Liquid crystal Anti-blue light eye protection window film and preparation method therefor

Abstract

The present invention relates to the technical field of optical thin films. Disclosed are a liquid crystal anti-blue light eye protection window film and a preparation method therefor. The liquid crystal anti-blue light eye protection window film comprises the following structures: from top to bottom, a scratch-resistant layer (4), a substrate layer (3), a bonding adhesive (2), a liquid crystal layer (1), a bonding adhesive (2), a substrate layer (3), a mounting adhesive layer (5), and a release layer (6). The liquid crystal layer (1) is prepared from a liquid crystal mixture, components in the liquid crystal mixture comprising, by mass percentage, 30-60 wt% of a right-handed chiral nematic liquid crystal, 1-10 wt% of a right-handed chiral dopant, 20-35 wt% of a photosensitive monomer, 0.5-3 wt% of a photoinitiator, 10-30 wt% of a diluent, and 0.1-1% of an interfacial agent.

Description

A liquid crystal blue light blocking eye protection window film and its preparation method Technical Field

[0001] This invention relates to the field of optical thin film technology, specifically to a liquid crystal type blue light blocking eye protection window film and its preparation method. Background Technology

[0002] Medical studies have shown that blue light, especially short-wavelength blue light in the wavelength range of 415nm-455nm, can cause various harms to the eyes due to its high-energy characteristics, as detailed below;

[0003] Damage to the retina: Short-wavelength blue light is high-energy visible light (HEV light), which can penetrate the cornea and lens of the eye to reach the retina, causing photochemical damage. Short-wavelength blue light can cause retinal pigment epithelial cells (RPE) to produce excessive free radicals, leading to cellular oxidative stress and death. Prolonged exposure to blue light may damage photosensitive pigments (such as rhodopsin) in retinal cells, causing irreversible retinal degeneration.

[0004] Potentially induces macular degeneration: The macula is the most sensitive part of the retina, and blue light exposure may cause abnormal cell function in the macular region, even being associated with the development of age-related macular degeneration (AMD). Accelerates oxidative damage to the lens and cornea: Long-term exposure to blue light may accelerate lens oxidation, inducing or worsening cataracts. Although the cornea can absorb some short-wavelength blue light, its protective capacity is limited, and long-term exposure may lead to corneal inflammation.

[0005] Causes visual fatigue and dry eyes: Enhanced scattering: Short-wavelength blue light is easily scattered within the human eye (mainly in the vitreous region), leading to blurred vision and reduced contrast, thus exacerbating the burden on the eyes. When people are driving or using electronic products, the strong stimulation of short-wavelength blue light will cause scattering within the human eye, resulting in blurred vision and dizziness. Blue light radiation may also interfere with tear film secretion, leading to dry eyes.

[0006] Potential impact on children's eye development: Children's lenses are not fully developed and have a poorer ability to filter blue light, thus posing a higher risk of retinal damage from blue light. Prolonged exposure to blue light may increase the risk of myopia and eye strain in children.

[0007] Window film is widely used in automobiles, ships, and architectural glass. In recent years, with the rapid development of the national economy, cars have become more common in households, and people are using cars more frequently and for longer periods of time. As a result, people's eyes are exposed to various lights for longer periods of time, especially when driving at night. The various glaring LED lights in the environment contain a large amount of short-wavelength blue light, which 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.

[0008] According to the guidelines issued by the international organization ICNIRP (PUBLISHED IN: HEALTH PHYSICS 105(1):74‐96;2013), the blue light damage coefficient at 435nm wavelength in the full spectrum range is 1, reaching its maximum value. The blue light damage coefficients in the remaining 415nm~455nm bands are almost all above 0.9, and the blue light damage coefficients in the 460nm~480nm band are 0.4~0.8.

[0009] This invention aims to design an optical film that can be applied to window films of automobiles or other vehicles, or to electronic products, to reduce blue light damage. Summary of the Invention

[0010] The purpose of this invention is to provide a liquid crystal type blue light blocking eye protection window film and its preparation method, so as to solve the problems raised in the prior art.

[0011] To achieve the above objectives, the present invention provides the following technical solution:

[0012] A liquid crystal type blue light blocking eye protection window film, the liquid crystal type blue light blocking eye protection window film includes the following structure from top to bottom: scratch-resistant layer 4, substrate layer 3, adhesive 2, liquid crystal layer 1, adhesive 2, substrate layer 3, mounting adhesive layer 5, and release layer 6.

[0013] Furthermore, the liquid crystal layer 1 is prepared from a liquid crystal mixture, wherein the components in the liquid crystal mixture, by mass percentage, include: 30-60 wt% right-handed chiral nematic liquid crystal, 1-10 wt% right-handed chiral dopant, 20-35 wt% photosensitive monomer, 0.5-3 wt% photoinitiator, 10-30 wt% diluent, and 0.1-1% surfactant.

[0014] Furthermore, the right-handed chiral nematic liquid crystal model includes any one of Merck E7 liquid crystal, MLC-6608, E44, and B2;

[0015] Furthermore, the right-handed chiral dopant includes any one of CB15, R5011, and S811;

[0016] Furthermore, the photosensitive monomer includes polyurethane acrylate;

[0017] Furthermore, the photoinitiator includes either TMPTA or HEA;

[0018] Furthermore, the diluent includes any one of alcohols, ethers, and toluene solvents;

[0019] Furthermore, the surfactant includes BYK-341;

[0020] Furthermore, the thickness of the liquid crystal layer 1 is 1-20 μm; the thickness of the adhesive 2 is 1-5 μm; the thickness of the substrate layer 3 is 10-200 μm; the thickness of the scratch-resistant layer 4 is 1-5 μm; and the thickness of the mounting adhesive layer 5 is 10-30 μm.

[0021] Furthermore, the adhesive 2 is composed of any one of acrylic pressure-sensitive adhesive or acrylic photocurable adhesive; the substrate layer 3 is composed of any one of transparent glass or polymer film; the scratch-resistant layer 4 is prepared from scratch-resistant coating, which is composed of any one of acrylic photocurable adhesive or modified acrylic polymer coating; the mounting adhesive layer 5 is prepared from mounting adhesive, which is composed of any one of acrylic pressure-sensitive adhesive, silicone, or polyurethane adhesive; and the release layer 6 is prepared from release film.

[0022] Furthermore, the modified acrylic polymer coating comprises, by mass percentage, 3-4.5 wt% acrylic resin, 1-4 wt% phthalic anhydride, 0.2-0.3 wt% triarylsulfonium hexafluorophosphate, 6-9 wt% modified epoxy resin, 1-4 wt% perfluorohexyl modified POSS, and the remainder being dichloromethane.

[0023] Furthermore, the preparation method of the modified epoxy resin includes the following steps: Step A: 711 epoxy resin, acrylic acid, 3,3'-dithiodipropionic acid, and hydroquinone are added to a reaction vessel. Under a nitrogen atmosphere, tetrabutylammonium bromide is added, and the mixture is heated to 90-92°C for 1-1.5 h, and then heated to 110-115°C for 2-2.5 h to obtain the modified acrylic epoxy resin;

[0024] Step B: Add 3,4-epoxycyclohexyl methacrylate, modified acrylic epoxy resin, azobisisobutyronitrile, and anhydrous tetrahydrofuran to a reaction vessel. Under a nitrogen atmosphere, heat to 60-65℃ and react for 12-14 hours. Cool to room temperature, add the product solution to excess hexane to form a polymer precipitate, centrifuge to settle the polymer, remove the supernatant to obtain a crude product, add the crude product to anhydrous tetrahydrofuran, precipitate again in excess hexane, purify once, and dry by rotary evaporation to obtain the modified epoxy resin.

[0025] Furthermore, in the preparation process of the modified acrylic epoxy resin, the mass ratio of 711 epoxy resin: acrylic acid: 3,3'-dithiodipropionic acid is (8-10):(2-2.3):(1-1.3); the amount of hydroquinone added is 0.2-0.3 wt% of the mass of acrylic acid; in the preparation process of the modified epoxy resin, the mass ratio of modified acrylic epoxy resin: 3,4-epoxycyclohexyl methacrylate: azobisisobutyronitrile is (7.7-8.5):(1.5-3.3):(0.03-0.04).

[0026] Furthermore, the preparation method of the perfluorohexyl modified POSS includes the following steps: adding epoxy cyclohexyl POSS, tridecafluoroheptanoic acid, and tetrabutylammonium bromide to 1,4-dioxane, heating to reflux for 8-10 hours, cooling to room temperature, and rotary drying. The product is then added to chloroform and extracted twice with 0.1M sodium bicarbonate aqueous solution, followed by two extractions with deionized water. The chloroform layer is dried with anhydrous magnesium sulfate, filtered, and rotary dried to obtain a crude product. The crude product is then added to acetonitrile, filtered, and vacuum dried to obtain perfluorohexyl modified POSS.

[0027] Furthermore, in the preparation process of the perfluorohexyl modified POSS, the molar ratio of epoxy cyclohexyl POSS: tridecafluoroheptanoic acid: tetrabutylammonium bromide is (7.47-7.96):(4.11-4.32):(1.33-1.42).

[0028] A method for preparing a liquid crystal-type blue light blocking eye protection window film, characterized by the following steps: S1: mixing right-handed chiral nematic liquid crystal, right-handed chiral dopant, photosensitive monomer, photoinitiator, diluent and surfactant in a uniform ratio to obtain a liquid crystal mixture; coating the liquid crystal mixture on the surface of substrate layer 3, evaporating the solvent at 60-120℃, and photocuring to obtain liquid crystal layer 1;

[0029] S2: Peel the liquid crystal layer 1 from the substrate layer 3, apply adhesive 2 to the upper and lower surfaces of the liquid crystal layer 1 respectively, and attach the substrate layer 3 to the upper and lower adhesive 2 surfaces of the liquid crystal layer 1, and cure.

[0030] S3: Apply the scratch-resistant coating to the surface of one side of the substrate layer 3, and cure it to obtain the scratch-resistant layer 4;

[0031] S4: Apply the mounting adhesive to the surface of another substrate layer 3, attach the release film to the surface of the mounting adhesive, and cure to obtain a liquid crystal type anti-blue light eye protection window film.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] 1. This invention utilizes the basic characteristics of Bragg reflection of photonic crystals in a self-made liquid crystal layer to selectively reflect specific wavelengths of the spectrum, thereby achieving efficient reflection of the target wavelength to block harmful blue light. The liquid crystal coating is used for reflection, avoiding color shift or fading problems caused by traditional absorption methods. Furthermore, the liquid crystal anti-blue light eye protection window film is made thinner, greatly expanding the application scenarios of the liquid crystal anti-blue light eye protection window film.

[0034] 2. This invention uses high-transparency, high-transmittance 711 epoxy resin as the matrix resin, and prepares a modified acrylic epoxy resin by reacting it with acrylic acid and 3,3'-dithiodipropionic acid. Introducing dynamic two-stream segments into the resin matrix endows the coating with excellent self-healing properties, greatly improving the wear resistance of the scratch-resistant layer in practical applications.

[0035] 3. Based on the modified acrylic epoxy resin, 3,4-epoxycyclohexyl methacrylate, which has a similar functional group structure to perfluorohexyl-modified POSS, was used as a monomer to copolymerize with the modified acrylic epoxy resin to prepare a modified epoxy resin. Utilizing the property of "like dissolves like," the dispersibility and compatibility of the modified epoxy resin and perfluorohexyl-modified POSS in acrylic resin are greatly improved.

[0036] 4. Grafting tridecafluoroheptanoyl groups onto epoxy cyclohexyl POSS and modifying it can greatly improve the anti-fouling and fingerprint-inhibiting properties of liquid crystal blue light blocking eye protection window film by utilizing its fluorinating agent properties.

[0037] 5. This invention further combines the hard and brittle properties of perfluorohexyl-modified POSS as an inorganic filler with the flexible properties of organic materials (acrylic resin, modified epoxy resin). The cycloaliphatic epoxy-functionalized modified epoxy resin, perfluorohexyl-modified POSS, and thermosetting hydroxyl-functionalized acrylic resin are crosslinked with the crosslinking agent phthalic anhydride to form a highly crosslinked organic-inorganic coating network. Two different curing materials are mixed, and a dual-curing process is introduced, which involves ultraviolet irradiation of epoxy ring-opening polymerization and heat treatment curing of epoxy, hydroxyl, and anhydride groups. The synergistic effect of different curing properties maximizes the wear resistance of the coating. Attached Figure Description

[0038] Figure 1 is a schematic diagram of the structure of a liquid crystal type anti-blue light eye protection window film according to the present invention;

[0039] The components are: liquid crystal layer 1, adhesive layer 2, substrate layer 3, scratch-resistant layer 4, mounting adhesive layer 5, and release layer 6.

[0040] Figure 2 shows the transmittance spectrum of incident light at different angles in Embodiment 8 of the present invention. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0042] In the following examples, the epoxy resin used is Epikote 190; the right-handed chiral nematic liquid crystal is Merck E7 liquid crystal; the right-handed chiral dopant is CB15; the photosensitive monomer is polyurethane acrylate; the photoinitiator is TMPTA; the surfactant is BYK-341; the PET film specifications are: haze ≤1.5%, transmittance ≥90%; the acrylate UV-curable adhesive is DSP 3195DM; the acrylic resin is KN7760T thermosetting acrylic resin; and all other raw materials are commercially available.

[0043] The preparation method of modified epoxy resin includes the following steps: Step A: 8g of 711 epoxy resin, 2g of acrylic acid, 1g of 3,3'-dithiodipropionic acid and 0.04g of hydroquinone are added to a reaction vessel. Under a nitrogen atmosphere, 0.3g of tetrabutylammonium bromide is added, and the mixture is heated to 90°C and reacted for 1h. Then it is heated to 110°C and reacted for 2h to obtain modified acrylic epoxy resin.

[0044] Step B: 7.7g of 3,4-epoxycyclohexyl methacrylate, 1.5g of modified acrylic epoxy resin, 0.03g of azobisisobutyronitrile, and 120mL of anhydrous tetrahydrofuran were added to a reaction vessel. Under a nitrogen atmosphere, the mixture was heated to 60℃ and reacted for 12h. After cooling to room temperature, the product solution was added to excess hexane to form a polymer precipitate. The polymer was centrifuged to settle, and the supernatant was removed to obtain a crude product. The crude product was added to anhydrous tetrahydrofuran and precipitated again in excess hexane. The purification cycle was repeated once, and the product was dried by rotary evaporation to obtain the modified epoxy resin.

[0045] The preparation method of perfluorohexyl modified POSS includes the following steps: 7.47 mmol of epoxycyclohexyl POSS, 4.11 mmol of tridecafluoroheptanoic acid, and 1.33 mmol of tetrabutylammonium bromide are added to 50 mL of 1,4-dioxane, heated to reflux for 8 h, cooled to room temperature, and dried by rotary evaporation. The product is added to chloroform and extracted twice with 0.1 M sodium bicarbonate aqueous solution, followed by two extractions with deionized water. The chloroform layer is dried with anhydrous magnesium sulfate, filtered, and dried by rotary evaporation to obtain the crude product. The crude product is added to acetonitrile, filtered, and dried under vacuum to obtain perfluorohexyl modified POSS.

[0046] Example 1: A method for preparing a liquid crystal-type blue light blocking eye protection window film: including the following steps: S1: Mix 30wt% of right-handed chiral nematic liquid crystal, 5wt% of right-handed chiral dopant, 35wt% of photosensitive monomer, 2wt% of photoinitiator, 27wt% of diluent and 1wt% of surfactant in a uniform ratio to obtain a liquid crystal mixture; coat the liquid crystal mixture on the surface of substrate layer 3, evaporate the solvent at 80℃, and photocur to obtain liquid crystal layer 1;

[0047] S2: Peel the liquid crystal layer 1 from the substrate layer 3, apply acrylic pressure-sensitive adhesive 2 to the upper and lower surfaces of the liquid crystal layer 1 respectively, and attach the PET film substrate layer 3 to the surface of the upper and lower acrylic pressure-sensitive adhesive 2 of the liquid crystal layer 1, and perform heat curing treatment.

[0048] S3: Apply acrylic photocurable adhesive to the surface of one side of substrate layer 3, and perform photocuring treatment to obtain scratch-resistant layer 4;

[0049] S4: Apply acrylic pressure-sensitive adhesive to the surface of another substrate layer 3, attach PET release film to the surface of the adhesive, and perform heat curing to obtain liquid crystal type anti-blue light eye protection window film.

[0050] In Example 1, the thickness of liquid crystal layer 1 is 1 μm, the thickness of adhesive 2 is 1 μm, the thickness of substrate layer 3 is 23 μm, the thickness of scratch-resistant layer 4 is 5 μm, and the thickness of mounting adhesive layer 5 is 10 μm.

[0051] Example 2: A method for preparing a liquid crystal-type blue light blocking eye protection window film: including the following steps: S1: 40wt% of dextrorotatory chiral nematic liquid crystal, 5wt% of dextrorotatory chiral dopant, 30wt% of photosensitive monomer, 2wt% of photoinitiator, 22wt% of diluent and 1wt% of surfactant are mixed evenly according to the specified ratio to obtain a liquid crystal mixture; the liquid crystal mixture is coated on the surface of substrate layer 3, the solvent is evaporated at 80℃, and photocuring is performed to obtain liquid crystal layer 1;

[0052] The remaining steps are the same as in Example 1.

[0053] Example 3: A method for preparing a liquid crystal-type blue light blocking eye protection window film: including the following steps: S1: Mix 50wt% of right-handed chiral nematic liquid crystal, 5wt% of right-handed chiral dopant, 25wt% of photosensitive monomer, 2wt% of photoinitiator, 17wt% of diluent and 1wt% of surfactant in a uniform ratio to obtain a liquid crystal mixture; coat the liquid crystal mixture on the surface of substrate layer 3, evaporate the solvent at 80℃, and photocur to obtain liquid crystal layer 1;

[0054] The remaining steps are the same as in Example 1.

[0055] Example 4: A method for preparing a liquid crystal-type blue light blocking eye protection window film: including the following steps: S1: 60wt% of dextrorotatory chiral nematic liquid crystal, 5wt% of dextrorotatory chiral dopant, 20wt% of photosensitive monomer, 2wt% of photoinitiator, 12wt% of diluent and 1wt% of surfactant are mixed evenly according to the specified ratio to obtain a liquid crystal mixture; the liquid crystal mixture is coated on the surface of substrate layer 3, the solvent is evaporated at 80℃, and photocured to obtain liquid crystal layer 1;

[0056] The remaining steps are the same as in Example 1.

[0057] Example 5: A method for preparing a liquid crystal-type blue light blocking eye protection window film: In Example 5, the thickness of liquid crystal layer 1 is 3μm.

[0058] The remaining steps are the same as in Example 1.

[0059] Example 6: A method for preparing a liquid crystal-type blue light blocking eye protection window film: In Example 6, the thickness of the liquid crystal layer 1 is 3μm.

[0060] The remaining steps are the same as in Example 2.

[0061] Example 7: A method for preparing a liquid crystal-type blue light blocking eye protection window film: In Example 7, the thickness of liquid crystal layer 1 is 3μm.

[0062] The remaining steps are the same as in Example 3.

[0063] Example 8: A method for preparing a liquid crystal-type blue light blocking eye protection window film: In Example 8, the thickness of the liquid crystal layer 1 is 3μm.

[0064] The remaining steps are the same as in Example 4.

[0065] Example 9: A method for preparing a liquid crystal-type blue light blocking eye protection window film: In Example 9, the thickness of the liquid crystal layer 1 is 5 μm.

[0066] The remaining steps are the same as in Example 1.

[0067] Example 10: A method for preparing a liquid crystal-type blue light blocking eye protection window film: In Example 10, the thickness of the liquid crystal layer 1 is 5 μm.

[0068] The remaining steps are the same as in Example 2.

[0069] Example 11: A method for preparing a liquid crystal-type blue light blocking eye protection window film: In Example 11, the thickness of liquid crystal layer 1 is 5 μm.

[0070] The remaining steps are the same as in Example 3.

[0071] Example 12: A method for preparing a liquid crystal-type blue light blocking eye protection window film: In Example 12, the thickness of liquid crystal layer 1 is 5 μm.

[0072] The remaining steps are the same as in Example 4.

[0073] Example 13: A method for preparing a liquid crystal-type blue light blocking eye protection window film: including the following steps: S1: 60wt% of right-handed chiral nematic liquid crystal, 5wt% of right-handed chiral dopant, 20wt% of photosensitive monomer, 2wt% of photoinitiator, 12wt% of diluent and 1wt% of surfactant are mixed evenly according to the specified ratio to obtain a liquid crystal mixture; the liquid crystal mixture is coated on the surface of substrate layer 3, the solvent is evaporated at 80℃, and photocured to obtain liquid crystal layer 1;

[0074] S2: Peel the liquid crystal layer 1 from the substrate layer 3, apply acrylic pressure-sensitive adhesive 2 to the upper and lower surfaces of the liquid crystal layer 1 respectively, and attach the PET film substrate layer 3 to the surface of the upper and lower acrylic pressure-sensitive adhesive 2 of the liquid crystal layer 1, and perform heat curing treatment.

[0075] S3: 3wt% acrylic resin, 1wt% phthalic anhydride, 0.2wt% triarylsulfonium hexafluorophosphate, 6wt% modified epoxy resin, 1wt% perfluorohexyl modified POSS are added sequentially to 88.8wt% dichloromethane and stirred evenly to obtain modified acrylic polymer coating.

[0076] S4: Apply the modified acrylic polymer coating to the surface of one side of the substrate layer 3, dry at 70℃ for 20 min to remove the solvent, cure under ultraviolet light for 30 min, and heat cure at 140℃ for 30 min to obtain the scratch-resistant layer 4.

[0077] S5: Apply acrylic pressure-sensitive adhesive to the surface of another substrate layer 3, attach PET release film to the surface of the adhesive, and perform heat curing to obtain liquid crystal type anti-blue light eye protection window film.

[0078] In Example 1, the thickness of liquid crystal layer 1 is 3μm, the thickness of adhesive 2 is 1μm, the thickness of substrate layer 3 is 23μm, the thickness of scratch-resistant layer 4 is 5μm, and the thickness of mounting adhesive layer 5 is 10μm.

[0079] Example 14: A method for preparing a liquid crystal type blue light blocking eye protection window film: including the following steps: S3: 4.5wt% acrylic resin, 4wt% phthalic anhydride, 0.3wt% triarylsulfonium hexafluorophosphate, 9wt% modified epoxy resin, 4wt% perfluorohexyl modified POSS are sequentially added to 78.2wt% dichloromethane and stirred evenly to obtain a modified acrylic polymer coating;

[0080] The remaining steps are the same as in Example 13.

[0081] Comparative Example 1: A method for preparing a liquid crystal-type blue light blocking eye protection window film: including the following steps: S1: 70wt% of right-handed chiral nematic liquid crystal, 5wt% of right-handed chiral dopant, 15wt% of photosensitive monomer, 2wt% of photoinitiator, 7wt% of diluent and 1wt% of surfactant are mixed evenly according to the specified ratio to obtain a liquid crystal mixture; the liquid crystal mixture is coated on the surface of substrate layer 3, the solvent is evaporated at 80℃, and photocuring is performed to obtain liquid crystal layer 1;

[0082] S2: Peel the liquid crystal layer 1 from the substrate layer 3, apply acrylic pressure-sensitive adhesive 2 to the upper and lower surfaces of the liquid crystal layer 1 respectively, and attach the PET film substrate layer 3 to the surface of the upper and lower acrylic pressure-sensitive adhesive 2 of the liquid crystal layer 1, and perform heat curing treatment.

[0083] S3: Apply acrylic photocurable adhesive to the surface of one side of substrate layer 3, and perform photocuring treatment to obtain scratch-resistant layer 4;

[0084] S4: Apply acrylic pressure-sensitive adhesive to the surface of another substrate layer 3, attach PET release film to the surface of the adhesive, and perform heat curing to obtain liquid crystal type anti-blue light eye protection window film.

[0085] In Comparative Example 1, the thickness of liquid crystal layer 1 is 1 μm, the thickness of adhesive 2 is 1 μm, the thickness of substrate layer 3 is 23 μm, the thickness of scratch-resistant layer 4 is 5 μm, and the thickness of mounting adhesive layer 5 is 10 μm.

[0086] Comparative Example 2: A method for preparing a liquid crystal-type blue light blocking eye protection window film: including the following steps: S1: 30wt% of right-handed chiral nematic liquid crystal, 5wt% of right-handed chiral dopant, 35wt% of photosensitive monomer, 2wt% of photoinitiator, 27wt% of diluent and 1wt% of surfactant are mixed evenly according to the specified ratio to obtain a liquid crystal mixture; the liquid crystal mixture is coated on the surface of substrate layer 3, the solvent is evaporated at 80℃, and photocuring is performed to obtain liquid crystal layer 1;

[0087] S2: Peel the liquid crystal layer 1 from the substrate layer 3, apply acrylic pressure-sensitive adhesive 2 to the upper and lower surfaces of the liquid crystal layer 1 respectively, and attach the PET film substrate layer 3 to the surface of the upper and lower acrylic pressure-sensitive adhesive 2 of the liquid crystal layer 1, and perform heat curing treatment.

[0088] S3: Apply acrylic photocurable adhesive to the surface of one side of substrate layer 3, and perform photocuring treatment to obtain scratch-resistant layer 4;

[0089] S4: Apply acrylic pressure-sensitive adhesive to the surface of another substrate layer 3, attach PET release film to the surface of the adhesive, and perform heat curing to obtain liquid crystal type anti-blue light eye protection window film.

[0090] In Comparative Example 2, the thickness of liquid crystal layer 1 is 7 μm, the thickness of adhesive 2 is 1 μm, the thickness of substrate layer 3 is 23 μm, the thickness of scratch-resistant layer 4 is 5 μm, and the thickness of mounting adhesive layer 5 is 10 μm.

[0091] Comparative Example 3: A method for preparing a liquid crystal type blue light blocking eye protection window film: including the following steps: S3: 5wt% acrylic resin, 4.5wt% phthalic anhydride, 0.4wt% triarylsulfonium hexafluorophosphate, 10.5wt% modified epoxy resin, 6wt% perfluorohexyl modified POSS are added sequentially to 73.6wt% dichloromethane and stirred evenly to obtain a modified acrylic polymer coating;

[0092] The remaining steps are the same as in Example 13.

[0093] Experiment: Blue light protection optical performance test: The transmittance and reflectance of the full spectrum of light incident at 90° were measured using a spectrophotometer. The experimental results are shown in Table 1 below.

[0094] Table 1. Test data on reflectance / transmittance performance of liquid crystal blue light blocking eye protection window film.

[0095]

[0096] Conclusion: The above experiments show that when the liquid crystal concentration is 60% and the liquid crystal layer thickness is 3μm, the liquid crystal type blue light blocking eye protection window film prepared in Example 8 has the best overall performance.

[0097] Comparative Example 1 increased the proportion of liquid crystal concentration, which improved the 435nm reflectivity, but resulted in a significant decrease in overall transmittance and reduced overall performance.

[0098] Comparative Example 2 increased the thickness of the liquid crystal layer, which improved the reflectivity by 435nm, but resulted in a significant reduction in the overall transmittance and a decrease in overall performance.

[0099] Comparative Example 3 increased the proportion of each component in the modified acrylic polymer coating compared to Example 13, resulting in reduced dispersion performance and affecting the final light transmittance of the liquid crystal anti-blue light eye protection window film.

[0100] Experiment: The abrasion resistance of the liquid crystal blue light blocking eye protection window films prepared in Examples 8, 13, 15, and Comparative Example 3 was tested; nanoindentation analysis was performed using a nanoindenter. The maximum load was set to 200 mN. The loading and unloading rate was 10 mN / s, and the holding time after reaching the maximum load was 1 s. The experimental results are shown in Table 2 below.

[0101] Table 2. Test data on the abrasion resistance of liquid crystal blue light blocking eye protection window film.

[0102]

[0103] Conclusion: Examples 13 and 14 further optimized the coating composition of the scratch-resistant layer 4 based on Example 8, significantly improving the scratch and abrasion resistance of the liquid crystal blue light blocking eye protection window film while retaining its optimal overall performance. Although Comparative Example 3 exhibits excellent abrasion resistance, its light transmittance is significantly reduced, resulting in decreased overall performance, according to the experimental data in Table 1.

[0104] 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 its spirit or essential characteristics. 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, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A liquid crystal type anti-blue light eye-protecting window film, characterized in that: The liquid crystal anti-blue light eye protection window film includes the following structure: from top to bottom, it consists of a scratch-resistant layer (4), a substrate layer (3), an adhesive (2), a liquid crystal layer (1), an adhesive (2), a substrate layer (3), an installation adhesive layer (5), and a release layer (6).

2. The liquid crystal type anti-blue light eye protection window film according to claim 1, characterized in that: The liquid crystal layer (1) is prepared from a liquid crystal mixture, wherein the components in the liquid crystal mixture are, by mass percentage, 30-60 wt% right-handed chiral nematic liquid crystal, 1-10 wt% right-handed chiral dopant, 20-35 wt% photosensitive monomer, 0.5-3 wt% photoinitiator, 10-30 wt% diluent and 0.1-1% surfactant.

3. The liquid crystal type anti-blue light eye protection window film according to claim 1, characterized in that: The thickness of the liquid crystal layer (1) is 1-20 μm; the thickness of the adhesive (2) is 1-5 μm; the thickness of the substrate layer (3) is 10-200 μm; the thickness of the scratch-resistant layer (4) is 1-5 μm; and the thickness of the mounting adhesive layer (5) is 10-30 μm.

4. The liquid crystal type anti-blue light eye protection window film according to claim 1, characterized in that: The adhesive (2) is composed of either acrylic pressure-sensitive adhesive or acrylic photocurable adhesive; the substrate layer (3) is composed of either transparent glass or polymer film; the scratch-resistant layer (4) is prepared by scratch-resistant coating, which is composed of either acrylic photocurable adhesive or modified acrylic polymer coating; the mounting adhesive layer (5) is prepared by mounting adhesive, which is composed of either acrylic pressure-sensitive adhesive, silicone, or polyurethane adhesive; and the release layer (6) is prepared by release film.

5. The liquid crystal type anti-blue light eye protection window film according to claim 4, characterized in that: The modified acrylic polymer coating comprises the following components by mass percentage: 3-4.5 wt% acrylic resin, 1-4 wt% phthalic anhydride, 0.2-0.3 wt% triarylsulfonium hexafluorophosphate, 6-9 wt% modified epoxy resin, 1-4 wt% perfluorohexyl modified POSS, and the remainder being dichloromethane.

6. The liquid crystal type anti-blue light eye protection window film according to claim 5, characterized in that: The method for preparing the modified epoxy resin includes the following steps: Step A: 711 epoxy resin, acrylic acid, 3,3'-dithiodipropionic acid, and hydroquinone are added to a reaction vessel. Under a nitrogen atmosphere, tetrabutylammonium bromide is added, and the mixture is heated to 90-92°C for 1-1.5 h, and then heated to 110-115°C for 2-2.5 h to obtain the modified acrylic epoxy resin. Step B: Add 3,4-epoxycyclohexyl methacrylate, modified acrylic epoxy resin, azobisisobutyronitrile, and anhydrous tetrahydrofuran to a reaction vessel, heat to 60-65℃ for 12-14 hours under a nitrogen atmosphere, cool to room temperature, and purify to obtain the modified epoxy resin.

7. A liquid crystal type anti-blue light eye protection window film according to claim 6, characterized in that: In the preparation of modified acrylic epoxy resin, the mass ratio of 711 epoxy resin: acrylic acid: 3,3'-dithiodipropionic acid is (8-10):(2-2.3):(1-1.3); the amount of hydroquinone added is 0.2-0.3 wt% of the mass of acrylic acid; in the preparation of modified epoxy resin, the mass ratio of modified acrylic epoxy resin: 3,4-epoxycyclohexyl methacrylate: azobisisobutyronitrile is (7.7-8.5):(1.5-3.3):(0.03-0.04).

8. The liquid crystal type anti-blue light eye protection window film according to claim 5, characterized in that: The preparation method of the perfluorohexyl modified POSS includes the following steps: adding epoxy cyclohexyl POSS, tridecafluoroheptanoic acid, and tetrabutylammonium bromide to 1,4-dioxane, heating to reflux for 8-10 hours, cooling to room temperature, and purifying to obtain perfluorohexyl modified POSS.

9. A liquid crystal type anti-blue light eye protection window film according to claim 8, characterized in that: In the preparation of perfluorohexyl modified POSS, the molar ratio of epoxycyclohexyl POSS: tridecafluoroheptanoic acid: tetrabutylammonium bromide is (7.47-7.96):(4.11-4.32):(1.33-1.42).

10. A method for preparing a liquid crystal-type blue light blocking eye protection window film, characterized in that: Includes the following steps: S1: Mix the right-handed chiral nematic liquid crystal, right-handed chiral dopant, photosensitive monomer, photoinitiator, diluent and surfactant in the specified ratio to obtain a liquid crystal mixture; coat the liquid crystal mixture on the surface of the substrate layer (3), evaporate the solvent at 60-120℃, and photocur to obtain the liquid crystal layer (1). S2: Peel the liquid crystal layer (1) from the substrate layer (3), apply adhesive (2) to the upper and lower surfaces of the liquid crystal layer (1), attach the substrate layer (3) to the upper and lower adhesive (2) surfaces of the liquid crystal layer (1), and cure. S3: Apply the scratch-resistant coating to the surface of the substrate layer (3) on one side and cure it to obtain the scratch-resistant layer (4). S4: Apply the mounting adhesive to the surface of another substrate layer (3), attach the release film to the surface of the mounting adhesive, and cure to obtain a liquid crystal type anti-blue light eye protection window film.

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