Antibacterial tpe plastic rubber particles and preparation method thereof

Abstract

The application relates to the technical field of plastic rubber particles, and discloses an antibacterial TPE plastic rubber particle and a preparation method thereof. The antibacterial TPE plastic rubber particle comprises the following raw materials in parts by weight: SEBS 50-60 parts, polypropylene 20-30 parts, white oil 20-30 parts, sodium carboxymethyl cellulose 5-10 parts, antioxidant 1010 0.5-1 part, coupling agent KH550 1-1.5 parts, carbon fiber 2-3 parts, modified antibacterial agent 0.5-1 part, and modified light stabilizer 2-4 parts. In the application, the modified antibacterial agent is prepared through multiple mechanisms to synergistically resist bacteria, can inhibit bacterial reproduction and metabolism, and reduces the pollution risk caused by the breeding of microorganisms; the modified light stabilizer is prepared, can efficiently absorb ultraviolet rays and block the photoaging chain reaction, effectively resists the erosion of ultraviolet rays on the plastic, and prolongs the service life of the product.

Description

Technical Field

[0001] This invention relates to the field of plastic granule technology, specifically to an antibacterial TPE plastic granule and its preparation method. Background Technology

[0002] Thermoplastic elastomers (TPEs), with their excellent elastic recovery, good biocompatibility, and flexible processing and molding characteristics, coupled with their environmental friendliness, non-toxicity, and high biocompatibility, have expanded their applications from the medical field to everyday consumer and industrial settings. They are widely used not only in the surfaces of medical catheters and contact parts of rehabilitation equipment, but also in children's toy shells, appliance buttons, sports equipment grips, and public facility handrails. In these applications, the problems caused by microbial growth are particularly prominent, affecting not only health but also user experience and product lifespan. Therefore, antibacterial properties have become a core performance requirement for TPE materials in various fields. Furthermore, some outdoor TPE products need to withstand natural sunlight; ordinary TPEs are prone to aging, yellowing, and reduced elasticity under ultraviolet radiation, shortening product lifespan.

[0003] Patent application number 202010224684.9 discloses a TPE material with antibacterial conductivity and its preparation method. It uses an inorganic metal ion-based antibacterial agent to improve the material's antibacterial effect, which is durable and has good biocompatibility. However, the antibacterial spectrum of a single metal ion is relatively narrow, and its inhibitory effect on highly drug-resistant strains may be insufficient. Patent application number 201810308607.4 discloses a TPE for syringe pistons and its preparation method. It uses an inorganic silver-loaded antibacterial agent and a nano-titanium dioxide antibacterial agent to improve the material's antibacterial efficiency and broad antibacterial range. However, the antibacterial effect of titanium dioxide depends on ultraviolet light activation; its antibacterial efficiency will significantly decrease when used in the absence of light. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides an antibacterial TPE plastic granule and its preparation method.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] An antibacterial TPE plastic granule comprises the following raw materials in parts by weight: 50-60 parts SEBS, 20-30 parts polypropylene, 20-30 parts white oil, 5-10 parts sodium carboxymethyl cellulose, 0.5-1 part antioxidant 1010, 1-1.5 parts coupling agent KH550, 2-3 parts carbon fiber, 0.5-1 part modified antibacterial agent, and 2-4 parts modified light stabilizer;

[0007] The modified antibacterial agent is prepared by the following steps:

[0008] Step A1: Mix protocatechuic acid, 4-bromo-1-butanol and acetonitrile, stir in an ice bath, add 98wt% concentrated sulfuric acid, react for 3h, then stir at room temperature for 24h, add saturated sodium bicarbonate solution, filter under reduced pressure and dry to obtain catechol ester derivatives.

[0009] Furthermore, the ratio of protocatechuic acid, 4-bromo-1-butanol, acetonitrile, concentrated sulfuric acid, and saturated sodium bicarbonate solution is 1-2 mol: 2.5-5 mol: 50 mL: 10-15 mL: 200-300 mL;

[0010] In step A1, protocatechuic acid and 4-bromo-1-butanol undergo esterification, introducing a bromine group into the system and providing reaction conditions for subsequent nucleophilic substitution reactions.

[0011] Step A2: Mix the catechol ester derivative with acetonitrile, and add it dropwise to a 50wt% suspension of 4-dimethylaminobenzoic acid acetonitrile at 45°C. React for 12 hours, cool to room temperature, precipitate, wash, filter under reduced pressure, and dry to obtain the catechol ester quaternary ammonium salt derivative.

[0012] Furthermore, the ratio of catechol ester derivatives, acetonitrile, and 4-dimethylaminobenzoic acid acetonitrile suspension is 0.5-1 mol: 30-50 mL: 180-350 mL;

[0013] In step A2, the catechol ester derivative and 4-dimethylaminobenzoic acid undergo a nucleophilic substitution reaction, introducing a carboxyl group to provide reaction conditions for the subsequent esterification grafting reaction. The resulting quaternary ammonium salt structure can disrupt the cell membrane structure, inhibit bacterial enzyme activity, interfere with the physiological functions of microorganisms, and improve the bactericidal effect.

[0014] Step A3: Under nitrogen protection, chitosan, catechol ester quaternary ammonium salt derivative and dimethyl sulfoxide are mixed to obtain solution 1. Then, dicyclohexylcarbodiimide, 4-dimethylaminopyridine and dimethyl sulfoxide are mixed to obtain solution 2. Solution 2 is added dropwise to solution 1 within 2 hours. The reaction is carried out at room temperature for 48 hours. After filtration, separation, washing and drying, chitosan derivative is obtained.

[0015] Furthermore, the ratio of chitosan, catechol ester quaternary ammonium salt derivative and dimethyl sulfoxide in solution 1 is 0.01-0.015 mol: 0.3-0.4 mol: 500 mL;

[0016] Furthermore, the ratio of dicyclohexylcarbodiimide, 4-dimethylaminopyridine, and dimethyl sulfoxide in solution 2 is 0.7-0.9 mol: 0.07-0.09 mol: 150-170 mL;

[0017] In step A3, chitosan and catechin ester quaternary ammonium salt derivatives undergo an esterification grafting reaction. Introducing chitosan into the system can disrupt the integrity of bacterial cell membranes, inhibit the synthesis of nucleic acids and proteins, and also block the acquisition of essential nutrients for bacterial metabolism by binding to metal ions on the bacterial outer membrane, thereby inhibiting toxin production and microbial development.

[0018] Step A4: Mix chitosan derivative and ethanol, and add it dropwise to 30wt% nano titanium dioxide ethanol dispersion. The dropwise addition time is 15min. The reaction is carried out under nitrogen protection at a reaction temperature of 50℃ for 6h. After that, the mixture is filtered, washed and dried to obtain the modified antibacterial agent.

[0019] Furthermore, the ratio of chitosan derivative, ethanol, and nano-titanium dioxide ethanol dispersion is 0.1-0.2 mol: 300-400 mL: 450-600 mL;

[0020] In step A4, the catechol structure in the chitosan derivative adsorbs onto the surface of nano-titanium dioxide, introducing nano-titanium dioxide into the system. Under light irradiation, it generates reactive oxygen species with strong oxidizing properties, which can destroy the cell membranes of bacteria and viruses, leading to the death of microorganisms. Furthermore, it has high chemical stability and good thermal stability, ensuring that the system can maintain its antibacterial properties even in harsh environments such as high temperature and humidity.

[0021] The modified light stabilizer is prepared by the following steps:

[0022] Step B1: Mix cyanuric chloride and acetone, stir at 0°C for 20 min, then add dropwise N,N-dimethylformamide (DMF) solution containing UV absorber UV-P, add 20wt% sodium hydroxide aqueous solution, and react at 5°C until the acidity or alkalinity of the system no longer changes, to obtain intermediate product 1.

[0023] Furthermore, the ratio of cyanuric chloride, acetone, UV absorber UV-P, DMF and sodium hydroxide aqueous solution is 1-2 mol: 100-200 mL: 1-2 mol: 50-100 mL: 100-150 mL;

[0024] In step B1, the first carbon-chlorine bond of cyanuric chloride undergoes a substitution reaction with the hydroxyl group of the ultraviolet absorber UV-P, introducing benzotriazole into the system. After absorbing ultraviolet light, the conjugated π electron system within the molecule undergoes an electronic transition, converting the ultraviolet light into low-energy heat or harmless radiation. The triazine ring also has the ability to absorb ultraviolet light and can inhibit the propagation of free radical chain reactions, thereby delaying fading, yellowing, and other phenomena during the aging process of the system.

[0025] Step B2: Heat intermediate product 1 obtained in step B1 to 10°C, add tetramethylpiperidinol DMF solution dropwise to intermediate product 1, and simultaneously heat to 35°C. Add 20wt% sodium hydroxide aqueous solution and react until the acidity or alkalinity of the system no longer changes. Then heat to 60°C and add 1,3-propanediamine. The reaction temperature is 85°C and react until the acidity or alkalinity of the system no longer changes. Cool to room temperature, filter under reduced pressure, wash, and dry to obtain intermediate product 2.

[0026] Furthermore, the ratio of intermediate 1, tetramethylpiperidinol DMF solution, sodium hydroxide aqueous solution and 1,3-propanediamine is 250-450 mL: 50-100 mL: 50-100 mL: 1-2 mol;

[0027] Furthermore, the tetramethylpiperidinol DMF solution is prepared by mixing and stirring tetramethylpiperidinol and DMF at a volume ratio of 1-2 mol: 50-100 mL;

[0028] In step B2, the second carbon-chlorine bond of cyanuric chloride in intermediate product 1 undergoes a substitution reaction with the hydroxyl group in tetramethylpiperidine alcohol, introducing the tetramethylpiperidine structure into the system. Under light irradiation, it can absorb energy and be converted into nitric oxide free radicals, which can terminate the chain oxidation reaction and thus inhibit photoaging. Subsequently, the third carbon-nitrogen bond of cyanuric chloride undergoes a substitution reaction with 1,3-propanediamine, introducing the amino group into the system and providing reaction conditions for the subsequent ring-opening reaction.

[0029] Step B3: Mix intermediate product 2, furfural and anhydrous ethanol, heat to 65°C under nitrogen protection, stir for 3 hours, then filter, wash and dry to obtain the modified light stabilizer.

[0030] Furthermore, the ratio of intermediate product 2, furfural, and anhydrous ethanol is 0.5-1 mol: 0.5-1 mol: 200-300 mL;

[0031] In step B3, intermediate product 2 and furfural undergo a Schiff base condensation reaction, introducing furan into the system. The oxygen atom on the furan ring can react with free radicals to generate stable oxidation products, thereby terminating the chain oxidation reaction. At the same time, it works synergistically with tetramethylpiperidine to further delay the aging of the system.

[0032] A method for preparing antibacterial TPE plastic granules includes the following steps:

[0033] Step S1: Weigh the raw materials according to the weight proportions, mix SEBS and white oil in a high-speed mixer, control the mixing speed at 500-600 r / min for 10 min, add polypropylene, sodium carboxymethyl cellulose, antioxidant 1010, coupling agent KH550, carbon fiber, modified antibacterial agent and modified light stabilizer, and mix at 700-900 r / min for 20-30 min to obtain the mixed material;

[0034] Step S2: The mixed material is heated and melted through a twin-screw extruder, then extruded, granulated, and cooled to obtain a TPE blend material. The extruder temperature is 190-200℃.

[0035] Step S3: The TPE blend material is fed into a granulator to obtain antibacterial TPE plastic granules.

[0036] The beneficial effects of this invention are:

[0037] The antibacterial TPE plastic granules of this invention can be widely used in the production of packaging, furniture, automobiles, medical consumables, baby products, outdoor products, and other fields. Adding these plastic granules during production enhances the antibacterial properties of the product. Through the synergistic antibacterial action of the modified antibacterial agent, bacterial reproduction and metabolism are inhibited, giving the product long-lasting antibacterial properties, reducing the risk of contamination caused by microbial growth, and extending the product's lifespan. Simultaneously, in synergy with the modified light stabilizer, it can efficiently absorb ultraviolet light and block the photoaging chain reaction, effectively resisting the erosion of plastics by ultraviolet light and preventing problems such as fading, deformation, and cracking caused by prolonged outdoor exposure. Compared with existing technologies, the plastic granules produced by this invention achieve both antibacterial and anti-aging functions, meeting the high requirements for the functionality and safety of plastic products in various fields, and have broad application prospects.

[0038] The modified antibacterial agent of this invention first undergoes an esterification reaction with protocatechuic acid and 4-bromo-1-butanol to introduce a bromine group into the system, providing reaction conditions for subsequent nucleophilic substitution reactions. Then, a nucleophilic substitution reaction occurs with 4-dimethylaminobenzoic acid, introducing a quaternary ammonium salt structure that can disrupt cell membrane structure, inhibit bacterial enzyme activity, interfere with microbial physiological functions, and improve bactericidal effects. Next, an esterification grafting reaction occurs with chitosan, introducing chitosan into the system. This chitosan can disrupt the integrity of bacterial cell membranes, inhibit nucleic acid and protein synthesis, and can also block the acquisition of essential nutrients for bacterial metabolism by binding to metal ions on the bacterial outer membrane, thereby inhibiting toxin production and microbial development. Finally, nano-titanium dioxide is introduced into the system. Under light irradiation, it can generate highly oxidizing reactive oxygen species that can destroy the cell membranes of bacteria and viruses, leading to microbial death. Furthermore, its high chemical and thermal stability ensures that the system maintains its antibacterial properties even in harsh environments such as high temperature and humidity.

[0039] The modified light stabilizer of this invention first utilizes the substitution reaction between the first carbon-chlorine bond of cyanuric chloride and the hydroxyl group of the ultraviolet absorber UV-P. After absorbing ultraviolet light, the conjugated π-electron system within the benzotriazole molecule undergoes an electronic transition, converting the ultraviolet light into low-energy heat or harmless radiation. The triazine ring also has the ability to absorb ultraviolet light and can inhibit the propagation of free radical chain reactions, thereby delaying fading, yellowing, and other phenomena during the aging process of the system. Next, the second carbon-chlorine bond of cyanuric chloride reacts with the hydroxyl group in tetramethylpiperidine alcohol. Tetramethylpiperidine can absorb energy under light and convert into nitric oxide free radicals, which can terminate the chain oxidation reaction, thereby inhibiting photoaging. Subsequently, the third carbon-nitrogen bond of cyanuric chloride undergoes a substitution reaction with 1,3-propanediamine, introducing an amino group into the system. Finally, it undergoes a Schiff base condensation reaction with furfural, introducing furan into the system. The oxygen atom on the furan ring can react with free radicals to generate stable oxidation products, thereby terminating the chain oxidation reaction. Simultaneously, it synergistically works with tetramethylpiperidine to further delay the aging of the system. Detailed Implementation

[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Example 1: The modified antibacterial agent was prepared by the following steps:

[0042] Step A1: Mix protocatechuic acid, 4-bromo-1-butanol and acetonitrile, stir in an ice bath, add 98wt% concentrated sulfuric acid, react for 3 h, then stir at room temperature for 24 h, add saturated sodium bicarbonate solution, filter under reduced pressure and dry to obtain catechol ester derivatives. The ratio of protocatechuic acid, 4-bromo-1-butanol, acetonitrile, concentrated sulfuric acid and saturated sodium bicarbonate solution is 1 mol: 2.5 mol: 50 mL: 10 mL: 200 mL.

[0043] Step A2: The catechol ester derivative and acetonitrile were mixed and added dropwise to a 50wt% suspension of 4-dimethylaminobenzoic acid acetonitrile at 45℃. The reaction was carried out for 12 hours, cooled to room temperature, precipitated, washed, filtered under reduced pressure, and dried to obtain the catechol ester quaternary ammonium salt derivative. The ratio of catechol ester derivative, acetonitrile, and 4-dimethylaminobenzoic acid acetonitrile suspension was 0.5mol:30mL:180mL.

[0044] Step A3: Under nitrogen protection, chitosan, catechol ester quaternary ammonium salt derivative, and dimethyl sulfoxide are mixed to obtain solution 1. Then, dicyclohexylcarbodiimide, 4-dimethylaminopyridine, and dimethyl sulfoxide are mixed to obtain solution 2. Solution 2 is added dropwise to solution 1 over 2 hours. The reaction is carried out at room temperature for 48 hours. After filtration, separation, washing, and drying, chitosan derivative is obtained. The ratio of chitosan, catechol ester quaternary ammonium salt derivative, and dimethyl sulfoxide in solution 1 is 0.01 mol: 0.3 mol: 500 mL. The ratio of dicyclohexylcarbodiimide, 4-dimethylaminopyridine, and dimethyl sulfoxide in solution 2 is 0.7 mol: 0.07 mol: 150 mL.

[0045] Step A4: Mix chitosan derivative and ethanol, and add it dropwise to a 30wt% nano-titanium dioxide ethanol dispersion over 15 min. React under nitrogen protection at 50℃ for 6 h. After filtration, washing, and drying, the modified antibacterial agent is obtained. The ratio of chitosan derivative, ethanol, and nano-titanium dioxide ethanol dispersion is 0.1 mol: 300 mL: 450 mL.

[0046] The modified light stabilizer is prepared by the following steps:

[0047] Step B1: Mix cyanuric chloride and acetone, stir at 0°C for 20 min, then add DMF solution containing UV-P ultraviolet absorber dropwise, add 20wt% sodium hydroxide aqueous solution, and react at 5°C until the acidity or alkalinity of the system no longer changes, to obtain intermediate product 1. The ratio of cyanuric chloride, acetone, UV-P ultraviolet absorber, DMF and sodium hydroxide aqueous solution is 1mol:100mL:1mol:50mL:100mL.

[0048] Step B2: Heat intermediate product 1 obtained in step B1 to 10°C, add tetramethylpiperidinol DMF solution dropwise to intermediate product 1, and simultaneously heat to 35°C. Add 20wt% sodium hydroxide aqueous solution and react until the acidity or alkalinity of the system no longer changes. Then heat to 60°C and add 1,3-propanediamine. The reaction temperature is 85°C and react until the acidity or alkalinity of the system no longer changes. Cool to room temperature, filter under reduced pressure, wash, and dry to obtain intermediate product 2. The ratio of intermediate product 1, tetramethylpiperidinol DMF solution, sodium hydroxide aqueous solution, and 1,3-propanediamine is 250mL:50mL:50mL:1mol. The tetramethylpiperidinol DMF solution is prepared by mixing and stirring tetramethylpiperidinol and DMF at a ratio of 1mol:50mL.

[0049] Step B3: Mix intermediate product 2, furfural and anhydrous ethanol, heat to 65°C under nitrogen protection, stir for 3 hours, then filter, wash and dry to obtain modified light stabilizer. The ratio of intermediate product 2, furfural and anhydrous ethanol is 0.5 mol: 0.5 mol: 200 mL.

[0050] Example 2: The modified antibacterial agent was prepared by the following steps:

[0051] Step A1: Mix protocatechuic acid, 4-bromo-1-butanol and acetonitrile, stir in an ice bath, add 98wt% concentrated sulfuric acid, react for 3 h, then stir at room temperature for 24 h, add saturated sodium bicarbonate solution, filter under reduced pressure and dry to obtain catechol ester derivatives. The ratio of protocatechuic acid, 4-bromo-1-butanol, acetonitrile, concentrated sulfuric acid and saturated sodium bicarbonate solution is 1.5 mol: 3.5 mol: 50 mL: 12 mL: 250 mL.

[0052] Step A2: The catechol ester derivative and acetonitrile were mixed and added dropwise to a 50wt% suspension of 4-dimethylaminobenzoic acid acetonitrile at 45℃. The reaction was carried out for 12 hours, cooled to room temperature, precipitated, washed, filtered under reduced pressure, and dried to obtain the catechol ester quaternary ammonium salt derivative. The ratio of catechol ester derivative, acetonitrile, and 4-dimethylaminobenzoic acid acetonitrile suspension was 0.75mol:40mL:265mL.

[0053] Step A3: Under nitrogen protection, chitosan, catechol ester quaternary ammonium salt derivative, and dimethyl sulfoxide are mixed to obtain solution 1. Then, dicyclohexylcarbodiimide, 4-dimethylaminopyridine, and dimethyl sulfoxide are mixed to obtain solution 2. Solution 2 is added dropwise to solution 1 over 2 hours. The reaction is carried out at room temperature for 48 hours. After filtration, separation, washing, and drying, chitosan derivative is obtained. The ratio of chitosan, catechol ester quaternary ammonium salt derivative, and dimethyl sulfoxide in solution 1 is 0.012 mol: 0.35 mol: 500 mL. The ratio of dicyclohexylcarbodiimide, 4-dimethylaminopyridine, and dimethyl sulfoxide in solution 2 is 0.8 mol: 0.08 mol: 160 mL.

[0054] Step A4: Mix chitosan derivative and ethanol, and add it dropwise to a 30wt% nano-titanium dioxide ethanol dispersion over 15 min. React under nitrogen protection at 50°C for 6 h. After filtration, washing, and drying, obtain the modified antibacterial agent. The ratio of chitosan derivative, ethanol, and nano-titanium dioxide ethanol dispersion is 0.15 mol: 350 mL: 525 mL.

[0055] The modified light stabilizer is prepared by the following steps:

[0056] Step B1: Mix cyanuric chloride and acetone, stir at 0°C for 20 min, then add DMF solution containing UV-P ultraviolet absorber dropwise, add 20wt% sodium hydroxide aqueous solution, and react at 5°C until the acidity or alkalinity of the system no longer changes, to obtain intermediate product 1. The ratio of cyanuric chloride, acetone, UV-P ultraviolet absorber, DMF and sodium hydroxide aqueous solution is 1.5mol:150mL:1.5mol:75mL:125mL.

[0057] Step B2: Heat intermediate product 1 obtained in step B1 to 10°C, add tetramethylpiperidinol DMF solution dropwise to intermediate product 1, and simultaneously heat to 35°C. Add 20wt% sodium hydroxide aqueous solution and react until the acidity or alkalinity of the system no longer changes. Then heat to 60°C and add 1,3-propanediamine. The reaction temperature is 85°C, and the reaction continues until the acidity or alkalinity of the system no longer changes. Cool to room temperature, filter under reduced pressure, wash, and dry to obtain intermediate product 2. The ratio of intermediate product 1, tetramethylpiperidinol DMF solution, sodium hydroxide aqueous solution, and 1,3-propanediamine is 350mL:75mL:75mL:1.5mol. The tetramethylpiperidinol DMF solution is prepared by mixing and stirring tetramethylpiperidinol and DMF in a ratio of 1.5mol:75mL.

[0058] Step B3: Mix intermediate product 2, furfural and anhydrous ethanol, heat to 65°C under nitrogen protection, stir for 3 hours, then filter, wash and dry to obtain modified light stabilizer. The ratio of intermediate product 2, furfural and anhydrous ethanol is 0.75mol:0.75mol:250mL.

[0059] Example 3: The modified antibacterial agent was prepared by the following steps:

[0060] Step A1: Mix protocatechuic acid, 4-bromo-1-butanol and acetonitrile, stir in an ice bath, add 98wt% concentrated sulfuric acid, react for 3 hours, then stir at room temperature for 24 hours, add saturated sodium bicarbonate solution, filter under reduced pressure and dry to obtain catechol ester derivatives. The ratio of protocatechuic acid, 4-bromo-1-butanol, acetonitrile, concentrated sulfuric acid and saturated sodium bicarbonate solution is 2mol:5mol:50mL:15mL:300mL.

[0061] Step A2: The catechol ester derivative and acetonitrile were mixed and added dropwise to a 50 wt% suspension of 4-dimethylaminobenzoic acid acetonitrile at 45 °C. The mixture was reacted for 12 h, cooled to room temperature, precipitated, washed, filtered under reduced pressure, and dried to obtain the catechol ester quaternary ammonium salt derivative. The ratio of catechol ester derivative, acetonitrile, and 4-dimethylaminobenzoic acid acetonitrile suspension was 1 mol: 50 mL: 350 mL.

[0062] Step A3: Under nitrogen protection, chitosan, catechol ester quaternary ammonium salt derivative, and dimethyl sulfoxide are mixed to obtain solution 1. Then, dicyclohexylcarbodiimide, 4-dimethylaminopyridine, and dimethyl sulfoxide are mixed to obtain solution 2. Solution 2 is added dropwise to solution 1 over 2 hours. The reaction is carried out at room temperature for 48 hours. After filtration, separation, washing, and drying, chitosan derivative is obtained. The ratio of chitosan, catechol ester quaternary ammonium salt derivative, and dimethyl sulfoxide in solution 1 is 0.015 mol: 0.4 mol: 500 mL. The ratio of dicyclohexylcarbodiimide, 4-dimethylaminopyridine, and dimethyl sulfoxide in solution 2 is 0.9 mol: 0.09 mol: 170 mL.

[0063] Step A4: Mix chitosan derivative and ethanol, and add it dropwise to a 30wt% nano-titanium dioxide ethanol dispersion over 15 min. React under nitrogen protection at 50°C for 6 h. After filtration, washing, and drying, the modified antibacterial agent is obtained. The ratio of chitosan derivative, ethanol, and nano-titanium dioxide ethanol dispersion is 0.2 mol: 400 mL: 600 mL.

[0064] The modified light stabilizer is prepared by the following steps:

[0065] Step B1: Mix cyanuric chloride and acetone, stir at 0°C for 20 min, then add DMF solution containing UV-P ultraviolet absorber dropwise, add 20wt% sodium hydroxide aqueous solution, and react at 5°C until the acidity or alkalinity of the system no longer changes, to obtain intermediate product 1. The ratio of cyanuric chloride, acetone, UV-P ultraviolet absorber, DMF and sodium hydroxide aqueous solution is 2mol:200mL:2mol:100mL:150mL.

[0066] Step B2: Heat intermediate product 1 obtained in step B1 to 10°C, add tetramethylpiperidinol DMF solution dropwise to intermediate product 1, and simultaneously heat to 35°C. Add 20wt% sodium hydroxide aqueous solution and react until the acidity or alkalinity of the system no longer changes. Then heat to 60°C and add 1,3-propanediamine. The reaction temperature is 85°C and react until the acidity or alkalinity of the system no longer changes. Cool to room temperature, filter under reduced pressure, wash, and dry to obtain intermediate product 2. The ratio of intermediate product 1, tetramethylpiperidinol DMF solution, sodium hydroxide aqueous solution, and 1,3-propanediamine is 450mL:100mL:100mL:2mol. The tetramethylpiperidinol DMF solution is prepared by mixing and stirring tetramethylpiperidinol and DMF at a ratio of 2mol:100mL.

[0067] Step B3: Mix intermediate product 2, furfural and anhydrous ethanol, heat to 65°C under nitrogen protection, stir for 3 hours, then filter, wash and dry to obtain the modified light stabilizer. The ratio of intermediate product 2, furfural and anhydrous ethanol is 1 mol: 1 mol: 300 mL.

[0068] Example 4: A method for preparing antibacterial TPE plastic granules, comprising the following steps:

[0069] 50 parts SEBS, 20 parts polypropylene, 20 parts white oil, 5 parts sodium carboxymethyl cellulose, 0.5 parts antioxidant 1010, 1 part coupling agent KH550, 2 parts carbon fiber, 0.5 parts modified antibacterial agent prepared in Example 1, and 2 parts modified light stabilizer prepared in Example 1.

[0070] Step S1: Weigh the raw materials according to the weight proportions, mix SEBS and white oil in a high-speed mixer, control the mixing speed at 500 r / min for 10 min, add polypropylene, sodium carboxymethyl cellulose, antioxidant 1010, coupling agent KH550, carbon fiber, modified antibacterial agent prepared in Example 1 and modified light stabilizer prepared in Example 1, mix at 700 r / min for 20 min to obtain the mixed material;

[0071] Step S2: The mixed material is heated and melted through a twin-screw extruder, then extruded, granulated, and cooled to obtain a TPE blend material. The extruder temperature is 190℃.

[0072] Step S3: The TPE blend material is fed into a granulator to obtain antibacterial TPE plastic granules.

[0073] Example 5: A method for preparing antibacterial TPE plastic granules, comprising the following steps:

[0074] 55 parts SEBS, 25 parts polypropylene, 25 parts white oil, 7 parts sodium carboxymethyl cellulose, 0.5 parts antioxidant 1010, 1 part coupling agent KH550, 3 parts carbon fiber, 0.5 parts modified antibacterial agent prepared in Example 2, and 3 parts modified light stabilizer prepared in Example 2.

[0075] Step S1: Weigh the raw materials according to the weight proportions, mix SEBS and white oil in a high-speed mixer, control the mixing speed at 600 r / min for 10 min, add polypropylene, sodium carboxymethyl cellulose, antioxidant 1010, coupling agent KH550, carbon fiber, modified antibacterial agent prepared in Example 2 and modified light stabilizer prepared in Example 2, mix at 900 r / min for 25 min to obtain the mixed material;

[0076] Step S2: The mixed material is heated and melted through a twin-screw extruder, then extruded, granulated, and cooled to obtain a TPE blend material. The extruder temperature is 195℃.

[0077] Step S3: The TPE blend material is fed into a granulator to obtain antibacterial TPE plastic granules.

[0078] Example 6: A method for preparing antibacterial TPE plastic granules, comprising the following steps:

[0079] 60 parts SEBS, 30 parts polypropylene, 30 parts white oil, 10 parts sodium carboxymethyl cellulose, 1 part antioxidant 1010, 1.5 parts coupling agent KH550, 3 parts carbon fiber, 1 part modified antibacterial agent prepared in Example 3, and 4 parts modified light stabilizer prepared in Example 3.

[0080] Step S1: Weigh the raw materials according to the weight proportions, mix SEBS and white oil in a high-speed mixer, control the mixing speed at 600 r / min for 10 min, add polypropylene, sodium carboxymethyl cellulose, antioxidant 1010, coupling agent KH550, carbon fiber, modified antibacterial agent prepared in Example 3 and modified light stabilizer prepared in Example 3, mix at 900 r / min for 30 min to obtain the mixed material;

[0081] Step S2: The mixed material is heated and melted through a twin-screw extruder, then extruded, granulated, and cooled to obtain a TPE blend material. The extruder temperature is 200℃.

[0082] Step S3: The TPE blend material is fed into a granulator to obtain antibacterial TPE plastic granules.

[0083] Comparative Example 1: This comparative example is a TPE plastic granule. The difference between this example and Example 6 is that an inorganic copper ion antibacterial agent is used instead of the modified antibacterial agent prepared in Example 3. All other aspects are the same.

[0084] Comparative Example 2: This comparative example is a TPE plastic granule. The difference between this example and Example 6 is that light stabilizer 770 is used instead of the modified light stabilizer prepared in Example 3. All other aspects are the same.

[0085] Comparative Example 3: This comparative example is a TPE plastic granule. The difference between this example and Example 6 is that an inorganic copper ion antibacterial agent is used instead of the modified antibacterial agent prepared in Example 3, and light stabilizer 770 is used instead of the modified light stabilizer prepared in Example 3. All other aspects are the same.

[0086] The performance of the plastic granules prepared in Examples 4-6 and Comparative Examples 1-3 was tested:

[0087] Tensile strength and elongation at break: tested in accordance with GB / T 528-2009;

[0088] Performance test after 1000h UV lamp aging: Test conditions were 4h UV aging at 60℃, followed by 4h condensation at 50℃, with a UV spectrum wavelength of 340nm and a radiation intensity of 1.19w / m². 2 ;

[0089] Antibacterial performance testing: The test was conducted in accordance with GB / T 31402-2015 to examine the antibacterial rate of the particles after 24 hours.

[0090] The test results are shown in Table 1:

[0091] Table 1: Performance Test Results

[0092]

[0093] As shown in Table 1, the tensile strength of the plastic granules prepared by this invention is above 9.7 MPa, and the elongation at break is above 459%. After photoaging tests, the change rate of tensile strength and the change rate of elongation at break of Example 6 are both higher than those of Comparative Example 2, indicating that the modified light stabilizer prepared by this invention has a better aging resistance effect. In addition, the antibacterial rate of Example 6 is higher than that of Comparative Example 1, indicating that the modified antibacterial agent prepared by this invention has better antibacterial properties. This proves that the plastic granules prepared by this invention have achieved the expected results in terms of mechanical properties, antibacterial properties, and photoaging resistance.

[0094] The above content is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the scope defined by the inventive concept, they should all fall within the protection scope of the present invention.

Claims

1. An antibacterial TPE plastic granule, characterized in that, The raw materials include the following parts by weight: SEBS 50-60 parts, polypropylene 20-30 parts, white oil 20-30 parts, sodium carboxymethyl cellulose 5-10 parts, antioxidant 1010 0.5-1 part, coupling agent KH550 1-1.5 parts, carbon fiber 2-3 parts, modified antibacterial agent 0.5-1 part, and modified light stabilizer 2-4 parts; The modified antibacterial agent is prepared by the following steps: Step A1: Mix protocatechuic acid, 4-bromo-1-butanol and acetonitrile, stir in an ice bath, add 98wt% concentrated sulfuric acid, react for 3h, then stir at room temperature for 24h, add saturated sodium bicarbonate solution, filter under reduced pressure and dry to obtain catechol ester derivatives. Step A2: Mix the catechol ester derivative with acetonitrile, and add it dropwise to a 50wt% suspension of 4-dimethylaminobenzoic acid acetonitrile at 45°C. React for 12 hours, cool to room temperature, precipitate, wash, filter under reduced pressure, and dry to obtain the catechol ester quaternary ammonium salt derivative. Step A3: Under nitrogen protection, chitosan, catechol ester quaternary ammonium salt derivative and dimethyl sulfoxide are mixed to obtain solution 1. Then, dicyclohexylcarbodiimide, 4-dimethylaminopyridine and dimethyl sulfoxide are mixed to obtain solution 2. Solution 2 is added dropwise to solution 1 within 2 hours. The reaction is carried out at room temperature for 48 hours. After filtration, separation, washing and drying, chitosan derivative is obtained. Step A4: Mix chitosan derivative and ethanol, and add it dropwise to 30wt% nano titanium dioxide ethanol dispersion. The dropwise addition time is 15min. The reaction is carried out under nitrogen protection at a reaction temperature of 50℃ for 6h. After that, the mixture is filtered, washed and dried to obtain the modified antibacterial agent. The modified light stabilizer is prepared by the following steps: Step B1: Mix cyanuric chloride and acetone, stir at 0°C for 20 min, then add DMF solution containing UV-P ultraviolet absorber dropwise, add 20 wt% sodium hydroxide aqueous solution, and react at 5°C until the acidity or alkalinity of the system no longer changes, to obtain intermediate product 1. Step B2: Heat intermediate product 1 obtained in step B1 to 10°C, add tetramethylpiperidinol DMF solution dropwise to intermediate product 1, and simultaneously heat to 35°C. Add 20wt% sodium hydroxide aqueous solution and react until the acidity or alkalinity of the system no longer changes. Then heat to 60°C and add 1,3-propanediamine. The reaction temperature is 85°C and react until the acidity or alkalinity of the system no longer changes. Cool to room temperature, filter under reduced pressure, wash, and dry to obtain intermediate product 2. Step B3: Mix intermediate product 2, furfural and anhydrous ethanol, heat to 65°C under nitrogen protection, stir for 3 hours, then filter, wash and dry to obtain the modified light stabilizer.

2. The antibacterial TPE plastic granules according to claim 1, characterized in that, In step A1, the ratio of protocatechuic acid, 4-bromo-1-butanol, acetonitrile, concentrated sulfuric acid, and saturated sodium bicarbonate solution is 1-2 mol: 2.5-5 mol: 50 mL: 10-15 mL: 200-300 mL.

3. The antibacterial TPE plastic granules according to claim 1, characterized in that, In step A2, the ratio of catechol ester derivative, acetonitrile, and 4-dimethylaminobenzoic acid acetonitrile suspension is 0.5-1 mol: 30-50 mL: 180-350 mL.

4. The antibacterial TPE plastic granules according to claim 1, characterized in that, In step A3, the ratio of chitosan, catechol ester quaternary ammonium salt derivative, and dimethyl sulfoxide in solution 1 is 0.01-0.015 mol: 0.3-0.4 mol: 500 mL, and the ratio of dicyclohexylcarbodiimide, 4-dimethylaminopyridine, and dimethyl sulfoxide in solution 2 is 0.7-0.9 mol: 0.07-0.09 mol: 150-170 mL.

5. The antibacterial TPE plastic granules according to claim 1, characterized in that, In step A4, the ratio of chitosan derivative, ethanol, and nano-titanium dioxide ethanol dispersion is 0.1-0.2 mol: 300-400 mL: 450-600 mL.

6. The antibacterial TPE plastic granules according to claim 1, characterized in that, In step B1, the ratio of cyanuric chloride, acetone, UV absorber UV-P, DMF, and sodium hydroxide aqueous solution is 1-2 mol: 100-200 mL: 1-2 mol: 50-100 mL: 100-150 mL.

7. The antibacterial TPE plastic granules according to claim 1, characterized in that, In step B2, the ratio of intermediate product 1, tetramethylpiperidinol DMF solution, sodium hydroxide aqueous solution, and 1,3-propanediamine is 250-450 mL: 50-100 mL: 50-100 mL: 1-2 mol. The tetramethylpiperidinol DMF solution is prepared by mixing and stirring tetramethylpiperidinol and DMF in a ratio of 1-2 mol: 50-100 mL.

8. The antibacterial TPE plastic granules according to claim 1, characterized in that, In step B3, the ratio of intermediate product 2, furfural, and anhydrous ethanol is 0.5-1 mol: 0.5-1 mol: 200-300 mL.

9. A method for preparing antibacterial TPE plastic granules according to any one of claims 1-8, characterized in that, The antibacterial TPE plastic granules are prepared by the following steps: Step S1: Weigh the raw materials according to the weight proportions, mix SEBS and white oil in a high-speed mixer, control the mixing speed at 500-600 r / min for 10 min, add polypropylene, sodium carboxymethyl cellulose, antioxidant 1010, coupling agent KH550, carbon fiber, modified antibacterial agent and modified light stabilizer, and mix at 700-900 r / min for 20-30 min to obtain the mixed material; Step S2: The mixed material is heated and melted through a twin-screw extruder, then extruded, granulated, and cooled to obtain a TPE blend material. The extruder temperature is 190-200℃. Step S3: The TPE blend material is fed into a granulator to obtain antibacterial TPE plastic granules.

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