Colored polyethylene fiber and preparation method thereof

Abstract

The invention discloses a colored polyethylene fiber and a preparation method thereof, and belongs to the technical field of colored fiber preparation, the colored polyethylene fiber comprises the following raw materials by weight: 80-100 parts of composite polyethylene, 5-8 parts of antibacterial color master batch, 1-2 parts of an antioxidant, 1-2 parts of an ultraviolet light absorber, 2-3 parts of a lubricant and 1-2 parts of a flexibilizer; the antibacterial color master batch of the antibacterial whitening agent with quaternary ammonium salt and quaternary phosphonium salt structures and the silver-loaded titanium dioxide is prepared, a double-bond structure of the antibacterial whitening agent and the silver-loaded titanium dioxide cooperate to improve the wear resistance of the material, and the antibacterial whitening agent and the silver-loaded titanium dioxide improve the coloring uniformity of fibers by absorbing or reflecting natural light; and the degradation of the dye by microorganisms is obviously reduced through the composite sterilization effect, so that the color fastness grade of the fiber is improved.

Description

Technical Field

[0001] The invention relates to the technical field of colored fiber preparation, and in particular to a colored polyethylene fiber and a preparation method thereof. Background Art

[0002] Colored polyethylene fiber is an advanced fiber material that combines mechanical properties and color stability. It is widely used in protective equipment, outdoor products and high-performance textiles. This fiber uses masterbatch dyeing technology to evenly disperse the pigment into the polyethylene matrix before the fiber is formed to achieve efficient coloring. Compared with the traditional post-dyeing process, masterbatch dyeing can significantly improve the color fastness and avoid fading caused by friction, washing or light, while reducing wastewater discharge during the dyeing process. In addition, in order to enhance the functionality of the fiber, antibacterial brighteners are added to the masterbatch to give the fiber long-lasting antibacterial properties. The combination of the antibacterial component and the polyethylene matrix is ​​stable and not easily invalidated by use or washing. It effectively inhibits bacterial growth and meets application scenarios with high requirements for hygiene and safety.

[0003] Prior art CN118531523A discloses a solution-dyed polylactic acid fiber and a preparation method thereof, wherein a special masterbatch for polylactic acid fiber is prepared using polylactic acid as a substrate, micron-grade color powder and a high-efficiency dispersant, etc., and then the masterbatch, polylactic acid and a modifier are used to extrude and granulate through a mixer and a twin-screw extruder, and the fiber is spun through a spinning machine to obtain a solution-dyed polylactic acid fiber with no color / mixed color and reduced barrel bursting. The masterbatch is melted and dispersed evenly during the polylactic acid spinning crystallization process, thereby greatly improving the rigidity of the polylactic acid fiber.

[0004] However, the above patent content is to achieve the purpose of coloring the polylactic acid fiber stock solution by preparing a special masterbatch for polylactic acid fiber. However, the pigment used in the process of preparing the masterbatch is an organic dye. The lack of antibacterial properties of the material itself will lead to a large number of microorganisms growing during the use of the fiber, causing the microorganisms to degrade the dye. Therefore, the antibacterial properties of polylactic acid fibers colored with organic dyes need to be further improved, and the color fastness of the fiber also needs to be further improved.

[0005] In view of the technical defects in this aspect, a solution is now proposed. Summary of the invention

[0006] The object of the present invention is to provide a colored polyethylene fiber and a preparation method thereof, so as to solve the technical problem that the color fastness and bactericidal performance of the colored polyethylene fiber in the prior art need to be further improved.

[0007] The object of the present invention can be achieved by the following technical solutions: A colored polyethylene fiber, comprising the following raw materials in parts by weight: 80-100 parts of composite polyethylene, 5-8 parts of antibacterial masterbatch, 1-2 parts of antioxidant, 1-2 parts of ultraviolet absorber, 2-3 parts of lubricant, and 1-2 parts of toughening agent;

[0008] The preparation method of the composite polyethylene is as follows: Place azobisisobutyronitrile and o-xylene in a high-pressure reaction kettle. After introducing ethylene, the temperature of the high-pressure reaction kettle is raised to 160-180 °C, and the pressure is raised to 15-18 MPa. After constant temperature and pressure polymerization for 40-60 min, the pressure is released. Add an antibacterial brightening agent to the reaction kettle, and after heat preservation reaction for 30-40 min, post-treatment is carried out to obtain composite polyethylene.

[0009] The reaction principle of preparing composite polyethylene is as follows: Under high temperature, high pressure and the catalysis of azobisisobutyronitrile, the double bond of ethylene breaks to generate free radicals, which continuously polymerize to produce a long-chain structure. After the initial polymerization and pressure release, an antibacterial brightening agent is added to the reaction kettle. A large number of double bond structures in the antibacterial brightening agent play a chain extension role on the ethylene chain segments, thereby hybridizing the ethylene chain segments to obtain composite polyethylene.

[0010] Further, the dosage ratio of azobisisobutyronitrile, o-xylene, ethylene and antibacterial brightening agent is 0.6-0.8 g: 30-40 mL: 12-15 g: 4-5 g. The post-treatment includes: after the reaction is completed, the reaction kettle is cooled to room temperature, and the reaction solution is added to a rotary evaporator with a water bath temperature of 80-100 °C, and vacuum distilled until no liquid is collected to obtain composite polyethylene.

[0011] Further, the antioxidant is one or more of antioxidant 1010, triphenyl phosphite and dilauryl sulfide; the ultraviolet absorber is one or two of 2-hydroxy-4-octyloxybenzophenone and bis(2,2,6,6-tetramethylpiperidinyl) sebacate; the lubricant is one or more of calcium stearate, oxidized polyethylene wax and montan wax; the toughening agent is one or more of dioctyl phthalate, diisononyl phthalate and tributyl citrate.

[0012] Further, the preparation method of the antibacterial brightening agent includes the following steps:

[0013] A1. Add hybrid brightening agent, diphenylphosphine, chloroplatinic acid and dimethyl sulfoxide to a reaction kettle, raise the temperature of the reaction kettle to 40-50 °C, and carry out heat preservation reaction for 1-2 h to obtain an antibacterial brightening agent precursor;

[0014] The reaction equation for preparing composite polyethylene is:

[0015]

[0016] The reaction principle for preparing composite polyethylene is as follows: under the catalysis of chloroplatinic acid, the P-H bond of diphenylphosphine undergoes a P-H addition reaction with the alkenylamino group and double bond on the surface of the hybrid brightening agent to obtain the precursor of the antibacterial brightening agent.

[0017] A2. Add the precursor of the antibacterial brightening agent, allyl chloride, and N,N-dimethylformamide into the reaction kettle. Raise the temperature of the reaction kettle to 40 - 60 °C, keep it warm and stir for 1 - 2 h, then obtain the antibacterial brightening agent.

[0018] The reaction equation for preparing composite polyethylene is:

[0019]

[0020] The reaction principle for preparing composite polyethylene is: the tertiary amino group and tertiary phosphine group on the precursor of the antibacterial brightening agent act as strong nucleophiles, and the lone pair electrons on their nitrogen and phosphorus atoms attack the carbon atom on allyl chloride. The chlorine group on allyl chloride acts as a leaving group and falls off under nucleophilic attack to form chloride ions. After the reaction, finally, a positively charged tetra-substituted nitrogen cation and phosphorus cation are formed, and finally, the antibacterial brightening agent is obtained.

[0021] Furthermore, in step A1, the dosage ratio of the hybrid brightening agent, diphenylphosphine, chloroplatinic acid, and dimethyl sulfoxide is 4 - 5 g : 1 - 2 g : 0.3 - 0.5 g : 20 - 25 mL. The post-treatment includes: after the reaction is completed, cool the reaction kettle to room temperature, add the reaction solution into a rotary evaporator with a water bath temperature of 80 - 100 °C, and distill under reduced pressure until no liquid is collected to obtain the precursor of the antibacterial brightening agent;

[0022] Furthermore, in step A2, the dosage ratio of the precursor of the antibacterial brightening agent, allyl chloride, and N,N-dimethylformamide is 8 - 9 g : 2 - 3 g : 30 - 35 mL. The stirring rate of the reaction kettle is 60 - 80 rpm. The post-treatment includes: after the reaction is completed, cool the reaction kettle to room temperature, add the reaction solution into a rotary evaporator with a water bath temperature of 80 - 100 °C, and distill under reduced pressure until no liquid is collected to obtain the antibacterial brightening agent.

[0023] Furthermore, the preparation method of the hybrid brightening agent includes the following steps:

[0024] B1. Add 4,4'-bis[2-(o-cyanophenyl)vinyl]benzene, n-propylamine, samarium diiodide, and toluene into the reaction kettle. Raise the temperature of the reaction kettle to 40 - 50 °C, keep it warm and react for 1 - 2 h, and then obtain the modified brightening agent through post-treatment;

[0025] The reaction equation for preparing the modified brightening agent is:

[0026]

[0027] In the formula: .

[0028] The reaction principle for preparing the modified optical brightener is as follows: The nitrogen atom of n-propylamine is electron-rich. Catalyzed by samarium diiodide, it initiates a nucleophilic attack on the carbon atom of the nitrile group of 4,4'-bis[2-(o-cyanophenyl)vinyl]benzene to form an imine intermediate. The imine intermediate further undergoes a proton transfer reaction to generate the corresponding amino-substituted product, thus obtaining the modified optical brightener. Among them, the mass spectrometry analysis data of the modified optical brightener are: m / z: 432.18 (100.0%), 433.22 (27.2%), 434.23 (4.1%), 434.21 (3.4%), 435.18 (1.1%).

[0029] B2. Add the modified optical brightener, 4-(dimethylamino)butyraldehyde, aluminum chloride, and N,N-dimethylformamide into a reaction kettle. Raise the temperature of the reaction kettle to 100 - 120 °C, keep the temperature for reaction for 1 - 2 h, and perform post-treatment to obtain the hybrid optical brightener.

[0030] The reaction equation for preparing the hybrid optical brightener is as follows:

[0031]

[0032] The reaction principle for preparing the hybrid optical brightener is as follows: The nitrogen atom in the secondary amino group on the modified optical brightener has a lone pair of electrons and exhibits nucleophilicity. At the beginning of the reaction, the nitrogen atom of the secondary amino group will conduct a nucleophilic attack on the carbon of the aldehyde group to form a transition state, that is, a hydroxylamine-type intermediate with a hydroxyl group and a new carbon-nitrogen bond, and further undergo a dehydration reaction to lose a water molecule, form a double bond, generate an enamine group, and finally obtain the hybrid optical brightener through preparation. Among them, the mass spectrometry analysis data of the hybrid optical brightener are: 616.1(100.0%), 617.5 (46.1%), 618.2(10.4%), 619.6(1.5%).

[0033] Furthermore, in step B1, the dosage ratio of 4,4'-bis[2-(o-cyanophenyl)vinyl]benzene, n-propylamine, samarium diiodide, and toluene is 5 - 6 g: 2 - 3 g: 0.3 - 0.5 g: 25 - 30 mL. The post-treatment includes: after the reaction is completed, cool the reaction kettle to room temperature, add the reaction solution into a rotary evaporator with a water bath temperature of 80 - 100 °C, and perform vacuum distillation until no liquid is collected to obtain the modified optical brightener;

[0034] Further, in step B2, the dosage ratio of the modified brightening agent, 4-(dimethylamino) butyraldehyde, aluminum chloride, and N,N-dimethylformamide is 8-10 g: 1-2 g: 0.2-0.3 g: 40-45 mL. The post-treatment includes: after the reaction is completed, the reaction kettle is cooled to room temperature, and the reaction solution is added into a rotary evaporator with a water bath temperature of 80-100 °C, and vacuum distilled until no liquid is collected, obtaining the hybrid brightening agent.

[0035] Further, the preparation method of the antibacterial masterbatch includes the following steps:

[0036] C1. Add rutile titanium dioxide, 3-aminopropyltriethoxysilane, deionized water, and sodium hydroxide powder into a reaction kettle and stir. The temperature of the reaction kettle is raised to 40-60 °C, and keep stirring for 20-40 min. After post-treatment, modified titanium dioxide is obtained;

[0037] The reaction principle for preparing the modified titanium dioxide is: under alkaline conditions, the siloxy group of 3-aminopropyltriethoxysilane undergoes hydrolysis to form a silanol structure, and an elimination reaction occurs with the hydroxyl group on the surface of the diamond-type titanium dioxide, so that the silane coupling agent structure forms a crosslink with the titanium dioxide, and finally the modified titanium dioxide is prepared.

[0038] C2. Add the modified titanium dioxide, silver nitrate solution, and polyvinylpyrrolidone into a reaction kettle. The temperature of the reaction kettle is raised to 40-60 °C. After keeping stirring for 10-15 min, sodium borohydride is added into the reaction kettle, and keep reacting for 30-40 min to obtain silver-loaded titanium dioxide;

[0039] The reaction principle for preparing the silver-loaded titanium dioxide is: the amino group on the surface of the modified titanium dioxide undergoes a coordination reaction with silver ions, and a stable chemical adsorption layer is formed with Ag⁺ through lone pair electrons. While fixing the silver ions, it also provides a reaction site for the reduction of silver ions by sodium borohydride, enabling silver particles to adhere to the surface of the modified titanium dioxide, and finally the silver-loaded titanium dioxide is prepared.

[0040] C3. Add pigment blue BO, silver-loaded titanium dioxide, polyethylene resin, polyethylene wax, and calcium stearate into a twin-screw extruder and melt-extrude to obtain the antibacterial masterbatch precursor;

[0041] C4. Use a granulator to cut the antibacterial masterbatch precursor into uniform particles, and pass through an 8-16 mesh sieve to obtain the antibacterial masterbatch.

[0042] Further, in step C1, the dosage ratio of rutile titanium dioxide, 3-aminopropyltriethoxysilane, deionized water and sodium hydroxide powder is 8-10 g: 1-2 g: 20-30 mL: 0.5-0.8 g. The stirring rate of the reaction kettle is 60-80 rpm. The post-treatment includes: after the reaction is completed, when the temperature of the reaction kettle drops to room temperature, filter the reaction solution by suction to collect the filter cake. After washing the precipitate 3-5 times with anhydrous ethanol and deionized water, transfer the precipitate to a drying oven at 60-80 °C for vacuum drying to constant weight to obtain modified titanium dioxide;

[0043] Further, in step C2, the dosage ratio of modified titanium dioxide, silver nitrate solution, polyvinylpyrrolidone and sodium borohydride is 5-6 g: 10-15 mL: 0.5-0.8 g: 1-2 g. The stirring rate of the reaction kettle is 60-80 rpm. The concentration of the silver nitrate solution is 0.1-0.2 mol / L. The post-treatment includes: after the reaction is completed, when the temperature of the reaction kettle drops to room temperature, filter the reaction solution by suction to collect the filter cake. After washing the precipitate 3-5 times with anhydrous ethanol and deionized water, transfer the precipitate to a drying oven at 60-80 °C for vacuum drying to constant weight to obtain silver-loaded titanium dioxide;

[0044] Further, in step C3, the dosage ratio of pigment blue BO, silver-loaded titanium dioxide, polyethylene resin, polyethylene wax and calcium stearate is 40-50 g: 1-2 g: 10-15 g: 30-40 g: 4-6 g: 1-2 g. The temperatures of the seven temperature zones of the twin-screw extruder from the feed inlet to the discharge outlet are 160 °C, 160 °C, 165 °C, 165 °C, 175 °C, 180 °C, 180 °C in sequence. The main machine speed of the twin-screw extruder is 80-120 rpm, and the pressure is 100-150 bar.

[0045] The present invention also provides a method for preparing colored polyethylene fibers, including the following steps:

[0046] S1. Add composite polyethylene, antibacterial masterbatch, antioxidant, ultraviolet absorber, lubricant and toughening agent into a twin-screw extruder for melt extrusion to obtain molten polyethylene;

[0047] S2. Extrude the molten polyethylene through a spinneret and transfer it to a side-blowing chamber, and obtain colored polyethylene fibers after air-cooling and solidification.

[0048] Further, in step S1, the temperatures of the seven temperature zones of the twin-screw extruder from the feed inlet to the discharge outlet are 200 °C, 200 °C, 205 °C, 205 °C, 215 °C, 220 °C, 220 °C in sequence. The main machine speed of the twin-screw extruder is 80-120 rpm, and the pressure is 100-150 bar.

[0049] Further, in step S2, the orifice of the spinneret plate is circular, the mesh number is 32 - 64, the orifice diameter is 0.07 - 0.09 mm, and the spinning pressure is 80 - 150 bar; the cold air is air, the relative humidity is 30 - 50%, the temperature is 20 - 30 °C, and the flow rate is maintained at 5 - 10 m / s.

[0050] The present invention has the following beneficial effects:

[0051] 1. A large number of double bonds are introduced during the preparation process of the antibacterial brightening agent in the present invention. During the reaction process, a three-dimensional network structure is formed through chemical cross-linking, significantly improving the wear resistance of the fiber. The cross-linked structure enhances the binding force between fiber molecules, restricts the sliding of molecular chains, increases the hardness of the fiber surface, making it not easily damaged during the friction process. And it cooperates synergistically with the silver-loaded titanium dioxide in the antibacterial masterbatch. The silver-loaded titanium dioxide enhances the fiber hardness, improves the interfacial binding force, and provides a microscopic lubrication effect, significantly improving the wear resistance of the material. The high-hardness filling effect reduces deformation and wear, the interfacial stability delays crack propagation, and the micro-lubrication effect reduces the friction coefficient, significantly improving the wear resistance and tensile resistance of the fiber.

[0052] 2. The structure of the antibacterial brightening agent is introduced into the composite polyethylene, and at the same time, the structure of silver-loaded titanium dioxide is introduced into the antibacterial masterbatch in the present invention. The antibacterial brightening agent absorbs ultraviolet light and releases visible blue light, and the silver-loaded titanium dioxide scatters and reflects light. The two cooperate synergistically to make the blue tone more saturated and bright, significantly improving the coloring effect of pigment blue by enhancing the color saturation of the colored fiber. And the positive charges on the quaternary ammonium salt and quaternary phosphonium salt structures of the antibacterial brightening agent can adsorb pigment molecules through electrostatic attraction, making them more stably attached to polyethylene, increasing the deposition amount of pigment on the material surface, thereby improving the depth and uniformity of coloring.

[0053] 3. The antibacterial brightening agent of the present invention depends on the positively charged cationic part in its molecular structure through the internal composite quaternary ammonium salt and quaternary phosphonium salt structures to interact with the negatively charged cell membrane of bacteria. The cationic head combines with the cell membrane to extract lipids or water on the membrane, and the hydrophobic tail embeds into the membrane, resulting in the rupture and leakage of the cell membrane and penetrating into the cell interior, interfering with enzyme activity and DNA replication, preventing the growth of microorganisms, and causing bacteria to die quickly. At the same time, through the broad-spectrum antibacterial properties of silver ions in the silver-loaded titanium dioxide and the photocatalytic ability of titanium dioxide, silver ions can damage the bacterial cell wall, inhibit the activity of metabolic enzymes, and interfere with DNA replication, while titanium dioxide generates reactive oxygen species under ultraviolet light illumination to oxidize and sterilize. The two work synergistically to achieve all-weather sterilization, while improving the stability and sterilization efficiency of the material. The antibacterial brightening agent and the silver-loaded titanium dioxide greatly improve the antibacterial performance of the material through synergistic cooperation, and the introduction reduces the degradation of dyes by microorganisms and improves the adhesion of dyes to fibers, thereby significantly improving the color fastness of the material. Detailed implementation mode

[0054] The technical scheme of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] The rutile titanium dioxide used in the present invention was purchased from Hebei Laiyi New Materials Co., Ltd., with a product number of 9969;

[0056] The phthalocyanine blue used in the present invention was purchased from Tianjin Huli Chemical Co., Ltd., with the item number being 102P;

[0057] The pigment blue BO used in the present invention is purchased from Shanghai Unicolor Chemical Co., Ltd. and its index number is pigment blue 1.

[0058] Example 1

[0059] This embodiment provides a method for preparing an antibacterial whitening agent for colored polyethylene fibers, comprising the following steps:

[0060] Step ①, preparation of modified brightener

[0061] Weigh: 500.04,4'-bis[2-(o-cyanophenyl)vinyl]benzene, 200.0g n-propylamine, 30.0g samarium diiodide and 2500.0mL toluene and add them into a reactor. The temperature of the reactor is raised to 40°C and the reaction is kept warm for 1h. After the reaction is completed, the reactor is cooled to room temperature and the reaction liquid is added to a rotary evaporator with a water bath temperature of 80°C. Reduce pressure distillation is performed until no liquid is produced to obtain a modified brightener.

[0062] Step ②: Preparation of hybrid whitening agent

[0063] Weigh: 800.0g of modified whitening agent, 100.0g of 4-(dimethylamino)butyraldehyde, 20.0g of aluminum chloride and 4000.0mL of N,N-dimethylformamide and add them into a reactor. The temperature of the reactor is raised to 100°C and the reaction is kept warm for 1h. After the reaction is completed, the reactor is cooled to room temperature and the reaction liquid is added to a rotary evaporator with a water bath temperature of 80°C. Distill under reduced pressure until no liquid is extracted to obtain a hybrid whitening agent.

[0064] Step ③: Preparation of antibacterial whitening agent precursor

[0065] Weigh: 400.0 g of hybrid brightening agent, 100.0 g of diphenylphosphine, 30.0 g of chloroplatinic acid and 2000.0 mL of dimethyl sulfoxide and add them to the reaction kettle. Raise the temperature of the reaction kettle to 40 °C, keep the temperature for reaction for 1 h. After the reaction is completed, cool the reaction kettle to room temperature. Add the reaction solution to a rotary evaporator with a water bath temperature of 80 °C, and perform vacuum distillation until no liquid is collected to obtain the precursor of the antibacterial brightening agent.

[0066] Step ④, prepare the antibacterial brightening agent

[0067] Weigh: 800.0 g of the precursor of the antibacterial brightening agent, 200.0 g of allyl chloride and 3000.0 mL of N,N-dimethylformamide and add them to the reaction kettle. Raise the temperature of the reaction kettle to 40 °C, keep stirring for 1 h, then set the stirring rate of the reaction kettle to 60 rpm. After the reaction is completed, cool the reaction kettle to room temperature. Add the reaction solution to a rotary evaporator with a water bath temperature of 80 °C, and perform vacuum distillation until no liquid is collected to obtain the antibacterial brightening agent.

[0068] Example 2

[0069] This example provides a preparation method of an antibacterial brightening agent for coloring polyethylene fibers, including the following steps:

[0070] Step ①, prepare the modified brightening agent

[0071] Weigh: 600.0 g of 4,4'-bis[2-(o-cyanophenyl)vinyl]benzene, 300.0 g of n-propylamine, 50.0 g of samarium diiodide and 3000.0 mL of toluene and add them to the reaction kettle. Raise the temperature of the reaction kettle to 50 °C, keep the temperature for reaction for 2 h. After the reaction is completed, cool the reaction kettle to room temperature. Add the reaction solution to a rotary evaporator with a water bath temperature of 100 °C, and perform vacuum distillation until no liquid is collected to obtain the modified brightening agent.

[0072] Step ②, prepare the hybrid brightening agent

[0073] Weigh: 1000.0 g of the modified brightening agent, 200.0 g of 4-(dimethylamino)butyraldehyde, 30.0 g of aluminum chloride and 4500.0 mL of N,N-dimethylformamide and add them to the reaction kettle. Raise the temperature of the reaction kettle to 120 °C, keep the temperature for reaction for 2 h. After the reaction is completed, cool the reaction kettle to room temperature. Add the reaction solution to a rotary evaporator with a water bath temperature of 100 °C, and perform vacuum distillation until no liquid is collected to obtain the hybrid brightening agent.

[0074] Step ③, prepare the precursor of the antibacterial brightening agent

[0075] Weigh: 500.0 g of hybrid brightening agent, 200.0 g of diphenylphosphine, 50.0 g of chloroplatinic acid and 2500.0 mL of dimethyl sulfoxide and add them to the reaction kettle. Raise the temperature of the reaction kettle to 50 °C, keep the temperature for reaction for 2 h. After the reaction is completed, cool the reaction kettle to room temperature. Add the reaction solution to a rotary evaporator with a water bath temperature of 100 °C and perform vacuum distillation until no liquid is collected to obtain the antibacterial brightening agent precursor.

[0076] Step ④, prepare the antibacterial brightening agent

[0077] Weigh: 900.0 g of antibacterial brightening agent precursor, 300.0 g of allyl chloride and 3200.0 mL of N,N-dimethylformamide and add them to the reaction kettle. Raise the temperature of the reaction kettle to 50 °C, keep stirring for 2 h, then set the stirring rate of the reaction kettle to 80 rpm. After the reaction is completed, cool the reaction kettle to room temperature. Add the reaction solution to a rotary evaporator with a water bath temperature of 90 °C and perform vacuum distillation until no liquid is collected to obtain the antibacterial brightening agent.

[0078] Example 3

[0079] This example provides a preparation method of an antibacterial brightening agent for coloring polyethylene fibers, including the following steps:

[0080] Step ①, prepare the modified brightening agent

[0081] Weigh: 550.0 g of 4,4'-bis[2-(o-cyanophenyl)vinyl]benzene, 250.0 g of n-propylamine, 40.0 g of samarium diiodide and 2700.0 mL of toluene and add them to the reaction kettle. Raise the temperature of the reaction kettle to 45 °C, keep the temperature for reaction for 2 h. After the reaction is completed, cool the reaction kettle to room temperature. Add the reaction solution to a rotary evaporator with a water bath temperature of 90 °C and perform vacuum distillation until no liquid is collected to obtain the modified brightening agent.

[0082] Step ②, prepare the hybrid brightening agent

[0083] Weigh: 900.0 g of modified brightening agent, 150.0 g of 4-(dimethylamino)butyraldehyde, 25.0 g of aluminum chloride and 4200.0 mL of N,N-dimethylformamide and add them to the reaction kettle. Raise the temperature of the reaction kettle to 110 °C, keep the temperature for reaction for 2 h. After the reaction is completed, cool the reaction kettle to room temperature. Add the reaction solution to a rotary evaporator with a water bath temperature of 90 °C and perform vacuum distillation until no liquid is collected to obtain the hybrid brightening agent.

[0084] Step ③, prepare the antibacterial brightening agent precursor

[0085] Weigh: 450.0 g of the hybrid fluorescent brightener, 150.0 g of diphenylphosphine, 40.0 g of chloroplatinic acid and 2400.0 mL of dimethyl sulfoxide and add them to the reaction kettle. Raise the temperature of the reaction kettle to 45 °C, keep the temperature for reaction for 2 h. After the reaction is completed, cool the reaction kettle to room temperature. Add the reaction solution to a rotary evaporator with a water bath temperature of 90 °C, and carry out vacuum distillation until no liquid is collected to obtain the antibacterial brightener precursor.

[0086] Step ④, preparing the antibacterial brightener

[0087] Weigh: 850.0 g of the antibacterial brightener precursor, 250.0 g of allyl chloride and 3200.0 mL of N,N-dimethylformamide and add them to the reaction kettle. Raise the temperature of the reaction kettle to 50 °C, keep stirring for 2 h, then the stirring rate of the reaction kettle is 70 rpm. After the reaction is completed, cool the reaction kettle to room temperature. Add the reaction solution to a rotary evaporator with a water bath temperature of 90 °C, and carry out vacuum distillation until no liquid is collected to obtain the antibacterial brightener.

[0088] Example 4

[0089] This example provides a preparation method of composite polyethylene for coloring polyethylene fibers, including the following steps:

[0090] Weigh: 60.0 g of azobisisobutyronitrile and 3000.0 mL of o-xylene and place them in a high-pressure reaction kettle. After introducing 1200.0 g of ethylene, raise the temperature of the high-pressure reaction kettle to 160 °C and the pressure to 15 MPa. After constant temperature and constant pressure polymerization for 40 min, relieve the pressure. Add 400.0 g of the antibacterial brightener to the reaction kettle, keep the temperature for reaction for 30 min. After the reaction is completed, cool the reaction kettle to room temperature. Add the reaction solution to a rotary evaporator with a water bath temperature of 80 °C, and carry out vacuum distillation until no liquid is collected to obtain the composite polyethylene.

[0091] Example 5

[0092] This example provides a preparation method of composite polyethylene for coloring polyethylene fibers, including the following steps:

[0093] Weigh: 80.0 g of azobisisobutyronitrile and 4000.0 mL of o-xylene and place them in a high-pressure reaction kettle. After introducing 1500.0 g of ethylene, raise the temperature of the high-pressure reaction kettle to 180 °C and the pressure to 18 MPa. After constant temperature and constant pressure polymerization for 60 min, relieve the pressure. Add 500.0 g of the antibacterial brightener to the reaction kettle, keep the temperature for reaction for 40 min. After the reaction is completed, cool the reaction kettle to room temperature. Add the reaction solution to a rotary evaporator with a water bath temperature of 100 °C, and carry out vacuum distillation until no liquid is collected to obtain the composite polyethylene.

[0094] Example 6

[0095] This embodiment provides a method for preparing composite polyethylene for coloring polyethylene fibers, comprising the following steps:

[0096] Weigh: 70.0 g of azobisisobutyronitrile and 3500.0 mL of o-xylene and place them in a high-pressure reactor. After introducing 1200.0 g of ethylene, the temperature of the high-pressure reactor rises to 170 °C and the pressure rises to 16 MPa. After constant temperature and pressure polymerization for 40 min, the pressure is released. Then, 450.0 g of antibacterial brightening agent is added to the reactor. After heat preservation reaction for 35 min, after the reaction is completed, the reactor is cooled to room temperature. The reaction solution is added to a rotary evaporator with a water bath temperature of 90 °C, and vacuum distillation is carried out until no liquid is extracted to obtain composite polyethylene.

[0097] Example 7

[0098] This embodiment provides a method for preparing an antibacterial brightening agent for coloring polyethylene fibers, comprising the following steps:

[0099] Step (1), preparing modified titanium dioxide

[0100] Weigh: 800.0 g of rutile titanium dioxide, 100.0 g of 3-aminopropyltriethoxysilane, 2400.0 mL of deionized water and 60.0 g of sodium hydroxide powder and add them to the reactor for stirring. The stirring rate of the reactor is 60 rpm. The temperature of the reactor rises to 40 °C, and heat preservation stirring is carried out for 20 min. After the reaction is completed, when the temperature of the reactor drops to room temperature, the reaction solution is filtered by suction to collect the filter cake. After washing the precipitate 3 times with absolute ethanol and deionized water, the precipitate is transferred to a drying oven at 60 °C for vacuum drying to constant weight to obtain modified titanium dioxide.

[0101] Step (2), preparing silver-loaded titanium dioxide

[0102] Weigh: 500.0 g of modified titanium dioxide, 1000.0 mL of 0.1 mol / L silver nitrate solution and 50.0 g of polyvinylpyrrolidone and add them to the reactor. The temperature of the reactor rises to 40 °C. After heat preservation stirring for 10 min, the stirring rate of the reactor is 80 rpm. 100.0 g of sodium borohydride is added to the reactor, and heat preservation reaction is carried out for 30 min. After the reaction is completed, when the temperature of the reactor drops to room temperature, the reaction solution is filtered by suction to collect the filter cake. After washing the precipitate 3 times with absolute ethanol and deionized water, the precipitate is transferred to a drying oven at 60 °C for vacuum drying to constant weight to obtain silver-loaded titanium dioxide.

[0103] Step (3), preparing the precursor of antibacterial masterbatch

[0104] Weigh: 4000.0 g of Pigment Blue BO, 1000.0 g of silver-loaded titanium dioxide, 3000.0 g of polyethylene resin, 400.0 g of polyethylene wax, and 100.0 g of calcium stearate and add them to a twin-screw extruder. The temperatures of the seven temperature zones of the twin-screw extruder from the feed inlet to the discharge outlet are 160 °C, 160 °C, 165 °C, 165 °C, 175 °C, 180 °C, and 180 °C in sequence. The main motor speed of the twin-screw extruder is 80 rpm, and the pressure is 100 bar. Melting and extrusion are carried out to obtain the antibacterial masterbatch precursor.

[0105] Step (4), preparing the antibacterial masterbatch

[0106] Use a pelletizer to cut the antibacterial masterbatch precursor into uniform particles, and pass through an 8-mesh sieve to obtain the antibacterial masterbatch.

[0107] Example 8

[0108] This example provides a preparation method of an antibacterial brightening agent for coloring polyethylene fibers, including the following steps:

[0109] Step (1), preparing modified titanium dioxide

[0110] Weigh: 1000.0 g of rutile titanium dioxide, 200.0 g of 3-aminopropyltriethoxysilane, 3000.0 mL of deionized water, and 80.0 g of sodium hydroxide powder and add them to a reaction kettle for stirring. The stirring rate of the reaction kettle is 80 rpm. The temperature of the reaction kettle is raised to 60 °C, and it is kept warm and stirred for 40 min. After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, filter the reaction solution by suction to collect the filter cake. After washing the precipitate 5 times with anhydrous ethanol and deionized water, transfer the precipitate to a drying oven at 80 °C for vacuum drying to constant weight to obtain modified titanium dioxide.

[0111] Step (2), preparing silver-loaded titanium dioxide

[0112] Weigh: 600.0 g of modified titanium dioxide, 1500.0 mL of 0.2 mol / L silver nitrate solution, and 80.0 g of polyvinylpyrrolidone and add them to a reaction kettle. The temperature of the reaction kettle is raised to 60 °C. After keeping warm and stirring for 15 min, the stirring rate of the reaction kettle is 80 rpm. Add 200.0 g of sodium borohydride to the reaction kettle and keep the reaction at a constant temperature for 40 min. After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, filter the reaction solution by suction to collect the filter cake. After washing the precipitate 5 times with anhydrous ethanol and deionized water, transfer the precipitate to a drying oven at 80 °C for vacuum drying to constant weight to obtain silver-loaded titanium dioxide.

[0113] Step (3), preparing the antibacterial masterbatch precursor

[0114] Weigh: 5000.0 g of Pigment Blue BO, 1500.0 g of silver-loaded titanium dioxide, 4000.0 g of polyethylene resin, 600.0 g of polyethylene wax and 200.0 g of calcium stearate and add them to a twin-screw extruder. The temperatures of the seven temperature zones of the twin-screw extruder from the feed inlet to the discharge outlet are 160 °C, 160 °C, 165 °C, 165 °C, 175 °C, 180 °C, 180 °C in sequence. The main machine speed of the twin-screw extruder is 100 rpm, the pressure is 150 bar, and melt extrusion is carried out to obtain an antibacterial masterbatch precursor.

[0115] Step (4), preparing an antibacterial masterbatch

[0116] Use a pelletizer to cut the antibacterial masterbatch precursor into uniform particles, and pass through a 16-mesh sieve to obtain the antibacterial masterbatch.

[0117] Example 9

[0118] This example provides a preparation method of an antibacterial brightening agent for coloring polyethylene fibers, including the following steps:

[0119] Step (1), preparing modified titanium dioxide

[0120] Weigh: 900.0 g of rutile titanium dioxide, 150.0 g of 3-aminopropyltriethoxysilane, 2500.0 mL of deionized water and 60.0 g of sodium hydroxide powder and add them to a reaction kettle for stirring. The stirring rate of the reaction kettle is 70 rpm. The temperature of the reaction kettle is raised to 50 °C, and keep stirring for 30 min. After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, filter the reaction solution by suction to collect the filter cake. After washing the precipitate 4 times with absolute ethanol and deionized water, transfer the precipitate to a drying oven at 70 °C for vacuum drying to constant weight to obtain modified titanium dioxide.

[0121] Step (2), preparing silver-loaded titanium dioxide

[0122] Weigh: 550.0 g of modified titanium dioxide, 1200.0 mL of 0.2 mol / L silver nitrate solution and 60.0 g of polyvinylpyrrolidone and add them to a reaction kettle. The temperature of the reaction kettle is raised to 50 °C. After keeping stirring for 12 min, the stirring rate of the reaction kettle is 70 rpm. Add 150.0 g of sodium borohydride to the reaction kettle, and keep the reaction for 35 min. After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, filter the reaction solution by suction to collect the filter cake. After washing the precipitate 4 times with absolute ethanol and deionized water, transfer the precipitate to a drying oven at 70 °C for vacuum drying to constant weight to obtain silver-loaded titanium dioxide.

[0123] Step (3), preparing an antibacterial masterbatch precursor

[0124] Weigh: 4500.0 g of Pigment Blue BO, 1200.0 g of silver-loaded titanium dioxide, 3600.0 g of polyethylene resin, 500.0 g of polyethylene wax, and 150.0 g of calcium stearate and add them to a twin-screw extruder. The temperatures of the seven temperature zones of the twin-screw extruder from the feed inlet to the discharge outlet are 160 °C, 160 °C, 165 °C, 165 °C, 175 °C, 180 °C, and 180 °C in sequence. The main machine speed of the twin-screw extruder is 100 rpm, the pressure is 120 bar, and melt extrusion is carried out to obtain an antibacterial masterbatch precursor.

[0125] Step (4), preparing an antibacterial masterbatch

[0126] Use a pelletizer to cut the antibacterial masterbatch precursor into uniform particles, and pass through a 12-mesh sieve to obtain the antibacterial masterbatch.

[0127] Example 10

[0128] This example provides a method for preparing colored polyethylene fibers, including the following steps:

[0129] Step one, preparing molten polyethylene

[0130] Weigh: 8000.0 g of the composite polyethylene prepared in Example 4, 500.0 g of the antibacterial masterbatch prepared in Example 7, 100.0 g of triphenyl phosphite, 100.0 g of 2-hydroxy-4-octyloxybenzophenone, 200.0 g of calcium stearate, and 100.0 g of dioctyl phthalate and add them to a twin-screw extruder. The temperatures of the seven temperature zones of the twin-screw extruder from the feed inlet to the discharge outlet are 200 °C, 200 °C, 205 °C, 205 °C, 215 °C, 220 °C, and 220 °C in sequence. The main machine speed of the twin-screw extruder is 80 rpm, the pressure is 120 bar, and melt extrusion is carried out to obtain molten polyethylene.

[0131] Step two, preparing colored polyethylene fibers

[0132] Extrude the molten polyethylene through a spinneret. The orifice of the spinneret is circular, the mesh number is 32, the aperture is 0.07 mm, and the spinning pressure is 80 bar. Transfer it to the side blowing chamber. The cold air is air, the relative humidity is 30%, the temperature is 20 °C, and the flow rate is maintained at 5 m / s. After air-cooling and solidification, colored polyethylene fibers are obtained.

[0133] Example 11

[0134] This example provides a method for preparing colored polyethylene fibers, including the following steps:

[0135] Step one, preparing molten polyethylene

[0136] Weigh: 10000.0 g of the composite polyethylene prepared in Example 5, 800.0 g of the antibacterial masterbatch prepared in Example 8, 200.0 g of triphenyl phosphite, 200.0 g of 2-hydroxy-4-octyloxybenzophenone, 300.0 g of calcium stearate, and 200.0 g of dioctyl phthalate were added to a twin-screw extruder. The temperatures of the seven temperature zones of the twin-screw extruder from the feed inlet to the discharge outlet were 200 °C, 200 °C, 205 °C, 205 °C, 215 °C, 220 °C, and 220 °C in sequence. The main machine speed of the twin-screw extruder was 120 rpm, the pressure was 150 bar, and molten extrusion was carried out to obtain molten polyethylene.

[0137] Step Two: Prepare Colored Polyethylene Fibers

[0138] The molten polyethylene was extruded through a spinneret. The orifice of the spinneret was circular, the mesh number was 64, the aperture was 0.09 mm, and the spinning pressure was 150 bar. It was transferred to a side blow room. The cold air was air, the relative humidity was 50%, the temperature was 30 °C, and the flow rate was maintained at 10 m / s. After air-cooling and solidification, colored polyethylene fibers were obtained.

[0139] Example 12

[0140] This example provides a method for preparing colored polyethylene fibers, including the following steps:

[0141] Step One: Prepare Molten Polyethylene

[0142] Weigh: 9000.0 g of the composite polyethylene prepared in Example 6, 800.0 g of the antibacterial masterbatch prepared in Example 9, 150.0 g of triphenyl phosphite, 150.0 g of 2-hydroxy-4-octyloxybenzophenone, 240.0 g of calcium stearate, and 150.0 g of dioctyl phthalate were added to a twin-screw extruder. The temperatures of the seven temperature zones of the twin-screw extruder from the feed inlet to the discharge outlet were 200 °C, 200 °C, 205 °C, 205 °C, 215 °C, 220 °C, and 220 °C in sequence. The main machine speed of the twin-screw extruder was 100 rpm, the pressure was 120 bar, and molten extrusion was carried out to obtain molten polyethylene.

[0143] Step Two: Prepare Colored Polyethylene Fibers

[0144] The molten polyethylene was extruded through a spinneret. The orifice of the spinneret was circular, the mesh number was 48, the aperture was 0.08 mm, and the spinning pressure was 120 bar. It was transferred to a side blow room. The cold air was air, the relative humidity was 40%, the temperature was 24 °C, and the flow rate was maintained at 8 m / s. After air-cooling and solidification, colored polyethylene fibers were obtained.

[0145] Comparative Example 1

[0146] The difference between this comparative example and Example 12 is that the antibacterial brightening agent is not used in the preparation of the composite polyethylene used in Step 1.

[0147] Comparative Example 2

[0148] The difference between this comparative example and Example 12 is that the antibacterial brightening agent used in the composite polyethylene used in Step 1 is replaced with a hybrid brightening agent in an equal amount during the preparation process.

[0149] Comparative Example 3

[0150] The difference between this comparative example and Example 12 is that the silver-loaded titanium dioxide is not used in the preparation of the antibacterial masterbatch used in Step 1.

[0151] Performance test:

[0152] Referring to the standard GB / T 9867-2008 "Rubber, vulcanized or thermoplastic - Determination of abrasion resistance (rotary roller abrader method)", the volume abrasion of the colored polyethylene fibers prepared in Examples 10-12 and Comparative Examples 1-3 was tested;

[0153] Referring to the standard GB / T 1040.3-2006 "Plastics - Determination of tensile properties - Part 3: Test conditions for films and sheets", the tensile strength of the colored polyethylene fibers prepared in Examples 10-12 and Comparative Examples 1-3 was measured;

[0154] Referring to the standard GB / T 250-2008 "Textiles - Tests for colour fastness - Grey scale for assessing change in colour", the fastness grade and colour difference grade of the colored polyethylene fibers prepared in Examples 10-12 and Comparative Examples 1-3 were tested;

[0155] Referring to the standard GB / T 20944.3-2008 "Textiles - Evaluation of antibacterial properties - Part 3: Oscillation method", the antibacterial rate of the colored polyethylene fibers prepared in Examples 10-12 and Comparative Examples 1-3 was detected. Among them, the selected strains were the Gram-positive bacterium Staphylococcus aureus, the Gram-negative bacterium Escherichia coli, and the fungus Candida albicans. The specific data are shown in Table 1.

[0156] Table 1 - Performance test data table of each sample

[0157]

[0158] Data analysis:

[0159] Comparative analysis of the data in Table 1 shows that the volume abrasion of the colored polyethylene fibers prepared by the present invention is 35 mm 3, the tensile strength is 63.8 MPa, the color difference grade is 5, the fastness grade is 5, the killing rate of Staphylococcus aureus is 99.8%, the killing rate of Escherichia coli is 99.9%, and the killing rate of Candida albicans is 75.6%;

[0160] By comparing the test data of volume abrasion and tensile strength, it can be found that the wear resistance of the colored polyethylene fiber prepared in Example 12 is significantly better than that of the colored polyethylene fibers prepared in Comparative Example 1 and Comparative Example 3. This shows that by introducing a large number of double bonds in the preparation process of the antibacterial brightening agent and forming a three-dimensional network structure through chemical cross-linking during the reaction, the wear resistance of the fiber is significantly improved. The cross-linked structure enhances the binding force between fiber molecules, restricts the sliding of molecular chains, increases the hardness of the fiber surface, making it not easily damaged during friction. And it cooperates synergistically with the silver-loaded titanium dioxide in the antibacterial masterbatch. The silver-loaded titanium dioxide enhances the fiber hardness, improves the interfacial binding force and provides a micro-lubrication effect, significantly improving the wear resistance of the material. The high-hardness filling effect reduces deformation and wear, the interfacial stability delays crack propagation, and the micro-lubrication effect reduces the friction coefficient, significantly improving the wear resistance and tensile resistance of the fiber;

[0161] By comparing the test data of color difference grades, it can be found that the fastness grade of the colored polyethylene fiber prepared in Example 12 is significantly better than that of the colored polyethylene fibers prepared in Comparative Example 1 and Comparative Example 3. This shows that by introducing the antibacterial brightening agent structure into the composite polyethylene and at the same time introducing the silver-loaded titanium dioxide structure into the antibacterial masterbatch, the antibacterial brightening agent absorbs ultraviolet light and releases visible blue light, and the silver-loaded titanium dioxide scatters and reflects light. The two cooperate synergistically to make the blue tone more saturated and bright, and significantly improve the coloring effect of pigment blue by enhancing the color saturation of the colored fiber. Moreover, the positive charges on the quaternary ammonium salt and quaternary phosphonium salt structures of the antibacterial brightening agent can adsorb pigment molecules through electrostatic attraction, making them more stably attached to polyethylene, increasing the deposition amount of pigments on the material surface, and thus improving the depth and uniformity of coloring;

[0162] It can be found by comparing the test data of color fastness and bactericidal performance that the antibacterial brightening agent depends on the positively charged cationic part in its molecular structure through the internal composite quaternary ammonium salt and quaternary phosphonium salt structures, interacts with the negatively charged cell membrane of bacteria, the cationic head binds to the cell membrane to extract lipids or moisture on the membrane, and the hydrophobic tail embeds into the membrane, resulting in the rupture and leakage of the cell membrane, and penetrates into the cell interior, interfering with enzyme activity and DNA replication, preventing the growth of microorganisms, causing bacteria to die quickly. At the same time, through the broad-spectrum antibacterial property of silver ions in silver-loaded titanium dioxide and the photocatalytic ability of titanium dioxide, silver ions can destroy the bacterial cell wall, inhibit the activity of metabolic enzymes and interfere with DNA replication, while titanium dioxide sterilizes by generating reactive oxygen species under ultraviolet light irradiation. The two work together to achieve all-weather sterilization, while improving the stability and sterilization efficiency of the material. The antibacterial brightening agent and silver-loaded titanium dioxide greatly improve the bactericidal performance of the material through synergistic cooperation, and introduce reduction of the degradation of dyes by microorganisms and improvement of the adhesion of dyes to fibers, thus significantly improving the color fastness of the material;

[0163] In summary, it is by preparing an antibacterial color masterbatch of an antibacterial brightening agent with quaternary ammonium salt and quaternary phosphonium salt structures and silver-loaded titanium dioxide. Among them, the double bond structure of the antibacterial brightening agent and the silver-loaded titanium dioxide cooperate synergistically to improve the wear resistance of the material. The antibacterial brightening agent and silver-loaded titanium dioxide improve the coloring uniformity of the fiber by absorbing or reflecting natural light, and significantly reduce the degradation of dyes by microorganisms through composite bactericidal action, thereby improving the color fastness grade of the fiber.

[0164] Obviously, according to the content of this specification, many modifications and changes can be made. This specification selects and specifically describes these embodiments to better explain the principle and practical application of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A colored polyethylene fiber, characterized in that: The raw material composition includes the following parts by weight: 80-100 parts of composite polyethylene, 5-8 parts of antibacterial masterbatch, 1-2 parts of antioxidant, 1-2 parts of ultraviolet absorber, 2-3 parts of lubricant and 1-2 parts of toughening agent; The preparation method of the composite polyethylene is as follows: azobisisobutyronitrile and o-xylene are placed in a high-pressure reactor, ethylene is introduced, the temperature of the high-pressure reactor is increased to 160-180°C, the pressure is increased to 15-18MPa, constant temperature and pressure polymerization is performed for 40-60 minutes, and then the pressure is released, an antibacterial whitening agent is added to the reactor, the reaction is kept warm for 30-40 minutes, and then post-processing is performed to obtain the composite polyethylene.

2. A colored polyethylene fiber according to claim 1, characterized in that: The dosage ratio of azobisisobutyronitrile, o-xylene, ethylene and antibacterial brightener is 0.6-0.8g:30-40mL:12-15g:4-5g.

3. A colored polyethylene fiber according to claim 1, characterized in that: The preparation method of the antibacterial whitening agent comprises the following steps: A1. Add the hybrid whitening agent, diphenylphosphine, chloroplatinic acid and dimethyl sulfoxide into a reaction kettle, raise the temperature of the reaction kettle to 40-50° C., and keep the temperature for 1-2 hours to obtain an antibacterial whitening agent precursor; A2. Add the antibacterial whitening agent precursor, allyl chloride and N,N-dimethylformamide into a reaction kettle, raise the temperature of the reaction kettle to 40-60°C, keep warm and stir for 1-2 hours to obtain the antibacterial whitening agent.

4. A colored polyethylene fiber according to claim 1, characterized in that: In step A1, the usage ratio of the hybrid whitening agent, diphenylphosphine, chloroplatinic acid and dimethyl sulfoxide is 4-5g:1-2g:0.3-0.5g:20-25mL; in step A2, the usage ratio of the antibacterial whitening agent precursor, allyl chloride and N,N-dimethylformamide is 8-9g:2-3g:30-35mL.

5. A colored polyethylene fiber according to claim 3, characterized in that: The preparation method of the hybrid whitening agent comprises the following steps: B1. Add 4,4'-bis[2-(o-cyanophenyl)vinyl]benzene, n-propylamine, samarium diiodide and toluene into a reaction kettle, raise the temperature of the reaction kettle to 40-50°C, keep the temperature for 1-2h, and post-treat to obtain a modified brightener; B2. Add the modified brightener, 4-(dimethylamino)-n-butyraldehyde, aluminum chloride and N,N-dimethylformamide into the reactor, increase the temperature of the reactor to 100-120°C, keep the reaction warm for 1-2 hours, and post-treat to obtain the hybrid brightener.

6. A colored polyethylene fiber according to claim 5, characterized in that: In step B1, the amount ratio of 4,4'-bis[2-(o-cyanophenyl)vinyl]benzene, n-propylamine, samarium diiodide and toluene is 5-6g:2-3g:0.3-0.5g:25-30mL; in step B2, the amount ratio of modified brightener, 4-(dimethylamino)butyraldehyde, aluminum chloride and N,N-dimethylformamide is 8-10g:1-2g:0.2-0.3g:40-45mL.

7. A colored polyethylene fiber according to claim 1, characterized in that: The preparation method of the antibacterial masterbatch comprises the following steps: C1. Add rutile titanium dioxide, 3-aminopropyltriethoxysilane, deionized water and sodium hydroxide powder into a reactor and stir. The temperature of the reactor is raised to 40-60° C. and stirred for 20-40 minutes. Post-process to obtain modified titanium dioxide. C2, adding modified titanium dioxide, silver nitrate solution and polyvinyl pyrrolidone into a reactor, raising the temperature of the reactor to 40-60°C, stirring for 10-15 minutes, adding sodium borohydride into the reactor, and reacting for 30-40 minutes to obtain silver-loaded titanium dioxide; C3, adding pigment blue BO, silver-loaded titanium dioxide, polyethylene resin, polyethylene wax and calcium stearate into a twin-screw extruder, and melt-extruded to obtain an antibacterial masterbatch precursor; C4. Use a pelletizer to cut the antibacterial masterbatch precursor into uniform particles, and pass them through an 8-16 mesh sieve to obtain the antibacterial masterbatch.

8. A colored polyethylene fiber according to claim 5, characterized in that: In step C1, the amount ratio of rutile titanium dioxide, 3-aminopropyltriethoxysilane, deionized water and sodium hydroxide powder is 8-10g:1-2g:20-30mL:0.5-0.8g; in step C2, the amount ratio of modified titanium dioxide, silver nitrate solution, polyvinyl pyrrolidone and sodium borohydride is 5-6g:10-15mL:0.5-0.8g:1-2g, and the concentration of silver nitrate solution is 0.1-0.2mol / L; in step C3, the amount ratio of pigment blue BO, silver-loaded titanium dioxide, polyethylene resin, polyethylene wax and calcium stearate is 40-50g:10-15g:30-40g:4-6g:1-2g.

9. The method for preparing a colored polyethylene fiber according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1, adding composite polyethylene, antibacterial masterbatch, antioxidant, ultraviolet absorber, lubricant and toughening agent into a twin-screw extruder for melt extrusion to obtain molten polyethylene; S2. The molten polyethylene is extruded through a spinneret and transferred to a side-blowing chamber, and then solidified by air cooling to obtain colored polyethylene fibers.

10. The method for preparing a colored polyethylene fiber according to claim 9, characterized in that: In step S2, the holes of the spinneret are circular, the mesh number is 32-64, the pore size is 0.07-0.09 mm, and the spinning pressure is 80-150 bar; the cold wind is air, the relative humidity is 30-50%, the temperature is 20-30°C, and the flow rate is maintained at 5-10 m / s.

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