Antibacterial PVC (polyvinyl chloride) plate containing oyster shells and preparation method of antibacterial PVC plate

Abstract

The invention discloses an antibacterial PVC plate containing oyster shells and a preparation method of the antibacterial PVC plate, and relates to the technical field of PVC plates. The preparation method comprises the following steps: 1, sequentially loading zinc and silver on oyster shell powder to obtain an oyster shell antibacterial agent; step 2: (1) compounding the oyster shell antibacterial agent with molybdenum oxide to obtain a composite filler; (2) pretreating the composite filler with a coupling agent to obtain a modified composite filler; and 3, uniformly mixing polyvinyl chloride resin, maleic anhydride modified polyvinyl chloride, the modified composite filler, a heat stabilizer, a lubricant, a plasticizer, an initiator and a foaming agent, carrying out melt extrusion, and pressing into a plate, thereby obtaining the antibacterial PVC plate. The prepared antibacterial PVC board not only has excellent antibacterial property, but also has excellent mechanical property and flame retardance.

Description

Technical Field

[0001] The present invention relates to the technical field of PVC plates, and specifically to an antibacterial PVC plate containing oyster shells and a preparation method thereof. Background Art

[0002] PVC (polyvinyl chloride) plates are a high-yield general plastic with advantages such as light weight, corrosion resistance, and easy processing, and are widely used in fields such as architectural decoration, medical facilities, food packaging, and household items. However, traditional PVC materials themselves do not have antibacterial properties and are easily eroded by microorganisms during long-term use, resulting in performance degradation. Especially in a humid environment, the lack of antibacterial properties limits their application scope.

[0003] In the prior art, introducing antibacterial agents can effectively increase the antibacterial properties of PVC plates, generally including organic antibacterial agents or inorganic antibacterial agents; however, adding organic antibacterial agents has significant short-term effects, but there are problems such as easy migration, poor durability, possible generation of drug resistance, and environmental toxicity. Inorganic antibacterial agents have better durable antibacterial properties, but there are problems of high cost and poor dispersibility. On the other hand, calcium oxide generated by high-temperature calcination of oyster shells has strong alkalinity and photocatalytic activity and can produce antibacterial effects; however, it has problems of poor dispersibility and compatibility in PVC plates, which will lead to a decrease in mechanical strength. In addition, the flame retardancy of PVC plates needs to be further improved.

[0004] In summary, to solve the above problems, it is of great significance to prepare an antibacterial PVC plate containing oyster shells. Summary of the Invention

[0005] The purpose of the present invention is to provide an antibacterial PVC plate containing oyster shells and a preparation method thereof to solve the problems raised in the above background art.

[0006] To solve the above technical problems, the present invention provides the following technical solutions:

[0007] A preparation method of an antibacterial PVC plate containing oyster shells includes the following steps:

[0008] Step 1: Load zinc and silver onto oyster shell powder in sequence to obtain an oyster shell antibacterial agent;

[0009] Step 2: (1) Compound the oyster shell antibacterial agent with molybdenum oxide to obtain a composite filler; (2) Pretreat the composite filler with a coupling agent to obtain a modified composite filler;

[0010] Step 3: Mix polyvinyl chloride resin, maleic anhydride-modified polyvinyl chloride, modified composite filler, heat stabilizer, lubricant, plasticizer, initiator, and foaming agent evenly, melt-extrude, and then press into a plate to obtain an antibacterial PVC plate.

[0011] More preferably, the raw materials of the antibacterial PVC sheet include the following components: by weight, 60-70 parts of polyvinyl chloride resin, 10-15 parts of maleic anhydride modified polyvinyl chloride, 20-25 parts of modified composite filler, 2-3 parts of heat stabilizer, 0.5-1 part of lubricant, 2-3 parts of plasticizer, 0.1-0.2 part of initiator, and 3-6 parts of foaming agent.

[0012] More preferably, the temperature of the melt extrusion is 140-145 °C; the process of pressing into a sheet is as follows: maintaining at 2-3 MPa for 100-120 seconds, at 6-7 MPa for 180-200 seconds, and at 10-12 MPa for 180-200 seconds.

[0013] More preferably, the preparation method of the oyster shell antibacterial agent is as follows: adding oyster shell powder into a zinc nitrate solution with a concentration of 0.4-0.5 mol / L, stirring for 20-24 hours, filtering and drying, heat-treating at 500-600 °C for 3-4 hours, and then cooling; transferring it into a silver nitrate solution with a concentration of 0.1-0.12 mol / L, adding corn starch, stirring in the dark for 40-48 hours, washing and drying to obtain the oyster shell antibacterial agent;

[0014] In the raw materials of the oyster shell antibacterial agent, the ratio of oyster shell powder to zinc nitrate solution, silver nitrate solution, and corn starch is 1 g:(50-60 mL):(10-15 mL):0.1 g.

[0015] More preferably, in the composite filler, the mass ratio of the oyster shell antibacterial agent to molybdenum oxide is 1:1.

[0016] More preferably, the preparation method of the modified composite filler is as follows: adding the composite filler and polyether titanate into an ethanol aqueous solution with a concentration of 90-95 wt%, stirring at 70-75 °C for 4-5 hours, and drying to obtain the modified composite filler; among them, the mass ratio of the composite filler to polyether titanate is (16-20):(4-5).

[0017] More preferably, the preparation method of the polyether titanate is as follows: adding isooctanol, polyethylene glycol, and 1,5-hexadiene-3,4-diol into dichloromethane, adding phosphorus pentoxide, and stirring at 60-65 °C for 1-2 hours; adding a titanium isopropoxide-dichloromethane solution, dropping sodium pyrophosphate, and heating to 80-85 °C and stirring for 2-3 hours, and then removing the solvent to obtain the polyether titanate;

[0018] In the raw materials of the polyether titanate, the molar ratio of isooctanol, polyethylene glycol, 1,5-hexadiene-3,4-diol, titanium isopropoxide, and sodium pyrophosphate is 1:(0.85-0.9):(0.1-0.15):(2.8-3.4):1.

[0019] More preferably, the average molecular weight of the polyethylene glycol is 2000-4000.

[0020] More preferably, the heat stabilizer includes a barium-zinc liquid stabilizer; the lubricant includes one of polyethylene wax and calcium stearate; the plasticizer includes one of epoxidized soybean oil and dioctyl phthalate; the initiator includes dibenzoyl peroxide.

[0021] An antibacterial PVC sheet and a preparation method thereof containing oyster shells.

[0022] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: In this application, an oyster shell antibacterial agent is prepared based on oyster shells, and it is introduced into the PVC sheet as a composite filler together with molybdenum oxide, achieving synergistic flame retardancy on the basis of synergistic antibacterial properties; and a specifically prepared polyether titanate is used to modify the composite filler, effectively improving the dispersibility and interfacial properties of the composite filler in the PVC sheet, and improving comprehensive properties such as flame retardancy while ensuring mechanical properties.

[0023] First, oyster shell is a calcium carbonate-containing porous material with certain antibacterial properties. Using biological wastes such as oyster shells as raw materials not only reduces costs but also realizes the recycling of resources. However, when used directly, the antibacterial performance is average; in order to effectively improve the antibacterial property, in the solution, zinc and silver are successively loaded on it; compared with single metal loading, the dual-metal loading enables the oyster powder, zinc oxide, and silver to produce a synergistic effect, effectively improving its antibacterial property. At the same time, due to the dual loading, in order to inhibit the aggregation during the later loading, corn starch is introduced during the silver loading process. It not only acts as a reducing agent but also can effectively inhibit aggregation. At the same time, the reduced silver can form a flower shape, maximizing the antibacterial property of the oyster shell antibacterial agent. At the same time, the oyster shell antibacterial agent also has good flame retardant properties.

[0024] Second, molybdenum oxide also has certain antibacterial and flame retardant properties. Compared with introducing only the oyster shell antibacterial agent as a filler, its compounding with molybdenum oxide to form a composite filler can improve the antibacterial property of the PVC sheet, and has a significant inhibitory effect on Escherichia coli, Staphylococcus aureus, etc., with high and long-lasting antibacterial efficiency. At the same time, there is a synergistic effect on the flame retardant property, effectively reducing the heat release rate and smoke generation rate of the PVC sheet. During the process, the oyster shell antibacterial agent can cause early pyrolysis of PVC, and its pores can adsorb salt spray to form a physical barrier, while molybdenum trioxide promotes the cross-linking reaction of polyvinyl chloride in a wider temperature range by catalyzing the pyrolysis of aromatics that are not easily converted and the dehydrochlorination reaction, which can generate a large amount of stable carbon residues in the condensed phase, resulting in better flame retardant and smoke suppression effects and contributing to self-extinguishing.

[0025] Thirdly, in order to effectively improve the dispersibility of the composite filler, promote the crosslinking property with the remaining PVC, and ensure the mechanical properties of the PVC board, in the solution, polyether titanate is prepared for modification. Among them, polyether titanate contains titanium and phosphorus, which can further promote flame retardancy; and it contains a long polyethylene glycol chain segment, which can effectively inhibit the aggregation of the composite filler and effectively improve the dispersibility; at the same time, due to the long polyethylene glycol chain segment, mechanical interlocking can occur between the polyethylene glycol chain segment and the polyvinyl chloride molecular chain, effectively increasing the interfacial interaction; the unsaturated groups contained can crosslink with maleic anhydride-modified polyvinyl chloride, further promoting the interfacial interaction. It should be noted that: the molecular weight of polyethylene glycol in polyether titanate needs to be limited, and the molecular weight will affect the interfacial adhesion, so as to ensure the overall mechanical properties. Detailed implementation mode

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0027] It should be noted that the following parts are by weight, and there are no special restrictions on the purchase manufacturers of all raw materials involved in the present invention. Exemplarily, including: in the following embodiments, the CAS number of isooctanol is 26952-21-6, the CAS number of 1,5-hexadiene-3,4-diol is 1069-23-4, the CAS number of titanium isopropoxide is 546-68-9, the CAS number of sodium pyrophosphate is 7722-88-5, the brand of oyster shell powder is Snowt, the brand of polyvinyl chloride resin is Zhonghe, and the product number is 1000109; the brand of epoxidized soybean oil is Hongyunchang Chemical Industry, and the product number is 00084; molybdenum oxide is molybdenum trioxide, and the brand is Shanghai Pande; maleic anhydride-modified polyvinyl chloride is prepared based on part 1.3 of the prior art Zhang Wenlong's "Preparation of Maleic Anhydride Grafted Modified Chlorinated Polyvinyl Chloride and Its Application in PVC".

[0028] Preparation of polyether titanate: Add isooctanol, polyethylene glycol 4000, and 1,5-hexadiene-3,4-diol to dichloromethane, add phosphorus pentoxide, and stir at 65 °C for 1 hour; add titanium isopropoxide-dichloromethane solution, dropwise add sodium pyrophosphate, and raise the temperature to 80 °C and stir for 3 hours. Remove the solvent to obtain polyether titanate; among them, the molar ratio of isooctanol, polyethylene glycol, 1,5-hexadiene-3,4-diol, titanium isopropoxide, and sodium pyrophosphate is 1:0.88:0.12:3:1.

[0029] Example 1: A preparation method of an antibacterial PVC board containing oyster shell, comprising the following steps:

[0030] Step 1: Add oyster shell powder into a 0.5 mol / L zinc nitrate solution, stir for 24 hours, filter and dry, then heat-treat at 600 °C for 4 hours and cool down; transfer it to a 0.1 mol / L silver nitrate solution, add corn starch, stir in the dark for 48 hours, wash and dry to obtain an oyster shell antibacterial agent; wherein, the ratio of oyster shell powder to zinc nitrate solution, silver nitrate solution, and corn starch is 1 g: 50 mL: 10 mL: 0.1 g;

[0031] Step 2: (1) Compound the oyster shell antibacterial agent and molybdenum oxide in a mass ratio of 1:1 to obtain a composite filler; (2) Add the composite filler and polyether titanate into a 95 wt% ethanol aqueous solution in sequence, stir at 70 °C for 4 hours, and dry to obtain a modified composite filler; wherein, the mass ratio of the composite filler to polyether titanate is 20:4.

[0032] Step 3: Mix 68 parts of polyvinyl chloride resin, 13 parts of maleic anhydride-modified polyvinyl chloride, 24 parts of the modified composite filler, 2 parts of barium-zinc liquid stabilizer, 1 part of polyethylene wax, 2 parts of epoxidized soybean oil, 0.1 part of dibenzoyl peroxide, and 4 parts of AC blowing agent evenly, melt-extrude at 145 °C and then press into a plate. During the process: maintain at 3 MPa for 100 seconds, 7 MPa for 200 seconds, and 12 MPa for 200 seconds to obtain an antibacterial PVC plate.

[0033] Example 2: A preparation method of an antibacterial PVC plate containing oyster shells, comprising the following steps:

[0034] Step 1: Add oyster shell powder into a 0.5 mol / L zinc nitrate solution, stir for 24 hours, filter and dry, then heat-treat at 600 °C for 4 hours and cool down; transfer it to a 0.1 mol / L silver nitrate solution, add corn starch, stir in the dark for 48 hours, wash and dry to obtain an oyster shell antibacterial agent; wherein, the ratio of oyster shell powder to zinc nitrate solution, silver nitrate solution, and corn starch is 1 g: 50 mL: 10 mL: 0.1 g;

[0035] Step 2: (1) Compound the oyster shell antibacterial agent and molybdenum oxide in a mass ratio of 1:1 to obtain a composite filler; (2) Add the composite filler and polyether titanate into a 95 wt% ethanol aqueous solution in sequence, stir at 70 °C for 4 hours, and dry to obtain a modified composite filler; wherein, the mass ratio of the composite filler to polyether titanate is 16:4.

[0036] Step 3: Mix 60 parts of polyvinyl chloride resin, 10 parts of maleic anhydride modified polyvinyl chloride, 20 parts of modified composite filler, 2 parts of barium zinc liquid stabilizer, 0.5 part of polyethylene wax, 2 parts of epoxidized soybean oil, 0.1 part of dibenzoyl peroxide, and 3 parts of AC blowing agent evenly, melt and extrude at 145 °C, and then press into a plate. During the process: keep at 3 MPa for 100 seconds, 7 MPa for 200 seconds, and 12 MPa for 200 seconds to obtain the antibacterial PVC plate.

[0037] Example 3: A preparation method of an antibacterial PVC plate containing oyster shell, comprising the following steps:

[0038] Step 1: Add oyster shell powder to a 0.5 mol / L zinc nitrate solution, stir for 24 hours, filter and dry, heat-treat at 600 °C for 4 hours, and cool down; transfer it to a 0.1 mol / L silver nitrate solution, add corn starch, stir in the dark for 48 hours, wash and dry to obtain the oyster shell antibacterial agent; wherein, the ratio of oyster shell powder to zinc nitrate solution, silver nitrate solution, and corn starch is 1 g:50 mL:10 mL:0.1 g;

[0039] Step 2: (1) Compound the oyster shell antibacterial agent and molybdenum oxide in a mass ratio of 1:1 to obtain a composite filler; (2) Add the composite filler and polyether titanate to an aqueous ethanol solution of 95 wt% in sequence, stir at 70 °C for 4 hours, and dry to obtain the modified composite filler; wherein, the mass ratio of the composite filler to polyether titanate is 20:5.

[0040] Step 3: Mix 70 parts of polyvinyl chloride resin, 15 parts of maleic anhydride modified polyvinyl chloride, 25 parts of modified composite filler, 3 parts of barium zinc liquid stabilizer, 1 part of polyethylene wax, 3 parts of epoxidized soybean oil, 0.2 part of dibenzoyl peroxide, and 6 parts of AC blowing agent evenly, melt and extrude at 145 °C, and then press into a plate. During the process: keep at 3 MPa for 100 seconds, 7 MPa for 200 seconds, and 12 MPa for 200 seconds to obtain the antibacterial PVC plate.

[0041] Comparative Example 1: Use oyster shell powder modified with single zinc; the rest is the same as in Example 1; it includes the following steps:

[0042] Step 1: Add oyster shell powder to a 0.5 mol / L zinc nitrate solution, stir for 24 hours, filter and dry, heat-treat at 600 °C for 4 hours, and cool down; obtain the oyster shell antibacterial agent; wherein, the ratio of oyster shell powder to zinc nitrate solution is 1 g:50 mL;

[0043] Step 2: (1) Compound oyster shell antibacterial agent and molybdenum oxide in a mass ratio of 1:1 to obtain a composite filler; (2) Add the composite filler and polyether titanate to 95wt% ethanol aqueous solution in sequence, stir at 70°C for 4 hours, and dry to obtain a modified composite filler; wherein, the mass ratio of the composite filler to polyether titanate is 20:4.

[0044] Step 3: Mix 68 parts of polyvinyl chloride resin, 13 parts of maleic anhydride modified polyvinyl chloride, 24 parts of modified composite filler, 2 parts of barium zinc liquid stabilizer, 1 part of polyethylene wax, 2 parts of epoxidized soybean oil, 0.1 part of dibenzoyl peroxide, and 4 parts of AC foaming agent evenly, melt and extrude at 145°C, and then press into a plate. During the process: keep at 3MPa for 100 seconds, 7MPa for 200 seconds, and 12MPa for 200 seconds to obtain an antibacterial PVC sheet.

[0045] Comparative Example 2: Use oyster shell antibacterial agent and zinc oxide as the composite filler; the rest is the same as in Example 1; including the following steps:

[0046] Step 1: Add oyster shell powder to 0.5mol / L zinc nitrate solution, stir for 24 hours, filter and dry, place it in a heat treatment at 600°C for 4 hours, and cool down; transfer it to 0.1mol / L silver nitrate solution, add corn starch, stir in the dark for 48 hours, wash and dry to obtain oyster shell antibacterial agent; wherein, the ratio of oyster shell powder to zinc nitrate solution, silver nitrate solution, and corn starch is 1g:50mL:10mL:0.1g;

[0047] Step 2: (1) Compound oyster shell antibacterial agent and zinc oxide in a mass ratio of 1:1 to obtain a composite filler; (2) Add the composite filler and polyether titanate to 95wt% ethanol aqueous solution in sequence, stir at 70°C for 4 hours, and dry to obtain a modified composite filler; wherein, the mass ratio of the composite filler to polyether titanate is 20:4.

[0048] Step 3: Mix 68 parts of polyvinyl chloride resin, 13 parts of maleic anhydride modified polyvinyl chloride, 24 parts of modified composite filler, 2 parts of barium zinc liquid stabilizer, 1 part of polyethylene wax, 2 parts of epoxidized soybean oil, 0.1 part of dibenzoyl peroxide, and 4 parts of AC foaming agent evenly, melt and extrude at 145°C, and then press into a plate. During the process: keep at 3MPa for 100 seconds, 7MPa for 200 seconds, and 12MPa for 200 seconds to obtain an antibacterial PVC sheet.

[0049] Comparative Example 3: Replace the silane coupling agent; the rest is the same as in Example 1; including the following steps:

[0050] Step 1: Add oyster shell powder into a 0.5 mol / L zinc nitrate solution, stir for 24 hours, filter, dry, heat-treat at 600 °C for 4 hours, and then cool down; transfer it to a 0.1 mol / L silver nitrate solution, add corn starch, stir in the dark for 48 hours, wash and dry to obtain an oyster shell antibacterial agent; wherein, the ratio of oyster shell powder to zinc nitrate solution, silver nitrate solution, and corn starch is 1 g: 50 mL: 10 mL: 0.1 g;

[0051] Step 2: (1) Compound the oyster shell antibacterial agent and molybdenum oxide in a mass ratio of 1:1 to obtain a composite filler; (2) Add the composite filler and KH172 successively into a 95 wt% ethanol aqueous solution, stir at 70 °C for 4 hours, and dry to obtain a modified composite filler; wherein, the mass ratio of the composite filler to polyether titanate is 20:4.

[0052] Step 3: Mix 68 parts of polyvinyl chloride resin, 13 parts of maleic anhydride-modified polyvinyl chloride, 24 parts of modified composite filler, 2 parts of barium-zinc liquid stabilizer, 1 part of polyethylene wax, 2 parts of epoxidized soybean oil, 0.1 part of dibenzoyl peroxide, and 4 parts of AC blowing agent evenly, melt-extrude at 145 °C, and then press into a plate. During the process: keep at 3 MPa for 100 seconds, 7 MPa for 200 seconds, and 12 MPa for 200 seconds to obtain an antibacterial PVC sheet.

[0053] Comparative Example 4: Adjust the molecular weight of polyethylene glycol in polyether titanate; the rest is the same as in Example 1; the difference lies in:

[0054] Preparation in advance: Preparation of polyether titanate: Add isooctanol, polyethylene glycol 600, 1,5-hexadiene-3,4-diol into dichloromethane, add phosphorus pentoxide, stir at 65 °C for 1 hour; add titanium isopropoxide-dichloromethane solution, dropwise add sodium pyrophosphate, heat up to 80 °C and stir for 3 hours, remove the solvent to obtain polyether titanate; wherein, the molar ratio of isooctanol, polyethylene glycol, 1,5-hexadiene-3,4-diol, titanium isopropoxide, and sodium pyrophosphate is 1:0.88:0.12:3:1.

[0055] Step 1: Add oyster shell powder into a 0.5 mol / L zinc nitrate solution, stir for 24 hours, filter, dry, heat-treat at 600 °C for 4 hours, and then cool down; transfer it to a 0.1 mol / L silver nitrate solution, add corn starch, stir in the dark for 48 hours, wash and dry to obtain an oyster shell antibacterial agent; wherein, the ratio of oyster shell powder to zinc nitrate solution, silver nitrate solution, and corn starch is 1 g: 50 mL: 10 mL: 0.1 g;

[0056] Step 2: (1) Mix oyster shell antibacterial agent and molybdenum oxide in a mass ratio of 1:1 to obtain a composite filler; (2) Add the composite filler and polyether titanate to an aqueous ethanol solution of 95 wt% in sequence, stir at 70 °C for 4 hours, and dry to obtain a modified composite filler; wherein, the mass ratio of the composite filler to polyether titanate is 20:4.

[0057] Step 3: Mix 68 parts of polyvinyl chloride resin, 13 parts of maleic anhydride-modified polyvinyl chloride, 24 parts of modified composite filler, 2 parts of barium-zinc liquid stabilizer, 1 part of polyethylene wax, 2 parts of epoxidized soybean oil, 0.1 part of dibenzoyl peroxide, and 4 parts of AC blowing agent evenly, melt-extrude at 145 °C, and then press into a plate. During the process: keep at 3 MPa for 100 seconds, 7 MPa for 200 seconds, and 12 MPa for 200 seconds to obtain an antibacterial PVC plate.

[0058] Performance test 1: For the antibacterial PVC plates prepared in the examples and comparative examples, detect the antibacterial rate of Escherichia coli according to the standard of GB / T31402, and leave them standing at room temperature for 200 days according to the standard of QB / T2591, and then detect the antibacterial rate of Escherichia coli again to calculate the retention rate. Detect its notch impact strength according to GB / T1043.1; use an oxygen index analyzer to detect its limiting oxygen index; the obtained data are shown in the following table:

[0059] Sample Antibacterial rate % Antibacterial retention rate % <![CDATA[Notched impact strength kj / m 2 > Limiting oxygen index % Example 1 99.5 98.7 14.48 30.7 Comparative Example 1 98.6 94.3 14.20 29.3 Comparative Example 2 99.6 98.5 14.35 28.9 Comparative Example 3 99.4 95.4 12.89 28.4 Comparative Example 4 99.5 97.3 13.45 29.2

[0060] Conclusion: It can be seen from the data in the above table that in this application, an oyster shell antibacterial agent and molybdenum oxide form a composite filler and are modified with a specific silane coupling agent, and are introduced into the PVC plate, effectively improving the antibacterial property and flame retardancy synergistically while ensuring the mechanical properties. In Comparative Examples 1-4, in Comparative Example 1, due to the use of single-zinc modified oyster shell powder, the performance decreased slightly; in Comparative Example 2, due to the use of zinc oxide and oyster shell antibacterial agent, the flame retardancy decreased slightly; in Comparative Example 3, due to the replacement of the silane coupling agent, the performance decreased to a large extent; in Comparative Example 4, due to the decrease in the molecular weight of polyethylene glycol in the silane coupling agent, the interfacial performance decreased, resulting in a decrease in related properties.

[0061] Performance test 2: Conduct Shore hardness and anti-deformation tests on the antibacterial PVC plates with different thicknesses prepared in Example 1.

[0062] Result: The Shore hardness of the antibacterial PVC plate with a thickness of 9 mm and a density of 0.7 kg / m 3 is 57; the instantaneous strain result of the antibacterial PVC plate with a thickness of 18 mm and a density of 0.7 kg / m 3 is 71 mm, and the change value of the deformation amount after 3 days of loading is 38 mm.

[0063] Performance Test 3: Detect the heavy metals of the antibacterial PVC board prepared in Example 1 according to the standard of GB / T26125.

[0064] Results: In the antibacterial PVC board with a thickness of 9 mm, the MDL of cadmium is 8.3, the MDL of lead is 3.9, and the MDL of mercury is 8.2.

[0065] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preparation method of an antibacterial PVC sheet containing oyster shells, characterized in that: It includes the following steps: Step 1: Load zinc and silver onto oyster shell powder in sequence to obtain oyster shell antibacterial agent. Step 2: (1) Compound the oyster shell antibacterial agent with molybdenum oxide to obtain a composite filler; (2) Pretreat the composite filler with a coupling agent to obtain a modified composite filler. Step 3: Mix polyvinyl chloride resin, maleic anhydride modified polyvinyl chloride, modified composite filler, heat stabilizer, lubricant, plasticizer, initiator, and foaming agent evenly, melt and extrude, and then press into a plate to obtain an antibacterial PVC plate.

2. The preparation method of an antibacterial PVC sheet containing oyster shells according to claim 1, characterized in that: The raw materials of the antibacterial PVC plate include the following components: by weight, 60 - 70 parts of polyvinyl chloride resin, 10 - 15 parts of maleic anhydride modified polyvinyl chloride, 20 - 25 parts of modified composite filler, 2 - 3 parts of heat stabilizer, 0.5 - 1 part of lubricant, 2 - 3 parts of plasticizer, 0.1 - 0.2 part of initiator, and 3 - 6 parts of foaming agent.

3. The preparation method of an antibacterial PVC sheet containing oyster shells according to claim 1, characterized in that: The temperature of the melt extrusion is 140 - 145 °C; the process of pressing into a plate is: maintaining at 2 - 3 MPa for 100 - 120 seconds, at 6 - 7 MPa for 180 - 200 seconds, and at 10 - 12 MPa for 180 - 200 seconds.

4. The preparation method of an antibacterial PVC sheet containing oyster shells according to claim 1, characterized in that: The preparation method of the oyster shell antibacterial agent is: Add oyster shell powder into a zinc nitrate solution with a concentration of 0.4 - 0.5 mol / L, stir for 20 - 24 hours, filter and dry, heat-treat at 500 - 600 °C for 3 - 4 hours, and cool down; Transfer it into a silver nitrate solution with a concentration of 0.1 - 0.12 mol / L, add corn starch, stir in the dark for 40 - 48 hours, wash and dry to obtain the oyster shell antibacterial agent. In the raw materials of the oyster shell antibacterial agent, the ratio of oyster shell powder to zinc nitrate solution, silver nitrate solution, and corn starch is 1 g : (50 - 60 mL) : (10 - 15 mL) : 0.1 g.

5. The preparation method of an antibacterial PVC sheet containing oyster shells according to claim 1, characterized in that: In the composite filler, the mass ratio of the oyster shell antibacterial agent to molybdenum oxide is 1:

1.

6. The preparation method of an antibacterial PVC sheet containing oyster shells according to claim 1, characterized in that: The preparation method of the modified composite filler is: Add the composite filler and polyether titanate into an ethanol aqueous solution with a concentration of 90 - 95 wt%, stir at 70 - 75 °C for 4 - 5 hours, and dry to obtain the modified composite filler; Among them, the mass ratio of the composite filler to polyether titanate is (16 - 20) : (4 - 5).

7. The preparation method of an antibacterial PVC sheet containing oyster shells according to claim 6, characterized in that: The preparation method of the polyether titanate is: Add isooctanol, polyethylene glycol, 1,5 - hexadiene - 3,4 - diol into dichloromethane, add phosphorus pentoxide, stir at 60 - 65 °C for 1 - 2 hours; Add titanium isopropoxide - dichloromethane solution, dropwise add sodium pyrophosphate, heat up to 80 - 85 °C and stir for 2 - 3 hours, and remove the solvent to obtain the polyether titanate. In the raw materials of the polyether titanate, the molar ratio of isooctanol, polyethylene glycol, 1,5 - hexadiene - 3,4 - diol, titanium isopropoxide, and sodium pyrophosphate is 1 : (0.85 - 0.9) : (0.1 - 0.15) : (2.8 - 3.4) :

1.

8. The preparation method of an antibacterial PVC sheet containing oyster shells according to claim 7, characterized in that: The average molecular weight of the polyethylene glycol is 2000 - 4000.

9. The preparation method of an antibacterial PVC sheet containing oyster shells according to claim 1, characterized in that: The heat stabilizer includes barium-zinc liquid stabilizer; the lubricant includes one of polyethylene wax and calcium stearate; the plasticizer includes one of epoxidized soybean oil and dioctyl phthalate; the initiator includes benzoyl peroxide.

10. An antibacterial PVC sheet produced by the method for preparing an antibacterial PVC sheet containing oyster shells according to any one of claims 1 to 9.