Odorless antibacterial hydrophobic PVC composite material and preparation method thereof

Abstract

The application discloses a kind of odorless antibacterial hydrophobic PVC composite material and its preparation method, belong to high polymer material technical field.The composite material provided by the application, by weight fraction, its raw material composition includes: polyvinyl chloride resin, acetyl citric acid tributyl ester, stabilizer, antioxidant, ultraviolet absorber, nano silver antibacterial agent, food-grade antifungal agent, lubricant, stearic acid surface modification nanoscale calcium carbonate, coumarin.The preparation method includes the following steps: polyvinyl chloride resin, stabilizer, antioxidant, ultraviolet absorber, nano silver antibacterial agent, food-grade antifungal agent and stearic acid surface modification nanoscale calcium carbonate are mixed to prepare premix;The remaining raw materials are added to the premix, mixed to prepare mixed material;The mixed material is plasticized, extruded into shape, cools, to prepare composite material.The composite material prepared by the application has good physical and mechanical properties, excellent antibacterial performance and hydrophobic performance, and is odorless and environmentally friendly.

Description

Technical Field

[0001] This application belongs to the field of polymer materials technology, specifically relating to an odorless antibacterial hydrophobic PVC composite material and its preparation method. Background Technology

[0002] Polyvinyl chloride (PVC) is widely used in various fields such as construction, medical, food packaging, and electronics due to its excellent processing performance, low cost, and good mechanical strength. However, with the increasing complexity of application environments, traditional PVC materials have gradually revealed some performance deficiencies in practical use, especially in terms of antibacterial properties, hydrophobicity, and odor control, making it difficult to meet the demands of modern industry and consumers for high-quality and environmentally friendly materials.

[0003] Currently, most antibacterial PVC materials on the market use a single antibacterial component, resulting in a narrow antibacterial spectrum that cannot effectively combat the invasion of various bacteria and fungi. Furthermore, the antibacterial effect has poor durability, failing to meet the requirements for long-term use. In addition, conventional methods to improve the hydrophobic properties of materials mainly involve adding additives such as silicone oil and fluorocarbons. While these can improve the waterproof performance of the material surface to some extent, they often affect the material's mechanical and processing properties, leading to problems such as embrittlement and easy surface peeling, thus impacting its practical application. Simultaneously, many PVC materials release a certain odor during processing or use, especially noticeable in high-temperature or humid environments. This odor not only affects the user experience but also limits its application in odor-sensitive fields such as food packaging and medical devices.

[0004] Therefore, there is an urgent need to develop an odorless and environmentally friendly PVC composite material that can maintain good physical and mechanical properties while possessing excellent antibacterial and hydrophobic properties. Summary of the Invention

[0005] In view of this, this application provides an odorless antibacterial and hydrophobic PVC composite material and its preparation method. The odorless antibacterial and hydrophobic PVC composite material provided by this application can maintain good physical and mechanical properties while possessing excellent antibacterial and hydrophobic properties.

[0006] In a first aspect, this application provides an odorless, antibacterial, and hydrophobic PVC composite material, which, by weight, comprises: 80-120 parts of polyvinyl chloride resin, 50-80 parts of tributyl acetylacetonate, 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 antifungal agent, 0.2-1 part of lubricant, 8-15 parts of stearic acid-modified nano-sized 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 in this application, using specific raw materials, significantly improves the antibacterial and hydrophobic properties of the material while maintaining the basic properties of PVC resin, without sacrificing its mechanical properties. This application utilizes the combined action of tributyl acetylacetic acid and stearic acid-modified nano-calcium carbonate, which not only enhances the mechanical properties of the material but also significantly improves its surface hydrophobicity, reduces water absorption, and makes it suitable for long-term use in humid environments. The combined use of stabilizers, antioxidants, and ultraviolet absorbers further enhances the material's weather resistance and service life.

[0008] In this application, nano-silver-based antibacterial agents and food-grade antifungal agents work together to form a broad-spectrum, long-lasting antibacterial system, effectively inhibiting the growth of bacteria and fungi. The addition of coumarin further enhances the material's antibacterial properties and, to some extent, masks any potential odors from other components, resulting in an overall odorless and environmentally friendly material. Lubricants improve processing fluidity, ensuring excellent material molding performance.

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

[0010] By employing the above-mentioned technical solution, the acetylated tributyl citrate (ATBC) and stearic acid-modified nano-sized calcium carbonate of this application work synergistically to significantly improve the physical and mechanical properties, antibacterial properties, and hydrophobic properties of PVC composite materials. A specific weight ratio helps the stearic acid-modified nano-sized calcium carbonate to be better dispersed in the PVC matrix, further enhancing the material's impact strength. Furthermore, the good dispersibility and plasticizing effect of ATBC ensures the uniform distribution of antibacterial components throughout the material, thereby further extending the antibacterial time and enhancing the antibacterial effect. Moreover, the combined use of ATBC and stearic acid-modified nano-sized calcium carbonate can form a dense protective film on the material surface, significantly improving the material's hydrophobic properties and reducing the possibility of moisture 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, trinonylphenyl phosphite, and dilauryl thiodipropionate.

[0012] By adopting the above technical solutions, the stabilizers and antioxidants of this application can significantly improve the thermal stability and processing performance of the material, inhibit oxidation reactions, prevent oxidative aging of the material during storage or use, and thus extend 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 resorcinol monobenzoate.

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

[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 nano-silver-based antibacterial agent of this application effectively inhibits the growth of bacteria (such as Escherichia coli and Staphylococcus aureus), fungi, and molds by slowly releasing silver ions to disrupt the cell membrane structure of microorganisms and interfere with their metabolism and DNA replication processes. It exhibits stronger stability and controllable release capability, resulting in a longer-lasting antibacterial effect. It can endow PVC composite materials with efficient, broad-spectrum, and long-lasting antibacterial properties, and also possesses good thermal stability, processing adaptability, and environmental friendliness.

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

[0018] By adopting the above technical solution, the nano-silver-based antibacterial agent of this application, in synergy with coumarin, further enhances the antibacterial effect, broadens the antibacterial spectrum, and strengthens the inhibitory ability against a variety of bacteria and fungi. A specific weight ratio can improve initial antibacterial efficiency and enhance long-term antibacterial stability, thereby prolonging the duration of the antibacterial effect.

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

[0020] By adopting the above technical solution, the food-grade anti-mold agent of this application can effectively inhibit the growth of mold, significantly improve the anti-mold ability, ensure that the material is protected from microbial attack during long-term use, and meet food standards, and is 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 this application can improve processing fluidity and increase molding efficiency. It also helps to improve the surface finish and smoothness of the finished product, and reduce defects such as bubbles and silver streaks.

[0023] Secondly, this application provides a method for preparing the above-mentioned odorless, antibacterial, and hydrophobic PVC composite material, comprising the following steps: Step S1: Mix the polyvinyl chloride resin, stabilizer, antioxidant, ultraviolet absorber, nano-silver antibacterial agent, food-grade mildew inhibitor and stearic acid surface-modified nano-sized calcium carbonate at a mixing temperature of 80℃~100℃ and a mixing time of 5min~15min to obtain a premix. Step S2: Slowly add the acetylacetic acid tributyl ester, lubricant and coumarin to the premix and mix to obtain a mixture. The mixing temperature is 100℃~120℃ and the mixing time is 10min~20min. Step S3: Plasticize the mixture at a temperature of 160℃~180℃, extrude it, and cool it to obtain an odorless antibacterial hydrophobic PVC composite material.

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

[0025] Optionally, the preparation method of the stearic acid surface-modified nano-sized calcium carbonate is as follows: stirring and mixing nano-sized 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-sized calcium carbonate; the content of stearic acid in the stearic acid surface-modified nano-sized calcium carbonate is 1% to 3%.

[0026] By adopting the above technical solution, the stearic acid-modified nano-sized calcium carbonate prepared in this application not only enhances the waterproof and moisture-proof performance of the material, but also maintains stable antibacterial and mechanical properties in humid environments. By controlling the stearic acid content to 1%–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, this modification process is environmentally friendly, safe, and simple to operate.

[0027] In summary, the present invention has 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 to significantly improve the antibacterial and hydrophobic properties of the material while maintaining the basic properties of PVC resin, without sacrificing its mechanical properties.

[0028] 2. This application uses acetylated 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 synergistic effect 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 Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0031] The inventors of this application discovered in their research on antibacterial and hydrophobic PVC materials that: existing antibacterial PVC materials have a single antibacterial component, a narrow antibacterial spectrum, and poor durability of antibacterial effects. They also suffer from insufficient hydrophobic properties, leading to the release of odors during processing or use.

[0032] To address the aforementioned issues, this application proposes an odorless, antibacterial, and hydrophobic PVC composite material, comprising, by weight: 80-120 parts polyvinyl chloride resin, 50-80 parts tributyl acetylacetonate, 0.5-4 parts stabilizer, 0.1-0.5 parts antioxidant, 0.05-0.4 parts ultraviolet absorber, 1-5 parts nano-silver antibacterial agent, 0.5-3 parts food-grade antifungal agent, 0.2-1 part lubricant, 8-15 parts stearic acid-modified nano-sized calcium carbonate, and 0.05-0.5 parts coumarin.

[0033] This application also proposes a method for preparing the above-mentioned odorless antibacterial hydrophobic PVC composite material, including the following steps: Step S1, mixing polyvinyl chloride resin, stabilizer, antioxidant, ultraviolet absorber, nano-silver antibacterial agent, food-grade antifungal agent and stearic acid surface-modified nano-sized calcium carbonate, mixing temperature is 80℃~100℃, mixing time is 5min~15min, to obtain a premix; Step S2: Slowly add acetylacetic acid tributyl ester, lubricant and coumarin to the premix and mix to obtain a mixture. The mixing temperature is 100℃~120℃ and the mixing time is 10min~20min. Step S3: Plasticize the mixture at a temperature of 160℃~180℃, extrude it, and cool it to obtain an odorless antibacterial hydrophobic PVC composite material.

[0034] The solution of this application will be described below with reference to the following specific embodiments. Unless otherwise specified, the raw materials used in the following embodiments are all from commercially available products, and the devices or equipment used are all purchased from conventional market sales channels. Specific Implementation

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

[0036] Examples 1-3 Example 1 This embodiment provides an odorless, antibacterial, and hydrophobic PVC composite material, which, by weight, comprises: 80 parts of polyvinyl chloride resin, 80 parts of tributyl acetylacetonate, 4 parts of stabilizer, 0.1 parts of antioxidant, 0.05 parts of ultraviolet absorber, 5 parts of nano-silver antibacterial agent, 0.5 parts of food-grade antifungal agent, 0.2 parts of lubricant, 15 parts of stearic acid surface-modified nano-sized calcium carbonate, and 0.05 parts of coumarin lactone. Among them, 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 includes the following steps: Step S1: Mix polyvinyl chloride resin, stabilizer, antioxidant, ultraviolet absorber, nano silver antibacterial agent, food-grade mildew inhibitor and stearic acid surface-modified nano-sized calcium carbonate. The mixing temperature is 80℃ and the mixing time is 15min to obtain a premix. Step S2: Slowly add acetylacetic acid tributyl ester, lubricant and coumarin to the premix and mix to obtain a mixture. The mixing temperature is 100℃ and the mixing time is 20min. Step S3: Plasticize the mixture at a temperature of 160°C, extrude it, and cool it to obtain an odorless, antibacterial, and hydrophobic PVC composite material.

[0037] Example 2 This embodiment provides an odorless, antibacterial, and hydrophobic PVC composite material, which, by weight, comprises: 100 parts of polyvinyl chloride resin, 65 parts of tributyl acetylacetonate, 2 parts of stabilizer, 0.3 parts of antioxidant, 0.2 parts of ultraviolet absorber, 3 parts of nano-silver antibacterial agent, 2 parts of food-grade antifungal agent, 0.6 parts of lubricant, 12 parts of stearic acid surface-modified nano-sized calcium carbonate, and 0.3 parts of coumarin lactone. Among them, 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 includes the following steps: Step S1: Mix polyvinyl chloride resin, stabilizer, antioxidant, ultraviolet absorber, nano silver antibacterial agent, food-grade mildew inhibitor and stearic acid surface-modified nano-sized calcium carbonate. The mixing temperature is 90℃ and the mixing time is 10min to obtain a premix. Step S2: Slowly add acetylacetic acid tributyl ester, lubricant and coumarin to the premix and mix to obtain a mixture. The mixing temperature is 110℃ and the mixing time is 15min. Step S3: Plasticize the mixture at a temperature of 170°C, extrude it, and cool it to obtain an odorless, antibacterial, and hydrophobic PVC composite material.

[0038] Example 3 This embodiment provides an odorless, antibacterial, and hydrophobic PVC composite material, which, by weight, comprises: 120 parts of polyvinyl chloride resin, 50 parts of tributyl acetylacetonate, 0.5 parts of stabilizer, 0.5 parts of antioxidant, 0.4 parts of ultraviolet absorber, 1 part of nano-silver antibacterial agent, 3 parts of food-grade antifungal agent, 1 part of lubricant, 8 parts of stearic acid surface-modified nano-sized calcium carbonate, and 0.5 parts of coumarin. Among them, 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 includes the following steps: Step S1: Mix polyvinyl chloride resin, stabilizer, antioxidant, ultraviolet absorber, nano silver antibacterial agent, food-grade mildew inhibitor and stearic acid surface-modified nano-sized calcium carbonate. The mixing temperature is 100℃ and the mixing time is 5min to obtain a premix. Step S2: Slowly add acetylacetic acid tributyl ester, lubricant and coumarin to the premix and mix to obtain a mixture. The mixing temperature is 120℃ and the mixing time is 10min. Step S3: Plasticize the mixture at a temperature of 180°C, extrude it, and cool it to obtain an odorless, antibacterial, and hydrophobic PVC composite material.

[0039] Comparative Examples 1-3 Comparative Example 1 The difference between Comparative Example 1 and Example 2 is that Comparative Example 1 did not contain acetylthiose tributyl citrate.

[0040] Comparative Example 2 The difference between Comparative Example 2 and Example 2 is that Comparative Example 2 did not include stearic acid-modified nano-sized calcium carbonate.

[0041] Comparative Example 3 The difference between Comparative Example 3 and Example 2 is that no coumarol was added in Comparative Example 3.

[0042] Experimental testing Test items and test methods: Mechanical properties: The notched impact strength of the prepared composite material is tested according to GB / T 1043.1-2008 "Determination of impact properties of simply supported plastic beams"; Antibacterial properties: The antibacterial and antifungal rating of the composite material was tested according to JIS Z 2911:2010 Method A; Hydrophobic properties: The water absorption rate of the prepared composite material was tested according to GB / T 1034-2008 "Determination of Water Absorption of Plastics"; Odor test: Trained professionals were organized to smell the prepared composite material at room temperature and 60% relative humidity, and scored according to the following scoring system: 0 points: Absolutely no odor, fully meets the odorless standard; 1 point: A very faint odor that is almost imperceptible and can only be detected when you sniff carefully; 2 points: Slight but noticeable odor, but not easily noticed under normal use conditions; 3 points: Moderate odor, detectable at normal distance, but not pungent; 4 points: Strong odor, which may cause discomfort, but not to an unbearable degree; 5 stars: The odor is extremely strong and unbearable, severely impacting the user experience.

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

[0044] Table 1 As can be seen from the test results in Table 1, 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 low water absorption, indicating that the composite material has excellent antibacterial and hydrophobic properties, and the odor test score is 0, that is, there is no odor.

[0045] In Comparative Example 1, without the addition of acetylthiol tributyl ester, the notched impact strength of the prepared composite material decreased and the water absorption rate increased, indicating that both the mechanical properties and hydrophobic properties of the composite material decreased.

[0046] In Comparative Example 2, without the addition of stearic acid to modify the surface of nano-sized calcium carbonate, the notched impact strength of the resulting composite material decreased significantly, while the water absorption rate increased, indicating that both the mechanical properties and hydrophobic properties of the composite material decreased.

[0047] Comparative Example 3, which did not contain coumarin, produced a composite material with an antibacterial and antifungal grade of 1 and an odor test score of 1, indicating that the antibacterial performance of the composite material decreased and an odor appeared.

[0048] Examples 4-13 Example 4 The difference between Example 4 and Example 2 is that in Example 4, the total weight of acetylated tributyl citrate and stearic acid-modified nano-sized calcium carbonate is 77 parts, and the weight ratio of acetylated tributyl citrate to stearic acid-modified nano-sized 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 acetylated tributyl citrate and stearic acid-modified nano-sized calcium carbonate is 77 parts, and the weight ratio of acetylated tributyl citrate to stearic acid-modified nano-sized 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 trinonylphenyl phosphite.

[0052] Example 8 The difference between Example 8 and Example 2 is that in Example 8, the ultraviolet absorber is resorcinol monobenzoate.

[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 the nano-silver antibacterial agent and coumarin is 3.3 parts, and the weight ratio of the 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 antifungal agent 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 hydrophobic PVC composite materials prepared in Examples 4 to 13 were tested for notched impact strength, antibacterial and antifungal grade, and water absorption rate, and odor was also tested. The test results are shown in Table 2.

[0059] Table 2 As can be seen from the test results in Table 2, the difference between Example 4, Example 5 and Example 2 is that the weight ratio of acetylacetic acid tributyl ester to stearic acid surface-modified nano-sized calcium carbonate is different. Among them, the composite material prepared in Example 4 has the highest notched impact strength, the lowest water absorption rate, and the best mechanical properties and hydrophobic properties.

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

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

[0062] The difference between Examples 12 and 13 and Example 2 is that different food-grade antifungal agents and lubricants were selected respectively. The resulting composite material has good mechanical properties, excellent antibacterial and hydrophobic properties, and no odor.

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

Claims

1. An odorless, antibacterial, hydrophobic PVC composite material, characterized in that, By weight, its raw material composition includes: 80-120 parts polyvinyl chloride resin, 50-80 parts tributyl acetylacetonate, 0.5-4 parts stabilizer, 0.1-0.5 parts antioxidant, 0.05-0.4 parts ultraviolet absorber, 1-5 parts nano-silver antibacterial agent, 0.5-3 parts food-grade antifungal agent, 0.2-1 part lubricant, 8-15 parts stearic acid surface-modified nano-sized calcium carbonate, and 0.05-0.5 parts coumarin. The weight ratio of the acetylic acid tributyl ester to the stearic acid-modified nano-sized calcium carbonate is 5~8:

1.

2. 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, trinonylphenyl phosphite, and dilauryl thiodipropionate.

3. 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 resorcinol monobenzoate.

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

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

1.

6. The composite material according to claim 1, characterized in that, The food-grade antifungal agent includes at least one of sorbic acid, calcium propionate, sodium diacetate, and natamycin.

7. 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.

8. A method for preparing the odorless antibacterial hydrophobic PVC composite material according to any one of claims 1 to 7, characterized in that, Includes the following steps: Step S1: Mix the polyvinyl chloride resin, stabilizer, antioxidant, ultraviolet absorber, nano-silver antibacterial agent, food-grade mildew inhibitor and stearic acid surface-modified nano-sized calcium carbonate at a mixing temperature of 80℃~100℃ and a mixing time of 5min~15min to obtain a premix. Step S2: Slowly add the acetylacetic acid tributyl ester, lubricant and coumarin to the premix and mix to obtain a mixture. The mixing temperature is 100℃~120℃ and the mixing time is 10min~20min. Step S3: Plasticize the mixture at a temperature of 160℃~180℃, extrude it, and cool it to obtain an odorless antibacterial hydrophobic PVC composite material.

9. The preparation method according to claim 8, characterized in that, The preparation method of the stearic acid surface-modified nano-sized calcium carbonate is as follows: nano-calcium carbonate powder is stirred and mixed with water to obtain a calcium carbonate suspension; stearic acid is added, and the mixture is heated and stirred. Centrifugation, washing, and drying are performed to obtain the stearic acid-modified nano-sized calcium carbonate; the stearic acid content in the stearic acid-modified nano-sized calcium carbonate is 1%~3%.

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