High-weather-resistance and scratch-resistance PVC wallboard and preparation method thereof

Abstract

The invention relates to a high-weather-resistance scratch-resistant PVC wallboard and a preparation method thereof, and belongs to the technical field of new material preparation. The PVC wallboard disclosed by the invention is mainly prepared from a surface-layer composition and a bottom-layer composition through a co-extrusion process. The PVC wallboard prepared by the preparation method disclosed by the invention is relatively high in hardness and strength, relatively high in scratch resistance and relatively good in weather resistance.

Description

Technical Field

[0001] This invention belongs to the field of new material preparation technology, and relates to a high weather-resistant and scratch-resistant PVC wall panel and its preparation method. Background Technology

[0002] With improvements in production technology, many decorative materials are gradually shifting towards newer models, and PVC wall panels are now a fashionable favorite in the market. In the current market for interior and exterior decorative materials, PVC wall panels (polyvinyl chloride wall panels) occupy an important place due to their waterproof and moisture-proof properties, ease of installation, and high cost-effectiveness. However, for consumers, the durability of wall panels remains the most crucial consideration, with weather resistance (resistance to aging and deformation) and scratch resistance (susceptibility to scratches) being key factors determining the product's lifespan.

[0003] Weather resistance refers to a material's ability to resist erosion from natural environmental factors such as sunlight, temperature changes, and wind and rain. For PVC wall panels, this is one of their weakest points. In practical applications, if the wall panels are installed outdoors in direct sunlight or near heat sources (such as kitchen stoves), prolonged exposure to heat can easily cause warping, buckling, or even detachment. Alternatively, under long-term exposure to sun and rain, inferior or untreated PVC wall panels may still face the risks of fading, surface powdering, and molecular chain breakage, leading to brittleness.

[0004] Scratch resistance directly affects whether a wall surface can maintain its appearance over long-term use. The performance of PVC wall panels in this regard varies greatly, depending on their density and surface treatment process. Traditional ordinary PVC boards (such as PVC foam boards) have low surface hardness. According to tests, the pencil hardness of low-density foam boards is only 1-2H. When subjected to friction from keys, metal zippers, or hard objects, they are prone to plastic deformation, leaving dents or scratches that cannot be removed by wiping. If scratches damage the printed decorative layer or coating on the surface, it not only affects the appearance but may also create a potential problem for subsequent stain penetration. Especially in kitchens or public places, frequent wiping and friction will cause the surface gloss of ordinary PVC boards to quickly decrease, making them look old. Summary of the Invention

[0005] The main objective of this invention is to provide a high weather-resistant and scratch-resistant PVC wall panel and its preparation method. This PVC wall panel can meet the weather resistance requirements of outdoor wall panels and is also suitable for indoor wall decoration that is frequently touched.

[0006] The present invention employs the following technical solutions to achieve the above objectives: A highly weather-resistant and scratch-resistant PVC wall panel is mainly prepared by a co-extrusion process using a top and bottom layer combination. Specifically, the top layer composition contains 100 parts by weight of PVC resin, 20-25 parts by weight of glass fiber reinforced ABS material, 10-15 parts by weight of vinyl ester resin, 4-6 parts by weight of calcium-zinc stabilizer, 3-5 parts by weight of modified nano-silica, 8-12 parts by weight of rutile titanium dioxide, 10-15 parts by weight of nano-calcium carbonate, and 0.3-0.5 parts by weight of ethylhexyl methoxycinnamate. The composition contains, by weight, 0.3-0.5 parts of 2-hydroxy-4-methoxybenzophenone and 0.8-1.2 parts of oxidized polyethylene wax; the base composition contains 100 parts of PVC resin, 4-5 parts of calcium-zinc stabilizer, 6-8 parts of chlorinated polyethylene, 1.5-2.5 parts of processing aid, 2-4 parts of titanium dioxide, 40-60 parts of calcium carbonate, 5-8 parts of flame retardant, 0.5-0.8 parts of stearic acid and 0.4-0.6 parts of polyethylene wax.

[0007] Furthermore, the flame retardant in the underlying composition is a mixture of antimony trioxide and zinc borate in a weight ratio of 3:1.

[0008] Furthermore, the method for preparing the modified nano-silica in the surface composition is as follows: Nano-silica was dispersed in an ethanol-water mixture, and hexadecyltrimethoxysilane was added to adjust the pH to 4.5-5.0. The temperature was then raised to 75-80℃ and maintained for 4-6 hours. The temperature was then lowered to 60-70℃, and methylglucose sesquistearate was added and maintained for 2-3 hours. The temperature was then raised to 80-85℃, and trimethylsiloxysilicate was added and maintained for 2-3 hours. The product was washed with anhydrous ethanol and dried at 60-70℃ to obtain modified nano-silica.

[0009] Furthermore, the amount of hexadecyltrimethoxysilane added is 3% to 5% of the mass of nano-silica; the amount of methylglucose sesquistearate added is 5% to 8% of the mass of nano-silica; and the amount of trimethylsiloxysilicate added is 2% to 3% of the mass of nano-silica.

[0010] This invention provides a method for preparing the high weather-resistant and scratch-resistant PVC wall panel, which mainly includes the following steps: Step 1, Surface raw material pretreatment: PVC resin, glass fiber reinforced ABS material, and vinyl ester resin are added to a hot mixer and heated to 80°C. Calcium-zinc stabilizer and modified nano-silica are then added and mixed. The temperature is raised to 90°C, and rutile titanium dioxide, nano-calcium carbonate, ethylhexyl methoxycinnamate, and 2-hydroxy-4-methoxybenzophenone are added and mixed. The temperature is raised to 110~120°C, and oxidized polyethylene wax is added. The mixture is then heated to 125°C and transferred to a cold mixer and cooled to 40~50°C to obtain the surface raw material. Step 2, Pretreatment of bottom raw materials: PVC resin, calcium-zinc stabilizer, and chlorinated polyethylene are added to a hot mixer. When the temperature reaches 80°C, processing aids, titanium dioxide, calcium carbonate, and flame retardant are added and mixed. When the temperature reaches 100-110°C, stearic acid and polyethylene wax are added and mixed. After reaching 120°C, the material is transferred to a cold mixer and cooled to 45°C to obtain the bottom raw material. Step 3, extrusion granulation: The cooled surface material and bottom material are plasticized and granulated separately through an extruder to obtain surface material granules and bottom material granules; the granules are dried at 80℃ for 3~4 hours for later use. Step 4, co-extrusion molding: The main extruder temperature is 175~185℃, which plasticizes the bottom layer material granules into a molten state; the auxiliary extruder temperature is 170~180℃, which plasticizes the surface layer material granules; the co-extrusion die is 185~190℃; after extrusion, it enters the shaping tank, is vacuum shaped, and then gradually cooled and shaped in a 15~20℃ cooling water tank. Finally, it is pulled out by a traction machine, cut according to specifications, and then post-processed.

[0011] Furthermore, in step 3, the extrusion temperatures are: 160-170℃ in the barrel section, 170-180℃ in the compression section, and 175-185℃ in the homogenization section.

[0012] The present invention has the following beneficial effects: To enhance the scratch resistance and weather resistance of PVC wall panels, silica is typically added. However, while simply adding silica provides some improvement, the effect is not ideal, and silica is prone to agglomeration and uneven dispersion. Therefore, this invention involves appropriate modification of the nano-silica. Associative silane coupling agents, methyl glucosesquistearate, and trimethylsiloxysilicate are used to hydrophobically modify the surface of the nano-silica. This modification not only improves the hydrophobic properties of the nano-silica but also prevents the agglomeration of silica ions, enhancing its dispersion stability in the matrix. The hydrophobically modified nano-silica can be uniformly dispersed in PVC, forming a hydrophobic barrier that isolates water and corrosive substances, reducing surface energy. Nano-silica can absorb and scatter ultraviolet rays in sunlight. It works synergistically with other ultraviolet absorbers to reduce the damaging effect of ultraviolet rays on the PVC molecular chain and delay the yellowing, differentiation, and decline in mechanical properties of wall panels under long-term sun exposure. At the same time, uniformly dispersed nano-silica has high hardness and can form a rigid skeleton on and inside the PVC surface. When the wall panel surface is scratched by external force, it can effectively resist the formation of scratches and improve the hardness, wear resistance, and scratch resistance of the wall panel.

[0013] The components and methods provided by this invention can significantly improve the outdoor durability, surface abrasion resistance, and scratch resistance of PVC wall panels, enabling PVC wall panels to meet both indoor and outdoor use requirements. Detailed Implementation

[0014] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art will fall within the scope of protection of the claims of this application.

[0015] Example 1 Step 1, Surface raw material pretreatment: First, nano-silica was dispersed in an ethanol-water mixture (95:5, v / v), and hexadecyltrimethoxysilane (3% by mass of nano-silica) was added. The pH was adjusted to 4.5, and the temperature was raised to 80°C and maintained for 4 hours. Then, the temperature was lowered to 70°C, and methylglucose sesquistearate (8% by mass of nano-silica) was added and maintained for 3 hours. The temperature was then raised to 85°C, and trimethylsiloxysilicate (2% by mass of nano-silica, dispersed in cyclopentamethoxysilane at a ratio of 1:3, w / w) was added and maintained for 2 hours. The product was washed with anhydrous ethanol and dried at 70°C to obtain modified nano-silica. This process was carried out in a high-speed mixer. Next, 100 parts by weight of PVC resin, 25 parts by weight of glass fiber reinforced ABS material, and 10 parts by weight of vinyl ester resin are added to a hot mixer and heated to 80°C. Then, 6 parts by weight of calcium-zinc stabilizer and 3 parts by weight of modified nano-silica are added and mixed. The temperature is then raised to 90°C, and 12 parts by weight of rutile titanium dioxide, 10 parts by weight of nano-calcium carbonate, 0.5 parts by weight of ethylhexyl methoxycinnamate, and 0.3 parts by weight of 2-hydroxy-4-methoxybenzophenone are added and mixed. The temperature is then raised to 120°C, and 0.8 parts by weight of oxidized polyethylene wax are added. The mixture is then heated to 125°C and mixed. The material is then transferred to a cold mixer and cooled to 50°C to obtain the surface material. Step 2, Pretreatment of bottom raw materials: 100 parts by weight of PVC resin, 5 parts by weight of calcium-zinc stabilizer, and 6 parts by weight of chlorinated polyethylene were added to a hot mixer. When the temperature reached 80°C, 2.5 parts by weight of processing aid (ACR-401), 2 parts by weight of titanium dioxide, 60 parts by weight of calcium carbonate, and 5 parts by weight of flame retardant (antimony trioxide-zinc borate = 3:1, w / w) were added and mixed. When the temperature reached 110°C, 0.8 parts by weight of stearic acid and 0.4 parts by weight of polyethylene wax were added and mixed. After reaching 120°C, the material was transferred to a cold mixer and cooled to 45°C to obtain the bottom raw material. Step 3, extrusion granulation: The cooled surface material and bottom material are plasticized and granulated by extruder to obtain surface material granules and bottom material granules respectively; extrusion temperature: barrel section 170℃, compression section 180℃, homogenization section 185℃; screw speed: 400 rpm; the granules are dried at 80℃ for 4 hours for later use. Step 4, co-extrusion molding: Set the main extruder temperature to 185℃ to plasticize the bottom layer material granules into a molten state; set the auxiliary extruder temperature to 170℃ to plasticize the surface layer material granules; set the co-extrusion die temperature to 185℃; after extrusion at 3m / min, the material enters the shaping tank for vacuum shaping, then is gradually cooled and shaped in a 20℃ cooling water tank, and finally pulled out by a traction machine (3m / min), cut according to specifications, and undergo post-processing.

[0016] Example 2 Step 1, Surface raw material pretreatment: First, nano-silica was dispersed in an ethanol-water mixture (95:5, v / v), and hexadecyltrimethoxysilane (5% by mass of nano-silica) was added. The pH was adjusted to 5.0, and the temperature was raised to 75°C and maintained for 6 hours. Then, the temperature was lowered to 60°C, and methylglucose sesquistearate (5% by mass of nano-silica) was added and maintained for 2 hours. The temperature was then raised to 80°C, and trimethylsiloxysilicate (3% by mass of nano-silica, dispersed in cyclopentamethoxysilane at a ratio of 1:3, w / w) was added and maintained for 3 hours. The product was washed with anhydrous ethanol and dried at 60°C to obtain modified nano-silica. This process was carried out in a high-speed mixer. Next, 100 parts by weight of PVC resin, 20 parts by weight of glass fiber reinforced ABS material, and 15 parts by weight of vinyl ester resin are added to a hot mixer and heated to 80°C. Then, 4 parts by weight of calcium-zinc stabilizer and 5 parts by weight of modified nano-silica are added and mixed. The temperature is then raised to 90°C, and 8 parts by weight of rutile titanium dioxide, 15 parts by weight of nano-calcium carbonate, 0.3 parts by weight of ethylhexyl methoxycinnamate, and 0.5 parts by weight of 2-hydroxy-4-methoxybenzophenone are added and mixed. The temperature is then raised to 110°C, and 1.2 parts by weight of oxidized polyethylene wax are added. The temperature is then raised to 125°C and mixed. The material is then transferred to a cold mixer and cooled to 40°C to obtain the surface raw material. Step 2, Pretreatment of bottom raw materials: 100 parts by weight of PVC resin, 4 parts by weight of calcium-zinc stabilizer, and 8 parts by weight of chlorinated polyethylene were added to a hot mixer. When the temperature reached 80°C, 1.5 parts by weight of processing aid (ACR-401), 4 parts by weight of titanium dioxide, 40 parts by weight of calcium carbonate, and 8 parts by weight of flame retardant (antimony trioxide-zinc borate = 3:1, w / w) were added and mixed. When the temperature reached 100°C, 0.5 parts by weight of stearic acid and 0.6 parts by weight of polyethylene wax were added and mixed. After reaching 120°C, the material was transferred to a cold mixer and cooled to 45°C to obtain the bottom raw material. Step 3, extrusion granulation: The cooled surface material and bottom material are plasticized and granulated by extruder to obtain surface material granules and bottom material granules respectively; extrusion temperature: barrel section 160℃, compression section 170℃, homogenization section 175℃; screw speed: 400 rpm; the granules are dried at 80℃ for 3 hours for later use. Step 4, co-extrusion molding: Set the main extruder temperature to 175℃ to plasticize the bottom layer granules into a molten state; set the auxiliary extruder temperature to 180℃ to plasticize the surface layer granules; set the co-extrusion die temperature to 190℃; after extrusion at 1.5m / min, the material enters the shaping tank for vacuum shaping, then is gradually cooled and shaped in a 15℃ cooling water tank, and finally pulled out by a traction machine (1.5m / min), cut according to specifications, and undergo post-processing.

[0017] Example 3 Step 1, Surface raw material pretreatment: First, nano-silica was dispersed in an ethanol-water mixture (95:5, v / v), and hexadecyltrimethoxysilane (4% by mass of nano-silica) was added. The pH was adjusted to 5.0, and the temperature was raised to 75°C and maintained for 5 hours. Then, the temperature was lowered to 70°C, and methylglucose sesquistearate (6% by mass of nano-silica) was added and maintained for 3 hours. The temperature was then raised to 80°C, and trimethylsiloxysilicate (3% by mass of nano-silica, dispersed in cyclopentamethoxysilane at a ratio of 1:3, w / w) was added and maintained for 3 hours. The product was washed with anhydrous ethanol and dried at 70°C to obtain modified nano-silica. This process was carried out in a high-speed mixer. Next, 100 parts by weight of PVC resin, 23 parts by weight of glass fiber reinforced ABS material, and 12 parts by weight of vinyl ester resin are added to a hot mixer and heated to 80°C. Then, 5 parts by weight of calcium-zinc stabilizer and 4 parts by weight of modified nano-silica are added and mixed. The mixture is then heated to 90°C and 10 parts by weight of rutile titanium dioxide, 13 parts by weight of nano-calcium carbonate, 0.4 parts by weight of ethylhexyl methoxycinnamate, and 0.4 parts by weight of 2-hydroxy-4-methoxybenzophenone are added and mixed. The mixture is then heated to 110°C and 1.0 part by weight of oxidized polyethylene wax is added. Finally, the mixture is heated to 125°C and mixed. The material is then transferred to a cold mixer and cooled to 50°C to obtain the surface material. Step 2, Pretreatment of bottom raw materials: 100 parts by weight of PVC resin, 4 parts by weight of calcium-zinc stabilizer, and 7 parts by weight of chlorinated polyethylene were added to a hot mixer. When the temperature reached 80°C, 2.0 parts by weight of processing aid (ACR-401), 3 parts by weight of titanium dioxide, 50 parts by weight of calcium carbonate, and 6 parts by weight of flame retardant (antimony trioxide-zinc borate = 3:1, w / w) were added and mixed. When the temperature reached 110°C, 0.6 parts by weight of stearic acid and 0.5 parts by weight of polyethylene wax were added and mixed. After reaching 120°C, the material was transferred to a cold mixer and cooled to 45°C to obtain the bottom raw material. Step 3, extrusion granulation: The cooled surface material and bottom material are plasticized and granulated by extruder to obtain surface material granules and bottom material granules respectively; extrusion temperature: barrel section 170℃, compression section 170℃, homogenization section 185℃; screw speed: 400 rpm; the granules are dried at 80℃ for 3 hours for later use. Step 4, co-extrusion molding: Set the main extruder temperature to 180℃ to plasticize the bottom layer material granules into a molten state; set the auxiliary extruder temperature to 170℃ to plasticize the surface layer material granules; set the co-extrusion die temperature to 185℃; after extrusion at 2.0 m / min, the material enters the shaping tank for vacuum shaping, and then is gradually cooled and shaped in a 15℃ cooling water tank. Finally, it is pulled out by a traction machine (2.0 m / min), cut according to specifications, and then post-processed.

[0018] Comparative Example 1 Step 1, Raw material pretreatment: 100 parts by weight of PVC resin, 23 parts by weight of glass fiber reinforced ABS material, and 12 parts by weight of vinyl ester resin were added to a hot mixer and heated to 80°C. 5 parts by weight of calcium-zinc stabilizer and 4 parts by weight of nano-silica were added and mixed. The temperature was then raised to 90°C, and 10 parts by weight of rutile titanium dioxide, 13 parts by weight of nano-calcium carbonate, 0.4 parts by weight of ethylhexyl methoxycinnamate, and 0.4 parts by weight of 2-hydroxy-4-methoxybenzophenone were added and mixed. The temperature was then raised to 110°C, and 1.0 part by weight of oxidized polyethylene wax was added. The temperature was then raised to 125°C and mixed. The mixture was then transferred to a cold mixer, cooled to 50°C, and allowed to stand for maturation to obtain the raw material. Step 2, extrusion molding: The matured raw material is extruded and shaped through an extruder. The extrusion temperature is 180℃ in the barrel area and 180℃ in the die area. The screw speed is 400 rpm. After flowing through the die, it enters the shaping tank for vacuum shaping. Then it is gradually cooled and shaped in a 15℃ cooling water tank. Finally, it is pulled out by a traction machine (2.0m / min), cut according to specifications, and then processed.

[0019] Comparative Example 2 Step 1, Surface raw material pretreatment: First, nano-silica and hexadecyltrimethoxysilane (2% by mass of nano-silica) are mixed in a high-speed mixer to obtain modified nano-silica; Next, 100 parts by weight of PVC resin, 23 parts by weight of glass fiber reinforced ABS material, and 12 parts by weight of vinyl ester resin are added to a hot mixer and heated to 80°C. Then, 5 parts by weight of calcium-zinc stabilizer and 4 parts by weight of modified nano-silica are added and mixed. The mixture is then heated to 90°C and 10 parts by weight of rutile titanium dioxide, 13 parts by weight of nano-calcium carbonate, 0.4 parts by weight of ethylhexyl methoxycinnamate, and 0.4 parts by weight of 2-hydroxy-4-methoxybenzophenone are added and mixed. The mixture is then heated to 110°C and 1.0 part by weight of oxidized polyethylene wax is added. Finally, the mixture is heated to 125°C and mixed. The material is then transferred to a cold mixer and cooled to 50°C to obtain the surface material. Step 2, Pretreatment of bottom raw materials: 100 parts by weight of PVC resin, 4 parts by weight of calcium-zinc stabilizer, and 7 parts by weight of chlorinated polyethylene were added to a hot mixer. When the temperature reached 80°C, 2.0 parts by weight of processing aid (ACR-401), 3 parts by weight of titanium dioxide, 50 parts by weight of calcium carbonate, and 6 parts by weight of flame retardant (antimony trioxide-zinc borate = 3:1, w / w) were added and mixed. When the temperature reached 110°C, 0.6 parts by weight of stearic acid and 0.5 parts by weight of polyethylene wax were added and mixed. After reaching 120°C, the material was transferred to a cold mixer and cooled to 45°C to obtain the bottom raw material. Step 3, extrusion granulation: The cooled surface material and bottom material are plasticized and granulated by extruder to obtain surface material granules and bottom material granules respectively; extrusion temperature: barrel section 170℃, compression section 170℃, homogenization section 185℃; screw speed: 400 rpm; the granules are dried at 80℃ for 3 hours for later use. Step 4, co-extrusion molding: Set the main extruder temperature to 180℃ to plasticize the bottom layer material granules into a molten state; set the auxiliary extruder temperature to 170℃ to plasticize the surface layer material granules; set the co-extrusion die temperature to 185℃; after extrusion at 2.0 m / min, the material enters the shaping tank for vacuum shaping, and then is gradually cooled and shaped in a 15℃ cooling water tank. Finally, it is pulled out by a traction machine (2.0 m / min), cut according to specifications, and then post-processed.

[0020] Comparative Example 3 Step 1, Surface raw material pretreatment: First, nano-silica was dispersed in an ethanol-water mixture (95:5, v / v), and hexadecyltrimethoxysilane (4% of the mass of nano-silica) was added. The pH was adjusted to 5.0, the temperature was raised to 75°C, and the mixture was kept at this temperature for 5 hours. Then, the temperature was raised to 80°C, and trimethylsiloxysilicate (3% of the mass of nano-silica, dispersed in cyclopentamethoxysilane at a ratio of 1:3, w / w) was added. The mixture was kept at this temperature for 3 hours, the product was washed with anhydrous ethanol, and dried at 70°C to obtain modified nano-silica. This process was carried out in a high-speed mixer. Next, 100 parts by weight of PVC resin, 23 parts by weight of glass fiber reinforced ABS material, and 12 parts by weight of vinyl ester resin are added to a hot mixer and heated to 80°C. Then, 5 parts by weight of calcium-zinc stabilizer and 4 parts by weight of modified nano-silica are added and mixed. The mixture is then heated to 90°C and 10 parts by weight of rutile titanium dioxide, 13 parts by weight of nano-calcium carbonate, 0.4 parts by weight of ethylhexyl methoxycinnamate, and 0.4 parts by weight of 2-hydroxy-4-methoxybenzophenone are added and mixed. The mixture is then heated to 110°C and 1.0 part by weight of oxidized polyethylene wax is added. Finally, the mixture is heated to 125°C and mixed. The material is then transferred to a cold mixer and cooled to 50°C to obtain the surface material. Step 2, Pretreatment of bottom raw materials: 100 parts by weight of PVC resin, 4 parts by weight of calcium-zinc stabilizer, and 7 parts by weight of chlorinated polyethylene were added to a hot mixer. When the temperature reached 80°C, 2.0 parts by weight of processing aid (ACR-401), 3 parts by weight of titanium dioxide, 50 parts by weight of calcium carbonate, and 6 parts by weight of flame retardant (antimony trioxide-zinc borate = 3:1, w / w) were added and mixed. When the temperature reached 110°C, 0.6 parts by weight of stearic acid and 0.5 parts by weight of polyethylene wax were added and mixed. After reaching 120°C, the material was transferred to a cold mixer and cooled to 45°C to obtain the bottom raw material. Step 3, extrusion granulation: The cooled surface material and bottom material are plasticized and granulated by extruder to obtain surface material granules and bottom material granules respectively; extrusion temperature: barrel section 170℃, compression section 170℃, homogenization section 185℃; screw speed: 400 rpm; the granules are dried at 80℃ for 3 hours for later use. Step 4, co-extrusion molding: Set the main extruder temperature to 180℃ to plasticize the bottom layer material granules into a molten state; set the auxiliary extruder temperature to 170℃ to plasticize the surface layer material granules; set the co-extrusion die temperature to 185℃; after extrusion at 2.0 m / min, the material enters the shaping tank for vacuum shaping, and then is gradually cooled and shaped in a 15℃ cooling water tank. Finally, it is pulled out by a traction machine (2.0 m / min), cut according to specifications, and then post-processed.

[0021] Performance Testing: Weather Resistance and Scratch Resistance Testing of PVC Wall Panels The PVC wall panels obtained in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests, and then placed in an artificial aging test instrument for aging tests according to GB / T16422.3-2014 (UVA-340, 8h irradiation, 60℃, 4h condensation, 50% humidity, no spraying). The performance was measured after aging for 360h and 1000h, respectively. The test results are shown in Table 1 below.

[0022] Table 1 Weather resistance test results of PVC wall panels As shown in Table 1, the PVC wall panels prepared in Examples 1-3 have significantly higher hardness than those in Comparative Examples 1-3. Their tensile and flexural strengths before and after the aging test are also significantly higher than those in Comparative Examples 1-3. This demonstrates that the addition of modified nano-silica in this invention can significantly increase the hardness and strength of the PVC wall panels, resulting in higher weather resistance and scratch resistance. Comparative Example 1 did not use the traditional PVC preparation method; it added ordinary nano-silica, which had the lowest hardness and poor scratch resistance. Furthermore, after the aging test, its tensile and flexural strengths decreased significantly, indicating poor weather resistance. Comparative Example 2 used modified nano-silica modified only with a silane coupling agent, which improved hardness and strength, but the effect was not ideal. Comparative Example 3 lacked methylglucose sesquistearate in its nano-silica modification process, and its PVC wall panels still had lower hardness and strength than those in Examples 1-3 of this invention.

Claims

1. A highly weather-resistant and scratch-resistant PVC wall panel, characterized in that, The PVC wall panel is made by co-extrusion of a top and bottom layer. The surface composition contains 100 parts by weight of PVC resin, 20-25 parts by weight of glass fiber reinforced ABS material, 10-15 parts by weight of vinyl ester resin, 4-6 parts by weight of calcium zinc stabilizer, 3-5 parts by weight of modified nano silica, 8-12 parts by weight of rutile titanium dioxide, 10-15 parts by weight of nano calcium carbonate, 0.3-0.5 parts by weight of ethylhexyl methoxycinnamate, 0.3-0.5 parts by weight of 2-hydroxy-4-methoxybenzophenone, and 0.8-1.2 parts by weight of oxidized polyethylene wax. The base composition contains 100 parts by weight of PVC resin, 4-5 parts by weight of calcium-zinc stabilizer, 6-8 parts by weight of chlorinated polyethylene, 1.5-2.5 parts by weight of processing aid, 2-4 parts by weight of titanium dioxide, 40-60 parts by weight of calcium carbonate, 5-8 parts by weight of flame retardant, 0.5-0.8 parts by weight of stearic acid, and 0.4-0.6 parts by weight of polyethylene wax.

2. The PVC wall panel according to claim 1, characterized in that, The flame retardant in the underlying composition is a mixture of antimony trioxide and zinc borate.

3. The PVC wall panel according to claim 2, characterized in that, The weight ratio of antimony trioxide to zinc borate is 3:

1.

4. The PVC wall panel according to any one of claims 1-3, characterized in that, The method for preparing the modified nano-silica in the surface composition is as follows: Nano-silica was dispersed in an ethanol-water mixture, and hexadecyltrimethoxysilane was added to adjust the pH to 4.5-5.

0. The temperature was then raised to 75-80℃ and maintained for 4-6 hours. The temperature was then lowered to 60-70℃, and methylglucose sesquistearate was added and maintained for 2-3 hours. The temperature was then raised to 80-85℃, and trimethylsiloxysilicate was added and maintained for 2-3 hours. The product was washed with anhydrous ethanol and dried at 60-70℃ to obtain modified nano-silica.

5. The PVC wall panel according to claim 4, characterized in that, The amount of hexadecyltrimethoxysilane added is 3% to 5% of the mass of nano-silica.

6. The PVC wall panel according to claim 4, characterized in that, The amount of methyl glucosesquistearate added is 5-8% of the mass of nano-silica.

7. The PVC wall panel according to claim 4, characterized in that, The amount of trimethylsiloxysilicate added is 2-3% of the mass of nano-silica.

8. A method for preparing a PVC wall panel as described in any one of claims 1-7, characterized in that, Includes the following steps: Step 1, Surface raw material pretreatment: PVC resin, glass fiber reinforced ABS material, and vinyl ester resin are added to a hot mixer and heated to 80°C. Calcium-zinc stabilizer and modified nano-silica are then added and mixed. The temperature is raised to 90°C, and rutile titanium dioxide, nano-calcium carbonate, ethylhexyl methoxycinnamate, and 2-hydroxy-4-methoxybenzophenone are added and mixed. The temperature is raised to 110~120°C, and oxidized polyethylene wax is added. The mixture is then heated to 125°C and transferred to a cold mixer and cooled to 40~50°C to obtain the surface raw material. Step 2, Pretreatment of bottom raw materials: PVC resin, calcium-zinc stabilizer, and chlorinated polyethylene are added to a hot mixer. When the temperature reaches 80°C, processing aids, titanium dioxide, calcium carbonate, and flame retardant are added and mixed. When the temperature reaches 100-110°C, stearic acid and polyethylene wax are added and mixed. After reaching 120°C, the material is transferred to a cold mixer and cooled to 45°C to obtain the bottom raw material. Step 3, extrusion granulation: The cooled surface material and bottom material are plasticized and granulated by extruder to obtain surface material granules and bottom material granules; the granules are dried at 80℃ for 3~4 hours for later use. Step 4, co-extrusion molding: The main extruder temperature is 175~185℃, which plasticizes the bottom layer material granules into a molten state; the auxiliary extruder temperature is 170~180℃, which plasticizes the surface layer material granules; the co-extrusion die is 185~190℃; after extrusion, it enters the shaping tank, is vacuum shaped, and then gradually cooled and shaped in a 15~20℃ cooling water tank. Finally, it is pulled out by a traction machine, cut according to specifications, and then post-processed.

9. The method for preparing PVC wall panels according to claim 9, characterized in that, In step 3, the extrusion temperatures are: 160-170℃ in the barrel section, 170-180℃ in the compression section, and 175-185℃ in the homogenization section.

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