Process and apparatus for the preparation of pigments

Abstract

A pigment preparation method and apparatus are disclosed. The pigment preparation method includes: mixing a crude pigment with a dispersion to form a slurry; extracting the slurry and spraying it through a nozzle to form a pigment mixture; and filtering the pigment mixture to remove the dispersion, thereby obtaining the pigment. Therefore, this pigment preparation method can produce pigments with advantages such as high transparency, high color purity, and high depolymerization effect. Furthermore, this pigment preparation method also has advantages such as simple operation, low cost, and ease of surface modification and coating treatment.

Description

Technical Field

[0001] Embodiments of this disclosure relate to a pigment preparation method and a pigment preparation apparatus. Background Technology

[0002] Pigments, as colorants, are widely used in various fields. Different applications have different performance requirements for pigments; high-temperature applications (e.g., engineering plastics) require pigments with high heat resistance, and the chemical structure of the pigment is the main factor determining its heat resistance; while the field of colored photoresist requires pigments with high thermal stability, good solvent resistance, excellent system compatibility, and ultra-high contrast and light transmittance.

[0003] On the other hand, various properties of pigments, such as hue, transparency (hiding power), tinting strength, thermal stability, and solubility, are directly related to the pigment's chemical composition, molecular structure, crystal morphology, particle size and shape, and surface properties. Pigments are dispersed into the substance being colored as fine particles during coloring. Therefore, by adjusting parameters such as the pigment's crystal morphology, particle size distribution, particle shape, and surface properties through a post-processing technique known as "pigmentation," pigments can acquire superior properties. Thus, pigmentation is particularly important in pigment production. Summary of the Invention

[0004] This disclosure provides a pigment preparation method and apparatus. The pigment preparation method involves first dispersing the pigment particles and then spraying them through a nozzle. This deagglomerates the aggregated pigment particles, and through shearing and compression, the pigment particles undergo appropriate crystal growth, resulting in smaller particle size, less particle size variation, and an aspect ratio closer to 1. Consequently, the pigment exhibits advantages such as higher transparency, higher color purity, and better deagglomeration effect. Furthermore, this pigment preparation method is simple to operate, low in cost, and facilitates surface modification and coating treatment.

[0005] At least one embodiment of this disclosure provides a pigment preparation method, comprising: mixing a crude pigment with a dispersion to form a slurry; extracting the slurry and spraying it through a nozzle to form a pigment mixture; and filtering the pigment mixture to remove the dispersion, thereby obtaining the pigment.

[0006] For example, one embodiment of the pigment preparation method provided in this disclosure further includes: providing a baffle plate inside the nozzle to increase the shear force on the mixed slurry.

[0007] For example, one embodiment of the pigment preparation method provided in this disclosure further includes: adjusting the pressure of the mixed slurry through the nozzle according to the type of pigment.

[0008] For example, one embodiment of the pigment preparation method provided in this disclosure further includes: adjusting the temperature of the mixed slurry to control the temperature of the mixed slurry within a preset temperature range.

[0009] For example, in a pigment preparation method provided in one embodiment of this disclosure, more than 95% of the pigment particles in the pigment have a particle size range of 15-50 nanometers.

[0010] For example, one embodiment of the pigment preparation method provided in this disclosure further includes: adding a surfactant to the mixed slurry to coat the depolymerized pigment particles in the mixed slurry.

[0011] For example, in a pigment preparation method provided in one embodiment of this disclosure, the process of extracting the mixed slurry and spraying it through a nozzle to form a pigment mixture further includes: extracting the mixed slurry and circulating it through the nozzle to form the pigment mixture.

[0012] At least one embodiment of this disclosure also provides a pigment preparation apparatus, comprising: a slurry container configured to contain a mixed slurry or pigment mixture, the mixed slurry being formed by mixing a crude pigment with a dispersion; an extraction device connected to the slurry container and configured to extract the mixed slurry from the slurry container; and a nozzle connected to the extraction device and configured to spray the mixed slurry to form the pigment mixture.

[0013] For example, in a pigment preparation apparatus provided in one embodiment of this disclosure, a baffle is provided inside the nozzle to increase the shear force on the mixed slurry.

[0014] For example, in a pigment preparation apparatus provided in an embodiment of this disclosure, a plurality of blocking plates are provided inside the nozzle, and the distance between adjacent blocking plates ranges from 0.1 to 10 mm.

[0015] For example, in a pigment preparation apparatus provided in one embodiment of this disclosure, there is a torsional angle between the surface of the blocking sheet and the cross-section of the nozzle at the location of the blocking sheet.

[0016] For example, in a pigment preparation apparatus provided in an embodiment of this disclosure, the nozzle includes: a fluid input end; a first sub-part connected to the fluid input end and having a first inner diameter; and a second sub-part connected to the first sub-part and having a second inner diameter, wherein the ratio of the second inner diameter to the first inner diameter is in the range of 0.2-0.6.

[0017] For example, in a pigment preparation apparatus provided in one embodiment of this disclosure, the nozzle further includes a third sub-section connected to the second sub-section and having a third inner diameter, the third inner diameter being larger than the second inner diameter.

[0018] For example, in a pigment preparation apparatus provided in one embodiment of this disclosure, the extraction device includes: an extraction pipe, one end of which is connected to the slurry container and the other end of which is connected to the nozzle; an extraction pump located between the extraction pipes; and a drive device connected to the extraction pump and configured to drive the extraction pump, wherein the rotational speed of the drive device is adjustable to adjust the pressure of the mixed slurry passing through the nozzle via the extraction pump.

[0019] For example, a pigment preparation apparatus provided in one embodiment of this disclosure further includes at least one of a temperature regulating device, a stirring device, and a filtering device. The temperature regulating device is configured to regulate the temperature of the mixed slurry. The stirring device is located in the slurry container and is configured to stir the mixed slurry. The filtering device is configured to filter the pigment mixture to remove the dispersion liquid in order to obtain pigment. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this disclosure and are not intended to limit this disclosure.

[0021] Figure 1 This is a schematic diagram of a pigment preparation method provided in an embodiment of the present disclosure;

[0022] Figure 2 This is a schematic diagram of a pigment preparation apparatus provided in one embodiment of the present disclosure;

[0023] Figure 3A , Figure 3B and Figure 3C A schematic cross-sectional view of a nozzle provided in one embodiment of this disclosure;

[0024] Figure 4 A schematic diagram of another pigment preparation apparatus provided in an embodiment of this disclosure; and

[0025] Figure 5 This is a schematic diagram of another pigment preparation apparatus provided in an embodiment of the present disclosure. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0027] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that an element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0028] In this field, common pigment processing methods mainly include grinding, heat treatment, pressure treatment, solvent treatment, and acid methods (including acid dissolution, acid swelling, and acid slurry methods). A suitable pigment processing method can be selected based on the state of the raw pigment, the desired final state of the pigment, and the pigment's physicochemical properties.

[0029] However, all the methods mentioned above have some unavoidable drawbacks. Grinding requires a large amount of electrical energy, grinding aids, and media; furthermore, some pigments are unsuitable for grinding due to their sensitivity to it. Heat treatment requires significant thermal energy, and the growth of pigment particles is uneven, making it difficult to control their shape. Furthermore, small particles tend to agglomerate and are difficult to deagglomerate, resulting in significant particle size variations and poor color purity. Pressure treatment places high demands on the preparation equipment and suffers from the same problem of ineffectiveness as heat treatment. Solvent treatment requires large amounts of organic solvents, some of which are flammable and explosive. Solvent recovery also consumes a lot of energy, and solvent treatment suffers from the same problem of ineffectiveness as heat treatment. Finally, acid treatment generates large amounts of acidic wastewater, which is costly to treat and also presents the problem of difficulty in controlling pigment particle size.

[0030] On the other hand, fields such as colored photoresist place high demands on the transparency, color purity, and deagglomeration effect of pigment particles. To achieve high transparency, pigment particles need to have a small particle size, such as less than 50 nanometers, or even less than 30 nanometers; to achieve high color purity, the particle size needs to be relatively uniform; and to achieve good deagglomeration performance, the aspect ratio of the pigment particles needs to be closer to 1 (the shape should be close to spherical or cubic). However, it is difficult for the various methods described above to simultaneously meet all these requirements.

[0031] To address this, this disclosure provides a pigment preparation method comprising: mixing a crude pigment with a dispersion to form a slurry; extracting the slurry and spraying it through a nozzle to form a pigment mixture; and filtering the pigment mixture to remove the dispersion, thereby obtaining the pigment. This pigment preparation method, by first dispersing and then spraying through a nozzle, deagglomerates the aggregated pigment particles. Through shearing and compression, the pigment particles undergo appropriate crystal growth, resulting in smaller particle size, less particle size variation, and an aspect ratio closer to 1. Consequently, the pigment exhibits advantages such as higher transparency, higher color purity, and better deagglomeration effect. Furthermore, this pigment preparation method also offers advantages such as simple operation, low cost, and ease of surface modification and coating treatment.

[0032] This disclosure also provides a pigment preparation apparatus, comprising a slurry container, an extraction device, and a nozzle. The slurry container is configured to hold a mixed slurry or pigment mixture, wherein the mixed slurry is formed by mixing crude pigment with a dispersion liquid. The extraction device is connected to the slurry container and configured to extract the mixed slurry from the slurry container. The nozzle is connected to the extraction device and configured to spray the mixed slurry to form the pigment mixture. Thus, this pigment preparation apparatus can disperse crude pigment by holding the mixed slurry in the slurry container, and then spray the mixed slurry through the extraction device and nozzle, causing the aggregated primary pigment particles to deagglomerate. Through shearing and compression, the pigment particles undergo appropriate crystal growth, resulting in smaller particle size, smaller particle size variation, and a length-to-width ratio closer to 1. Therefore, the pigment has advantages such as higher transparency, higher color purity, and higher deagglomeration effect. Furthermore, this pigment preparation method also has advantages such as simple operation, low cost, and ease of surface modification and coating treatment.

[0033] The pigment preparation method and pigment preparation apparatus provided in the embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0034] One embodiment of this disclosure provides a method for preparing a pigment. Figure 1 This is a schematic diagram illustrating a pigment preparation method according to an embodiment of this disclosure. Figure 1As shown, the pigment preparation method includes the following steps S101-S103.

[0035] Step S101: Mix the crude pigment with the dispersion to form a slurry.

[0036] Step S102: Extract the above-mentioned mixed slurry and spray it through a nozzle to form a pigment mixture.

[0037] Step S103: Filter the pigment mixture to remove the dispersion to obtain the pigment.

[0038] It should be noted that the crude pigment in the embodiments of this disclosure includes primary pigment particles with a particle size of less than 20 nm, or even less than 10 nm. Because these primary pigment particles are extremely small, they have a very large surface area and very high surface energy. To reduce surface energy, a large number of primary pigment particles will aggregate together in a face-to-face manner, and the size of these aggregated large particles reaches 500 nm or even larger. These aggregated large particles have very low chromatic power and poor transparency, which cannot meet the requirements for coloring. Therefore, the pigment preparation method described in the embodiments of this disclosure is not a method for preparing pigment materials, but rather a post-processing method or pigmentation method for pigments.

[0039] In the pigment preparation method provided in this disclosure, crude pigment is mixed with a dispersion to form a slurry, which is then sprayed through a nozzle. This method, by first dispersing and then spraying, deagglomerates the aggregated pigment particles. Through shearing and compression, the pigment particles undergo appropriate crystal growth, resulting in smaller particle size, less particle size variation, and an aspect ratio closer to 1. Consequently, the pigment exhibits advantages such as higher transparency, higher color purity, and better deagglomeration effect. Furthermore, this pigment preparation method is simple to operate, low in cost, and facilitates surface modification and coating treatment.

[0040] For example, more than 95% of the pigment particles in the pigment obtained above have a particle size range of 15-50 nanometers; further, more than 95% of the pigment particles in the pigment obtained above have a particle size range of 20-50 nanometers; further, more than 95% of the pigment particles in the pigment obtained above have a particle size range of 20-30 nanometers.

[0041] It is worth noting that the above embodiments only describe the key steps, and the embodiments may include, but are not limited to, the key steps described above, and may also include other steps. Some optional steps will be described below.

[0042] In some examples, the pigment preparation method may further include: placing a baffle plate inside the nozzle to increase the shear force on the mixed slurry, resulting in smaller pigment particle size and less particle size variation. It should be noted that the aforementioned less particle size variation refers to a smaller difference in the particle size of different pigment particles.

[0043] For example, the baffle plate can be fixed to the inner wall of the nozzle by welding or other means; of course, the embodiments disclosed herein include, but are not limited to, other fixing methods can also be used to set the baffle plate inside the nozzle.

[0044] For example, the aforementioned blocking plate can be a blade, and its shape can be triangular, rectangular, fan-shaped, etc. The embodiments disclosed herein are not limited thereto, as long as it can block the fluid.

[0045] For example, the surface of the baffle plate can also have a torsional angle with the cross-section of the nozzle at the location of the baffle plate, thereby causing the passing slurry to rotate and further improving the dispersion and shearing effects.

[0046] For example, multiple baffles can be provided inside the nozzle, and these baffles can be distributed around the inner wall of the nozzle. Of course, the embodiments disclosed herein include, but are not limited to, only one baffle can be provided, or it can be a plate-like structure with through holes provided inside the nozzle.

[0047] In some examples, the pigment preparation method may further include adjusting the pressure of the mixed slurry through the nozzle according to the type of pigment. By adjusting the pressure of the mixed slurry through the nozzle, the pigment preparation method can regulate the shear force and pressure received by the mixed slurry, thereby controlling the particle size, particle size uniformity, and deagglomeration effect of the final obtained pigment particles, thus meeting the needs of different types of pigments.

[0048] In some examples, the pigment preparation method may further include: adjusting the temperature of the mixed slurry to control the temperature of the mixed slurry within a preset temperature range, thereby enabling better dispersion of the primary pigment particles and making the growth of pigment particles more controllable, further improving the particle size uniformity.

[0049] For example, the temperature of the mixed slurry can be controlled within a preset temperature range using heating devices, thermometers, and temperature control devices.

[0050] For example, the preset temperature range mentioned above can be 60-120 degrees Celsius; further, the preset temperature range mentioned above can be 80-100 degrees Celsius; further, the preset temperature range mentioned above can be 90-95 degrees Celsius.

[0051] In some examples, the pigment preparation method may further include: adding a surfactant to the slurry to coat the depolymerized pigment particles in the slurry, thereby further improving the depolymerization performance of the pigment particles.

[0052] In some examples, the pigment preparation method may further include: adding a pigment derivative to the mixture slurry to modify the pigment.

[0053] In some examples, the steps described above for extracting the slurry and spraying it through a nozzle to form a pigment mixture include: extracting the slurry and circulating it through the nozzle to form the pigment mixture. That is, the slurry, after one or more sprays, is sprayed again to circulate it, thereby making the various parameters of the pigment particles in the final pigment mixture more uniform, thus improving product quality.

[0054] For example, the mixed slurry in the slurry container can be extracted and then sprayed back into the slurry container through a nozzle to achieve cyclic spraying; alternatively, the mixed slurry in the first slurry container can be extracted and sprayed into the second slurry container through a nozzle, and then the mixed slurry in the second slurry container can be extracted and sprayed into the first or third slurry container through a nozzle to achieve cyclic spraying.

[0055] In some examples, the dispersion described above may include at least one of water and an organic liquid. That is, the slurry described above may be a slurry formed from crude pigment and water, a slurry formed from crude pigment and an organic liquid, or a slurry formed from crude pigment, water, and an organic liquid. Since organic liquids have a significant effect on the growth and deagglomeration of pigment particles, appropriate organic liquids can be selected to form the dispersion depending on the type of pigment. These organic liquids can be used alone, in combination, or mixed with water in different proportions.

[0056] For example, organic liquids can be selected from aromatic hydrocarbons, alcohols, ketones, esters, etc., with aromatic hydrocarbons and alcohols being preferred solvents.

[0057] In some examples, the nozzle can be a conventional nozzle or a venturi nozzle to increase the flow rate and thus improve efficiency.

[0058] In some examples, the pigment preparation method may further include: stirring the mixture slurry to further improve dispersion efficiency and uniformity, thereby preventing pigment particle sedimentation. Of course, embodiments of this disclosure include, but are not limited to, the stirring of the mixture slurry may not be performed.

[0059] The following describes the pigment preparation method provided in this disclosure using the preparation of Pigment Green 58 as an example. First, 1000 grams of crude Pigment Green 58 is mixed with deionized water in a slurry container to obtain 20 liters of mixed slurry. The crude Pigment Green 58 can be obtained by bromination and chlorination of zinc phthalocyanine, containing 66.7% bromine and 1.9% chlorine. Then, the mixed slurry is pumped out using a centrifugal pump, and its pressure is adjusted to 0.5 MPa and sprayed through a nozzle back into the slurry container. Simultaneously, the temperature of the mixed slurry is controlled at 90-95 degrees Celsius using a temperature control device, and the mixture is circulated and sprayed in the slurry container for 2 hours. Subsequently, the centrifugal pump is turned off, and the mixed slurry is cooled to room temperature to obtain a pigment mixture. The pigment mixture is removed and filtered to obtain a filter cake, which is then dried in an oven until the moisture content is below 1%, ultimately yielding the pigment. After testing, the final pigment particles were found to be brick-shaped with an average particle size of 40.0 × 27.5 nm and a major-minor axis ratio of 1.45. Furthermore, when used in color filter testing, the pigment dispersed well, and the contrast, transparency, and chroma all reached high levels.

[0060] It should be noted that although Pigment Green 58 has been described above as an example, the pigment preparation method provided in this disclosure is not limited to the preparation of Pigment Green 58, nor is it limited to applications in the field of color filters. Many other pigments, such as Carbazole Violet (CI Pigment Violet 23), Phthalocyanine Green (CI Pigment Green 59), and Quinacridone Red (CI Pigment Red 122), can also be prepared using the pigment preparation method provided in this disclosure. Furthermore, the pigment preparation method provided in this disclosure is also applicable to many other fields, including inkjet printing.

[0061] One embodiment of this disclosure also provides a pigment preparation apparatus. Figure 2 This is a schematic diagram of a pigment preparation apparatus provided according to an embodiment of the present disclosure. Figure 2 As shown, the pigment preparation apparatus 100 includes a slurry container 110, an extraction device 120, and a nozzle 130. The slurry container 110 is configured to contain a mixed slurry or pigment mixture, wherein the mixed slurry is formed by mixing crude pigment with a dispersion. The extraction device 120 is connected to the slurry container 110 and is configured to extract the mixed slurry from the slurry container 110. The nozzle 130 is connected to the extraction device 120 and is configured to spray the mixed slurry to form a pigment mixture.

[0062] In the pigment preparation apparatus provided in this embodiment, the apparatus can mix crude pigment with a dispersion to form a slurry using a slurry container, and then spray the slurry through an extraction device and a nozzle. This causes the aggregated pigment particles to deagglomerate, and through shearing and compression, the pigment particles undergo appropriate crystal growth, resulting in a pigment with small particle size, small particle size variation, and excellent deagglomeration performance. Therefore, this pigment has advantages such as high transparency, high color purity, and high deagglomeration effect. Furthermore, this pigment preparation method also has advantages such as simple operation, low cost, and ease of surface modification and coating treatment.

[0063] For example, more than 95% of the pigment particles in the pigment obtained above have a particle size range of 15-50 nanometers; further, more than 95% of the pigment particles in the pigment obtained above have a particle size range of 20-50 nanometers; further, more than 95% of the pigment particles in the pigment obtained above have a particle size range of 20-30 nanometers.

[0064] It should be noted that the pigment preparation method provided in this disclosure can be filtered using a conventional filtration device. Therefore, the pigment preparation apparatus provided in this disclosure may not include a filtration device; after the pigment mixture is prepared, it is filtered using another filtration device. Additionally, the pigment preparation apparatus provided in this disclosure also includes necessary pipes, valves, and other components, which will not be described in detail here.

[0065] In some examples, the slurry container 110 may be made of stainless steel. Of course, embodiments of this disclosure include, but are not limited to, other materials may also be used to make the slurry container.

[0066] In some examples, such as Figure 2 As shown, a baffle plate 135 is provided inside the nozzle 130 to increase the shear force on the mixed slurry.

[0067] In some examples, such as Figure 2 As shown, the nozzle 130 includes a fluid outlet 130B. In the extending direction of the nozzle 130, the distance between the baffle 135 and the fluid outlet 130B can range from 10 to 20 mm, for example, 15 mm.

[0068] Figure 3A , Figure 3B and Figure 3C This is a schematic cross-sectional view of a nozzle according to an embodiment of the present disclosure. Figure 3A , Figure 3B and Figure 3CAs shown, a baffle plate 135 is fixed to the inner wall of the nozzle 130. For example, the baffle plate 135 can be fixed to the inner wall of the nozzle 130 by welding. Of course, the embodiments of this disclosure include, but are not limited to, other fixing methods can also be used to set the baffle plate inside the nozzle.

[0069] In some examples, such as Figure 3A and Figure 3B As shown, the baffle 135 can be a blade, with one end fixed to the inner wall of the nozzle 130 and the other end suspended. Figure 3A As shown, the shape of the blocking plate 135 can be triangular; as Figure 3B As shown, the shape of the blocking plate 135 can be rectangular. Of course, this embodiment of the present disclosure does not impose specific limitations on the shape of the blocking plate, as long as it can block the fluid.

[0070] In some examples, such as Figure 3A and Figure 3B As shown, the nozzle 130 is provided with multiple baffles 135 inside; in this case, the distance between adjacent baffles 135 is in the range of 0.1-10 mm, such as 0.2 mm, 0.4 mm, 1 mm, 2 mm, etc., so as to avoid the gap between the baffles being too large and thus failing to form effective resistance, and also to avoid the blockage caused by the gap being too small.

[0071] In some examples, the surface of the baffle plate may also have a torsional angle with the cross-section of the nozzle at the location of the baffle plate, thereby causing the passing slurry to rotate, further enhancing dispersion and shearing effects.

[0072] In some examples, such as Figure 3C As shown, the baffle 135 can also take other forms, such as a plate-like structure with through holes, which can also increase the shear force on the mixed slurry.

[0073] In some examples, such as Figure 2 As shown, the nozzle 130 includes a fluid inlet 130A, a first sub-section 131, and a second sub-section 132. The first sub-section 131 is connected to the fluid inlet 130A and has a first inner diameter. The second sub-section 132 is connected to the first sub-section 131 and has a second inner diameter. The ratio of the second inner diameter to the first inner diameter ranges from 0.2 to 0.6. Therefore, this nozzle allows the mixed slurry flowing through it to have suitable flow velocity and pressure, resulting in smaller particle size differences in the pigment particles and a length-to-diameter ratio closer to 1.

[0074] For example, the inner diameter of the first sub-part 131 can be 25 mm, and the inner diameter of the second sub-part can be 10 mm; the ratio of the second inner diameter to the first inner diameter is in the range of 0.4.

[0075] In some examples, such as Figure 2 As shown, the extraction device 120 includes an extraction pipe 121, an extraction pump 122, and a drive device 123. One end of the extraction pipe 121 is connected to the slurry container 110, and the other end is connected to the nozzle 130. The extraction pump 122 is located between the extraction pipes 121 to pressurize the mixed slurry in the extraction pipes 121, thereby achieving extraction and subsequent spraying. The drive device 123 is connected to the extraction pump 122 and is configured to drive the extraction pump 122. The rotational speed of the drive device 123 is adjustable to regulate the pressure of the mixed slurry passing through the nozzle 130 via the extraction pump 122. Thus, this pigment preparation device can regulate the shear force and pressure received by the mixed slurry, thereby regulating the particle size, particle size uniformity, and deagglomeration effect of the final obtained pigment particles, thereby meeting the needs of different types of pigments.

[0076] For example, the extraction pump can be a centrifugal pump, and the drive device can be an electric motor. Of course, the embodiments disclosed herein are not limited to this; other types of pumps can also be used for the extraction pump, and hydraulic motors, internal combustion engines, etc., can also be used as the drive device.

[0077] In some examples, such as Figure 2 As shown, the pigment preparation apparatus 100 also includes a temperature control device 140 for adjusting the temperature of the mixed slurry, thereby enabling better dispersion of the primary pigment particles and making the growth of pigment particles more controllable, further improving the uniformity of particle size.

[0078] For example, such as Figure 2 As shown, the temperature regulating device 140 includes a heating device 141, a thermometer 142, and a temperature control device 143. The heating device 141 is used to heat the mixed slurry, the thermometer 142 is used to measure the temperature of the mixed slurry, and the temperature control device 143 is used to control the heating device 141 according to the temperature measured by the thermometer 142, thereby controlling the temperature of the mixed slurry within a preset temperature range. It should be noted that although... Figure 2 The heating device 141 is located outside the slurry container 110, but this is not limited to the embodiments disclosed herein, and the heating device may also be located inside the slurry container.

[0079] For example, the temperature control device may also include a cooling device to better control the temperature of the mixed slurry within a preset temperature range.

[0080] For example, the preset temperature range mentioned above can be 60-120 degrees Celsius; further, the preset temperature range mentioned above can be 80-100 degrees Celsius; further, the preset temperature range mentioned above can be 90-95 degrees Celsius.

[0081] In some examples, such as Figure 2As shown, the nozzle 130 is located above the slurry container 110, thereby drawing in the mixed slurry and circulating it through the nozzle to form a pigment mixture. In other words, the mixed slurry can be drawn from the slurry container and then sprayed back into the slurry container through the nozzle to achieve cyclic spraying. Therefore, this pigment preparation apparatus can make the various parameters of the pigment particles in the final pigment mixture more uniform, thereby improving product quality.

[0082] In some examples, such as Figure 2 As shown, the pigment preparation apparatus 100 also includes a pressure gauge 190 located at the end of the extraction pipe 121 connected to the nozzle 130, thereby detecting the pressure of the mixed slurry in the extraction pipe 121.

[0083] The following describes the working process of the pigment preparation apparatus provided in this embodiment of the present disclosure, taking the preparation of pigment green 58 as an example. First, 1000 grams of crude pigment green 58 is mixed with deionized water in a 30-liter stainless steel slurry container to obtain 20 liters of mixed slurry. The crude pigment green 58 can be obtained by bromination and chlorination of zinc phthalocyanine, containing 66.7% bromine and 1.9% chlorine. A thermometer is installed in a suitable position in the slurry container to measure and control the temperature of the mixed slurry inside. A valve and an outlet pipe are provided at the bottom of the slurry container for discharging the slurry. The outlet pipe is connected to a tee to connect to a centrifugal pump, and the outlet of the centrifugal pump is connected via a pipe... The mixture is directed to a nozzle located above the slurry container. A centrifugal pump is then used to extract the slurry mixture, adjusting its pressure to 0.5 MPa. The mixture is then sprayed through the nozzle and returned to the slurry container. Simultaneously, a temperature control device maintains the temperature of the slurry mixture at 90-95 degrees Celsius, and the mixture is circulated within the container for 2 hours. Subsequently, the centrifugal pump is turned off, and the slurry mixture is cooled to room temperature to obtain a pigment mixture. The pigment mixture is then removed and filtered to obtain a filter cake, which is dried in an oven until the moisture content is below 1%, ultimately yielding the pigment. Testing revealed that the final pigment particles are brick-shaped with an average particle size of 40.0 × 27.5 nm and a major-to-minor axis ratio of 1.45. Furthermore, when used in color filter testing, the pigment exhibits good dispersion, and high levels of contrast, transparency, and chroma.

[0084] It should be noted that although Pigment Green 58 has been described above as an example, the pigment preparation apparatus provided in this disclosure is not limited to the preparation of Pigment Green 58, nor is it limited to applications in the field of color filters. Many other pigments, such as Carbazole Violet (CI Pigment Violet 23), Phthalocyanine Green (CI Pigment Green 59), and Quinacridone Red (CI Pigment Red 122), can also be prepared using the pigment preparation apparatus provided in this disclosure. Furthermore, the pigment preparation apparatus provided in this disclosure is also applicable to many other fields, including inkjet printing.

[0085] Figure 4 This is a schematic diagram of another pigment preparation apparatus provided in one embodiment of the present disclosure. Figure 4 As shown, the pigment preparation apparatus 100 includes a slurry container 110, an extraction device 120, a nozzle 130, and a filter device 150. The slurry container 110 is configured to contain a mixed slurry or pigment mixture, wherein the mixed slurry is formed by mixing crude pigment with a dispersion. The extraction device 120 is connected to the slurry container 110 and configured to extract the mixed slurry from the slurry container 110. The nozzle 130 is connected to the extraction device 120 and configured to spray the mixed slurry to form a pigment mixture. The filter device 150 is configured to filter the pigment mixture to remove the dispersion, thereby obtaining pigment.

[0086] In the pigment preparation apparatus provided in this embodiment, the apparatus can mix crude pigment with a dispersion to form a slurry using a slurry container, and then spray the slurry through an extraction device and a nozzle. This causes the aggregated pigment particles to deagglomerate, and through shearing and compression, the pigment particles undergo appropriate crystal growth, resulting in a pigment with small particle size, small particle size variation, and excellent deagglomeration performance. Therefore, this pigment has advantages such as high transparency, high color purity, and high deagglomeration effect. Furthermore, this pigment preparation method also has advantages such as simple operation, low cost, and ease of surface modification and coating treatment.

[0087] In some examples, such as Figure 4 As shown, the pigment preparation apparatus 100 may further include a stirring device 160; the stirring device 160 is located in the slurry container 110 and is configured to stir and mix the slurry. Therefore, the pigment preparation apparatus can further improve dispersion efficiency and increase the uniformity of the mixed slurry, preventing pigment particle sedimentation.

[0088] In some examples, such as Figure 4 As shown, nozzle 130 and Figure 2 The nozzle 130 shown is different; it also includes a third sub-section 133 connected to the second sub-section 132 and having a third inner diameter; the third inner diameter is larger than the second inner diameter. Thus, the nozzle has a Venturi structure, which allows for better regulation of the flow rate and pressure of the mixed slurry flowing through the nozzle.

[0089] Figure 5 This is a schematic diagram of another pigment preparation apparatus provided in an embodiment of the present disclosure. Figure 5 Only the slurry container 110, extraction pipe 121, and nozzle 130 are shown; other components of the pigment preparation apparatus 100 can be found in reference to [other components]. Figure 2 or Figure 4 The pigment preparation apparatus 100 shown is as follows. Figure 5As shown, the pigment preparation apparatus 100 includes a plurality of nozzles 130; the plurality of nozzles 130 are respectively connected to the extraction device 120 and configured to spray the mixed slurry to form a pigment mixture. The plurality of nozzles 130 can be arranged in a linear or arrayed manner, thereby improving efficiency.

[0090] The following points need to be explained:

[0091] (1) The accompanying drawings of the embodiments of this disclosure only involve the structures involved in the embodiments of this disclosure. Other structures can be referred to the general design.

[0092] (2) Where there is no conflict, features of the same embodiment and different embodiments of this disclosure can be combined with each other.

[0093] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A pigment preparation device, comprising: a slurry container configured to contain a pigment crude mixture slurry or a pigment mixture liquid, the pigment crude mixture slurry being formed by mixing a pigment crude with a dispersion liquid; an extraction device connected to the slurry container and configured to extract the pigment crude mixture slurry in the slurry container; and a nozzle connected to the extraction device and configured to spray the pigment crude mixture slurry to form the pigment mixture liquid, wherein the nozzle is internally provided with a plurality of blocking pieces to increase the shear force on the pigment crude mixture slurry, and the distance between adjacent blocking pieces ranges from 0.1 to 10 millimeters. The blocking pieces are fixed on the inner side wall of the nozzle.

2. The pigment preparation apparatus according to claim 1, wherein The shape of the blocking pieces includes a triangle or a rectangle.

3. The pigment preparation apparatus according to claim 1, wherein The surface of the blocking piece has a torsion angle with the cross section of the nozzle at the position where the blocking piece is located.

4. The pigment preparation apparatus according to claim 2, wherein The nozzle comprises:

5. The pigment preparation apparatus according to any one of claims 1 to 4, wherein a fluid input end; a first sub-portion connected to the fluid input end and having a first inner diameter; a second sub-portion connected to the first sub-portion and having a second inner diameter, wherein the ratio of the second inner diameter to the first inner diameter ranges from 0.2 to 0.

6. The nozzle further comprises:

6. The pigment preparation apparatus according to claim 5, wherein a third sub-portion connected to the second sub-portion and having a third inner diameter, wherein the third inner diameter is greater than the second inner diameter. The extraction device comprises:

7. The pigment preparation apparatus according to any one of claims 1 to 4, wherein an extraction pipeline having one end connected to the slurry container and the other end connected to the nozzle; an extraction pump located between the extraction pipelines; and a driving device connected to the extraction pump and configured to drive the extraction pump, wherein the rotational speed of the driving device is adjustable to adjust the pressure of the pigment crude mixture slurry passing through the nozzle by the extraction pump. 8.The pigment preparation device according to any one of claims 1-4, further comprising at least one of a temperature adjusting device configured to adjust the temperature of the pigment crude mixture slurry, a stirring device located in the slurry container and configured to stir the pigment crude mixture slurry, and a filtering device configured to filter the pigment mixture liquid to remove the dispersion liquid to obtain a pigment. 9.A pigment preparation method using the pigment preparation device according to any one of claims 1-8, comprising: mixing a pigment crude with a dispersion liquid to form a pigment crude mixture slurry, wherein the pigment crude comprises agglomerated large particles, and the agglomerated large particles comprise pigment primary particles agglomerated in a face-to-face manner, and the particle size of the pigment primary particles is less than or equal to 20 nanometers; adjusting the temperature of the pigment crude mixture slurry, extracting the pigment crude mixture slurry, and spraying the pigment crude mixture slurry through a nozzle to form a pigment mixture liquid, so that the crystal of the pigment primary particles grows and the agglomerated pigment primary particles are deagglomerated to form pigment particles, and more than 95% of the particle size of the pigment particles ranges from 15 to 50 nanometers; and filtering the pigment mixture liquid to remove the dispersion liquid to obtain a pigment. ​ 10. The method of claim 9, further comprising: providing a baffle inside the inner wall of the nozzle to increase the shearing force on the pigment crude mixture slurry.

11. The method of claim 9, further comprising: adjusting the pressure of the pigment crude mixture slurry through the nozzle according to the type of the pigment.

12. The method of any one of claims 9-11, further comprising: controlling the temperature of the pigment crude mixture slurry to be within a preset temperature range to control the growth of the pigment particles.

13. The method of preparing pigments according to any one of claims 9-11, wherein, more than 95% of the pigment particles in the pigment have a particle size within a range of 20-30 nanometers.

14. The method of any one of claims 9-11, further comprising: adding a surfactant to the pigment crude mixture slurry to coat the pigment particles that have been depolymerized in the pigment crude mixture slurry.

15. The method of preparing pigments according to any one of claims 9-11, wherein, extracting the pigment crude mixture slurry and spraying the pigment crude mixture slurry through a nozzle to form a pigment mixture further comprises: extracting the pigment crude mixture slurry and circulating the pigment crude mixture slurry through the nozzle to form the pigment mixture.

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