A breathable and dust-proof wall cloth and its preparation method

Abstract

The present invention relates to the field of wall coverings, and specifically to a breathable and dust-proof wall covering and a preparation method thereof. The present invention overcomes the problems of insufficient breathability and dust-proof performance of wall coverings in the prior art. By using cotton fibers, PET fibers and modified fibers, nanofibers are prepared by electrospinning, and particle composites are introduced into the nanofibers to obtain a composite fiber layer; a prepolymer formed by isocyanate and polyether diol is chain-extended, reacted with modified nano silver, and additives are added to obtain a polyurethane protective layer emulsion. According to the order of PET non-woven fabric, composite fiber layer, and polyurethane protective layer, a breathable and dust-proof wall covering is prepared by thermal curing; by changing the types and amounts of fibers, adjusting the electrospinning parameters, and adjusting the porosity of the nanofibers, the breathability of the wall covering is synergistically improved; by introducing a polyurethane protective layer and using particle composites in combination, the hydrophobicity of the wall covering is improved while the dust-proof performance is enhanced; by introducing modified nano silver, the antibacterial performance of the wall covering is improved.

Description

Technical Field

[0001] The present invention relates to the field of wall coverings, and particularly to a breathable and dust-proof wall covering and a preparation method thereof. Background Art

[0002] With the improvement of people's living standards, the requirements for indoor decoration and environment have also increased, especially for the decoration of walls. In the past, people used paint to brush the wall surface, but the paint contains a large amount of substances harmful to the human body, which is not conducive to environmental protection; gradually, wallpaper has been widely used. However, a large amount of pollution will be generated during the manufacture of wallpaper, and it faces problems of insufficient water resistance and poor air permeability after long-term use; subsequently, people began to use fabrics to decorate the wall surface, but the fabrics are expensive, difficult to adhere well to the wall, and at the same time, the breathable and dust-proof effects are not good.

[0003] Wall coverings, also known as wall fabrics, usually use cotton cloth as the base cloth, and apply printing or embossing on the base cloth, or are woven with large jacquard. The patterns used are mostly geometric patterns and floral patterns, and are gradually accepted by people. However, in the prior art, most of the preparation methods of traditional fabrics consume a large amount of resources, and it is difficult to effectively guarantee the quality of each piece of fabric during batch preparation. The existing fabrics are usually woven with natural fibers, but the fabrics made of natural fibers also have some imperfections. The mechanical strength of cotton cloth is not high, and the waterproof and breathable performance of the fabric is relatively general; while the prepared waterproof fabrics sacrifice air permeability and dust-proof performance in order to be waterproof, resulting in poor comprehensive practicability of the fabric and further restricting the use range of wall coverings.

[0004] In the prior art, many modification measures have been made for the antibacterial performance of wall coverings, and the antibacterial performance of wall coverings is improved by adding antibacterial agents or additives. However, the addition of additives has a great impact on the breathable and dust-proof performance of wall coverings. How to meet the high air permeability and high dust-proof performance during the use of wall coverings is a difficult problem to be solved at present.

[0005] Therefore, a breathable and dust-proof wall covering and a preparation method thereof are proposed. Summary of the Invention

[0006] The object of the present invention is to provide a breathable and dust-proof wall cloth and a preparation method thereof. By using cotton fibers, PET fibers and modified fibers, nanofibers are prepared by electrospinning, and particulate composites are introduced into the nanofibers to obtain a composite fiber layer; a prepolymer formed by isocyanate and polyether diol is chain-extended, reacted with modified nano-silver, and additives are added to obtain a polyurethane protective layer emulsion. Finally, a breathable and dust-proof wall cloth is prepared by thermosetting PET non-woven fabric, the composite fiber layer and the polyurethane protective layer; by changing the types and amounts of fibers, the tensile properties and breathability of the wall cloth are improved; by adjusting the electrospinning parameters, the porosity of the nanofibers is adjusted to improve the breathability of the wall cloth; by using particulate composites formed by carbon nanotubes and nano-titanium dioxide, the dust-proof performance of the wall cloth is improved; by introducing a polyurethane protective layer, the hydrophobicity of the wall cloth is improved while the dust-proof performance is enhanced; by introducing modified nano-silver, the antibacterial performance of the wall cloth is improved.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] On the one hand, the present invention provides a preparation method of a breathable and dust-proof wall cloth, and the preparation of the breathable and dust-proof wall cloth comprises the following steps:

[0009] S1 Bond one side of the composite fiber layer and the non-woven fabric layer, and dry to obtain a composite material;

[0010] S2 Coat the side of the composite material that is not bonded to the non-woven fabric with a polyurethane protective layer emulsion, and cure to obtain a wall cloth composite; pass the wall cloth composite through a hot air drying furnace to obtain a breathable and dust-proof wall cloth;

[0011] The composite fiber layer comprises nanofibers and particulate composites;

[0012] The non-woven fabric layer is PET non-woven fabric;

[0013] The polyurethane protective layer emulsion comprises isocyanate, a chain extender and modified nano-silver.

[0014] Preferably, the preparation of the nanofibers comprises the following steps:

[0015] Dissolve 10 - 25 parts of cotton fibers, PET fibers and modified fibers in a mixed solvent with a mass ratio of DMF to ethanol of 3:2, stir at 50 °C for 12 h to obtain a transparent solution; add the transparent solution into a 10 ml medical disposable syringe, and prepare electrospun fibers by electrospinning; dry the electrospun nanofibers at 60 °C for 6 h to obtain the nanofibers.

[0016] Preferably, the modified fiber is selected from one of nylon fiber, hemp fiber, acrylic fiber and glass fiber; the mass ratio of cotton fiber to the PET fiber is 1 - 3:1 - 7.

[0017] Preferably, the injection rate of the electrospinning method is 5 - 15 μL / min; the receiving distance of the electrospinning method is 20 - 40 cm; the voltage of the electrospinning method is 8 - 15 KV.

[0018] Preferably, the preparation of the composite fiber comprises the following steps:

[0019] Add the particle composite into 100 mL of ethanol, and ultrasonically disperse for 30 min to obtain a dispersion; cut the nanofibers into thin slices, immerse them in the dispersion, ultrasonically treat for 10 min, and vacuum dry at 60 °C for 3 h to obtain a composite fiber layer.

[0020] Preferably, the preparation of the particle composite comprises the following steps:

[0021] Add carbon nanotubes into acetic acid solution for soaking, and wash with deionized water to obtain treated carbon nanotubes; add the treated carbon nanotubes into a 50% ethanol solution to obtain a dispersion; dissolve tetraethyl titanate in absolute ethanol to obtain a solution; dropwise add the acetic acid solution into the solution to obtain a titanium precursor solution; add the dispersion into the titanium precursor solution, stir and mix evenly, raise the temperature for reaction to obtain a composite; wash the composite with deionized water and vacuum dry to obtain a particle composite; the mass ratio of carbon nanotubes to nano-titanium dioxide in the particle composite is 1 - 3:1 - 2.

[0022] Preferably, the preparation of the polyurethane protective layer emulsion comprises the following steps:

[0023] Add polyether diol and isocyanate into a three-necked flask, heat up to 80 °C, add dibutyltin dilaurate, and react for 2 h to obtain a mixed solution; cool the mixed solution to 50 °C, add a chain extender, adjust the viscosity of the system with acetone, and keep the temperature for reaction to obtain a polyurethane prepolymer; disperse 8 - 25 parts of modified nano-silver in absolute ethanol, and disperse at high speed to obtain a dispersion system; under the protection of nitrogen, slowly add the dispersion system into the polyurethane prepolymer, stir and mix evenly, and react to obtain a mixed system; add antioxidant 1010, silicone defoamer and acetone dilution into the mixed system, stir and disperse, and filter to obtain a polyurethane protective layer emulsion.

[0024] Preferably, the isocyanate is selected from one of toluene diisocyanate, hexamethylene diisocyanate, and tridecafluoro isocyanate; the chain extender is a mixture of 2,2 - bis(4-hydroxyphenyl)hexafluoropropane and 1,4-butanediol in a mass ratio of 1:1; the -NCO / -OH molar ratio in the polyurethane prepolymer is 0.8 - 1.5:1.

[0025] Preferably, the preparation of the modified nano-silver comprises the following steps:

[0026] Dissolve the modifier in 95% ethanol solution, adjust the pH of the system with acetic acid, and stir to obtain a silane coupling agent solution; slowly add nano-silver to the silane coupling agent solution, and react to obtain a modified system; dry the modified system at 100 °C for 2 h and grind it to obtain modified nano-silver; wherein the modifier is selected from one of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, methacryloxypropyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane; the mass ratio of the modifier to nano-silver is 1:5-8.

[0027] On the other hand, the present invention provides a breathable and dust-proof wall cloth prepared by the method as described above. The breathable and dust-proof wall cloth successively comprises a polyurethane protective layer, a composite fiber layer, and a PET non-woven fabric layer from top to bottom; the thickness of the polyurethane protective layer is 4-5 mm; the thickness of the PET non-woven fabric layer is 4-5 mm; the thickness of the composite fiber layer is 3-4 mm.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] 1. By using cotton fibers, PET fibers, and modified fibers, the present invention utilizes the high breathability of cotton fibers and PET fibers; with the high-strength effect of the modified fibers, nanofibers are prepared by electrospinning. Through the synergistic effect of various fibers, while improving the tensile strength of the wall cloth, its breathability is maintained.

[0030] 2. By preparing nanofibers through electrospinning, by changing the injection rate, receiving distance, and voltage adjustment during the electrospinning process, adjusting the process parameters, controlling the fiber diameter, and increasing the fiber porosity, under the synergistic effect of various fibers, the breathability of the wall cloth is improved.

[0031] 3. By introducing particle composites on the surface of the nanofibers, the present invention utilizes the uniform distribution of titanium dioxide particles in the pores of the nanofibers to improve the binding stability between the particle composites and the nanofiber layer; at the same time, carbon nanotubes provide more polar groups, improving the binding ability between the polyurethane coating and the composite fiber layer. During the curing process, a stable three-dimensional network structure is formed, further improving the dust-proof performance of the wall cloth.

[0032] 4. By introducing a polyurethane protective layer, the present invention utilizes the particle composites to improve the binding ability between the polyurethane protective layer and the composite cellulose. At the same time, by introducing fluorinated isocyanate in the preparation of the polyurethane protective layer, while improving the hydrophobic performance of the wall cloth, it synergistically improves the dust-proof performance of the wall cloth with the particle composites.

[0033] 5. By introducing modified nano-silver into the polyurethane protective layer, the present invention utilizes the addition of the modifier to improve the binding stability between the nano-silver and the polyurethane. At the same time, more cross-linking sites are formed during the curing process, which is beneficial to the formation of a three-dimensional network structure, improving the antibacterial ability while increasing the dust-proof performance of the wall cloth. Brief Description of the Drawings

[0034] Figure 1 It is a schematic structural diagram of the breathable and dust-proof wall cloth designed by the present invention;

[0035] Figure 2 It is a graph showing the changes in tensile strength and air permeability of Example 1, Examples 5 - 7 of the present invention.

[0036] In the figure: 1, PET non-woven fabric layer; 2, composite fiber layer; 3, polyurethane protective layer. Detailed Embodiments

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0038] In the present invention, KH-560 is 3-(2,3-epoxypropoxy)propyltrimethoxysilane, CAS: 2530-83-8; KH-570 is methacryloxypropyltrimethoxysilane, CAS: 2530-85-0; KH-792 is N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, CAS: 1760-24-3; PET is polyethylene terephthalate.

[0039] The present invention provides a breathable and dust-proof wall cloth and its preparation method. As Figure 1 shown, the breathable and dust-proof wall cloth is composed of a PET non-woven fabric layer 1, a composite fiber layer 2, and a polyurethane protective layer 3. Specifically referring to Figures 1 to 2 , the technical solution is as follows:

[0040] Example 1

[0041] Dissolve 40 parts of cotton fiber, 60 parts of PET fiber, and 25 parts of nylon fiber in an organic solvent (DMF: ethanol = 3:2), stir at 50°C for 12 h to obtain a transparent solution; add the transparent solution into a 10 ml medical disposable syringe, use a 20-gauge stainless steel flat needle to control the injection rate of the transparent solution at 10 μL / min, keep the distance between the spinneret and the receiving plate at 30 cm, apply a high voltage of 12 KV to the needle, control the temperature at 40°C, keep the relative humidity at 30% ± 5%, and ground the aluminum foil on the receiving plate to collect the electrospun nanofibers injected; dry the electrospun nanofibers in a vacuum drying oven at 60°C for 6 h to obtain nanofibers.

[0042] Add 50 parts of carbon nanotubes to 10% acetic acid solution and soak for 3 h, then wash with deionized water to obtain treated carbon nanotubes; add the treated carbon nanotubes to a mixed solution of 50% ethanol and water to obtain a dispersion; dissolve tetraethyl titanate in absolute ethanol to obtain a solution; add acetic acid solution dropwise to the solution at a rate of 2 drops per second to obtain a titanium precursor solution; slowly add 50 parts of the dispersion to 50 parts of the titanium precursor solution, stir at 100 r / min, mix evenly, heat the system to 80 °C and react for 2 h to obtain a composite; wash the composite with deionized water and vacuum dry for 2 h to obtain a particulate composite; cut the nanofibers into thin slices of 4×4 cm 2 ; add the particulate composite to 100 mL of ethanol, ultrasonically disperse for 30 min to obtain a dispersion; immerse the fiber thin slices in the dispersion and ultrasonically treat for 10 min to make titanium dioxide nanoparticles evenly distributed in the pores of the nanofibers, and vacuum dry at 60 °C for 3 h to obtain a composite fiber layer;

[0043] Dissolve 5 parts of KH-560 in 95% ethanol solution, adjust the pH of the system to 3 with acetic acid, and stir in a magnetic stirrer at 50 °C for 2 h to prepare a silane coupling agent solution; slowly add 30 parts of nano silver to the silane coupling agent solution and react at 50 °C for 2 h to obtain a modified system; dry the modified system at 100 °C for 2 h and grind for 30 min to obtain modified nano silver. After dehydrating 50 parts of polyether diol and 60 parts of toluene diisocyanate at 100 °C for 2 h, add them to a three-necked flask, heat to 80 °C and stir for 30 min, add 2 parts of the catalyst dibutyltin dilaurate, and react for 2 h to obtain a mixed solution; cool the mixed solution to 50 °C, add 300 parts of a mixture of 2,2-bis(4-hydroxyphenyl)hexafluoropropane and 1,4-butanediol (the mass ratio of 2,2-bis(4-hydroxyphenyl)hexafluoropropane to 1,4-butanediol is 1:1), and use 20 ml of acetone to adjust the viscosity of the system, and keep the temperature for reaction for 30 min to obtain a polyurethane prepolymer; disperse 20 parts of modified nano silver in absolute ethanol and disperse with a high-speed disperser for 30 min to obtain a dispersion system; under nitrogen protection, slowly add the dispersion system to 100 parts of the polyurethane prepolymer, stir and mix evenly at 50 rpm, heat to 60 °C, and react for 2 h to obtain a mixed system; add 5 parts of antioxidant 1010, 1 part of organosilicon defoamer and 5 ml of acetone to dilute 100 parts of the mixed system, stir and disperse at 200 rpm for 30 min, and filter to obtain a polyurethane protective layer emulsion.

[0044] Bond and adhere one side of the composite fiber layer to the PET non-woven fabric layer, and keep it in a vacuum drying oven at 120 °C and 200 Pa for 2 hours to obtain a composite material; coat the non-bonded non-woven fabric side of the composite material with a polyurethane protective layer emulsion using a roll coater, heat it up to 80 °C, and carry out a curing reaction for 2 hours to obtain a wall covering composite; dry the wall covering composite through a hot air drying furnace, with the drying temperature being 100 °C and the drying time being 5 hours to obtain a breathable and dust-proof wall covering.

[0045] Examples 2 - 13 Refer to the preparation steps and parameter conditions of Example 1, with the differences shown in Table 1.

[0046] Table 1 Breathability performance test of Examples 1 - 13 and Comparative Examples 1 - 4

[0047]

[0048] Comparative Example 1 Refer to the preparation steps and parameter conditions of Example 1, with the difference being that no modified fibers are added.

[0049] Comparative Example 2 Refer to the preparation steps and parameter conditions of Example 1, with the difference being that only cotton fibers are added.

[0050] Comparative Example 3 Refer to the preparation steps and parameter conditions of Example 1, with the difference being that only PET fibers are added.

[0051] Comparative Example 4 Refer to the preparation steps and parameter conditions of Example 1, with the difference being that electrospinning is not used to prepare nanofibers, and a conventional warp knitting, weft knitting or knitting method is used to obtain fiber materials.

[0052] Example 14 Breathability performance test

[0053] For the breathable and dust-proof wall coverings prepared in Examples 1 - 13 and Comparative Examples 1 - 4, the air permeability of the fabrics was detected by the constant pressure difference flow measurement method, and the air permeability performance of the samples was tested using a TQD - G1 air permeability tester. The air permeability performance test was carried out according to the GB / T5453 - 1997 standard; the tensile strength of the wall coverings prepared in Examples 1 - 13 and Comparative Examples 1 - 4 was tested according to ASTM D - 50395; the test results are shown in Table 2; the changes in the tensile strength and air permeability performance of Examples 1, 5 - 7 are as Figure 2 shown.

[0054] Table 2 Breathability performance test of Examples 1 - 13 and Comparative Examples 1 - 4

[0055]

[0056] It can be seen from the results in Table 2 that the wall fabrics prepared without adding modified fibers in Comparative Examples 1-3 have a significant decrease in tensile strength compared to Examples 1-13. The addition of cotton fibers and PET fibers can increase the fiber porosity of the wall fabric, and the electrospinning fiber process is used to improve the air permeability of nanofibers. However, the strength of cotton fibers and PET fibers is poor, and the spinning success rate decreases due to the reduction in strength during the electrospinning process, reducing the production efficiency. By introducing modified fibers, the strength of the fibers can be increased, improving the overall mechanical properties of the wall fabric; in Comparative Example 4, the strength of the wall fabric obtained without using electrospinning is less affected, but the air permeability of the wall fabric is significantly reduced. During the electrospinning process, the porosity of the modified fibers can be increased, and at the same time, the fibers form an uneven pore size distribution, further improving the air permeability of the wall fabric; it can be seen from the results of Examples 1-4 that the use of modified fibers with high strength significantly improves the tensile strength of the wall fabric. However, due to the differences in the solubility and compatibility of polymer fibers, the use of glass fibers reduces the solubility of the fiber solution, and the effective content of glass fibers in the modified fibers obtained by electrospinning is low, resulting in a low overall mechanical property of the wall fabric and reducing the air permeability of the wall fabric at the same time; it can be seen from the results of Examples 1, 5-7 that as the amount of modified fibers increases, the tensile strength of the wall fabric gradually increases, but the air permeability shows a gradually decreasing trend. The introduction of excessive nylon fibers leads to a decrease in the compatibility of the modified fibers, and the bonding force decreases during the curing process with the non-woven fabric, further reducing the mechanical properties of the wall fabric; it can be seen from the results of Examples 1, 8-11 that the change in the amount of cotton fibers and PET fibers has a significant impact on the mechanical properties and air permeability of the wall fabric; cotton fibers have high flexibility and air permeability, PET fibers have excellent strength and air permeability, and at the same time, they can improve the compatibility with the non-woven fabric matrix, increasing the bonding strength. By controlling the mass ratio of cotton fibers and PET fibers, the high strength of the wall fabric can be effectively maintained while improving the air permeability; it can be seen from the results of Examples 1, 12-13 that with the change in the organic solvent ratio, the impact on the tensile strength is small, but the increase in DMF improves the dissolution of cellulose, resulting in a significant improvement in the air permeability of the wall fabric.

[0057] Examples 15-24 Refer to the preparation method and parameter conditions of Example 1, with the differences shown in Table 3.

[0058] Table 3 Parameter changes in Examples 15-24

[0059]

[0060] Comparative Example 4 Refer to the preparation steps and parameter conditions of Example 1, with the difference that electrospinning is not used to prepare nanofibers, and conventional warp knitting, weft knitting or knitting methods are used to obtain fiber materials.

[0061] Comparative Example 5 Referring to the preparation steps and parameter conditions of Example 17, the difference is that only DMF is used as the organic solvent.

[0062] Comparative Example 6 Referring to the preparation steps and parameter conditions of Example 17, the difference is that only ethanol is used as the organic solvent.

[0063] Example 25 Measurement of air permeability

[0064] The wall fabrics prepared in Examples 15 - 24 and Comparative Examples 4 - 6 were tested according to GB / T 5453—1997 "Determination of air permeability of textiles" using a YG461E-Ⅲ type automatic air permeability tester; the pressure difference of the instrument was set to 100 Pa, and multiple parts of each fabric were tested, and the average value of 5 test results was taken. At the same time, the porosity of Examples 15 - 24 and Comparative Examples 4 - 6 was measured; the porosity of nanofibers was measured by the gravimetric method. First, the mass of the nanofibers in the dry state was measured, then the nanofibers were soaked in ethanol for 1 h, and the completely permeated nanofibers were weighed after soaking. The masses of the dry nanofibers and the wet nanofibers were recorded as W1 and W2 respectively. The porosity (P) was calculated by the following formula: P = (W2 - W1) / (ρV), where ρ is the density of ethanol and V is the volume of the nanofibers; the test results are shown in Table 4.

[0065] Table 4 Measurement of air permeability of Examples 15 - 24 and Comparative Examples 4 - 6

[0066]

[0067] From the results of Comparative Example 4, it can be seen that the nanofibers prepared without using electrospinning have a small porosity, a relatively thick diameter of the fiber material, and a significant decrease in air permeability; in Comparative Examples 5-6, the nanofibers obtained using a single solvent have a low porosity and poor air permeability. Since DMF has a high solubility in the fibers, the fiber concentration in the obtained fiber solution is high, the fiber diameter becomes thicker, the fiber porosity decreases, and the air permeability weakens; at the same time, the high boiling point of DMF causes incomplete evaporation of the solvent during the receiving process, and the fibers are easily adhered to each other to form a dense film, resulting in a decrease in air permeability; using ethanol as a solvent cannot fully dissolve the fiber material, and thus fiber particles are generated, affecting the porosity of the nanofibers; from the results of Examples 15-18, it can be seen that as the size of the needle head model decreases, the air permeability shows a gradually increasing trend. Due to the decrease in the needle head model, the diameter of the obtained fiber material decreases, the free space rate increases, and the air permeability increases. However, too small a model causes a decrease in the mechanical strength of the fiber material during the injection process, affecting the overall performance of the wall covering; from the results of Example 17 and Examples 19-24, it can be seen that the change of electrospinning parameters has an obvious impact on the air permeability of the wall covering. Too fast injection rate results in an increase in fiber diameter, a decrease in fiber porosity, and a decrease in air permeability. Extending the receiving distance allows the fibers to have enough time to solidify before reaching the collector, resulting in a higher porosity and better air permeability; under high-voltage conditions, the fiber stretching is enhanced, the diameter decreases, forming finer fibers, further increasing the porosity and air permeability. However, too high a voltage will cause fiber breakage, resulting in fiber structure defects and affecting the mechanical properties of the wall covering.

[0068] Example 26

[0069] The carbon nanotubes were added to a 10% acetic acid solution and soaked for 3 h, and then washed with deionized water to obtain treated carbon nanotubes; the treated carbon nanotubes were added to a mixed solution of 50% ethanol and water to obtain a dispersion; tetraethyl titanate was dissolved in absolute ethanol to obtain a solution; acetic acid solution was added dropwise to the solution at a rate of 2 drops / second to obtain a titanium precursor solution; the dispersion was slowly added to the titanium precursor solution, and stirred at 100 r / min to mix evenly. The system was heated to 80 °C and reacted for 2 h to obtain a composite; the composite was washed with deionized water and vacuum dried for 2 h to obtain a particulate composite; the remaining preparation was carried out as in the method of Example 17.

[0070] Example 27

[0071] The carbon nanotubes were added to a 10% acetic acid solution and soaked for 3 h, and then washed with deionized water to obtain treated carbon nanotubes; the treated carbon nanotubes were added to a mixed solution of 50% ethanol and water to obtain a dispersion; tetraethyl titanate was dissolved in absolute ethanol to obtain a solution; acetic acid solution was added dropwise to the solution at a rate of 2 drops per second to obtain a titanium precursor solution; the titanium precursor solution was slowly added to the dispersion, and stirred at 100 r / min to mix evenly, and the temperature of the system was raised to 80 °C and reacted for 2 h to obtain a composite; the composite was washed with deionized water and dried in vacuum for 2 h to obtain a particulate composite; the remaining preparation was carried out as shown in the method of Example 17.

[0072] Examples 28 - 30 refer to the preparation method and parameter conditions of Example 26, and the differences are shown in Table 5.

[0073] Comparative Example 7 refers to the preparation method and parameter conditions of Example 26, except that the particulate composite is not used.

[0074] Comparative Example 8 refers to the preparation method and parameter conditions of Example 26, except that only nano - titanium dioxide is added.

[0075] Comparative Example 9 refers to the preparation method and parameter conditions of Example 26, except that only carbon nanotubes are added.

[0076] Example 31 Dust - proof performance test

[0077] The wall fabrics prepared in Examples 26 - 30 and Comparative Examples 7 - 9 were subjected to dust - proof performance test: 5 g of dry dust was evenly sprinkled on the surface of the wall fabric samples, and the dust particle size was kept at 2.5 μm - 10 μm. Then the samples were tilted by 90°, and a fan was used to blow cyclically for 1 h. The mass of the sample before the experiment was recorded as M0, the mass of the dust was recorded as M1, and the mass after tilting was recorded as M2. The formula for the dust removal rate λ is: λ = ((M0 + M1)-M2) / M1; the test results are shown in Table 5.

[0078] Table 5 Test results of Examples 26 - 30 and Comparative Examples 7 - 9

[0079]

[0080] It can be seen from the results in Table 5 that in Comparative Example 7, the composite fibers were obtained by treating nanofibers without adding particle composites, and the dust-proof performance of the prepared wall cloth decreased significantly compared with Examples 26-30. The dust removal rate was low, and dust was easily enriched on the surface of the wall cloth. At the same time, the electrostatic effect of the fibers further increased the adsorption performance of dust on the wall cloth surface. Compared with Comparative Example 7, the dust removal rates in Comparative Examples 8-9 were significantly improved, further indicating that the addition of inorganic particles can effectively reduce the dust adsorption effect of the wall cloth. From the results of Examples 26-27, since the particle size of the inorganic particles is very small, it can fill the tiny pores or roughness on the surface of the wall cloth, making the surface of the wall cloth smoother. The smooth surface can reduce the adhesion of dust and lower the probability of dust adhering to the wall cloth. At the same time, titanium dioxide particles are evenly distributed in the pores of the nanofibers, improving the binding stability between the particle composite and the composite fiber layer. The introduction of carbon nanotubes provides more polar groups, improving the binding ability between the polyurethane coating and the composite fiber layer. During the curing process, a stable three-dimensional network structure is formed. Changing the loading method of carbon nanotubes and nano-titanium dioxide will further affect the overall binding ability between the polyurethane protective layer and the composite fiber, reducing the dust-proof performance. By achieving a balance between the polyurethane protective layer on the wall cloth surface and the surface inorganic particles, the inorganic particles will not migrate and agglomerate in the composite fiber layer, further improving the dust-proof effect of the wall cloth.

[0081] Example 32

[0082] Dissolve 5 parts of KH-560 in 95% ethanol solution, adjust the pH of the system to 3 with acetic acid, and stir in a magnetic stirrer at 50 °C for 2 h to obtain a silane coupling agent solution; slowly add 30 parts of nano-silver to the silane coupling agent solution, and react at 50 °C for 2 h to obtain a modified system; dry the modified system at 100 °C for 2 h and grind for 30 min to obtain modified nano-silver.

[0083] After dehydrating 90 parts of polyether diol and 90 parts of diphenylmethane diisocyanate at 100 °C for 2 h, add them to a three-necked flask, heat up to 80 °C and stir for 30 min, add 0.03 mmol of catalyst dibutyltin dilaurate, and react for 2 h to obtain a mixed solution; cool the mixed solution to 50 °C, add a chain extender, and use 5 ml of acetone to adjust the viscosity of the system, and keep the temperature for reaction for 30 min to obtain a polyurethane prepolymer; disperse the modified nano-silver in absolute ethanol, and disperse it with a high-speed disperser for 30 min to obtain a dispersion system; under the protection of nitrogen, slowly add the dispersion system to the polyurethane prepolymer, stir and mix evenly at 50 rpm, heat up to 60 °C, and react for 2 h to obtain a mixed system; add 5 parts of antioxidant 1010, 1 part of organosilicon defoamer and 5 ml of acetone dilution to 100 parts of the mixed system, stir and disperse at 200 rpm for 30 min, and filter to obtain a polyurethane protective layer emulsion.

[0084] Examples 33 - 39 Refer to the preparation method and parameter conditions of Example 32, with the differences shown in Table 6.

[0085] Comparative Example 10 Refer to the preparation method and parameter conditions of Example 32, except that no polyurethane protective layer is added.

[0086] Comparative Example 11 Refer to the preparation method and parameter conditions of Example 32. The difference is that after the particle composite is mixed with the polyurethane protective layer emulsion, it is directly infiltrated and cured with the composite fiber.

[0087] Comparative Example 12 Refer to the preparation method and parameter conditions of Example 32, except that the hot air drying furnace drying treatment is not carried out.

[0088] Example 40 Waterproof performance test

[0089] The wall fabrics prepared in Examples 32 - 39 and Comparative Examples 10 - 12 were subjected to waterproof performance tests. The test method was carried out in accordance with GB / T 4745 - 2012 "Testing and Evaluation of Water Resistance of Textiles - Spray Test Method". At the same time, dustproof performance tests were carried out. The method referred to Example 31. The test results are shown in Table 6; among them, the waterproof grade 2 means preventing dripping when tilted at 15 degrees; grade 6 means preventing strong water flow impact; grade 7 means preventing short - time immersion; grade 8 means preventing long - time immersion.

[0090] Table 6 Test results of Examples 32 - 39 and Comparative Examples 10 - 12

[0091]

[0092] It can be seen from the results in Table 6 that the water resistance and dust-proof performance of the wall cloth prepared without the polyurethane coating protection layer in Comparative Example 10 are significantly lower than those in the examples. The addition of carbon nanotubes and nano-titanium dioxide on the surface of the composite fiber improves the hydrophilicity of the wall cloth, and water droplets can form a relatively uniform film on the surface. Utilizing the "self-cleaning" effect of inorganic particles, moisture can be more easily separated from dust, reducing dust adhesion. However, the exhibited hydrophilicity reduces the water resistance of the wall cloth and increases the difficulty in the washing and treatment processes of the wall cloth; in Comparative Example 11, the particle composite and the polyurethane protection layer are coated on the fiber surface simultaneously, which is not conducive to the bonding ability between the polyurethane protection layer and the composite fiber, and the peeling of the coating during long-term use further affects the comprehensive performance of the wall cloth material; in Comparative Example 12, the use of a hot air drying furnace is not used, and the dust-proof performance decreases; in Examples 32-37, by adjusting the type and dosage of isocyanate and using fluorinated isocyanate, as the dosage increases, the hydrophobic property gradually improves. However, the reduction of cross-linking sites during the curing process affects the formation of the three-dimensional network structure, showing a reduced dust-proof performance; the introduction of the polyurethane protection layer synergistically with the particle composite improves the dust-proof performance of the wall cloth. The low surface energy of the fluorinated isocyanate migrates to the surface of the wall cloth, increasing the contact angle on the wall cloth surface, making it difficult for dust to adhere, and gravity can carry away more dust, improving the dust removal rate; it can be seen from the results of Example 34 and Examples 38-39 that the introduction of the fluorinated chain extender can improve the hydrophobic property, but the dust removal rate decreases. Due to the large introduction of non-polar groups, the cross-linking sites decrease, the network structure is not rich during the curing process, and the dust adsorption ability increases; the synergistic use of 1,4-butanediol and 2,2-bis(4-hydroxyphenyl)hexafluoropropane can further improve the hydrophobicity and dust-proof performance of the wall cloth.

[0093] Examples 41-48 Refer to the preparation steps and parameter conditions of Example 34, with the differences shown in Table 7.

[0094] Comparative Example 13 Refer to the preparation steps and parameter conditions of Example 34, with the difference that modified nano-silver is not added.

[0095] Comparative Example 14 Refer to the preparation steps and parameter conditions of Example 34, with the difference that the nano-silver is not subjected to modification treatment.

[0096] Comparative Example 15 Refer to the preparation steps and parameter conditions of Example 34, with the difference that the modified nano-silver is added as an additive to the polyurethane coating.

[0097] Example 49 Antibacterial performance test

[0098] The wall coverings prepared in Examples 41-48 and Comparative Examples 13-15 were tested for antibacterial properties. According to the test method of GB / T 20944.3-2008, bacterial suspensions of Staphylococcus aureus and Escherichia coli were prepared. The wall coverings were cut into samples of 4 mm × 4 mm, sterilized at high temperature, and then the samples were placed in the bacterial suspension. After shaking for 10 min at 25°C, samples were taken to calculate the antibacterial rate of the samples. The test results are shown in Table 7.

[0099] Table 7 Determination of Antibacterial Properties of Examples 41-48 and Comparative Examples 13-15

[0100]

[0101] From the results in Table 7, it can be seen that the antibacterial rates of the wall coverings prepared without adding modified nano-silver in Comparative Example 13 against Staphylococcus aureus and Escherichia coli decreased significantly. The addition of nano-silver can provide a higher antibacterial rate. However, the antibacterial properties of Comparative Examples 14-15 were improved compared with Comparative Example 13, but were significantly lower than those of Examples 41-48. Due to the addition of KH-560 as a modifier, the modified nano-silver reacts with polyurethane, stably binding the nano-silver between the protective layers to prevent the nano-silver from falling off during use and thus reducing antibacterial properties. At the same time, more cross-linking sites are formed during the curing process, which is beneficial to the formation of a three-dimensional network structure, increasing the dust-proof performance of the wall covering while improving the antibacterial ability. From the results of Examples 41-45 and Examples 47-48, it can be seen that as the amount of nano-silver increases, the antibacterial properties of the wall covering gradually increase and tend to be stable. However, the addition of excessive nano-silver will further reduce the mechanical properties of the wall covering and the strength will decrease. From the results of Examples 41 and Examples 45-46, it can be seen that the change in the type of modifier affects the antibacterial properties of the wall covering. Using a silane coupling agent with polar groups can enable the modified nano-silver to react fully with polyurethane, and during the curing process, through the cross-linking effect of the polar groups, a stable three-dimensional network structure is formed while improving the antibacterial properties of the wall covering.

[0102] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A preparation method of a breathable and dust-proof wall cloth, characterized in that: The preparation of the breathable and dust-proof wall cloth includes the following steps: S1 Bond and laminate one side of the composite fiber layer with the non-woven fabric layer, and dry to obtain a composite material; S2 Coat the side of the composite material that is not bonded to the non-woven fabric layer with a polyurethane protective layer emulsion, and cure to obtain a wall cloth composite; Pass the wall cloth composite through a hot air drying furnace to obtain the breathable and dust-proof wall cloth; The composite fiber layer includes a nanofiber and particle composite; Dissolve 10 - 25 parts of cotton fiber, PET fiber, and modified fiber in a mixed solvent with a mass ratio of DMF to ethanol of 3:2, stir at 50 °C for 12 h to obtain a transparent solution; Add the transparent solution into a 10 ml medical disposable syringe, and obtain electrospun fibers by electrospinning; Dry the electrospun fibers at 60 °C for 6 h to obtain the nanofibers; The modified fiber is selected from one of nylon fiber, hemp fiber, acrylic fiber, and glass fiber; Soak carbon nanotubes in acetic acid solution, wash with deionized water to obtain treated carbon nanotubes; Add the treated carbon nanotubes into a 50% ethanol solution to obtain a dispersion; Dissolve tetraethyl titanate in absolute ethanol to obtain a solution; Dropwise add the acetic acid solution into the solution to obtain a titanium precursor solution; Add the dispersion into the titanium precursor solution, stir and mix evenly, and carry out a temperature-raising reaction to obtain a composite containing nano-titanium dioxide; Wash the composite with deionized water and vacuum dry to obtain the particle composite containing the nano-titanium dioxide; Add the particle composite into 100 mL of ethanol, ultrasonically disperse for 30 min to obtain a dispersion; Cut the nanofibers into thin slices, immerse them in the dispersion, ultrasonically treat for 10 min, and vacuum dry at 60 °C for 3 h to obtain the composite fiber layer; The non-woven fabric layer is a PET non-woven fabric; The polyurethane protective layer emulsion includes isocyanate, chain extender, and modified nano-silver; Add polyether diol and the isocyanate into a three-necked flask, heat up to 80 °C, add dibutyltin dilaurate, and react for 2 h to obtain a mixed solution; Cool the mixed solution to 50 °C, add the chain extender, adjust the system viscosity with acetone, and carry out a heat preservation reaction to obtain a polyurethane prepolymer; Disperse 8 - 25 parts of the modified nano-silver in absolute ethanol, and disperse at high speed to obtain a dispersion system; Under the protection of nitrogen, slowly add the dispersion system into the polyurethane prepolymer, stir and mix evenly, and react to obtain a mixed system; Add antioxidant 1010, silicone defoamer, and acetone dilution into the mixed system, stir and disperse, and filter to obtain the polyurethane protective layer emulsion; Dissolve the modifier in a 95% ethanol solution, adjust the pH of the system with acetic acid, and stir to obtain a silane coupling agent solution; Slowly add nano-silver into the silane coupling agent solution, and react to obtain a modified system; Dry the modified system at 100 °C for 2 h and grind to obtain the modified nano-silver; The modifier is selected from one of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, methacryloxypropyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.

2. The preparation method of a breathable and dust-proof wall cloth according to claim 1, characterized in that: The mass fraction ratio of the cotton fiber to the PET fiber is 1-3:1-7.

3. The preparation method of a breathable and dust-proof wall cloth according to claim 1, characterized in that: The injection rate of the electrospinning method is 5-15 μL / min; the receiving distance of the electrospinning method is 20-40 cm; the voltage of the electrospinning method is 8-15 KV.

4. The preparation method of a breathable and dust-proof wall cloth according to claim 1, characterized in that: The mass fraction ratio of the carbon nanotubes to the nano-titanium dioxide in the particle composite is 1-3:1-2.

5. The preparation method of a breathable and dust-proof wall cloth according to claim 1, characterized in that: The isocyanate is selected from one of toluene diisocyanate, hexamethylene diisocyanate, and tridecafluoro isocyanate; the chain extender is a mixture of 2,2-bis(4-hydroxyphenyl)hexafluoropropane and 1,4-butanediol in a mass fraction ratio of 1:1; the -NCO / -OH molar ratio in the polyurethane prepolymer is 0.8-1.5:

1.

6. The preparation method of a breathable and dust-proof wall cloth according to claim 1, characterized in that: The mass fraction ratio of the modifier to the nano-silver is 1:5-8.

7. An air-permeable and dust-proof wall cloth prepared by the method according to claim 1, characterized in that: The breathable dust-proof wall cloth comprises a polyurethane protective layer, a composite fiber layer, and a PET non-woven fabric layer from top to bottom in sequence.

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