UV ink dispersant and preparation method thereof

Abstract

The invention belongs to the technical field of dispersing agents, and particularly relates to a UV ink dispersing agent and a preparation method thereof. The molecular structure of the UV ink dispersant is shown as a formula I, the number-average molecular weight is preferably 5000-30000, and phenyl and tertiary amino in the dispersant molecule are anchoring groups, so that the dispersant is anchored on the surfaces of toner particles; an aliphatic lactone oligomer chain plays a solvation chain role, so that toner particles are effectively dispersed and prevented from being gathered; the low glass transition temperature acrylate structure allows the dispersant to be used in the form of a 100% oil, thus not altering the 100% cure and low VOC characteristics of the UV ink. The dispersant obtained according to the preferable scheme has excellent dispersing performance, the obtained color paste is small in viscosity and particle size and narrow in particle size distribution, the adaptability to toner is better, and compared with commercial representative products, the dispersant has obvious advantages and important application prospects.

Description

Technical Field

[0001] This invention belongs to the field of dispersant technology, specifically relating to a UV ink dispersant and its preparation method. Background Technology

[0002] UV inks are a type of ink that undergoes a polymerization reaction under ultraviolet light to form a cured ink layer. They are characterized by fast curing speed, almost 100% curing, and very low VOCs. Their curing reaction can be carried out at room temperature, making them a green, environmentally friendly, and energy-saving product. With increasingly stringent environmental protection requirements, UV inks are attracting more and more attention. Summary of the Invention

[0003] UV inks are composed of reactive prepolymers, photoinitiators, reactive diluents, and pigments. To ensure good dispersion of pigments in UV inks, specialized dispersants must be added to stabilize and completely wet the associated organic pigments. High-performance dispersants must contain two basic components in their molecular structure: first, anchoring groups, which anchor the dispersant molecules to the surface of pigment particles through interactions such as ionic bonds, hydrogen bonds, coordination bonds, and van der Waals forces; and second, solvation chains, which, when dissolved in the dispersion medium, exhibit an extended conformation, acting as a steric hindrance to prevent pigment particle aggregation. Due to the special nature of UV inks, there are also special requirements for the dispersants used in them: (1) Based on the characteristics of UV inks being 100% curable and having very little VOC, it is required that the dispersant be added in a 100% manner rather than in a solution manner, so as to avoid the introduction of solvents that would damage the 100% curing characteristics of UV inks. This requires that the dispersant used be preferably an oily substance with a certain degree of fluidity, which dissolves quickly and is easy to operate; (2) Since most of the reactive prepolymers and reactive diluents in UV inks are low to medium polar acrylates, in order to make the dispersant have good solubility in the reactive diluent and good compatibility with the reactive prepolymer, The polarity of the dispersant should be compatible with that of the reactive diluent and prepolymer. Therefore, there are significant limitations on the anchoring groups and solvation chains contained in the dispersant molecules. Strongly polar anchoring groups (such as ionic anchoring groups) and highly polar solvation chains (such as polyethers) should not be used. (3) The molecular weight (chain length) and molecular weight distribution of the solvation chain have a significant impact on the performance of the dispersant. If the solvation chain is too short, it will not be able to play a stereoblocking role. If it is too long, it may fold and affect its effectiveness. It may even cause the solvation chains on the surface of different pigment particles to become entangled, which will increase the viscosity of the ink. Therefore, controlling the molecular weight of the solvation chain and obtaining a narrow molecular weight distribution is of great significance for obtaining excellent dispersion performance. In addition, high-performance UV ink dispersants not only require small dispersed pigment particles, especially for inkjet printing UV inks, the pigment particle size should be <1 micrometer. At the same time, low viscosity is also required to ensure good flowability.

[0004] Given the special requirements of UV inks for the dispersants used, dispersants that work well in other fields cannot be simply applied to UV inks. Instead, targeted molecular design is required based on the characteristics of UV inks. Therefore, designing and synthesizing high-performance UV ink dispersants remains a challenge.

[0005] To overcome the shortcomings of the prior art, this invention provides a UV ink dispersant and its preparation method. In the dispersant of this invention, phenyl and tertiary amino groups act as anchoring groups, anchoring the dispersant molecules to the surface of pigment particles through intermolecular forces and polar interactions. The aliphatic lactone oligomer chains in the dispersant molecules act as solvation chains, exhibiting excellent compatibility with commonly used acrylate reactive diluents and reactive prepolymers in UV inks, thus providing excellent steric stabilization, effectively dispersing pigment particles and preventing their aggregation. The low glass transition temperature acrylate structure in the dispersant molecules makes the resulting dispersant an oily substance at room temperature, convenient to use, and rapidly dissolving, allowing it to be added to UV inks in 100% form, thereby ensuring 100% curing and low VOC characteristics of UV inks. The dispersant obtained by the preferred embodiment of this invention has excellent dispersing performance, resulting in pigment pastes with small viscosity and particle size, narrow particle size distribution, and better adaptability to pigments. Compared with representative commercial products, it has significant advantages and important application prospects.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A first aspect of this invention provides a UV ink dispersant, the molecular structure of which is shown in Formula I: Where: R1, R1 ’ R1 ’’ R1 ’’’ Independently selected from H and CH3; R2 is a group containing a benzene ring; R3 is... and At least one of the following: R4 is selected from -CH3, -CH2CH3; R5 is at least one of butyl, isooctyl, hydroxyethyl, hydroxypropyl; m:n:p:q is 11~55:2~19.8:1:0.14~28.5; x is 2~8; the number average molecular weight of the UV ink dispersant is 5000~30000.

[0007] Furthermore, R2 is , and At least one of them.

[0008] Furthermore, R1, R1 ’ R1 ’’ R1 ’’’All are H; R4 is -CH3.

[0009] Furthermore, R5 is isooctyl.

[0010] A second aspect of the present invention provides a method for preparing the above-mentioned UV ink dispersant, wherein the dispersant is obtained by free radical copolymerization of a phenyl-containing vinyl monomer M1, an aliphatic lactone oligomer acrylate monomer M2, a tertiary amine-containing acrylate monomer M3, and an acrylate monomer M4 with a low glass transition temperature (glass transition temperature < 0°C); the preparation method includes the following steps: (1) Dissolve monomers M1, M2, M3 and M4 in a solvent to prepare a mixed monomer solution. Take 10~30% and add it to the reactor as a base, and add the remainder dropwise during the reaction. (2) Dissolve the initiator in a solvent to prepare an initiator solution, of which 10-30% is added at the beginning of the reaction to start the reaction, 10-20% is reserved as initiator replenishment solution, and the rest is reserved as initiator drop solution to be added dropwise during the reaction; (3) Add solvent and 10-30% mixed monomer solution as base solution to reaction flask, heat to 70-80℃, add 10-30% initiator solution to start reaction, and add the remaining mixed monomer solution and initiator drop solution dropwise. After the dropwise addition is completed, continue reaction for 1-2 h, add initiator replenishment solution, and raise temperature to 80-90℃ to continue reaction for 1-2 h. (4) After the reaction is complete, the solvent is removed by distillation to obtain the UV ink dispersant.

[0011] Further, the phenyl-containing vinyl monomer M1 is at least one of styrene, benzyl acrylate, benzyl methacrylate, 2-phenoxyethyl acrylate, and 2-phenoxyethyl methacrylate.

[0012] Furthermore, the phenyl-containing vinyl monomer M1 is styrene.

[0013] Furthermore, the aliphatic lactone oligomer acrylate monomer M2 is initiated by hydroxyethyl acrylate or hydroxyethyl methacrylate as an initiator under the action of a catalyst. -caprolactone, - It is obtained by ring-opening polymerization of valproic acid lactone or mixtures thereof, and the molecular structure of the aliphatic lactone oligomer acrylate monomer M2 is shown in Formula II: In the formula, R1 ’ Selected from -H, CH3; y=2~8, z=0~6, y+z=2~8, y+z=x of structural formula I.

[0014] Furthermore, the R1’ It is -H.

[0015] Furthermore, the acrylate monomer M3 containing a tertiary amino group is at least one of dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, and diethylaminoethyl methacrylate.

[0016] Furthermore, the acrylate monomer M3 containing tertiary amino group is dimethylaminoethyl acrylate.

[0017] Furthermore, the acrylate monomer M4 with a low glass transition temperature is at least one of butyl acrylate, isooctyl acrylate, hydroxyethyl acrylate, and hydroxypropyl acrylate, and the low glass transition temperature refers to a glass transition temperature below 0 °C.

[0018] Furthermore, the acrylate monomer M4 is isooctyl acrylate.

[0019] Furthermore, the initiator is an oil-soluble free radical polymerization initiator.

[0020] Furthermore, the initiator is any one of benzoyl peroxide, azobisisobutyronitrile, and dimethyl azobisisobutyrate, and the amount of the initiator is 0.5 to 2.5% of the total mass of the monomer.

[0021] Furthermore, the initiator is azobisisobutyronitrile or dimethyl azobisisobutyrate.

[0022] Furthermore, the solvent is at least one of aromatic solvents, alcohol solvents, and alcohol ether solvents.

[0023] Furthermore, the solvent is at least one of isopropanol and propylene glycol methyl ether.

[0024] Compared with the prior art, the beneficial effects of the present invention are: This invention provides a UV ink dispersant and its preparation method. The number-average molecular weight of the UV ink dispersant is preferably 5000-30000. In the dispersant, phenyl and tertiary amino groups act as anchoring groups, anchoring the dispersant molecules to the surface of pigment particles through intermolecular forces and polar interactions. The aliphatic lactone oligomer chains in the dispersant molecules act as solvation chains, providing excellent steric hindrance stability, effectively dispersing pigment particles and preventing their aggregation. The low glass transition temperature acrylate structure in the dispersant molecules makes the resulting dispersant an oily substance at room temperature, convenient to use, and rapidly dissolving, allowing it to be added to UV inks in 100% form, thus ensuring 100% curing and low VOC characteristics of the UV ink. The dispersant obtained by the preferred embodiment of this invention has excellent dispersing performance, resulting in pigment pastes with small viscosity and particle size, narrow particle size distribution, and better adaptability to pigments. Compared with representative commercial products, it has significant advantages and important application prospects.

[0025] Specifically, the present invention has the following advantages: (1) The UV ink dispersant of the present invention uses non-polar phenyl as the main anchoring group and medium-polar tertiary amino as the auxiliary anchoring group, thereby improving the anchoring ability of dispersant molecules on the surface of pigment particles through the synergistic effect of the two.

[0026] (2) The UV ink dispersant of the present invention uses aliphatic lactone oligomers as solvation chains, which not only has excellent compatibility with commonly used acrylate reactive diluents and reactive prepolymers in UV inks, but also the aliphatic lactone oligomers are obtained by ring-opening polymerization of the corresponding aliphatic lactones. Not only is the molecular weight precisely controllable, but the molecular weight distribution is also narrow, which is conducive to obtaining excellent stereoblocking effect.

[0027] (3) This invention introduces an acrylate structure with a low glass transition temperature into the UV ink dispersant molecule. On the one hand, this ensures a low glass transition temperature of the resulting dispersant polymer molecules; on the other hand, it reduces the crystallinity of the lactone oligomer chain, thus making the resulting dispersant a fluid oil at room temperature. This makes it easy to operate and dissolves quickly. More importantly, it can be added to UV ink in 100% form, which is crucial for maintaining the 100% curing and low VOC characteristics of UV ink. Compared with representative UV ink dispersants on the market, the dispersant obtained by the preferred embodiment of this invention has excellent dispersing performance. Not only is the viscosity and particle size of the resulting color paste smaller and the particle size distribution narrower, but it also has better adaptability to color powder, showing significant application prospects. Attached Figure Description

[0028] Figure 1 The particle size distribution curve of the phthalocyanine blue (7679W) color paste prepared by the UV ink dispersant in Example 1 is shown.

[0029] Figure 2 The particle size distribution curve of the phthalocyanine blue (7679W) color paste prepared by the UV ink dispersant in Example 2 is shown.

[0030] Figure 3 The particle size distribution curve of the phthalocyanine blue (7679W) color paste prepared by the UV ink dispersant in Example 3 is shown.

[0031] Figure 4 The particle size distribution curve of the phthalocyanine blue (7679W) color paste prepared by the UV ink dispersant in Example 4 is shown.

[0032] Figure 5 The particle size distribution curve of the phthalocyanine blue (7679W) color paste prepared by the UV ink dispersant in Example 5 is shown.

[0033] Figure 6 The particle size distribution curve of the phthalocyanine blue (7679W) color paste prepared by the UV ink dispersant in Example 6 is shown.

[0034] Figure 7 The particle size distribution curve of the phthalocyanine blue (7679W) color paste prepared by the UV ink dispersant in Example 7 is shown.

[0035] Figure 8 The particle size distribution curve of the phthalocyanine blue (7679W) color paste prepared by the UV ink dispersant in Example 8 is shown.

[0036] Figure 9 The particle size distribution curve of the phthalocyanine blue (7679W) color paste prepared by the UV ink dispersant in Example 9 is shown.

[0037] Figure 10 The particle size distribution curve of the phthalocyanine blue (7679W) color paste prepared by the UV ink dispersant in Comparative Example 1.

[0038] Figure 11 The particle size distribution curve of the phthalocyanine blue (7679W) color paste prepared by the UV ink dispersant in Comparative Example 2.

[0039] Figure 12 The particle size distribution curve of the phthalocyanine blue (7110F) color paste prepared by the UV ink dispersant in Example 4 is shown.

[0040] Figure 13 The particle size distribution curve of the phthalocyanine blue (7110F) color paste prepared by the UV ink dispersant in Example 6 is shown.

[0041] Figure 14 The particle size distribution curve of the phthalocyanine blue (7110F) color paste prepared by the UV ink dispersant in Example 7 is shown.

[0042] Figure 15The particle size distribution curve of the phthalocyanine blue (7110F) color paste prepared by the UV ink dispersant in Comparative Example 2. Detailed Implementation

[0043] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0044] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.

[0045] The number-average molecular weights (Mi) of the aliphatic lactone oligomer acrylate monomers and dispersants in the following examples are: n The determination was performed by GPC under the following conditions: using an Agilent PL-GPC 50 gel permeation chromatography system at 40 °C, with tetrahydrofuran as the mobile phase and polystyrene as the standard.

[0046] This invention uses aliphatic lactone oligomer acrylate monomer M2 hydroxyethyl acrylate or hydroxyethyl methacrylate as an initiator to initiate the polymerization of aliphatic lactone monomers under the action of a catalyst. -caprolactone, It is obtained by ring-opening polymerization of valproic acid or a mixture thereof. Hydroxyethyl acrylate and Taking the reaction of caprolactone as an example, the reaction formula is shown below: The corresponding synthesis method is as follows: add to the reaction flask - Caprolactone and polymerization inhibitor p-methoxyphenol were stirred and heated to 104 °C. Then, p-toluenesulfonic acid and hydroxyethyl acrylate were added as catalysts. The mixture was heated to 107 °C and reacted for 8.5 h. The reaction was stopped by cooling to obtain the aliphatic lactone oligomer acrylate monomer M2.

[0047] Five aliphatic lactone oligomers with acrylate monomer M2 were prepared by changing the molar ratio of aliphatic lactone monomer to hydroxyethyl acrylate and the types of aliphatic lactone monomer. The molar ratio of the reactants and the molecular structural formulas of the products are listed below: 1. When the molar ratio of caprolactone to hydroxyethyl acrylate is 2 / 1, an aliphatic lactone oligomer acrylate monomer M2-1 is obtained, whose M... n =470, PDI=1.44, the structural formula is: ; 2. When the molar ratio of caprolactone to hydroxyethyl acrylate is 4 / 1, an aliphatic lactone oligomer acrylate monomer M2-2 is obtained, whose M... n =630, PDI=1.40, the structural formula is: ; 3. When the molar ratio of caprolactone to hydroxyethyl acrylate is 6 / 1, the aliphatic lactone oligomer acrylate monomer M2-3 is obtained, and its M... n =860, PDI=1.24, the structural formula is: ; 4. -caprolactone / When the molar ratio of valproic acid lactone to hydroxyethyl acrylate is 2 / 2 / 1, the aliphatic lactone oligomer acrylate monomer M2-4 is obtained. n =720, PDI=1.22, the structural formula is: ; 5. -caprolactone / When the molar ratio of valproic acid lactone to hydroxyethyl acrylate is 4 / 2 / 1, the aliphatic lactone oligomer acrylate monomer M2-5 is obtained. n =810, PDI=1.23, the structural formula is: .

[0048] The following are specific embodiments of the UV ink dispersant and its preparation according to the present invention.

[0049] Example 1 The structural formula of the dispersant in this embodiment is as follows: In the formula: m:n:p:q = 30:10.4:1:0.28. Number-average molecular weight M n =7040.

[0050] The preparation method is as follows: (1) Prepare a monomer solution by mixing 0.375 g (0.0024 mol) of dimethylaminoethyl methacrylate, 0.125 g (0.00068 mol) of isooctyl acrylate, 7.5 g (0.072 mol) of styrene, 12 g (0.025 mol) of lactone oligomer acrylate M2-1, and 10 g of propylene glycol methyl ether; (2) Dissolve 0.3g of initiator AIBN and 10g of propylene glycol methyl ether to prepare an initiator solution; (3) Add 10g of propylene glycol methyl ether and 3g of monomer solution to the reaction flask as a base solution. After heating to 75°C, add 1g of initiator solution to start the reaction. At the same time, add the remaining monomer solution and 8g of initiator drop solution dropwise over a certain period of time. After the dropwise addition is complete, continue the reaction for 1.5 h. Add the remaining initiator solution and raise the temperature to 85°C to continue the reaction for 1.5 h.

[0051] (4) After the reaction is completed, the solvent is removed by distillation to obtain an oily substance with certain fluidity, which is the UV ink dispersant of Example 1, with a number average molecular weight of 7040.

[0052] Examples 2-9 The preparation methods of UV ink dispersants in Examples 2-9 are the same as those in Example 1, except that the composition of the reactive monomers is changed. The composition of the reactive monomers and the number-average molecular weight of the obtained UV ink dispersants in each example are shown in Table 1.

[0053] Table 1 Test Example: Dispersant Dispersion Performance Test To investigate the dispersing performance of the dispersant of this invention, two representative UV ink dispersants (BASF PX4701 and PX4310) were used as Comparative Example 1 and Comparative Example 2, respectively. Tetrahydrofurfuryl methacrylate, a commonly used reactive diluent in UV inks, was used as the dispersion medium for grinding the pigments. At the same time, to investigate the adaptability of the dispersant to the pigments, two phthalocyanine blue pigments were compared and tested: (a) domestic Shuangle Pigment Phthalocyanine Blue 7679W; (b) imported BASF Phthalocyanine Blue 7110F.

[0054] The testing methods and conditions are as follows: 3.75 g of dispersant and 38.75 g of tetrahydrofurfuryl methacrylate were added to the grinding jar of a 100 mL x 4 planetary ball mill. After stirring and dissolving evenly, 7.5 g of phthalocyanine blue pigment and 30 g of zirconium beads with a particle size of 1 mm were added. The mixture was ground at 300 rpm for 2 h to obtain a color paste. The viscosity of the color paste was measured using a BGD 152 / 2S smart viscometer at 12 rpm and 25 °C. The particle size and particle size distribution (width coefficient) of the pigment in the color paste were measured using an LT3600 Plus laser particle size analyzer.

[0055] The viscosity, particle size, and distribution results of the phthalocyanine blue (7679W) color pastes prepared by the UV ink dispersants in Examples 1-9 and Comparative Examples 1-2 are shown in Table 2. The corresponding particle size distribution curves of the color pastes are shown in Table 2. Figure 1-11 As shown.

[0056] Table 2 The viscosity, particle size, and distribution results of the phthalocyanine blue (7110F) color pastes prepared by the UV ink dispersants in Examples 4, 6, 7, and Comparative Example 2 are shown in Table 3. The corresponding particle size distribution curves of the color pastes are shown in Table 3. Figure 12-15 As shown. Table 3 It is evident that, for domestically produced color powders, the color pastes obtained by the dispersants prepared in Examples 1-9 of this invention not only have significantly lower viscosity than the comparative examples, but also exhibit significantly smaller particle sizes. For imported color powders, the color pastes obtained by the dispersants of the preferred embodiment of this invention have viscosity comparable to the comparative examples, but smaller particle sizes and narrower particle size distributions. This indicates that the dispersant of the preferred embodiment of this invention not only has a better dispersion effect than the comparative examples, but also exhibits better adaptability to color powders.

[0057] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A UV ink dispersant, characterized in that, The molecular structure of the UV ink dispersant is shown in Formula I: Formula I Where: R1, R1 ’ R1 ’’ R1 ’’’ Independently selected from H and CH3; R2 is a group containing a benzene ring; R3 is... and At least one of the following: R4 is selected from -CH3, -CH2CH3; R5 is at least one of butyl, isooctyl, hydroxyethyl, hydroxypropyl; m:n:p:q is 11~55:2~19.8:1:0.14~28.5; x is 2~8; the number average molecular weight of the UV ink dispersant is 5000~30000.

2. The UV ink dispersant according to claim 1, characterized in that, R2 is , and At least one of them.

3. The UV ink dispersant according to claim 1, characterized in that, R1, R1 ’ R1 ’’ R1 ’’’ All are H; R4 is -CH3.

4. A method for preparing a UV ink dispersant as described in any one of claims 1-3, characterized in that, The dispersant is obtained by free radical copolymerization of a phenyl-containing vinyl monomer M1, an aliphatic lactone oligomer acrylate monomer M2, a tertiary amine-containing acrylate monomer M3, and an acrylate monomer with a low glass transition temperature M4; the preparation method includes the following steps: (1) Dissolve monomers M1, M2, M3 and M4 in a solvent to prepare a mixed monomer solution. Take 10~30% and add it to the reactor as a base, and add the remainder dropwise during the reaction. (2) Dissolve the initiator in a solvent to prepare an initiator solution, of which 10-30% is added at the beginning of the reaction to start the reaction, 10-20% is reserved as initiator replenishment solution, and the rest is reserved as initiator drop solution to be added dropwise during the reaction; (3) Add solvent and 10-30% mixed monomer solution as base solution to reaction flask, heat to 70-80 ℃, add 10-30% initiator solution to start reaction, and add the remaining mixed monomer solution and initiator drop solution dropwise. After the dropwise addition is completed, continue reaction for 1-2 h, add initiator replenishment solution, and raise temperature to 80-90 ℃ to continue reaction for 1-2 h. (4) After the reaction is complete, the solvent is removed by distillation to obtain the UV ink dispersant.

5. The method for preparing a UV ink dispersant according to claim 4, characterized in that, The phenyl-containing vinyl monomer M1 is at least one of styrene, benzyl acrylate, benzyl methacrylate, 2-phenoxyethyl acrylate, and 2-phenoxyethyl methacrylate.

6. The method for preparing a UV ink dispersant according to claim 4, characterized in that, The aliphatic lactone oligomer acrylate monomer M2 is initiated by hydroxyethyl acrylate or hydroxyethyl methacrylate as an initiator under the action of a catalyst. -caprolactone, - It is obtained by ring-opening polymerization of valproic acid lactone or mixtures thereof, and the molecular structure of the aliphatic lactone oligomer acrylate monomer M2 is shown in Formula II: Formula II In the formula, R1 ’ Selected from -H, CH3; y=2~8, z=0~6, y+z=2~8, y+z=x of structural formula I.

7. The method for preparing a UV ink dispersant according to claim 4, characterized in that, The acrylate monomer M3 containing a tertiary amino group is at least one of dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, and diethylaminoethyl methacrylate.

8. The method for preparing a UV ink dispersant according to claim 4, characterized in that, The acrylate monomer M4 with a low glass transition temperature is at least one of butyl acrylate, isooctyl acrylate, hydroxyethyl acrylate, and hydroxypropyl acrylate, and the low glass transition temperature means a glass transition temperature below 0 °C.

9. The method for preparing a UV ink dispersant according to claim 4, characterized in that, The initiator is any one of benzoyl peroxide, azobisisobutyronitrile, and dimethyl azobisisobutyrate, and the amount of the initiator is 0.5 to 2.5% of the total mass of the monomer.

10. The method for preparing a UV ink dispersant according to claim 4, characterized in that, The solvent is at least one of isopropanol and propylene glycol methyl ether.

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