Method for preparing blue-light-blocking and eye-protective automotive window film and use thereof
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-03-17
- Publication Date
- 2026-08-13
Smart Images
Figure PCTCN2025082858-APPB-I100001 
Figure PCTCN2025082858-APPB-I100002
Abstract
Description
A method for preparing a blue light blocking and eye-protecting car window film and its application Technical Field
[0001] This invention relates to the field of optical thin film technology, specifically a method for preparing a blue light blocking and eye-protecting car window film and its application. Background Technology
[0002] Blue light, especially short-wavelength blue light in the 415nm-455nm range, poses various health risks to the eyes due to its high energy. Short-wavelength blue light can penetrate the cornea and lens to reach the retina, causing excessive free radical production in retinal pigment epithelial cells, leading to oxidative stress and cell death. Prolonged exposure to blue light can also cause irreversible retinal degeneration. Long-term exposure may accelerate lens oxidation, increasing oxidative damage to the lens and cornea, and potentially inducing or worsening cataracts. Short-wavelength blue light is easily scattered within the eye, causing blurred vision and reduced contrast, thus increasing eye strain. When driving or using electronic devices, the strong scattering of short-wavelength blue light within the eye can cause blurred vision and dizziness. Blue light radiation can also interfere with tear film secretion, leading to dry eyes.
[0003] Window film is widely used in automobiles, ships, and architectural glass. With rapid economic development, people are using cars more and more frequently and for longer periods of time, and their eyes are exposed to various lights for longer periods of time, especially when driving at night. The large amount of short-wave blue light contained in various glaring LED lights in the environment can cause glare and dizziness in the short term, leading to driving fatigue and affecting driving safety. Long-term exposure can cause various eye damages.
[0004] To address the aforementioned problems, this invention provides a method for preparing a blue light blocking and eye-protecting car window film and its application. Summary of the Invention
[0005] The purpose of this invention is to provide a method for preparing a blue light blocking and eye-protecting car window film to solve the problems raised in the prior art.
[0006] A method for preparing a blue light blocking and eye-protecting car window film includes the following steps:
[0007] Step 1: Take the PET film, clean and dry it to obtain the pretreated PET film;
[0008] Step 2: The pretreated PET film is coated. A high refractive index film is first deposited on the surface of the pretreated PET film, and then low refractive index film and high refractive index film are deposited alternately to obtain blue light blocking and eye protection car window film.
[0009] 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.
[0010] Ideally, the deposition cycle consists of a low-refractive-index film followed by a high-refractive-index film, and the number of cycles is 1-6.
[0011] Ideally, the silicon dioxide layer has a refractive index of 1.45-1.47 and a thickness of 74-75 nm; the titanium dioxide layer has a refractive index of 2.4-2.55 and a thickness of 44-45 nm.
[0012] Ideally, the PET film has a refractive index of 1.64-1.65 and a visible light transmittance of 90-92%.
[0013] In a more optimized manner, the blue light blocking eye-protecting window film also has a hardened coating layer applied to the PET surface on the other side of the coating. Its preparation method includes the following steps:
[0014] S1: Take the PET film, clean and dry it to obtain the pretreated PET film;
[0015] S2: The pretreated PET film is coated with a low refractive index film and a high refractive index film in sequence on the surface of the pretreated PET film.
[0016] S3: Take hydrophobically modified acrylic resin, hydrophobically modified silica, and photoinitiator, stir evenly to obtain a hardened coating layer; apply the hardened coating layer to the surface of the coated PET film, cure, and obtain a blue light blocking and eye-protecting car window film.
[0017] In a more optimized manner, the hardened coating layer is composed of the following components, by weight: 90-100 parts hydrophobic modified acrylic resin, 18-22 parts hydrophobic modified silica, and 0.1-1 parts photoinitiator.
[0018] In a more optimized manner, the preparation method of the hydrophobic modified silica is as follows: take porous silica and deionized water, disperse them by ultrasonication, add sodium hydroxide dropwise, adjust the pH value to 8.5-9, add tris(hydroxymethyl)aminomethane, stir for 1-2 hours, add octadecylamine ethanol solution, stir for 7-10 hours, wash, filter, and dry to obtain hydrophobic modified silica.
[0019] The method for preparing the porous silica is as follows: take tetraethyl orthosilicate, methanol, and ammonia, stir for 120-130 min, add hydrochloric acid dropwise to 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, filter and dry to obtain porous silica.
[0020] A more optimized method for preparing the hydrophobically modified acrylic resin includes the following steps:
[0021] Step A: Take diphenylsilanediol, 3-glycidyl etheroxypropyl dimethoxymethylsilane, and barium hydroxide, mix them evenly, introduce nitrogen gas, heat to 80-85℃, react for 6-7 hours, and then vacuum dry at 60-65℃ for 4-5 hours to obtain epoxy polysiloxane.
[0022] Step B: Take xylene, heat it to 90-95℃, add epoxy polysiloxane, add azobisisobutyronitrile, react for 30-40 min, add dropwise a mixture of methyl methacrylate, butyl acrylate, styrene, methacrylic acid, and hydroxypropyl acrylate, add azobisisobutyronitrile, react for 3-4 h, heat it to 100-105℃, add dropwise azobisisobutyronitrile, add epoxy polysiloxane, react for 2-3 h, and obtain hydrophobic modified acrylic resin.
[0023] A method for preparing a blue light blocking and eye-protecting car window film.
[0024] Application of a type of window film in automobiles, ships, and architectural glass.
[0025] To achieve the above objectives, the present invention provides the following technical solution:
[0026] Compared with the prior art, the beneficial effects of the present invention are:
[0027] 1. This patent invention discloses a window film that can effectively block harmful short-wavelength blue light in the wavelength range of 415nm-455nm. This invention utilizes the alternating deposition of high-refractive-index titanium dioxide and low-refractive-index silicon dioxide to construct a multi-layered coating structure. The optical thickness of the coating satisfies the Bragg reflection condition, enhancing reflection at a wavelength of 435nm and thus providing blue light protection.
[0028] 2. This invention uses tannic acid to prepare silica. Tannic acid can act as a pore-forming agent, resulting in a larger surface area of the prepared silica, allowing for the grafting of more octadecylamine. Furthermore, because this invention uses tannic acid and gallic acid to modify silica, tannic acid and gallic acid can synergistically modify silica with octadecylamine to enhance its hydrophobic properties, thereby improving the hydrophobic performance of the window film.
[0029] 3. This invention uses epoxy-based polysiloxanes to hydrophobically modify acrylic resins. Epoxy-based polysiloxanes have excellent hydrophobicity, and a large number of epoxy groups are introduced into their outer molecular chains, so that the hydrophobically modified acrylic resins prepared contain epoxy groups, which enhances the dispersibility of hydrophobically modified silica in the acrylic resin matrix, thereby further enhancing the hydrophobic properties of the window film. Detailed Implementation
[0030] 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.
[0031] In all embodiments and comparative examples of this invention: PET: refractive index 1.65, transmittance at 435nm 90%, visible light transmittance 90%, can be purchased from Nan Ya Plastics in Taiwan, model: BH215; silicon dioxide: refractive index 1.45; titanium dioxide: refractive index 2.4.
[0032] Example 1 (TiO) ₂ / SiO ₂ / TiO ₂ / PET): A method for preparing a blue light blocking and eye-protecting car window film, comprising the following steps:
[0033] Step 1: Take the PET film, clean and dry it to obtain the pretreated PET film;
[0034] Step 2: The pretreated PET film is coated with a high-refractive-index film, a low-refractive-index film, and a high-refractive-index film sequentially to obtain a blue light blocking and eye-protecting car window film. A single-cycle coating structure is adopted. The high-refractive-index material is titanium dioxide with a thickness of λ / 4nH=435 / (4*2.4)=45nm and a thickness bandwidth of ±10%. The low-refractive-index material is silicon dioxide with a thickness of λ / 4nH=435 / (4*1.45)=75nm and a thickness bandwidth of ±10%.
[0035] Example 2 (TiO) ₂ / SiO ₂ / TiO ₂ / SiO ₂ / TiO ₂ / PET): It adopts a dual-cycle coating structure, and the rest is the same as in Example 1:
[0036] Step 1: Take the PET film, clean and dry it to obtain the pretreated PET film;
[0037] Step 2: The pretreated PET film is coated with 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 sequentially to obtain a blue light blocking and eye-protecting window film. A dual-cycle coating structure is adopted. The high refractive index material is titanium dioxide with a thickness of 45nm and a thickness bandwidth of ±10%. The low refractive index material is silicon dioxide with a thickness of 75nm and a thickness bandwidth of ±10%.
[0038] Example 3: A three-cycle coating structure is adopted, and the rest is the same as in Example 1.
[0039] Example 4: A four-cycle coating structure is adopted, and the rest is the same as in Example 1.
[0040] Example 5: A five-cycle coating structure is used, and the rest is the same as in Example 1.
[0041] Example 6: A six-cycle coating structure is used, and the rest is the same as in Example 1.
[0042] Example 7 (Ag / PET): Using Ag as the coating material, the coating thickness is 5nm, including the following steps:
[0043] Step 1: Take the PET film, clean and dry it to obtain the pretreated PET film;
[0044] Step 2: Coating the pretreated PET film with Ag, with a coating thickness of 5nm, to obtain a blue light blocking and eye-protecting car window film.
[0045] Example 8: Ag was used as the coating material, and the coating thickness was 10 nm. The rest was the same as in Example 12.
[0046] Example 9: Ag was used as the coating material, and the coating thickness was 15 nm. The rest was the same as in Example 12.
[0047] Example 10: Ag was used as the coating material, and the coating thickness was 20 nm. The rest was the same as in Example 12.
[0048] Example 11 (TiO) ₂ / SiO ₂ / TiO ₂ / Ag / PET): Using Ag as the coating material, the coating thickness is 5nm, and then a single-cycle coating structure is deposited on the silver layer: including the following steps:
[0049] Step 1: Take the PET film, clean and dry it to obtain the pretreated PET film;
[0050] Step 2: The pretreated PET film is coated with Ag to form a 5nm thick layer. Then, a single-cycle coating structure is used to coat a 45nm thick titanium dioxide layer, a 75nm thick silicon dioxide layer, and another 45nm thick titanium dioxide layer in sequence to obtain a blue light blocking and eye protection car window film.
[0051] Example 12: Ag was used as the coating material, the coating thickness was 10 nm, and then a single-cycle coating structure was deposited on the silver layer. The rest was the same as in Example 16.
[0052] Example 13: A method for preparing a blue light blocking and eye-protecting car window film, comprising the following steps:
[0053] Step 1: Take hydrophobically modified acrylic resin, hydrophobically modified silica, and photoinitiator 1-hydroxycyclohexylphenyl ketone, stir evenly to obtain a hardened coating layer; coat the hardened coating layer onto the other side of the PET film prepared in Example 6 after coating treatment, and cure it. The thickness of the hardened layer is 5μm to obtain a blue light blocking and eye protection car window film.
[0054] The hardened coating consists of the following components, in parts by weight: 95 parts hydrophobic modified acrylic resin, 20 parts hydrophobic modified silica, and 0.5 parts photoinitiator 1-hydroxycyclohexylphenyl ketone.
[0055] The method for preparing the hydrophobically modified silica includes the following steps:
[0056] S1: Take 10 mL of tetraethyl orthosilicate, 40 mL of methanol, and 15 mL of 0.02 mol / L ammonia solution, stir for 125 min, add 0.1 mol / L hydrochloric acid to adjust the pH 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 solution, filter and dry to obtain porous silica;
[0057] S2: Take 2g of porous silica and 100mL of deionized water, disperse by ultrasonication, add 0.1% sodium hydroxide dropwise, adjust the pH to 8.8, add 0.5g of tris(hydroxymethyl)aminomethane, stir for 1.5h, add 80g of 2% octadecylamine ethanol solution, stir for 8h, wash, and obtain hydrophobic modified silica;
[0058] The preparation method of the hydrophobic modified acrylic resin includes the following steps:
[0059] Step A: Take 10g of diphenylsilanediol, 12g of 3-glycidyl etheroxypropyl dimethoxymethylsilane, and 0.04g of barium hydroxide, mix them evenly, introduce nitrogen gas, heat to 82℃, react for 6.5h, and dry under vacuum at 62℃ for 4.5h to obtain epoxy polysiloxane.
[0060] Step B: Take 65g of xylene, heat to 92℃, add 5g of epoxy polysiloxane, add 0.5g of azobisisobutyronitrile, react for 35min, add 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 to 102℃, add 0.5g of azobisisobutyronitrile, add 5g of epoxy polysiloxane, react for 2.5h to obtain hydrophobic modified acrylic resin.
[0061] Example 14: A method for preparing a blue light blocking and eye-protecting car window film, comprising the following steps:
[0062] Step 1: Take hydrophobically modified acrylic resin, hydrophobically modified silica, and photoinitiator 1-hydroxycyclohexylphenyl ketone, stir evenly to obtain a hardened coating layer; apply the hardened coating layer to the surface of the PET film prepared in Example 6 after coating treatment, and cure it. The thickness of the hardened layer is 5μm to obtain a blue light blocking and eye protection car window film.
[0063] The hardened coating consists of the following components, by weight: 90 parts hydrophobic modified acrylic resin, 18 parts hydrophobic modified silica, and 0.1 parts photoinitiator 1-hydroxycyclohexylphenyl ketone.
[0064] The method for preparing the hydrophobically modified silica includes the following steps:
[0065] S1: Take 10 mL of tetraethyl orthosilicate, 40 mL of methanol, and 15 mL of 0.02 mol / L ammonia solution, stir for 120 min, add 0.1 mol / L hydrochloric acid to adjust the pH 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 solution, filter and dry to obtain porous silica;
[0066] S2: Take 2g of porous silica and 100mL of deionized water, disperse by ultrasonication, add 0.1% sodium hydroxide dropwise, adjust the pH to 8.5, add 0.5g of tris(hydroxymethyl)aminomethane, stir for 1h, add 80g of 2% octadecylamine ethanol solution, stir for 7h, wash, and obtain hydrophobic modified silica.
[0067] The preparation method of the hydrophobic modified acrylic resin includes the following steps:
[0068] Step A: Take 10g of diphenylsilanediol, 12g of 3-glycidyl etheroxypropyl dimethoxymethylsilane, and 0.04g of barium hydroxide, mix them evenly, introduce nitrogen gas, heat to 80℃, react for 6h, and dry under vacuum at 60℃ for 4h to obtain epoxy polysiloxane.
[0069] Step B: Take 65g of xylene, heat to 90℃, add 5g of epoxy polysiloxane, add 0.5g of azobisisobutyronitrile, react for 30min, add 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 3h, heat to 100℃, add 0.5g of azobisisobutyronitrile, add 5g of epoxy polysiloxane, react for 2h to obtain hydrophobic modified acrylic resin.
[0070] Example 15: A method for preparing a blue light blocking and eye-protecting car window film, comprising the following steps:
[0071] Step 1: Take hydrophobically modified acrylic resin, hydrophobically modified silica, and photoinitiator 1-hydroxycyclohexylphenyl ketone, stir evenly to obtain a hardened coating layer; apply the hardened coating layer to the other side of the PET film prepared in Example 6 after coating treatment, and cure it. The thickness of the hardened layer is 5μm to obtain a blue light blocking and eye protection car window film.
[0072] The hardened coating consists of the following components, in parts by weight: 100 parts hydrophobic modified acrylic resin, 22 parts hydrophobic modified silica, and 1 part photoinitiator 1-hydroxycyclohexylphenyl ketone.
[0073] The method for preparing the hydrophobically modified silica includes the following steps:
[0074] S1: Take 10 mL of tetraethyl orthosilicate, 40 mL of methanol, and 15 mL of 0.02 mol / L ammonia solution, stir for 130 min, add 0.1 mol / L hydrochloric acid to adjust the pH to 5.5, add 0.5 g of tannic acid and 0.2 g of gallic acid, stir for 4 h, then adjust the pH of the solution to 8.0 with 28% ammonia solution, filter and dry to obtain porous silica;
[0075] S2: Take 2g of porous silica and 100mL of deionized water, disperse by ultrasonication, add 0.1% sodium hydroxide dropwise, adjust the pH to 9, add 0.5g of tris(hydroxymethyl)aminomethane, stir for 2h, add 80g of 2% octadecylamine ethanol solution, stir for 10h, wash, and obtain hydrophobic modified silica.
[0076] The preparation method of the hydrophobic modified acrylic resin includes the following steps:
[0077] Step A: Take 10g of diphenylsilanediol, 12g of 3-glycidyl etheroxypropyl dimethoxymethylsilane, and 0.04g of barium hydroxide, mix them evenly, introduce nitrogen gas, heat to 85℃, react for 7h, and dry under vacuum at 65℃ for 5h to obtain epoxy polysiloxane.
[0078] Step B: Take 65g of xylene, heat to 95℃, add 5g of epoxy polysiloxane, add 0.5g of azobisisobutyronitrile, react for 40min, add 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 to 105℃, add 0.5g of azobisisobutyronitrile, add 5g of epoxy polysiloxane, react for 3h to obtain hydrophobic modified acrylic resin.
[0079] Comparative Example 1: Silicon dioxide was prepared without the use of tannic acid; all other aspects were the same as in Example 18.
[0080] Step 1: Take hydrophobically modified acrylic resin, hydrophobically modified silica, and photoinitiator 1-hydroxycyclohexylphenyl ketone, stir evenly to obtain a hardened coating layer; apply the hardened coating layer to the other side of the PET film prepared in Example 6 after coating treatment, and cure it. The thickness of the hardened layer is 5μm to obtain a blue light blocking and eye protection car window film.
[0081] The hardened coating consists of the following components, in parts by weight: 95 parts hydrophobic modified acrylic resin, 20 parts hydrophobic modified silica, and 0.5 parts photoinitiator 1-hydroxycyclohexylphenyl ketone.
[0082] The method for preparing the hydrophobically modified silica includes the following steps:
[0083] S1: Take 10 mL of tetraethyl orthosilicate, 40 mL of methanol, and 15 mL of 0.02 mol / L ammonia solution, stir for 125 min, add 0.1 mol / L hydrochloric acid to adjust the pH to 5.2, add 0.2 g of gallic acid, stir for 3.5 h, then adjust the pH of the solution to 7.8 with 28% ammonia solution, filter and dry to obtain porous silica;
[0084] S2: Take 2g of porous silica and 100mL of deionized water, disperse by ultrasonication, add 0.1% sodium hydroxide dropwise, adjust the pH to 8.8, add 0.5g of tris(hydroxymethyl)aminomethane, stir for 1.5h, add 80g of 2% octadecylamine ethanol solution, stir for 8h, wash, and obtain hydrophobic modified silica;
[0085] The preparation method of the hydrophobic modified acrylic resin includes the following steps:
[0086] Step A: Take 10g of diphenylsilanediol, 12g of 3-glycidyl etheroxypropyl dimethoxymethylsilane, and 0.04g of barium hydroxide, mix them evenly, introduce nitrogen gas, heat to 82℃, react for 6.5h, and dry under vacuum at 62℃ for 4.5h to obtain epoxy polysiloxane.
[0087] Step B: Take 65g of xylene, heat to 92℃, add 5g of epoxy polysiloxane, add 0.5g of azobisisobutyronitrile, react for 35min, add 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 to 102℃, add 0.5g of azobisisobutyronitrile, add 5g of epoxy polysiloxane, react for 2.5h to obtain hydrophobic modified acrylic resin.
[0088] Comparative Example 2: The acrylic resin was not hydrophobically modified using epoxy-based polysiloxanes; all other aspects were the same as in Example 18.
[0089] Step 1: Take hydrophobically modified acrylic resin, hydrophobically modified silica, and photoinitiator 1-hydroxycyclohexylphenyl ketone, stir evenly to obtain a hardened coating layer; apply the hardened coating layer to the other side of the PET film prepared in Example 6 after coating treatment, and cure it. The thickness of the hardened layer is 5μm to obtain a blue light blocking and eye protection car window film.
[0090] The hardened coating consists of the following components, in parts by weight: 95 parts acrylic resin, 20 parts hydrophobically modified silica, and 0.5 parts photoinitiator 1-hydroxycyclohexylphenyl ketone.
[0091] The method for preparing the hydrophobically modified silica includes the following steps:
[0092] S1: Take 10 mL of tetraethyl orthosilicate, 40 mL of methanol, and 15 mL of 0.02 mol / L ammonia solution, stir for 125 min, add 0.1 mol / L hydrochloric acid to adjust the pH 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 solution, filter and dry to obtain porous silica;
[0093] S2: Take 2g of porous silica and 100mL of deionized water, disperse by ultrasonication, add 0.1% sodium hydroxide dropwise, adjust the pH to 8.8, add 0.5g of tris(hydroxymethyl)aminomethane, stir for 1.5h, add 80g of 2% octadecylamine ethanol solution, stir for 8h, wash, and obtain hydrophobic modified silica;
[0094] The preparation method of the acrylic resin includes the following steps:
[0095] Take 65g of xylene, heat to 92℃, add 0.5g of azobisisobutyronitrile, react for 35min, add dropwise a mixture of 11g methyl methacrylate, 35g butyl acrylate, 30g styrene, 1.3g methacrylic acid, and 21g hydroxypropyl acrylate, add 1g of azobisisobutyronitrile, react for 3.5h, heat to 102℃, add dropwise 0.5g of azobisisobutyronitrile, add 5g of epoxy polysiloxane, react for 2.5h to obtain acrylic resin.
[0096] Comparative Example 3: Gallic acid was not added; all other aspects were the same as in Example 18.
[0097] Step 1: Take hydrophobically modified acrylic resin, hydrophobically modified silica, and photoinitiator 1-hydroxycyclohexylphenyl ketone, stir evenly to obtain a hardened coating layer; apply the hardened coating layer to the other side of the PET film prepared in Example 6 after coating treatment, and cure it. The thickness of the hardened layer is 5μm to obtain a blue light blocking and eye protection car window film.
[0098] The hardened coating consists of the following components, in parts by weight: 95 parts hydrophobic modified acrylic resin, 20 parts hydrophobic modified silica, and 0.5 parts photoinitiator 1-hydroxycyclohexylphenyl ketone.
[0099] The method for preparing the hydrophobically modified silica includes the following steps:
[0100] S1: Take 10 mL of tetraethyl orthosilicate, 40 mL of methanol, and 15 mL of 0.02 mol / L ammonia solution, stir for 125 min, add 0.1 mol / L hydrochloric acid to adjust the pH 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 solution, filter and dry to obtain porous silica;
[0101] S2: Take 2g of porous silica and 100mL of deionized water, disperse by ultrasonication, add 0.1% sodium hydroxide dropwise, adjust the pH to 8.8, add 0.5g of tris(hydroxymethyl)aminomethane, stir for 1.5h, add 80g of 2% octadecylamine ethanol solution, stir for 8h, wash, and obtain hydrophobic modified silica;
[0102] The preparation method of the hydrophobic modified acrylic resin includes the following steps:
[0103] Step A: Take 10g of diphenylsilanediol, 12g of 3-glycidyl etheroxypropyl dimethoxymethylsilane, and 0.04g of barium hydroxide, mix them evenly, introduce nitrogen gas, heat to 82℃, react for 6.5h, and dry under vacuum at 62℃ for 4.5h to obtain epoxy polysiloxane.
[0104] Step B: Take 65g of xylene, heat to 92℃, add 5g of epoxy polysiloxane, add 0.5g of azobisisobutyronitrile, react for 35min, add 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 to 102℃, add 0.5g of azobisisobutyronitrile, add 5g of epoxy polysiloxane, react for 2.5h to obtain hydrophobic modified acrylic resin.
[0105] Experiment 1:
[0106] The anti-blue light eye-protecting car window films prepared in Examples 1-18 were subjected to performance testing. The test T... 435 (%) represents the transmittance at a wavelength of 435nm. The lower the transmittance, the better the blue light protection effect. The visible light transmittance data are shown in the table below:
[0107]
[0108] Conclusion: Comparison of the data in the table shows that this invention utilizes the alternating deposition of high-refractive-index titanium dioxide and low-refractive-index silicon dioxide to construct a multi-layer coating structure. The optical thickness of the coating satisfies the Bragg reflection condition, enhancing reflection at a wavelength of 435nm. In Example 1, the coating thickness was 45nm+75nm+45nm; in Example 2, it was 45nm+75nm+45nm+75nm+45nm, and so on. In Example 6, silicon dioxide and titanium dioxide were used as the low-refractive-index and high-refractive-index films, respectively, and were deposited alternately for six cycles. The resulting window film achieved a visible light transmittance of 62% and a transmittance of 22% at a wavelength of 435nm. This low transmittance indicates good blue light protection for the eyes, demonstrating excellent blue light protection while maintaining high visible light transmittance.
[0109] Experiment 2:
[0110] The hydrophobic properties of the blue light blocking and eye-protecting car window films prepared in Examples 18-20 and Comparative Examples 1-3 were tested. The water contact angle of the car window film surface was measured, and the data are shown in the table below:
[0111]
[0112] Conclusion: The data comparison in the table shows that in Comparative Example 1, without the use of tannic acid to prepare silica, the amount of grafted octadecylamine decreased, resulting in poorer hydrophobicity and a smaller water contact angle in the blue light blocking and eye-protecting window film. In Comparative Example 2, without the use of epoxy-based polysiloxanes to hydrophobically modify the acrylic resin, the water contact angle decreased, resulting in poor hydrophobicity. In Comparative Example 3, without the addition of gallic acid, the hydrophobicity of the blue light blocking and eye-protecting window film decreased, and the water contact angle also decreased. Examples 13-15 of this invention use tannic acid to prepare silica. Tannic acid can act as a pore-forming agent, resulting in a larger surface area of the prepared silica, allowing for the grafting of more octadecylamine. Furthermore, since this invention uses tannic acid and gallic acid to modify silica, tannic acid and gallic acid can synergistically modify silica with octadecylamine to enhance the hydrophobic properties of the hardened layer. In Examples 13-15 of this invention, epoxy-based polysiloxanes were used to hydrophobically modify acrylic resins. Epoxy-based polysiloxanes have excellent hydrophobicity, and a large number of epoxy groups were introduced into their outer molecular chains, so that the hydrophobically modified acrylic resins prepared contain epoxy groups, which enhances the dispersibility of hydrophobically modified silica in the acrylic resin matrix, thereby further enhancing the hydrophobic properties of the window film.
[0113] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.
Claims
1. A method for preparing a blue light blocking and eye-protecting car window film, characterized in that: Includes the following steps: Step 1: Take the PET film, clean and dry it to obtain the pretreated PET film; Step 2: The pretreated PET film is coated. A high refractive index film is first deposited on the surface of the pretreated PET film, and then low refractive index film and high refractive index film are deposited alternately to obtain blue light blocking and eye protection car 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 blocking and eye-protecting car window film according to claim 1, characterized in that: The deposition cycle consists of a low-refractive-index film followed by a high-refractive-index film, and the number of cycles is 1-6.
3. The method for preparing a blue light blocking and eye-protecting car window film according to claim 1, characterized in that: The silicon dioxide layer has a refractive index of 1.45-1.47 and a thickness of 74-75 nm; the titanium dioxide layer has a refractive index of 2.4-2.55 and a thickness of 44-45 nm.
4. The method for preparing a blue light blocking and eye-protecting car window film according to claim 1, characterized in that: The PET film has a refractive index of 1.64-1.65 and a visible light transmittance of 90-92%.
5. The method for preparing a blue light blocking and eye-protecting car window film according to claim 1, characterized in that: The blue light blocking and eye-protecting window film also has a hardened coating layer applied to the PET surface on the other side of the coating. Its preparation method includes the following steps: S1: Take the PET film, clean and dry it to obtain the pretreated PET film; S2: The pretreated PET film is coated with a low refractive index film and a high refractive index film in sequence on the surface of the pretreated PET film. S3: Take hydrophobically modified acrylic resin, hydrophobically modified silica, and photoinitiator, stir evenly to obtain a hardened coating layer; apply the hardened coating layer to the surface of the coated PET film, cure, and obtain a blue light blocking and eye-protecting car window film.
6. The method for preparing a blue light blocking and eye-protecting car window film according to claim 5, characterized in that: The hardened coating consists of the following components, by weight: 90-100 parts hydrophobic modified acrylic resin, 18-22 parts hydrophobic modified silica, and 0.1-1 parts photoinitiator.
7. The method for preparing a blue light blocking and eye-protecting car window film according to claim 6, characterized in that: The preparation method of the hydrophobic modified silica is as follows: take porous silica and deionized water, disperse them by ultrasonication, add sodium hydroxide dropwise, adjust the pH value to 8.5-9, add tris(hydroxymethyl)aminomethane, stir for 1-2 hours, add octadecylamine ethanol solution, stir for 7-10 hours, wash, filter, and dry to obtain hydrophobic modified silica. The method for preparing the porous silica is as follows: take tetraethyl orthosilicate, methanol, and ammonia, stir for 120-130 min, add hydrochloric acid dropwise to 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, filter and dry to obtain porous silica.
8. The method for preparing a blue light blocking and eye-protecting car window film according to claim 6, characterized in that: The preparation method of the hydrophobically modified acrylic resin includes the following steps: Step A: Take diphenylsilanediol, 3-glycidyl etheroxypropyl dimethoxymethylsilane, and barium hydroxide, mix them evenly, introduce nitrogen gas, heat to 80-85℃, react for 6-7 hours, and then vacuum dry at 60-65℃ for 4-5 hours to obtain epoxy polysiloxane. Step B: Take xylene, heat it to 90-95℃, add epoxy polysiloxane, add azobisisobutyronitrile, react for 30-40 min, add dropwise a mixture of methyl methacrylate, butyl acrylate, styrene, methacrylic acid, and hydroxypropyl acrylate, add azobisisobutyronitrile, react for 3-4 h, heat it to 100-105℃, add dropwise azobisisobutyronitrile, add epoxy polysiloxane, react for 2-3 h, and obtain hydrophobic modified acrylic resin.
9. The window film prepared by the method of preparing a blue light blocking and eye-protecting window film according to any one of claims 1-8.
10. The application of the window film according to claim 9 in automobiles, ships, and architectural glass.