Pigment modifier with naphthalimide structure and method for preparing modified pigment from pigment modifier

Abstract

The invention belongs to the technical field of pigment modification, and provides a pigment modifier with a naphthalimide structure and a method for preparing a modified pigment from the pigment modifier. The structural formula of the pigment modifier with the naphthalimide structure is shown in the specification. The pigment is modified by the pigment modifier with the naphthalimide structure, and the pigment modifier with the naphthalimide structure is grafted on the surface of the pigment through diazotization reaction, so that the self-dispersion function of the pigment can be realized; according to the present invention, the nano-scale dispersion effect of the pigment can be achieved without adding the auxiliary agents such as the surfactant, the dispersant, the wetting agent and the like, and the color expressive force of the pigment is improved so as to provide the modified pigment with characteristics of high brightness, high coloring strength and excellent smoothness.

Description

Technical Field

[0001] This invention relates to the field of pigment modification technology, and in particular to a pigment modifier having a naphthalimide structure and a method for preparing the modified pigment therefrom. Background Technology

[0002] Inkjet printing technology emerged in the 1980s. Early inks were made by directly dissolving pigments in the ink, resulting in poor durability and water resistance. Later, carbon black was used to replace black azo dyes, improving the stability of the ink. However, it still had performance limitations when applied to high-end printing technologies such as office supplies and outdoor advertising.

[0003] The development of high-quality nano-water-based pigment inks has always revolved around formulation and modification technologies. For example, adding additives to pigment inks helps disperse pigments and increases tinting strength; attaching modifiers to the surface of pigment particles allows the pigment particles to be uniformly dispersed in the medium through intermolecular forces, thus improving tinting strength. Patents CN101597441A, CN101379143A, and CN101970586A disclose methods for grafting modification onto the pigment surface to improve the pigment's dispersion performance in the medium and enhance its compatibility with the dispersion medium. While these methods can provide pigments with a certain degree of dispersibility, they cannot establish synergistic relationships between dispersibility, stability, and tinting strength, thereby failing to precisely control the various properties of the pigment.

[0004] Therefore, providing new pigment modifiers that enable pigments to exhibit excellent performance in terms of dispersibility, stability, and coloring ability is of great significance for high-end applications of pigment inks. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a pigment modifier with a naphthalimide structure and a method for preparing the modified pigment therefrom.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a pigment modifier having a naphthalimide structure, wherein the structural formula of the pigment modifier having a naphthalimide structure is as follows: ; Where R1 is -(CH2) n -Q or -C6H4-(Sp)m-(CH2)nQ, R2 contains -SO3H or H; Q contains a carboxyl group, a sulfonic acid group, a phosphoric acid group, a phosphonic acid group, or a geminosine group; Sp includes -CO2-, -O-, -NR3, -CO-, -CONR3-, -SO2NR3-, where R3 includes H or C1~C6 alkyl groups; m is 0 or 1, and n is any integer from 0 to 6.

[0007] Preferably, the pigment modifier having a naphthalimide structure is any one of the following structural formulas: , , , , , , , , , , , , , , , , , , , .

[0008] The present invention also provides a method for preparing modified pigments using the pigment modifier having the aforementioned naphthalimide structure, comprising the following steps: A pigment modifier with a naphthalimide structure, pigment, hydrochloric acid, sodium nitrite solution, and water are mixed and subjected to a diazotization reaction to obtain the modified pigment.

[0009] Preferably, the mass ratio of the pigment modifier having a naphthalimide structure to the pigment is 0.1 to 3:1, and the mass ratio of the pigment to water is 1:5 to 20.

[0010] Preferably, the mass ratio of the pigment modifier with the naphthalimide structure to sodium nitrite in the sodium nitrite solution is 5~10:1, and the mass fraction of the sodium nitrite solution is 5~25%.

[0011] Preferably, the mass ratio of the pigment modifier with the naphthalimide structure to hydrochloric acid is 3~5:1, and the mass fraction of hydrochloric acid is 30~40%.

[0012] Preferably, the temperature of the diazotization reaction is 25~50℃.

[0013] Preferably, after the diazotization reaction is completed, the pH value of the reaction system is first adjusted to 7-9, and then solid-liquid separation is performed to obtain the modified pigment.

[0014] The beneficial effects of this invention are: This invention relates to a pigment modifier with a naphthalimide structure that modifies pigments. By grafting the pigment modifier with the naphthalimide structure onto the pigment surface through a diazotization reaction, the pigment can achieve self-dispersion. Nanoscale dispersion of pigments can be achieved without the addition of surfactants, dispersants, wetting agents, or other additives. At the same time, it improves the color performance of pigments, giving the modified pigments higher brightness, higher color strength, and excellent smoothness. Detailed Implementation

[0015] This invention provides a pigment modifier having a naphthalimide structure, wherein the structural formula of the pigment modifier having a naphthalimide structure is as follows: ; Where R1 is -(CH2) n -Q or -C6H4-(Sp)m-(CH2)nQ, R2 contains -SO3H or H; Q contains a carboxyl group, a sulfonic acid group, a phosphoric acid group, a phosphonic acid group, or a geminosine group; Sp includes -CO2-, -O-, -NR3, -CO-, -CONR3-, -SO2NR3-, where R3 includes H or C1~C6 alkyl groups; m is 0 or 1, and n is any integer from 0 to 6.

[0016] In this invention, the pigment modifier having a naphthalimide structure is preferably any one of the following structural formulas: , , , , , , , , , , , , , , , , , , , .

[0017] The present invention also provides a method for preparing modified pigments using the pigment modifier having the aforementioned naphthalimide structure, comprising the following steps: A pigment modifier with a naphthalimide structure, pigment, hydrochloric acid, sodium nitrite solution, and water are mixed and subjected to a diazotization reaction to obtain the modified pigment.

[0018] In this invention, the mass ratio of the pigment modifier having a naphthalimide structure to the pigment is preferably 0.1 to 3:1, more preferably 0.5 to 2:1, and even more preferably 1 to 1.5:1; the mass ratio of the pigment to water is preferably 1:5 to 20, more preferably 1:8 to 15, and even more preferably 1:10 to 12.

[0019] In this invention, the mass ratio of the pigment modifier with the naphthalimide structure to sodium nitrite in the sodium nitrite solution is preferably 5-10:1, more preferably 6-9:1, and even more preferably 7-8:1. The mass fraction of the sodium nitrite solution is preferably 5-25%, more preferably 10-20%, and even more preferably 15%.

[0020] In this invention, the mass ratio of the pigment modifier with the naphthalimide structure to hydrochloric acid is preferably 3-5:1, more preferably 3.5-4.5:1, and even more preferably 4:1. The mass fraction of hydrochloric acid is preferably 30-40%, more preferably 32-38%, and even more preferably 34-36%.

[0021] In this invention, the temperature of the diazotization reaction is preferably 25~50℃, more preferably 30~45℃, and even more preferably 35~40℃.

[0022] In this invention, the endpoint of the diazotization reaction is preferably detected by H acid solution.

[0023] In this invention, after the diazotization reaction is completed, it is preferable to first adjust the pH value of the reaction system to 7-9, and then perform solid-liquid separation to obtain the modified pigment, and it is even more preferable to adjust the pH value to 8.

[0024] In this invention, the reagent used to adjust the pH value of the reaction system is preferably an alkaline solution, which preferably includes one or more of sodium carbonate solution, sodium bicarbonate solution, potassium carbonate solution, potassium bicarbonate solution, sodium hydroxide solution, and potassium hydroxide solution.

[0025] In this invention, the pigment preferably includes one or more of the following: black pigment, blue pigment, brown pigment, cyan pigment, green pigment, white pigment, purple pigment, red pigment, yellow pigment, and orange pigment.

[0026] In this invention, the black pigment preferably comprises carbon black; The blue pigment preferably comprises one or more of Pigment Blue 15, Pigment Blue 15:3, and Pigment Blue 15:4; The purple pigment preferably comprises pigment purple 19; The red pigment preferably comprises Pigment Red 122; The yellow pigment preferably includes pigment yellow 74, pigment yellow 155, pigment yellow 128, pigment yellow 218, pigment yellow 220, and pigment yellow 211.

[0027] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0028] Example 1

[0029] Add 300 mL of deionized water, 29.3 g (0.1 mol) of 4-amino-6-sulfonic acid-1,8-naphthalenedicarboxylic anhydride, and 7.5 g (0.1 mol) of glycine to a three-necked flask. Stir until homogeneous. At room temperature, add 100 mL of a 1 mol / L sodium carbonate aqueous solution dropwise over 30 min. After the addition is complete, heat the three-necked flask to 100 °C and maintain the temperature at 100 °C with stirring at 300 rpm for 4 h. After the reaction is complete, cool to room temperature and adjust the pH of the reaction system to 2 using 36% hydrochloric acid, precipitating a yellow solid. Filter the solid, wash the filter cake with water, and then dry it at 60 °C for 24 h to obtain 28.5 g of modifier 1 (0.0814 mol).

[0030] In this embodiment, the yield of modifier 1 was 81.4%, and the purity of modifier 1 was 95.3% as determined by HPLC. The reaction route of modifier 1 is as follows: .

[0031] The structure of modifier 1 was characterized, and the result was: m / z = 350.02; 1 H-NMR(600MHz,DMSO-D6)δ:3.79ppm(s,2H,CH2),5.79ppm(s,2H,NH2),7.22ppm(d,1H, CH),7.95ppm(s,1H,CH),8.24ppm(d,1H,CH),8.64ppm(s,1H,CH),13.03ppm(s,1H,OH).

[0032] Example 2

[0033] Add 300 mL of deionized water, 29.3 g (0.1 mol) of 4-amino-6-sulfonic acid-1,8-naphthalenedicarboxylic anhydride, and 12.5 g (0.1 mol) of taurine to a three-necked flask. Stir until homogeneous. At room temperature, add 100 mL of a 1 mol / L sodium carbonate aqueous solution dropwise over 30 min. After the addition is complete, heat the three-necked flask to 100 °C and maintain the temperature at 100 °C with stirring at 300 rpm for 4 h. After the reaction is complete, cool to room temperature and adjust the pH of the reaction system to 2 using 36% hydrochloric acid, precipitating a yellow solid. Filter the solid, wash the filter cake with water, and then dry it at 60 °C for 24 h to obtain 30.5 g of modifier 2 (0.0763 mol).

[0034] In this embodiment, the yield of modifier 2 was 76.3%, and the purity of modifier 2, as determined by HPLC, was 96.5%. The reaction route of modifier 2 is as follows: .

[0035] The structure of modifier 2 was characterized, and the result was: m / z = 400.00; 1 H-NMR(600MHz,DMSO-D6)δ:3.71ppm(t,2H,CH2),3.76ppm(t,2H,CH2),5.79ppm(s,2H, NH2),7.22ppm(d,1H,CH),7.95ppm(s,1H,CH),8.24ppm(d,1H,CH),8.64ppm(s,1H,CH).

[0036] Example 3

[0037] Add 300 mL of deionized water, 29.3 g (0.1 mol) of 4-amino-6-sulfonic acid-1,8-naphthalenedicarboxylic anhydride, 13.7 g (0.1 mol) of p-aminobenzoic acid, and 0.53 g (0.005 mol) of triethanolamine to a three-necked flask. Stir until homogeneous. At room temperature, add 100 mL of 1 mol / L sodium carbonate aqueous solution dropwise over 30 min. After the addition is complete, heat the three-necked flask to 100 °C and maintain the temperature at 100 °C with stirring at 300 rpm for 4 h. After the reaction is complete, cool to room temperature and adjust the pH of the reaction system to 2 using 36% hydrochloric acid, precipitating a yellow solid. Filter the solid, wash the filter cake with water, and then dry it at 60 °C for 24 h to obtain 35 g of modifier 3 (0.085 mol).

[0038] In this embodiment, the yield of modifier 3 was 85.0%, and the purity of modifier 3 was 94.5% as determined by HPLC. The reaction route of modifier 3 is as follows: .

[0039] The structure of modifier 3 was characterized, and the result was: m / z = 412.04; 1 H-NMR(600MHz,DMSO-D6)δ:5.79ppm(s,2H,NH2),7.22ppm(d,1H,CH),7.38ppm(d,2H,CH),7.95p pm(s,1H,CH),8.04ppm(d,2H,CH),8.24ppm(d,1H,CH),8.64ppm(s,1H,CH),12.74ppm(s,1H,OH).

[0040] Example 4

[0041] Add 300 mL of deionized water, 29.3 g (0.1 mol) of 4-amino-6-sulfonic acid-1,8-naphthalenedicarboxylic anhydride, 39 g (0.1 mol) of 4-(4-aminobenzamido)-1-hydroxybutylidene-1,1-diphosphonic acid monosodium salt, and 0.53 g (0.005 mol) of triethanolamine to a three-necked flask. Stir until homogeneous. At room temperature, add 100 mL of 1 mol / L sodium carbonate aqueous solution dropwise to the three-necked flask, completing the addition over 30 min. After the addition is complete, heat the three-necked flask to 100 °C and maintain the temperature at 100 °C with stirring at 300 r / min for 4 h. After the reaction is complete, cool to room temperature and adjust the pH of the reaction system to 2 using 36% hydrochloric acid, precipitating a yellow solid. Filter and wash the filter cake with water, then dry at 60 °C for 24 h to obtain 46 g of modifier 4 (0.0715 mol).

[0042] In this embodiment, the yield of modifier 4 was 71.5%, and the purity of modifier 4, as determined by HPLC, was 91.5%. The reaction route of modifier 4 is as follows: .

[0043] The structure of modifier 4 was characterized, and the result was m / z = 643.04; 1H-NMR(600MHz,DMSO-D6)δ:1.50-1.60ppm(m,4H,CH2CH2),2.70ppm(s,1H,COH),3.30ppm(m,2H,CH2),4.80ppm(s,4H,POH),5.24ppm(t,1H,NH), 5.79ppm(s,2H,NH2),7.22ppm(d,1H,CH),7.35ppm(d,2H,CH),7.76ppm(d,2H,CH),7.95ppm(s,1H,CH),8.24ppm(d,1H,CH),8.64ppm(s,1H,CH).

[0044] Example 5

[0045] Add 300 mL of deionized water, 25.7 g (0.1 mol) of 4-amino-1,8-naphthalenedicarboxylic anhydride, and 7.5 g (0.1 mol) of glycine to a three-necked flask. Stir until homogeneous. At room temperature, add 100 mL of a 1 mol / L sodium carbonate aqueous solution dropwise over 30 min. After the addition is complete, heat the three-necked flask to 100 °C and maintain the temperature at 100 °C with stirring at 300 rpm for 4 h. After the reaction is complete, cool to room temperature and adjust the pH of the reaction system to 2 using 36% hydrochloric acid, precipitating a yellow solid. Filter the solid, wash the filter cake with water, and then dry it at 60 °C for 24 h to obtain 26.7 g of modifier 5 (0.085 mol).

[0046] In this embodiment, the yield of modifier 5 was 85.0%, and the purity of modifier 5 was 95.5% as determined by HPLC. The reaction route of modifier 5 is as follows: .

[0047] The structure of modifier 5 was characterized, and the result was: m / z = 270.06; 1 H-NMR(600MHz,DMSO-D6)δ:3.79ppm(s,2H,CH2),5.79ppm(s,2H,NH2),7.22ppm(d,1H,C H),7.71ppm(m,1H,CH),8.45ppm(d,1H,CH),8.52ppm(d,2H,2CH),12.74ppm(s,1H,OH).

[0048] Example 6

[0049] Add 300 mL of deionized water, 25.7 g (0.1 mol) of 4-amino-1,8-naphthalenedicarboxylic anhydride, and 12.5 g (0.1 mol) of taurine to a three-necked flask. Stir until homogeneous. At room temperature, add 100 mL of a 1 mol / L sodium carbonate aqueous solution dropwise over 30 min. After the addition is complete, heat the three-necked flask to 100 °C and maintain the temperature at 100 °C with stirring at 300 rpm for 4 h. After the reaction is complete, cool to room temperature and adjust the pH of the reaction system to 2 using 36% hydrochloric acid, precipitating a yellow solid. Filter the solid, wash the filter cake with water, and then dry it at 60 °C for 24 h to obtain 29.5 g of modifier 6 (0.081 mol).

[0050] In this embodiment, the yield of modifier 6 was 81.0%, and the purity of modifier 6, as determined by HPLC, was 96.2%. The reaction route of modifier 6 is as follows: .

[0051] The structure of modifier 6 was characterized, and the result was: m / z = 320.05; 1 H-NMR(600MHz,DMSO-D6)δ:3.71ppm(t,2H,CH2),3.76ppm(t,2H,CH2),5.79ppm(s,2H,N H2),7.22ppm(d,1H,CH),7.71ppm(m,1H,CH),8.45ppm(d,1H,CH),8.52ppm(d,2H,2CH).

[0052] Example 7

[0053] Add 300 mL of deionized water, 25.7 g (0.1 mol) of 4-amino-1,8-naphthalenedicarboxylic anhydride, 13.7 g (0.1 mol) of p-aminobenzoic acid, and 0.53 g (0.005 mol) of triethanolamine to a three-necked flask. Stir until homogeneous. At room temperature, add 100 mL of 1 mol / L sodium carbonate aqueous solution dropwise over 30 min. After the addition is complete, heat the three-necked flask to 100 °C and maintain the temperature at 100 °C with stirring at 300 rpm for 4 h. After the reaction is complete, cool to room temperature and adjust the pH of the reaction system to 2 using 36% hydrochloric acid, precipitating a yellow solid. Filter the solid, wash the filter cake with water, and then dry it at 60 °C for 24 h to obtain 33.5 g of modifier 7 (0.0891 mol).

[0054] In this embodiment, the yield of modifier 7 was 89.1%, and the purity of modifier 7 was 93.5% as determined by HPLC. The reaction route of modifier 7 is as follows: .

[0055] The structure of modifier 7 was characterized, and the result was m / z = 332.08; 1 H-NMR(600MHz,DMSO-D6)δ:5.79ppm(s,2H,NH2),7.22ppm(d,1H,CH),7.38ppm(d,2H,CH),7.71pp m(m,1H,CH),8.04ppm(d,2H,CH),8.45ppm(d,1H,CH),8.52ppm(d,2H,2CH),12.74ppm(s,1H,OH).

[0056] Example 8

[0057] Add 300 mL of deionized water, 25.7 g (0.1 mol) of 4-amino-1,8-naphthalenedicarboxylic anhydride, 39 g (0.1 mol) of 4-(4-aminobenzamido)-1-hydroxybutylidene-1,1-diphosphonic acid monosodium salt, and 0.53 g (0.005 mol) of triethanolamine to a three-necked flask. Stir until homogeneous. At room temperature, add 100 mL of 1 mol / L sodium carbonate aqueous solution dropwise over 30 min. After the addition is complete, heat the three-necked flask to 100 °C and maintain the temperature at 100 °C with stirring at 300 rpm for 4 h. After the reaction is complete, cool to room temperature and adjust the pH of the reaction system to 2 using 36% hydrochloric acid, precipitating a yellow solid. Filter the solid, wash the filter cake with water, and then dry it at 60 °C for 24 h to obtain 45 g of modifier 8 (0.0741 mol).

[0058] In this embodiment, the yield of modifier 8 was 74.1%, and the purity of modifier 8, as determined by HPLC, was 92.5%. The reaction route of modifier 8 is as follows: .

[0059] The structure of modifier 8 was characterized, and the result was m / z = 563.09; 1H-NMR(600MHz,DMSO-D6)δ:1.50-1.60ppm(m,4H,CH2CH2),2.70ppm(s,1H,COH),3.30ppm(m,2H,CH2),4.80ppm(s,4H,POH), 5.24ppm(t,1H,NH),5.79ppm(s,2H,NH2),7.22ppm(d,1H,CH),7.35ppm(d,2H,CH),7.71ppm(m,1H,CH),7.76ppm(d,2H,CH), 8.45ppm(d,1H,CH),8.52ppm(d,2H,2CH).

[0060] Application Example 1

[0061] Add 150g of carbon black to a four-necked flask, then add 1500mL of distilled water and stir until homogeneous. Next, add 20g of modifier and 1.5g of 36% hydrochloric acid, and stir at 300r / min for 30min. Then, add 15g of 20% sodium nitrite solution dropwise over 1 hour. After the addition is complete, raise the temperature to 50℃ and perform a diazotization reaction at 50℃. The reaction endpoint is detected using a freshly prepared H-acid solution (one drop of the reaction solution and one drop of the H-acid solution are placed on filter paper; the endpoint is reached when no color change occurs at the point where they meet). After the reaction, adjust the pH of the reaction system to 8 using 20% ​​sodium hydroxide solution. After filtration, wash the filter cake with 500mL of deionized water to obtain 300g of wet filter cake with a solid content of 50%. Mix the 300g wet filter cake with 700g of deionized water and disperse at 3000r / min using a disc disperser for 2 hours to obtain a black slurry. Black slurry was added to a horizontal sand mill, along with zirconium beads (0.3 mm in diameter, 20% of the mass of the black slurry). The milling process was repeated for 4 hours to obtain a crude modified pigment with a D50 of 125 nm. The crude modified pigment was then filtered through a filter membrane to obtain the modified pigment, labeled K01.

[0062] Application Example 2

[0063] Replace the carbon black in Application Example 1 with pigment blue 15:3, otherwise remain the same as in Application Example 1.

[0064] The modified pigment crude obtained in this application example has a D50 of 128 nm and is labeled as CO1.

[0065] Application Example 3

[0066] Replace the carbon black in Application Example 1 with Pigment Red 122, and everything else is the same as in Application Example 1.

[0067] The modified pigment crude obtained in this application example has a D50 of 116 nm and is labeled as M01.

[0068] Application Example 4

[0069] Replace the carbon black in Application Example 1 with Pigment Yellow 74, otherwise remain the same as in Application Example 1.

[0070] The modified pigment crude obtained in this application example has a D50 of 120 nm and is labeled as Y01.

[0071] Application Example 5

[0072] Replace modifier 1 in Application Example 1 with modifier 2, and everything else is the same as in Application Example 1.

[0073] The modified pigment crude obtained in this application example has a D50 of 115 nm, and the modified pigment is labeled as K02.

[0074] Application Example 6

[0075] Replace the carbon black in Application Example 5 with pigment blue 15:3, otherwise remain the same as in Application Example 5.

[0076] The modified pigment crude obtained in this application example has a D50 of 125 nm, and the modified pigment is labeled CO2.

[0077] Application Example 7

[0078] Replace the carbon black in Application Example 5 with Pigment Red 122, otherwise remain the same as in Application Example 5.

[0079] The modified pigment crude obtained in this application example has a D50 of 115 nm, and the modified pigment is labeled as M02.

[0080] Application Example 8

[0081] Replace the carbon black in Application Example 5 with Pigment Yellow 74, otherwise remain the same as in Application Example 5.

[0082] The modified pigment crude obtained in this application example has a D50 of 122 nm, and the modified pigment is labeled as Y02.

[0083] Application Example 9

[0084] Replace modifier 1 in Application Example 1 with modifier 3, and everything else is the same as in Application Example 1.

[0085] The modified pigment crude obtained in this application example has a D50 of 128 nm and is labeled as K03.

[0086] Application Example 10

[0087] Replace the carbon black in Application Example 9 with pigment blue 15:3, otherwise remain the same as in Application Example 9.

[0088] The modified pigment crude obtained in this application example has a D50 of 126 nm and is labeled as CO3.

[0089] Application Example 11

[0090] Replace the carbon black in Application Example 9 with Pigment Red 122, otherwise remain the same as in Application Example 9.

[0091] The modified pigment crude obtained in this application example has a D50 of 117 nm and is labeled as M03.

[0092] Application Example 12

[0093] Replace the carbon black in Application Example 9 with Pigment Yellow 74, otherwise remain the same as in Application Example 9.

[0094] The modified pigment crude obtained in this application example has a D50 of 125 nm and is labeled as Y03.

[0095] Application Example 13

[0096] Replace modifier 1 in Application Example 1 with modifier 4, and everything else is the same as in Application Example 1.

[0097] The modified pigment crude obtained in this application example has a D50 of 120 nm and is labeled as K04.

[0098] Application Example 14

[0099] Replace the carbon black in Application Example 13 with pigment blue 15:3, otherwise the same as in Application Example 13.

[0100] The modified pigment crude obtained in this application example has a D50 of 125 nm and is labeled as CO4.

[0101] Application Example 15

[0102] Replace the carbon black in Application Example 13 with Pigment Red 122, otherwise remain the same as in Application Example 13.

[0103] The modified pigment crude obtained in this application example has a D50 of 114 nm and is labeled as M04.

[0104] Application Example 16

[0105] Replace the carbon black in Application Example 13 with Pigment Yellow 74, otherwise remain the same as in Application Example 13.

[0106] The modified pigment crude obtained in this application example has a D50 of 120 nm and is labeled as Y04.

[0107] Application Example 17

[0108] Replace modifier 1 in Application Example 1 with modifier 5, and everything else is the same as in Application Example 1.

[0109] The modified pigment crude obtained in this application example has a D50 of 122 nm and is labeled as K05.

[0110] Application Example 18

[0111] Replace the carbon black in Application Example 17 with pigment blue 15:3, otherwise remain the same as in Application Example 17.

[0112] The modified pigment crude obtained in this application example has a D50 of 123 nm and is labeled as C05.

[0113] Application Example 19

[0114] Replace the carbon black in Application Example 17 with Pigment Red 122, otherwise remain the same as in Application Example 17.

[0115] The modified pigment crude obtained in this application example has a D50 of 115 nm and is labeled as M05.

[0116] Application Example 20

[0117] Replace the carbon black in Application Example 17 with Pigment Yellow 74, otherwise remain the same as in Application Example 17.

[0118] The modified pigment crude obtained in this application example has a D50 of 140 nm and is labeled as Y05.

[0119] Application Example 21

[0120] Replace modifier 1 in Application Example 1 with modifier 6, otherwise the same as in Application Example 1.

[0121] The modified pigment crude obtained in this application example has a D50 of 115 nm and is labeled as K06.

[0122] Application Example 22

[0123] Replace the carbon black in Application Example 21 with pigment blue 15:3, otherwise the same as in Application Example 21.

[0124] The modified pigment crude obtained in this application example has a D50 of 125 nm and is labeled as C06.

[0125] Application Example 23

[0126] Replace the carbon black in Application Example 21 with Pigment Red 122, and everything else is the same as in Application Example 21.

[0127] The modified pigment crude obtained in this application example has a D50 of 115 nm and is labeled as M06.

[0128] Application Example 24

[0129] Replace the carbon black in Application Example 1 with Pigment Yellow 74, otherwise the same as in Application Example 21.

[0130] The modified pigment crude obtained in this application example has a D50 of 135 nm and is labeled as Y06.

[0131] Application Example 25

[0132] Replace modifier 1 in Application Example 1 with modifier 7, and everything else is the same as in Application Example 1.

[0133] The modified pigment crude obtained in this application example has a D50 of 118 nm and is labeled as K07.

[0134] Application Example 26

[0135] Replace the carbon black in Application Example 25 with pigment blue 15:3, otherwise the same as in Application Example 25.

[0136] The modified pigment crude obtained in this application example has a D50 of 122 nm and is labeled as C07.

[0137] Application Example 27

[0138] Replace the carbon black in Application Example 25 with Pigment Red 122, otherwise remain the same as in Application Example 25.

[0139] The modified pigment crude obtained in this application example has a D50 of 118 nm and is labeled as M07.

[0140] Application Example 28

[0141] Replace the carbon black in Application Example 25 with Pigment Yellow 74, otherwise remain the same as in Application Example 25.

[0142] The modified pigment crude obtained in this application example has a D50 of 138 nm and is labeled as Y07.

[0143] Application Example 29

[0144] Replace modifier 1 in Application Example 1 with modifier 8, otherwise the same as in Application Example 1.

[0145] The modified pigment crude obtained in this application example has a D50 of 122 nm and is labeled as K08.

[0146] Application Example 30

[0147] Replace the carbon black in Application Example 29 with pigment blue 15:3, otherwise the same as in Application Example 29.

[0148] The modified pigment crude obtained in this application example has a D50 of 123 nm and is labeled as C08.

[0149] Application Example 31

[0150] Replace the carbon black in Application Example 29 with Pigment Red 122, otherwise remain the same as in Application Example 29.

[0151] The modified pigment crude obtained in this application example has a D50 of 116 nm and is labeled as M08.

[0152] Application Example 32

[0153] Replace the carbon black in Application Example 29 with Pigment Yellow 74, otherwise remain the same as in Application Example 29.

[0154] The modified pigment crude obtained in this application example has a D50 of 130 nm and is labeled as Y08.

[0155] Comparative Application Example 1

[0156] The Cabot sample CAB-O-JET 4155K, labeled K00, has a D50 of 130 nm.

[0157] Comparative Application Example 2

[0158] The Cabot sample CAB-O-JET 4507C, labeled C00, has a D50 of 135 nm.

[0159] Comparative Application Example 3

[0160] The Cabot sample CAB-O-JET 4673M, labeled M00, has a D50 of 130 nm.

[0161] Comparative Application Example 4

[0162] The Cabot sample CAB-O-JET 4774Y, labeled Y00, has a D50 of 150 nm.

[0163] The modified pigments used in Application Examples 1-32 and Comparative Application Examples 1-4 were formulated into inks. By mass fraction, each ink consisted of 30% modified pigment, 30% binder W6110, 2% wetting agent propylene glycol, 0.1% pH adjuster triethanolamine, 0.1% antibacterial agent BIT20, and the remainder distilled water. The inks were tested, with flowability characterized by the time it took for 300 mL of ink to pass through a 47 mm diameter filter membrane. Color density (OD) was tested by printing the ink onto A4 paper using a Focus Athena-Jet Plus A2 DTG printer, printing at 18 cm... A 6cm color patch was used, and the color density value of the solid area filled with the maximum printing density was measured using an eXact spectrophotometer. The measurement was repeated three times, and the average OD value was calculated. Table 1 shows the test results of the modified pigments and inks.

[0164] Table 1 Test Results of Modified Pigments and Inks

[0165] As shown in Table 1, the modified pigments prepared in the examples all have particle sizes below 150 nm, exhibiting good dispersibility. Their physicochemical properties, such as particle size distribution, viscosity, and flowability, all meet the requirements. Compared to the corresponding Cabot samples, the modified pigments prepared in the examples all possess extremely high color densities. These results demonstrate that the modified pigments prepared from the pigment modifier with the naphthalimide structure of this invention exhibit excellent dispersibility and extremely high color strength.

[0166] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A pigment modifier having a naphthalimide structure, characterized in that, The structural formula of the pigment modifier with a naphthimide structure is as follows: ; Where R1 is -(CH2) n -Q or -C6H4-(Sp)m-(CH2)nQ, R2 contains -SO3H or H; Q contains a carboxyl group, a sulfonic acid group, a phosphoric acid group, a phosphonic acid group, or a geminosine group; Sp includes -CO2-, -O-, -NR3, -CO-, -CONR3-, -SO2NR3-, where R3 includes H or C1~C6 alkyl groups; m is 0 or 1, and n is any integer from 0 to 6.

2. The pigment modifier having a naphthalimide structure according to claim 1, characterized in that, The pigment modifier having a naphthalimide structure is any one of the following structural formulas: 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 。 3. A method for preparing modified pigments using the pigment modifier with a naphthalimide structure as described in claim 1 or 2, characterized in that, It includes the following steps: A pigment modifier with a naphthalimide structure, pigment, hydrochloric acid, sodium nitrite solution, and water are mixed and subjected to a diazotization reaction to obtain the modified pigment.

4. The method according to claim 3, characterized in that, The mass ratio of the pigment modifier with the naphthalimide structure to the pigment is 0.1 to 3:1, and the mass ratio of the pigment to water is 1:5 to 20.

5. The method according to claim 3 or 4, characterized in that, The pigment modifier with the naphthalimide structure and the sodium nitrite solution have a mass ratio of 5~10:1, and the sodium nitrite solution has a mass fraction of 5~25%.

6. The method according to claim 5, characterized in that, The mass ratio of the pigment modifier with the naphthalimide structure to hydrochloric acid is 3~5:1, and the mass fraction of hydrochloric acid is 30~40%.

7. The method according to claim 6, characterized in that, The diazotization reaction is carried out at a temperature of 25~50℃.

8. The method according to claim 6 or 7, characterized in that, After the diazotization reaction is completed, the pH value of the reaction system is first adjusted to 7-9, and then solid-liquid separation is performed to obtain the modified pigment.

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