A fine surface treatment method for halogenated zinc phthalocyanine

Abstract

The present application relates to the surface treatment method of pigment, especially relates to a kind of fine surface treatment method of green zinc halogenation phthalocyanine (pigment). Zinc halogenation phthalocyanine is added to NaCl-AlCl3 molten salt system, then ester is added, after reaction, the reactant is watered out zinc phthalocyanine halide, that is, the finished product pigment zinc halogenation phthalocyanine with excellent performance is obtained.The method of the present application uses a new method by controlling the parameter condition of reaction, and prepares green zinc phthalocyanine pigment with small particle size and concentrated distribution and excellent performance, simultaneously proposes a new process route for fine surface treatment of zinc halogenation phthalocyanine, reduces the process method of secondary agglomeration of zinc halogenation phthalocyanine, the present application is simple, easy to implement, and has very good application prospect.

Description

Technical Field

[0001] This invention relates to a surface treatment method for pigments, and particularly to a fine surface treatment method for green zinc halide phthalocyanine (pigment). Background Technology

[0002] Zinc halide phthalocyanine is an important organic pigment. According to patent JP19970285066, it is widely used in textiles, printing, inks, coatings, and other fields. However, zinc halide phthalocyanine pigments have some problems in practical applications. For example, they are prone to aggregation in humid environments, affecting the dispersibility and coloring effect. Furthermore, the crystal structure and surface morphology of zinc halide phthalocyanine pigments also affect their transparency, color vibrancy, and lightfastness. To solve these problems, researchers have used surface finishing techniques to improve zinc phthalocyanine pigments.

[0003] To address the issue of zinc halide phthalocyanine pigments easily agglomerating, surface treatment techniques can be employed, such as using surfactants or polymer coating methods, to form a stable surface coating layer. This prevents the pigment particles from adsorbing onto each other, thereby improving their moisture resistance and allowing the pigment to be more stably dispersed in the medium, maintaining its good dyeing effect.

[0004] To address the crystal structure and surface morphology issues of zinc halide phthalocyanine pigments, chemical synthesis can be used to recrystallize the pigments. By controlling the conditions during crystal nucleation and growth, the morphology and size of the pigment crystals can be modulated, thereby affecting their transparency and color vibrancy. Simultaneously, surface modification techniques, such as surface modification and nanostructure design, can be employed to regulate the morphology and structure of the pigment surface, improving its uniform deposition and color stability on material surfaces, thus enhancing its application in textiles, plastics, and other materials. For example, in patent JP20210514647, the inventors used recrystallization of zinc halide phthalocyanine to alter its crystal form, enabling it to meet production requirements.

[0005] To address the light resistance issue of zinc halide phthalocyanine pigments, surface fine treatment techniques, such as the introduction of surface light stabilizers, can be used to form a surface protective layer with resistance to ultraviolet and visible light. This effectively prevents light from irradiating and oxidizing the pigment, improves its resistance to light decay, and thus extends its durability in practical use.

[0006] In recent years, research in the physical chemistry and electrochemistry of molten salts has been very active. For example, patent KR20130011317A states that compared with aqueous solutions and organic electrolytes, the advantages of molten salt electrolytes mainly include high conductivity, fast electrode reaction rate, and high decomposition potential. From a chemical perspective, the characteristics of aluminohalates lie in their structure and strong acidity. Although aluminum bonds are mainly ionic, AlCl3 has a tendency to form stable dimer molecules, generating a non-ionic melt. Therefore, the addition of NaCl can combine with AlCl3 to form a highly ionized liquid mixture, while lowering the overall melting point of the system.

[0007] To address the existing problems of zinc halide phthalocyanine and to better meet the pigment quality requirements of different fields, thereby promoting the widespread application of zinc halide phthalocyanine pigments in textiles, printing, inks, coatings, and other fields, a fine surface treatment method for zinc halide phthalocyanine is proposed. Summary of the Invention

[0008] The purpose of this invention is to provide a fine surface treatment method for zinc halide phthalocyanine.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A fine surface treatment method for zinc halide phthalocyanine involves adding zinc halide phthalocyanine to a NaCl-AlCl3 molten salt system, followed by the addition of esters. After the reaction, the reactants are precipitated with water to obtain zinc phthalocyanine halides, thus obtaining high-performance finished pigment zinc halide phthalocyanine.

[0011] The zinc halide phthalocyanine is represented by general formula I.

[0012]

[0013] In the formula, X1-X16 can be selected from H, Cl, and Br, either the same or different, and X1-X16 cannot all be H.

[0014] Preferably, X1-X16 contain at least 10 halogens.

[0015] Even better, the zinc halide phthalocyanine is a mixture with a halogenation degree where the average total number of chlorine and bromine atoms is more than 15, of which bromine atoms must be greater than or equal to 13, and the average number of chlorine atoms must be less than 2 but greater than 1.

[0016] The zinc halide phthalocyanine can be prepared according to existing techniques.

[0017] To elaborate further,

[0018] Using zinc halide phthalocyanine as raw material, under nitrogen protection and at temperature T1, zinc halide phthalocyanine is gradually added to a NaCl-AlCl3 mixture system and heated to T2. When the system is completely free of solid particles, esters are added to the system, and the reaction is maintained at this temperature for 2-4 hours. After cooling to T3, the reaction solution is slowly added to water while maintaining the temperature at 20-25℃. After the addition is complete, the mixture is stirred at this temperature for 30-50 minutes. The mixture is then filtered and washed with water until the conductivity of the filtrate is <20μs / cm to obtain zinc halide phthalocyanine filter cake. The finished pigment is then dried.

[0019] The temperature T1 is selected from 0℃ to 50℃;

[0020] The T2 is selected from 110℃-150℃, preferably from 120℃-140℃;

[0021] The T3 is selected from 30℃-50℃.

[0022] The ester is one or more selected from β-propiolactone, γ-butyrolactone, δ-valerolactone, 6-hexanolactone, δ-octanolactone, and δ-undecaprolactone. γ-Butyrolactone and / or δ-valerolactone are preferred.

[0023] The NaCl-AlCl3 molten salt system wherein the mass ratio of NaCl to AlCl3 is 1:10-10:1, more preferably 1:8-5:2.

[0024] The zinc halide phthalocyanine accounts for 0.1-0.8 times (by mass) of the NaCl-AlCl3 molten salt system.

[0025] The esters constitute 0.01-0.2 times (molar ratio) of the zinc halide phthalocyanine.

[0026] The drying process involves drying at 105°C until the moisture content of the pigment solids is less than 0.5%.

[0027] The water is industrial deionized water.

[0028] Advantages of this invention:

[0029] The present invention provides a fine surface treatment method for zinc phthalocyanine by mixing zinc halide phthalocyanine into a NaCl-AlCl3 molten system, adding ester substances, and after the reaction is complete, pouring the reactants into deionized water to precipitate extremely fine and well-dispersed zinc halide phthalocyanine. By controlling the reaction parameters during the reaction process, the existing technology is optimized, and a green zinc phthalocyanine pigment with excellent performance, high light transmittance, and high contrast is prepared. The method of the present invention is simple, easy to implement, and has very good application prospects.

[0030] The specific testing method is as follows:

[0031] The following examples further illustrate specific embodiments of the present invention. It should be noted that the specific embodiments described herein are merely for illustration and explanation and are not intended to limit the scope of the present invention.

[0032] The present invention involves adding zinc halide phthalocyanine to a NaCl-AlCl3 molten salt system, followed by the addition of various esters to induce a lactone reaction in the zinc halide phthalocyanine. This causes a change in the surface of the zinc halide phthalocyanine. After the reaction is complete, the reaction system is poured into deionized water to precipitate the refined zinc phthalocyanine halides. The product is then filtered, washed, and dried to obtain a finished pigment with excellent properties. This invention refines the surface of zinc halide phthalocyanine pigment by introducing a lactone structure and controlling reaction parameters to produce a green zinc phthalocyanine pigment with small and concentrated particle size, good stability, strong dispersibility, and excellent color brightness and light resistance. This better meets the pigment quality requirements of different fields and promotes the widespread application of zinc halide phthalocyanine pigments in textiles, printing, inks, coatings, and other fields. Simultaneously, the process route refines the surface of zinc halide phthalocyanine, reducing secondary agglomeration. This invention is simple, easy to implement, and has excellent application prospects.

[0033] The zinc halide phthalocyanine and deionized water used in the examples were prepared in the laboratory. AlCl3, NaCl, nitrogen, and the esters involved were all chemical reagents from Sinopharm Group.

[0034] The method for preparing zinc halide phthalocyanine used in the following examples refers to patent CN112189037A, namely: 91g sulfonyl chloride, 109g aluminum chloride, 15g sodium chloride, 30g zinc phthalocyanine, and 230g bromine are added to a 300ml flask. The temperature is raised to 130℃ and maintained at 130℃ for 40h. The reaction mixture is extracted into water, filtered, washed with water, and dried to obtain crude zinc halide phthalocyanine pigment. The pH difference between the filtrate and the washing water is ±0.2.

[0035] Example 1

[0036] Add 117g (99.5%, 2mol) NaCl and 44.5g (99.5%, 0.33mol) AlCl3 to a 250ml four-necked flask equipped with a stirrer and condenser. After stirring until homogeneous, heat to 120℃. Slowly add 65g of zinc halide phthalocyanine solid while stirring, maintaining a constant temperature of 120℃. After the addition is complete, quickly add 1g of γ-butyrolactone to the system. Maintain the temperature for 2 hours while keeping the stirring rapid. After the temperature maintenance is complete, continue stirring and allow the system to cool naturally to 40℃. Pour the reaction solution into deionized water, keeping the temperature below 20℃. After pouring, maintain the temperature and stir for 30 minutes. Filter and wash with water until the conductivity of the filtrate is 16μs / cm to obtain a surface-treated zinc halide phthalocyanine filter cake. Dry the cake in an oven at 105℃ to obtain the finished pigment.

[0037] Example 2

[0038] Add 58.5g (99.5%, 1mol) NaCl and 133.5g (99.5%, 1mol) AlCl3 to a 250ml four-necked flask equipped with a stirrer and condenser. After stirring evenly, heat to 135℃. Slowly add 30g of zinc halide phthalocyanine solid while stirring, maintaining the temperature at a constant 135℃. After the addition is complete, quickly add 0.5g of δ-valerolactone to the system. Maintain the temperature for 2 hours while keeping the stirring rapid. After the temperature maintenance is complete, continue stirring and allow the system to cool naturally until it reaches 40℃. Pour the reaction solution into deionized water, maintaining the temperature of the reaction solution below 20℃. After pouring, maintain the temperature and stir for 30 minutes. Filter and wash with water until the conductivity of the filtrate is 18μs / cm to obtain a surface-treated zinc halide phthalocyanine filter cake. Dry the cake in an oven at 105℃ to obtain the finished pigment.

[0039] Comparative Example 1

[0040] 100g of zinc halide phthalocyanine, 800g of pulverized NaCl, and 180g of diethylene glycol were mixed in a kneader and kneaded at 90℃ for 8 hours. After kneading, the resulting mixture was placed in warm water at 60℃ to precipitate. After stirring for 1 hour, it was filtered and the filter cake was repeatedly washed until the pH of the filter cake filtrate was 7 and the conductivity was 18μs / cm.

[0041] Comparative Example 2

[0042] Add 58.5g (99.5%, 1mol) NaCl and 133.5g (99.5%, 1mol) AlCl3 to a 250ml four-necked flask equipped with a stirrer and condenser. After stirring until homogeneous, heat to 170℃. Slowly add 50g of zinc halide phthalocyanine solid while stirring, maintaining a constant temperature of 170℃. After the addition is complete, quickly add 5g of δ-valerolactone to the system. Maintain the temperature for 2 hours while keeping the stirring rapid. After the temperature maintenance is complete, continue stirring and allow the system to cool naturally to 40℃. Pour the reaction solution into deionized water, keeping the temperature below 20℃. After pouring, maintain the temperature and stir for 30 minutes. Filter and wash with water until the conductivity of the filtrate is 18μs / cm to obtain a surface-treated zinc halide phthalocyanine filter cake. Dry the cake in an oven at 105℃ to obtain the finished pigment.

[0043] The performance of the pigments in Example 1, Example 2, Comparative Example 1, and Comparative Example 2 were tested and analyzed respectively, and the procedures were as follows:

[0044] Primary particle size test

[0045] The average particle size of the primary particles mentioned above is evaluated based on the equivalent diameter of a circle with the same area as the particle image in the photographic image observed and captured by an electron scanning microscope (JSM-IT810), unless otherwise stated. Specifically, the equivalent diameter of the circle is calculated based on 50 particles, and the average value of this diameter is taken as the average particle size of the primary particles.

[0046] Secondary particle size test

[0047] First, a dispersion was prepared: 40g of the pigment to be tested was mixed evenly with 50g of anhydrous ethanol. The mixture was then dispersed in a sand mill (PML easy Cenomic S2) at 2000 rpm for 2 hours using 0.5mm diameter zirconia beads. The dispersion was then filtered through a 5μm filter to obtain the desired pigment dispersion. The dispersion was then diluted to 15% of its initial concentration, and dynamic light scattering particle size analysis was performed using a Malvern-zetasizerlab.

[0048] BET test

[0049] The samples from the examples and comparative examples were ground into a uniform powder. The samples were then placed in a vacuum at a specific processing temperature to remove adsorbed gases and moisture from the surface. The samples were placed in an adsorption instrument (McAsAP2460) with liquid nitrogen at a temperature of 77.35 K. Adsorption isotherms were measured by gradually increasing the nitrogen pressure. Under low pressure, gas molecules adsorb onto the sample surface to form a monolayer. Based on the adsorption isotherm data, the BET equation was used for fitting to obtain the slope and intercept of the adsorption isotherm. The specific surface area of ​​the sample was calculated based on the parameters in the BET equation.

[0050] Stability test

[0051] First, prepare the dispersion: Take 40g of the pigment to be tested and mix it evenly with 50g of anhydrous ethanol. Then, disperse the mixture in a sand mill (PML easy Cenomic S2) at 2000 rpm for 2 hours using 0.5mm diameter zirconia beads. Filter the mixture through a 5μm filter to obtain the dispersion of the corresponding pigment. After standing for 24 hours and 7 days, observe the sedimentation with the naked eye and check whether the dispersion is uniformly layered.

[0052] Light resistance test

[0053] Take 0.5g of the sample from the examples and comparative examples, grind it into a uniform powder, add 2g of ink oil, set the flat grinder to grind 50 times each time, grind each sample 3 times, then scrape the sample with a scraper, cover half of the scraped sample with black paper, place it under a 300w xenon lamp for 6 hours to observe its fading.

[0054] Table 1. Basic performance test data of different samples

[0055]

[0056] Table 2 Application performance test data of different samples

[0057]

[0058] In summary, by using the NaCl-AlCl3 molten salt system to perform fine surface treatment on zinc halide phthalocyanine, a green zinc phthalocyanine pigment with small particle size, concentrated distribution, and excellent performance can be prepared. Furthermore, a novel process route for fine surface treatment of zinc halide phthalocyanine is proposed, reducing secondary agglomeration. This invention is simple, easy to implement, and has excellent application prospects.

Claims

1. A method for fine surface treatment of zinc halide phthalocyanine, characterized in that: Using zinc halide phthalocyanine as raw material, under nitrogen protection and at temperature T1, zinc halide phthalocyanine is gradually added to a NaCl-AlCl3 mixture system and heated to T2. When the system is completely free of solid particles, esters are added to the system, and the reaction is maintained at this temperature for 2-4 hours. After cooling to T3, the reaction solution is slowly added to water while maintaining the temperature at 15-25℃. After the addition is complete, the mixture is stirred at this temperature for 30-50 minutes. The mixture is then filtered and washed with water until the conductivity of the filtrate is <20μs / cm to obtain zinc halide phthalocyanine filter cake. The finished pigment is then dried. The temperature T1 is selected from 0℃ to 50℃; The T2 is selected from 110℃-150℃; The T3 is selected from 30℃-50℃; The zinc halide phthalocyanine accounts for 0.1-0.8 times the mass ratio of the NaCl-AlCl3 molten salt system; The esters constitute 0.01-0.2 times the molar ratio of zinc phthalocyanine halide; The ester is one or more of β-propiolactone, γ-butyrolactone, δ-valerolactone, 6-hexylactone, δ-octanolactone, and β-undecylactone.

2. The fine surface treatment method for zinc halide phthalocyanine according to claim 1, characterized in that: The NaCl-AlCl3 molten salt system has a NaCl to AlCl3 mass ratio of 1:10-10:

1.

3. The fine surface treatment method for zinc halide phthalocyanine according to claim 1, characterized in that: The drying process involves drying at 105°C until the moisture content of the pigment solids is less than 0.5%.

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