Mite-proof antibacterial composite down and preparation method thereof

Abstract

This invention relates to the field of down fabric technology, specifically to a mite-proof and antibacterial composite down and its preparation method. The mite-proof and antibacterial composite down includes two outer fabric layers, two inner down-proof fabric layers, two nanocellulose / chitosan composite layers, and down filling. The nanocellulose / chitosan composite layers are prepared from the following components: aqueous polyurethane emulsion, nanocellulose, chitosan, chitosan-modified wood vinegar powder, natural genipin, and a dispersant. Chitosan is added in the form of an acetate-sodium acetate buffer solution with a pH of 4.0–4.8. This invention, through the synergistic effect of chitosan-modified wood vinegar powder and nanocellulose, combined with an aqueous polyurethane matrix, can simultaneously achieve high repellency, high antibacterial rate, and excellent wash resistance. Furthermore, the nanocellulose enhances the interfacial bonding strength of the nanocellulose / chitosan composite layer, significantly improving interlayer adhesion strength and down-proof performance.

Description

Technical Field

[0001] This invention relates to the field of down fabric technology, specifically to a mite-proof and antibacterial composite down and its preparation method. Background Technology

[0002] Down-filled garments, using down as the filling material, are a primary choice for winter clothing due to their excellent warmth retention. Because of their down filling, the fabric typically needs to possess certain antibacterial properties. In recent years, adding chemical agents with antibacterial or mite-repellent effects to textiles to provide mite-proof and antibacterial functions during use has become a new development trend.

[0003] CN118404873B discloses an anti-mite and antibacterial down jacket fabric and its preparation method. The fabric incorporates wood vinegar powder in a functional membrane between the outer layer and the lining to achieve antibacterial and anti-mite properties. However, wood vinegar powder, chitosan, nano-silica, and polyurethane have poor compatibility, easily leading to uneven dispersion of the wood vinegar powder and potential loss of antibacterial and anti-mite effects in localized areas. Furthermore, the phenols and organic acids in the wood vinegar powder are highly water-soluble and easily dissolve and are lost from the functional membrane during repeated washing, significantly reducing the fabric's long-lasting antibacterial and anti-mite performance and making it unsuitable for long-term use. Summary of the Invention

[0004] The purpose of this invention is to provide a mite-proof and antibacterial composite down and its preparation method, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, in one aspect, the present invention provides the following technical solution: a mite-proof and antibacterial composite down, comprising: Two outer layers of fabric; Two inner layers of down-proof fabric are respectively placed on the inside of the two outer layers of fabric; Two nanocellulose / chitosan composite layers are respectively disposed between the outer fabric and the corresponding inner down-proof fabric. The nanocellulose / chitosan composite layer is an in-situ cross-linked and cured structure, which bonds the outer fabric and the inner down-proof fabric together. And down filling, which is contained and confined between the two layers of the inner down-proof fabric.

[0006] Preferably, the outer fabric is a plain weave fabric made of polyester filament with a warp and weft density of 300-350 threads / inch; the inner down-proof fabric is taffeta made of 20D / 12F ultrafine polyester filament with a warp and weft density of 400-500 threads / inch.

[0007] The nanocellulose / chitosan composite layer is prepared from the following components in parts by weight: 100 parts of waterborne polyurethane emulsion, 47-53 parts of nanocellulose, 20-26 parts of chitosan, 11-17 parts of chitosan-modified wood vinegar powder, 0.5-1.5 parts of natural genipin, and 0.8-1.2 parts of dispersant.

[0008] Except for the waterborne polyurethane emulsion, which is calculated by its total emulsion mass, all other components are calculated by their dry basis mass.

[0009] Preferably, the solid content of the aqueous polyurethane emulsion is 28% to 32%, and the average particle size is 50 to 100 nm, which is beneficial for forming a dense and flexible film structure.

[0010] Chitosan is added in the form of an acetate-sodium acetate buffer solution with a pH of 4.0 to 4.8. The pH of the acetate-sodium acetate buffer solution is stabilized in the range of 4.0 to 4.8 by adjusting the molar ratio of acetic acid to sodium acetate, so as to ensure that the chitosan is completely dissolved and that no phase separation occurs during subsequent mixing.

[0011] Preferably, the preparation method of the chitosan-modified wood vinegar powder includes the following steps: mixing chitosan with a degree of deacetylation ≥85% with wood vinegar solution, controlling the molar ratio of free amino groups in chitosan to total reactive carbonyl compounds in wood vinegar solution to be 1.2:1 to 1.4:1, stirring at 240 to 420 rpm at 50 to 65°C for 60 to 120 min, using an acetate-sodium acetate buffer solution to control the pH value of the system to 3.8 to 4.4 during the reaction, gradually precipitating microspheres, and after solid-liquid separation, washing 2 to 3 times with an acetate-sodium acetate buffer solution with a pH value of 4.2 to 4.4, and freeze-drying to obtain the chitosan-modified wood vinegar powder.

[0012] Preferably, the total reactive carbonyl compounds include aldehydes, ketones, and α,β-unsaturated carbonyl compounds in wood vinegar, specifically covering 1-hydroxy-2-butanone, furfural, 2-cyclopenten-1-one, and 3-hydroxy-2-butanone. The total amount is determined by hydroxylamine hydrochloride titration to ensure accurate reaction measurement and avoid insufficient cross-linking or residual irritants due to neglecting the activity of multiple components.

[0013] In one specific embodiment, the wood vinegar comprises, by mass percentage: 93.97% water, 2.87% acetic acid, 0.41% propionic acid, 0.84% ​​1-hydroxy-2-butanone, 0.08% 2-ethoxypropane, 0.69% furfural, 0.09% 2-cyclopenten-1-one, 0.05% 3-methylpyridine, 0.77% γ-butyrolactone, 0.07% 3-hydroxy-2-butanone, and 0.16% other components.

[0014] Preferably, the dispersant is selected from sodium polyacrylate, sodium hexametaphosphate, or a combination thereof, and is used to improve the dispersion stability of the solid components in the formulation of the nanocellulose / chitosan composite layer in an aqueous system.

[0015] On the other hand, the present invention also provides the following technical solution: the preparation method of the above-mentioned anti-mite and antibacterial composite down includes the following steps: (1) Chitosan was dissolved in an acetate-sodium acetate buffer solution with a pH of 4.0-4.8 to obtain a chitosan solution; the aqueous polyurethane emulsion was placed in a high-shear emulsifier, and nanocellulose, chitosan-modified wood vinegar powder and dispersant were added sequentially under high-speed shear at 10,000-14,000 rpm, and sheared and dispersed for 15-25 min until a uniform, flowable and flocculated dispersion was formed; chitosan solution and natural genipin were added to the dispersion, and then stirred at 800-1000 rpm at 40-60℃ for 30-60 min to obtain a composite slurry; (2) Plasma treatment is performed on the opposing surfaces of the outer fabric and the inner downproof fabric. (3) The composite slurry is coated on the inner side of the outer layer fabric and the outer side of the inner layer anti-down-draining fabric after plasma treatment. Then the two layers of fabric are bonded together with the coated surfaces, pre-dried at 60-90℃ for 5-10 min, and then cured at 110-130℃ for 2-5 min to form a nanocellulose / chitosan composite layer and obtain the composite fabric. (4) Place the two composite fabrics together with their respective inner down-proof fabric sides facing each other, sew along three sides, and use the fourth side as the down filling port. Fill the cavity between the two inner down-proof fabrics through the down filling port, and then sew the down filling port to obtain mite-proof and antibacterial composite down.

[0016] Preferably, in step (2), the parameters of the plasma treatment are: 70-90 W radio frequency power in an Ar / O2 mixed atmosphere, 30-60 s residence time in the plasma region, and the volume ratio of Ar to O2 is 3:1-5:1.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention utilizes the synergistic effect of chitosan-modified wood vinegar powder and nanocellulose, combined with an aqueous polyurethane matrix, to simultaneously achieve high repellency, high antibacterial rate, and excellent washability. Furthermore, by enhancing the interfacial bonding force of the nanocellulose / chitosan composite layer through nanocellulose, it significantly improves the interlayer bonding strength and down-proof performance. 2. In this invention, the nanocellulose, chitosan, and wood vinegar powder in the nanocellulose / chitosan composite layer are all biomass conversion materials, which not only avoids skin irritation that may be caused by synthetic materials, but also enables resource recycling. Attached Figure Description

[0018] Figure 1 The image shows the differential FTIR spectra of chitosan-modified wood vinegar powder prepared in Example 1 and pure chitosan. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0020] This embodiment provides a mite-proof and antibacterial composite down feather, comprising two outer fabric layers, two inner down-proof fabric layers, two nanocellulose / chitosan composite layers, and down filling. The two inner down-proof fabric layers are located inside the two outer fabric layers. The two nanocellulose / chitosan composite layers are disposed between each outer fabric layer and its corresponding inner down-proof fabric layer. The nanocellulose / chitosan composite layers have an in-situ cross-linked and cured structure, bonding the outer fabric layers and inner down-proof fabric layers together. The down filling is contained and confined between the two inner down-proof fabric layers.

[0021] The outer fabric is a plain weave fabric made of polyester filament with a warp and weft density of 320 threads / inch. The inner down-proof fabric is taffeta made of 20D / 12F ultrafine polyester filament with a warp and weft density of 450 threads / inch.

[0022] This embodiment also provides a method for preparing the above-mentioned anti-mite and antibacterial composite down, including the following steps: (1) Accurately weigh the following by weight: 100 parts of waterborne polyurethane emulsion (30% solid content, 80 nm average particle size), 50 parts of nanocellulose, 23 parts of chitosan, 14 parts of chitosan-modified wood vinegar powder, 1.0 part of natural genipin, and 1.0 part of sodium polyacrylate; dissolve the chitosan in an acetate-sodium acetate buffer solution with a pH of 4.5 to prepare a chitosan solution with a concentration of 6.4 wt%; place the waterborne polyurethane emulsion in a high-shear emulsifier, and under high-speed shear at 12,000 rpm, add nanocellulose, chitosan-modified wood vinegar powder and sodium polyacrylate in sequence, and shear and disperse for 20 min until a uniform, flowable and flocculated dispersion is formed; add the chitosan solution and natural genipin to the dispersion, and then stir at 900 rpm at 50℃ for 45 min to obtain a composite slurry; (2) Plasma treatment is performed on the opposing surfaces of the outer fabric and the inner downproof fabric; the parameters of the plasma treatment are: 80 W radio frequency power in Ar / O2 mixed atmosphere, 45 s residence time in plasma region, and the volume ratio of Ar to O2 is 4:1. (3) The composite slurry is coated on the inner side of the outer layer fabric and the outer side of the inner layer downproof fabric after plasma treatment. Then the two layers of fabric are bonded together with the coated surfaces, pre-dried at 75°C for 7.5 min, and then cured at 120°C for 3.5 min to form a nanocellulose / chitosan composite layer and obtain the composite fabric. (4) Place the two composite fabrics together with their respective inner down-proof fabric sides facing each other, sew along three sides, and use the fourth side as the down filling port. Fill the cavity between the two inner down-proof fabrics through the down filling port, and then sew the down filling port to obtain mite-proof and antibacterial composite down.

[0023] The preparation method of chitosan-modified wood vinegar powder includes the following steps: chitosan with a degree of deacetylation of 90% is mixed with wood vinegar solution, the molar ratio of free amino groups in chitosan to total reactive carbonyl compounds in wood vinegar solution is controlled at 1.3:1, and the mixture is stirred at 360 rpm for 90 min at 58℃. During the reaction, the pH value of the system is controlled at 4.0 using an acetate-sodium acetate buffer solution. Microspheres gradually precipitate during the reaction. After solid-liquid separation, the mixture is washed three times with an acetate-sodium acetate buffer solution with a pH of 4.3 and then freeze-dried to obtain chitosan-modified wood vinegar powder.

[0024] The structure of the chitosan-modified wood vinegar powder prepared in Example 1 was characterized by FTIR spectra measured using the KBr pellet method (sample:KBr=1:100) (scanning range 4000–400 cm⁻¹). -1 4 cm resolution -1 ), and using the spectrum of pure chitosan processed by the same method as a reference baseline, differential subtraction was performed to obtain the differential FTIR spectrum, such as Figure 1 As shown.

[0025] Please see Figure 1 It can be seen that at 1635 cm -1 A significant positive absorption peak was observed near the 1600 cm⁻¹, attributed to the characteristic vibration of the C=N Schiff base formed by the condensation of furfural carbonyl and chitosan free amino groups, confirming that the two underwent in-situ covalent cross-linking under acidic conditions; at 1600 cm⁻¹... -1 A faint shoulder peak was observed near the location and attributed to the C=C stretching vibration of the furan ring in incompletely reacted furfural and its overlap with the bending vibration of the residual amino group in chitosan; at 1560 cm⁻¹ -1The broadened positive shoulder peak observed near the Schiff base is attributed to the bending vibrations of the protonated amine groups generated during the reaction, resulting from the rearrangement of the electron cloud of the chitosan molecular chain and the reconstruction of the hydrogen bond network after the formation of the Schiff base. The synergistic presentation of these characteristic peaks systematically elucidates that molecular-level chemical bonding occurred between chitosan and the wood vinegar components, rather than physical mixing. Example 2

[0026] The difference from Example 1 is as follows: The outer fabric is a plain weave fabric made of polyester filament with a warp and weft density of 300 threads / inch. The inner down-proof fabric is taffeta made of 20D / 12F ultrafine polyester filament with a warp and weft density of 400 threads / inch.

[0027] The preparation method of anti-mite and antibacterial composite down includes the following steps: (1) Accurately weigh the following by weight: 100 parts of waterborne polyurethane emulsion (solid content 28%, average particle size 100 nm), 47 parts of nanocellulose, 20 parts of chitosan, 11 parts of chitosan-modified wood vinegar powder, 0.5 parts of natural genipin, and 0.8 parts of sodium polyacrylate; dissolve the chitosan in an acetate-sodium acetate buffer solution with a pH of 4.0 to prepare a chitosan solution with a concentration of 5.3 wt%; place the waterborne polyurethane emulsion in a high-shear emulsifier, and under high-speed shear at 10,000 rpm, add nanocellulose, chitosan-modified wood vinegar powder and sodium polyacrylate in sequence, and shear and disperse for 15 min until a uniform, flowable and flocculated dispersion is formed; add the chitosan solution and natural genipin to the dispersion, and then stir at 800 rpm at 40℃ for 30 min to obtain a composite slurry; (2) Plasma treatment is performed on the opposing surfaces of the outer fabric and the inner downproof fabric; the parameters of the plasma treatment are: 70 W radio frequency power in Ar / O2 mixed atmosphere, 30 s residence time in plasma region, and the volume ratio of Ar to O2 is 3:1. (3) The composite slurry is coated on the inner side of the outer layer fabric and the outer side of the inner layer anti-down-draining fabric after plasma treatment. Then the two layers of fabric are bonded together with the coated surfaces, pre-dried at 60℃ for 5 min, and then cured at 110℃ for 2 min to form a nanocellulose / chitosan composite layer, thus obtaining the composite fabric. (4) Place the two composite fabrics together with their respective inner down-proof fabric sides facing each other, sew along three sides, and use the fourth side as the down filling port. Fill the cavity between the two inner down-proof fabrics through the down filling port, and then sew the down filling port to obtain mite-proof and antibacterial composite down.

[0028] The preparation method of chitosan-modified wood vinegar powder includes the following steps: chitosan with a deacetylation degree of 85% is mixed with wood vinegar solution, the molar ratio of free amino groups in chitosan to total reactive carbonyl compounds in wood vinegar solution is controlled at 1.2:1, and the mixture is stirred at 240 rpm for 60 min at 50℃. During the reaction, the pH value of the system is controlled at 3.8 using an acetate-sodium acetate buffer solution. Microsphere precipitates are gradually formed during the reaction. After solid-liquid separation, the mixture is washed twice with an acetate-sodium acetate buffer solution with a pH of 4.2 and then freeze-dried to obtain chitosan-modified wood vinegar powder. Example 3

[0029] The difference from Example 1 is as follows: The outer fabric is a plain weave fabric made of polyester filament with a warp and weft density of 350 threads / inch. The inner down-proof fabric is taffeta made of 20D / 12F ultrafine polyester filament with a warp and weft density of 500 threads / inch.

[0030] The preparation method of anti-mite and antibacterial composite down includes the following steps: (1) Accurately weigh the following by weight: 100 parts of waterborne polyurethane emulsion (solid content 32%, average particle size 50 nm), 53 parts of nanocellulose, 26 parts of chitosan, 17 parts of chitosan-modified wood vinegar powder, 1.5 parts of natural genipin, and 1.2 parts of sodium hexametaphosphate; dissolve the chitosan in an acetate-sodium acetate buffer solution with a pH of 4.8 to prepare a chitosan solution with a concentration of 7.5 wt%; place the waterborne polyurethane emulsion in a high-shear emulsifier, and under high-speed shear at 14,000 rpm, add nanocellulose, chitosan-modified wood vinegar powder and sodium hexametaphosphate in sequence, and shear and disperse for 25 min until a uniform, flowable and flocculated dispersion is formed; add the chitosan solution and natural genipin to the dispersion, and then stir at 1000 rpm at 60℃ for 60 min to obtain a composite slurry; (2) Plasma treatment is performed on the opposing surfaces of the outer fabric and the inner downproof fabric; the parameters of the plasma treatment are: 90 W radio frequency power in Ar / O2 mixed atmosphere, 60 s residence time in plasma region, and the volume ratio of Ar to O2 is 5:1. (3) The composite slurry is coated on the inner side of the outer layer fabric and the outer side of the inner layer anti-down-draining fabric after plasma treatment. Then the two layers of fabric are bonded together with the coated surfaces, pre-dried at 90℃ for 10 min, and then cured at 130℃ for 5 min to form a nanocellulose / chitosan composite layer, thus obtaining the composite fabric. (4) Place the two composite fabrics together with their respective inner down-proof fabric sides facing each other, sew along three sides, and use the fourth side as the down filling port. Fill the cavity between the two inner down-proof fabrics through the down filling port, and then sew the down filling port to obtain mite-proof and antibacterial composite down.

[0031] The preparation method of chitosan-modified wood vinegar powder includes the following steps: chitosan with a degree of deacetylation of 95% is mixed with wood vinegar solution, the molar ratio of free amino groups in chitosan to total reactive carbonyl compounds in wood vinegar solution is controlled at 1.4:1, and the mixture is stirred at 420 rpm for 120 min at 65℃. During the reaction, the pH value of the system is controlled at 4.4 using an acetate-sodium acetate buffer solution. Microspheres gradually precipitate during the reaction. After solid-liquid separation, the mixture is washed three times with an acetate-sodium acetate buffer solution at pH 4.4 and then freeze-dried to obtain chitosan-modified wood vinegar powder. Example 4

[0032] The difference from Example 1 is as follows: The outer fabric is a plain weave fabric made of polyester filament with a warp and weft density of 340 threads / inch. The inner down-proof fabric is taffeta made of 20D / 12F ultrafine polyester filament with a warp and weft density of 480 threads / inch.

[0033] The preparation method of anti-mite and antibacterial composite down includes the following steps: (1) Accurately weigh the following by weight: 100 parts of waterborne polyurethane emulsion (solid content 31%, average particle size 75 nm), 50 parts of nanocellulose, 24 parts of chitosan, 14 parts of chitosan-modified wood vinegar powder, 1.1 parts of natural genipin, and 0.9 parts of sodium hexametaphosphate; dissolve the chitosan in an acetate-sodium acetate buffer solution with a pH of 4.2 to prepare a chitosan solution with a concentration of 6.2 wt%; place the waterborne polyurethane emulsion in a high-shear emulsifier, and under high-speed shear at 13,200 rpm, add nanocellulose, chitosan-modified wood vinegar powder and sodium hexametaphosphate in sequence, and shear and disperse for 18 min until a uniform, flowable and flocculated dispersion is formed; add the chitosan solution and natural genipin to the dispersion, and then stir at 960 rpm at 55℃ for 36 min to obtain a composite slurry; (2) Plasma treatment is performed on the opposing surfaces of the outer fabric and the inner downproof fabric; the parameters of the plasma treatment are: 75 W radio frequency power in Ar / O2 mixed atmosphere, 50 s residence time in plasma region, and the volume ratio of Ar to O2 is 3.5:1.

[0034] (3) The composite slurry is coated on the inner side of the outer layer fabric and the outer side of the inner layer anti-down-draining fabric after plasma treatment. Then the two layers of fabric are bonded together with the coated surfaces, pre-dried at 80℃ for 6 min, and then cured at 125℃ for 4 min to form a nanocellulose / chitosan composite layer, thus obtaining the composite fabric. (4) Place the two composite fabrics together with their respective inner down-proof fabric sides facing each other, sew along three sides, and use the fourth side as the down filling port. Fill the cavity between the two inner down-proof fabrics through the down filling port, and then sew the down filling port to obtain mite-proof and antibacterial composite down.

[0035] The preparation method of chitosan-modified wood vinegar powder includes the following steps: chitosan with a degree of deacetylation of 85% is mixed with wood vinegar solution, the molar ratio of free amino groups in chitosan to total reactive carbonyl compounds in wood vinegar solution is controlled at 1.3:1, and the mixture is stirred at 300 rpm for 80 min at 62℃. During the reaction, the pH value of the system is controlled at 4.2 using an acetate-sodium acetate buffer solution. Microspheres gradually precipitate during the reaction. After solid-liquid separation, the mixture is washed twice with an acetate-sodium acetate buffer solution at pH 4.2 and freeze-dried to obtain chitosan-modified wood vinegar powder.

[0036] Comparative Example 1 The difference from Example 1 is that the chitosan-modified wood vinegar powder is replaced with an equal mass of unmodified wood vinegar powder, which is directly obtained from wood vinegar liquid by freeze-drying.

[0037] Comparative Example 2 The difference from Example 1 is that nanocellulose is replaced with an equal mass of microcrystalline cellulose, the average particle size of which is 20 μm.

[0038] Test Example 1: Anti-mite and antibacterial performance test The composite fabrics prepared in Examples 1-4 and Comparative Examples 1-2, wherein the wet film coating thickness of the composite slurry was 25 μm, were subjected to the following tests in sequence: Anti-mite effect: Referring to the test method published in GB / T 24253-2009, the composite fabric was cut into circles with a diameter of 58 mm as samples. The test mite species was dust mite, and the results were expressed as repellency rate.

[0039] Antibacterial rate: Referring to the test method disclosed in GB / T 20944.3-2008, the composite fabric was cut into 5 mm × 5 mm pieces as samples. Staphylococcus aureus and Escherichia coli were used as test bacteria. The antibacterial rate of the samples was tested before washing and after 5 standard washes (according to test condition A disclosed in GB / T 3921-2008).

[0040] The test results are shown in Table 1.

[0041]

[0042] As shown in Table 1, compared with the comparative example, the composite fabrics prepared in the examples all exhibited excellent mite-repellent properties and long-lasting antibacterial activity. This indicates that the unmodified wood vinegar powder, due to its high water solubility, is easily lost during washing and cannot meet the requirements for long-term use. Furthermore, the lack of nanocellulose leads to uneven dispersion of functional components and weak interfacial bonding, making it impossible to effectively anchor the active ingredients. Therefore, this invention, through the synergistic effect of chitosan-modified wood vinegar powder and nanocellulose, combined with an aqueous polyurethane matrix, can simultaneously achieve high repellency, high antibacterial rate, and excellent wash resistance.

[0043] Test Example 2: Mechanical Performance Test The composite fabrics prepared in Examples 1-4 and Comparative Examples 1-2, wherein the wet film coating thickness of the composite slurry was 25 μm, were subjected to the following tests in sequence: Peel strength: The composite fabric was cut into samples with a length of 150 mm and a width of 25 mm. The T-shaped peel method was used for testing. The specific operation was as follows: first, 50 mm of the sample was manually pre-peeled from one end. Then, the two peeled parts were clamped in the upper and lower clamps of the universal testing machine and tested at a tensile speed of 100 mm / min. The average peel strength during the peeling process was recorded. The result is expressed as N / 25 mm.

[0044] Down leakage rate: A double-layered bag measuring 20 cm × 20 cm was made from the composite fabric and filled with 30 g of standard duck down. The bag was then patted at a frequency of 200 times / min for 10 minutes in a down leakage tester. After resting for 1 minute, the number of down feathers penetrating to the outer surface was counted. The results were expressed as feathers / 100 cm. 2 express.

[0045] The test results are shown in Table 2.

[0046]

[0047] As shown in Table 2, compared with the comparative example, the composite fabrics of the examples all exhibited excellent interlayer bonding strength and down-proof performance. The comparison between Example 1 and Comparative Example 2 shows that the peel strength increased from 2.8 N / 25 mm to 4.8 N / 25 mm after the addition of nanocellulose, and the down-proof performance was significantly improved. This confirms that the introduction of chitosan-modified wood vinegar powder and nanocellulose has a synergistic effect on improving mechanical properties.

[0048] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A mite-proof and antibacterial composite down, characterized in that, include: Two outer layers of fabric; Two inner layers of down-proof fabric are respectively placed on the inside of the two outer layers of fabric; Two nanocellulose / chitosan composite layers are respectively disposed between the outer fabric and the corresponding inner down-proof fabric. The nanocellulose / chitosan composite layer is an in-situ cross-linked and cured structure, which bonds the outer fabric and the inner down-proof fabric together. And down filling, which is contained and confined between the two inner down-proof fabric layers; The nanocellulose / chitosan composite layer is prepared from the following components in parts by weight: 100 parts of waterborne polyurethane emulsion, 47-53 parts of nanocellulose, 20-26 parts of chitosan, 11-17 parts of chitosan-modified wood vinegar powder, 0.5-1.5 parts of natural genipin, and 0.8-1.2 parts of dispersant. Except for the aqueous polyurethane emulsion, which is calculated by its total emulsion mass, all other components are calculated by their dry basis mass; chitosan is added in the form of an acetate-sodium acetate buffer solution with a pH of 4.0 to 4.

8.

2. The anti-mite and antibacterial composite down according to claim 1, characterized in that, The outer fabric is a plain weave fabric made of polyester filament with a warp and weft density of 300-350 threads / inch; the inner down-proof fabric is taffeta made of 20D / 12F ultrafine polyester filament with a warp and weft density of 400-500 threads / inch.

3. The anti-mite and antibacterial composite down according to claim 1, characterized in that, The waterborne polyurethane emulsion has a solid content of 28% to 32% and an average particle size of 50 to 100 nm.

4. The anti-mite and antibacterial composite down according to claim 1, characterized in that, The dispersant is selected from sodium polyacrylate, sodium hexametaphosphate, or a combination thereof.

5. The anti-mite and antibacterial composite down according to claim 1, characterized in that, The preparation method of the chitosan-modified wood vinegar powder includes the following steps: chitosan with a degree of deacetylation ≥85% is mixed with wood vinegar solution, the molar ratio of free amino groups in chitosan to total reactive carbonyl compounds in wood vinegar solution is controlled at 1.2:1 to 1.4:1, and the mixture is stirred at 240 to 420 rpm at 50 to 65°C for 60 to 120 min. During the reaction, the pH value of the system is controlled at 3.8 to 4.4 using an acetate-sodium acetate buffer solution. Microsphere precipitates are gradually formed during the reaction. After solid-liquid separation, the mixture is washed 2 to 3 times with an acetate-sodium acetate buffer solution with a pH value of 4.2 to 4.4, and then freeze-dried to obtain the chitosan-modified wood vinegar powder.

6. The anti-mite and antibacterial composite down according to claim 5, characterized in that, The total reactive carbonyl compounds include aldehydes, ketones, and α,β-unsaturated carbonyl compounds in wood vinegar, and their total amount is determined by hydroxylamine hydrochloride titration.

7. A method for preparing anti-mite and antibacterial composite down as described in any one of claims 1 to 6, characterized in that, Includes the following steps: (1) Chitosan was dissolved in an acetate-sodium acetate buffer solution with a pH of 4.0-4.8 to obtain a chitosan solution; the aqueous polyurethane emulsion was placed in a high-shear emulsifier, and nanocellulose, chitosan-modified wood vinegar powder and dispersant were added sequentially under high-speed shear at 10,000-14,000 rpm, and sheared and dispersed for 15-25 min until a uniform, flowable and flocculated dispersion was formed; chitosan solution and natural genipin were added to the dispersion, and then stirred at 800-1000 rpm at 40-60℃ for 30-60 min to obtain a composite slurry; (2) Plasma treatment is performed on the opposing surfaces of the outer fabric and the inner downproof fabric. (3) The composite slurry is coated on the inner side of the outer layer fabric and the outer side of the inner layer anti-down-draining fabric after plasma treatment. Then the two layers of fabric are bonded together with the coated surfaces, pre-dried at 60-90℃ for 5-10 min, and then cured at 110-130℃ for 2-5 min to form a nanocellulose / chitosan composite layer and obtain the composite fabric. (4) Place the two composite fabrics together with their respective inner down-proof fabric sides facing each other, sew along three sides, and use the fourth side as the down filling port. Fill the cavity between the two inner down-proof fabrics through the down filling port, and then sew the down filling port to obtain mite-proof and antibacterial composite down.

8. The method for preparing anti-mite and antibacterial composite down according to claim 7, characterized in that, In step (2), the parameters of the plasma treatment are: under an Ar / O2 mixed atmosphere, the radio frequency power is 70-90 W, the residence time in the plasma region is 30-60 s, and the volume ratio of Ar to O2 is 3:1-5:1.

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