A dye bath composition for photonic crystal pigments and a coloring method thereof

Abstract

This invention belongs to the field of materials technology, specifically relating to a dye bath composition for photonic crystal pigments and its coloring method. The dye bath composition for photonic crystal pigments includes water, an organic solvent, a surfactant, and a solvent dye. This dye bath composition can penetrate into the interstitial layer of the photonic crystal pigment, thereby achieving secondary coloring of the photonic crystal pigment and imparting stronger hiding power and richer multi-angle colors. This invention also provides a method for secondary coloring of photonic crystal pigments using the above-mentioned dye bath composition. This coloring method has the advantages of high coloring efficiency, uniform coloring, and simple operation, enabling rapid, large-scale coloring processing in industrial applications.

Description

Technical Field

[0001] This invention belongs to the field of materials technology, specifically relating to a dye bath composition for photonic crystal pigments and its coloring method. Background Technology

[0002] The color of matter is mainly divided into chemical color and structural color. Chemical color is produced by pigments in a substance through chromophores, while structural color is achieved through its internal microstructure. Structural color is ubiquitous in nature, such as in butterfly wings and peacock feathers. When the internal microstructure of a substance is disordered, light is mainly scattered; when the internal microstructure is ordered, diffraction or interference (Bragg diffraction) mainly occurs, forming structural color. Through further design, by creating a refractive index difference within the microstructure, structural colors that vary with angle can be obtained, the so-called iridescent colors (rainbow colors).

[0003] The rainbow effect generated by the Bragg diffraction principle is used to create iridescent films, which have many advantages such as vibrant colors and environmental friendliness, and are widely used in decoration and packaging. Technologies that can be used to manufacture iridescent films include multilayer coating, multilayer co-extrusion, liquid crystal polymerization, photonic crystals, nanoimprinting, and laser engraving.

[0004] Photonic crystals are formed by the three-dimensional orderly arrangement of microspheres. When light is incident on a photonic crystal, due to its periodic structure, the light undergoes diffraction or interference, thus reflecting light of a specific wavelength, known as Bragg reflection. Furthermore, as the size of the microspheres and the lattice spacing change, the photonic crystal can reflect light from the ultraviolet to the infrared band. When the reflected wavelength is within the visible light range, it can produce iridescent colors as a structural color. The reflectivity changes with variations in the refractive index of the microsphere material and the number of periodic structural layers. By processing the microspheres onto thin films and crystallizing them through self-assembly, bending-induced oscillation shearing, and other techniques, iridescent thin films (photonic crystal thin films) are formed.

[0005] Oligomers and monomers are added to a microsphere emulsion to fill the gaps between microspheres, and the crystalline arrangement of the microspheres is fixed by adding a photoinitiator to initiate cross-linking of the oligomers and monomers, thereby obtaining a photonic crystal film (e.g., Chinese invention patent CN111363393B). After pulverization, a photonic crystal pigment can be obtained.

[0006] Due to their microsphere material and crystalline arrangement, photonic crystal pigments can form narrow and deep reflectance spectral curves, thus possessing high saturation and high transmittance that ordinary pigments or dyes do not have. Correspondingly, the high transmittance also brings the disadvantages of low reflectance and low hiding power. Therefore, in the fields of inks, coatings, and plastics, simply mixing photonic crystal pigments with organic pigments or dyes with strong hiding power often results in the color of the photonic crystal pigments being masked by the pigments, thus failing to fully present their dazzling visual effect. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the first objective of this invention is to provide a dye bath composition for photonic crystal pigments. In the presence of water, solvent, and surfactant, the pigment in this composition can penetrate into the interstitial layer of the photonic crystal pigment, forming a more complex superposition of the absorption colors of the photonic crystal, Bragg diffraction, and dye. This achieves secondary coloring of the photonic crystal pigment, giving it stronger hiding power and richer multi-angle colors.

[0008] The second objective of this invention is to provide a coloring method for a dye bath composition for photonic crystal pigments, which has the advantages of high coloring efficiency, uniform coloring, and simple operation.

[0009] To achieve the first objective of this invention, the following technical solution is adopted:

[0010] A dye bath composition for photonic crystal pigments, comprising water, an organic solvent, a surfactant, and a solvent dye.

[0011] Preferably, the photonic crystal pigment dye bath composition comprises the following components in parts by weight: 20-80 parts water, 20-80 parts organic solvent, 0.1-1 parts surfactant, and 0.1-5 parts solvent dye.

[0012] Preferably, the surfactant includes at least one of anionic surfactant, cationic surfactant, and nonionic surfactant.

[0013] More preferably, the surfactant includes at least one of alkylphenol polyoxyethylene ether nonionic surfactants and fluorocarbon nonionic surfactants.

[0014] More preferably, the surfactant is an alkylphenol polyoxyethylene ether nonionic surfactant, including nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, dodecyl polyoxyethylene ether, dinonylphenol polyoxyethylene ether, etc.

[0015] Most preferably, the surfactant is polyethylene glycol octylphenyl ether.

[0016] Preferably, the mass ratio of the solvent dye to the surfactant is greater than 1:1.

[0017] Preferably, the organic solvent includes at least one of ethanol, ethylene glycol, propylene glycol, glycerol, ethylene glycol methyl ether, propylene glycol methyl ether, ethylene glycol butyl ether, dimethylformamide, dimethylacetamide, and N-methylpyrrolidone.

[0018] Preferably, the solvent dye includes at least one of the following: metal complex dyes, anthraquinone dyes, azo dyes, phthalocyanine dyes, quinoline dyes, pyrene dyes, cyanine dyes, indigo dyes, nitroso dyes, nitro dyes, sulfur dyes, arylmethane dyes, quinone imine dyes, copper hydroxyl dyes, and flavonoid dyes.

[0019] To achieve the second objective of this invention, this invention provides a secondary coloring method for photonic crystal pigments (i.e., a coloring method using the above-mentioned photonic crystal pigment dye bath composition), comprising the following steps: adding the photonic crystal pigment to the above-mentioned photonic crystal pigment dye bath composition for coloring treatment, followed by filtration, washing with water and drying, thereby achieving secondary coloring treatment of the photonic crystal pigment.

[0020] Specifically, the above method includes the following steps:

[0021] Step 1: Mix and stir water, organic solvent, surfactant and solvent dye to dissolve them, and prepare the dye bath composition for photonic crystal pigments;

[0022] Step 2: The prepared photonic crystal pigment is heated to a certain temperature using a dye bath composition; under stirring conditions, the photonic crystal pigment is added to the heated dye bath composition for secondary coloring treatment; then it is filtered, washed with water and dried to obtain the secondary colored photonic crystal pigment.

[0023] Preferably, the temperature of the above-mentioned photonic crystal pigment dye bath composition is controlled at 25-99°C before the photonic crystal pigment is added.

[0024] Preferably, the photonic crystal pigment is added to the dye bath composition for coloring treatment for 20-30 minutes.

[0025] Preferably, the photonic crystal pigment is a composition formed by orderly arranged nanospheres with gaps filled by an acrylate polymer. The photonic crystal pigment can be prepared using some publicly available techniques in the art, such as the method disclosed in Chinese patent application CN117534796A.

[0026] More preferably, the nanospheres are selected from at least one of polymer microspheres, inorganic microspheres, and polymer-inorganic composite microspheres; the polymer microspheres include at least one of polystyrene microspheres and core-shell structured polymer microspheres, and the inorganic microspheres include at least one of silicon dioxide, titanium dioxide, iron tetroxide, and zinc sulfide;

[0027] The average particle size of the nanospheres is 100-400 nm, and the polydispersity index (PDI) is less than 0.15.

[0028] The acrylate polymer is formed by the polymerization of at least one of (meth)acrylate monomers and (meth)acrylate oligomers through thermal or photoinitiation.

[0029] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0030] 1. This invention provides a dye bath composition for photonic crystal pigments. In the presence of water, solvent and surfactant, the pigment in the dye bath composition can penetrate into the interstitial layer of the photonic crystal pigment, forming a more complex superposition of the absorption colors of the photonic crystal, Bragg diffraction and dye, thereby realizing secondary coloring of the photonic crystal pigment, giving the photonic crystal pigment stronger hiding power and richer multi-angle colors.

[0031] 2. The present invention also provides a method for secondary coloring of photonic crystal pigments using the above-mentioned dye bath composition for photonic crystal pigments. This coloring method has the advantages of high coloring efficiency, uniform coloring, and simple operation, and can realize rapid and large-scale coloring processing in industry. Attached Figure Description

[0032] Figure 1 A 500x microscope image of the photonic crystal pigment with black, green and blue colors prepared in Example 1;

[0033] Figure 2 A 500x microscope image of the photonic crystal pigment prepared in Comparative Example 1;

[0034] Figure 3 A photograph of the photonic crystal pigment with black, green and blue colors prepared in Example 1;

[0035] Figure 4 A photograph of the photonic crystal pigment prepared for Comparative Example 1.

[0036] Figure 5 This is a photograph of the photonic crystal pigment prepared for Comparative Example 2.

[0037] Figure 6 This is a photograph of the photonic crystal pigment prepared in Comparative Example 3. Detailed Implementation

[0038] The present invention will be further described in detail below with reference to embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto. All raw materials involved in the present invention can be purchased directly from the market. For process parameters not specifically specified, conventional techniques can be referred to.

[0039] This invention provides a photonic crystal composition, which preferably comprises the following components in parts by weight: 20-80 parts water; 20-80 parts organic solvent; 0.1-1 part surfactant; and 0.1-5 parts solvent dye.

[0040] The surfactant can be at least one of anionic surfactants, cationic surfactants, and nonionic surfactants, preferably at least one of alkylphenol polyoxyethylene ether nonionic surfactants and fluorocarbon nonionic surfactants, more preferably alkylphenol polyoxyethylene ether nonionic surfactants, including nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, dodecyl polyoxyethylene ether, dinonylphenol polyoxyethylene ether, etc. The surfactant enables the dye to penetrate more effectively into the pigment interstitial layer of the photonic crystal. Experiments have shown that nonionic surfactants are more effective. In this embodiment of the invention, polyethylene glycol octylphenyl ether is used as an example, but it is not intended to limit the invention to only polyethylene glycol octylphenyl ether.

[0041] The surfactant is used in quantities of 0.1-1 parts by mass. For example, in specific embodiments, it can be 0.1 parts, 0.2 parts, 0.5 parts, 1 part, etc. When the surfactant is used in the above-mentioned quantity range, it can better cooperate with the solvent dye to achieve secondary coloring of photonic crystal pigment.

[0042] The organic solvents used are preferably water-miscible. Examples of such solvents include ethanol, ethylene glycol, propylene glycol, glycerol, ethylene glycol methyl ether, propylene glycol methyl ether, ethylene glycol butyl ether, dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. Other commonly used water-miscible organic solvents in the art can also achieve the purpose of this invention and should also fall within the scope of protection of this invention. The ratio of organic solvent to water does not have a critical impact on the effect of the dye bath composition; combinations where water is more than organic solvent, organic solvent is more than water, or both are used in equal amounts are all acceptable.

[0043] The solvent dyes include metal complex dyes, anthraquinone dyes, azo dyes, phthalocyanine dyes, quinoline dyes, pyrene dyes, cyanine dyes, indigo dyes, nitroso dyes, nitro dyes, sulfur dyes, arylmethane dyes, quinone imine dyes, hydroxy copper dyes, flavonoid dyes, etc., and their mass ratio with the surfactant is greater than 1:1 to ensure that the photonic crystal pigments can be better colored in the second stage.

[0044] This invention also provides a method for secondary coloring of photonic crystal pigments. Specifically, it is a method for secondary coloring of photonic crystal pigments using the above-mentioned photonic crystal pigment dye bath composition, including the following steps: adding the photonic crystal pigment to the above-mentioned photonic crystal pigment dye bath composition for coloring treatment, followed by filtration, washing with water and drying, thereby realizing the secondary coloring treatment of photonic crystal pigments.

[0045] Photonic crystal pigments are a physical color-generating phenomenon that utilizes the interaction between natural light and the microscopic structure of matter. Unlike traditional dyes and pigments, their color originates from the micro- and nanoscale structures within photonic crystals, hence the term "structural color." Due to their high light transmittance, photonic crystal pigments are easily masked when mixed with organic pigments or dyes, affecting the final appearance. However, the dye bath composition provided by this invention allows the solvent dye to penetrate the interstitial layer of the photonic crystal pigment at an appropriate temperature (room temperature or appropriate heating), forming a more complex superposition of photonic crystal and Bragg diffraction with dye absorption colors. This achieves secondary coloring of the photonic crystal pigment, overcoming the problem of color masking. Because the solvent dye penetrates into the interstitial layer of the photonic crystal pigment, the photonic crystal pigment after secondary coloring not only retains the characteristics of structural color but also possesses stronger hiding power and richer multi-angle colors.

[0046] Based on the secondary coloring mechanism of the dye bath composition described in this invention (solvent dye penetrates into the interstitial layer of the photonic crystal pigment, forming a more complex superposition of the reflected color of the photonic crystal and the absorbed color of the dye), the photonic crystal pigment described in this invention is preferably a composition made of ordered nanospheres filled with acrylate polymers. This type of photonic crystal mainly consists of microspheres and interstitial layers supporting the microspheres. The microspheres are primarily composed of polystyrene, acrylic, etc., and color is produced through Bragg diffraction formed by the ordered crystallization of the microspheres. The interstitial layer is generally filled with acrylate polymers to maintain the stability of the crystal, preventing the photonic crystal pigment from collapsing during secondary coloring.

[0047] The photonic crystal pigment of this invention can be prepared using some publicly available techniques in the art, such as Chinese patent application CN117534796A. Preferably, the nanospheres are selected from polymer microspheres, inorganic microspheres, and polymer-inorganic composite microspheres; the polymer microspheres include at least one of polystyrene microspheres and core-shell structured polymer microspheres; the inorganic microspheres include at least one of silicon dioxide, titanium dioxide, iron oxide, and zinc sulfide; the average particle size of the nanospheres is 100-400 nm, and the polydispersity index (PDI) is less than 0.15; the acrylate polymer is formed by thermally or photoinitiated polymerization of at least one of (meth)acrylate monomers and (meth)acrylate oligomers.

[0048] Table 1. Types of raw materials used in Examples 1-5

[0049] Nonionic surfactants Polyethylene glycol octylphenyl ether X-100 Produced by Haian Petrochemical Plant, Jiangsu Province Metal complex dyes Solvent Black 34 B-10 Produced by Nantong Zhengyan New Material Technology Co., Ltd. Anthraquinone dyes Solvent Violet 36 3R GRAN Produced by Lanxess Chemical (China) Co., Ltd. azo dyes Solvent Red 195 Solvaperm Red G Produced by Clariant Chemicals (China) Co., Ltd. Phthalocyanine dyes Solvent Blue 67 Orasol Blue 825 Produced by Taiyang Chemical New Materials (Shanghai) Co., Ltd. Photonic crystal pigment blue-green T80-406 Homemade, D90≤260μm Photonic crystal pigment Golden Red T80-234 Homemade, D90≤270μm Photonic crystal pigment Orange-red T80-134 Homemade, D90≤220μm

[0050] Example 1

[0051] This embodiment provides a secondary coloring method for photonic crystal pigments, including the following steps:

[0052] Step 1: Sequentially mix and stir 50g water, 48.5g propylene glycol methyl ether, 0.5g X-100, and 1g B-10 to form a dye bath composition;

[0053] Step 2: Heat the above dye bath composition to 50°C;

[0054] Step 3: Under high-speed stirring, add 10g of T80-406 to the dye bath composition of Step 2 and perform a secondary coloring treatment for 20min;

[0055] Step 4: After completing Step 3, filter the sample using a 100-mesh filter bag, wash it three times with water, and dry it at 60°C for 24 hours to obtain a photonic crystal pigment with black, green, and blue colors.

[0056] Example 2

[0057] This embodiment provides a secondary coloring method for photonic crystal pigments, including the following steps:

[0058] Step 1: Sequentially mix and stir 79.4g water, 20g ethanol, 0.1g X-100, and 0.5g Solvaperm Red G to form a dye bath composition;

[0059] Step 2: Maintain the above dye bath composition at a temperature of 25°C;

[0060] Step 3: Under high-speed stirring, add 10g of T80-406 to the dye bath composition of Step 2 and perform a secondary coloring treatment for 20min;

[0061] Step 4: After completing Step 3, filter the sample using a 100-mesh filter bag, wash it three times with water, and dry it at 60°C for 24 hours to obtain a photonic crystal pigment with red, green, and blue colors.

[0062] Example 3

[0063] This embodiment provides a secondary coloring method for photonic crystal pigments, including the following steps:

[0064] Step 1: Sequentially mix and stir 50g water, 46.9g N-methylpyrrolidone, 0.1g X-100, 0.5g B-10, and 2.5g 3R GRAN to form a dye bath composition;

[0065] Step 2: Maintain the above dye bath composition at a temperature of 60°C;

[0066] Step 3: Under high-speed stirring, add 40g of T80-406 to the dye bath composition of Step 2 and perform a secondary coloring treatment for 20min;

[0067] Step 4: After completing Step 3, filter the sample using a 100-mesh filter bag, wash it three times with water, and dry it at 60°C for 24 hours to obtain a photonic crystal pigment with black, orange, blue, and green colors.

[0068] Example 4

[0069] This embodiment provides a secondary coloring method for photonic crystal pigments, including the following steps:

[0070] Step 1: Sequentially mix and stir 20g water, 78g ethylene glycol, 1g X-100, and 1g 3R GRAN to form a dye bath composition;

[0071] Step 2: Heat the above dye bath composition to 99°C;

[0072] Step 3: Under high-speed stirring, add 10g of T80-234 to the dye bath composition in Step 2 and perform a secondary coloring treatment for 20min;

[0073] Step 4: After completing Step 3, filter the sample using a 100-mesh filter bag, wash it three times with water, and dry it at 60°C for 24 hours to obtain a photonic crystal pigment with purple-red-green colors.

[0074] Example 5

[0075] This embodiment provides a secondary coloring method for photonic crystal pigments, including the following steps:

[0076] Step 1: Sequentially mix and stir 50g water, 44.9g N-methylpyrrolidone, 0.1g X-100, and 5g Solvaperm RedG to form a dye bath composition;

[0077] Step 2: Maintain the above dye bath composition at a temperature of 60°C;

[0078] Step 3: Under high-speed stirring, add 40g of T80-134 to the dye bath composition of Step 2 and perform a secondary coloring treatment for 20min;

[0079] Step 4: After completing Step 3, filter the sample using a 100-mesh filter bag, wash it three times with water, and dry it at 60°C for 24 hours to obtain a photonic crystal pigment with orange, blue, and green colors.

[0080] Comparative Example 1

[0081] Photonic crystal pigment blue-green T80-406 was prepared according to the method described in Example 1 of Chinese patent application CN117534796A. The nanospheres used were polystyrene microspheres with a particle size of 240 nm and a polydispersity index (PDI) of 0.08. A physical image of the prepared photonic crystal pigment blue-green T80-406 is shown below. Figure 4 As shown.

[0082] Comparative Example 2

[0083] Photonic crystal pigment Gold Red T80-234 was prepared according to the method described in Example 1 of Chinese patent application CN117534796A. The nanospheres used were polystyrene microspheres with a particle size of 250 nm and a polydispersity index (PDI) of 0.08. A physical image of the prepared photonic crystal pigment Gold Red T80-234 is shown below. Figure 5 As shown.

[0084] Comparative Example 3

[0085] Photonic crystal pigment Orange-Red T80-134 was prepared according to the method described in Example 1 of Chinese patent application CN117534796A, wherein the nanospheres used were polystyrene microspheres with a particle size of 260 nm and a polydispersity index (PDI) of 0.1. A physical image of the prepared photonic crystal pigment Orange-Red T80-134 is shown below. Figure 6 As shown.

[0086] Comparative Examples 1-3 were prepared using the method described in Example 1 of CN117534796A to produce photonic crystal pigments. The nanospheres used were all polystyrene microspheres. By controlling the particle size of the microspheres, photonic crystal pigments of different colors were obtained.

[0087] Test Evaluation:

[0088] 1. Add 1g of photonic crystal pigment, 10g of silicone base agent (PDMS), and 1g of silicone curing agent of Examples (1-5) and Comparative Examples (1-3) to a container in sequence, and stir evenly; use a 250μm film forming device to coat the film on the test card paper, heat and cure at 80℃ for 10min; use visual observation to observe the color at multiple angles of 90°, 45°, and 15° respectively.

[0089] The Lab value on white cardstock was measured using a Sanench colorimeter (model: NR60C).

[0090] 2. The hiding power test shall be conducted in accordance with GB / T1726-1979 "Determination of Hiding Power of Coatings".

[0091] Table 2 Test Evaluation Results

[0092] L 40.8 37.2 37.3 46.1 54.4 92.9 92.9 92.9 a -2.1 63.4 36.3 46.8 19.4 -0.8 0.3 0.1 b -9.1 -5.8 -55 -38.1 -71 2.7 3.1 3.7 90° viewing angle green green green Golden Red Orange-red green Golden Red Orange-red 45° viewing angle blue blue blue green green blue green green 15° viewing angle black red Purple Purple blue colorless colorless colorless <![CDATA[Hiding power g / m 2 > 80 210 320 240 120 470 530 560

[0093] Figure 1 A 500x microscope image of the photonic crystal pigment with black, green and blue colors prepared in Example 1; Figure 2 A 500x microscope image of the photonic crystal pigment prepared in Comparative Example 1; Figure 3A photograph of the photonic crystal pigment with black, green and blue colors prepared in Example 1; Figure 4 A photograph of the photonic crystal pigment prepared for Comparative Example 1. From... Figures 1-4 As can be seen from the test results in Table 2, in the dye bath composition provided by this invention, the dissolved dye, in the presence of water, solvent, and surfactant, can penetrate into the interstitial layer, forming a more complex superposition of photonic crystal and Bragg diffraction with the absorption color of the dye, thus achieving secondary coloring of the photonic crystal pigment. The photonic crystal pigment after secondary coloring with the dye bath composition described in this invention has a more vibrant color and stronger hiding power. Moreover, within the preferred dosage range described in this invention, the secondary coloring effect of the photonic crystal pigment is even better. For example, in Example 1, the color of the photonic crystal pigment after secondary coloring is significantly more vibrant, and the hiding power of the photonic crystal pigment after secondary coloring is also significantly improved (from 470 g / m² before secondary coloring). 2 Reduced to 80g / m 2 ).

[0094] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for secondary coloring of photonic crystal pigments, characterized in that, The method includes the following steps: adding a photonic crystal pigment, formed by orderly arranging of nanospheres and filling the gaps with an acrylate polymer, to a photonic crystal pigment dye bath composition for coloring treatment, followed by filtration, washing with water and drying to complete the secondary coloring treatment of the photonic crystal pigment; the temperature of the coloring treatment is 50℃-99℃; The photonic crystal pigment dye bath composition comprises the following components in parts by weight: 20-80 parts water, 20-80 parts organic solvent, 0.1-1 parts surfactant, and 0.1-5 parts solvent dye, wherein the surfactant is an alkylphenol polyoxyethylene ether nonionic surfactant.

2. The coloring method according to claim 1, characterized in that: Add the photonic crystal pigment to the dye bath composition and perform coloring treatment for 20-30 minutes.

3. The coloring method according to claim 1, characterized in that: The photonic crystal pigment is formed by orderly arranging of nanospheres and filling the gaps with acrylate polymer; the nanospheres are selected from at least one of polymer microspheres, inorganic microspheres and polymer-inorganic composite microspheres; the polymer microspheres include at least one of polystyrene microspheres and core-shell structured polymer microspheres; the inorganic microspheres include at least one of silicon dioxide, titanium dioxide, iron tetroxide and zinc sulfide. The nanospheres have an average particle size of 100-400 nm and a polydispersity index (PDI) of less than 0.

15. The acrylate polymer is formed by the polymerization of at least one of (meth)acrylate monomers and (meth)acrylate oligomers through thermal or photoinitiation.

4. The coloring method according to claim 1, characterized in that: The organic solvent includes at least one of ethylene glycol, propylene glycol, glycerol, ethylene glycol methyl ether, propylene glycol methyl ether, ethylene glycol butyl ether, dimethylformamide, dimethylacetamide, and N-methylpyrrolidone.

5. The coloring method according to claim 1, characterized in that: The solvent dye includes at least one of metal complex dyes, anthraquinone dyes, azo dyes, and phthalocyanine dyes.

6. The coloring method according to claim 1, characterized in that: The mass ratio of the solvent dye to the surfactant is greater than 1:1.

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