An ABS composite antibacterial plastic, its preparation method and application

Abstract

The present invention belongs to the technical field of antibacterial plastics, and particularly relates to an ABS composite antibacterial plastic, a preparation method thereof and an application. The ABS composite antibacterial plastic provided by the present invention comprises an ABS plastic, an antibacterial agent dispersed in the ABS plastic and connected to the ABS plastic through a silane coupling agent, and also comprises a toughening agent and a dispersing agent; the antibacterial agent comprises quaternary ammonium salt modified SiO2 nanoparticles and nano zinc oxide. The antibacterial rate of the ABS composite antibacterial plastic provided by the present invention against Escherichia coli and Staphylococcus aureus is greater than 99% and 98% respectively under light conditions and non-light conditions, and the antibacterial ability is long-lasting and stable.

Description

Technical Field

[0001] The present invention belongs to the technical field of antibacterial plastics, and particularly relates to an ABS composite antibacterial plastic, a preparation method thereof, and an application thereof. Background Art

[0002] ABS resin is a tough and rigid general thermoplastic synthetic resin, which is widely used in the teaching and toy industries such as parts of desks, chairs, and toys. These ABS products provide convenience, but they ignore the functionality of the material itself. Over time, they are prone to dirt and bacteria growth, thus threatening the physical health of teenagers who have long-term close contact with them. At present, the mainstream method on the market is to introduce silver ion antibacterial agents into ABS to endow it with antibacterial properties. However, the cost of such antibacterial agents is relatively high, and there may be a risk of metal ion migration, resulting in deterioration of antibacterial performance and even harm to the physical health of users.

[0003] After the 19th century, zinc oxide has not only been used in cosmetics, including sunscreen, toothpaste, and shampoo, but zinc has also been used as a food additive. Zinc oxide nanoparticles have characteristics such as non-specific activity, small particle size, large specific surface area, low cost, and high efficiency. They have strong antimicrobial ability against a variety of bacteria and low toxicity to human cells. Unfortunately, the antibacterial property of zinc oxide nanoparticles is the result of the combined action of two antibacterial mechanisms: photocatalysis and metal ion dissolution. When there is no light, only antibacterial action occurs due to metal ion dissolution, resulting in poor antibacterial effect in dark places. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide an ABS composite antibacterial plastic, a preparation method thereof, and an application thereof. The ABS composite antibacterial plastic provided by the present invention has excellent antibacterial properties under both light and dark conditions, and the antibacterial ability is long-lasting and stable.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] The present invention provides an ABS composite antibacterial plastic, which includes an ABS plastic, an antibacterial agent dispersed in the ABS plastic and connected to the ABS plastic through a silane coupling agent, and also includes a toughening agent and a dispersing agent;

[0007] The antibacterial agent includes quaternary ammonium salt modified SiO2 nanoparticles and nano zinc oxide.

[0008] Preferably, the mass ratio of the quaternary ammonium salt modified SiO2 nanoparticles to the nano zinc oxide is (1-2):(1-2).

[0009] Preferably, the mass ratio of the ABS plastic to the antibacterial agent is 50:(4-10).

[0010] Preferably, the particle size of the quaternary ammonium salt-modified SiO2 nanoparticles is 10-200 nm; the particle size of the nano-zinc oxide is 200 nm-1 μm.

[0011] Preferably, the silane coupling agent is one or more of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, and N-β(aminoethyl)-γ-aminopropyltrimethoxysilane.

[0012] Preferably, the mass ratio of the ABS plastic to the silane coupling agent is 50:(2-5).

[0013] The present invention also provides a method for preparing the ABS composite antibacterial plastic described in the above technical solution, including the following steps:

[0014] Mix the ABS plastic, silane coupling agent, antibacterial agent, toughening agent, and dispersant, and perform extrusion and molding in sequence to obtain the ABS composite antibacterial plastic.

[0015] Preferably, the temperature of the extrusion is 180-240 °C.

[0016] Preferably, the molding is injection molding; the temperature of the injection molding is 220-240 °C.

[0017] The present invention also provides the application of the ABS composite antibacterial plastic described in the above technical solution or the ABS composite antibacterial plastic prepared by the preparation method described in the above technical solution in teaching aids and / or toys.

[0018] The present invention provides an ABS composite antibacterial plastic, including an ABS plastic, an antibacterial agent dispersed in the ABS plastic and connected to the ABS plastic through a silane coupling agent, and also including a toughening agent and a dispersant; the antibacterial agent includes quaternary ammonium salt-modified SiO2 nanoparticles and nano-zinc oxide.

[0019] The antibacterial mechanism of nano-zinc oxide in the ABS composite antibacterial plastic provided by the present invention mainly includes three effects: First, nano-zinc oxide continuously releases zinc ions, which will enter the cell membrane and then damage the cell membrane, thereby killing bacteria. Second, nano-zinc oxide can interact with the cell wall on the surface of bacteria, damage the cell wall of bacteria, cause the release of contents, and thus kill bacteria. Third, under the irradiation of ultraviolet light, nano-zinc oxide will generate electron-hole pairs. Electrons and holes migrate from the conduction band and valence band to the surface of zinc oxide particles respectively. The adsorbed water or hydroxyl groups are transformed into hydroxyl free radicals, and the adsorbed oxygen is transformed into reactive oxygen species. Hydroxyl free radicals and reactive oxygen species have extremely strong chemical activities and can react with most organic substances to kill most bacteria and viruses. From the above mechanism, when irradiated with ultraviolet light, the three antibacterial mechanisms work together to efficiently kill bacteria. Without light, the third mechanism cannot take effect, resulting in a decrease in the antibacterial effect of nano-zinc oxide. At this time, the quaternary ammonium salt-modified SiO2 nanoparticles present in the composite material show an auxiliary synergistic effect. The quaternary ammonium salt adsorbs to the surface of the bacteria, inserts the hydrophobic group into the lipid layer, changes the permeability of the cell membrane, destroys the membrane structure, affects the cell metabolism process, and then the bacteria die, making up for the instability of the antibacterial effect of nano-zinc oxide without light. By combining quaternary ammonium salt-modified SiO2 nanoparticles, the synergistic effect enables the ABS composite antibacterial plastic to have excellent antibacterial properties under both light and dark conditions, and the antibacterial ability is long-lasting and stable. The results of the examples show that the ABS composite antibacterial plastic provided by the present invention has antibacterial rates against Escherichia coli and Staphylococcus aureus greater than 99% and 98% respectively under light and dark conditions, and the antibacterial ability is long-lasting and stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the mechanism of quaternary ammonium salt-modified SiO2 nanoparticles;

[0021] Figure 2 It is the appearance diagram of ABS plastic and the ABS composite antibacterial plastics obtained in Examples 1-4. DETAILED DESCRIPTION OF THE INVENTION

[0022] The present invention provides an ABS composite antibacterial plastic, which includes ABS plastic, an antibacterial agent dispersed in the ABS plastic and connected to the ABS plastic through a silane coupling agent, and also includes a toughening agent and a dispersant;

[0023] The antibacterial agent includes quaternary ammonium salt-modified SiO2 nanoparticles and nano-zinc oxide.

[0024] Unless otherwise specified, the present invention has no special requirements for the sources of the raw materials used, and commercially available products well-known to those skilled in the art can be used.

[0025] The ABS composite antibacterial plastic provided by the present invention includes ABS plastic.

[0026] In the present invention, the ABS plastic is preferably the Taiwan Chi Mei 758 type of ABS plastic.

[0027] The ABS composite antibacterial plastic provided by the present invention comprises an antibacterial agent dispersed in the ABS plastic and connected to the ABS plastic through a silane coupling agent. In the present invention, the antibacterial agent comprises quaternary ammonium salt modified SiO2 nanoparticles and nano zinc oxide; the particle size of the quaternary ammonium salt modified SiO2 nanoparticles is preferably 10 - 200 nm, more preferably 50 - 150 nm; the particle size of the nano zinc oxide is preferably 200 nm - 1 μm, more preferably 500 nm - 1 μm; the mass ratio of the quaternary ammonium salt modified SiO2 nanoparticles to the nano zinc oxide is preferably (1 - 2):(1 - 2), more preferably 1:1; the mass ratio of the ABS plastic to the antibacterial agent is preferably 50:(4 - 10), more preferably 50:(5 - 8), and most preferably 50:(5 - 6).

[0028] In the present invention, the preparation method of the quaternary ammonium salt modified SiO2 nanoparticles preferably comprises the following steps:

[0029] Mix SiO2 nanoparticles and an oxidant for activation treatment to obtain SiO2 nanoparticles with active hydroxyl groups;

[0030] Mix the SiO2 nanoparticles with active hydroxyl groups, a first silane coupling agent and a first solvent for silanization treatment to obtain silanized SiO2 nanoparticles;

[0031] Mix the silanized SiO2 nanoparticles, vinylpyridine, an initiator and a second solvent, and carry out a polymerization reaction under anaerobic conditions to obtain SiO2 nanoparticles grafted with polyvinylpyridine;

[0032] Mix the SiO2 nanoparticles grafted with polyvinylpyridine, ethyl bromoacetate and a third solvent, and carry out a quaternization reaction under anaerobic conditions to obtain quaternary ammonium salt modified SiO2 nanoparticles.

[0033] The present invention preferably mixes SiO2 nanoparticles and an oxidant for activation treatment to obtain SiO2 nanoparticles with active hydroxyl groups.

[0034] In the present invention, the oxidant preferably comprises sulfuric acid and hydrogen peroxide; the volume ratio of the sulfuric acid to the hydrogen peroxide is preferably 7:3; the mass percentage concentration of the hydrogen peroxide is 30%; the mass ratio of the SiO2 nanoparticles to the oxidant is preferably 1:(2 - 4), more preferably 1:(2 - 3.5); the particle size of the SiO2 nanoparticles is preferably 10 - 100 nm, more preferably 20 - 50 nm.

[0035] In the present invention, the activation treatment is preferably carried out under stirring; the stirring rate is preferably 200 - 300 rpm, more preferably 200 - 250 rpm; the activation treatment time is preferably 24 - 48 h, more preferably 24 - 36 h; the activation treatment temperature is preferably 60 - 70 °C, more preferably 65 - 70 °C.

[0036] After the activation treatment is completed, the present invention preferably further includes: washing and drying the activated SiO2 nanoparticles in sequence to obtain SiO2 nanoparticles with active hydroxyl groups. In the present invention, the washing is preferably carried out with distilled water and ethanol in sequence; the drying is preferably vacuum drying; the drying temperature is preferably 50 - 80 °C, more preferably 60 - 70 °C; the drying time is preferably 12 - 24 h, more preferably 12 - 16 h; the vacuum degree of the vacuum drying is preferably 0.085 - 0.09 MPa, more preferably 0.09 MPa.

[0037] After obtaining the SiO2 nanoparticles with active hydroxyl groups, the present invention preferably mixes the SiO2 nanoparticles with active hydroxyl groups, the first siloxane coupling agent and the first solvent, and carries out a silanization treatment to obtain silanized SiO2 nanoparticles.

[0038] In the present invention, the first siloxane coupling agent preferably includes one or more of vinyltrimethoxysilane, methacryloxypropyltris(trimethylsiloxy)silane, and methacryloxypropylbis(trimethylsiloxy)silanol, more preferably methacryloxypropyltris(trimethylsiloxy)silane. When the siloxane coupling agent is the above several kinds, the present invention has no special limitation on the ratio of different kinds of siloxane coupling agents, and any ratio can be used.

[0039] In the present invention, the mass ratio of the SiO2 nanoparticles with active hydroxyl groups to the first siloxane coupling agent is preferably 1:(0.01 - 0.1), more preferably 1:(0.06 - 0.1); the first solvent is preferably toluene; the mass ratio of the SiO2 nanoparticles with active hydroxyl groups to the first solvent is preferably 1:(5 - 40), more preferably 1:(5 - 20); the silanization treatment is preferably carried out under the condition of condensation reflux; the silanization treatment temperature is preferably 40 - 80 °C, more preferably 50 - 60 °C; the silanization treatment time is preferably 8 - 18 h, more preferably 10 - 15 h.

[0040] After the silanization treatment is completed, the present invention preferably further includes: sequentially performing solid-liquid separation and drying on the product after the silanization treatment to obtain silanized SiO2 nanoparticles. In the present invention, the solid-liquid separation is preferably centrifugation; the rotation speed of the centrifugation is preferably 6000-9000 rpm, more preferably 7000-9000 rpm; the time of the centrifugation is preferably 5-10 min, more preferably 7-10 min; the drying is preferably vacuum drying; the temperature of the drying is preferably 60-70 °C, more preferably 60-65 °C; the time of the drying is preferably 12-24 h, more preferably 16-20 h; the vacuum degree of the vacuum drying is preferably 0.085-0.09 MPa, more preferably 0.09 MPa.

[0041] After obtaining the silanized SiO2 nanoparticles, the present invention mixes the silanized SiO2 nanoparticles, vinylpyridine, an initiator, and a second solvent, and performs a polymerization reaction under an anaerobic condition to obtain SiO2 nanoparticles grafted with polyvinylpyridine.

[0042] In the present invention, the vinylpyridine is preferably one or more of 2-vinylpyridine, 4-vinylpyridine, 2-methyl-5-vinylpyridine, and 5-ethyl-2-vinylpyridine, more preferably 4-vinylpyridine. When the vinylpyridine is the above several kinds, the present invention has no special limitation on the ratio of different kinds of vinylpyridine, and any ratio is acceptable.

[0043] In the present invention, the second solvent is preferably ethanol; the initiator is preferably azobisisobutyronitrile (AIBN); the mass ratio of the silanized SiO2 nanoparticles to vinylpyridine is preferably 1:(2-3), more preferably 1:2; the mass ratio of the silanized SiO2 nanoparticles to the initiator is preferably 1:(0.001-0.1), more preferably 1:(0.005-0.05); the mass ratio of the silanized SiO2 nanoparticles to the second solvent is preferably 1:(15-35), more preferably 1:(18-32).

[0044] In the present invention, the temperature of the polymerization reaction is preferably 50-80 °C, more preferably 60-70 °C; the time of the polymerization reaction is preferably 8-36 h, more preferably 8-24 h.

[0045] After the polymerization reaction is completed, the present invention preferably further includes: filtering, extracting, washing and drying the product obtained from the polymerization reaction in sequence to obtain SiO2 nanoparticles grafted with polyvinylpyridine. In the present invention, the extraction agent used for extraction is preferably toluene; the temperature of the extraction is preferably 16-35 °C, more preferably 20-25 °C; the time of the extraction is preferably 24-36 h, more preferably 24-30 h; the washing liquid used for washing is preferably ethanol; the number of times of washing is preferably 3 times; the drying is preferably vacuum drying; the temperature of the drying is preferably 50-60 °C, more preferably 60 °C; the time of the drying is preferably 12-24 h, more preferably 12-18 h; the vacuum degree of the vacuum drying is preferably 0.085-0.09 MPa, more preferably 0.09 MPa.

[0046] After obtaining the SiO2 nanoparticles grafted with polyvinylpyridine, the present invention preferably mixes the SiO2 nanoparticles grafted with polyvinylpyridine, ethyl bromoacetate and a third solvent, and conducts a quaternization reaction under an anaerobic condition to obtain quaternary ammonium salt-modified SiO2 nanoparticles.

[0047] In the present invention, the third solvent is preferably toluene; the mass ratio of the SiO2 nanoparticles grafted with polyvinylpyridine to ethyl bromoacetate is preferably 1:(2-6), more preferably 1:(3-5); the mass ratio of the SiO2 nanoparticles grafted with polyvinylpyridine to the third solvent is preferably 1:(10-50), more preferably 1:(10-20).

[0048] In the present invention, the temperature of the quaternization reaction is preferably 20-80 °C, more preferably 50-60 °C; the time of the quaternization reaction is preferably 24-48 h, more preferably 24-36 h.

[0049] After the quaternization reaction is completed, the present invention preferably further includes: drying the product obtained from the quaternization reaction to obtain quaternary ammonium salt-modified SiO2 nanoparticles. In the present invention, the drying is preferably vacuum drying; the temperature of the drying is preferably 50-90 °C, more preferably 60-80 °C; the time of the drying is preferably 12-24 h, more preferably 12-16 h; the vacuum degree of the vacuum drying is preferably 0.085-0.09 MPa, more preferably 0.09 MPa.

[0050] In the present invention, a polymer is grafted onto the surface of SiO2 nanoparticles by covalent bonding, and then a quaternary ammonium salt is generated through a quaternization reaction.

[0051] In the present invention, the silane coupling agent is preferably one or more of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, and N-β(aminoethyl)-γ-aminopropyltrimethoxysilane, more preferably γ-aminopropyltriethoxysilane or N-β(aminoethyl)-γ-aminopropyltrimethoxysilane; the mass ratio of the ABS plastic to the silane coupling agent is preferably 50:(2-5), more preferably 50:(2-4).

[0052] In the present invention, the antibacterial agent is connected to the ABS plastic through a silane coupling agent, and the antibacterial agent is not easily detached.

[0053] The ABS composite antibacterial plastic provided by the present invention includes a toughening agent. In the present invention, the toughening agent preferably includes a maleic anhydride grafted toughening agent, allyl acrylate, or ethylene-propylene-diene terpolymer, more preferably a maleic anhydride grafted toughening agent; the mass ratio of the ABS plastic to the toughening agent is preferably 50:(5-15), more preferably 50:(7-12); the maleic anhydride grafted toughening agent is purchased from Nanjing Sute Polymer Technology Co., Ltd.; the manufacturer of the ethylene-propylene-diene terpolymer is JPC of Japan, and the product model is EMA-EBO5OS.

[0054] The ABS composite antibacterial plastic provided by the present invention includes a dispersant. In the present invention, the dispersant preferably includes one or more of barium stearate, stearic acid, and calcium stearate, more preferably barium stearate; the mass ratio of the ABS plastic to the dispersant is preferably 50:(2-4), more preferably 50:(2-3).

[0055] The antibacterial mechanism of nano-zinc oxide mainly includes three effects: First, nano-zinc oxide continuously releases zinc ions, which will enter the cell membrane and then damage the cell membrane, thereby killing bacteria. Second, nano-zinc oxide can interact with the cell wall on the surface of bacteria, damage the cell wall of bacteria, cause the release of contents and thus kill bacteria. Third, under the irradiation of ultraviolet light, nano-zinc oxide will generate electron-hole pairs. Electrons and holes migrate from the conduction band and valence band to the surface of zinc oxide particles respectively. The adsorbed water or hydroxyl groups are converted into hydroxyl radicals, and the adsorbed oxygen is converted into reactive oxygen species. Hydroxyl radicals and reactive oxygen species have extremely strong chemical activities and can react with most organic substances to kill most bacteria and viruses. From the above mechanism, when irradiated by ultraviolet light, the three antibacterial mechanisms work together to efficiently kill bacteria. Without light, the third mechanism cannot take effect, resulting in a decrease in the antibacterial effect of nano-zinc oxide. At this time, the quaternary ammonium salt-modified SiO2 nanoparticles present in the composite material show an auxiliary synergistic effect. The quaternary ammonium salt adsorbs to the surface of the bacteria, inserts the hydrophobic group into the lipid layer, changes the cell membrane permeability, destroys the membrane structure, affects the cell metabolism process, and then the bacteria die, making up for the instability of the antibacterial effect of nano-zinc oxide in the absence of light. By combining quaternary ammonium salt-modified SiO2 nanoparticles, the ABS composite antibacterial plastic has excellent antibacterial properties under both light and dark conditions, and the antibacterial ability is long-lasting and stable.

[0056] The present invention also provides a preparation method of the ABS composite antibacterial plastic described in the above technical solution, including the following steps:

[0057] Mix ABS plastic, silane coupling agent, antibacterial agent, toughening agent and dispersant, and perform extrusion and molding in sequence to obtain the ABS composite antibacterial plastic.

[0058] In the present invention, the mixing is preferably carried out at 500-1000 rpm under stirring conditions; the stirring rate is preferably 600-800 rpm; the mixing time is preferably 10-30 min, more preferably 10-20 min; the extrusion temperature is preferably 180-240 °C, more preferably 200-230 °C; the molding is preferably injection molding; the injection molding temperature is preferably 220-240 °C, more preferably 220-230 °C.

[0059] In the embodiment of the present invention, the equipment used for extrusion is a twin-screw extruder; the extrusion temperatures of the twin-screw extruder are as follows: the temperature of the first temperature zone is 200 °C, the temperature of the second temperature zone is 210 °C, the temperature of the third temperature zone is 220 °C, the temperature of the fourth temperature zone is 230 °C, the temperature of the fifth temperature zone is 230 °C, and the temperature of the sixth temperature zone is 230 °C.

[0060] The present invention also provides the application of the ABS composite antibacterial plastic described in the above technical solution or the ABS composite antibacterial plastic prepared by the preparation method described in the above technical solution in teaching aids and / or toys.

[0061] The present invention has no special limitation on the application of the ABS composite antibacterial plastic in teaching aids and / or toys, and the well-known application methods in the art can be adopted.

[0062] Next, the technical solutions in the present invention will be clearly and completely described in conjunction with the embodiments in the present invention, but they cannot be understood as limiting the protection scope of the present invention.

[0063] Example 1

[0064] 100 g of SiO2 nanoparticles (particle size of 20 nm) and 200 g of an oxidant (a mixed solution of sulfuric acid and hydrogen peroxide (30 wt.%) with a volume ratio of 7:3) are mixed and stirred at 200 rpm at 60 °C for 24 h, then washed 3 times each with distilled water and ethanol, and vacuum dried at 60 °C and a vacuum degree of 0.09 MPa for 12 h to obtain SiO2 nanoparticles with active hydroxyl groups;

[0065] 100 g of SiO2 nanoparticles with active hydroxyl groups are mixed with 10 g of vinyltrimethoxysilane in excess and 1 L of toluene solution, refluxed under condensation at 60 °C for 12 h, centrifuged at 9000 rpm for 10 min, and then dried in a vacuum drying oven at 70 °C and a vacuum degree of 0.09 MPa for 24 h; 100 g of the obtained particles are mixed evenly with 1 L of ethanol and 200 g of 2-vinylpyridine, polymerized at 60 °C for 8 h under anaerobic conditions with 1 g of AIBN as an initiator, the reaction product is filtered, extracted with toluene at 25 °C for 24 h, washed 3 times with ethanol, and vacuum dried at 60 °C and a vacuum degree of 0.09 MPa for 12 h;

[0066] 100 g of the obtained particles are mixed evenly with 1.5 L of toluene and 600 g of ethyl bromoacetate, and subjected to quaternization reaction at 60 °C for 24 h under oxygen-free conditions, and vacuum dried at 60 °C and a vacuum degree of 0.09 MPa for 12 h to obtain quaternary ammonium salt-modified SiO2 nanoparticles (particle size of 50 nm);

[0067] 50 parts of ABS plastic, 2 parts of γ-aminopropyltriethoxysilane, 6 parts of toughening agent (maleic anhydride grafted toughening agent), 2 parts of dispersant (barium stearate), 5 parts of antibacterial agent, and the antibacterial agent is a quaternary ammonium salt modified SiO2 nanoparticle and nanozinc oxide (particle size of 500 nm) with a mass ratio of 1:1. After stirring and mixing at 800 rpm for 10 min, it is extruded through a twin-screw extruder. The temperatures of the extruder are as follows: the temperature of the first temperature zone is 200 °C, the temperature of the second temperature zone is 210 °C, the temperature of the third temperature zone is 220 °C, the temperature of the fourth temperature zone is 230 °C, the temperature of the fifth temperature zone is 230 °C, and the temperature of the sixth temperature zone is 230 °C. After cooling, air-drying and pelletizing, masterbatch is obtained. The masterbatch is molded in an injection molding machine at 220 °C to obtain ABS composite antibacterial plastic.

[0068] Example 2

[0069] 60 g of SiO2 nanoparticles (particle size of 100 nm) and 180 g of oxidant (a mixed solution of sulfuric acid and hydrogen peroxide (30 wt.%) with a volume ratio of 7:3) are mixed and stirred at 300 rpm at 65 °C for 36 h, then washed 3 times each with distilled water and ethanol, and vacuum dried at 60 °C and a vacuum degree of 0.09 MPa for 12 h to obtain SiO2 nanoparticles with active hydroxyl groups;

[0070] 60 g of SiO2 nanoparticles with active hydroxyl groups are mixed with 3.6 g of excess methacryloxypropyltris(trimethylsiloxy)silane and 450 mL of toluene solution, refluxed at 60 °C for 8 h, centrifuged at 9000 rpm for 10 min, and then dried in a vacuum drying oven at 60 °C and a vacuum degree of 0.09 MPa for 24 h; 60 g of the obtained particles are mixed evenly with 750 mL of ethanol and 180 g of 4-vinylpyridine, polymerized at 60 °C for 8 h under anaerobic conditions with 3 g of AIBN as the initiator, the product is filtered, extracted with toluene at 25 °C for 24 h, washed 3 times with ethanol, and vacuum dried at 60 °C and a vacuum degree of 0.09 MPa for 24 h;

[0071] 60 g of the obtained particles are mixed evenly with 750 mL of toluene and 300 g of ethyl bromoacetate, and subjected to quaternization reaction at 60 °C for 24 h under oxygen-free conditions, and vacuum dried at 60 °C and a vacuum degree of 0.09 MPa for 12 h to obtain quaternary ammonium salt modified SiO2 nanoparticles (particle size of 150 nm);

[0072] Mix 50 parts of ABS plastic, 3 parts of γ-aminopropyltriethoxysilane, 5 parts of toughening agent (maleic anhydride grafted toughening agent), 2 parts of dispersant (barium stearate), and 5 parts of antibacterial agent. The antibacterial agent is a quaternary ammonium salt modified SiO2 nanoparticle and nanozinc oxide (particle size 500 nm) with a mass ratio of 2:1. After stirring and mixing at 1000 rpm for 30 min, extrude through a twin-screw extruder. The temperatures of the extruder are as follows: the temperature of the first temperature zone is 200 °C, the second temperature zone is 210 °C, the third temperature zone is 220 °C, the fourth temperature zone is 230 °C, the fifth temperature zone is 230 °C, and the sixth temperature zone is 230 °C. After cooling, air drying, and pelletizing, obtain masterbatch. Molding the masterbatch in an injection molding machine at 230 °C to obtain ABS composite antibacterial plastic.

[0073] Example 3

[0074] Mix 50 g of SiO2 nanoparticles (particle size 20 nm) and 150 g of oxidant (a mixed solution of sulfuric acid and hydrogen peroxide (30 wt.%) with a volume ratio of 7:3) and stir at 200 rpm at 70 °C for 24 h. Then wash 3 times each with distilled water and ethanol, and vacuum dry at 60 °C and a vacuum degree of 0.09 MPa for 12 h to obtain SiO2 nanoparticles with active hydroxyl groups;

[0075] Mix 50 g of SiO2 nanoparticles with active hydroxyl groups with 5 g excess of methacryloxypropyltris(trimethylsiloxy)silane and 1 L of toluene solution, reflux at 60 °C for 8 h, centrifuge at 8000 rpm for 10 min, and then dry in a vacuum drying oven at 60 °C and a vacuum degree of 0.09 MPa for 24 h; Mix 50 g of the obtained particles with 1 L of ethanol and 150 g of 5-ethyl-2-vinylpyridine evenly, use 5 g of AIBN as an initiator, and carry out a polymerization reaction at 60 °C under anaerobic conditions for 36 h. Filter the product, extract with toluene at 25 °C for 36 h, wash 3 times with ethanol, and vacuum dry at 60 °C and a vacuum degree of 0.09 MPa for 24 h;

[0076] Mix 50 g of the obtained particles with 1 L of toluene and 150 g of ethyl bromoacetate evenly, carry out a quaternization reaction at 60 °C under oxygen-free conditions for 24 h, and vacuum dry at 60 °C and a vacuum degree of 0.09 MPa for 12 h to obtain quaternary ammonium salt modified SiO2 nanoparticles (particle size 50 nm);

[0077] Mix 50 parts of ABS plastic, 5 parts of N-β(aminoethyl)-γ-aminopropyltrimethoxysilane, 3 parts of toughening agent (maleic anhydride grafted toughening agent), 2 parts of dispersant (barium stearate), and 10 parts of antibacterial agent. The antibacterial agent is a quaternary ammonium salt modified SiO2 nanoparticle and nanozinc oxide (particle size 500nm) with a mass ratio of 1:1. After stirring and mixing at 500 rpm for 30 min, extrude through a twin-screw extruder. The temperatures of the extruder are as follows: the temperature of the first temperature zone is 200 °C, the temperature of the second temperature zone is 210 °C, the temperature of the third temperature zone is 220 °C, the temperature of the fourth temperature zone is 230 °C, the temperature of the fifth temperature zone is 230 °C, and the temperature of the sixth temperature zone is 230 °C. After cooling, air-drying, and pelletizing, obtain the masterbatch. Mould the masterbatch in an injection moulding machine at 220 °C to obtain the ABS composite antibacterial plastic.

[0078] Example 4

[0079] Mix 80 g of SiO2 nanoparticles (particle size 50 nm) and 280 g of oxidant (a mixed solution of sulfuric acid and hydrogen peroxide (30 wt.%) with a volume ratio of 7:3). Stir at 200 rpm at 60 °C for 24 h, then wash 3 times each with distilled water and ethanol, and vacuum dry at 60 °C and a vacuum degree of 0.09 MPa for 12 h to obtain SiO2 nanoparticles with active hydroxyl groups.

[0080] Mix 80 g of SiO2 nanoparticles with active hydroxyl groups with 8 g of excessive methacryloxypropyltris(trimethylsiloxy)silane and 800 g of toluene solution. Carry out condensation reflux at 60 °C for 8 h, centrifuge at 9000 rpm for 10 min, and then dry in a vacuum drying oven at 60 °C and a vacuum degree of 0.09 MPa for 24 h. Mix 80 g of the obtained particles evenly with 1 L of ethanol and 240 g of 2-vinylpyridine, use 0.48 g of AIBN as the initiator, and carry out polymerization reaction at 60 °C under anaerobic conditions for 12 h. Filter the product, extract with toluene at 25 °C for 24 h, then wash 3 times with ethanol, and vacuum dry at 60 °C and a vacuum degree of 0.09 MPa for 24 h.

[0081] Mix 80 g of the obtained particles evenly with 1 L of toluene and 160 g of ethyl bromoacetate, carry out quaternization reaction at 60 °C under oxygen-free conditions for 24 h, and vacuum dry at 60 °C and a vacuum degree of 0.09 MPa for 12 h to obtain quaternary ammonium salt modified SiO2 nanoparticles (particle size 90 nm).

[0082] Mix 50 parts of ABS plastic, 3 parts of γ-aminopropyltriethoxysilane, 5 parts of toughening agent (maleic anhydride grafted toughening agent), 2 parts of dispersant (barium stearate), and 4 parts of antibacterial agent. The antibacterial agent is a quaternary ammonium salt modified SiO2 nanoparticle and nanozinc oxide (particle size of 500 nm) with a mass ratio of 1:1. After stirring and mixing at 500 rpm for 30 min, extrude through a twin-screw extruder. The temperatures of the extruder are as follows: the temperature of the first temperature zone is 200 °C, the temperature of the second temperature zone is 210 °C, the temperature of the third temperature zone is 220 °C, the temperature of the fourth temperature zone is 230 °C, the temperature of the fifth temperature zone is 230 °C, and the temperature of the sixth temperature zone is 230 °C. After cooling, air-drying, and pelletizing, obtain the masterbatch. Molding the masterbatch in an injection molding machine at 220 °C to obtain the ABS composite antibacterial plastic.

[0083] Comparative Example 1

[0084] Use ABS plastic as the comparative example.

[0085] Performance Test

[0086] (1) The appearances of the ABS plastic and the ABS composite antibacterial plastics obtained in Examples 1 to 4 are as Figure 2 shown, where a is the ABS plastic, and b to e are the ABS composite antibacterial plastics obtained in Examples 1 to 4 respectively.

[0087] It can be Figure 2 seen that the ABS composite antibacterial plastic prepared by the present invention has uniform color and luster and a smooth surface.

[0088] (2) According to the "Test Method for Antibacterial Properties of Plastic Surfaces" (GB / T 31402-2015), conduct a 24-hour antibacterial test on the ABS composite antibacterial plastics prepared in Examples 1 to 4. The test results are shown in Table 1.

[0089] Table 1 Antibacterial Properties of ABS Composite Antibacterial Plastics under Light and Shading Conditions

[0090]

[0091]

[0092] It can be seen from Table 1 that the ABS composite antibacterial plastic prepared by the present invention still has good antibacterial properties under shading conditions.

[0093] (3) According to the "Test Method for Antibacterial Properties of Plastic Surfaces" (GB / T 31402-2015), monitor the long-term antibacterial property of the ABS composite antibacterial plastics obtained in Examples 1 to 4 (placed at room temperature for 30 to 360 days). The test results are shown in Table 2.

[0094] Table 2 Long-Term Antibacterial Properties of the Surface of ABS Composite Antibacterial Plastics (under Light)

[0095]

[0096] As can be seen from Table 2, the ABS composite antibacterial plastic in the present invention has long-term antibacterial properties.

[0097] Although the above embodiments have described the present invention in detail, they are only a part of the embodiments of the present invention rather than all of them. People can also obtain other embodiments based on these embodiments without creative efforts, and these embodiments all fall within the protection scope of the present invention.

Claims

1. An ABS composite antibacterial plastic, characterized in that, It is composed of ABS plastic, an antibacterial agent dispersed in the ABS plastic and connected to the ABS plastic through a silane coupling agent, a toughening agent, and a dispersant; The antibacterial agent is composed of quaternary ammonium salt-modified SiO2 nanoparticles and nano-zinc oxide; The preparation method of the quaternary ammonium salt-modified SiO2 nanoparticles includes the following steps: Mix SiO2 nanoparticles and an oxidant for activation treatment to obtain SiO2 nanoparticles with active hydroxyl groups; Mix the SiO2 nanoparticles with active hydroxyl groups, a first siloxane coupling agent, and a first solvent for silanization treatment to obtain silanized SiO2 nanoparticles; Mix the silanized SiO2 nanoparticles, vinylpyridine, an initiator, and a second solvent, and carry out a polymerization reaction under anaerobic conditions to obtain SiO2 nanoparticles grafted with polyvinylpyridine; Mix the SiO2 nanoparticles grafted with polyvinylpyridine, ethyl bromoacetate, and a third solvent, and carry out a quaternization reaction under anaerobic conditions to obtain quaternary ammonium salt-modified SiO2 nanoparticles; The oxidant is sulfuric acid and hydrogen peroxide; the volume ratio of sulfuric acid to hydrogen peroxide is 7:3; the mass percentage concentration of hydrogen peroxide is 30%; the mass ratio of SiO2 nanoparticles to the oxidant is 1:(2 - 4); the activation treatment is carried out under stirring; the stirring rate is 200 - 300 rpm; the activation treatment time is 24 - 48 h; the activation treatment temperature is 60 - 70 °C; The mass ratio of the SiO2 nanoparticles with active hydroxyl groups to the first siloxane coupling agent is 1:(0.01 - 0.1); The vinylpyridine is one or more of 2-vinylpyridine, 4-vinylpyridine, 2-methyl-5-vinylpyridine, and 5-ethyl-2-vinylpyridine; The mass ratio of the quaternary ammonium salt-modified SiO2 nanoparticles to nano-zinc oxide is (1 - 2):(1 - 2).

2. The ABS composite antibacterial plastic according to claim 1, characterized in that, The mass ratio of the ABS plastic to the antibacterial agent is 50:(4 - 10).

3. The ABS composite antibacterial plastic according to claim 1, characterized in that, The particle size of the quaternary ammonium salt-modified SiO2 nanoparticles is 10 - 200 nm; the particle size of the nano-zinc oxide is 200 nm - 1 μm.

4. The ABS composite antibacterial plastic according to claim 1, wherein The silane coupling agent is one or more of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, and N-β(aminoethyl)-γ-aminopropyltrimethoxysilane.

5. The ABS composite antibacterial plastic according to claim 1 or 4, characterized in that, The mass ratio of the ABS plastic to the silane coupling agent is 50:(2 - 5).

6. The preparation method of the ABS composite antibacterial plastic according to any one of claims 1 to 5, characterized in that, It includes the following steps: Mix the ABS plastic, silane coupling agent, antibacterial agent, toughening agent, and dispersant, and carry out extrusion and molding in sequence to obtain ABS composite antibacterial plastic.

7. The preparation method according to claim 6, characterized in that, The temperature of the extrusion is 180 - 240 °C.

8. The preparation method according to claim 6, characterized in that, The molding is injection molding; the temperature of the injection molding is 220 - 240 °C.

9. Application of the ABS composite antibacterial plastic according to any one of claims 1 - 5 or the ABS composite antibacterial plastic prepared by the preparation method according to any one of claims 6 - 8 in teaching aids and / or toys.

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