Antibacterial master batch for nylon 6 fiber and preparation method and application thereof

Abstract

The application relates to an antibacterial master batch for nylon 6 fibers and a preparation method and application thereof, and belongs to the technical field of functional master batch materials.The formula of the antibacterial master batch for nylon 6 fibers is as follows: 77%-89% of spinning-grade nylon 6 chips, 10%-20% of nano-grade antibacterial powder and 1%-3% of composite dispersant powder; the antibacterial master batch for nylon 6 fibers is prepared through the raw material quantitative feeding, melting plasticizing, screw shearing, water cooling granulation, vibration screening and vacuum drying procedures of a parallel co-rotating twin-screw extruding granulator; the antibacterial master batch for nylon 6 fibers prepared by the application has a water content of 300-500ppm, a melt index of 34.2-37.1g / 10min and a relative viscosity of 1.69-2.03, has efficient and stable antibacterial function, can effectively solve the master batch sticking problem and the phenomenon of broken yarns in the spinning process; the antibacterial master batch for nylon 6 fibers can be used for the production of antibacterial nylon 6 civil long filament fibers, and the prepared fibers have excellent spinning performance and outstanding antibacterial performance on escherichia coli and staphylococcus aureus.

Description

Technical Field

[0001] This invention relates to an antibacterial masterbatch for nylon 6 fiber, its preparation method and application, belonging to the field of functional masterbatch material technology. Background Technology

[0002] Nylon 6 civilian filament fiber is one of the main raw materials for textiles and occupies an important position in synthetic fiber products. Fabrics made from it have many advantages such as high strength, abrasion resistance, and low weight, making it one of the most important fiber materials on the market today. However, the nylon industry's product structure is relatively simple, and developing high-performance, multi-functional nylon products remains a pain point and a challenge for the industry's development.

[0003] Antibacterial products are in high demand in the current fiber products market, and achieving both effective antibacterial function and comfortable, durable high-performance fibers remains a key technology that urgently needs development. Currently, antibacterial fibers generally use fibers containing silver-based antibacterial agents; however, the safety of silver-containing antibacterial auxiliaries in textiles used on the human body remains controversial. Copper-based antibacterial agents have better stability, but their antibacterial performance is poor, and the low-carbon and environmentally friendly issues of metal antibacterial agents still need to be addressed.

[0004] In recent years, research has found that photodynamic antibacterial methods, compared with other antibacterial methods, can generate reactive oxygen species that exert antibacterial effects. Antibacterial activity can be effectively imparted to cellulose by chemical modification and alteration of the cellulose backbone. This method exhibits good biocompatibility and stability, without damaging the strength or texture of cellulose. However, no improved techniques for modifying and altering cellulose matrices using photodynamic methods to obtain antibacterial nylon 6 fibers have been reported to date.

[0005] Patent CN104098893A discloses a conductive and antibacterial polyamide 6 / polypropylene composite material and its preparation method. This invention uses silver-zinc-based inorganic antibacterial agents and graphene as additives to prepare polyamide 6 / polypropylene composite materials. However, graphene agglomeration occurs, and nano-silver-zinc-based inorganic antibacterial agents have been banned from use in textiles by countries such as the United States. Patent CN113787786A discloses a luminescent energy storage long-lasting photodynamic antibacterial fabric and its preparation method. It solves the technical problems that microorganisms easily grow and multiply on the surface of fabrics, and that ordinary fabrics loaded with photosensitive antibacterial agents have difficulty producing antibacterial effects in dark room environments. However, this invention is mainly applied to woven cotton fabrics or nonwoven fabric substrates made of polypropylene, and has not yet solved the technical problems of antibacterial properties of nylon 6 masterbatch. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides an antibacterial masterbatch for nylon 6 fibers, its preparation method, and its application. It has a highly efficient and stable antibacterial function, effectively solves the problem of masterbatch sticking to the plate, and reduces the phenomenon of yarn breakage during the spinning process.

[0007] The technical solution of the present invention is as follows:

[0008] One of the objectives of this invention is to provide an antibacterial masterbatch for nylon 6 fibers, comprising the following components by mass fraction: 77%-89% spinning-grade nylon 6 chips, 10%-20% nano-grade antibacterial cellulose powder, and 1%-3% composite dispersant powder.

[0009] Furthermore, the relative viscosity of the spinning-grade nylon 6 chips is 2.47-2.50.

[0010] Furthermore, the nanoscale antibacterial cellulose powder is prepared by photodynamic antibacterial method, which is obtained by covalently binding two functional groups, protoporphyrin IX and quaternary ammonium salt, to the cellulose backbone.

[0011] Furthermore, the method for preparing the nanoscale antibacterial cellulose is as follows:

[0012] (1) Microcrystalline cellulose was added to 1-allyl-3-methylimidazolium chloride, and the mixture was stirred at 80°C to obtain a homogeneous solution;

[0013] (2) In a separate flask, N,N'-carbonyldiimidazole and protoporphyrin IX were added to dimethyl sulfoxide and stirred at 80°C for 15 min to obtain activated protoporphyrin IX; in another flask, N,N'-carbonyldiimidazole and (3-carboxypropyl)trimethylammonium chloride were dissolved in dimethyl sulfoxide and the solution was stirred at 80°C until no gas escaped.

[0014] (3) The two solutions obtained in step (2) are added to the cellulose solution and reacted at 80°C for 20 h to obtain nano-sized antibacterial cellulose.

[0015] Furthermore, in the preparation of nanoscale antibacterial cellulose in step (1), the mass ratio of 1-allyl-3-methylimidazolium chloride to microcrystalline cellulose is 1:0.0252, and in step (2), the mass ratio of dimethyl sulfoxide to N,N'-carbonyldiimidazole to protoporphyrin is 1:7.2:25, and the mass ratio of dimethyl sulfoxide to N,N'-carbonyldiimidazole to (3-carboxypropyl)trimethylammonium chloride is 1:0.24:0.14.

[0016] Furthermore, the composite dispersant powder comprises a polyether ester polymer and an amide dispersant, wherein the mass ratio of the polyether ester polymer to the amide dispersant is 1:1-4.

[0017] Furthermore, the antibacterial masterbatch for nylon 6 fiber has a viscosity of 2.320, a water content of 568.27 ppm, and a weight of 1.525 g / 100 particles.

[0018] The second objective of this invention is to provide a method for preparing antibacterial masterbatch for nylon 6 fibers.

[0019] Furthermore, it includes the following steps:

[0020] S1. Quantitative feeding of raw materials: The main feeding position and the side feeding position are linked to feed the raw materials. The spinning grade nylon 6 chips are added at the main feeding position, and the nano-grade antibacterial cellulose powder and composite dispersant powder are added at the side feeding position.

[0021] S2, Melting and Plasticizing: The raw material in step (1) is melted and plasticized by controlling the temperature of each section of the twin-screw extruder. The temperature of the first section is 210℃; the temperature of the second section is 220℃; the temperature of the third section is 225℃; the temperature of the fourth section is 210-220℃; the temperature of the fifth section is 205-210℃; the temperature of the sixth section is 200-205℃; the temperature of the seventh section is 190-200℃; the temperature of the eighth section is 180-185℃; the temperature of the ninth section is 175-180℃; and the temperature of the die head section is 230-240℃.

[0022] S3, Screw shearing: A 600-mesh filter screen is added to the head of the screw shearing machine to control the overall melting pressure of the head to stabilize at 1.3-1.5MPa, and the plasticized polymer melt is sheared. The main speed of the screw shearing machine is 540-580r / min.

[0023] S4, water-cooled pelletizing: the polymer melt obtained in step (3) is water-cooled and pelletized, wherein the main speed of the pelletizer is 850-1000 r / min;

[0024] S5. Vibration screening: The masterbatch in step (4) is screened by vibration, wherein the screen mesh diameter is 2-8mm;

[0025] S6. Vacuum drying.

[0026] The third objective of this invention is to provide an antibacterial masterbatch for nylon 6 fibers for use in the production of nylon 6 civilian filament fibers.

[0027] Furthermore, the standard fabric sample of Nylon 6 civilian filament fiber has an antibacterial rate of 99.9% against Staphylococcus aureus.

[0028] The beneficial effects of this invention are as follows:

[0029] 1. The present invention discloses a method for preparing nanoscale antibacterial cellulose, which innovatively employs photodynamic antibacterial method to endow cellulose with antibacterial function, and then prepares high-strength antibacterial nylon material through heterogeneous nucleation. The photodynamic antibacterial method utilizes the regularly distributed hydroxyl backbone along the cellulose to covalently bind the functional groups protoporphyrin IX (PpIX) and quaternary ammonium salt (QAS) to the cellulose backbone. Due to the anchoring effect of the cellulose skeleton and the electrostatic repulsion between QAS groups, the quenching effect caused by the aggregation of protoporphyrin IX can be suppressed. Simultaneously, the introduction of the positively charged quaternary ammonium salt functional group also endows the antibacterial cellulose with good water solubility. The resulting antibacterial cellulose can interact with electronegative bacteria, not only giving the prepared cellulose rich in cellulose derivatives and highly efficient and stable antibacterial function, but also facilitating subsequent freeze-drying of the cellulose to produce nanoscale antibacterial cellulose powder, which is then melted with nylon 6 chips and a composite dispersant.

[0030] 2. This invention adds antibacterial cellulose and a composite dispersant to nylon 6 chips. The antibacterial cellulose enables the three components to have high selectivity, compatibility, and stability after melt co-extrusion without damaging the strength or texture of the cellulose. The composite dispersant, composed of polyether ester polymer and amide dispersant, has good thermal stability and long-lasting antistatic effect, protecting the amino acids in collagen peptides from damage during masterbatch preparation. This ensures that the types and quantities of amino acids in the fiber fabric made from the masterbatch remain stable at a high level. The antibacterial nylon 6 fiber masterbatch raw material selected in this invention can exert a synergistic effect, effectively solving the problem of masterbatch sticking to the plate in the later stage and reducing the probability of yarn breakage during spinning.

[0031] 3. The antibacterial nylon 6 fiber masterbatch described in this invention exhibits excellent physical and chemical properties, with a moisture content of 300-500 ppm, a melt index of 34.2-37.1 g / 10 min, and a relative viscosity of 1.69-2.03. Furthermore, the preparation method is simple, low-cost, safe, harmless, and environmentally friendly, offering high economic benefits and suitability for industrial production. The nylon 6 civilian filament fiber prepared from the masterbatch has a stable and efficient antibacterial effect, effectively inhibiting the attachment and growth of Escherichia coli and Staphylococcus aureus, with an antibacterial rate exceeding 99%. In addition, the fiber's spinnability and post-processing properties are greatly improved, exhibiting excellent aging resistance and better mechanical properties. Attached Figure Description

[0032] Figure 1 The antibacterial performance of the antibacterial nylon 6 masterbatch sample prepared in Example 1 of this invention is compared with that of the control group. Detailed Implementation

[0033] The present invention will be further described below with reference to preferred embodiments. The endpoints and any values ​​of the ranges disclosed in the present invention are not limited to the precise ranges or values. These ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed herein.

[0034] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0035] In the quantitative experiments in the following examples, three replicate experiments were set up, and the average value of the results was taken.

[0036] Unless otherwise specified, the experimental methods described in the following examples are conventional methods.

[0037] In this invention, the weight analysis of 100 masterbatches was performed using an electronic balance of model ME104E purchased from Mettler Toledo Instruments (Shanghai) Co., Ltd.

[0038] The moisture content of the masterbatch was analyzed using a Karl 860KFThermoprep sample heating processor purchased from Metrohm China Ltd., Switzerland.

[0039] The melt flow index analysis of the masterbatch was conducted using a ZRZ1452 melt flow rate testing machine purchased from Metersbonwe Industrial Systems (China) Co., Ltd.

[0040] The relative viscosity analysis of the masterbatch was conducted using a PV60AVS600 viscometer purchased from Shanghai Luwen Scientific Instruments Co., Ltd.

[0041] The fiber fineness was tested using a YG086 yarn length measuring machine purchased from Changzhou Bafang Lishi Textile Instrument Co., Ltd.

[0042] The fiber breaking strength was tested using a YG023B fully automatic single yarn strength tester purchased from Changzhou Bafang Lishi Textile Instrument Co., Ltd.

[0043] The fiber breaking elongation was tested using a YG023B fully automatic single yarn strength tester purchased from Changzhou Bafang Lishi Textile Instrument Co., Ltd.

[0044] The fiber evenness was tested using a CFE400C evenness tester purchased from Suzhou Changfeng Instrument Co., Ltd.

[0045] The oil content of the fibers was tested using an MQC model oil analyzer purchased from Shanghai Linwen Instrument Co., Ltd.

[0046] The fiber boiling water shrinkage rate was tested using a YG368 fully automatic shrinkage tester purchased from Changzhou Bafang Lishi Textile Instrument Co., Ltd.

[0047] The fiber network was tested using a standard light source box of model Cac 1200L (YG60) and a water bath, purchased from Changzhou Bafang Lishi Textile Instrument Co., Ltd.

[0048] The hardness of the fiber cake was tested using an HP 5 hardness tester purchased from SCHMIDT, Germany.

[0049] Example 1

[0050] This embodiment provides an antibacterial masterbatch for nylon 6 fibers, with the following formulation by weight percentage: 89% spinning-grade bright nylon 6 chips, 10% nano-grade antibacterial cellulose powder, and 1% composite dispersant powder. Its preparation method includes the following steps:

[0051] (1) 0.126 g of microcrystalline cellulose was added to 5 g of 1-allyl-3-methylimidazolium chloride, and the mixture was stirred at 80 °C to obtain a homogeneous solution; 10.8 mg of N,N'-carbonyldiimidazole and 37.5 mg of PpIX were added to 1.5 g of DMSO in a separate flask, and the mixture was stirred at 80 °C for 15 minutes to obtain activated PpIX; in another flask, 0.9728 g of N,N'-carbonyldiimidazole and 0.5448 g of (3-carboxypropyl)trimethylammonium chloride were dissolved in 4 g of DMSO, and the mixture was stirred at 80 °C until no gas escaped; the above two solutions were added to the cellulose solution, and the reaction was carried out at 80 °C for 20 hours to obtain antibacterial cellulose;

[0052] (2) The antibacterial cellulose solution was precipitated in ethanol, washed three times, and dried to obtain powder by freeze drying. The obtained powder and the composite dispersant powder (in powder form, the same below) were added to the side feed position of a parallel co-rotating twin-screw extruder granulator by loss weighing, and the feeding speed of the side feed position was controlled at 25 Hz. The composite dispersant was composed of 1.5% Jiahe Chemical JHX 100 (amide dispersant) and 0.5% Shanghai Hesu Cli 330 (polyether ester polymer).

[0053] (3) Preparation of antibacterial masterbatch for nylon 6 fiber, the specific steps are as follows:

[0054] S1. Quantitative feeding of raw materials: The main feeding position and the side feeding position are linked to feed the raw materials. The spinning grade nylon 6 chips are added at the main feeding position, and the nano-grade antibacterial cellulose powder and composite dispersant powder are added at the side feeding position.

[0055] S2, Melting and Plasticizing: The raw material in step (1) is melted and plasticized by controlling the temperature of each section of the twin-screw extruder. The temperature of the first section is 210℃; the temperature of the second section is 220℃; the temperature of the third section is 225℃; the temperature of the fourth section is 210-220℃; the temperature of the fifth section is 205-210℃; the temperature of the sixth section is 200-205℃; the temperature of the seventh section is 190-200℃; the temperature of the eighth section is 180-185℃; the temperature of the ninth section is 175-180℃; and the temperature of the die head section is 230-240℃.

[0056] S3, Screw shearing: A 600-mesh filter screen is added to the head of the screw shearing machine to control the overall melting pressure of the head to stabilize at 1.3MPa, and shearing the plasticized polymer melt. The main speed of the screw shearing machine is 540r / min.

[0057] S4, Water-cooled pelletizing: The polymer melt obtained in step (3) is water-cooled and pelletized, wherein the main rotation speed of the pelletizer is 850 r / min;

[0058] S5. Vibration screening: the masterbatch in step (4) is screened by vibration, wherein the screen mesh diameter is 4-6mm;

[0059] S6. Vacuum drying to obtain masterbatch for antibacterial nylon 6 fiber.

[0060] Example 2

[0061] This embodiment provides an antibacterial masterbatch for nylon 6 fibers, with the following formulation by weight percentage: 85% spinning-grade bright nylon 6 chips, 13% nano-grade antibacterial cellulose powder, and 2% composite dispersant powder. Its preparation method includes the following steps:

[0062] (1) 0.126 g of microcrystalline cellulose was added to 5 g of 1-allyl-3-methylimidazolium chloride, and the mixture was stirred at 80 °C to obtain a homogeneous solution; 10.8 mg of N,N'-carbonyldiimidazole and 37.5 mg of PpIX were added to 1.5 g of DMSO in a separate flask, and the mixture was stirred at 80 °C for 15 minutes to obtain activated PpIX; in another flask, 0.9728 g of N,N'-carbonyldiimidazole and 0.5448 g of (3-carboxypropyl)trimethylammonium chloride were dissolved in 4 g of DMSO, and the mixture was stirred at 80 °C until no gas escaped; the above two solutions were added to the cellulose solution, and the reaction was carried out at 80 °C for 20 hours to obtain antibacterial cellulose;

[0063] (2) The antibacterial cellulose solution was precipitated in ethanol, washed three times, and dried to obtain powder by freeze drying. The obtained powder and the composite dispersant powder (in powder form, the same below) were added to the side feed position of a parallel co-rotating twin-screw extruder granulator by loss weighing, and the feeding speed of the side feed position was controlled at 25 Hz. The composite dispersant was composed of 1.5% Jiahe Chemical JHX 100 (amide dispersant) and 0.5% Shanghai Hesu Cli 330 (polyether ester polymer).

[0064] (3) Preparation of antibacterial masterbatch for nylon 6 fiber, the specific steps are as follows:

[0065] S1. Quantitative feeding of raw materials: The main feeding position and the side feeding position are linked to feed the raw materials. The spinning grade nylon 6 chips are added at the main feeding position, and the nano-grade antibacterial cellulose powder and composite dispersant powder are added at the side feeding position.

[0066] S2, Melting and Plasticizing: The raw material in step (1) is melted and plasticized by controlling the temperature of each section of the twin-screw extruder. The temperature of the first section is 210℃; the temperature of the second section is 220℃; the temperature of the third section is 225℃; the temperature of the fourth section is 210-220℃; the temperature of the fifth section is 205-210℃; the temperature of the sixth section is 200-205℃; the temperature of the seventh section is 190-200℃; the temperature of the eighth section is 180-185℃; the temperature of the ninth section is 175-180℃; and the temperature of the die head section is 230-240℃.

[0067] S3, Screw shearing: A 600-mesh filter screen is added to the head of the screw shearing machine to control the overall melting pressure of the head to stabilize at 1.4MPa, and shearing the plasticized polymer melt. The main speed of the screw shearing machine is 560r / min.

[0068] S4, Water-cooled pelletizing: The polymer melt obtained in step (3) is water-cooled and pelletized, wherein the main speed of the pelletizer is 900 r / min;

[0069] S5. Vibration screening: The masterbatch in step (4) is screened by vibration, wherein the screen mesh diameter is 2-4 mm;

[0070] S6. Vacuum drying to obtain masterbatch for antibacterial nylon 6 fiber.

[0071] Example 3

[0072] This embodiment provides an antibacterial masterbatch for nylon 6 fibers, with the following formulation by weight percentage: 83% spinning-grade bright nylon 6 chips, 15% nano-grade antibacterial cellulose powder, and 2% composite dispersant powder. Its preparation method includes the following steps:

[0073] (1) 0.126 g of microcrystalline cellulose was added to 5 g of 1-allyl-3-methylimidazolium chloride, and the mixture was stirred at 80 °C to obtain a homogeneous solution; 10.8 mg of N,N'-carbonyldiimidazole and 37.5 mg of PpIX were added to 1.5 g of DMSO in a separate flask, and the mixture was stirred at 80 °C for 15 minutes to obtain activated PpIX; in another flask, 0.9728 g of N,N'-carbonyldiimidazole and 0.5448 g of (3-carboxypropyl)trimethylammonium chloride were dissolved in 4 g of DMSO, and the mixture was stirred at 80 °C until no gas escaped; the above two solutions were added to the cellulose solution, and the reaction was carried out at 80 °C for 20 hours to obtain antibacterial cellulose;

[0074] (2) The antibacterial cellulose solution was precipitated in ethanol, washed three times, and dried to obtain powder by freeze drying. The obtained powder and the composite dispersant powder (in powder form, the same below) were added to the side feed position of a parallel co-rotating twin-screw extruder granulator by loss weighing, and the feeding speed of the side feed position was controlled at 25 Hz. The composite dispersant was composed of 1.5% Jiahe Chemical JHX 100 (amide dispersant) and 0.5% Shanghai Hesu Cli 330 (polyether ester polymer).

[0075] (3) Preparation of antibacterial masterbatch for nylon 6 fiber, the specific steps are as follows:

[0076] S1. Quantitative feeding of raw materials: The main feeding position and the side feeding position are linked to feed the raw materials. The spinning grade nylon 6 chips are added at the main feeding position, and the nano-grade antibacterial cellulose powder and composite dispersant powder are added at the side feeding position.

[0077] S2, Melting and Plasticizing: The raw material in step (1) is melted and plasticized by controlling the temperature of each section of the twin-screw extruder. The temperature of the first section is 210℃; the temperature of the second section is 220℃; the temperature of the third section is 225℃; the temperature of the fourth section is 210-220℃; the temperature of the fifth section is 205-210℃; the temperature of the sixth section is 200-205℃; the temperature of the seventh section is 190-200℃; the temperature of the eighth section is 180-185℃; the temperature of the ninth section is 175-180℃; and the temperature of the die head section is 230-240℃.

[0078] S3, Screw shearing: A 600-mesh filter screen is added to the head of the screw shearing machine to control the overall melting pressure of the head to stabilize at 1.4MPa, and shearing the plasticized polymer melt. The main speed of the screw shearing machine is 570r / min.

[0079] S4, Water-cooled pelletizing: The polymer melt obtained in step (3) is water-cooled and pelletized, wherein the main speed of the pelletizer is 950 r / min;

[0080] S5. Vibration screening: the masterbatch in step (4) is screened by vibration, wherein the screen mesh diameter is 4-6mm;

[0081] S6. Vacuum drying to obtain masterbatch for antibacterial nylon 6 fiber.

[0082] Example 4

[0083] This embodiment provides a method for preparing antibacterial masterbatch for nylon 6 fibers, with the following formula by mass percentage: 77% spinning-grade bright nylon 6 chips, 20% nano-grade antibacterial cellulose powder, and 3% composite dispersant powder. The method includes the following steps:

[0084] (1) 0.126 g of microcrystalline cellulose was added to 5 g of 1-allyl-3-methylimidazolium chloride, and the mixture was stirred at 80 °C to obtain a homogeneous solution; 10.8 mg of N,N'-carbonyldiimidazole and 37.5 mg of PpIX were added to 1.5 g of DMSO in a separate flask, and the mixture was stirred at 80 °C for 15 minutes to obtain activated PpIX; in another flask, 0.9728 g of N,N'-carbonyldiimidazole and 0.5448 g of (3-carboxypropyl)trimethylammonium chloride were dissolved in 4 g of DMSO, and the mixture was stirred at 80 °C until no gas escaped; the above two solutions were added to the cellulose solution, and the reaction was carried out at 80 °C for 20 hours to obtain antibacterial cellulose;

[0085] (2) The antibacterial cellulose solution was precipitated in ethanol, washed three times, and dried to obtain powder by freeze drying. The obtained powder and the composite dispersant powder (in powder form, the same below) were added to the side feed position of a parallel co-rotating twin-screw extruder granulator by loss weighing, and the feeding speed of the side feed position was controlled at 25 Hz. The composite dispersant was composed of 1.5% Jiahe Chemical JHX 100 (amide dispersant) and 0.5% Shanghai Hesu Cli 330 (polyether ester polymer).

[0086] (3) Preparation of antibacterial masterbatch for nylon 6 fiber, the specific steps are as follows:

[0087] S1. Quantitative feeding of raw materials: The main feeding position and the side feeding position are linked to feed the raw materials. The spinning grade nylon 6 chips are added at the main feeding position, and the nano-grade antibacterial cellulose powder and composite dispersant powder are added at the side feeding position.

[0088] S2, Melting and Plasticizing: The raw material in step (1) is melted and plasticized by controlling the temperature of each section of the twin-screw extruder. The temperature of the first section is 210℃; the temperature of the second section is 220℃; the temperature of the third section is 225℃; the temperature of the fourth section is 210-220℃; the temperature of the fifth section is 205-210℃; the temperature of the sixth section is 200-205℃; the temperature of the seventh section is 190-200℃; the temperature of the eighth section is 180-185℃; the temperature of the ninth section is 175-180℃; and the temperature of the die head section is 230-240℃.

[0089] S3, Screw shearing: A 600-mesh filter screen is added to the head of the screw shearing machine to control the overall melting pressure of the head to stabilize at 1.5MPa, and shearing the plasticized polymer melt. The main speed of the screw shearing machine is 580r / min.

[0090] S4, Water-cooled pelletizing: The polymer melt obtained in step (3) is water-cooled and pelletized, wherein the main speed of the pelletizer is 1000 r / min;

[0091] S5. Vibration screening: the masterbatch in step (4) is screened by vibration, wherein the screen mesh diameter is 6-8mm;

[0092] S6. Vacuum drying to obtain masterbatch for antibacterial nylon 6 fiber.

[0093] Antibacterial performance test

[0094] (1) Using Escherichia coli (number: ATCC25922) and Staphylococcus aureus (number: ATCC29213) as strains, take 3 12 mL bacterial culture tubes, add 3 mL of LB liquid medium to each, pick single colonies from the solid medium of Escherichia coli and Staphylococcus aureus respectively and add them to the liquid medium, and use another tube as a blank control. Place them in a constant temperature shaker (37℃, 200 rpm) and shake overnight (15 h);

[0095] (2) Take 1 mL of bacterial culture from each bacterial culture tube, centrifuge at 8000 rpm for 3 min, resuspend in sterile PBS, dilute the bacterial culture to 106 CFU / mL, and then take 400 μL of the bacterial culture dilution sample and add it to the corresponding numbered centrifuge tube; add 400 μL of sterile water to the control group, then add 100 μL of the diluted bacterial culture, and then place the centrifuge tube in a constant temperature shaker at 37℃ for 6 h;

[0096] (3) After cultivation, the diluted bacterial culture was inoculated onto LB solid medium. Then, the masterbatch product was continuously diluted 10-fold and 1000-fold using sterile PBS. 100 μL of the masterbatch dilution was evenly spread onto LB solid medium and incubated at 37℃ for 18 h. The culture was then removed, photographed, and the colony count was recorded. The counting principle was based on the national standard GB4789.2-2016, and the colony count was selected to be between 30 CFU and 300 CFU.

[0097] The performance of POY 85D / 24F produced by the masterbatch of antibacterial nylon 6 fiber obtained in Examples 1-4 was tested, and the results of each indicator are shown in Table 1.

[0098] Table 1. Test results of antibacterial nylon 6 fiber masterbatches prepared in Examples 1-4

[0099]

[0100] The antibacterial properties of the antibacterial nylon 6 fiber prepared in Example 1 were tested using masterbatch, and the results are shown in Table 2.

[0101] Table 2. Test results of the antibacterial nylon 6 fiber masterbatch prepared in Example 1.

[0102]

[0103] As can be seen from the data in the attached table, the antibacterial nylon 6 fiber masterbatch provided in Example 1 performed well in the antibacterial performance test. The number of colonies in the effect group-1 and effect group-2 was significantly less than that in the control group, and it had a significant inhibitory effect on the colony concentration. The antibacterial rate against Escherichia coli reached 99.8%, and the antibacterial rate against Staphylococcus aureus reached 99.9%.

[0104] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. An antibacterial masterbatch for nylon 6 fiber, characterized in that, It includes the following components by mass fraction: 77%-89% spinning-grade nylon 6 chips, 10%-20% nano-grade antibacterial cellulose powder, and 1%-3% composite dispersant powder; The nanoscale antibacterial cellulose powder was prepared by photodynamic antibacterial method, which was obtained by covalently binding two functional groups, protoporphyrin IX and quaternary ammonium salt, to the cellulose backbone; The method for preparing the nanoscale antibacterial cellulose is as follows: (1) Microcrystalline cellulose was added to 1-allyl-3-methylimidazolium chloride, and the mixture was stirred at 80°C to obtain a homogeneous solution; (2) In a separate flask, N,N'-carbonyldiimidazole and protoporphyrin IX were added to dimethyl sulfoxide and stirred at 80°C for 15 min to obtain activated protoporphyrin IX; in another flask, N,N'-carbonyldiimidazole and (3-carboxypropyl)trimethylammonium chloride were dissolved in dimethyl sulfoxide and the solution was stirred at 80°C until no gas escaped. (3) The two solutions obtained in step (2) are added to the homogeneous cellulose solution prepared in (1) and reacted at 80°C for 20 h to obtain nano-sized antibacterial cellulose.

2. The antibacterial masterbatch for nylon 6 fiber according to claim 1, characterized in that, The relative viscosity of the spinning-grade nylon 6 chips is 2.47-2.

50.

3. The antibacterial masterbatch for nylon 6 fiber according to claim 1, characterized in that, In step (1), the mass ratio of 1-allyl-3-methylimidazolium chloride to microcrystalline cellulose is 1:0.0252.

4. The antibacterial masterbatch for nylon 6 fiber according to claim 1, characterized in that, In step (2), the mass ratio of dimethyl sulfoxide: N,N'-carbonyldiimidazole: protoporphyrin is 100:0.72:2.5, and the mass ratio of dimethyl sulfoxide: N,N'-carbonyldiimidazole: (3-carboxypropyl)trimethylammonium chloride is 4000:0.9728:0.5448.

5. The antibacterial masterbatch for nylon 6 fiber according to claim 1, characterized in that, The composite dispersant powder comprises a polyether ester polymer and an amide dispersant, wherein the mass ratio of the polyether ester polymer to the amide dispersant is 1:1-4.

6. A method for preparing antibacterial masterbatch for nylon 6 fibers as described in claim 1, characterized in that, Includes the following steps: S1. Quantitative feeding of raw materials: The main feeding position and the side feeding position are linked to feed the raw materials. The spinning grade nylon 6 chips are added at the main feeding position, and the nano-grade antibacterial cellulose powder and composite dispersant powder are added at the side feeding position. S2, Melting and Plasticizing: The raw material in step (1) is melted and plasticized by controlling the temperature of each section of the twin-screw extruder. The temperature of the first section is 210℃; the temperature of the second section is 220℃; the temperature of the third section is 225℃; the temperature of the fourth section is 210-220℃; the temperature of the fifth section is 205-210℃; the temperature of the sixth section is 200-205℃; the temperature of the seventh section is 190-200℃; the temperature of the eighth section is 180-185℃; the temperature of the ninth section is 175-180℃; and the temperature of the die head section is 230-240℃. S3, Screw shearing: Add a 600-mesh filter screen to the head of the screw shearing machine to control the overall melting pressure of the head to stabilize at 1.3-1.5MPa, and then shear the plasticized polymer melt. The main speed of the screw shearing machine is 540-580r / min. S4, water-cooled pelletizing: the polymer melt obtained in step (3) is water-cooled and pelletized, wherein the main speed of the pelletizer is 850-1000 r / min; S5. Vibration screening: the masterbatch in step (4) is vibrated and screened, wherein the screen mesh diameter is 2-8 mm; S6. Vacuum drying.

7. The application of the antibacterial masterbatch for nylon 6 fiber according to claim 1 in the production of nylon 6 civilian filament fiber.

8. The application of the antibacterial masterbatch for nylon 6 fiber according to claim 7 in nylon 6 civilian filament fiber, characterized in that, The standard nylon 6 civilian filament fiber fabric sample showed an antibacterial rate of 99.9% against Staphylococcus aureus.

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