Lightweight diatom ooze PVC wallboard and preparation method thereof

Abstract

The application discloses a light diatom ooze PVC wallboard and a preparation method thereof, and relates to the technical field of building materials.The light diatom ooze PVC wallboard comprises the following raw materials in parts by weight: 40-75 parts of PVC resin powder, 15-40 parts of modified composite calcium powder, 5-15 parts of modified diatom ooze powder, 0.5-2 parts of a coupling agent, 0-1.5 parts of a foaming agent, 3-6 parts of an environment-friendly stabilizer, 1-3 parts of a lubricant, 3-10 parts of a toughening agent and 0.5-1.5 parts of a processing aid.The modified composite calcium powder and the modified diatom ooze powder are added to significantly improve the impact resistance, scratch resistance and environmental protection of the wallboard;and through the layered design of the same raw materials but different content, the light diatom ooze PVC wallboard prepared realizes the optimal balance of mechanical properties and functional characteristics, has the properties of decoration, safety and environmental protection, and can be widely applied to the fields of fabricated buildings, indoor partition walls, fireproof suspended ceilings and the like, and has significant market competitiveness.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building materials, in particular to a light diatom ooze PVC wallboard and a preparation method thereof. BACKGROUND

[0002] With the increasing demand of the state for energy saving and environmental protection of building decoration materials and the increasing scarcity of wood resources, wood is replaced by plastic, which becomes the development direction of green building materials in China. PVC co-extrusion foam board is widely used in indoor decoration, public building partition, floor and other fields due to its small density, low thermal conductivity, dimensional stability, corrosion resistance, moisture resistance, good sound absorption performance, excellent flame retardant performance and chemical resistance, and easy to be processed by conventional machinery. PVC co-extrusion foam board, also known as snow board and Andy board, is a kind of PVC low foaming board, which is made of PVC resin as the main raw material, a certain amount of foaming agent and other additives, and is extruded and processed. At present, the PVC industry is developing rapidly all over the world, and has broad prospects, but the toughness of the PVC co-extrusion foam board is not enough, it is easy to break, and the foaming process is difficult to control, so the performance of the foam board manufactured is difficult to meet the use requirements of people.

[0003] Although PVC foam board has such a wide application space, its actual market share is low, especially in home decoration materials. The main restricting factor is that the products are of different quality, the products are not satisfactory in strength, rigidity, thermal stability and other aspects, and there is a safety hazard when used. In order to improve the comprehensive performance of PVC board, the most common method is to use high molecular materials and inorganic fillers to modify the blending. Traditional PVC wallboard uses calcium powder as filler, but has problems of insufficient impact resistance, poor scratch resistance and the like. Diatom ooze has good function of purifying indoor air, which can improve environmental performance, but its compatibility with PVC matrix is poor, which affects the mechanical properties. Therefore, the existing PVC co-extrusion foam board has defects of insufficient impact resistance, poor wear resistance and insufficient environmental performance, so that the use of the technology is very limited. SUMMARY

[0004] The purpose of the present application is to provide a light diatom ooze PVC wallboard and a preparation method thereof, which solves the following technical problems:

[0005] The existing PVC co-extrusion foam board used for wallboard material has problems of insufficient impact resistance, poor scratch resistance and insufficient environmental performance.

[0006] The purpose of the present application can be achieved by the following technical solutions:

[0007] A light diatom ooze PVC wallboard, at least comprising the following raw materials by weight:

[0008] 40-75 parts PVC resin powder, 15-40 parts modified composite calcium powder, 5-15 parts modified diatomaceous earth powder, 0.5-2 parts coupling agent, 0-1.5 parts foaming agent, 3-6 parts environmentally friendly stabilizer, 1-3 parts lubricant, 3-10 parts toughening agent, and 0.5-1.5 parts processing aid.

[0009] Preferably, the lightweight diatomaceous earth PVC wall panel includes at least a PVC layer and a PVC foam layer, wherein the PVC foam layer is disposed between the two PVC layers.

[0010] Preferably, the PVC layer comprises at least the following raw materials by weight: 60-75 parts PVC resin powder, 15-25 parts modified composite calcium powder, 5-15 parts modified diatomaceous earth powder, 3-6 parts environmentally friendly stabilizer, 1.5-3 parts lubricant, 3-8 parts toughening agent, 0.5-1.5 parts coupling agent, and 0.5-1.5 parts processing aid.

[0011] The PVC foam layer comprises at least the following raw materials by weight: 40-60 parts PVC resin powder, 20-40 parts modified composite calcium powder, 5-15 parts modified diatomaceous earth powder, 0.8-1.5 parts foaming agent, 0.5-2 parts coupling agent, 3-6 parts environmentally friendly stabilizer, 1-3 parts lubricant, 3-10 parts toughening agent, and 0.5-1.5 parts processing aid.

[0012] Preferably, the preparation method of the modified diatomaceous earth includes the following steps:

[0013] Diatomaceous earth is added to hydrochloric acid solution, washed and dried to obtain activated diatomaceous earth;

[0014] The activated diatomaceous earth was added to the hydrolysate of the silane coupling agent, washed and dried to obtain modified diatomaceous earth.

[0015] Preferably, the mass ratio of the diatomaceous earth to the silane coupling agent is 100:1-2.

[0016] Preferably, the preparation method of modified composite calcium powder includes the following steps:

[0017] Sodium carbonate solution is added to calcium chloride solution, then barium chloride solution is added, and sodium carbonate solution is added again. The mixture is precipitated, filtered, washed, and dried to obtain barium carbonate-coated calcium sulfate.

[0018] Sulfur trioxide gas is passed into the barium carbonate-coated calcium sulfate to obtain composite calcium powder;

[0019] The composite calcium powder was added to deionized water, stirred, and then the hydrolyzed surface modifier was added. The mixture was reacted, filtered, washed, and dried to obtain the modified composite calcium powder.

[0020] Preferably, the molar ratio of calcium ions to barium ions in the modified composite calcium powder is 8-15:1.

[0021] Preferably, the mass ratio of the surface modifier to the composite calcium powder is 0.5-3:100.

[0022] Preferably, the coupling agent is any one or a mixture of aluminate coupling agents, borate coupling agents, silane coupling agents, titanate coupling agents, and maleic anhydride coupling agents; the environmentally friendly stabilizer is a calcium-zinc composite environmentally friendly stabilizer; the foaming agent is any one or a mixture of azodicarbonamide, sodium bicarbonate, or benzenesulfonyl hydrazine; the processing aid is any one or a mixture of polymethyl methacrylate, dioctyl phthalate, and ACR resin; the lubricant is any one or a mixture of stearic acid, calcium stearate, polyethylene wax, or oxidized polyethylene wax; and the toughening agent is any one or a mixture of chlorinated polyethylene, methyl methacrylate-butadiene-styrene copolymer, or ethylene-vinyl acetate copolymer.

[0023] A method for preparing lightweight diatomaceous earth PVC wall panels includes at least the following preparation steps:

[0024] The raw materials of the PVC layer and the PVC foam layer are added to a high-speed mixer according to the weight ratio to obtain the PVC layer mixture and the PVC foam layer mixture.

[0025] The PVC layer mixture and the PVC foam layer mixture are respectively added to the main extruder and the auxiliary extruder, and then extruded from the outlet of the main and auxiliary extruders. The mixture enters the mold through the feed inlet of the mold via the distributor, cools and solidifies, forming a structure with a PVC foam layer in the middle and PVC layers on the top and bottom, thus obtaining a lightweight diatomaceous earth PVC wall panel.

[0026] The beneficial effects of this invention are:

[0027] The lightweight diatomaceous earth PVC wall panel prepared by this invention is a three-layer PVC co-extruded foamed board, with a PVC board as the surface layer and a PVC foamed board as the core layer. In this invention, the PVC board and PVC foamed board comprise PVC resin powder, modified composite calcium powder, modified diatomaceous earth powder, coupling agent, foaming agent, environmentally friendly stabilizer, lubricant, toughening agent, and processing aids. The high resin content of the PVC board in this invention imparts high strength and wear resistance to the surface layer, while the high calcium powder filling in the PVC foamed board imparts impact resistance to the core layer. The lightweight diatomaceous earth PVC wall panel prepared by this invention has the advantages of flame retardancy, waterproofing, moisture resistance, insect resistance, zero formaldehyde, easy processing, and time and convenience. By adding modified composite calcium powder and modified diatomaceous earth, the impact resistance, scratch resistance, and environmental friendliness of the wall panel are significantly improved, while reducing formulation costs. This invention achieves an optimal balance between mechanical properties, functional characteristics, and production costs through a layered design using the same raw materials but different content. The PVC board of the lightweight diatomaceous earth PVC wall panel focuses on high strength and surface functionality, while the PVC foam board focuses on lightweight and multifunctionality. The synergy between the two creates a superior effect, combining decorative, safety, and environmental protection features. It can be widely used in prefabricated buildings, interior partitions, fireproof ceilings, and other fields, and has significant market competitiveness.

[0028] This invention utilizes a silane coupling agent to surface-modify diatomaceous earth, resulting in modified diatomaceous earth. The amino groups of the silane coupling agent form hydrogen bonds with the chlorine atoms of the PVC molecular chain, while the siloxane groups condense with the hydroxyl groups on the diatomaceous earth surface. This significantly enhances the interfacial bonding and functional properties between the diatomaceous earth and PVC. The porous structure of the modified diatomaceous earth absorbs stress and forms a "soft-hard" gradient with the rigid particles of modified composite calcium powder, improving the impact resistance of lightweight diatomaceous earth PVC wall panels. Furthermore, the porous structure of the diatomaceous earth can adsorb formaldehyde from the air, purifying the air and making it an excellent environmentally friendly interior decoration material that meets people's requirements for a healthy and environmentally friendly living environment.

[0029] The modified composite calcium powder prepared by this invention is surface-modified barium sulfate-modified calcium carbonate. Barium sulfate has high hardness and high density. After coating light calcium carbonate, it can significantly improve the compressive strength, wear resistance, and impact resistance of the composite material. As a filler added to PVC wall panels, it can better disperse stress and reduce crack propagation. The barium sulfate coating layer can reduce the surface energy of light calcium carbonate and inhibit its agglomeration tendency, thereby improving the uniformity of filler dispersion in the matrix. The surface of barium sulfate can be further modified by coupling agents to enhance the interfacial bonding force with the PVC matrix and reduce interfacial defects between the filler and the matrix. This invention can impart high performance to light calcium carbonate with only a small amount of barium sulfate through a coating process. Compared with directly using a high proportion of barium sulfate, the cost is significantly reduced, and the low cost and easy processing characteristics of light calcium carbonate are retained. Detailed Implementation

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1: The preparation method of modified composite calcium powder includes the following steps:

[0032] Prepare a 0.1 mol / L sodium carbonate solution and a 0.1 mol / L calcium chloride solution containing 0.7 wt% sodium hydroxide. Add sodium carbonate solution dropwise to the calcium chloride solution at 30°C until the remaining percentage of calcium ions is 30 wt%. Dissolve barium chloride in a small amount of water with a molar ratio of barium ions to calcium ions of 1:10 and add it to the above reaction system. Continue to add sodium carbonate solution dropwise at 30°C until both calcium and barium ions are completely precipitated. After filtration, washing, and drying, obtain barium carbonate-coated calcium carbonate.

[0033] Sulfur trioxide gas is passed into the above-mentioned barium carbonate-coated calcium carbonate, and barium carbonate is converted into barium sulfate through gas-solid conversion to obtain composite calcium powder.

[0034] The above-mentioned composite calcium powder was added to 100 mL of deionized water and stirred rapidly at room temperature for 1 hour. Then, the hydrolyzed surface modifier KH570 was added, with the mass ratio of composite calcium powder to surface modifier being 100:1. The mixture was reacted in a 70°C water bath for 2 hours, filtered, and the solid obtained by filtration was thoroughly washed with deionized water. After drying for 12 hours, the modified composite calcium powder was obtained by grinding.

[0035] Example 2: The preparation method of modified composite calcium powder includes the following steps:

[0036] Prepare a 0.1 mol / L sodium carbonate solution and a 0.1 mol / L calcium chloride solution containing 0.7 wt% sodium hydroxide. Add sodium carbonate solution dropwise to the calcium chloride solution at 30°C until the remaining percentage of calcium ions is 30 wt%. Dissolve barium chloride with a molar ratio of barium ions to calcium ions of 1:12 in a small amount of water and add it to the above reaction system. Continue to add sodium carbonate solution dropwise at 30°C until both calcium ions and barium ions are completely precipitated. After filtration, washing, and drying, obtain barium carbonate-coated calcium carbonate.

[0037] Sulfur trioxide gas is passed into the above-mentioned barium carbonate-coated calcium carbonate, and barium carbonate is converted into barium sulfate through gas-solid conversion to obtain composite calcium powder.

[0038] The above-mentioned composite calcium powder was added to 100 mL of deionized water and stirred rapidly at room temperature for 1 hour. Then, the hydrolyzed surface modifier KH570 was added, with the mass ratio of composite calcium powder to surface modifier being 100:1. The mixture was reacted in a 70°C water bath for 2 hours, filtered, and the solid obtained by filtration was thoroughly washed with deionized water. After drying for 12 hours, the modified composite calcium powder was obtained by grinding.

[0039] Example 3: The preparation method of modified diatomaceous earth includes the following steps:

[0040] Add 100g of dry diatomaceous earth to a 1mol / L hydrochloric acid solution, stir at room temperature for 4 hours, let stand for 10 minutes, discard the supernatant, wash, and dry at 60℃ for 24 hours to obtain activated diatomaceous earth mud.

[0041] Dissolve 1.5g KH-550 in a mixed solution of 450mL ethanol and 50mL water, stir magnetically for 10 minutes, and hydrolyze until transparent. Add the above diatom mud to the hydrolysate of silane coupling agent, heat in a water bath at 60℃, stir continuously for 4 hours, wash, and vacuum dry at 80℃ for 12 hours to obtain modified diatom mud.

[0042] Example 4: A lightweight diatomaceous earth PVC wall panel is made by the following method:

[0043] The raw materials for the PVC layer (65 parts by weight of PVC resin powder SG-5, 20 parts by weight of modified composite calcium powder prepared in Example 1, 10 parts by weight of modified diatomaceous earth powder prepared in Example 3, 5 parts by weight of calcium-zinc composite environmentally friendly stabilizer, 2 parts by weight of calcium stearate, 5 parts by weight of chlorinated polyethylene, 1 part by weight of silane coupling agent and 1 part by weight of methyl methacrylate-butadiene-styrene copolymer) and the PVC foam layer (50 parts by weight of PVC resin powder SG-5, 30 parts by weight of modified composite calcium powder prepared in Example 1, 10 parts by weight of modified diatomaceous earth powder prepared in Example 3, 1 part by weight of azodicarbonamide, 1 part by weight of silane coupling agent, 3 parts by weight of calcium-zinc composite environmentally friendly stabilizer, 2 parts by weight of calcium stearate, 5 parts by weight of chlorinated polyethylene and 1 part by weight of methyl methacrylate-butadiene-styrene copolymer) were added to a high-speed mixer to obtain the PVC layer mixture and the PVC foam layer mixture.

[0044] The above-mentioned PVC layer mixture and PVC foam layer mixture are added to the main extruder and the auxiliary extruder respectively, and then extruded from the discharge ports of the main and auxiliary extruders. The specific temperatures of each zone of the main and auxiliary extruders are: Zone 1 150-160℃, Zone 2 155-165℃, Zone 3 165-175℃, Zone 4 170-180℃, Die 165-175℃, Die lip 150-160℃. The mixture enters the die through the feed port of the die via a distributor, cools and solidifies, forming a structure with a PVC foam layer in the middle and two PVC layers on the top and bottom, thus obtaining a lightweight diatomaceous earth PVC wall panel.

[0045] Example 5: A lightweight diatomaceous earth PVC wall panel is made by the following method:

[0046] In this embodiment, the raw materials for the PVC layer are 65 parts by weight of PVC resin powder SG-5, 20 parts by weight of the modified composite calcium powder prepared in Example 2, 10 parts by weight of the modified diatomaceous earth powder prepared in Example 3, 5 parts by weight of calcium-zinc composite environmentally friendly stabilizer, 2 parts by weight of calcium stearate, 5 parts by weight of chlorinated polyethylene, 1 part by weight of silane coupling agent, and 1 part by weight of methyl methacrylate-butadiene-styrene copolymer. The raw materials for the PVC foaming layer are 50 parts by weight of PVC resin powder SG-5, 30 parts by weight of the modified composite calcium powder prepared in Example 2, 10 parts by weight of the modified diatomaceous earth powder prepared in Example 3, 1 part by weight of azodicarbonamide, 1 part by weight of silane coupling agent, 3 parts by weight of calcium-zinc composite environmentally friendly stabilizer, 2 parts by weight of calcium stearate, 5 parts by weight of chlorinated polyethylene, and 1 part by weight of methyl methacrylate-butadiene-styrene copolymer. Apart from this, this embodiment is exactly the same as Example 4, and will not be repeated here.

[0047] Example 6 A lightweight diatomaceous earth PVC wall panel is made by the following method:

[0048] In this embodiment, the raw materials for the PVC layer are 70 parts by weight of PVC resin powder SG-5, 15 parts by weight of the modified composite calcium powder prepared in Example 1, 10 parts by weight of the modified diatomaceous earth powder prepared in Example 3, 5 parts by weight of calcium-zinc composite environmentally friendly stabilizer, 2 parts by weight of calcium stearate, 5 parts by weight of chlorinated polyethylene, 1 part by weight of silane coupling agent, and 1 part by weight of methyl methacrylate-butadiene-styrene copolymer. The raw materials for the PVC foaming layer are 55 parts by weight of PVC resin powder SG-5, 35 parts by weight of the modified composite calcium powder prepared in Example 1, 10 parts by weight of the modified diatomaceous earth powder prepared in Example 3, 1 part by weight of azodicarbonamide, 1 part by weight of silane coupling agent, 3 parts by weight of calcium-zinc composite environmentally friendly stabilizer, 2 parts by weight of calcium stearate, 5 parts by weight of chlorinated polyethylene, and 1 part by weight of methyl methacrylate-butadiene-styrene copolymer. Apart from this, this embodiment is exactly the same as Example 4, and will not be repeated here.

[0049] Example 7 A lightweight diatomaceous earth PVC wall panel is made by the following method:

[0050] In this embodiment, the raw materials for the PVC layer are 70 parts by weight of PVC resin powder SG-5, 15 parts by weight of the modified composite calcium powder prepared in Example 2, 10 parts by weight of the modified diatomaceous earth powder prepared in Example 3, 5 parts by weight of calcium-zinc composite environmentally friendly stabilizer, 2 parts by weight of calcium stearate, 5 parts by weight of chlorinated polyethylene, 1 part by weight of silane coupling agent, and 1 part by weight of methyl methacrylate-butadiene-styrene copolymer. The raw materials for the PVC foaming layer are 55 parts by weight of PVC resin powder SG-5, 35 parts by weight of the modified composite calcium powder prepared in Example 2, 10 parts by weight of the modified diatomaceous earth powder prepared in Example 3, 1 part by weight of azodicarbonamide, 1 part by weight of silane coupling agent, 3 parts by weight of calcium-zinc composite environmentally friendly stabilizer, 2 parts by weight of calcium stearate, 5 parts by weight of chlorinated polyethylene, and 1 part by weight of methyl methacrylate-butadiene-styrene copolymer. Apart from this, this embodiment is exactly the same as Example 4, and will not be repeated here.

[0051] Comparative Example 1: The preparation method of the mixture of modified barium sulfate and modified calcium carbonate includes the following steps:

[0052] Barium sulfate and calcium carbonate with a molar ratio of barium ions to calcium ions of 1:10 were added to 100 mL of deionized water. After stirring rapidly at room temperature for 1 h, hydrolyzed surface modifier KH570 was added. The mass ratio of composite calcium powder to surface modifier was 100:1. The mixture was reacted in a 70 °C water bath for 2 h, filtered, and the solid obtained by filtration was thoroughly washed with deionized water. After drying for 12 h, the mixture was ground to obtain a mixture of modified barium sulfate and modified calcium carbonate.

[0053] Compared with Example 4, Comparative Example 2 only replaced the modified composite calcium powder prepared in Example 1 with the modified diatomaceous earth prepared in Example 3. The other components and preparation methods were completely the same as those in Example 4.

[0054] Compared with Example 4, Comparative Example 3 only replaced the modified diatomaceous earth prepared in Example 3 with the modified composite calcium powder prepared in Example 1. The other components and preparation methods were completely the same as those in Example 4.

[0055] Compared with Example 4, Comparative Example 4 only replaced the modified composite calcium powder prepared in Example 3 with the modified barium sulfate and modified calcium carbonate mixture prepared in Comparative Example 1 by mass. The remaining components and preparation methods were completely the same as those in Example 4.

[0056] Compared with Example 4, Comparative Example 5 only replaced the modified composite calcium powder prepared in Example 3 with unmodified calcium carbonate in Example 4. The other components and preparation methods were completely the same as those in Example 4.

[0057] Comparative Example 6: A lightweight diatomaceous earth PVC wall panel is made by the following method:

[0058] In this embodiment, the raw materials for the PVC layer are 65 parts by weight of PVC resin powder SG-5, 20 parts by weight of the modified composite calcium powder prepared in Example 1, 10 parts by weight of the modified diatomaceous earth powder prepared in Example 3, 5 parts by weight of calcium-zinc composite environmentally friendly stabilizer, 2 parts by weight of calcium stearate, 5 parts by weight of chlorinated polyethylene, 1 part by weight of silane coupling agent, and 1 part by weight of methyl methacrylate-butadiene-styrene copolymer. The raw materials for the PVC foaming layer are 65 parts by weight of PVC resin powder SG-5, 20 parts by weight of the modified composite calcium powder prepared in Example 1, 10 parts by weight of the modified diatomaceous earth powder prepared in Example 3, 5 parts by weight of calcium-zinc composite environmentally friendly stabilizer, 2 parts by weight of calcium stearate, 5 parts by weight of chlorinated polyethylene, 1 part by weight of silane coupling agent, 1 part by weight of methyl methacrylate-butadiene-styrene copolymer, and 1 part by weight of azodicarbonamide. Apart from this, this embodiment is exactly the same as that in Example 4, and will not be repeated here.

[0059] Comparative Example 7: A lightweight diatomaceous earth PVC wall panel is made by the following method:

[0060] In this embodiment, the raw materials for the PVC layer are 50 parts by weight of PVC resin powder SG-5, 30 parts by weight of the modified composite calcium powder prepared in Example 1, 10 parts by weight of the modified diatomaceous earth powder prepared in Example 3, 1 part by weight of silane coupling agent, 3 parts by weight of calcium-zinc composite environmentally friendly stabilizer, 2 parts by weight of calcium stearate, 5 parts by weight of chlorinated polyethylene, and 1 part by weight of methyl methacrylate-butadiene-styrene copolymer. The raw materials for the PVC foaming layer are 50 parts by weight of PVC resin powder SG-5, 30 parts by weight of the modified composite calcium powder prepared in Example 1, 10 parts by weight of the modified diatomaceous earth powder prepared in Example 3, 1 part by weight of azodicarbonamide, 1 part by weight of silane coupling agent, 3 parts by weight of calcium-zinc composite environmentally friendly stabilizer, 2 parts by weight of calcium stearate, 5 parts by weight of chlorinated polyethylene, and 1 part by weight of methyl methacrylate-butadiene-styrene copolymer. Apart from this, this embodiment is exactly the same as Example 4, and will not be repeated here.

[0061] The performance of the lightweight diatomaceous earth PVC wall panels obtained in Examples 4-7 and Comparative Examples 2-7 was tested below, and the test results are shown in Table 1.

[0062] Table 1: Statistical table of wall panel performance test data in Examples 4-7 and Comparative Examples 2-7

[0063] Impact strength kJ.m 2 ]] Bending strength MPa Tensile strength MPa Thermal conductivity W / m˙K Formaldehyde absorption rate % Pencil hardness Example 4 9.5 35 25 0.068 82 H Example 5 9.2 34 24 0.070 80 H Example 6 8.8 38 26 0.072 78 2H Example 7 8.7 37 25 0.073 77 2H Comparative Example 2 7.0 28 20 0.075 92 B Comparative Example 3 6.8 42 28 0.085 55 F Comparative Example 4 7.5 30 22 0.078 75 HB Comparative Example 5 5.5 25 18 0.090 70 3B Comparative Example 6 6.0 28 18 0.095 75 4B Comparative Example 7 7.2 30 20 0.080 78 B

[0064] As shown in Table 1, the lightweight diatomaceous earth PVC wall panel prepared by this invention possesses lightweight, impact resistance, and scratch resistance. Through differentiated design of the PVC layer and PVC foam layer, the surface layer achieves decorative and load-bearing functions, while the core layer focuses on lightweight and thermal insulation. Together, they achieve the goal of "lightweight, high-strength, and multifunctional." In Comparative Example 2, without the addition of modified composite calcium powder, the resulting lightweight diatomaceous earth PVC wall panel exhibited decreased flexural strength and scratch resistance. In Comparative Example 3, without the addition of modified diatomaceous earth, the resulting lightweight diatomaceous earth PVC wall panel showed a decreased formaldehyde adsorption rate. In Comparative Example 4, without the composite of barium sulfate and calcium carbonate, the resulting lightweight diatomaceous earth PVC wall panel showed a significant decrease in impact resistance. In Comparative Example 5, without modification of the calcium powder, the resulting lightweight diatomaceous earth PVC wall panel showed a decrease in impact resistance. In Comparative Examples 6 and 7, the PVC layer and PVC foam layer had the same content of components other than the foaming agent, resulting in lightweight diatomaceous earth PVC wall panels that could not achieve a performance balance.

[0065] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A lightweight diatomaceous earth PVC wall panel, characterized in that, The lightweight diatomaceous earth PVC wall panel includes at least a PVC layer and a PVC foam layer, wherein the PVC foam layer is disposed between the two PVC layers; The PVC layer comprises at least the following raw materials by weight: 60-75 parts PVC resin powder, 15-20 parts modified composite calcium powder, 5-15 parts modified diatomaceous earth powder, 3-6 parts environmentally friendly stabilizer, 1.5-3 parts lubricant, 3-8 parts toughening agent, 0.5-1.5 parts coupling agent, and 0.5-1.5 parts processing aid. The PVC foam layer comprises at least the following raw materials by weight: 50-55 parts PVC resin powder, 30-40 parts modified composite calcium powder, 5-15 parts modified diatomaceous earth powder, 0.8-1.5 parts foaming agent, 0.5-2 parts coupling agent, 3-6 parts environmentally friendly stabilizer, 1-3 parts lubricant, 3-10 parts toughening agent, and 0.5-1.5 parts processing aid; The preparation method of modified composite calcium powder includes the following steps: Sodium carbonate solution is added to calcium chloride solution, then barium chloride solution is added, and sodium carbonate solution is added again. The mixture is then precipitated, filtered, washed, and dried to obtain barium carbonate-coated calcium carbonate. Sulfur trioxide gas is passed into the barium carbonate-coated calcium carbonate, and barium carbonate is converted into barium sulfate through gas-solid conversion to obtain composite calcium powder. The composite calcium powder was added to deionized water, stirred, and then the hydrolyzed surface modifier was added. The mixture was reacted, filtered, washed, and dried to obtain the modified composite calcium powder.

2. The lightweight diatomaceous earth PVC wall panel according to claim 1, characterized in that, The preparation method of the modified diatomaceous earth includes the following steps: Diatomaceous earth is added to hydrochloric acid solution, washed and dried to obtain activated diatomaceous earth; The activated diatomaceous earth was added to the hydrolysate of the silane coupling agent, washed and dried to obtain modified diatomaceous earth.

3. The lightweight diatomaceous earth PVC wall panel according to claim 2, characterized in that, The mass ratio of the diatomaceous earth to the silane coupling agent is 100:1-2.

4. The lightweight diatomaceous earth PVC wall panel according to claim 1, characterized in that, The molar ratio of calcium ions to barium ions in the modified composite calcium powder is 8-15:

1.

5. A lightweight diatomaceous earth PVC wall panel according to claim 1, characterized in that, The mass ratio of the surface modifier to the composite calcium powder is 0.5-3:

100.

6. The lightweight diatomaceous earth PVC wall panel according to claim 1, characterized in that, The coupling agent is any one or a mixture of aluminate coupling agents, borate coupling agents, silane coupling agents, titanate coupling agents, and maleic anhydride coupling agents; the environmentally friendly stabilizer is a calcium-zinc composite environmentally friendly stabilizer; the foaming agent is any one or a mixture of azodicarbonamide, sodium bicarbonate, or benzenesulfonyl hydrazine; the processing aid is any one or a mixture of polymethyl methacrylate, dioctyl phthalate, and ACR resin; the lubricant is any one or a mixture of stearic acid, calcium stearate, polyethylene wax, or oxidized polyethylene wax; and the toughening agent is any one or a mixture of chlorinated polyethylene, methyl methacrylate-butadiene-styrene copolymer, or ethylene-vinyl acetate copolymer.

7. A method for preparing a lightweight diatomaceous earth PVC wall panel according to any one of claims 1-6, characterized in that, It includes at least the following preparation steps: The raw materials for the PVC layer and the PVC foam layer are added to a high-speed mixer according to the weight ratio to obtain the PVC layer mixture and the PVC foam layer mixture. The PVC layer mixture and the PVC foam layer mixture are respectively added to the main extruder and the auxiliary extruder, and then extruded from the outlet of the main and auxiliary extruders. The mixture enters the mold through the feed inlet of the mold via the distributor, cools and solidifies, forming a structure with a PVC foam layer in the middle and PVC layers on the top and bottom, thus obtaining a lightweight diatomaceous earth PVC wall panel.