High-strength polyamide fiber and preparation method thereof

Abstract

The invention discloses a high-strength polyamide fiber and a preparation method thereof, and relates to the technical field of chemical fiber, the high-strength polyamide fiber is prepared from the following raw materials by weight: 100 parts of functional polyamide, 3-5 parts of a coupling agent, 10-20 parts of reinforced fiber, 1-2 parts of an antioxidant, 0.6-1 part of a lubricant, and 1-3 parts of 2, 4, 6-trivinyl boroxane. The functional polyamide comprises a structural unit introduced by the following monomers: benzoguanamine, 2, 3-quinolindicarboxylic acid and 2, 2 '-bis (trifluoromethyl) diaminobiphenyl. The high-strength polyamide fiber is high in strength and excellent in ultraviolet aging resistance and heat aging resistance.

Description

Technical Field

[0001] The invention relates to the technical field of chemical fibers, and in particular to a high-strength nylon fiber and a preparation method thereof. Background Art

[0002] Nylon is the trade name of polyamide fiber, also known as nylon. It is the first fiber in the world to achieve industrialization. Due to its good moisture absorption, softness and good elasticity, it is suitable for underwear, sportswear and other fabrics, and has good wearing comfort. However, since the amide bond of nylon fiber is prone to high-temperature hydrolysis and cracking, and is easy to break under light, especially under ultraviolet light, the macromolecular chain segments become shorter, the molecular weight decreases, and oxidation aging occurs. The strength of the fiber and the finished product is seriously reduced, which is difficult to meet the needs of social development. High-strength nylon fiber has attracted much attention.

[0003] At present, in the production process of high-strength nylon fiber, some functional masterbatch is usually added to the polymer to improve the strength, but the functional masterbatch often has the phenomenon of uneven dispersion, which makes the distribution of fiber crystal area different, thus resulting in uneven fiber breaking strength and low durability. In addition, the high-strength nylon fiber on the market also has more or less defects such as insufficient UV resistance, poor heat aging resistance, and short service life.

[0004] In order to solve the above technical problems, a Chinese invention patent with authorization announcement number CN109402764B discloses a high-strength, low-elongation nylon 6 staple fiber and a preparation method thereof, wherein the method comprises: spinning a high-strength, low-elongation nylon 6 melt to obtain high-strength, low-elongation nylon 6 staple fibers, wherein the high-strength, low-elongation nylon 6 is obtained by subjecting a mixture to a chain growth reaction on the surface of a reinforcing powder, a ring-opening pre-condensation reaction, a final condensation reaction and a viscosity-increasing reaction, wherein the mixture is mainly composed of caprolactam, a reinforcing powder coated with a catalyst on the surface and water, and the obtained high-strength, low-elongation nylon 6 staple fibers have a linear density of 0.89 to 2.22 dtex, a breaking strength of ≥6.0 cN / dtex, and an elongation at break of ≤45%. The invention discloses a high-strength, low-strength nylon 6 staple fiber and its preparation method. The reinforcing powder enhances the mechanical properties of the nylon 6 staple fiber. The chain growth reaction on the surface of the reinforcing powder makes the reinforcing powder well dispersed in the fiber, so that the high-strength, low-strength nylon 6 staple fiber finally obtained has good mechanical properties, uniform strength distribution and high quality. However, its UV aging resistance and heat aging resistance still need to be further improved.

[0005] It can be seen that the development of a high-strength nylon fiber with high strength, excellent resistance to ultraviolet aging and heat aging and its preparation method meets market demand, has broad market value and application prospects, and is of great significance to promoting the development of the nylon fiber field. Summary of the invention

[0006] The main purpose of the present invention is to provide a high-strength nylon fiber with high strength, excellent anti-ultraviolet aging performance and heat aging resistance and a preparation method thereof.

[0007] To achieve the above purpose, the present invention provides a high-strength nylon fiber, which is made of the following raw materials calculated by weight: 100 parts of functional polyamide, 3-5 parts of coupling agent, 10-20 parts of reinforcing fiber, 1-2 parts of antioxidant, 0.6-1 part of lubricant, and 1-3 parts of 2,4,6-trivinyl cycloboroxine; the functional polyamide includes structural units introduced by the following monomers: benzoguanamine, 2,3-quinolinedicarboxylic acid, and 2,2'-bis(trifluoromethyl)diaminobiphenyl.

[0008] Preferably, the preparation method of the functional polyamide comprises the following steps: adding benzoguanamine, 2,3-quinolinedicarboxylic acid, 2,2'-bis(trifluoromethyl)diaminobiphenyl and a catalyst to a high boiling point solvent and mixing them evenly to obtain a mixture, then adding the mixture to a reaction kettle, replacing the air in the kettle with an inert gas, reacting at 120-130°C under normal pressure for 3-5 hours, heating to 230-250°C, and performing a polycondensation reaction at 300-500 Pa for 15-22 hours, then cooling to room temperature, adjusting to normal pressure, precipitating in water, washing the crude product with ethanol for 3-6 times, and then drying it in a vacuum drying oven at 85-95°C to constant weight to obtain the functional polyamide.

[0009] Preferably, the molar ratio of the benzoguanamine, 2,3-quinolinedicarboxylic acid, 2,2'-bis(trifluoromethyl)diaminobiphenyl, catalyst and high boiling point solvent is 0.7:1:0.3:(0.8-1):(8-15).

[0010] Preferably, the catalyst is at least one of thiophosphonate, phosphorous acid, and thiophosphoramide; the high boiling point solvent is dimethyl sulfoxide; and the inert gas is any one of nitrogen, helium, neon, and argon.

[0011] Preferably, the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570; the antioxidant is at least one of antioxidant 1010 and antioxidant 168; and the lubricant is at least one of pentaerythritol stearate and ethylene bisstearamide.

[0012] Preferably, the reinforcing fiber is at least one of nano-carbon fiber and nano-boron fiber.

[0013] Preferably, the average diameter of the reinforcing fiber is 100-300 nm, and the aspect ratio is (20-30):1.

[0014] Another object of the present invention is to provide a method for preparing the high-strength nylon fiber, comprising the following steps: Step S1, after the dried functional polyamide, coupling agent, reinforcing fiber, antioxidant and lubricant are mixed evenly to obtain a mixed material, the mixed material is added into a twin-screw extruder for melt extrusion and granulation, and then melt-spinned by a melt spinning machine, and a single filament is ejected from a spinneret; Step S2, the monofilaments are bundled at the bundling oiling point and oiled on the surface of the bundle, wherein the spinning oil contains 2,4,6-trivinyl cycloboroxine; Step S3, heat-stretching the oiled tow in sequence, using a nitrogen atmosphere 60 The fiber is grafted by radiation with a Co-γ ray source, passed through a sub-assembly network device, and then wound at a winding head to obtain high-strength nylon fiber.

[0015] Preferably, the melt temperature of the melt extrusion granulation in step S1 is 235-285° C., and the extrusion pressure is 8-10 MPa.

[0016] Preferably, the process parameters of the melt spinning in step S1 are: spinning temperature 230-270° C., winding speed 1000-1500 m / min, and drafting multiple 2-4.

[0017] Preferably, the stretching ratio of the heat stretching in step S3 is 1-2.

[0018] Preferably, the radiation grafting in step S3 is carried out at room temperature, with an absorbed dose of 5 to 40 kGy and a dose rate of 5 to 20 kGy / h.

[0019] Preferably, the network pressure of the sub-packaging network device in step S3 is 1-2kgf / cm 2 .

[0020] Due to the application of the above technical solution, the present invention has the following beneficial effects: (1) The method for preparing high-strength nylon fiber disclosed in the present invention has simple process, convenient operation and control, high preparation efficiency and finished product qualification rate, low energy consumption, low dependence on equipment, suitable for continuous large-scale production, and high promotion and application value. Through the reasonable selection of preparation process parameters, the comprehensive performance (strength, anti-ultraviolet aging performance and heat aging performance) and performance stability of the prepared product are good.

[0021] (2) The high-strength nylon fiber disclosed in the present invention is made of the following raw materials calculated by weight: 100 parts of functional polyamide, 3-5 parts of coupling agent, 10-20 parts of reinforcing fiber, 1-2 parts of antioxidant, 0.6-1 parts of lubricant, and 1-3 parts of 2,4,6-trivinyl cycloboroxine; the functional polyamide includes the following monomer-introduced structural units: benzoguanamine, 2,3-quinolinedicarboxylic acid, and 2,2'-bis(trifluoromethyl)diaminobiphenyl. Through the mutual coordination and joint action of the raw materials, the nylon fiber product has high strength and excellent UV aging resistance and heat aging resistance.

[0022] (3) The high-strength nylon fiber disclosed in the present invention introduces benzoguanamine, quinoline, fluorinated biphenyl and boroxine structures into the fiber molecular structure through the reasonable selection of the types and dosage ratios of various raw materials. These structures, under the multiple effects of electronic effect, steric effect and conjugation effect, make the fiber product stronger and have better anti-ultraviolet aging performance and heat aging performance. Through radiation grafting, an interpenetrating network structure is formed on the fiber surface, which can further improve the above properties. DETAILED DESCRIPTION

[0023] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations. Example 1

[0024] A high-strength nylon fiber is made of the following raw materials calculated by weight: 100 parts of functional polyamide, 3 parts of coupling agent, 10 parts of reinforcing fiber, 1 part of antioxidant, 0.6 parts of lubricant, and 1 part of 2,4,6-trivinyl cycloboroxine; the functional polyamide includes structural units introduced by the following monomers: benzoguanamine, 2,3-quinolinedicarboxylic acid, and 2,2'-bis(trifluoromethyl)diaminobiphenyl.

[0025] The preparation method of the functional polyamide comprises the following steps: adding benzoguanamine, 2,3-quinoline dicarboxylic acid, 2,2'-bis(trifluoromethyl)diaminobiphenyl and a catalyst to a high boiling point solvent and mixing them evenly to obtain a mixed material, then adding the mixed material to a reaction kettle, replacing the air in the kettle with an inert gas, reacting at 120°C for 3 hours under normal pressure, heating to 230°C, carrying out a polycondensation reaction at 300 Pa for 15 hours, cooling to room temperature, adjusting to normal pressure, precipitating in water, washing the crude product with ethanol for 3 times, and then drying it in a vacuum drying oven at 85°C to constant weight to obtain the functional polyamide; the molar ratio of the benzoguanamine, 2,3-quinoline dicarboxylic acid, 2,2'-bis(trifluoromethyl)diaminobiphenyl, catalyst and high boiling point solvent is 0.7:1:0.3:0.8:8; the catalyst is a thiophosphonate; the high boiling point solvent is dimethyl sulfoxide; and the inert gas is nitrogen. Through GPC test, the M of the functional polyamide was measured. n =16183g / mol,M W / M n =1.418; through elemental analysis and weight change calculation, the molar ratio of the structural units introduced by benzoguanamine, 2,3-quinolinedicarboxylic acid and 2,2'-bis(trifluoromethyl)diaminobiphenyl in the functional polyamide is the same as the theoretical value.

[0026] The coupling agent is silane coupling agent KH550; the antioxidant is antioxidant 1010; the lubricant is pentaerythritol stearate; the reinforcing fiber is nano-carbon fiber; the average diameter of the reinforcing fiber is 100nm, and the aspect ratio is 20:1.

[0027] A method for preparing the high-strength nylon fiber comprises the following steps: Step S1, after the dried functional polyamide, coupling agent, reinforcing fiber, antioxidant and lubricant are mixed evenly to obtain a mixed material, the mixed material is added into a twin-screw extruder for melt extrusion and granulation, and then melt-spinned by a melt spinning machine, and a single filament is ejected from a spinneret; Step S2, the monofilaments are bundled at the bundling oiling point and oiled on the surface of the bundle, wherein the spinning oil contains 2,4,6-trivinyl cycloboroxine; Step S3, heat-stretching the oiled tow in sequence, using a nitrogen atmosphere 60 The fiber is grafted by radiation with a Co-γ ray source, passed through a sub-assembly network device, and then wound at a winding head to obtain high-strength nylon fiber.

[0028] The melting temperature of the melt extrusion granulation in step S1 is 235°C, and the extrusion pressure is 8MPa; the process parameters of the melt spinning in step S1 are: spinning temperature 230°C, winding speed 1000m / min, and draft ratio 3; the stretching ratio of the hot stretching in step S3 is 2; the radiation grafting in step S3 is carried out at room temperature, the absorbed dose is 5kGy, and the dose rate is 5kGy / h.

[0029] The network pressure of the sub-packaging network device in step S3 is 1kgf / cm 2 . Example 2

[0030] A high-strength nylon fiber is made of the following raw materials calculated by weight: 100 parts of functional polyamide, 3.5 parts of coupling agent, 13 parts of reinforcing fiber, 1.2 parts of antioxidant, 0.7 parts of lubricant, and 1.5 parts of 2,4,6-trivinyl cycloboroxine; the functional polyamide includes structural units introduced by the following monomers: benzoguanamine, 2,3-quinolinedicarboxylic acid, and 2,2'-bis(trifluoromethyl)diaminobiphenyl.

[0031] The preparation method of the functional polyamide comprises the following steps: adding benzoguanamine, 2,3-quinoline dicarboxylic acid, 2,2'-bis(trifluoromethyl)diaminobiphenyl and a catalyst to a high boiling point solvent and mixing them evenly to obtain a mixed material, then adding the mixed material to a reaction kettle, replacing the air in the kettle with an inert gas, reacting at 123°C for 3.5 hours under normal pressure, heating to 235°C, carrying out a polycondensation reaction at 350 Pa for 17 hours, cooling to room temperature, adjusting to normal pressure, precipitating in water, washing the crude product with ethanol for 4 times, and then drying it in a vacuum drying oven at 87°C to constant weight to obtain the functional polyamide; the molar ratio of the benzoguanamine, 2,3-quinoline dicarboxylic acid, 2,2'-bis(trifluoromethyl)diaminobiphenyl, catalyst and high boiling point solvent is 0.7:1:0.3:0.85:10; the catalyst is phosphorous acid; the high boiling point solvent is dimethyl sulfoxide; and the inert gas is helium.

[0032] The coupling agent is silane coupling agent KH560; the antioxidant is antioxidant 168; the lubricant is ethylene bis stearamide; the reinforcing fiber is nano boron fiber; the average diameter of the reinforcing fiber is 150nm, and the aspect ratio is 23:1.

[0033] A method for preparing the high-strength nylon fiber comprises the following steps: Step S1, after the dried functional polyamide, coupling agent, reinforcing fiber, antioxidant and lubricant are mixed evenly to obtain a mixed material, the mixed material is added into a twin-screw extruder for melt extrusion and granulation, and then melt-spinned by a melt spinning machine, and a single filament is ejected from a spinneret; Step S2, the monofilaments are bundled at the bundling oiling point and oiled on the surface of the bundle, wherein the spinning oil contains 2,4,6-trivinyl cycloboroxine; Step S3, heat-stretching the oiled tow in sequence, using a nitrogen atmosphere 60 The fiber is grafted by radiation with a Co-γ ray source, passed through a sub-assembly network device, and then wound at a winding head to obtain high-strength nylon fiber.

[0034] The melt temperature of the melt extrusion granulation in step S1 is 255°C, and the extrusion pressure is 8.5MPa; the process parameters of the melt spinning in step S1 are: spinning temperature 245°C, winding speed 1200m / min, and draft multiple 3; the stretch ratio of the hot stretching in step S3 is 2; the radiation grafting in step S3 is carried out at room temperature, the absorbed dose is 10kGy, and the dose rate is 8kGy / h; the network pressure of the sub-packaging network device in step S3 is 1.2kgf / cm 2 . Example 3

[0035] A high-strength nylon fiber is made of the following raw materials calculated by weight: 100 parts of functional polyamide, 4 parts of coupling agent, 15 parts of reinforcing fiber, 1.5 parts of antioxidant, 0.8 parts of lubricant, and 1-3 parts of 2,4,6-trivinyl cycloboroxine; the functional polyamide includes structural units introduced by the following monomers: benzoguanamine, 2,3-quinolinedicarboxylic acid, and 2,2'-bis(trifluoromethyl)diaminobiphenyl.

[0036] The preparation method of the functional polyamide comprises the following steps: adding benzoguanamine, 2,3-quinoline dicarboxylic acid, 2,2'-bis(trifluoromethyl)diaminobiphenyl and a catalyst to a high boiling point solvent and mixing them evenly to obtain a mixed material, then adding the mixed material to a reaction kettle, replacing the air in the kettle with an inert gas, reacting at 125°C for 4 hours under normal pressure, heating to 240°C, carrying out a polycondensation reaction at 400 Pa for 19 hours, cooling to room temperature, adjusting to normal pressure, precipitating in water, washing the crude product with ethanol for 5 times, and then drying it in a vacuum drying oven at 90°C to constant weight to obtain the functional polyamide; the molar ratio of the benzoguanamine, 2,3-quinoline dicarboxylic acid, 2,2'-bis(trifluoromethyl)diaminobiphenyl, catalyst and high boiling point solvent is 0.7:1:0.3:0.9:12; the catalyst is thiophosphoramide; the high boiling point solvent is dimethyl sulfoxide; and the inert gas is neon.

[0037] The coupling agent is silane coupling agent KH570; the antioxidant is antioxidant 1010; the lubricant is pentaerythritol stearate; the reinforcing fiber is nano-carbon fiber; the average diameter of the reinforcing fiber is 200nm, and the aspect ratio is 25:1.

[0038] A method for preparing the high-strength nylon fiber comprises the following steps: Step S1, after the dried functional polyamide, coupling agent, reinforcing fiber, antioxidant and lubricant are mixed evenly to obtain a mixed material, the mixed material is added into a twin-screw extruder for melt extrusion and granulation, and then melt-spinned by a melt spinning machine, and a single filament is ejected from a spinneret; Step S2, the monofilaments are bundled at the bundling oiling point and oiled on the surface of the bundle, wherein the spinning oil contains 2,4,6-trivinyl cycloboroxine; Step S3, heat-stretching the oiled tow in sequence, using a nitrogen atmosphere 60 The fiber is grafted by radiation with a Co-γ ray source, passed through a sub-assembly network device, and then wound at a winding head to obtain high-strength nylon fiber.

[0039] The melt temperature of the melt extrusion granulation in step S1 is 265°C, and the extrusion pressure is 9MPa; the process parameters of the melt spinning in step S1 are: spinning temperature 250°C, winding speed 1300m / min, and draft ratio 3; the stretch ratio of the hot stretching in step S3 is 2; the radiation grafting in step S3 is carried out at room temperature, the absorbed dose is 25kGy, and the dose rate is 10kGy / h; the network pressure of the sub-packaging network device in step S3 is 1.5kgf / cm 2 . Example 4

[0040] A high-strength nylon fiber is made of the following raw materials calculated by weight: 100 parts of functional polyamide, 4.5 parts of coupling agent, 18 parts of reinforcing fiber, 1.8 parts of antioxidant, 0.9 parts of lubricant, and 1-3 parts of 2,4,6-trivinyl cycloboroxine; the functional polyamide includes structural units introduced by the following monomers: benzoguanamine, 2,3-quinolinedicarboxylic acid, and 2,2'-bis(trifluoromethyl)diaminobiphenyl.

[0041] The preparation method of the functional polyamide comprises the following steps: adding benzoguanamine, 2,3-quinolinedicarboxylic acid, 2,2'-bis(trifluoromethyl)diaminobiphenyl and a catalyst into a high boiling point solvent and mixing them evenly to obtain a mixed material; then adding the mixed material into a reaction kettle; replacing the air in the kettle with an inert gas; reacting at 128°C for 4.5 hours under normal pressure; heating the mixture to 245°C; performing a polycondensation reaction at 450 Pa for 20 hours; cooling the mixture to room temperature; adjusting the mixture to normal pressure; and precipitating the mixture in water. , wash the crude product with ethanol for 6 times, and then dry it in a vacuum drying oven at 93°C to constant weight to obtain functional polyamide; the molar ratio of benzoguanamine, 2,3-quinolinedicarboxylic acid, 2,2'-bis(trifluoromethyl)diaminobiphenyl, catalyst, and high boiling point solvent is 0.7:1:0.3:0.95:14; the catalyst is a mixture of thiophosphonate, phosphorous acid, and thiophosphoramide in a mass ratio of 1:1:3; the high boiling point solvent is dimethyl sulfoxide; and the inert gas is nitrogen.

[0042] The coupling agent is a mixture of silane coupling agent KH550, silane coupling agent KH560 and silane coupling agent KH570 in a mass ratio of 1:2:3; the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 3:5; the lubricant is a mixture of pentaerythritol stearate and ethylene bisstearamide in a mass ratio of 1:1; the reinforcing fiber is a mixture of nano carbon fiber and nano boron fiber in a mass ratio of 1:4; the average diameter of the reinforcing fiber is 250nm, and the aspect ratio is 28:1.

[0043] A method for preparing the high-strength nylon fiber comprises the following steps: Step S1, after the dried functional polyamide, coupling agent, reinforcing fiber, antioxidant and lubricant are mixed evenly to obtain a mixed material, the mixed material is added into a twin-screw extruder for melt extrusion and granulation, and then melt-spinned by a melt spinning machine, and a single filament is ejected from a spinneret; Step S2, the monofilaments are bundled at the bundling oiling point and oiled on the surface of the bundle, wherein the spinning oil contains 2,4,6-trivinyl cycloboroxine; Step S3, heat-stretching the oiled tow in sequence, using a nitrogen atmosphere 60 The fiber is grafted by radiation with a Co-γ ray source, passed through a sub-assembly network device, and then wound at a winding head to obtain high-strength nylon fiber.

[0044] The melt temperature of the melt extrusion granulation in step S1 is 280°C, and the extrusion pressure is 9.5MPa; the process parameters of the melt spinning in step S1 are: spinning temperature 265°C, winding speed 1400m / min, and draft multiple 3; the stretch ratio of the hot stretching in step S3 is 2; the radiation grafting in step S3 is carried out at room temperature, the absorbed dose is 35kGy, and the dose rate is 15kGy / h; the network pressure of the sub-packaging network device in step S3 is 1.8kgf / cm 2 . Example 5

[0045] A high-strength nylon fiber is made of the following raw materials calculated by weight: 100 parts of functional polyamide, 5 parts of coupling agent, 20 parts of reinforcing fiber, 2 parts of antioxidant, 1 part of lubricant, and 3 parts of 2,4,6-trivinyl cycloboroxine; the functional polyamide includes structural units introduced by the following monomers: benzoguanamine, 2,3-quinolinedicarboxylic acid, and 2,2'-bis(trifluoromethyl)diaminobiphenyl.

[0046] The preparation method of the functional polyamide comprises the following steps: adding benzoguanamine, 2,3-quinoline dicarboxylic acid, 2,2'-bis(trifluoromethyl)diaminobiphenyl and a catalyst to a high boiling point solvent and mixing them evenly to obtain a mixed material, then adding the mixed material to a reaction kettle, replacing the air in the kettle with an inert gas, reacting at 130°C for 5 hours under normal pressure, heating to 250°C, carrying out a polycondensation reaction at 500 Pa for 22 hours, cooling to room temperature, adjusting to normal pressure, precipitating in water, washing the crude product with ethanol for 6 times, and then drying it in a vacuum drying oven at 95°C to constant weight to obtain the functional polyamide; the molar ratio of the benzoguanamine, 2,3-quinoline dicarboxylic acid, 2,2'-bis(trifluoromethyl)diaminobiphenyl, catalyst and high boiling point solvent is 0.7:1:0.3:1:15; the catalyst is a thiophosphonate; the high boiling point solvent is dimethyl sulfoxide; and the inert gas is helium.

[0047] The coupling agent is silane coupling agent KH560; the antioxidant is antioxidant 1010; the lubricant is pentaerythritol stearate; the reinforcing fiber is nano-carbon fiber; the average diameter of the reinforcing fiber is 300nm, and the aspect ratio is 30:1.

[0048] A method for preparing the high-strength nylon fiber comprises the following steps: Step S1, after the dried functional polyamide, coupling agent, reinforcing fiber, antioxidant and lubricant are mixed evenly to obtain a mixed material, the mixed material is added into a twin-screw extruder for melt extrusion and granulation, and then melt-spinned by a melt spinning machine, and a single filament is ejected from a spinneret; Step S2, the monofilaments are bundled at the bundling oiling point and oiled on the surface of the bundle, wherein the spinning oil contains 2,4,6-trivinyl cycloboroxine; Step S3, heat-stretching the oiled tow in sequence, using a nitrogen atmosphere 60 The fiber is grafted by radiation with a Co-γ ray source, passed through a sub-assembly network device, and then wound at a winding head to obtain high-strength nylon fiber.

[0049] The melt temperature of the melt extrusion granulation in step S1 is 285°C, and the extrusion pressure is 10MPa; the process parameters of the melt spinning in step S1 are: spinning temperature 270°C, winding speed 1500m / min, and draft multiple 3; the stretch ratio of the hot stretching in step S3 is 2; the radiation grafting in step S3 is carried out at room temperature, the absorbed dose is 40kGy, and the dose rate is 20kGy / h; the network pressure of the sub-packaging network device in step S3 is 2kgf / cm 2 .

[0050] Comparative Example 1 A high-strength nylon fiber and a preparation method thereof, which are similar to those in Example 1, except that an equal amount of benzoguanamine is used to replace 2,2'-bis(trifluoromethyl)diaminobiphenyl.

[0051] Comparative Example 2 A high-strength nylon fiber and a preparation method thereof, which are similar to those in Example 1, except that an equal amount of 2,2'-bis(trifluoromethyl)diaminobiphenyl is used instead of benzoguanamine.

[0052] Comparative Example 3 A high-strength nylon fiber and a preparation method thereof, which are similar to Example 1, except that there is no radiation grafting step.

[0053] In order to further illustrate the beneficial technical effects of the high-strength nylon fibers involved in each embodiment of the present invention, relevant performance tests were performed on the high-strength nylon fibers involved in Examples 1-5 and Comparative Examples 1-2. The test results are shown in Table 1. The test method is as follows: (1) Dry breaking strength: refer to GB / T 14344-2022 "Test method for tensile properties of chemical fiber filaments" to test the dry breaking strength.

[0054] (2) Heat aging resistance: Each product was placed in a heat aging chamber for artificial accelerated hot air aging at 85°C for 96 hours. The heat aging resistance was measured by the retention rate of dry breaking strength after aging. The larger the retention rate, the better the heat aging resistance.

[0055] (3) Anti-ultraviolet aging performance: Each product was exposed to an artificial xenon lamp for 250 hours, and the retention rate of dry breaking strength after aging was used to measure the heat aging resistance. The larger the retention rate, the better the anti-ultraviolet aging performance.

[0056] Table 1 Test items Dry breaking strength Heat aging resistance Anti-ultraviolet aging performance unit cN / dtex % % Example 1 10.13 98.79 99.35 Example 2 10.42 98.86 99.45 Example 3 10.91 98.97 99.60 Example 4 11.15 99.18 99.82 Example 5 11.47 99.32 99.95 Comparative Example 1 9.20 96.46 99.03 Comparative Example 2 9.31 96.73 97.64 Comparative Example 3 9.03 95.47 98.79 It can be seen from Table 1 that the high-strength nylon fibers involved in the embodiments of the present invention have better breaking strength, UV aging resistance and heat aging resistance, and the combined use of benzoguanamine, 2,2'-bis(trifluoromethyl)diaminobiphenyl and radiation grafting is beneficial to improving the above properties.

[0057] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A high-strength nylon fiber, characterized in that: The invention is prepared from the following raw materials calculated by weight: 100 parts of functional polyamide, 3-5 parts of coupling agent, 10-20 parts of reinforcing fiber, 1-2 parts of antioxidant, 0.6-1 parts of lubricant and 1-3 parts of 2,4,6-trivinyl cycloboroxine; the functional polyamide comprises structural units introduced by the following monomers: benzoguanamine, 2,3-quinolinedicarboxylic acid and 2,2'-bis(trifluoromethyl)diaminobiphenyl.

2. The high-strength nylon fiber according to claim 1, characterized in that: The preparation method of the functional polyamide comprises the following steps: adding benzoguanamine, 2,3-quinolinedicarboxylic acid, 2,2'-bis(trifluoromethyl)diaminobiphenyl and a catalyst into a high boiling point solvent and mixing them evenly to obtain a mixed material, then adding the mixed material into a reaction kettle, replacing the air in the kettle with an inert gas, reacting at 120-130°C under normal pressure for 3-5 hours, heating to 230-250°C, carrying out a polycondensation reaction at 300-500 Pa for 15-22 hours, cooling to room temperature, adjusting to normal pressure, precipitating in water, washing the crude product with ethanol for 3-6 times, and drying in a vacuum drying oven at 85-95°C to constant weight to obtain the functional polyamide.

3. The high-strength nylon fiber according to claim 2, characterized in that: The molar ratio of the benzoguanamine, 2,3-quinolinedicarboxylic acid, 2,2'-bis(trifluoromethyl)diaminobiphenyl, catalyst and high boiling point solvent is 0.7:1:0.3:(0.8-1):(8-15).

4. The high-strength nylon fiber according to claim 2, characterized in that: The catalyst is at least one of thiophosphonate, phosphorous acid, and thiophosphoramide; the high boiling point solvent is dimethyl sulfoxide; and the inert gas is any one of nitrogen, helium, neon, and argon.

5. The high-strength nylon fiber according to claim 1, characterized in that: The coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570; the antioxidant is at least one of antioxidant 1010 and antioxidant 168; and the lubricant is at least one of pentaerythritol stearate and ethylene bisstearamide.

6. The high-strength nylon fiber according to claim 1, characterized in that: The reinforcing fiber is at least one of nano-carbon fiber and nano-boron fiber.

7. The high-strength nylon fiber according to claim 1, characterized in that: The average diameter of the reinforcing fiber is 100-300nm, and the aspect ratio is (20-30):

1.

8. A method for preparing the high-strength nylon fiber according to any one of claims 1 to 7, characterized in that: The steps include: Step S1, after the dried functional polyamide, coupling agent, reinforcing fiber, antioxidant and lubricant are mixed evenly to obtain a mixed material, the mixed material is added into a twin-screw extruder for melt extrusion and granulation, and then melt-spinned by a melt spinning machine, and a single filament is ejected from a spinneret; Step S2, the monofilaments are bundled at the bundling oiling point and oiled on the surface of the bundle, wherein the spinning oil contains 2,4,6-trivinyl cycloboroxine; Step S3, heat-stretching the oiled tow in sequence, using a nitrogen atmosphere 60 The fiber is grafted by radiation with a Co-γ ray source, passed through a sub-assembly network device, and then wound at a winding head to obtain high-strength nylon fiber.

9. The method for preparing high-strength nylon fiber according to claim 8, characterized in that: The melt temperature of the melt extrusion granulation in step S1 is 235-285° C., and the extrusion pressure is 8-10 MPa; the process parameters of the melt spinning in step S1 are: spinning temperature 230-270° C., winding speed 1000-1500 m / min, and draft multiple 2-4.

10. The method for preparing high-strength nylon fiber according to claim 8, characterized in that: The stretching ratio of the thermal stretching in step S3 is 1-2; the radiation grafting in step S3 is carried out at room temperature, the absorbed dose is 5-40 kGy, and the dose rate is 5-20 kGy / h; the network pressure of the sub-packaging network device in step S3 is 1-2 kgf / cm 2 .