Preparation method of chinlon 6 fiber with heat retention property

Abstract

The invention relates to the technical field of textile, and particularly discloses a preparation method of chinlon 6 fiber with heat retention property, and the chinlon 6 fiber with heat retention property is prepared by melting and spinning heat storage PA6 master batch; the heat storage PA6 master batch is obtained by filling a porous structure of PA6 resin with a phase change material, and the PA6 resin is obtained through a pore-foaming agent reaction. According to the invention, the porous structure of the PA6 resin is filled with the phase change material, and the phase change material is encapsulated in the pore channels by the high-pore structure, so that the loss of the phase change material is reduced, and the heat retention property and durability of the prepared fiber are improved.

Description

Technical Field

[0001] The present application relates to the technical field of textiles, and more specifically, to a preparation method of polyamide 6 fiber with heat preservation performance. Background Art

[0002] Polyamide 6 fiber, also known as nylon 6 or polyamide 6, is one of the main varieties of synthetic fibers. Its molecular structure is arranged regularly and many hydrogen bonds are formed between macromolecules, making polyamide 6 fiber have the characteristics of high strength, good resilience, excellent wear resistance and strong moisture absorption ability, and is applied to fields such as clothing or home textiles. As one of the main raw materials for clothing textiles, how to improve the heat preservation performance of polyamide 6 staple fiber is an issue that people and researchers attach great importance to.

[0003] Heat preservation fibers mainly reduce the heat dissipated by the human body through heat conduction, heat convection and heat radiation and other ways, or utilize the energy in the environment through physical and chemical changes to achieve the effect of heating and heat preservation.

[0004] The patent application document with the publication number of CN103451756A discloses a preparation method of phase change fiber, which includes the following steps: (1) preparing microcapsule phase change materials; (2) preparing sensible heat or latent heat composite energy storage phase change materials; (3) spinning the microcapsule phase change materials, the sensible heat or latent heat composite phase change materials and the polymer solution together to obtain phase change fiber materials.

[0005] In this patent application document, by adding microcapsule phase change materials to the spinning solution, when adding a conventional amount of phase change materials, the content of the effective component of the prepared fiber phase change is limited; if the purpose of improving the heat preservation performance of the prepared fiber is achieved by increasing the addition amount of the phase change materials, but too much phase change materials will make the spinning effect poor, and finally the heat preservation performance of the fiber made is not strong.

[0006] Therefore, improving the heat preservation performance of fibers is of great significance to the development of the fabrics made therefrom. Summary of the Invention

[0007] In order to improve the heat preservation performance of polyamide 6 fiber, the present application provides a preparation method of polyamide 6 fiber with heat preservation performance.

[0008] The present application provides a preparation method of polyamide 6 fiber with heat preservation performance, and adopts the following technical scheme: A preparation method of polyamide 6 fiber with heat preservation performance is obtained by melt spinning a heat storage PA6 masterbatch; the heat storage PA6 masterbatch is obtained by filling a phase change material into the porous structure of PA6 resin; the PA6 resin is obtained by reacting with a pore-forming agent.

[0009] By adopting the above technical solution, when the ambient temperature is relatively high, its heat is transferred to the fabric, causing the fiber temperature to rise and exceed the phase transition point of the phase change material. At this time, the phase change material undergoes a phase change and absorbs heat, thereby reducing the human body's perceived temperature; on the contrary, when the ambient temperature is relatively low, the phase change material undergoes a phase change again and releases heat, increasing the human body's perceived temperature; therefore, by adding a phase change material to the PA6 masterbatch, the fiber can have good warmth retention; at the same time, in this application, the phase change material is filled in the porous structure of the PA6 resin, and the high-porosity structure encapsulates the phase change material inside the pores, reducing the loss of the phase change material and improving the warmth retention and durability of the prepared fiber.

[0010] Preferably, the phase change material is: graphene grafted polyethylene glycol.

[0011] By adopting the above technical solution, the phase change material formed by effectively combining polyethylene glycol as the phase change material and graphene as the heat-conducting material maintains its solid shape during the phase change. The reason lies in the characteristics of polyethylene glycol and graphene itself: graphene is a substance with a two-dimensional honeycomb lattice structure composed of carbon hexagons. In addition to retaining the relatively high thermal conductivity of flake graphite, it also has good adsorption and self-compactness; while polyethylene glycol is a good polymer phase change material with a very high crystallization rate, a large phase change enthalpy, no corrosion, stable performance, not prone to supercooling phenomenon and phase separation, and low price. The combination of a heat-conducting material and a phase change material can endow the phase change material with excellent heat-conducting ability, improve its heat transfer rate and photothermal conversion effect, thereby improving the heat storage capacity of the phase change material.

[0012] Preferably, the preparation method of the graphene grafted polyethylene glycol is: obtained by coating a polyethylene glycol solution on the surface of graphene and then performing plasma surface treatment in a nitrogen or ammonia atmosphere.

[0013] By adopting the above technical solution, plasma is used to generate amino groups on the surface of graphene in an atmosphere of nitrogen-containing gas. The amino groups interact with the hydroxyl groups of polyethylene glycol to form chemical hydrogen bonds, thereby realizing the effective combination of the two; at the same time, due to the excellent properties of polyethylene glycol, it can not only improve the adhesion between the phase change material and the PA6 resin, but also improve the dispersion of graphene in the PA6 resin, further improving the heat storage performance of the phase change material.

[0014] Preferably, the concentration of the polyethylene glycol solution is 60%-80%, and the molecular weight is 4000-15000.

[0015] By adopting the above technical solution, the phase change temperatures of polyethylene glycols with different molecular weights are different. As the degree of polymerization increases, the van der Waals forces between molecules also increase, resulting in an increase in its phase change temperature. However, when the degree of polymerization of polyethylene glycol is too large, the PEG chain is too long, which leads to easy entanglement between the chains, hinders the formation of regular crystallization, reduces the crystallinity, and decreases the phase change enthalpy. Therefore, by optimizing the molecular weight of polyethylene glycol, a higher phase change enthalpy is obtained, improving its heat storage capacity.

[0016] Preferably, the preparation method of the PA6 resin is as follows: melt 100 parts by weight of PA6 chips, add 5 - 10 parts by weight of a pore-forming agent and 8 - 16 parts by weight of a surfactant, mix evenly, wash with water, extrude, and granulate to obtain PA6 resin with a pore size of 0.1 - 1 μm.

[0017] By adopting the above technical solution, the preparation method is simple. After treating the PA6 chips with a pore-forming agent, PA6 resin with a porous structure is obtained. The high-porosity structure can encapsulate the phase change material inside the pores, reducing the loss of the phase change material and improving the warmth retention and durability of the prepared fibers.

[0018] Preferably, the pore-forming agent is a mixture of zinc oxide and cyclohexane with a mass ratio of (6 - 8):(2 - 4); the surfactant is a mixture of sodium dodecylbenzenesulfonate and calcium dodecylbenzenesulfonate with a mass ratio of (3 - 5):(5 - 7).

[0019] By adopting the above technical solution, while using zinc oxide as an inorganic pore-forming agent, a small amount of cyclohexane is added as an organic pore-forming agent. When the solid zinc oxide and the liquid cyclohexane are mixed, it is easier to form a uniform mixture, and both can avoid the extrusion of some inorganic powders during the process of cyclohexane changing from liquid to solid during the reaction, improving the pore-forming effect.

[0020] The surfactant can reduce the surface tension of the mixture, promote the uniform dispersion of the pore-forming agent and the PA6 resin, and improve the uniformity of the pores of the PA6 resin; at the same time, in combination with the pore-forming agent, it can change the position of the pores, making the arrangement of the pores more compact and orderly, greatly enhancing the stability and dispersion of the pore structure and improving the pore-forming effect.

[0021] Preferably, the preparation method of the heat storage PA6 masterbatch is as follows: mix a phase change material and PA6 resin with a mass ratio of (1 - 3):(7 - 9), and stir to obtain the heat storage PA6 masterbatch.

[0022] Preferably, the stirring rate is 3500 - 5500 rpm, and the stirring time is 0.5 - 1 h.

[0023] By adopting the above technical solution, the phase change material can be encapsulated into the porous structure of PA6 resin through stirring, with simple operation, enabling the porous PA6 resin to effectively adsorb and carry the phase change material, and finally obtaining the masterbatch.

[0024] Preferably, the spinning temperature during spinning is 270 - 280 °C.

[0025] By adopting the above technical solution, whether the spinning temperature is appropriately selected directly affects the quality of the fiber and the normal progress of the spinning process. If the spinning temperature is too high, the thermal decomposition of the polymer will be aggravated, resulting in a decrease in relative molecular mass and the appearance of bubble filaments, and capillary fracture will occur due to too low melt viscosity, forming a "spout head". For the heat-preserving polyamide 6 fiber, a higher content of the phase change material can not only play a role in heat storage but also increase the impurities in the melt. When the spinning temperature is too high, the residence time of the melt is long, and the content of low-molecular substances in the melt increases, which will seriously affect the fiber quality; if the spinning temperature is too low, the melt viscosity will be too high, increasing the burden of pump transportation, often resulting in leakage of materials, and the die swell phenomenon of the extrudate will become more serious, and even the "melt fracture" phenomenon will occur, affecting normal spinning. In severe cases, hard head filaments will appear, the hand feeling will be hard, the breakage during post-drawing will increase, and even stretching cannot be carried out. The fluctuation of the spinning temperature will also affect the fiber quality. Therefore, optimizing the spinning temperature during the spinning process can improve the spinning quality.

[0026] Preferably, during the spinning process, the cooling air used is dew point air at 19 - 21 °C, and the air supply speed is 0.3 - 0.8 m / s.

[0027] By adopting the above technical solution, during spinning, the cooling conditions should be ensured to be stable and uniform, avoiding being affected by external conditions, so that the temperature change, speed change, solidification point position, and axial tension of the polymer melt filament during the cooling and forming process are kept stable. The control of the cooling conditions is mainly to control the temperature and air volume of the cooling air.

[0028] In summary, the present application has the following beneficial effects: 1. The polyamide 6 fiber prepared by melt spinning the heat storage PA6 masterbatch made by filling the phase change material into the porous structure of PA6 resin in the present application has good heat preservation performance; 2. In the present application, polyethylene glycol is grafted onto the surface of graphene by using plasma in a nitrogen-containing gas atmosphere, realizing the effective combination of the phase change material and the heat-conducting material, endowing the phase change material with excellent heat-conducting ability, improving its heat transfer rate and photothermal conversion effect, and thus improving the heat storage ability of the phase change material; 3. In the present application, the phase change material is encapsulated into the porous structure of PA6 resin by high-speed stirring of PA6 resin and the phase change material, with a simple method and strong feasibility. Detailed implementation mode

[0029] The present application will be further described in detail below in conjunction with Preparation Examples, Examples and Comparative Examples. The raw materials involved in the present application can all be obtained commercially.

[0030] Preparation Example Preparation Example 1 In this preparation example, the heat storage PA6 masterbatch was prepared according to the following method: (1) Preparation of the phase change material: Immerse graphene powder in a polyethylene glycol solution with a molecular weight of 10,000, where the mass fraction of polyethylene glycol is 70%. After soaking at room temperature for 3 h, take it out, dry it at 75 °C to remove the solvent, then put it into a plasma generating device, and perform plasma surface modification in an ammonia atmosphere. The treatment power is 300 W, and the treatment time is 10 min. Then wash it with deionized water to remove the un-grafted polyethylene glycol, dry and grind it to obtain graphene-grafted polyethylene glycol with an average particle size of 10 nm. (2) Preparation of PA6 resin: Melt 100 g of PA6 chips at 220 °C for 60 min, add 5.6 g of zinc oxide, 2.4 g of cyclohexane, 4.8 g of sodium dodecylbenzenesulfonate and 7.2 g of calcium dodecylbenzenesulfonate, mix evenly and react, then wash successively with hydrochloric acid and deionized water, extrude and pelletize to obtain PA6 resin with an average particle size of 0.5 μm. (3) Add 20 g of the above phase change material and 80 g of PA6 resin to a high-speed mixer, and stir at a high speed of 4500 rpm for 45 min to obtain the heat storage PA6 masterbatch.

[0031] Preparation Example 2 In this preparation example, the heat storage PA6 masterbatch was prepared according to the following method: (1) Preparation of the phase change material: Immerse graphene powder in a polyethylene glycol solution with a molecular weight of 4000, where the mass fraction of polyethylene glycol is 80%. After soaking at room temperature for 3 h, take it out, dry it at 75 °C to remove the solvent, then put it into a plasma generating device, and perform plasma surface modification in an ammonia atmosphere. The treatment power is 300 W, and the treatment time is 10 min. Then wash it with deionized water to remove the un-grafted polyethylene glycol, dry and grind it to obtain graphene-grafted polyethylene glycol with an average particle size of 10 nm. (2) Preparation of PA6 resin: Melt 100 g of PA6 chips at 220 °C for 60 min, add 3 g of zinc oxide, 2 g of cyclohexane, 2.4 g of sodium dodecylbenzenesulfonate and 5.6 g of calcium dodecylbenzenesulfonate, mix evenly and react, then wash successively with hydrochloric acid and deionized water, extrude and pelletize to obtain PA6 resin with an average particle size of 1 μm. (3) Add the above 10 g of phase change material and 90 g of PA6 resin to a high-speed mixer, and stir at a speed of 3500 rpm for 60 min to obtain the heat storage PA6 masterbatch.

[0032] Preparation Example 3 In this preparation example, the heat storage PA6 masterbatch was prepared according to the following method: (1) Preparation of the phase change material: Immerse graphene powder in a polyethylene glycol solution with a molecular weight of 15000, the mass fraction of polyethylene glycol is 60%, take it out after soaking at room temperature for 3 h, dry it at 75 °C to remove the solvent, then put it into a plasma generating device, and perform plasma surface modification in an ammonia atmosphere. The treatment power is 300 W, and the treatment time is 10 min. Then wash it with deionized water to remove the un-grafted polyethylene glycol, dry and grind it to obtain graphene-grafted polyethylene glycol with an average particle size of 10 nm. (2) Preparation of PA6 resin: Melt 100 g of PA6 chips at 220 °C for 60 min, add 8 g of zinc oxide, 2 g of cyclohexane, 8 g of sodium dodecylbenzenesulfonate and 8 g of calcium dodecylbenzenesulfonate, mix evenly and react, then wash with hydrochloric acid and deionized water in turn, extrude and pelletize to obtain PA6 resin with an average particle size of 0.1 μm. (3) Add the above 30 g of phase change material and 70 g of PA6 resin to a high-speed mixer, and stir at a speed of 5500 rpm for 30 min to obtain the heat storage PA6 masterbatch.

[0033] Preparation Example 4 In this preparation example, the heat storage PA6 masterbatch was prepared according to the following method: (1) Preparation of PA6 resin: Melt 100 g of PA6 chips at 220 °C for 60 min, add 8 g of zinc oxide, 2 g of cyclohexane, 8 g of sodium dodecylbenzenesulfonate and 8 g of calcium dodecylbenzenesulfonate, mix evenly and react, then wash with hydrochloric acid and deionized water in turn, extrude and pelletize to obtain PA6 resin. (2) Add 30 g of polyethylene glycol and 70 g of the above PA6 resin to a high-speed mixer, and stir at a speed of 5500 rpm for 30 min to obtain the heat storage PA6 masterbatch.

[0034] Preparation Example 5 In this preparation example, the heat storage PA6 masterbatch was prepared according to the following method: (1) Preparation of the phase change material: Immerse graphene powder in a polyethylene glycol solution with a molecular weight of 15000, the mass fraction of polyethylene glycol is 60%, take it out after soaking at room temperature for 3 h, dry it at 75 °C to remove the solvent, then wash it with deionized water to remove the excess polyethylene glycol, dry and grind it to obtain graphene-grafted polyethylene glycol with an average particle size of 10 nm. (2)Preparation of PA6 resin: 100 g of PA6 chips were melted at 220 °C for 60 min. After adding 8 g of zinc oxide, 2 g of cyclohexane, 8 g of sodium dodecylbenzenesulfonate and 8 g of calcium dodecylbenzenesulfonate and mixing evenly for reaction, they were washed successively with hydrochloric acid and deionized water, and then extruded and pelletized to obtain PA6 resin; (3)30 g of the above phase change material and 70 g of PA6 resin were added to a high-speed mixer and stirred at a high speed of 5500 rpm for 30 min to obtain a heat storage PA6 masterbatch.

[0035] Example Example 1 In this example, the heat-insulating polyamide 6 fiber was prepared according to the following steps: (1)The heat storage PA6 masterbatch was dried in a blower at 110 °C for 3 h for standby, and the heat storage PA6 masterbatch was obtained from Preparation Example 1; (2)The dried heat storage PA6 masterbatch was added to a screw extruder to be melted to obtain a melt. The melt entered the spinning box and was ejected from the spinneret to form filaments. Then, it was cooled by blowing, oiled, wound, bundled, stretched, heat-set, crimped, and cut to make a heat-insulating polyamide 6 fiber; the temperature of the spinning box was 275 °C; during cooling, a slow cooling method was adopted under the spinneret, that is, the area 21 cm below the spinneret was the slow cooling zone, and then dew point air cooling was carried out, the air temperature was 20 °C, and the air speed was 0.5 m / s; the draw ratio was 1.3 times; the winding speed was 5500 m / min.

[0036] Example 2 The difference between this example and Example 1 is that in this example, the heat storage PA6 masterbatch was obtained from Preparation Example 2.

[0037] Example 3 The difference between this example and Example 1 is that in this example, the heat storage PA6 masterbatch was obtained from Preparation Example 3.

[0038] Example 4 The difference between this example and Example 1 is that in this example, the heat storage PA6 masterbatch was obtained from Preparation Example 4.

[0039] Example 5 The difference between this example and Example 1 is that in this example, the heat storage PA6 masterbatch was obtained from Preparation Example 5.

[0040] Comparative example Comparative example 1 In this comparative example, the heat-insulating polyamide 6 fiber was prepared according to the following steps: (1) The heat storage PA6 masterbatch (obtained by mixing 30 g of polyethylene glycol and 70 g of PA6 chips and extruding and pelletizing) was dried in a blower at 110 °C for 3 h for standby; (2) The dried heat storage PA6 masterbatch was added to a screw extruder to be melted into a melt. The melt entered the spinning box, was ejected through a spinneret to form silk threads, and then was cooled by blowing, oiled, wound, bundled, stretched, heat-set, crimped, and cut to make polyamide 6 fibers with warmth retention; the temperature of the spinning box was 275 °C; during cooling, a slow cooling method was adopted under the spinneret, that is, the area 21 cm below the spinneret was the slow cooling zone, and then dew point air cooling was carried out, the air temperature was 20 °C, and the wind speed was 0.5 m / s; the draw ratio was 1.3 times; the winding speed was 5500 m / min.

[0041] Comparative Example 2 In this comparative example, the polyamide 6 fibers with warmth retention were prepared according to the following steps: (1) 70 g of PA6 chips were dried in a blower at 110 °C for 3 h for standby; (2) The dried PA6 chips were added to a screw extruder to be melted into a melt, and 30 g of polyethylene glycol was added to form a mixture. The mixture entered the spinning box, was ejected through a spinneret to form silk threads, and then was cooled by blowing, oiled, wound, bundled, stretched, heat-set, crimped, and cut to make polyamide 6 fibers with warmth retention; the temperature of the spinning box was 275 °C; during cooling, a slow cooling method was adopted under the spinneret, that is, the area 21 cm below the spinneret was the slow cooling zone, and then dew point air cooling was carried out, the air temperature was 20 °C, and the wind speed was 0.5 m / s; the draw ratio was 1.3 times; the winding speed was 5500 m / min.

[0042] Comparative Example 3 In this comparative example, the polyamide 6 fibers with warmth retention were prepared according to the following steps: (1) The heat storage PA6 masterbatch was dried in a blower at 110 °C for 3 h for standby; (2) The dried heat storage PA6 masterbatch was added to a screw extruder to be melted into a melt. The melt entered the spinning box, was ejected through a spinneret to form silk threads, and then was cooled by blowing, oiled, wound, bundled, stretched, heat-set, crimped, and cut to make polyamide 6 fibers with warmth retention; the temperature of the spinning box was 275 °C; during cooling, a slow cooling method was adopted under the spinneret, that is, the area 21 cm below the spinneret was the slow cooling zone, and then dew point air cooling was carried out, the air temperature was 20 °C, and the wind speed was 0.5 m / s; the draw ratio was 1.3 times; the winding speed was 5500 m / min.

[0043] The heat storage PA6 masterbatch was prepared by the following preparation method: (1)Preparation of phase change material: Immerse graphene powder into polyethylene glycol solution with a molecular weight of 15,000. The concentration of polyethylene glycol is 60%. Take it out after soaking at room temperature for 3 h, dry it at 75 °C to remove the solvent, and then put it into a plasma generating device for plasma surface modification in an ammonia atmosphere. The treatment power is 300 W and the treatment time is 10 min. Then wash it with deionized water to remove the un-grafted polyethylene glycol, dry and grind it to obtain graphene grafted polyethylene glycol with an average particle size of 10 nm. (2)Mix 30 g of the above phase change material with 70 g of PA6 chips, extrude and granulate to obtain heat storage PA6 masterbatch.

[0044] Performance detection test method Use a water cup filled with water at 37.0 °C to simulate human body temperature. After coating 3 layers with the polyamide 6 fibers prepared in each example and comparative example as samples, place them at -20 °C to detect the temperature change of the simulated water (measure once every 20 min), and record the measurement result as A; at the same time, place the samples at 80 °C to detect the temperature change of the simulated water (measure once every 20 min), and record the measurement result as B. The measurement results are shown in Table 1.

[0045] Table 1 Performance detection data table of Examples 1-5 and Comparative Examples 1-3

[0046] Combined with Example 4 and Comparative Examples 1-3 and referring to Table 1, it can be seen that the warmth retention property of the polyamide 6 fibers prepared in Example 4 is better than that of the polyamide 6 fibers prepared in Comparative Examples 1-3, indicating that the polyamide 6 fibers prepared by filling the phase change material into the porous structure of PA6 resin in this application can encapsulate the phase change material inside the pores by the porous structure of PA6 resin, reducing the loss of the phase change material and improving the warmth retention property and durability of the prepared fibers.

[0047] Combined with Example 4 and Example 5 and referring to Table 1, it can be seen that in this application, a phase change material is prepared by compounding polyethylene glycol and graphene. The compounding of a heat-conducting material and the phase change material can endow the phase change material with excellent heat-conducting ability, improve its heat transfer rate and photothermal conversion effect, thereby improving the heat storage ability of the prepared polyamide 6 fibers.

[0048] Combined with Example 1 and Example 5 and referring to Table 1, it can be seen that in this application, polyethylene glycol is grafted onto the surface of graphene by plasma surface treatment in a nitrogen-containing gas atmosphere, which not only improves the dispersion of graphene in the resin matrix; but also the change in the surface structure of the material after plasma treatment improves the adhesion, which is beneficial to the attachment of the phase change material on PA4 resin, can further improve the combination of the phase change material and the resin, and improves the warmth retention property of the prepared polyamide 6 fibers.

[0049] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment that do not contribute creatively as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A method for preparing nylon 6 fiber with warmth retention, characterized in that: The heat storage PA6 masterbatch is prepared by melt spinning; the heat storage PA6 masterbatch is obtained by filling the phase change material in the porous structure of the PA6 resin, and the PA6 resin is obtained by reacting with a porogen.

2. The method for preparing the nylon 6 fiber with warmth retention according to claim 1, characterized in that: The phase change material is: graphene grafted polyethylene glycol.

3. The method for preparing the nylon 6 fiber with warmth retention according to claim 2, characterized in that: The preparation method of the graphene grafted polyethylene glycol is as follows: a polyethylene glycol solution is coated on the surface of the graphene and then the surface is subjected to plasma treatment in a nitrogen or ammonia atmosphere to obtain the graphene grafted polyethylene glycol.

4. The method for preparing the nylon 6 fiber with thermal insulation properties according to claim 3, characterized in that: The concentration of the polyethylene glycol solution is 60%-80%, and the molecular weight is 4000-15000.

5. The method for preparing the nylon 6 fiber with warmth retention according to claim 1, characterized in that: The preparation method of the PA6 resin is as follows: 100 parts by weight of PA6 chips are melted, 5-10 parts by weight of a porogen and 8-16 parts by weight of a surfactant are added and mixed evenly, and then the PA6 resin is obtained by washing, extruding and granulating in sequence.

6. The method for preparing the nylon 6 fiber with warmth retention according to claim 5, characterized in that: The porogen is a mixture of zinc oxide and cyclohexane in a mass ratio of (6-8):(2-4); the surfactant is a mixture of sodium dodecylbenzene sulfonate and calcium dodecylbenzene sulfonate in a mass ratio of (3-5):(5-7).

7. The method for preparing the nylon 6 fiber with thermal insulation properties according to claim 1, characterized in that: The preparation method of the heat storage PA6 masterbatch is: mixing a phase change material with a PA6 resin, and stirring to obtain the heat storage PA6 masterbatch.

8. The method for preparing the nylon 6 fiber with warmth retention according to claim 7, characterized in that: The stirring rate is 3500-5500 rpm, and the stirring time is 0.5-1 h.

9. The method for preparing the nylon 6 fiber with thermal insulation properties according to claim 1, characterized in that: The spinning temperature during the spinning is 270-280°C.

10. The method for preparing nylon 6 fiber with thermal insulation properties according to claim 1, characterized in that: During the spinning process, the cooling air blowing uses dew point air of 19-21° C. and the air supply speed is 0.3-0.8 m / s.

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