Modified nano-copper antibacterial composite material and preparation method thereof
Nanocopper particles are prepared through liquid phase reduction method and surface modification, which solves the dispersion and antibacteriality of thermoplastic polymer materials, and achieves efficient antibacterial effects at low concentrations. They are suitable for food packaging, medical devices, and building materials and other fields.
Patent Information
- Application Number
- CN202510475090.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-16
- Publication Date
- 2025-07-04
AI Technical Summary
The existing thermoplastic polymer materials have problems such as poor dispersion, weak interface compatibility, high cost, and unfriendly environment in the antibacterial functional modification, making it difficult to achieve a balance of high dispersion-low concentration-high antibacterial activity.
Nanocopper particles were prepared by liquid phase reduction method, and surface functional modification was performed, combined with thermoplastic resin for melt blending, extrusion and granulation, and modified nanocopper antibacterial composite materials were prepared to ensure that the nanocopper was evenly dispersed in the resin and had high antibacterial properties.
It achieves low cost, high dispersion and high antibacterial properties. Nanocopper can achieve an antibacterial rate of 90%-99% in thermoplastic resins with a concentration of only 100-700 ppm, without affecting the mechanical properties of the material.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of antibacterial polymer composite materials, and particularly relates to a modified nano-copper antibacterial composite material and a preparation method thereof, which are applicable to the antibacterial functional modification of thermoplastic resin materials. Background Art
[0002] Thermoplastic polymer materials (such as polypropylene, polyethylene, etc.) are widely used in fields such as food packaging, medical devices, daily consumer goods, and building materials due to their excellent chemical stability, processing flexibility, and cost advantages. However, microorganisms are easily attached to the plastic surface and form biofilms, becoming a breeding ground for bacteria (such as Escherichia coli, Staphylococcus aureus) and fungi. This not only accelerates material aging but also may cause cross-infection, threatening public health safety. Therefore, antibacterial functional modification of thermoplastic materials to endow them with long-term antibacterial ability has become a key technical requirement for improving product safety and added value.
[0003] Currently, the commonly used antibacterial agents in the industry mainly include the following categories: (1) Nano-silver (Ag NPs): Although it has broad-spectrum antibacterial properties (antibacterial rate > 99%), its raw material cost is high (the price of silver is about 850 US dollars per kilogram, while the price of copper is only 7 US dollars per kilogram), and the release of silver ions may be toxic to mammalian cells (such as inducing oxidative stress), restricting its application in food contact materials and the medical field.
[0004] (2) Natural antibacterial agents (such as chitosan): Although they have good biocompatibility, their antibacterial activity is significantly affected by the pH value, and they are easily degraded in a humid and hot environment, making it difficult to meet the requirements of long-term stability (for example, the antibacterial rate of a chitosan coating drops by more than 1 / 3 within 30 days).
[0005] (3) Organic antibacterial agents (such as quaternary ammonium salts, triclosan): There are problems such as easy migration and poor heat resistance. Long-term use may induce bacterial drug resistance and cause environmental residues.
[0006] In addition, the nano-metal / polymer composite systems in the prior art generally face two major bottlenecks: (1) Poor dispersibility: Nano-particles are prone to agglomeration, resulting in a decrease in antibacterial activity. High concentrations (such as 200 - 500 ppm for nano-silver) are required to achieve the desired effect, further driving up the cost.
[0007] (2) Weak interfacial compatibility: The binding force between unmodified nano-particles and the resin matrix is insufficient, and they are easily migrated to the material surface during the processing, resulting in functional failure.
[0008] In view of the above problems, developing a low-cost, highly dispersed, and environmentally friendly antibacterial composite material has become a technical difficulty that urgently needs to be overcome in this field. Based on this, the present invention proposes to use nano-copper as the core, and through the collaborative design of surface functional modification and resin matrix, to achieve the balance of "high dispersibility - low concentration - high antibacterial activity", providing an innovative solution for the antibacterial functionalization of thermoplastic materials. Summary of the Invention
[0009] Aiming at the deficiencies of the technology, the present invention proposes a modified nano-copper antibacterial composite material and its preparation method, which can achieve the purposes of high dispersion - low addition - high antibacterial property.
[0010] The object of the present invention can be achieved by the following technical solutions: A preparation method of a modified nano-copper antibacterial composite material, which comprises the following steps: S1. Preparation of nano-copper by liquid-phase reduction method: In a liquid-phase system, by adding a dispersant and a composite modifier I, controlling the reaction temperature and reaction time to obtain a nano-copper dispersion; specifically: dispersing a copper precursor in deionized water, adding a certain amount of composite modifier I, heating to 80 ± 2 °C, and then adding a reducing agent hydrazine hydrate solution (80 ± 5 wt%) according to the molar ratio of copper precursor to reducing agent of 1:1.5 - 2.0. After reacting for a period of time, a nano-copper dispersion is obtained; S2. Surface functional modification of nano-copper: Introducing a surface modifier to conduct functional modification on nano-copper to enhance the antibacterial property of nano-copper powder; specifically: adding a certain amount of composite modifier II to the nano-copper dispersion obtained in S1, continuing to react for 0.5 - 2 h, and then obtaining well-dispersed, chemically stable, and excellent antibacterial property modified nano-copper powder through centrifugation, drying, and grinding; S3. Preparation of modified nano-copper antibacterial masterbatch: After blending the modified nano-copper powder obtained in S2 with an additive, blending with a thermoplastic resin, and performing melt blending, extrusion, and pelletizing to obtain a high-concentration modified nano-copper polymer antibacterial masterbatch, and then preparing a low-concentration modified nano-copper polymer antibacterial masterbatch by blending with a thermoplastic resin through a concentration dilution method; S4. Preparation of modified nano-copper antibacterial composite material: Passing the low-concentration modified nano-copper polymer antibacterial masterbatch prepared in S3 through a flat vulcanizer and a blown film machine to respectively obtain a modified nano-copper polymer antibacterial composite sheet and a modified nano-copper polymer antibacterial composite film, realizing the uniform dispersion of nano-copper in the thermoplastic material.
[0011] Specifically, the copper precursor in step S1 can be one or more of copper sulfate, copper nitrate, copper chloride, etc.
[0012] Specifically, the "reacting for a period of time" in step S1 means that the particle size of nano copper can be adjusted to 30 - 60 nm within 0 - 30 min, to 60 - 100 nm within 1 - 2 h, and the copper element content is 95 wt% - 99 wt%.
[0013] Specifically, the first composite modifier described in step S1 includes but is not limited to at least one of polyacrylic acid, long - carbon - chain silane coupling agent, polyvinylpyrrolidone, etc. The mass of the first composite modifier can be 3 wt% - 5 wt% of the mass of the copper precursor, which can improve the dispersibility of nano copper.
[0014] Specifically, the second composite modifier described in step S2 includes but is not limited to at least one of chitosan, sulfadiazine, quaternary ammonium salt silane, etc. The mass of the second composite modifier can be 1 wt% - 5 wt% of the mass of the copper precursor, which can improve the antibacterial property of nano copper. Further, the "chemically stable" in step S2 means that the prepared modified nano copper can be stored in a room - temperature air atmosphere for more than 3 months.
[0015] Specifically, in the high - concentration nano - copper polymer antibacterial masterbatch in step S3, the concentration of modified nano copper does not exceed 10 wt%, and in the low - concentration nano - copper polymer antibacterial masterbatch, the concentration of modified nano copper is 100 - 900 ppm. The thermoplastic resin includes but is not limited to at least one of polypropylene, polyethylene, polyvinyl chloride, polystyrene, polyethylene terephthalate, polyamide, polylactic acid, and polyvinylidene chloride, etc.
[0016] Specifically, the additives described in step S3 include but are not limited to at least one of white oil, epoxidized soybean oil, epoxidized linseed oil, dioctyl phthalate, and dibutyl phthalate, etc. The mass of the additives can be 5 wt% - 13 wt% of the mass of the thermoplastic resin.
[0017] Specifically, the thickness of the prepared antibacterial composite sheet in step S4 can be 1.0 ± 0.1 mm, and the thickness of the antibacterial composite film can be 40 - 80 μm.
[0018] The present invention provides a modified nano - copper antibacterial composite material prepared by the above - mentioned preparation method.
[0019] Further, for the above - mentioned modified nano - copper antibacterial composite material, when the concentration of modified nano copper is 100 - 300 ppm, the antibacterial rate of the modified nano - copper antibacterial composite material is greater than 90%, and when the concentration of modified nano copper is 500 - 700 ppm, the antibacterial rate of the modified nano - copper antibacterial composite material is greater than 99%.
[0020] The innovative points of the present invention are listed as follows: (1) Adding a surface modification modifier directly after the synthesis of nano copper significantly improves the dispersibility and antibacterial property of nano copper. (2) Design of low concentration - high antibacterial rate: In thermoplastic resins, nano copper only needs a concentration of 100 - 700 ppm to achieve: 100 - 300 ppm: antibacterial rate > 90%; 500 - 700 ppm: antibacterial rate > 99% (standard of GB / T 21510 - 2008). (3) Through the processes of melt blending and extrusion granulation, it is adapted to thermoplastic resins such as polypropylene (PP) and polyethylene (PE), ensuring the uniform dispersion of nano copper (no visible agglomeration) and not affecting the mechanical properties of the base material.
[0021] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: 1) The modified nano copper antibacterial composite material described in the present invention has broad-spectrum antibacterial property, low price, simple preparation process, and is easy to industrialize.
[0022] 2) The nano copper prepared in the present invention has significantly improved dispersibility and antibacterial performance after surface modification functional modification. When the nano copper concentration in thermoplastic resins is 100 - 300 ppm, the antibacterial rate > 90% (GB / T 21510 - 2008), and the dosage is reduced by 1 / 3 compared with similar products. Description of the Drawings
[0023] Figure 1 It is the particle size distribution diagram (left) and TEM diagram (right) of the modified nano copper obtained in Example 1; Figure 2 It is the SEM (a1, a2) and EDS (b1, b2) photos of the modified nano copper in PP sheet and film in Example 1; Figure 3 It is the antibacterial rate diagram of the Cu / PP composite sheet (left) and film (right) prepared in Example 1; Figure 4 It is the particle size distribution diagram (left) and TEM diagram (right) of the modified nano copper obtained in Example 2; Figure 5 It is the SEM (a1, a2) and EDS (b1, b2) photos of the modified nano copper in PP sheet and film in Example 2; Figure 6 It is the antibacterial rate diagram of the Cu / PP composite sheet (left) and film (right) prepared in Example 2; Figure 7 It is the antibacterial rate diagram of the Cu / LDPE composite film prepared in Example 3. Detailed Embodiments
[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
[0025] The antibacterial performance of the present invention was investigated with reference to the national standard GB / T 21510-2008. In this method, the inoculated bacterial suspension was placed on the sample to be tested, and the film sticking method was used to make the bacterial suspension uniformly contact the sample to be tested. After a certain period of cultivation, the number of viable bacteria in the sample was detected, and then the antibacterial rate of the sample could be calculated. The calculation formula for the antibacterial rate is as follows: Antibacterial rate R = (A - B) / A × 100% Where: A - the average recovery number after the control sample contacts the bacteria for a certain period of time, with the unit of colony forming unit per milliliter (cfu / mL); B - the average recovery number after the test sample contacts the bacteria for a certain period of time, with the unit of colony forming unit per milliliter (cfu / mL).
[0026] Bacteria for detection: Escherichia coli (ATCC25922).
[0027] Example 1: The preparation method of the modified nano-copper antibacterial composite material includes the following steps: Step 1: Disperse 5 g of copper sulfate (CuSO4·5H2O) in 200 mL of deionized water, add 0.2 g of dodecyltrimethoxysilane (A-1230), stir and heat up to 80 °C, then add a hydrazine hydrate solution (concentration 80 wt%) according to the molar ratio of copper precursor to reducing agent of 1:2, and maintain the reaction for 30 minutes to obtain a nano-copper dispersion with an average particle size of 50 nm.
[0028] Step 2: Add 5 wt% of cetyltrimethylammonium bromide based on the mass of the copper precursor, continue the reaction for 1 h, then centrifuge, dry and grind the reaction solution to obtain monodispersed modified nano-copper powder with excellent antibacterial performance.
[0029] Step 3: Take 50 g of modified nano-copper powder and blend it with 50 g of epoxy soybean oil, then blend it with 450 g of polypropylene particles. After melt blending, extrude and pelletize through a twin-screw extruder to prepare a high-concentration Cu / PP antibacterial masterbatch.
[0030] Step 4: Weigh (0.5 g, 1.5 g, 2.5 g, 3.5 g, and 4.5 g) of Cu / PP antibacterial masterbatch respectively. After blending with 500 g of polypropylene granules through a twin-screw extruder, Cu / PP antibacterial composite sheet and Cu / PP antibacterial composite film are respectively prepared through a flat vulcanizer and a single-screw extrusion blown film machine. The thickness of the sheet is 1 mm, and the thickness of the film is 70 μm. And antibacterial evaluation is carried out on the sheet and the film with reference to the national standard GB / T 21510-2008.
[0031] Figure 1 This is the XRD pattern and particle size distribution diagram of the modified nano copper product prepared in this example. It can be seen from the figure that the prepared modified nano copper has no oxidation phenomenon, is evenly dispersed, and the average particle size is 50 nm.
[0032] Figure 2 This is the SEM image and EDS image of the modified nano copper in the PP sheet and film prepared in this example. It can be seen from the figure that the prepared modified nano copper is evenly dispersed in the PP resin.
[0033] Figure 3 This is the antibacterial effect diagram of the Cu / PP composite antibacterial sheet and antibacterial film prepared in this example. It can be seen from the figure that when the concentration of the modified nano copper is 100 ppm, the antibacterial rates of the Cu / PP composite antibacterial sheet and antibacterial film are both greater than 90%; when the concentration of the modified nano copper is 500 ppm, the antibacterial rates of the Cu / PP composite antibacterial sheet and antibacterial film are both greater than 99%.
[0034] Example 2: The preparation method of the modified nano copper antibacterial composite material includes the following steps: Step 1: Disperse 5 g of copper sulfate (CuSO4·5H2O) in 200 mL of deionized water, add 0.2 g of dodecyltrimethoxysilane (A-1230) as a dispersant, stir and heat up to 80°C, then add hydrazine hydrate solution (concentration 80 wt%) according to the molar ratio of copper precursor to reducing agent of 1:2, and react for 1 hour to obtain a nano copper dispersion with an average particle size of 80 nm.
[0035] Step 2: Add 5 wt% of the modifier quaternized chitosan based on the mass of the copper precursor, continue to react for 1 h, then centrifuge, dry, and grind the reaction solution to obtain monodisperse and excellent antibacterial performance modified nano copper powder.
[0036] Step 3: Take 50 g of modified nano copper powder and blend it with 50 g of epoxidized soybean oil, then blend it with 450 g of polypropylene granules. After melt blending, extrude and pelletize through a twin-screw extruder to prepare a high-concentration Cu / PP antibacterial masterbatch.
[0037] Step 4: Weigh (0.5 g, 1.5 g, 2.5 g, 3.5 g, and 4.5 g) of Cu / PP antibacterial masterbatch respectively. After blending 500 g of polypropylene granules with a twin-screw extruder, Cu / PP composite antibacterial sheet and Cu / PP composite antibacterial film are respectively prepared through a flat vulcanizing instrument and a single-screw extrusion blown film machine. The thickness of the sheet is 1 mm, and the thickness of the film is 70 μm. And antibacterial evaluation is carried out on the sheet and the film with reference to the national standard GB / T21510-2008.
[0038] Figure 4 This is the XRD pattern and particle size distribution diagram of the modified nano copper product prepared in this example. It can be seen from the figure that the prepared modified nano copper has no oxidation phenomenon, and the average particle size is 80 nm.
[0039] Figure 5 This is the SEM image and EDS image of the modified nano copper in the PP sheet and film prepared in this example. It can be seen from the figure that the prepared modified nano copper is evenly dispersed in the PP resin.
[0040] Figure 6 This is the antibacterial effect diagram of the Cu / PP composite antibacterial sheet and antibacterial film prepared in this example. It can be seen from the figure that when the concentration of the modified nano copper is 300 ppm, the antibacterial rate is greater than 90%; when the concentration of the modified nano copper is 500 ppm, the antibacterial rate is greater than 99%.
[0041] Example 3: The preparation method of the modified nano copper antibacterial composite material includes the following steps: Step 1: Disperse 5 g of copper sulfate (CuSO4·5H2O) in 200 mL of deionized water, add 0.2 g of dodecyltrimethoxysilane (A-1230), stir and heat up to 80 °C, then add hydrazine hydrate solution (concentration 80 wt%) according to the molar ratio of copper precursor to reducing agent of 1:2, and react for 1 h to obtain a nano copper dispersion with an average particle size of 80 nm.
[0042] Step 2: Add 5 wt% of cetyltrimethylammonium bromide based on the mass of the copper precursor, continue to react for 1 h, then centrifuge, dry, and grind the reaction solution to obtain monodispersed modified nano copper powder with excellent antibacterial performance.
[0043] Step 3: Take 50 g of modified nano copper powder and blend it with 50 g of epoxidized soybean oil, then blend it with 450 g of low-density polyethylene granules. After melt blending, extrude and pelletize through a twin-screw extruder to prepare a high-concentration Cu / LDPE antibacterial masterbatch.
[0044] Step 4: Weigh out (1.5 g, 2.5 g, and 3.5 g) of Cu / LDPE antibacterial masterbatch respectively. After blending 500 g of low-density polyethylene particles through a twin-screw extruder, a Cu / LDPE antibacterial composite film is prepared by a single-screw extrusion blown film machine, and the film thickness is 70 μm. And the antibacterial evaluation of the film is carried out with reference to the national standard GB / T 21510-2008.
[0045] Figure 7 This is the antibacterial effect diagram of the Cu / LDPE composite antibacterial sheet prepared in this example. It can be seen from the figure that when the concentration of modified nano-copper is 300 ppm, the antibacterial rate is greater than 90%; when the concentration of modified nano-copper is 500 ppm, the antibacterial rate is greater than 99%.
Claims
1. A preparation method of a modified nano-copper antibacterial composite material, characterized in that, It includes the following steps: S1. Disperse the copper precursor in deionized water, add a certain amount of composite modifier I, heat it to 80 ± 2 °C, and then add a hydrazine hydrate solution according to the molar ratio of copper precursor to reducing agent of 1:1.5 - 2.
0. After reacting for a period of time, a nano - copper dispersion is obtained; S2. Add a certain amount of composite modifier II to the nano - copper dispersion obtained in S1, continue to react for 0.5 - 2 h, and then obtain modified nano - copper powder through centrifugation, drying, and grinding; S3. Blend the modified nano - copper powder obtained in S2 with an auxiliary agent, and then blend it with a thermoplastic resin. After melt - blending, extrusion, and pelletizing, a high - concentration modified nano - copper polymer antibacterial masterbatch is prepared. Then, a low - concentration modified nano - copper polymer antibacterial masterbatch is prepared by the concentration dilution method; S4. Pass the low - concentration modified nano - copper polymer antibacterial masterbatch prepared in S3 through a flat vulcanizer and a blown - film machine to obtain a modified nano - copper polymer antibacterial composite sheet and a modified nano - copper polymer antibacterial composite film.
2. The preparation method of the modified nano-copper antibacterial composite material according to claim 1, characterized in that, The copper precursor described in step S1 is one or more of copper sulfate, copper nitrate, and copper chloride.
3. The preparation method of the modified nano copper antibacterial composite material according to claim 1, characterized in that, The "reacting for a period of time" described in step S1 means that: reacting for 0 - 30 min can control the nano - copper particle size within 30 - 60 nm; reacting for 1 - 2 h can control the nano - copper particle size within 60 - 100 nm; the copper element content is 95 wt% - 99 wt%.
4. The preparation method of the modified nano-copper antibacterial composite material according to claim 1, characterized in that, The composite modifier I described in step S1 is not limited to at least one of polyacrylic acid, long - carbon - chain silane coupling agent, and polyvinylpyrrolidone, and the mass of the composite modifier I is 3 wt% - 5 wt% of the mass of the copper precursor.
5. The preparation method of the modified nano-copper antibacterial composite material according to claim 1, characterized in that, The composite modifier II described in step S2 is not limited to at least one of chitosan, sulfadiazine, and quaternary ammonium salt silane, and the mass of the composite modifier II is 1 wt% - 5 wt% of the mass of the copper precursor.
6. The preparation method of the modified nano copper antibacterial composite material according to claim 1, characterized in that, In the high - concentration modified nano - copper polymer antibacterial masterbatch in step S3, the concentration of modified nano - copper does not exceed 10 wt%, and in the low - concentration nano - copper polymer antibacterial masterbatch, the concentration of modified nano - copper is 100 - 900 ppm; the thermoplastic resin is not limited to at least one of polypropylene, polyethylene, polyvinyl chloride, polystyrene, polyethylene terephthalate, polyamide, polylactic acid, and polyvinylidene chloride.
7. The preparation method of the modified nano-copper antibacterial composite material according to claim 1, characterized in that, The auxiliary agent described in step S3 is not limited to at least one of white oil, epoxidized soybean oil, epoxidized linseed oil, dioctyl phthalate, and dibutyl phthalate, and the mass of the auxiliary agent is 5 wt% - 13 wt% of the mass of the thermoplastic resin.
8. The preparation method of the modified nano copper antibacterial composite material according to claim 1, characterized in that, The thickness of the prepared antibacterial composite sheet in step S4 is 1.0 ± 0.1 mm, and the thickness of the antibacterial composite film is 40 - 80 μm.
9. A modified nano - copper antibacterial composite material prepared by the preparation method according to any one of claims 1 to 8.
10. The modified nano-copper antibacterial composite material according to claim 9, characterized in that, When the concentration of modified nano - copper is 100 - 300 ppm, the antibacterial rate of the modified nano - copper antibacterial composite material is greater than 90%, and when the concentration of modified nano - copper is 500 - 700 ppm, the antibacterial rate of the modified nano - copper antibacterial composite material is greater than 99%.