Preparation method of negative ion plastic plate

Abstract

The invention relates to the technical field of plastic plate preparation, in particular to a preparation method of a negative ion plastic plate. The invention discloses a preparation method of a negative ion plastic plate, which comprises the following steps: pretreating reinforced polypropylene to obtain fine particles, preparing silane coated functional mineral powder, carrying out surface modification, and forming a network-mineral powder composite dispersed phase with plasma treated composite cellulose powder; mixing the dispersed phase with pretreated polypropylene fine particles, composite cellulose aerogel particles and other raw materials according to a specific mass ratio, adding an adhesive and a lubricant, stirring, melting and granulating to obtain negative ion plastic master batch; and the master batch is subjected to preheating, casting, gradient cooling, trimming and curing treatment, and finally the negative ion plastic plate is prepared. By optimizing the raw material ratio and process parameters, the dispersity of functional components and the stability of the material are improved, it is ensured that the product continuously releases negative ions, the process is controllable, and industrial production is easy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of plastic plate preparation, and particularly relates to a preparation method of a negative ion plastic plate. BACKGROUND

[0002] Reinforced polypropylene is widely used in the field of plastic plates as a kind of high polymer material with excellent mechanical properties, good processing fluidity and high cost performance. In order to give it the function of releasing negative ions, the existing technology often adds functional mineral powder such as tourmaline powder and germanium powder to the reinforced polypropylene matrix to prepare a composite plate, but there are core technical bottlenecks such as insufficient interface compatibility, easy agglomeration of functional mineral powder, and difficulty in balancing mechanical properties and functions.

[0003] A preparation method of a negative ion plastic plate is disclosed in Chinese Patent No. CN102336945A, which is to use one of polyethylene, polypropylene, polystyrene and acrylonitrile-butadiene-styrene copolymer as the main raw material, add tourmaline ore powder, germanite powder and flint powder as functional components, and add plant cellulose, adhesive, lubricant, coupling agent and other auxiliary materials, mix and stir all the materials in a stirrer, and then cast and press to form the negative ion plastic plate. This patent only simply adds a titanate coupling agent, does not modify the non-polar polypropylene substrate, and does not do targeted coating or modification treatment on the polar functional mineral powder, which cannot break the interface barrier between the substrate and the mineral powder, resulting in poor combination between the two, and easy interface peeling problem. Without special dispersion design, only through conventional stirring and mixing, no dispersion carrier or network structure is constructed, the functional mineral powder is easy to aggregate in the processing process, and cannot be uniformly dispersed in the substrate, affecting the global consistency of the negative ion release. Without multi-component synergistic ratio optimization and without designing an adaptive processing process connection, mineral powder agglomeration and poor interface combination will lead to a decrease in the mechanical strength of the plate, and the simple casting process cannot guarantee the stability of the material structure, so that the function addition and the mechanical property improvement conflict with each other.

[0004] A high-transparency anti-fouling coated plate is disclosed in Chinese Patent Publication No. CN221737317U. The technical solution of the coated plate includes, from bottom to top, a substrate layer, a plastic plate layer, a negative ion coating layer, a corrosion-resistant layer, an impregnated glue film paper layer, a UV coating layer, and an oil stain-resistant film. The UV coating layer is divided into a UV adhesion transparent primer layer, a UV colored primer layer, and a UV showering high-gloss topcoat layer. The oil stain-resistant film is made of high-density polyethylene fiber material. The substrate layer surface is provided with a cavity, and the plastic plate layer bottom is provided with an adaptive protrusion. The two are fixed by composite glue. The assembly of the multi-layer structure is realized. The negative ion coating layer of the patent is directly attached to the surface of the plastic plate layer. The surface of the plastic plate layer is not modified, and the interface transition structure between the coating and the substrate is not designed. The interface bonding force between the plastic plate layer and the negative ion coating layer is weak. Long-term use may cause coating peeling and falling off. Only a single coating form is used to give the negative ion function. The negative ion functional components are not dispersed, optimized, or fixed. The functional components are easily unevenly distributed in the coating, resulting in large fluctuations in the release of negative ions. After the coating is worn, the negative ion function will be lost directly, and the function sustainability cannot be guaranteed. In the multi-layer superposition structure, the material properties of each layer are quite different. The components are not designed for collaborative adaptation. The existence of the negative ion coating layer and the corrosion-resistant layer may reduce the impact resistance and flexibility of the overall structure. At the same time, the substrate and the plastic plate layer are only bonded by glue and cooperate with the protrusion. Long-term stress may cause interlayer separation, affecting the overall mechanical stability of the plate.

[0005] In summary, these deficiencies limit the application of enhanced polypropylene-based negative ion plastic plates, and there is an urgent need for a preparation technology that can solve the above problems. SUMMARY

[0006] To solve the above problems, the purpose of the present application is to provide a preparation method of a negative ion plastic plate, which specifically comprises the following steps: S001, taking enhanced polypropylene, adding a cleaning agent, and performing ultrasonic cleaning treatment, rinsing treatment, drying treatment, crushing treatment, and plasma treatment to obtain pretreated enhanced polypropylene fine particles; S002, taking pretreated functional mineral powder, adding deionized water, and performing ultrasonic dispersion treatment and dehydration treatment. Then, a sol agent is added and subjected to stirring treatment and drying treatment to obtain silane-coated functional mineral powder; S003, taking composite cellulose dry powder and performing brittle fracture treatment, screening treatment, and vacuum drying treatment to obtain composite cellulose aerogel particles; S004, taking the silane-coated functional mineral powder and performing stirring treatment. Then, a coupling agent is added and subjected to spraying treatment and reaction treatment to obtain surface-modified functional mineral powder; S005, taking the surface modified functional mineral powder, adding the plasma treated composite cellulose dry powder for network fixation treatment, to obtain a network-mineral powder composite dispersed phase with mineral powder embedded in the cellulose-chitosan network, denoted as network-mineral powder composite dispersed phase; S006, taking the pretreated enhanced polypropylene fine particles, network-mineral powder composite dispersed phase, composite cellulose dry powder, isomeric tridecanol polyoxyethylene ether dispersant, and composite cellulose aerogel particles for mixing to obtain a primary mixed material, adding polyvinyl alcohol adhesive and zinc stearate lubricant for stirring treatment, melt granulation treatment, to obtain a negative ion plastic master batch. S007, preheating the negative ion plastic master batch, casting and pressing, gradient cooling, trimming, and curing, to obtain a negative ion plastic plate.

[0007] The enhanced polypropylene in step S001 is high-performance polypropylene obtained by enhancing and modifying polypropylene with glass fibers; the cleaning agent is a deionized water cleaning agent containing 1% fatty alcohol polyoxyethylene ether, and the ultrasonic treatment conditions are 200 W ultrasonic cleaning for 5 min, 3 times; the rinsing treatment is rinsing with deionized water twice; the drying treatment conditions are 90 ℃ drying for 2.5 h; the crushing treatment is to a particle size of 0.9-1.1 mm; and the plasma treatment conditions are argon, 80 W plasma treatment for 8 min.

[0008] The pretreated functional mineral powder in step S002 is prepared by airflow crushing, screening, mixing, and vacuum drying at 65 ℃ for 2 h of tourmaline powder, germanium powder, and flint powder, wherein the tourmaline powder and flint powder are screened with a 10 μm screen, and the germanium powder is screened with a 200 nm screen, and the tourmaline powder, germanium powder, and flint powder are mixed in a mass ratio of 10:3:2; the mass ratio of deionized water to pretreated functional mineral powder is 4:1; the ultrasonic dispersion treatment conditions are 300 W for 30 min; the dehydration treatment conditions are centrifugation at 5000 r / min for 10 min, and then drying at 70 ℃ and -0.09 MPa for 4 h; the sol agent is prepared by mixing silane coupling agent KH-570 and anhydrous ethanol in a volume ratio of 1:10; the volume-to-mass ratio of the sol agent to the pretreated functional mineral powder is 1:3; the stirring treatment conditions are 300 r / min for 30 min; and the drying treatment conditions are 80 ℃ for 1 h.

[0009] The composite cellulose dry powder in step S003 is prepared by mixing cellulose nanofibrils and chitosan at a mass ratio of 8:2, adding 1.5% of deionized water based on the mass of the composite cellulose dry powder, ultrasonicating at 400 W for 30 min, spray drying at an inlet temperature of 170 DEG C and an outlet temperature of 80 DEG C, a feeding pump of 20 mL / min and a rotating speed of 25000 r / min, and drum drying at 72 DEG C for 3 h; the brittle fracture treatment is performed under liquid nitrogen; the screening treatment selects particles with a particle size of 1-2 mm; and the vacuum drying treatment is performed at 80 DEG C and a pressure of-0.09 MPa for 2 h.

[0010] The stirring treatment in step S004 is stirred at 900 r / min for 30 s; the coupling agent is prepared by mixing silane coupling agent KH-570 and anhydrous ethanol at a volume ratio of 1:25; the volume-mass ratio of the coupling agent to the silane-coated functional mineral powder is 0.3:1; the spraying treatment is performed at a spraying speed of 6 mL / min and an atomization pressure of 0.3 MPa; and the reaction treatment is performed at 82 DEG C and a rotating speed of 900 r / min for 1.2 h.

[0011] The composite cellulose dry powder after plasma treatment in step S005 is prepared by argon plasma treatment at 100 W for 5 min; the mass ratio of the composite cellulose dry powder after plasma treatment to the surface-modified functional mineral powder is 1:6.5; and the network fixation treatment is performed at a rotating speed of 1200 r / min for 20 min and cooled to room temperature.

[0012] The mass ratio of the pretreated reinforced polypropylene fine particles, the network-mineral powder composite dispersion phase, the composite cellulose dry powder, the isomeric tridecanol polyoxyethylene ether dispersant and the composite cellulose aerogel particles in step S006 is 68:18:4.6:0.5:3, and the mass ratio of the primary mixture, polyvinyl alcohol adhesive and zinc stearate lubricant is 94.1:2:0.3; the stirring treatment is performed at 105 DEG C and a rotating speed of 700 r / min for 40 min; the melt granulation treatment is performed at an inlet temperature of 115 DEG C, a melting section of 150 DEG C, a die section of 135 DEG C, a screw rotating speed of 50 r / min and a cooling water temperature of 28 DEG C, and then cut into particles with a length of 4 mm.

[0013] The preheating treatment in step S007 is performed at 85 DEG C for 45 min; the cast pressing treatment is performed at 135 DEG C and a pressure of 220 MPa for 35 min; the gradient cooling treatment is performed by first cooling to 75 DEG C under a pressure of 220 MPa and keeping the temperature for 8 min, and then cooling at a rate of 1.5 DEG C / min; and the solidification treatment is performed at 75 DEG C for 2 h.

[0014] Compared with the prior art, the present application has the following advantages: 1. The present application is aimed at enhancing polypropylene and functional mineral powder, two types of core raw materials, and designing a special multi-level modification path. After systematic pretreatment of the reinforcing polypropylene, it is assisted by plasma treatment to optimize its surface activity and polarity; the functional mineral powder is then subjected to silane coating treatment and coupling agent surface modification in sequence to build a surface structure suitable for the reinforcing polypropylene matrix. Reinforcing polypropylene itself is a non-polar material, and its interfacial compatibility with polar functional mineral powder is poor. Multi-level modification changes the surface properties of the two types of raw materials, breaks the inherent interfacial barrier, and forms a stable interfacial bonding layer. Through multi-level modification, the interfacial compatibility of reinforcing polypropylene and functional mineral powder is improved, and the bonding strength is enhanced, which not only fully retains the excellent mechanical properties of reinforcing polypropylene itself, but also enables the functional mineral powder to be stably attached to the matrix, providing a core guarantee for the subsequent synergistic optimization of material function and structure.

[0015] 2. The present application takes reinforcing polypropylene as the matrix core and builds a composite dispersed phase of mineral powder embedded in the cellulose-chitosan network. The composite cellulose is first treated by plasma, and then the network is fixed by treating it with the surface-modified functional mineral powder. The spatial network structure of the cellulose-chitosan network physically constrains and dispersively supports the functional mineral powder. In the reinforcing polypropylene matrix, the functional mineral powder tends to agglomerate due to its own characteristics, while the cellulose-chitosan network can act as a "dispersion carrier" to uniformly lock the mineral powder particles in the network pores, preventing their aggregation during the melting processing and molding of reinforcing polypropylene. The composite dispersed phase provides a stable dispersion environment for the functional mineral powder through the physical constraint and dispersion support of the cellulose-chitosan network, effectively reducing the risk of aggregation of the functional mineral powder during the melting processing and molding of reinforcing polypropylene, thereby ensuring the global consistency of the negative ion release function, while avoiding the possible damage to the matrix structure caused by the aggregation of the mineral powder. This allows the material to have core functions while maintaining the structural stability and reliability of the reinforcing polypropylene.

[0016] 3. The present application takes reinforcing polypropylene as the core matrix, combines the pretreated reinforcing polypropylene with the network-mineral powder composite dispersed phase, composite cellulose aerogel particles, and other core components to form a synergistic composite system with specific dispersants, adhesives, and lubricants. Reinforcing polypropylene provides basic structural support as the matrix, the network-mineral powder composite dispersed phase imparts core functions, and other components play the roles of dispersion, adhesion, and lubrication, respectively. Through the functional complementation of each component, the shortcomings of single reinforcing polypropylene in functional expansion and processing adaptation are addressed. Multi-component synergistic design not only relies on the excellent performance of reinforcing polypropylene to ensure the basic quality of the material, but also enables the material to have both negative ion release function and good processing fluidity through the synergistic effect of each component, avoiding the damage to the original advantages of reinforcing polypropylene caused by functional addition, and achieving the dual optimization of material function and processing performance.

[0017] 4.The application combines the pretreatment of raw materials with subsequent processing steps organically, so that the entire processing flow of the reinforced polypropylene is more in line with its material properties. The method focuses on the connection and coordination between processes, avoids thermal degradation or structural defects during processing, and promotes the full integration of components and polypropylene. Thus, the molding advantages of the material are fully utilized, and the molding quality, dimensional stability and structural uniformity of the product are improved, so that the comprehensive performance of the final product better meets the actual application requirements. DETAILED DESCRIPTION

[0018] The application will be further described below in conjunction with specific embodiments. EMBODIMENT

[0019] A preparation method of a negative ion plastic plate, specifically comprising the following steps: S001, 600 g of reinforced polypropylene was taken, 1% fatty alcohol polyoxyethylene ether-containing deionized water cleaner was added, 3 times of 200 W ultrasonic cleaning for 5 min, 2 times of deionized water rinsing, 90 ℃ drying for 2.5 h, crushing to a particle size of 0.9-1.1 mm, argon, 80 W plasma treatment for 8 min, to obtain the pretreated reinforced polypropylene fine particles; Preparation of pretreated functional mineral powder, tourmaline powder, germanium powder and flint powder were respectively subjected to air flow crushing, tourmaline powder and flint powder were crushed with a 10 μm screen, germanium powder was crushed with a 200 nm screen, 200 g of tourmaline powder, 60 g of germanium powder and 40 g of flint powder were mixed, and vacuum drying was performed at 65 ℃ for 2 h to obtain the pretreated functional mineral powder; Preparation of sol agent, 6 mL of silane coupling agent KH-570 and 60 mL of anhydrous ethanol were mixed uniformly to obtain the sol agent; S002, 180 g of pretreated functional mineral powder was taken and added into 720 mL of deionized water, 300 W dispersion for 30 min, 5000 r / min centrifugation for 10 min, 70 ℃, -0.09 MPa drying for 4 h, 60 mL of sol agent was added, 300 r / min stirring for 30 min, 80 ℃ drying for 1 h, to obtain the silane-coated functional mineral powder; Preparation of composite cellulose dry powder, 80 g of cellulose nanofibril and 20 g of chitosan were mixed, 1.5 g of deionized water was added, 400 W ultrasonic treatment for 30 min, 170 ℃ inlet air temperature, 80 ℃ outlet air temperature, 20 mL / min feeding pump, 25000 r / min spray drying, 72 ℃ air drying for 3 h, to obtain the composite cellulose dry powder; S003, 25 g of the composite cellulose dry powder was mechanically brittle fractured under liquid nitrogen, and particles with a particle size of 1-2 mm were screened and selected, and the particles were dried at 80 DEG C and -0.09 MPa for 2 h to obtain the composite cellulose aerogel particles; Preparation of the coupling agent, 2 mL of silane coupling agent KH-570 was mixed with 50 mL of anhydrous ethanol to obtain the coupling agent; S004, 160 g of the silane-coated functional mineral powder was stirred at 900 r / min for 30 s, 48 mL of the coupling agent was added, and the spray treatment was performed at a spray speed of 6 mL / min and an atomization pressure of 0.3 MPa, and the reaction was performed at 82 DEG C and 900 r / min for 1.2 h to obtain the surface-modified functional mineral powder; Preparation of the composite cellulose dry powder after plasma treatment, 25 g of the composite cellulose dry powder was treated with argon plasma at 100 W for 5 min to obtain the composite cellulose dry powder after plasma treatment; S005, 130 g of the surface-modified functional mineral powder was added with 20 g of the composite cellulose dry powder after plasma treatment, and the network fixation treatment was performed at 1200 r / min for 20 min, and the temperature was cooled to room temperature to obtain the network-mineral powder composite dispersed phase of the mineral powder embedded in the cellulose-chitosan network, which was denoted as network-mineral powder composite dispersed phase; S006, 340 g of the pretreated enhanced polypropylene fine particles, 90 g of the network-mineral powder composite dispersed phase, 23 g of the composite cellulose dry powder, 2.5 g of the isomeric tridecanol polyoxyethylene ether dispersant, and 15 g of the composite cellulose aerogel particles were mixed to obtain a primary mixture, 10 g of polyvinyl alcohol adhesive and 1.5 g of zinc stearate lubricant were added, and the mixture was stirred at 105 DEG C and 700 r / min for 40 min, the feeding section was at 115 DEG C, the melting section was at 150 DEG C, the die head section was at 135 DEG C, the screw rotation speed was 50 r / min, and the cooling water temperature was 28 DEG C, and the mixture was cut into particles with a length of 4 mm to obtain the negative ion plastic master batch; S007, the negative ion plastic master batch was preheated at 85 DEG C for 45 min, and was subjected to casting pressure treatment at 135 DEG C and 220 MPa for 35 min, and was cooled to 75 DEG C under 220 MPa, and was kept at 75 DEG C for 8 min, and was cooled at a rate of 1.5 DEG C / min, and was subjected to edge trimming and solidification treatment at 75 DEG C for 2 h to obtain the negative ion plastic plate, which was denoted as the test sample.

[0020] Comparative Example 1 A method for preparing a negative ion plastic plate without multi-stage modification treatment, specifically comprising the following steps: The difference from the embodiment is that S001, the enhanced polypropylene is only subjected to ultrasonic cleaning treatment, rinsing treatment, drying treatment, and crushing treatment with a 1% fatty alcohol polyoxyethylene ether-containing deionized water cleaner, and is not subjected to plasma treatment, to obtain the pretreated functional mineral powder; and the pretreated functional mineral powder is used to replace the surface-modified functional mineral powder in S005. The preparation of the sol agent, S002, the preparation of the coupling agent, and S004 are not performed, and the remaining steps (the preparation of the pretreated functional mineral powder, the preparation of the composite cellulose dry powder, the preparation of the composite cellulose dry powder after plasma treatment, S005-S007) are consistent with the embodiment, to obtain a control 1.

[0021] Comparative Example 2 A preparation method of a negative ion plastic plate without a network-mineral powder composite dispersed phase, specifically comprising the following steps: The difference from the embodiment is that S005 is not performed. The surface-modified functional mineral powder is used to replace the network-mineral powder composite dispersed phase in S006. The remaining steps (S001, the preparation of the pretreated functional mineral powder, the preparation of the sol agent, S002, the preparation of the composite cellulose dry powder, S003, the preparation of the coupling agent, S004, the preparation of the composite cellulose dry powder after plasma treatment, S007) are consistent with the embodiment, to obtain a control 2.

[0022] Comparative Example 3 A preparation method of a negative ion plastic plate without multi-component synergistic design, specifically comprising the following steps: The difference from the embodiment is that no isomeric tridecanol polyoxyethylene ether dispersant and polyvinyl alcohol adhesive is added in S006. The remaining steps (S001, the preparation of the pretreated functional mineral powder, the preparation of the sol agent, S002, the preparation of the composite cellulose dry powder, S003, the preparation of the coupling agent, S004, the preparation of the composite cellulose dry powder after plasma treatment, S005, S007) are consistent with the embodiment, to obtain a control 3.

[0023] Experimental Example 1 In this experimental example, the test sample of the embodiment and the control samples 1-3 are subjected to interfacial compatibility testing, specifically comprising the following steps: The test sample, control sample 1, control sample 2, and control sample 3 are cut into 10 mm x 25 mm x 5 mm samples, with 3 parallel samples in each group. The two ends of the sample were fixed on the tensile machine clamps respectively, and the tensile test was carried out at a range of 50 MPa and a stretching speed of 1 mm / min. The maximum tensile force value at the time of fracture was recorded, the average value was taken, and the tensile shear strength was calculated according to the ratio of the average maximum tensile force value to the bonding area of the sample. The test results are shown in Table 1.

[0024] Table 1: Interface compatibility test results

[0025] As can be seen from Table 1, the anion plastic plate of the embodiment has the best interface compatibility, and the tensile shear strengths of the samples show obvious differences. The tensile shear strength of the embodiment is the highest, reaching 4.5 MPa, which is higher than that of all the comparative examples. The strength of Comparative Example 1 (without multi-stage modification treatment) is the lowest, only 2.9 MPa, which is the most different from the embodiment. The strength of Comparative Example 2 (without network-mineral powder composite dispersion phase) is 3.6 MPa, and the strength of Comparative Example 3 (without multi-component synergistic design) is 3.4 MPa, both of which are between the embodiment and Comparative Example 1.

[0026] Comparative Example 1 lacks the steps of polypropylene plasma treatment, mineral powder silane coating and coupling modification, resulting in insufficient interfacial bonding force between the polymer and the mineral powder, and the strength decreases. Comparative Example 2 does not prepare the composite dispersion phase, and the mineral powder cannot form a stable dispersion network in the matrix, the interface compatibility is damaged, and the strength is lower than that of the embodiment. Comparative Example 3 does not add dispersant and adhesive, resulting in uneven dispersion of components and insufficient bonding strength, and the strength is lower than that of the embodiment and Comparative Example 2.

[0027] In summary, the embodiment improves the interfacial bonding tightness of the anion plastic plate through the comprehensive process of polypropylene plasma treatment, multi-stage modification of mineral powder, network-mineral powder composite dispersion phase construction and synergistic addition of dispersant-adhesive. The absence or simplification of each single process will lead to a decrease in interface compatibility, and ultimately a decrease in tensile shear strength.

[0028] Experimental Example 2 In this experimental example, the test samples of the embodiment and the control samples of Comparative Examples 1-3 were subjected to mechanical property tests, which included the following steps: 1. Tensile strength test The test samples, control sample 1, control sample 2, and control sample 3 were cut into dumbbell-shaped samples, wherein the total length was 170 mm, the narrow parallel part length was 80±2 mm, the transition radius was 24±1 mm, the wide parallel part distance was 109.3±3.2 mm, the end width was 20.0±0.2 mm, the narrow part width was 10.0±0.2 mm, the preferred thickness was 4.0±0.2 mm, the gauge length was 75.0±0.5 mm, and the initial distance between the clamps was 115±1 mm, with 5 parallel samples in each group. Tensile strength tests were conducted at a range of 100 MPa and a tensile speed of 50 mm / min. The maximum load at fracture was recorded, and the average value was taken. The tensile strength was calculated based on the ratio of the average maximum load to the cross-sectional area of ​​the specimen. The test results are shown in Table 2.

[0029] 2. Bending strength test Take the test sample, reference 1, reference 2, and reference 3 and cut them into 80 mm × 10 mm × 4 mm samples, with 5 parallel samples in each group; The bending strength test was conducted with a span of 64 mm and a loading speed of 2 mm / min. The maximum bending load at fracture was recorded and the average value was taken. The bending strength was calculated by multiplying the average maximum bending load by 3, the span, the reciprocal of 2, the reciprocal of the specimen width, and the reciprocal of the square of the specimen thickness. The test results are shown in Table 2.

[0030] Table 2 Mechanical Performance Test Results

[0031] As can be seen from Table 2, the negative ion plastic plate of the embodiment has the best mechanical properties. Its tensile strength (38.2 MPa) and flexural strength (48.1 MPa) are both higher than those of the three comparative examples. Due to the simplification of the preparation process or the absence of key components, the mechanical properties of each comparative example have decreased to varying degrees.

[0032] The tensile strength, from highest to lowest, is as follows: Example 1 (38.2 MPa), Comparative Example 2 (32.2 MPa), Comparative Example 3 (31.4 MPa), and Comparative Example 1 (30.5 MPa). Example 1 shows a 25.2% improvement over Comparative Example 1, which has the worst performance. The flexural strength, from highest to lowest, is as follows: Example 1 (48.1 MPa), Comparative Example 2 (40.7 MPa), Comparative Example 3 (39.8 MPa), and Comparative Example 1 (38.4 MPa). Example 1 shows a 25.3% improvement over Comparative Example 1.

[0033] Comparative Example 1, lacking multi-stage modification processes such as plasma treatment of polypropylene, silane coating of functional mineral powder, and coupling agent modification, exhibited poor compatibility between the mineral powder and the substrate, resulting in the worst mechanical properties. Comparative Example 2, without preparing a network-mineral powder composite dispersed phase, suffered from uneven dispersion of the functional mineral powder in the substrate, failing to form a stable reinforcing network, and thus exhibited weaker performance than the examples. Comparative Example 3, lacking the addition of isomeric tridecyl alcohol polyoxyethylene ether dispersant and polyvinyl alcohol binder, suffered from insufficient inter-component bonding, resulting in lower tensile and flexural strengths than the examples.

[0034] In summary, the three core processes employed in the embodiments—multi-stage modification treatment, network-mineral powder composite dispersed phase design, and multi-component synergistic formulation—effectively improved the tensile and flexural strength of the negative ion plastic plate, demonstrating that the preparation process can optimize the mechanical properties of the material.

[0035] Experimental Example 3 In this experimental example, the test sample of the embodiment and the control samples of Comparative Examples 1-3 were tested for negative ion release stability, which included the following steps: The test sample, control sample 1, control sample 2, and control sample 3 were cut into samples of 100 mm x 100 mm x 5 mm, with 2 parallel samples in each group, and placed in a 23°C, 45% RH environment for 24 hours. The range was adjusted to R2, the probe of the tester was placed 5 cm from the surface of the sample, and the test was performed every 8 hours for 72 hours. The amount of negative ion release was recorded each time, and the coefficient of variation of the amount of negative ion release was calculated. The test results are shown in Table 3.

[0036] Table 3. Test results of mechanical properties

[0037] As can be seen from Table 3, the negative ion release stability of the negative ion plastic plate of the embodiment is the best, with a coefficient of variation of only 0.39%, which is much lower than that of the three comparative examples. Due to the absence or simplification of key steps in the preparation process, the negative ion release stability of each comparative example is significantly decreased, and the coefficient of variation is more than 1%.

[0038] The coefficient of variation from small to large is the embodiment (0.39%), comparative example 2 (1.25%), comparative example 3 (1.85%), and comparative example 1 (2.73%). The coefficient of variation of the embodiment is only 14.3% of that of comparative example 1 and 21.1% of that of comparative example 3, and the stability advantage is extremely obvious. The coefficient of variation of comparative example 1 is the largest, and the negative ion release stability is the worst among all samples.

[0039] Comparative example 1 lacks the multi-stage modification process of plasma treatment of polypropylene, silane coating of functional mineral powder, and coupling agent modification, resulting in weak interfacial bonding force between the mineral powder and the substrate, uneven dispersion, large fluctuation of negative ion release amount, and the highest coefficient of variation. Comparative example 2 does not prepare a network-mineral powder composite dispersion phase, and the functional mineral powder cannot form a stable release network, but only exists in the form of simply modified mineral powder, so the release stability is weaker than that of the embodiment. Comparative example 3 does not add isomeric tridecanol polyoxyethylene ether dispersant and polyvinyl alcohol adhesive, and the dispersion and bonding force between components are insufficient, resulting in a larger fluctuation range of negative ion release amount than the embodiment.

[0040] In summary, the three key processes of multi-stage modification treatment, network-mineral powder composite dispersion phase construction, and multi-component synergistic ratio used in the embodiment effectively reduce the fluctuation range of the negative ion release amount and improve the release stability. The absence or simplification of any one of the key processes will result in a significant decrease in stability, proving that the complete preparation process is the key to ensuring the stability of negative ion release.

[0041] The above merely describes the technical solutions of the present application and is not limited, and any equal modification and change of the technical solutions of the present application by the ordinary person in the art, as long as it does not deviate from the overall concept of the present application, still belongs to the scope of the present application.

Claims

1. A method for producing a negative ion plastic plate, characterized by, The preparation method of the negative ion plastic plate specifically comprises the following steps: S001, taking the reinforced polypropylene, adding a cleaning agent, performing ultrasonic cleaning treatment, rinsing treatment, drying treatment, crushing treatment, and plasma treatment, to obtain the pretreated reinforced polypropylene fine particles; S002, taking the pretreated functional mineral powder, adding deionized water, performing ultrasonic dispersion treatment and dehydration treatment, adding a sol agent, and performing stirring treatment and drying treatment, to obtain the silane-coated functional mineral powder; S003, taking the composite cellulose dry powder to perform brittle fracture treatment, screening treatment, and vacuum drying treatment, to obtain the composite cellulose aerogel particles; S004, taking the silane-coated functional mineral powder to perform stirring treatment, adding a coupling agent to perform spray treatment and reaction treatment, to obtain the surface-modified functional mineral powder; S005, taking the surface-modified functional mineral powder, adding the composite cellulose dry powder treated by plasma to perform network fixing treatment, to obtain the network-mineral powder composite dispersed phase of the mineral powder embedded in the cellulose-chitosan network, denoted as network-mineral powder composite dispersed phase; S006, taking the pretreated reinforced polypropylene fine particles, the network-mineral powder composite dispersed phase, the composite cellulose dry powder, isomeric tridecanol polyoxyethylene ether dispersant, and the composite cellulose aerogel particles to perform mixing, to obtain a primary mixture, adding polyvinyl alcohol adhesive and zinc stearate lubricant to perform stirring treatment and melt granulation treatment, to obtain the negative ion plastic master batch; S007, performing preheating treatment, casting pressure treatment, gradient cooling treatment, edge trimming, and curing treatment on the negative ion plastic master batch, to obtain the negative ion plastic plate.

2. The production method according to claim 1, characterized by, In step S001, the reinforced polypropylene is high-performance polypropylene obtained by reinforcing and modifying polypropylene with glass fibers; the cleaning agent is a deionized water cleaning agent containing 1% fatty alcohol polyoxyethylene ether.

3. The production method according to claim 1, characterized by, In step S002, the pretreated functional mineral powder is prepared by airflow crushing, screening, mixing, and vacuum drying at 65 ℃ for 2 h of tourmaline powder, germanium powder, and flint powder, wherein the tourmaline powder and flint powder are screened with a 10 μm screen, the germanium powder is screened with a 200 nm screen, and the tourmaline powder, germanium powder, and flint powder are mixed at a mass ratio of 10:3:2; the mass ratio of deionized water to pretreated functional mineral powder is 4:1; the sol agent is prepared by mixing silane coupling agent KH-570 and anhydrous ethanol at a volume ratio of 1:10; and the volume-to-mass ratio of the sol agent to the pretreated functional mineral powder is 1:

3.

4. The method of claim 1, wherein, In step S003, the composite cellulose dry powder is prepared by mixing cellulose nanofilaments and chitosan at a mass ratio of 8:2, adding 1.5% deionized water based on the mass of the composite cellulose dry powder, performing ultrasonic treatment, spray drying, and air drying; and the brittle fracture treatment is performed by mechanical brittle fracture under liquid nitrogen.

5. The preparation method according to claim 1, characterized in that, In step S004, the coupling agent is prepared by mixing silane coupling agent KH-570 and anhydrous ethanol at a volume ratio of 1:25; and the volume-to-mass ratio of the coupling agent to the silane-coated functional mineral powder is 0.3:

1.

6. The method of claim 1, wherein, In step S005, the mass ratio of the composite cellulose dry powder treated by plasma to the surface-modified functional mineral powder is 1:6.

5.

7. The preparation method according to claim 1, characterized in that, The mass ratio of the pre-processed enhanced polypropylene fine particles, the network-mineral powder composite dispersion phase, the composite cellulose dry powder, the isomeric tridecanol polyoxyethylene ether dispersant, and the composite cellulose aerogel particles in step S006 is 68:18:4.6:0.5:3, and the mass ratio of the primary mixture, the polyvinyl alcohol binder, and the zinc stearate lubricant is 94.1:2:0.3.

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