Odorless antibacterial hydrophobic PVC composite material and preparation method thereof

Abstract

The invention discloses an odorless antibacterial hydrophobic PVC composite material and a preparation method thereof, and belongs to the technical field of high polymer materials. The composite material provided by the invention is prepared from the following raw materials in parts by weight: polyvinyl chloride resin, acetyl tributyl citrate, a stabilizer, an antioxidant, an ultraviolet light absorber, a nano-silver antibacterial agent, a food-grade mildew preventive, a lubricant, stearic acid surface modified nanoscale calcium carbonate and coumarolactone. The preparation method comprises the following steps: mixing the polyvinyl chloride resin, the stabilizer, the antioxidant, the ultraviolet light absorber, the nano-silver antibacterial agent, the food-grade mildew preventive and the stearic acid surface modified nanoscale calcium carbonate to prepare a premix; adding the rest raw materials into the premix, and mixing to obtain a mixture; and plastifying the mixture, carrying out extrusion molding, and cooling to obtain the composite material. The composite material prepared by the invention has good physical and mechanical properties, excellent antibacterial property and hydrophobic property, and is odorless and environment-friendly.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of polymer materials, and particularly relates to a tasteless antibacterial hydrophobic PVC composite material and a preparation method thereof. BACKGROUND

[0002] Polyvinyl chloride (PVC) is widely used in the fields of construction, medical treatment, food packaging, electronic appliances and the like due to its excellent processing performance, low cost and good mechanical strength. However, with the increasing complexity of application environment, the traditional PVC material gradually exposes some performance deficiencies in the actual use process, especially in terms of antibacterial property, hydrophobicity and odor control, and it is difficult to meet the needs of modern industry and consumers for high-quality environment-friendly materials.

[0003] At present, the antibacterial PVC materials on the market mostly use a single antibacterial component, and the antibacterial spectrum is narrow, which cannot effectively resist the invasion of various bacteria and fungi, and the durability of the antibacterial effect is poor, which cannot meet the requirements of long-term use. In addition, in terms of improving the hydrophobicity of the material, the conventional methods mainly include adding silicone oil, fluorocarbon compounds and other additives, which can improve the waterproof performance of the material surface to a certain extent, but often affect the mechanical properties and processing performance of the material, leading to problems such as material brittleness, surface easy to fall off and the like, which affect the actual application effect. At the same time, many PVC materials will release a certain odor during processing or use, especially in high-temperature or humid environment. Such odor not only affects the user experience, but also limits its application in the fields sensitive to odor such as food packaging and medical devices to a certain extent.

[0004] Therefore, it is urgent to develop a tasteless environment-friendly PVC composite material which can have excellent antibacterial property and hydrophobicity on the basis of maintaining good physical and mechanical properties. SUMMARY

[0005] Therefore, the application provides a tasteless antibacterial hydrophobic PVC composite material and a preparation method thereof. The tasteless antibacterial hydrophobic PVC composite material provided by the application can have excellent antibacterial property and hydrophobicity on the basis of maintaining good physical and mechanical properties.

[0006] In a first aspect, the application provides a tasteless antibacterial hydrophobic PVC composite material, and the raw material composition thereof comprises, by weight fraction, 80-120 parts of polyvinyl chloride resin, 50-80 parts of acetyl citrate tributyl ester, 0.5-4 parts of stabilizer, 0.1-0.5 parts of antioxidant, 0.05-0.4 parts of ultraviolet absorber, 1-5 parts of nano-silver antibacterial agent, 0.5-3 parts of food-grade mildew inhibitor, 0.2-1 parts of lubricant, 8-15 parts of stearic acid surface modified nano calcium carbonate and 0.05-0.5 parts of coumarin.

[0007] By adopting the above technical solution, the odorless, antibacterial, and hydrophobic PVC composite material provided by this application uses specific raw materials. On the basis of maintaining the basic properties of PVC resin, it significantly improves the antibacterial and hydrophobic properties of the material without sacrificing its mechanical properties. This application uses acetyl tributyl citrate and stearic acid surface-modified nano-calcium carbonate to work together, not only enhancing the mechanical properties of the material, but also significantly improving its surface hydrophobicity and reducing water absorption, making it suitable for long-term use in humid environments. The combined use of stabilizers, antioxidants, and ultraviolet absorbers further improves the material's weather resistance and service life.

[0008] In this application, the nanosilver antimicrobial agent and food-grade mildew inhibitor work together to form a broad-spectrum, long-lasting antimicrobial system, effectively inhibiting the growth of bacteria and fungi. The addition of coumarin further enhances the material's antimicrobial properties and, to a certain extent, masks any odors introduced by other ingredients, resulting in an odorless and environmentally friendly material overall. The lubricant improves processing fluidity, ensuring excellent material forming properties.

[0009] Optionally, the weight ratio of the acetyl tributyl citrate to the stearic acid surface-modified nano-scale calcium carbonate is 5 to 8:1.

[0010] By adopting the above technical solution, the acetyl tributyl citrate (ATBC) of the present application and stearic acid surface modified nano-scale calcium carbonate work together to significantly improve the physical and mechanical properties, antibacterial properties and hydrophobicity of PVC composite materials. The specific weight ratio helps stearic acid surface modified nano-scale calcium carbonate to be better dispersed in the PVC matrix, further enhancing the impact strength of the material. In addition, the good dispersibility and plasticizing effect of ATBC can also ensure the uniform distribution of antibacterial ingredients in the whole material, thereby further extending the antibacterial time and enhancing the antibacterial effect. And ATBC is used in conjunction with stearic acid surface modified nano-scale calcium carbonate to form a dense protective film on the material surface, significantly improving the hydrophobicity of the material and reducing the possibility of water penetration.

[0011] Optionally, the stabilizer includes at least one of zinc stearate, dibutyltin monooctyl maleate, and basic lead sulfate; The antioxidant includes at least one of butylated hydroxyanisole, trisnonylphenyl phosphite, and dilauryl thiodipropionate.

[0012] By adopting the above technical solution, the stabilizer and antioxidant of the present application can significantly improve the thermal stability and processing performance of the material, inhibit oxidation reactions, and prevent oxidative aging of the material during storage or use, thereby extending the service life of the material.

[0013] Optionally, the ultraviolet absorber includes at least one of 2-hydroxy-4-octyloxybenzophenone, 2-(2'-hydroxy-3',5'-di-tert-phenyl)-5-chlorobenzotriazole, and monobenzoic acid resorcinol ester.

[0014] By adopting the above technical solution, the ultraviolet absorber of the present application can significantly improve the material's resistance to ultraviolet aging and effectively prevent the material from yellowing, embrittlement, cracking and other problems caused by light.

[0015] Optionally, the nano-silver antibacterial agent includes at least one of silver-loaded zeolite, silver-loaded titanium dioxide, and silver-loaded zirconium phosphate.

[0016] By adopting the above technical solution, the nanosilver-based antimicrobial agent of the present application slowly releases silver ions to destroy the cell membrane structure of microorganisms, interfere with their metabolism and DNA replication, and thus effectively inhibit the growth of bacteria (such as Escherichia coli and Staphylococcus aureus), fungi, and molds. It has stronger stability and controlled release ability, and the antimicrobial effect is more lasting. It can endow PVC composite materials with high-efficiency, broad-spectrum, and long-lasting antimicrobial properties, and also has good thermal stability, process adaptability, and environmental friendliness.

[0017] Optionally, the weight ratio of the nano-silver antibacterial agent to the coumarin is 12 to 18:1.

[0018] By adopting the above technical solution, the nanosilver antimicrobial agent of this application works together with coumarin to further enhance the antimicrobial effect, broaden the antimicrobial spectrum, and strengthen the inhibitory capacity against a variety of bacteria and fungi. The specific weight ratio can improve the initial antimicrobial efficiency and enhance the long-term antimicrobial stability, thereby prolonging the duration of the antimicrobial effect.

[0019] Optionally, the food-grade mildew inhibitor includes at least one of sorbic acid, calcium propionate, sodium diacetate, and natamycin.

[0020] By adopting the above technical solution, the food-grade mildew inhibitor of the present application can effectively inhibit the growth of mold, significantly improve the anti-mildew ability, ensure that the material is protected from microbial invasion during long-term use, and comply with food standards and be environmentally friendly and safe.

[0021] Optionally, the lubricant is selected from at least one of erucamide, oxidized polyethylene wax, and fatty alcohol polyoxyethylene ether.

[0022] By adopting the above technical solution, the lubricant of the present application can improve processing fluidity and molding efficiency, and also help to improve the surface finish and flatness of the finished product and reduce defects such as bubbles and silver streaks.

[0023] In a second aspect, the present application provides a method for preparing the above-mentioned odorless, antibacterial, hydrophobic PVC composite material, comprising the following steps: Step S1, mixing the polyvinyl chloride resin, stabilizer, antioxidant, ultraviolet absorber, nano-silver antibacterial agent, food-grade mildewcide and stearic acid surface-modified nano-calcium carbonate at a mixing temperature of 80° C. to 100° C. for 5 min to 15 min to prepare a premix; Step S2, slowly adding the acetyl tributyl citrate, lubricant and coumarin to the premix, mixing to obtain a mixture, the mixing temperature being 100° C. to 120° C., and the mixing time being 10 min to 20 min; Step S3, plasticizing the mixture at a plasticizing temperature of 160° C. to 180° C., extruding and molding, and cooling to obtain an odorless, antibacterial, and hydrophobic PVC composite material.

[0024] By adopting the above technical solution, the preparation method provided in this application ensures the uniform dispersion and joint action of each component in the PVC matrix through staged mixing and control of process parameters, and can produce a composite material with good physical and mechanical properties, excellent antibacterial properties and hydrophobic properties.

[0025] Optionally, the preparation method of the stearic acid surface-modified nano-scale calcium carbonate is: stirring and mixing nano-calcium carbonate powder with water to obtain a calcium carbonate suspension; adding stearic acid, heating and stirring; centrifuging, washing, and drying to obtain the stearic acid surface-modified nano-scale calcium carbonate; the content of stearic acid in the stearic acid surface-modified nano-scale calcium carbonate is 1% to 3%.

[0026] By adopting the above technical solution, the stearic acid-surface-modified nanoscale calcium carbonate prepared in this application not only enhances the material's waterproof and moisture-proof properties, but also maintains stable antibacterial and mechanical properties in humid environments. By controlling the stearic acid content to 1% to 3%, not only is the dispersibility and compatibility of the nanofiller significantly improved, but the hydrophobicity and mechanical properties of the material are also enhanced. Furthermore, the modification process is environmentally friendly, safe, and simple to operate.

[0027] In summary, the present invention includes at least one of the following beneficial technical effects: 1. The odorless, antibacterial, and hydrophobic PVC composite material provided in this application uses specific raw materials. While maintaining the basic properties of PVC resin, it significantly improves the antibacterial and hydrophobic properties of the material without sacrificing its mechanical properties.

[0028] 2. This application uses acetyl tributyl citrate and stearic acid to surface-modify nano-calcium carbonate, which not only enhances the mechanical properties of the material, but also significantly improves its surface hydrophobicity and reduces water absorption, making it suitable for long-term use in humid environments.

[0029] 3. The preparation method provided in this application ensures the uniform dispersion and joint action of each component in the PVC matrix through staged mixing and control of process parameters, and can produce a composite material with good physical and mechanical properties, excellent antibacterial properties and hydrophobic properties. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0031] The inventors of this application discovered during their research on antimicrobial and hydrophobic PVC materials that existing antimicrobial PVC materials have a single antimicrobial component, a narrow antimicrobial spectrum, and poor durability of antimicrobial effects. Furthermore, they suffer from insufficient hydrophobicity and release odor during processing or use.

[0032] In order to solve the above problems, the present application proposes an odorless, antibacterial, hydrophobic PVC composite material, the raw materials of which include, by weight: 80-120 parts of polyvinyl chloride resin, 50-80 parts of acetyl tributyl citrate, 0.5-4 parts of stabilizer, 0.1-0.5 parts of antioxidant, 0.05-0.4 parts of ultraviolet absorber, 1-5 parts of nano-silver antibacterial agent, 0.5-3 parts of food-grade mildewcide, 0.2-1 parts of lubricant, 8-15 parts of stearic acid surface-modified nano-calcium carbonate, and 0.05-0.5 parts of coumarin.

[0033] The present application also proposes a method for preparing the above-mentioned odorless, antibacterial, hydrophobic PVC composite material, comprising the following steps: Step S1, mixing polyvinyl chloride resin, a stabilizer, an antioxidant, an ultraviolet absorber, a nano-silver antibacterial agent, a food-grade mildewcide, and stearic acid-surface-modified nano-scale calcium carbonate at a mixing temperature of 80° C. to 100° C. for a mixing time of 5 min to 15 min to prepare a premix; Step S2, slowly adding acetyl tributyl citrate, lubricant and coumarin to the premix, mixing to obtain a mixture, the mixing temperature being 100° C. to 120° C., and the mixing time being 10 min to 20 min; Step S3: plasticizing the mixture at a plasticizing temperature of 160° C. to 180° C., extruding and molding the mixture, and cooling the mixture to obtain an odorless, antibacterial, and hydrophobic PVC composite material.

[0034] The scheme of the present application is described below with reference to the following specific examples. Unless otherwise specified, the raw materials used in the following examples are all from common commercial products, and the devices or equipment used are all purchased from conventional market sales channels. Specific embodiments

[0035] The preparation method of the stearic acid surface-modified nano-scale calcium carbonate used in Examples 1 to 3 is as follows: nano-calcium carbonate powder is stirred and mixed with water to prepare a calcium carbonate suspension; stearic acid is added, heated to 90° C. and stirred for 40 minutes; centrifuged, washed, and dried to prepare the stearic acid surface-modified nano-scale calcium carbonate; The average particle size of the nano-calcium carbonate powder is 70nm; the content of stearic acid in the stearic acid surface-modified nano-scale calcium carbonate is 2%.

[0036] Examples 1 to 3 Example 1 The present embodiment provides an odorless, antibacterial, hydrophobic PVC composite material, the raw materials of which, by weight, include: 80 parts of polyvinyl chloride resin, 80 parts of acetyl tributyl citrate, 4 parts of a stabilizer, 0.1 parts of an antioxidant, 0.05 parts of an ultraviolet absorber, 5 parts of a nano-silver antibacterial agent, 0.5 parts of a food-grade mildewcide, 0.2 parts of a lubricant, 15 parts of nano-scale calcium carbonate surface-modified with stearic acid, and 0.05 parts of coumarin. The polyvinyl chloride resin is PVC-2500; the stabilizer is zinc stearate; the antioxidant is butylated hydroxyanisole; the ultraviolet absorber is 2-hydroxy-4-octyloxybenzophenone; the nano-silver antibacterial agent is silver-loaded zeolite; the food-grade mildew inhibitor is sorbic acid; and the lubricant is erucamide. The preparation method comprises the following steps: Step S1, mixing polyvinyl chloride resin, stabilizer, antioxidant, ultraviolet absorber, nano-silver antibacterial agent, food-grade mildewcide and stearic acid surface-modified nano-scale calcium carbonate at a mixing temperature of 80° C. and a mixing time of 15 minutes to prepare a premix; Step S2: slowly adding acetyl tributyl citrate, lubricant and coumarin to the premix, and mixing to obtain a mixture at a mixing temperature of 100° C. and a mixing time of 20 min; Step S3: plasticizing the mixture at a plasticizing temperature of 160° C., extruding and molding, and cooling to obtain an odorless, antibacterial, and hydrophobic PVC composite material.

[0037] Example 2 The present embodiment provides an odorless, antibacterial, hydrophobic PVC composite material, the raw materials of which, by weight, include: 100 parts of polyvinyl chloride resin, 65 parts of acetyl tributyl citrate, 2 parts of a stabilizer, 0.3 parts of an antioxidant, 0.2 parts of an ultraviolet absorber, 3 parts of a nano-silver antibacterial agent, 2 parts of a food-grade mildewcide, 0.6 parts of a lubricant, 12 parts of nano-scale calcium carbonate surface-modified with stearic acid, and 0.3 parts of coumarin. The polyvinyl chloride resin is PVC-2500; the stabilizer is zinc stearate; the antioxidant is butylated hydroxyanisole; the ultraviolet absorber is 2-hydroxy-4-octyloxybenzophenone; the nano-silver antibacterial agent is silver-loaded zeolite; the food-grade mildew-proof agent is sorbic acid; and the lubricant is erucamide. The preparation method comprises the following steps: Step S1, the polyvinyl chloride resin, the stabilizer, the antioxidant, the ultraviolet absorber, the nano-silver antibacterial agent, the food-grade mildew-proof agent and the stearic acid surface modified nano-sized calcium carbonate are mixed, the mixing temperature is 90℃, and the mixing time is 10min, so as to obtain a premix; Step S2, the acetyl tributyl citrate, the lubricant and the scilliroside are slowly added into the premix, and the mixture is mixed to obtain a mixed material, the mixing temperature is 110℃, and the mixing time is 15min; Step S3, the mixed material is plasticized, the plasticizing temperature is 170℃, the plasticized material is extruded into a shape, and then cooled, so as to obtain the odorless antibacterial and hydrophobic PVC composite material.

[0038] Example 3 The example provides an odorless antibacterial and hydrophobic PVC composite material, and the raw material composition comprises, by weight fraction, polyvinyl chloride resin 120 parts, acetyl tributyl citrate 50 parts, stabilizer 0.5 parts, antioxidant 0.5 parts, ultraviolet absorber 0.4 parts, nano-silver antibacterial agent 1 part, food-grade mildew-proof agent 3 parts, lubricant 1 part, stearic acid surface modified nano-sized calcium carbonate 8 parts and scilliroside 0.5 parts. The polyvinyl chloride resin is PVC-2500; the stabilizer is zinc stearate; the antioxidant is butylated hydroxyanisole; the ultraviolet absorber is 2-hydroxy-4-octyloxybenzophenone; the nano-silver antibacterial agent is silver-loaded zeolite; the food-grade mildew-proof agent is sorbic acid; and the lubricant is erucamide. The preparation method comprises the following steps: Step S1, the polyvinyl chloride resin, the stabilizer, the antioxidant, the ultraviolet absorber, the nano-silver antibacterial agent, the food-grade mildew-proof agent and the stearic acid surface modified nano-sized calcium carbonate are mixed, the mixing temperature is 100℃, and the mixing time is 5min, so as to obtain a premix; Step S2, the acetyl tributyl citrate, the lubricant and the scilliroside are slowly added into the premix, and the mixture is mixed to obtain a mixed material, the mixing temperature is 120℃, and the mixing time is 10min; Step S3, the mixed material is plasticized, the plasticizing temperature is 180℃, the plasticized material is extruded into a shape, and then cooled, so as to obtain the odorless antibacterial and hydrophobic PVC composite material.

[0039] Comparative Examples 1-3 Comparative Example 1 The difference between the comparative example 1 and the example 2 is that the acetyl tributyl citrate is not added in the comparative example 1.

[0040] Comparative Example 2 The difference between Comparative Example 2 and Example 2 is that, in Comparative Example 2, no stearic acid surface-modified nano-scale calcium carbonate is added.

[0041] Comparative Example 3 The difference between Comparative Example 3 and Example 2 is that coumarin is not added in Comparative Example 3.

[0042] Experimental testing Test items and test methods Mechanical properties: Test the notched impact strength of the prepared composite material according to GB / T 1043.1-2008 "Determination of impact properties of simply supported beams of plastics"; Antibacterial performance: The antibacterial and mildew-proof grade of the prepared composite material is tested according to JIS Z 2911:2010 Method A; Hydrophobicity: The water absorption rate of the prepared composite material was tested according to GB / T 1034-2008 "Determination of Water Absorption of Plastics". Odor detection: Trained professionals were organized to smell the prepared composite material at room temperature and 60% relative humidity and score it according to the following scoring system: 0 points: No odor at all, fully meeting the odorless standard; 1 point: A slight odor that is barely perceptible and can only be detected by careful sniffing; 2 points: slight but noticeable odor, but not easily noticed under normal use conditions; 3 points: Moderately strong odor, detectable at a normal distance, but not pungent; 4 points: Strong odor, which may cause discomfort, but not to the point of being unbearable; 5 points: Very strong odor, unbearable, seriously affecting the user experience.

[0043] The odorless, antibacterial, and hydrophobic PVC composite materials prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were tested for notched impact strength, antibacterial and mildew resistance, and water absorption, and were also tested for odor. The test results are shown in Table 1.

[0044] Table 1 From the test results in Table 1, it can be seen that the odorless, antibacterial, and hydrophobic PVC composite materials prepared in Examples 1 to 3 have good mechanical properties, an antibacterial and mildew-proof grade of 0, and a low water absorption rate, indicating that the composite materials have excellent antibacterial and hydrophobic properties, and the odor test score is 0, that is, there is no odor.

[0045] The notched impact strength of the composite material prepared in Comparative Example 1 is decreased, and the water absorption is increased, indicating that the mechanical properties and hydrophobic properties of the composite material are decreased.

[0046] The notched impact strength of the composite material prepared in Comparative Example 2 is significantly decreased, and the water absorption is increased, indicating that the mechanical properties and hydrophobic properties of the composite material are decreased.

[0047] The antibacterial and mildew-proof grade of the composite material prepared in Comparative Example 3 is 1, and the odor detection is 1 point, indicating that the antibacterial properties of the composite material are decreased, and odor appears.

[0048] Examples 4-13 Example 4 The difference between Example 4 and Example 2 is that in Example 4, the total weight of acetyl tri-butyl citrate and stearic acid surface modified nano calcium carbonate is 77 parts, and the weight ratio of acetyl tri-butyl citrate to stearic acid surface modified nano calcium carbonate is 6.5:1.

[0049] Example 5 The difference between Example 5 and Example 2 is that in Example 5, the total weight of acetyl tri-butyl citrate and stearic acid surface modified nano calcium carbonate is 77 parts, and the weight ratio of acetyl tri-butyl citrate to stearic acid surface modified nano calcium carbonate is 8:1.

[0050] Example 6 The difference between Example 6 and Example 2 is that in Example 6, the stabilizer is basic lead sulfate.

[0051] Example 7 The difference between Example 7 and Example 2 is that in Example 7, the antioxidant is trisnonylphenyl phosphite.

[0052] Example 8 The difference between Example 8 and Example 2 is that in Example 8, the ultraviolet absorber is m-benzene dicarboxylic acid resorcinol ester.

[0053] Example 9 The difference between Example 9 and Example 2 is that in Example 9, the nano silver antibacterial agent is silver-loaded titanium dioxide.

[0054] Example 10 The difference between Example 10 and Example 4 is that in Example 10, the total weight of nano silver antibacterial agent and coumarin is 3.3 parts, and the weight ratio of nano silver antibacterial agent to coumarin is 15:1.

[0055] Example 11 The difference between Example 11 and Example 4 is that in Example 11, the total weight of the nano-silver antibacterial agent and coumarin is 3.3 parts, and the weight ratio of the nano-silver antibacterial agent to coumarin is 18:1.

[0056] Example 12 The difference between Example 12 and Example 2 is that in Example 12, the food-grade mildew inhibitor is calcium propionate.

[0057] Example 13 The difference between Example 13 and Example 2 is that in Example 13, the lubricant is oxidized polyethylene wax.

[0058] The odorless, antibacterial, and hydrophobic PVC composite materials prepared in Examples 4 to 13 were tested for notched impact strength, antibacterial and mildew resistance, and water absorption, and were also tested for odor. The test results are shown in Table 2.

[0059] Table 2 From the test results in Table 2, it can be seen that the difference between Example 4 and Example 5 and Example 2 is that the weight ratios of acetyl tributyl citrate and stearic acid surface-modified nano-scale calcium carbonate are different. Among them, the composite material prepared in Example 4 has the highest notched impact strength and the lowest water absorption rate, and the mechanical properties and hydrophobic properties of the composite material are the best.

[0060] The difference between Examples 6 to 9 and Example 2 is that different stabilizers, antioxidants, ultraviolet absorbers, and nano-silver antibacterial agents were selected respectively, and the prepared composite materials have good mechanical properties, excellent antibacterial and hydrophobic properties, and no odor.

[0061] The difference between Example 10 and Example 11 and Example 4 is that the weight ratios of the nano-silver antibacterial agent and coumarin are different, and the mechanical properties and hydrophobic properties of the composite materials do not change much.

[0062] The difference between Example 12 and Example 13 and Example 2 is that different food-grade mildew inhibitors and lubricants are selected respectively, and the prepared composite materials have good mechanical properties, excellent antibacterial and hydrophobic properties, and no odor.

[0063] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the principles of the present application should be included in the scope of protection of the present application.

Claims

1. An odorless, antibacterial, hydrophobic PVC composite material, characterized in that: The raw material composition includes, by weight, 80 to 120 parts of polyvinyl chloride resin, 50 to 80 parts of acetyl tributyl citrate, 0.5 to 4 parts of stabilizer, 0.1 to 0.5 parts of antioxidant, 0.05 to 0.4 parts of ultraviolet absorber, 1 to 5 parts of nano silver antibacterial agent, 0.5 to 3 parts of food grade mildew inhibitor, 0.2 to 1 parts of lubricant, 8 to 15 parts of stearic acid surface modified nano calcium carbonate, and 0.05 to 0.5 parts of coumarin.

2. The composite material according to claim 1, characterized in that The weight ratio of the acetyl tributyl citrate to the stearic acid surface-modified nano-scale calcium carbonate is 5 to 8:

1.

3. The composite material according to claim 1, characterized in that The stabilizer includes at least one of zinc stearate, dibutyltin monooctyl maleate, and basic lead sulfate; The antioxidant includes at least one of butylated hydroxyanisole, trisnonylphenyl phosphite, and dilauryl thiodipropionate.

4. The composite material according to claim 1, characterized in that The ultraviolet absorber includes at least one of 2-hydroxy-4-octyloxybenzophenone, 2-(2'-hydroxy-3',5'-di-tert-phenyl)-5-chlorobenzotriazole, and monobenzoic acid resorcinol ester.

5. The composite material according to claim 1, characterized in that The nano silver antibacterial agent comprises at least one of silver-loaded zeolite, silver-loaded titanium dioxide and silver-loaded zirconium phosphate.

6. The composite material according to claim 1, characterized in that The weight ratio of the nano silver antibacterial agent to the coumarin is 12 to 18:

1.

7. The composite material according to claim 1, characterized in that The food-grade mildew inhibitor comprises at least one of sorbic acid, calcium propionate, sodium diacetate and natamycin.

8. The composite material according to claim 1, characterized in that The lubricant is selected from at least one of erucamide, oxidized polyethylene wax, and fatty alcohol polyoxyethylene ether.

9. A method for preparing the odorless, antibacterial, hydrophobic PVC composite material according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step S1, mixing the polyvinyl chloride resin, stabilizer, antioxidant, ultraviolet absorber, nano-silver antibacterial agent, food-grade mildewcide and stearic acid surface-modified nano-calcium carbonate at a mixing temperature of 80° C. to 100° C. for 5 min to 15 min to prepare a premix; Step S2, slowly adding the acetyl tributyl citrate, lubricant and coumarin to the premix, mixing to obtain a mixture, the mixing temperature being 100° C. to 120° C., and the mixing time being 10 min to 20 min; Step S3, plasticizing the mixture at a plasticizing temperature of 160° C. to 180° C., extruding and molding, and cooling to obtain an odorless, antibacterial, and hydrophobic PVC composite material.

10. The preparation method according to claim 9, characterized in that The preparation method of the stearic acid surface-modified nano-scale calcium carbonate comprises the following steps: stirring and mixing nano-scale calcium carbonate powder and water to obtain a calcium carbonate suspension; adding stearic acid, heating and stirring; centrifuging, washing, and drying to obtain the stearic acid surface-modified nano-scale calcium carbonate; the content of stearic acid in the stearic acid surface-modified nano-scale calcium carbonate is 1% to 3%.

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