A method for preparing a black perylene-based pigment

Abstract

The application discloses a preparation method of black perylene pigments, which comprises the following steps: under the protection of nitrogen, inorganic alkali and organic alkali are dissolved in polar halogenated aromatic hydrocarbon, and then the mixture is heated to 100-150 DEG C under stirring; after the solid is completely dissolved, compound 4 and compound 5 are added at the same time; after the addition is completed, the temperature is increased to 150-190 DEG C, and the reaction is carried out for 8-14 hours; the heating is stopped, and the mixture is naturally cooled to room temperature; and after post-treatment, black solid is obtained; the prepared black solid is subjected to pigmentization processing together with a ball mill by using a ball milling method, so that the black perylene pigments are obtained; and the product prepared by the preparation method of the black perylene pigments is a chemical mixed product, and the color light of the product is consistent with that of C.I. Pigment Black 32.

Description

Technical Field

[0001] This invention relates to methods for preparing black organic pigments, specifically, to a method for preparing CI pigment black 32. Background Technology

[0002] Perylene pigments are a class of high-performance pigments, possessing chemical and thermal stability and application properties unmatched by ordinary pigments. Most perylene pigments have a color spectrum of scarlet, maroon, and purplish-red. CI Pigment Black 32 is unique, exhibiting a pure black color spectrum, but like other varieties in this series, it also possesses high lightfastness and weather fastness. It exhibits very high migration fastness in plastics and excellent recoating resistance in coatings. Furthermore, it plays a special role in specialty inks.

[0003] CI Pigment Black 32 (chemical composition: N,N-p-methoxy-3,4,9,10-perylenetetracarboxylic dibenzylamine, compound 1) is a black variety of perylene pigment, mainly used in the formulation of automotive coatings, and the processing of black plastics and inks. The traditional method for preparing CI Pigment Black 32 involves first reacting 3,4,9,10-perylenetetracarboxylic dianhydride (compound 2) with N-p-methoxybenzylamine to obtain N,N-p-methoxy-3,4,9,10-perylenetetracarboxylic dibenzylamine, and then performing pigment processing to obtain a commercially available organic pigment (Shen Yongjia, Varieties and Applications of Organic Pigments, Chemical Industry Press, 2002). The problem with the above process is that the manufacturing process of perylene anhydride is very complicated, roughly as follows: 1,8-naphthylimide (compound 3) is reacted with molten KOH at 220-250°C to form perylene imide, which is then converted into perylene anhydride by oxidation in concentrated sulfuric acid, as shown in reaction formula 1 (Willy Herbst, Klaus Hunger, Industrial Organic Pigments: Production, Properties, Applications, 4th, Revised Edition, Wiley-VCH, Weinheim, 2011).

[0004]

[0005] The defects of the above-mentioned process for manufacturing CI Pigment Black 32 are: ① The alkaline fusion reaction of 1,8-naphthylimide in molten KOH to generate perylene imide needs to be carried out at 220-250℃. To ensure the reactants have sufficient fluidity, the amount of KOH used is more than three times the weight of 1,8-naphthylimide. Even so, the viscosity of the reactants is still relatively high, resulting in insufficient mass transfer between reactants and a complex composition of the alkaline fusion reaction product. After the reaction, to obtain the desired product, water needs to be added for dilution, causing the perylene imide to precipitate from the dilute alkaline solution, thus consuming a large amount of KOH. To dispose of this dilute alkaline solution, a large amount of acid must be used for neutralization, resulting in a large amount of salt with no recovery value. ② Because the alkaline fusion reaction is carried out at 220-250℃, side reactions inevitably occur during the reaction process. Therefore, the yield of perylene imide synthesized under traditional alkaline fusion reaction conditions is less than 50%. ③ After perylene imide is oxidized to perylene anhydride, its purity does not meet the requirements for subsequent pigment production. Therefore, it needs to be refined using an "alkali dissolution-acid precipitation" method, which consumes a large amount of acid and alkali. It is evident that the traditional method for preparing perylene imide has drawbacks such as lengthy reaction steps, high chemical consumption, and environmental unfriendliness; it is a typical high-energy-consuming, high-material-consuming, and high-polluting process.

[0006] To overcome the shortcomings of traditional processes, Sakamoto et al. disclosed a method for preparing perylene imide and its derivatives, which involves alkali fusion of 1,8-naphthalene imide or its derivatives in potassium tert-butoxide / 1,5-diazabicyclo[4.3.0]-5-nonene (DBN) / diethylene glycol dimethyl ether. This method can obtain perylene imide or its derivatives in high yield and high purity, as shown in reaction formula 2 (Sakamoto T, Pac CA “Green” Route to Perylene Dyes: Direct Coupling Reactions of 1,8-Naphthalimide and Related Compounds under Mild Conditions Using a “New” Base Complex Reagent, t-BuOK / DBN[J].The Journal of Organic Chemistry, 2001, 66(1):94-98.).

[0007]

[0008] However, research has found that although the perylene imide derivatives obtained by the method of Reaction Formula 2 do indeed have the chemical structure shown in Reaction Formula 2, their color as an organic pigment is not entirely the same as that of commercial CI Pigment Black 32, and their blackness is insufficient. Therefore, the reaction conditions shown in Reaction Formula 2 cannot replace the traditional process for manufacturing CI Pigment Black 32. Furthermore, even when the product obtained from Reaction Formula 2 is further processed using the pigmentation technology of CI Pigment Black 32, the resulting black organic pigment still exhibits a significant difference in color compared to existing commercial CI Pigment Black 32. This is why, although the method for synthesizing perylene imide and its derivatives shown in Reaction Formula 2 was disclosed in 2001, more than 20 years later, no company producing CI Pigment Black 32 has reported using the technology shown in Reaction Formula 2 to manufacture CI Pigment Black 32. In view of this, providing a simple and environmentally friendly method for preparing perylene imide, and processing it to achieve a color identical to that of commercial CI Pigment Black 32, is the technical problem that this invention aims to solve. Summary of the Invention

[0009] The purpose of this invention is to provide a method for preparing a black perylene pigment.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] The first aspect of the present invention provides a method for preparing a black perylene pigment, comprising the following steps:

[0012]

[0013] Under nitrogen protection, inorganic and organic bases are dissolved in polar haloaromatic hydrocarbons and heated to 100–150°C (preferably 120–140°C) with stirring. After the solid is completely dissolved, compounds 4 and 5 are added simultaneously. After the addition is complete, the temperature is raised to 150–190°C (preferably 170°C) and the reaction is carried out for 8–14 hours (preferably 10 hours). Heating is then stopped, and the mixture is allowed to cool naturally to room temperature. After post-treatment, a black solid is obtained.

[0014] The molar ratio of compound 4 to compound 5 is 1:0.1 to 0.5 (preferably 1:0.3).

[0015] The ratio of the total moles of compounds 4 and 5 to the moles of the base is 1:2 to 10 (preferably 1:6.1 to 1:7.3), and the base includes organic bases and inorganic bases, with the molar ratio of organic bases to inorganic bases being 1.1 to 2:1 (preferably 1.37:1 to 1.67:1).

[0016] The inorganic base is selected from cesium carbonate, cesium formate, cesium sulfate, cesium hydroxide, or their monohydrates, preferably cesium carbonate and cesium formate.

[0017] The organic base is selected from 1,8-diazabicycloundec-7-ene (DBU), 1,5-dioxabicyclo[4.3.0]non-5-ene (DBN), and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD).

[0018] The polar halogenated aromatic hydrocarbons are selected from o-dichlorobenzene or 1,2,4-trichlorobenzene.

[0019] The prepared black solid is ball-milled together with grinding media to obtain the black perylene pigment. The mass ratio of the black solid to the grinding media is as follows: the mass ratio of stainless steel balls, black solid, anhydrous calcium chloride, butyl acetate, and calcium stearate is 50-150:5-10:15-25:2-6:1 (preferably 100:7.5:20:4:1).

[0020] The total mass ratio of compounds 4 and 5 to the mass ratio of the polar haloaromatic hydrocarbon is 1:3 to 5 (preferably 1:4.3 or 1:4.8).

[0021] The process of obtaining a black solid after post-treatment includes the following steps: diluting with C1-C3 monohydric fatty alcohols and filtering; washing the filter cake with C1-C3 monohydric fatty alcohols until no polar halogenated aromatic hydrocarbons are found; and drying to obtain a black solid.

[0022] The C1-C3 monohydric fatty alcohols are selected from methanol, ethanol, and propanol.

[0023] The diameter of the stainless steel ball is 0.2 to 0.5 cm.

[0024] The process of pigmenting the prepared black solid by ball milling together with ball milling material includes the following steps:

[0025] The prepared black solid was added to a planetary ball mill, and grinding media (stainless steel beads, anhydrous calcium chloride, butyl acetate, and calcium stearate) were added. The milling was carried out for 3 to 8 hours (preferably 5 hours). The grinding media was then sieved, and the steel beads were removed. The mixture was poured into hot water and stirred for 0.5 to 2 hours (preferably 1 hour). The mixture was then filtered, and the filter cake was washed with hot water and deionized water until the conductivity of the filtrate was less than 300 microsiemens. The mixture was then dried to obtain the black perylene pigment.

[0026] By adopting the above technical solution, the present invention has the following advantages and beneficial effects:

[0027] The preparation method of the black perylene pigment provided by this invention produces a chemically mixed product. After ball milling, its color is consistent with that of CI Pigment Black 32. Simultaneously, its color vibrancy is also consistent with that of CI Pigment Black 32.

[0028] The method for preparing black perylene pigments provided by this invention is simple and environmentally friendly. At the same time, the pigment processing (ball milling) of the obtained product can overcome the defects of the prior art.

[0029] Research has shown that while physical color mixing can alter the hue of pigments, the resulting pigments exhibit significantly lower vibrancy compared to existing CI pigment black 32 products, thus failing to meet customer requirements. This invention addresses these technical problems by employing two measures: a) using a "chemical mixing" method to resolve the hue difference issue; and b) using ball milling pigmentization technology to address the hue vibrancy problem. Detailed Implementation

[0030] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0031] The reference material used in this invention is CI Pigment Black 32, produced by Liaoning Lian Gang Dyestuff Chemical Co., Ltd., brand name Perylene Bright Black S-1086. The raw materials used are: 1,8-naphthalenedicarboxylic anhydride, industrial grade, produced by Liaoning Lian Gang Dyestuff Chemical Co., Ltd.; p-methoxybenzylamine, 1-naphthylmethylamine, and cesium carbonate, analytical grade, Aladdin Chemical Technology Co., Ltd.; cesium formate, analytical grade, Shanghai Shitang Industrial Co., Ltd.; potassium tert-butoxide, 1,5-dioxabicyclo[4.3.0]non-5-ene (DBN), and 1,8-diazabicycloundec-7-ene (DBU), all analytical grade, Saen Chemical Technology Co., Ltd.; 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), chemically pure, Shanghai Jingfu Biotechnology Co., Ltd.; o-dichlorobenzene and 1,2,4-trichlorobenzene, chemically pure, Shanghai Aladdin Reagent Co., Ltd.

[0032] Example 1

[0033] The preparation reactions of compounds 4 and 5 are as follows:

[0034]

[0035] Under nitrogen protection, anhydrous ethanol (250 mL) was added to a 500 mL three-necked flask, followed by stirring and the addition of 1,8-naphthalene anhydride (39.6 g, 0.20 mol) and para-methoxybenzylamine (27.4 g, 0.20 mol). After the addition was complete, the mixture was heated to reflux and reacted for 3 h. Thin-layer chromatography (TLC) was performed until the substrate spots disappeared. Heating was then stopped, and the mixture was allowed to cool naturally to room temperature. The mixture was filtered, and the filter cake was washed with ethanol and water, and dried to give a pink compound 4 (60.2 g), with a yield of 95%.

[0036]

[0037] Following the preparation method of compound 4, 1-naphthylmethylamine was used instead of p-methoxybenzylamine to obtain off-white compound 5 (60.6 g), with a yield of 90%.

[0038] A method for preparing a black perylene pigment includes the following steps:

[0039]

[0040]

[0041] Under nitrogen protection, cesium carbonate (100.8 g, 0.30 mol), 1,8-diazabicycloundec-7-ene DBU (76.0 g, 0.50 mol), and o-dichlorobenzene (180 g) were added to a 500 mL three-necked flask. The mixture was heated to 120 °C with stirring. After the solid was completely dissolved, compound 4 (31.8 g, 0.10 mol) and compound 5 (10.1 g, 0.03 mol) were added. After the addition was complete, the temperature was raised to 170 °C, and silica gel thin-plate chromatography (TLC) was performed until the substrate spots completely disappeared (approximately 10 h). Heating was then stopped, and the mixture was allowed to cool naturally to room temperature. After dilution with methanol, the mixture was filtered to obtain a filtrate and a filter cake. The filter cake was washed with methanol until the o-dichlorobenzene odor was eliminated, and a washing liquid was obtained. The filter cake was dried to obtain a black solid (32.5 g). Methanol, 1,8-diazabicycloundec-7-ene (DBU), and o-dichlorobenzene can be recovered by vacuum distillation of the above filtrate and washing liquid, respectively.

[0042] The resulting black solid was a mixture, the main component of which was N,N'-p-methoxy-3,4,9,10-peryltetracarboxylic dibenzylamine (compound 1, formed by the self-condensation and ring-closure of N-p-methoxy-1,8-naphthodicarboxylic benzylamine). It also contained compound 3 (a product of the self-condensation and ring-closure of N-1'-naphthomethyl-1,8-naphthoamide) and compound 2 (an asymmetric product formed by the mixed condensation and ring-closure of N-p-methoxy-1,8-naphthodicarboxylic benzylamine and N-1'-naphthomethyl-1,8-naphthodiamide). The resulting black solid was a "chemically mixed" product. After ball milling, its hue was identical to that of commercial CI Pigment Black 32, and both exhibited the same hue brightness.

[0043] Example 2

[0044] Under nitrogen protection, cesium carbonate (130.3 g, 0.40 mol), 1,8-diazabicycloundec-7-ene (83.6 g, 0.55 mol), and 1,2,4-trichlorobenzene (200 g) were added to a 500 mL three-necked flask. The mixture was heated to 120 °C with stirring. After the solid was completely dissolved, compound 4 (31.8 g, 0.10 mol) and compound 5 (10.1 g, 0.03 mol) were added. After the addition was complete, the temperature was raised to 170 °C and the reaction was monitored by TLC until the starting material spot disappeared (approximately 10 h). Heating was then stopped, and the mixture was allowed to cool naturally to room temperature. After dilution with ethanol, the mixture was filtered. The filter cake was washed with ethanol until the odor of 1,2,4-trichlorobenzene was eliminated. After drying the filter cake, a black solid (34.2 g) was obtained.

[0045] Example 3

[0046] Under nitrogen protection, cesium formate (54.8 g, 0.40 mol), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (76.5 g, 0.55 mol), and o-dichlorobenzene (180 g) were added to a 500 mL three-necked flask. The mixture was heated to 120 °C with stirring. After the solids were completely dissolved, compound 4 (31.8 g, 0.10 mol) and compound 5 (10.1 g, 0.03 mol) were added. After the addition was complete, the temperature was raised to 170 °C and the reaction was monitored by TLC until the starting material spots disappeared (approximately 8 h). Heating was then stopped, and the mixture was allowed to cool naturally to room temperature. After dilution with ethanol, the mixture was filtered. The filter cake was washed with ethanol until the o-dichlorobenzene odor was eliminated. The filter cake was dried to obtain a black solid (30.5 g).

[0047] Example 4

[0048] Under nitrogen protection, cesium formate (54.8 g, 0.40 mol), 1,8-diazabicycloundec-7-ene (83.6 g, 0.55 mol), and 1,2,4-trichlorobenzene (180 g) were added to a 500 mL three-necked flask. The mixture was heated to 120 °C with stirring. After the solids were completely dissolved, compound 4 (31.8 g, 0.10 mol) and compound 5 (10.1 g, 0.03 mol) were added. After the addition was complete, the temperature was raised to 170 °C and the reaction was monitored by TLC until the starting material spots disappeared (approximately 8 h). Heating was then stopped, and the mixture was allowed to cool naturally to room temperature. After dilution with ethanol, the mixture was filtered. The filter cake was washed with ethanol until no o-dichlorobenzene odor was detected. After drying the filter cake, a black solid (31.5 g) was obtained.

[0049] Comparative Example 1

[0050] Perylene diimide derivatives were prepared according to the method described by Sakamoto et al. (Sakamoto T, Pac CA “Green” Route to PeryleneDyes: Direct Coupling Reactions of 1,8-Naphthalimide and Related Compounds under Mild Conditions Using a “New” Base Complex Reagent, t-BuOK / DBN[J].The Journal of Organic Chemistry, 2001, 66(1):94-98.).

[0051] Potassium tert-butoxide (30.3 g, 0.27 mol), 1,5-dioxabicyclo[4.3.0]non-5-ene (44.7 g, 0.36 mol), and diethylene glycol dimethyl ether (90 mL) were added to a 100 mL three-necked flask. The mixture was heated to 130 °C under nitrogen protection. Once the solid was completely dissolved, compound 4 (28.6 g, 0.09 mol) was added. After the addition was complete, the reaction was allowed to proceed for 3 h. Heating was then stopped, and the mixture was cooled to room temperature. The solution was diluted with diethylene glycol dimethyl ether and filtered. The filter cake was washed with diethylene glycol dimethyl ether. After drying, a black solid (22.9 g) was obtained, with a yield of 80%.

[0052] Example 5

[0053] The black solids prepared in Examples 1 to 4 and Comparative Example 1 were processed into pigments by ball milling. The ball milling process is shown in Table 1. The ball milling was carried out in a planetary ball mill (Nanjing Nanda Instrument Co., Ltd., model QM-3SP2).

[0054] The black solids (crude pigments) prepared in Examples 1-4 and Comparative Example 1 were added to a ball mill, and then anhydrous calcium chloride, butyl acetate, calcium stearate, and stainless steel beads were added respectively. The milling was carried out at 495 rpm for 5 hours. After milling, the milled material was sieved, and the steel beads were poured into hot water with a weight of 20 times that of the milled material. After stirring for 1 hour, the mixture was filtered. The filter cake was washed with hot water and deionized water until the conductivity of the filtrate was less than 300 microsiemens. The mixture was dried at 60°C to constant weight to obtain pigment samples 1-5 (pigmentation of the products obtained in Examples 1-4 yielded pigments 1-4, and pigmentation of the product obtained in Comparative Example 1 yielded pigment 5).

[0055] Table 1 Ball Milling Batching Table

[0056] Stainless steel beads (0.2-0.5cm in diameter) 100 crude pigment 7.5 Anhydrous calcium chloride 20 Butyl acetate 4 Calcium stearate 1

[0057] The crude pigment refers to the black solid obtained from Examples 1-4 and Comparative Example 1.

[0058] The color properties (color, tinting strength and vividness) of pigments 1 to 5 were determined using commercial Perylene Black S-1086 as the standard sample.

[0059] (1) Preparation of pigment paste:

[0060] In a covered glass bottle, add glass beads (2.5 mm in diameter, 60 g), 7.5 g of the sample to be tested (pigment 1-5), 7.5 g of dispersant (a mixture of dispersant 24000 (purchased from Lubrizol Specialty Chemicals (Shanghai) Co., Ltd.) and butyl acetate in a 1:1 mass ratio), and 20 g of diluent (a mixture of butyl acetate and ethanol in a 1:1 mass ratio). Cover the bottle and seal it with tape. Place the glass bottle on a pigment shaker (purchased from Dongguan Wanjiang Weihong Instrument Business Department) and shake until the pigment fineness is below 15 μm (detected using a Hagermann particle size analyzer). Then add 35 g of diluent (a mixture of butyl acetate and ethanol in a 1:1 mass ratio) to obtain the pigment paste.

[0061] (2) Determination of pigment hue and tinting strength:

[0062] Preparation of color card for measuring pigment color: Use a pipette to draw 4-5 ml of pigment paste prepared in step (1), drop it onto color card paper, and scrape the sample with a 3K scraper to obtain a color card for measuring pigment color.

[0063] Preparation of a color card for determining the tinting strength of pigments: Take 5g of the pigment paste obtained in step (1) and add it to 10g of water-based white paint (white latex paint B1, Shanghai Nippon Paint Co., Ltd.). Stir evenly with a high-speed mixer to obtain a pigment-to-white paste. Use a pipette to draw 4-5ml of the pigment-to-white paste and drop it onto the color card paper. Use a 3K scraper to scrape the sample to obtain a color card for testing the tinting strength of the pigment. The tinting strength of the pigment is expressed as the K / S value.

[0064] After the pigments on the color chart have dried, the color chart can be tested with a colorimeter (purchased from Datacolor, USA) to measure the pigment color and pigment tinting strength. The specific results are shown in Tables 2 and 3.

[0065] Table 2. Pigment colorimetric test data

[0066] Standard 25.0 -0.6 -0.4 ---- ---- Pigment 1 25.2 -0.6 -0.5 Approximate to standard <2％ Pigment 2 25.4 -0.7 -0.5 Approximate to standard <2％ Pigment 3 25.1 -0.6 -0.4 Approximate to standard <2％ Pigment 4 25.1 -0.7 -0.5 Approximate to standard <2％ Pigment 5 23.5 -0.8 -1.0 It is more blue and green than the standard. 6.2％

[0067] Table 3. Pigment Tinting Strength Test Data

[0068] Standard 49.9 -6.7 -0.7 100--- <2％ Pigment 1 51.5 -6.7 -0.7 100.3 <2％ Pigment 2 52.4 -6.7 -0.6 100.8 <2％ Pigment 3 52.3 -6.8 -0.7 99.7 <2％ Pigment 4 49.7 -6.2 -0.6 101.1 <2％ Pigment 5 47.5 -7.9 -0.9 85.9 7％

[0069] In Tables 2 and 3, L represents brightness. If the difference in L value between the tested sample and the standard sample is positive, it indicates that the tested sample is brighter than the standard sample; conversely, if the difference in L value between the tested sample and the standard sample is negative, it indicates that the tested sample is darker than the standard sample. The larger the absolute value of the difference, the greater the degree of deviation.

[0070] 'a' represents redness / greenness. If the difference between the 'a' value of the tested sample and the standard sample is positive, it indicates that the tested sample is redder than the standard sample; conversely, if the difference between the 'a' value of the tested sample and the standard sample is negative, it indicates that the tested sample is greener than the standard sample. The larger the absolute value of the difference, the greater the degree of deviation.

[0071] b represents the yellow-blue tint. If the difference in b values ​​between the tested sample and the standard sample is positive, it indicates that the tested sample is more yellow than the standard sample; conversely, if the difference in b values ​​between the tested sample and the standard sample is negative, it indicates that the tested sample is more blue than the standard sample. The larger the absolute value of the difference, the greater the degree of deviation.

[0072] ΔE* is a comprehensive index of color difference, indicating the magnitude of the total color difference. A larger value indicates a greater degree of total color difference. Typically, the acceptable value for ΔE* on a sample is between 1% and 2%.

[0073] The K / S value represents the depth of the color; a higher value indicates a stronger tinting strength.

[0074] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing a black perylene-based pigment, characterized in that, Includes the following steps: ； Under nitrogen protection, inorganic bases and organic bases are dissolved in polar haloaromatic hydrocarbons and heated to 100-150 °C with stirring. When the solid is completely dissolved, compounds 4 and 5 are added simultaneously. After the addition is complete, the temperature is raised to 150-190 °C and the reaction is carried out for 8-14 hours. Heating is stopped and the mixture is allowed to cool naturally to room temperature. After post-treatment, a black solid is obtained. The prepared black solid was subjected to pigmentation processing together with ball milling material using a ball milling method to obtain the black perylene pigment; The process of pigmenting the prepared black solid by ball milling together with ball milling material includes the following steps: The prepared black solid was added to a planetary ball mill, and grinding media was added. The milling process lasted for 3 to 8 hours. The grinding media was then sieved to remove steel balls. The mixture was poured into hot water and stirred for 0.5 to 2 hours. The mixture was then filtered. The filter cake was washed with hot water and deionized water until the conductivity of the filtrate was less than 300 microsiemens. The filtrate was then dried to obtain the black perylene pigment. The molar ratio of compound 4 to compound 5 is 1:0.1~0.5; The ratio of the total moles of compounds 4 and 5 to the moles of the base is 1:2 to 10, and the base is an organic base and an inorganic base, with a molar ratio of organic base to inorganic base of 1.1 to 2:

1. The inorganic base is selected from cesium carbonate and cesium formate; The organic base is selected from 1,8-diazabicycloundec-7-ene and 1,5,7-triazabicyclo[4.4.0]dec-5-ene; The process of obtaining a black solid after post-treatment includes the following steps: diluting with C1-C3 monohydric fatty alcohols and filtering; washing the filter cake with C1-C3 monohydric fatty alcohols until no polar halogenated aromatic hydrocarbons are found; and drying to obtain a black solid.

2. The method for preparing black perylene pigment according to claim 1, characterized in that, The abrasive ball is composed of stainless steel beads, anhydrous calcium chloride, butyl acetate, and calcium stearate. The mass ratio of the black solid to the abrasive ball is as follows: the mass ratio of stainless steel beads, black solid, anhydrous calcium chloride, butyl acetate, and calcium stearate is 50~150:5~10:15~25:2~6:

1.

3. The method for preparing black perylene pigment according to claim 1, characterized in that, The polar halogenated aromatic hydrocarbons are selected from o-dichlorobenzene or 1,2,4-trichlorobenzene.

4. The method for preparing black perylene pigment according to claim 1, characterized in that, The total mass ratio of compounds 4 and 5 to the mass ratio of the polar haloaromatic hydrocarbons is 1:3~5.

5. The method for preparing black perylene pigment according to claim 2, characterized in that, The diameter of the stainless steel ball is 0.2~0.5cm.

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