Pigment modifier for water-based system and application of pigment modifier

Abstract

The invention belongs to the technical field of pigments for water-based systems, and particularly relates to a pigment modifier for a water-based system and application of the pigment modifier for the water-based system, 4-aminobenzylphosphonic acid is adopted as the pigment modifier for the water-based system, and-PO3H2 hydrophilic groups are grafted to the surfaces of pigment particles through specific diazotization reaction of the pigment modifier for the water-based system, so that the pigment modifier for the water-based system is obtained. The organic pigment is endowed with electrostatic stability in a water-based system, so that the pigment can form a stable water-based dispersion under the condition of not using an additional dispersing auxiliary agent, and the brilliance and tinting strength of the pigment are further improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of pigments for water-based systems, and particularly relates to a pigment modifier for water-based systems and application thereof. Background Art

[0002] Organic pigments, due to their exceptional properties, such as vibrant colors, broad color spectrum, simple production processes, and low toxicity, are widely used in a wide range of industries, including coatings, inks, pigment printing, plastics, and rubber. To meet the demands for high fastness and environmental performance, one of the main trends in the development of inks is water-based printing. Therefore, the development of pigments with excellent dispersibility and the ability to meet the performance requirements of various water-based systems has become a key research topic in pigment development technology.

[0003] Organic pigments are typically modified using surfactants. The fundamental principle behind this modification is that the molecules contain hydrophilic or lipophilic groups. These groups adsorb onto the surface of the pigment particles based on their charge, increasing their affinity with the carrier and allowing them to be fully dispersed in the aqueous system. Using high-molecular-weight surfactants to modify pigments results in organic pigments that are easily wettable and have good dispersion stability, but this is at a higher cost. Summary of the Invention

[0004] To overcome the above problems, the present invention provides a pigment modifier for a water-based system and its application. 4-aminobenzylphosphonic acid is prepared by hydrolyzing diethyl 4-aminobenzylphosphonate under acidic conditions. 4-aminobenzylphosphonic acid is then grafted onto the surface of the pigment particles through a specific diazotization reaction to impart electrostatic stability to the organic pigment in the water-based system. This allows the pigment to form a stable water-based dispersion without the use of additional dispersing aids, further improving the pigment's brightness and tinting strength.

[0005] A pigment modifier for a water-based system, wherein the modifier is 4-aminobenzylphosphonic acid.

[0006] The preparation method of 4-aminobenzylphosphonic acid comprises the following steps: dissolving diethyl 4-aminobenzylphosphonate in hydrochloric acid, stirring, cooling, removing the solvent under reduced pressure, and vacuum drying to obtain 4-aminobenzyl phosphoric acid.

[0007] When the 4-aminobenzylphosphonic acid is used to modify azo pigments, the prepared modified azo pigments have a tinting strength of 115-143%. When the 4-aminobenzylphosphonic acid is used to modify a non-azo pigment, the prepared modified non-azo pigment has a tinting strength of 108-114%.

[0008] The present invention also provides an application of the above-mentioned modifier in modifying azo pigments, and the application method is as follows: S101, diazotizing 4-aminobenzylphosphonic acid to obtain a 4-aminobenzylphosphonic acid diazonium salt solution; S102, adding the coupling solution to the 4-aminobenzylphosphonic acid diazonium salt solution by reverse coupling, stirring until the diazonium salt disappears, to obtain an azo pigment derivative; S103, mixing the azo pigment matrix and the azo pigment derivative, washing, and drying to obtain a modified azo pigment.

[0009] In step S101, the method for preparing the 4-aminobenzylphosphonic acid diazonium salt solution specifically comprises: adding 4-aminobenzyl phosphoric acid to a hydrochloric acid solution, stirring, cooling, adding sodium nitrite, and stirring at a pH of 1 to 3 to obtain 4-aminobenzylphosphonic acid diazonium salt. The hydrochloric acid solution comprises 0.1 to 0.2 parts of hydrochloric acid (30 to 38 wt%) and 3 to 5 parts of water; and the molar ratio of sodium nitrite to 4-aminobenzyl phosphoric acid is (1.05 to 1.1):1.

[0010] Preferably, after stirring is completed, excess nitrite ions are removed by adding sulfamic acid.

[0011] In step S102, the molar ratio of the 4-aminobenzylphosphonic acid diazonium salt in the 4-aminobenzylphosphonic acid diazonium salt solution to the coupling component in the coupling solution is 1:(2.1-2.5).

[0012] In step S103 , the mass ratio of the azo pigment matrix to the azo pigment derivative is (90-96):(4-10).

[0013] In step S103, the washing method adopted is dead-end filtration; specifically, a lignin loose nanofiltration membrane is used as the filter membrane, the feed liquid is added to the dead-end filter, the pigment slurry is magnetically stirred, pure water is added, and the pigment slurry completes the washing process under the push of nitrogen. Pure water is added in a cycle to wash until the pH is 7, and the filter cake is obtained by nitrogen pressure filtration.

[0014] The present invention also provides an application of the above-mentioned modifier in the modification of non-azo pigments, and the application method is as follows: S201, beating and grinding 4-aminobenzylphosphonic acid and a non-azo pigment precursor in an aqueous ammonia solution to obtain a mixed slurry; S202, adding nitrite and hydrochloric acid to the mixed slurry to diazotize 4-aminobenzylphosphonic acid to obtain 4-aminobenzylphosphonic acid diazonium salt, and reacting the salt with the non-azo pigment matrix; S203, adding polyetheramine, stirring, washing, and drying to obtain a modified non-azo pigment.

[0015] The non-azo pigments include phthalocyanine, quinacridone, and dioxazine pigments.

[0016] In step S201, the concentration of the ammonia aqueous solution is 0.001-0.0015 g / mL; the mass ratio of the 4-aminobenzylphosphonic acid to the non-azo pigment precursor is (0.05-0.15):1.

[0017] In step S201, zirconium oxide beads are added before beating and grinding, and the mass ratio of the zirconium oxide beads to the non-azo pigment matrix is (6.6-10):1.

[0018] In step S201, when dissolving the non-azo pigment matrix, adding a small amount of ammonia water is beneficial to the dispersion of the pigment matrix in water. At the same time, zirconia beads are used for beating and grinding, and the fine pigment matrix particles are more susceptible to diazotization and coupling reactions.

[0019] Step S202 specifically includes adding sodium nitrite to the mixed slurry, stirring at 70-90°C for 30-90 minutes, adding hydrochloric acid, adjusting the pH to 1-3, and maintaining the mixture for 30-90 minutes. The molar ratio of sodium nitrite to 4-aminobenzylphosphonic acid is (1.2-1.6):1.

[0020] In step S203, the mass ratio of the polyetheramine to the non-azo pigment matrix is (0.05-0.20):1. The number average molecular weight of the polyetheramine is 2000-2500.

[0021] The polyetheramine and 4-aminobenzyl phosphoric acid act synergistically to jointly improve the hydrophilicity and water dispersibility of the modified non-azo pigment: on the one hand, after the 4-aminobenzyl phosphoric acid grafts the phosphate group onto the pigment matrix, the strong polarity of the phosphate group itself attracts water molecules to form a primary hydrophilic layer. However, its short-chain structure has limited contribution to steric hindrance. The long-chain polyether structure of the polyetheramine forms a hydrogen bond network with water molecules, extending the thickness of the hydrophilic layer, enhancing the thickness of the hydrophilic layer, and enhancing the long-term hydrophilic stability of the pigment, thereby compensating for the problem of insufficient extremely hydrophilic chain length of the phosphate. On the other hand, the phosphate group is ionized and negatively charged, preventing pigment particle aggregation through electrostatic repulsion. On this basis, the amino group of the polyetheramine is protonated under acidic conditions, which can form local charge compensation with the negative charge of the phosphate group, reducing the risk of overall charge overload of the system, while enhancing the electrostatic and spatial dual stabilization effect between particles.

[0022] In step S203, the stirring temperature is 60-90°C, and the stirring time is 1-2 hours.

[0023] In step S203, the washing method adopted is dead-end filtration; specifically, a lignin loose nanofiltration membrane is used as the filter membrane, the feed liquid is added to the dead-end filter, the pigment slurry is magnetically stirred, pure water is added, and the pigment slurry completes the washing process under the push of nitrogen. Pure water is added in a cycle to wash until the pH is 7, and the filter cake is obtained by nitrogen pressure filtration.

[0024] Beneficial effects 1. The present invention adopts 4-aminobenzylphosphonic acid as a modifier for the first time. The hydrophilic group -PO3H2 is grafted onto the surface of the pigment particles through a diazotization reaction, which gives the organic pigment electrostatic stability in the aqueous system. As a result, the pigment can form a stable aqueous dispersion without the use of additional dispersing agents, further improving the pigment's brightness and tinting strength.

[0025] 2. The modifier 4-aminobenzylphosphonic acid used in the present invention can not only improve the tinting strength of the modified pigment and the dispersion stability in the aqueous system, but also is easy to produce and low in cost, and has great application prospects in actual production.

[0026] 3. The present invention adopts the dead-end filtration method for washing the pigment slurry for the first time, so that as much hydrophilic pigment derivative as possible is retained during the washing process to improve the hydrophilicity of the modified pigment.

[0027] 4. When the present invention uses 4-aminobenzylphosphonic acid as a modifier in the modification of non-azo pigments, it innovatively uses polyetheramine and the modifier to work synergistically to jointly improve the hydrophilicity of the non-azo pigments and the dispersion stability in the aqueous medium, thereby solving the problem of poor hydrophilicity of non-azo pigments due to poor polarity. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Improves the dispersion stability of Pigment Yellow 74 matrix and modified Pigment Yellow 74; Figure 2 Improve the dispersion stability of Pigment Red 122 matrix and modified Pigment Red 122; Figure 3 For the dispersion stability of Pigment Violet 23 matrix and modified Pigment Violet 23 Figure 4 It is used to improve the dispersion stability of phthalocyanine blue matrix and modified phthalocyanine blue. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below through specific embodiments of the present invention. However, it should not be understood that the present invention is limited to the following embodiments. All technologies implemented based on the above contents of the present invention belong to the scope of the present invention.

[0030] In the following examples and comparative examples, red base B was purchased from Wujiang Jinsui Chemical Co., Ltd.; PR122 was purchased from Lily Group Co., Ltd.; Permanent Purple RL was purchased from Shanghai Yingyan Chemical Group; Phthalocyanine Blue was purchased from Hebei Merida Pigment Co., Ltd.; Polyetheramine L-207 was purchased from Huntsman Chemical Trading Co., Ltd.; the remaining raw materials were commercially available unless otherwise specified.

[0031] The lignin loose nanofiltration membrane is a homemade product. The preparation method is as follows: 20 mL of a 3 wt% aqueous solution of quaternized lignin (QL) at pH 12 is poured onto the surface of a polysulfone (PS) substrate membrane and allowed to adsorb for 5 minutes. The remaining solution is then discarded, and the QL-adsorbed membrane is rinsed with deionized water for 2 minutes to remove unadsorbed QL. The QL-adsorbed membrane is then air-dried for 14 minutes. After drying, 20 mL of a 0.08 wt% triphosgene (TP) solution in n-hexane is poured onto the QL-adsorbed membrane as the organic phase for 1 minute to form a QL / TP separation layer through cross-linking. Unreacted TP is then rinsed with n-hexane solution. Finally, the membrane is placed in an oven at 60°C for 5 minutes for further cross-linking, resulting in a lignin loose nanofiltration membrane that is then stored in deionized water.

[0032] The quaternized lignin (QL) is prepared by using alkaline lignin (AL) as a film-forming material, formaldehyde (HCHO) and diethylenetriamine (DETA) as modifiers, and synthesizing aminated lignin (AAL) through a Mannich reaction; and then the quaternized lignin (QL) is obtained through a quaternization reaction of AAL with methyl iodide (CH3I).

[0033] Example 1. Preparation of modified pigment yellow 74 1. Preparation of Pigment Yellow 74 Matrix 1.1. At 30°C, add 4.21g hydrochloric acid (36wt%) to 25mL of water and stir for 5min. Add 3g of Red Base B (100%) and 30g of zirconium oxide beads over 10min and stir for 30min. Adjust the volume to 35mL with water. At 0°C, add 1.3g of sodium nitrite over 2min to adjust the pH to 1.0, ensuring a constant excess of nitrite ions. Stir for 2h. Adjust the volume to 60mL with ice water, add 0.07g of sulfamic acid to remove excess nitrite ions, and stir for 5min. When the starch potassium iodide test paper turns colorless, filter to obtain the diazo solution.

[0034] 1.2. Heat 37 mL of water to 30°C, add 1.58 g of NaOH, and stir for 5 minutes. Add 4 g of o-methoxyacetyl acetanilide (98 wt%) and stir for 15 minutes until completely dissolved. Adjust the volume to 61 mL with water. Add 2.26 g of acetic acid (99.5 wt%) and stir for 5 minutes at 13°C. Check the pH at 5.4. Adjust the volume to 79 mL with water at 25°C to prepare the first coupling solution.

[0035] 1.3. At 25°C, add the diazonium solution to the first coupling solution over 20 minutes. Add 60% of the diazonium salt solution during the first 5 minutes, and use an H acid test to confirm that there is no excess diazonium salt. If the pH drops to 4.5, adjust the pH to 5.6 with 20wt% sodium carbonate solution and continue coupling to ensure that there is no excess diazonium salt. After coupling, add 10mL of cold water and stir for 15 minutes. Add 1.44g of 50wt% NaOH to adjust the pH from 5 to 11. Add dissolved transparent maleic rosin solution (0.6g maleic rosin, 0.15g NaOH, 10mL water) and stir for 15 minutes. Rapidly raise the temperature to 90°C, add aluminum sulfate to adjust the pH to 6.5, and stir for 10 minutes to obtain Pigment Yellow 74 precursor.

[0036] The preparation mechanism of the Pigment Yellow 74 matrix is as follows:

[0037] 2. Preparation of modified derivatives 2.1. Dissolve diethyl 4-aminobenzylphosphonate (0.5 g, 2.06 mmol) in 30.4 g of hydrochloric acid (36 wt%) and 20 mL of water. Stir at 100°C for 24 h. Cool the resulting solution to room temperature, remove the solvent under reduced pressure, and dry in vacuo to obtain 0.34 g of crystalline 4-aminobenzylphosphonic acid.

[0038] 2.2. At 25°C, add 0.16 g of hydrochloric acid (36 wt%) to 4 ml of water, then add 0.095 g (0.51 mmol) of 4-aminobenzylphosphonic acid. Stir for 30 minutes until dissolved and transparent. Cool to 0°C with ice, then add 0.038 g (0.55 mmol) of sodium nitrite. Stir for 15 minutes at a pH of 1.0. Add 0.06 g of aminosulfonic acid to remove excess nitrite ions to obtain a 4-aminobenzylphosphonic acid diazonium salt solution.

[0039] The preparation mechanism of the 4-aminobenzylphosphonic acid diazonium salt is as follows: .

[0040] 2.3. At 30°C, add 0.03 g of NaOH to 4 mL of water, add 0.256 g (1.24 mmol) of o-methoxyacetyl acetanilide, and stir for 10 min until dissolved and transparent. Add 0.022 g of acetic acid (99.5 wt%) to precipitate the o-methoxyacetyl acetanilide to obtain a second coupling solution. Check the acid value; the pH is 10.0.

[0041] 2.4. Reverse couple the second coupling solution to the 4-aminobenzylphosphonic acid diazonium salt solution over 2 minutes. Detect the acid value to be 4.6. Stir for 30 minutes until the diazonium salt disappears (colorless in the H acid seepage test) to obtain the Pigment Yellow 74 derivative.

[0042] The preparation mechanism of the Pigment Yellow 74 derivative is as follows:

[0043] 3. Preparation of modified pigment yellow 74 When the pigment yellow 74 matrix is kept at 90℃ for 10 minutes, the modified pigment yellow 74 derivative is heated to 40℃ and quickly added, and the mixture is stirred for 1 hour and cooled. Among them, the pigment yellow 74 matrix is 7g and the pigment yellow 74 derivative is 0.351g.

[0044] Dead-end filtration was performed using a lignin loose nanofiltration membrane. The pigment slurry was added to the dead-end filter and magnetically stirred. 200 mL of purified water was added and nitrogen was introduced at a pressure of 0.5 MPa to complete the washing process. Purified water was then added to the slurry until the pH reached 7. The filter cake was filtered under nitrogen pressure and dried at 60°C to obtain Modified Pigment Yellow 74.

[0045] Comparative Example 1: This comparative example uses the Pigment Yellow 74 matrix prepared in Example 1.

[0046] Example 2, Preparation of Modified Pigment Red 122: Dissolve diethyl 4-aminobenzylphosphonate (1.0 g, 4.12 mmol) in 60.8 g of hydrochloric acid (36 wt%) and 40 mL of water. Stir at 100°C for 24 h. Cool the resulting solution to room temperature, and remove the solvent under reduced pressure. Dry under vacuum to obtain 0.68 g of crystalline 4-aminobenzylphosphonic acid.

[0047] To 90ml of water, add 0.4g of 25% ammonia aqueous solution and stir thoroughly. Then add 2.887g (0.00848mol) of PR122 and 0.376g (0.00202mol) of 4-aminobenzylphosphoric acid. Add 25g of zirconium oxide beads and blend for 1 hour. Add sodium nitrite solution (sodium nitrite (99wt%) 0.218g, water 0.5g) and stir at 80°C for 1 hour. Add hydrochloric acid (36wt% 0.75g) to adjust the pH to 2. Incubate for 1 hour. Add 0.47g of polyetheramine L-207 and heat to 90°C, stirring for 1 hour. Dead-end filtration: Using a lignin loose nanofiltration membrane as the filter membrane, the slurry is added to the dead-end filter, the pigment slurry is magnetically stirred, 200ml of pure water is added, and nitrogen is introduced at a pressure of 0.5MPa to allow the salt water to pass through the membrane to complete the washing process. Pure water is then added in a cycle to wash until the pH reaches 7. The filter cake is filtered under nitrogen pressure and dried at 85℃.

[0048] The preparation mechanism of the modified Pigment Red 122 is as follows:

[0049] Comparative Example 2: PR122 is used for comparison.

[0050] Example 3, Preparation of Modified Pigment Violet 23: Dissolve diethyl 4-aminobenzylphosphonate (1.0 g, 4.12 mmol) in 60.8 g of hydrochloric acid (36 wt%) and 40 mL of water. Stir at 100°C for 24 h. Cool the resulting solution to room temperature, and remove the solvent under reduced pressure. Dry under vacuum to obtain 0.68 g of crystalline 4-aminobenzylphosphonic acid.

[0051] To 90ml of water, add 0.4g of aqueous ammonia and stir thoroughly. Then add 5g (0.00848mol) of Permanent Violet RL (Pigment Violet 23) and 0.414g (0.00222mol) of 4-aminobenzyl phosphoric acid. Add 50g of zirconium oxide beads and blend for 1 hour. Add sodium nitrite solution (sodium nitrite (99wt%) 0.24g, water 0.5g) and stir at 80°C for 1 hour. Add hydrochloric acid (36wt% 0.74g) to adjust the pH to 2. After addition, incubate for 1 hour. Add 0.52g of polyetheramine L-207 and heat to 90°C, stirring for 1 hour. Dead-end filtration: Using a lignin loose nanofiltration membrane as the filter membrane, the pigment slurry is added to the dead-end filter, magnetically stirred, and 200 ml of pure water is added. Nitrogen is introduced at a pressure of 0.5 MPa to complete the washing process of the pigment slurry. Pure water is added cyclically to wash until the pH reaches 7. The filter cake is obtained by nitrogen pressure filtration and dried at 85°C.

[0052] The preparation mechanism of the modified pigment violet 23 is as follows:

[0053] Comparative Example 3: Permanent Violet RL (i.e. Pigment Violet 23) was used for comparison.

[0054] Example 4, Preparation of Modified Phthalocyanine Blue: Dissolve diethyl 4-aminobenzylphosphonate (1.0 g, 4.12 mmol) in 60.8 g of hydrochloric acid (36 wt%) and 40 mL of water. Stir at 100°C for 24 h. Cool the resulting solution to room temperature, and remove the solvent under reduced pressure. Dry under vacuum to obtain 0.68 g of crystalline 4-aminobenzylphosphonic acid.

[0055] To 90ml of water, add 0.4g of aqueous ammonia and stir thoroughly. Then add 4.9g (0.00848mol) of phthalocyanine blue and 0.451g (0.00242mol) of 4-aminobenzylphosphoric acid. Add 33g of zirconium oxide beads and grind for 1 hour. Add sodium nitrite solution (sodium nitrite (99wt%) 0.262g, water 0.6g) and stir at 80°C for 1 hour. Add hydrochloric acid (36wt% 0.80g) to adjust the pH to 2. After addition, incubate for 1 hour. Add 0.56g of polyetheramine L-207 and heat to 90°C, stirring for 1 hour. Dead-end filtration: Using a lignin loose nanofiltration membrane as the filter membrane, the pigment slurry is added to the dead-end filter, magnetically stirred, and 200 ml of pure water is added. Nitrogen is introduced at a pressure of 0.5 MPa to complete the washing process of the pigment slurry. Pure water is added cyclically to wash until the pH reaches 7. The filter cake is obtained by nitrogen pressure filtration and dried at 85°C.

[0056] The preparation mechanism of the modified phthalocyanine blue is as follows:

[0057] Comparative Example 4: Unmodified phthalocyanine blue was used for comparison.

[0058] Comparative Example 5: This comparative example is the same as Example 2, except that the polyetheramine L-207 is replaced by fatty alcohol polyoxyethylene ether OS-15 of equal mass.

[0059] Table 1 Color properties of modified pigments

[0060] As shown in Table 1, the vividness of the pigments in Examples 1-4 was improved compared to those in Comparative Examples 1-4 (ΔC > 0). Furthermore, tinting strength was also improved, from 100% to 108.1% to 142.1%. Furthermore, the contact angles of Examples 1-4 were all lower than those of Comparative Examples 1-4, indicating that the modified pigments prepared in Examples 1-4 have effectively improved their hydrophilicity.

[0061] In addition, if Figures 1 to 4 The dispersion stability performance diagrams of the pigments prepared in Examples 1 to 4 and Comparative Examples 1 to 4 are respectively shown. It can be seen from the diagram that the dispersion stability of the modified pigments is improved. The modified pigments have lower light transmittance and good dispersion stability in water; the dispersion stability of the modified pigments shows an improving trend.

[0062] As shown in Table 1, the modified Pigment Yellow 74 prepared in Example 1 has a tinting strength of up to 142.1% and a contact angle of 63.8° compared to the modified Pigment Yellow 74 prepared in Comparative Example 1. This is because the derivative formed by 4-aminobenzyl phosphoric acid and o-methoxyacetylacetanilide has the same or similar skeleton structure as the treated pigment (pigment matrix). Its addition during the synthesis reaction as a crystal growth inhibitor for the pigment particles improves the tinting strength of the pigment. At the same time, the -PO3H2 (phosphate group) hydrophilic group grafted onto the surface of the pigment particles improves the surface polarity of the pigment.

[0063] According to Table 1, the modified Pigment Red 122 prepared in Example 2 has a tinting strength of 113.9% and a contact angle of 51.5° compared with the modified Pigment Red 122 prepared in Comparative Example 2. This is because the diazonium salt used contains a phosphate group, which can increase the hydrophilicity of the modified Pigment Red 122, making it easy to disperse in an aqueous medium, and also greatly contributes to improving the tinting strength of the modified pigment.

[0064] According to Table 1, the tinting strength and hydrophilicity of the modified pigment red 122 prepared in Example 2 are inferior to those of the modified pigment yellow 74 prepared in Example 1. However, compared with Comparative Example 5, the tinting strength and hydrophilicity are greatly improved. This is because, in Example 2, the synergistic enhancement of the hydrophilization of the phosphate group and the polyetheramine and the charge synergistic effect jointly promote the improvement of the performance of the modified pigment red 122; while in Comparative Example 5, fatty alcohol polyoxyethylene ether is used as a hydrophilic additive, but it cannot achieve synergistic enhancement with the phosphate group, so the tinting strength and hydrophilicity are not significantly improved.

[0065] like Figure 1-4 The figures show the dispersion stability of the modified pigments prepared in Examples 1 to 4 and Comparative Examples 1 to 4, respectively. It can be seen from the figures that the dispersion stability of the modified pigment yellow 74, pigment red 122, pigment violet 23 and pigment blue 15 in the aqueous system is significantly better than that of the unmodified pigments.

Claims

1. A pigment modifier for a water-based system, characterized in that: The modifier is 4-aminobenzylphosphonic acid; When the 4-aminobenzylphosphonic acid is used to modify azo pigments, the prepared modified azo pigments have a tinting strength of 115-143%. When the 4-aminobenzylphosphonic acid is used to modify a non-azo pigment, the prepared modified non-azo pigment has a tinting strength of 108-114%.

2. Use of the modifier according to claim 1 in modifying azo pigments, characterized in that: The application method is: S101, diazotizing 4-aminobenzylphosphonic acid to obtain a 4-aminobenzylphosphonic acid diazonium salt solution; S102, adding the coupling solution to the 4-aminobenzylphosphonic acid diazonium salt solution by reverse coupling, stirring until the diazonium salt disappears, to obtain an azo pigment derivative; S103, mixing the azo pigment matrix and the azo pigment derivative, washing, and drying to obtain a modified azo pigment.

3. The use of the modifier according to claim 2 in an azo pigment modifier, characterized in that: In step S101, the preparation method of the 4-aminobenzylphosphonic acid diazonium salt solution is specifically as follows: 4-aminobenzyl phosphoric acid is added to a hydrochloric acid solution, stirred, cooled, sodium nitrite is added, and stirred at a pH of 1 to 3 to obtain 4-aminobenzylphosphonic acid diazonium salt; The hydrochloric acid solution contains 0.1-0.2 parts of hydrochloric acid with a mass fraction of 30-38 wt% and 3-5 parts of water; the molar ratio of sodium nitrite to 4-aminobenzyl phosphoric acid is (1.05-1.1):

1.

4. The use of the modifier according to claim 2 in an azo pigment modifier, characterized in that: In step S102, the molar ratio of the 4-aminobenzylphosphonic acid diazonium salt in the 4-aminobenzylphosphonic acid diazonium salt solution to the coupling component in the coupling solution is 1:(2.1-2.5).

5. The use of the modifier according to claim 2 in an azo pigment modifier, characterized in that: In step S103 , the mass ratio of the azo pigment matrix to the azo pigment derivative is (90-96):(4-10).

6. The use of the modifier according to claim 2 in an azo pigment modifier, characterized in that: In step S103, the washing method adopted is dead-end filtration; a lignin loose nanofiltration membrane is used as the filtration membrane.

7. Use of the modifier according to claim 1 in modifying non-azo pigments, characterized in that: The application method is: S201, beating and grinding 4-aminobenzylphosphonic acid and a non-azo pigment precursor in an aqueous ammonia solution to obtain a mixed slurry; S202, adding nitrite and hydrochloric acid to the mixed slurry to diazotize 4-aminobenzylphosphonic acid to obtain 4-aminobenzylphosphonic acid diazonium salt, and reacting the salt with the non-azo pigment matrix; S203, adding polyetheramine, stirring, washing, and drying to obtain a modified non-azo pigment; The non-azo pigments include phthalocyanine, quinacridone, and dioxazine pigments.

8. The use of the modifier according to claim 7 in a non-azo pigment modifier, characterized in that: In step S201, the mass ratio of the 4-aminobenzylphosphonic acid to the non-azo pigment precursor is (0.05-0.15):1; Preferably, in step S201, zirconium oxide beads are added before beating and grinding, and the mass ratio of the zirconium oxide beads to the non-azo pigment matrix is (6.6-10):

1.

9. The use of the modifier according to claim 7 in a non-azo pigment modifier, characterized in that: Step S202 specifically includes: adding sodium nitrite to the mixed slurry, stirring at 70-90° C. for 30-90 minutes, adding hydrochloric acid, adjusting the pH to 1-3, and keeping the mixture warm for 30-90 minutes; The molar ratio of sodium nitrite to 4-aminobenzylphosphonic acid is (1.2-1.6):

1.

10. Use of the modifier according to claim 7 in a non-azo pigment modifier, characterized in that: In step S203, the mass ratio of the polyetheramine to the non-azo pigment matrix is (0.05-0.20):1; Preferably, the number average molecular weight of the polyetheramine is 2000-2500.

Images