Preparation method of high-strength and high-toughness chinlon industrial yarn

Abstract

The invention relates to the technical field of chinlon industrial yarns, and discloses a preparation method of a high-strength and high-toughness chinlon industrial yarn, which comprises the following steps: (1) preparing raw materials; (2) mixing the materials; (3) melt spinning; (4) stretching and heat treatment; (5) fiber surface modification; according to the invention, by fusing the advantages of high crystallization speed of nylon 6 and high melting point and high strength of nylon 66, a matrix material with good processing fluidity is formed, and the strength and fatigue cycle resistance of the chinlon industrial fiber are obviously improved. By introducing the maleic anhydride grafting agent, polar groups can be introduced among molecular chains through grafting reaction, so that the hydrogen bond density and crystallinity are remarkably improved, the molecular chains are arranged more regularly, and the tensile strength and heat resistance of the material are improved. The sea-island structure of the polyether ester elastomer effectively absorbs impact energy, so that the elongation at break is greater than or equal to 28%; the nano silicon dioxide inhibits crack propagation, and the service life of the material is remarkably prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of nylon industrial yarns, in particular to a method for preparing high-strength and high-tenacity nylon industrial yarns. Background Art

[0002] As a key branch of high-performance synthetic fibers, nylon industrial yarn (polyamide industrial yarn) is widely used in key applications such as tire cord, lifting belts, safety ropes, and conveyor belts due to its excellent abrasion and chemical resistance and ease of processing. In tire cord, it plays a key role in dispersing internal tire stress and ensuring driving safety. In load-bearing materials such as lifting belts, it must withstand high-frequency dynamic loads, placing stringent demands on the material's strength, toughness, and fatigue resistance.

[0003] With the development of high-end manufacturing and infrastructure construction, the market demand for the performance of nylon industrial yarn has been upgraded from a single strength indicator to multiple performance requirements such as strength, toughness, and fatigue resistance.

[0004] Traditional nylon industrial yarn is typically produced using a single nylon resin (such as nylon 6 or nylon 66) as the matrix through a simple blending and single-stage drawing process. However, this method has the following technical bottlenecks: Molecular structure defects: The hydrogen bond density between the molecular chains of a single resin matrix is ​​insufficient, and the crystallinity control is limited, resulting in a low ceiling of material strength (conventional breaking strength is mostly 8.0-9.0 cN / dtex) and insufficient toughness (elongation at break ≤25%), making it difficult to cope with complex stress environments.

[0005] Weak interfacial bonding: Nanofillers that have not undergone surface modification (such as silica) have poor compatibility with the matrix, are prone to agglomeration, and cannot effectively transfer loads, limiting the improvement of material strength and fatigue resistance.

[0006] Insufficient regulation: Traditional stretching processes mostly use single-stage or double-stage stretching, resulting in uneven fiber orientation and significant residual internal stress, which leads to poor dimensional stability at high temperatures, easy stress concentration under cyclic loads, and short fatigue life (conventional fatigue resistance cycle number <8000 times).

[0007] In summary, existing technologies are difficult to meet the high-end field's demand for nylon industrial yarn's "high strength, high toughness and long life". Summary of the Invention

[0008] In view of the problems in the prior art, the present invention provides a method for preparing high-strength and high-tenacity nylon industrial yarn.

[0009] The technical solution adopted by the present invention to solve the technical problem is: a method for preparing high-strength and high-tenacity nylon industrial yarn, comprising the following steps: (1) Raw material preparation: select nylon 6 and nylon 66 in a mass ratio of 7-8:2.5 to make a copolymer as the matrix material. This ratio can make the performance advantages of nylon 6 and nylon 66 complement each other, give the matrix material good comprehensive performance, and provide a basis for the subsequent preparation of high-performance nylon industrial yarn; prepare 0.6-1.0wt% maleic anhydride grafting agent, which can enhance the interaction between molecular chains, improve the crystallinity and strength of the material, and help improve the overall mechanical properties of nylon industrial yarn; prepare 0.28-0.45wt% nano-silica, which can enhance the rigidity, hardness and wear resistance of the material and improve the physical properties of the material; prepare 1.2-2.8wt% polyether ester elastomer, which can improve the toughness and elasticity of the material, so that the nylon industrial yarn has better buffering performance when subjected to stress and is not easy to break.

[0010] (2) Mixing: Mix the above-mentioned base material with maleic anhydride grafting agent and nano-silica, then add polyether ester elastomer and mix evenly to obtain a spinning mixture.

[0011] (3) Melt spinning: Add the spinning mixture to the screw extruder and use the screw extruder for melt spinning; use a spinneret for spinning, the spinneret aperture is 0.16-0.20mm, and the aspect ratio is 3:1. This design can reduce the risk of melt fracture, make the spun fibers uniform in thickness, and improve the fiber quality and production efficiency.

[0012] (4) Stretching and heat treatment: Three-level gradient heat stretching is used to obtain fibers that have been stretched and heat treated.

[0013] (5) Fiber surface modification: The fibers after stretching and heat treatment are treated with plasma to obtain high-strength and high-tenacity nylon industrial yarn.

[0014] As a further technical solution, the method for preparing the copolymer in step (1) is as follows: accurately weighing nylon 6 and nylon 66 slices in proportion, placing the slices in a vacuum drying oven, and drying them at 80-100°C for 12-14 hours. This drying process can remove moisture from the slices and prevent moisture from affecting the quality of the copolymer in subsequent reactions; adding the dried nylon 6 and nylon 66 slices into a reactor, raising the temperature in the reactor to 250-265°C at a rate of 6-7°C / min to completely melt the slices, and maintaining stirring during the process. Slowly heating and stirring can make the slices evenly heated and melted. , avoid local overheating and material decomposition; after the slices are completely melted, maintain the reaction temperature for 1-1.5 hours, add 0.01-0.02% trimethyl phosphate of the total mass of the raw materials, trimethyl phosphate as a catalyst can accelerate the reaction speed and improve production efficiency; adjust the pressure in the reactor to 0.5-0.6MPa, continue stirring and reacting for 2 hours, extrude the copolymer in the reactor through the bottom discharge port, cut into particles after water cooling, and dry to obtain, appropriate pressure and reaction time can make the copolymerization reaction more complete, water cooling and drying treatment can make the copolymer particles have good physical properties and processing properties.

[0015] As a further technical solution, the nano-silica in step (1) is nano-silica that has been surface-treated with a silane coupling agent KH550 and has a particle size of 25-40 nm. The silane coupling agent treatment can enhance the interfacial bonding between the nano-silica and the matrix material, allowing the nano-silica to better play a reinforcing role. The appropriate particle size range can ensure that the nano-silica is uniformly dispersed in the matrix.

[0016] As a further technical solution, the elastic modulus of the polyetherester elastomer in step (1) is 20-25 MPa, the number average molecular weight is 8000-12000 g / mol, the glass transition temperature is -30°C--20°C, and the molar ratio of the polyester segment to the polyether segment in its molecular chain is 1:2-3. These parameters enable the polyetherester elastomer to have good elasticity and toughness, and to synergize with the matrix material to effectively improve the comprehensive performance of the nylon industrial yarn.

[0017] As a further technical solution, the mixing in step (2) is carried out at 110° C. and 500 r / min for 30 min. This condition can promote sufficient contact and mixing between the molecules of each raw material, thereby ensuring the uniformity and stability of the spinning mixture.

[0018] As a further technical solution, in step (3), the screw extrusion temperature is controlled in sections, with the first zone being 252-258°C, the second zone being 267-273°C, and the third zone being 272-278°C. Reasonable section-by-section temperature control can enable the spinning mixture to reach the optimal melting and flow state at different stages, thereby ensuring the spinning quality.

[0019] As a further technical solution, the three-stage gradient heat stretching in step (4) includes: the first stage is carried out at 82-88°C, with a stretching ratio of 2.0; the second stage is carried out at 121-125°C, with a stretching ratio of 1.5; the third stage is carried out at 160-172°C, with a stretching ratio of 1.2; and then heat setting at 192-198°C for 12-14 minutes to eliminate internal stress and stabilize the crystalline structure. This gradient heat stretching and heat setting process can gradually optimize the molecular structure of the fiber and improve the strength, toughness and dimensional stability of the fiber.

[0020] As a further technical solution, in step (5), the plasma treatment power is 120-150 W, the treatment time is 8-10 min, and neon is used as the plasma treatment gas. Appropriate power and time as well as specific treatment gas can effectively improve the surface properties of the fiber and enhance the functionality and applicability of the fiber. Beneficial effects of the present invention: The present invention combines the high crystallization speed of nylon 6 with the high melting point and high strength advantages of nylon 66 to form a matrix material with good processing fluidity, which significantly improves the strength and fatigue cycle resistance of nylon industrial fibers.

[0021] The introduction of maleic anhydride grafting agent can introduce polar groups between molecular chains through grafting reaction, significantly improving the hydrogen bond density and crystallinity, making the molecular chains more regularly arranged, thereby improving the tensile strength and heat resistance of the material.

[0022] The high specific surface area of ​​nano-silica particles and the modification of silane coupling agents enable them to form a strong interface bond with the matrix, effectively disperse external loads, inhibit crack propagation, and at the same time act as a nucleating agent to promote matrix crystallization, achieving the dual effects of "reinforcement and toughening"; through microphase separation to form an "island structure", the elastomer "island phase" is evenly distributed in the matrix "sea phase", giving the fiber surface a flexible buffer layer, increasing the elongation at break and fatigue resistance, while improving the melt fluidity.

[0023] The multi-stage gradient thermal stretching process gradually optimizes the fiber orientation through graded stretching, avoiding the molecular chain breakage caused by single-stage high-magnification stretching, making the fiber axial molecular chain arrangement more orderly, and increasing the orientation degree by more than 30%; the three-level temperature gradient setting: low-temperature stretching fixes the initial orientation structure, medium temperature promotes the movement of molecular chain segments to improve the orientation, and high temperature eliminates internal stress and stabilizes crystallization, ultimately forming a "high strength-low internal stress" fiber structure, and improving fatigue cycle resistance.

[0024] Neon plasma treatment introduces oxygen-containing polar groups (such as hydroxyl and carboxyl) on the fiber surface, increasing the surface energy by 20%-30%, significantly enhancing the surface properties and improving the interface strength of the composite material.

[0025] Heat setting eliminates tensile residual stress through high-temperature relaxation, stabilizes the β-crystal structure, and improves fiber dimensional stability and strength properties.

[0026] High-strength mechanism: Increased hydrogen bonding density between molecular chains (maleic anhydride grafting) and the physical crosslinking effect of nano-silica enhance molecular chain slippage resistance, resulting in a breaking strength exceeding 9.8 cN / dtex, meeting the strength requirements of high-end load-bearing materials. The island-in-the-sea structure of the polyetherester elastomer effectively absorbs impact energy, achieving an elongation at break of ≥28%. Nano-silica inhibits crack propagation, and the uniformly oriented structure formed by gradient stretching disperses stress concentration under cyclic loading, achieving fatigue resistance of over 12,500 cycles and significantly extending the material's service life. DETAILED DESCRIPTION

[0027] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0028] The present invention provides a method for preparing high-strength and high-tenacity nylon industrial yarn, comprising the following steps: (1) Raw material preparation: select nylon 6 and nylon 66 in a mass ratio of 7-8:2.5 to make a copolymer as the base material; prepare 0.6-1.0wt% of maleic anhydride grafting agent, 0.28-0.45wt% of nano-silica, and 1.2-2.8wt% of polyether ester elastomer; the nano-silica is nano-silica that has been surface-treated with a silane coupling agent KH550 and has a particle size of 25-40nm; the polyether ester elastomer has an elastic modulus of 20-25MPa, a number average molecular weight of 8000-12000g / mol, a glass transition temperature of -30℃--20℃, and a molar ratio of polyester segments to polyether segments in its molecular chain of 1:2-3.

[0029] (2) Mixing: The above-mentioned base material is mixed with maleic anhydride grafting agent and nano-silica, and then polyether ester elastomer is added. The mixture is stirred at 110°C and 500 r / min for 30 minutes to obtain a spinning mixture.

[0030] (3) Melt spinning: Add the spinning mixture to the screw extruder and use the screw extruder for melt spinning. The screw extrusion temperature is controlled in sections, with zone 1 at 252-258°C, zone 2 at 267-273°C, and zone 3 at 272-278°C. Use a spinneret for spinning, with a spinneret aperture of 0.16-0.20 mm and an aspect ratio of 3:1 to reduce the risk of melt fracture.

[0031] (4) Stretching and heat treatment: A three-stage gradient heat stretching process is used. The first stage is carried out at 82-88°C with a stretching ratio of 2.0; the second stage is carried out at 121-125°C with a stretching ratio of 1.5; and the third stage is carried out at 160-172°C with a stretching ratio of 1.2. The fibers are then heat-set at 192-198°C for 12-14 minutes to eliminate internal stress and stabilize the crystalline structure, thereby obtaining fibers that have undergone stretching and heat treatment. (5) Fiber surface modification: The fibers that have undergone stretching and heat treatment are subjected to plasma treatment. The plasma treatment power is 120-150W, the treatment time is 8-10 minutes, and neon gas is used as the plasma treatment gas. Finally, high-strength and high-tenacity nylon industrial yarn is obtained.

[0032] The method for preparing the copolymer in step (1) is as follows: accurately weigh nylon 6 and nylon 66 slices in proportion, place the slices in a vacuum drying oven, and dry them at 80-100°C for 12-14 hours; add the dried nylon 6 and nylon 66 slices into a reactor, increase the temperature in the reactor to 250-265°C at a rate of 6-7°C / min to completely melt the slices, and keep stirring during the process; after the slices are completely melted, keep the reaction temperature for 1-1.5 hours, add 0.01-0.02% of the total weight of the raw materials of trimethyl phosphate, adjust the pressure in the reactor to 0.5-0.6MPa, continue stirring and reacting for 2 hours, extrude the copolymer in the reactor through the bottom discharge port, water-cool, cut into particles, and dry to obtain.

[0033] The following are specific embodiments Example 1 (1) Raw material preparation: Select nylon 6 and nylon 66 in a mass ratio of 7:2.5 to make a copolymer as the matrix material; prepare 0.6wt% of maleic anhydride grafting agent, 0.28wt% of nano-silica with a particle size of 25nm and surface treated with silane coupling agent KH550, and 1.2wt% of polyether ester elastomer (elastic modulus of 20MPa, number average molecular weight of 8000g / mol, glass transition temperature of -30℃, and a molar ratio of polyester segment to polyether segment of 1:2). Copolymer preparation: Weigh nylon 6 and nylon 66 chips in proportion, dry them at 80℃ for 14 hours, heat them to 250℃ at a rate of 6℃ / min to completely melt the chips, maintain the reaction temperature for 1.5 hours, add 0.01% of the total weight of the raw materials, adjust the pressure in the reactor to 0.5MPa, continue stirring and reacting for 2 hours, extrude the copolymer, water-cool, cut into pellets, and dry.

[0034] (2) Mixing: Stir at 110°C and 500 r / min for 30 min to obtain a spinning mixture.

[0035] (3) Melt spinning: screw extrusion temperature: zone 1 252 °C, zone 2 267 °C, zone 3 272 °C; spinneret aperture 0.16 mm, aspect ratio 3:1.

[0036] (4) Stretching and heat treatment: The first stage is stretched at 82°C with a stretching ratio of 2.0, the second stage is stretched at 121°C with a stretching ratio of 1.5, and the third stage is stretched at 160°C with a stretching ratio of 1.2; then heat-set at 192°C for 14 minutes.

[0037] (5) Fiber surface modification: plasma treatment power 120W, treatment time 10min, neon gas used.

[0038] Example 2 (1) Raw material preparation: Nylon 6 and nylon 66 were prepared into a copolymer in a mass ratio of 7.5:2.5; maleic anhydride grafting agent 0.8wt%, nanosilica 0.36wt% (particle size 30nm), polyether ester elastomer 2.0wt% (elastic modulus 23MPa, number average molecular weight 10000g / mol, glass transition temperature -25℃, molar ratio 1:2.5). Copolymer preparation: The chips were dried at 90℃ for 13 hours, heated to 258℃ at 6.5℃ / min to melt, and 0.015% trimethyl phosphate was added. The mixture was reacted at a pressure of 0.55MPa for 2 hours.

[0039] (2) Mixing: Stir at 110°C and 500 r / min for 30 min to obtain a spinning mixture.

[0040] (3) Melt spinning: screw extrusion temperature: zone 1 252 °C, zone 2 267 °C, zone 3 272 °C; spinneret aperture 0.16 mm, aspect ratio 3:1.

[0041] (4) Stretching and heat treatment: The first stage is stretched at 82°C with a stretching ratio of 2.0, the second stage is stretched at 121°C with a stretching ratio of 1.5, and the third stage is stretched at 160°C with a stretching ratio of 1.2; then heat-set at 192°C for 14 minutes.

[0042] (5) Fiber surface modification: plasma treatment power 120W, treatment time 10min, neon gas used.

[0043] Example 3 (1) Raw material preparation: Nylon 6 and nylon 66 were prepared into a copolymer in a mass ratio of 8:2.5; maleic anhydride grafting agent 1.0wt%, nanosilica 0.45wt% (particle size 40nm), polyether ester elastomer 2.8wt% (elastic modulus 25MPa, number average molecular weight 12000g / mol, glass transition temperature -20℃, molar ratio 1:3). Copolymer preparation: The slices were dried at 100℃ for 12 hours, heated to 265℃ at 7℃ / min to melt, 0.02% trimethyl phosphate was added, and the mixture was reacted at a pressure of 0.6MPa for 2 hours.

[0044] (2) Mixing: Stir at 110°C and 500 r / min for 30 min to obtain a spinning mixture.

[0045] (3) Melt spinning: screw extrusion temperature: zone 1 252 °C, zone 2 267 °C, zone 3 272 °C; spinneret aperture 0.16 mm, aspect ratio 3:1.

[0046] (4) Stretching and heat treatment: The first stage is stretched at 82°C with a stretching ratio of 2.0, the second stage is stretched at 121°C with a stretching ratio of 1.5, and the third stage is stretched at 160°C with a stretching ratio of 1.2; then heat-set at 192°C for 14 minutes.

[0047] (5) Fiber surface modification: plasma treatment power 120W, treatment time 10min, neon gas used.

[0048] Example 4 (1) Raw material preparation: Nylon 6 and nylon 66 were prepared into a copolymer in a mass ratio of 7.5:2.5; maleic anhydride grafting agent 0.8wt%, nanosilica 0.36wt% (particle size 30nm), polyether ester elastomer 2.0wt% (elastic modulus 23MPa, number average molecular weight 10000g / mol, glass transition temperature -25℃, molar ratio 1:2.5). Copolymer preparation: The chips were dried at 90℃ for 13 hours, heated to 258℃ at 6.5℃ / min to melt, and 0.015% trimethyl phosphate was added. The mixture was reacted at a pressure of 0.55MPa for 2 hours.

[0049] (2) Mixing: Stir at 110°C and 500 r / min for 30 min to obtain a spinning mixture.

[0050] (3) Melt spinning: screw extrusion temperature: zone 1 252 °C, zone 2 267 °C, zone 3 272 °C; spinneret aperture 0.16 mm, aspect ratio 3:1.

[0051] (4) Stretching and heat treatment: first level 85℃, second level 123℃, third level 166℃, heat setting 195℃, 13min.

[0052] (5) Fiber surface modification: plasma treatment power 120W, treatment time 10min, neon gas used.

[0053] Example 5 (1) Raw material preparation: Nylon 6 and nylon 66 were prepared into a copolymer in a mass ratio of 8:2.5; maleic anhydride grafting agent 1.0wt%, nanosilica 0.45wt% (particle size 40nm), polyether ester elastomer 2.8wt% (elastic modulus 25MPa, number average molecular weight 12000g / mol, glass transition temperature -20℃, molar ratio 1:3). Copolymer preparation: The slices were dried at 100℃ for 12 hours, heated to 265℃ at 7℃ / min to melt, 0.02% trimethyl phosphate was added, and the mixture was reacted at a pressure of 0.6MPa for 2 hours.

[0054] (2) Mixing: Stir at 110°C and 500 r / min for 30 min to obtain a spinning mixture.

[0055] (3) Melt spinning: screw extrusion temperature: zone 1 252 °C, zone 2 267 °C, zone 3 272 °C; spinneret aperture 0.16 mm, aspect ratio 3:1.

[0056] (4) Stretching and heat treatment: The first stage is stretched at 82°C with a stretching ratio of 2.0, the second stage is stretched at 121°C with a stretching ratio of 1.5, and the third stage is stretched at 160°C with a stretching ratio of 1.2; then heat-set at 192°C for 14 minutes.

[0057] (5) Fiber surface modification: plasma treatment power 150W, treatment time 8min, neon gas used.

[0058] Comparative Example Comparative Example 1 The technical solution of Example 1 differs from that of Example 1 in that the copolymer is replaced by nylon 6, and the rest of the technical solution remains unchanged.

[0059] Comparative Example 2 The technical solution of Example 1 differs from that of Example 1 in that the copolymer is replaced by nylon 66, and the rest of the technical solution remains unchanged.

[0060] Comparative Example 3 The difference from the technical solution of Example 1 is that only the first level of stretching and heat treatment is performed, and the rest of the technical solutions remain unchanged.

[0061] test Mechanical properties testing Test method: The breaking strength and elongation at break are tested in accordance with GB / T16258-2008 "Textiles - Determination of breaking strength and elongation at break". Ten specimens are taken from each group and the average value is taken: Table 1 It can be seen from Table 1 that the nylon industry prepared by the present invention has excellent strength properties.

[0062] Fatigue resistance test Test purpose: To evaluate the fatigue resistance of nylon industrial yarn under cyclic loading and simulate the long-term stress conditions in actual use.

[0063] Test method: Refer to GB / T3916-2013 "Textiles - Determination of breaking strength and elongation at break" using a fatigue testing machine. Set the cyclic load to 50% of the breaking strength and the tensile frequency to 10 times / minute. Record the number of cycles until the sample breaks. Test results: Table 2 It can be seen from Table 2 that the fatigue cycle resistance of the nylon industrial yarn prepared by the present invention is significantly improved.

[0064] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing high-strength and high-tenacity nylon industrial yarn, characterized in that: The following steps are involved: (1) Raw material preparation: select nylon 6 and nylon 66 in a mass ratio of 7-8:2.5 to make a copolymer as the base material; Prepare 0.6-1.0 wt% of maleic anhydride grafting agent, 0.28-0.45 wt% of nano-silica, and 1.2-2.8 wt% of polyether ester elastomer; (2) Mixing: Mix the above-mentioned base material with maleic anhydride grafting agent and nano-silica, then add polyether ester elastomer and mix evenly to obtain a spinning mixture; (3) Melt spinning: Add the spinning mixture to the screw extruder and use the screw extruder for melt spinning; Spinning is done using a spinneret with an aperture of 0.16-0.20 mm and an aspect ratio of 3:1 to reduce the risk of melt fracture; (4) Stretching and heat treatment: three-level gradient heat stretching is used to obtain stretched and heat-treated fibers; (5) Fiber surface modification: The fibers after stretching and heat treatment are treated with plasma to obtain high-strength and high-tenacity nylon industrial yarn.

2. The method for preparing high-strength and high-tenacity nylon industrial yarn according to claim 1, characterized in that: The method for preparing the copolymer in step (1) is as follows: accurately weighing nylon 6 and nylon 66 slices in proportion, placing the slices in a vacuum drying oven, and drying at 80-100°C for 12-14 hours; adding the dried nylon 6 and nylon 66 slices into a reactor, raising the temperature in the reactor to 250-265°C at a rate of 6-7°C / min to completely melt the slices, and stirring during the process; after the slices are completely melted, maintaining the reaction temperature for 1-1.5 hours, adding 0.01-0.02% of the total weight of the raw materials of trimethyl phosphate, adjusting the pressure in the reactor to 0.5-0.6MPa, continuing to stir and react for 2 hours, extruding the copolymer in the reactor through the bottom discharge port, water-cooling, cutting into particles, and drying to obtain.

3. The method for preparing high-strength and high-tenacity nylon industrial yarn according to claim 1, characterized in that: The nano-silica in step (1) is nano-silica that has been surface-treated with a silane coupling agent KH550 and has a particle size of 25-40 nm.

4. The method for preparing high-strength and high-tenacity nylon industrial yarn according to claim 1, characterized in that: The polyetherester elastomer in step (1) has an elastic modulus of 20-25 MPa, a number average molecular weight of 8000-12000 g / mol, a glass transition temperature of -30°C to -20°C, and a molar ratio of polyester segments to polyether segments in its molecular chain of 1:2-3.

5. The method for preparing high-strength and high-tenacity nylon industrial yarn according to claim 1, characterized in that: The mixing in step (2) is carried out at 110° C. and stirring at a speed of 500 r / min for 30 min.

6. The method for preparing high-strength and high-tenacity nylon industrial yarn according to claim 1, characterized in that: In step (3), the screw extrusion temperature is controlled in sections, with the first zone being 252-258°C, the second zone being 267-273°C, and the third zone being 272-278°C.

7. The method for preparing high-strength and high-tenacity nylon industrial yarn according to claim 1, characterized in that: The three-stage gradient heat stretching in step (4) includes: the first stage is carried out at 82-88°C, with a stretching ratio of 2.0; the second stage is carried out at 121-125°C, with a stretching ratio of 1.5; the third stage is carried out at 160-172°C, with a stretching ratio of 1.2; and then heat setting is carried out at 192-198°C for 12-14 minutes.

8. The method for preparing high-strength and high-tenacity nylon industrial yarn according to claim 1, characterized in that: In step (5), the plasma treatment power is 120-150 W, and the treatment time is 8-10 min.

9. The method for preparing high-strength and high-tenacity nylon industrial yarn according to claim 8, characterized in that: The plasma processing gas is neon gas.

Images