PA66 eight-end spun super high strength industrial yarn and preparation method thereof

Abstract

The application provides PA66 eight-head spinning super-high-strength industrial yarn and a preparation method thereof, and belongs to the technical field of nylon. Amino-modified metal organic framework is coupled with tannic acid modified polyacenic polymer, is added into a high-viscosity slurry of molten nylon 66, is uniformly mixed, is melt-extruded and spun, is cooled by side blowing to form a yarn bundle, is oiled, is drafted and shaped, and is wound into a yarn drum to obtain the PA66 eight-head spinning super-high-strength industrial yarn. The PA66 eight-head spinning super-high-strength industrial yarn prepared by the application has high mechanical strength and small thermal shrinkage. The modifier contains rich amino and carboxyl structures, can form hydrogen bonds with the high polymer structure of nylon 66 to realize uniform dispersion, and thus improves the mechanical properties, antistatic properties and flame-retardant properties of the nylon 66 high-strength yarn, has good shape retention, and has a good application prospect.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of nylon, in particular to PA66 eight-end spinning super-high-strength industrial yarn and a preparation method thereof. BACKGROUND

[0002] The nylon 66 industry began to realize industrialization in 1939 and is widely applied to the fields of chemical fibers and engineering plastics, in particular in the past 10 years, the world nylon consumption increases at an average annual rate of about 7.5%. As one kind of engineering plastics, nylon is widely applied to many fields such as military textiles, industry, clothing, decoration and engineering plastics.

[0003] On the basis of the POY-DTY production technology of Nylstar company, through the retransformation of key equipment, production process exploration and optimization, a series of ultra-fine denier nylon 66 DTY fibers such as 31dtex / 23f, 44dtex / 34f, 64dtex / 68f, 78dtex / 152f and 78dtex / 168f are independently developed and successfully put into the market, the quality level reaches or approaches the same brand products of European and American manufacturers, and good benefits are obtained. At present, the ultra-fine denier fiber accounts for more than 30% of the total amount of POY-DTY products of the company, and the domestic market share ranks the forefront.

[0004] The PA66 fiber is obtained by the polycondensation reaction of ethylenediamine containing 6 carbon atoms and adipic acid containing 6 carbon atoms to obtain a polyamide resin, and then melt spinning; the PA66 fiber molecular chain has high order and arrangement regularity, has excellent molecular chain orientation and crystallinity, and has hydrogen bond and van der waals force and other intermolecular forces, so that it has excellent mechanical properties and good rigidity and strength, but due to the regular structure of the PA66 molecular chain, the branch chain and the hetero chain are less, the intermolecular force is less, the molecular chain is easy to slip, the fiber produces irreversible deformation in the use process, which makes the PA66 fiber have poor shape retention in the use process, is easy to deform and cause creep, and has poor antistatic property, is easy to produce static electricity in the use process and destroy the original use comfort of the fiber. And the mechanical strength is low, which limits its application. SUMMARY

[0005] The purpose of the application is to provide a PA66 eight-end spinning super-high-strength industrial yarn and a preparation method thereof, the prepared PA66 eight-end spinning super-high-strength industrial yarn has high mechanical strength and small thermal shrinkage, the modifier contains rich amino and carboxyl structures, can form hydrogen bonds with the nylon 66 high molecular structure to realize uniform dispersion, thereby improving the mechanical properties, antistatic property and flame retardant property of the nylon 66 high-strength yarn, and the shape retention is good, and the application prospect is good.

[0006] The technical scheme of the present application is implemented as follows:

[0007] The present application provides a preparation method of PA66 eight-head spinning super-high-strength industrial yarn, amino-modified metal organic framework is coupled with tannic acid modified polyacenic polymer by being added into high-viscosity slurry of molten nylon 66, uniformly mixed, melt extrusion spinning, the yarn is cooled by side blowing to form a bundle, oiled, drawn and set, and wound into a yarn drum to obtain PA66 eight-head spinning super-high-strength industrial yarn.

[0008] As a further improvement of the present application, the following steps are included:

[0009] S1. Preparation of UiO-66-NH2: zirconium tetrachloride and 2-amino terephthalic acid are added into N,N-dimethylformamide, acetic acid is added, ultrasonic stirring is performed to uniformly disperse, hydrothermal reaction is performed, centrifugation is performed, washing is performed, and drying is performed to obtain UiO-66-NH2;

[0010] S2. Preparation of polyacenic polymer: phenol, formaldehyde and ammonia water are mixed, heated and refluxed, stirring reaction is performed, the pH value of the solution is adjusted, heating reaction is continuously performed, zinc chloride is added, heating solidification is performed, thermal cracking is performed, crushing is performed, and ball milling is performed to obtain polyacenic polymer;

[0011] S3. Preparation of tannic acid modified polyacenic polymer: polyacenic polymer is added into water, tannic acid and a catalyst are added, heating stirring reaction is performed, centrifugation is performed, washing is performed, and drying is performed to obtain tannic acid modified polyacenic polymer;

[0012] S4. Preparation of modifier: tannic acid modified polyacenic polymer is added into water, NHS and EDC are added, stirring activation is performed, UiO-66-NH2 is added, stirring reaction is performed, centrifugation is performed, washing is performed, and drying is performed to obtain the modifier;

[0013] S5. Solid phase tackification and moisture adjustment: nylon 66 spinning grade chips are subjected to solid phase tackification and moisture adjustment treatment to obtain nylon 66 medium-high tack chips;

[0014] S6. Melt extrusion spinning: the nylon 66 medium-high tack chips are sent to a screw extruder, the modifier is added, melt extrusion is performed, filtration is performed, and spinning is performed through an eight-head spinning device;

[0015] S7. Cooling, oiling, drawing, setting and winding: the yarn is cooled by side blowing to form a bundle, oiled, drawn, set and wound into a yarn drum to obtain PA66 eight-head spinning super-high-strength industrial yarn.

[0016] As a further improvement of the present application, the mass ratio of the zirconium tetrachloride, 2-amino terephthalic acid, and acetic acid in step S1 is 0.12-0.17:0.11-0.14:2-3, the power of the ultrasonic stirring dispersion is 1000-2000W, the time is 10-20min, the temperature of the hydrothermal reaction is 120-130℃, and the time is 20-24h.

[0017] As a further improvement of the present application, the molar ratio of the phenol and formaldehyde in step S2 is 1:1-1.2, the mass ratio of the ammonia water and zinc chloride is 5-7:0.5-1, the time of the heating reflux stirring reaction is 2-4h, the pH value of the solution is adjusted to 4-6, the time of the continued heating reaction is 1-3h, the temperature of the heating solidification is 65-75℃, the time is 24-28h, the temperature of the thermal cracking is 1100-1200℃, and the time is 2-4h.

[0018] As a further improvement of the present application, the mass ratio of the polybenzene, tannic acid, and catalyst in step S3 is 10:2-3:0.5-1, the catalyst is Tris-HCl solution with pH=8.5-9.5, the temperature of the heating stirring reaction is 40-50℃, and the time is 3-5h.

[0019] As a further improvement of the present application, the mass ratio of the tannic acid modified polybenzene, NHS, EDC, and UiO-66-NH2 in step S4 is 10-12:3-4:2-3:4-7, the time of the stirring activation is 20-40min, and the time of the stirring reaction is 10-12h.

[0020] As a further improvement of the present application, the relative viscosity of the nylon 66 spinning grade chip in step S5 is 2.2-2.3, the water content of the nylon 66 high viscosity chip is 650-750ppm, and the relative viscosity is 3.3-3.5, the solid phase tackifying is carried out on the chip under the condition of 140-170℃, and the nitrogen is used for countercurrent circulation.

[0021] As a further improvement of the present application, the addition amount of the modifier in step S6 is 3-5wt%, the temperature of the melt extrusion is 280-300℃, and the fineness of the jet spinning is 0.03-0.05mm.

[0022] As a further improvement of the present application, the additional amount of the oil in step S7 is controlled to be 0.5-1.5%; the drafting setting is achieved by 1-stage preheating, 2-stage stretching and 2-stage setting between six pairs of hot rollers: wherein the temperature of the first pair of hot rollers is 30-40 DEG C, the temperature of the second pair of hot rollers is 45-55 DEG C, the first pair of hot rollers and the second pair of hot rollers play a preheating role for the yarn, and the stretching ratio is 1-1.01 times; and the winding speed is 3000-4000 m / min.

[0023] The present application further protects a PA66 eight-end special high-strength industrial yarn prepared by the above preparation method.

[0024] The present application has the following beneficial effects:

[0025] The present application couples a metal organic framework UiO-66-NH2 with tannic acid modified polyacenic carbon by adding it into the nylon 66 spinning dope, the UiO-66-NH2 has a high specific surface area and pore volume, which enables it to provide more contact area when used as a reinforcing body to interact with the nylon matrix, facilitates the diffusion of nylon molecules in its pores, increases the adhesion of the interface, and thus improves the mechanical properties of the composite material. The tannic acid modified polyacenic carbon is coupled with the UiO-66-NH2 through dehydration condensation, has a large specific surface area, greatly improves the dispersibility of the modifier in the nylon 66 dope, the UiO-66-NH2 has good conductivity and electrostatic repulsion properties, enhances the electrical conductivity of the material, thereby improving the antistatic performance, at the same time, the prepared modifier has a porous performance, which enables it to effectively capture and adsorb water molecules, the presence of water helps to improve the electrical conductivity of the nylon 66 high-strength yarn.

[0026] The phenolic resin obtained by high-temperature pyrolysis has a graphite-like structure of polyacenic carbon nanoparticles with a conjugated structure, a very low hydrogen content, and will not generate toxic and corrosive gases when heated, and can greatly reduce the smoke emission, has good thermal stability, and when burning, no black smoke, no dripping, carbonization, which improves the combustion behavior of the nylon material. At the same time, the polyacenic carbon particles form a thick protective carbon layer on the surface of the polymer after burning, reducing the mass and heat transfer between the gas phase and the condensed phase, improving the flame retardant performance of the prepared nylon 66 high-strength yarn. In addition, the tannic acid modified polyacenic carbon can form a conductive path in the nylon 66 material through the multi-ring and conjugated structure, and the multi-carboxyl and amino structure can make the modifier particles uniformly dispersed in the nylon 66, the distance between the particles is small, the conductive carriers can easily migrate, thereby forming a conductive network, the resistivity is greatly reduced, the prepared nylon 66 high-strength yarn has good antistatic performance, at the same time, the molecular structure of the tannic acid modified polyacenic carbon contains benzene rings, which enables it to form a strong interfacial bonding force with the nylon 66. Good interfacial bonding can effectively transfer stress and reduce stress concentration, thereby improving the overall mechanical properties of the composite material.

[0027] Compared with directly adding UiO-66 or polyacenic molecules in a nylon 66 slurry and then performing spinning, the PA66 eight-end spun super-high-strength industrial yarn prepared by the method has higher mechanical strength, small thermal shrinkage, and the modifier contains rich amino and carboxyl structures, can form hydrogen bonds with the high molecular structure of nylon 66 to achieve uniform dispersion, thereby improving the mechanical properties, antistatic properties, flame retardant properties, and shape retention of the nylon 66 high-strength yarn, and has a good application prospect. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0029] NHS, N-hydroxysuccinimide; EDC, 1-ethyl-(3-dimethylaminopropyl) carbodiimide.

[0030] Embodiment 1

[0031] The present embodiment provides a preparation method of PA66 eight-end spun super-high-strength industrial yarn, comprising the following steps:

[0032] S1. Preparation of UiO-66-NH2: 0.12 g of zirconium tetrachloride and 0.11 g of 2-amino terephthalic acid are added to 50 mL of N,N-dimethylformamide, 2 g of acetic acid is added, 1000 W ultrasonic stirring and dispersion for 10 min, 120℃ hydrothermal reaction for 20 h, centrifugation, washing, and drying to obtain UiO-66-NH2;

[0033] S2. Preparation of polyacenic molecules: 0.1 mol of phenol, 0.1 mol of formaldehyde, and 5 g of ammonia water are mixed, heated to reflux and stirred for reaction for 2 h, the pH value of the solution is adjusted to 4, heating reaction is continued for 1 h, 0.5 g of zinc chloride is added, heating at 65℃, solidification for 24 h, 1100℃ pyrolysis for 2 h, crushing, and ball milling for 1 h to obtain polyacenic molecules;

[0034] S3. Preparation of tannic acid modified polyacenic molecules: 1 g of polyacenic molecules is added to 200 mL of water, 0.2 g of tannic acid and 0.05 g of catalyst are added, heated to 40℃, stirred for reaction for 3 h, centrifuged, washed, and dried to obtain tannic acid modified polyacenic molecules;

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

[0036] S4. Preparation of modifier: 1 g of tannic acid modified polyacene was added to 100 mL of water, 0.3 g of NHS and 0.2 g of EDC were added, stirred for 20 min, 0.4 g of UiO-66-NH2 was added, stirred for 10 h, centrifuged, washed, dried, and the modifier was prepared;

[0037] S5. Solid phase tackification and moisture adjustment: the nylon 66 spinning grade chip with a relative viscosity of 2.2 was subjected to solid phase tackification and moisture adjustment treatment to obtain nylon 66 medium-high tack chip, the water content was 650 ppm, and the relative viscosity was 3.3;

[0038] The solid phase tackification is carried out on the chip under the condition of 140℃ and using nitrogen for countercurrent circulation;

[0039] S6. Melt extrusion spinning: the nylon 66 medium-high tack chip was sent to a screw extruder, the modifier was added in an amount of 3wt%, and melt extrusion was carried out at 280℃, filtration, jetting was carried out through an eight-head spinning device, and the jetting fineness was 0.05mm;

[0040] S7. Cooling, oiling, drafting, winding: the yarn was cooled to form a yarn bundle through side blowing, oiled, the oil addition amount was controlled to be 0.5%, drafted, wound into a yarn can, the winding speed was 3000m / min, and PA66 eight-head spun super-high-strength industrial yarn was prepared;

[0041] The drafting is realized through 1 segment of preheating, 2 segments of stretching, and 2 segments of setting between six pairs of hot rollers: the temperature of the first pair of hot rollers is 30℃, the temperature of the second pair of hot rollers is 45℃, the first pair of hot rollers and the second pair of hot rollers preheat the yarn, and the stretching ratio is 1 times.

[0042] Example 2

[0043] The embodiment provides a preparation method of PA66 eight-head spun super-high-strength industrial yarn, which comprises the following steps:

[0044] S1. Preparation of UiO-66-NH2: 0.17 g of zirconium tetrachloride and 0.14 g of 2-amino terephthalic acid were added to 50 mL of N,N-dimethylformamide, 3 g of acetic acid was added, 2000W ultrasonic stirring was carried out for 20 min, 130℃ hydrothermal reaction was carried out for 24 h, centrifugation, washing, and drying were carried out, and UiO-66-NH2 was prepared;

[0045] S2. Preparation of polyacene: 0.1 mol of phenol, 0.12 mol of formaldehyde, and 7 g of ammonia water were mixed, heated to reflux and stirred for 4 h, the pH value of the solution was adjusted to 6, heating was continued for 3 h, 1 g of zinc chloride was added, heating was carried out at 75℃, and solidification was carried out for 28 h, 1200℃ pyrolysis was carried out for 4 h, crushing was carried out, ball milling was carried out for 1 h, and polyacene was prepared;

[0046] S3. Preparation of tannic acid modified polyacenic hydrocarbon: 1 g of polyacenic hydrocarbon was added to 200 mL of water, 0.3 g of tannic acid and 0.1 g of catalyst were added, heated to 50°C, stirred for 5 h, centrifuged, washed, dried, and tannic acid modified polyacenic hydrocarbon was prepared;

[0047] The catalyst is Tris-HCl solution with pH = 9.5;

[0048] S4. Preparation of modifier: 1.2 g of tannic acid modified polyacenic hydrocarbon was added to 100 mL of water, 0.4 g of NHS and 0.3 g of EDC were added, stirred for 40 min, 0.7 g of UiO-66-NH2 was added, stirred for 12 h, centrifuged, washed, dried, and the modifier was prepared;

[0049] S5. Solid phase tackification and moisture conditioning: nylon 66 spinning grade chips with a relative viscosity of 2.3 were subjected to solid phase tackification and moisture conditioning treatment to obtain nylon 66 medium-high tack chips with a water content of 750 ppm and a relative viscosity of 3.5;

[0050] The solid phase tackification is carried out by countercurrent circulation of the chips at 170°C using nitrogen;

[0051] S6. Melt extrusion spinning: the nylon 66 medium-high tack chips were fed into a screw extruder, the modifier was added in an amount of 5 wt%, and melt extrusion was carried out at 300°C, followed by filtration, jetting through an eight-head spinning device, and the jetted filament had a fineness of 0.05 mm;

[0052] S7. Cooling, oiling, drafting, setting, and winding: the yarn was cooled into a yarn bundle by side blowing, oiled with an oil addition amount controlled to 1.5%, drafted, set, and wound into a yarn can at a winding speed of 3800 m / min to obtain PA66 eight-head spun super-high-strength industrial yarn;

[0053] The drafting and setting are achieved through 1 stage of preheating, 2 stages of stretching, and 2 stages of setting between six pairs of hot rollers: the temperature of the first pair of hot rollers is 40°C, the temperature of the second pair of hot rollers is 55°C, the first pair of hot rollers and the second pair of hot rollers preheat the yarn, and the stretching ratio is 1.01 times.

[0054] Example 3

[0055] The present embodiment provides a preparation method of PA66 eight-head spun super-high-strength industrial yarn, which comprises the following steps:

[0056] S1. Preparation of UiO-66-NH2: 0.16 g of zirconium tetrachloride and 0.13 g of 2-amino terephthalic acid were added to 50 mL of N,N-dimethylformamide, 2.5 g of acetic acid was added, 1500 W ultrasonic stirring was carried out for 15 min, 125°C hydrothermal reaction was carried out for 22 h, centrifugation, washing, and drying were carried out, and UiO-66-NH2 was prepared;

[0057] S2. Preparation of polynaphthalene: 0.1 mol of phenol, 0.11 mol of formaldehyde, 6 g of ammonia water were mixed, heated to reflux and stirred for 3 h, the pH value of the solution was adjusted to 5, and the reaction was continued to heat for 2 h, 0.7 g of zinc chloride was added, heated to 70 ℃, solidified for 26 h, pyrolysis at 1150 ℃ for 3 h, and then crushed and ball milled for 1 h to obtain polynaphthalene;

[0058] S3. Preparation of tannic acid modified polynaphthalene: 1 g of polynaphthalene was added to 200 mL of water, 0.25 g of tannic acid and 0.07 g of catalyst were added, heated to 45 ℃, stirred for 4 h, centrifuged, washed and dried to obtain tannic acid modified polynaphthalene;

[0059] The catalyst is Tris-HCl solution with pH = 9;

[0060] S4. Preparation of modifier: 1.1 g of tannic acid modified polynaphthalene was added to 100 mL of water, 0.35 g of NHS and 0.25 g of EDC were added, stirred for 30 min, 0.5 g of UiO-66-NH2 was added, stirred for 11 h, centrifuged, washed and dried to obtain the modifier;

[0061] S5. Solid phase tackification and moisture adjustment: the nylon 66 spinning grade chip with a relative viscosity of 2.25 was subjected to solid phase tackification and moisture adjustment treatment to obtain nylon 66 medium-high tack chip, the water content was 700 ppm, and the relative viscosity was 3.4;

[0062] The solid phase tackification is carried out by countercurrent circulation of nitrogen at 155 ℃;

[0063] S6. Melt extrusion spinning: the nylon 66 medium-high tack chip was sent to a screw extruder, the modifier was added in an amount of 4 wt%, and melt extrusion was carried out at 290 ℃, followed by filtration, jetting through an eight-head spinning device, and the jetted filament had a fineness of 0.05 mm;

[0064] S7. Cooling, oiling, drafting, setting and winding: the yarn was cooled to form a yarn bundle by side blowing, oiled, the oil addition amount was controlled to be 1%, drafted, set and wound into a yarn can, the winding speed was 3500 m / min, and PA66 eight-head spun super-high-strength industrial yarn was prepared;

[0065] The drafting and setting are realized by 1-stage preheating, 2-stage stretching and 2-stage setting between six pairs of hot rollers: the temperature of the first pair of hot rollers is 35 ℃, the temperature of the second pair of hot rollers is 50 ℃, the first pair of hot rollers and the second pair of hot rollers preheat the yarn, and the stretching ratio is 1.005 times.

[0066] Comparative Example 1

[0067] The difference compared with Example 3 is that no UiO-66-NH2 is added.

[0068] The details are as follows:

[0069] S1. Preparation of polyacenic hydrocarbon: 0.1 mol of phenol, 0.11 mol of formaldehyde, and 6 g of ammonia water were mixed, heated to reflux and stirred for reaction for 3 h, the pH value of the solution was adjusted to 5, heating was continued for reaction for 2 h, 0.7 g of zinc chloride was added, heating was carried out at 70°C, solidification was carried out for 26 h, pyrolysis was carried out at 1150°C for 3 h, crushing was carried out, ball milling was carried out for 1 h, and polyacenic hydrocarbon was prepared.

[0070] S2. Preparation of tannic acid modified polyacenic hydrocarbon: 1 g of polyacenic hydrocarbon was added to 200 mL of water, 0.25 g of tannic acid and 0.07 g of catalyst were added, heating was carried out to 45°C, stirring was carried out for reaction for 4 h, centrifugation was carried out, washing was carried out, drying was carried out, and tannic acid modified polyacenic hydrocarbon was prepared.

[0071] The catalyst is Tris-HCl solution with pH = 9;

[0072] S3. Solid phase tackification and moisture adjustment: nylon 66 spinning grade chips with a relative viscosity of 2.25 were subjected to solid phase tackification and moisture adjustment treatment, obtaining nylon 66 medium-high tack chips, the water content was 700 ppm, and the relative viscosity was 3.4;

[0073] The solid phase tackification is carried out on the chips under the condition of 155°C by using nitrogen for countercurrent circulation;

[0074] S4. Melt extrusion spinning: the nylon 66 medium-high tack chips were sent to a screw extruder, tannic acid modified polyacenic hydrocarbon was added, the addition amount was 4 wt%, melt extrusion was carried out at 290°C, filtration was carried out, and spinning was carried out through an eight-head spinning device, the spun fineness was 0.05 mm;

[0075] S5. Cooling, oiling, drafting, setting, and winding: the yarn was cooled to form a yarn bundle through side blowing, oiled, the oil addition amount was controlled to be 1%, drafted, set, and wound into a yarn can, the winding speed was 3500 m / min, and PA66 eight-head spun super-high-strength industrial yarn was prepared.

[0076] The drafting and setting are realized through 1 section of preheating, 2 sections of stretching, and 2 sections of setting between six pairs of hot rollers: 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 have a preheating effect on the yarn, and the stretching ratio is 1.005 times.

[0077] Comparative Example 2

[0078] The difference compared with Example 3 is that no tannic acid modified polyacenic hydrocarbon is added.

[0079] The details are as follows:

[0080] Preparation of S1. UiO-66-NH2: 0.16 g of zirconium tetrachloride, 0.13 g of 2-amino terephthalic acid were added to 50 mL of N,N-dimethylformamide, 2.5 g of acetic acid was added, and the slice was dispersed by ultrasonic stirring at 1500 W for 15 min, and then hydrothermal reaction was carried out at 125°C for 22 h. After centrifugation, washing and drying, UiO-66-NH2 was prepared;

[0081] S2. Solid phase tackification and moisture conditioning: the nylon 66 spinning grade chip with a relative viscosity of 2.25 was subjected to solid phase tackification and moisture conditioning to obtain a nylon 66 medium-high tack chip with a water content of 700 ppm and a relative viscosity of 3.4;

[0082] The solid phase tackification was carried out on the chip by countercurrent circulation of nitrogen at 155°C;

[0083] S3. Melt extrusion spinning: the nylon 66 medium-high tack chip was fed into a screw extruder, and UiO-66-NH2 was added in an amount of 4 wt%, and melt extrusion was carried out at 290°C, followed by filtration, spinning through an eight-head spinning device, and the spun yarn had a fineness of 0.05 mm;

[0084] S4. Cooling, oiling, drafting, setting and winding: the yarn was cooled into a yarn bundle by side blowing, oiled with an oil addition of 1%, drafted, set and wound into a bobbin at a speed of 3500 m / min to obtain a PA66 eight-head spun super-high-strength industrial yarn;

[0085] The drafting and setting were achieved by 1 stage of preheating, 2 stages of stretching and 2 stages of setting between six pairs of hot rollers: the temperature of the first pair of hot rollers was 35°C, the temperature of the second pair of hot rollers was 50°C, the first pair of hot rollers and the second pair of hot rollers preheated the yarn, and the stretching ratio was 1.005 times.

[0086] Comparative Example 3

[0087] Compared with Example 3, the difference is that the polyacene is not modified by tannic acid.

[0088] The specific process is as follows:

[0089] S1. Preparation of UiO-66-NH2: 0.16 g of zirconium tetrachloride, 0.13 g of 2-amino terephthalic acid were added to 50 mL of N,N-dimethylformamide, 2.5 g of acetic acid was added, and the slice was dispersed by ultrasonic stirring at 1500 W for 15 min, and then hydrothermal reaction was carried out at 125°C for 22 h. After centrifugation, washing and drying, UiO-66-NH2 was prepared;

[0090] S2. Preparation of polynaphthalene: 0.1 mol of phenol, 0.11 mol of formaldehyde, 6 g of ammonia water were mixed, heated to reflux and stirred for 3 h, the pH value of the solution was adjusted to 5, the heating was continued for 2 h, 0.7 g of zinc chloride was added, heated to 70 ℃, solidified for 26 h, pyrolyzed at 1150 ℃ for 3 h, crushed, and ball milled for 1 h to obtain polynaphthalene;

[0091] S3. Preparation of modifier: 1.1 g of polynaphthalene was added to 100 mL of water, 0.35 g of NHS and 0.25 g of EDC were added, stirred for 30 min, 0.5 g of UiO-66-NH2 was added, stirred for 11 h, centrifuged, washed, and dried to obtain the modifier;

[0092] S4. Solid phase tackification and moisture conditioning: the nylon 66 spinning grade chip with a relative viscosity of 2.25 was subjected to solid phase tackification and moisture conditioning treatment to obtain nylon 66 medium-high tack chip, the water content was 700 ppm, and the relative viscosity was 3.4;

[0093] The solid phase tackification was carried out on the chip under the condition of 155 ℃ and using nitrogen for countercurrent circulation;

[0094] S5. Melt extrusion spinning: the nylon 66 medium-high tack chip was sent to a screw extruder, the modifier was added, the addition amount was 4 wt%, and melt extrusion was carried out at 290 ℃, filtration was carried out, and the spun yarn was obtained through an eight-head spinning device, the spun yarn had a fineness of 0.05 mm;

[0095] S6. Cooling, oiling, drawing setting, and winding: the yarn was cooled to form a yarn bundle through side blowing, oiled, the oil addition amount was controlled to be 1%, drawn and set, and wound into a yarn can, the winding speed was 3500 m / min, and PA66 eight-head spun super-high-strength industrial yarn was prepared;

[0096] The drawing setting was realized through 1 section of preheating, 2 sections of stretching, and 2 sections of setting between six pairs of hot rollers: the temperature of the first pair of hot rollers was 35 ℃, the temperature of the second pair of hot rollers was 50 ℃, the first pair of hot rollers and the second pair of hot rollers preheated the yarn, and the stretching ratio was 1.005 times.

[0097] Comparative example 4

[0098] Compared with example 3, the difference lies in that the modifier was prepared by mixing 1.1 g of polynaphthalene and UiO-66.

[0099] The specific process is as follows:

[0100] S1. Preparation of UiO-66: 0.16 g of zirconium tetrachloride and 0.13 g of phthalic acid were added to 50 mL of N,N-dimethylformamide, 2.5 g of acetic acid was added, 1500 W ultrasonic stirring was carried out for 15 min, hydrothermal reaction was carried out at 125 ℃ for 22 h, centrifugation, washing, and drying were carried out to obtain UiO-66;

[0101] S2. Preparation of polyacene: 0.1 mol of phenol, 0.11 mol of formaldehyde, 6 g of ammonia water are mixed, heated to reflux and stirred for reaction for 3 h, the pH value of the solution is adjusted to 5, heating is continued for reaction for 2 h, 0.7 g of zinc chloride is added, heating is carried out at 70 DEG C, solidification is carried out for 26 h, pyrolysis is carried out at 1150 DEG C for 3 h, crushing is carried out, ball milling is carried out for 1 h, and polyacene is prepared;

[0102] S3. Preparation of modifier: 1.1 g of polyacene and 0.5 g of UiO-66 are uniformly mixed to prepare the modifier;

[0103] S4. Solid phase tackification and moisture adjustment: nylon 66 spinning grade chips with a relative viscosity of 2.25 are subjected to solid phase tackification and moisture adjustment treatment to obtain nylon 66 medium-high tack chips, the water content is 700 ppm, and the relative viscosity is 3.4;

[0104] The solid phase tackification is carried out on the chips by adopting nitrogen for countercurrent circulation under the condition of 155 DEG C;

[0105] S5. Melt extrusion spinning: the nylon 66 medium-high tack chips are sent to a screw extruder, the modifier is added, the addition amount is 4 wt%, melt extrusion is carried out at 290 DEG C, filtration is carried out, and the spinning is carried out through an eight-head spinning device, the spun fineness is 0.05 mm;

[0106] S6. Cooling, oiling, drafting, setting and winding: the yarn is cooled to form a yarn bundle through side blowing, is oiled, the oil addition amount is controlled to be 1%, is drafted and set, and is wound into a yarn can to obtain PA66 eight-head spun super-high-strength industrial yarn;

[0107] The drafting and setting are realized through 1-stage preheating, 2-stage stretching and 2-stage setting between six pairs of hot rollers, wherein the temperature of the first pair of hot rollers is 35 DEG C, the temperature of the second pair of hot rollers is 50 DEG C, the first pair of hot rollers and the second pair of hot rollers preheat the yarn, and the stretching ratio is 1.005 times.

[0108] Test Example 1

[0109] The PA66 eight-head spun super-high-strength industrial yarn prepared from the examples 1-3 and the comparative examples 1-4 is subjected to performance testing, and the results are shown in Table 1.

[0110] Table 1

[0111]

[0112] It can be known from the above table that the PA66 eight-head spun super-high-strength industrial yarn prepared from the examples 1-3 has good comprehensive performance.

[0113] Test Example 2

[0114] The PA66 eight-end spun super-high strength industrial yarns prepared in Examples 1-3 and Comparative Examples 1-4 of the present application were melt-extruded to prepare standard samples.

[0115] The oxygen index was tested according to the standard GB / T 2406.2-2009.

[0116] The flame-retardant grade was tested according to the standard UL-94.

[0117] The results are shown in Table 3.

[0118] Table 2

[0119] Group Limiting oxygen index (%) Flame retardant rating (UL-94) Example 1 33.2 V-0 Example 2 33.9 V-0 Example 3 34.1 V-0 Comparative Example 1 31.3 V-0 Comparative Example 2 26.9 V-2 Comparative Example 3 28.1 V-1 Comparative Example 4 32.0 V-0

[0120] From the above table, it can be seen that the PA66 eight-end spun super-high strength industrial yarns prepared in Examples 1-3 of the present application have good flame-retardant properties.

[0121] Test Example 3

[0122] The PA66 eight-end spun super-high strength industrial yarns prepared in Examples 1-3 and Comparative Examples 1-4 of the present application were tested for aging resistance, and the retention rate of breaking strength after various aging experiments was tested, and the results are shown in Table 3.

[0123] Short-term heat aging: temperature 105℃, duration 408h;

[0124] Short-term wet aging: temperature 70℃, humidity 95±2%, duration 408h;

[0125] Long-term heat aging: temperature 105℃, duration 1000h;

[0126] Long-term wet aging: temperature 70℃, humidity 95±2%, duration 1000h.

[0127] Table 3

[0128]

[0129] From the above table, it can be seen that the PA66 eight-end spun super-high strength industrial yarns prepared in Examples 1-3 of the present application have good aging resistance.

[0130] The above description is merely preferred embodiments of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A process for the production of PA66 eight-end spun high tenacity industrial yarn characterized in that, Comprise the following steps: S1. Preparation of UiO-66-NH2: zirconium tetrachloride, 2-amino terephthalic acid are added to N,N-dimethylformamide, acetic acid is added, ultrasonic stirring is uniformly dispersed, hydrothermal reaction is carried out, centrifugation, washing, drying, and UiO-66-NH2 is prepared; S2. Preparation of polyparaphenylene: phenol, formaldehyde, ammonia water are mixed, heated to reflux and stirred, the pH value of the solution is adjusted, heating reaction is continued, zinc chloride is added, heating and solidification are carried out, thermal cracking is carried out, crushing is carried out, ball milling is carried out, and polyparaphenylene is prepared; S3. Preparation of tannic acid modified polyparaphenylene: polyparaphenylene is added to water, tannic acid and a catalyst are added, heating and stirring reaction is carried out, centrifugation, washing, drying, and tannic acid modified polyparaphenylene is prepared; S4. Preparation of modifier: tannic acid modified polyparaphenylene is added to water, NHS and EDC are added, stirring activation is carried out, UiO-66-NH2 is added, stirring reaction is carried out, centrifugation, washing, drying, and the modifier is prepared; S5. Solid-phase tackification and moisture adjustment: nylon 66 spinning chips are subjected to solid-phase tackification and moisture adjustment treatment, and nylon 66 medium-high tack chips are obtained; S6. Melt extrusion spinning: the nylon 66 medium-high tack chips are sent to a screw extruder, the modifier is added, melt extrusion is carried out, filtration is carried out, and spinning is carried out through an eight-head spinning device; S7. Cooling, oiling, drafting and setting, and winding: the yarn is cooled to form a yarn bundle through side blowing, is oiled, is drafted and set, and is wound into a yarn can, and PA66 eight-head spun super-high-strength industrial yarn is prepared.

2. The production method according to claim 1, characterized by, The mass ratio of zirconium tetrachloride, 2-amino terephthalic acid, and acetic acid in step S1 is 0.12-0.17:0.11-0.14:2-3, the power of ultrasonic stirring dispersion is 1000-2000W, the time is 10-20min, the temperature of hydrothermal reaction is 120-130℃, and the time is 20-24h.

3. The production method according to claim 1, characterized by, The molar ratio of phenol and formaldehyde in step S2 is 1:1-1.2, the mass ratio of ammonia water and zinc chloride is 5-7:0.5-1, the time of heating reflux stirring reaction is 2-4h, the pH value of the solution is adjusted to 4-6, the time of continued heating reaction is 1-3h, the temperature of heating and solidification is 65-75℃, the time is 24-28h, the temperature of thermal cracking is 1100-1200℃, and the time is 2-4h.

4. The method of claim 1, wherein, The mass ratio of polyparaphenylene, tannic acid, and catalyst in step S3 is 10:2-3:0.5-1, the catalyst is Tris-HCl solution with pH=8.5-9.5, the temperature of heating and stirring reaction is 40-50℃, and the time is 3-5h.

5. The preparation method according to claim 1, characterized in that The mass ratio of tannic acid modified polyparaphenylene, NHS, EDC, and UiO-66-NH2 in step S4 is 10-12:3-4:2-3:4-7, the time of stirring activation is 20-40min, and the time of stirring reaction is 10-12h.

6. The method of claim 1, wherein, The relative viscosity of the nylon 66 spinning grade chip in step S5 is 2.2-2.3, the water content of the nylon 66 medium-high viscosity chip is 650-750 ppm, the relative viscosity is 3.3-3.5, and the solid phase viscosity increase is carried out by reverse flow circulation of the chip at 140-170℃ under the condition of nitrogen.

7. The preparation method according to claim 1, characterized in that The adding amount of the modifier in step S6 is 3-5wt%, the temperature of the melt extrusion is 280-300℃, and the fineness of the jet is 0.03-0.05mm.

8. The method of claim 1, wherein, The oil addition control in step S7 is 0.5-1.5%; the drawing and setting is realized by 1 stage of preheating, 2 stages of stretching and 2 stages of setting between six pairs of hot rollers: the temperature of the first pair of hot rollers is 30-40℃, the temperature of the second pair of hot rollers is 45-55℃, the first pair of hot rollers and the second pair of hot rollers have a preheating effect on the yarn, and the stretching ratio is 1-1.01 times; and the winding speed is 3000-4000m / min.

9. A PA66 eight-end spinning high-strength industrial yarn prepared by the preparation method of any one of claims 1-8.

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