Anti-graffiti film and manufacturing method thereof

Abstract

The present invention discloses an anti-graffiti film and a method for manufacturing the same, comprising a super-hydrophobic layer, a bridging layer, a polyvinyl chloride resin layer, a pressure-sensitive adhesive layer, and a release layer connected in sequence. The super-hydrophobic layer serves to prevent graffiti. The bridging layer serves to enhance interlayer adhesion between the super-hydrophobic layer and the polyvinyl chloride resin layer. The polyvinyl chloride resin layer increases the elongation of the film after film formation, makes the film more flexible, and has better adhesion to curved surfaces. The present invention achieves a balance between mechanical properties, aging resistance, and anti-graffiti properties through a three-layer structural design comprising a super-hydrophobic layer, a bridging layer, and a polyvinyl chloride resin layer, thereby realizing a film material that has both high aging resistance and flexibility and can effectively prevent graffiti. The film is suitable for pasting on curved surfaces and has low production costs. The precise design of the layer thickness ratio balances the mechanical properties of each layer, so that the anti-graffiti film has good flexibility and ductility while maintaining sufficient strength and durability.

Description

Technical Field

[0001] The present invention relates to the field of film technology, and in particular to an anti-graffiti film and a manufacturing method thereof. Background Art

[0002] Traditional anti-graffiti films often use a rigid substrate or interlayer material like PET, coated with an anti-graffiti layer. The high modulus of these materials results in insufficient flexibility, making them prone to warping and delamination when applied to curved or irregular surfaces. Furthermore, anti-graffiti films are often used to protect outdoor signs, and conventional materials are susceptible to degradation due to factors such as UV radiation, hydrolysis, and climate change, reducing their lifespan and anti-graffiti effectiveness. Therefore, improvements are needed to address these issues. Summary of the Invention

[0003] The present invention addresses the defects of the prior art such as difficulty in laminating to curved surfaces and insufficient aging resistance, and provides a new anti-graffiti film and a manufacturing method thereof.

[0004] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0005] An anti-graffiti film comprises a super-hydrophobic layer, a bridging layer, a polyvinyl chloride resin layer, a pressure-sensitive adhesive layer, and a release layer connected in sequence, wherein the thickness ratio of the super-hydrophobic layer, the bridging layer, and the polyvinyl chloride resin layer is 0.8-1.2:1.8-2.2:1.8-2.2.

[0006] The super-hydrophobic layer has an anti-graffiti function. The bridging layer between the super-hydrophobic layer and the polyvinyl chloride resin layer plays a role in improving the interlayer adhesion. The polyvinyl chloride resin layer makes the film elongation higher after film formation, the film layer is more flexible, and has better adhesion to curved surfaces. The present invention balances the mechanical properties, aging resistance, and anti-graffiti properties through the three-layer structure design of the super-hydrophobic layer, the bridging layer, and the polyvinyl chloride resin layer, and realizes a film material that has high aging resistance and flexibility and can effectively prevent graffiti. It is suitable for pasting on curved surfaces and has low production costs. The precise design of the layer thickness ratio balances the mechanical properties of each layer, so that the anti-graffiti film has good flexibility and ductility while maintaining sufficient strength and durability.

[0007] Preferably, in the anti-graffiti film described above, the super-hydrophobic layer is composed of acrylic resin A, glass microspheres, fluorosilicone resin or silicone resin, butylated amino resin, weak acid catalyst, and diluent in a mass ratio of 80-100:10-15:1-5:5-15:0.1-0.3:20-30.

[0008] The mass ratio of each component is controlled within a certain range to ensure the chemical stability and physical properties of the super-hydrophobic layer and optimize the durability and functionality of the film. The addition of fluorosilicone resin or siloxane resin provides additional hydrophobic properties, and the combination with acrylic resin A enhances the overall waterproof and anti-fouling capabilities. Butyl ether amino resin acts as a cross-linking agent to enhance the adhesion between the super-hydrophobic layer and other layers, improve the stability of the overall structure, and impart excellent flexibility to the cross-linked coating. The addition of a weak acid catalyst helps to control the speed and efficiency of the curing reaction, ensuring uniform curing of the coating and avoiding defects. The appropriate addition of a diluent improves the fluidity of the coating, facilitates the implementation of the coating process, and improves production efficiency. The addition of glass microspheres enhances the wear resistance and surface roughness of the super-hydrophobic layer, while preventing adhesive stickers and labels from sticking to the film surface, further enhancing the anti-graffiti effect.

[0009] This design results in a transparent super-hydrophobic layer with a concave-convex structure, achieving an anti-sticking effect without affecting the transparency and aesthetics of the film. The addition of fluorosilicone or siloxane resin to acrylic resin A provides excellent super-hydrophobic properties, making it difficult for liquids to form droplets on the film surface and adhere, effectively preventing graffiti and contamination. Fluorosilicone or siloxane resins generally have good chemical resistance and UV stability, making the film material resistant to corrosion from a variety of chemicals, suitable for a variety of environments, and reducing material degradation caused by UV exposure.

[0010] Preferably, in the anti-graffiti film described above, the acrylic resin A is a methyl methacrylate-butyl methacrylate-hydroxyethyl acrylate copolymer, and the acrylic resin A has a number average molecular weight of 50,000 to 80,000, a glass transition temperature of 5° C. to 15° C., and a hydroxyl value of 15 mg KOH / g to 25 mg KOH / g.

[0011] The above copolymer provides good flexibility, enhanced chemical resistance, and weather resistance, making the superhydrophobic layer adaptable to a wider range of application environments and surfaces. A glass transition temperature of 5°C to 15°C means that acrylic resin A can maintain flexibility at lower temperatures, helping to maintain the performance of the film material in lower temperature environments. A hydroxyl value of 15 mg KOH / g to 25 mg KOH / g indicates that acrylic resin A contains an appropriate amount of hydroxyl groups, which helps improve its adhesion to other materials and strengthen the bonding between layers. At the same time, the appropriate hydroxyl content and cross-linking agent result in a coating with outstanding chemical resistance and longer outdoor durability. A number average molecular weight of 50,000 to 80,000 can form a tough and somewhat flexible film layer on the substrate surface. This molecular weight range better balances the physical and chemical resistance of the cross-linked system, effectively improving the wear resistance and scratch resistance of the anti-graffiti film in practical applications, better resisting damage to the film layer by external forces, and extending the service life of the film.

[0012] Preferably, in the above-mentioned anti-graffiti film, the average particle size of the glass microspheres is 50 μm to 90 μm, and the protruding height of the glass microspheres is 20% to 40% of the total thickness of the super-hydrophobic layer.

[0013] The protrusion height of the glass microspheres refers to the height of the protruding portion of the acrylic resin A layer in the super-hydrophobic layer. This protrusion height accounts for 20% to 40% of the total super-hydrophobic layer thickness. The specific diameter range and protrusion height of the glass microspheres increase the surface roughness of the super-hydrophobic layer, thereby improving its graffiti resistance, particularly its anti-sticking properties. The protrusions of the glass microspheres make it more difficult for adhesive tape materials to adhere to the anti-graffiti layer through surface contact, while the uneven surface also makes graffiti more difficult to remove. The contact angle between a surface and a liquid is an important indicator of surface hydrophobicity. A higher water contact angle indicates lower surface tension, making it more difficult for graffiti materials, such as ink, to spread on the surface of the graffiti layer. Generally, higher protrusion heights of the glass microspheres improve their tape and graffiti resistance. However, excessive protrusion heights can negatively impact lamination quality, making degassing difficult during lamination, affecting the product's appearance, and affecting the smoothness of the final coating.

[0014] Preferably, in the anti-graffiti film described above, the bridging layer is composed of a mixture of acrylic resin B and ternary chloroacetic acid resin in a mass ratio of 80-100:5-20:5-10, and an isocyanate curing agent or an amino curing agent.

[0015] The super-hydrophobic layer contains more glass microsphere fillers and super-hydrophobic additives. When directly connected to the polyvinyl chloride resin layer, the adhesion performance is also insufficient. Therefore, the bridging layer plays a role in improving interlayer adhesion between the super-hydrophobic layer and the polyvinyl chloride resin layer, and further optimizes the mechanical properties of the film. The mixture formed by adding some ternary chloroacetic acid resins to acrylic resin B can strengthen the adhesion to the super-hydrophobic layer and the polyvinyl chloride resin layer. After curing with a curing agent, the bridging layer forms a three-dimensional network structure with higher flexibility and chemical resistance. At the same time, the flexibility of the entire anti-graffiti film can be improved, making it easier to fit various curved surfaces. The ternary chloroacetic acid resin adopts vinyl chloride-vinyl acetate-vinyl alcohol terpolymer.

[0016] Preferably, in the anti-graffiti film described above, the polyvinyl chloride resin layer is composed of polyvinyl chloride resin, polymer plasticizer, stabilizer, antioxidant, ultraviolet absorber, free radical scavenger, polyolefin elastomer, and organic solvent in a mass ratio of 80-100:30-50:1-5:1-3:1-3:1-2:10-20:10-30.

[0017] The addition of polymer plasticizers plasticizes the PVC resin, increasing its elongation after film formation and making the film more flexible. Especially when heated, it exhibits excellent plasticity, resulting in excellent adhesion to curved surfaces. The addition of stabilizers helps prevent degradation of the PVC resin layer during processing and use, improving the material's long-term stability. Antioxidants prevent oxidative degradation and extend the product's service life. UV absorbers absorb UV rays of varying wavelengths, reducing damage to the PVC resin layer and improving weather resistance. Free radical scavengers trap free radicals, preventing chain breakage and degradation, thereby enhancing the material's aging resistance. The addition of polyolefin elastomers enhances the elasticity of the PVC resin layer, allowing the film to recover after external forces and promoting adhesion to the crosslinking layer. The addition of organic solvents improves the processing properties of the PVC resin layer, facilitating coating and molding. The synergistic effect of these additives with the PVC resin further optimizes the film's surface properties and internal structure, enhancing its practicality and cost-effectiveness.

[0018] Preferably, in the anti-graffiti film described above, the degree of polymerization of the polyvinyl chloride resin is 800-1200, the polymer plasticizer is a mixture of one or more of epoxy soybean oil, adipic acid polyester plasticizer, hydrogenated terpene resin, and nitrile rubber, and the organic solvent is a mixture of tetrahydrofuran and cyclohexanone.

[0019] Polymer plasticizers have high heat resistance and can improve the heat resistance of the PVC resin layer, maintaining its stability at higher temperatures. They can also significantly enhance the flexibility of the PVC resin layer. A mixture of tetrahydrofuran and cyclohexanone, as an organic solvent, can improve the solubility and fluidity of the PVC resin, enhancing coating and processing efficiency. The synergistic effect of the PVC resin's degree of polymerization and the polymer plasticizer imparts excellent flexibility to the anti-graffiti film. The film is less susceptible to brittle cracking and breakage under temperature fluctuations and external forces, maintaining excellent anti-graffiti properties over the long term while also possessing a certain level of mechanical strength and durability.

[0020] Preferably, in the above-mentioned anti-graffiti film, the polyolefin elastomer is a hydrogenated styrene block copolymer or a maleic anhydride grafted styrene-ethylene / butylene-styrene block copolymer, and the styrene content of the polyolefin elastomer is 25% to 35%.

[0021] This copolymer provides excellent elasticity and flexibility, making the PVC resin layer more flexible and resilient. It also significantly improves the PVC resin layer's impact resistance, reduces damage from external impacts, and extends the product's service life. Precise control of the styrene content helps improve the material's wear resistance, reducing wear and tear during daily use and maintaining the product's long-lasting performance. Polyolefin elastomers inherently possess excellent flexibility and elasticity. A styrene content of 25% to 35% allows this anti-graffiti film to adapt to substrate surfaces of varying shapes and curvatures while maintaining its anti-graffiti properties, while also promoting adhesion to the bridging layer.

[0022] A method for manufacturing an anti-graffiti film comprises the following steps:

[0023] S1: taking a PET base film, coating a polyvinyl chloride resin mixture on the PET base film, drying the coating to obtain a polyvinyl chloride resin layer, coating a bridging coating on the polyvinyl chloride resin layer, drying the coating to obtain a bridging layer, coating a super-hydrophobic coating on the bridging layer, drying the coating to obtain a super-hydrophobic layer, and then obtaining an upper composite body, which is then rolled up;

[0024] S2: Take the release material, unwind the material, apply pressure-sensitive adhesive on the release surface of the release material, dry it after coating, obtain a pressure-sensitive adhesive layer and a release layer, and then obtain a lower composite body. The lower composite body enters the composite roller. At the same time, the upper composite body is unrolled and enters the peeling mechanism to peel off the PET base film. The peeled upper composite body passes through the cloth guide mechanism and enters the composite roller. The peeled PET base film enters the material receiving machine for receiving. The polyvinyl chloride resin layer side of the upper composite body and the pressure-sensitive adhesive layer side of the lower composite body are laminated to obtain an anti-graffiti film, which is finally rolled up.

[0025] Step S1 is used to produce the upper composite layer. Step S2 is used to produce the lower composite layer and laminate it with the upper composite layer. The continuous coating and drying steps simplify the manufacturing process and improve production efficiency. The drying step ensures the uniformity and consistency of the coating. The continuous unloading, coating, and drying steps simplify the manufacturing process and improve production efficiency and output. Precise coating and lamination processes improve material utilization and reduce waste. By optimizing the lamination process, the anti-graffiti film's flexibility is enhanced, making it adaptable to a wider range of application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the present invention.

[0027] Reference numerals: super-hydrophobic layer 1 , bridging layer 2 , polyvinyl chloride resin layer 3 , pressure-sensitive adhesive layer 4 , release layer 5 . DETAILED DESCRIPTION

[0028] The following is combined with Figure 1 The present invention is further described in detail with specific embodiments, but they are not intended to limit the present invention:

[0029] Example

[0030] An anti-graffiti film comprises a super-hydrophobic layer 1, a bridging layer 2, a polyvinyl chloride resin layer 3, a pressure-sensitive adhesive layer 4, and a release layer 5, which are connected in sequence. The thickness ratio of the super-hydrophobic layer 1, the bridging layer 2, and the polyvinyl chloride resin layer 3 is 0.8-1.2:1.8-2.2:1.8-2.2.

[0031] Preferably, the super-hydrophobic layer 1 is composed of acrylic resin A, glass microspheres, fluorosilicone resin or silicone resin, butylated amino resin, weak acid catalyst, and diluent in a mass ratio of 80-100:10-15:1-5:5-15:0.1-0.3:20-30.

[0032] Preferably, the acrylic resin A is a methyl methacrylate-butyl methacrylate-hydroxyethyl acrylate copolymer, and the acrylic resin A has a number average molecular weight of 50,000 to 80,000, a glass transition temperature of 5° C. to 15° C., and a hydroxyl value of 15 mg KOH / g to 25 mg KOH / g.

[0033] Preferably, the average particle size of the glass microspheres is 50 μm to 90 μm, and the protruding height of the glass microspheres is 20% to 40% of the total thickness of the super-hydrophobic layer 1 .

[0034] Preferably, the bridging layer 2 is composed of a mixture of acrylic resin B, ternary chloroacetic acid resin, and isocyanate curing agent or amino curing agent in a mass ratio of 80-100:5-20:5-10.

[0035] Preferably, the polyvinyl chloride resin layer 3 is composed of polyvinyl chloride resin, polymer plasticizer, stabilizer, antioxidant, ultraviolet absorber, free radical scavenger, polyolefin elastomer and organic solvent in a mass ratio of 80-100:30-50:1-5:1-3:1-3:1-2:10-20:10-30.

[0036] Preferably, the degree of polymerization of the polyvinyl chloride resin is 800-1200, the polymer plasticizer is a mixture of one or more of epoxy soybean oil, adipic acid polyester plasticizer, hydrogenated terpene resin, and nitrile rubber, and the organic solvent is a mixture of tetrahydrofuran and cyclohexanone.

[0037] Preferably, the polyolefin elastomer is a hydrogenated styrene block copolymer or a maleic anhydride grafted styrene-ethylene / butylene-styrene block copolymer, and the styrene content of the polyolefin elastomer is 25% to 35%.

[0038] Preferably, a method for manufacturing an anti-graffiti film comprises the following steps:

[0039] S1: taking a PET base film, coating a polyvinyl chloride resin mixture on the PET base film, drying after coating to obtain a polyvinyl chloride resin layer 3, coating a bridging coating on the polyvinyl chloride resin layer 3, drying after coating to obtain a bridging layer 2, coating a super-hydrophobic coating on the bridging layer 2, drying after coating to obtain a super-hydrophobic layer 1, and then obtaining an upper composite body, which is then rolled up;

[0040] S2: Take the release material, unwind the material, apply pressure-sensitive adhesive on the release surface of the release material, dry it after coating, obtain the pressure-sensitive adhesive layer 4 and the release layer 5, and then obtain the lower composite body. The lower composite body enters the composite roller. At the same time, the upper composite body is unwound and enters the peeling mechanism to peel off the PET base film. The peeled upper composite body passes through the cloth guide mechanism and enters the composite roller. The peeled PET base film enters the material receiving machine for receiving. The polyvinyl chloride resin layer 3 side of the upper composite body and the pressure-sensitive adhesive layer 4 side of the lower composite body are laminated to obtain the anti-graffiti film, which is finally rolled up.

[0041] The thickness ratios of the super-hydrophobic layer 1, the bridging layer 2 and the polyvinyl chloride resin layer 3 are as follows: the super-hydrophobic layer 1 can be 0.8, 1 and 1.2; the bridging layer 2 can be 1.8, 2 and 2.2; and the polyvinyl chloride resin layer 3 can be 1.8, 2 and 2.2.

[0042] The mass fractions of each component in the super-hydrophobic layer 1 are as follows: acrylic resin A can be 80, 90, 100; glass microspheres can be 10, 12.5, 15; fluorosilicone resin can be 1, 2.5, 5; siloxane resin can be 1, 2.5, 5; butylated amino resin can be 5, 10, 15; weak acid catalyst can be 0.1, 0.2, 0.3; and diluent can be 20, 25, 30. When applying the super-hydrophobic coating, the viscosity of the super-hydrophobic coating mixture can be well controlled, and the stirring and mixing state can be always maintained during the feeding process to prevent the glass microspheres from settling rapidly due to gravity or stacking of the glass microspheres.

[0043] The weak acid catalyst can be a phosphoric acid derivative catalyst or a citric acid derivative catalyst. The diluent can be one or a mixture of ethyl acetate, butyl acetate, methyl isobutyl ketone, and cyclohexanone.

[0044] The number average molecular weight of acrylic resin A may be 50,000, 65,000, or 80,000, the glass transition temperature may be 5° C., 10° C., or 15° C., and the hydroxyl value may be 15 mg KOH / g, 20 mg KOH / g, or 25 mg KOH / g.

[0045] The average particle size of the glass microspheres can be 50 μm, 70 μm, or 90 μm, and the protruding height of the glass microspheres can be 20%, 30%, or 40% of the total thickness of the super-hydrophobic layer 1 .

[0046] The mass fractions of each component in the polyvinyl chloride resin layer 3 are as follows: polyvinyl chloride resin can be 80, 90, or 100; polymer plasticizer can be 30, 40, or 50; stabilizer can be 1, 3, or 5; antioxidant can be 1, 2, or 3; ultraviolet absorber can be 1, 2, or 3; free radical scavenger can be 1, 1.5, or 2; polyolefin elastomer can be 10, 15, or 20; and organic solvent can be 10, 20, or 30.

[0047] Stabilizers can be one or a mixture of barium zinc, calcium zinc, zinc stearate, and calcium stearate. Antioxidants can be one or a mixture of phosphites and hindered phenols. UV absorbers can be benzotriazoles, such as UV-328 and UV-329, triazines, such as UV-405 and UV-460, and benzophenones, such as UV-531. UV absorbers can be one or a mixture of the above. Free radical scavengers can be one or a mixture of hindered amines and benzoates.

[0048] The degree of polymerization of the polyvinyl chloride resin may be 800, 1000, or 1200. The mass ratio of tetrahydrofuran to cyclohexanone in the mixture of tetrahydrofuran and cyclohexanone may be 60-80:20-40, for example, 60:40, 80:20, 70:30, or 60:20 or 80:40.

[0049] The styrene content of the polyolefin elastomer may be 25%, 30%, or 35%.

[0050] The weight fraction of acrylic resin B in bridge layer 2 can be 80, 90, or 100 parts, the weight fraction of ternary vinyl acetate resin can be 5, 12.5, or 20 parts, and the weight fraction of isocyanate curing agent or amino curing agent can be 5, 7.5, or 10 parts. Either isocyanate curing agent or amino curing agent can be used. The acrylic resin B in bridge layer 2 is an acrylic resin with butyl acrylate as the main monomer, and the ternary vinyl acetate resin is a vinyl chloride-vinyl acetate-vinyl alcohol terpolymer.

[0051] The polyvinyl chloride resin mixed liquid consists of polyvinyl chloride resin, polymer plasticizer, stabilizer, antioxidant, ultraviolet absorber, free radical scavenger, polyolefin elastomer and organic solvent.

[0052] The nitrile rubber of the polymer plasticizer is butadiene-acrylonitrile copolymer.

[0053] The fluorosilicone resin can be Shin-Etsu Chemical's KY-1203, the siloxane resin can be Tego protect 5000, and the glass microspheres can be those from Zhejiang Longyou Daoming Optics Co., Ltd., with a refractive index of 1.9 and a main particle size range of 63μm to 75μm. The glass microspheres should be randomly distributed within the 63μm to 75μm range and mixed for use.

[0054] Set up the following products:

[0055] Sample 1: The weight percentages of each component in super-hydrophobic layer 1 are: acrylic resin A (80%), glass microspheres (10%), fluorosilicone resin (1%), butylated amino resin (5%), weak acid catalyst (0.1%), and diluent (20%). Acrylic resin A has a number-average molecular weight of 50,000, a glass transition temperature of 5°C, and a hydroxyl value of 15 mg KOH / g. The protrusion height of the glass microspheres is 20% of the total thickness of super-hydrophobic layer 1. The weight percentages of each component in polyvinyl chloride resin layer 3 are: polyvinyl chloride resin (80%), polymer plasticizer (30%), stabilizer (1%), antioxidant (1%), UV absorber (1%), free radical scavenger (1%), polyolefin elastomer (10%), and organic solvent (10%). The degree of polymerization of the polyvinyl chloride resin is 800. The styrene content of the polyolefin elastomer is 25%. In crosslinking layer 2, the weight percentages of acrylic resin B are: 80%, ternary chloroacetic acid resin (5%), and isocyanate curing agent (5%).

[0056] Sample 2: The weight percentages of each component in super-hydrophobic layer 1 are: acrylic resin A (90%), glass microspheres (12.5%), fluorosilicone resin (2.5%), butylated amino resin (10%), weak acid catalyst (0.2%), and diluent (25%). Acrylic resin A has a number-average molecular weight of 65,000, a glass transition temperature of 10°C, and a hydroxyl value of 20 mg KOH / g. The protrusion height of the glass microspheres is 30% of the total thickness of super-hydrophobic layer 1. The weight percentages of each component in polyvinyl chloride resin layer 3 are: polyvinyl chloride resin (90%), polymer plasticizer (40%), stabilizer (3%), antioxidant (2%), UV absorber (2%), free radical scavenger (1.5%), polyolefin elastomer (15%), and organic solvent (20%). The degree of polymerization of the polyvinyl chloride resin is 1000. The styrene content of the polyolefin elastomer is 30%. The mass fraction of acrylic resin B in the bridging layer 2 is 90, the mass fraction of ternary chloroacetic acid resin is 12.5, and the mass fraction of isocyanate curing agent is 7.5.

[0057] Sample 3: The weight percentages of each component in super-hydrophobic layer 1 are: acrylic resin A (100%), glass microspheres (15%), fluorosilicone resin (5%), butylated amino resin (15%), weak acid catalyst (0.3%), and diluent (30%). Acrylic resin A has a number-average molecular weight of 80,000, a glass transition temperature of 15°C, and a hydroxyl value of 25 mg KOH / g. The protrusion height of the glass microspheres is 40% of the total thickness of super-hydrophobic layer 1. The weight percentages of each component in polyvinyl chloride resin layer 3 are: polyvinyl chloride resin (100%), polymer plasticizer (50%), stabilizer (5%), antioxidant (3%), UV absorber (3%), free radical scavenger (2%), polyolefin elastomer (20%), and organic solvent (30%). The degree of polymerization of the polyvinyl chloride resin is 1200. The styrene content of the polyolefin elastomer is 35%. The mass fraction of acrylic resin B in the bridging layer 2 is 100, the mass fraction of ternary chloroacetic acid resin is 20, and the mass fraction of isocyanate curing agent is 10.

[0058] Comparative Example 1: The same as Sample 2, but without the polyvinyl chloride resin layer.

[0059] Comparative Example 2: The same as Sample 2, but without the bridging layer.

[0060] Comparative Example 3: Same as Sample 2, but without glass microspheres, fluorosilicone resin or silicone resin.

[0061] Conduct the following experiment:

[0062] 1. Tensile strength, elongation at break:

[0063] The Guangdong Kejian KJ-1075 electronic tensile testing machine was used to perform tensile testing on 25mm*150mm samples.

[0064] 2. Anti-graffiti effect:

[0065] Take a 100*100mm sample respectively, write graffiti on its surface with an oil-based marker, then wipe it with dust-free paper, and observe the wiping effect of the surface.

[0066] 3. Anti-sticking effect:

[0067] Take a 100*100mm sample and stick it to an aluminum plate. Then stick a 25mm wide and 50mm long Tesa 7475 standard tape on the surface of the anti-graffiti film. After 30 minutes, use a hair dryer with a wind speed of 20m / s to blow air from the edge of the tape at a distance of 100mm from the film surface and an inclination angle of 30°. Stop after 1 minute and observe whether the tape is blown off.

[0068] 4. Salt spray resistance:

[0069] A 75 mm x 150 mm specimen was placed on a clean aluminum plate. A knife was used to cut the specimen diagonally, forming an "X"-shaped cut. The cut should penetrate the specimen and reach the aluminum plate. A glass measuring cup with a glass cover was filled with a 25°C, 4% saline solution (4 g NaCl dissolved in 96 mL distilled water). Half the specimen was immersed in the solution for 16 hours. After removal from the cup, the salt deposits on the specimen were rinsed off. After a 10-minute recovery period, the specimen's appearance was inspected.

[0070] 5. Xenon lamp aging:

[0071] Weathering resistance evaluation: 120 mm x 50 mm anti-graffiti film samples were cut and affixed to glass substrates. These samples were then placed in an ATLAS CI65A aging test chamber for 3000 hours. According to national standard GB / T 16422.3, the aging test chamber used a xenon lamp as the light source, with a blackboard temperature of 65°C, a relative humidity of 50%, a spectral wavelength between 290 nm and 800 nm, and an illuminance of 550 watts per square meter. The test was conducted using continuous illumination and periodic water spraying, with a spray cycle of 18 minutes / 102 minutes (spraying time / non-spraying time). After the test, the samples were thoroughly rinsed with clean water and then wiped dry with a clean soft cloth. The surface of the samples was then measured using a colorimeter and the post-test values ​​compared with the pre-test values. ΔE represents the color difference.

[0072] Evaluation criteria:

[0073] A: ∆E is less than 2;

[0074] B: △E is greater than 2 and less than 4;

[0075] C: △E is greater than 4 and less than 8;

[0076] D: △E is 8 or above.

[0077] The experimental data are as follows:

[0078] Tensile strength MPa Elongation at break Graffiti effect Anti-stick effect Salt spray resistance Xenon lamp aging performance Sample 1 35 121% Erasable, no marks Falling off good A Sample 2 32 133% Erasable, no marks Falling off good A Sample 3 38 118% Erasable, no marks Falling off good A Comparative Example 1 47 18% Erasable, no marks Falling off good A Comparative Example 2 24 57% (the super-hydrophobic layer and the polyvinyl chloride resin layer began to delaminate on the broken end surface during the stretching process) Erasable, no marks Falling off good After 500 hours, the super hydrophobic layer falls off Comparative Example 3 35 145% Cannot be erased Not falling off good A

[0079] Comparative Example 1 does not contain a polyvinyl chloride resin layer, and has a high tensile strength and a low elongation at break. The polyvinyl chloride resin layer makes the film elongation higher after film formation, making the film more flexible and having better adhesion to curved surfaces.

[0080] Comparative Example 2 does not contain a bridging layer, and the super-hydrophobic layer and the polyvinyl chloride resin layer are easily separated. The bridging layer increases the interlayer adhesion between the super-hydrophobic layer and the polyvinyl chloride resin layer and the tensile strength of the entire film, thereby preventing the layers from separating due to aging.

[0081] Comparative Example 3 does not contain glass microspheres, fluorosilicone resin or silicone resin, and has moderate tensile strength and elongation at break, but the tape is easily adhered to the surface.

[0082] In short, the above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made within the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. An anti-graffiti film, characterized by: The invention comprises a super-hydrophobic layer (1), a bridging layer (2), a polyvinyl chloride resin layer (3), a pressure-sensitive adhesive layer (4), and a release layer (5) connected in sequence, wherein the thickness ratio of the super-hydrophobic layer (1), the bridging layer (2), and the polyvinyl chloride resin layer (3) is 0.8-1.2:1.8-2.2:1.8-2.2, and the super-hydrophobic layer (1) is composed of acrylic resin A, glass microspheres, fluorosilicone resin or silicone resin, butylated amino resin, The invention relates to a novel polyvinyl chloride resin layer comprising a weak acid catalyst and a diluent, wherein the bridging layer (2) comprises a mixture of acrylic resin B and ternary chloroacetic acid resin in a mass ratio of 80-100:5-20:5-10, and an isocyanate curing agent or an amino curing agent, and the polyvinyl chloride resin layer (3) comprises a polyvinyl chloride resin, a polymer plasticizer, a stabilizer, an antioxidant, an ultraviolet absorber, a free radical scavenger, a polyolefin elastomer, and an organic solvent in a mass ratio of 80-100:30-50:1-5:1-3:1-3:1-2:10-20:10-30.

2. The anti-graffiti film according to claim 1, characterized in that: The acrylic resin A is a methyl methacrylate-butyl methacrylate-hydroxyethyl acrylate copolymer, and has a number average molecular weight of 50,000 to 80,000, a glass transition temperature of 5° C. to 15° C., and a hydroxyl value of 15 mg KOH / g to 25 mg KOH / g.

3. The anti-graffiti film according to claim 1, characterized in that: The average particle size of the glass microspheres is 50 μm to 90 μm, and the protruding height of the glass microspheres is 20% to 40% of the total thickness of the super-hydrophobic layer (1).

4. The anti-graffiti film according to claim 1, characterized in that: The polymerization degree of the polyvinyl chloride resin is 800-1200, the polymer plasticizer is a mixture of one or more of epoxy soybean oil, adipic acid polyester plasticizer, hydrogenated terpene resin, and nitrile rubber, and the organic solvent is a mixture of tetrahydrofuran and cyclohexanone.

5. The anti-graffiti film according to claim 1, characterized in that: The polyolefin elastomer is a hydrogenated styrene block copolymer or a maleic anhydride grafted styrene-ethylene / butylene-styrene block copolymer, and the styrene content of the polyolefin elastomer is 25% to 35%.

6. The method for manufacturing an anti-graffiti film according to claim 1, wherein: The following steps are involved: S1: taking a PET base film, coating a polyvinyl chloride resin mixture on the PET base film, drying after coating to obtain a polyvinyl chloride resin layer (3), coating a bridging coating on the polyvinyl chloride resin layer (3), drying after coating to obtain a bridging layer (2), coating a super-hydrophobic coating on the bridging layer (2), drying after coating to obtain a super-hydrophobic layer (1), and then obtaining an upper composite body, which is then rolled up; S2: Take the release material, unwind the material, apply pressure-sensitive adhesive to the release surface of the release material, dry it after coating, obtain a pressure-sensitive adhesive layer (4) and a release layer (5), and then obtain a lower composite body. The lower composite body enters the composite roller. At the same time, the upper composite body is unrolled and enters the peeling mechanism to peel off the PET base film. The peeled upper composite body passes through the cloth guide mechanism and enters the composite roller. The peeled PET base film enters the material receiving machine for receiving. The polyvinyl chloride resin layer (3) side of the upper composite body and the pressure-sensitive adhesive layer (4) side of the lower composite body are laminated to obtain an anti-graffiti film, which is finally rolled up.

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