PVC matt film and preparation method thereof

Abstract

The application belongs to the technical field of film processing, and particularly relates to a PVC matt film and a preparation method thereof. The PVC matt film comprises the following components in parts by mass: PVC resin 80-90 parts, environment-friendly oil 20-25 parts, soybean oil 2-5 parts, SiO2 matt microspheres 3-5 parts, color powder mixture 0.08-0.16 parts, stabilizer 1.5-3.5 parts, and synergist 0.2-0.4 parts. The PVC matt film prepared by the application has good formability and good matt performance.

Description

Technical Field

[0001] This invention belongs to the field of thin film processing technology, specifically relating to a PVC matte film and its preparation method. Background Technology

[0002] Polyvinyl chloride (PVC) film is widely used in packaging, printing, decoration, stationery, and daily consumer goods due to its excellent mechanical properties, chemical resistance, ease of processing, and cost advantages. Among them, matte PVC film with a soft matte texture effectively avoids glare, fingerprint residue, and visual fatigue caused by high-gloss films, making it the preferred material for products such as photo albums, gift boxes, and folders.

[0003] To achieve a matte finish, the industry has developed various technical approaches. Early methods, such as surface mechanical embossing, involved physically imprinting a hot PVC film with an embossing roller bearing a finely textured surface, creating a macroscopic uneven structure on the film's surface to scatter light. However, this method results in films with a rough feel, prone to dust accumulation, and poor optical uniformity. More significantly, the embossing process severely damages the film's structure, leading to a significant decrease in transparency, typically resulting in only semi-transparent or opaque surfaces, thus limiting its applications.

[0004] The coating method involves applying a UV or thermosetting coating containing matting particles onto a PVC base film, which can achieve a delicate touch and a uniform appearance; however, this method is complex, costly, and requires strong adhesion between the coating and the base film.

[0005] Currently, the mainstream technology for preparing PVC matte films relies on directly adding matting agents to the formulation. However, this method still has the following problems: First, the refractive index difference between conventional inorganic fillers and PVC is large, which easily causes strong bulk scattering, resulting in a significant decrease in film transmittance and whitening / hazing. Second, the matting agent has poor compatibility with the PVC / plasticizer system, easily agglomerating, leading to uneven gloss on the film surface, and the agglomerates become stress weaknesses, impairing the mechanical properties of the film.

[0006] Chinese patent application CN107841060A discloses a modified matting film, which is made from the following raw materials in parts by weight: 65-80 parts by weight of polyvinyl chloride resin; 22-40 parts by weight of matting resin; 20-40 phr of dioctyl phthalate; 8-20 phr of epoxy linseed oil; 2-5 phr of heat stabilizer; 0.3-0.5 phr of antioxidant; 0.1-1.0 phr of UV absorber; and 0.6-2 phr of nano-scale anti-sticking agent. This method aims to achieve matting by incomplete plasticization of the matting resin during processing, forming microscopic protrusions on the film surface in situ. Its matting effect essentially depends on the microstructure formed by the specific matting resin under a specific process window. Uniformity and stability are highly sensitive to process parameters such as temperature and shear force; improper control can easily lead to inconsistent matting effects. Furthermore, the surface micro-protrusions may be subject to wear under long-term friction or external force, affecting the durability of the matting effect. Summary of the Invention

[0007] Existing PVC matte film technologies rely on matte resins with microstructure, and their performance is easily affected by process variations. To address this issue, this invention provides a PVC matte film and its preparation method.

[0008] To achieve the objectives of this invention, the following technical solution is adopted: In a first aspect, the present invention provides a PVC matte film comprising the following components in parts by weight: 80-90 parts PVC resin, 20-25 parts environmentally friendly oil, 2-5 parts soybean oil, 3-5 parts SiO2 matting microspheres, 0.08-0.16 parts color powder mixture, 1.5-3.5 parts stabilizer, and 0.2-0.4 parts synergist.

[0009] By adopting the above technical solutions, PVC resin is used as the core substrate of the film to ensure the basic mechanical properties of the matting film. A composite plasticizing system is formed by combining environmentally friendly oil and soybean oil to improve the flexibility and folding resistance of the film. Simultaneously, the synergistic effect of soybean oil and environmentally friendly oil optimizes the system's compatibility. SiO2 matting microspheres produce uniform micro-scattering of light, reducing specular reflection and enhancing diffuse reflection, thus achieving a stable and soft matting effect. The colorant mixture can fine-tune the film's color and enhance its appearance. The combination of stabilizers and synergists provides the system with high thermal stability and processing safety, preventing PVC from decomposing and discoloring during high-temperature processing.

[0010] Furthermore, the SiO2 matting microspheres have a core-shell structure; wherein the core layer is mesoporous SiO2 and the shell layer is organosilicon resin.

[0011] Furthermore, the preparation method of the SiO2 matting microspheres includes the following steps: (1) Mix mesoporous SiO2 with anhydrous ethanol evenly, add stearic acid coupling agent and heat to 40-50℃ for 1-1.5h, add silane coupling agent KH-570 and react for 30-45min to obtain mesoporous SiO2 dispersion. (2) Mix methylphenyl silicone resin, mesoporous SiO2 dispersion and anhydrous ethanol evenly, add dibutyltin dilaurate and polyethylene glycol 400 and mix evenly to obtain SiO2 matting microsphere precursor system; (3) Nitrogen gas was introduced into the SiO2 matting microsphere precursor system, the temperature was raised to carry out the reaction, and the mixture was cooled and dried to obtain SiO2 matting microspheres.

[0012] By adopting the above technical solution, step (1) modifies the mixture of stearic acid coupling agent and KH-570 to achieve hydrophobic sealing and coupling bridging, preventing the adsorption of environmentally friendly oil, soybean oil and other components in the PVC system by mesoporous SiO2, and enhancing the coating strength of the subsequent organosilicon resin shell; in step (2), the catalyst dibutyltin dilaurate can promote the low-temperature cross-linking and film formation of organosilicon resin, and polyethylene glycol 400 prevents particle agglomeration, ensuring that the final composite powder has uniform particle size and excellent dispersibility; in step (3), the nitrogen environment can isolate oxygen, prevent the organosilicon resin from oxidizing and turning yellow, and at the same time steadily remove the solvent, promote the uniform film formation of the shell, and avoid the shell cracking and peeling. The obtained SiO2 matting microspheres not only retain the porous structure of mesoporous SiO2 to achieve the functions of matting and adsorbing low molecular weight volatiles, but also avoid the adsorption of oil plasticizers by SiO2 through the hydrophobic shell of organosilicon.

[0013] Further, in step (1), the ratio of the amount of mesoporous SiO2, anhydrous ethanol, stearic acid coupling agent and silane coupling agent KH-570 is 100g∶(350-550)mL∶(1.1-1.8)g∶(0.6-0.9)g.

[0014] By adopting the above technical solution, the two coupling agents can be uniformly dispersed in the system under this ratio, and fully contact the surface of mesoporous SiO2 to form a uniform dispersion without agglomeration.

[0015] Furthermore, the ratio of mesoporous SiO2, methylphenyl silicone resin, anhydrous ethanol, dibutyltin dilaurate and polyethylene glycol 400 is 100g:(15-20)g:(50-100)mL:(0.1-0.2)g:(0.3-0.5)g.

[0016] The mass of the above-mentioned methylphenyl silicone resin is based on the solid content of the methylphenyl silicone resin.

[0017] By adopting the above technical solution, methylphenyl silicone resin can form a shell of suitable thickness on the surface of mesoporous SiO2 at this dosage, which can effectively protect the mesoporous structure, improve scratch resistance and stain resistance, and prevent the powder particle size from being too large and the light transmittance from decreasing due to excessive shell thickness.

[0018] Furthermore, in step (3), the reaction temperature is 50-60℃ and the reaction time is 2-3h.

[0019] By adopting the above technical solution, the reaction environment is mild, which can prevent the organosilicon resin from yellowing and ensure the light transmittance of the film. At the same time, the temperature can prevent the pore structure of mesoporous SiO2 from shrinking and collapsing due to heat, thus preserving its functions of micro-scattering extinction and adsorption of low molecular weight volatiles. The reaction time of 2-3 hours allows the organosilicon resin to slowly and uniformly deposit on the surface of mesoporous SiO2, forming a continuous, dense shell with a suitable thickness. Too short a time will result in incomplete coating, while too long a time will easily cause the shell to be too thick or block the mesopores, affecting the extinction effect.

[0020] Furthermore, the color powder mixture is prepared by mixing ultramarine, ultramarine blue and white pigments in a mass ratio of (13-15):(0.4-0.5):1.

[0021] By adopting the above technical solution, a high proportion of ultramarine violet can neutralize the yellow phase produced by PVC resin during processing, thereby improving the whiteness and transparency of the film. A small amount of ultramarine blue assists in color adjustment, which can refine the color and make the film surface color more uniform and pure. White pigment further brightens the film and works synergistically with ultramarine violet and ultramarine blue to optimize the appearance of the film. The proportion of the three is reasonable, and the color adjustment effect is stable.

[0022] Furthermore, the PVC matte film also includes 0.3-0.6 parts of lubricant and 2-4 parts of toughening agent.

[0023] By adopting the above technical solutions, the lubricant can effectively reduce the friction between the PVC melt and the processing equipment, improve the melt flowability, and avoid problems such as sticking to the roller and flow marks; the toughening agent can improve the impact resistance and flexibility of the PVC matte film, compensate for the slight increase in rigidity after the addition of SiO2 matte microspheres, and make the PVC matte film have both a good matte appearance and excellent mechanical properties.

[0024] Secondly, the present invention also provides a method for preparing the above-mentioned PVC matte film, comprising the following steps: Weigh the above components according to the formula, mix them evenly in a high-speed mixer, extrude and granulate them using a twin-screw extruder, and cast them into a film to obtain a PVC matte film.

[0025] By adopting the above technical solution, the preparation method has a short process and high processing efficiency, and can ensure stable and consistent matting effect, mechanical properties and appearance quality, making it suitable for large-scale production.

[0026] Furthermore, the extrusion temperature is 140-180℃.

[0027] By adopting the above technical solution, the temperature can ensure that the PVC resin is fully plasticized, avoid the thermal degradation and yellowing of PVC caused by excessive temperature, or the decomposition of additives such as lubricants and toughening agents, so that the extrusion process is stable and controllable, and the final PVC matte film has the best appearance, mechanical properties and matte effect.

[0028] In summary, the beneficial effects of this invention are: (1) The proportions of each component of the PVC matte film of the present invention are scientific and synergistic, which solves the problems of poor flexibility, uneven plasticization and easy yellowing of traditional PVC matte film. The PVC matte film obtained has good formability and stable performance. (2) The SiO2 matte microspheres prepared in this invention are core-shell structures with hydrophobically modified mesoporous SiO2 as the core and organosilicon resin as the shell, achieving a synergistic balance between porous structure and light transmittance; the organosilicon resin itself has excellent wear resistance and low surface energy characteristics, which can improve the scratch resistance and anti-fouling properties of the film surface; at the same time, the organosilicon shell layer makes the powder more dispersed in the PVC system, avoids large-area agglomeration, and makes the transparent matte effect of the matte film more uniform, without local high gloss or fog spots, and the light transmittance is stable. Attached Figure Description

[0029] Figure 1 This is a TEM image of the SiO2 extinction microspheres of the present invention; Figure 2 This is a photograph of the PVC matte film prepared according to the present invention. Detailed Implementation

[0030] The present invention will be further described below with reference to specific embodiments.

[0031] Unless otherwise specified, the experimental methods used in the following examples and comparative examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples and comparative examples are commercially available.

[0032] Mesoporous SiO2: MCM-41 type, pore size 5-20nm, specific surface area 800-1200m² 2 / g, particle size 100-200nm; Methylphenyl silicone resin: solid content 50%; White pigment: titanium dioxide; Stabilizer: Calcium-zinc stabilizer; Synergist: Epoxy fatty acid methyl ester; Toughening agent: methyl methacrylate-butadiene-styrene copolymer; Lubricant: Polyethylene wax.

[0033] Preparation example: SiO2 matting microspheres Preparation Example 1 The preparation method of SiO2 matting microspheres in this example includes the following specific steps: (1) Add 100g of mesoporous SiO2 to 400mL of anhydrous ethanol, place it in a high-speed disperser, disperse it at 1000r / min for 30min, add 1.2g of stearic acid coupling agent, heat to 45℃, react at a constant temperature for 1.5h, add 0.9g of silane coupling agent KH-570, keep at 45℃, and continue to react for 40min to obtain mesoporous SiO2 dispersion; (2) Add 35g of methylphenyl silicone resin to the mesoporous SiO2 dispersion, add 100mL of anhydrous ethanol, stir at 800r / min for 20min, then add 0.2g of dibutyltin dilaurate catalyst and 0.35g of polyethylene glycol 400 and continue stirring for 10min to obtain SiO2 matting microsphere precursor; (3) Transfer the SiO2 matting microsphere precursor to the reactor, control the temperature at 55℃, turn on the slow nitrogen flow, stir at 500r / min for 3h, and cool naturally to room temperature to obtain SiO2 matting microsphere wet powder. Transfer the wet powder to the vacuum drying oven and dry at 60℃ for 6h to obtain SiO2 matting microspheres.

[0034] TEM morphology images of SiO2 extinction microspheres are shown below. Figure 1 . Figure 1 The microspheres are spherical in shape, with a dark-colored core in the center and a light-colored shell at the edge, which is a uniform and dense shell.

[0035] Preparation Example 2 The preparation method of SiO2 matting microspheres in this example includes the following specific steps: (1) Add 100g of mesoporous SiO2 to 350mL of anhydrous ethanol, place it in a high-speed disperser, disperse at 1000r / min for 30min, add 1.6g of stearic acid coupling agent, heat to 40℃, react at a constant temperature for 1.5h, add 0.9g of silane coupling agent KH-570, maintain 40℃, and continue to react for 40min to obtain mesoporous SiO2 dispersion; (2) Add 30g of methylphenyl silicone resin to the mesoporous SiO2 dispersion, add 100mL of anhydrous ethanol, stir at 800r / min for 20min, then add 0.1g of dibutyltin dilaurate catalyst and 0.4g of polyethylene glycol 400 and continue stirring for 10min to obtain SiO2 matting microsphere precursor; (3) Transfer the SiO2 matting microsphere precursor to the reactor, control the temperature at 50°C, turn on the slow nitrogen flow, stir at 500 r / min for 2 h, and cool naturally to room temperature to obtain SiO2 matting microsphere wet powder. Transfer the wet powder to a vacuum drying oven and dry at 60°C for 6 h to obtain SiO2 matting microspheres.

[0036] Preparation Example 3 The preparation method of SiO2 matting microspheres in this example includes the following specific steps: (1) Add 100g of mesoporous SiO2 to 450mL of anhydrous ethanol, place it in a high-speed disperser, disperse it at 1000r / min for 30min, add 1.1g of stearic acid coupling agent, heat to 40℃, react at a constant temperature for 1h, add 0.7g of silane coupling agent KH-570, keep at 40℃, and continue to react for 45min to obtain mesoporous SiO2 dispersion; (2) Add 40g of methylphenyl silicone resin to the mesoporous SiO2 dispersion, add 50mL of anhydrous ethanol, stir at 800r / min for 20min, then add 0.2g of dibutyltin dilaurate catalyst and 0.5g of polyethylene glycol 400 and continue stirring for 10min to obtain SiO2 matting microsphere precursor. (3) Transfer the SiO2 matting microsphere precursor to the reactor, control the temperature at 60°C, turn on the slow nitrogen flow, stir at 500 r / min for 2 h, and cool naturally to room temperature to obtain SiO2 matting microsphere wet powder. Transfer the wet powder to the vacuum drying oven and dry at 60°C for 6 h to obtain SiO2 matting microspheres.

[0037] Preparation Example 4 The preparation method of SiO2 matting microspheres in this example includes the following specific steps: (1) Add 100g of mesoporous SiO2 to 550mL of anhydrous ethanol, place it in a high-speed disperser, disperse it at 1000r / min for 30min, add 1.8g of stearic acid coupling agent, heat to 50℃, react at a constant temperature for 1h, add 0.8g of silane coupling agent KH-570, keep at 50℃, and continue to react for 30min to obtain mesoporous SiO2 dispersion; (2) Add 35g of methylphenyl silicone resin to the mesoporous SiO2 dispersion, add 50mL of anhydrous ethanol, stir at 800r / min for 20min, then add 0.15g of dibutyltin dilaurate catalyst and 0.4g of polyethylene glycol 400 and continue stirring for 10min to obtain SiO2 matting microsphere precursor. (3) Transfer the SiO2 matting microsphere precursor to the reactor, control the temperature at 55℃, turn on the slow nitrogen flow, stir at 500r / min for 3h, and cool naturally to room temperature to obtain SiO2 matting microsphere wet powder. Transfer the wet powder to the vacuum drying oven and dry at 60℃ for 6h to obtain SiO2 matting microspheres.

[0038] Preparation Example 5 The preparation method of SiO2 matting microspheres in this example includes the following specific steps: (1) Add 100g of mesoporous SiO2 to 450mL of anhydrous ethanol, place it in a high-speed disperser, disperse it at 1000r / min for 30min, add 1.3g of stearic acid coupling agent, heat to 45℃, keep the temperature constant for 1.5h, continue to add 0.6g of silane coupling agent KH-570, keep at 45℃, continue to react for 45min, and obtain mesoporous SiO2 dispersion; (2) Add 30g of methylphenyl silicone resin to the mesoporous SiO2 dispersion, add 70mL of anhydrous ethanol, stir at 800r / min for 20min, then add 0.15g of dibutyltin dilaurate catalyst and 0.4g of polyethylene glycol 400 and continue stirring for 10min to obtain SiO2 matting microsphere precursor; (3) Transfer the SiO2 matting microsphere precursor to the reactor, control the temperature at 60°C, turn on the slow nitrogen flow, stir at 500 r / min for 3 h, and cool naturally to room temperature to obtain SiO2 matting microsphere wet powder. Transfer the wet powder to the vacuum drying oven and dry at 60°C for 6 h to obtain SiO2 matting microspheres.

[0039] Preparation Example 6 The preparation method of SiO2 matting microspheres in this example includes the following specific steps: (1) Add 100g of mesoporous SiO2 to 400mL of anhydrous ethanol, place it in a high-speed disperser, disperse it at 1000r / min for 30min, add 1.5g of stearic acid coupling agent, heat to 45℃, keep the temperature constant for 1.5h, continue to add 0.8g of silane coupling agent KH-570, keep at 45℃, continue to react for 45min, and obtain mesoporous SiO2 dispersion; (2) Add 30g of methylphenyl silicone resin to the mesoporous SiO2 dispersion, add 80mL of anhydrous ethanol, stir at 800r / min for 20min, then add 0.2g of dibutyltin dilaurate catalyst and 0.4g of polyethylene glycol 400 and continue stirring for 10min to obtain SiO2 matting microsphere precursor; (3) Transfer the SiO2 matting microsphere precursor to the reactor, control the temperature at 60°C, turn on the slow nitrogen flow, stir at 500 r / min for 3 h, and cool naturally to room temperature to obtain SiO2 matting microsphere wet powder. Transfer the wet powder to the vacuum drying oven and dry at 60°C for 6 h to obtain SiO2 matting microspheres.

[0040] Example: PVC matte film Example 1 This embodiment of a PVC matte film is composed of the following components in parts by weight: 80 parts PVC resin, 20.8 parts environmentally friendly oil, 3.2 parts soybean oil, 4 parts SiO2 matting microspheres prepared in Preparation Example 1, 0.15 parts color powder mixture, 2.2 parts stabilizer, and 0.2 parts synergist; The pigment mixture is prepared by mixing ultramarine, ultramarine blue and white pigments in a mass ratio of 13:0.45:1.

[0041] The specific steps of the preparation method of the PVC matte film in this embodiment are as follows: Weigh the above components according to the specified ratio, add each component to a high-speed mixer, mix at 80°C for 10 minutes to obtain a premix; add the premix to a twin-screw extruder, control the extrusion temperature at 140-180°C, and extrude granulate to obtain PVC matte granules; cast the PVC matte granules into a film at 160-190°C using a casting machine, cool and set to obtain a PVC matte film.

[0042] Example 2 This embodiment of a PVC matte film is composed of the following components in parts by weight: The mixture consists of 82.7 parts PVC resin, 22.5 parts environmentally friendly oil, 4.4 parts soybean oil, 4.5 parts SiO2 matting microspheres prepared in Preparation Example 1, 0.16 parts color powder mixture, 2.9 parts stabilizer, and 0.4 parts synergist. The pigment mixture is prepared by mixing ultramarine, ultramarine blue and white pigments in a mass ratio of 14:0.4:1.

[0043] The specific steps of the preparation method of the PVC matte film in this embodiment are as follows: Weigh the above components according to the specified ratio, add each component to a high-speed mixer, mix at 80°C for 10 minutes to obtain a premix; add the premix to a twin-screw extruder, control the extrusion temperature at 140-180°C, and extrude granulate to obtain PVC matte granules; cast the PVC matte granules into a film at 160-190°C using a casting machine, cool and set to obtain a PVC matte film.

[0044] Example 3 This embodiment of a PVC matte film is composed of the following components in parts by weight: 90 parts PVC resin, 25 parts environmentally friendly oil, 3 parts soybean oil, 5 parts SiO2 matting microspheres prepared in Preparation Example 2, 0.1 parts color powder mixture, 1.5 parts stabilizer, and 0.3 parts synergist; The pigment mixture is prepared by mixing ultramarine, ultramarine blue and white pigments in a mass ratio of 13:0.4:1.

[0045] The specific steps of the preparation method of the PVC matte film in this embodiment are as follows: Weigh the above components according to the specified ratio, add each component to a high-speed mixer, mix at 80°C for 10 minutes to obtain a premix; add the premix to a twin-screw extruder, control the extrusion temperature at 140-180°C, and extrude granulate to obtain PVC matte granules; cast the PVC matte granules into a film at 160-190°C using a casting machine, cool and set to obtain a PVC matte film.

[0046] Example 4 This embodiment of a PVC matte film is composed of the following components in parts by weight: 87.5 parts PVC resin, 25 parts environmentally friendly oil, 3.9 parts soybean oil, 3 parts SiO2 matte microspheres prepared in Preparation Example 2, 0.15 parts color powder mixture, 3.5 parts stabilizer, 0.25 parts synergist, 0.6 parts lubricant, and 4 parts toughening agent; The pigment mixture is prepared by mixing ultramarine, ultramarine blue and white pigments in a mass ratio of 13:0.5:1.

[0047] The preparation method of the PVC matte film in this embodiment is the same as in Embodiment 1.

[0048] Example 5 This embodiment of a PVC matte film is composed of the following components in parts by weight: 88 parts PVC resin, 23.9 parts environmentally friendly oil, 2 parts soybean oil, 5 parts SiO2 matting microspheres prepared in Preparation Example 5, 0.12 parts color powder mixture, 1.5 parts stabilizer, 0.3 parts synergist, 0.5 parts lubricant, and 2 parts toughening agent; The pigment mixture is prepared by mixing ultramarine, ultramarine blue and white pigments in a mass ratio of 13:0.4:1.

[0049] The preparation method of the PVC matte film in this embodiment is the same as in Embodiment 1.

[0050] Example 6 This embodiment of a PVC matte film is composed of the following components in parts by weight: 83.4 parts PVC resin, 20 parts environmentally friendly oil, 4.8 parts soybean oil, 4 parts SiO2 matte microspheres prepared in Preparation Example 4, 0.08 parts color powder mixture, 3 parts stabilizer, 0.34 parts synergist, 0.3 parts lubricant, and 2.5 parts toughening agent; The pigment mixture is prepared by mixing ultramarine, ultramarine blue and white pigments in a mass ratio of 14:0.4:1.

[0051] The preparation method of the PVC matte film in this embodiment is the same as in Embodiment 1.

[0052] Comparative Example 1 The difference between this comparative example and Example 4 is that an equal amount of ordinary silica microspheres are used instead of SiO2 matting microspheres, while the rest are the same as in Example 4.

[0053] Comparative Example 2 The difference between this comparative example and Example 4 is that the SiO2 matting microspheres used in this comparative example have not been modified with a coupling agent, while all other aspects are the same as in Example 4.

[0054] Comparative Example 3 The difference between this comparative example and Example 4 is that SiO2 matting microspheres were not added; otherwise, they are the same as in Example 4.

[0055] Comparative Example 4 The difference between this comparative example and Example 4 is that the color powder mixture in this comparative example is prepared by mixing ultramarine, ultramarine blue and white pigment in a ratio of 5:2:1, while the rest is the same as in Example 4.

[0056] Comparative Example 5 The difference between this comparative example and Example 4 is that the PVC matte film in this comparative example is composed of the following components in parts by weight, while the rest are the same as in Example 4: 87.5 parts PVC resin, 12 parts environmentally friendly oil, 15 parts soybean oil, 3 parts SiO2 matting microspheres prepared in Preparation Example 1, 0.15 parts color powder mixture, 3.5 parts stabilizer, 0.25 parts synergist, 0.6 parts lubricant, and 4 parts toughening agent; The pigment mixture is prepared by mixing ultramarine, ultramarine blue and white pigments in a mass ratio of 13:0.5:1.

[0057] Related performance tests The PVC matte films prepared in Examples 1-6 and Comparative Examples 1-5 were subjected to relevant performance tests, and the test results are shown in Table 1.

[0058] Light transmittance and haze: The haze and light transmittance of PVC matte film were determined according to GB / T 2410-2008 "Determination of light transmittance and haze of transparent plastics" using a C light source. Tensile strength: The tensile strength of PVC matte film was tested according to GB / T 1040.3-2006 "Determination of tensile properties of plastics"; Gloss: The gloss of PVC matte film at 60° was determined according to GB / T 8807-1988 "Test Method for Specular Gloss of Plastics".

[0059] Table 1 Test Results

[0060] As shown in Table 1: Comparing Comparative Example 1 with Example 4, it can be seen that ordinary silica microspheres have a weak scattering effect on light, thus reducing haze, increasing light transmittance, significantly increasing gloss, and having a poor matting effect. At the same time, ordinary silica microspheres have poor compatibility with PVC matrix, toughening agent and other components, resulting in a decrease in the internal bonding force of the film and a significant reduction in tensile strength.

[0061] Comparing Comparative Example 2 with Example 4, it can be seen that the unmodified SiO2 has poor compatibility with the PVC matrix and the silicone resin shell, which leads to particle agglomeration, forming large light scatterers that block light from passing through and reduce light transmittance. At the same time, the agglomerates become weak points inside the membrane, which are prone to breakage under stress, resulting in reduced tensile strength.

[0062] Comparing Comparative Example 3 with Example 4, it can be seen that without the addition of matting microspheres, light incident on the membrane surface has almost no effective scattering effect, and most of the light undergoes specular reflection, resulting in extremely low haze and high gloss.

[0063] Comparing Comparative Example 4 with Example 4, it can be seen that the proportions of ultramarine blue and ultramarine violet are high, while the proportion of white pigment is too low. The haze and gloss are basically normal, but the light transmittance is reduced. The color powder ratio of the present invention can effectively balance the color-tuning effect and light transmittance of the film, and avoid performance deterioration caused by improper color powder ratio.

[0064] Comparing Comparative Example 5 with Example 4, it can be seen that insufficient use of environmentally friendly oil and excessive use of soybean oil lead to excessive plasticization of the membrane and a decrease in tensile strength.

[0065] The PVC matting film prepared by this invention has a close ratio of transverse to longitudinal tensile strength, exhibiting good mechanical isotropy. This indicates that the core-shell matting microspheres are uniformly dispersed in the PVC matrix and firmly bonded to the matrix, without introducing obvious weak interfaces or directional defects. The haze and transmittance of the PVC matting film are relatively balanced, resulting in good matting performance.

[0066] See actual product image of PVC matte film. Figure 2 The PVC matte film has a uniform matte texture, with no obvious mirror reflection, and the film surface is flat.

[0067] The present invention has been described above by way of example. It should be noted that any simple modifications, alterations or other equivalent substitutions that can be made by those skilled in the art without creative effort without departing from the core of the present invention fall within the protection scope of the present invention.

Claims

1. A PVC matte film, characterized in that, The PVC matte film comprises the following components in parts by weight: 80-90 parts PVC resin, 20-25 parts environmentally friendly oil, 2-5 parts soybean oil, 3-5 parts SiO2 matting microspheres, 0.08-0.16 parts color powder mixture, 1.5-3.5 parts stabilizer, and 0.2-0.4 parts synergist; The SiO2 extinction microspheres have a core-shell structure; wherein the core layer is mesoporous SiO2, and the shell layer is organosilicon resin; the mesoporous... for Type, aperture Specific surface area Particle size ; The PVC matte film also includes 0.3-0.6 parts of lubricant and 2-4 parts of toughening agent; the synergist is epoxy fatty acid methyl ester; the toughening agent is methyl methacrylate-butadiene-styrene copolymer; The preparation method of the SiO2 matting microspheres includes the following steps: (1) Mix mesoporous SiO2 with anhydrous ethanol evenly, add stearic acid coupling agent and heat to 40-50℃ for 1-1.5h, add silane coupling agent KH-570 and react for 30-45min to obtain mesoporous SiO2 dispersion. (2) Mix methylphenyl silicone resin, mesoporous SiO2 dispersion and anhydrous ethanol evenly, add dibutyltin dilaurate and polyethylene glycol 400 and mix evenly to obtain SiO2 matting microsphere precursor system; (3) Nitrogen gas was introduced into the SiO2 matting microsphere precursor system, the temperature was raised to carry out the reaction, and the mixture was cooled and dried to obtain SiO2 matting microspheres. The color powder mixture is prepared by mixing ultramarine, ultramarine blue and white pigments in a mass ratio of (13-15):(0.4-0.5):

1.

2. The PVC matte film according to claim 1, characterized in that, In step (1), the ratio of the amount of mesoporous SiO2, anhydrous ethanol, stearic acid coupling agent and silane coupling agent KH-570 is 100g∶(350-550)mL∶(1.1-1.8)g∶(0.6-0.9)g.

3. The PVC matte film according to claim 1, characterized in that, The ratio of mesoporous SiO2, methylphenyl silicone resin, anhydrous ethanol, dibutyltin dilaurate and polyethylene glycol 400 is 100g:(15-20)g:(50-100)mL:(0.1-0.2)g:(0.3-0.5)g.

4. The PVC matte film according to claim 1, characterized in that, In step (3), the reaction temperature is 50-60℃ and the reaction time is 2-3h.

5. A method for preparing a PVC matte film according to any one of claims 1-4, characterized in that, Includes the following steps: Weigh the above components according to the formula, mix them evenly in a high-speed mixer, extrude and granulate them using a twin-screw extruder, and cast them into a film to obtain a PVC matte film.

6. The method for preparing a PVC matte film according to claim 5, characterized in that, The extrusion temperature is 140-180℃.

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