Starch-based dispersing agent for dispersing disperse dye as well as preparation method and application of starch-based dispersing agent

Abstract

The invention discloses a starch-based dispersant for dispersing a disperse dye and a preparation method and application of the starch-based dispersant. According to the method, acidolysis starch obtained by acid degradation is used as a polymer skeleton and is subjected to a substitution reaction with aromatic sulfonic acid substituted cyanuric chloride to prepare the starch-based dispersant. According to the prepared starch-based dispersing agent, disperse dye is wrapped in particles through a polymer skeleton, the hydrophilicity of the dye particles is improved by virtue of hydrophilic groups, and meanwhile, particle aggregation is broken by virtue of steric hindrance repulsive force and electrostatic repulsive force, so that the dispersion stability of a dye system is kept; in addition, the starch-based dispersing agent also has good high-temperature stability, low contamination to fibers, no toxicity, no odor, clean production environment and good dispersity, can be used for dispersing disperse dyes for dyeing synthetic fiber polyester and the like, and has a wide application prospect.

Description

Technical Field

[0001] The present invention relates to the field of textile technology, and particularly relates to a starch-based dispersant for dispersing disperse dyes, a preparation method thereof and an application thereof. Background Art

[0002] Polyester fiber is one of the most widely used fibers in the world at present. It has a highly dense crystalline structure, which enables polyester fiber to resist the absorption of dyes. Therefore, the coloring process is usually carried out using disperse dyes under high temperature or high pressure. Due to its hydrophobic chemical structure, disperse dyes can enhance the molecular affinity with polyester fiber, but this structure also results in poor solubility in water. However, in the coloring process of polyester, disperse dyes need to be finely dispersed and remain stable in an aqueous medium. The use of a suitable dispersant can prepare a stable dye dispersion, thereby achieving a uniform coloring effect. In this process, the dispersant plays a crucial role in the stability of disperse dyes. On the one hand, the dispersant can migrate to the liquid-solid interface and prevent particle aggregation or agglomeration by changing the interfacial tension, electrostatic repulsion or steric hindrance effect. On the other hand, the dispersant can also form micelles in the dyeing medium, playing a certain solubilizing role for the dyes.

[0003] At present, the common commercial dispersants mainly include petroleum-based dispersants and lignin-based dispersants. In the production process of petroleum-based dispersants, there are often problems such as the volatilization of naphthalene or naphthalene-based intermediates, which results in a strong smell and high toxicity in the production environment (Qian Chunxia, He Quanhui, Zhao Peng, etc. Preparation of liquid disperse dyes and selection of dispersants [J]. Dyes and Pigments, 2021, 58(05): 43-48+34.). The domestic lignosulfonates mainly come from the reprocessing of papermaking waste liquor. Its advantages are rich raw materials and low cost. However, due to the relatively dark color of the papermaking waste liquor itself, the prepared lignosulfonates are prone to stain the fibers, thus being restricted to a certain extent in the field of light color applications (Yufei Xiu, Kezhong Wang, Chaoxia Wang, et al. Comparative analysis of ultrafine fluorescent dispersed dye paste and its stability with naphthalene sulphonic derivative dispersant [J]. Pigment & Resin Technology, 2013, 42(6): 406-410.). Therefore, the development of new dye dispersants with good biocompatibility, excellent dispersion performance and little influence on fiber dyeing has become an important trend in the research field of dye auxiliaries.

[0004] As a biological macromolecule, starch widely exists in plants, animals, fungi and bacteria. The hydroxyl groups on the starch molecular chain can introduce groups with different properties through chemical modification, thereby obtaining hydrophilic or hydrophobic characteristics. However, due to its high molecular weight and poor water solubility, native starch is greatly restricted in its applications in many fields. By using methods such as acid hydrolysis (e.g., dilute hydrochloric acid, sulfuric acid), oxidants (e.g., hydrogen peroxide, sodium periodate), enzymatic hydrolysis (e.g., using amylase), thermal degradation, ultrasonic degradation, and radiation degradation (e.g., γ-rays), the glycosidic bonds or other chemical bonds in the starch chain can be effectively broken to reduce the molecular weight of starch.

[0005] However, there is currently no relevant report on preparing a starch-based dispersant using starch as a substrate. Therefore, the preparation of starch-based dispersants has very broad application prospects in the dispersion application of disperse dyes. Summary of the Invention

[0006] The object of the present invention is to overcome the above-mentioned defects existing in the prior art, and to provide a starch-based dispersant for the dispersion of disperse dyes, its preparation method and application. Using acid-hydrolyzed starch obtained by acid degradation as a substrate, a substitution reaction is carried out with arylsulfonic acid-substituted cyanuric chloride, and then a starch-based dispersant is prepared; this starch-based dispersant can wrap the disperse dyes with its polymer skeleton. The sulfonic acid groups therein can not only generate sulfonate ions through ionization to provide electrostatic repulsion, further enhancing the repulsive force between particles, but also significantly improve the wettability of the dispersion system, promoting the uniform dispersion of dye particles. This starch-based dispersant has very broad application prospects in the dispersion application of disperse dyes.

[0007] To achieve the above object, the technical solution of the present invention is as follows:

[0008] A starch-based dispersant for the dispersion of disperse dyes, the starch-based dispersant is an arylsulfonic acid group-containing starch-based dye dispersant; the structural general formula of the arylsulfonic acid group-containing starch-based dye dispersant is shown in Formula I:

[0009] [A(B) i n ;

[0010] Wherein, A is a starch polysaccharide unit residue after acid hydrolysis; B is a substituent on the starch polysaccharide unit residue; i is the degree of substitution, 0 < i < 3; n is the degree of polymerization of the starch degradation product, which is an integer from 1 to 1000;

[0011] Wherein, the substituent B is an arylsulfonic acid group-containing group with a triazine ring as a bridging group, randomly substituting the H on the -OH in the starch polysaccharide unit, and its structural general formula is shown in Formula I-1:

[0012] ​

[0013] Wherein, R1, R2, R3 and R4 are each independently selected from -H, and at least one of R1, R2, R3 and R4 is selected from R1, R2, R3 and R4 may be the same or different.

[0014] Optionally, the weight-average molecular weight of the starch-based dye dispersant containing an aromatic sulfonic acid group is 11×10 4 g·mol -1 ~23×10 4 g·mol -1 .

[0015] Optionally, the disperse dye is a dye without water-soluble groups in its molecular structure.

[0016] Optionally, the disperse dye includes at least one of azo disperse dyes, anthraquinone disperse dyes and heterocyclic disperse dyes.

[0017] The present invention also discloses a preparation method of the starch-based dispersant for dispersing disperse dyes as described above, including the following steps:

[0018] (1) Cyanuric chloride and the aromatic sulfonic acid group-containing compound are added to water at a molar ratio of 1:2, and the reaction is carried out at -5°C to 40°C to obtain a sulfonic acid compound containing a triazine structure;

[0019] (2) The sulfonic acid compound containing a triazine structure is mixed with acid-hydrolyzed starch and an alkali, and the reaction is carried out at 40°C to 80°C, and after washing and drying, the starch-based dispersant is obtained.

[0020] Optionally, in step (2), the preparation method of the acid-hydrolyzed starch specifically includes the following steps: Starch is added to water, and the gelatinization reaction is carried out at 70°C to 90°C; after gelatinization, the temperature is lowered to 50°C to 80°C, and an appropriate amount of concentrated hydrochloric acid is quickly added to prepare a hydrochloric acid hydrolysis solution of 0.1 mol·L -1 ~1 mol·L -1 , and acid hydrolysis is carried out for 1 to 10 h, and the acid-hydrolyzed starch is obtained after washing and drying with ethanol.

[0021] Optionally, in step (2), the alkali includes at least one of KOH and NaOH.

[0022] Optionally, in step (2), the molar ratio of the sulfonic acid compound containing a triazine structure, acid-hydrolyzed starch and alkali is 0.1 to 3:1:0.1 to 1.

[0023] The present invention also discloses an application of the starch-based dispersant for disperse dyes as described above. The method of the application is a wet grinding method, which specifically includes: adding the starch-based dispersant, disperse dyes and water into a sand grinding tube for mixing, and then adding zirconia beads for sand grinding and dispersing treatment until the dye particle size is 150 nm to 500 nm.

[0024] Optionally, the mass-volume ratio of the starch-based dispersant, water and disperse dyes is 3 g∶7.5 mL∶(1 - 6) g.

[0025] Optionally, the time of the sand grinding and dispersing treatment is 12 h to 48 h.

[0026] Optionally, the mixing time is 30 min to 60 min.

[0027] Optionally, the diameter of the zirconia beads is 1 mm to 2 mm.

[0028] Optionally, the mass of the added zirconia beads is 40 g to 60 g.

[0029] Optionally, the sand grinding tube is a glass sand grinding tube.

[0030] Implementing the embodiments of the present invention will have the following beneficial effects:

[0031] The present invention provides a starch-based dispersant for disperse dyes, its preparation method and application. The method uses acid-hydrolyzed starch obtained by acid degradation as a polymer backbone, and reacts with aromatic sulfonic acid-substituted cyanuric chloride to prepare a starch-based dispersant with a weight average molecular weight of 11×10 4 g·mol -1 ~23×10 4 g·mol -1 , which is used to disperse disperse dyes for dyeing synthetic fibers such as polyester.

[0032] The starch-based dispersant provided by the present invention wraps the disperse dyes in particles through its polymer backbone, improves the hydrophilicity of the dye particles by means of hydrophilic groups, and at the same time relies on steric hindrance repulsion and electrostatic repulsion to break particle agglomeration, thereby maintaining the dispersion stability of the dye system. This starch-based dispersant has good high-temperature stability, low fiber staining, is non-toxic and odorless, has a clean production environment, good dispersibility, and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is the infrared spectrum of the starch-based dispersant of Example 1 of the present invention.

[0034] Figure 2 It is the dye spotting effect diagram obtained from Examples 5 - 10 of the present invention and Comparative Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited in any way.

[0036] The 1#, 2#, 3#, and 4# starch-based dispersants exemplified in the following embodiments have the following structural formulas respectively:

[0037]

[0038] where R is respectively

[0039] Example 1

[0040] The preparation method of the 1# starch-based dispersant specifically includes: adding cyanuric chloride (0.05 mol), sulfanilic acid (0.05 mol), and an appropriate amount of ice cubes into a beaker, and performing the first substitution under the conditions of a temperature of 0 °C and a pH of 5. After 2 h, the temperature is raised to 25 °C, sulfanilic acid (0.05 mol) is added, the pH is adjusted to 7, and the second substitution reaction is carried out. After 4 h, potassium acetate is added to precipitate a solid, which is washed with absolute ethanol, filtered, dried, and pulverized to obtain an arylsulfonic acid group modifier containing a triazine structure. 0.03 mol of starch (calculated as polysaccharide units) and 25 g of water are added to a reactor, and gelatinization is carried out at 90 °C for 1 h. Then the temperature is lowered to 60 °C, and an appropriate amount of concentrated hydrochloric acid is added to prepare a 0.5 mol·L -1 hydrolysis solution. After acid hydrolysis and neutralization, it is precipitated with ethanol and dried to obtain acid-hydrolyzed starch. Acid-hydrolyzed starch (0.03 mol), modifier (0.012 mol), and NaOH (0.024 mol) are added to the reactor, and the reaction is carried out at 60 °C for 5 h. The solid is precipitated in ethanol, filtered, dried, and pulverized to obtain the 1# starch-based dispersant containing an arylsulfonic acid group with a triazine structure.

[0041] The above product is subjected to dialysis treatment, dried, and the degree of substitution of the product is calculated to be 0.28, and the effective conversion rate of the group is 70%. The infrared analysis spectrum is as attached Figure 1 , and characteristic peaks of the triazine ring (1620 cm -1 , 1580 cm -1 ) appear in the infrared spectrum of the product, the asymmetric stretching vibration absorption peak of S=O in the sulfonic acid group (1240 cm -1 ), and the stretching vibration absorption peak of υ(C-N) (1039 cm -1 ), indicating that a chemical reaction has occurred between the modifier and the acid-hydrolyzed starch, and the 1# starch-based dispersant is synthesized.

[0042] The specific chemical reaction equation is as follows:

[0043]

[0044] Example 2

[0045] The preparation method of the 2# starch-based dispersant specifically includes: adding cyanuric chloride (0.05 mol), sulfanilic acid (0.05 mol) and an appropriate amount of ice cubes into a beaker, and performing the first substitution under the conditions of a temperature of 0 °C and a pH of 5. After 2 h, the temperature is raised to 35 °C, anthranilic acid (0.05 mol) is added, the pH is adjusted to 7, and the second substitution reaction is carried out. After 4 h, potassium acetate is added to precipitate a solid, which is washed with absolute ethanol, filtered, dried, and pulverized to obtain an aromatic sulfonic acid group modifier containing a triazine structure. 0.03 mol of starch (counted by polysaccharide units) and 25 g of water are added into a reactor, and gelatinized at 90 °C for 1 h. Then the temperature is lowered to 80 °C, and an appropriate amount of concentrated hydrochloric acid is added to prepare a 0.3 mol·L -1 hydrolysis solution. After acid hydrolysis for 4 h, it is neutralized, precipitated by ethanol, and dried to obtain acid-hydrolyzed starch. Acid-hydrolyzed starch (0.03 mol), modifier (0.006 mol) and NaOH (0.009 mol) are added into the reactor, and the reaction is carried out at 80 °C for 5 h. The solid is precipitated in ethanol, filtered, dried, and pulverized to obtain the 2# starch-based dispersant containing an aromatic sulfonic acid group with a triazine structure.

[0046] The specific chemical reaction equations are as follows:

[0047]

[0048] Example 3

[0049] The preparation method of the 3# starch-based dispersant specifically includes: adding cyanuric chloride (0.05 mol), sulfanilic acid (0.05 mol) and an appropriate amount of ice cubes into a beaker, and performing the first substitution under the conditions of a temperature of 0 °C and a pH of 5. After 2 h, the temperature is raised to 30 °C, 2-naphthylamine-1-sulfonic acid (0.05 mol) is added, the pH is adjusted to 7, and the second substitution reaction is carried out. After 4 h, potassium acetate is added to precipitate a solid, which is washed with absolute ethanol, filtered, dried, and pulverized to obtain an aromatic sulfonic acid group modifier containing a triazine structure. 0.03 mol of starch (counted by polysaccharide units) and 25 g of water are added into a reactor, and gelatinized at 90 °C for 1 h. Then the temperature is lowered to 70 °C, and an appropriate amount of concentrated hydrochloric acid is added to prepare a 0.7 mol·L -1 hydrolysis solution. After acid hydrolysis for 1 h, it is neutralized, precipitated by ethanol, and dried to obtain acid-hydrolyzed starch. Acid-hydrolyzed starch (0.03 mol), modifier (0.018 mol) and KOH (0.036 mol) are added into the reactor, and the reaction is carried out at 70 °C for 5 h. The solid is precipitated in ethanol, filtered, dried, and pulverized to obtain the 3# starch-based dispersant containing an aromatic sulfonic acid group with a triazine structure.

[0050] The specific chemical reaction equations are as follows:

[0051]

[0052] Example 4

[0053] The preparation method of the 4# starch-based dispersant specifically includes: adding cyanuric chloride (0.05 mol), 2-naphthylamine-1-sulfonic acid (0.05 mol) and an appropriate amount of ice cubes into a beaker, and carrying out the first substitution under the conditions of a temperature of 0 °C and a pH of 5. After 2 h, the temperature is raised to 40 °C, 2-naphthylamine-6-sulfonic acid (0.05 mol) is added, the pH is adjusted to 7, and the second substitution reaction is carried out. After 4 h, potassium acetate is added to precipitate solids, which are washed with absolute ethanol, filtered, dried, and pulverized to obtain an arylsulfonic acid group modifier containing a triazine structure. 0.03 mol of starch (calculated based on polysaccharide units) and 25 g of water are added to a reactor, and gelatinization is carried out at 90 °C for 1 h. Then the temperature is lowered to 75 °C, and an appropriate amount of concentrated hydrochloric acid is added to prepare a 0.8 mol·L -1 hydrolysis solution. After acid hydrolysis for 1 h, it is neutralized, precipitated with ethanol, and dried to obtain acid-hydrolyzed starch. Acid-hydrolyzed starch (0.03 mol), modifier (0.03 mol) and KOH (0.04 mol) are added to the reactor, and the reaction is carried out at 75 °C for 5 h. Solids are precipitated in ethanol, filtered, dried, and pulverized to obtain the 4# starch-based dispersant containing an arylsulfonic acid group with a triazine structure.

[0054] The specific chemical reaction equations are as follows:

[0055]

[0056] Example 5

[0057] 3 g of the 1# starch-based dispersant with a weight average molecular weight of 11.0×10 4 g·mol -1 , 7.5 mL of deionized water and 3 g of the original Disperse Orange 30 are added to a 100 mL sand mill tube, and the stirring speed is controlled at 200 r·min -1 using a digital display mechanical stirrer, and stirring is carried out for 30 min. Then 45 g of zirconia beads with a diameter of 1.8 mm are added to the container for sand milling and dispersing for 48 h.

[0058] Example 6

[0059] 3 g of the 1# starch-based dispersant with a weight average molecular weight of 13.2×10 4 g·mol -1 , 7.5 mL of deionized water and 2 g of the original Disperse Orange 30 are added to a 100 mL sand mill tube, and the stirring speed is controlled at 200 r·min -1 using a digital display mechanical stirrer, and stirring is carried out for 40 min. Then 60 g of zirconia beads with a diameter of 1.8 mm are added to the container for sand milling and dispersing for 24 h.

[0060] Example 7

[0061] 3 g of starch-based dispersant 1 with a weight-average molecular weight of 15.0×10 4 g·mol -1 , 7.5 mL of deionized water and 1 g of raw Disperse Orange 30 were added to a 100 mL sand mill tube, and the stirring speed was controlled at 200 r·min -1 with a digital display mechanical stirrer for 50 min. Then, 50 g of zirconia beads with a diameter of 1.8 mm were added to the container for sanding and dispersing for 24 h.

[0062] Example 8

[0063] 3 g of starch-based dispersant 1 with a weight-average molecular weight of 18.0×10 4 g·mol -1 , 7.5 mL of deionized water and 4 g of raw Disperse Orange 30 were added to a 100 mL sand mill tube, and the stirring speed was controlled at 200 r·min -1 with a digital display mechanical stirrer for 50 min. Then, 45 g of zirconia beads with a diameter of 1.8 mm were added to the container for sanding and dispersing for 36 h.

[0064] Example 9

[0065] 3 g of starch-based dispersant 1 with a weight-average molecular weight of 21.1×10 4 g·mol -1 , 7.5 mL of deionized water and 5 g of raw Disperse Orange 30 were added to a 100 mL sand mill tube, and the stirring speed was controlled at 200 r·min -1 with a digital display mechanical stirrer for 60 min. Then, 50 g of zirconia beads with a diameter of 1.8 mm were added to the container for sanding and dispersing for 48 h.

[0066] Example 10

[0067] 3 g of starch-based dispersant 1 with a weight-average molecular weight of 23.0×10 4 g·mol -1 , 7.5 mL of deionized water and 6 g of raw Disperse Orange 30 were added to a 100 mL sand mill tube, and the stirring speed was controlled at 200 r·min -1 with a digital display mechanical stirrer for 50 min. Then, 60 g of zirconia beads with a diameter of 1.8 mm were added to the container for sanding and dispersing for 36 h.

[0068] Examples 11 - 13

[0069] Compared with Example 5, the difference in this example is only that: in Examples 11 - 13, 2# starch-based dispersant, 3# starch-based dispersant, and 4# starch-based dispersant were used respectively.

[0070] Examples 14 - 16

[0071] This example is different from Example 6 only in that: Examples 14 - 16 respectively use 2# starch - based dispersant, 3# starch - based dispersant, and 4# starch - based dispersant.

[0072] Examples 17 - 19

[0073] This example is different from Example 7 only in that: Examples 17 - 19 respectively use 2# starch - based dispersant, 3# starch - based dispersant, and 4# starch - based dispersant.

[0074] Examples 20 - 22

[0075] This example is different from Example 8 only in that: Examples 20 - 22 respectively use 2# starch - based dispersant, 3# starch - based dispersant, and 4# starch - based dispersant.

[0076] Examples 23 - 25

[0077] This example is different from Example 9 only in that: Examples 23 - 25 respectively use 2# starch - based dispersant, 3# starch - based dispersant, and 4# starch - based dispersant.

[0078] Examples 26 - 28

[0079] This example is different from Example 10 only in that: Examples 26 - 28 respectively use 2# starch - based dispersant, 3# starch - based dispersant, and 4# starch - based dispersant.

[0080] Comparative Example 1

[0081] Disperse Orange 30 was sand - ground and dispersed according to the method of Example 5, with the difference that: the starch - based dispersant was replaced with an equal mass of commercial dispersant NNO.

[0082] Test Example

[0083] The dispersion performance results of Examples 5 - 28 and Comparative Example 1 are shown in Table 1 below. The dye spotting effects of Examples 5, 10, and Comparative Example 1 are as Figure 2 shown.

[0084] Table 1 Dispersion performance of Examples 1 - 26 and Comparative Example 1

[0085]

[0086]

[0087] The above-described embodiments merely represent several implementation manners of the present invention. Their descriptions are relatively specific and detailed, but they should not be construed as limitations on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent shall be subject to the appended claims.

Claims

1. A starch-based dispersant for the dispersion of disperse dyes, characterized in that, The starch-based dispersant is an aromatic sulfonic acid group-containing starch-based dye dispersant; the structural general formula of the aromatic sulfonic acid group-containing starch-based dye dispersant is shown in Formula I: [A(B) i n ;​ Wherein, A is a starch polysaccharide unit residue after acid hydrolysis; B is a substituent on the starch polysaccharide unit residue; i is the degree of substitution, 0 < i < 3; n is the degree of polymerization of the starch degradation product, which is an integer from 1 to 1000; Wherein, the substituent B is an aromatic sulfonic acid group-containing group with a triazine ring as a bridging group, randomly substituting the H on -OH in the starch polysaccharide unit, and its structural general formula is shown in Formula I-1: wherein, R1, R2, R3 and R4 are each independently selected from -H, and at least one of R1, R2, R3 and R4 is selected from R1, R2, R3 and R4 may be the same or different.

2. The starch-based dispersant for the dispersion of disperse dyes according to claim 1, characterized in that, The weight-average molecular weight of the aromatic sulfonic acid group-containing starch-based dye dispersant is 11×10 4 g·mol -1 ~23×10 4 g·mol -1 .

3. The starch-based dispersant for dispersing disperse dyes according to claim 1, characterized in that, The disperse dye is a dye without water-soluble groups in its molecular structure.

4. The starch-based dispersant for the dispersion of disperse dyes according to claim 3, characterized in that, The disperse dye includes at least one of azo disperse dyes, anthraquinone disperse dyes, and heterocyclic disperse dyes.

5. A preparation method of a starch-based dispersant for disperse dye dispersion according to any one of claims 1-4, characterized in that, It includes the following steps: (1) Add cyanuric chloride and an aromatic sulfonic acid group-containing compound to water in a molar ratio of 1:2, and react at -5°C to 40°C to obtain a sulfonic acid compound containing a triazine structure; (2) Mix the sulfonic acid compound containing a triazine structure with acid-hydrolyzed starch and an alkali, react at 40°C to 80°C, and wash and dry to obtain the starch-based dispersant.

6. The preparation method according to claim 5, characterized in that, In step (2), the preparation method of the acid-hydrolyzed starch specifically includes the following steps: adding starch into water, and carrying out a gelatinization reaction at 70°C to 90°C; after gelatinization, cooling down to 50°C to 80°C, and quickly adding an appropriate amount of concentrated hydrochloric acid to prepare a hydrochloric acid hydrolysis solution with a concentration of 0.1 mol·L -1 ~1 mol·L -1 , carrying out acid hydrolysis, and obtaining the acid-hydrolyzed starch after washing and drying with ethanol.

7. The preparation method according to claim 5, characterized in that, In step (2), the alkali includes at least one of NaOH and KOH; The molar ratio of the sulfonic acid compound containing a triazine structure, acid-hydrolyzed starch, and alkali is 0.1 to 3:1:0.1 to 1.

8. Use of a starch-based dispersant for dispersing disperse dyes as described in any one of claims 1-4, characterized in that, The method of the application includes: adding the starch-based dispersant, disperse dye, and water into a sand mill tube for mixing, and then adding zirconia beads for sand milling and dispersion treatment until the dye particle size is 150 nm to 500 nm.

9. The application according to claim 8, characterized in that, The mass-volume ratio of the starch-based dispersant, water, and disperse dye is 3 g∶7.5 mL∶(1 to 6) g; The time for the sand milling and dispersion treatment is 12 h to 48 h; The time for the mixing is 30 min to 60 min; The diameter of the zirconia beads is 1 mm to 2 mm.

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