Preparation method and product of quasi-monolayer arranged down flakes based on electrospinning technology

Abstract

The present application discloses a method for preparing a quasi-monolayer arranged down flake based on electrospinning technology and the prepared product. The method for preparing the quasi-monolayer arranged down flake based on electrospinning technology includes: preparing down subjected to plasma treatment; preparing allyl-terminated polyurethane; preparing a down flake with a composite structure having a fiber membrane on the upper and lower layers and down in the middle layer according to the allyl-terminated polyurethane and the down subjected to plasma treatment; irradiating the down flake with an ultraviolet lamp, thereby triggering a thiol-ene click reaction between the thiol groups on the surface of the down and the allyl groups in the fiber membrane, so as to form strong S-C covalent bonds, and finally obtaining a quasi-monolayer arranged down flake with a composite structure bonded by covalent bonds. The quasi-monolayer arranged down flake prepared by the method for preparing the quasi-monolayer arranged down flake based on electrospinning technology of the present application can achieve the high thermal insulation effect of the quasi-monolayer arranged down and will not be lost due to down accumulation.

Description

Technical Field

[0001] This application relates to the technical field of textile material preparation, and particularly relates to a method for preparing a quasi-single-layer arranged down flake based on electrospinning technology and a quasi-single-layer arranged down flake based on electrospinning technology. Background Art

[0002] Down is a natural fiber floc material with low density, strong heat preservation performance, and high resilience. The multi-level branched structure in space of down endows it with a very high specific surface area, which can adsorb a large number of air molecules to form a static air layer to hinder the transfer of heat and achieve excellent heat insulation effect. It is highly favored in the field of high-end clothing, quilts and other heat insulation. However, the random arrangement between down aggregates and the inability to form a strong binding force result in fiber accumulation; in addition, the down leakage phenomenon caused by its special acute angle structure seriously affects the aesthetic degree, heat preservation rate, fluffiness and other use experiences of down products. Currently, the down leakage phenomenon is mainly controlled by coating technology to prepare anti-down leakage fabrics, but this will cause problems such as increased fabric weight, poor skin-friendliness and airtightness, and is helpless for fiber accumulation.

[0003] At present, there is no method and process for fixing down by electrospinning technology to prepare a single-layer arranged down flake. The patented technologies in the field of processing anti-down leakage fabrics to control the down leakage phenomenon currently include: Patent: CN102720000B. The use of non-woven technology has developed rapidly, and the technology of making fiber flakes with hot-melt fibers has become increasingly mature. Using non-woven technology, hot-melt fibers are mixed with traditional down, laid into a web and then slightly needled, and finally shaped into flakes by hot melting.

[0004] For example, the patent with application number 200310116840.6 fills down into a hot-melt adhesive mesh packaging bag, and then uses a needling device or hydroentangling to perform a cladding process on the down-filled bag to make a down-filled composite bag, and then conducts a heat treatment to obtain a sandwich down flake. The patent with application number 201210293409.8 uses a metal-plated polymer composite film and a quasi-single-layer down laminate fixed by an interlayer spacer warp-knitted mesh to form a heat-insulating composite film with a quasi-single-layer down mesh spacer. The above two methods have problems of reducing the air permeability of down products and significantly increasing the weight per square meter. The patent with application number 201910006231.6 uses plant and animal fibers and low-melting-point fibers laid into a web as the upper and lower flake layers, spreads down fibers or single or mixed products of plant and animal fibers and low-melting-point fibers as the middle flake layer, and finally hot-melts the lower, middle, and upper three flake layers into one body. However, it is not a pure down flake, which increases the density of the flake, and the heat preservation effect of pure down will be reduced compared. For this reason, some patents have been improved to obtain pure down flakes. The patent with application number 202011417593.3, through two down-laying processes, makes the first and second down layers bond under the action of starch adhesive, and then stitches them into the down jacket liner cloth. Then, the starch adhesive is enzymatically hydrolyzed to restore the fluffiness of the down again. This method makes it difficult to effectively fix the down in the down product and still cannot solve the problem of down accumulation during wearing. The patent with application number 202110061556.1 invented a preparation device, but mainly realizes the uniform laying and adsorption of down materials by spraying glue to prepare pure down flakes. The patent with application number 202110059954.X mixes acrylate rubber powder, glue, and down in proportion, and prepares pure down flakes through a constant-temperature composite shaping treatment process. The above two methods use adhesives to cause physical adhesion between the down clusters in the down, which although ensures that there is no relative displacement during wearing, will cause the fibers in the same down cluster to stick to each other, making the fluffiness of the down cluster smaller, and will also lead to the reduction of the specific surface area of the down due to the coverage of the adhesive barbules, thus resulting in a decrease in the heat preservation effect of the down flake.

[0005] Thus, it can be seen that although the existing processing technologies of down flakes have targeted to solve certain problems in terms of structural design and construction methods, there are still some defects. In order to overcome these problems existing in the prior art, industry players are also actively researching and developing, and trying to use new technologies in the textile field to provide new processing technologies for down flakes. Currently, there is no method and process for preparing a quasi-single-layer arranged down flake based on electrospinning technology by specifically synthesizing a new type of polyurethane and combining the electrospinning technology to perform a thiol-ene click reaction on the down.

[0006] Therefore, it is hoped that there is a technical solution to solve or at least alleviate the above deficiencies of the prior art. Summary of the Invention

[0007] An object of the present invention is to provide a method for preparing a quasi-single-layer arranged down fiber web based on electrospinning technology to at least solve one of the above technical problems.

[0008] In one aspect of the present invention, there is provided a method for preparing a quasi-single-layer arranged down fiber web based on electrospinning technology, the method for preparing the quasi-single-layer arranged down fiber web based on electrospinning technology comprising:

[0009] Preparing down subjected to plasma treatment;

[0010] Preparing allyl-terminated polyurethane;

[0011] Preparing a down fiber web with a composite structure having a fiber membrane as the upper and lower layers and down as the middle layer according to the allyl-terminated polyurethane and the down subjected to plasma treatment;

[0012] Irradiating the down fiber web with a composite structure having a fiber membrane as the upper and lower layers and down as the middle layer with an ultraviolet lamp, thereby triggering a thiol-ene click reaction between the thiol groups on the surface of the down and the allyl groups in the fiber membrane, so as to form strong S-C covalent bonds, and finally obtaining a quasi-single-layer arranged down fiber web with a covalently bonded composite structure.

[0013] Optionally, the preparing down subjected to plasma treatment includes:

[0014] Pre-treating the down with acetone;

[0015] Washing and drying the down treated with acetone with deionized water;

[0016] Placing the dried and baked down in a constant temperature and humidity environment for humidity adjustment;

[0017] Subjecting the humidity-adjusted down to plasma treatment.

[0018] Optionally, the pre-treating the down with acetone includes:

[0019] Soaking in acetone for 30 min to wash away impurities on the surface of the down;

[0020] The washing and drying the down treated with acetone with deionized water includes:

[0021] Washing the acetone on the down with deionized water and drying in a blast drying oven for 3 h at a temperature of 105 °C;

[0022] The placing the dried and baked down in a constant temperature and humidity environment for humidity adjustment includes:

[0023] Place the dried and baked down feathers in a temperature and humidity controlled environment at 20±2°C and a relative humidity of 65±2% for conditioning;

[0024] The parameters of the plasma treatment are as follows:

[0025] The output power selected for the plasma treatment is 100 - 500 W, the action time selected is 60 - 300 s, the reaction gas is air, and the reaction pressure is 30 Pa.

[0026] Optionally, the preparation of allyl-terminated polyurethane includes:

[0027] React diisocyanate and polyol to prepare a prepolymer with isocyanate groups at the ends;

[0028] Add solvent, small molecule diol and catalyst dibutyltin dilaurate to the prepolymer for chain extension to obtain isocyanate-terminated polyurethane;

[0029] Add diamine to the isocyanate-terminated polyurethane at low temperature to obtain amino-terminated polyurethane;

[0030] Add allyl glycidyl ether to the amino-terminated polyurethane, raise the temperature for reaction, and obtain allyl-terminated polyurethane.

[0031] Optionally, the preparation of a down flake with a composite structure having a fiber film on the upper and lower layers and down in the middle layer from the allyl-terminated polyurethane and the plasma-treated down includes:

[0032] Arrange the plasma-treated down neatly to form a quasi-single-layer arrangement state;

[0033] Prepare a polymer spinning solution by mixing the allyl-terminated polyurethane or a mixture thereof with other polymers. Using the fixed quasi-single-layer arranged down as the receiving plate, spin the polymer spinning solution through electrospinning on the upper layer of the receiving plate to obtain a down flake with a fiber film on one side;

[0034] Turn the side without the fiber film of the down flake with a fiber film on one side upwards, and spin the polymer spinning solution through electrospinning on the upper layer of the receiving plate again to obtain a down flake with a composite structure having a fiber film on the upper and lower layers and down in the middle layer in a sandwich structure.

[0035] Optionally, the ultraviolet lamp irradiation of the prepared down flake to initiate a thiol-ene click reaction between the thiol groups on the surface of the down and the allyl groups in the fiber film, forming strong S-C covalent bonds, and finally obtaining a quasi-single-layer arranged down flake with a covalently bonded composite structure includes:

[0036] The down flake with a composite structure having a fiber membrane on the upper and lower layers and down in the middle layer is placed under an ultraviolet lamp of 100 - 1000W, triggering a thiol-ene click reaction between the thiol groups on the surface of the down and the allyl groups in the fiber membrane, so as to form strong S-C covalent bonds, and finally obtaining a quasi-monolayer arranged down flake with a composite structure bonded by covalent bonds.

[0037] Optionally, the diisocyanate is one or a combination of more than one of toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), lysine diisocyanate (LDI);

[0038] The polyol is one or a combination of more than one of polycaprolactone / poly(ethylene adipate)diol / polytetrahydrofuran diol / poly(propylene oxide)diol, poly(butylene adipate)diol / polyethylene glycol, and the small molecule diol is one or a combination of more than one of ethylene glycol, 1,4-butanediol, 1,6-hexanediol;

[0039] The diamine is one or a combination of more than one of ethylenediamine, butanediamine, hexanediamine;

[0040] The amino-terminated polyurethane is allyl-terminated polyurethane.

[0041] Optionally, the electrospinning voltage is 10 - 50 kV, the receiving distance is 5 - 50 cm, the feeding speed of the spinning solution is 0.2 - 15 mL / h, and the thickness of the obtained fiber membrane is 5 - 50 μm.

[0042] The present application also provides a quasi-monolayer arranged down flake based on electrospinning technology, and the quasi-monolayer arranged down flake based on electrospinning technology is prepared by the preparation method of the quasi-monolayer arranged down flake based on electrospinning technology as described above.

[0043] Optionally, the thermal resistance of the quasi-monolayer arranged down flake based on electrospinning technology ≥ 1.0 m 2 ·K·W -1 , the air permeability ≥ 30 mm / s, the moisture permeability ≥ 9 kg·m -2 ·d -1 , the gram weight per square meter ≤ 100 g / m 2 .

[0044] Beneficial effects

[0045] The preparation method of the quasi-monolayer arranged down flake based on electrospinning technology of the present application has the following advantages:

[0046] 1. This application increases the mercapto groups on the surface of down fibers through plasma technology, and specifically synthesizes a new type of allyl-terminated polyurethane. Through ultraviolet treatment, a thiol-ene click reaction occurs between it and the mercapto groups on the down, forming strong S-C covalent bonds to fix the down, effectively preventing the phenomenon of down leakage.

[0047] 2. This application uses advanced electrospinning technology to bond the upper and lower layers of the quasi-monolayer arranged down respectively through polymer fiber membranes, effectively retaining the quasi-monolayer arrangement state of the down. The heat preservation effect is 50% higher than that of the existing randomly arranged down.

[0048] 3. The inherent low density and high porosity characteristics of the electrospun fiber membrane in this application ensure the air permeability and moisture permeability of the down flake.

[0049] 4. The quasi-monolayer arranged down flake in this application is convenient for modular production, and is expected to eliminate the down filling process in the preparation process of down products that generate flying down, so as to improve the working environment and production safety of workers in down product enterprises.

[0050] 5. The quasi-monolayer arranged down flake in this application provides a candidate fashion design element with excellent lightness and heat preservation for the field of clothing design. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is a schematic flow chart of a method for preparing a quasi-monolayer arranged down flake based on electrospinning technology provided by an embodiment of this application.

[0052] Figure 2 is a schematic diagram of the synthesis mechanism of allyl-terminated polyurethane in an embodiment of this application;

[0053] Figure 3 is a schematic diagram of the preparation process of a quasi-monolayer arranged down flake based on electrospinning technology in an embodiment of this application;

[0054] Figure 4 is a schematic diagram of the thiol-ene click reaction between allyl-terminated polyurethane and down containing mercapto groups in an embodiment of this application.

[0055] Figure 5 is a schematic diagram of the structure of a quasi-monolayer arranged down flake prepared based on electrospinning technology in an embodiment of this application;

[0056] Figure 6 is a schematic diagram of a quasi-monolayer arranged down flake prepared based on electrospinning technology in an embodiment of this application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0057] To make the objectives, technical solutions, and advantages of the present application more clear, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the accompanying drawings in the embodiments of the present application. In the drawings, the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout. The described embodiments are some, but not all, of the embodiments of the present application. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application and should not be construed as a limitation of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application. The embodiments of the present application will be described in detail below with reference to the drawings.

[0058] Figure 1 FIG. 4 is a schematic flowchart of a method for preparing a quasi-monolayer arranged down fiber sheet based on electrospinning technology provided by an embodiment of the present application.

[0059] As Figure 1 shown, the method for preparing a quasi-monolayer arranged down fiber sheet based on electrospinning technology includes:

[0060] Step 1: Prepare down for plasma treatment;

[0061] Step 2: Prepare allyl-terminated polyurethane;

[0062] Step 3: Prepare a down fiber sheet with a composite structure having a fiber membrane as the upper and lower layers and down as the middle layer according to the allyl-terminated polyurethane and the down for plasma treatment;

[0063] Step 4: Irradiate the down fiber sheet with a composite structure having a fiber membrane as the upper and lower layers and down as the middle layer with an ultraviolet lamp, thereby initiating a thiol-ene click reaction between the thiol groups on the surface of the down and the allyl groups in the fiber membrane, so that a strong S-C covalent bond is formed, and finally a quasi-monolayer arranged down fiber sheet with a covalently bonded composite structure is obtained.

[0064] The method for preparing a quasi-monolayer arranged down fiber sheet based on electrospinning technology of the present application has the following advantages:

[0065] 1. This application increases the thiol groups on the surface of down fibers through plasma technology and specifically synthesizes a new type of allyl-terminated polyurethane. Through ultraviolet treatment, it undergoes a thiol-ene click reaction with the thiol groups on the down, forming strong S-C covalent bonds to fix the down, effectively preventing the phenomenon of down leakage. Specifically, there are a large number of alkenyl groups in the allyl polyurethane that are not contained in ordinary polyurethane, and the alkenyl groups can undergo a click reaction with the thiol groups. This polyurethane adhesive is specifically synthesized for bonding down containing a large number of thiol groups using an electrospun fiber membrane. Because the electrospun fibers are thin and the bonding area with the down is small, a greater force (forming covalent bonds) is required to ensure the bonding strength to the down. 2. This application uses advanced electrospinning technology to bond the upper and lower layers of the quasi-monolayer arranged down respectively through a polymer fiber membrane, effectively retaining the quasi-monolayer arrangement state of the down. The heat preservation effect is 50% higher than that of the existing randomly arranged down.

[0066] 3. The inherent low density and high porosity characteristics of the electrospun fiber membrane in this application ensure the air permeability and moisture permeability of the down flake.

[0067] 4. The quasi-monolayer arranged down flake in this application is convenient for modular production, and is expected to eliminate the down filling process in the preparation of down products that generate flying down, so as to improve the working environment and production safety of workers in down product enterprises.

[0068] 5. The quasi-monolayer arranged down flake in this application provides a candidate fashion design element with excellent lightness and heat preservation in the field of clothing design.

[0069] In this embodiment, the down for plasma treatment in the preparation includes:

[0070] Pre-treat the down with acetone;

[0071] Wash and dry the down treated with acetone with deionized water;

[0072] Place the dried and baked down in a constant temperature and humidity environment for humidity adjustment;

[0073] Perform plasma treatment on the humidity-adjusted down.

[0074] In this embodiment, the pre-treatment of the down with acetone includes:

[0075] Soak in acetone for 30 min to wash off the impurities on the surface of the down;

[0076] The washing and drying of the down treated with acetone with deionized water includes:

[0077] Wash the acetone on the down with deionized water, put it in a blast drying oven and dry for 3 h at a temperature of 105 °C;

[0078] The humidity conditioning of the dried and baked down feathers in a constant temperature and humidity environment includes:

[0079] The humidity conditioning of the dried and baked down feathers is carried out in a constant temperature and humidity environment with a temperature of 20 ± 2 °C and a relative humidity of 65 ± 2%.

[0080] The parameters of the plasma treatment are as follows:

[0081] The output power selected for the plasma treatment is 100 - 500 W, the action time selected is 60 - 300 s, the reaction gas is air, and the reaction pressure is 30 Pa.

[0082] See Figure 2 , in this embodiment, the preparation of allyl-terminated polyurethane includes:

[0083] Reacting a diisocyanate and a polyol to prepare a prepolymer with an isocyanate group at the end;

[0084] Adding a solvent, a small molecule diol and a catalyst dibutyltin dilaurate into the prepolymer for chain extension to obtain an isocyanate group-terminated polyurethane; in this embodiment, the solvent added into the prepolymer can be acetone, methyl ethyl ketone, toluene, N,N-dimethylformamide, etc.

[0085] Adding a diamine to the isocyanate group-terminated polyurethane at a low temperature to obtain an amino group-terminated polyurethane;

[0086] Adding allyl glycidyl ether into the amino group-terminated polyurethane and heating for reaction to obtain an allyl-terminated polyurethane.

[0087] In this embodiment, the preparation of a down flake with a composite structure having a fiber membrane on the upper and lower layers and down in the middle layer from the allyl-terminated polyurethane and the plasma-treated down feathers includes:

[0088] Arranging the plasma-treated down feathers neatly to form a quasi-single-layer arrangement state;

[0089] Preparing a spinning solution of a polymer by mixing the allyl-terminated polyurethane or a mixture thereof with other polymers, using the fixed quasi-single-layer arranged down feathers as a receiving plate, and spinning the polymer spinning solution on the upper layer of the receiving plate through an electrospinning process to obtain a down flake with a fiber membrane on one side; in this embodiment, other polymers include common polymers such as ordinary polyurethane and polyacrylonitrile that can be electrospun.

[0090] Turn the side without the fiber film of the down flake with the fiber film on one side upwards, and spin the polymer spinning solution again through the electrospinning process on the upper layer of the receiving plate to obtain a down flake with a composite structure of a sandwich structure, where the upper and lower layers are fiber films and the middle layer is down.

[0091] In this embodiment, the prepared down flake is irradiated with an ultraviolet lamp, thereby triggering a thiol-ene click reaction between the thiol groups on the surface of the down and the allyl groups in the fiber film, forming strong S-C covalent bonds, and finally obtaining a quasi-monolayer arranged down flake with a covalently bonded composite structure, including:

[0092] Put the down flake with a composite structure of fiber films on the upper and lower layers and down in the middle layer under an ultraviolet lamp of 100 - 1000W for irradiation, trigger a thiol-ene click reaction between the thiol groups on the surface of the down and the allyl groups in the fiber film, form strong S-C covalent bonds, and finally obtain a quasi-monolayer arranged down flake with a covalently bonded composite structure.

[0093] In this embodiment, the diisocyanate is one or a combination of more than one of toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), lysine diisocyanate (LDI);

[0094] The polyol is one or a combination of more than one of polycaprolactone / poly(ethylene adipate) glycol / polytetrahydrofuran glycol / poly(propylene oxide) glycol, poly(butylene adipate) diol / polyethylene glycol, and the small molecule diol is one or a combination of more than one of ethylene glycol, 1,4-butanediol, 1,6-hexanediol;

[0095] The diamine is one or a combination of more than one of ethylenediamine, butanediamine, hexanediamine;

[0096] The terminal amino polyurethane is terminal allyl polyurethane.

[0097] In this embodiment, the electrospinning voltage is 10 - 50 kV, the receiving distance is 5 - 50 cm, the feeding speed of the spinning solution is 0.2 - 15 mL / h, and the thickness of the obtained fiber film is 5 - 50 μm.

[0098] This application also provides a quasi-monolayer arranged down flake based on electrospinning technology, which is characterized in that the quasi-monolayer arranged down flake based on electrospinning technology is prepared by the preparation method of the quasi-monolayer arranged down flake based on electrospinning technology as described in any one of claims 1 to 8.

[0099] In this embodiment, the thermal resistance of the quasi-monolayer arranged down flake based on electrospinning technology ≥ 1.0 m2 ·K·W -1 with an air permeability of ≥ 30 mm / s and a moisture permeability of ≥ 9 kg·m -2 ·d -1 and a grammage of ≤ 100 g / m 2 .

[0100] The present application will be further elaborated in detail by way of example below. It should be understood that this example does not constitute any limitation to the present application.

[0101] In the examples, unless otherwise specified, the experimental methods used are all conventional methods. The equipment, materials, reagents, etc. used, unless otherwise specified, can all be obtained from commercial channels. According to the GB / T 5453-1997 standard, the air permeability of the fabric was measured using a YG461E fabric air permeability tester, and the test specimen size was (100×100) mm 2 , and the test air pressure difference was 100 Pa. According to the desiccant method of the ASTM E96-CaCl2 standard, the moisture permeability of the fabric was tested using a YG 216-II type water vapor permeation tester. The test specimen size was (80×80) mm 2 , and the test conditions of the specimen were 38 °C, relative humidity 90%, and the test time was 90 min. Specific Example 1

[0103] See Figure 3 , a quasi-single-layer arranged down flake based on electrospinning technology and its preparation method, the steps are as follows:

[0104] Before plasma treatment, the down was pretreated with acetone, soaked in acetone for 30 min, and the oil agents and other impurities on the surface of the down were washed off. Then the acetone on the down was washed with deionized water and dried in a blast drying oven for 3 h at a temperature of 105 °C. After drying, it was placed in a constant temperature and humidity environment at a temperature of 20±2 °C and a relative humidity of 65±2% for humidity adjustment and waiting for test use. The output power selected for plasma treatment was 200 W, the action time selected was 100 s, the reaction gas was air, and the reaction pressure was 30 Pa. The down was subjected to plasma treatment and set aside.

[0105] 48.8 g of isophorone diisocyanate and 200 g of polyethylene adipate glycol (M = 2000) were reacted at 80 °C for 30 min to prepare a prepolymer with an isocyanate group at the end. Then 50 g of acetone, 9 g of 1,4-butanediol and 0.02 g of dibutyltin dilaurate were added for chain extension to obtain an isocyanate-terminated polyurethane. 1.2 g of ethylenediamine was added under a 5 °C ice bath and reacted for 20 min to obtain an amino-terminated polyurethane. 2.28 g of allyl glycidyl ether was added and reacted at 60 °C for 1 h to obtain an allyl-terminated polyurethane. It was used as a spinning polymer and set aside.

[0106] Using a mixed solution obtained by uniformly mixing N,N-dimethylformamide and acetone in a mass ratio of 1:1 as a solvent, a 15% by mass allyl-terminated polyurethane solution was prepared, and after stirring evenly, a polyurethane spinning solution was obtained; using a copper plate with quasi-monolayer arranged plasma-treated down on it as a receiving plate, the spinning voltage was 30 kV, the receiving distance was 20 cm, and the feeding speed of the spinning solution was 5 mL / h. A down flake with a fiber film on one side was prepared on the quasi-monolayer arranged down by electrospinning. Then, the side of the obtained down flake without the fiber film was facing up, and spinning was carried out again to obtain a down flake with a composite structure of a sandwich structure with fiber films on the upper and lower layers and down in the middle layer.

[0107] See Figure 5 and Figure 6 , the prepared down flake was placed under a 1000 W ultraviolet lamp and irradiated for 3 min to initiate a thiol-ene click reaction between the thiol groups on the surface of the down and the allyl groups in the fiber film ( Figure 4 as shown), so as to form strong S-C covalent bonds, and finally a down flake with a covalently bonded composite structure was obtained. The thickness of this fiber film was about 20 μm, and a down flake with a composite structure of a sandwich structure with fiber films on the upper and lower layers and down in the middle layer was obtained. The thermal resistance of the down flake = 1.042 m 2 ·K·W -1 , the air permeability = 35.5 mm / s, the moisture permeability = 9.45 kg·m -2 ·d -1 , and the grammage per square meter was ≤44.5 g / m 2 . Specific Example 2

[0109] A quasi-monolayer arranged down flake based on electrospinning technology and its preparation method are as follows:

[0110] Before plasma treatment, the down was pretreated with acetone, soaked in acetone for 30 min to wash off impurities such as sizing agents on the surface of the down. Then, the acetone on the down was washed with deionized water, and it was placed in a forced-air oven and dried for 3 h at a temperature of 105 °C. After drying, it was placed in a constant temperature and humidity environment at a temperature of 20 ± 2 °C and a relative humidity of 65 ± 2% for humidity adjustment and waiting for testing. The output power selected for plasma treatment was 100 W, the action time selected was 300 s, the reaction gas was air, and the reaction pressure was 30 Pa. The down was subjected to plasma treatment and set aside.

[0111] 55 g of diphenylmethane - 4,4'-diisocyanate and 200 g of polyethylene adipate glycol (M = 2000) were reacted at 70 °C for 30 min to prepare a prepolymer with isocyanate groups at the ends. Then, 30 g of acetone, 20 g of N,N-dimethylformamide, 6.2 g of ethylene glycol, and 0.02 g of dibutyltin dilaurate were added for chain extension to obtain a polyurethane with isocyanate groups at the ends. 2.32 g of hexamethylenediamine was added under a 5 °C ice bath and reacted for 20 min to obtain an amino-terminated polyurethane. 2.28 g of allyl glycidyl ether was added and reacted at 60 °C for 1 h to obtain an allyl-terminated polyurethane. It was reserved as a spinning polymer.

[0112] Using a mixed solution prepared by uniformly mixing N,N-dimethylformamide and dichloromethane in a mass ratio of 1:1 as the solvent, after mixing allyl-terminated polyurethane and polyether-type polyurethane in a mass ratio of 1:1, a mixed solution with a mass fraction of 15% was prepared and stirred evenly to obtain a polyurethane spinning solution; using a copper plate with quasi-monolayer arranged plasma-treated down feathers fixed on it as the receiving plate, with a voltage of 20 kV, a receiving distance of 10 cm, and a feeding speed of the spinning solution of 2.5 mL / h, a down feather flake with a fiber membrane on one side was prepared on the quasi-monolayer arranged down feathers by electrospinning. Then, the side without the fiber membrane of the obtained down feather flake was turned upwards and spun again to obtain a down feather flake with a composite structure of a sandwich structure with fiber membranes on the upper and lower layers and down feathers in the middle layer.

[0113] The prepared down feather flake was placed under a 1000 W ultraviolet lamp for irradiation for 3 min to initiate a thiol-ene click reaction between the thiol groups on the surface of the down feathers and the allyl groups in the fiber membrane, forming strong S-C covalent bonds, and finally obtaining a down feather flake with a covalently bonded composite structure. The thickness of this fiber membrane was approximately 30 μm. A down feather flake with a composite structure of a sandwich structure with fiber membranes on the upper and lower layers and down feathers in the middle layer was obtained, and the thermal resistance of the down feather flake ≥ 1.541 m 2 ·K·W -1 , the air permeability ≥ 28.4 mm / s, and the moisture permeability = 8.55 kg·m -2 ·d -1 , and the grammage per square meter = 52.3 g / m 2 .

[0114] In this embodiment, the principle of the present invention to solve the above problems is based on the characteristics that the surface of down fiber contains free sulfhydryl groups and disulfide bonds. By combining plasma technology, the disulfide bonds are broken to increase the content of sulfhydryl groups. And based on the mechanism of thiol-ene click reaction, a new type of allyl-terminated polyurethane is synthesized specifically. Using electrostatic technology, an electrospun fiber membrane of allyl-terminated polyurethane or a mixture of allyl-terminated polyurethane and other polymer fibers is prepared, and the upper and lower layers of the quasi-single-layer arranged down are chemically crosslinked. As a protein fiber, down contains a large number of sulfhydryl groups on its surface, which can form strong S-C covalent bonds with the allyl-terminated polyurethane in the electrospinning raw material through thiol-ene click reaction to firmly fix the down and prevent relative displacement between the individual down clusters without damaging the internal structure of the down. To achieve that the high-efficiency heat preservation effect of the quasi-single-layer arranged down will not be lost due to down accumulation. Based on the above principle, the embodiments in this specification provide a method for preparing a single-layer arranged down flake using electrospinning technology, including:

[0115] Before the plasma treatment, the down is pretreated with acetone, soaked in acetone for 30 min to wash off impurities such as sizing agents on the surface of the down. Then the acetone on the down is washed off with deionized water, and it is placed in a blast drying oven and dried for 3 h at a temperature of 105 °C. After drying, it is placed in a constant temperature and humidity environment with a temperature of 20 ± 2 °C and a relative humidity of 65 ± 2% for humidity adjustment and waiting for test use. The output power selected for the plasma treatment is 100 - 500 W respectively, the action time selected is 60 - 300 s respectively, the reaction gas is air, and the reaction pressure is 30 Pa. The down is subjected to plasma treatment and reserved.

[0116] A prepolymer with an isocyanate group at the end is prepared by reacting diisocyanate and polyol at a certain temperature (55 °C - 90 °C). Then, a solvent, a small molecule diol, and a catalyst dibutyltin dilaurate are added for chain extension to obtain an isocyanate-terminated polyurethane. At a low temperature (0 °C - 10 °C), diamine is added to obtain an amino-terminated polyurethane, and allyl glycidyl ether is added, and the temperature is raised for reaction (40 °C - 70 °C) for a certain time to obtain an allyl-terminated polyurethane. It is used as a spinning polymer and reserved.

[0117] The plasma-treated down is neatly arranged to form a quasi-single-layer arrangement state. The prepared allyl-terminated polyurethane or a polymer spinning solution prepared by mixing it with other polymers is used. With the fixed quasi-single-layer arranged down as the receiving plate, electrospinning is carried out on the upper layer of the receiving plate to obtain a down flake with a fiber membrane on one side. Then, the side of the obtained down flake without the fiber membrane is turned upwards, and the polymer solution is prepared again and electrospun to obtain a down flake with a composite structure of a fiber membrane on the upper and lower layers and down in the middle layer, having a sandwich structure.

[0118] Put the prepared down flakes under a 100 - 1000W ultraviolet lamp for irradiation for a certain time (5min - 30min), triggering the thiol - ene click reaction between the thiols on the surface of the down and the allyl groups in the fiber membrane, so as to form strong S - C covalent bonds, and finally obtain down flakes with a covalently - bonded composite structure.

[0119] Preferably, in step 1, the output power of treating the down by plasma technology is 200 - 300W respectively, the selected action time is 100 - 200s respectively, the reaction gas is air, and the reaction pressure is 30Pa.

[0120] In this embodiment, the diisocyanate is one or a combination of toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), lysine diisocyanate (LDI), etc., the polyol is one or a combination of polycaprolactone / poly(ethylene adipate) glycol / polytetrahydrofuran glycol / poly(propylene oxide) glycol, poly(butylene adipate) diol / polyethylene glycol, etc., the small - molecule diol is one or a combination of ethylene glycol, 1,4 - butanediol, 1,6 - hexanediol, etc. The diamine is one or a combination of ethylenediamine, butanediamine, hexanediamine, etc. The finally synthesized polyurethane is allyl - terminated polyurethane.

[0121] In this embodiment, the high - molecular polymer in the spinning solution is allyl - terminated polyurethane or a mixture of allyl - terminated polyurethane and a combination of one or more of lactic acid, polyacrylonitrile, polyamide, polystyrene, polyurea, and polyurethane - urea, and the mass fraction of the spinning solution is 5 - 30%.

[0122] In this embodiment, the electrospun high - molecular polymer solution can be of the same type or different types.

[0123] In this embodiment, the electrospinning voltage is 10 - 50kV, the receiving distance is 5 - 50cm, the feeding speed of the spinning solution is 0.2 - 15mL / h, and the thickness of the obtained fiber membrane is 5 - 50μm.

[0124] In this embodiment, finally, after ultraviolet treatment, the electrospun fiber membrane and the quasi - monolayer - arranged down are chemically crosslinked through the thiol - ene click reaction.

[0125] In this embodiment, the finally obtained quasi - monolayer - arranged down flakes based on electrospinning technology are characterized in that their structure is: the down flakes have a sandwich structure, with electrospun fiber membranes on the upper and lower layers and quasi - monolayer - arranged down in the inner layer.

[0126] In this embodiment, the thermal resistance of the prepared down flakes ≥ 1m2 ·K·W-1, air permeability ≥ 30 mm / s, water vapor transmission rate ≥ 9 kg·m -2 ·d -1 The square gram weight of the prepared down flake is ≤ 50 g / m 2 。

[0127] In this embodiment, the prepared down flake has a stable structure and is cuttable.

[0128] In addition, it is obvious that the word "including" does not exclude other units or steps. The multiple units, modules or devices stated in the apparatus claims can also be implemented by one unit or a general apparatus through software or hardware.

[0129] Although the present invention has been described in detail above with general descriptions and specific embodiments, on the basis of the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A method for preparing a quasi-single-layer arranged down flake based on electrospinning technology, characterized in that, The preparation method of the quasi-monolayer arranged down fiber web based on the electrospinning technology includes: Preparing down that undergoes plasma treatment; Preparing allyl-terminated polyurethane; Preparing a down fiber web with a composite structure having a fiber membrane as the upper and lower layers and down as the middle layer according to the allyl-terminated polyurethane and the down that undergoes plasma treatment; Irradiating the down fiber web with a composite structure having a fiber membrane as the upper and lower layers and down as the middle layer with an ultraviolet lamp, thereby triggering a thiol-ene click reaction between the thiol groups on the surface of the down and the allyl groups in the fiber membrane, so that a strong S-C covalent bond is formed, and finally obtaining a quasi-monolayer arranged down fiber web with a covalently bonded composite structure.

2. The preparation method of the quasi-single-layer arranged down flake based on the electrospinning technology according to claim 1, wherein, The preparation of the down that undergoes plasma treatment includes: Pre-treating the down with acetone; Washing and drying the down treated with acetone with deionized water; Placing the dried and baked down in a constant temperature and humidity environment for humidity adjustment; Performing plasma treatment on the humidity-adjusted down.

3. The method for preparing a quasi-single-layer arranged down flake based on the electrospinning technique according to claim 2, wherein, The pre-treatment of the down with acetone includes: Soaking in acetone for 30 min to wash away impurities on the surface of the down; The washing and drying of the down treated with acetone with deionized water includes: Washing the acetone on the down with deionized water and drying in a blast drying oven for 3 h at a temperature of 105 °C; The placing of the dried and baked down in a constant temperature and humidity environment for humidity adjustment includes: Placing the dried and baked down in a constant temperature and humidity environment with a temperature of 20 ± 2 °C and a relative humidity of 65 ± 2% for humidity adjustment; The parameters of the plasma treatment are as follows: The output power selected for the plasma treatment is 100 - 500 W, the action time selected is 60 - 300 s, the reaction gas is air, and the reaction pressure is 30 Pa.

4. The method for preparing a quasi-monolayer arranged down flake based on the electrospinning technique according to claim 3, characterized in that, The preparation of the allyl-terminated polyurethane includes: Preparing a prepolymer with an isocyanate group at the end by reacting a diisocyanate and a polyol; Adding a solvent, a small molecule diol, and a catalyst dibutyltin dilaurate into the prepolymer for chain extension to obtain an isocyanate-terminated polyurethane; Adding a diamine to the isocyanate-terminated polyurethane at a low temperature to obtain an amino-terminated polyurethane; Adding allyl glycidyl ether to the amino-terminated polyurethane and heating the reaction to obtain an allyl-terminated polyurethane.

5. The method for preparing a quasi-single-layer arranged down flake based on electrospinning technology according to claim 4, wherein The preparation of the down fiber web with a composite structure having a fiber membrane as the upper and lower layers and down as the middle layer according to the allyl-terminated polyurethane and the down that undergoes plasma treatment includes: Arranging the plasma-treated down neatly to form a quasi-monolayer arrangement state; Mixing the allyl-terminated polyurethane or a mixture thereof with other polymers to prepare a polymer spinning solution, using the fixed quasi-monolayer arranged down as the receiving plate, and spinning through the polymer spinning solution on the upper layer of the receiving plate by the electrospinning process to obtain a down fiber web with a fiber membrane on one side; Turning the side without the fiber membrane of the down fiber web with a fiber membrane on one side upwards, and spinning through the polymer spinning solution on the upper layer of the receiving plate again by the electrospinning process to obtain a down fiber web with a composite structure having a fiber membrane as the upper and lower layers and down as the middle layer with a sandwich structure.

6. The method for preparing a quasi-monolayer arranged down flake based on the electrospinning technique according to claim 5, characterized in that, The down flake with a composite structure having fiber membranes on the upper and lower layers and down in the middle layer is irradiated with an ultraviolet lamp, thereby triggering a thiol-ene click reaction between the thiol groups on the surface of the down and the allyl groups in the fiber membrane, forming strong S-C covalent bonds, and finally obtaining a quasi-monolayer arrangement of down flakes with a composite structure bonded by covalent bonds, including: The down flake with a composite structure having fiber membranes on the upper and lower layers and down in the middle layer is placed under an ultraviolet lamp with a power of 100-1000W for irradiation, triggering a thiol-ene click reaction between the thiol groups on the surface of the down and the allyl groups in the fiber membrane, forming strong S-C covalent bonds, and finally obtaining a quasi-monolayer arrangement of down flakes with a composite structure bonded by covalent bonds.

7. The method for preparing a quasi-monolayer arranged down flake based on the electrospinning technology according to claim 6, characterized in that, The diisocyanate is one or a combination of more of toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), lysine diisocyanate (LDI); The polyol is one or a combination of more of polycaprolactone / poly(ethylene adipate) glycol / polytetrahydrofuran glycol / poly(propylene oxide) glycol, poly(butylene adipate) diol / polyethylene glycol, and the small molecule diol is one or a combination of more of ethylene glycol, 1,4-butanediol, 1,6-hexanediol; The diamine is one or a combination of more of ethylenediamine, butanediamine, hexanediamine.

8. The method for preparing a quasi-single-layer arranged down flake based on the electrospinning technique according to claim 7, wherein The electrospinning voltage is 10-50 kV, the receiving distance is 5-50 cm, the feeding speed of the spinning solution is 0.2-15 mL / h, and the thickness of the obtained fiber membrane is 5-50 μm.

9. A quasi-single-layer arranged down flake based on electrospinning technology, characterized in that, The quasi-monolayer arrangement of down flakes based on the electrospinning technology is prepared by the method for preparing the quasi-monolayer arrangement of down flakes based on the electrospinning technology according to any one of claims 1 to 8.

10. The quasi-single-layer arranged down flake based on the electrospinning technology according to claim 9, characterized in that The thermal resistance of the quasi-single-layer arranged down flake based on the electrospinning technology ≥ 1.0 m 2 ·K·W -1 , the air permeability ≥ 30 mm / s, the moisture permeability ≥ 9 kg·m -2 ·d -1 , the gram weight per square meter ≤ 100 g / m 2 .

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