A preparation method of a red organic pigment for liquid crystal color filter materials

Abstract

The present invention discloses a preparation method of a red organic pigment for liquid crystal color filter materials, comprising the following steps: adding a hyperbranched polymer nano-dispersant into ethyl acetate, adding crude Pigment Red 122 and calcium chloride to obtain a mixed slurry; adding the mixed slurry into a ball mill for grinding to obtain a ground slurry; transferring the ground slurry into an aqueous solution of dodecylamine polyoxyethylene ether, stirring and keeping warm, and filtering to obtain a surface-modified slurry; adding the surface-modified slurry into a DMF solution containing a hyperbranched polymer nano-dispersant, performing ultrasonic treatment, and filtering to obtain a final slurry; drying to obtain the product. By improving the processing technology of the pigment, the pigment particles are refined to the nano level, and the dispersion stability and fluidity of the pigment are improved. The prepared red organic pigment has a uniform particle size distribution, high color purity and good optical properties, and is suitable for color filters of liquid crystal displays.

Description

Technical Field

[0001] The present invention relates to the technical field of pigments, and particularly to a preparation method of a red organic pigment for liquid crystal color filter materials. Background Art

[0002] Color liquid crystal displays (LCDs) are one of the most common display devices today and are widely used in various electronic products such as televisions, computers, mobile phones, etc. The display principle of a liquid crystal display is mainly achieved through the cooperation of a color filter (CF) and liquid crystal materials to display the colors of an image. A color filter usually consists of red, green, and blue primary color sub-pixels, and each color sub-pixel forms the corresponding color through the backlight provided by a light source. Specifically, the backlight passes through each pixel unit of the color filter, and in each of the red, green, and blue sub-pixels, the transmission of light is controlled by the opening and closing of the liquid crystal, thereby generating a complete color image.

[0003] The red, green, and blue colors in a color filter are mainly achieved through different organic pigment layers to allow the transmission of light of specific wavelengths and provide the required color performance. Organic pigments have high color saturation and good light resistance, so they are widely used in displays. In a color filter, the use of pigments usually requires high color purity, good transparency, and the ability to maintain a stable color under long-term light exposure. Commonly used red organic pigments include quinacridone, diketopyrrolopyrrole (DPP), etc. These pigments have high color vividness and excellent light resistance and are important material sources for color filters.

[0004] During the coating process of a color filter, organic pigments need to adhere to the filter substrate with extremely high dispersion uniformity to ensure the consistency of their color display effects. The dispersibility of pigment particles directly affects the transparency and durability of the filter. In traditional preparation processes, pigments usually need to be nano-sized through ultra-fine grinding, ultrasonic dispersion, etc., but these methods still have limitations in terms of the uniformity of pigment particle distribution, the accuracy of size control, and the stability of dispersion. In addition, organic pigments have poor storage stability in the dispersion medium and tend to aggregate or settle easily, resulting in the formation of an uneven coloring layer during the coating process of the filter. Summary of the Invention

[0005] Based on the problems existing in the background technology, the present invention provides a preparation method of a red organic pigment for liquid crystal color filter materials. By improving the processing technology of the pigment, the pigment particles are refined to the nanometer level, and through specific dispersion treatment, the dispersion stability and fluidity of the pigment are improved. The prepared red organic pigment has a uniform particle size distribution, high color purity and good optical properties, and is suitable for color filters of liquid crystal displays.

[0006] The present invention is implemented through the following technical solutions:

[0007] A preparation method of a red organic pigment for liquid crystal color filter materials, comprising the following steps:

[0008] S1. Add a hyperbranched polymer nano-dispersant into ethyl acetate, then continue to add crude Pigment Red 122 and calcium chloride, and mix evenly to obtain a mixed slurry;

[0009] S2. Add the mixed slurry into a ball mill and grind it wet to obtain a ground slurry;

[0010] S3. Transfer the ground slurry into an aqueous solution of dodecylamine polyoxyethylene ether, stir and keep warm, and then filter to obtain a surface-modified slurry;

[0011] S4. Add the surface-modified slurry into a DMF solution containing a hyperbranched polymer nano-dispersant, perform ultrasonic treatment, and then filter to obtain a final slurry;

[0012] S5. Dry the final slurry to obtain the red organic pigment for liquid crystal color filter materials.

[0013] Further, in step S1, the hyperbranched polymer nano-dispersant is a hyperbranched polyacrylamide-methyl acrylate copolymer.

[0014] Further, the preparation method of the hyperbranched polyacrylamide-methyl acrylate copolymer is specifically as follows: Add acrylamide and methyl methacrylate into a DMF solution, add ethylene glycol dimethacrylate, and mix evenly; under nitrogen protection, heat to 60 °C, and sequentially add azobisisobutyronitrile to initiate a polymerization reaction. After stirring and reacting for 8 - 10 h, slowly drop the reaction solution into ice ethanol for precipitation, washing, and drying to obtain the hyperbranched polyacrylamide-methyl acrylate copolymer.

[0015] Further, the mass ratio of acrylamide to methyl methacrylate is 1:(2 - 5); the dosage of ethylene glycol dimethacrylate accounts for 4 - 6% of the total mass of acrylamide; the dosage of azobisisobutyronitrile accounts for 0.1 - 1% of the total mass of acrylamide and methyl methacrylate.

[0016] Further, in step S1, the specific amounts of the raw material components by weight are as follows: 2-5 parts of hyperbranched polymer nano-dispersant, 80-120 parts of crude Pigment Red 122, 100-200 parts of calcium chloride, and 25-40 parts of ethyl acetate.

[0017] Further, in step S2, zirconia beads with a diameter of 0.5-1 mm are used as the grinding medium for wet grinding. The rotational speed of the ball mill is 800-1000 revolutions per minute, the grinding time is 10-12 h, and the grinding temperature is lower than 40°C.

[0018] Further, in step S3, the mass fraction of the dodecylamine polyoxyethylene ether aqueous solution is 2-3%; the heat preservation temperature is 50-60°C, and the time is 3-4 h.

[0019] Further, in step S3, the mass ratio of the ground slurry to the dodecylamine polyoxyethylene ether aqueous solution is 1:(1-2).

[0020] Further, in step S4, the mass fraction of the hyperbranched polymer nano-dispersant in the DMF solution containing the hyperbranched polymer nano-dispersant is 2-3%, and ultrasonic treatment is performed for 30-60 min.

[0021] Further, in step S4, the mass ratio of the surface-modified slurry to the DMF solution containing the hyperbranched polymer nano-dispersant is 1:(1.5-3).

[0022] Advantages of the present invention:

[0023] 1. The dispersant used in the present invention is a hyperbranched polymer. The hyperbranched polymer has a highly branched structure, enabling it to be effectively dispersed in the liquid phase. This helps to improve the dispersion state of the pigment in the solution, prevent pigment aggregation or precipitation, and thus enhance the stability and uniformity of the pigment. Especially in liquid crystal display applications, the uniform dispersion of the pigment is the key to achieving high-quality colors.

[0024] 2. Through surface modification, dodecylamine polyoxyethylene ether is added to the surface of the pigment to improve the compatibility between the pigment and the liquid crystal material. This is crucial for ensuring the uniformity and stability of the liquid crystal color filter material. Especially in liquid crystal displays, good compatibility between the pigment and the substrate can effectively improve the display effect. In addition, surface modification helps to functionalize the pigment, enhancing its optical properties, chemical resistance, heat resistance, etc.

[0025] 3. Adding a hyperbranched polymer nano-dispersant to the surface-modified slurry further enhances the dispersion stability of the pigment. This two-stage application of the dispersant can ensure the long-term stability of the pigment in the liquid crystal color filter material and prevent the re-aggregation of pigment particles. Using a hyperbranched polymer as a dispersant can effectively improve the optical effect of the pigment, enhance color purity, reduce light scattering and occlusion effects between particles, and thus enhance the brightness and color contrast of the liquid crystal color filter material.

[0026] 4. The red organic pigment prepared by the method of the present invention has a finer particle size, good dispersion, and can improve the compatibility with the liquid crystal display substrate after surface modification, further enhancing its optical properties and ensuring color accuracy and vividness. In liquid crystal color filter applications, this red organic pigment can effectively adjust light transmittance and light reflection, providing more stable and accurate colors. The surface modification and the use of hyperbranched polymers endow the pigment with stronger chemical resistance and light resistance. Especially in the liquid crystal display environment, the pigment needs to withstand various chemical media and ultraviolet light irradiation. Such a pigment can maintain its color stability and extend its service life. Specific Embodiments

[0027] The technical solutions of the present invention will be further described in detail below with reference to specific embodiments, but the protection scope of the present invention is not limited to the following embodiments.

[0028] Example 1

[0029] A preparation method of a red organic pigment for liquid crystal color filter materials includes the following steps:

[0030] S1. Preparation of hyperbranched polymer nano-dispersant: Add 10 parts of acrylamide and 30 parts of methyl methacrylate to a DMF solution, add 1 part of ethylene glycol dimethacrylate, and stir evenly; under nitrogen protection, heat to 60 °C, and sequentially add 0.33 parts of azobisisobutyronitrile to initiate the polymerization reaction. After stirring and reacting for 8 - 10 h, after the reaction is completed, slowly drop the reaction solution into ice ethanol for precipitation washing and drying to obtain a hyperbranched polyacrylamide-methyl acrylate copolymer;

[0031] S2. Add 3 parts of the hyperbranched polymer nano-dispersant to 25 parts of ethyl acetate, then add 100 parts of crude pigment red 122 and 150 parts of calcium chloride, and mix evenly to obtain a mixed slurry;

[0032] S3. Add the mixed slurry to a ball mill, use zirconia beads with a diameter of 0.5 - 1 mm as the grinding medium, the rotation speed of the ball mill is 800 revolutions per minute, the grinding time is 12 h, and the grinding temperature is below 40 °C for wet grinding to obtain the ground slurry;

[0033] S4. Transfer the ground slurry to an aqueous solution of polyoxyethylene laurylamine with a mass fraction of 2%, and the mass ratio of the ground slurry to the aqueous solution of polyoxyethylene laurylamine is 1:1. Stir and keep warm at 60 °C for 3 h, then filter to obtain the surface-modified slurry;

[0034] S5. Add the surface-modified slurry to a DMF solution containing a hyperbranched polymer nano-dispersant with a mass fraction of 2%. The mass ratio of the surface-modified slurry to the DMF solution containing the hyperbranched polymer nano-dispersant is 1:2. Perform ultrasonic treatment for 30 min, then filter to obtain the final slurry;

[0035] S6. Dry the final slurry to obtain the red organic pigment for liquid crystal color filter materials.

[0036] Example 2

[0037] The difference between this example and Example 1 is that in step S2, 5 parts of the hyperbranched polymer nano-dispersant are added to 25 parts of ethyl acetate, then 90 parts of crude pigment red 122 and 150 parts of calcium chloride are added and mixed evenly to obtain a mixed slurry; the other steps are the same as those in Example 1.

[0038] Comparative Example 1

[0039] The dispersant used is WinSperse 3200 (Weipos New Materials (Weifang) Co., Ltd.);

[0040] The specific preparation steps are as follows:

[0041] S1. Add 3 parts of the dispersant WinSperse 3200 to 25 parts of ethyl acetate, then add 100 parts of crude pigment red 122 and 150 parts of calcium chloride and mix evenly to obtain a mixed slurry;

[0042] S2. Add the mixed slurry to a ball mill, use zirconia beads with a diameter of 0.5 - 1 mm as the grinding medium, the rotation speed of the ball mill is 800 r / min, the grinding time is 12 h, and the grinding temperature is below 40 °C for wet grinding to obtain the ground slurry;

[0043] S3. Transfer the ground slurry to an aqueous solution of polyoxyethylene laurylamine with a mass fraction of 2%, and the mass ratio of the ground slurry to the aqueous solution of polyoxyethylene laurylamine is 1:1. Stir and keep warm at 60 °C for 3 h, then filter to obtain the surface-modified slurry;

[0044] S4. Dry the final slurry to obtain the red organic pigment for liquid crystal color filter materials.

[0045] Comparative Example 2

[0046] The difference between this comparative example and Example 1 lies in that the dispersant used is a polyacrylamide-methyl acrylate copolymer, and its preparation method is as follows: 30 parts of acrylamide and 10 parts of methyl methacrylate are added to 50 parts of DMF solution, 1 part of ethylene glycol dimethacrylate is added, and the mixture is stirred evenly; under nitrogen protection, it is heated to 60 °C, and 0.33 parts of azobisisobutyronitrile are added in sequence to initiate the polymerization reaction. After stirring and reacting for 8 - 10 h, it is cooled to room temperature. After the reaction, the reaction solution is slowly dropped into ice ethanol for precipitation, washing, and drying to obtain the polyacrylamide-methyl acrylate copolymer; the remaining steps are the same as those in Example 1.

[0047] Comparative Example 3

[0048] The difference between this comparative example and Example 1 is that step S5 is not included in the preparation steps. The modified slurry prepared in step S4 is directly freeze-dried; the remaining steps are the same as those in Example 1.

[0049] Application Example 1

[0050] The pigment of Example 1 is prepared into a red color paste; the specific method is as follows: 5.7 g of red organic pigment, 4.5 g of grinding resin BM52 (produced by Shanghai Boli'er Chemical Industry), 2.3 g of grinding aid WinSperse 3030 (Weipos New Materials (Weifang) Co., Ltd.), 25.5 g of propylene glycol methyl ether acetate. In a grinding tank, 0.1 mm zirconium balls are added, and they are mixed and dispersed by a Mickey double planetary dynamic ball mill for 24 hours to obtain a red color paste.

[0051] Application Example 2

[0052] The pigment obtained in Example 2 with the same weight is used to replace the pigment of Example 1 used in Application Example 1, and the remaining components, component dosages, and operating processes are the same as those in Application Example 1.

[0053] Comparative Application Example 1

[0054] The pigment obtained in Comparative Example 1 with the same weight is used to replace the pigment of Example 1 used in Application Example 1, and the remaining components, component dosages, and operating processes are the same as those in Application Example 1.

[0055] Comparative Application Example 2

[0056] The pigment obtained in Comparative Example 2 with the same weight is used to replace the pigment of Example 1 used in Application Example 1, and the remaining components, component dosages, and operating processes are the same as those in Application Example 1.

[0057] Comparative Application Example 3

[0058] The pigment obtained in Comparative Example 3 with the same weight is used to replace the pigment of Example 1 used in Application Example 1, and the remaining components, component dosages, and operating processes are the same as those in Application Example 1.

[0059] Comparative Application Example 4

[0060] Use the untreated commercial Pigment Red 122 of the same weight to replace the pigment of Example 1 used in Application Example 1, and the other components, component dosages, and operating processes are the same as those in Application Example 1.

[0061] Perform performance tests on the red color pastes prepared in Application Examples 1-2 and Comparative Application Examples 1-3.

[0062] Particle Size Test

[0063] Use a particle size analyzer 90Plus to test the average particle size and particle size distribution of the red color pastes obtained in the application examples and comparative application examples.

[0064] Viscosity Test and Dispersion Stability Test

[0065] Let the red color pastes prepared in Application Examples 1-2 and Comparative Application Examples 1-3 stand at room temperature for 1 day, take samples, and use a viscometer DV2T to test the initial viscosity; place the remaining red color pastes at 40°C for 7 days, take samples, and use a viscometer DV2T to test the viscosity after 7 days.

[0066] Chemical Resistance

[0067] Form a coating film on a 6 cm × 6 cm glass sheet with the red color pastes obtained in the application examples and comparative application examples through a spin coater, pre-bake at 120°C for 3 minutes, and then place it in an oven at 230°C for 30 minutes.

[0068] Immerse the prepared smear in propylene glycol monomethyl ether acetate (PGMEA) solvent at 60°C for 10 minutes, and observe and evaluate the color change before and after. Here, use the following equation to calculate the color change, and the values calculated using the equation are shown in Table 1 below.

[0069] ΔEab* = [(ΔL*) 2 +(Δa*) 2 +(Δb*) 2 1 / 2

[0070] In the equation, ΔL*, Δa*, and Δb* represent the color changes defined by L*, a*, and b* observed using a three-dimensional colorimeter.

[0071] Evaluation Criteria

[0072] ○: Good chemical resistance (no pattern change, Δ(Eab*) less than 3.0)

[0073] △: General chemical resistance (slight pattern change, Δ(Eab*) is 3.0 to less than 5.0)

[0074] ​×: Poor chemical resistance (pattern change, Δ(Eab*) is 5.0 or greater)

[0075] Smear contrast test

[0076] The above-mentioned smear measures the ratio of the brightness when the polarizing plate is in the orthogonal position to the brightness when the polarizing plate is in the parallel position through a contrast tester (Koban Electric CT-1 in Japan), which is the contrast. Assuming that the contrast obtained by testing with Comparative Application Example 4 is 100, the contrast values obtained by testing other application examples and comparative application examples are compared with it, and the contrast data shown in Table 1 are obtained.

[0077] All test results are shown in Table 1.

[0078] Table 1

[0079]

[0080] It can be seen from the data in Table 1 that the average particle size of the red color pastes prepared by using Example 1 and Example 2 of the present invention is smaller, the particle size distribution is narrower, the storage stability is better, the prepared smear has good chemical resistance, and the contrast is close to that of the commercially available Pigment Red 122, showing obvious advantages. The red organic pigment prepared by the present invention can be used for the preparation of a colorant for red pixel points of liquid crystal color filter materials. In the preparation of Comparative Example 1, the dispersant WinSperse 3200 was used, and after the treatment with the aqueous solution of dodecylamine polyoxyethylene ether in the preparation process, it was directly filtered and dried without secondary treatment with a dispersant, and finally the performance of the obtained red color paste was reduced. In the preparation of Comparative Example 2, a polyacrylamide-methyl acrylate copolymer was used as the dispersant, and the amounts of polyacrylamide and methyl methacrylate were adjusted. Finally, the prepared copolymer was more inclined to a linear structure rather than a hyperbranched structure, and the increase in the amount of acrylamide led to an increase in the hydrophilicity of the copolymer, which was instead not conducive to the improvement of the dispersibility of the organic pigment. Therefore, the performance of the final color paste was also reduced. In Comparative Example 3, after wet grinding, it was treated with an aqueous solution of dodecylamine polyoxyethylene ether and then directly filtered and dried without secondary treatment with a dispersant, and the dispersion stability of the red color paste was reduced, and the color contrast was slightly reduced.

[0081] In one embodiment, after obtaining the red organic pigment for liquid crystal color filter materials, the preparation method of the red organic pigment for liquid crystal color filter materials further includes:

[0082] S6. Conduct compliance testing on the obtained red organic pigment for liquid crystal color filter materials. When the test situation parameters reflect that the compliance testing is unqualified, based on the test situation parameters, adaptively establish a problem tracing model for the preparation process, and based on the problem tracing model for the preparation process (at least including: the above steps S1 to S5), conduct problem tracing, and online solve the traced problems;

[0083] Among them, in S6, the method of adaptively formulating a problem tracing model for the preparation process based on the detection situation parameters includes:

[0084] S611. Extract features from the detection situation parameters to obtain multiple parameter features;

[0085] In S611, the detection situation parameters are the result parameters of the compliance detection of the obtained red organic pigment for liquid crystal color filter materials; a compliance index is preset, and monitoring situation parameters are generated based on the difference relationship between the detection results and the compliance index; the extracted parameter features are the relevant data features of the detection situation parameters;

[0086] S612. Map each parameter feature to the problem graph to obtain multiple mapped problems; among them, the mapped problems are the problems corresponding to the root nodes and branch nodes of the tree - like data structure in which each parameter feature occupies all leaf nodes in the problem graph;

[0087] In S612, there are multiple tree - like data structures in the problem graph. In one tree - like data structure, the root node is the beginning of a detection process problem. There are multiple branch edges diverging from the root node, and there are multiple branch nodes on the branch edges. One branch edge represents the change process of a problem parameter in the detection process problem. The sequentially connected branch nodes are the multiple process items of this change process. The terminal of one branch edge is the leaf node, and the leaf node is the change result of a problem parameter; when the parameter feature occupies all leaf nodes, all the problems corresponding to the root nodes and branch nodes of the corresponding tree - like data structure need to be traced;

[0088] S613. Generate templates based on the problem tracing rules, and generate multiple problem tracing rules according to each mapped problem;

[0089] In S613, the problem tracing rule is a rule for tracing whether there are mapped problems in the preparation process;

[0090] S614. Formulate a problem tracing model for the preparation process based on each problem tracing rule;

[0091] In S614, finally, based on each problem tracing rule, a problem tracing model for the preparation process is formulated. When formulating, multiple problem tracing rules can be sorted to form a system working module with sequential rule execution as the problem tracing model for the preparation process;

[0092] Among them, in S6, the method of online solving the traced problems includes:

[0093] S621. Analyze the knowledge requirements of the traced problems to obtain multiple knowledge requirements;

[0094] In S621, when performing knowledge requirement analysis, analyze what kind of knowledge is needed to solve the problem obtained by tracing, that is, the knowledge requirement;

[0095] S622. Traverse each knowledge requirement in turn;

[0096] S623. Each time during traversal, parse the requirement type of the traversed knowledge requirement; the requirement type is divided into two types: active requirement and passive requirement;

[0097] In S623, the requirement type of the knowledge requirement is divided into two types, active and passive; active means that it can be acquired based on knowledge alone; passive means that it needs to be connected with other knowledge to be acquired based on knowledge;

[0098] S624. When the requirement type of the knowledge requirement is an active requirement, acquire the corresponding first target knowledge based on the knowledge requirement;

[0099] In S624, the form of the first target knowledge can be expert experience, etc.;

[0100] S625. Connect the knowledge requirements with passive requirement types to obtain connected knowledge requirements, and acquire the corresponding second target knowledge based on the connected knowledge requirements;

[0101] In S625, similarly, the form of the second target knowledge can be expert experience, etc.; the second target knowledge can meet all the knowledge requirements for connection;

[0102] S626. Generate a problem-solving strategy based on the first target knowledge and the second target knowledge;

[0103] In S626, after acquiring the first target knowledge and the second target knowledge, generate a problem-solving strategy based on the two;

[0104] S627. Solve the problem obtained by tracing online based on the problem-solving strategy.

[0105] In S627, finally, solve the problem obtained by tracing online based on the problem-solving strategy; online means that the system makes corresponding adjustment controls on the equipment control involved in the preparation process.

[0106] The embodiments of the present invention have achieved the following beneficial effects:

[0107] 1. In the prior art, many preparation processes often rely on experience or fixed detection standards to identify and solve problems. However, in this embodiment, a problem tracing model is introduced through adaptive feedback on the compliance detection results during the preparation process, which can accurately analyze the specific reasons for each detection failure. Compared with the traditional preparation process, when the quality is unqualified, in-depth analysis can be carried out through the automated problem tracing model to fundamentally find problems in the preparation, and then improve the preparation quality.

[0108] 2. Problem diagnosis in the prior art is often solved through manual detection and manual analysis, with low efficiency and prone to ignoring potential factors. In this embodiment, through the extraction of detection parameter features, the detection results are converted into quantifiable feature data, and then these data are mapped to the problem map to obtain multiple potential problems, thereby realizing comprehensive and efficient problem tracing. The tree structure of the problem map helps to achieve multi-level and multi-angle analysis, can more comprehensively identify and analyze the root causes of problems, and avoids missing important factors.

[0109] 3. During the problem tracing process, in this embodiment, the required knowledge types are determined through knowledge demand analysis, and expert experience or other relevant knowledge is obtained according to the demand types. The distinction between active demand and passive demand makes the knowledge acquisition process more accurate and efficient, and can effectively support online adjustment and problem solving.

[0110] 4. By introducing the combination of an adaptive problem tracing model, knowledge demand analysis, expert experience, and online control adjustment, the automation level, intelligent level, and problem-solving efficiency of the preparation process of red organic pigments for liquid crystal color filter materials are significantly improved, and problems can be quickly located and solved when they occur, thereby reducing quality fluctuations and resource waste in production.

[0111] Finally, it should be noted that the above embodiments only represent several implementation manners of the present invention and are not intended to limit the present invention. For those of ordinary skill in the art, any modifications, equivalent replacements, improvements, etc. made without departing from the concept of the present invention shall be included within the protection scope of the present invention. Therefore, the protection scope of this invention patent shall be subject to the appended claims.

Claims

1. A preparation method of a red organic pigment for liquid crystal color filter materials, characterized in that, It includes the following steps: S1. Add the hyperbranched polymer nano-dispersant into ethyl acetate, then continue to add the crude pigment red 122 and calcium chloride, and mix evenly to obtain a mixed slurry; S2. Add the mixed slurry into a ball mill and conduct wet grinding to obtain the ground slurry; S3. Transfer the ground slurry into an aqueous solution of dodecylamine polyoxyethylene ether, stir and keep warm, then filter to obtain the surface-modified slurry; S4. Add the surface-modified slurry into a DMF solution containing the hyperbranched polymer nano-dispersant, conduct ultrasonic treatment, and then filter to obtain the final slurry; S5. Dry the final slurry to obtain the red organic pigment for liquid crystal color filter materials; In step S1, the hyperbranched polymer nano-dispersant is a hyperbranched polyacrylamide-methyl acrylate copolymer; The preparation method of the hyperbranched polyacrylamide-methyl acrylate copolymer is specifically as follows: Add acrylamide and methyl methacrylate into a DMF solution, add ethylene glycol dimethacrylate, and stir evenly; under the protection of nitrogen, heat to 60 °C, and sequentially add azobisisobutyronitrile to initiate the polymerization reaction. After stirring and reacting for 8 - 10 h, slowly drop the reaction solution into ice ethanol for precipitation, wash, filter, and dry to obtain the hyperbranched polyacrylamide-methyl acrylate copolymer; The mass ratio of acrylamide to methyl methacrylate is 1:(2 - 5); the dosage of ethylene glycol dimethacrylate accounts for 4 - 6% of the total mass of acrylamide; the dosage of azobisisobutyronitrile accounts for 0.1 - 1% of the total mass of acrylamide and methyl methacrylate.

2. The preparation method of the red organic pigment for liquid crystal color filter materials according to claim 1, wherein In step S1, the specific amounts of each raw material component by weight are: 2 - 5 parts of the hyperbranched polymer nano-dispersant, 80 - 120 parts of the crude pigment red 122, 100 - 200 parts of calcium chloride, and 25 - 40 parts of ethyl acetate.

3. The preparation method of the red organic pigment for liquid crystal color filter materials according to claim 1, characterized in that, In step S2, zirconia beads with a diameter of 0.5 - 1 mm are used as the grinding medium for wet grinding, the rotation speed of the ball mill is 800 - 1000 r / min, the grinding time is 10 - 12 h, and the grinding temperature is lower than 40 °C.

4. The preparation method of the red organic pigment for liquid crystal color filter materials according to claim 1, characterized in that, In step S3, the mass fraction of the aqueous solution of dodecylamine polyoxyethylene ether is 2 - 3%; the heat preservation temperature is 50 - 60 °C, and the time is 3 - 4 h.

5. The preparation method of the red organic pigment for liquid crystal color filter materials according to claim 1, characterized in that, In step S3, the mass ratio of the ground slurry to the aqueous solution of dodecylamine polyoxyethylene ether is 1:(1 - 2).

6. The preparation method of the red organic pigment for liquid crystal color filter materials according to claim 1, characterized in that, In step S4, the mass fraction of the hyperbranched polymer nano-dispersant in the DMF solution containing the hyperbranched polymer nano-dispersant is 2 - 3%, and ultrasonic treatment is carried out for 30 - 60 min.

7. The preparation method of the red organic pigment for liquid crystal color filter materials according to claim 1, characterized in that, In step S4, the mass ratio of the surface-modified slurry to the DMF solution containing the hyperbranched polymer nano-dispersant is 1:(1.5 - 3).

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