Antibacterial PVC plate containing oyster shell and preparation method thereof

Abstract

The application discloses an antibacterial PVC plate containing oyster shells and a preparation method thereof, and relates to the technical field of PVC plates. Step 1: oyster shell powder is loaded with zinc and silver in sequence to obtain an oyster shell antibacterial agent; Step 2: (1) the oyster shell antibacterial agent is compounded with molybdenum oxide to obtain a composite filler; (2) the composite filler is pretreated with a coupling agent to obtain a modified composite filler; Step 3: 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 are uniformly mixed, melt-extruded, and then pressed into a plate to obtain the antibacterial PVC plate. The prepared antibacterial PVC plate not only has excellent antibacterial property, but also has excellent mechanical property and flame retardancy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of PVC plate, and particularly relates to an antibacterial PVC plate containing oyster shells and a preparation method thereof. BACKGROUND

[0002] PVC (polyvinyl chloride) plate is a kind of high-yield general-purpose plastic with the advantages of light weight, corrosion resistance, easy processing, etc., and is widely used in fields such as building decoration, medical facilities, food packaging and household supplies. However, the traditional PVC material itself does not have antibacterial properties, and is easily eroded by microorganisms during long-term use, resulting in performance degradation, especially in a humid environment, the lack of antibacterial properties limits its application range.

[0003] In the prior art, the introduction of antibacterial agents can effectively increase the antibacterial properties of PVC plate, generally including organic antibacterial agents or inorganic antibacterial agents; however, the addition of organic antibacterial agents has a significant short-term effect, but has problems such as easy migration, poor durability, possible drug resistance and environmental toxicity. On the other hand, calcium oxide generated by calcining oyster shells has strong alkalinity and photocatalytic activity, and can produce antibacterial effect; however, it has problems of poor dispersibility and compatibility in PVC plate, which can cause a decrease in mechanical strength. In addition, it is also necessary to further improve the flame retardance of the PVC plate.

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

[0005] The present application aims to provide an antibacterial PVC plate containing oyster shells and a preparation method thereof, to solve the problems raised in the background.

[0006] In order to solve the above technical problems, the present application provides the following technical solutions:

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

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

[0009] 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;

[0010] Step 3: uniformly mixing polyvinyl chloride resin, maleic anhydride modified polyvinyl chloride, modified composite filler, heat stabilizer, lubricant, plasticizer, initiator and foaming agent, melt extruding, and then pressing into a plate to obtain the antibacterial PVC plate.

[0011] More preferably, the raw materials of the antibacterial PVC plate include the following components: 60-70 parts by weight 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 parts of initiator, and 3-6 parts of foaming agent.

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

[0013] More preferably, the preparation method of the oyster shell antibacterial agent is as follows: oyster shell powder is added to a 0.4-0.5mol / L zinc nitrate solution, stirred for 20-24 hours, filtered, dried, heated at 500-600℃ for 3-4 hours, and cooled; then it is transferred to a 0.1-0.12mol / L silver nitrate solution, corn starch is added, stirred in the dark for 40-48 hours, washed and dried to obtain the oyster shell antibacterial agent.

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

[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: the composite filler and polyether titanate are sequentially added to 90-95wt% ethanol aqueous solution, stirred at 70-75℃ for 4-5 hours, and dried to obtain the modified composite filler; wherein 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: isooctanol, polyethylene glycol, 1,5-hexadiene-3,4-diol, and phosphorus pentoxide are added to dichloromethane, stirred at 60-65℃ for 1-2 hours; titanium isopropoxide-dichloromethane solution is added, sodium pyrophosphate is added dropwise, and stirred at 80-85℃ for 2-3 hours; and the solvent is removed 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 comprises a barium zinc liquid stabilizer; the lubricant comprises one of polyethylene wax, calcium stearate; the plasticizer comprises one of epoxidized soybean oil, dioctyl phthalate; the initiator comprises dibenzoyl peroxide.

[0021] An antibacterial PVC plate containing oyster shell and a preparation method thereof.

[0022] Compared with the prior art, the application has the beneficial effects that: in the application, the oyster shell is used as a basis to prepare an oyster shell antibacterial agent, which is introduced into the PVC plate as a composite filler with molybdenum oxide, and the antibacterial and flame-retardant effects are synergistic; and the composite filler is modified by using a specially prepared polyether titanate, which effectively improves the dispersibility and interfacial properties of the composite filler in the PVC plate, and improves the comprehensive properties such as flame retardancy on the basis of ensuring the mechanical properties.

[0023] Firstly, the oyster shell is a porous material containing calcium carbonate and has certain antibacterial properties; using biological waste such as oyster shell as a raw material not only reduces the cost but also realizes the recycling of resources. However, the antibacterial performance is generally poor when used directly; in order to effectively improve the antibacterial properties, the oyster shell is sequentially loaded with zinc and silver in the scheme; compared with single loading of one kind of metal, double metal loading makes the oyster shell powder, zinc oxide and silver produce a synergistic effect, effectively improving the antibacterial properties. At the same time, due to double loading, in order to inhibit the aggregation of the later loading, corn starch is introduced during the silver loading process, which not only acts as a reducing agent but also effectively inhibits aggregation, and the reduced silver can form a flower shape, which can maximize the antibacterial properties of the oyster shell antibacterial agent. The oyster shell antibacterial agent also has good flame-retardant properties.

[0024] Secondly, molybdenum trioxide also has certain antibacterial and flame-retardant properties; compared with single introduction of the oyster shell antibacterial agent as a filler, the molybdenum trioxide is compounded with the oyster shell antibacterial agent to form a composite filler, which can significantly inhibit the growth of E. coli and Staphylococcus aureus and has high and long-lasting antibacterial efficiency. At the same time, the flame-retardant properties have a synergistic effect, effectively reducing the heat release rate and smoke generation rate of the PVC plate. During the process, the oyster shell antibacterial agent can cause early pyrolysis of the PVC, the voids can adsorb salt mist to form a physical barrier, and the molybdenum trioxide catalyzes the dehydrochlorination reaction of the aromatic hydrocarbons that are not easily converted by catalytic pyrolysis, and promotes the crosslinking reaction of the polyvinyl chloride in a wider temperature range, which can generate a large amount of stable carbon residues in the condensed phase, and the flame-retardant and smoke suppression effects are better, which helps self-extinguish.

[0025] Thirdly, in order to effectively improve the dispersibility of the composite filler, promote the cross-linking of the remaining PVC, and ensure the mechanical properties of the PVC plate, the polyether titanate is prepared for modification in the scheme, wherein the polyether titanate contains titanium and phosphorus, which can further promote the flame retardancy; and it contains a long polyethylene glycol 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 segment, mechanical interlocking can be generated between the polyethylene glycol segment and the polyvinyl chloride molecular chain, effectively increasing the interfacial action; the unsaturated group can cross-link with the maleic anhydride modified polyvinyl chloride, further promoting the interfacial action. 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, thereby ensuring the overall mechanical properties. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be described below in a clear and complete manner. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0027] It should be noted that the following parts are by weight, and there is no special restriction on the purchase manufacturer of all raw materials involved in the present application, which exemplarily includes: 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 Snote, the brand of polyvinyl chloride resin is Zhonghe, and the article number is 1000109, the brand of epoxy soybean oil is Hongyun Chang Chemical, and the article number is 00084; the brand of molybdenum trioxide is Shanghai Pander, and the maleic anhydride modified polyvinyl chloride is prepared based on the existing technology Zhang Wenlong's content in part 1.3 of “Preparation of Maleic Anhydride Grafted Modified Chlorinated Polyvinyl Chloride and Its Application in PVC”.

[0028] Preparation of polyether titanate: iso-octanol, polyethylene glycol 4000, 1,5-hexadiene-3,4-diol, and 1,5-hexadiene-3,4-diol are added to dichloromethane, and phosphorus pentoxide is added, and stirred at 65℃ for 1 hour; titanium isopropoxide-dichloromethane solution is added, and sodium pyrophosphate is added dropwise, and the temperature is raised to 80℃ and stirred for 3 hours, and the solvent is removed, and polyether titanate is obtained; wherein the molar ratio of iso-octanol, 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 plate containing oyster shells, comprising the following steps:

[0030] Step 1: add oyster shell powder to a 0.5 mol / L zinc nitrate solution, stir for 24 hours, filter, dry, heat treat at 600°C for 4 hours, cool down; transfer it to a 0.1 mol / L silver nitrate solution, add corn starch, stir in the dark for 48 hours, wash, dry, and obtain an 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;

[0031] Step 2: (1) compound the oyster shell antibacterial agent with molybdenum oxide at a mass ratio of 1:1 to obtain a composite filler; (2) add the composite filler and polyether titanate to 95wt% ethanol water solution in sequence, stir at 70°C for 4 hours, dry, and obtain a modified composite filler; wherein the mass ratio of the composite filler and 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 modified composite filler, 2 parts of barium-zinc liquid stabilizer, 1 part of polyethylene wax, 2 parts of epoxy soybean oil, 0.1 part of dibenzoyl peroxide, and 4 parts of AC foaming agent uniformly, melt extrude at 145°C, and then press into a plate, during which: 3MPa for 100 seconds, 7MPa for 200 seconds, and 12MPa 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 to a 0.5 mol / L zinc nitrate solution, stir for 24 hours, filter, dry, heat treat at 600°C for 4 hours, cool down; transfer it to a 0.1 mol / L silver nitrate solution, add corn starch, stir in the dark for 48 hours, wash, dry, and obtain an 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;

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

[0036] Step 3: 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 parts of polyethylene wax, 2 parts of epoxy soybean oil, 0.1 parts of dibenzoyl peroxide, 3 parts of AC foaming agent are uniformly mixed, melt extruded at 145℃, and then pressed into a plate, during which: 3MPa for 100 seconds, 7MPa for 200 seconds, 12MPa for 200 seconds, to obtain an antibacterial PVC plate.

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

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

[0039] Step 2: (1) Compound the oyster shell antibacterial agent with molybdenum oxide at a mass ratio of 1:1 to obtain a composite filler; (2) Add the composite filler and polyether titanate to 95wt% ethanol water solution in sequence, stir at 70℃ for 4 hours, and dry to obtain a modified composite filler; wherein the mass ratio of the composite filler and 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 epoxy soybean oil, 0.2 parts of dibenzoyl peroxide, and 6 parts of AC foaming agent uniformly, melt extrude at 145℃, and then press into a plate, during which: 3MPa for 100 seconds, 7MPa for 200 seconds, 12MPa for 200 seconds, to obtain an antibacterial PVC plate.

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

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

[0043] Step 2: (1) The oyster shell antibacterial agent was compounded with molybdenum oxide at a mass ratio of 1:1 to obtain a composite filler; (2) The composite filler and polyether titanate were sequentially added to a 95wt% ethanol aqueous solution, stirred at 70°C for 4 hours, dried to obtain a modified composite filler; wherein the mass ratio of the composite filler and polyether titanate was 20:4.

[0044] Step 3: 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 epoxy soybean oil, 0.1 part of dibenzoyl peroxide, 4 parts of AC foaming agent were uniformly mixed, melt extruded at 145°C, and then pressed into a plate, during which: 3MPa for 100 seconds, 7MPa for 200 seconds, 12MPa for 200 seconds, to obtain an antibacterial PVC plate.

[0045] Comparative Example 2: The oyster shell antibacterial agent and zinc oxide were used as the composite filler; the rest was the same as Example 1; including the following steps:

[0046] Step 1: The oyster shell powder was added to a 0.5mol / L zinc nitrate solution, stirred for 24 hours, filtered, dried, and heated at 600°C for 4 hours, and then cooled; it was transferred to a 0.1mol / L silver nitrate solution, cornstarch was added, stirred in the dark for 48 hours, washed and dried to obtain the oyster shell antibacterial agent; wherein the ratio of oyster shell powder, zinc nitrate solution, silver nitrate solution and cornstarch was 1g:50mL:10mL:0.1g;

[0047] Step 2: (1) The oyster shell antibacterial agent was compounded with zinc oxide at a mass ratio of 1:1 to obtain a composite filler; (2) The composite filler and polyether titanate were sequentially added to a 95wt% ethanol aqueous solution, stirred at 70°C for 4 hours, dried to obtain a modified composite filler; wherein the mass ratio of the composite filler and polyether titanate was 20:4.

[0048] Step 3: 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 epoxy soybean oil, 0.1 part of dibenzoyl peroxide, 4 parts of AC foaming agent were uniformly mixed, melt extruded at 145°C, and then pressed into a plate, during which: 3MPa for 100 seconds, 7MPa for 200 seconds, 12MPa for 200 seconds, to obtain an antibacterial PVC plate.

[0049] Comparative Example 3: The silane coupling agent was replaced; the rest was the same as Example 1; including the following steps:

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

[0051] Step 2: (1) compound the oyster shell antibacterial agent with molybdenum oxide according to a mass ratio of 1:1 to obtain a composite filler; (2) add the composite filler and KH172 successively to 95wt% ethanol aqueous solution, stir at 70℃ for 4 hours, dry to obtain a modified composite filler; wherein the mass ratio of the composite filler and 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 epoxy soybean oil, 0.1 part of dibenzoyl peroxide, 4 parts of AC foaming agent uniformly, melt extrude at 145℃, then press into a plate, during which: 3MPa for 100 seconds, 7MPa for 200 seconds, 12MPa for 200 seconds, to obtain an antibacterial PVC plate.

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

[0054] Preparation: preparation of polyether titanate: add isooctanol, polyethylene glycol 600, 1,5-hexadiene-3,4-diol into dichloromethane, add phosphorus pentoxide, stir at 65℃ for 1 hour; add titanium isopropoxide-dichloromethane solution, drop sodium pyrophosphate, heat to 80℃ 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, sodium pyrophosphate is 1:0.88:0.12:3:1.

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

[0056] Step 2: (1) The oyster shell antibacterial agent was compounded with molybdenum oxide at a mass ratio of 1:1 to obtain a composite filler; (2) the composite filler and polyether titanate were sequentially added to a 95wt% ethanol aqueous solution, stirred at 70°C for 4 hours, dried to obtain a modified composite filler; wherein the mass ratio of the composite filler and polyether titanate was 20:4.

[0057] Step 3: 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 epoxy soybean oil, 0.1 part of dibenzoyl peroxide, 4 parts of AC foaming agent were uniformly mixed, melt extruded at 145°C, and then pressed into a plate, during which: 3MPa for 100 seconds, 7MPa for 200 seconds, 12MPa for 200 seconds, to obtain an antibacterial PVC plate.

[0058] Performance Test 1: The antibacterial PVC plate prepared in the examples and comparative examples was detected for the bacteriostatic rate of E. coli according to the standard of GB / T31402, and then detected for the bacteriostatic rate of E. coli again after standing at room temperature for 200 days according to the standard of QB / T2591, and the retention rate was calculated. The notched impact strength was detected according to GB / T1043.1; the limiting oxygen index was detected using an oxygen index tester; the obtained data are shown in the following table:

[0059] Sample % Bacteriostatic rate % Bacteriostatic retention rate Notched Charpy 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: From the data in the above table, it can be seen that: the composite filler formed by the oyster shell antibacterial agent and molybdenum oxide and modified by a specific silane coupling agent is introduced into the PVC plate, which effectively improves the antibacterial property and flame retardancy on the basis of ensuring the mechanical property. In Comparative Examples 1-4, the performance of Comparative Example 1 slightly decreased due to the use of single zinc modified oyster shell powder; the flame retardancy of Comparative Example 2 slightly decreased due to the use of zinc oxide and oyster shell antibacterial agent; the performance of Comparative Example 3 greatly decreased due to the change of silane coupling agent; the performance of Comparative Example 4 decreased due to the decrease of the molecular weight of polyethylene glycol in the silane coupling agent, which led to the decrease of the interfacial property and the related performance.

[0061] Performance Test 2: The antibacterial PVC plates of different thicknesses prepared in Example 1 were tested for Shore hardness and deformation resistance.

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

[0063] Performance test 3: The prepared antibacterial PVC plate in Example 1 was detected according to the standard of GB / T26125 to detect heavy metals.

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

[0065] Finally, it should be noted that the above only describes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application 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 make equivalent replacements to some technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing an antibacterial PVC sheet containing oyster shells, characterized in that: It comprises the following steps: Step 1: add oyster shell powder to 0.4-0.5 mol / L zinc nitrate solution, stir for 20-24 hours, filter, dry, heat treat at 500-600 DEG C for 3-4 hours, cool down; transfer it to 0.1-0.12 mol / L silver nitrate solution, add corn starch, stir in the dark for 40-48 hours, wash, dry, and obtain oyster shell antibacterial agent; Step 2: (1) compound the oyster shell antibacterial agent with molybdenum oxide to obtain a composite filler; (2) add the composite filler and polyether titanate to 90-95 wt% aqueous ethanol solution in sequence, stir at 70-75 DEG C for 4-5 hours, dry, and obtain 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 uniformly, melt extrude, then press into a plate to obtain antibacterial PVC plate; The raw material of the oyster shell antibacterial agent comprises oyster shell powder, zinc nitrate solution, silver nitrate solution, corn starch, and the ratio is 1g:(50-60 mL):(10-15 mL):0.1g; The mass ratio of the oyster shell antibacterial agent to molybdenum oxide in the composite filler is 1:1; the mass ratio of the composite filler to polyether titanate in the modified composite filler is (16-20):(4-5); The raw material of the antibacterial PVC plate comprises the following components: 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 parts of initiator, and 3-6 parts of foaming agent.

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

3. The method of claim 1, wherein the method of preparing the antibacterial PVC sheet containing oyster shells is characterized by: The preparation method of the polyether titanate is: add isooctanol, polyethylene glycol, 1,5-hexadiene-3,4-diol to dichloromethane, add phosphorus pentoxide, stir at 60-65 DEG C for 1-2 hours; add titanium isopropoxide-dichloromethane solution, drop sodium pyrophosphate, heat to 80-85 DEG C and stir for 2-3 hours, remove the solvent, and obtain polyether titanate; The molar ratio of isooctanol, polyethylene glycol, 1,5-hexadiene-3,4-diol, titanium isopropoxide and sodium pyrophosphate in the raw material of the polyether titanate is 1:(0.85-0.9):(0.1-0.15):(2.8-3.4):

1.

4. The method of claim 3, wherein the method comprises the steps of: a) mixing the oyster shell powder with the PVC compound; b) extruding the mixture; c) drying the extruded mixture; d) molding the dried mixture; and e) curing the molded mixture. The average molecular weight of the polyethylene glycol is 2000-4000.

5. The method of claim 1, wherein the method of preparing an antibacterial PVC sheet containing oyster shells is characterized by: The heat stabilizer is barium zinc liquid stabilizer; the lubricant is one of polyethylene wax and calcium stearate; the plasticizer is one of epoxy soybean oil and dioctyl phthalate; the initiator is dibenzoyl peroxide.

6. The antibacterial PVC plate according to the preparation method of claim 1-5.