An easily dyeable and antioxidant nylon filament and its preparation method

Abstract

The present invention provides an easily dyeable and antioxidant nylon filament and a preparation method thereof, belonging to the technical field of nylon. Porous silica nanospheres coated with polydopamine are copolymerized with a silane coupling agent and an antioxidant coupling agent of 3,5-di-tert-butyl-4-hydroxystyrene acid, and graphene oxide is coated on the surface. Then it is added to caprolactam, and 6-aminocaproic acid is added. The mixture is heated, stirred under reduced pressure, discharged, cooled, dried, sliced to obtain nylon chips, and then through melt extrusion, spinning, cooling, oiling, drawing and setting, winding to obtain the easily dyeable and antioxidant nylon filament. The easily dyeable and antioxidant nylon 66 filament fiber of the present invention has the advantages of good heat-oxidation aging resistance, easy adsorption of colorant molecules, easy dyeing, high strength, good rigidity, impact resistance, oil and chemical resistance, wear resistance and self-lubrication, etc., especially better hardness, rigidity, heat resistance and creep properties.

Description

Technical Field

[0001] The present invention relates to the technical field of nylon, and particularly relates to an easily dyeable and antioxidant nylon filament and a preparation method thereof. Background Art

[0002] Ultra-fine fiber filament fabrics are now widely used in people's lives, mainly used in high-end casual jackets for men and women, windbreakers, casual suits, trouser fabrics, casual cotton-padded clothes, and casual down jacket fabrics. Generally, it is mainly made of sea-island ultra-fine fiber filaments or polyester-polyamide ultra-fine fiber filaments. The fabric is produced through processes such as pre-shrinking, alkali weight reduction and fiber opening, pre-setting, raising and sanding, and dyeing to produce this kind of leather-like velvet fabric. The molecular structure characteristics of nylon (containing amide groups, similar to protein structure) have good hydrophilic and skin-friendly properties, such as sweating absorption, light weight, good toughness, good resilience, and resistance to acids and alkalis. It is one of the most suitable artificial fabrics for human wear and is widely used in fields such as knitted underwear, socks, sportswear, ski jackets, and tights. The application in clothing is also one of the main uses of nylon fibers. The micro-fineness of nylon 6 fibers can further improve the quality and value of the fibers and manufacture high-grade clothing products that meet the fashion trend and taste. The single filament fineness of nylon 6 fibers obtained by the direct melt spinning method can reach 0.80 dtex.

[0003] However, the technology for directly producing differential micro-fine denier nylon 6 POY fibers by using the conventional spinning improvement method is not yet mature. There are two reasons for this phenomenon: on the one hand, the process for producing differential micro-fine denier polyamide by using the sea-island spinning method is complex, costly, and will cause a large amount of organic matter emissions and environmental pollution, which significantly limits its popularization and application; on the other hand, due to the characteristics of nylon itself, a large number of hydrogen bonds are contained in its molecular structure, the crystallization speed is fast, the crystallinity is high, and it is not easy to be stretched and deformed.

[0004] Nylon materials are widely used in spinning, injection molding, and film products due to their unique performance advantages. However, nylon itself is easily oxidized and yellowed, and ultimately leads to a decrease in its mechanical properties, which is a major drawback. Adding a certain amount of antioxidant during the forming process is a simple and common method. However, due to the small addition amount and uneven dispersion of the antioxidant, its effect cannot be best reflected. Preparing antioxidant masterbatches by blending can alleviate the drawback of uneven dispersion of the antioxidant to a certain extent. However, preparing antioxidant masterbatches by blending itself will cause a certain degree of thermal degradation, which also has certain limitations in fields with high requirements for the stability of nylon raw materials such as high-speed fiber production. In addition, the specific surface area of ultra-fine denier nylon fibers increases, the dye uptake rate increases, the levelness becomes worse, and uneven dyeing is likely to occur.

[0005] Chinese Patent CN1309899C dyes the superfine fibers of the fabric after chemical fiber fibrillation and mechanical fibrillation. Since the suede fabric is made of fibers such as polyester island fiber and polyester-polyamide superfine fiber, the fiber fineness reaches about 0.2 dtex after fibrillation. The specific surface area of the fiber reaches dozens of times that of conventional fibers. Therefore, the adsorption capacity of the fiber surface is greatly enhanced during the dispersion dyeing. Some dyes combine with the fiber for dyeing, while 1 / 4 - 1 / 3 of the dyes are adsorbed on the surface of the fiber, often entering the sewage during fabric washing, increasing COD emissions and causing environmental pollution. Summary of the Invention

[0006] The purpose of the present invention is to provide an easily dyeable antioxidant nylon filament and its preparation method, which has good anti-thermal-oxidative aging performance, is easy to adsorb colorant molecules, is easy to dye, has high strength, good rigidity, impact resistance, oil and chemical resistance, wear resistance and self-lubrication, etc. In particular, the hardness, rigidity, heat resistance and creep properties are better.

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

[0008] The present invention provides a preparation method of an easily dyeable antioxidant nylon filament. Coupling the porous silica nanospheres modified by polydopamine coating with a silane coupling agent to copolymerize an antioxidant of 3,5-di-tert-butyl-4-hydroxystyrenic acid, coating graphene oxide on the surface, adding it to caprolactam, adding 6-aminocaproic acid, heating under reduced pressure and stirring for reaction, discharging, cooling, drying, slicing to obtain nylon slices, and then through melt extrusion, spinning, cooling, oiling, drawing and setting, winding to obtain an easily dyeable antioxidant nylon filament.

[0009] As a further improvement of the present invention, it includes the following steps:

[0010] S1. Dissolve an alkyl orthosilicate in an organic solvent to obtain solution A; dissolve a pore-forming agent and an emulsifier in water to obtain solution B; drop solution A into solution B, emulsify, adjust the pH value of the solution, stir for reaction, centrifuge, wash, and dry to obtain porous silica nanospheres;

[0011] S2. Add the porous silica nanospheres into water, add dopamine hydrochloride and a catalyst, heat and stir for reaction, centrifuge, wash, and dry to obtain modified porous silica nanospheres;

[0012] S3. Add 3,5-di-tert-butyl-4-hydroxystyrenic acid into ethanol, add a silane coupling agent with a double bond and an initiator, heat and stir for reaction, filter, wash, and dry to obtain an antioxidant;

[0013] S4. Add antioxidants to water, add NHS (N-Hydroxy succinimide) and EDC (1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide), stir to activate, add modified porous silica nanospheres, stir and react, centrifuge, wash, and dry to obtain a conjugate;

[0014] S5. Add the conjugate to the graphene oxide aqueous dispersion, ultrasonically disperse evenly, and spray dry to obtain a wrinkled coating modifier;

[0015] S6. Heat and melt caprolactam, add 6-aminocaproic acid and the wrinkled coating modifier, stir and mix evenly, heat and stir under reduced pressure to react, discharge and cool, dry, slice to obtain nylon slices;

[0016] S7. Send the nylon slices to a screw extruder, pressurize and transport the melt to the spinning box, measure through a metering pump and then spin through a spinning pack, the filaments are cooled by side blowing to form a filament bundle, the cooled filament bundle is oiled to eliminate static electricity, the oiled filament bundle is subjected to drawing and setting treatment, and the set filament bundle is wound into a filament bobbin to obtain easily dyed and antioxidant nylon filaments.

[0017] As a further improvement of the present invention, in step S1, the alkyl orthosilicate is methyl orthosilicate or ethyl orthosilicate, the mass ratio of the alkyl orthosilicate, pore-forming agent, and emulsifier is 12-15:1-2:0.5-1, the pore-forming agent is selected from at least one of cetyltrimethylammonium chloride, ethylene oxide-propylene oxide triblock copolymer PEO20-PPO70-PEO20, or ethylene oxide-propylene oxide triblock copolymer PEO106-PPO70-PEO106, the emulsifier is selected from at least one of Tween-20, Tween-40, Tween-60, Tween-80, or Tween-85, the pH value of the adjusted solution is 9-10, and the stirring reaction time is 10-12 h.

[0018] As a further improvement of the present invention, in step S2, the mass ratio of the porous silica nanospheres, dopamine hydrochloride, and catalyst is 10-12:4-6:1-2, the catalyst is a Tris-HCl solution with pH = 8.5-9.5, the temperature of the heating and stirring reaction is 45-55 °C, and the time is 3-5 h.

[0019] As a further improvement of the present invention, in step S3, the mass ratio of 3,5-di-tert-butyl-4-hydroxystyrene acid, the silane coupling agent with a double bond and the initiator is 4-7:3-5:0.01-0.02. The silane coupling agent with a double bond is selected from at least one of KH570, A151, and A171. The initiator is azobisisobutyronitrile. The temperature of the heating and stirring reaction is 50-60 °C, and the time is 3-5 h.

[0020] As a further improvement of the present invention, in step S4, the mass ratio of the antioxidant, NHS, EDC, and the modified porous silica nanospheres is 4-7:1-2:1-2:10. The time for stirring activation is 20-30 min, and the time for the stirring reaction is 8-10 h.

[0021] As a further improvement of the present invention, in step S5, the concentration of the graphene oxide aqueous dispersion is 0.5-1 mg / mL, and the liquid-solid ratio of the graphene oxide aqueous dispersion to the conjugate is 3-5 mL:1 g.

[0022] As a further improvement of the present invention, in step S6, the temperature for heating and melting is 70-75 °C. The mass ratio of caprolactam, 6-aminocaproic acid, and the wrinkled coating modifier is 100:1-2:7-12. The temperature of the heating, decompression, and stirring reaction is 240-260 °C, the rotation speed is 100-150 r / min, the reaction pressure is 0.02-0.08 MPa, and the time is 3-5 h.

[0023] As a further improvement of the present invention, in step S7, the temperature of the melt extrusion is 280-300 °C. The fineness of the filaments extruded by the spinneret is 0.05-0.1 mm, and the oil pick-up amount is controlled at 0.5-1.5%. The drawing and setting are realized through 1 stage of preheating, 2 stages of stretching, and 2 stages of setting between six pairs of hot rolls: among them, the temperature of the first pair of hot rolls is 30-40 °C, the temperature of the second pair of hot rolls is 45-55 °C. The first pair of hot rolls and the second pair of hot rolls preheat the filament strip, and the draw ratio is 1-1.01 times. The winding speed is 3000-4000 m / min.

[0024] The present invention further protects an easily dyeable and antioxidant nylon filament prepared by the above preparation method.

[0025] The present invention has the following beneficial effects:

[0026] The present invention copolymerizes 3,5 - di - tert - butyl - 4 - hydroxystyrene acid with a silane coupling agent having a double bond to prepare an antioxidant. On the one hand, the antioxidant has a silane structure and can bind well with silica nanospheres. On the other hand, the molecular structure contains a macromolecular antioxidant with polar groups, a rigid five - membered ring, and long - chain alkyl para - substituents. By using the free - radical polymerization method, a macromolecular antioxidant with a large relative molecular mass, good heat resistance, and high thermal - oxidative aging resistance efficiency is prepared. It can significantly improve the thermal - oxidative aging resistance performance of nylon, has good dispersibility, does not cause a decrease in the mechanical properties of nylon filaments, and the antioxidant itself is not easily decomposed. In addition, the macromolecular antioxidant has abundant carboxyl groups on it, and can be coupled with the amino groups on the modified porous silica nanospheres by activating the carboxyl groups, thus forming a conjugate. When this conjugate is added to nylon, it can significantly improve the mechanical strength of nylon filaments. Also, due to the large specific surface area of the porous silica nanospheres, it is easy to adsorb colorant molecules, and the polydopamine coated on it can form complex bonds or hydrogen bonds with metal ions and colorant molecules, thus having a good color - fixing effect and being easy to dye.

[0027] Graphene oxide has good compatibility with nylon, but directly adding it easily agglomerates and affects the mechanical properties of nylon. By coating graphene oxide on the surface of the conjugate and forming wrinkles through spray drying, the uniform dispersion of the nano - wrinkled coating modifier is achieved, and the effective contact promotes the formation of a heat - conduction network, thereby increasing its thermal conductivity, promoting the dispersion and compatibility of the wrinkled coating modifier in nylon materials, and it is not easily agglomerated by itself, which helps to improve the mechanical properties, heat - dissipation performance, and reduce the thermal shrinkage rate of the material.

[0028] The easily - dyeable antioxidant nylon 66 filament fiber of the present invention has the advantages of good thermal - oxidative aging resistance, easy adsorption of colorant molecules, easy dyeing, high strength, good rigidity, impact resistance, oil and chemical resistance, wear resistance, and self - lubrication, etc., especially better hardness, rigidity, heat resistance, and creep properties. Specific embodiments

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a 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 those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] The 0.5mg / mL graphene oxide aqueous dispersion is purchased from Jiangsu Xianfeng Nano Materials Technology Co., Ltd.

[0031] Example 1

[0032] This example provides a preparation method for easily - dyeable antioxidant nylon filaments, including the following steps:

[0033] S1. Dissolve 12 g of methyl orthosilicate in 200 mL of dichloromethane to obtain solution A; dissolve 1 g of cetyltrimethylammonium chloride and 0.5 g of Tween-40 in 300 mL of water to obtain solution B; add solution A dropwise to solution B, emulsify at 7000 r / min for 15 min, adjust the pH value of the solution to 9, stir and react for 10 h, centrifuge, wash, and dry to prepare porous silica nanospheres;

[0034] S2. Add 10 g of porous silica nanospheres to 200 mL of water, add 4 g of dopamine hydrochloride and 1 g of catalyst, heat to 45 °C, stir and react for 3 h, centrifuge, wash, and dry to prepare modified porous silica nanospheres;

[0035] The catalyst is a Tris-HCl solution with pH = 8.5;

[0036] S3. Add 4 g of 3,5-di-tert-butyl-4-hydroxycinnamic acid to 200 mL of ethanol, add 3 g of silane coupling agent A151 and 0.01 g of azobisisobutyronitrile, heat to 50 °C, stir and react for 3 h, filter, wash, and dry to prepare an antioxidant;

[0037] S4. Add 4 g of the antioxidant to 200 mL of water, add 1 g of NHS and 1 g of EDC, stir and activate for 20 min, add 10 g of modified porous silica nanospheres, stir and react for 8 h, centrifuge, wash, and dry to prepare a conjugate;

[0038] S5. Add 10 g of the conjugate to 30 mL of 0.5 mg / mL graphene oxide aqueous dispersion, ultrasonically disperse at 1000 W for 10 min, and spray dry to prepare a wrinkled coating modifier;

[0039] S6. Heat 100 g of caprolactam to 75 °C for melting, add 1 g of 6-aminocaproic acid and 7 g of the wrinkled coating modifier, stir and mix for 15 min, heat and stir under reduced pressure for reaction, the temperature is 240 °C, the rotation speed is 100 r / min, the reaction pressure is 0.02 MPa, the time is 3 h, discharge and cool, dry, slice to prepare nylon slices;

[0040] S7. Feed nylon chips into a screw extruder, heat to 280 °C to obtain a melt, convey the melt to a spinning box under pressure, meter it through a metering pump, and then extrude it through a spinning pack. The fineness of the extruded filaments is 0.1 mm. The filaments are cooled by side blowing to form a tow. Eliminate static electricity from the cooled tow by applying oil, and control the oil content to 0.5%. Perform drawing and setting on the oiled tow. The drawing and setting are achieved through 1 stage of preheating, 2 stages of stretching, and 2 stages of setting between six pairs of hot rolls: among them, the temperature of the first pair of hot rolls is 30 °C, the temperature of the second pair of hot rolls is 45 °C, the first pair of hot rolls and the second pair of hot rolls preheat the filaments, and the draw ratio is 1 time. Wind the set tow into a bobbin at a winding speed of 3000 m / min to obtain easily dyeable and antioxidant nylon filaments.

[0041] Example 2

[0042] This example provides a method for preparing easily dyeable and antioxidant nylon filaments, including the following steps:

[0043] S1. Dissolve 15 g of tetraethyl orthosilicate in 200 mL of dichloromethane to obtain solution A; dissolve 2 g of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer PEO106-PPO70-PEO106 and 1 g of Tween-60 in 300 mL of water to obtain solution B; drop solution A into solution B, emulsify at 7000 r / min for 15 min, adjust the pH value of the solution to 10, stir and react for 12 h, centrifuge, wash, and dry to obtain porous silica nanospheres.

[0044] S2. Add 12 g of porous silica nanospheres to 200 mL of water, add 6 g of dopamine hydrochloride and 2 g of catalyst, heat to 55 °C, stir and react for 5 h, centrifuge, wash, and dry to obtain modified porous silica nanospheres.

[0045] The catalyst is a Tris-HCl solution with pH = 9.5.

[0046] S3. Add 7 g of 3,5-di-tert-butyl-4-hydroxycinnamic acid to 200 mL of ethanol, add 5 g of silane coupling agent A171 and 0.02 g of azobisisobutyronitrile, heat to 60 °C, stir and react for 5 h, filter, wash, and dry to obtain an antioxidant.

[0047] S4. Add 7 g of antioxidant to 200 mL of water, add 2 g of NHS and 2 g of EDC, stir and activate for 30 min, add 10 g of modified porous silica nanospheres, stir and react for 10 h, centrifuge, wash, and dry to obtain a conjugate.

[0048] S5. Add 10 g of the conjugate to 50 mL of a 0.5 mg / mL graphene oxide aqueous dispersion, ultrasonically disperse it at 1000 W for 10 min, and spray dry to obtain a wrinkled coating modifier;

[0049] S6. Heat 100 g of caprolactam to 75 °C for melting, add 2 g of 6-aminocaproic acid and 12 g of the wrinkled coating modifier, stir and mix for 15 min, heat under reduced pressure and stir to react at a temperature of 260 °C, a rotation speed of 150 r / min, a reaction pressure of 0.08 MPa, and a time of 5 h. Discharge and cool, dry, slice to obtain nylon chips;

[0050] S7. Feed the nylon chips into a screw extruder, heat to 300 °C to obtain a melt, convey the melt to a spinning box under pressure, measure it by a metering pump, and then spin it through a spinning pack. The fineness of the spun silk is 0.1 mm. The silk strand is cooled by side blowing to form a silk bundle. Eliminate static electricity from the cooled silk bundle by applying oil. The oil content is controlled at 1.5%. Perform stretching and setting treatment on the oiled silk bundle. The stretching and setting are achieved through 1 stage of preheating, 2 stages of stretching, and 2 stages of setting between six pairs of hot rolls: among them, the temperature of the first pair of hot rolls is 40 °C, the temperature of the second pair of hot rolls is 55 °C. The first pair of hot rolls and the second pair of hot rolls preheat the silk strand, and the stretching ratio is 1.01 times. Wind the set silk bundle into a silk bobbin. The winding speed is 4000 m / min to obtain easily dyeable and antioxidant nylon filaments.

[0051] Example 3

[0052] This example provides a method for preparing easily dyeable and antioxidant nylon filaments, including the following steps:

[0053] S1. Dissolve 13 g of tetraethyl orthosilicate in 200 mL of dichloromethane to obtain solution A; dissolve 1.5 g of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer PEO20-PPO70-PEO20 and 0.8 g of Tween-85 in 300 mL of water to obtain solution B; drop solution A into solution B, emulsify at 7000 r / min for 15 min, adjust the pH value of the solution to 9.5, stir and react for 11 h, centrifuge, wash, and dry to obtain porous silica nanospheres;

[0054] S2. Add 11 g of porous silica nanospheres to 200 mL of water, add 5 g of dopamine hydrochloride and 1.5 g of catalyst, heat to 50 °C, stir and react for 4 h, centrifuge, wash, and dry to obtain modified porous silica nanospheres;

[0055] The catalyst is a Tris-HCl solution with pH = 9;

[0056] S3. Add 5.5 g of 3,5-di-tert-butyl-4-hydroxystyrenic acid to 200 mL of ethanol, add 4 g of silane coupling agent KH570 and 0.015 g of azobisisobutyronitrile, heat to 55 °C, stir and react for 4 h, filter, wash, and dry to obtain an antioxidant;

[0057] S4. Add 5 g of antioxidant to 200 mL of water, add 1.5 g of NHS and 1.2 g of EDC, stir and activate for 25 min, add 10 g of modified porous silica nanospheres, stir and react for 9 h, centrifuge, wash, and dry to obtain a conjugate;

[0058] S5. Add 10 g of conjugate to 40 mL of 0.5 mg / mL graphene oxide aqueous dispersion, ultrasonically disperse at 1000 W for 10 min, and spray dry to obtain a wrinkled coating modifier;

[0059] S6. Heat 100 g of caprolactam to 75 °C to melt it, add 1.5 g of 6-aminocaproic acid and 10 g of wrinkled coating modifier, stir and mix for 15 min, heat under reduced pressure and stir to react, the temperature is 250 °C, the rotation speed is 120 r / min, the reaction pressure is 0.05 MPa, the time is 4 h, discharge and cool, dry, slice to obtain nylon chips;

[0060] S7. Send the nylon chips to a screw extruder, heat to 290 °C to obtain a melt, convey the melt to a spinning box under pressure, measure through a metering pump and then spin through a spinning pack, the fineness of the spun silk is 0.1 mm, the silk strand is cooled by side blowing to form a tow, the static electricity of the cooled tow is eliminated by oiling, the oil content is controlled at 1%, and the oiled tow is subjected to drawing and setting treatment, the drawing and setting are achieved through 1-stage preheating, 2-stage drawing, and 2-stage setting between six pairs of hot rollers: among them, the temperature of the first pair of hot rollers is 35 °C, the temperature of the second pair of hot rollers is 50 °C, the first pair of hot rollers and the second pair of hot rollers preheat the silk strand, and the draw ratio is 1 times; wind the set tow into a silk bobbin, and the winding speed is 3500 m / min to obtain easily dyed and antioxidant nylon filaments.

[0061] Comparative Example 1

[0062] Compared with Example 3, the difference is that the pore-forming agent ethylene oxide-propylene oxide triblock copolymer PEO20-PPO70-PEO20 was not added in step S1.

[0063] Specifically as follows:

[0064] S1. Dissolve 13 g of tetraethyl orthosilicate in 200 mL of dichloromethane to obtain solution A; dissolve 2.3 g of Tween-85 in 300 mL of water to obtain solution B; add solution A dropwise to solution B, emulsify at 7000 r / min for 15 min, adjust the pH value of the solution to 9.5, stir and react for 11 h, centrifuge, wash, and dry to obtain porous silica nanospheres.

[0065] Comparative Example 2

[0066] Compared with Example 3, the difference lies in that step S2 is not carried out.

[0067] Specifically as follows:

[0068] S1. Dissolve 13 g of tetraethyl orthosilicate in 200 mL of dichloromethane to obtain solution A; dissolve 1.5 g of poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) PEO20-PPO70-PEO20 and 0.8 g of Tween-85 in 300 mL of water to obtain solution B; add solution A dropwise to solution B, emulsify at 7000 r / min for 15 min, adjust the pH value of the solution to 9.5, stir and react for 11 h, centrifuge, wash, and dry to obtain porous silica nanospheres;

[0069] S2. Add 5.5 g of 3,5-di-tert-butyl-4-hydroxycinnamic acid to 200 mL of ethanol, add 4 g of silane coupling agent KH570 and 0.015 g of azobisisobutyronitrile, heat to 55 °C, stir and react for 4 h, filter, wash, and dry to obtain an antioxidant;

[0070] S3. Add 5 g of the antioxidant to 200 mL of water, add 1.5 g of NHS and 1.2 g of EDC, stir and activate for 25 min, add 10 g of porous silica nanospheres, stir and react for 9 h, centrifuge, wash, and dry to obtain a conjugate;

[0071] S4. Add 10 g of the conjugate to 40 mL of graphene oxide aqueous dispersion, ultrasonically disperse at 1000 W for 10 min, and spray dry to obtain a wrinkled coating modifier;

[0072] S5. Heat 100 g of caprolactam to 75 °C to melt it, add 1.5 g of 6-aminocaproic acid and 10 g of the wrinkled coating modifier, stir and mix for 15 min, heat under reduced pressure and stir to react, the temperature is 250 °C, the rotation speed is 120 r / min, the reaction pressure is 0.05 MPa, the time is 4 h, discharge and cool, dry, slice to obtain nylon slices;

[0073] S6. Feed nylon chips into a screw extruder, heat to 290 °C to obtain a melt, convey the melt to a spinning box under pressure, measure it with a metering pump, and then extrude through a spinning component. The fineness of the extruded filaments is 0.1 mm. The filaments are cooled by side blowing to form a tow. The cooled tow is oiled to eliminate static electricity, and the oil content is controlled at 1%. The oiled tow is subjected to drawing and setting treatment, which is achieved by 1 stage of preheating, 2 stages of drawing, and 2 stages of setting between six pairs of hot rollers: among them, the temperature of the first pair of hot rollers is 35 °C, the temperature of the second pair of hot rollers is 50 °C, the first pair of hot rollers and the second pair of hot rollers preheat the filaments, and the draw ratio is 1 time; wind the set filaments into a bobbin, and the winding speed is 3500 m / min to produce easily dyeable and antioxidant nylon filaments.

[0074] Comparative Example 3

[0075] Compared with Example 3, the difference is that step S3 is not carried out, and the antioxidant in step S4 is 3,5 - di - tert - butyl - 4 - hydroxystyrene acid.

[0076] Specifically as follows:

[0077] S1. Dissolve 13 g of tetraethyl orthosilicate in 200 mL of dichloromethane to obtain solution A; dissolve 1.5 g of poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) PEO20 - PPO70 - PEO20 and 0.8 g of Tween - 85 in 300 mL of water to obtain solution B; drop solution A into solution B, emulsify at 7000 r / min for 15 min, adjust the pH value of the solution to 9.5, stir and react for 11 h, centrifuge, wash, and dry to obtain porous silica nanospheres;

[0078] S2. Add 11 g of porous silica nanospheres to 200 mL of water, add 5 g of dopamine hydrochloride and 1.5 g of catalyst, heat to 50 °C, stir and react for 4 h, centrifuge, wash, and dry to obtain modified porous silica nanospheres;

[0079] The catalyst is a Tris - HCl solution with pH = 9;

[0080] S3. Add 5 g of 3,5 - di - tert - butyl - 4 - hydroxystyrene acid to 200 mL of water, add 1.5 g of NHS and 1.2 g of EDC, stir and activate for 25 min, add 10 g of modified porous silica nanospheres, stir and react for 9 h, centrifuge, wash, and dry to obtain a conjugate;

[0081] S4. Add 10 g of conjugate to 40 mL of graphene oxide aqueous dispersion, ultrasonically disperse at 1000 W for 10 min, and spray dry to obtain a wrinkled coating modifier;

[0082] S5. Heat 100 g of caprolactam to 75 °C for melting, add 1.5 g of 6-aminocaproic acid and 10 g of wrinkled coating modifier, stir and mix for 15 min, heat under reduced pressure and stir for reaction, with the temperature at 250 °C, the rotation speed at 120 r / min, the reaction pressure at 0.05 MPa, and the time at 4 h. Discharge the material and cool it, then dry and slice it to obtain nylon slices;

[0083] S6. Feed the nylon slices into a screw extruder, heat to 290 °C to obtain a melt, convey the melt to a spinning box under pressure, meter it through a metering pump and then extrude it through a spinning pack. The fineness of the extruded filaments is 0.1 mm. The filaments are cooled by side air blowing to form a tow. Eliminate static electricity from the cooled tow by applying oil, with the oil attachment amount controlled at 1%. Conduct stretching and setting treatment on the oiled tow. The stretching and setting are achieved through 1 section of preheating, 2 sections of stretching, and 2 sections of setting between six pairs of hot rollers: Among them, the temperature of the first pair of hot rollers is 35 °C, the temperature of the second pair of hot rollers is 50 °C, and the first pair of hot rollers and the second pair of hot rollers play a preheating role for the filaments, with a stretching ratio of 1 time; Wind the set tow into a filament bobbin, with the winding speed at 3500 m / min, to obtain easily dyeable and antioxidant nylon filaments.

[0084] Comparative Example 4

[0085] Compared with Example 3, the difference lies in that step S5 is not carried out.

[0086] Specifically as follows:

[0087] S1. Dissolve 13 g of tetraethyl orthosilicate in 200 mL of dichloromethane to obtain solution A; dissolve 1.5 g of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer PEO20-PPO70-PEO20 and 0.8 g of Tween-85 in 300 mL of water to obtain solution B; drop solution A into solution B, emulsify at 7000 r / min for 15 min, adjust the pH value of the solution to 9.5, stir and react for 11 h, centrifuge, wash, and dry to obtain porous silica nanospheres;

[0088] S2. Add 11 g of porous silica nanospheres to 200 mL of water, add 5 g of dopamine hydrochloride and 1.5 g of catalyst, heat to 50 °C, stir and react for 4 h, centrifuge, wash, and dry to obtain modified porous silica nanospheres;

[0089] The catalyst is a Tris-HCl solution with pH = 9;

[0090] S3. Add 5.5 g of 3,5-di-tert-butyl-4-hydroxystyrene acid to 200 mL of ethanol, add 4 g of silane coupling agent KH570 and 0.015 g of azobisisobutyronitrile, heat to 55 °C, stir and react for 4 h, filter, wash, and dry to obtain an antioxidant;

[0091] S4. Add 5 g of antioxidant to 200 mL of water, add 1.5 g of NHS and 1.2 g of EDC, stir and activate for 25 min, add 10 g of modified porous silica nanospheres, stir and react for 9 h, centrifuge, wash, and dry to obtain the conjugate;

[0092] S5. Heat 100 g of caprolactam to 75 °C to melt it, add 1.5 g of 6-aminocaproic acid and 10 g of the conjugate, stir and mix for 15 min, heat and stir under reduced pressure for reaction, the temperature is 250 °C, the rotation speed is 120 r / min, the reaction pressure is 0.05 MPa, the time is 4 h, discharge the material and cool, dry, slice to obtain nylon slices;

[0093] S6. Feed the nylon slices into a screw extruder, heat to 290 °C to obtain a melt, convey the melt to a spinning box under pressure, meter it through a metering pump and then spin it through a spinning pack. The fineness of the spun yarn is 0.1 mm. The yarn is cooled by side blowing to form a yarn bundle. The cooled yarn bundle is electrostatically eliminated by oiling. The oil content is controlled at 1%. The oiled yarn bundle is subjected to drawing and setting treatment. The drawing and setting are achieved through 1 stage of preheating, 2 stages of drawing, and 2 stages of setting between six pairs of hot rollers: among them, the temperature of the first pair of hot rollers is 35 °C, the temperature of the second pair of hot rollers is 50 °C, the first pair of hot rollers and the second pair of hot rollers preheat the yarn, and the draw ratio is 1 time; wind the set yarn bundle into a yarn bobbin, and the winding speed is 3500 m / min to obtain easily dyeable and antioxidant nylon filaments.

[0094] Comparative Example 5

[0095] Compared with Example 3, the difference is that steps S3 and S4 are not carried out, and in step S5, the conjugate is replaced by modified porous silica nanospheres.

[0096] Specifically as follows:

[0097] S1. Dissolve 13 g of tetraethyl orthosilicate in 200 mL of dichloromethane to obtain solution A; dissolve 1.5 g of ethylene oxide-propylene oxide triblock copolymer PEO20-PPO70-PEO20 and 0.8 g of Tween-85 in 300 mL of water to obtain solution B; drop solution A into solution B, emulsify at 7000 r / min for 15 min, adjust the pH value of the solution to 9.5, stir and react for 11 h, centrifuge, wash, and dry to obtain porous silica nanospheres;

[0098] S2. Add 11 g of porous silica nanospheres to 200 mL of water, add 5 g of dopamine hydrochloride and 1.5 g of catalyst, heat to 50 °C, stir and react for 4 h, centrifuge, wash, and dry to obtain modified porous silica nanospheres;

[0099] The catalyst is a Tris-HCl solution with a pH of 9;

[0100] S3. Add 10 g of modified porous silica nanospheres to 40 mL of graphene oxide aqueous dispersion, ultrasonically disperse for 10 min at 1000 W, and spray dry to obtain a wrinkled coating modifier;

[0101] S4. Heat 100 g of caprolactam to 75 °C to melt it, add 1.5 g of 6-aminocaproic acid and 10 g of the wrinkled coating modifier, stir and mix for 15 min, heat under reduced pressure and stir to react at a temperature of 250 °C, a rotation speed of 120 r / min, a reaction pressure of 0.05 MPa, and a time of 4 h. Discharge and cool, dry, slice to obtain nylon chips;

[0102] S5. Feed the nylon chips into a screw extruder, heat to 290 °C to obtain a melt, pressurize and transport the melt to a spinning box, meter it through a metering pump, and then spray the melt through a spinning pack. The fineness of the filaments ejected by the spinneret is 0.1 mm. The filaments are cooled by side blowing to form a tow. Eliminate static electricity from the cooled tow by applying oil, and control the oil absorption amount to 1%. Perform drawing and setting on the oiled tow. The drawing and setting are achieved through 1 stage of preheating, 2 stages of drawing, and 2 stages of setting between six pairs of hot rolls: Among them, the temperature of the first pair of hot rolls is 35 °C, the temperature of the second pair of hot rolls is 50 °C, and the first pair of hot rolls and the second pair of hot rolls preheat the filaments, and the draw ratio is 1 time; Wind the set tow into a bobbin, and the winding speed is 3500 m / min to obtain easily dyed and antioxidant nylon filaments.

[0103] Test Example 1 Yellow Index Test

[0104] Take the easily dyed and antioxidant nylon filaments prepared in Examples 1-3 or Comparative Examples 1-5 and place them in a ventilated thermal aging test chamber. Set the aging chamber temperature to 180 °C, the opening of the ventilation valve to 1 / 2, and perform ventilation by blowing air. After 120 min, take out the samples to be tested, and measure their yellow index (YI value) using a CM-3600d spectrophotometer according to HG / 3862-2006.

[0105] The results are shown in Table 1.

[0106] Table 1

[0107] Group Yellow Index (YI value) Example 1 12.1 Example 2 11.9 Example 3 11.4 Comparative Example 1 12.4 Comparative Example 2 27.5 Comparative Example 3 23.9 Comparative Example 4 14.5 Comparative Example 5 34.8

[0108] As can be seen from the above table, the yellow values of the easily dyed and antioxidant nylon filaments prepared in Examples 1-3 of the present invention are very low, and they have a good effect of resisting color change.

[0109] Test Example 2

[0110] The easily dyeable and antioxidant nylon filaments prepared in Examples 1-3 or Comparative Examples 1-5 were placed in a ventilation type thermal aging test chamber. The temperature of the aging chamber was set at 180 °C, the opening degree of the ventilation valve was 1 / 2, and air was exchanged by blowing. After 120 min, the samples to be tested were taken out, and the breaking strength and elongation at break of the samples to be tested were measured before and after the thermal oxygen aging test.

[0111] The results are shown in Table 2.

[0112] Table 2

[0113]

[0114] As can be seen from the above table, the easily dyeable and antioxidant nylon filaments prepared in Examples 1-3 of the present invention have good mechanical properties and good antioxidant properties.

[0115] Test Example 3

[0116] The easily dyeable and antioxidant nylon filaments prepared in Examples 1-3 or Comparative Examples 1-5 were subjected to performance tests.

[0117] The results are shown in Table 3.

[0118] Table 3

[0119] Group Heat shrinkage rate (%) Coefficient of variation of linear density (%) Example 1 1.7 0.44 Example 2 1.8 0.45 Example 3 1.5 0.42 Comparative Example 1 2.0 0.48 Comparative Example 2 2.7 0.54 Comparative Example 3 3.3 0.87 Comparative Example 4 5.9 1.95 Comparative Example 5 7.8 2.89

[0120] As can be seen from the above table, the easily dyeable and antioxidant nylon filaments prepared in Examples 1-3 of the present invention have good comprehensive properties.

[0121] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preparation method of easily dyeable and antioxidant nylon filaments, characterized in that, A silane coupling agent with a double bond and 3,5-di-tert-butyl-4-hydroxystyrene acid are copolymerized through the double bond under the conditions of an initiator, heating and stirring to obtain an antioxidant. The antioxidant and the porous silica nanospheres coated with polydopamine are coupled through an amidation reaction under the conditions of NHS / EDC activator and stirring. The coupling product is ultrasonically dispersed and spray-dried in the graphene oxide aqueous dispersion to form a wrinkled coating modifier. The wrinkled coating modifier is added to caprolactam, and 6-aminocaproic acid is added. The reaction is carried out by heating under reduced pressure with stirring, the material is discharged and cooled, dried, sliced to obtain nylon slices, and then through melt extrusion, spinning, cooling, oiling, drawing and setting, winding to obtain easily dyeable and antioxidant nylon filaments.

2. The preparation method according to claim 1, characterized in that, It includes the following steps: S1. Dissolve an alkyl orthosilicate in an organic solvent to obtain solution A; dissolve a pore-forming agent and an emulsifier in water to obtain solution B; drop solution A into solution B, emulsify, adjust the pH value of the solution, stir and react, centrifuge, wash, and dry to obtain porous silica nanospheres; S2. Add the porous silica nanospheres into water, add dopamine hydrochloride and a catalyst, heat and stir to react, centrifuge, wash, and dry to obtain modified porous silica nanospheres; S3. Add 3,5-di-tert-butyl-4-hydroxystyrene acid into ethanol, add a silane coupling agent with a double bond and an initiator, heat and stir to react, filter, wash, and dry to obtain an antioxidant; S4. Add the antioxidant into water, add NHS and EDC, stir and activate, add the modified porous silica nanospheres, stir and react, centrifuge, wash, and dry to obtain a conjugate; S5. Add the conjugate into the graphene oxide aqueous dispersion, ultrasonically disperse it evenly, and spray-dry to obtain a wrinkled coating modifier; S6. Heat and melt caprolactam, add 6-aminocaproic acid and the wrinkled coating modifier, stir and mix evenly, heat and stir under reduced pressure to react, discharge and cool, dry, slice to obtain nylon slices; S7. Send the nylon slices to a screw extruder, pressurize and convey the melt to a spinning box, measure it through a metering pump and then spin it through a spinning pack. The filament is cooled by side blowing to form a filament bundle. Eliminate static electricity from the cooled filament bundle by oiling, perform drawing and setting treatment on the oiled filament bundle, and wind the set filament bundle into a filament bobbin to obtain easily dyeable and antioxidant nylon filaments.

3. The preparation method according to claim 2, characterized in that, In step S1, the alkyl orthosilicate is methyl orthosilicate or ethyl orthosilicate. The mass ratio of the alkyl orthosilicate, the pore-forming agent, and the emulsifier is 12-15:1-2:0.5-1. The pore-forming agent is selected from at least one of cetyltrimethylammonium chloride, ethylene oxide-propylene oxide triblock copolymer PEO20-PPO70-PEO20, or ethylene oxide-propylene oxide triblock copolymer PEO106-PPO70-PEO106. The emulsifier is selected from at least one of Tween-20, Tween-40, Tween-60, Tween-80, or Tween-85. The adjusted solution pH value is 9-10, and the stirring reaction time is 10-12 h.

4. The preparation method according to claim 2, characterized in that, In step S2, the mass ratio of the porous silica nanospheres, dopamine hydrochloride, and catalyst is 10 - 12:4 - 6:1 - 2. The catalyst is a Tris-HCl solution with a pH of 8.5 - 9.

5. The temperature of the heating and stirring reaction is 45 - 55°C, and the time is 3 - 5 h.

5. The preparation method according to claim 2, characterized in that, In step S3, the mass ratio of 3,5-di-tert-butyl-4-hydroxystyrene acid, the silane coupling agent with a double bond, and the initiator is 4 - 7:3 - 5:0.01 - 0.

02. The silane coupling agent with a double bond is selected from at least one of KH570, A151, and A171. The initiator is azobisisobutyronitrile. The temperature of the heating and stirring reaction is 50 - 60°C, and the time is 3 - 5 h.

6. The preparation method according to claim 2, characterized in that, In step S4, the mass ratio of the antioxidant, NHS, EDC, and the modified porous silica nanospheres is 4 - 7:1 - 2:1 - 2:

10. The time for stirring activation is 20 - 30 min, and the time for the stirring reaction is 8 - 10 h.

7. The preparation method according to claim 2, characterized in that, In step S5, the concentration of the graphene oxide aqueous dispersion is 0.5 - 1 mg / mL, and the liquid-solid ratio of the graphene oxide aqueous dispersion to the conjugate is 3 - 5 mL:1 g.

8. The preparation method according to claim 2, wherein, In step S6, the temperature of the heating and melting is 70 - 75°C. The mass ratio of caprolactam, 6-aminocaproic acid, and the wrinkled coating modifier is 100:1 - 2:7 - 12. The temperature of the heating and reduced-pressure stirring reaction is 240 - 260°C, the rotation speed is 100 - 150 r / min, the reaction pressure is 0.02 - 0.08 MPa, and the time is 3 - 5 h.

9. The preparation method according to claim 2, characterized in that, In step S7, the temperature of the melt extrusion is 280 - 300°C. The fineness of the filaments extruded from the spinneret is 0.05 - 0.1 mm, and the oil content is controlled to be 0.5 - 1.5%. The drawing and setting are achieved through 1 stage of preheating, 2 stages of stretching, and 2 stages of setting between six pairs of hot rollers: among them, the temperature of the first pair of hot rollers is 30 - 40°C, the temperature of the second pair of hot rollers is 45 - 55°C. The first pair of hot rollers and the second pair of hot rollers preheat the filament. The drawing ratio is 1 - 1.01 times. The winding speed is 3000 - 4000 m / min.

10. An easily dyeable and antioxidant nylon filament prepared by the preparation method according to any one of claims 1 - 9.

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