A colored passive radiation cooling coating fabric and preparation method thereof

Abstract

The present invention discloses a colored passive radiation cooling coating fabric, comprising a fiber fabric and a daytime passive radiation coating and a modified organic pigment coating sequentially coated on the surface of the fiber fabric; the daytime passive radiation coating is an inorganic nanoparticle coating; the inorganic particle coating has high reflectivity to visible light-near infrared sunlight and high emissivity in an atmospheric window of 8 to 13 μm. The present invention also discloses a method for preparing a colored passive radiation cooling fabric. The colored passive radiation cooling coating fabric of the present invention is obtained by composite assembly of multiple functional coatings, so that ordinary fiber fabrics have excellent high reflection of visible-near infrared sunlight and strong radiation of infrared in an atmospheric window (8 to 13 μm), thereby realizing efficient radiation cooling under sunlight. At the same time, the outermost colored coating gives the fiber fabric a color effect, and its application range is wider.

Description

Technical Field

[0001] The invention relates to the technical field of passive radiation refrigeration materials, and in particular to a colored passive radiation refrigeration coating fabric and a preparation method thereof. Background Art

[0002] Faced with the increasing demand for cooling and energy consumption, a method is urgently needed to solve the problem. Radiative cooling is a method that can achieve passive radiation cooling without external energy input and by utilizing the characteristics of the material itself. Daytime passive radiation cooling materials utilize their high reflectivity to sunlight and high mid-infrared emissivity in the atmospheric window (8~13 μm) to transfer heat from the atmospheric window to outer space by radiation, thereby achieving a cooling effect without any energy input. This material has great potential in energy saving. If it can be industrialized, it will greatly reduce energy consumption for cooling.

[0003] In the current research on daytime passive radiation cooling materials, in order to ensure that the materials have high reflectivity to sunlight, the cooling materials are designed to be white, but for aesthetic reasons, pure white cannot meet the practical application in real life. More importantly, there are still limited examples of colored daytime passive radiation cooling used in fabrics, and existing research mainly focuses on the following aspects:

[0004] 1) Combine colored inorganic pigment coating with polymer layer to realize multi-layer structure. The inorganic pigment colored coating provides color, and the polymer layer improves reflectivity and emissivity by adjusting the microstructure, such as introducing multi-sized holes in the polymer layer. The inorganic pigment coating with this structure will absorb light in the visible light band to generate radiation energy, and will also absorb part of the radiation energy in the infrared band, reducing the overall cooling power.

[0005] 2) Using structural colors, colors are generated through the interaction of special structures with natural light (scattering, interference, diffraction, etc.). Although structural colors can avoid absorbing light and generating radiation energy, compared with the colors produced by pigments, structural colors are extremely light and far less saturated, which limits the practical application of structural colors.

[0006] The Chinese patent document with publication number CN111155332A discloses a radiative cooling passive cooling fabric, which is constructed by magnetron sputtering a high reflective layer (silver layer or aluminum layer) and coating a layer of silica microspheres on both sides of the ordinary fiber fabric to construct a multi-layer structure, and realizes the passive radiative cooling function of the fiber fabric through the synergistic effect of the multi-layer structure. Compared with ordinary fabrics, this fabric can reduce 1~5℃, but the magnetron sputtered silver layer increases its cost, and the color is only monotonous white, which cannot meet daily needs.

[0007] The Chinese patent document with publication number CN111996679A discloses a colorful radiation cooling flexible composite film, which prepares a polymer fiber film by electrospinning, doped with inorganic pigments and phase change microcapsules, and achieves a relative cooling effect of up to 10°C through the synergistic effect of phase change heat absorption and radiation cooling of the phase change microcapsules. However, the cost of using the phase change microcapsules is increased, and the invention adopts the electrospinning method, which is not universal for ordinary fiber fabrics. Summary of the invention

[0008] The present invention provides a colored passive radiation cooling coating fabric and a preparation method thereof, which overcomes the problems of monotonous color, complex preparation method, high cost and the like in the prior art, and is conducive to the industrial application of colored passive radiation cooling coating fabric.

[0009] The specific technical solutions of the present invention are as follows:

[0010] A colored passive radiation cooling coating fabric comprises a fiber fabric and a daytime passive radiation coating and a modified organic pigment coating sequentially coated on the surface of the fiber fabric;

[0011] The daytime passive radiation coating is an inorganic nanoparticle coating; the inorganic particle coating has high reflectivity to visible light-near infrared sunlight and high emissivity in the 8-13 μm atmospheric window.

[0012] Preferably, the preparation method of the modified organic pigment is:

[0013] (i) adding a dispersant to water and adjusting the pH value thereof to 6.5-8.5, then adding organic pigment particles, and mixing by ultrasonication to obtain an aqueous phase;

[0014] (ii) uniformly mixing the polymer monomer and the co-emulsifier to obtain an oil phase;

[0015] (iii) mixing the aqueous phase and the oil phase and ultrasonicating them, adding an aqueous initiator solution dropwise to the mixed system, and reacting at 70-75° C. to obtain a modified organic pigment.

[0016] The polymer monomer is at least one of butyl acrylate (BA), methyl methacrylate (MMA) and styrene; and the solvent is n-hexadecane or n-hexadecanol.

[0017] Further preferably, the polymer monomers are butyl acrylate and methyl methacrylate, and the mass ratio of butyl acrylate to methyl methacrylate is 1:1; based on the mass of the polymer monomers, the amount of the co-emulsifier added is 1.5%.

[0018] The modified organic pigment is a composite particle of an organic pigment wrapped in a polymer. The butyl acrylate, methyl methacrylate or styrene chain segments that constitute the outer shell layer of the composite particles contain abundant CO, CH and C=O groups. The stretching vibration of its molecular structure is within the mid-infrared wavelength range, so it can generate strong infrared radiation, which helps to increase the infrared emissivity of the fabric at the atmospheric window.

[0019] The organic pigment particles are at least one of phthalocyanine blue BGS, benzidine yellow 1138 and permanent red F3RK. The organic pigment has high reflectivity.

[0020] Preferably, the coating amount of the modified organic pigment coating is 0.02-0.03 mg / cm 2 .

[0021] The particle size distribution of the inorganic nanoparticles is nanometer-level, the sunlight reflectivity thereof is above 90%, and the mid-infrared radiation rate thereof is above 85%.

[0022] Preferably, the inorganic nanoparticles are at least one of silicon dioxide, titanium dioxide, aluminum oxide, aluminum phosphate, and barium sulfate particles.

[0023] The binding force between inorganic particles and fabrics is very weak. In order to improve the binding strength between inorganic nanoparticles and fabrics, preferably, the preparation method of the daytime passive radiation coating includes:

[0024] The adhesive polydimethylsiloxane (PDMS) is dissolved in an organic solvent, and then inorganic nanoparticles are dispersed therein and stirred to obtain an inorganic nanoparticle dispersion; the inorganic nanoparticle dispersion is sprayed on the fabric and dried to obtain a daytime passive radiation coating.

[0025] The present invention utilizes PDMS to combine inorganic nanoparticles onto fabrics, which can not only improve the adhesion strength of the inorganic nanoparticles but also make the fabrics have a certain waterproof effect.

[0026] The mass ratio of the binder to the organic solvent is 1:50-100.

[0027] The organic solvent is tetrahydrofuran.

[0028] In the inorganic nanoparticle dispersion, the mass fraction of the inorganic nanoparticles is 5-20%.

[0029] Further preferably, in the inorganic nanoparticle dispersion, the mass fraction of the inorganic nanoparticles is 10-15%.

[0030] Preferably, the mass ratio of the daytime passive radiation coating to the fiber fabric is 1:0.5-1.5.

[0031] The fiber fabric is cotton fabric, polyester fabric, spandex fabric, nylon fabric, polyester fiber fabric and the like.

[0032] The present invention also provides a method for preparing the above-mentioned colored passive radiation cooling coating fabric, comprising the following steps:

[0033] (1) dissolving the adhesive polydimethylsiloxane (PDMS) into an organic solvent, dispersing the inorganic nanoparticles therein, and stirring to obtain an inorganic nanoparticle dispersion;

[0034] The inorganic nanoparticle dispersion is coated on the fiber fabric and dried to obtain a daytime passive radiation coating;

[0035] (2) Spraying the modified organic pigment solution onto the daytime passive radiation coating and drying it to obtain the colorful passive radiation refrigeration coating fabric.

[0036] In the inorganic particle dispersion of step (1), the mass fraction of the inorganic nanoparticles is 5-20%; based on the mass of the inorganic nanoparticles, the amount of polydimethylsiloxane added is 10-20%.

[0037] By adding different mass fractions of inorganic particles into the inorganic nanoparticle dispersion, under the same fabric treatment conditions, the coating amount of the radiant cooling fabric finally prepared is different, thus affecting its passive radiant cooling effect.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The colored passive radiation cooling coating fabric provided by the present invention is obtained by composite assembly of multiple functional coatings, so that ordinary fiber fabrics have excellent visible-near infrared sunlight high reflection and strong infrared radiation in the atmospheric window (8-13 μm), thereby realizing efficient radiation cooling under sunlight. At the same time, the outermost organic pigment coating makes the fiber fabric have richer colors, does not require a highly reflective silver layer, has lower cost, and has a wider range of applications.

[0040] The invention has low cost and simple operation, realizes radiation cooling on a color basis, and has great significance in the field of energy conservation and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is the visible-near infrared reflection spectrum of the colored passive radiation cooling coated fabric in Example 1;

[0042] Figure 2 is a SEM image of the colored passive radiation cooling coating in Example 1;

[0043] Figure 3This is a temperature reduction comparison curve diagram obtained by the simulation device for the colored passive radiation cooling coating fabric in Example 1. DETAILED DESCRIPTION

[0044] In the following examples, the modified organic pigment used was prepared by the following preparation process:

[0045] According to the corresponding ratio, the oil phase containing the polymer and the water phase containing the dispersant and the pigment are accurately prepared, mixed, ultrasonically dispersed for 25 minutes using a cell crusher, and then an initiator is added to carry out a polymerization reaction at 75°C to obtain an organic pigment composite particle suspension.

[0046] Example 1

[0047] A colored passive radiation cooling coating fabric is prepared by the following steps:

[0048] 1) According to the following weight ratio, 25 parts of butyl acrylate, 25 parts of methyl methacrylate, and 0.75 parts of n-hexadecane are mixed as an oil phase; 0.5 parts of DNS-86 dispersant are added to 450 parts of deionized water, and then 0.8 parts of sodium bicarbonate are added; the water phase and the oil phase are mixed, ultrasonicated for 20 minutes, and then 0.8 parts of potassium persulfate are added, and a polymerization reaction is carried out at 75°C for 2 hours to obtain an organic pigment composite particle suspension.

[0049] 2) Take 1 part of PDMS and add it to 50 parts of tetrahydrofuran and mix well. Then add 10 parts of silica particles and stir to mix well.

[0050] 3) The cotton fabric is immersed in the inorganic particle suspension in step 2) for 2-3 times and dried, and then the organic pigment composite particle suspension in step 1) is sprayed on the fabric for 1-2 times and dried to obtain a colored passive radiation cooling coating fabric.

[0051] Figure 1 The reflectance spectrum of the colored passive radiation cooling coating fabric in Example 1 in the visible-near infrared band under an ultraviolet spectrophotometer. The colored fabric absorbs sunlight of a specific wavelength in the visible light band to present a colorful appearance, and still has a high reflectance in the near-infrared band to ensure a good radiation cooling effect;

[0052] Figure 2 This is a microscopic structure of the surface of the colored passive radiation cooling coating in Example 1 under a desktop scanning electron microscope. It can be observed that the inorganic particles are fixed on the fabric by the polymer, and the organic pigments are attached to the surface of the particles;

[0053] Figure 3This is a temperature reduction comparison curve of the colored passive radiation cooling coated fabric in Example 1 under a simulated light source. It can be seen from the figure that the colored passive radiation cooling fabric has an excellent cooling effect.

[0054] Example 2

[0055] A colored passive radiation cooling coating fabric is prepared by the following steps:

[0056] 1) According to the following weight ratio, 25 parts of butyl acrylate, 25 parts of styrene, and 0.75 parts of n-hexadecane are mixed as the oil phase; 0.5 parts of DNS-86 dispersant are added to 450 parts of deionized water, and then 0.8 parts of sodium bicarbonate are added; the water phase and the oil phase are mixed, ultrasonicated for 20 minutes, and then 0.8 parts of potassium persulfate are added, and a polymerization reaction is carried out at 75°C for 2 hours to obtain an organic pigment composite particle suspension.

[0057] 2) Take 1 part of PDMS and add it to 50 parts of tetrahydrofuran and mix well. Then add 10 parts of silica particles and stir to mix well.

[0058] 3) The cotton fabric is immersed in the inorganic particle suspension in step 2) for 2-3 times and dried, and then the organic pigment composite particle suspension in step 1) is sprayed on the fabric for 1-2 times and dried to obtain a colored passive radiation cooling coating fabric.

[0059] Example 3

[0060] A colored passive radiation cooling coating fabric is prepared by the following steps:

[0061] 1) According to the following weight ratio, 25 parts of styrene, 25 parts of methyl methacrylate, and 0.75 parts of n-hexadecane are mixed as an oil phase; 0.5 parts of DNS-86 dispersant are added to 450 parts of deionized water, and then 0.8 parts of sodium bicarbonate are added; the water phase and the oil phase are mixed, ultrasonicated for 20 minutes, and then 0.8 parts of potassium persulfate are added, and a polymerization reaction is carried out at 75°C for 2 hours to obtain an organic pigment composite particle suspension.

[0062] 2) Take 1 part of PDMS and add it to 50 parts of tetrahydrofuran and mix well. Then add 10 parts of silica particles and stir to mix well.

[0063] 3) The cotton fabric is immersed in the inorganic particle suspension in step 2) for 2-3 times and dried, and then the organic pigment composite particle suspension in step 1) is sprayed on the fabric for 1-2 times and dried to obtain a colored passive radiation cooling coating fabric.

[0064] Example 4

[0065] A colored passive radiation cooling coating fabric is prepared by the following steps:

[0066] 1) According to the following weight ratio, 25 parts of butyl acrylate, 25 parts of methyl methacrylate, and 0.75 parts of n-hexadecane are mixed as an oil phase; 0.5 parts of DNS-86 dispersant are added to 450 parts of deionized water, and then 0.8 parts of sodium bicarbonate are added; the water phase and the oil phase are mixed, ultrasonicated for 20 minutes, and then 0.8 parts of potassium persulfate are added, and a polymerization reaction is carried out at 75°C for 2 hours to obtain an organic pigment composite particle suspension.

[0067] 2) Take 1 part of PDMS and add it to 50 parts of tetrahydrofuran and mix well. Then add 10 parts of silica particles and stir to mix well.

[0068] 3) Immerse the nylon fabric in the inorganic particle suspension in step 2) for 2-3 times and dry it, then spray the organic pigment composite particle suspension in step 1) onto the fabric for 1-2 times and dry it to obtain the colored passive radiation cooling coating fabric.

[0069] Example 5

[0070] A colored passive radiation cooling coating fabric is prepared by the following steps:

[0071] 1) According to the following weight ratio, 25 parts of butyl acrylate, 25 parts of methyl methacrylate, and 0.75 parts of n-hexadecane are mixed as an oil phase; 0.5 parts of DNS-86 dispersant are added to 450 parts of deionized water, and then 0.8 parts of sodium bicarbonate are added; the water phase and the oil phase are mixed, ultrasonicated for 20 minutes, and then 0.8 parts of potassium persulfate are added, and a polymerization reaction is carried out at 75°C for 2 hours to obtain an organic pigment composite particle suspension.

[0072] 2) Take 1 part of PDMS and add it to 50 parts of tetrahydrofuran and mix well. Then add 10 parts of silica particles and stir to mix well.

[0073] 3) Immerse the polyester fabric in the inorganic particle suspension in step 2) for 2-3 times and dry it, then spray the organic pigment composite particle suspension in step 1) onto the fabric for 1-2 times and dry it to obtain the colored passive radiation cooling coating fabric.

[0074] Example 6

[0075] A colored passive radiation cooling coating fabric is prepared by the following steps:

[0076] 1) According to the following weight ratio, 25 parts of butyl acrylate, 25 parts of methyl methacrylate, and 0.75 parts of n-hexadecane are mixed as an oil phase; 0.5 parts of DNS-86 dispersant are added to 450 parts of deionized water, and then 0.8 parts of sodium bicarbonate are added; the water phase and the oil phase are mixed, ultrasonicated for 20 minutes, and then 0.8 parts of potassium persulfate are added, and a polymerization reaction is carried out at 75°C for 2 hours to obtain an organic pigment composite particle suspension.

[0077] 2) Take 1 part of PDMS and add it to 50 parts of tetrahydrofuran and mix well. Then add 10 parts of silica particles and stir to mix well.

[0078] 3) Immerse the acrylic fabric in the inorganic particle suspension in step 2) for 2-3 times and dry it, then spray the organic pigment composite particle suspension in step 1) onto the fabric for 1-2 times and dry it to obtain the colored passive radiation cooling coating fabric.

[0079] Example 7

[0080] A colored passive radiation cooling coating fabric is prepared by the following steps:

[0081] 1) According to the following weight ratio, 25 parts of butyl acrylate, 25 parts of methyl methacrylate, and 0.75 parts of n-hexadecane are mixed as an oil phase; 0.5 parts of DNS-86 dispersant are added to 450 parts of deionized water, and then 0.8 parts of sodium bicarbonate are added; the water phase and the oil phase are mixed, ultrasonicated for 20 minutes, and then 0.8 parts of potassium persulfate are added, and a polymerization reaction is carried out at 75°C for 2 hours to obtain an organic pigment composite particle suspension.

[0082] 2) Take 1 part of PDMS and add it to 50 parts of tetrahydrofuran and mix well. Then add 10 parts of silica particles and stir to mix well.

[0083] 3) The spandex fabric is immersed in the inorganic particle suspension in step 2) for 2-3 times and dried, and then the organic pigment composite particle suspension in step 1) is sprayed on the fabric for 1-2 times and dried to obtain a colored passive radiation cooling coating fabric.

[0084] Example 8

[0085] A colored passive radiation cooling coating fabric is prepared by the following steps:

[0086] 1) According to the following weight ratio, 25 parts of butyl acrylate, 25 parts of methyl methacrylate, and 0.75 parts of n-hexadecane are mixed as an oil phase; 0.5 parts of DNS-86 dispersant are added to 450 parts of deionized water, and then 0.8 parts of sodium bicarbonate are added; the water phase and the oil phase are mixed, ultrasonicated for 20 minutes, and then 0.8 parts of potassium persulfate are added, and a polymerization reaction is carried out at 75°C for 2 hours to obtain an organic pigment composite particle suspension.

[0087] 2) Take 1 part of PDMS and add it to 50 parts of tetrahydrofuran and mix well. Then add 10 parts of titanium dioxide particles and stir to mix well.

[0088] 3) The cotton fabric is immersed in the inorganic particle suspension in step 2) for 2-3 times and dried, and then the organic pigment composite particle suspension in step 1) is sprayed on the fabric for 1-2 times and dried to obtain a colored passive radiation cooling coating fabric.

[0089] Example 9

[0090] A colored passive radiation cooling coating fabric is prepared by the following steps:

[0091] 1) According to the following weight ratio, 25 parts of butyl acrylate, 25 parts of methyl methacrylate, and 0.75 parts of n-hexadecane are mixed as an oil phase; 0.5 parts of DNS-86 dispersant are added to 450 parts of deionized water, and then 0.8 parts of sodium bicarbonate are added; the water phase and the oil phase are mixed, ultrasonicated for 20 minutes, and then 0.8 parts of potassium persulfate are added, and a polymerization reaction is carried out at 75°C for 2 hours to obtain an organic pigment composite particle suspension.

[0092] 2) Take 1 part of PDMS and add it to 50 parts of tetrahydrofuran and mix well. Then add 10 parts of alumina particles and stir to mix well.

[0093] 3) The cotton fabric is immersed in the inorganic particle suspension in step 2) for 2-3 times and dried, and then the organic pigment composite particle suspension in step 1) is sprayed on the fabric for 1-2 times and dried to obtain a colored passive radiation cooling coating fabric.

[0094] Example 10

[0095] A colored passive radiation cooling coating fabric is prepared by the following steps:

[0096] 1) According to the following weight ratio, 25 parts of butyl acrylate, 25 parts of methyl methacrylate, and 0.75 parts of n-hexadecane are mixed as an oil phase; 0.5 parts of DNS-86 dispersant are added to 450 parts of deionized water, and then 0.8 parts of sodium bicarbonate are added; the water phase and the oil phase are mixed, ultrasonicated for 20 minutes, and then 0.8 parts of potassium persulfate are added, and a polymerization reaction is carried out at 75°C for 2 hours to obtain an organic pigment composite particle suspension.

[0097] 2) Take 1 part of PDMS and add it to 50 parts of tetrahydrofuran and mix well. Then add 10 parts of silicon nitride particles and stir to mix well.

[0098] 3) The cotton fabric is immersed in the inorganic particle suspension in step 2) for 2-3 times and dried, and then the organic pigment composite particle suspension in step 1) is sprayed on the fabric for 1-2 times and dried to obtain a colored passive radiation cooling coating fabric.

[0099] Embodiment 11

[0100] A colored passive radiation cooling coating fabric is prepared by the following steps:

[0101] 1) According to the following weight ratio, 25 parts of butyl acrylate, 25 parts of methyl methacrylate, and 0.75 parts of n-hexadecane are mixed as an oil phase; 0.5 parts of DNS-86 dispersant are added to 450 parts of deionized water, and then 0.8 parts of sodium bicarbonate are added; the water phase and the oil phase are mixed, ultrasonicated for 20 minutes, and then 0.8 parts of potassium persulfate are added, and a polymerization reaction is carried out at 75°C for 2 hours to obtain an organic pigment composite particle suspension.

[0102] 2) Take 1 part of PDMS and add it to 50 parts of tetrahydrofuran and mix well. Then add 10 parts of aluminum phosphate particles and stir to mix well.

[0103] 3) The cotton fabric is immersed in the inorganic particle suspension in step 2) for 2-3 times and dried, and then the organic pigment composite particle suspension in step 1) is sprayed on the fabric for 1-2 times and dried to obtain a colored passive radiation cooling coating fabric.

[0104] Example 12

[0105] A colored passive radiation cooling coating fabric is prepared by the following steps:

[0106] 1) According to the following weight ratio, 25 parts of butyl acrylate, 25 parts of methyl methacrylate, and 0.75 parts of n-hexadecane are mixed as an oil phase; 0.5 parts of DNS-86 dispersant are added to 450 parts of deionized water, and then 0.8 parts of sodium bicarbonate are added; the water phase and the oil phase are mixed, ultrasonicated for 20 minutes, and then 0.8 parts of potassium persulfate are added, and a polymerization reaction is carried out at 75°C for 2 hours to obtain an organic pigment composite particle suspension.

[0107] 2) Take 1 part of PDMS and add it to 50 parts of tetrahydrofuran and mix well. Then add 10 parts of barium sulfate particles and stir to mix well.

[0108] 3) The cotton fabric is immersed in the inorganic particle suspension in step 2) for 2-3 times and dried, and then the organic pigment composite particle suspension in step 1) is sprayed on the fabric for 1-2 times and dried to obtain a colored passive radiation cooling coating fabric.

[0109] The colored passive radiation cooling coating fabrics prepared in Examples 2-12 have a similar cooling effect as that in Example 1.

[0110] The embodiments described above provide a detailed description of the technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, supplements and equivalent substitutions made within the scope of the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A colored passive radiation cooling coating fabric, characterized in that: The invention comprises a fiber fabric and a daytime passive radiation coating and a modified organic pigment coating sequentially coated on the surface of the fiber fabric; the coating amount of the modified organic pigment coating is 0.02-0.03 mg / cm 2 ; The daytime passive radiation coating is an inorganic nanoparticle coating; The method for preparing the colored passive radiation cooling coating fabric comprises the following steps: (1) dissolving the adhesive polydimethylsiloxane in an organic solvent, dispersing the inorganic nanoparticles therein, and stirring to obtain an inorganic nanoparticle dispersion; The inorganic nanoparticle dispersion is coated on the fiber fabric and dried to obtain a daytime passive radiation coating; (2) spraying the modified organic pigment solution on the daytime passive radiation coating and drying it to obtain the colored passive radiation refrigeration coating fabric; The preparation method of the modified organic pigment is: (i) adding a dispersant to water and adjusting its pH value to 6.5-8.5, then adding organic pigment particles, and mixing uniformly by ultrasonication to obtain an aqueous phase; the organic pigment particles are at least one of phthalocyanine blue BGS, benzidine yellow 1138, and permanent red F3RK; (ii) uniformly mixing a polymer monomer and a co-emulsifier long-chain alkane to obtain an oil phase; the polymer monomer is at least one of butyl acrylate, methyl methacrylate, and styrene; the co-emulsifier is n-hexadecane or n-hexadecanol; (iii) mixing the aqueous phase and the oil phase and ultrasonicating, adding an initiator aqueous solution dropwise to the mixed system, and reacting at 70-75° C. to obtain a modified organic pigment; The inorganic nanoparticles have a particle size distribution of nanometer level, a solar reflectivity of more than 90%, and a mid-infrared radiation rate of more than 85%; the inorganic nanoparticles are at least one of silicon dioxide, titanium dioxide, aluminum oxide, aluminum phosphate, and barium sulfate particles; The mass ratio of the daytime passive radiation coating to the fiber fabric is 1:0.5~1.

5.

2. The colored passive radiation cooling coating fabric according to claim 1, characterized in that: The fiber fabric is cotton fabric, polyester fabric, spandex fabric, nylon fabric or polyester fiber fabric.

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