Self-dispersing pigment color paste and preparation method thereof

Abstract

The invention relates to the technical field of pigment color paste, in particular to self-dispersing pigment color paste and a preparation method thereof, and the self-dispersing pigment color paste is prepared from pigment, sulfonamide diazonium salt and deionized water. The pigment is modified by adopting the sulfanilamide diazonium salt, a surfactant and a dispersing agent are not added, and the prepared self-dispersing pigment color paste is low in viscosity, high in surface tension, strong in tinting strength, high in fastness, bright in color and good in dispersion stability and storage stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pigment paste, and in particular to a self-dispersing pigment paste and a preparation method thereof. BACKGROUND

[0002] In the field of digital paint printing, water-based ink, etc., the core of pigment dispersion technology is to achieve stable dispersion and performance optimization of pigment particles. Traditional pigment dispersion technology mainly relies on adding polymers or surfactants to achieve the desired particle size distribution through mechanical grinding.

[0003] For example, Chinese patent application CN119119802A provides a pigment nano paste for digital inkjet printing, which improves the uniform dispersion performance of pigments in the nano paste by using methyl isocyanate modified styrene-acrylic resin as a dispersant and a surfactant. However, the pigment paste prepared by the above method has problems such as large particle size, high viscosity, and low surface tension, which limits its application in digital paint printing.

[0004] Chinese patent CN116120787B provides a self-dispersing inorganic pigment paste and a preparation method thereof, which uses a silane coupling agent as a bridge-based triazine compound to modify the surface of inorganic pigments to improve the self-dispersing performance of the self-dispersing inorganic pigment paste, but its water resistance and color strength still need to be further improved. SUMMARY

[0005] To solve the problems in the prior art, the present application provides a self-dispersing pigment paste in the first aspect, and the preparation raw materials include pigments, sulfonamide-based diazonium salt, and deionized water.

[0006] In one embodiment, the mass ratio of the pigments to the sulfonamide-based diazonium salt is 1:(0.1-1.5). The mass ratio can be 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.45, 1:0.75, 1:1, or 1:1.5.

[0007] In one embodiment, the sulfonamide-based diazonium salt includes p-aminobenzenesulfonamide diazonium salt.

[0008] In the present application, the p-aminobenzene sulfonamide diazonium salt is selected to modify the pigment, and the mass ratio of the pigment and the sulfonamide group diazonium salt is controlled to be 1:(0.1-1.5). On the one hand, the sulfonamide group can form hydrogen bonds with the hydroxyl groups in the cellulose in the paper, thereby improving the binding force between the color paste and the substrate and enhancing the color fastness. On the other hand, when the mass ratio of the pigment and the sulfonamide group diazonium salt is 1:(0.1-1.5), the grafting amount of the sulfonamide group on the surface of the pigment is moderate, thereby improving the dispersion stability of the pigment color paste, avoiding agglomeration caused by insufficient grafting amount, and avoiding the increase of conductivity caused by excessive grafting amount, and destroying the self-dispersing effect. In the third aspect, the water solubility of the sulfonamide group is weak, which can form a hydrophobic micro-layer on the surface of the pigment, reduce the penetration of water into the pigment-fiber interface, and improve the water resistance of the pigment and the good wet rubbing fastness.

[0009] In an embodiment, the preparation method of the p-aminobenzene sulfonamide diazonium salt comprises the following steps:

[0010] After the p-aminobenzene sulfonamide, deionized water and hydrochloric acid are mixed, the temperature is lowered to 0℃, and the sodium nitrite solution is added. The reaction is carried out at 0-15℃ for 30-60min, and the p-aminobenzene sulfonamide diazonium salt is obtained by filtration.

[0011] In an embodiment, the mass ratio of the p-aminobenzene sulfonamide, hydrochloric acid and sodium nitrite solution is 1:(2-4):(1-1.4).

[0012] In an embodiment, the hydrochloric acid is hydrochloric acid with a mass concentration of 31%.

[0013] In an embodiment, the mass concentration of sodium nitrite in the sodium nitrite solution is 30%.

[0014] In the present application, the pigment is a colored pigment without primary amine. In an embodiment, the pigment comprises any one of phthalocyanine pigments, quinacridone pigments, anthraquinone pigments and carbon black.

[0015] In an embodiment, the phthalocyanine pigment comprises any one of pigment blue 15:3 and pigment blue 15:4.

[0016] In an embodiment, the quinacridone pigment comprises any one of pigment orange 48, pigment orange 49, pigment red 122, pigment red 192, pigment red 202, pigment red 206, pigment red 207, pigment red 209, pigment violet 19 and pigment violet 42.

[0017] In an embodiment, the anthraquinone pigment comprises any one of pigment red 43 and pigment red 194.

[0018] The second aspect of the present application provides a preparation method of a self-dispersing pigment color paste, comprising the following steps:

[0019] After the pigment is dispersed in deionized water, the sulfonamide diazonium salt is added, the pH is adjusted to 7, and the reaction is carried out at 40-80 DEG C for 2-4 hours, and then the self-dispersing pigment paste is obtained after concentration after grinding, desalination and purification.

[0020] Advantages

[0021] 1. In the present application, the sulfonamide diazonium salt is used to modify the pigment, which can improve the water resistance of the self-dispersing paste and enhance the color fastness.

[0022] 2. In the present application, the mass ratio of the pigment and the sulfonamide diazonium salt is controlled to be 1: (0.1-1.5), which can improve the dispersion stability of the pigment paste, and the viscosity changes little after aging for 7 days.

[0023] 3. The paste prepared in the present application has achieved a technical breakthrough in dispersion stability, viscosity ≤2.84 mPa·s, and surface tension ≥65 mN / m, and the preparation process is simple, the cost is low, and it is suitable for industrial production.

[0024] 4. The self-dispersing pigment paste prepared in the present application does not add surfactants and dispersants, can adjust the surface properties of the ink and endow the pigment with water-soluble function, has low viscosity, high surface tension, strong tinting strength, high fastness, bright color and other advantages. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The figure is a comparison of the coloring effects of Example 1 and Comparative Example 1, where a is Example 1 and b is Comparative Example 1.

[0026] Figure 2 The figure is a comparison of the coloring effects of Example 3 and Comparative Example 2, where c is Example 3 and d is Comparative Example 2.

[0027] Figure 3 The figure is a comparison of the coloring effects of Example 5 and Comparative Example 3, where e is Example 5 and f is Comparative Example 3.

[0028] Figure 4 The figure is a comparison of the coloring effects of Example 6 and Comparative Example 4, where g is Example 6 and h is Comparative Example 4. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with examples and drawings. It should be understood that the specific examples described herein are only used to explain the present application and not to limit the present application. The experimental methods not specified in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments not specified by the manufacturer are all conventional products that can be purchased on the market.

[0030] Embodiment 1

[0031] The first aspect of the embodiment provides a self-dispersing pigment paste, and raw materials for preparation include 30 g of pigment, 6 g of sulfonamide diazonium salt, and 170 mL of deionized water.

[0032] The sulfonamide diazonium salt is p-aminobenzenesulfonamide diazonium salt.

[0033] The preparation method of the p-aminobenzenesulfonamide diazonium salt includes:

[0034] 70 g of p-aminobenzenesulfonamide is added to 200 mL of water, 160 g of hydrochloric acid with a mass concentration of 31% is added, the temperature is reduced to 0°C, 98 g of sodium nitrite solution with a mass concentration of 30% is added, and the reaction is carried out at 8°C for 45 min. After the reaction is completed, filtration is performed to obtain the p-aminobenzenesulfonamide diazonium salt.

[0035] The p-aminobenzenesulfonamide is purchased from Shaanxi Liedu Pharmaceutical Chemical Co., Ltd.

[0036] The pigment is pigment violet 19, which is purchased from Hangzhou Hecai Pigment Chemical Co., Ltd., and the model is pigment violet 02.

[0037] The second aspect of the embodiment provides a preparation method of a self-dispersing pigment paste, which includes the following steps:

[0038] After the pigment is dispersed in deionized water, the sulfonamide diazonium salt is added, a sodium hydroxide solution with a mass concentration of 30% is added dropwise to adjust the pH to 7, the reaction is carried out at 40°C for 4 h, after the reaction is completed, grinding is performed for 10 h, and after desalination, purification, and concentration, the self-dispersing pigment paste is obtained.

[0039] Embodiment 2

[0040] The first aspect of the embodiment provides a self-dispersing pigment paste, and raw materials for preparation include 30 g of pigment, 6 g of sulfonamide diazonium salt, and 170 mL of deionized water.

[0041] The sulfonamide diazonium salt is p-aminobenzenesulfonamide diazonium salt.

[0042] The preparation method of the p-aminobenzenesulfonamide diazonium salt includes:

[0043] 70 g of p-aminobenzenesulfonamide is added to 200 mL of water, 160 g of hydrochloric acid with a mass concentration of 31% is added, the temperature is reduced to 0°C, 98 g of sodium nitrite solution with a mass concentration of 30% is added, and the reaction is carried out at 8°C for 45 min. After the reaction is completed, filtration is performed to obtain the p-aminobenzenesulfonamide diazonium salt.

[0044] The p-aminobenzenesulfonamide is purchased from Shaanxi Liedu Pharmaceutical Chemical Co., Ltd.

[0045] The pigment is pigment purple 19, purchased from Hangzhou Hecai Pigment Chemical Co., Ltd., model PR254.

[0046] The second aspect of the embodiment provides a preparation method of the self-dispersing pigment paste, including the following steps:

[0047] After the pigment is dispersed in the deionized water, the sulfonamide diazonium salt is added, the mass concentration of 30% sodium hydroxide solution is added dropwise to adjust the PH to 7, and the reaction is carried out at 70 DEG C for 2 h. After the reaction is completed, grinding is carried out for 8 h. After the salt is removed, purified and concentrated, the self-dispersing pigment paste is obtained.

[0048] Example 3

[0049] The first aspect of the embodiment provides a self-dispersing pigment paste, and the preparation raw materials include 30 g of pigment, 4.5 g of sulfonamide diazonium salt and 100 mL of deionized water.

[0050] The sulfonamide diazonium salt is p-aminobenzenesulfonamide diazonium salt.

[0051] The preparation method of the p-aminobenzenesulfonamide diazonium salt includes:

[0052] 70 g of p-aminobenzenesulfonamide is added to 200 mL of water, 160 g of hydrochloric acid with a mass concentration of 31% is added, the temperature is reduced to 0 DEG C, 98 g of sodium nitrite solution with a mass concentration of 30% is added, the reaction is carried out at 8 DEG C for 45 min, and the p-aminobenzenesulfonamide diazonium salt is obtained after the reaction is completed and filtration.

[0053] The p-aminobenzenesulfonamide is purchased from Shaanxi Lieduo Pharmaceutical Chemical Co., Ltd.

[0054] The pigment is pigment blue 15:3, purchased from Anhui Shenlanhua Color Material Co., Ltd., model BF435KW.

[0055] The second aspect of the embodiment provides a preparation method of the self-dispersing pigment paste, including the following steps:

[0056] After the pigment is dispersed in the deionized water, the sulfonamide diazonium salt is added, the mass concentration of 30% sodium hydroxide solution is added dropwise to adjust the PH to 7, and the reaction is carried out at 70 DEG C for 2 h. After the reaction is completed, grinding is carried out for 8 h. After the salt is removed, purified and concentrated, the self-dispersing pigment paste is obtained.

[0057] Example 4

[0058] The first aspect of the embodiment provides a self-dispersing pigment paste, and the preparation raw materials include 30 g of pigment, 4.5 g of sulfonamide diazonium salt and 100 mL of deionized water.

[0059] The sulfonamide diazonium salt is p-aminobenzenesulfonamide diazonium salt.

[0060] The preparation method of the p-aminobenzene sulfonamide diazonium salt comprises the following steps:

[0061] 70g of p-aminobenzene sulfonamide is added into 200mL of water, 160g of hydrochloric acid with a mass concentration of 31% is added, the temperature is reduced to 0°C, 98g of sodium nitrite solution with a mass concentration of 30% is added, the reaction is carried out at 8°C for 45min, and the p-aminobenzene sulfonamide diazonium salt is obtained after filtration.

[0062] The p-aminobenzene sulfonamide is purchased from Shaanxi Liedu Pharmaceutical Chemical Co., Ltd.

[0063] The pigment is pigment blue 15:3, which is purchased from Anhui Shenlan Huase Material Co., Ltd. and has a model number of BF435KW.

[0064] The second aspect of the embodiment provides a preparation method of a self-dispersing pigment color paste, which comprises the following steps:

[0065] After the pigment is dispersed in deionized water, the sulfonamide-based diazonium salt is added, a sodium hydroxide solution with a mass concentration of 30% is added dropwise to adjust the pH to 7, the reaction is carried out at 40°C for 4h, and the self-dispersing pigment color paste is obtained after grinding for 10h, desalination, purification and concentration.

[0066] Embodiment 5

[0067] The first aspect of the embodiment provides a self-dispersing pigment color paste, and the preparation raw materials comprise 30g of pigment, 45g of sulfonamide-based diazonium salt and 180mL of deionized water.

[0068] The sulfonamide-based diazonium salt is a p-aminobenzene sulfonamide diazonium salt.

[0069] The preparation method of the p-aminobenzene sulfonamide diazonium salt comprises the following steps:

[0070] 70g of p-aminobenzene sulfonamide is added into 200mL of water, 160g of hydrochloric acid with a mass concentration of 31% is added, the temperature is reduced to 0°C, 98g of sodium nitrite solution with a mass concentration of 30% is added, the reaction is carried out at 8°C for 45min, and the p-aminobenzene sulfonamide diazonium salt is obtained after filtration.

[0071] The p-aminobenzene sulfonamide is purchased from Shaanxi Liedu Pharmaceutical Chemical Co., Ltd.

[0072] The pigment is pigment red 122, which is purchased from Wenzhou Jinyuan New Material Technology Co., Ltd. and has a model number of pigment red 1221D.

[0073] The second aspect of the embodiment provides a preparation method of a self-dispersing pigment color paste, which comprises the following steps:

[0074] The pigment is dispersed in deionized water, then the sulfonamide diazonium salt is added, a 30% mass concentration sodium hydroxide solution is added dropwise to adjust the pH to 7, and the reaction is carried out at 40°C for 4h. After the reaction is completed, grinding is carried out for 10h. After desalination, purification and concentration, the self-dispersing pigment color paste is obtained.

[0075] Example 6

[0076] The first aspect of the embodiment provides a self-dispersing pigment color paste, and the raw materials for preparation include 30g of pigment, 6g of sulfonamide diazonium salt and 170mL of deionized water.

[0077] The sulfonamide diazonium salt is p-aminobenzenesulfonamide diazonium salt.

[0078] The preparation method of the p-aminobenzenesulfonamide diazonium salt includes:

[0079] 70g of p-aminobenzenesulfonamide is added to 200mL of water, 160g of 31% mass concentration hydrochloric acid is added, the temperature is lowered to 0°C, 98g of 30% mass concentration sodium nitrite solution is added, and the reaction is carried out at 8°C for 45min. After the reaction is completed, filtration is carried out to obtain the p-aminobenzenesulfonamide diazonium salt.

[0080] The p-aminobenzenesulfonamide is purchased from Shaanxi Lieduo Pharmaceutical Chemical Co., Ltd.

[0081] The pigment is carbon black from Weifang Bolacarbon Material Co., Ltd., model number Raven 1040.

[0082] The second aspect of the embodiment provides a preparation method of a self-dispersing pigment color paste, including the following steps:

[0083] The pigment is dispersed in deionized water, then the sulfonamide diazonium salt is added, a 30% mass concentration sodium hydroxide solution is added dropwise to adjust the pH to 7, and the reaction is carried out at 40°C for 4h. After the reaction is completed, grinding is carried out for 10h. After desalination, purification and concentration, the self-dispersing pigment color paste is obtained.

[0084] Example 7

[0085] The first aspect of the embodiment provides a self-dispersing pigment color paste, and the raw materials for preparation include 30g of pigment, 6g of sulfonamide diazonium salt and 170mL of deionized water.

[0086] The sulfonamide diazonium salt is p-aminobenzenesulfonamide diazonium salt.

[0087] The preparation method of the p-aminobenzenesulfonamide diazonium salt includes:

[0088] 70g p-aminobenzenesulfonamide was added into 200mL water, 160g of 31% mass concentration hydrochloric acid was added, and the temperature was reduced to 0°C. 98g of 30% mass concentration sodium nitrite solution was added, and the reaction was carried out at 8°C for 45min. After the reaction was completed, the p-aminobenzenesulfonamide diazonium salt was obtained by filtration.

[0089] The p-aminobenzenesulfonamide was purchased from Shaanxi Liedu Pharmaceutical Chemical Co., Ltd.

[0090] The pigment was carbon black, model number Raven 1040, from Weifang Bolacarbon Material Co., Ltd.

[0091] The second aspect of the embodiment provided a preparation method of the self-dispersing pigment paste, which included the following steps:

[0092] After the pigment was dispersed in deionized water, the sulfonamide-based diazonium salt was added, a 30% mass concentration sodium hydroxide solution was added dropwise to adjust the pH to 7, and the reaction was carried out at 40°C for 4h. After the reaction was completed, the product was ground for 10h, and after desalination, purification and concentration, the self-dispersing pigment paste was obtained.

[0093] Comparative Example 1

[0094] The comparative example provided a preparation method of a pigment paste, specifically: 30g of pigment, 22.5g of dispersant DX778, 0.4g of wetting agent DX517, 0.3g of defoaming agent FX2907 and 146.8g of deionized water were mixed and stirred uniformly to obtain the pigment paste.

[0095] The pigment was pigment violet 19, purchased from Hangzhou Hecai Pigment Chemical Co., Ltd., model number PR254.

[0096] The dispersant DX778, the wetting agent DX517 and the defoaming agent FX2907 were all from Hi-Tech (Nanjing) Co., Ltd.

[0097] Figure 1 The figure was a comparison of the coloring effects of Example 1 and Comparative Example 1, where a was Example 1 and b was Comparative Example 1.

[0098] Comparative Example 2

[0099] The comparative example provided a preparation method of a pigment paste, specifically: 30g of pigment, 20.5g of dispersant DX778, 0.3g of wetting agent DX517, 0.3g of defoaming agent FX2907 and 148.9g of deionized water were mixed and stirred uniformly to obtain the pigment paste.

[0100] The pigment was pigment blue 15:3, purchased from Anhui Shenlanhua Color Material Co., Ltd., model number BF435KW.

[0101] The dispersant DX778, the wetting agent DX517 and the defoaming agent FX2907 are all from the HiChem High-tech (Nanjing) Co., Ltd.

[0102] Figure 2 For the coloring effect comparison chart of Example 3 and Comparative Example 2, the chart is shown in the figure, c is Example 3, and d is Comparative Example 2.

[0103] Comparative Example 3

[0104] The present comparative example provides a preparation method of a pigment paste, specifically: 30 g of a pigment, 25 g of a dispersant DX778, 0.5 g of a wetting agent DX517, 0.3 g of a defoaming agent FX2907 and 144.2 g of deionized water are uniformly mixed and stirred to obtain the pigment paste.

[0105] The pigment is pigment red 122, which is purchased from Wenzhou Jinyuan New Material Technology Co., Ltd., and the model is pigment red 1221D.

[0106] The dispersant DX778, the wetting agent DX517 and the defoaming agent FX2907 are all from the HiChem High-tech (Nanjing) Co., Ltd.

[0107] Figure 3 For the coloring effect comparison chart of Example 5 and Comparative Example 3, the chart is shown in the figure, e is Example 5, and f is Comparative Example 3.

[0108] Comparative Example 4

[0109] The present comparative example provides a preparation method of a pigment paste, specifically: 30 g of a pigment, 18 g of a dispersant DX778, 0.3 g of a wetting agent DX517, 0.3 g of a defoaming agent FX2907 and 151.4 g of deionized water are uniformly mixed and stirred to obtain the pigment paste.

[0110] The pigment is carbon black, which is from Weifang Bolacarbon Material Co., Ltd., and the model is Raven 1040.

[0111] The dispersant DX778, the wetting agent DX517 and the defoaming agent FX2907 are all from the HiChem High-tech (Nanjing) Co., Ltd.

[0112] Figure 4 For the coloring effect comparison chart of Example 6 and Comparative Example 4, the chart is shown in the figure, g is Example 6, and h is Comparative Example 4.

[0113] Comparative Example 5

[0114] The present comparative example provides a pigment paste, which is modified by a sulfanilic acid diazonium salt, specifically a product with the model AP220M produced by Shenzhen Moku New Material Group Co., Ltd.

[0115] Comparative Example 6

[0116] This comparative example provides a pigment paste, which uses p-aminobenzenesulfonic acid diazonium salt to modify pigments, specifically a product with a model number of AP230C produced by Shenzhen Moku New Material Group Co., Ltd.

[0117] Comparative Example 7

[0118] This comparative example provides a pigment paste, which uses p-aminobenzenesulfonic acid diazonium salt to modify pigments, specifically a product with a model number of AP260M produced by Shenzhen Moku New Material Group Co., Ltd.

[0119] Comparative Example 8

[0120] This comparative example provides a pigment paste, which uses p-aminobenzenesulfonic acid diazonium salt to modify pigments, specifically a product with a model number of AP210BK produced by Shenzhen Moku New Material Group Co., Ltd.

[0121] Performance Test

[0122] 1. The conductivity, viscosity, surface tension, and filterability (0.45 um membrane) of the pigment paste prepared in each example and comparative example were tested before and after aging for 7 days, and the comparative examples were tested at room temperature. The test results are shown in Table 1. The aging conditions are as follows: after being placed in a 60°C oven for seven days, the sample was taken out and allowed to stand until the temperature of the sample solution dropped to room temperature.

[0123] 2. Color strength test: The color density of the pigment paste prepared in Examples 1, 3, 5, 6 and Comparative Examples 1-4 was tested using a handheld spectrophotometer, and the test results are shown in Table 2.

[0124] In the table, L* represents brightness or lightness, and the lower the L value, the darker and more dull the color.

[0125] a* represents the position of the color on the red-green axis. A positive a value indicates a color bias towards red, and a negative a value indicates a color bias towards green.

[0126] b* represents the position of the color on the yellow-blue axis. A positive b value indicates a color bias towards yellow, and a negative b value indicates a color bias towards blue.

[0127] 3. Dry and wet rub fastness test: The dry and wet rub fastness of samples from Examples 1, 3, 5, 7 and Comparative Examples 5-8 was tested, and the test method is as follows:

[0128] The sample (sample) was rubbed with a rubbing white cotton cloth on a rubbing color fastness tester, and the color picking on the white cotton cloth was evaluated using a color picking gray card.

[0129] Equipment: Rubbing Color Fastness Tester

[0130] Friction head: diameter: 16 mm; reciprocating stroke: 104 ± 3 mm; vertical pressure: 9 N ± 10%; sample size: > 50 mm x 130 mm; sample number: two (oblique sampling: 45 degrees to the warp and weft, if the fabric is twill, sampling in the direction opposite the twill) to test dry and wet rubbing fastness respectively;

[0131] Friction cloth: standard white cotton cloth: desized, bleached, free of optical brightening agents and finishing agents;

[0132] Size: 50 mm x 50 mm;

[0133] Drying device: AATCC water absorption paper or water press;

[0134] Grey card: AATCC staining grey card:

[0135] Sample conditioning: temperature 21 ± 1 °C, relative humidity 65 ± 2%;

[0136] Conditioning time: 4 h.

[0137] Dry rubbing operation steps:

[0138] Lay the conditioned sample flat on the friction tester with sandpaper, and require the length direction of the test to be consistent with the stroke direction of the instrument.

[0139] Fix the conditioned standard rubbing white cotton cloth parallel to the rubbing direction in the vertical direction on the friction head with a spring clamp, and gently place the friction head on the front part of the sample. Shake the friction arm at a speed of 1 revolution per second, and rub for 10 revolutions.

[0140] Remove the standard rubbing white cotton cloth, and rate after conditioning (when rating, place three un-rubbed white cotton cloths under the white cotton cloth).

[0141] Wet rubbing operation steps:

[0142] Soak the standard rubbing white cotton cloth in distilled water to ensure that the water content is 65 ± 5%, and follow the above dry rubbing steps. The test results are shown in Table 3, wherein the color difference values corresponding to the staining levels are as follows: 5 levels: 0-0.20, 4-5 levels: 0.21-2.50, 4 levels: 2.51-4.60, 3-4 levels: 4.61-6.40, 3 levels: 6.41-9.0, 2-3 levels: 9.01-12.70, 2 levels: 12.71-17.90, 1-2 levels: 17.91-25.50, 1 level: > 25.51.

[0143] Table 1

[0144]

[0145]

[0146] Table 2

[0147] Sample Color density L* a* b* Example 1 1.241 38.18 50.26 11.57 Example 3 1.372 31.16 0.24 -38.16 Example 5 1.167 36.55 49.43 -8.05 Example 6 1.293 17.90 0.24 1.15 Comparative Example 1 1.070 42.19 49.56 4.92 Comparative Example 2 1.094 35.12 2.06 -36.47 Comparative Example 3 1.110 39.36 50.68 -6.67 Comparative Example 4 1.078 24.09 0.39 1.65

[0148] Table 3

[0149]

[0150]

[0151] As can be seen from Tables 1-3 and Figures 1-4 , the self-dispersible pigment paste prepared in the present application has low viscosity, low conductivity and high surface tension, and the performance is obviously better than that of the pigment paste prepared by using the traditional dispersant in the corresponding comparative example; as can be seen from the filterability test, the particle size of the self-dispersible pigment paste prepared in the present application is smaller than that of the pigment paste prepared by using the traditional dispersant in the corresponding comparative example; after the aging resistance test, it still has good dispersion stability and storage stability; as can be seen from the color density test, the self-dispersible pigment paste prepared in the present application has higher tinting strength and brighter color than the comparative example; as can be seen from the dry and wet rub fastness test, compared with the modification of the pigment by using p-aminobenzenesulfonic acid diazonium salt, the product of the present application prepared by modifying the pigment by using p-aminobenzenesulfonamide diazonium salt has more excellent dry and wet rub fastness.

Claims

1. A self-dispersing pigment paste, characterized in that: The preparation raw materials include pigment, sulfonamide diazonium salt and deionized water.

2. The self-dispersing pigment paste according to claim 1, characterized in that The mass ratio of the pigment to the sulfonamide diazonium salt is 1:(0.1-1.5).

3. The self-dispersing pigment paste according to claim 2, characterized in that The sulfonamide diazonium salt includes p-aminobenzenesulfonamide diazonium salt.

4. The self-dispersing pigment paste according to claim 3, characterized in that The preparation method of the diazonium salt of p-aminobenzenesulfonamide comprises: p-Aminobenzenesulfonamide, deionized water and hydrochloric acid are mixed and then cooled to 0°C, sodium nitrite solution is added, reacted at 0-15°C for 30-60 minutes, and filtered to obtain the p-Aminobenzenesulfonamide diazonium salt.

5. The self-dispersing pigment paste according to claim 4, characterized in that The mass ratio of the aminobenzenesulfonamide, hydrochloric acid and sodium nitrite solution is 1:(2-4):(1-1.4).

6. The self-dispersible pigment paste according to claim 1, characterized in that The pigment includes any one of phthalocyanine pigments, quinacridone pigments, anthraquinone pigments and carbon black.

7. The self-dispersible pigment paste according to claim 6, characterized in that The phthalocyanine pigment includes any one of Pigment Blue 15:3 and Pigment Blue 15:

4.

8. The self-dispersible pigment paste according to claim 6, characterized in that The quinacridone pigment includes any one of Pigment Orange 48, Pigment Orange 49, Pigment Red 122, Pigment Red 192, Pigment Red 202, Pigment Red 206, Pigment Red 207, Pigment Red 209, Pigment Violet 19, and Pigment Violet 42.

9. The self-dispersible pigment paste according to claim 6, characterized in that The anthraquinone pigment includes any one of Pigment Red 43 and Pigment Red 194.

10. A method for preparing the self-dispersible pigment paste according to any one of claims 1 to 9, characterized in that: The following steps are involved: After dispersing the pigment in deionized water, sulfonamide diazonium salt is added, the pH is adjusted to 7, and the reaction is carried out at 40-80° C. for 2-4 hours. Then, the self-dispersible pigment paste is obtained after grinding, desalting, purification and concentration.

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