Plant-based antibacterial master batch, preparation method and application

Abstract

The invention provides a plant-based antibacterial master batch as well as a preparation method and application thereof. The antibacterial master batch comprises thermoplastic polymer resin, a compatilizer, a coupling agent, a lubricant, an antioxidant, a pigment filler and a plant-based antibacterial agent. According to the invention, a plant-based material is chemically activated to obtain a porous material, and the plant-based antibacterial agent is obtained by physically adsorbing an inorganic antibacterial material. And mixing the plant-based antibacterial agent with thermoplastic polymer resin, a compatilizer, a coupling agent, a lubricant, an antioxidant and pigments and fillers, and performing twin-screw extrusion granulation to obtain the plant-based antibacterial master batch. And carrying out cold mixing, drying and injection molding on the plant-based antibacterial master batch and thermoplastic polymer resin to obtain the plant-based antibacterial modified plastic product. The plant-based antibacterial master batch can delay the release of an inorganic antibacterial material, prolong the antibacterial time efficiency, provide a plant-imitated apparent effect and touch feeling for plastic products, and meanwhile, is energy-saving, emission-reducing, green and environment-friendly.

Description

Technical Field

[0001] The present invention relates to the field of modification of thermoplastic polymer resin materials, and particularly to a plant-based antibacterial masterbatch, a preparation method and an application thereof. Background Art

[0002] As an important part of environmentally friendly materials, plant-based modified plastics have low density (can replace glass fiber reinforced materials), are biodegradable, have a unique apparent touch, and some materials meet food-grade safety standards. In recent years, their application proportion in fields such as tableware, water cups, toys, appliance handles, packaging boxes, kitchenware, daily necessities, automobiles, and household appliances has increased significantly. China is a large agricultural country, with rich sources of plant-based materials that are green and environmentally friendly and meet the requirements of sustainable development, and their high-value utilization is of great significance.

[0003] Antibacterial modified plastics are materials obtained by functionalizing polymer resin materials by adding antibacterial agents (such as inorganic antibacterial agents, organic antibacterial agents, natural antibacterial agents, etc.), which have the ability to inhibit the growth of microorganisms such as bacteria and molds, while retaining the mechanical properties and processability of the resin materials. With the improvement of people's living standards, antibacterial modified plastics are increasingly coming into people's view. It is expected that the output will exceed 200,000 tons in 2025 and will be widely used in household appliances such as: refrigerator liners, air conditioner filters, washing machine gaskets, and smart toilet lids; food health industries such as: fresh food packaging films and boxes, beverage bottles and caps, antibacterial tableware, and antibacterial kitchenware; medical health industries such as: disposable medical devices, medical packaging materials, and rehabilitation aids; daily necessities industries such as: children's toys and children's auxiliary tools. However, currently, antibacterial materials generally have the problem that antibacterial agents are prone to migration and failure, and a relatively high cost is required to improve stability.

[0004] Chinese invention patent CN 118085416 discloses a modified coffee residue, a preparation method thereof, and a polyolefin composite material containing coffee residue, which uses chlorinated modified coffee residue to improve the fluidity, compatibility, dispersibility, heat resistance, flame retardancy and other properties of polyolefin resin, making it have the advantages of easy processing, low cost, low density, and strength. However, there are deficiencies such as insufficient specific surface area of the modified coffee residue, harm to the human body caused by residual chlorine elements, wear during long-term use due to the addition of coffee residue to the product, and easy growth of bacteria and molds in contact with the water environment, which affect human health and the appearance of the product.

[0005] Chinese Invention Patent CN 118216518 discloses a silver ion antibacterial composition and its preparation method. Nano silver, MOF-5 and deionized water are added to a stirring kettle for stirring, so that the nano silver is adsorbed in the voids on the surface of MOF-5. When this silver ion antibacterial composition works, the nano silver in the voids on the surface of MOF-5 will be continuously released, achieving the purpose of continuous and efficient antibacterial; through the use of adhesives, film-forming agents and film-forming aids, the adhesion performance of the silver ion antibacterial composition can be improved, enabling the silver ion antibacterial composition to adhere to the articles that need to be antibacterial, facilitating use. However, its manufacturing process is relatively complex, with high costs and does not meet environmental protection requirements. Summary of the Invention

[0006] The purpose of the present invention is to provide a plant-based antibacterial masterbatch, which can delay the release of inorganic antibacterial materials and extend the antibacterial time limit; provide a plant-like appearance effect and touch for plastic products, while saving energy, reducing emissions and being environmentally friendly.

[0007] Another purpose of the present invention is to provide a preparation method and application of the above-mentioned plant-based antibacterial masterbatch.

[0008] To achieve the above purpose, the solution of the present invention is as follows:

[0009] A plant-based antibacterial masterbatch, by weight, its components include:

[0010] Thermoplastic polymer resin, 60 - 75 parts by weight, preferably 65 - 70 parts by weight;

[0011] Plant-based antibacterial agent, 20 - 35 parts by weight, preferably 25 - 30 parts by weight;

[0012] Compatibilizer, 2 - 6 parts by weight, preferably 3 - 5 parts by weight;

[0013] Coupling agent, 0.1 - 0.9 parts by weight, preferably 0.2 - 0.8 parts by weight;

[0014] Lubricant, 0.1 - 0.7 parts by weight, preferably 0.2 - 0.6 parts by weight;

[0015] Antioxidant, 0.1 - 0.7 parts by weight, preferably 0.2 - 0.6 parts by weight;

[0016] Pigment and filler, 0.1 - 2 parts by weight, preferably 0.5 - 1.5 parts by weight.

[0017] In the present invention, the thermoplastic polymer resin is one or more of olefin polymers, biodegradable polymers, polyamide polymers, including but not limited to one or more of polypropylene, polyethylene, polyvinyl chloride, polycaprolactam, poly(ω-aminoundecanoyl), polystyrene, polylactic acid;

[0018] Preferably, the thermoplastic polymer resin is one or more of polypropylene and polylaurolactam;

[0019] Preferably, the thermoplastic polymer resin has a melt flow rate (MFR) of 3-50 g / 10 min, more preferably 10-40 g / min, under the conditions of a temperature of 230° C. and a load mass of 2.16 kg.

[0020] In the present invention, the preparation method of the plant-based antibacterial agent is:

[0021] (1) crushing the plant material (e.g., by cryogenic grinding) to obtain a plant powder with a mesh size of 100-150 mesh, placing the plant powder in an alkaline solution, and soaking it at a temperature of 50-80° C. for 30-60 minutes for degreasing; wherein the alkaline solution can be one or more of a sodium hydroxide solution, a potassium hydroxide solution, a sodium carbonate solution, and a potassium carbonate solution, and the concentration thereof is 1-5 wt%;

[0022] (2) The defatted plant powder is activated by an activator; wherein the activation treatment is carried out under microwave conditions, the reaction temperature is 300-400°C, and the reaction time is 5-30min; wherein the microwave power is 100-350W, and the mass ratio of the plant powder to the activator is 1:2-4; if the microwave power is too high and the reaction time is too long, the plant powder will be over-activated, although the porosity and specific surface area will increase, but it will cause pore collapse, skeleton destruction and reduced pore connectivity, thereby affecting the mechanical strength and adsorption capacity of the porous plant powder.

[0023] (3) The activated plant powder is rinsed multiple times with deionized water and dried to obtain a porous plant powder; wherein the porous plant powder has a porosity of 60-80% and a specific surface area of 1100-2200 m2 / g, preferably a porosity of 65-75% and a specific surface area of 1200-2000 m2 / g;

[0024] (4) The inorganic antibacterial material is dissolved in deionized water under microwave conditions with a microwave power of 200-300 W, and the porous plant powder is immersed in the inorganic antibacterial material solution. The temperature is controlled to 40-120°C for reaction for 3-9 hours, filtered, and dried at 100-120°C for 1-2 hours under inert gas protection to obtain a plant-based antibacterial agent; wherein the mass ratio of the porous plant powder to the inorganic antibacterial material solution is 1:2-5.

[0025] In the preparation method of the plant-based antibacterial agent described in the present invention, the plant-based materials are natural plant fibers, plant processing residues, agricultural residues, etc., including but not limited to one or more of bamboo fibers, cotton fibers, coconut fiber, palm fiber, wood fiber, hemp fiber, wheat straw, rice husk, corn straw, coffee grounds, peanut shells, and woodworking sawdust, preferably one or more of bamboo fibers and hemp fibers.

[0026] In the preparation method of the plant-based antibacterial agent described in the present invention, the activator is a chemical activator, including but not limited to one or more of zinc chloride, potassium hydroxide, liquid chlorine, ferric chloride, sodium hydroxide, and phosphoric acid, preferably one or more of phosphoric acid and zinc chloride.

[0027] In the preparation method of the plant-based antibacterial agent described in the present invention, the inorganic antibacterial material is one or more of nano metals, nano metal oxides, and metal salts that can generate antibacterial metal ions, including but not limited to one or more of nano silver, nano zinc oxide, nano cuprous oxide, nano copper oxide, silver nitrate, silver sulfate, silver fluoride, zinc chloride, zinc bromide, zinc sulfate, zinc nitrate, copper sulfate, and copper chloride. Preferably, silver nitrate and nano zinc oxide are compounded, and the mass ratio of silver ions to zinc ions contained in the compounded inorganic antibacterial material is 1:1 - 1:10, preferably 1:4 - 1:7.

[0028] In the preparation method of the plant-based antibacterial agent described in the present invention, the concentration of the inorganic antibacterial material in the inorganic antibacterial material solution is 7 - 27.5 wt%.

[0029] In the present invention, the compatibilizer is a maleic anhydride graft compatibilizer, including but not limited to one or more of PE-g-MAH, PP-g-MAH, EVA-g-MAH, ABS-g-MAH, and POE-g-MAH, preferably PP-g-MAH; its grafting rate is 0.4 - 1.6 wt%, preferably 0.6 - 1.2 wt%.

[0030] In the present invention, the coupling agent is one or more of silane coupling agents and titanate coupling agents, including but not limited to one or more of γ-glycidoxypropyltrimethoxysilane (KH-560), γ-aminopropyltriethoxysilane (KH-550), N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane (KH-602), and triisooctanoyl titanate isopropyl ester (TTS), preferably γ-aminopropyltriethoxysilane (KH-550).

[0031] The lubricant is one or more of fatty acid esters, montan wax, aliphatic amides and esters, polyethylene wax, and metal soaps, including but not limited to one or more of E wax, zinc stearate, magnesium stearate, and ethylene bisstearamide, preferably ethylene bisstearamide (EBS).

[0032] In the present invention, the antioxidant is one or more of, including but not limited to, antioxidant 1010, antioxidant 1098, antioxidant 168, antioxidant S9228, antioxidant 245, antioxidant GA-80, antioxidant 1076, and antioxidant 626. Preferably, it is one or several of antioxidant 1010, antioxidant 1098, and antioxidant 168.

[0033] In the present invention, the pigment and filler are one or several of inorganic pigments, organic pigments, dyes, and mineral fillers, including but not limited to titanium dioxide, zinc sulfide, carbon black, iron oxide red, ultramarine blue, ultramarine violet, titanium yellow, cobalt blue, cobalt green, phthalocyanine blue, phthalocyanine green, organic red #254, organic yellow #191, organic red #122, organic orange #64, organic yellow #180, dye red #135, dye red #179, organic orange #68, talc powder, calcium carbonate, and barium sulfate, and can be combined according to actual requirements.

[0034] Preferably, the thermoplastic polymer resin, coupling agent, compatibilizer, lubricant, antioxidant, and pigment and filler in the present invention are all commercially available mature products.

[0035] In the present invention, the preparation method of the plant-based antibacterial masterbatch includes:

[0036] In a high-speed mixer, the plant-based antibacterial agent and the coupling agent are mixed for 1 - 3 minutes and then added into the side-feed loss-in-weight feeder of a twin-screw extruder;

[0037] In another high-speed mixer, the thermoplastic polymer resin, compatibilizer, lubricant, antioxidant, and pigment and filler are added and mixed for 3 - 5 minutes and then added into the main-feed loss-in-weight feeder of the twin-screw extruder;

[0038] The mixture is extruded, cooled, pelletized, and dried through the twin-screw extruder to obtain the plant-based antibacterial masterbatch.

[0039] In a specific embodiment, in the preparation method, the processing temperature of the twin-screw extruder is as follows: zone 1: 170 - 180 °C, zone 2: 170 - 180 °C, zone 3: 170 - 180 °C, zone 4: 170 - 180 °C, zone 5: 170 - 180 °C, zone 6: 180 - 190 °C, zone 7: 180 - 190 °C, zone 8: 180 - 190 °C, zone 9: 180 - 190 °C, zone 10: 180 - 190 °C, zone 11: 180 - 190 °C, zone 12: 180 - 190 °C, and the head temperature is 195 °C. The main machine speed is 150 - 250 r / min, the feeding amount of the feeder is 20 - 30 kg / h, and the side-feed forced feeder is located in the 10th zone of the twin-screw extruder.

[0040] In the present invention, a method for using the plant-based antibacterial masterbatch is also provided, including:

[0041] Weigh the plant-based antibacterial masterbatch and the thermoplastic polymer resin according to a certain mass ratio. After cold mixing and drying, set a certain injection molding process for injection molding to obtain the plant-based antibacterial modified plastic products. The mass ratio of the plant-based antibacterial masterbatch to the thermoplastic polymer resin is 40-50:50-60.

[0042] The advantages or beneficial effects of the present invention are as follows:

[0043] (1) In the present invention, a chemical activator is used to activate and process plant-based materials with a specific mesh number through etching the carbon skeleton and catalyzing the devolatilization reaction to obtain porous plant-based powder with a microporous-mesoporous composite structure. The porous plant-based powder can effectively adsorb inorganic antibacterial materials and obtain plant-based antibacterial agents through physical adsorption. The plant-based antibacterial agents are mixed with thermoplastic polymer resins, compatibilizers, coupling agents, lubricants, antioxidants, pigments, and fillers, and then extruded to obtain plant-based antibacterial masterbatches. The plant-based antibacterial masterbatches can delay the release of inorganic antibacterial materials and extend the antibacterial time limit. The plant-based antibacterial modified plastic products obtained by injection molding have long-term stable antibacterial performance during use.

[0044] (2) In the present invention, by using plant-based materials in combination with various pigments and fillers, the plastic products are provided with an imitation plant appearance effect and touch, while also saving energy, reducing emissions, and being green and environmentally friendly. Specific embodiments

[0045] The following further illustrates the present invention in combination with embodiments. The following embodiments are only for the illustration of the present invention and are not used to limit the protection scope of the present invention.

[0046] The relevant raw materials used in the embodiments and comparative examples of the present invention are as follows:

[0047] 1. Polypropylene EP548R is from Borouge Pte. Ltd., and its melt index is 21 g / 10 min under the conditions of 230 °C and 2.16 kg; polypropylene HP500N is from Borouge Pte. Ltd., and its melt index is 12 g / 10 min under the conditions of 230 °C and 2.16 kg; polypropylene AX164 is from Polyolefins Singapore Pte. Ltd., and its melt index is 50 g / 10 min under the conditions of 230 °C and 2.16 kg; high-density polyethylene HD5740EA-B is from Lotte Chemical, and its melt index is 4 g / 10 min under the conditions of 230 °C and 2.16 kg; PA12 L1000 is from Wanhua Chemical Group Co., Ltd., and its melt index is 38 g / 10 min under the conditions of 230 °C and 2.16 kg;

[0048] 2. The compatibilizers CMG9801 (grafting rate 0.5 - 0.8 wt%) and CMG5701 (grafting rate 0.8 - 1.2 wt%) are from Jia Yirong Polymers (Shanghai) Co., Ltd.;

[0049] 3. The lubricant EB - FF is from Kao Corporation of Japan;

[0050] 4. The silane coupling agents KH - 550 and KH - 560 are from Hangzhou Jessica Chemical Co., Ltd.;

[0051] 5. The antioxidants 1010, 168, and 1098 are from BASF;

[0052] 6. Silver nitrate, phosphoric acid, sodium hydroxide, and zinc chloride are from Aladdin Reagents;

[0053] 7. The titanium dioxide 2233 is from Kronos;

[0054] 8. The hemp fiber is from Yunding New Materials Technology Co., Ltd.;

[0055] 9. The bamboo fiber is from Jiangxi Huazhu New Materials Technology Co., Ltd.;

[0056] 10. The nano - silver and nano - zinc oxide are from Zhongke Leiming (Beijing) Technology Co., Ltd.;

[0057] 11. 99% chlorine gas is from Wanhua Chlor - Alkali.

[0058] The test indicators for the antibacterial performance of the product are carried out in accordance with "GB / T 31402 - 2015". The test bacteria are Escherichia coli and Staphylococcus aureus, and the test indicator is that the antibacterial rate of the product is greater than or equal to 95%. The test is carried out in 3 ways:

[0059] Test 1 conducts the conventional antibacterial performance test; Test 2 conducts the antibacterial performance test according to the method of Test 1 after being placed in the same environment for 150 days as Test 1; Test 3 scratches 0.5 mm deep and 0.5 mm wide scratches longitudinally and horizontally on the surface of the product, then washes it with tap water in a circulating manner 40 times, and conducts the antibacterial performance test according to the method of Test 1. One of the judgment bases for the antibacterial performance of the product is: an antibacterial rate greater than 95% is excellent, greater than 90 and less than or equal to 95% is good, greater than 85% and less than or equal to 90 is general, greater than 75% and less than or equal to 85% is poor, and less than or equal to 75% is very poor.

[0060] Example 1

[0061] 1) Prepare the plant - based antibacterial agent:

[0062] Take 1 kg of bamboo fiber and obtain bamboo fiber powder with a mesh number of 100 by cryogenic grinding. Place the bamboo fiber powder in a 1 wt% NaOH solution, control the temperature at 50 °C and soak for 60 min for degreasing treatment; the degreased bamboo fiber powder is added to 2.5 kg of 80 wt% phosphoric acid solution under microwave conditions with a microwave power of 100 W for activation treatment, the reaction temperature is 400 °C, and the reaction time is 5 min; the activated bamboo fiber powder is rinsed 4 times with deionized water and dried at 100 °C for 2 h to obtain porous bamboo fiber powder, where the porosity of the porous bamboo fiber powder is 60% and the specific surface area is 1150 m² / g; the inorganic antibacterial materials silver nitrate and nano-zinc oxide are dissolved in deionized water under microwave conditions with a microwave power of 200 W to obtain an inorganic antibacterial material solution, where the mass ratio of silver nitrate, nano-zinc oxide, and deionized water in the inorganic antibacterial material solution is 1.7:13.5:84.8. Take 50 g of porous bamboo fiber powder in a reactor and immerse it in 250 g of the inorganic antibacterial material solution, control the temperature at 40 °C and react for 9 h, filter, and dry at 100 °C for 2 h under inert gas protection to obtain a plant-based antibacterial agent.

[0063] 2) Preparation of plant-based antibacterial masterbatch:

[0064] Weigh the materials according to the parts by weight in Table 1.

[0065] In a high-speed mixer, the plant-based antibacterial agent and the coupling agent are mixed for 1 min and then added to the side-feed loss-in-weight feeder of a twin-screw extruder; in another high-speed mixer, the thermoplastic polymer resin, compatibilizer, lubricant, antioxidant, and pigment filler are mixed for 3 min and then added to the main-feed loss-in-weight feeder of the twin-screw extruder; the mixture is extruded, cooled, pelletized, and dried by the twin-screw extruder to obtain a plant-based antibacterial masterbatch. Among them, the processing temperature of the twin-screw extruder is zone 1: 180 °C, zone 2: 180 °C, zone 3: 180 °C, zone 4: 180 °C, zone 5: 180 °C, zone 6: 190 °C, zone 7: 190 °C, zone 8: 190 °C, zone 9: 190 °C, zone 10: 190 °C, zone 11: 190 °C, zone 12: 190 °C, and the head: 195 °C. The main machine speed is 150 r / min, the feeding amount of the feeder is 20 kg / h, and the side-feed forced feeder is located in the 10th zone of the twin-screw extruder.

[0066] 3) Preparation of plant-based antibacterial modified plastic products:

[0067] Weigh 500 g of HP500N and 500 g of the plant-based antibacterial masterbatch, mix them cold, dry, and injection mold to obtain plant-based antibacterial modified plastic products.

[0068] Example 2

[0069] 1) Preparation of plant-based antibacterial agent:

[0070] Take 1 kg of hemp fiber and obtain hemp fiber powder with a mesh number of 150 by cryogenic grinding. The hemp fiber powder is placed in a 2 wt% NaOH solution, and degreasing treatment is carried out by soaking at 80 °C for 30 min. The degreased hemp fiber powder is added to 10 kg of 40 wt% zinc chloride solution under microwave conditions with a microwave power of 350 W for activation treatment. The reaction temperature is 350 °C, and the reaction time is 30 min. The activated hemp fiber powder is rinsed 6 times with deionized water and dried at 100 °C for 2 h to obtain porous hemp fiber powder. The porosity of the porous hemp fiber powder is 80%, and the specific surface area is 2190 m² / g. Inorganic antibacterial materials silver nitrate and nano-zinc oxide are dissolved in deionized water under microwave conditions with a microwave power of 300 W to obtain an inorganic antibacterial material solution. The mass ratio of silver nitrate, nano-zinc oxide, and deionized water in the inorganic antibacterial material solution is 8.5:6.8:84.7. Take 50 g of porous hemp fiber powder in a reactor and immerse it in 100 g of the inorganic antibacterial material solution, and react at 120 °C for 3 h, filter, and dry at 100 °C for 2 h under inert gas protection to obtain a plant-based antibacterial agent.

[0071] 2) Preparation of plant-based antibacterial masterbatch:

[0072] Weigh the materials according to the parts by weight in Table 1.

[0073] In a high-speed mixer, the plant-based antibacterial agent and the coupling agent are mixed for 3 min and then added to the side-feeding loss-in-weight feeder of the twin-screw extruder; in another high-speed mixer, the thermoplastic polymer resin, compatibilizer, lubricant, antioxidant, pigment and filler are mixed for 5 min and then added to the main-feeding loss-in-weight feeder of the twin-screw extruder; the mixture is extruded, cooled, pelletized and dried through the twin-screw extruder to obtain a plant-based antibacterial masterbatch. The processing temperature of the twin-screw extruder is 170 °C in zone 1, 170 °C in zone 2, 170 °C in zone 3, 170 °C in zone 4, 170 °C in zone 5, 180 °C in zone 6, 180 °C in zone 7, 180 °C in zone 8, 180 °C in zone 9, 180 °C in zone 10, 180 °C in zone 11, 180 °C in zone 12, and 195 °C at the die head. The main motor speed is 250 r / min, the feeding rate of the feeder is 30 kg / h, and the side-feeding forced feeder is located in the 10th zone of the twin-screw extruder.

[0074] 3) Preparation of plant-based antibacterial modified plastic products:

[0075] Weigh 500 g of EP548R and 500 g of the plant-based antibacterial masterbatch, mix them cold, dry them, and injection mold to obtain plant-based antibacterial modified plastic products.

[0076] Example 3

[0077] 1) Preparation of plant-based antibacterial agent:

[0078] Take 1 kg of bamboo fiber and obtain bamboo fiber powder with a mesh number of 120 by cryogenic grinding. Place the bamboo fiber powder in a 3 wt% KOH solution and soak it at 60 °C for 45 min for degreasing treatment. The degreased bamboo fiber powder is added to 7.5 kg of 40 wt% zinc chloride solution under microwave conditions with a microwave power of 300 W for activation treatment. The reaction temperature is 350 °C and the reaction time is 20 min. The activated bamboo fiber powder is rinsed 5 times with deionized water and dried at 120 °C for 1 h to obtain porous bamboo fiber powder, where the porosity of the porous bamboo fiber powder is 75% and the specific surface area is 2050 m² / g. The inorganic antibacterial materials, silver nanoparticles and zinc oxide nanoparticles, are dissolved in deionized water under microwave conditions with a microwave power of 250 W to obtain an inorganic antibacterial material solution, where the mass ratio of silver nanoparticles, zinc oxide nanoparticles, and deionized water in the inorganic antibacterial material solution is 5.1:22.4:72.5. Take 50 g of the porous bamboo fiber powder in a reactor and immerse it in 175 g of the inorganic antibacterial material solution, control the temperature at 80 °C and react for 6 h, filter, and dry at 100 °C for 2 h under inert gas protection to obtain a plant-based antibacterial agent.

[0079] 2) Preparation of plant-based antibacterial masterbatch:

[0080] Weigh the materials according to the parts by weight in Table 1.

[0081] Obtain the plant-based antibacterial masterbatch according to the preparation method of Example 1.

[0082] 3) Preparation of plant-based antibacterial modified plastic products:

[0083] Weigh 500 g of L1000 and 500 g of the plant-based antibacterial masterbatch, mix them cold, dry them, and injection mold them to obtain plant-based antibacterial modified plastic products.

[0084] Example 4

[0085] 1) Preparation of plant-based antibacterial agent:

[0086] Take 1 kg of bamboo fiber and obtain bamboo fiber powder with a mesh number of 135 by cryogenic grinding. Place the bamboo fiber powder in a 4 wt% NaOH solution and soak it at 70 °C for 50 min for degreasing treatment. The degreased bamboo fiber powder is added to 5 kg of 40 wt% zinc chloride solution under microwave conditions with a microwave power of 250 W for activation treatment. The reaction temperature is 300 °C and the reaction time is 10 min. The activated bamboo fiber powder is rinsed 4 times with deionized water and dried at 100 °C for 2 h to obtain porous bamboo fiber powder. The porosity of the porous bamboo fiber powder is 64% and the specific surface area is 1250 m² / g. The inorganic antibacterial materials silver nitrate and nano-zinc oxide are dissolved in deionized water under microwave conditions with a microwave power of 250 W to obtain an inorganic antibacterial material solution. The mass ratio of silver nitrate, nano-zinc oxide, and deionized water in the inorganic antibacterial material solution is 1.7:5.4:92.9. Take 50 g of porous bamboo fiber powder in the reactor and immerse it in 250 g of the inorganic antibacterial material solution, control the temperature at 40 °C and react for 4 h, filter, and dry at 100 °C for 2 h under inert gas protection to obtain a plant-based antibacterial agent.

[0087] 2) Preparation of plant-based antibacterial masterbatch:

[0088] Weigh the materials according to the parts by weight in Table 1.

[0089] Obtain the plant-based antibacterial masterbatch according to the preparation method of Example 2.

[0090] 3) Preparation of plant-based antibacterial modified plastic products:

[0091] Weigh 600 g of EP548R and 400 g of the plant-based antibacterial masterbatch, mix them cold, dry them, and inject them to obtain plant-based antibacterial modified plastic products.

[0092] Example 5

[0093] 1) Preparation of plant-based antibacterial agent:

[0094] Take 1 kg of bamboo fiber and obtain bamboo fiber powder with a mesh number of 140 by cryogenic grinding. The bamboo fiber powder is placed in a 5 wt% NaOH solution and soaked at 65 °C for 35 min for degreasing treatment; the degreased bamboo fiber powder is added to 3.75 kg of 80 wt% phosphoric acid solution under the condition of a microwave power of 200 W for activation treatment, the reaction temperature is 350 °C, and the reaction time is 15 min; the activated bamboo fiber powder is rinsed 5 times with deionized water and dried at 100 °C for 2 h to obtain porous bamboo fiber powder, where the porosity of the porous bamboo fiber powder is 70% and the specific surface area is 1640 m² / g; the inorganic antibacterial materials silver nitrate and nano-zinc oxide are dissolved in deionized water under the microwave condition of a microwave power of 200 W to obtain an inorganic antibacterial material solution, where the mass ratio of silver nitrate, nano-zinc oxide, and deionized water in the inorganic antibacterial material solution is 1.7:9.45:88.85. Take 50 g of porous bamboo fiber powder in the reactor and immerse it in 250 g of the inorganic antibacterial material solution, control the temperature at 120 °C and react for 5 h, filter, and dry at 100 °C for 2 h under the protection of inert gas to obtain a plant-based antibacterial agent.

[0095] 2) Preparation of plant-based antibacterial masterbatch:

[0096] Weigh the materials according to the parts by weight in Table 1.

[0097] Obtain the plant-based antibacterial masterbatch according to the preparation method of Example 2.

[0098] 3) Preparation of plant-based antibacterial modified plastic products:

[0099] Weigh 600 g of AX164 and 400 g of the plant-based antibacterial masterbatch, mix them cold, dry them, and injection mold them to obtain plant-based antibacterial modified plastic products.

[0100] Table 1 Formulation, product performance, and antibacterial performance of plant-based antibacterial masterbatch in Examples 1-5

[0101]

[0102] Comparative Example 1

[0103] 1) Prepare the plant-based antibacterial agent according to the same method as in Example 3, where the bamboo fiber is not subjected to cryogenic grinding treatment, and the porosity of the obtained porous plant powder is 55% and the specific surface area is 650 m² / g.

[0104] 2) Preparation of plant-based antibacterial masterbatch:

[0105] Weigh the materials according to the parts by weight in Table 2.

[0106] Prepare the plant-based antibacterial masterbatch according to the method of Example 3.

[0107] 3) Preparation of plant-based antibacterial modified plastic products:

[0108] Prepare a plant-based antibacterial modified plastic product according to the method of Example 3.

[0109] Comparative Example 2

[0110] 1) Prepare a plant-based antibacterial agent according to the same method as in Example 3, wherein 99% chlorine gas is introduced for activation treatment, the reaction temperature is 25 °C, and the reaction time is 3 h. The obtained porous plant-based powder has a porosity of 60% and a specific surface area of 825 m² / g.

[0111] 2) Prepare a plant-based antibacterial masterbatch:

[0112] Weigh the materials according to the parts by weight in Table 2.

[0113] Prepare a plant-based antibacterial masterbatch according to the method of Example 3.

[0114] 3) Prepare a plant-based antibacterial modified plastic product:

[0115] Prepare a plant-based antibacterial modified plastic product according to the method of Example 3.

[0116] Comparative Example 3

[0117] 1) Prepare a plant-based antibacterial agent according to the same method as in Example 3, wherein air is introduced for activation treatment of the plant-based powder at 650 °C for 2 h. The obtained porous plant-based powder has a porosity of 50% and a specific surface area of 575 m² / g.

[0118] 2) Prepare a plant-based antibacterial masterbatch:

[0119] Weigh the materials according to the parts by weight in Table 2.

[0120] Prepare a plant-based antibacterial masterbatch according to the method of Example 3.

[0121] 3) Prepare a plant-based antibacterial modified plastic product:

[0122] Prepare a plant-based antibacterial modified plastic product according to the method of Example 3.

[0123] Comparative Example 4

[0124] 1) Prepare a plant-based antibacterial agent according to the same method as in Example 3.

[0125] 2) Prepare a plant-based antibacterial masterbatch:

[0126] Weigh the materials according to the parts by weight in Table 2, and the preparation process is the same as that in Example 3.

[0127] 3) Prepare a plant-based antibacterial modified plastic product:

[0128] Prepare plant-based antibacterial modified plastic products according to the method of Example 3.

[0129] Comparative Example 5

[0130] 1) Prepare a plant-based antibacterial agent according to the same method as in Example 3, where the microwave power for the activation treatment of the plant powder is 500 W, the reaction time is 2 h, and the porosity of the obtained porous plant powder is 90% and the specific surface area is 2450 m² / g.

[0131] 2) Prepare a plant-based antibacterial masterbatch:

[0132] Weigh the materials according to the weight ratios in Table 2, and the preparation process is the same as in Example 3.

[0133] 3) Prepare plant-based antibacterial modified plastic products:

[0134] Prepare plant-based antibacterial modified plastic products according to the method of Example 3.

[0135] Table 2 Formulations, product properties, and antibacterial properties of plant-based antibacterial masterbatches for Comparative Examples 1-5

[0136]

[0137]

[0138] From the comparison of Table 1 and Table 2, it can be concluded that the plant-based antibacterial masterbatch prepared by the present invention can well adsorb inorganic antibacterial materials, and can delay the release of inorganic antibacterial materials, extend the antibacterial time limit, enable the products to have long-term stable antibacterial properties, provide a plant-like appearance and touch for the products while maintaining good properties, save energy, reduce emissions, and are green and environmentally friendly.

[0139] The above only describes the principle of this application and some preferred embodiments, and should not be regarded as a limitation of the whole of this application or as a limitation of the technical solutions of the application. It should be pointed out that for those of ordinary skill in the art, under the teaching of the principle and technical solutions of this application, several other variations can also be made, which should also be regarded as the protection scope of this application.

Claims

1. A plant-based antibacterial masterbatch, by weight, its components include: Thermoplastic polymer resin, 60 - 75 parts by weight, preferably 65 - 70 parts by weight; Plant-based antibacterial agent, 20 - 35 parts by weight, preferably 25 - 30 parts by weight; Compatibilizer, 2 - 6 parts by weight, preferably 3 - 5 parts by weight; Coupling agent, 0.1 - 0.9 parts by weight, preferably 0.2 - 0.8 parts by weight; Lubricant, 0.1 - 0.7 parts by weight, preferably 0.2 - 0.6 parts by weight; Antioxidant, 0.1 - 0.7 parts by weight, preferably 0.2 - 0.6 parts by weight; Pigment and filler, 0.1 - 2 parts by weight, preferably 0.5 - 1.5 parts by weight.

2. The plant-based antibacterial masterbatch according to claim 1, wherein The thermoplastic polymer resin is one or several of olefin polymers, degradable polymers, polyamide polymers, preferably one or several of polypropylene, polyethylene, polyvinyl chloride, polycaprolactam, poly(ω-aminoundecanoyl), polystyrene, polylactic acid; Preferably, under the conditions of a temperature of 230 °C and a load mass of 2.16 kg, the melt flow rate of the thermoplastic polymer resin is 3 - 50 g / 10 min, more preferably 10 - 40 g / 10 min.

3. The plant-based antibacterial masterbatch according to claim 1, wherein The preparation method of the plant-based antibacterial agent is as follows: (1) Crush the plant material to obtain a plant powder, and place the plant powder in an alkali solution for degreasing treatment; (2) Activate the degreased plant powder with an activator; (3) Rinse the activated plant powder with deionized water multiple times, and dry it to obtain a porous plant powder; Among them, the porosity of the porous plant powder is 60 - 80%, and the specific surface area is 1100 - 2200 m² / g, preferably the porosity is 65 - 75%, and the specific surface area is 1200 - 2000 m² / g; (4) Dissolve the inorganic antibacterial material in deionized water under microwave conditions, immerse the porous plant powder in the inorganic antibacterial material solution, react, filter, and dry under inert gas protection to obtain the plant-based antibacterial agent.

4. The plant-based antibacterial masterbatch according to claim 3, wherein, In step (1), the plant material includes one or several of bamboo fiber, cotton fiber, coconut fiber, palm fiber, wood fiber, hemp fiber, wheat straw, rice husk, corn straw, coffee grounds, peanut shells, wood sawdust; The mesh number of the plant powder is 100 - 150 mesh; The alkali solution is one or several of sodium hydroxide solution, potassium hydroxide solution, sodium carbonate solution, potassium carbonate solution, and its concentration is 1 - 5 wt%; The conditions for degreasing treatment are soaking at 50 - 80 °C for 30 - 60 min.

5. The plant-based antibacterial masterbatch according to claim 3, wherein, In step (2), the activator includes one or several of zinc chloride, potassium hydroxide, liquid chlorine, ferric chloride, sodium hydroxide, phosphoric acid; The activation treatment is carried out under microwave conditions, the reaction temperature is 300 - 400 °C, the reaction time is 5 - 30 min, the microwave power is 100 - 350 W, and the mass ratio of the plant powder to the activator is 1:2 - 4.

6. The plant-based antibacterial masterbatch according to claim 3, wherein, In step (4), the inorganic antibacterial material includes one or more of silver nanoparticles, zinc oxide nanoparticles, cuprous oxide nanoparticles, copper oxide nanoparticles, silver nitrate, silver sulfate, silver fluoride, zinc chloride, zinc bromide, zinc sulfate, zinc nitrate, copper sulfate, and copper chloride. Preferably, silver nitrate is compounded with zinc oxide nanoparticles, and the mass ratio of silver ions to zinc ions in the compounded inorganic antibacterial material is 1:1 - 1:10; The concentration of the inorganic antibacterial material in the inorganic antibacterial material solution is 7 - 27.5 wt%, and the mass ratio of the porous plant powder to the inorganic antibacterial material solution is 1:2 - 5; The microwave power is 200 - 300 W; Control the temperature at 40 - 120 °C and react for 3 - 9 h.

7. The plant-based antibacterial masterbatch according to claim 1, wherein, The compatibilizer is a maleic anhydride grafted compatibilizer, including one or more of PE-g-MAH, PP-g-MAH, EVA-g-MAH, ABS-g-MAH, and POE-g-MAH; its grafting rate is 0.4 - 1.6 wt%; and / or The coupling agent includes one or more of γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, and triisostearoyl titanate isopropyl ester.

8. The plant-based antibacterial masterbatch according to claim 1, wherein, The lubricant is one or more of fatty acid esters, montan wax, aliphatic amides and esters, polyethylene wax, and metal soaps. Preferably, it is one or more of E wax, zinc stearate, magnesium stearate, and ethylene bisstearamide; and / or The antioxidant includes one or more of antioxidant 1010, antioxidant 1098, antioxidant 168, antioxidant S9228, antioxidant 245, antioxidant GA-80, antioxidant 1076, and antioxidant 626; and / or The pigment and filler is one or more of inorganic pigments, organic pigments, dyes, and mineral fillers. Preferably, it is one or more of titanium dioxide, zinc sulfide, carbon black, iron oxide red, ultramarine blue, ultramarine violet, titanium yellow, cobalt blue, cobalt green, phthalocyanine blue, phthalocyanine green, organic red 254#, organic yellow 191#, organic red 122#, organic orange 64#, organic yellow 180#, dye red 135#, dye red 179#, organic orange 68#, talc powder, calcium carbonate, and barium sulfate.

9. The method for preparing the plant-based antibacterial masterbatch according to any one of claims 1 - 8, comprising: In a high-speed mixer, the plant-based antibacterial agent and the coupling agent are mixed and then added into the side feeding loss-in-weight weigher of a twin-screw extruder; In another high-speed mixer, the thermoplastic polymer resin, the compatibilizer, the lubricant, the antioxidant, and the pigment and filler are added and mixed, and then added into the main feeding loss-in-weight weigher of the twin-screw extruder; The mixture is extruded, cooled, pelletized, and dried through a twin-screw extruder to obtain the plant-based antibacterial masterbatch.

10. A plant-based antibacterial modified plastic product, which contains the plant-based antibacterial masterbatch according to any one of claims 1 - 8.

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