Antibacterial master batch for melt spinning spandex and preparation method of antibacterial master batch

Abstract

The invention provides an antibacterial master batch for melt spinning spandex and a preparation method thereof.The antibacterial master batch comprises spandex resin slices, a long-carbon-chain alkyl glycidyl ether modified guanidine salt polymer anti-harmful-microorganism material, a main antioxidant, an auxiliary antioxidant, a heat stabilizer, an anti-hydrolysis agent, a lubricant and a dispersing agent. Adding the mixture into a double-screw extruder; and under the protection of inert gas, carrying out melt blending on the blended materials through a twin-screw extruder, and granulating to obtain the antibacterial master batch for melt-spinning spandex. The antibacterial master batch for melt-spun spandex is applied to antibacterial modification of melt-spun spandex fibers, the addition amount of the antibacterial master batch is 2-10% of the mass of a melt-spun spandex slice base material, and the prepared antibacterial modified melt-spun spandex fibers have the antibacterial properties of durability, high efficiency, broad spectrum, washing resistance, dissolution resistance and the like.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials, specifically relating to an antibacterial masterbatch for melt-spun spandex and its preparation method. Background Technology

[0002] Spandex is the trade name for polyurethane elastomer elastic fiber in China; its international trade name is "Spandex". Due to its excellent elasticity, high strength, and good chemical resistance, spandex can be used to make elastic woven fabrics or textiles, such as various underwear, skiwear, sportswear, swimwear, spacesuits, elastic bandages, compression socks, car seat belts, and industrial elastic webbing. Spandex spinning methods include solution dry spinning, solution wet spinning, chemical reaction spinning, and melt spinning (abbreviated as: melt spinning). Currently, the main manufacturing processes for spandex include: 1. Solution dry spinning: The spandex polymer is dissolved in a suitable solvent to prepare a spinning solution with a certain viscosity, which is then extruded through a spinneret to form a fine stream. Under the action of hot air flow, the solvent evaporates rapidly, and the polymer stream solidifies to form fibers. Solution dry spinning is currently the mainstream production process for spandex, but this method requires large equipment investment, has a complex production process, high production costs, and poses a certain environmental pollution risk. 2. Solution wet spinning: The spandex polymer is dissolved in a solvent to make a spinning solution, which is then extruded through a spinneret and enters a coagulation bath. In the coagulation bath, the solvent and coagulant exchange, causing the polymer stream to solidify and form fibers. However, this method has low production efficiency, difficult solvent recovery, and causes some environmental pollution. 3. Chemical reaction spinning: Diisocyanate containing isocyanate groups is polymerized with raw materials such as polyether or polyester polyol containing hydroxyl groups under certain conditions, and extruded through spinnerets to form fibers during the reaction. However, this method has high requirements for raw materials and is difficult to control during the production process. 4. Melt spinning: Spandex polymer is heated above its melting point to make it molten, and then extruded through spinnerets and cooled and solidified in air to form fibers. This process has simple equipment, a short process flow, does not use solvents during production, and does not pollute the environment. It is a relatively environmentally friendly spinning process with low production costs. It is the most economical, most promising, and most competitive technology, known internationally as green spandex, and its development prospects are widely regarded as promising.

[0003] Spandex is commonly used in the manufacture of underwear, sportswear, and medical supplies—items that come into close contact with the human body. Without antibacterial modification, spandex easily becomes a breeding ground for microorganisms after absorbing sweat. The metabolic byproducts of these microorganisms produce unpleasant odors, affecting wearing comfort. Antibacterial modification reduces odor production, keeping clothing fresh even after prolonged wear or heavy sweating, thus improving wearer comfort and extending the garment's lifespan. Microbial growth on spandex fibers not only produces odors but can also cause health problems such as skin allergies and infections. Antibacterial modification effectively inhibits the growth and reproduction of bacteria, fungi, and other microorganisms, reducing the potential threat to human health and providing a more hygienic and safer environment for wearers.

[0004] Currently, the main manufacturing processes for antibacterial melt-spun spandex include (1) blending spinning: antibacterial masterbatch (or antibacterial agent) is blended with spandex chips before spinning, and then antibacterial spandex is produced by melt spinning process; (2) finishing process: antibacterial agent is attached to the fiber surface or introduced into the fiber interior by finishing ordinary spandex fiber, so that the fiber has antibacterial properties; the durability and longevity of antibacterial properties of finishing process are not as good as those of blending spinning process. The types of antibacterial agents that can be used to prepare antibacterial melt-spun spandex by blending spinning process are mainly divided into inorganic and organic types. Inorganic antibacterial agents mainly include metals and metal oxides. Inorganic metal antibacterial agents are mainly produced by introducing metal ions such as silver, copper, and zinc onto inorganic carriers such as phosphates and silicates. Inorganic metal oxide antibacterial agents mainly include titanium oxide, zinc oxide, cuprous oxide, etc., and generally use ceramics as carriers. The main advantage of inorganic antibacterial agents is their good heat resistance, but their disadvantages are high price, slow antibacterial effect, and easy aggregation in the matrix resin. Among them, silver-based substances have the strongest bactericidal ability, but there are problems such as silver ions being prone to discoloration and having slight toxicity. There is considerable controversy in Europe and the United States regarding the safety of silver ion antibacterial products. Organic antibacterial agents mainly include quaternary ammonium salts, quaternary phosphate salts, phenols, pyridines, alcohols, aldehydes, guanidines, and imidazoles. Organic antibacterial agents have high bactericidal efficiency and require less addition, but generally have disadvantages such as low heat resistance and easy precipitation. Among them, antibacterial agents containing guanidine salt polymers are considered to have great development potential. Guanidine salt polymers are cationic polyelectrolytes with guanidine salt groups. They mainly inhibit the action of harmful microbial cell lysis enzymes by forming electrostatic adsorption between the cations in the molecule and the anionic sites on the surface of bacterial cells, thereby deforming the cell surface structure and destroying the cell membrane, thus achieving the effect of inhibiting and disinfecting microorganisms. Guanidine salt polymers have the advantages of good water solubility, photothermal stability, high efficiency and broad spectrum of antibacterial properties, safety, low toxicity, non-irritation, no bacterial resistance, non-volatile, free of heavy metals and phenols, non-corrosive to various treated surfaces, and environmental friendliness. They have been widely used in medical disinfection, food and other daily necessities sterilization and disinfection. Since the guanidine group is a hydrophilic group, most guanidine salt polymers are highly water-soluble. Currently, they are mainly used in the form of aqueous solutions of guanidine salt polymers for surface disinfection of products and post-antibacterial finishing of textiles. However, when guanidine salt polymers are blended and modified with plastics or rubber, the products will gradually lose their antibacterial properties due to their poor water resistance because of their water solubility.

[0005] Therefore, how to improve the water resistance of polymer products containing guanidine salt polymers while maintaining the advantages of guanidine salt polymers in resisting harmful microorganisms is a topic worthy of research. Thus, it is necessary to develop a melt-spun spandex antibacterial masterbatch based on guanidine salt polymers that has high antibacterial efficiency, is resistant to leaching, has a long-lasting antibacterial effect, is safe, and has broad market prospects. Summary of the Invention

[0006] To address the problems existing in the prior art, the present invention provides an antibacterial masterbatch for melt-spun spandex and its preparation method. This antibacterial masterbatch for melt-spun spandex is used to manufacture spandex fiber products with antibacterial functions. The addition amount is 2% to 10% of the melt-spun fiber-grade spandex chip base material. The prepared antibacterial melt-spun spandex fiber products have excellent properties such as antibacterial properties, water resistance, long-lasting antibacterial effect, and safety.

[0007] The purpose of this invention is to provide an antibacterial masterbatch for melt-spun spandex, comprising the following components in parts by weight: 100 portions of spandex resin chips; 10-30 parts of long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material; 0.2~1.0 parts of the main antioxidant; 0.2-1.0 parts of auxiliary antioxidant; Heat stabilizer 0.2~1.5 parts; Anti-hydrolysis agent 0.2~5.0 parts; Lubricant 0.2~1.0 parts; Dispersant 0.2~5.0 parts.

[0008] The above-mentioned long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material includes the following components in the following ratio: the mass ratio of long-chain glycidyl ether to guanidine salt polymer is 1:0.5-2.

[0009] Preferably, the long-chain alkyl glycidyl ethers include at least one of C12-14-alkyl glycidyl ether, C16-alkyl glycidyl ether, and C18-alkyl glycidyl ether.

[0010] The guanidine salt polymers include at least one of polyhexamethylene guanidine hydrochloride, polyhexamethylene biguanidine hydrochloride, polyhexamethylene guanidine propionate, polyhexamethylene biguanidine propionate, polyhexamethylene guanidine nitrate, polyhexamethylene biguanidine nitrate, polyhexamethylene guanidine phosphate, polyhexamethylene biguanidine phosphate, polyhexamethylene guanidine carbonate, and polyhexamethylene biguanidine carbonate.

[0011] A method for preparing a long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material includes the following steps: Step (1): Under the protection of an inert gas, the guanidine salt polymer and anhydrous dimethylformamide (DMF) are added to the ultrasonic reactor and mixed to prepare a guanidine salt polymer solution with a mass concentration of 5% to 10%. Triethylamine is slowly added dropwise to the ultrasonic reactor to adjust the pH value of the guanidine salt polymer solution to 8.0 to 9.5. After stirring at room temperature for 1 to 2 hours, 2,4,6-tris(dimethylaminomethyl)phenol and butylhydroxytoluene are added to the reaction system. Step (2): Mix long-chain alkyl glycidyl ether with anhydrous dimethylformamide to prepare a long-chain alkyl glycidyl ether solution with a mass concentration of 20%~40%, and preheat it to 50~60℃. Then slowly add it dropwise into the ultrasonic reactor of step (1). During the dropwise addition, the ultrasonic generator of the ultrasonic reactor is started at the same time. After the dropwise addition is completed, under the protection of inert gas, the temperature is raised to 50℃~60℃ and the reaction is continuously stirred for 4~16 hours. Step (3): After the reaction in step (2) is completed, the reaction system is cooled to room temperature, a small amount of glacial acetic acid is added to adjust the pH value to neutral, the reaction solution is slowly poured into 5 times the volume of cold methanol, and the product is stirred vigorously to precipitate as a white flocculent precipitate. The product is then filtered using a Buchner funnel and the precipitate is collected. The precipitate is dispersed in a 1:1 mass ratio acetone / ethanol mixture and ultrasonically washed for 10 minutes. This is repeated 3 times until the washing solution is transparent. The washed precipitate is placed in a vacuum drying oven and dried at 50°C for 12 hours to obtain a white to light yellow long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material solid powder product.

[0012] Preferably, in the above preparation method, 2,4,6-tris(dimethylaminomethyl)phenol is selected from DMP-30, and its amount is 0.1% to 3% of the mass of long-chain alkyl glycidyl ether; butyl hydroxytoluene is selected from BHT, and its amount is 0.1% to 0.3% of the mass of long-chain alkyl glycidyl ether.

[0013] This invention relates to the preparation of a long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material. Using DMF as a solvent and a system pH of 8.0–9.5, and with DMP-30 as a catalyst, the epoxy groups of the long-chain alkyl glycidyl ether undergo a grafting reaction with the secondary amine groups of the guanidine salt polymer backbone, and also react with the primary amine groups at the chain ends of the guanidine salt polymer. This introduces the hydrophobic long-chain alkyl group into the water-soluble guanidine salt polymer molecular chain, thus hydrophobically modifying the water-soluble guanidine salt polymer and preparing the long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material.

[0014] Further, the primary antioxidant is selected from at least one of antioxidant 245, antioxidant 1010, antioxidant 1076, antioxidant 1098, antioxidant 1135, antioxidant 3114, antioxidant 1024, and antioxidant 1790; the secondary antioxidant is selected from at least one of antioxidant 168, tetraphenyl dipropylene glycol diphosphite, DLTDP, and DSTDP; the heat stabilizer is selected from at least one of calcium stearate, zinc stearate, and dibutyltin dilaurate; the anti-hydrolysis agent is carbodiimide and its derivatives; the lubricant is selected from at least one of stearate, silicone oil, polyethylene wax, and oxidized polyethylene wax; and the dispersant is selected from at least one of ethylene-acrylic acid copolymer and ethylene bis-stearamide.

[0015] The present invention also aims to provide a method for preparing antibacterial masterbatch for melt-spun spandex. This method employs a parallel-co-rotating twin-screw extruder with nitrogen protection during the production process. The extruder consists of thirteen sections. The method for preparing the antibacterial masterbatch includes the following steps: pre-drying spandex resin chips at 110°C under vacuum for 8 hours, resulting in a moisture content of less than 0.01%; drying a long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material, a primary antioxidant, a secondary antioxidant, a heat stabilizer, a lubricant, and a dispersant at 105°C for 2-3 hours; and then combining the dried spandex resin chips with the long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material and the primary antioxidant. After the auxiliary antioxidants, heat stabilizers, lubricants, and dispersants are mixed evenly in a certain proportion, they are added to the hopper of a twin-screw extruder. The hopper is protected by nitrogen gas. The temperature of each barrel of the twin-screw extruder is set to 140~220℃, and the screw speed is 200~350rpm. Nitrogen gas is introduced through the nitrogen gas inlet in the center of the top of the barrel from the 2nd to 4th, 6th to 8th, and 10th to 11th barrel sections from the feed inlet for protection. Vacuum degassing is performed by opening vacuum exhaust chambers on the 5th, 9th, and 12th barrel sections from the feed inlet. After the blended material is melt-blended by the twin-screw extruder, it is granulated by an air-cooled die pelletizing device. Nitrogen air cooling is used to protect the die head, and antibacterial masterbatch for melt-spun spandex is obtained.

[0016] The present invention also aims to provide a twin-screw extruder for preparing the above-mentioned antibacterial masterbatch, which is a parallel co-rotating meshing twin-screw extruder. The extruder barrel is divided into several sections, one of which or several consecutive sections form several groups. The extruder is equipped with an inert gas protection system, including an inert gas inlet pipe. The barrel is sequentially provided with an inert gas inlet component and a vacuum regulating gas outlet component. The cover plate of the extruder hopper is provided with an inert gas inlet component and a gas outlet component. The inert gas inlet component is connected to the inert gas inlet pipe. An inert gas air cooling component is also provided at the die of the extruder head.

[0017] The inert gas inlet assembly includes a valve, a pressure regulating assembly, and a flow regulating assembly.

[0018] In use, inert gas enters the cylinder through the inert gas inlet component and is discharged through the gas outlet component. The blended material is melt-blended and granulated after being processed by a twin-screw extruder. Inert gas protection is achieved at the die head through an inert gas air-cooling component, thus realizing inert gas protection for the material during the production process.

[0019] The present invention also aims to provide a melt-spun spandex, wherein the amount of antibacterial masterbatch added to the melt-spun spandex is 2 to 10% of the mass of the melt-spun spandex chip base material.

[0020] Compared with the prior art, the present invention has the following advantages: (1) The antibacterial masterbatch for melt-spun spandex of this application has good spinnability, good antibacterial efficiency and long-lasting effect, water resistance, safety and silver-free properties. It can be used to prepare melt-spun spandex products with antibacterial function. The addition amount is 2~10% of the melt-spun spandex chip base material. The prepared antibacterial melt-spun spandex products have the advantages of safety, broad spectrum, water resistance, and long-lasting antibacterial effect, and have broad market prospects and commercial value. (2) The preparation method of the antibacterial masterbatch for melt-spun spandex of this application has a simple process flow and is easy to prepare, which can meet the needs of mass production. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] This invention provides an antibacterial masterbatch for melt-spun spandex, which is used to manufacture spandex fiber products with antibacterial function. The amount added is 2% to 10% of the mass of melt-spun fiber-grade spandex chip base material. The prepared antibacterial melt-spun spandex fiber products have excellent properties such as antibacterial properties, water resistance, long-lasting antibacterial effect and safety.

[0023] The present invention relates to an antibacterial masterbatch for melt-spun spandex, comprising the following components in parts by weight: 100 portions of spandex resin chips; 10-30 parts of long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material; 0.2~1.0 parts of the main antioxidant; 0.2-1.0 parts of auxiliary antioxidant; Heat stabilizer 0.2~1.5 parts; Anti-hydrolysis agent 0.2~5.0 parts; Lubricant 0.2~1.0 parts; Dispersant 0.2~5.0 parts.

[0024] The long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material is prepared by reacting the epoxy groups of the long-chain alkyl glycidyl ether with the guanidine salt polymer in a mass ratio of 1:2 to 2:1. The preparation reaction uses DMF as solvent, triethylamine to adjust the pH of the system to 8.0 to 9.5, and DMP-30 as catalyst to graft the epoxy groups of the long-chain alkyl glycidyl ether onto the secondary amine groups of the guanidine salt polymer backbone, and also onto the primary amine groups at the chain ends of the guanidine salt polymer. This introduces the hydrophobic long-chain alkyl group into the water-soluble guanidine salt polymer molecular chain, thus hydrophobically modifying the water-soluble guanidine salt polymer and preparing the long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material.

[0025] Example 1 1. Prepare powder #1 of long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material for later use: (1) Add 1000g of polyhexamethylene guanidine hydrochloride and 9000g of anhydrous dimethylformamide into an ultrasonic reactor (ultrasonic frequency 20kHz, power 100w~1000w adjustable), replace the reactor with argon gas for protection, and stir evenly to prepare a 10% polyhexamethylene guanidine hydrochloride solution. (2) Slowly add triethylamine to the ultrasonic reactor. When the pH of the polyhexamethylene guanidine hydrochloride solution in the reactor reaches 9.0, stop adding triethylamine. After stirring at room temperature for 2 hours, add 20g DMP-30 and 3g BHT to the reactor and continue stirring at room temperature for 1 hour until homogeneous. (3) Prepare a 30% CHC Glycidyl Ether solution by mixing 1000g of CHC Glycidyl Ether with 3000g of anhydrous DMF, and preheat it to 50°C. Then slowly add it dropwise into the ultrasonic reactor mentioned above, while starting the ultrasonic generator and adjusting the power to 150w. (4) After the hexadecyl glycidyl ether solution prepared in step (3) is added dropwise, the temperature is raised to 55°C under argon protection and the reaction is carried out by continuous stirring for 12 hours. (5) After the reaction is complete, stop the ultrasonic generator and heating, continue stirring, and after the temperature of the reaction vessel system is reduced to room temperature, slowly add glacial acetic acid to adjust the pH value of the system to neutral. (6) Slowly pour the reaction liquid in the reactor into 5 times the volume of cold methanol, stir vigorously to precipitate flocculent precipitate, and then filter it with a Buchner funnel to collect the precipitate. (7) Disperse the precipitate collected in step (6) in a mixture of acetone / ethanol (mass ratio 1:1), and ultrasonically wash for 10 minutes. Repeat three times until the washing solution is clear. (8) Place the precipitate washed in step (7) in a vacuum drying oven and dry it at 50°C for 12 hours to obtain light yellow long carbon chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material powder 1#, which is used for further preparation of antibacterial masterbatch for melt spinning spandex.

[0026] 2. Preparation of antibacterial masterbatch (1) 25.0g of polycarbodiimide, 1910.0g of fiber-grade spandex resin chips (Elastollan® 1185A) pre-dried at 110°C for 8 hours, and other additives pre-dried at 105°C for 3 hours, including 500.0g of long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material powder 1#, 8.0g of antioxidant 1010, 8.0g of antioxidant 168, 10.0g of calcium stearate, 9.0g of polyethylene wax, and 30.0g of ethylene bis-stearamide, are thoroughly mixed in a mixer.

[0027] (2) The equipment for preparing antibacterial masterbatch is a parallel co-rotating meshing twin-screw extruder with a length-to-diameter ratio of 56. Multiple barrel sections are installed on the extruder body, and the hopper is installed on the extruder body and positioned close to the barrel. The barrel has thirteen sections, with the first section closest to the hopper. The extruder is equipped with a nitrogen protection system, including a nitrogen inlet pipe and a gas outlet pipe. Vacuum venting structures are located on the barrel sections at positions 5, 9, and 12. Nitrogen inlet components are located on the barrel sections at positions 2-4, 6-8, and 10-11. These components include a first valve, a pressure regulating component, and a flow regulating component. The hopper has a cover plate with a nitrogen inlet component and a nitrogen outlet component. A nitrogen air-cooling component is located at the die head of the extruder. The nitrogen inlet component is connected to the nitrogen inlet pipe, and the nitrogen outlet component is connected to the nitrogen outlet pipe. This achieves nitrogen protection of the material during the production process. The preparation device of this invention has a simple structure and reasonable design, which facilitates vacuum adjustment and inert gas protection during the preparation process, and has good application effect.

[0028] Add the mixture obtained in step (1) into the hopper of a twin-screw extruder protected by nitrogen, cover the hopper, open the stainless steel pipe valve for nitrogen inlet on the extruder head cover, set the barrel temperature of the parallel co-rotating twin-screw extruder to 140℃~220℃ and the screw speed to 300rpm, open the stainless steel gas valves of the nitrogen inlet at the center of the top of the barrels from the 2nd to 4th, 6th to 8th and 10th to 11th sections from the feed inlet, and introduce nitrogen for protection, and start the vacuum system, opening vacuum exhaust chambers on the 5th, 9th and 12th sections from the feed inlet for vacuum degassing. After the blended material is melt-blended by the twin-screw extruder, it is granulated by the air-cooled die-cutting device. Nitrogen air cooling is used to protect the die head, and antibacterial masterbatch 1# for melt-spun spandex is obtained.

[0029] 3. Preparation of melt-spun spandex fiber samples Weigh 75g of the antibacterial masterbatch 1# for melt-spun spandex obtained in step 2 and 4925g of fiber-grade melt-spun spandex resin chips (Elastollan® 1185A). After thoroughly mixing in a mixer, the mixture is vacuum dried at 110℃ for 8 hours and then added to the hopper of a screw extruder. The material is heated, melted, extruded, and then conveyed to a spinning device for spinning, cooling, drawing, oiling, and winding. The spinning process is as follows: screw speed 65rpm, spinning temperature 150℃~230℃, and spinning speed 200m / min. Antibacterial melt-spun spandex fiber test samples are prepared and their antibacterial properties are tested.

[0030] The 7.5g of antibacterial masterbatch 1# for melt-spun spandex and 492.5g of fiber-grade melt-spun spandex resin chips (Elastollan® 1185A) prepared in this embodiment were thoroughly mixed in a mixer. Then, a 50mm*50mm*3mm sample was injection molded at an injection temperature of 220℃ using an injection molding machine. The sample was then hot-pressed at 220℃ to a sheet with a thickness of about 2mm. Finally, the sample was cut into antibacterial spandex resin discs with a diameter of 5mm for testing the antibacterial substance leaching resistance.

[0031] Example 2 150g of antibacterial masterbatch 1# for melt-spun spandex prepared in Example 1 and 4850g of fiber-grade melt-spun spandex resin chips (Elastollan® 1185A) were thoroughly mixed in a mixer and then vacuum dried at 110°C for 8 hours. Antibacterial melt-spun spandex fiber test samples were prepared using the same sample preparation method as in Example 1, and their antibacterial properties were tested.

[0032] 15g of the antibacterial masterbatch 1# for melt-spun spandex prepared in Example 1 and 485g of fiber-grade melt-spun spandex resin chips (Elastollan® 1185A) were thoroughly mixed in a mixer. Then, a 50mm*50mm*3mm sample was injection molded at 220℃ using an injection molding machine. The sample was then hot-pressed at 220℃ to a thickness of about 2mm. Finally, the sample was cut into 5mm diameter antibacterial spandex resin disc test samples for antibacterial substance leaching resistance testing.

[0033] Comparative Example 1 Antibacterial masterbatch was prepared by replacing 500.0g of long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material powder 1# in Example 1 with 500g of polyhexamethylene guanidine hydrochloride. The rest was the same as in Example 1. The antibacterial melt-spun spandex test sample of Comparative Example 1 was prepared and tested for antibacterial performance and anti-dissolution properties of antibacterial substances.

[0034] Comparative Example 2 Antibacterial masterbatch was prepared by replacing 500.0g of long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material powder 1# in Example 1 with 500g of polyhexamethylene guanidine hydrochloride. The rest was the same as in Example 2. The antibacterial melt-spun spandex test sample of Comparative Example 2 was prepared and tested for antibacterial performance and anti-dissolution properties of antibacterial substances.

[0035] The test standards for Examples 1-2 and Comparative Examples 1-2 are as follows: 1. Antibacterial Test Standard: The antibacterial melt-spun spandex fiber test sample was placed in a polyester washing bag and washed 50 times according to the AAA grade test sample requirements of FZ / T73023-2006 "Antibacterial Knitted Fabrics". The antibacterial performance was then tested using the shaking method in Appendix D8. The tested bacteria were: Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 6538, and Candida albicans ATCC10231. After 50 washes, the test sample met the standard values ​​for 3A grade antibacterial knitted fabrics: the inhibition rates of Escherichia coli, Staphylococcus aureus, and Candida albicans were ≥70%, ≥80%, and ≥60%, respectively. 2. Antimicrobial substance leaching resistance test standard (inhibition ring width): Injection-molded round samples of spandex chips with a diameter of 5mm are tested according to GB 21551.1-2024 "Special requirements for antimicrobial materials with antimicrobial, bactericidal and purifying functions for household and similar electrical appliances" to determine the width of the inhibition ring. The inhibition ring width D≤5mm.

[0036] The test results are shown in the table below. As can be seen from the test results in the table, Examples 1 and 2 are melt-spun spandex fiber samples with the addition of the antibacterial masterbatch for melt-spun spandex of the present invention. After washing 50 times with water according to the AAA grade test sample requirements of FZ / T 73023-2006 "Antibacterial Knitted Fabrics", the antibacterial rates against Escherichia coli, Staphylococcus aureus and Candida albicans all greatly exceeded the standard index requirements, demonstrating good antibacterial performance. Furthermore, the antibacterial resin used to prepare the corresponding antibacterial melt-spun spandex fiber samples was injection molded and then hot-pressed into antibacterial spandex resin sheets, and the width of the inhibition ring was 0 mm. This further illustrates that the antibacterial agent of the antibacterial masterbatch for melt-spun spandex prepared according to the present invention has excellent anti-dissolution properties. In contrast, Comparative Examples 1 and 2, which contain highly water-soluble polyhexamethylene guanidine hydrochloride, showed a large loss of antibacterial active polyhexamethylene guanidine hydrochloride after washing 50 times, resulting in a very low antibacterial rate, which was far below the standard antibacterial index requirements, and thus did not have an effective antibacterial effect.

[0037] Therefore, as can be seen from the test results in the table, the antibacterial masterbatch for melt-spun spandex of the present invention has good antibacterial properties. It has high antibacterial efficiency, is resistant to water leaching, and is washable. It is also safe and silver-free. It can be used to prepare melt-spun spandex fiber products with antibacterial function. The addition amount is 2-10% of the fiber-grade melt-spun spandex chip resin matrix. The antibacterial grade of the prepared antibacterial melt-spun spandex fiber products even reaches the AAA level requirement, which can better meet the application needs. It also has the advantages of safety, broad spectrum, resistance to water leaching, and long-lasting antibacterial effect, and has broad market prospects and commercial value.

[0038] The above embodiments are for illustrative purposes only and are not intended to limit the invention. Those skilled in the art can make various changes or modifications without departing from the spirit and scope of the invention. Therefore, all equivalent technical solutions should also fall within the scope of the invention and should be defined by the claims.

Claims

1. An antibacterial masterbatch for melt-spun spandex, characterized in that, Includes the following components in parts by mass, 100 portions of spandex resin chips; 10-30 parts of long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material; 0.2~1.0 parts of the main antioxidant; 0.2-1.0 parts of auxiliary antioxidant; Heat stabilizer 0.2~1.5 parts; Anti-hydrolysis agent 0.2~5.0 parts; Lubricant 0.2~1.0 parts; Dispersant 0.2~5.0 parts.

2. The antibacterial masterbatch for melt-spun spandex according to claim 1, characterized in that, The long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material comprises the following components in the following ratio: the mass ratio of long-chain glycidyl ether to guanidine salt polymer is 1:0.5-2.

3. The antibacterial masterbatch for melt-spun spandex according to claim 2, characterized in that, The long-chain alkyl glycidyl ether is selected from at least one of C12-14-alkyl glycidyl ether, C16-alkyl glycidyl ether, and C18-alkyl glycidyl ether. The guanidine salt polymer is selected from at least one of polyhexamethylene guanidine hydrochloride, polyhexamethylene biguanidine hydrochloride, polyhexamethylene guanidine propionate, polyhexamethylene biguanidine propionate, polyhexamethylene guanidine nitrate, polyhexamethylene biguanidine nitrate, polyhexamethylene guanidine phosphate, polyhexamethylene biguanidine phosphate, polyhexamethylene guanidine carbonate, and polyhexamethylene biguanidine carbonate.

4. The antibacterial masterbatch for melt-spun spandex according to claim 2, characterized in that, The preparation method of the long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material includes the following steps: Step (1): Under the protection of an inert gas, the guanidine salt polymer and anhydrous dimethylformamide are added to the ultrasonic reactor and mixed to prepare a guanidine salt polymer solution with a mass concentration of 5%~10%. Triethylamine is slowly added dropwise to the ultrasonic reactor to adjust the pH value of the guanidine salt polymer solution to 8.0~9.

5. After stirring at room temperature for 1~2 hours, 2,4,6-tris(dimethylaminomethyl)phenol and butylhydroxytoluene are added to the reaction system. Step (2): Mix long-chain alkyl glycidyl ether with anhydrous dimethylformamide to prepare a long-chain alkyl glycidyl ether solution with a mass concentration of 20%~40%, and preheat it to 50~60℃. Then slowly add it dropwise into the ultrasonic reactor of step (1). During the dropwise addition, the ultrasonic generator of the ultrasonic reactor is started at the same time. After the dropwise addition is completed, under the protection of inert gas, the temperature is raised to 50℃~60℃ and the reaction is continuously stirred for 4~16 hours. Step (3): After the reaction in step (2) is completed, the reaction system is cooled to room temperature, a small amount of glacial acetic acid is added to adjust the pH value to neutral, the reaction solution is slowly poured into 5 times the volume of cold methanol, and the product is stirred vigorously to precipitate as a white flocculent precipitate. The product is then filtered using a Buchner funnel and the precipitate is collected. The precipitate is dispersed in a 1:1 mass ratio acetone / ethanol mixture and ultrasonically washed for 10 minutes. This is repeated 3 times until the washing solution is transparent. The washed precipitate is placed in a vacuum drying oven and dried at 50°C for 12 hours to obtain a white to light yellow long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material solid powder product.

5. The antibacterial masterbatch for melt-spun spandex according to claim 4, characterized in that, The amount of 2,4,6-tris(dimethylaminomethyl)phenol used is 0.1% to 3% of the mass of the long-chain alkyl glycidyl ether; the amount of butyl hydroxytoluene used is 0.1% to 0.3% of the mass of the long-chain alkyl glycidyl ether.

6. The antibacterial masterbatch for melt-spun spandex according to claim 1, characterized in that, The primary antioxidant is selected from at least one of antioxidant 245, antioxidant 1010, antioxidant 1076, antioxidant 1098, antioxidant 1135, antioxidant 3114, antioxidant 1024, and antioxidant 1790. The auxiliary antioxidant is selected from at least one of antioxidant 168, tetraphenyl dipropylene glycol diphosphite, DLTDP, and DSTDP; The heat stabilizer is selected from at least one of calcium stearate, zinc stearate, and dibutyltin dilaurate; The anti-hydrolysis agent is carbodiimide and its derivatives; The lubricant is selected from at least one of stearate, silicone oil, polyethylene wax, and oxidized polyethylene wax; The dispersant is selected from at least one of ethylene-acrylic acid copolymer and ethylene bis-stearamide.

7. The method for preparing antibacterial masterbatch according to any one of claims 1-6, characterized in that, A parallel, co-rotating, meshing twin-screw extruder is used, which provides nitrogen protection for the material during production. This extruder consists of thirteen barrel sections. The preparation method includes the following steps: Spandex resin chips were pre-dried under vacuum at 110°C for 8 hours, resulting in a moisture content of less than 0.01%. Long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material, primary antioxidant, secondary antioxidant, heat stabilizer, lubricant, and dispersant were dried separately at 105°C for 2-3 hours. The dried spandex resin chips were then mixed evenly with the long-chain alkyl glycidyl ether modified guanidine salt polymer antimicrobial material, primary antioxidant, secondary antioxidant, heat stabilizer, lubricant, and dispersant in a specific ratio. This mixture was then added to the hopper of a twin-screw extruder, and nitrogen was introduced into the hopper. For gas protection, the temperature of each barrel of the twin-screw extruder is set to 140~220℃, and the screw speed is 200~350rpm. Nitrogen gas is introduced through the nitrogen gas inlet at the center of the top of the barrel from the 2nd to 4th, 6th to 8th, and 10th to 11th barrel sections from the feed inlet for vacuum degassing. Vacuum exhaust chambers are opened on the 5th, 9th, and 12th barrel sections from the feed inlet for vacuum degassing. After the blended material is melt-blended by the twin-screw extruder, it is granulated by an air-cooled die pelletizing device. Nitrogen air cooling is used to protect the die head, thus producing the antibacterial masterbatch for melt-spun spandex.

8. A melt-spun spandex, characterized in that, The amount of antibacterial masterbatch prepared by the preparation method described in claim 7 is 2-10% of the mass of the melt-spun spandex chip base material.

Images