Composite silica gel protective film with blue light prevention function and preparation method thereof

Abstract

The invention discloses a composite silica gel protective film with an anti-blue-light function and a preparation method thereof. The protective film comprises an anti-blue-light functional layer, a base material layer and a hardened coating which are sequentially stacked. The protective film not only can efficiently filter blue light, but also can keep good light transmission, scratch resistance and physical properties, has the characteristics of easiness in preparation and controllable cost, and can meet the diversified requirements of modern electronic equipment on the screen protective film. The anti-blue-light function layer is good in anti-blue-light effect and has excellent absorption performance on ultraviolet light and blue light in the wave band of 280 nm to 420 nm, the blocking rate on the high-energy blue light wave band can reach 98%, the blue light blocking efficiency is stable, and the ultraviolet / blue light blocking rate can be kept at a high level after aging. Wherein the hardened coating has a good scratch-resistant effect, the pencil hardness (500g) can reach 3H, the wear resistance of the matrix is effectively enhanced, and the light transmission of the protective film is improved.

Description

Technical Field

[0001] This invention relates to the field of protective film materials, and in particular to a composite silicone protective film with blue light protection function and its preparation method. Background Technology

[0002] With the widespread use of electronic devices, especially smartphones, tablets, and computers, it has become commonplace for people to spend long hours working and living in front of screens. However, the visible light emitted by these devices contains a large amount of short-wavelength blue light (380-430nm), which has high energy and can penetrate the cornea and lens to reach the retina. Long-term exposure can lead to retinal cell damage, free radical generation, and consequently, various eye diseases such as retinal degeneration, glaucoma, and macular degeneration. Therefore, developing a screen protector that can effectively filter blue light and protect users' eyesight has significant practical importance and market value. Currently, existing blue light blocking screen protectors on the market mainly fall into two categories: one achieves the filtering effect by adding blue light absorbers, and the other achieves blue light reflection or blocking through special structural designs (such as photonic crystals). However, existing technologies have some shortcomings. For example, while adding blue light absorbers can effectively filter blue light, it reduces light transmittance. Under different aging conditions, blue light absorbers may undergo structural changes and lose their blue light absorption effect. In addition, most blue light blocking screen protectors lack scratch resistance, making them unsuitable for the use of electronic devices. While blue light blocking films using photonic crystal materials offer excellent optical performance and color balance, their complex production process, high cost, and stringent environmental requirements limit their large-scale application. Furthermore, although some blue light blocking films based on TPU or PET substrates provide some protection, their flexibility, weather resistance, and adhesion still need improvement. Summary of the Invention

[0003] The technical problem to be solved by this invention is to address the shortcomings of the prior art by providing a composite silicone protective film with blue light filtering function and its preparation method. It not only efficiently filters blue light but also maintains good light transmittance, scratch resistance, and physical properties, while being easy to manufacture and cost-effective, thus meeting the diverse needs of modern electronic devices for screen protectors.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is: a composite silicone protective film with blue light protection function, comprising a blue light protection functional layer, a substrate layer and a hardened coating layer stacked sequentially; The blue light blocking functional layer is obtained by coating and curing with a blue light blocking silicone pressure-sensitive adhesive. The blue light blocking silicone pressure-sensitive adhesive comprises the following raw material components by weight: 100-300 parts raw rubber; 200-400 parts of methyl MQ resin; 400-600 parts of the first solvent; 1-5 parts of crosslinking agent; 1-5 parts coupling agent; 1-5 parts catalyst; Inhibitor 1-5 parts; 3-5 parts blue light absorber; 5-10 parts of light stabilizer.

[0005] Preferably, the raw rubber is vinyl polydimethylsiloxane with a molecular weight of 300,000-500,000 and a vinyl content of 0.1-0.3%. The methyl MQ resin has a molecular weight of 3000-7000 and an MQ ratio of 0.7-0.9.

[0006] Preferably, the first solvent is at least one selected from toluene, ethyl acetate, butanone, and xylene; The crosslinking agent is a hydrogen-containing silicone oil with a hydrogen content of 0.5%-2%; The coupling agent is one or more of vinylsilane, methylvinylsilane, and acetylacetone silane.

[0007] Preferably, the catalyst is a dilute chloroplatinic silicone oil with a platinum content of 5000 ppm; The inhibitor is butynol; The blue light absorber is a triazine or azo-methoxyl dye; The light stabilizer is a hindered amine light stabilizer.

[0008] Preferably, the blue light blocking silicone pressure-sensitive adhesive is prepared by the following method: S1-1. Add raw rubber, methyl MQ resin and the first solvent to the container, stir at 400-600 rpm for 30-60 min, and then stir at 500-1200 rpm for 30-60 min. S1-2. Add crosslinking agent, coupling agent and inhibitor to the container, and stir and disperse at 500-2000 rpm for 10-30 min; S1-3. Add blue light absorber and light stabilizer to the container and stir at 500-1000 rpm for 30-60 minutes. S1-4. Add the catalyst to the container and stir at 500-1000 rpm for 20-60 min. S1-5. Filter, discard the filter residue, and obtain the blue light blocking silicone pressure-sensitive adhesive.

[0009] Preferably, the hardened coating is obtained by applying a hardening coating liquid and then curing it, wherein the hardening coating liquid comprises the following raw material components in parts by weight: 40-70 parts of multifunctional acrylate monomer; Contains 5-20 parts of Si methacrylate monomer; 2-10 parts of thiol monomer; 1-5 parts of nanoparticles; 1-5 parts of photoinitiator; Leveling agent 1-3 parts; The second solvent is 10-20 parts.

[0010] Preferably, the multifunctional acrylate monomer is selected from one or more of pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, and hexafunctional polyurethane acrylate. The Si-containing methacrylate monomer is a polyhedral oligomeric silsesquioxane (meth)acrylate; The thiol monomer is selected from one or more of n-dodecyl thiol, tert-dodecyl thiol, and n-octyl thiol.

[0011] Preferably, the nanoparticles are selected from one or both of nano-silica and nano-alumina.

[0012] Preferably, the photoinitiator is selected from one or two of photoinitiator TPO and photoinitiator 819; The leveling agent is selected from acrylate leveling agents; The second solvent is selected from at least one of toluene, ethyl acetate, butanone, and xylene.

[0013] Preferably, the hardening coating is prepared by the following method: S2-1. Under light-protected conditions, add multifunctional acrylate monomers, Si-containing methacrylate monomers, thiol monomers and nanoparticles to a transparent container, and stir for 30-60 minutes under nitrogen atmosphere at 800-1200 rpm. S2-2. Add some photoinitiator, purge with nitrogen, stir at 800-1200 rpm for 20-30 min, irradiate with UV light for 2-5 min, control the irradiation energy to be 300-800 mj / cm², raise the system temperature to 65℃-75℃ and stop irradiation, stop purging with nitrogen, add the remaining photoinitiator and leveling agent, stir at 400-500 rpm and cool to room temperature to obtain a premix. S2-3. Add a second solvent to the premix, adjust the viscosity range to 200-800 cps, filter, discard the filter residue, and obtain the hardened coating liquid.

[0014] This invention also provides a method for preparing the composite silicone protective film with blue light protection function as described above, comprising the following steps: Step 1: Apply blue light blocking silicone pressure-sensitive adhesive evenly to the first surface of the substrate layer, and cure at 140-170℃ for 3-5 minutes to form a blue light blocking functional layer. Step 2: Apply the hardening coating evenly to the second surface of the substrate layer, dry it at 60-80℃ for 5-10 minutes, and then irradiate it with UV light of wavelength 300-450nm for 15-45 seconds, controlling the irradiation energy to 300-1000mj / cm² to form a hardened coating, thereby obtaining the composite silicone protective film with blue light protection function.

[0015] The beneficial effects of this invention are: This invention provides a composite silicone protective film with blue light protection function, comprising a blue light protection functional layer, a substrate layer and a hardened coating layer stacked sequentially; this protective film can not only effectively filter blue light, but also maintain good light transmittance, scratch resistance and physical properties, while being easy to manufacture and cost-controllable, and can meet the diverse needs of modern electronic devices for screen protection films.

[0016] The blue light blocking functional layer prepared in this invention has a good blue light blocking effect, and has excellent absorption performance for ultraviolet and blue light in the 280nm-420nm band. The blocking rate for high-energy blue light can reach 98%, the blue light blocking efficiency is stable, and the ultraviolet / blue light blocking rate can remain at a high level after aging. The hardened coating prepared in this invention has good scratch resistance, and the pencil hardness (500g) can reach 3H. It effectively enhances the wear resistance of the substrate and improves the light transmittance of the protective film. Combined with the organosilicon anti-blue light pressure-sensitive adhesive layer, it adds scratch resistance and corrosion resistance to the composite protective film on the basis of blue light protection, and has good practicality in electronic product applications. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the composite silicone protective film with blue light protection function of the present invention.

[0018] Explanation of reference numerals in the attached figures: 1—Blue light blocking functional layer; 2—Substrate layer; 3—Curved coating. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.

[0020] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0021] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available. For examples where specific conditions are not specified, conventional conditions or conditions recommended by the manufacturer are followed. For reagents or instruments whose manufacturers are not specified, they are all commercially available products.

[0022] Reference Figure 1 The present invention provides a composite silicone protective film with blue light protection function, comprising a blue light protection functional layer 1, a substrate layer 2 and a hardened coating layer 3 stacked sequentially; The blue light blocking functional layer is obtained by coating and curing with a blue light blocking silicone pressure-sensitive adhesive. The blue light blocking silicone pressure-sensitive adhesive comprises the following raw material components by weight: 100-300 parts raw rubber; 200-400 parts of methyl MQ resin; 400-600 parts of the first solvent; 1-5 parts of crosslinking agent; 1-5 parts coupling agent; 1-5 parts catalyst; Inhibitor 1-5 parts; 3-5 parts blue light absorber; 5-10 parts of light stabilizer.

[0023] The blue light blocking silicone pressure-sensitive adhesive formed by the above formula can be applied to parts inside electronic and electrical products that require adhesion and sealing. It has strong adhesion, low modulus, and will not cause abrasion marks when used on electronic screens. In addition, the product has high tensile strength, which can overcome the tensile deformation during the pressing process after it is adhered to the material.

[0024] In a preferred embodiment, the raw rubber is a high molecular weight vinyl polydimethylsiloxane with a molecular weight of about 400,000 and a vinyl content of 0.1-0.3%. By selecting a high molecular weight vinyl polydimethylsiloxane as the base polymer and the main reactant of the pressure-sensitive adhesive, the bulk strength of the pressure-sensitive adhesive can be guaranteed, while ensuring that fingerprints and pause marks disappear quickly. At the same time, the aging stability of the pressure-sensitive adhesive is improved.

[0025] In a preferred embodiment, the methyl MQ resin has a molecular weight of 3000-7000 and an MQ ratio of 0.7-0.9. By selecting a silicone resin with a suitable MQ ratio and mixing it with a base polymer in an appropriate ratio, high adhesion strength of the pressure-sensitive adhesive is achieved, and it also improves the bulk strength of the adhesive after curing.

[0026] In a preferred embodiment, the first solvent is at least one of toluene, ethyl acetate, butanone, and xylene.

[0027] The crosslinking agent is hydrogen-containing silicone oil with a hydrogen content of 0.5%-2%. A suitable crosslinking agent is selected to control the appropriate crosslinking density, thereby achieving different modulus requirements.

[0028] The coupling agent is one or more of vinylsilane, methylvinylsilane, and acetylacetone silane.

[0029] In a preferred embodiment, the catalyst is a diluent of chloroplatinic silicone oil with a platinum content of 5000 ppm.

[0030] In a preferred embodiment, the inhibitor is butynol.

[0031] In a preferred embodiment, the blue light absorber is a triazine dye.

[0032] In a preferred embodiment, the light stabilizer is a hindered amine light stabilizer.

[0033] In a preferred embodiment, the blue light blocking silicone pressure-sensitive adhesive is prepared by the following method: S1-1. Add raw rubber, methyl MQ resin and the first solvent to the container, stir at 400-600 rpm for 30-60 min, and then stir at 500-1200 rpm for 30-60 min. S1-2. Add crosslinking agent, coupling agent and inhibitor to the container, and stir and disperse at 500-2000 rpm for 10-30 min; S1-3. Add blue light absorber and light stabilizer to the container and stir at 500-1000 rpm for 30-60 minutes. S1-4. Add the catalyst to the container and stir at 500-1000 rpm for 20-60 min. S1-5. Filter, discard the filter residue, and obtain the blue light blocking silicone pressure-sensitive adhesive.

[0034] The blue light blocking silicone pressure-sensitive adhesive prepared by this invention has a good blue light blocking effect, exhibiting excellent absorption performance for ultraviolet and blue light in the 280nm-420nm wavelength band. It can achieve a blocking rate of 98% for high-energy blue light, with stable blue light blocking efficiency, and the ultraviolet / blue light blocking rate can remain at a high level after aging. The preparation method of this invention is simple to operate and is conducive to industrial production and promotion.

[0035] In a preferred embodiment, the hardened coating is obtained by applying a hardening coating liquid and then curing it. The hardening coating liquid comprises the following raw material components by weight: 40-70 parts of multifunctional acrylate monomer; Contains 5-20 parts of Si methacrylate monomer; 2-10 parts of thiol monomer; 1-5 parts of nanoparticles; 1-5 parts of photoinitiator; Leveling agent 1-3 parts; The second solvent is 10-20 parts.

[0036] In a preferred embodiment, the multifunctional acrylate monomer is a hexafunctional polyurethane acrylate with six reactive functional groups, which can form a dense cross-linked network, thereby improving the hardness and durability after curing.

[0037] In a preferred embodiment, the Si-containing methacrylate monomer is trimethylsiloxymethacrylate (TRIS), which has good hydrophobicity and thermal stability, thereby improving the surface hardness and anti-aging properties after curing.

[0038] In a preferred embodiment, the thiol monomer is n-dodecyl thiol or tert-dodecyl thiol, used as a molecular weight regulator and chain transfer agent, which regulates the molecular weight distribution of the polymer by controlling the chain exchange process in the polymerization reaction.

[0039] In a preferred embodiment, the nanoparticles are selected from one or both of nano-silica and nano-alumina; they can improve the mechanical properties and thermal stability of the cross-linked network after curing.

[0040] In a preferred embodiment, the photoinitiator is selected from one or both of photoinitiator TPO and photoinitiator 819; more preferably, it is photoinitiator TPO.

[0041] In a preferred embodiment, the leveling agent is selected from acrylate leveling agents; In a preferred embodiment, the second solvent is selected from at least one of toluene, ethyl acetate, butanone, and xylene.

[0042] The hardening coating solution is prepared by the following method: S2-1. Under light-protected conditions, add multifunctional acrylate monomers, Si-containing methacrylate monomers, thiol monomers and nanoparticles to a transparent container, and stir for 30-60 minutes under nitrogen atmosphere at 800-1200 rpm. S2-2. Add some photoinitiator, purge with nitrogen, stir at 800-1200 rpm for 20-30 min, irradiate with UV light for 2-5 min, control the irradiation energy to be 300-800 mj / cm², raise the system temperature to 65℃-75℃ and stop irradiation, stop purging with nitrogen, add the remaining photoinitiator and leveling agent, stir at 400-500 rpm and cool to room temperature to obtain a premix. S2-3. Add the second solvent to the premix, adjust the viscosity range to 200-800 cps, filter, discard the filter residue, and obtain the hardened coating liquid.

[0043] This UV-curable hardened layer has good scratch resistance and a pencil hardness (500g) of 3H, effectively enhancing the wear resistance of the substrate and improving the light transmittance of the protective film. The preparation method of this invention is simple to operate and is conducive to industrial production and promotion.

[0044] This invention also provides a method for preparing the above-mentioned composite silicone protective film with blue light protection function, characterized by comprising the following steps: Step 1: Apply blue light blocking silicone pressure-sensitive adhesive evenly to the first surface of the substrate layer, and cure at 140-170℃ for 3-5 minutes to form a blue light blocking functional layer. Step 2: Apply the hardening coating evenly to the second surface of the substrate layer, dry it at 60-80℃ for 5-10 minutes, and then irradiate it with UV light of wavelength 300-450nm for 15-45 seconds, controlling the irradiation energy to 300-1000mj / cm² to form a hardened coating, thereby obtaining a composite silicone protective film with blue light protection function.

[0045] The above is the general concept of the present invention. Based on this, detailed embodiments and comparative examples are provided below to further illustrate the present invention.

[0046] All figures in the following examples and comparative examples are parts by weight.

[0047] Example 1: Preparation of a blue light blocking functional layer (1) Weigh 150 parts of raw rubber (vinyl content of 0.1%, specifically Dow Corning's RBG-0611 brand raw rubber), 200 parts of MQ resin (molecular weight of 3000, MQ ratio of 0.6, specifically DY-MQ102 brand resin from Shandong Dayi Chemical Co., Ltd.), 300 parts of toluene, 100 parts of ethyl acetate, 1 part of hydrogen-containing silicone oil (hydrogen content of 0.5%, specifically RH-H503 silicone oil from Zhejiang Runhe Organosilicon New Materials Co., Ltd.), 1 part of catalyst (chloroplatinic silicone oil dilution, with a platinum content of 5000ppm), 1 part of coupling agent (specifically GX-671 model from Anhui Sibao Organosilicon New Materials Co., Ltd.), 1 part of inhibitor (butynediol), 1 part of blue light absorber (triazine dye, specifically Blu-SHIELD B001 from Shanghai Kaibique Chemical Technology Co., Ltd.), and 5 parts of light stabilizer.

[0048] (2) Add raw rubber, MQ resin and solvent to the container, and stir and disperse with a high-speed disperser. Stir at 300 rpm for 30 min until the mixture becomes gel-like, and continue stirring at 600 rpm for 30 min. (3) Add crosslinking agent, coupling agent and inhibitor to the container, and disperse by high-speed stirring at 800 rpm for 20 min; (4) Add blue light absorber and light stabilizer to the container and stir at 800 rpm for 30 min; (5) Add the catalyst to the container and stir at 800 rpm for 30 min. (6) Filter twice with a 200-mesh filter cloth and discard the filter residue to obtain anti-blue light silicone pressure-sensitive adhesive; (7) Apply the blue light blocking silicone pressure-sensitive adhesive evenly to the surface of the substrate layer (optical PET film), and cure at 120° for 5 minutes to obtain the blue light blocking functional layer on the substrate layer.

[0049] Example 2: Preparation of a blue light blocking functional layer (1) Weigh 150 parts of raw rubber (vinyl content is 0.1%), 200 parts of MQ resin (molecular weight is 3000, MQ ratio is 0.6), 300 parts of toluene, 100 parts of ethyl acetate, 1 part of hydrogen-containing silicone oil (hydrogen content is 0.5%), 1 part of catalyst, 1 part of coupling agent and 1 part of inhibitor, 2 parts of blue light absorber and 5 parts of light stabilizer.

[0050] (2) Add raw rubber, MQ resin, and solvent to the container and stir and disperse using a high-speed disperser. Stir at 300 rpm for 30 minutes until the mixture becomes gel-like, then continue stirring at 600 rpm for 30 minutes. (3) Add crosslinking agent, coupling agent and inhibitor to the container, and disperse by high-speed stirring at 800 rpm for 20 min; (4) Add blue light absorber and light stabilizer to the container and stir at 800 rpm for 30 min; (5) Add the catalyst to the container and stir at 800 rpm for 30 min. (6) Filter twice with 200-mesh filter cloth; (7) Apply the blue light blocking silicone pressure-sensitive adhesive evenly to the surface of the substrate layer (optical PET film), and cure at 120° for 5 minutes to obtain the blue light blocking functional layer on the substrate layer.

[0051] Example 3: Preparation of a blue light blocking functional layer (1) Weigh 150 parts of raw rubber (vinyl content is 0.1%), 200 parts of MQ resin (molecular weight is 3000, MQ ratio is 0.6), 300 parts of toluene, 100 parts of ethyl acetate, 1 part of hydrogen-containing silicone oil (hydrogen content is 0.5%), 1 part of catalyst, 1 part of coupling agent and 1 part of inhibitor, 3 parts of blue light absorber and 5 parts of light stabilizer.

[0052] (2) Add raw rubber, MQ resin, and solvent to the container and stir and disperse using a high-speed disperser. Stir at 300 rpm for 30 minutes until the mixture becomes gel-like, then continue stirring at 600 rpm for 30 minutes. (3) Add crosslinking agent, coupling agent and inhibitor to the container, and disperse by high-speed stirring at 800 rpm for 20 min; (4) Add blue light absorber and light stabilizer to the container and stir at 800 rpm for 30 min; (5) Add the catalyst to the container and stir at 800 rpm for 30 min. (6) Filter twice with 200-mesh filter cloth; (7) Apply the blue light blocking silicone pressure-sensitive adhesive evenly to the surface of the substrate layer (optical PET film), and cure at 120° for 5 minutes to obtain the blue light blocking functional layer on the substrate layer.

[0053] Example 4: Preparation of a blue light blocking functional layer 1) Weigh 150 parts of raw rubber (vinyl content 0.1%), 200 parts of MQ resin (molecular weight 3000, MQ ratio 0.6), 300 parts of toluene, 100 parts of ethyl acetate, 1 part of hydrogen-containing silicone oil (hydrogen content 0.5%), 1 part of catalyst, 1 part of coupling agent and 1 part of inhibitor, 5 parts of blue light absorber and 10 parts of light stabilizer.

[0054] (2) Add raw rubber, MQ resin, and solvent to the container and stir and disperse using a high-speed disperser. Stir at 300 rpm for 30 minutes until the mixture becomes gel-like, then continue stirring at 600 rpm for 30 minutes. (3) Add crosslinking agent, coupling agent and inhibitor to the container, and disperse by high-speed stirring at 800 rpm for 20 min; (4) Add blue light absorber and light stabilizer to the container and stir at 800 rpm for 30 min; (5) Add the catalyst to the container and stir at 800 rpm for 30 min. (6) Filter twice with 200-mesh filter cloth; (7) Apply the blue light blocking silicone pressure-sensitive adhesive evenly to the surface of the substrate layer (optical PET film), and cure at 120° for 5 minutes to obtain the blue light blocking functional layer on the substrate layer.

[0055] Example 5: Preparation of a blue light blocking functional layer (1) Weigh 150 parts of raw rubber (vinyl content is 0.1%), 200 parts of MQ resin (molecular weight is 3000, MQ ratio is 0.6), 300 parts of toluene, 100 parts of ethyl acetate, 1 part of hydrogen-containing silicone oil (hydrogen content is 0.5%), 1 part of catalyst, 1 part of coupling agent and 1 part of inhibitor, 5 parts of blue light absorber and 5 parts of light stabilizer.

[0056] (2) Add raw rubber, MQ resin, and solvent to the container and stir and disperse using a high-speed disperser. Stir at 300 rpm for 30 minutes until the mixture becomes gel-like, then continue stirring at 600 rpm for 30 minutes. (3) Add crosslinking agent, coupling agent and inhibitor to the container, and disperse by high-speed stirring at 800 rpm for 20 min; (4) Add blue light absorber and light stabilizer to the container and stir at 800 rpm for 30 min; (5) Add the catalyst to the container and stir at 800 rpm for 30 min. (6) Filter twice with 200-mesh filter cloth; (7) Apply the blue light blocking silicone pressure-sensitive adhesive evenly to the surface of the substrate layer (optical PET film), and cure at 120° for 5 minutes to obtain the blue light blocking functional layer on the substrate layer.

[0057] Performance tests were conducted on the blue light blocking functional layers of Examples 1-5: Peel strength: The test standard is ASTM D3330; UV blocking rate: The test standard is GB / T 14571.4-2022; Blue light absorption rate: The test standard is GB / T 38120-2019; The test results are shown in Table 1 below: Table 1 Test Project Example 1 Example 2 Example 3 Example 4 Example 5 Thickness (μm) 50 50 50 50 50 Steel plate adhesion (gf / in) 1300 1100 1050 1050 980 UV blocking rate (%) 85 90 100 100 100 Blue light absorption rate (%) 35 45 60 85 85 QSUN - UV blocking rate after 7 days (%) 58 60 70 96 98 QSUN - Blue Light Absorption Rate After 7 Days (%) 20 24 42 70 80 Light transmittance (%) 92.7 92.5 91.6 91.2 91.2 Haze (%) 0.2 0.15 0.2 0.3 0.3 The test data shows that the prepared blue light blocking functional layer is relatively thin, with high adhesion, good blue light blocking effect, high light transmittance and low haze. In addition, with the addition of light stabilizer, the product has the ability to resist QSUN aging. This formula is more practical in actual applications.

[0058] Example 6 Preparation of a hardened coating (1) Weigh 60 parts of hexafunctional polyurethane acrylate (specifically, SM6329 from Jiangsu Sanmu Group, with a viscosity range of about 30,000 mPa·s), 20 parts of trimethylsiloxymethacrylate (TRIS), 3 parts of n-dodecyl mercaptan, 1 part of nano silica, 1 part of photoinitiator TPO, 1 part of leveling agent (specifically, MODAFLOW® 9200 from Allnex), and 20 parts of ethyl acetate.

[0059] (2) Add hexafunctional polyurethane acrylate, trimethylsiloxymethacrylate, n-dodecyl mercaptan and nano silica to a transparent container and stir at 800 rpm for 30 min under nitrogen atmosphere. (3) Under light-protected conditions, add 0.5 parts of photoinitiator TPO into the container, continuously purge with nitrogen, use a handheld UV lamp with an energy of 500 mj / cm², irradiate the container for 4 min, stop irradiation when the system temperature rises to 70°C, stop purging with nitrogen, add the remaining 0.5 parts of photoinitiator and leveling agent, and stir continuously at a stirring speed of 500 rpm until the system temperature drops to room temperature to obtain a premix. (4) Add ethyl acetate to the premix, adjust the viscosity range to 500 cps, and filter it in a double layer using a 500-mesh filter cloth to obtain the hardened coating solution; (5) Apply the hardening coating liquid evenly to the surface of the substrate layer (optical PET film) using a 2000 mesh bar, dry the solvent at 70°C for 5 min, and then cure it for 30 s using a UV curing machine (wavelength 365 nm, energy 800 mj / cm²) to obtain a hardened coating on the substrate layer.

[0060] Example 7 Preparation of a hardened coating (1) Weigh 60 parts of hexafunctional polyurethane acrylate (specifically, SM6329 from Jiangsu Sanmu Group, with a viscosity range of around 30,000 mPa·s), 20 parts of trimethylsiloxymethacrylate (TRIS), 3 parts of n-dodecyl mercaptan, 2 parts of nano silica, 1 part of photoinitiator TPO, 1 part of leveling agent (specifically, MODAFLOW® 9200 from Allnex), and 20 parts of ethyl acetate.

[0061] (2) Add hexafunctional polyurethane acrylate, trimethylsiloxymethacrylate, n-dodecyl mercaptan and nano silica to a transparent container and stir at 800 rpm for 30 min under nitrogen atmosphere. (3) Under light-protected conditions, add 0.5 parts of photoinitiator TPO into the container, continuously purge nitrogen gas, use a handheld UV lamp with an energy of 500 mj / cm², irradiate the container for 4 min, stop irradiation when the system temperature rises to 70°C, stop purging nitrogen gas, replenish the remaining photoinitiator and leveling agent, and continue stirring at a stirring speed of 500 rpm until the system temperature drops to room temperature to obtain a premix. (4) Add ethyl acetate to the premix, adjust the viscosity range to 500 cps, and filter it in a double layer using a 500-mesh filter cloth to obtain the hardened coating solution; (5) Apply the hardening coating liquid evenly to the surface of the substrate layer (optical PET film) using a 2000 mesh bar, dry the solvent at 70°C for 5 min, and then cure it for 30 s using a UV curing machine (wavelength 365 nm, energy 800 mj / cm²) to obtain a hardened coating on the substrate layer.

[0062] Example 8 Preparation of a hardened coating (1) Weigh 60 parts of hexafunctional polyurethane acrylate (specifically, SM6329 from Jiangsu Sanmu Group, with a viscosity range of around 30,000 mPa·s), 20 parts of trimethylsiloxymethacrylate (TRIS), 3 parts of n-dodecyl mercaptan, 5 parts of nano silica, 1 part of photoinitiator TPO, 1 part of leveling agent (specifically, MODAFLOW® 9200 from Allnex), and 20 parts of ethyl acetate.

[0063] (2) Add hexafunctional polyurethane acrylate, trimethylsiloxymethacrylate, n-dodecyl mercaptan and nano silica to a transparent container and stir at 800 rpm for 30 min under nitrogen atmosphere. (3) Under light-protected conditions, add 0.5 parts of photoinitiator TPO into the container, continuously purge nitrogen gas, use a handheld UV lamp with an energy of 500 mj / cm², irradiate the container for 4 min, stop irradiation when the system temperature rises to 70°C, stop purging nitrogen gas, replenish the remaining photoinitiator and leveling agent, and continue stirring at a stirring speed of 500 rpm until the system temperature drops to room temperature to obtain a premix. (4) Add ethyl acetate to the premix, adjust the viscosity range to 500 cps, and filter it in a double layer using a 500-mesh filter cloth to obtain the hardened coating solution; (5) Apply the hardening coating liquid evenly to the surface of the substrate layer (optical PET film) using a 2000 mesh bar, dry the solvent at 70°C for 5 min, and then cure it for 30 s using a UV curing machine (wavelength 365 nm, energy 800 mj / cm²) to obtain a hardened coating on the substrate layer.

[0064] Performance comparison of the blue light blocking functional layers in Examples 1-5: Pencil hardness (500g): The test standard is GB / T 6739-2006; Boiled Hundred-Fragrance Dish: The test standard is ASTM D3359.

[0065] The test results are shown in Table 2 below: Table 2 Test Project Example 6 Example 7 Example 8 Thickness (μm) 5 5 5 Pencil hardness (500g) 2H 2H 3H Boiled Hundreds of Cubes 1B 1B 0B The test data shows that the prepared UV-cured layer is relatively thin, yet possesses high hardness and good adhesion. Combined with the silicone anti-blue light pressure-sensitive adhesive layer, it enhances the scratch resistance and corrosion resistance of the composite protective film on top of blue light protection. This formula is more practical for actual electronic product applications.

[0066] Example 9 A composite silicone protective film with blue light protection function includes a blue light protection functional layer, a substrate layer and a hardened coating layer stacked sequentially.

[0067] The substrate layer is an optical PET film, the blue light blocking functional layer adopts any one of Examples 1-5, and the hardening coating adopts any one of Examples 6-8. The combination method is as follows: first, according to any one of Examples 1-5, an anti-blue light silicone pressure-sensitive adhesive is coated on the first surface of the optical PET film to form an anti-blue light functional layer, and then according to any one of Examples 6-8, a hardening coating is coated on the second surface of the optical PET film to form a hardening coating.

[0068] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details.

Claims

1. A composite silicone protective film with blue light protection function, characterized in that, It includes a blue light blocking functional layer, a substrate layer, and a hardened coating layer stacked in sequence; The blue light blocking functional layer is obtained by coating and curing with a blue light blocking silicone pressure-sensitive adhesive. The blue light blocking silicone pressure-sensitive adhesive comprises the following raw material components by weight: 100-300 parts raw rubber; 200-400 parts of methyl MQ resin; 400-600 parts of the first solvent; 1-5 parts of crosslinking agent; 1-5 parts coupling agent; 1-5 parts catalyst; Inhibitor 1-5 parts; 3-5 parts blue light absorber; 5-10 parts of light stabilizer.

2. The composite silicone protective film with blue light protection function according to claim 1, characterized in that, The raw rubber is vinyl polydimethylsiloxane with a molecular weight of 300,000-500,000 and a vinyl content of 0.1-0.3%. The methyl MQ resin has a molecular weight of 3000-7000 and an MQ ratio of 0.7-0.

9.

3. The composite silicone protective film with blue light protection function according to claim 1, characterized in that, The first solvent is at least one of toluene, ethyl acetate, butanone, and xylene; The crosslinking agent is a hydrogen-containing silicone oil with a hydrogen content of 0.5%-2%; The coupling agent is one or more of vinylsilane, methylvinylsilane, and acetylacetone silane.

4. The composite silicone protective film with blue light protection function according to claim 1, characterized in that, The catalyst is a dilute chloroplatinic silicone oil with a platinum content of 5000 ppm; The inhibitor is butynol; The blue light absorber is a triazine or azo-methoxyl dye; The light stabilizer is a hindered amine light stabilizer.

5. The composite silicone protective film with blue light protection function according to claim 1, characterized in that, The blue light blocking silicone pressure-sensitive adhesive is prepared by the following method: S1-1. Add raw rubber, methyl MQ resin and the first solvent to the container, stir at 400-600 rpm for 30-60 min, and then stir at 500-1200 rpm for 30-60 min. S1-2. Add crosslinking agent, coupling agent and inhibitor to the container, and stir and disperse at 500-2000 rpm for 10-30 min; S1-3. Add blue light absorber and light stabilizer to the container and stir at 500-1000 rpm for 30-60 minutes. S1-4. Add the catalyst to the container and stir at 500-1000 rpm for 20-60 min. S1-5. Filter, discard the filter residue, and obtain the blue light blocking silicone pressure-sensitive adhesive.

6. The composite silicone protective film with blue light protection function according to claim 1, characterized in that, The hardened coating is obtained by applying a hardening coating liquid and then curing it. The hardening coating liquid comprises the following raw material components by weight: 40-70 parts of multifunctional acrylate monomer; Contains 5-20 parts of Si methacrylate monomer; 2-10 parts of thiol monomer; 1-5 parts of nanoparticles; 1-5 parts of photoinitiator; Leveling agent 1-3 parts; The second solvent is 10-20 parts.

7. The composite silicone protective film with blue light protection function according to claim 6, characterized in that, The multifunctional acrylate monomer is selected from one or more of pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, and hexafunctional polyurethane acrylate; The Si-containing methacrylate monomer is a polyhedral oligomeric silsesquioxane (meth)acrylate; The thiol monomer is selected from one or more of n-dodecyl thiol, tert-dodecyl thiol, and n-octyl thiol.

8. The composite silicone protective film with blue light protection function according to claim 6, characterized in that, The nanoparticles are selected from one or both of nano-silica and nano-alumina; The photoinitiator is selected from one or both of photoinitiator TPO and photoinitiator 819; The leveling agent is selected from acrylate leveling agents; The second solvent is selected from at least one of toluene, ethyl acetate, butanone, and xylene.

9. The composite silicone protective film with blue light protection function according to claim 6, characterized in that, The hardening coating solution is prepared by the following method: S2-1. Under light-protected conditions, add multifunctional acrylate monomers, Si-containing methacrylate monomers, thiol monomers and nanoparticles to a transparent container, and stir for 30-60 minutes under nitrogen atmosphere at 800-1200 rpm. S2-2. Add some photoinitiator, purge with nitrogen, stir at 800-1200 rpm for 20-30 min, irradiate with UV light for 2-5 min, control the irradiation energy to be 300-800 mj / cm², raise the system temperature to 65℃-75℃ and stop irradiation, stop purging with nitrogen, add the remaining photoinitiator and leveling agent, stir at 400-500 rpm and cool to room temperature to obtain a premix. S2-3. Add a second solvent to the premix, adjust the viscosity range to 200-800 cps, filter, discard the filter residue, and obtain the hardened coating liquid.

10. A method for preparing a composite silicone protective film with blue light protection function as described in any one of claims 1-8, characterized in that, Includes the following steps: Step 1: Apply blue light blocking silicone pressure-sensitive adhesive evenly to the first surface of the substrate layer, and cure at 140-170℃ for 3-5 minutes to form a blue light blocking functional layer. Step 2: Apply the hardening coating evenly to the second surface of the substrate layer, dry it at 60-80℃ for 5-10 minutes, and then irradiate it with UV light of wavelength 300-450nm for 15-45 seconds, controlling the irradiation energy to 300-1000mj / cm² to form a hardened coating, thereby obtaining the composite silicone protective film with blue light protection function.

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