Dispersing agent for water-based color paste and preparation method of dispersing agent

Abstract

The invention relates to a dispersing agent for water-based color paste and a preparation method of the dispersing agent. According to the dispersing agent containing the hydrophilic and hydrophobic chain segments and capable of being specifically combined with the pigment particles, a polymerization product with narrow molecular weight distribution is obtained based on RAFT polymerization, and the problem that organic pigment is prone to agglomeration in a color paste system is avoided through wrapping of the hydrophobic chain segments of polyether in the structure on the pigment particles; a polyether solvation chain segment is introduced into the structure of the dispersing agent, so that the storage stability of the dispersing agent in a water phase is ensured; the high approximation of the acridone structure and common pigment structures such as quinacridone and isoindolinone ensures the coating effect of the dispersing agent on pigment particles, the dispersing agent has good dispersibility and compatibility in different aqueous systems, a specific dispersion effect is formed, the problems of high viscosity, difficult dispersion and the like of organic pigments in the aqueous systems are effectively solved, and the dispersing agent has good application prospects. The dispersant can be used as a dispersant or an additive of systems such as water-based color paste and water-based ink. The method can be widely used in the fields of inks and paints.

Description

Technical Field

[0001] This invention relates to a dispersant for aqueous color pastes and a method for preparing the same. Background Technology

[0002] In recent years, organic pigments have been widely used in coatings, inks, paints, plastics, textiles, and other applications due to their rich colors and diverse structures. However, in practical applications, when water-based pigment pastes made from organic pigments are used in water-based coatings, paints, and other dispersion systems, the non-polar or weakly polar nature of the pigment molecules results in low surface free energy and significant interfacial tension with the water medium. This makes it difficult for water molecules to effectively wet the pigment surface, leading to a tendency for partial pigment aggregation.

[0003] To address the dispersion problem of organic pigments in aqueous phases, surfactants such as dispersants are widely used as additives in formulations, most of which are prepared by free radical polymerization. Traditional free radical polymerization is simple and applicable to a wide range of monomers, but the polymer products have a wide molecular weight distribution and inconsistent chain lengths, resulting in poor wetting and dispersing properties in applications. To obtain polymer products with a narrow molecular weight distribution, controlled free radical polymerization is required. However, most current reports on controlled free radical polymerization describe polymerization conditions that are too demanding for large-scale industrial production. CN114369212A utilizes atom transfer radical (ATRP) polymerization with copper bromide as a catalyst to prepare a copolymer with a molecular weight distribution of 1.26, but the polymer contains copper ions that are difficult to remove. CN106543322A introduces a method for preparing coating dispersants by photo-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization at room temperature, but the reaction conditions under ultraviolet light irradiation are difficult to implement in subsequent reactor production. CN117887009A uses dioxane and other solvents as solvent phases, and after completing RAFT polymerization, the polymer is obtained by multiple purifications with undesirable solvents and drying. The implementation steps are cumbersome, and the solvent phase has a certain degree of toxicity. Summary of the Invention

[0004] To address the above problems, the present invention aims to provide a method for synthesizing a dispersant solution containing hydrophilic and hydrophobic segments that can specifically bind to pigment particles. The method uses an aqueous phase as the solvent phase for RAFT polymerization, which is simple to operate. The aqueous dispersion system obtained by this dispersant has high storage stability, and the polymerization product has no metal catalysis, resulting in higher dispersion efficiency. The addition amount is small, which can effectively prevent flocculation.

[0005] This invention provides a dispersant containing hydrophilic and hydrophobic segments that can specifically bind to pigment particles.

[0006] A dispersant for aqueous color pastes, with the structure shown in formula (Ⅰ): Ⅰ Where R is methyl or ethyl, M + for Na + or K + x is any integer between 5 and 15, and y is any integer between 10 and 20.

[0007] In addition, the present invention also provides a method for preparing a dispersant for aqueous color pastes.

[0008] A dispersant for aqueous color pastes and a method for preparing the same, comprising the following steps: S1. The reaction system containing 3-hydroxy-10-methylacridone and dihalopropane was reacted in an organic solvent under the catalysis of an alkaline catalyst. After extraction, separation, drying, and concentration, the mixture was purified by rapid column chromatography with a mixture of petroleum ether and ethyl acetate as the eluent to obtain the functionalized monomer shown in formula (II). II S2. The functionalized monomer obtained in step S1 is mixed with acrylic acid and allylated block polyether in water under the action of chain transfer agent and initiator, and the mixture is subjected to a controlled polymerization reaction for a certain time. The mixture is then neutralized with an alkaline aqueous solution of 20%-40% by mass until the pH is 7-8, to obtain the dispersant for water-based color paste.

[0009] Furthermore, In step S1, the chain transfer agent is 2-[(2-phenyl-1-thioethyl)thio]succinic acid.

[0010] In step S1, the reaction temperature is 0~40℃ and the reaction time is 10~15h; In step S1, the dihalopropane is one of 1,3-dibromopropane and 1,3-diiodopropane; In step S1, the alkaline catalyst is one or a mixture of several of potassium hydride, sodium hydride, potassium carbonate, potassium hydroxide, and sodium hydroxide. In step S1, the molar ratio of 3-hydroxy-10-methylacridone to dihalopropane is 1:3 to 1:10; In step S1, the molar ratio of 3-hydroxy-10-methylacridone to the alkaline catalyst is 1:4 to 1:10; In step S1, the organic solvent is one or a mixture of several of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, toluene, ethylbenzene, and dimethyl sulfoxide. In step S1, the eluent used for rapid column chromatography purification is a mixed solvent of petroleum ether and ethyl acetate with a volume ratio of 15:1 to 6:1. In step S2, the copolymerization reaction temperature is 50~120℃, and the copolymerization reaction time is 5-12h; In step S2, the allylated block polyether structure is as shown in formula (Ⅲ): III Where R is methyl or ethyl, x is any integer between 5 and 15, and y is any integer between 10 and 20; In step S2, the initiator is one or a mixture of several of the following: azobisisobutyramidine hydrochloride, azobisisobutyramidazole hydrochloride, azobisisobutyramidazole acid, and azobisisopropylimidazoline. In step S2, the molar ratio of the initiator to acrylic acid is 1:100 to 1:500. In step S2, the molar ratio of chain transfer agent to acrylic acid is 1:30 to 1:100; In step S2, the molar ratio of functionalized monomer to acrylic acid is 1:5 to 1:20. In step S2, the molar ratio of allylated block polyether to acrylic acid is 1:5 to 1:40. In step S2, the alkaline aqueous solution is either NaOH aqueous solution or KOH aqueous solution.

[0011] This invention utilizes RAFT polymerization to obtain polymer products with a narrow molecular weight distribution. The encapsulation of pigment particles by hydrophobic polyether segments within the dispersant structure avoids the problem of easy aggregation of organic pigments in color paste systems. The introduction of polyether solvation segments into the dispersant structure ensures its storage stability in the aqueous phase. The acridinone structure's high similarity to the structures of common pigments such as quinacridones and isoindolinones ensures the effective encapsulation of pigment particles by the dispersant. It exhibits good dispersibility and compatibility in various aqueous systems, forming a specific dispersion effect. This effectively solves the problems of high viscosity and poor dispersion of organic pigments in aqueous systems, and can be used as a dispersant or additive in water-based color pastes and inks. It can be widely used in inks, coatings, and other fields.

[0012] The beneficial effects of this invention are: This invention relates to a dispersant for water-based pigment pastes, which exhibits good dispersing performance and excellent viscosity reduction effect. Because its side chains contain polyether chain structures, it can effectively anchor pigment molecules and achieve dispersion and stabilization effects through steric hindrance. The dispersant synthesized by this invention is produced by RAFT polymerization, which can obtain a dispersant with a smaller molecular weight distribution value. Compared with the dispersants obtained by traditional free radical polymerization, the structure is more defined, and the structure of the dispersant can be better designed and modified. Detailed Implementation

[0013] The present invention will be described in detail below with reference to the embodiments. The chain transfer agent of the present invention is 2-[(2-phenyl-1-thioethyl)thio]succinic acid synthesized according to patent US20060223936. Example 1

[0014] (1) Carbon disulfide (4.0 g, 0.07 mol) was added to a three-necked flask containing a dry tetrahydrofuran solution (40 mL). Nitrogen gas was bubbled in while stirring, and the flask was cooled in an ice-water bath. After 20 min, a Grignard reagent benzyl magnesium chloride solution in diethyl ether (1.0 mol / L, 40 mL, 0.04 mol) was slowly added to the flask. After stirring for 30 min, 2-bromopropionic acid (3.6 mL, 6.2 g, 0.04 mol) was added, and the ice-water bath was removed. After reacting at room temperature for 48 h, the mixture was poured into ethyl acetate (200 mL) and washed successively with water (3 × 100 mL) and saturated sodium chloride solution (100 mL). The organic layer was dried over magnesium sulfate, and excess 2-bromopropionic acid was removed by concentration under reduced pressure. The concentrate was dissolved in diethyl ether (200 mL) and extracted with a 5% sodium bicarbonate aqueous solution (4 × 50 mL). The aqueous phases were combined, washed with ether (100 mL), and then acidified to pH < 1 with 2 mol / L hydrochloric acid. The resulting mixture was extracted with ethyl acetate (2 × 100 mL), and the organic phase extract was washed successively with water (2 × 50 mL) and saturated sodium chloride solution (50 mL), dried over magnesium sulfate, and the solvent was evaporated to obtain the chain transfer agent 2-[(2-phenyl-1-thioethyl)thio]succinic acid.

[0015] (2) Dissolve 3-hydroxy-10-methylacridone (27.0 g, 0.12 mol) in N,N-dimethylformamide (200 mL), place in an ice-water bath, stir continuously, slowly add sodium hydride (14.4 g, 0.6 mol), keep stirring in an ice-water bath for 30 min, add 1,3-dibromopropane (121.2 g, 0.6 mol), stir continuously at room temperature for 12 h, quench sodium hydride with an appropriate amount of ethanol, extract with ethyl acetate (3 × 100 mL), combine the organic phases, dry with magnesium sulfate, concentrate under reduced pressure, purify by rapid column chromatography, elute with a mixed solvent of petroleum ether and ethyl acetate at a volume ratio of 12:1, to obtain the functionalized monomer.

[0016] (3) Add allylated polyoxyethylene-polyoxypropylene block polyether (43.2 g, 0.04 mol, structural formula CH2=CHCH2O(CH2CHCH3O)7(CH2CH2O)) to a three-necked flask. 14H), functionalized monomer (10.6 g, 40 mmol), acrylic acid (21.6 g, 0.30 mol), and water (100 g) were stirred, nitrogen gas was bubbled in, and the temperature was gradually raised to 80 °C. Chain transfer agent (1.70 g, 6 mmol) and azobisisobutyramidine hydrochloride (0.54 g, 2.0 mmol) were dissolved in water (20 g) respectively, and placed in constant pressure dropping funnels. Under continuous nitrogen bubbling, both dropping funnels were opened simultaneously, and the dropping time was 1 h. After the dropping was completed, the reaction was maintained at 80 °C for 6 h. The mixture was neutralized with 30% NaOH solution until the pH was 7.5, and a dispersant with a molecular weight distribution of 1.12 for water-based pigment pastes was obtained. Example 2

[0017] (1) Same as step (1) in Example 1.

[0018] (2) Same as step (2) in Example 1.

[0019] (3) Add allylated polyoxyethylene-polyoxypropylene block polyether (43.2 g, 0.04 mol, structural formula CH2=CHCH2O(CH2CHCH3O)7(CH2CH2O)) to a three-necked flask. 14 H), functionalized monomers (15.9 g, 0.06 mol), acrylic acid (21.6 g, 0.30 mol), and water (100 g) were stirred, nitrogen gas was bubbled in, and the temperature was gradually raised to 80 °C. Chain transfer agent (2.84 g, 0.01 mol) and azobisisobutyramidine hydrochloride (0.54 g, 2.0 mmol) were dissolved in water (20 g) respectively, and placed in constant pressure dropping funnels. Under continuous nitrogen bubbling, both dropping funnels were opened simultaneously, and the dropping time was 1 h. After the dropping was completed, the reaction was maintained at 80 °C for 6 h. The mixture was neutralized with 30% NaOH solution until the pH was 7.5, and a dispersant with a molecular weight distribution of 1.18 for use in water-based pigment pastes was obtained. Example 3

[0020] (1) Same as step (1) in Example 1.

[0021] (2) Same as step (2) in Example 1.

[0022] (3) Add allylated polyoxyethylene-polyoxypropylene block polyether (43.2 g, 0.04 mol, structural formula CH2=CHCH2O(CH2CHCH3O)7(CH2CH2O)) to a three-necked flask. 14H), functionalized monomer (3.98 g, 15 mmol), acrylic acid (21.6 g, 0.30 mol), and water (100 g) were stirred, nitrogen gas was bubbled in, and the temperature was gradually raised to 80 °C. Chain transfer agent (2.84 g, 0.01 mol) and azobisisobutyramidine hydrochloride (0.54 g, 2.0 mmol) were dissolved in water (20 g) respectively, and placed in constant pressure dropping funnels. Under continuous nitrogen bubbling, both dropping funnels were opened simultaneously, and the dropping time was 1 h. After the dropping was completed, the reaction was maintained at 80 °C for 6 h. The mixture was neutralized with 30% NaOH solution until the pH was 7.5, and a dispersant with a molecular weight distribution of 1.20 for use in water-based pigment pastes was obtained. Example 4

[0023] (1) Same as step (1) in Example 1.

[0024] (2) Same as step (2) in Example 1.

[0025] (3) Add allylated polyoxyethylene-polyoxypropylene block polyether (43.2 g, 0.04 mol, structural formula CH2=CHCH2O(CH2CHCH3O)7(CH2CH2O)) to a three-necked flask. 14 H), functionalized monomers (15.9 g, 0.06 mol), acrylic acid (21.6 g, 0.30 mol), and water (100 g) were stirred, nitrogen gas was bubbled in, and the temperature was gradually raised to 80 °C. Chain transfer agent (0.85 g, 3 mmol) and azobisisobutyramidine hydrochloride (0.54 g, 2.0 mmol) were dissolved in water (20 g) respectively, and placed in constant pressure dropping funnels. Under continuous nitrogen bubbling, both dropping funnels were opened simultaneously, and the dropping time was 1 h. After the dropping was completed, the reaction was maintained at 80 °C for 6 h. The mixture was neutralized with 30% NaOH solution until the pH was 7.5, and a dispersant with a molecular weight distribution of 1.13 for use in water-based pigment pastes was obtained. Example 5

[0026] (1) Same as step (1) in Example 1.

[0027] (2) Same as step (2) in Example 1.

[0028] (3) Add allylated polyoxyethylene-polyoxypropylene block polyether (43.2 g, 0.04 mol, structural formula CH2=CHCH2O(CH2CHCH3O)7(CH2CH2O)) to a three-necked flask. 14H), functionalized monomer (3.98 g, 15 mmol), acrylic acid (21.6 g, 0.30 mol), and water (100 g) were stirred, nitrogen gas was bubbled in, and the temperature was gradually raised to 80 °C. Chain transfer agent (0.85 g, 3 mmol) and azobisisobutyramidine hydrochloride (0.54 g, 2.0 mmol) were dissolved in water (20 g) respectively, and placed in constant pressure dropping funnels. Under continuous nitrogen bubbling, both dropping funnels were opened simultaneously, and the dropping time was 1 h. After the dropping was completed, the reaction was maintained at 80 °C for 6 h. The mixture was neutralized with 30% NaOH solution until the pH was 7.5, and a dispersant with a molecular weight distribution of 1.17 for use in water-based pigment pastes was obtained. Example 6

[0029] (1) Same as step (1) in Example 1.

[0030] (2) Same as step (2) in Example 1.

[0031] (3) Add allylated polyoxyethylene-polyoxypropylene block polyether (31.5 g, 0.04 mol, structural formula CH2=CHCH2O(CH2CHCH3O)5(CH2CH2O)) to a three-necked flask. 10 H), functionalized monomer (10.6 g, 40 mmol), acrylic acid (21.6 g, 0.30 mol), and water (100 g) were stirred, nitrogen gas was bubbled in, and the temperature was gradually raised to 80 °C. Chain transfer agent (1.70 g, 6 mmol) and azobisisobutyramidine hydrochloride (0.54 g, 2.0 mmol) were dissolved in water (20 g) respectively, and placed in constant pressure dropping funnels. Under continuous nitrogen bubbling, both dropping funnels were opened simultaneously, and the dropping time was 1 h. After the dropping was completed, the reaction was maintained at 80 °C for 6 h. The mixture was neutralized with 30% NaOH solution until the pH was 7.5, and a dispersant with a molecular weight distribution of 1.13 for use in water-based pigment pastes was obtained. Example 7

[0032] (1) Same as step (1) in Example 1.

[0033] (2) Same as step (2) in Example 1.

[0034] (3) Add allylated polyoxyethylene-polyoxypropylene block polyether (54.7 g, 0.04 mol, structural formula CH2=CHCH2O(CH2CHCH3O)) to a three-necked flask. 15 (CH2CH2O) 10H), functionalized monomer (10.6 g, 40 mmol), acrylic acid (21.6 g, 0.30 mol), and water (100 g) were stirred, nitrogen gas was bubbled in, and the temperature was gradually raised to 80 °C. Chain transfer agent (1.70 g, 6 mmol) and azobisisobutyramidine hydrochloride (0.54 g, 2.0 mmol) were dissolved in water (20 g) respectively, and placed in constant pressure dropping funnels. Under continuous nitrogen bubbling, both dropping funnels were opened simultaneously, and the dropping time was 1 h. After the dropping was completed, the reaction was maintained at 80 °C for 6 h. The mixture was neutralized with 30% NaOH solution until the pH was 7.5, and a dispersant with a molecular weight distribution of 1.28 for use in water-based pigment pastes was obtained. Example 8

[0035] (1) Same as step (1) in Example 1.

[0036] (2) Same as step (2) in Example 1.

[0037] (3) Add allylated polyoxyethylene-polyoxypropylene block polyether (49.1 g, 0.04 mol, structural formula CH2=CHCH2O(CH2CHCH3O)5(CH2CH2O) to a three-necked flask. 20 H), functionalized monomer (10.6 g, 40 mmol), acrylic acid (21.6 g, 0.30 mol), and water (100 g) were stirred, nitrogen gas was bubbled in, and the temperature was gradually raised to 80 °C. Chain transfer agent (1.70 g, 6 mmol) and azobisisobutyramidine hydrochloride (0.54 g, 2.0 mmol) were dissolved in water (20 g) respectively, and placed in constant pressure dropping funnels. Under continuous nitrogen bubbling, both dropping funnels were opened simultaneously, and the dropping time was 1 h. After the dropping was completed, the reaction was maintained at 80 °C for 6 h. The mixture was neutralized with 30% NaOH solution until the pH was 7.5, and a dispersant with a molecular weight distribution of 1.20 for use in water-based pigment pastes was obtained. Example 9

[0038] (1) Same as step (1) in Example 1.

[0039] (2) Same as step (2) in Example 1.

[0040] (3) Add allylated polyoxyethylene-polyoxypropylene block polyether (72.3 g, 0.04 mol, structural formula CH2=CHCH2O(CH2CHCH3O)) to a three-necked flask. 15 (CH2CH2O) 20H), functionalized monomer (10.6 g, 40 mmol), acrylic acid (21.6 g, 0.30 mol), and water (100 g) were stirred, nitrogen gas was bubbled in, and the temperature was gradually raised to 80 °C. Chain transfer agent (1.70 g, 6 mmol) and azobisisobutyramidine hydrochloride (0.54 g, 2.0 mmol) were dissolved in water (20 g) respectively, and placed in constant pressure dropping funnels. Under continuous nitrogen bubbling, both dropping funnels were opened simultaneously, and the dropping time was 1 h. After the dropping was completed, the reaction was maintained at 80 °C for 6 h. The mixture was neutralized with 30% NaOH solution until the pH was 7.5, and a dispersant with a molecular weight distribution of 1.18 for use in water-based pigment pastes was obtained. Example 10

[0041] (1) Same as step (1) in Example 1.

[0042] (2) Same as step (2) in Example 1.

[0043] (3) Add allylated polyoxyethylene-polyoxypropylene block polyether (47.1 g, 0.04 mol, structural formula CH2=CHCH2O(CH2CHC2H5O)7(CH2CH2O) to a three-necked flask. 14 H), functionalized monomer (10.6 g, 40 mmol), acrylic acid (21.6 g, 0.30 mol), and water (100 g) were stirred, nitrogen gas was bubbled in, and the temperature was gradually raised to 80 °C. Chain transfer agent (1.70 g, 6 mmol) and azobisisobutyramidine hydrochloride (0.54 g, 2.0 mmol) were dissolved in water (20 g) respectively, and placed in constant pressure dropping funnels. Under continuous nitrogen bubbling, both dropping funnels were opened simultaneously, and the dropping time was 1 h. After the dropping was completed, the reaction was maintained at 80 °C for 6 h. The mixture was neutralized with 30% NaOH solution until the pH was 7.5, and a dispersant with a molecular weight distribution of 1.16 for use in water-based pigment pastes was obtained.

[0044] Comparative Example 1 The only difference between this comparative example and Example 1 is that the raw materials prepared in step (3) do not include chain transfer agents, resulting in a dispersant with a molecular weight distribution of 2.73.

[0045] Comparative Example 2 The only difference between this comparative example and Example 1 is that the raw materials prepared in step (3) do not include functionalized monomers, resulting in a dispersant with a molecular weight distribution of 1.22.

[0046] Comparative Example 3 The only difference between this comparative example and Example 1 is that the raw materials prepared in step (3) do not include allylated block polyether, resulting in a dispersant with a molecular weight distribution of 1.20.

[0047] Comparative Example 4 The only difference between this comparative example and Example 1 is that the raw materials prepared in step (3) do not include acrylic acid, resulting in a dispersant with a molecular weight distribution of 1.33.

[0048] Test Example 5 Using a laboratory sand mill, the total amount of the color paste formula was 100 g. The dispersant, organic pigment (pigment red PR122), defoamer, J61 resin, and water were added in sequence according to the proportion. After stirring evenly, 200 g of zirconium beads with a particle size of 1.2-1.4 mm were added and sealed in a glass jar. The mixture was shaken for 8 hours and then filtered to obtain the color paste.

[0049] The specific formula of the color paste prepared in this invention is shown in Table 1: Table 1

[0050] Performance testing (1) Viscosity: Measured using an NDJ-1B rotational viscometer, Shanghai Changji Geological Instrument Co., Ltd.; where "-" indicates that the viscosity is too high to be measured. (2) Particle size: Tested using an LS13320 laser particle size analyzer, Beckman Coulter, Inc., USA; where “\” indicates sedimentation or non-flowability, which cannot be tested; (3) Storage stability: Store at 50℃ for 7 days, observe the state of the pigment paste, and retest the particle size and viscosity.

[0051] The specific test results are shown in Table 2: Table 2

[0052] As can be seen from Table 2, the dispersant prepared in the embodiments of the present invention can be used for the dispersion of conventional organic pigments and can be used to prepare water-based color pastes with good storage stability, low viscosity and small particle size.

[0053] Based on test examples 1-10, after changing the amount of functionalized monomers and chain transfer agents in the copolymerization system and the proportion and type of epoxy alkyl in the allylated block polyether within an appropriate range, the viscosity and particle size of the PR122 aqueous dispersion system showed little change before and after storage at 50°C for 7 days.

[0054] Based on Test Example 1 and Comparative Test Examples 1-4, when the chain transfer agent and any one of the three monomers are missing in the copolymerization system, the storage stability of the corresponding PR122 aqueous dispersion system deteriorates significantly, and the initial viscosity and particle size of the pigment paste change significantly. This proves that the presence of the chain transfer agent and the three monomers in the controllable polymerization system is necessary to improve the subsequent application effect.

[0055] Based on Test Example 1 and Comparative Test Example 5, compared with the blank control group, the addition of the copolymerized dispersant can effectively reduce the viscosity and particle size of the PR122 aqueous dispersion system and avoid sedimentation, proving that the dispersant provided by the present invention has a good application effect on the organic pigment aqueous color paste system.

[0056] The applicant declares that the present invention is illustrated by the above embodiments to illustrate the dispersant and its preparation method, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvement to the present invention, equivalent substitution of each component of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A dispersant for aqueous color pastes, having the structure shown in formula (Ⅰ): Ⅰ in, R is methyl or ethyl, M + for Na + or K + x is any integer between 5 and 15, and y is any integer between 10 and 20.

2. The method for preparing the dispersant for aqueous color pastes according to claim 1, characterized in that, Includes the following steps: S1. The reaction system containing 3-hydroxy-10-methylacridone and dihalopropane was reacted in an organic solvent under the catalysis of an alkaline catalyst and purified by rapid column chromatography to obtain the functionalized monomer shown in formula (II); Ⅱ S2. The functionalized monomer obtained in step S1 is mixed with acrylic acid and allylated block polyether in water under the action of chain transfer agent and initiator to carry out a controlled polymerization reaction. Then, it is neutralized with an alkaline aqueous solution of 20%-40% by mass until the pH is 7-8 to obtain the dispersant for water-based color paste. The structure of the allylated block polyether is shown in formula (Ⅲ): Ⅲ Where R is methyl or ethyl, x is any integer between 5 and 15, and y is any integer between 10 and 20.

3. The preparation method according to claim 2, characterized in that, In step S1, the chain transfer agent is 2-[(2-phenyl-1-thioethyl)thio]succinic acid.

4. The preparation method according to claim 2, characterized in that, In step S1, the molar ratio of 3-hydroxy-10-methylacridone to dihalopropane is 1:3 to 1:10; the dihalopropane is 1,3-dibromopropane or 1,3-diiodopropane; the molar ratio of 3-hydroxy-10-methylacridone to alkaline catalyst is 1:4 to 1:

10.

5. The preparation method according to claim 2, characterized in that, The alkaline catalyst is one or a mixture of several of potassium hydride, sodium hydride, potassium carbonate, potassium hydroxide, and sodium hydroxide.

6. The preparation method according to claim 2, characterized in that, In step S1, the organic solvent is one or a mixture of several of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, toluene, ethylbenzene and dimethyl sulfoxide; the eluent used for rapid column chromatography purification is a mixed solvent of petroleum ether and ethyl acetate, with a volume ratio of 15:1 to 6:

1.

7. The preparation method according to claim 2, characterized in that, In step S1, the reaction temperature is 0~40℃ and the reaction time is 10~15h; in step S2, the copolymerization reaction temperature is 50~120℃ and the copolymerization reaction time is 5-12h.

8. The preparation method according to claim 2, characterized in that, In step S2, the molar ratio of the functionalized monomer to acrylic acid is 1:5 to 1:20; the molar ratio of the allylated block polyether to acrylic acid is 1:5 to 1:40; the molar ratio of the chain transfer agent to acrylic acid is 1:30 to 1:100; and the molar ratio of the initiator to acrylic acid is 1:100 to 1:

500.

9. The preparation method according to claim 2, characterized in that, The initiator is one or a mixture of several of the following: azobisisobutyramidine hydrochloride, azobisisobutyramidazole hydrochloride, azobisisobutyramidazole acid, and azobisisopropylimidazoline.

10. The preparation method according to claim 2, characterized in that, In step S2, the alkaline aqueous solution is a NaOH aqueous solution or a KOH aqueous solution.

Images