Preparation method of a down-like heat storage and insulation material

Abstract

The application provides a preparation method of a down-like heat storage and preservation material, and comprises the following steps: dissolving polylactic acid in a mixed solution of chloroform / acetone to obtain a polylactic acid solution; dissolving composite hollow spheres in a mixed solution of chloroform / acetone to obtain a composite hollow sphere solution; using the polylactic acid solution as a shell layer solution and the composite hollow sphere solution as a core layer solution, adopting a coaxial conjugate electrospinning instrument to prepare a fiber bundle, the spinning voltage is 12-14 kV, the distance between composite spinnerets is 25-30 cm, the flow rate of the shell layer solution is 0.5-3 mL / h, and the flow rate of the core layer solution is 0.5-3 mL / h, to obtain an electrospun fiber bundle; using the electrospun fiber bundle as a covering yarn and polylactic acid filaments as core yarns, the down-like heat storage and preservation material is obtained by covering. The application adopts the electrospinning method to prepare the fiber bundle, and adds the composite hollow spheres in the core layer of the fiber bundle, uses the electrospun fiber bundle as the covering layer and the ordinary filaments as the core layer, so that a heat storage and preservation effect of the down-like heat storage and preservation material is better than that of ordinary air long down material.

Description

Technical Field

[0001] This invention relates to the field of functional textile materials, specifically to a method for preparing a down-like heat-retaining and insulating material. Background Technology

[0002] Currently, the imitation down material on the market, collectively known as imitation down cotton, is a polyester fiber made from polyester, three-dimensional crimped hollow fiber, U-shaped hollow fiber, and ES fiber through special processing. Its fiber raw material is polyester. Imitation down cotton is lightweight, has a delicate and soft feel, good warmth retention, is not easily deformed, does not leak fibers, and has the feel of down with good warmth retention. It is widely used in down jackets, ski jackets, winter clothing, and other thermal wear.

[0003] The human body transfers heat to the outside world through clothing in three ways: conduction, convection, and radiation. Fibers that reduce conduction and convection are used for insulation, such as natural cotton, wool, down, and their biomimetic materials. However, these materials cannot completely and efficiently block conduction, convection, and radiation. Developing lightweight, insulating fibers, such as ultrafine, irregularly shaped, and hollow fibers, can increase the content of air with low thermal conductivity. Using metals with high heat reflectivity, such as aluminum, on the fabric surface can reduce heat diffusion caused by radiation; however, aluminum can only reflect heat and cannot absorb it.

[0004] Patent 201580011595.3 discloses an "integrated air-feather down" product that reproduces the structure of waterfowl down and achieves superior physical properties such as warmth, breathability, and antibacterial properties, making it an ideal alternative to natural down. Currently, air-feather down is made by weaving synthetic fibers into a down-like shape, which can achieve good insulation, but further improvements are needed. Summary of the Invention

[0005] The technical problem to be solved: The purpose of this invention is to provide a method for preparing a down-like heat-retaining and heat-insulating material. The method involves preparing fiber bundles by electrospinning and adding composite hollow spheres to the core layer of the fiber bundles. The electrospinned fiber bundles are used as the coating layer, and ordinary filaments are used as the core layer, resulting in a heat-retaining and heat-insulating material with better heat retention and insulation effects than ordinary air-based long-pile materials.

[0006] Technical solution: A method for preparing a down-like heat-retaining and insulating material, comprising the following steps:

[0007] Polylactic acid is dissolved in a chloroform / acetone mixture to obtain a polylactic acid solution with a concentration of 5-10%.

[0008] The composite hollow spheres were dissolved in a chloroform / acetone mixed solution to obtain a composite hollow sphere solution with a concentration of 5-10%.

[0009] Polylactic acid solution was used as the shell solution and composite hollow sphere solution was used as the core solution. Fiber bundles were prepared using a coaxial conjugate electrospinning apparatus. The spinning voltage was 12-14 kV, the spacing between the composite spinnerets was 25-30 cm, the flow rate of the shell solution was 0.5-3 mL / h, and the flow rate of the core solution was 0.5-3 mL / h, thus obtaining electrospun fiber bundles.

[0010] A down-like heat-retaining material is obtained by using electrospun fiber bundles as the covering yarn and polylactic acid filaments as the core yarn.

[0011] Preferably, the method for preparing the composite hollow sphere includes the following steps:

[0012] S1. Tetraethyl orthosilicate is added to a mixed solution of ammonia / ethanol / water, and hydrolyzed and condensed to obtain SiO2 nanoparticles. The SiO2 nanoparticles are dispersed in an aqueous solution of sodium hydroxide and reacted to obtain porous silica microspheres.

[0013] S2. Add ammonium tungstate to water, stir evenly, add sulfuric acid, continue stirring, then add ammonium sulfate, stir, and obtain a green solution. Add the porous silica microspheres prepared in step S1 to the above solution, stir and adsorb thoroughly to obtain precursor-coated silica composite particles.

[0014] S3. After reacting the mixed solution containing precursor-coated silica composite particles at a certain temperature, the composite particles are calcined to obtain WO3-coated silica composite particles.

[0015] S4. The WO3-coated silica composite particles were reacted with hydrogen as a reducing atmosphere to obtain tungsten-coated silica microspheres.

[0016] S5. The tungsten-coated silica microspheres prepared in step S4 are added to a mixed solution of n-butanol and ethanol, and then a n-butanol solution containing n-butyl titanate is added dropwise. The reaction is carried out, the precipitate is centrifuged and calcined to obtain composite hollow spheres.

[0017] Preferably, in step S1, the concentration of tetraethyl orthosilicate in the mixed solution is 1-3 wt%, the hydrolysis and condensation time is 5-24 h, the concentration of sodium hydroxide aqueous solution is 1-5 mol / L, and the reaction time is 10-20 h.

[0018] Preferably, in step S2, the mass molar ratio of ammonium tungstate, sulfuric acid, and ammonium sulfate is 1.5-2.5:5-10:2-4.

[0019] Preferably, in step S3, the reaction temperature is 120-140℃ and the time is 10-20h, and the calcination temperature is 550-620℃ and the time is 7-12h.

[0020] Preferably, the reduction temperature in step S4 is 750-900℃ and the time is 30-60min.

[0021] Preferably, in step S5, the reaction time is 8-15 hours, the calcination temperature is 550-600°C, and the time is 2-4 hours.

[0022] The above preparation method yields a down-like heat-retaining and insulating material.

[0023] Beneficial effects: The down-like heat-retaining and insulating material of this invention has the following advantages:

[0024] 1. In this invention, electrospinning is used to prepare the covering yarn of the down-like material. Electrospinning produces fiber bundles. The parallel structure of multiple nanofibers in the fiber bundles prepared by electrospinning can effectively reduce heat conduction and heat radiation, achieving the effect of heat insulation. The heat source can effectively reflect radiation energy after passing through the fiber bundles formed by multiple nanofibers, and at the same time redirect the absorbed heat to the direction parallel to the fiber, so that the fiber can effectively insulate. Moreover, the parallel arrangement of the fiber bundles formed by electrospinning and the pores between the fibers can form a heat-insulating space, improving the heat insulation effect.

[0025] 2. In this invention, an electrospun fiber bundle is prepared using a core-shell structure. The core layer of the fiber bundle is a composite hollow sphere, which is prepared by a layer-by-layer coating method. First, porous silica microspheres are prepared. The porous material improves the heat insulation effect of the fiber bundle. Second, a tungsten metal layer is coated on the outside of the silica microsphere. The tungsten metal layer has a low thermal conductivity and also has a certain heat reflection performance. Finally, a titanium dioxide layer is placed on the outside of the tungsten layer. Titanium dioxide can enhance the heat reflection effect of the particles and improve the heat storage and insulation effect of the material. Detailed Implementation

[0026] The present invention will be further described below with reference to embodiments. These embodiments are illustrative of the present invention, but the present invention is not limited to these embodiments:

[0027] Example 1

[0028] A method for preparing a down-like heat-retaining and insulating material includes the following steps:

[0029] Polylactic acid was dissolved in a chloroform / acetone mixture to obtain a 5% polylactic acid solution.

[0030] The composite hollow spheres were dissolved in a chloroform / acetone mixed solution to obtain a 5% composite hollow sphere solution.

[0031] Polylactic acid solution was used as the shell solution and composite hollow sphere solution was used as the core solution. Fiber bundles were prepared using a coaxial conjugate electrospinning apparatus. The spinning voltage was 12kV, the spacing between the composite spinnerets was 25cm, the flow rate of the shell solution was 0.5mL / h, and the flow rate of the core solution was 0.5mL / h, thus obtaining electrospun fiber bundles.

[0032] Using electrospun fiber bundles as the covering yarn and polylactic acid filaments as the core yarn, a down-like heat-retaining and heat-insulating material is obtained by covering.

[0033] The method for preparing the composite hollow sphere includes the following steps:

[0034] S1. Tetraethyl orthosilicate is added to a mixed solution of ammonia / ethanol / water, the concentration of tetraethyl orthosilicate in the mixed solution is 1wt%, and hydrolysis and condensation are carried out for 5h to obtain SiO2 nanoparticles. The SiO2 nanoparticles are dispersed in a 1mol / L sodium hydroxide aqueous solution and reacted for 10h to obtain porous silica microspheres.

[0035] S2. Add ammonium tungstate to water, stir evenly, add sulfuric acid, continue stirring, and then add ammonium sulfate. The mass molar ratio of ammonium tungstate, sulfuric acid and ammonium sulfate is 1.5:5:2. After stirring, a green solution is obtained. Add the porous silica microspheres prepared in step S1 to the above solution, stir and adsorb thoroughly to obtain precursor-coated silica composite particles.

[0036] S3. After reacting the mixed solution containing precursor-coated silica composite particles at a certain temperature (120°C for 20 hours), the composite particles are calcined at 620°C for 7 hours to obtain WO3-coated silica composite particles.

[0037] S4. The WO3-coated silica composite particles were reacted with hydrogen as a reducing atmosphere at a temperature of 750℃ for 60 min to obtain tungsten-coated silica microspheres.

[0038] S5. The tungsten-coated silica microspheres prepared in step S4 are added to a mixed solution of n-butanol and ethanol, and then a n-butanol solution containing n-butyl titanate is added dropwise. The reaction time is 8 h, the precipitate is centrifuged and calcined at 550 °C for 2 h to obtain composite hollow spheres.

[0039] Example 2

[0040] A method for preparing a down-like heat-retaining and insulating material includes the following steps:

[0041] Polylactic acid was dissolved in a chloroform / acetone mixture to obtain a 10% polylactic acid solution.

[0042] The composite hollow spheres were dissolved in a chloroform / acetone mixed solution to obtain a 10% composite hollow sphere solution.

[0043] Polylactic acid solution was used as the shell solution and composite hollow sphere solution was used as the core solution. Fiber bundles were prepared using a coaxial conjugate electrospinning apparatus. The spinning voltage was 14kV, the spacing between the composite spinnerets was 30cm, the flow rate of the shell solution was 2.5mL / h, and the flow rate of the core solution was 2mL / h, thus obtaining electrospun fiber bundles.

[0044] Using electrospun fiber bundles as the covering yarn and polylactic acid filaments as the core yarn, a down-like heat-retaining and heat-insulating material is obtained by covering.

[0045] The method for preparing the composite hollow sphere includes the following steps:

[0046] S1. Tetraethyl orthosilicate was added to a mixed solution of ammonia / ethanol / water, with a concentration of 3wt% in the mixed solution. After hydrolysis and condensation for 24 hours, SiO2 nanoparticles were obtained. The SiO2 nanoparticles were dispersed in a 5mol / L sodium hydroxide aqueous solution and reacted for 20 hours to obtain porous silica microspheres.

[0047] S2. Add ammonium tungstate to water, stir evenly, add sulfuric acid, continue stirring, and then add ammonium sulfate. The mass molar ratio of ammonium tungstate, sulfuric acid and ammonium sulfate is 2.5:10:4. After stirring, a green solution is obtained. Add the porous silica microspheres prepared in step S1 to the above solution, stir and adsorb thoroughly to obtain precursor-coated silica composite particles.

[0048] S3. After reacting the mixed solution containing precursor-coated silica composite particles at a certain temperature (140℃ for 10h), the composite particles are calcined at 550℃ for 12h to obtain WO3-coated silica composite particles.

[0049] S4. The WO3-coated silica composite particles were reacted with hydrogen as a reducing atmosphere at a temperature of 900℃ for 30 min to obtain tungsten-coated silica microspheres.

[0050] S5. The tungsten-coated silica microspheres prepared in step S4 are added to a mixed solution of n-butanol and ethanol, and then a n-butanol solution containing n-butyl titanate is added dropwise. The reaction time is 15 h, the precipitate is centrifuged and calcined at 550 °C for 4 h to obtain composite hollow spheres.

[0051] Example 3

[0052] A method for preparing a down-like heat-retaining and insulating material includes the following steps:

[0053] Polylactic acid was dissolved in a chloroform / acetone mixture to obtain a 7% polylactic acid solution.

[0054] The composite hollow spheres were dissolved in a chloroform / acetone mixed solution to obtain a 7% composite hollow sphere solution.

[0055] Polylactic acid solution was used as the shell solution and composite hollow sphere solution was used as the core solution. Fiber bundles were prepared using a coaxial conjugate electrospinning apparatus. The spinning voltage was 12kV, the spacing between the composite spinnerets was 25cm, the flow rate of the shell solution was 1.5mL / h, and the flow rate of the core solution was 1.2mL / h, thus obtaining electrospun fiber bundles.

[0056] Using electrospun fiber bundles as the covering yarn and polylactic acid filaments as the core yarn, a down-like heat-retaining and heat-insulating material is obtained by covering.

[0057] The method for preparing the composite hollow sphere includes the following steps:

[0058] S1. Tetraethyl orthosilicate was added to a mixed solution of ammonia / ethanol / water, with a concentration of 1.5 wt% in the mixed solution. After hydrolysis and condensation for 5 h, SiO2 nanoparticles were obtained. The SiO2 nanoparticles were dispersed in a 1.5 mol / L sodium hydroxide aqueous solution and reacted for 10 h to obtain porous silica microspheres.

[0059] S2. Add ammonium tungstate to water, stir evenly, add sulfuric acid, continue stirring, then add ammonium sulfate. The mass molar ratio of ammonium tungstate, sulfuric acid and ammonium sulfate is 1.8:7:2.5. After stirring, a green solution is obtained. Add the porous silica microspheres prepared in step S1 to the above solution, stir and adsorb thoroughly to obtain precursor-coated silica composite particles.

[0060] S3. After reacting the mixed solution containing precursor-coated silica composite particles at a certain temperature (140℃ for 10h), the composite particles are calcined at 560℃ for 10h to obtain WO3-coated silica composite particles.

[0061] S4. The WO3-coated silica composite particles were reacted with hydrogen as a reducing atmosphere at a temperature of 800℃ for 30 min to obtain tungsten-coated silica microspheres.

[0062] S5. The tungsten-coated silica microspheres prepared in step S4 are added to a mixed solution of n-butanol and ethanol, and then a n-butanol solution containing n-butyl titanate is added dropwise. The reaction time is 10 h, the precipitate is centrifuged and calcined at 580 °C for 2 h to obtain composite hollow spheres.

[0063] Example 4

[0064] A method for preparing a down-like heat-retaining and insulating material includes the following steps:

[0065] Polylactic acid was dissolved in a chloroform / acetone mixture to obtain a 9% polylactic acid solution.

[0066] The composite hollow spheres were dissolved in a chloroform / acetone mixed solution to obtain a composite hollow sphere solution with a concentration of 8%.

[0067] Polylactic acid solution was used as the shell solution and composite hollow sphere solution was used as the core solution. Fiber bundles were prepared using a coaxial conjugate electrospinning apparatus. The spinning voltage was 14 kV, the spacing between the composite spinnerets was 30 cm, the flow rate of the shell solution was 1.8 mL / h, and the flow rate of the core solution was 1.2 mL / h, thus obtaining electrospun fiber bundles.

[0068] Using electrospun fiber bundles as the covering yarn and polylactic acid filaments as the core yarn, a down-like heat-retaining and heat-insulating material is obtained by covering.

[0069] The method for preparing the composite hollow sphere includes the following steps:

[0070] S1. Tetraethyl orthosilicate was added to a mixed solution of ammonia / ethanol / water, with a concentration of 2.5 wt% in the mixed solution. After hydrolysis and condensation for 24 h, SiO2 nanoparticles were obtained. The SiO2 nanoparticles were dispersed in a 3.5 mol / L sodium hydroxide aqueous solution and reacted for 20 h to obtain porous silica microspheres.

[0071] S2. Add ammonium tungstate to water, stir evenly, add sulfuric acid, continue stirring, and then add ammonium sulfate. The mass molar ratio of ammonium tungstate, sulfuric acid and ammonium sulfate is 2.2:9:3.2. After stirring, a green solution is obtained. Add the porous silica microspheres prepared in step S1 to the above solution, stir and adsorb thoroughly to obtain precursor-coated silica composite particles.

[0072] S3. After reacting the mixed solution containing precursor-coated silica composite particles at a certain temperature (120°C for 20 hours), the composite particles are calcined at 600°C for 8 hours to obtain WO3-coated silica composite particles.

[0073] S4. The WO3-coated silica composite particles were reacted with hydrogen as a reducing atmosphere at a temperature of 850℃ for 60 min to obtain tungsten-coated silica microspheres.

[0074] S5. The tungsten-coated silica microspheres prepared in step S4 are added to a mixed solution of n-butanol and ethanol, and then a n-butanol solution containing n-butyl titanate is added dropwise. The reaction time is 9 h, the precipitate is centrifuged and calcined at 560 °C for 2.5 h to obtain composite hollow spheres.

[0075] Example 5

[0076] A method for preparing a down-like heat-retaining and insulating material includes the following steps:

[0077] Polylactic acid was dissolved in a chloroform / acetone mixture to obtain an 8% polylactic acid solution.

[0078] The composite hollow spheres were dissolved in a chloroform / acetone mixed solution to obtain a 7.5% composite hollow sphere solution.

[0079] Polylactic acid solution was used as the shell solution and composite hollow sphere solution was used as the core solution. Fiber bundles were prepared using a coaxial conjugate electrospinning apparatus. The spinning voltage was 13kV, the spacing between the composite spinnerets was 28cm, the flow rate of the shell solution was 2mL / h, and the flow rate of the core solution was 1.8mL / h, thus obtaining electrospun fiber bundles.

[0080] Using electrospun fiber bundles as the covering yarn and polylactic acid filaments as the core yarn, a down-like heat-retaining and heat-insulating material is obtained by covering.

[0081] The method for preparing the composite hollow sphere includes the following steps:

[0082] S1. Tetraethyl orthosilicate was added to a mixed solution of ammonia / ethanol / water, with a concentration of 2wt% in the mixed solution. After hydrolysis and condensation for 20 h, SiO2 nanoparticles were obtained. The SiO2 nanoparticles were dispersed in a 3.5 mol / L sodium hydroxide aqueous solution and reacted for 15 h to obtain porous silica microspheres.

[0083] S2. Add ammonium tungstate to water, stir evenly, add sulfuric acid, continue stirring, then add ammonium sulfate. The mass molar ratio of ammonium tungstate, sulfuric acid and ammonium sulfate is 2:8:3. After stirring, a green solution is obtained. Add the porous silica microspheres prepared in step S1 to the above solution, stir and adsorb thoroughly to obtain precursor-coated silica composite particles.

[0084] S3. After reacting the mixed solution containing precursor-coated silica composite particles at a certain temperature (130°C for 18 hours), the composite particles are calcined at 600°C for 10 hours to obtain WO3-coated silica composite particles.

[0085] S4. The WO3-coated silica composite particles were reacted with hydrogen as a reducing atmosphere at a temperature of 850℃ for 50 min to obtain tungsten-coated silica microspheres.

[0086] S5. The tungsten-coated silica microspheres prepared in step S4 are added to a mixed solution of n-butanol and ethanol, and then a n-butanol solution containing n-butyl titanate is added dropwise. The reaction time is 12 h, the precipitate is centrifuged and calcined at 580 °C for 3 h to obtain composite hollow spheres.

[0087] Comparative Example 1

[0088] A method for preparing a down-like heat-retaining and insulating material includes the following steps:

[0089] Polylactic acid was dissolved in a chloroform / acetone mixture to obtain an 8% polylactic acid solution.

[0090] The composite hollow spheres were dissolved in a chloroform / acetone mixed solution to obtain a 7.5% composite hollow sphere solution.

[0091] Polylactic acid solution was used as the shell solution and composite hollow sphere solution was used as the core solution. Fiber bundles were prepared using a coaxial conjugate electrospinning apparatus. The spinning voltage was 13kV, the spacing between the composite spinnerets was 28cm, the flow rate of the shell solution was 2mL / h, and the flow rate of the core solution was 1.8mL / h, thus obtaining electrospun fiber bundles.

[0092] Using electrospun fiber bundles as the covering yarn and polylactic acid filaments as the core yarn, a down-like heat-retaining and heat-insulating material is obtained by covering.

[0093] The method for preparing the composite hollow sphere includes the following steps:

[0094] S1. Tetraethyl orthosilicate was added to a mixed solution of ammonia / ethanol / water, with a concentration of 2wt% in the mixed solution. After hydrolysis and condensation for 20 h, SiO2 nanoparticles were obtained. The SiO2 nanoparticles were dispersed in a 3.5 mol / L sodium hydroxide aqueous solution and reacted for 15 h to obtain porous silica microspheres.

[0095] S2. Add the porous silica microspheres prepared in step S1 to a mixed solution of n-butanol and ethanol, then add a n-butanol solution containing n-butyl titanate dropwise. The reaction time is 12 h. Centrifuge to precipitate, and calcine the precipitate at 580 °C for 3 h to obtain composite hollow spheres.

[0096] Comparative Example 2

[0097] A method for preparing a down-like heat-retaining and insulating material includes the following steps:

[0098] Polylactic acid was dissolved in a chloroform / acetone mixture to obtain a 9% polylactic acid solution.

[0099] Composite hollow spheres were added to a polylactic acid solution, and the concentration of the composite hollow spheres in the polylactic acid solution was 2 wt% to obtain an electrospinning solution.

[0100] Fiber bundles were prepared using an electrospinning apparatus with a spinning voltage of 15kV, a spacing of 25cm between the composite spinnerets, and a spinning solution flow rate of 2.5mL / h to obtain electrospun fiber bundles.

[0101] Using electrospun fiber bundles as the covering yarn and polylactic acid filaments as the core yarn, a down-like heat-retaining and heat-insulating material is obtained by covering.

[0102] The method for preparing the composite hollow sphere includes the following steps:

[0103] S1. Tetraethyl orthosilicate was added to a mixed solution of ammonia / ethanol / water, with a concentration of 2.5 wt% in the mixed solution. After hydrolysis and condensation for 24 h, SiO2 nanoparticles were obtained. The SiO2 nanoparticles were dispersed in a 3.5 mol / L sodium hydroxide aqueous solution and reacted for 20 h to obtain porous silica microspheres.

[0104] S2. Add ammonium tungstate to water, stir evenly, add sulfuric acid, continue stirring, and then add ammonium sulfate. The mass molar ratio of ammonium tungstate, sulfuric acid and ammonium sulfate is 2.2:9:3.2. After stirring, a green solution is obtained. Add the porous silica microspheres prepared in step S1 to the above solution, stir and adsorb thoroughly to obtain precursor-coated silica composite particles.

[0105] S3. After reacting the mixed solution containing precursor-coated silica composite particles at a certain temperature (130°C for 15 hours), the composite particles are calcined at 600°C for 8 hours to obtain WO3-coated silica composite particles.

[0106] S4. The WO3-coated silica composite particles were reacted with hydrogen as a reducing atmosphere at a temperature of 850℃ for 60 min to obtain tungsten-coated silica microspheres.

[0107] S5. The tungsten-coated silica microspheres prepared in step S4 are added to a mixed solution of n-butanol and ethanol, and then a n-butanol solution containing n-butyl titanate is added dropwise. The reaction time is 9 h, the precipitate is centrifuged and calcined at 560 °C for 2.5 h to obtain composite hollow spheres.

[0108] Comparative Example 3

[0109] A method for preparing a down-like heat-retaining and insulating material includes the following steps:

[0110] The composite hollow spheres are mixed with polylactic acid granules in a certain proportion. The weight of the composite hollow spheres is 10 wt% of the total weight of the polylactic acid granules and the composite hollow spheres. Then the mixture of composite hollow spheres and polylactic acid granules is fed into a granulation screw extruder to produce composite hollow sphere modified polylactic acid masterbatch.

[0111] Composite hollow sphere modified polylactic acid masterbatch and polylactic acid dry chips are heated and melted at a mass ratio of 1:1 to process into bamboo charcoal polylactic acid melt, which is then melt-spun to obtain modified polylactic acid filaments.

[0112] A down-like heat-retaining and heat-insulating material is obtained by using modified polylactic acid filament as the covering yarn and polylactic acid filament as the core yarn.

[0113] The method for preparing the composite hollow sphere includes the following steps:

[0114] S1. Tetraethyl orthosilicate was added to a mixed solution of ammonia / ethanol / water, with a concentration of 2.5 wt% in the mixed solution. After hydrolysis and condensation for 24 h, SiO2 nanoparticles were obtained. The SiO2 nanoparticles were dispersed in a 3.5 mol / L sodium hydroxide aqueous solution and reacted for 20 h to obtain porous silica microspheres.

[0115] S2. Add ammonium tungstate to water, stir evenly, add sulfuric acid, continue stirring, and then add ammonium sulfate. The mass molar ratio of ammonium tungstate, sulfuric acid and ammonium sulfate is 2.2:9:3.2. After stirring, a green solution is obtained. Add the porous silica microspheres prepared in step S1 to the above solution, stir and adsorb thoroughly to obtain precursor-coated silica composite particles.

[0116] S3. After reacting the mixed solution containing precursor-coated silica composite particles at a certain temperature (125°C for 20 hours), the composite particles were calcined at 600°C for 8 hours to obtain WO3-coated silica composite particles.

[0117] S4. The WO3-coated silica composite particles were reacted with hydrogen as a reducing atmosphere at a temperature of 850℃ for 60 min to obtain tungsten-coated silica microspheres.

[0118] S5. The tungsten-coated silica microspheres prepared in step S4 are added to a mixed solution of n-butanol and ethanol, and then a n-butanol solution containing n-butyl titanate is added dropwise. The reaction time is 9 h, the precipitate is centrifuged and calcined at 560 °C for 2.5 h to obtain composite hollow spheres.

[0119] Performance testing:

[0120] The processes and parameters for covering yarn in Examples 1-5 and Comparative Examples 1-3 are the same. A flatbed thermal insulation instrument was used to test and compare the thermal insulation performance of Examples 1-5 and Comparative Examples 1-3. The specific operation is as follows: The down-like heat-retaining and insulating materials prepared in Examples 1-5 and Comparative Examples 1-3 were filled into the inner lining fabric of a 30cm × 30cm down jacket, with a unit filling amount of 100g / m². 2 After sealing, the samples were laid flat in the specified area for testing. The test temperature was (25±5)℃ and the relative humidity was (65±5)%. Each sample was tested 3 times and the average value was taken.

[0121] According to GB / T 30127-2013, the infrared heating performance of Comparative Examples 1-5 and Comparative Examples 1-3 was evaluated, and the specific procedures were as follows: The polyester filament down-like insulation material prepared in Examples 1-5 and Comparative Examples 1-3 was filled into the inner lining fabric of a 30cm×30cm down jacket, with a unit filling amount of 90g / m². 2 The sample was cut to a diameter of 60 mm and then tested.

[0122] Table 1

[0123] Thermal insulation rate / % Temperature rise difference / ℃ Example 1 81.2 3.5 Example 2 80.5 3.3 Example 3 82.3 3.6 Example 4 81.6 3.4 Example 5 82.0 3.5 Comparative Example 1 76.9 3.0 Comparative Example 2 75.2 3.2 Comparative Example 3 72.3 2.8

[0124] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing a down-like heat-retaining and insulating material, characterized in that, Includes the following steps: Polylactic acid is dissolved in a chloroform / acetone mixture to obtain a polylactic acid solution with a concentration of 5-10%. The composite hollow spheres were dissolved in a chloroform / acetone mixed solution to obtain a composite hollow sphere solution with a concentration of 5-10%. Polylactic acid solution was used as the shell solution and composite hollow sphere solution was used as the core solution. Fiber bundles were prepared using a coaxial conjugate electrospinning apparatus. The spinning voltage was 12-14 kV, the spacing between the composite spinnerets was 25-30 cm, the flow rate of the shell solution was 0.5-3 mL / h, and the flow rate of the core solution was 0.5-3 mL / h, thus obtaining electrospun fiber bundles. A down-like heat-retaining material is obtained by using electrospun fiber bundles as the covering yarn and polylactic acid filaments as the core yarn. The method for preparing the composite hollow sphere includes the following steps: S1. Tetraethyl orthosilicate is added to a mixed solution of ammonia / ethanol / water, and hydrolyzed and condensed to obtain SiO2 nanoparticles. The SiO2 nanoparticles are dispersed in an aqueous solution of sodium hydroxide and reacted to obtain porous silica microspheres. S2. Add ammonium tungstate to water, stir evenly, add sulfuric acid, continue stirring, then add ammonium sulfate, stir, and obtain a green solution. Add the porous silica microspheres prepared in step S1 to the above solution, stir and adsorb thoroughly to obtain precursor-coated silica composite particles. S3. After reacting the mixed solution containing precursor-coated silica composite particles at a certain temperature, the composite particles are calcined to obtain WO3-coated silica composite particles. S4. The WO3-coated silica composite particles were reacted with hydrogen as a reducing atmosphere to obtain tungsten-coated silica microspheres. S5. The tungsten-coated silica microspheres prepared in step S4 are added to a mixed solution of n-butanol and ethanol, and then a n-butanol solution containing n-butyl titanate is added dropwise. The reaction is carried out, the precipitate is centrifuged and calcined to obtain composite hollow spheres.

2. The method for preparing the down-like heat-retaining and insulating material according to claim 1, characterized in that: In step S1, the concentration of tetraethyl orthosilicate in the mixed solution is 1-3 wt%, the hydrolysis and condensation time is 5-24 h, the concentration of sodium hydroxide aqueous solution is 1-5 mol / L, and the reaction time is 10-20 h.

3. The method for preparing the down-like heat-retaining and insulating material according to claim 1, characterized in that: In step S2, the mass molar ratio of ammonium tungstate, sulfuric acid, and ammonium sulfate is 1.5-2.5:5-10:2-4.

4. The method for preparing the down-like heat-retaining and insulating material according to claim 1, characterized in that: In step S3, the reaction temperature is 120-140℃ and the time is 10-20h, and the calcination temperature is 550-620℃ and the time is 7-12h.

5. The method for preparing the down-like heat-retaining and insulating material according to claim 1, characterized in that: In step S4, the reduction temperature is 750-900℃ and the time is 30-60 minutes.

6. The method for preparing the down-like heat-retaining and insulating material according to claim 1, characterized in that: In step S5, the reaction time is 8-15 hours, the calcination temperature is 550-600℃, and the time is 2-4 hours.

7. A down-like heat-retaining and insulating material is prepared by the preparation method according to any one of claims 1-6.