Bacteriostatic stone-plastic floor and preparation method thereof

Abstract

The invention relates to the technical field of stone plastic floors, in particular to an antibacterial stone plastic floor which comprises a base material layer, a photocatalytic antibacterial layer and a surface hydrophobic film, the photocatalytic antibacterial layer is arranged on the surface of the base material layer, and the surface hydrophobic film is arranged on the surface of the photocatalytic antibacterial layer. The base material layer comprises the following components in parts by weight: 60-80 parts of polyvinyl chloride, 300-350 parts of calcium carbonate, 30-50 parts of a composite bacteriostatic agent and 1-5 parts of a coupling agent; through the synergistic effect of the compound bacteriostatic agent, the nano tea polyphenol (destroying bacterial cell membranes) and the chitosan (inhibiting bacterial metabolism) are slowly released through the modified zeolite carrier, the bacteriostasis rate on escherichia coli, staphylococcus aureus and the like is larger than 99.5%, and the bacteriostasis spectrum covers bacteria and molds.

Description

Technical Field

[0001] The invention relates to the technical field of stone plastic flooring, and in particular to an antibacterial stone plastic flooring and a preparation method thereof. Background Art

[0002] Stone plastic flooring is also called PVC flooring. Most of them are sheets. It is a new type of floor material with high quality and high technology. It uses refined calcium carbonate powder and PVC resin as the main raw materials to form a solid base layer with high density and high fiber mesh structure. The surface is impregnated with thermosetting melamine to form a wood grain or stone grain surface. The board is processed by extrusion, lamination, slicing, grooving and other processes.

[0003] Traditional stone plastic flooring is prone to breeding bacteria and mold in humid environments, especially posing health and safety risks in hospitals, kitchens and other scenarios. The existing technology mainly improves the antibacterial properties of stone plastic flooring by adding antibacterial agents, such as silver ions. However, silver ions are easily oxidized and discolored and are expensive. Single plant extracts have a narrow antibacterial spectrum and poor durability. Alternatively, antibacterial coatings are applied on the surface of stone plastic flooring to improve the antibacterial properties, but the surface coating is easily worn and falls off, resulting in rapid attenuation of the antibacterial properties. Summary of the invention

[0004] The purpose of the present invention is to overcome the problems existing in the prior art and to provide an antibacterial stone plastic floor and a preparation method thereof.

[0005] In order to achieve the above-mentioned object, the present invention provides an antibacterial stone plastic floor, comprising a substrate layer, a photocatalytic antibacterial layer and a surface hydrophobic film, wherein the photocatalytic antibacterial layer is arranged on the surface of the substrate layer, and the surface hydrophobic film is arranged on the surface of the photocatalytic antibacterial layer;

[0006] The substrate layer comprises the following components in parts by weight: 60-80 parts of polyvinyl chloride, 300-350 parts of calcium carbonate, 30-50 parts of composite antibacterial agent and 1-5 parts of coupling agent;

[0007] The photocatalytic antibacterial layer comprises a heterojunction composite of nano-titanium dioxide and graphite-phase carbon nitride, the mass ratio of nano-titanium dioxide to graphite-phase carbon nitride is 2:1 to 4:1, and the particle size is 20-50 nm.

[0008] Preferably, the surface hydrophobic film has a light transmittance of ≥85%, a contact angle of ≥110°, and a thickness of 10-30 μm.

[0009] Preferably, the composite antibacterial agent comprises the following components in parts by weight: 3 to 7 parts of nano-tea polyphenols, 2 to 6 parts of chitosan and 10 to 20 parts of zeolite powder.

[0010] Preferably, the preparation method of the composite antibacterial agent comprises the following steps:

[0011] a. Immerse zeolite powder in 2 mol / L HCl for 2 hours, wash until neutral, and calcine at 500 °C for 3 hours to expand the pores;

[0012] b. Disperse the activated zeolite powder in 2% acetic acid solution, add chitosan, stir at 60 °C for 4 hours to allow chitosan to enter the zeolite pores through electrostatic adsorption, then add silane coupling agent (KH-550), adjust the pH to 6, react at 70 °C for 2 hours, centrifuge, wash, and dry to obtain chitosan-modified zeolite support;

[0013] c. Immerse the modified zeolite support in glutaraldehyde solution, oscillate at 40 °C for 1 hour to activate the surface amino groups, add nano-tea polyphenols, adjust the pH to 6, react at 60 °C for 6 hours to bond the phenolic hydroxyl groups of tea polyphenols and the amino groups of chitosan through Schiff base reaction;

[0014] d. Finally, wash 3 times with PBS to remove unreacted substances, and dry in vacuum at 45 °C to obtain the composite antibacterial agent.

[0015] Preferably, the deacetylation degree of the chitosan is ≥90%, and the molecular weight is 5×10 4 。

[0016] Preferably, the pore size of the modified zeolite support is 2 - 5 nm, and the molar ratio of nano-tea polyphenols to chitosan is 1:2 to 1:4.

[0017] Preferably, the thickness of the photocatalytic antibacterial layer is 1 / 5 - 1 / 3 of the thickness of the substrate layer.

[0018] A preparation method of an antibacterial stone plastic floor, comprising the following steps:

[0019] S1. Substrate pretreatment: Mix polyvinyl chloride, calcium carbonate, and coupling agent, and perform activation treatment at 80 - 90 °C for 30 - 60 minutes to obtain a pretreated substrate;

[0020] S2. Antibacterial agent grafting: Mix the composite antibacterial agent with the pretreated substrate, and perform graft copolymerization by solid-phase mechanochemistry at 80 - 100 °C and 5 - 12 MPa pressure, and then extrude and mold through an extruder to obtain a substrate layer;

[0021] S3. Molding: Compose the substrate layer, photocatalytic antibacterial layer, and hydrophobic film layer through a hot pressing and composite process to form a complete antibacterial stone plastic floor blank;

[0022] S4. Calendering: Calender and shape the formed antibacterial stone plastic floor blank, and then cool to obtain the antibacterial stone plastic floor.

[0023] Preferably, in step S2, the reaction time of the solid-phase mechanochemistry method is 20 - 40 minutes, and the grafting rate of the antibacterial agent and PVC is 85% - 95%.

[0024] Preferably, the extrusion temperature of the base material layer is 150 - 170 °C, the extrusion temperature of the photocatalytic antibacterial layer is 140 - 150 °C, and the extrusion temperature of the hydrophobic film layer is 120 - 135 °C.

[0025] By the above technical solutions, the present invention has the following technical effects:

[0026] Through the synergistic effect of the composite bacteriostatic agent, nano - tea polyphenols (destroying the bacterial cell membrane) and chitosan (inhibiting bacterial metabolism) are slowly released through the modified zeolite carrier, and the antibacterial rate against Escherichia coli, Staphylococcus aureus, etc. is > 99.5%. Moreover, the antibacterial spectrum covers bacteria and molds. And through the photocatalytic antibacterial layer, the nitrogen - rich surface of graphitic carbon nitride adsorbs negatively charged bacteria through electrostatic interaction, enriches them on the catalyst surface, locally increases the ROS concentration, accelerates the killing process, and provides antibacterial effect. In addition, the contact angle of the surface hydrophobic film ≥ 110°, which can effectively block the penetration of moisture and further reduce the risk of mildew. Specific Embodiments

[0027] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range, between the endpoint values and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0028] Example 1

[0029] An antibacterial stone - plastic floor includes a base material layer, a photocatalytic antibacterial layer, and a surface hydrophobic film. The photocatalytic antibacterial layer is disposed on the surface of the base material layer, and the surface hydrophobic film is disposed on the surface of the photocatalytic antibacterial layer. The light transmittance of the surface hydrophobic film is ≥ 85%, the contact angle is ≥ 110°, and the thickness is 30 μm;

[0030] Among them, the base material layer includes the following components in parts by weight: 80 parts of polyvinyl chloride, 350 parts of calcium carbonate, 30 parts of composite bacteriostatic agent, and 5 parts of coupling agent;

[0031] Among them, the photocatalytic antibacterial layer contains a heterojunction composite of nano - titanium dioxide and graphitic carbon nitride. The mass ratio of nano - titanium dioxide to graphitic carbon nitride is 2:1, the particle size is 50 nm, and the thickness of the photocatalytic antibacterial layer is 1 / 5 of the thickness of the base material layer.

[0032] It should be noted that the preparation method of the photocatalytic antibacterial layer is as follows: Melamine or urea is placed in a crucible and heated to 550 °C at a rate of 5 °C / min in an air atmosphere, calcined for 4 hours, and ground into nanoscale powder (particle size 50 nm) after cooling to obtain graphitic carbon nitride. Anatase titanium dioxide (particle size 50 nm) is surface-modified by a silane coupling agent (such as KH-550) to enhance its dispersibility and interfacial bonding ability, and then nano-titanium dioxide can be obtained. Graphitic carbon nitride and nano-titanium dioxide are mixed at a mass ratio of 1:4, deionized water and ethanol (volume ratio 3:1) are added, and ultrasonic dispersion is carried out for 1 hour. Then it is transferred to a high-pressure reactor, and solvothermal reaction is carried out at 160 °C for 12 hours to form a tightly bound Z-type heterojunction structure. Then it is centrifuged, washed, dried to obtain composite photocatalytic powder. Then the composite photocatalytic powder and dispersant are successively put into a mixing tank, and mixing and stirring are carried out under precisely controlled temperature, pressure, time and rotation speed. Finally, the well-mixed raw materials are filled into an extruder, and extrusion molding is carried out under precisely controlled temperature, pressure, time and rotation speed to obtain the photocatalytic antibacterial layer.

[0033] It should be explained that the conduction band of graphitic carbon nitride (-1.1 eV) is higher than the valence band of titanium dioxide (+2.7 eV). Under light illumination, the photogenerated electrons (e - ) of graphitic carbon nitride recombine with the holes (h + ) of titanium dioxide, while the holes (h + ) of graphitic carbon nitride and the electrons (e - ) of titanium dioxide are retained to form a Z-type transmission path. The retained h + (graphitic carbon nitride) has strong oxidizing property and can directly attack the bacterial cell membrane; e - (titanium dioxide) reduces O2 to generate superoxide radicals (·O2 - ), which cooperate to damage the microbial DNA.

[0034] Among them, the composite antibacterial agent includes the following components in parts by weight: 3 parts of nano-tea polyphenols, 2 parts of chitosan and 10 parts of zeolite powder.

[0035] Specifically, the nano-tea polyphenols in this application are purchased from Shaanxi Xintianyu Biotechnology Co., Ltd. The action mechanism of the nano-tea polyphenols in this application is as follows: The tea polyphenol molecule contains multiple phenolic hydroxyl groups (-OH), has strong hydrophobicity and electron donor ability, can insert into the phospholipid bilayer of the bacterial cell membrane, and destroy its integrity; it binds to membrane proteins through hydrogen bonds and hydrophobic interactions, resulting in membrane perforation (TEM observation shows obvious rupture of the Escherichia coli cell membrane). After the cell membrane ruptures, intracellular ions (k + , Ca 2+) and protein efflux, and the bacteria die due to osmotic imbalance (verified by conductivity experiment, the conductivity of the solution increased by 200% after 1 hour of treatment). Tea polyphenols have a high affinity for the outer membrane lipopolysaccharide (LPS) of Gram-negative bacteria (such as Escherichia coli) and preferentially damage the outer membrane structure.

[0036] Specifically, chitosan was purchased from Huai'an Runjie Industry and Trade Company. Chitosan is used to inhibit bacterial metabolism and enzyme activity, and its mechanism of action is as follows: The molecular chain of chitosan is rich in amino groups (-NH2), which are protonated to positive charges (-NH3 + ) in an acidic environment and bind to the negatively charged lipopolysaccharide (LPS) or teichoic acid on the bacterial surface through electrostatic adsorption, blocking the nutrient absorption channel. Chitosan penetrates into the cell and binds to DNA to inhibit transcription (agarose gel electrophoresis shows that DNA migration is blocked); it inhibits the activity of key bacterial enzymes (such as ATPase and β-galactosidase) (enzyme activity tests show that the activity is reduced by 70%-85%), and has strong penetrability to the peptidoglycan layer of Staphylococcus aureus (Gram-positive bacteria) and the chitin cell wall of molds (SEM shows that the surface of the bacteria collapses).

[0037] Specifically, in this application, the modified zeolite carrier is used for slow release and synergistic enhancement, and its mechanism of action is as follows: After the zeolite is acidified to expand the pores (pore diameter 2-5 nm), tea polyphenols and chitosan molecules are loaded into the pores through capillary action (BET test shows that the pore volume is increased to 0.8 cm 3 / g); Nano-tea polyphenols (particle size 50-80 nm) are confined in the pores to avoid agglomeration and inactivation (TEM shows uniform dispersion). Chitosan forms hydrogen bonds with the silicon hydroxyl groups (Si-OH) on the zeolite surface through amino groups, and tea polyphenols crosslink with chitosan amino groups through phenolic hydroxyl groups (FT-IR shows a Schiff base characteristic peak at 1640 cm-1); in a humid environment, water molecules gradually break the hydrogen bonds to achieve slow release of the bacteriostatic agent (in vitro slow release experiment shows that the release rate in 30 days < 50%). The negatively charged zeolite surface adsorbs positively charged bacteria (such as Staphylococcus aureus), locally concentrating the concentration of the bacteriostatic agent and improving the contact efficiency (Zeta potential test shows that the bacterial adsorption rate > 80%); The zeolite adsorbs toxins (such as endotoxin) produced by bacterial metabolism to block secondary pollution.

[0038] It should be noted that the synergistic effect of nano-tea polyphenol chitosan and the modified zeolite carrier in this application is as follows: Tea polyphenols mainly attack the physical destruction of the cell membrane (highly effective against Gram-negative bacteria); Chitosan interferes with metabolism and enzyme activity (highly effective against Gram-positive bacteria and molds); The two work together to cover the common targets of bacteria and molds (such as cell membranes and metabolic enzymes). Tea polyphenols quickly damage the cell membrane, making it easier for chitosan to enter the cell; The zeolite carrier continuously releases the bacteriostatic agent to inhibit the regeneration of residual bacteria.

[0039] The composite bacteriostatic agent in this application is self-made, and the preparation method includes the following steps: First, soak zeolite powder in 2 mol / L HCl for 2 hours, wash it until neutral, and calcine it at 500 °C for 3 hours to expand the pores; then disperse the activated zeolite powder in 2% acetic acid solution, add chitosan, the deacetylation degree of chitosan ≥ 90%, and the molecular weight is 5×10 4 , stir at 60 °C for 4 hours to allow chitosan to enter the zeolite pores through electrostatic adsorption, then add silane coupling agent (KH-550), adjust the pH to 6, react at 70 °C for 2 hours, centrifuge, wash and dry to obtain chitosan-modified zeolite carrier. The pore size of the modified zeolite carrier is 5 nm, and the molar ratio of nano-tea polyphenols to chitosan is 1:2; then immerse the modified zeolite carrier in glutaraldehyde solution, oscillate at 40 °C for 1 hour to activate the surface amino groups, add nano-tea polyphenols, adjust the pH to 6, and react at 60 °C for 6 hours to bond the phenolic hydroxyl group of tea polyphenols and the amino group of chitosan through Schiff base reaction; finally, wash 3 times with PBS to remove unreacted substances, and dry in vacuum at 45 °C to obtain the composite bacteriostatic agent.

[0040] It should be noted that in this application, the amino group activity is the best when pH = 6.0, to avoid the auto-oxidation of tea polyphenols; the reaction temperature ≤ 60 °C is to prevent the degradation of chitosan chains, and through chemical bonding rather than physical mixing, to solve the problems of easy migration of tea polyphenols and poor solubility of chitosan. The zeolite pore size (2-5 nm) matches the bacteria size (0.5-5 μm), and the efficiency is improved through the "adsorption-killing" synergistic mechanism.

[0041] The preparation method of an antibacterial stone plastic floor in this embodiment includes the following steps: First, mix polyvinyl chloride, calcium carbonate and coupling agent, and activate at 90 °C for 60 minutes to obtain the pretreated substrate; then mix the composite bacteriostatic agent with the pretreated substrate, and carry out graft copolymerization by solid-phase mechanochemistry at 100 °C and 12 MPa pressure to obtain the substrate layer. The reaction time of the solid-phase mechanochemistry method is 40 minutes, and the grafting rate of the bacteriostatic agent and PVC is 95%; then laminate the substrate layer, photocatalytic antibacterial layer and hydrophobic film layer through a hot pressing and laminating process to form a complete antibacterial stone plastic floor blank; calender and shape the formed antibacterial stone plastic floor blank, and then cool it to obtain the antibacterial stone plastic floor.

[0042] It should be explained that in this application, graft copolymerization of the bacteriostatic agent and the PVC substrate layer is carried out by solid-phase mechanochemistry at 80-100 °C, to avoid destroying the activity of natural antibacterial components at high temperature (traditional process > 160 °C), so that the bonding strength of the bacteriostatic agent is increased by 50%, and the density uniformity error of the floor < 0.5% (the industry standard is 2%).

[0043] Example 2

[0044] The difference between this example and Example 1 is only that: in this example, there are 35 parts of the compound bacteriostatic agent, and other conditions are the same.

[0045] Example 3

[0046] The difference between this example and Example 1 is only that: in this example, there are 40 parts of the compound bacteriostatic agent, and other conditions are the same.

[0047] Example 4

[0048] The difference between this example and Example 1 is only that: in this example, there are 50 parts of the compound bacteriostatic agent, and other conditions are the same.

[0049] Comparative Example 1

[0050] According to the method of Example 1, the difference is that silver ions are used instead of the compound bacteriostatic agent.

[0051] Comparative Example 2

[0052] According to the method of Example 1, the difference is that it does not contain the compound bacteriostatic agent.

[0053] Comparative Example 3

[0054] According to the method of Example 1, the difference is that the ratio of the compound bacteriostatic agent is different, specifically as follows: the compound bacteriostatic agent includes the following components in parts by weight: 5 parts of nano-tea polyphenols, 3 parts of chitosan, and 15 parts of zeolite powder.

[0055] Comparative Example 4

[0056] According to the method of Example 1, the difference is that the ratio of the compound bacteriostatic agent is different, specifically as follows: the compound bacteriostatic agent includes the following components in parts by weight: 7 parts of nano-tea polyphenols, 6 parts of chitosan, and 20 parts of zeolite powder.

[0057] Experimental Example

[0058] 1. Bacteriostatic rate test: Referring to the ISO 22196 standard, the 24-hour bacteriostatic rate of Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 6538) was tested;

[0059] Samples were prepared according to Examples 1-4 and Comparative Examples 1-4, and the antibacterial properties of each sample non-woven fabric were tested with reference to the ISO 22196 standard;

[0060] First, place an antibacterial stone plastic floor on a petri dish, drop 25 μl of bacterial liquid on the surface, and incubate it for 10 min in an environment of light (irradiated with a xenon lamp with a 600 nm wavelength filter) and a dark room. Subsequently, the original bacterial liquid and the bacterial liquid on the sample were successively diluted 10^6 times in a centrifuge tube at equal gradients to prepare a 10-fold dilution series;

[0061] Take 10 μl of the solution from each centrifuge tube in the dilution series and inject it into a petri dish containing agar medium. Incubate it in a constant temperature incubator at 37 °C for 24 h. Finally, measure the number of colonies, calculate the antibacterial rate (%), and evaluate the antibacterial effect:

[0062] Inhibitory rate = (number of colonies inoculated in the original sample - number of remaining colonies after antibacterial treatment) / number of colonies inoculated in the original sample × 100%;

[0063] Two groups of bacteria were used for the bacterial solution, namely Staphylococcus aureus with a concentration of 1.36×10⁶ CFU / sample and Escherichia coli with a concentration of 1.79×10⁶ CFU / sample;

[0064] The experimental results are shown in Table 1.

[0065] Table 1

[0066]

[0067]

[0068] It can be seen from the data in Table 1 that:

[0069] The greater the content of the composite bacteriostatic agent within the scope of this application, that is, when the composite bacteriostatic agent is 40 parts, its antibacterial performance is better, with a slight improvement. The data of Example 4 and Comparative Example 1 in Table 1 have an obvious gap. Therefore, the antibacterial effect of the composite bacteriostatic agent in this application is significantly better than that of the silver ion system.

[0070] It should be noted that the data of Example 4 and Comparative Example 3 in Table 1 do not differ much. However, the antibacterial effect of Comparative Example 3 is better than that of Example 4. Therefore, when the composite bacteriostatic agent is 40 parts, and the composite bacteriostatic agent includes the following components in parts by weight: 5 parts of nano-tea polyphenols, 3 parts of chitosan, and 15 parts of zeolite powder, its antibacterial effect is the best.

[0071] 2. Abrasion resistance and aging resistance tests:

[0072] Carry out Taber wear test (CS-10 grinding wheel, 1000 g load) according to GB / T 4085-2015; Aging resistance test: QUV accelerated aging tester (UVB-313 lamp tube, 60 °C / 8 h light + 50 °C / 4 h condensation, cycle for 3000 hours);

[0073] The experimental results are shown in Table 2.

[0074] Table 2

[0075]

[0076]

[0077] It can be seen from the data in Table 2 that:

[0078] In this application, the composite bacteriostatic agent still maintains high bacteriostatic performance (>96%) after wear and aging, while the traditional silver ion system just meets the industry standard. Therefore, the synergistic effect of nano-tea polyphenol chitosan and modified zeolite carrier in this application is as follows: tea polyphenols mainly attack the physical damage of cell membranes (highly effective against Gram-negative bacteria); chitosan interferes with metabolism and enzyme activity (highly effective against Gram-positive bacteria and molds); the two work together to cover the common targets of bacteria and molds (such as cell membranes and metabolic enzymes). Tea polyphenols quickly damage the cell membrane, making it easier for chitosan to enter the cell; the zeolite carrier continuously releases the bacteriostatic agent to inhibit the regeneration of residual bacteria.

[0079] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. An antibacterial stone plastic floor, characterized in that, It includes a base material layer, a photocatalytic antibacterial layer, and a surface hydrophobic film. The photocatalytic antibacterial layer is disposed on the surface of the base material layer, and the surface hydrophobic film is disposed on the surface of the photocatalytic antibacterial layer; Among them, the base material layer includes the following components in parts by weight: 60-80 parts of polyvinyl chloride, 300-350 parts of calcium carbonate, 30-50 parts of a composite antibacterial agent, and 1-5 parts of a coupling agent; Among them, the photocatalytic antibacterial layer contains a heterojunction composite of nano-titanium dioxide and graphitic carbon nitride. The mass ratio of nano-titanium dioxide to nano-zinc oxide is 2:1 to 4:1, and the particle size is 20-50 nm.

2. The antibacterial stone plastic floor according to claim 1, characterized in that, The light transmittance of the surface hydrophobic film is ≥85%, the contact angle is ≥110°, and the thickness is 10-30 μm.

3. The antibacterial stone plastic floor according to claim 1, wherein The composite antibacterial agent includes the following components in parts by weight: 3-7 parts of nano-tea polyphenols, 2-6 parts of chitosan, and 10-20 parts of zeolite powder.

4. The antibacterial stone plastic floor according to claim 3, characterized in that, The preparation method of the composite antibacterial agent includes the following steps: a. Soak the zeolite powder in 2 mol / L HCl for 2 hours, wash it to neutral, and calcine it at 500 °C for 3 hours to expand the pores; b. Disperse the activated zeolite powder in a 2% acetic acid solution, add chitosan, stir at 60 °C for 4 hours to allow chitosan to enter the zeolite pores through electrostatic adsorption, then add a silane coupling agent (KH-550), adjust the pH to 6, react at 70 °C for 2 hours, centrifuge and wash, and then dry to obtain a chitosan-modified zeolite carrier; c. Immerse the modified zeolite carrier in a glutaraldehyde solution, oscillate at 40 °C for 1 hour to activate the surface amino groups, add nano-tea polyphenols, adjust the pH to 6, and react at 60 °C for 6 hours to bond the phenolic hydroxyl groups of tea polyphenols and the amino groups of chitosan through Schiff base reaction; d. Finally, wash 3 times with PBS to remove unreacted substances, and dry in vacuum at 45 °C to obtain the composite antibacterial agent.

5. The antibacterial stone plastic floor according to claim 4, characterized in that, The degree of deacetylation of the chitosan is ≥ 90%, and the molecular weight is 5×10 4 .

6. The antibacterial stone plastic floor according to claim 5, characterized in that, The pore diameter of the modified zeolite carrier is 2-5 nm, and the molar ratio of nano-tea polyphenols to chitosan is 1:2 to 1:

4.

7. The antibacterial stone plastic floor according to claim 4, wherein, The thickness of the photocatalytic antibacterial layer is 1 / 5-1 / 3 of the thickness of the base material layer.

8. A preparation method of an antibacterial stone plastic floor, applicable to the antibacterial stone plastic floor described in any one of claims 1-7, characterized in that, It includes the following steps: S1. Base material pretreatment: Mix polyvinyl chloride, calcium carbonate, and a coupling agent, and perform activation treatment at 80-90 °C for 30-60 minutes to obtain a pretreated base material; S2. Antibacterial agent grafting: Mix the composite antibacterial agent with the pretreated base material, and perform graft copolymerization by solid-phase mechanochemistry at 80-100 °C and a pressure of 5-12 MPa, and then extrude and mold through an extruder to obtain the base material layer; S3. Molding: Compose the base material layer, the photocatalytic antibacterial layer, and the hydrophobic film layer through a hot pressing and composite process to form a complete antibacterial stone plastic floor blank; S4. Calendering: Calender and shape the formed antibacterial stone plastic floor blank, and then cool to obtain the antibacterial stone plastic floor.

9. The preparation method of the antibacterial stone plastic floor according to claim 8, wherein, In step S2, the reaction time of the solid-phase mechanochemistry method is 20-40 minutes, and the grafting rate of the antibacterial agent and PVC is 85%-95%.

10. The preparation method of the antibacterial stone plastic floor according to claim 8, characterized in that, In step S2, the extrusion temperature of the base material layer is 150-170 °C.

Images