Dye dispersion, its preparation method, and dyeing method

Abstract

This invention provides a dye dispersion, its preparation method, and a dyeing method. The dye dispersion comprises a dye, a dispersant, and water. The dye has a particle size distribution D90 of 1 nm to 2.5 μm, and the dye has the structure shown in formula (I), formula (II), or formula (III), wherein R... 1 R 2 and R 3 It can be H, F, Cl, Br, or -SO3Na.

Description

Technical Field

[0001] This invention relates to a dye dispersion, its preparation method, and a dyeing method. Background Technology

[0002] Polyester fiber is a man-made fiber widely used in daily life, including in textiles, home furnishings, and furniture fillings. Due to its high hydrophobicity, polyester fiber is difficult to dye and is primarily dyed using disperse dyes. Disperse dyes are mainly based on azo and anthraquinone compounds, although heterocyclic disperse dyes also exist. However, traditional azo or anthraquinone dyes are generally petrochemically synthesized, and their raw materials often raise concerns about carcinogenicity and environmental impact. In response to the global trend towards non-toxic and low-carbon manufacturing, the textile industry is moving towards sustainable production, which will significantly limit the use of petrochemical dyes in the future.

[0003] Indigo dye can be derived from plant extracts or produced by microorganisms, meeting the textile industry's requirements for sustainable dyes. Because indigo dye itself is poorly soluble in water, dyeing typically requires the use of chemicals and repeated dyeing processes. It is then oxidized to become insoluble indigo, which adheres to the fiber, completing the dyeing process. The water-soluble form of reduced indigo dye has high alkalinity, which is destructive to alkali-sensitive fibers. Currently, there is no specific dyeing process for these fibers to facilitate dyeing.

[0004] Based on the above, the industry needs a novel indigo dye and dyeing method. Summary of the Invention

[0005] This invention provides a dye dispersion, its preparation method, and a dyeing method. According to an embodiment of the invention, the dye dispersion comprises a dye, a dispersant, and water. The dye has a particle size distribution D90 of 1 nm to 2.5 μm, and the dye has a structure shown in formula (I), formula (II), or formula (III).

[0006]

[0007]

[0008] , where R 1 R 2 and R 3 It can be H, F, Cl, Br, or -SO3Na independently.

[0009] This invention provides a method for preparing a dye dispersion, comprising the following steps: providing a composition comprising a dye, a dispersant, and water; and subjecting the composition to a homogenization treatment to obtain the aforementioned dye dispersion. The dye has a structure shown in formula (I), formula (II), or formula (III).

[0010]

[0011]

[0012] , where R 1 R 2 and R 3 It can be H, F, Cl, Br, or -SO3Na independently.

[0013] The present invention also provides a dyeing method comprising: performing a dyeing process on a fabric using a dye composition to obtain a colored fabric, wherein the dye composition comprises the dye dispersion described above. Attached Figure Description

[0014] Figure 1 A flowchart illustrating the steps of method 10 for preparing dye dispersion according to an embodiment of the present invention.

[0015] Figure 2 A flowchart illustrating the steps of the staining method 100 according to an embodiment of the present invention is provided.

[0016] In the attached figures, the following labels are used:

[0017] 10. Preparation method of dye dispersion;

[0018] Steps 12, 14, 102, and 104; and

[0019] 100 staining method. Detailed Implementation

[0020] The following provides a detailed description of the dye dispersion, its preparation method, and dyeing method according to the present invention. It should be understood that the following description provides many different embodiments for implementing different variations of the invention. The specific components and arrangements described below are merely illustrative of the invention. Of course, these are only examples and not limitations of the invention. In this invention, the term "about" means that the specified amount can be increased or decreased by an amount that is generally and reasonably understood by those skilled in the art.

[0021] The use of ordinal numbers such as "first," "second," "third," etc., in the specification and claims to modify the components of the claims does not imply or represent any prior ordinal number of the claimed component, nor does it represent the order of one claimed component with another, or the order of manufacturing methods. The use of these ordinal numbers is only to enable a claimed component with a certain name to be clearly distinguished from another claimed component with the same name.

[0022] The specific embodiments are merely illustrative of particular ways in which the invention is used and are not intended to limit the invention. Unless otherwise defined, all terms used in this invention (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary knowledge in the art to which this invention pertains.

[0023] This invention provides a dye dispersion, its preparation method, and a dyeing method. The dye dispersion of this invention can use dyes of microbial or chemical origin. Because the dyeing method of this invention breaks away from the traditional framework of requiring dye reduction before dyeing, it can perform non-reduction dyeing on fibers. Utilizing high temperature, fiber molecules swell, increasing porosity, and allowing smaller-particle-size dyes to penetrate the fiber interior to complete the dyeing process. Based on the above, this invention provides a non-toxic, low-carbon-emission, and environmentally friendly indigo dye dispersion that can be applied to the preparation of colored fibers, reducing the environmental and human health risks associated with traditional vat dyeing methods. According to embodiments of this invention, the dyeing method does not require the use of reducing agents or enzymes during the dyeing process and can be used under acidic conditions. The resulting colored fibers do not require multiple dyeing cycles to achieve high color depth and wash fastness, and are suitable for combining different indigo dyes to form colored fibers with various hues (e.g., red, blue, and purple).

[0024] According to an embodiment of the present invention, the dye dispersion comprises a dye having a low particle size distribution, a dispersant, and water. According to an embodiment of the present invention, the particle size distribution D90 of the dye can be from about 1 nm to 2.5 μm, for example, about 2 nm, 5 nm, 10 nm, 20 nm, 25 nm, 50 nm, 75 nm, 100 nm, 200 nm, 500 nm, 750 nm, 1 μm, 1.5 μm, 2 μm, or 2.5 μm. When the particle size distribution D90 of the dye is too large, when dyeing fibers (e.g., polyester fibers or natural fibers) using the dye dispersion, the larger dye particles do not easily penetrate the fiber interior, resulting in a decrease in the color depth and wash fastness of the dyed fibers, requiring multiple re-dyeing processes to maintain their color depth and wash fastness. Here, the particle size distribution D90 indicates that 90% of the total dye volume has a diameter smaller than the value defined by D90. According to an embodiment of the present invention, the particle size distribution D90 can be measured by dynamic light scattering (DLS).

[0025] According to an embodiment of the present invention, in the dye dispersion, the content of the dye is 9-90 parts by weight (e.g., 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, 75 parts by weight, 80 parts by weight, or 85 parts by weight); the content of the dispersant is 0.5-20 parts by weight (e.g., 0.7 parts by weight). The dye dispersion contains 1.0, 2, 3, 5, 10, or 15 parts by weight; and water content of 8-90 parts by weight (e.g., 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, or 85 parts by weight). When the content of each component in the dye dispersion is within the above range, the dye dispersion is suitable for the dyeing method described in this invention, and can be used for non-reductive dyeing of fibers (e.g., polyester fibers or natural fibers). High temperature causes fiber molecules to swell, increasing porosity and allowing the dye to penetrate the fiber interior to complete the dyeing process.

[0026] According to embodiments of the present invention, the dye comprises a compound having the structure shown in formula (I), formula (II), or formula (III).

[0027]

[0028] , where R 1 R 2 and R 3 It can be H, F, Cl, Br, or -SO3Na independently. For example, this dye can be...

[0029]

[0030]

[0031]

[0032] Wherein R is independently F, Cl, Br, or -SO3Na. According to embodiments of the present invention, the dye may be indigo, indirubin, 6,6'-dibromoindigo, dehydroindigo, indigo carmine, 4-chloroindigo, 5-chloroindigo, 6-chloroindigo, 6-flouroindigo, 6'-bromoindigo, or a combination thereof. According to embodiments of the present invention, the dye may be derived from microbial production, chemical synthesis, plant extraction, or a combination thereof. In some embodiments of the present invention, the dye may be derived from microbial production or plant extraction. According to embodiments of the present invention, the dye is not a vat dye and does not require a reduction process before use. According to embodiments of the present invention, the dye does not require pretreatment with protecting groups.

[0033] According to embodiments of the present invention, the dispersant may be a polyoxyethylene ether dispersant, a sodium lignosulfonate dispersant, a polyacrylic acid dispersant, a polyurethane dispersant, or a combination thereof. The molecular weight of the dispersant is not particularly limited. For example, the weight-average molecular weight (Mw) of the dispersant described in the present invention may be from about 1,000 g / mol to 300,000 g / mol, but the present invention is not limited thereto.

[0034] According to embodiments of the present invention, the dye dispersion of the present invention does not contain a reducing agent or an enzyme. Here, the reducing agent or enzyme refers to a reducing agent or enzyme used in conventional dyeing processes. According to embodiments of the present invention, the dye dispersion of the present invention is composed of the dye, dispersant, and water described in the present invention.

[0035] According to embodiments of the present invention, the present invention also provides a method for preparing a dye dispersion, for preparing the above-mentioned dye dispersion. Please refer to... Figure 1The preparation method 10 of the dye dispersion may include the following steps. First, a composition is provided, wherein the composition comprises a dye, a dispersant, and water (step 12), wherein the types of the dye and dispersant are as defined above. Next, the composition is subjected to a homogenization treatment (step 14) to obtain the dye dispersion of the present invention. In some embodiments, the homogenization treatment can make the particle size distribution D90 of the dye in the dye dispersion between 1 nm and 2.5 μm or 1 nm and 2 μm. In this way, when polyester fibers are dyed using the dye dispersion, the color depth and wash fastness of the resulting colored polyester fibers can be effectively increased, so colored polyester fibers with high color depth and wash fastness can be obtained with only a single dyeing.

[0036] According to embodiments of the present invention, the homogenization process can be ultrasonic vibration or ball milling. According to embodiments of the present invention, the ultrasonic vibration process involves placing the composition in an ultrasonic vibrator and vibrating it at 15°C to 50°C for approximately 5 to 120 minutes. The frequency and output power of the ultrasonic vibration used in this invention are not particularly limited and can be from 10 kHz to 25 kHz, with an output power from 10 W to 150 W. According to embodiments of the present invention, the ball milling process can be a planetary ball mill or a conventional ball mill. According to embodiments of the present invention, the ball milling time can be from 5 to 120 minutes, the ball milling speed can be between 100 rpm and 500 rpm, and the diameter of the grinding balls can be between 50 μm and 1 mm.

[0037] According to embodiments of the present invention, in the composition for preparing a dye dispersion, the dye content is 9-90 parts by weight; the dispersant content is 0.5-20 parts by weight; and the water content is 8-90 parts by weight. According to embodiments of the present invention, the composition does not contain a reducing agent or an enzyme. According to embodiments of the present invention, the composition for preparing a dye dispersion comprises the dye, dispersant, and water described in the present invention.

[0038] According to embodiments of the present invention, a staining method is also provided. Please refer to... Figure 2The dyeing method 100 may include: performing a dyeing process on a fabric (e.g., polyester fabric or natural fiber fabric) using a dye composition to obtain a colored fabric (e.g., colored polyester fabric or colored natural fiber fabric) (step 102). Furthermore, the dyeing method 100 may also include, after the dyeing process, performing a washing process (e.g., soaping, and / or water washing) and / or a drying process on the resulting material (step 104). According to embodiments of the present invention, the washing process and / or drying process are not particularly limited and may be conventional washing or drying processes used for dyed fabrics. According to embodiments of the present invention, the dye composition comprises the dye dispersion described herein.

[0039] According to embodiments of the present invention, in the dyeing method described herein, the dyeing temperature can be approximately 100°C to 130°C, and the dyeing time is 30 minutes to 2 hours. When the process temperature is too low, the fiber (e.g., polyester fiber or natural fiber) molecules are less likely to swell, failing to expand the gaps between fibers, resulting in dyes not easily penetrating the fiber interior. When the process temperature is too high, the dyeing process is energy-intensive and easily causes a reduction in the physical properties of the fabric.

[0040] According to embodiments of the present invention, the dye concentration in the dye composition can be from 0.1% to 15% of the fabric weight (owf), for example, 0.5% owf, 1% owf, 2% owf, 5% owf, 7% owf, 10% owf, or 12% owf. According to embodiments of the present invention, the dye composition can be an aqueous solution and may contain additives known for use in dyeing processes. It is noteworthy that the additives do not contain reducing agents or enzymes. According to embodiments of the present invention, the pH value of the dye composition can be from 4 to 7.

[0041] According to embodiments of the present invention, the fabric (e.g., polyester fabric or natural fiber fabric) may be polyethylene terephthalate, ethylene polyester, or a combination thereof.

[0042] According to embodiments of the present invention, the dye composition does not contain reducing agents or enzymes. In other words, the dyeing method according to the present invention does not use reducing agents or enzymes (i.e., the dyeing process is carried out without the use of reducing agents or enzymes).

[0043] According to embodiments of the present invention, the color depth (K / S value) of the dyed fabric (e.g., dyed polyester fabric or dyed natural fiber fabric) can be from 0.5 to 20, for example, 1, 2, 3, 4, 5, 10, or 15. According to embodiments of the present invention, the color depth (k / s) of the dyed fabric (e.g., dyed polyester fabric or dyed natural fiber fabric) can be measured using a color spectrophotometer (i1Basic Pro 2) (unit: K / S). According to embodiments of the present invention, the wash fastness of the dyed fabric can be from about 3 to 5, wherein the evaluation standard for wash fastness is AATCC 61.

[0044] To make the above-mentioned and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings.

[0045] Example 1

[0046] Pretreatment: Take 20 parts by weight of indigo (structure: (Source: Chemically synthesized, purchased from Sigma-Aldrich) (as dye), 5 parts by weight of polyoxyethylene ether dispersant (trade number Calever-140, sold by Central Asia Industrial Co., Ltd.), and 75 parts by weight of water were mixed. The resulting mixture was then homogenized to obtain a dye dispersion (1), wherein the homogenization process involved placing the dye dispersion in an ultrasonic oscillator and oscillating it at room temperature (25°C) for approximately 10 minutes (oscillation frequency of 20 kHz, output power of 15 W). Next, the particle size distribution D90 of the dye in the dye dispersion (1) was measured, and the D90 value was found to be 125 nm. The particle size distribution D90 was measured using dynamic light scattering (DLS).

[0047] Dyeing / washing process: Dye dispersion (1), polyoxyethylene ether dispersant (trade number Calever-140, sold by Central Asia Industrial Co., Ltd.), and water were mixed, and ammonium sulfate ((NH4)2SO4) (concentration of 1g / L) was added. The pH value was adjusted with acetic acid to obtain a dye composition (pH value of 5.5). 5g of polyester fabric (trade number Refined 75D / 72+40D OP, purchased from Fang An Co., Ltd.) was soaked in the dye composition (0.625g of dye dispersion (1)). The dye concentration was 2.5% owf. Then, 0.375g of polyoxyethylene ether dispersant was added to make the dispersant concentration in the dye composition 1% owf. Dyeing was carried out at 130°C for 60 minutes. Next, after cooling, the polyester fabric was removed and washed at 83°C for 20 minutes (washing conditions: sodium hydroxide (1g / L), ammonium sulfate (2g / L), 1.5% owf shrinkage agent (trade code ESKUDO RC-010, sold by Taiwan Jihwa Chemical Industry Co., Ltd.), and 3.5% owf sodium dithionite (Na2S2O4)). After drying, the colored polyester fabric (1) was obtained.

[0048] Next, the lightness (L*), red (a*), blue (b*), color depth (k / s), and wash fastness of the colored polyester fabric (1) were evaluated, and the results are shown in Table 1. The measurement methods for the lightness (L*), red (a*), and blue (b*) of the colored polyester fabric (1) can be found in the Journal of The Textile Institute, Vol. 110, 2019, pages 81-88. The color depth (k / s) of the colored polyester fabric was measured using a color spectrophotometer (i1Basic Pro 2) (unit: K / s). The wash fastness evaluation standard was AATCC 61.

[0049] Example 2

[0050] Example 2 was prepared according to the method for preparing the colored polyester fabric (1) described in Example 1, except that the dye concentration was increased from 2.5% owf to 5% owf (the particle size distribution D90 value of the dye in the dye dispersion (1) was 125 nm), resulting in a colored polyester fabric (2). Next, the lightness (L*), red (a*), blue (b*), color depth (k / s), and wash fastness of the colored polyester fabric (2) were evaluated, and the results are shown in Table 1.

[0051] Example 3

[0052] Example 3 was carried out according to the preparation method of the dye dispersion (1) described in Example 1, except that indigo was prepared as indirubin (structure: (Source: Chemical synthesis, purchased from Sigma-Aldrich) Substitution yields dye dispersion (2), with a particle size distribution D90 value of 130 nm for the dye in dye dispersion (2).

[0053] Next, the preparation method of the colored polyester fabric (1) described in Example 1 was followed, except that the dye dispersion (1) was replaced with dye dispersion (2) to obtain the colored polyester fabric (3). Then, the lightness (L*), red (a*), blue (b*), color depth (K / S), and wash fastness of the colored polyester fabric (3) were evaluated, and the results are shown in Table 1.

[0054] Table 1

[0055]

[0056] As shown in Table 1, the dyeing method described in this invention allows dyes with small particle sizes to penetrate the fiber and dye polyester fabrics without adding reducing agents or enzymes to the dye composition. The chemically derived indigo dye, after treatment, exhibits a color depth that increases with increasing dye concentration. The polyester fabrics dyed with indigo and indirubin possess blue and red hues and exhibit high wash fastness.

[0057] Comparative Example 1

[0058] Comparative Example 1 was prepared according to the method for preparing the dye dispersion (1) described in Example 1, except that no homogenization treatment was performed, resulting in a dye dispersion (3). Next, the particle size distribution D90 of the dye in the dye dispersion (3) was measured, and the D90 value was found to be 3 μm.

[0059] Next, the preparation method of the colored polyester fabric (1) described in Example 1 was followed, except that the dye dispersion (1) was replaced with dye dispersion (3) to obtain the colored polyester fabric (4). Then, the lightness (L*), red (a*), blue (b*), color depth (K / S), and wash fastness of the colored polyester fabric (4) were evaluated, and the results are shown in Table 2.

[0060] Comparative Example 2

[0061] Preprocessing: None.

[0062] Dyeing / washing process: 20 parts by weight of indigo (chemically synthesized) (as dye) and 80 parts by weight of water were mixed to obtain a dye dispersion (4). Then, the particle size distribution D90 of the dye in the dye dispersion (4) was measured, and the D90 value was found to be 5 μm.

[0063] Next, the preparation method of the colored polyester fabric (1) described in Example 1 was followed, except that the dye dispersion (1) was replaced with dye dispersion (4) to obtain the colored polyester fabric (5). Then, the lightness (L*), red (a*), blue (b*), color depth (K / S), and wash fastness of the colored polyester fabric (5) were evaluated, and the results are shown in Table 2.

[0064] Table 2

[0065]

[0066]

[0067] As shown in Table 2, compared with Example 1, the dyeing depth of polyester fabrics dyed with dye dispersions that were not homogenized (i.e., Comparative Examples 1 and 2) was lower. In addition, Comparative Examples 1 and 2 had similar dyeing depths. Even with the addition of dispersant to the dye dispersion, the reduction of dye particle size could not be improved without homogenization, resulting in poor dyeing depth.

[0068] Example 4

[0069] Pretreatment: Take 20 parts by weight of indigo (structure: (Source: Microbial production) (as dye), 5 parts by weight of polyoxyethylene ether dispersant (trade number Calever-140, sold by Central Asia Industrial Co., Ltd.), and 75 parts by weight of water were mixed. The resulting mixture was then homogenized to obtain a dye dispersion (5), wherein the homogenization process involved placing the dye dispersion in an ultrasonic oscillator and oscillating it at room temperature (25°C) for approximately 10 minutes (oscillation frequency of 20 kHz and output power of 15 W). The particle size distribution D90 of the dye in the dye dispersion (5) was then measured, and the D90 value was found to be 131 nm.

[0070] Dyeing / washing process: The dye dispersion (5), polyoxyethylene ether dispersant (trade number Calever-140, sold by Central Asia Industrial Co., Ltd.), and water were mixed, and ammonium sulfate ((NH4)2SO4) (concentration of 1 g / L) was added to adjust the pH value to obtain a dye composition (pH value of 5.5), wherein the concentration of polyoxyethylene ether dispersant added was 1% owf. Next, polyester fabric (trade number Refined 75D / 72+40D OP, purchased from Fang'an Co., Ltd.) was immersed in the dye composition (where the dye concentration was 2.5% owf) and dyed at 130°C for 60 minutes. Next, after cooling, the polyester fabric was removed and washed at 83°C for 20 minutes (washing conditions: sodium hydroxide (1g / L), ammonium sulfate (2g / L), 1.5% owf shrinkage agent (trade code ESKUDO RC-010, sold by Taiwan Jihwa Chemical Industry Co., Ltd.), and 3.5% owf sodium dithionite (Na2S2O4)). After drying, the colored polyester fabric (6) was obtained.

[0071] Next, the lightness (L*), red (a*), blue (b*), color depth (k / s), and wash fastness of the colored polyester fabric (6) were evaluated, and the results are shown in Table 3.

[0072] Example 5

[0073] Example 5 was carried out according to the preparation method of the colored polyester fabric (6) described in Example 4, except that the dye concentration was increased from 2.5% owf to 5% owf, resulting in a colored polyester fabric (7). Next, the lightness (L*), red (a*), blue (b*), color depth (k / s), and wash fastness of the colored polyester fabric (7) were evaluated, and the results are shown in Table 3.

[0074] Example 6

[0075] Example 6 was carried out according to the preparation method of the colored polyester fabric (6) described in Example 4, except that the dye concentration was increased from 2.5% owf to 7.5% owf, resulting in colored polyester fabric (8). Next, the lightness (L*), red (a*), blue (b*), color depth (k / s), and wash fastness of the colored polyester fabric (8) were evaluated, and the results are shown in Table 3.

[0076] Table 3

[0077]

[0078]

[0079] As shown in Table 3, the dyeing method described in this invention is also applicable to dyeing with indigo dye produced by microorganisms, with the color depth increasing with increasing dye concentration. It allows dyes with smaller particle sizes to penetrate the fiber and complete the dyeing of polyester fabrics without adding reducing agents or enzymes to the dye composition.

[0080] Comparative Example 3

[0081] Comparative Example 3 was prepared according to the method for preparing the dye dispersion (5) described in Example 4, except that no homogenization treatment was performed, resulting in a dye dispersion (6). Next, the particle size distribution D90 of the dye in the dye dispersion (6) was measured, and the D90 value was found to be 3 μm.

[0082] Next, the preparation method of the colored polyester fabric (6) described in Example 4 was followed, except that the dye dispersion (5) was replaced with the dye dispersion (6), to obtain the colored polyester fabric (9). Then, the lightness (L*), red (a*), blue (b*), color depth (K / S), and wash fastness of the colored polyester fabric (9) were evaluated, and the results are shown in Table 4.

[0083] Comparative Example 4

[0084] Preprocessing: None.

[0085] Dyeing / washing process: 20 parts by weight of indigo (derived from microbial production) were mixed with 80 parts by weight of water to obtain a dye dispersion (7). Then, the particle size distribution D90 of the dye in the dye dispersion (7) was measured, and the D90 value was found to be 8 μm.

[0086] Next, the preparation method of the colored polyester fabric (6) described in Example 4 was followed, except that the dye dispersion (5) was replaced with dye dispersion (7) to obtain the colored polyester fabric (10). Then, the lightness (L*), red (a*), blue (b*), color depth (K / S), and wash fastness of the colored polyester fabric (10) were evaluated, and the results are shown in Table 4.

[0087] Table 4

[0088]

[0089]

[0090] As shown in Table 4, compared with Example 4, the dye particle size of the dye dispersions that were not homogenized (i.e., Comparative Examples 3 and 4) was larger, resulting in a lower dyeing depth of the obtained colored polyester fabrics. Furthermore, even with the addition of a dispersant to the dye dispersion, the reduction in dye particle size could not be improved without homogenization, leading to a poorer dyeing depth.

[0091] Example 7

[0092] Pretreatment: Take 20 parts by weight of dye (indigo and indirubin in a ratio of 99:1, both from microbial production), 5 parts by weight of polyoxyethylene ether dispersant (trade code Calever-140, sold by Central Asia Industrial Co., Ltd.), and 75 parts by weight of water and mix them. Then, homogenize the mixture to obtain a dye dispersion (8), wherein the homogenization process involves placing the dye dispersion in an ultrasonic oscillator and shaking it at room temperature (25°C) for about 10 minutes (oscillation frequency of 20KHz, output power of 15W).

[0093] Dyeing / washing process: The dye dispersion (8), polyoxyethylene ether dispersant (trade number Calever-140, sold by Central Asia Industrial Co., Ltd.), and water were mixed, and ammonium sulfate ((NH4)2SO4) (concentration of 1 g / L) was added to adjust the pH value to obtain a dye composition (pH value of 5.5), wherein the concentration of polyoxyethylene ether dispersant added was 1% owf. Next, polyester fabric (trade number Refined 75D / 72+40D OP, purchased from Fang An Co., Ltd.) was immersed in the dye composition (where the dye concentration was 5% owf) and dyed at 130°C for 60 minutes. Next, after cooling, the polyester fabric was removed and washed at 83°C for 20 minutes (washing conditions: sodium hydroxide (1g / L), ammonium sulfate (2g / L), 1.5% owf shrinkage agent (trade code ESKUDO RC-010, sold by Taiwan Jihwa Chemical Industry Co., Ltd.), and 3.5% owf sodium dithionite (Na2S2O4)). After drying, colored polyester fabric (11) was obtained.

[0094] Next, the lightness (L*), red (a*), blue (b*), color depth (k / s), and wash fastness of the colored polyester fabric (11) were evaluated, and the results are shown in Table 5.

[0095] Example 8

[0096] Example 8 was prepared according to the method of preparing the dye dispersion (8) described in Example 7, except that the ratio of indigo to indirubin was adjusted from 99:1 to 1:60 to obtain the dye dispersion (9).

[0097] Next, the preparation method of the colored polyester fabric (11) described in Example 7 was followed, except that the dye dispersion (8) was replaced with dye dispersion (9) to obtain the colored polyester fabric (12). Then, the lightness (L*), red (a*), blue (b*), color depth (K / S), and wash fastness of the colored polyester fabric (12) were evaluated, and the results are shown in Table 5.

[0098] Example 9

[0099] Example 9 was carried out according to the preparation method of the dye dispersion (9) described in Example 7, except that the dye (a mixture of indigo and indirubin) was 6,6'-dibromoindigo (6,6'-dibromoindigo, with the structure of...). (Source: Microbial production) to obtain dye dispersion (10).

[0100] Next, the preparation method of the colored polyester fabric (11) described in Example 7 was followed, except that the dye dispersion (8) was replaced with dye dispersion (10) and the dye concentration was adjusted to 2.5% owf, to obtain the colored polyester fabric (13). Then, the lightness (L*), red (a*), blue (b*), color depth (K / S), and wash fastness of the colored polyester fabric (13) were evaluated, and the results are shown in Table 5.

[0101] Table 5

[0102]

[0103]

[0104] As shown in Table 5, after homogenization, the microbial dyes can be used to obtain colored polyester fabrics with different purple hues by adjusting the dye ratio. Furthermore, the dyeing method described in this invention can also be used with other indigo dyes (such as 6,6'-dibromoindigo) to obtain colored polyester fabrics with good color depth and wash fastness.

[0105] Based on the above, the dyeing method described in this invention breaks away from the traditional framework that requires dye reduction before dyeing. It enables non-reduction dyeing of polyester fibers, utilizing high temperatures to cause polyester fiber molecules to expand and increase porosity, allowing smaller-particle-size dyes to penetrate the fiber interior and complete the dyeing process. The resulting colored polyester fibers achieve high color depth and wash fastness without multiple dyeing cycles, and are suitable for dye combinations to create colored polyester fibers with various hues (e.g., red, blue, purple).

[0106] Although the present invention has been disclosed above with reference to several embodiments, it is not intended to limit the present invention. Anyone with common knowledge in the art can make any modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the appended claims.

Claims

1. A dye dispersion comprising: A dye having a particle size distribution D90 of 1 nm to 2.5 μm and having a structure as shown in formula (I), formula (II), or formula (III). ， wherein R 1 , R 2 , and R 3 are independently H, F, Cl, Br, or -SO3Na; A dispersant; and water.

2. The dye dispersion according to claim 1, wherein the dye is 9-90 parts by weight, the dispersant is 0.5-20 parts by weight, and the water is 8-90 parts by weight, and the total weight of the dye, dispersant, and water is 100 parts by weight.

3. The dye dispersion according to claim 1, wherein the dye is indigo, indirubin, 6,6'-dibromoindigo, dehydroindigo, sodium 5,5'-indigo disulfonate, 4-chloroindigo, 5-chloroindigo, 6-chloroindigo, 6-fluoroindigo, 6-bromoindigo, or a combination thereof.

4. The dye dispersion according to claim 1, wherein the dye is derived from microbial production, chemical synthesis, plant extraction, or a combination thereof.

5. The dye dispersion according to claim 1, wherein the dispersant is a polyoxyethylene ether dispersant, sodium lignosulfonate dispersant, acrylic acid dispersant, polyurethane dispersant, or a combination thereof.

6. A method for preparing a dye dispersion, comprising: A composition is provided, wherein the composition comprises a dye, a dispersant, and water, wherein the dye has a structure shown in formula (I), formula (II), or formula (III). ， wherein R 1 , R 2 , and R 3 are independently H, F, Cl, Br, or -SO3Na; and The composition was subjected to a homogenization process to obtain the dye dispersion of claim 1.

7. The method for preparing the dye dispersion according to claim 6, wherein the homogenization treatment is ultrasonic vibration treatment or ball milling treatment.

8. A staining method, comprising: A dyeing process is performed on a fabric using a dye composition to obtain a colored fabric, wherein the dye composition comprises the dye dispersion of claim 1.

9. The dyeing method according to claim 8, wherein the fabric is a polyester fabric or a natural fiber fabric.

10. The dyeing method according to claim 8, wherein the dye concentration in the dye composition is from 0.1% to 15% of the fabric weight.

11. The dyeing method according to claim 8, wherein the dye composition is an aqueous solution.

12. The dyeing method according to claim 8, wherein the pH value of the dye composition is 4 to 7.

13. The dyeing method according to claim 9, wherein the polyester fabric is polyethylene terephthalate, ethylene polyester, or a combination thereof.

14. The dyeing method according to claim 8, wherein the temperature of the dyeing process is 100°C to 130°C.

15. The dyeing method according to claim 8, wherein the dyeing process takes 30 minutes to 2 hours.

16. The dyeing method according to claim 8, wherein the dye composition does not contain a reducing agent or an enzyme.

17. The dyeing method according to claim 8, wherein the color depth of the dyed fabric is 0.5 to 20.

18. The dyeing method according to claim 8, wherein the wash fastness of the dyed fabric is 3 to 5, and the evaluation standard for the wash fastness is AATCC 61.

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