Polyurethane-coated phase-change microcapsule, temperature-regulating fiber and preparation method thereof

Abstract

The present invention relates to the technical field of phase change microcapsules and functional fibers, and specifically to a polyurethane-coated phase change microcapsule, a temperature regulating fiber and a preparation method. The polyurethane-coated phase change microcapsule uses a phase change material as a core material and a cross-linked polyurethane as a shell material. The temperature regulating fiber is obtained by mixing the phase change microcapsule into a spandex stock solution or a TPU solution through spinning. The phase change microcapsule uses a cross-linked polyurethane as a shell material, which overcomes the shortcomings of poor thermal stability and poor structural density of traditional linear polyurethane, and the prepared phase change microcapsule has excellent mechanical properties, solvent resistance, weather resistance and biocompatibility. The temperature regulating fiber has the advantages of excellent water washability and good fiber feel, and the material properties of the polyurethane shell material of the microcapsule have good compatibility with the fiber, which can greatly improve the bonding strength, solve the shortcomings of poor thermal stability and poor structural density of the phase change microcapsule, and improve the biocompatibility and bonding strength of the phase change microcapsule and the fiber.

Description

Technical Field

[0001] The invention relates to a polyurethane-coated phase-change microcapsule, a temperature-regulating fiber and a preparation method, and belongs to the technical field of phase-change microcapsules and functional fibers. Background Art

[0002] In recent years, phase change materials have been widely studied in the fields of solar energy storage, thermal regulation fibers, energy-saving building materials, heat transfer slurries, etc., due to their ability to store or release large amounts of heat in the form of latent heat through phase changes. Phase change materials have a series of advantages such as low cost and good chemical stability. However, their disadvantages are also obvious. Phase change materials will inevitably leak during repeated phase changes. Microencapsulation technology forms tiny particles by wrapping the core material with a polymer shell to prevent leakage of the phase change material. The phase change material wrapped in microcapsules can be more evenly dispersed in the substrate, so that the phase change material will not be affected by external materials even if a phase change occurs. This technology breaks the limitations on the use of phase change materials in application fields.

[0003] Phase change microcapsules are mainly composed of core materials and shell materials. The core materials can be divided into four forms of phase change materials: solid-liquid, solid-gas, liquid-gas and solid-solid according to their phase changes. Among them, solid-liquid phase change materials are widely used due to their advantages such as small volume change during phase change, high latent heat of phase change and high chemical stability. There are many types of shell materials, which can be roughly divided into three categories: natural polymer materials, synthetic polymer materials and inorganic materials. It should be noted that the shell material, as a wrapping material, cannot be used in solvents that can dissolve the core material, nor can it dissolve the phase change material. The shell material should have excellent thermal conductivity, heat resistance and stability. In addition, the wall material cannot react with the surrounding environment and should have a leak-proof function. Finally, the selection of shell materials must ensure low price and cost and abundant sources.

[0004] At present, phase change microcapsules are mostly applied to fibers and clothing through post-treatment, and a layer of phase change microcapsule solution is coated on the surface of the fiber or cloth. For example: Chinese patent application CN111905662A discloses a phase change microcapsule material with strong bonding force with fabric fibers, a preparation method and application, wherein cotton fiber and acrylic fiber mixed fiber are soaked in a slurry containing phase change microcapsules, and a temperature regulating fabric is prepared by heating and rolling processes. Chinese patent application CN110438611A discloses a yarn that can be temperature-controlled and its preparation process, wherein holy hemp fiber, honeycomb fiber, and cotton fiber are placed in a phase change microcapsule solution for soaking; the soaked fiber is placed in a clean and dry drying device for drying, and then the fiber is processed into yarn by a blending process, thereby preparing a textile yarn with temperature control function. However, these methods will cause the obtained temperature regulating fiber or fabric to easily leak materials, and the water washing resistance is poor, which leads to the fact that the intelligent temperature regulating fiber has not been widely used. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a polyurethane-coated phase change microcapsule, a temperature-regulating fiber and a preparation method. The shell material of the phase change microcapsule is a cross-linked structure, which overcomes the shortcomings of poor thermal stability and poor structural density of traditional linear polyurethanes. The temperature-regulating fiber obtained by mixing the polyurethane-coated phase change microcapsule into spandex and TPU stock solution and spinning has the advantages of uniform distribution, excellent water washability and good fiber feel, which can greatly improve the temperature-regulating performance and service life of the temperature-regulating fiber.

[0006] The technical solution of the present invention to solve the above technical problems is as follows: a method for preparing polyurethane-coated phase-change microcapsules, the preparation method comprising:

[0007] S1. Mix the core material, diisocyanate and chain extender to form oil phase A; add a crosslinking agent to distilled water to obtain an aqueous solution B; dissolve an emulsifier in distilled water to obtain an emulsifier solution C; the mass ratio of the diisocyanate to the crosslinking agent is 1:(0.3-1);

[0008] S2, adding the oil phase A to the emulsifier solution C, homogenizing, and forming an oil-in-water emulsion D; adding the aqueous solution B to the emulsion D, and preparing a phase change microcapsule emulsion under heating and stirring conditions;

[0009] S3, adding deionized water to the phase change microcapsule emulsion for washing, and then drying to obtain polyurethane-coated phase change microcapsules.

[0010] Furthermore, in step S1, the core material is at least one of n-hexadecane, n-octadecane, phase change paraffin, and butyl stearate;

[0011] The emulsifier is at least one of styrene-maleic anhydride copolymer sodium salt, polyvinyl alcohol, and sodium lauryl sulfate.

[0012] Further, in step S1, the diisocyanate is at least one of isophorone diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, and hexamethylene diisocyanate;

[0013] The chain extender is at least one of polyaspartic acid resin F420, polyaspartic acid resin F2850, diethylenetriamine (DETA), and tetraethylpentanediamine (TEPA).

[0014] Furthermore, in step S1, the cross-linking agent is at least one of pentaerythritol, trimethylolpropane, and triethanolamine.

[0015] Furthermore, the mass ratio of the diisocyanate to the chain extender is (3:1) to (1:3), the core-shell ratio of the polyurethane-coated phase change microcapsules is (0.8-3):1, and the mass concentration of the emulsifier in the emulsifier solution C is 1wt%-3wt%.

[0016] Furthermore, in step S2, the oil phase A is added to the emulsifier solution C, and homogenized at a rotation speed of 5000rpm-10000rpm for 3-10min to form an oil-in-water emulsion D; the aqueous solution B is added to the emulsion D, and the reaction is stirred at a temperature of 40-90°C and a rotation speed of 200rpm-500rpm for 4-7h to prepare a phase change microcapsule emulsion.

[0017] The invention also discloses a polyurethane-coated phase-change microcapsule, and the polyurethane-coated phase-change microcapsule is prepared by the preparation method of the invention.

[0018] The present invention also discloses a method for preparing the temperature regulating fiber, the preparation method comprising:

[0019] The polyurethane-coated phase-change microcapsules of the present invention are mixed into spandex stock solution, and the temperature-regulating fiber is obtained through a dry spinning process; or the polyurethane-coated phase-change microcapsules of the present invention are mixed into TPU melt, and the temperature-regulating fiber is obtained through granulation and melt spinning processes.

[0020] Furthermore, the amount of the polyurethane-coated phase-change microcapsules added is 1%-2% of the mass of the spandex stock solution or the TPU melt;

[0021] The spinning temperature in the dry spinning process is 180-230°C; the spinning temperature in the melt spinning process is 200-220°C.

[0022] The invention also discloses a temperature regulating fiber, and the temperature regulating fiber is prepared according to the preparation method of the invention.

[0023] The beneficial effects of the present invention are:

[0024] The polyurethane-coated phase-change microcapsules of the present invention use cross-linked polyurethane as the shell material, and the cross-linked structure thereof greatly improves the stability and structural density of the phase-change microcapsules, overcoming the shortcomings of poor thermal stability and poor structural density of traditional linear polyurethanes. The phase-change microcapsules of the present invention have excellent mechanical properties, solvent resistance, weather resistance, biocompatibility, etc.

[0025] The present invention obtains the temperature-regulating fiber by mixing the polyurethane-coated phase-change microcapsules into spandex and TPU stock solution through spinning, which has the advantages of uniform distribution, excellent water-washing resistance, good fiber feel, excellent temperature-regulating performance, etc., and the material properties of the polyurethane shell material of the microcapsule have good compatibility with the fiber, which can greatly improve the bonding strength. The two work together to solve the shortcomings of poor thermal stability and poor structural density of the phase-change microcapsules, and improve the biocompatibility and bonding strength of the phase-change microcapsules with spandex and TPU fibers. DETAILED DESCRIPTION

[0026] The specific implementation of the present invention is described in detail below. The present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used are only for describing specific embodiments and are not intended to limit the present invention.

[0028] A method for preparing polyurethane-coated phase-change microcapsules, the preparation method comprising:

[0029] S1. Mix the core material, diisocyanate and chain extender to form oil phase A; add a crosslinking agent to distilled water to obtain an aqueous solution B; dissolve an emulsifier in distilled water to obtain an emulsifier solution C; the mass ratio of the diisocyanate to the crosslinking agent is 1:(0.3-1);

[0030] S2, adding the oil phase A to the emulsifier solution C, homogenizing, and forming an oil-in-water emulsion D; adding the aqueous solution B to the emulsion D, and preparing a phase change microcapsule emulsion under heating and stirring conditions;

[0031] S3, adding deionized water to the phase change microcapsule emulsion for washing, and then drying to obtain polyurethane-coated phase change microcapsules.

[0032] Specifically, in step S1, the core material is at least one of n-hexadecane, n-octadecane, phase change paraffin, and butyl stearate;

[0033] The emulsifier is at least one of styrene-maleic anhydride copolymer sodium salt (SMA), polyvinyl alcohol (PVA), and sodium dodecyl sulfate (SDS).

[0034] Specifically, in step S1, the diisocyanate is at least one of isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), and hexamethylene diisocyanate (HDI);

[0035] The chain extender is at least one of polyaspartic acid resin F420, polyaspartic acid resin F2850, diethylenetriamine (DETA), and tetraethylpentanediamine (TEPA).

[0036] Specifically, in step S1, the cross-linking agent is at least one of pentaerythritol, trimethylolpropane, and triethanolamine.

[0037] Specifically, the mass ratio of the diisocyanate to the chain extender is (3:1) to (1:3), the core-shell ratio of the polyurethane-coated phase change microcapsules is (0.8-3):1, and the mass concentration of the emulsifier in the emulsifier solution C is 1wt%-3wt%.

[0038] Specifically, in step S2, the oil phase A is added to the emulsifier solution C, and homogenized at a rotation speed of 5000rpm-10000rpm for 3-10min to form an oil-in-water emulsion D; the aqueous solution B is added to the emulsion D, and the reaction is stirred at a temperature of 40-90°C and a rotation speed of 200rpm-500rpm for 4-7h to prepare a phase change microcapsule emulsion.

[0039] A polyurethane-coated phase-change microcapsule is prepared according to the preparation method of the present invention.

[0040] A method for preparing a temperature-regulating fiber, the preparation method comprising:

[0041] The polyurethane-coated phase-change microcapsules of the present invention are mixed into spandex stock solution, and the temperature-regulating fiber is obtained through a dry spinning process; or the polyurethane-coated phase-change microcapsules of the present invention are mixed into TPU melt, and the temperature-regulating fiber is obtained through granulation and melt spinning processes.

[0042] Specifically, the amount of the polyurethane-coated phase-change microcapsules added is 1%-2% of the mass of the spandex stock solution or the TPU melt;

[0043] The spinning temperature in the dry spinning process is 180-230°C; the spinning temperature in the melt spinning process is 200-220°C.

[0044] In the embodiment of the present invention, the solid content of the spandex stock solution is 38%, and the viscosity is 3200P; the melt index of the TPU melt is 17g / 10min (190°C, 2.16kg).

[0045] A temperature regulating fiber is prepared according to the preparation method of the present invention.

[0046] Example 1

[0047] 1. Preparation of phase change microcapsules:

[0048] (1) At 40°C, 10 g of n-hexadecane, 6 g of hexamethylene diisocyanate (HDI) and 2 g of diethylenetriamine (DETA) were mixed to form oil phase A;

[0049] (2) Add 2 g of cross-linking agent triethanolamine to 20 ml of distilled water to obtain aqueous solution B;

[0050] (3) dissolving 6 g of styrene-maleic anhydride copolymer sodium salt (SMA) in 200 ml of distilled water as emulsifier solution C;

[0051] (4) Adding the oil phase A to the emulsifier solution C and homogenizing at a speed of 5000 rpm for 10 min to form an oil-in-water (O / W) emulsion D;

[0052] (5) Adding aqueous solution B to emulsion D, placing the mixture in a water bath at 40°C, and reacting the mixture at a speed of 500 rpm for 7 h to prepare a polyurethane-coated phase change microcapsule emulsion;

[0053] (6) The phase change microcapsule emulsion obtained by the reaction is washed with deionized water for 2-3 times, and then placed in a vacuum oven at 60°C and dried for 8 hours to obtain polyurethane-coated phase change microcapsules.

[0054] 2. Preparation of intelligent temperature regulating fiber:

[0055] Phase change microcapsules are added to spandex stock solution and fully stirred and mixed (mixing temperature is 75°C), wherein the amount of polyurethane-coated phase change microcapsules added is 1% of the mass of the spandex stock solution; spandex intelligent temperature regulating fibers are obtained by dry spinning, wherein the spinning temperature of the dry spinning is 200°C.

[0056] Example 2

[0057] 1. Preparation of phase change microcapsules:

[0058] (1) At 40°C, 30 g of butyl stearate, 6 g of isophorone diisocyanate (IPDI) and 2 g of tetraethylpentanediamine (TEPA) were mixed to form oil phase A;

[0059] (2) Add 2 g of cross-linking agent triethanolamine to 20 ml of distilled water to obtain aqueous solution B;

[0060] (3) Dissolve 2 g of sodium dodecyl sulfate (SDS) in 200 ml of distilled water as emulsifier solution C;

[0061] (4) Adding the oil phase A to the emulsifier solution C and homogenizing at a speed of 10,000 rpm for 3 min to form an oil-in-water (O / W) emulsion D;

[0062] (5) Adding aqueous solution B to emulsion D, placing the mixture in a water bath at 90°C, and reacting the mixture at 200 rpm for 4 h to prepare a polyurethane-coated phase change microcapsule emulsion;

[0063] (6) The phase change microcapsule emulsion obtained by the reaction is washed with deionized water for 2-3 times, and then placed in a vacuum oven at 60°C and dried for 8 hours to obtain polyurethane-coated phase change microcapsules.

[0064] 2. Preparation of intelligent temperature regulating fiber:

[0065] Phase change microcapsules are added to TPU melt for granulation, wherein the amount of polyurethane-coated phase change microcapsules added is 2% of the mass of the TPU melt; then TPU intelligent temperature regulating fibers are obtained by melt spinning, wherein the spinning temperature of the melt spinning is 220°C.

[0066] Example 3

[0067] 1. Preparation of phase change microcapsules:

[0068] (1) At 40°C, 10 g of n-octadecane, 2 g of toluene diisocyanate (TDI) and 6 g of polyaspartic acid resin F2850 were mixed to form oil phase A;

[0069] (2) Add 2 g of cross-linking agent pentaerythritol to 20 ml of distilled water to obtain aqueous solution B;

[0070] (3) Dissolve 4 g of polyvinyl alcohol (PVA) in 200 ml of distilled water as emulsifier solution C;

[0071] (4) Adding the oil phase A to the emulsifier solution C and homogenizing at 7000 rpm for 5 min to form an oil-in-water (O / W) emulsion D;

[0072] (5) Adding aqueous solution B to emulsion D, placing the mixture in a water bath at 80°C, and reacting at a speed of 400 rpm for 5 h to prepare a polyurethane-coated phase change microcapsule emulsion;

[0073] (6) The phase change microcapsule emulsion obtained by the reaction is washed with deionized water for 2-3 times, and then placed in a vacuum oven at 60°C and dried for 8 hours to obtain polyurethane-coated phase change microcapsules.

[0074] 2. Preparation of intelligent temperature regulating fiber:

[0075] Phase change microcapsules are added to TPU melt for granulation, wherein the amount of polyurethane-coated phase change microcapsules added is 1% of the mass of the TPU melt; then TPU intelligent temperature regulating fibers are obtained by melt spinning, wherein the spinning temperature of the melt spinning is 220°C.

[0076] Example 4

[0077] 1. Preparation of phase change microcapsules:

[0078] (1) At 40°C, 20 g of phase change wax, 6.6 g of isophorone diisocyanate (IPDI) and 13.2 g of polyaspartic acid resin F2850 were mixed to form oil phase A;

[0079] (2) Add 2 g of cross-linking agent pentaerythritol to 20 ml of distilled water to obtain aqueous solution B;

[0080] (3) dissolving 4 g of styrene-maleic anhydride copolymer sodium salt (SMA) in 200 ml of distilled water as emulsifier solution C;

[0081] (4) Adding the oil phase A to the emulsifier solution C and homogenizing at a speed of 10,000 rpm for 5 min to form an oil-in-water (O / W) emulsion D;

[0082] (5) Adding aqueous solution B to emulsion D, placing the mixture in a water bath at 90°C, and reacting the mixture at 400 rpm for 5 h to prepare a polyurethane-coated phase change microcapsule emulsion;

[0083] (6) The phase change microcapsule emulsion obtained by the reaction is washed with deionized water for 2-3 times, and then placed in a vacuum oven at 60°C and dried for 8 hours to obtain polyurethane-coated phase change microcapsules.

[0084] 2. Preparation of intelligent temperature regulating fiber:

[0085] Phase change microcapsules are added to spandex stock solution and fully stirred and mixed (mixing temperature is 75°C), and the amount of polyurethane-coated phase change microcapsules added is 2% of the mass of the spandex stock solution; spandex intelligent temperature regulating fibers are obtained by dry spinning, wherein the spinning temperature of the dry spinning is 180°C.

[0086] Example 5

[0087] 1. Preparation of phase change microcapsules:

[0088] (1) At 40°C, 20 g of n-octadecane, 8 g of diphenylmethane diisocyanate (MDI) and 4 g of polyaspartic acid resin F420 were mixed to form oil phase A;

[0089] (2) Add 3 g of cross-linking agent pentaerythritol to 20 ml of distilled water to obtain aqueous solution B;

[0090] (3) dissolving 4 g of styrene-maleic anhydride copolymer sodium salt (SMA) in 200 ml of distilled water as emulsifier solution C;

[0091] (4) Adding the oil phase A to the emulsifier solution C and homogenizing at a speed of 5000 rpm for 7 min to form an oil-in-water (O / W) emulsion D;

[0092] (5) Adding aqueous solution B to emulsion D, placing the mixture in a water bath at 80°C, and reacting at a speed of 400 rpm for 5 h to prepare a polyurethane-coated phase change microcapsule emulsion;

[0093] (6) The phase change microcapsule emulsion obtained by the reaction is washed with deionized water for 2-3 times, and then placed in a vacuum oven at 60°C and dried for 8 hours to obtain polyurethane-coated phase change microcapsules.

[0094] 2. Preparation of intelligent temperature regulating fiber:

[0095] Phase change microcapsules are added to spandex stock solution and fully stirred and mixed (mixing temperature is 75°C), and the amount of polyurethane-coated phase change microcapsules added is 1.5% of the mass of the spandex stock solution; spandex intelligent temperature regulating fibers are obtained by dry spinning, wherein the spinning temperature of the dry spinning is 230°C.

[0096] Comparative Example 1

[0097] Phase change microcapsules and temperature regulating fibers were prepared by the same method as in Example 4, except that no core material was added. The specific preparation process is as follows:

[0098] 1. Preparation of phase change microcapsules:

[0099] (1) At 40°C, 6.6 g of isophorone diisocyanate (IPDI) and 13.2 g of polyaspartic acid resin F2850 were mixed to form oil phase A;

[0100] (2) Add 2 g of cross-linking agent pentaerythritol to 20 ml of distilled water to obtain aqueous solution B;

[0101] (3) dissolving 4 g of styrene-maleic anhydride copolymer sodium salt (SMA) in 200 ml of distilled water as emulsifier solution C;

[0102] (4) Adding the oil phase A to the emulsifier solution C and homogenizing at a speed of 10,000 rpm for 5 min to form an oil-in-water (O / W) emulsion D;

[0103] (5) Adding aqueous solution B to emulsion D, placing the mixture in a water bath at 90°C, and reacting the mixture at 400 rpm for 5 h to prepare a polyurethane-coated phase change microcapsule emulsion;

[0104] (6) The phase change microcapsule emulsion obtained by the reaction is washed with deionized water for 2-3 times, and then placed in a vacuum oven at 60°C and dried for 8 hours to obtain polyurethane-coated phase change microcapsules.

[0105] 2. Preparation of intelligent temperature regulating fiber:

[0106] Phase change microcapsules are added to spandex stock solution and fully stirred and mixed (mixing temperature is 75°C), and the amount of polyurethane-coated phase change microcapsules added is 2% of the mass of the spandex stock solution; spandex intelligent temperature regulating fibers are obtained by dry spinning, wherein the spinning temperature of the dry spinning is 180°C.

[0107] Comparative Example 2

[0108] Phase change microcapsules and temperature regulating fibers were prepared by the same method as in Example 4, except that the amount of crosslinking agent added was reduced so that the mass ratio of diisocyanate to crosslinking agent was 1:0.1. The specific preparation process is as follows:

[0109] 1. Preparation of phase change microcapsules:

[0110] (1) At 40°C, 20 g of phase change wax, 6.6 g of isophorone diisocyanate (IPDI) and 13.2 g of polyaspartic acid resin F2850 were mixed to form oil phase A;

[0111] (2) Add 0.66 g of cross-linking agent pentaerythritol to 20 ml of distilled water to obtain aqueous solution B;

[0112] (3) dissolving 4 g of styrene-maleic anhydride copolymer sodium salt (SMA) in 200 ml of distilled water as emulsifier solution C;

[0113] (4) Adding the oil phase A to the emulsifier solution C and homogenizing at a speed of 10,000 rpm for 5 min to form an oil-in-water (O / W) emulsion D;

[0114] (5) Adding aqueous solution B to emulsion D, placing the mixture in a water bath at 90°C, and reacting the mixture at 400 rpm for 5 h to prepare a polyurethane-coated phase change microcapsule emulsion;

[0115] (6) The phase change microcapsule emulsion obtained by the reaction is washed with deionized water for 2-3 times, and then placed in a vacuum oven at 60°C and dried for 8 hours to obtain polyurethane-coated phase change microcapsules.

[0116] 2. Preparation of intelligent temperature regulating fiber:

[0117] Phase change microcapsules are added to spandex stock solution and fully stirred and mixed (mixing temperature is 75°C), and the amount of polyurethane-coated phase change microcapsules added is 2% of the mass of the spandex stock solution; spandex intelligent temperature regulating fibers are obtained by dry spinning, wherein the spinning temperature of the dry spinning is 180°C.

[0118] Comparative Example 3

[0119] Phase change microcapsules and temperature regulating fibers were prepared by the same method as in Example 4, except that the amount of crosslinking agent added was increased so that the mass ratio of diisocyanate to crosslinking agent was 1:1.5. The specific preparation process is as follows:

[0120] 1. Preparation of phase change microcapsules:

[0121] (1) At 40°C, 20 g of phase change wax, 6.6 g of isophorone diisocyanate (IPDI) and 13.2 g of polyaspartic acid resin F2850 were mixed to form oil phase A;

[0122] (2) Add 9.9 g of cross-linking agent pentaerythritol to 20 ml of distilled water to obtain aqueous solution B;

[0123] (3) dissolving 4 g of styrene-maleic anhydride copolymer sodium salt (SMA) in 200 ml of distilled water as emulsifier solution C;

[0124] (4) Adding the oil phase A to the emulsifier solution C and homogenizing at a speed of 10,000 rpm for 5 min to form an oil-in-water (O / W) emulsion D;

[0125] (5) Adding aqueous solution B to emulsion D, placing the mixture in a water bath at 90°C, and reacting the mixture at 400 rpm for 5 h to prepare a polyurethane-coated phase change microcapsule emulsion;

[0126] (6) The phase change microcapsule emulsion obtained by the reaction is washed with deionized water for 2-3 times, and then placed in a vacuum oven at 60°C and dried for 8 hours to obtain polyurethane-coated phase change microcapsules.

[0127] 2. Preparation of intelligent temperature regulating fiber:

[0128] Phase change microcapsules are added to spandex stock solution and fully stirred and mixed (mixing temperature is 75°C), and the amount of polyurethane-coated phase change microcapsules added is 2% of the mass of the spandex stock solution; spandex intelligent temperature regulating fibers are obtained by dry spinning, wherein the spinning temperature of the dry spinning is 180°C.

[0129] Comparative Example 4

[0130] Phase change microcapsules and temperature regulating fibers were prepared by the same method as in Example 4, except that the stirring speed in step (5) was increased. The specific preparation process is as follows:

[0131] 1. Preparation of phase change microcapsules:

[0132] (1) At 40°C, 20 g of phase change wax, 6.6 g of isophorone diisocyanate (IPDI) and 13.2 g of polyaspartic acid resin F2850 were mixed to form oil phase A;

[0133] (2) Add 2 g of cross-linking agent pentaerythritol to 20 ml of distilled water to obtain aqueous solution B;

[0134] (3) dissolving 4 g of styrene-maleic anhydride copolymer sodium salt (SMA) in 200 ml of distilled water as emulsifier solution C;

[0135] (4) Adding the oil phase A to the emulsifier solution C and homogenizing at a speed of 10,000 rpm for 5 min to form an oil-in-water (O / W) emulsion D;

[0136] (5) Adding aqueous solution B to emulsion D, placing the mixture in a water bath at 90°C, and reacting the mixture at a speed of 600 rpm for 5 h to prepare a polyurethane-coated phase change microcapsule emulsion;

[0137] (6) The phase change microcapsule emulsion obtained by the reaction is washed with deionized water for 2-3 times, and then placed in a vacuum oven at 60°C and dried for 8 hours to obtain polyurethane-coated phase change microcapsules.

[0138] 2. Preparation of intelligent temperature regulating fiber:

[0139] Phase change microcapsules are added to spandex stock solution and fully stirred and mixed (mixing temperature is 75°C), and the amount of polyurethane-coated phase change microcapsules added is 2% of the mass of the spandex stock solution; spandex intelligent temperature regulating fibers are obtained by dry spinning, wherein the spinning temperature of the dry spinning is 180°C.

[0140] Comparative Example 5

[0141] Phase change microcapsules and temperature regulating fibers were prepared by the same method as in Example 4, except that the stirring speed in step (5) was reduced. The specific preparation process is as follows:

[0142] 1. Preparation of phase change microcapsules:

[0143] (1) At 40°C, 20 g of phase change wax, 6.6 g of isophorone diisocyanate (IPDI) and 13.2 g of polyaspartic acid resin F2850 were mixed to form oil phase A;

[0144] (2) Add 2 g of cross-linking agent pentaerythritol to 20 ml of distilled water to obtain aqueous solution B;

[0145] (3) dissolving 4 g of styrene-maleic anhydride copolymer sodium salt (SMA) in 200 ml of distilled water as emulsifier solution C;

[0146] (4) Adding the oil phase A to the emulsifier solution C and homogenizing at a speed of 10,000 rpm for 5 min to form an oil-in-water (O / W) emulsion D;

[0147] (5) Adding aqueous solution B to emulsion D, placing the mixture in a water bath at 90°C, and reacting the mixture at a speed of 100 rpm for 5 h to prepare a polyurethane-coated phase change microcapsule emulsion;

[0148] (6) The phase change microcapsule emulsion obtained by the reaction is washed with deionized water for 2-3 times, and then placed in a vacuum oven at 60°C and dried for 8 hours to obtain polyurethane-coated phase change microcapsules.

[0149] 2. Preparation of intelligent temperature regulating fiber:

[0150] Phase change microcapsules are added to spandex stock solution and fully stirred and mixed (mixing temperature is 75°C), and the amount of polyurethane-coated phase change microcapsules added is 2% of the mass of the spandex stock solution; spandex intelligent temperature regulating fibers are obtained by dry spinning, wherein the spinning temperature of the dry spinning is 180°C.

[0151] Comparative Example 6

[0152] Phase change microcapsules and temperature regulating fibers were prepared by the same method as in Example 1, except that the spinning temperature was increased. The spinning temperature of Comparative Example 6 was 250° C. The specific preparation process is as follows:

[0153] 1. Preparation of phase change microcapsules:

[0154] (1) At 40°C, 10 g of n-hexadecane, 6 g of hexamethylene diisocyanate (HDI) and 2 g of diethylenetriamine (DETA) were mixed to form oil phase A;

[0155] (2) Add 2 g of cross-linking agent triethanolamine to 20 ml of distilled water to obtain aqueous solution B;

[0156] (3) dissolving 6 g of styrene-maleic anhydride copolymer sodium salt (SMA) in 200 ml of distilled water as emulsifier solution C;

[0157] (4) Adding the oil phase A to the emulsifier solution C and homogenizing at a speed of 5000 rpm for 10 min to form an oil-in-water (O / W) emulsion D;

[0158] (5) Adding aqueous solution B to emulsion D, placing the mixture in a water bath at 40°C, and reacting the mixture at a speed of 500 rpm for 7 h to prepare a polyurethane-coated phase change microcapsule emulsion;

[0159] (6) The phase change microcapsule emulsion obtained by the reaction is washed with deionized water for 2-3 times, and then placed in a vacuum oven at 60°C and dried for 8 hours to obtain polyurethane-coated phase change microcapsules.

[0160] 2. Preparation of intelligent temperature regulating fiber:

[0161] Phase change microcapsules are added to spandex stock solution and fully stirred and mixed (mixing temperature is 75°C), and the amount of polyurethane-coated phase change microcapsules added is 1% of the mass of the spandex stock solution; spandex intelligent temperature regulating fibers are obtained by dry spinning, wherein the spinning temperature of the dry spinning is 250°C.

[0162] Comparative Example 7

[0163] Phase change microcapsules and temperature regulating fibers were prepared by the same method as in Example 1, except that the melt spinning temperature was lowered. In Comparative Example 7, the melt spinning temperature was 180°C.

[0164] 1. Preparation of phase change microcapsules:

[0165] (1) At 40°C, 30 g of butyl stearate, 6 g of isophorone diisocyanate (IPDI) and 2 g of tetraethylpentanediamine (TEPA) were mixed to form oil phase A;

[0166] (2) Add 2 g of cross-linking agent triethanolamine to 20 ml of distilled water to obtain aqueous solution B;

[0167] (3) Dissolve 2 g of sodium dodecyl sulfate (SDS) in 200 ml of distilled water as emulsifier solution C;

[0168] (4) Adding the oil phase A to the emulsifier solution C and homogenizing at a speed of 10,000 rpm for 3 min to form an oil-in-water (O / W) emulsion D;

[0169] (5) Adding aqueous solution B to emulsion D, placing the mixture in a water bath at 90°C, and reacting the mixture at 200 rpm for 4 h to prepare a polyurethane-coated phase change microcapsule emulsion;

[0170] (6) The phase change microcapsule emulsion obtained by the reaction is washed with deionized water for 2-3 times, and then placed in a vacuum oven at 60°C and dried for 8 hours to obtain polyurethane-coated phase change microcapsules.

[0171] 2. Preparation of intelligent temperature regulating fiber:

[0172] Phase change microcapsules are added to TPU melt for granulation, wherein the amount of polyurethane-coated phase change microcapsules added is 2% of the mass of the TPU melt; then TPU intelligent temperature regulating fibers are obtained by melt spinning, wherein the spinning temperature of the melt spinning is 180°C.

[0173] The phase change microcapsules and temperature regulating fibers (TPU fiber and spandex fiber are both 100D) prepared in the above embodiments and comparative examples were tested for performance indicators. The specific test results are shown in Tables 1 and 2 below, and the test methods involved are as follows: The phase change latent heat test of the phase change microcapsules and phase change temperature regulating fibers is tested according to standard T / CTES 1005-2017.

[0174] Washing resistance test: The thermoregulating fiber was immersed in 500 mL of distilled water, washed with shaking at 40°C for 15 min, and washed 5 times. The changes in heat storage performance before and after washing were analyzed by DSC. The test was conducted according to standard T / CTES 1005-2017.

[0175] Fiber tensile strength and elongation at break test standard: The spandex yarn tensile performance test method is tested according to standard FZ / T50006-2013.

[0176] Table 1 Test data of latent heat performance of phase change microcapsules and temperature regulating fibers

[0177]

[0178] Table 2 Test data of strength and washability of thermoregulating fibers

[0179]

[0180] From the data in Table 1 and Table 2 above, it can be seen that the temperature-regulating fibers prepared by using the phase-change microcapsules of the present invention in Examples 1 to 5 have a high latent heat of fusion, so that the temperature-regulating fibers have a good temperature-regulating function. At the same time, the temperature-regulating fibers have a good resistance to water washing and still maintain a good temperature-regulating performance after multiple water washings. In addition, the phase-change microcapsules of the present invention have a good compatibility with the fibers. After the phase-change microcapsules are added to the fibers, the phase-change microcapsules are evenly distributed in the fibers, so that the fibers still have a good strength performance and feel.

[0181] From the comparison of the performance data of Comparative Example 1 and Example 4, it can be seen that the phase change microcapsules prepared by the preparation method of the present invention in Example 4 have higher latent heat, and adding them to the fibers is beneficial to improving the temperature regulating performance of the fibers. If the core material is not added when preparing the phase change microcapsules, the fibers will not have temperature regulating performance.

[0182] From the comparison of the performance data of Comparative Example 2 and Example 4, it can be seen that if the amount of cross-linking agent added is reduced, the particle size distribution of the phase change microcapsules will become wider and the melting latent heat of the phase change microcapsules and the intelligent temperature-regulating fibers will decrease. This is because a reduction in the amount of cross-linking agent added will lead to a decrease in the shell material density of the phase change microcapsules, and the microcapsules will rupture when stirred or heated, thereby affecting their temperature-regulating performance.

[0183] From the comparison of the performance data of Comparative Example 3 and Example 4, it can be seen that: if the amount of cross-linking agent added is increased, the strength performance of the fiber will decrease and the melting latent heat of the phase change microcapsule will decrease. This is because the increase in the amount of cross-linking agent added will cause the phase change microcapsule shell material to become denser and the hardness to increase. On the one hand, the compatibility of the phase change microcapsule with the fiber will be reduced, resulting in a decrease in the mechanical properties of the fiber. On the other hand, during the preparation process of the phase change microcapsule, as the amount of cross-linking agent added increases, the reaction rate of the shell material increases, resulting in the core material not being fully coated in the shell material.

[0184] From the comparison of the performance data of Comparative Example 4 and Example 4, it can be seen that if the stirring speed is too fast during the preparation of the phase change microcapsules, the particle size of the phase change microcapsules will become smaller and the latent heat of melting will decrease, because the increase in the stirring rate during the reaction will reduce the stability of the oil-in-water (O / W) emulsion, resulting in demulsification, thereby affecting the particle size and latent heat of melting of the phase change microcapsules.

[0185] From the comparison of the performance data of Comparative Example 5 and Example 4, it can be seen that if the stirring speed is too slow during the preparation of the phase change microcapsules, the particle size of the phase change microcapsules will increase and the melting latent heat will decrease, because the reduced stirring speed during the reaction cannot effectively maintain the stability of the oil-in-water (O / W) emulsion, thereby affecting the particle size and melting latent heat of the phase change microcapsules. Therefore, using a suitable stirring speed during the preparation of the phase change microcapsules is more conducive to obtaining phase change microcapsules with controllable particle size, higher core material coverage and higher melting latent heat.

[0186] From the comparison of the performance data of Comparative Example 6 and Example 1, it can be seen that if the dry spinning temperature is too high, the solvent will evaporate too quickly in the fiber channel and the solvent mixing rate on the fiber surface will be inconsistent, thereby producing the phenomenon of hooked fibers and affecting the mechanical properties of the fibers. Therefore, the spinning temperature specified in the present invention is more conducive to obtaining temperature-regulating fibers with excellent performance.

[0187] From the comparison of the performance data of Comparative Example 7 and Example 1, it can be seen that if the melt spinning temperature is lowered, the TPU will not be completely melted, the fluidity of the melt will be weak, and it will not be able to pass through the spinneret continuously and stably. The produced fibers are uneven, thereby affecting the mechanical properties of the fibers. Therefore, the spinning temperature specified in the present invention is more conducive to obtaining temperature-regulating fibers with excellent performance.

[0188] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are exhaustively listed. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0189] For those skilled in the art, several modifications and improvements may be made without departing from the concept of the present invention, all of which belong to the protection scope of the present invention. The protection scope of the present invention shall be based on the attached claims.

Claims

1. A method for preparing a temperature-regulating fiber, characterized in that: The preparation method is: The polyurethane-coated phase-change microcapsules are mixed into the spandex stock solution, and the temperature-regulating fiber is obtained by dry spinning process; Alternatively, the polyurethane-coated phase-change microcapsules are mixed into the TPU melt and the temperature-regulating fibers are obtained by granulation and melt spinning processes; The spinning temperature in the dry spinning process is 180-230°C; the spinning temperature in the melt spinning process is 200-220°C; The preparation method of the polyurethane-coated phase-change microcapsules is as follows: S1. Mix the core material, diisocyanate and chain extender to form oil phase A; add a crosslinking agent to distilled water to obtain an aqueous solution B; dissolve an emulsifier in distilled water to obtain an emulsifier solution C; the mass ratio of the diisocyanate to the crosslinking agent is 1:(0.3-1); the mass ratio of the diisocyanate to the chain extender is (3:1)~(1:3); S2, adding the oil phase A to the emulsifier solution C, homogenizing, and forming an oil-in-water emulsion D; adding the aqueous solution B to the emulsion D, and preparing a phase change microcapsule emulsion under heating and stirring conditions; S3, adding deionized water to the phase change microcapsule emulsion for washing, and then drying to obtain polyurethane-coated phase change microcapsules; The specific operation of step S2 is: adding the oil phase A to the emulsifier solution C, homogenizing at a speed of 5000rpm-10000rpm for 3-10min to form an oil-in-water emulsion D; adding the aqueous solution B to the emulsion D, stirring and reacting at a temperature of 40-90°C and a speed of 200rpm-500rpm for 4-7h to prepare a phase change microcapsule emulsion; The chain extender is at least one of polyaspartic acid resin F420, polyaspartic acid resin F2850, diethylenetriamine, and tetraethylpentanediamine; The cross-linking agent is at least one of pentaerythritol, trimethylolpropane and triethanolamine.

2. The method for preparing a temperature-regulating fiber according to claim 1, characterized in that: In step S1, the core material is at least one of n-hexadecane, n-octadecane, phase change paraffin, and butyl stearate; The emulsifier is at least one of styrene-maleic anhydride copolymer sodium salt, polyvinyl alcohol, and sodium lauryl sulfate.

3. The method for preparing a temperature-regulating fiber according to claim 1, characterized in that: In step S1, the diisocyanate is at least one of isophorone diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, and hexamethylene diisocyanate.

4. The method for preparing a temperature-regulating fiber according to claim 1, characterized in that: The core-shell ratio of the polyurethane-coated phase-change microcapsules is (0.8-3):1, and the mass concentration of the emulsifier in the emulsifier solution C is 1wt%-3wt%.

5. The method for preparing a temperature-regulating fiber according to claim 1, characterized in that: The added amount of the polyurethane-coated phase-change microcapsules is 1%-2% of the mass of the spandex stock solution or the TPU melt.

6. A temperature regulating fiber, characterized in that: The temperature regulating fiber is prepared according to the preparation method according to any one of claims 1-5.

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