, add 1 g of azobisisobutyronitrile, react for 3 h, heat up to 100 °C, dropwise add 0.5 g of azobisisobutyronitrile, add 5 g of epoxy polyorganosiloxane, and react for 2 h to obtain hydrophobically modified acrylic resin.

[0035] Example 15: A preparation method of a blue light blocking and eye protection window film includes the following steps: Step 1: Take the hydrophobically modified acrylic resin, hydrophobically modified silica, and photoinitiator 1-hydroxycyclohexyl phenyl ketone, stir evenly to obtain a hardening layer coating; coat the hardening layer coating on the other surface of the PET film after coating treatment prepared in Example 6 and cure it. The thickness of the hardening layer is 5 μm to obtain a blue light blocking and eye protection window film; The hardening layer coating is composed of the following components, by mass: 100 parts of hydrophobically modified acrylic resin, 22 parts of hydrophobically modified silica, and 1 part of photoinitiator 1-hydroxycyclohexyl phenyl ketone; The preparation method of the hydrophobically modified silica includes the following steps: S1: Take 10mL of ethyl orthosilicate, 40mL of methanol, and 15mL of 0.02mol / L ammonia water, stir for 130min, add 0.1mol / L hydrochloric acid dropwise to adjust the pH value to 5.5, add 0.5g of tannic acid and 0.2g of gallic acid, stir for 4h, then adjust the pH value of the solution to 8.0 with 28% ammonia water, filter and dry to obtain porous silica; S2: Take 2 g of porous silica and 100 mL of deionized water, disperse by ultrasonication, add 0.1% sodium hydroxide by mass, adjust the pH value to 9, add 0.5 g of tris(hydroxymethyl)aminomethane, stir for 2 h, add 80 g of 2% octadecylamine ethanol solution by mass, stir for 10 h, wash, and obtain hydrophobically modified silica; The preparation method of the hydrophobically modified acrylic resin comprises the following steps: Step A: Take 10g of diphenylsilanediol, 12g of 3-glycidyloxypropyldimethoxymethylsilane, and 0.04g of barium hydroxide, mix them evenly, introduce nitrogen, heat to 85°C, react for 7h, and vacuum dry at 65°C for 5h to obtain epoxy polysiloxane; Step B: Take 65g of xylene, heat it to 95°C, add 5g of epoxy polysiloxane, add 0.5g of azobisisobutyronitrile, react for 40min, add dropwise a mixture of 11g of methyl methacrylate, 35g of butyl acrylate, 30g of styrene, 1.3g of methacrylic acid, and 21g of hydroxypropyl acrylate, add 1g of azobisisobutyronitrile, react for 4h, heat it to 105°C, add dropwise 0.5g of azobisisobutyronitrile, add 5g of epoxy polysiloxane, react for 3h to obtain a hydrophobically modified acrylic resin.

[0036] Comparative Example 1: tannic acid was not used to prepare silicon dioxide, and the rest was the same as Example 18: Step 1: Take a hydrophobically modified acrylic resin, hydrophobically modified silica, and a photoinitiator 1-hydroxycyclohexyl phenyl ketone, stir them evenly to obtain a hardened layer coating; apply the hardened layer coating to the other side of the PET film after the coating treatment prepared in Example 6, and cure it. The thickness of the hardened layer is 5 μm, and a blue light protection window film is obtained; The hardening layer coating is composed of the following components, calculated by weight: 95 parts of hydrophobically modified acrylic resin, 20 parts of hydrophobically modified silica, and 0.5 parts of photoinitiator 1-hydroxycyclohexyl phenyl ketone; The preparation method of the hydrophobically modified silica comprises the following steps: S1: Take 10 mL of tetraethyl orthosilicate, 40 mL of methanol, and 15 mL of ammonia water with a concentration of 0.02 mol / L, stir for 125 min, add hydrochloric acid with a concentration of 0.1 mol / L dropwise to adjust the pH value to 5.2, add 0.2 g of gallic acid, stir for 3.5 h, then use ammonia water with a mass fraction of 28% to adjust the pH of the solution to 7.8, filter and dry to obtain porous silica; S2: Take 2 g of porous silica and 100 mL of deionized water, disperse ultrasonically, add sodium hydroxide with a mass fraction of 0.1% dropwise to adjust the pH value to 8.8, add 0.5 g of tris(hydroxymethyl)aminomethane, stir for 1.5 h, add 80 g of octadecylamine ethanol solution with a mass fraction of 2%, stir for 8 h, wash to obtain hydrophobically modified silica; The preparation method of the hydrophobically modified acrylic resin includes the following steps: Step A: Take 10 g of diphenylsilanediol, 12 g of 3-glycidoxypropyl dimethoxymethylsilane, and 0.04 g of barium hydroxide, mix evenly, introduce nitrogen, heat up to 82 °C, react for 6.5 h, and vacuum dry at 62 °C for 4.5 h to obtain epoxy polyorganosiloxane; Step B: Take 65 g of xylene, heat up to 92 °C, add 5 g of epoxy polyorganosiloxane, add 0.5 g of azobisisobutyronitrile, react for 35 min, dropwise add a mixture of 11 g of methyl methacrylate, 35 g of butyl acrylate, 30 g of styrene, 1.3 g of methacrylic acid, and 21 g of hydroxypropyl acrylate, add 1 g of azobisisobutyronitrile, react for 3.5 h, heat up to 102 °C, dropwise add 0.5 g of azobisisobutyronitrile, add 5 g of epoxy polyorganosiloxane, and react for 2.5 h to obtain hydrophobically modified acrylic resin.

[0037] Comparative Example 2: The acrylic resin is not hydrophobically modified with epoxy polyorganosiloxane, and the rest is the same as in Example 18: Step 1: Take the hydrophobically modified acrylic resin, hydrophobically modified silica, and photoinitiator 1-hydroxycyclohexyl phenyl ketone, stir evenly to obtain a hardening layer coating; coat the hardening layer coating on the other surface of the PET film after coating treatment prepared in Example 6 and cure it. The thickness of the hardening layer is 5 μm to obtain an anti-blue light and eye-protecting window film; The hardening layer coating is composed of the following components by mass: 95 parts of acrylic resin, 20 parts of hydrophobically modified silica, and 0.5 part of photoinitiator 1-hydroxycyclohexyl phenyl ketone; The preparation method of the hydrophobically modified silica includes the following steps: S1: Take 10 mL of tetraethyl orthosilicate, 40 mL of methanol, and 15 mL of ammonia water with a concentration of 0.02 mol / L, stir for 125 min, add hydrochloric acid with a concentration of 0.1 mol / L dropwise to adjust the pH value to 5.2, add 0.5 g of tannic acid and 0.2 g of gallic acid, stir for 3.5 h, then adjust the pH of the solution to 7.8 with 28% ammonia water by mass fraction, filter and dry to obtain porous silica; S2: Take 2 g of porous silica and 100 mL of deionized water, disperse ultrasonically, add sodium hydroxide with a mass fraction of 0.1% dropwise to adjust the pH value to 8.8, add 0.5 g of tris(hydroxymethyl)aminomethane, stir for 1.5 h, add 80 g of octadecylamine ethanol solution with a mass fraction of 2%, stir for 8 h, and wash to obtain hydrophobically modified silica; The preparation method of the acrylic resin includes the following steps: Take 65 g of xylene, heat up to 92 °C, add 0.5 g of azobisisobutyronitrile, react for 35 min, add dropwise a mixture of 11 g of methyl methacrylate, 35 g of butyl acrylate, 30 g of styrene, 1.3 g of methacrylic acid, and 21 g of hydroxypropyl acrylate, add 1 g of azobisisobutyronitrile, react for 3.5 h, heat up to 102 °C, add dropwise 0.5 g of azobisisobutyronitrile, add 5 g of epoxy group polysiloxane, and react for 2.5 h to obtain acrylic resin.

[0038] Comparative Example 3: Without adding gallic acid, the rest is the same as Example 18: Step 1: Take hydrophobically modified acrylic resin, hydrophobically modified silica, and photoinitiator 1-hydroxycyclohexyl phenyl ketone, stir evenly to obtain a hardening layer coating; coat the hardening layer coating on the other surface of the PET film after coating treatment prepared in Example 6 and cure it. The thickness of the hardening layer is 5 μm to obtain an anti-blue light and eye-protecting window film; The hardening layer coating is composed of the following components, by mass fraction: 95 parts of hydrophobically modified acrylic resin, 20 parts of hydrophobically modified silica, and 0.5 part of photoinitiator 1-hydroxycyclohexyl phenyl ketone; The preparation method of the hydrophobically modified silica includes the following steps: S1: Take 10 mL of tetraethyl orthosilicate, 40 mL of methanol, and 15 mL of ammonia water with a concentration of 0.02 mol / L, stir for 125 min, add hydrochloric acid with a concentration of 0.1 mol / L dropwise to adjust the pH value to 5.2, add 0.5 g of tannic acid, stir for 3.5 h, then adjust the pH of the solution to 7.8 with 28% ammonia water by mass fraction, filter and dry to obtain porous silica; S2: Take 2 g of porous silica and 100 mL of deionized water, ultrasonically disperse them, add sodium hydroxide with a mass fraction of 0.1%, adjust the pH value to 8.8, add 0.5 g of tris(hydroxymethyl)aminomethane, stir for 1.5 h, add 80 g of an 18-amine ethanol solution with a mass fraction of 2%, stir for 8 h, and wash to obtain hydrophobically modified silica; The preparation method of the hydrophobically modified acrylic resin includes the following steps: Step A: Take 10 g of diphenylsilanediol, 12 g of 3-glycidoxypropyl dimethoxymethylsilane, and 0.04 g of barium hydroxide, mix them evenly, introduce nitrogen, heat up to 82 °C, react for 6.5 h, and vacuum dry at 62 °C for 4.5 h to obtain epoxy polyorganosiloxane; Step B: Take 65 g of xylene, heat up to 92 °C, add 5 g of epoxy polyorganosiloxane, add 0.5 g of azobisisobutyronitrile, react for 35 min, dropwise add a mixture of 11 g of methyl methacrylate, 35 g of butyl acrylate, 30 g of styrene, 1.3 g of methacrylic acid, and 21 g of hydroxypropyl acrylate, add 1 g of azobisisobutyronitrile, react for 3.5 h, heat up to 102 °C, dropwise add 0.5 g of azobisisobutyronitrile, add 5 g of epoxy polyorganosiloxane, and react for 2.5 h to obtain hydrophobically modified acrylic resin.

[0039] Experiment 1: Take the anti-blue light and eye-protecting window films prepared in Examples 1-18 for performance testing. Test T 435 (%) i.e., the transmittance at a wavelength of 435 nm. The smaller this transmittance, the better the anti-blue light and eye-protecting effect; the visible light transmittance. The obtained data are shown in the following table:

[0040] Conclusion: It can be seen from the comparison of the data in the table that the present invention constructs a multi-layer coating structure by alternately depositing a high refractive index material titanium dioxide and a low refractive index material silica. The optical thickness of the coating satisfies the Bragg reflection condition, and the reflection at a wavelength of 435 nm can be enhanced. The coating thickness of Example 1 is 45 nm + 75 nm + 45 nm, the coating thickness of Example 2 is 45 nm + 75 nm + 45 nm + 75 nm + 45 nm, and so on; the coating of Example 6 uses silica and titanium dioxide as the low refractive index film and the high refractive index film respectively, and alternately deposits silica and titanium dioxide for six cycles. The visible light transmittance of the obtained window film can reach 62%, and the transmittance at a wavelength of 435 nm is 22%. This transmittance is very small, and the anti-blue light and eye-protecting effect is good. While the anti-blue light effect is excellent, the visible light transmittance is also very high.

[0041] Experiment 2: The hydrophobic performance of the blue light-blocking and eye-protecting window films prepared in Examples 18-20 and Comparative Examples 1-3 was tested, and the water contact angles on the surfaces of the window films were measured. The obtained data are shown in the following table:

[0042] Conclusion: From the comparison of the data in the table, it can be seen that in Comparative Example 1, tannic acid was not used to prepare silica, resulting in fewer grafted octadecylamines and poorer hydrophobicity of the blue light-blocking and eye-protecting window film, with a smaller water contact angle. In Comparative Example 2, epoxy group-containing polysiloxane was not used to hydrophobically modify the acrylic resin, resulting in a smaller water contact angle and poor hydrophobicity. In Comparative Example 3, gallic acid was not added, leading to poorer hydrophobicity of the blue light-blocking and eye-protecting window film and a smaller water contact angle. In Examples 13-15 of the present invention, tannic acid was used to prepare silica. Tannic acid can act as a pore-forming agent, increasing the surface area of the prepared silica and allowing more octadecylamines to be grafted. Secondly, since tannic acid and gallic acid were used to modify silica in the present invention, tannic acid and gallic acid can synergistically hydrophobically modify silica with octadecylamine, enhancing the hydrophobic performance of the hardening layer. In Examples 13-15 of the present invention, epoxy group-containing polysiloxane was used to hydrophobically modify the acrylic resin. Epoxy group-containing polysiloxane has excellent hydrophobicity, and a large number of epoxy groups were introduced into the outer molecular chain, resulting in epoxy groups in the prepared hydrophobically modified acrylic resin, enhancing the dispersion of the hydrophobically modified silica in the acrylic resin matrix and further enhancing the hydrophobic performance of the window film.

[0043] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, in any regard, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention.

Claims

1. A method for preparing a blue light protection window film, characterized in that: The following steps are involved: Step 1: Take the PET film, wash and dry it to obtain a pretreated PET film; Step 2: performing a coating treatment on the pretreated PET film, first depositing a layer of high refractive index film on the surface of the pretreated PET film, and then alternately depositing a low refractive index film and a high refractive index film to obtain a blue light protection window film; The low refractive index film is a silicon dioxide layer; the high refractive index film is a titanium dioxide layer.

2. The method for preparing a blue light protection window film according to claim 1, characterized in that: The low refractive index film plus the high refractive index film constitutes a deposition cycle, and the number of the cycles is 1-6 times.

3. The method for preparing a blue light protection window film according to claim 1, characterized in that: The refractive index of the silicon dioxide layer is 1.45-1.47, and the thickness is 74-75 nm; the refractive index of the titanium dioxide layer is 2.4-2.55, and the thickness is 44-45 nm.

4. The method for preparing a blue light protection window film according to claim 1, characterized in that: The refractive index of the PET film is 1.64-1.65, and the visible light transmittance is 90-92%.

5. The method for preparing a blue light protection window film according to claim 1, characterized in that: The anti-blue light eye protection car window film is also coated with a hardening layer coating on the PET surface on the other side of the coating, and the preparation method thereof comprises the following steps: S1: taking a PET film, washing and drying it to obtain a pretreated PET film; S2: performing film coating on the pretreated PET film, coating a low refractive index film and a high refractive index film on the surface of the pretreated PET film in sequence; S3: Take a hydrophobically modified acrylic resin, hydrophobically modified silica, and a photoinitiator, stir them evenly to obtain a hardened layer coating; apply the hardened layer coating to the surface of the PET film after coating treatment, and cure it to obtain an anti-blue light eye-protection car window film.

6. The method for preparing a blue light protection window film according to claim 5, characterized in that: The hardening layer coating is composed of the following components, calculated by weight: 90-100 parts of hydrophobically modified acrylic resin, 18-22 parts of hydrophobically modified silica, and 0.1-1 part of a photoinitiator.

7. The method for preparing a blue light protection window film according to claim 6, characterized in that: The preparation method of the hydrophobically modified silica is as follows: taking porous silica and deionized water, ultrasonically dispersing, dropping sodium hydroxide, adjusting the pH value to 8.5-9, adding tris(hydroxymethyl)aminomethane, stirring for 1-2 hours, adding octadecylamine ethanol solution, stirring for 7-10 hours, washing, filtering, and drying to obtain hydrophobically modified silica; The preparation method of the porous silica is as follows: taking tetraethyl orthosilicate, methanol and ammonia water, stirring for 120-130 minutes, dropping hydrochloric acid, adjusting the pH value to 5.0-5.5, adding tannic acid and gallic acid, stirring for 3-4 hours, and then adjusting the pH value of the solution to 7.5-8.0 with ammonia water, filtering and drying to obtain porous silica.

8. The method for preparing a blue light protection window film according to claim 6, characterized in that: The preparation method of the hydrophobically modified acrylic resin comprises the following steps: Step A: Take diphenylsilanediol, 3-glycidyloxypropyldimethoxymethylsilane and barium hydroxide, mix them evenly, introduce nitrogen, heat to 80-85° C., react for 6-7 hours, and vacuum dry at 60-65° C. for 4-5 hours to obtain epoxy polysiloxane; Step B: Take xylene, heat it to 90-95°C, add epoxy polysiloxane, add azobisisobutyronitrile, react for 30-40 minutes, drop a mixture of methyl methacrylate, butyl acrylate, styrene, methacrylic acid, and hydroxypropyl acrylate, add azobisisobutyronitrile, react for 3-4 hours, heat it to 100-105°C, drop azobisisobutyronitrile, add epoxy polysiloxane, react for 2-3 hours, and obtain a hydrophobically modified acrylic resin.

9. A vehicle window film prepared according to the method for preparing a blue light blocking and eye protection vehicle window film according to any one of claims 1 to 8.

10. Use of the vehicle window film according to claim 9 in automobiles, ships and architectural glass.

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