Copper phthalocyanine pigment dispersion liquid as well as preparation method and application thereof

Abstract

The invention relates to pigment dispersion liquid and provides copper phthalocyanine pigment dispersion liquid as well as a preparation method and application thereof. The copper phthalocyanine pigment dispersion liquid provided by the invention comprises the following components in percentage by weight based on the total weight of 100%: 5-25% of a modified pigment, 5-25% of a solvent and the balance of a solvent, 3%-30% of a first dispersant; 50%-85% of a solvent; and 0.5%-15% of polyacrylate. The modified pigment comprises a copper phthalocyanine pigment and a surface modifier attached to the surface of the copper phthalocyanine pigment, wherein the surface modifier contains polar groups; the first dispersant contains an amino group. According to the copper phthalocyanine pigment, polar groups are introduced to the surfaces of the copper phthalocyanine pigment molecules through the surface modifier, the polarity difference between pigment particles and a dispersion medium is improved, agglomeration of the pigment particles is effectively prevented, and the copper phthalocyanine pigment dispersion liquid is dispersed more uniformly. Amino groups in the first dispersing agent can form hydrogen bonds with polar groups adsorbed on the surface of the copper phthalocyanine pigment, and the hydrogen bonds further promote dispersion of pigment particles in the medium.

Description

Technical Field

[0001] The present application belongs to the technical field of color pastes, and in particular relates to a copper phthalocyanine pigment dispersion and a preparation method and application thereof. Background Art

[0002] Color filters are an important component of display devices (such as liquid crystal displays) and are used to display and filter colors. Copper phthalocyanine pigment dispersion is the key coloring material for blue pixels in color filters. Copper phthalocyanine, also known as phthalocyanine blue, has a complex molecular structure consisting of four isoindolin rings forming a closed sixteen-membered ring with a copper ion at the center. Due to the low surface polarity of copper phthalocyanine pigments, the interaction force between copper phthalocyanine and the surrounding medium is small, resulting in poor dispersibility in solvents or dispersants. The pigment particles are easily agglomerated, resulting in uneven dispersion, which will affect the coloring effect of the pigment and will also have a negative impact on stability and leveling. Summary of the invention

[0003] The purpose of the present application is to provide a copper phthalocyanine pigment dispersion and a preparation method and application thereof, aiming to solve the problem of poor dispersibility of the copper phthalocyanine pigment dispersion.

[0004] In order to achieve the above application purpose, the technical solution adopted in this application is as follows:

[0005] In a first aspect, an embodiment of the present application provides a copper phthalocyanine pigment dispersion, which comprises the following components in weight percentage, based on the total weight of the copper phthalocyanine pigment dispersion being 100%:

[0006]

[0007] The modified pigment comprises a copper phthalocyanine pigment and a surface modifier attached to the surface of the copper phthalocyanine pigment; the surface modifier contains a polar group; and the first dispersant contains an amine group.

[0008] In the copper phthalocyanine pigment dispersion of the embodiment of the present application, polar groups are introduced into the surface of the copper phthalocyanine pigment through surface modification, which improves the polarity difference between the pigment particles and the dispersion medium, effectively reduces the risk of pigment particle agglomeration, and makes the copper phthalocyanine pigment dispersion more evenly dispersed. The amine group contained in the first dispersant can form hydrogen bonds with the polar groups of the surface modifier, and the hydrogen bonding further promotes the dispersion of the pigment particles in the medium, while the polyacrylate has a large steric hindrance, and its addition can reduce the aggregation of the pigment particles in the dispersion medium. Therefore, the embodiment of the present application can make the copper phthalocyanine pigment particles uniformly distributed in the dispersion through the joint action of each content component in the copper phthalocyanine pigment dispersion, improve the physical and chemical stability of the dispersion, and at the same time, it is not easy to stratify and settle during the preparation and storage process, and has high uniformity and consistency.

[0009] In some embodiments, the polar group includes at least one of a hydroxyl group, a carboxyl group, a carbonyl group, a thiol group, a urea group, an aldehyde group, and an ester group.

[0010] In some embodiments, the surface modifier includes at least one of polyethylene glycol, polyvinyl alcohol, sodium polyacrylate, polymethyl acrylate, carboxymethyl cellulose, methyl cellulose, dimethyl carbonate, diethyl carbonate, mercaptopropionic acid, mercaptoethanol, glutaraldehyde, 4-hydroxyvaleraldehyde, and ureapropyltriethoxysilane.

[0011] In some embodiments, the first dispersant includes DISPERBYK-130, DISPERBYK-161, DISPERBYK-162, DISPERBYK-163, DISPERBYK-180, DISPERBYK-182, DISPERBYK-183, DISPERBYK-184, DISPERBYK-185, DISPERBYK-2000, DISPERBYK-2000, DISPERBYK-2001, DISPERBYK-2002, DISPERBYK-2003, DISPERBYK-2004, DISPERBYK-2005, DISPERBYK-2006, DISPERBYK-2007, DISPERBYK-2008, DISPERBYK-2009, DISPERBYK-2001, DISPERBYK-2003, DISPERBYK-2004, DISPERBYK-2005, DISPERBYK-2006, DISPERBYK-2007, DISPERBYK-2008, DISPERBYK-2009, DISPERBYK-200 PERBYK-2001, DISPERBYK-2020, DISPERBYK-2050, DISPERBYK-2070, DISPERBYK-2150, EFKA-150 3. EFKA-4010, EFKA-4020, EFKA-4300, EFKA-4330, EFKA-4340, EFKA-4520, EFKA-4530, Solsperse at least one of Solsperse 18000, Solsperse 20000, Solsperse 21000, Solsperse 24000, Solsperse 26000, Solsperse 27000, Solsperse 28000, Solsperse 32000, Solsperse 36000, Solsperse 37000, Solsperse 38000, Solsperse 41000, Solsperse 42000, Solsperse 43000, Solsperse 46000, Solsperse 54000, Solsperse 71000, Ajisper PB-711, Ajisper PB-821, Ajisper PB-822, Ajisper PB-814, and Ajisper PB-824.

[0012] In some embodiments, the copper phthalocyanine pigment dispersion further comprises a second dispersant, and the second dispersant contains a sulfonic acid group. The sulfonic acid group dissociates into sulfonate ions, thereby generating electrostatic repulsion, which can prevent the agglomeration of pigment ions, and the steric hindrance effect of the amine group and the electrostatic repulsion of the sulfonic acid group can cooperate with each other to prevent the agglomeration of pigment particles, thereby improving the dispersibility and stability of the pigment dispersion.

[0013] In some embodiments, based on the total weight of the copper phthalocyanine pigment dispersion being 100%, the weight percentage of the second dispersant is 0.5% to 5%. When the amount of the second dispersant is within the above range, it can produce better synergy with the first dispersant.

[0014] In some embodiments, the second dispersant includes at least one of sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, and acrylic acid-sulfonate copolymer.

[0015] In some embodiments, the particle size of the modified pigment is 25 nm to 60 nm. Controlling the particle size of the modified pigment within the above range can significantly improve the contrast and color expression of the color filter.

[0016] In some embodiments, the acid value of the polyacrylate is 30 mgKOH / g to 150 mgKOH / g. Controlling the acid value of the polyacrylate within the above range helps to form a more stable dispersion system.

[0017] In some embodiments, the number average molecular weight of the polyacrylate is 3000 g / mol to 30000 g / mol. Controlling the number average molecular weight of the polyacrylate within the above range can make the pigment particles evenly dispersed and improve the stability of the dispersion system.

[0018] In some embodiments, the solvent includes propylene glycol methyl ether acetate and propylene glycol methyl ether, and the mass ratio of the propylene glycol methyl ether acetate to the propylene glycol methyl ether is 2:3 to 3:2. The mixed use of the two solvents can further enhance the dispersion of the pigment particles in the solvent system to form a uniform and stable pigment dispersion. Controlling the mass ratio of propylene glycol methyl ether acetate to propylene glycol methyl ether within the above range is more suitable for the copper phthalocyanine pigment dispersion system of the present application.

[0019] In a second aspect, the present application provides a method for preparing a copper phthalocyanine pigment dispersion, comprising the following steps:

[0020] The copper phthalocyanine pigment is subjected to surface modification treatment by using a surface modifier to obtain an initial modified pigment;

[0021] The initial modified pigment is mixed with an inorganic salt and a salt-milling solvent, and then subjected to salt-milling treatment, and then washed and dried to obtain a modified pigment;

[0022] The modified pigment is mixed with a first dispersant, polyacrylate and a solvent to obtain the copper phthalocyanine pigment dispersion.

[0023] The preparation method of the present application uses a surface modifier to modify the surface of the copper phthalocyanine pigment. The surface modification improves the compatibility of the surface of the pigment particles with the dispersion medium, improves the stability of the dispersion system, and prevents the agglomeration of the pigment particles during the salt milling process, thereby shortening the salt milling time and improving the production efficiency. The salt milling treatment also reduces the particle size and particle size distribution of the pigment particles, thereby improving the tinting power of the copper phthalocyanine pigment.

[0024] In some embodiments, the inorganic salt includes at least one of sodium chloride, calcium chloride, sodium sulfate, potassium chloride, and barium chloride.

[0025] In some embodiments, the salt milling solvent includes at least one of 2-methoxyethanol, 2-butoxyethanol, 2-(isopentyloxy)ethanol, 2-(hexyloxy)ethanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, and dipropylene glycol monoethyl ether.

[0026] In some embodiments, the mass ratio of the copper phthalocyanine pigment to the surface modifier is 1:1 to 10:1.

[0027] In some embodiments, the surface modification treatment is performed at a temperature of 40° C. to 100° C. and for a time of 2 h to 12 h.

[0028] In some embodiments, the mass ratio of the initial modified pigment, the inorganic salt, and the salt-milling solvent is 1:(1-5):(5-10).

[0029] In some embodiments, the mixing process includes grinding the modified pigment, the first dispersant, the polyacrylate and the solvent at a rotation speed of 500 rpm to 3000 rpm.

[0030] In a third aspect, the present application provides a use of the copper phthalocyanine pigment dispersion of the first aspect in a color filter. The copper phthalocyanine pigment dispersion provided in the present application has high contrast, high tinting strength and excellent stability, and is suitable for color filters in liquid crystal displays. DETAILED DESCRIPTION

[0031] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0032] In this application, the term "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0033] In this application, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple, respectively.

[0034] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0035] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0036] The weight of the relevant components mentioned in the embodiment description of the present application can not only refer to the specific content of each component, but also represent the proportional relationship between the weights of the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the embodiment description of the present application, it is within the scope disclosed in the embodiment description of the present application. Specifically, the mass described in the embodiment description of the present application can be a mass unit known in the chemical industry such as μg, mg, g, kg, etc.

[0037] The terms "first" and "second" are used only for descriptive purposes to distinguish objects such as substances from each other, and should not be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. For example, without departing from the scope of the embodiments of the present application, the first XX may also be referred to as the second XX, and similarly, the second XX may also be referred to as the first XX. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0038] Since the molecules of copper phthalocyanine pigments are non-polar or weakly polar as a whole, there is a difference in polarity between the surface structure of the pigment and the dispersion medium, and the pigment particles are prone to agglomeration, resulting in problems such as uneven dispersion and poor stability of the pigment dispersion.

[0039] Based on this, an embodiment of the present application provides a copper phthalocyanine pigment dispersion, which, based on the total weight of the copper phthalocyanine pigment dispersion as 100%, includes the following components in weight percentage: 5% to 25% modified pigment; 3% to 30% dispersant; 50% to 85% solvent; 0.5% to 15% polyacrylate; the modified pigment includes a copper phthalocyanine pigment and a surface modifier attached to the surface of the copper phthalocyanine pigment, the surface modifier containing a polar group; the first dispersant contains an amine group.

[0040] First, in the copper phthalocyanine pigment dispersion of the present application, the copper phthalocyanine pigment surface is attached with a surfactant, and the surfactant contains polar groups. The polar groups can improve the wetting properties of the pigment particle surface, making the pigment more easily wetted by the dispersion medium, thereby reducing the agglomeration between the pigment particles and improving the dispersion stability. Secondly, the pigment dispersion of the present application also includes a first dispersant containing an amine group, and the first dispersant molecule contains a free amine group. This group can be adsorbed on the surface of the pigment particles to form an adsorption layer, thereby improving the dispersibility of the pigment particles in the liquid medium. Third, since the amine group is also a polar group, the nitrogen atom and hydrogen atom in the amine group can form hydrogen bonds with the polar groups adsorbed on the surface of the copper phthalocyanine pigment, and the hydrogen bonding further promotes the dispersion of the pigment particles in the medium. In summary, the polar groups adsorbed on the surface of the copper phthalocyanine pigment, the amine groups in the first dispersant, and the hydrogen bonds formed between the polar groups and the amine groups synergistically promote the dispersion of the copper phthalocyanine pigment in the liquid medium. In addition, the copper phthalocyanine pigment dispersion of the present application also contains polyacrylate, which has a large steric hindrance. Its addition can not only reduce the interfacial tension between the pigment particles and the dispersion medium, but also prevent the aggregation and sedimentation of the pigment particles.

[0041] Therefore, the present application makes the copper phthalocyanine pigment particles evenly distributed in the dispersion through the combined action of various components in the copper phthalocyanine pigment dispersion, thereby improving the physical and chemical stability of the dispersion. At the same time, stratification and sedimentation are not prone to occur during the preparation and storage process, thereby providing a copper phthalocyanine pigment dispersion with high uniformity and consistency.

[0042] In the present application, the weight percentage of polyacrylate in the copper phthalocyanine pigment dispersion is 0.5% to 15%. As an example, the weight percentage can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 5%, 6%, 7%, 8%, 10%, 12%, 15% and other typical but non-limiting values. The selection of the amount of polyacrylate added is mainly affected by the type of pigment and the surface properties of the pigment. The copper phthalocyanine pigment of the present application is a particle with polar groups adsorbed on the surface. The polyacrylate is selected in the above-mentioned addition range, and the dispersion effect of the dispersion is better.

[0043] The weight percentage of the modified pigment of the present application in the copper phthalocyanine pigment dispersion is 15% to 25%. As an example, its weight percentage can be 15%, 15.5%, 16%, 16.5%, 17%, 17.5%, 18%, 20%, 25% and other typical but non-restrictive values. The pigment content in the pigment dispersion currently on the market is about 12%. In the dispersion of the present application, the weight content of the modified pigment is more than 15%, which means that in the color filter prepared by the dispersion of the present application, more pigment particles participate in the absorption and reflection process of light, which can improve the color saturation of the filter. At the same time, it also means that for the same chromaticity point, the film thickness of the coating using the pigment dispersion of the present application is lower, which improves production efficiency and reduces production costs.

[0044] In some embodiments, copper phthalocyanine pigments may be selected from pigment blue 15:1 (index number PB15:1), pigment blue 15:2 (index number PB15:2), pigment blue 15:3 (index number PB15:3), pigment blue 15:4 (index number PB15:4), pigment blue 15:5 (index number PB15:5), pigment blue 15:6 (index number PB15:6), etc.

[0045] The modified pigment includes a copper phthalocyanine pigment and a surface modifier attached to the surface of the copper phthalocyanine pigment. Specifically, the surface modifier includes at least one of polyethylene glycol, polyvinyl alcohol, sodium polyacrylate, polymethyl acrylate, carboxymethyl cellulose, methyl cellulose, dimethyl carbonate, diethyl carbonate, mercaptopropionic acid, mercaptoethanol, glutaraldehyde, 4-hydroxyvaleraldehyde, and ureapropyltriethoxysilane. In some embodiments, the surface modifier attached to the surface of the copper phthalocyanine pigment contains a polar group. A polar group refers to a group whose positive and negative charge centers do not overlap. The polarity of the group can be characterized by a dipole moment. In the embodiment of the present application, the dipole moment μ of the polar group is >0.5. In the embodiment of the present application, such a polar group in the surface modifier includes at least one of a hydroxyl group, a carboxyl group, a carbonyl group, a thiol group, a urea group, an aldehyde group, and an ester group.

[0046] Through surface modification, the polar groups in the above-mentioned surface modifiers can interact with the surface of copper phthalocyanine pigments through electrostatic adsorption, hydrogen bonds, chemical bonds and the like. For example, the polar groups contained in surface modifiers such as polyethylene glycol, polyvinyl alcohol, and methyl cellulose include hydroxyl groups, the polar groups contained in sodium polyacrylate and carboxymethyl cellulose include carboxyl groups, and the polar groups contained in polymethyl acrylate include ester groups. For example, through the surface modification of polyethylene glycol, alcoholic hydroxyl groups can be adsorbed on the pigment surface. Alcoholic hydroxyl groups have good hydrophilicity and solvent affinity. The presence of alcoholic hydroxyl groups can reduce interfacial tension, form hydrogen bonds or van der Waals forces, etc. during the dispersion process, and can also improve the dispersibility of the dispersant. For another example, through the surface modification of carboxymethyl cellulose, carboxyl groups can be firmly adsorbed on the surface of the pigment molecules, enhancing the interaction between the dispersant and the pigment particles, and the presence of carboxyl groups can prevent the agglomeration between the pigment particles and enhance the dispersibility. The molecular weight of the surface modifier is not specifically limited here, and surface modifiers of different molecular weights can perform different degrees of surface modification on the pigment molecules. For example, the molecular weight of polyethylene glycol can be 2000 g / mol, 4000 g / mol, 8000 g / mol, etc., which are typical but non-limiting values.

[0047] The weight percentage of the first dispersant in the present application in the dispersion is 3% to 30%. As an example, its weight percentage can be 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 20%, 25%, 30% and other typical but non-restrictive values. The content of the dispersant in the pigment dispersion directly affects the dispersion effect of the pigment, the stability of the dispersion, etc., and its addition amount is usually determined according to the type of pigment, the amount of pigment added, and the type of dispersant. If the addition amount is too small, the dispersion effect is not ideal, and if the addition amount is too large, the viscosity of the dispersion may increase and the fluidity may deteriorate. Since the pigment of the present application is a copper phthalocyanine pigment, polar groups are adsorbed on its surface, and the first dispersant selected contains an amine group, the above addition amount can better promote the dispersion uniformity and stability of the dispersion.

[0048] In some embodiments, the first dispersant can be a polymer dispersant containing an amine group. For example, BYK-Chemie products include: DISPERBYK-130, DISPERBYK-161, DISPERBYK-162, DISPERBYK-163, DISPERBYK-180, DISPERBYK-182, DISPERBYK-183, DISPERBYK-184, DISPERBYK-185, DISPERBYK-2000, DISPERBYK-2001, DISPERBYK-2020, DISPERBYK-2050, DISPERBYK-2070, DISPERBYK-2150; Ciba Specialty Chemicals Chemicals: EFKA-1503, EFKA-4010, EFKA-4020, EFKA-4300, EFKA-4330, EFKA-4340, EFKA-4520, EFKA-4530; Lubrizol: Solsperse18000, Solsperse20000, Solsperse21000, Solsperse24000, Solsperse26000, Sols perse27000, Solsperse28000, Solsperse32000, Solsperse36000, Solsperse37000, Solsperse38000, Solsperse41000, Solsperse42000, Solsperse43000, Solsperse46000, Solsperse54000, Solsperse71000; products of Ajinomoto Fine-Techno Co., Ltd.: AjisperPB-711, AjisperPB-821, AjisperPB-822, AjisperPB-814, AjisperPB-824. Among them, DISPERBYK-163, DISPERBYK-167, DISPERBYK-2000, DISPERBYK-2001, EFKA-4310, EFKA-4320, Solsperse28000, Solsperse24000, etc., these polymer dispersants contain tertiary amines in their structures. Tertiary amines refer to amine compounds with three organic groups attached to the nitrogen atom. This material has a high solubility in organic solvents and is easy to form hydrogen bonds with other molecules.

[0049] In some embodiments, the copper phthalocyanine pigment dispersion also includes a second dispersant, which contains a sulfonic acid group. The sulfonic acid group is a strongly acidic group. When it interacts with the pigment particles, the sulfonic acid group will dissociate into sulfonate ions, thereby generating electrostatic repulsion. The electrostatic repulsion provided by the sulfonic acid group can prevent the agglomeration of the pigment ions, and the amine group can fix the dispersant on the surface of the pigment particles through the anchoring effect. The combination of the two effects allows the dispersant to form a stable and uniform dispersion layer on the surface of the pigment particles. At the same time, the steric hindrance effect of the amine group and the electrostatic repulsion of the sulfonic acid group can cooperate with each other to prevent the agglomeration between the pigment particles and improve the dispersibility and stability of the pigment dispersion. As an example, the second dispersant can include sulfonate surfactants, such as sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, etc.; polymer sulfonate dispersants, such as acrylic acid-sulfonate copolymers, etc. can also be listed.

[0050] In some embodiments, the weight percentage of the second dispersant is 0.5% to 5% based on the total weight of the copper phthalocyanine pigment dispersion as 100%. As an example, the weight percentage can be 0.5%, 0.8%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, 2.0%, 3%, 5%, etc. Typical but non-limiting values. When the amount of the second dispersant is within the above range, it can produce better synergy with the first dispersant.

[0051] In some embodiments, the particle size of the modified pigment is 25nm to 50nm. As an example, the particle size of the modified pigment can be typical but non-limiting values ​​such as 25nm, 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, etc. The particle size range of the modified pigment can be obtained by transmission electron microscopy. In the color filter, the particle size of the pigment affects the tinting power of the pigment dispersion, the optical properties and color expression of the filter. The pigment particles with smaller particle size have a larger specific surface area and can absorb and reflect light more effectively, which means higher tinting power; and the smaller particle size can reduce the scattering and diffuse reflection of light and improve the transmittance of light. Controlling the particle size of the modified pigment within the above range can significantly improve the contrast and color expression of the color filter.

[0052] In some embodiments, the acid value of polyacrylate is 30 mgKOH / g to 150 mgKOH / g. The acid value of polyacrylate refers to the content of carboxyl groups in polyacrylate, which is usually obtained by neutralizing the carboxyl groups in the resin with potassium hydroxide and calculating the content of carboxyl groups. Specifically, it refers to the number of milligrams (mg) of potassium hydroxide required to neutralize the solid components of 1 g of polyacrylate. As an example, the acid value of polyacrylate can be typical but non-limiting values ​​such as 30 mgKOH / g, 50 mgKOH / g, 100 mgKOH / g, 110 mgKOH / g, 120 mgKOH / g, 130 mgKOH / g, 140 mgKOH / g, and 150 mgKOH / g. Since the acid value of polyacrylate indicates the content of carboxyl groups in acrylate, the presence of carboxyl groups helps the dispersibility of pigment particles in the medium, and also helps the dispersibility of polyacrylate in the medium. Controlling the acid value of polyacrylate within the above range helps to form a more stable dispersion system.

[0053] In some embodiments, the number average molecular weight of the polyacrylate is 3000 g / mol to 30000 g / mol. As an example, the number average molecular weight of the polyacrylate can be 3000 g / mol, 5000 g / mol, 10000 g / mol, 11000 g / mol, 12000 g / mol, 13000 g / mol, 14000 g / mol, 15000 g / mol, 16000 g / mol, 17000 g / mol, 18000 g / mol, 19000 g / mol, 20000 g / mol, 25000 g / mol, 30000 g / mol, etc., which are typical but non-limiting values. The molecular weight of the polyacrylate affects the dispersibility and stability of the pigment dispersion. By controlling the number average molecular weight of the polyacrylate within the above range, the resin can form a suitable protective layer on the pigment particles in the dispersion system, thereby providing a suitable spatial barrier for the pigment particles, which not only makes the pigment particles uniformly dispersed but also improves the stability of the dispersion system.

[0054] In some embodiments, the solvent includes propylene glycol methyl ether acetate and propylene glycol methyl ether, and the mass ratio of propylene glycol methyl ether acetate to propylene glycol methyl ether is 2:3 to 3:2. The solvent system of the copper phthalocyanine pigment dispersion of the present application selects a mixed solvent system of propylene glycol methyl ether acetate and propylene glycol methyl ether. Propylene glycol methyl ether acetate and propylene glycol methyl ether are both good solvents. Mixing them can further enhance the dispersion of pigment particles in the solvent system to form a uniform and stable pigment dispersion. In addition, the mixed solvent system can also improve the fluidity of the pigment dispersion, making the pigment dispersion easier to apply. At the same time, during the pigment dispersion process, the mixed solvent system can make the pigment dispersed more quickly and evenly, reducing the time required for the sanding process and improving production efficiency. As an example, the mass ratio of propylene glycol methyl ether acetate to propylene glycol methyl ether can be typical but non-limiting values ​​such as 2:3, 4:5, 1:1, 5:4, 3:2, etc. Controlling the mass ratio of propylene glycol methyl ether acetate to propylene glycol methyl ether within the above range is more suitable for the copper phthalocyanine pigment dispersion system of the present application.

[0055] In a second aspect, an embodiment of the present application provides a method for preparing a copper phthalocyanine pigment dispersion, comprising the following steps: performing surface modification treatment on the copper phthalocyanine pigment using a surface modifier to obtain an initial modified pigment; mixing the initial modified pigment with an inorganic salt and a salt grinding solvent and performing salt grinding treatment, and then washing and drying to obtain a modified pigment; mixing the modified pigment with a first dispersant, a polyacrylate and a solvent to obtain a copper phthalocyanine pigment dispersion.

[0056] After the polar groups are introduced into the surface of the copper phthalocyanine pigment, the preparation method of the present application performs salt milling and sand milling treatment. On the one hand, the surface modification improves the compatibility between the surface of the pigment particles and the dispersion medium, improves the stability of the dispersion system, and prevents the agglomeration of the pigment particles during the salt milling process, thereby shortening the salt milling time and improving production efficiency. On the other hand, the preparation method of the present application reduces the particle size and particle size distribution of the pigment particles through the salt milling treatment, and improves the tinting power of the copper phthalocyanine pigment. The copper phthalocyanine pigment dispersion obtained by the preparation method has excellent dispersibility, stability, and tinting power.

[0057] The steps for preparing the copper phthalocyanine pigment dispersion are described in detail below.

[0058] Step S1: Use a surface modifier to perform surface modification treatment on the copper phthalocyanine pigment to obtain an initial modified pigment. In the present application, a surfactant is attached to the surface of the copper phthalocyanine pigment through surface modification treatment, thereby introducing polar groups on the surface of the copper phthalocyanine pigment.

[0059] In some embodiments, step S1 is specifically as follows: filtering the copper phthalocyanine pigment water solution to obtain a water-containing filter cake, adding it to water and stirring it for pre-dispersion, then adding a surface modifier for heating reaction, and after the reaction is completed, washing, filtering, and drying the product to obtain an initial modified pigment.

[0060] In some embodiments, the mass ratio of copper phthalocyanine pigment to surface modifier is 1:1 to 10:1. As an example, the mass ratio of copper phthalocyanine pigment to surface modifier can be typical but non-limiting values ​​such as 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, etc. The surface modifier is adsorbed on the surface of the pigment particles through physical and / or chemical effects to improve its dispersion properties. If the amount of surface modifier is too small, the dispersion effect of the surface-modified pigment particles may be poor. If the amount is too large, it will increase the cost and may also cause other adverse reactions. Controlling the mass ratio of copper phthalocyanine pigment to surface modifier within the above range can better balance the relationship between dispersion effect and cost.

[0061] In some embodiments, the temperature of the surface modification treatment is 40°C to 100°C, and the time is 2h to 12h. Increasing the surface treatment temperature can improve the efficiency of the surface modification. As an example, the temperature of the surface modification treatment is 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, etc., which are typical but non-limiting values. The treatment time varies depending on the treatment temperature and the type of surface modifier, and is not specifically limited here.

[0062] Step S2: salt-milling the initial modified pigment, inorganic salt and salt-milling solvent, and then washing and drying to obtain the modified pigment. The preparation method of the present application adjusts the size of the pigment particles through salt-milling treatment to improve the tinting power and dispersibility of the pigment. The method adopts a processing sequence of first improving the surface polarity of the pigment particles through surface modification and then salt-milling. The surface modification enhances the dispersibility of the pigment particles in the salt-milling solvent, which is conducive to the salt-milling. At the same time, the surface roughness of the pigment particles is improved through surface modification, so that the surface roughness is moderate, which also helps to enhance the salt-milling effect. Using this processing sequence, a better overall effect can be obtained.

[0063] In some embodiments, step S2 specifically comprises: mixing the initial modified pigment with an organic solvent and an inorganic salt, placing the mixture in a kneader for salt grinding, and then washing, filtering and drying the product to obtain the modified pigment.

[0064] In some embodiments, the inorganic salt includes at least one of sodium chloride, calcium chloride, sodium sulfate, potassium chloride, and barium chloride.

[0065] In some embodiments, inorganic salts with a particle size range of micrometers are selected. The micrometer-sized inorganic salts have a larger contact area with the material being salt-milled, which helps to enhance the salt-milling effect and improve the efficiency of salt-milling. At the same time, the micrometer-sized inorganic salts are easier to disperse during the salt-milling process and reduce agglomeration.

[0066] In some embodiments, the salt grinding solvent can be selected from aromatic solvents, alcohol solvents, ester solvents, etc. Specifically, the salt grinding solvent can include alkoxy alcohol solvents such as 2-methoxyethanol, 2-butoxyethanol, 2-(isopentyloxy)ethanol, 2-(hexyloxy)ethanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, etc.; diol solvents such as diethylene glycol, triethylene glycol, liquid polyethylene glycol, dipropylene glycol, low molecular weight polypropylene glycol, etc. can also be listed; ether solvents such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, etc. can also be listed.

[0067] In some embodiments, the mass ratio of the initial modified pigment, the inorganic salt and the salt milling solvent is 1:(1-5):(5-10). The addition amount of the above inorganic salt can promote the salt milling process. The addition amount of the above salt milling solvent can dissolve or disperse the inorganic salt and the salt milling object, and make the salt milling process have a higher efficiency.

[0068] In some embodiments, after the salt milling treatment, the salt milling product needs to be washed and filtered multiple times to remove the inorganic salt and salt milling solvent in the product until the conductivity of the filtrate is less than 3 μs / cm, which is considered to be clean, and then dried to obtain the modified pigment. The conductivity detection method can be detected by a conductivity meter measurement method, a direct measurement method, and the like.

[0069] Step S3: mixing the modified pigment with the first dispersant, polyacrylate and solvent to obtain a copper phthalocyanine pigment dispersion.

[0070] In some embodiments, the mixing process includes mixing the modified pigment, the first dispersant, the polyacrylate and the solvent and then grinding the mixture at a rotation speed of 500 rpm to 3000 rpm.

[0071] In some embodiments, step S3 specifically comprises: mixing the modified pigment, the first dispersant, the polyacrylate, and the solvent, placing the mixture in a sand mill for sand grinding, and filtering to obtain a pigment dispersion. The preparation method of the present application can further refine the pigment particles and improve the dispersion stability through sand grinding.

[0072] In some other embodiments, step S3 specifically comprises: mixing the modified pigment, the first dispersant, the second dispersant, the polyacrylate and the solvent, placing the mixture in a sand mill for sand grinding, and filtering to obtain a pigment dispersion.

[0073] In some embodiments, the sanding temperature is 10°C to 100°C, preferably 10°C to 60°C, more preferably 10°C to 40°C. The sanding speed is 500rpm to 3000rpm, preferably 1000rpm to 2000rpm, more preferably 1000rpm to 1500rpm. The sanding time is 8h to 72h.

[0074] In a third aspect, an embodiment of the present application provides an application of a copper phthalocyanine pigment dispersion in a color filter.

[0075] The application of copper phthalocyanine pigment dispersion in color filter mainly includes the following steps: the copper phthalocyanine pigment dispersion is evenly coated on the substrate of the color filter through a coating device (such as a spin coater, a spray coater, etc.). After coating, the coating is cured. The curing treatment can be thermal curing, light curing or ultraviolet curing. After curing, a specific pattern is formed on the cured coating by processes such as photolithography and etching to realize the function of the color filter. The color filter prepared using the copper phthalocyanine pigment dispersion of the present application has high contrast, high tinting strength and excellent stability.

[0076] The following describes the invention in conjunction with specific embodiments.

[0077] Example 1

[0078] The embodiment of the present application provides a copper phthalocyanine pigment dispersion, which includes the following components in weight percentage based on the total weight of the copper phthalocyanine pigment dispersion as 100%: 15% of modified pigment; 5% of first dispersant; 79% of solvent; and 1% of polyacrylate. The modified pigment includes copper phthalocyanine pigment PB15:6 and polyethylene glycol attached to its surface. The first dispersant is DISPERBYK-163 produced by BYK Chemical Company. The solvent is propylene glycol methyl ether acetate. The acid value of the selected polyacrylate is 120 mgKOH / g and the number average molecular weight is 15000 g / mol.

[0079] The preparation method of the copper phthalocyanine pigment dispersion provided in the embodiment of the present application comprises the following steps:

[0080] (1) Filter the copper phthalocyanine pigment PB15:6 aqueous solution to obtain a water-containing filter cake, weigh 100 g, add it into water, stir and pre-disperse it, then add 10 g of surface modifier polyethylene glycol, heat and react at 70° C. for 5 hours. After the reaction is completed, wash, filter and dry the product to obtain the initial modified pigment.

[0081] (2) The initial modified pigment is mixed with diethylene glycol and micron-grade sodium chloride, and ground in a kneader. The salt grinding temperature is 60° C., the salt grinding speed is 1000 rpm, and the salt grinding time is 12 hours. The initial modified pigment is 100 g, the micron-grade sodium chloride is 500 g, and the diethylene glycol is 800 g. The ground product is washed and filtered until the filtrate conductivity is less than 3 μs / cm, and then dried to obtain the modified pigment.

[0082] (3) 150 g of the modified pigment was mixed with 50 g of the first dispersant, 10 g of polyacrylate, and 790 g of propylene glycol methyl ether acetate solvent, and the mixture was placed in a sand mill for sand grinding at a temperature of 20° C., a sand grinding speed of 1500 rpm, and a sand grinding time of 12 hours to obtain a copper phthalocyanine pigment dispersion.

[0083] Example 2

[0084] The embodiment of the present application provides a copper phthalocyanine pigment dispersion, which is different from Example 1 in that the content of each component is different. Specifically, the embodiment of the present application, based on the total weight of the copper phthalocyanine pigment dispersion as 100%, includes the following components in weight percentage: 23% modified pigment; 10% first dispersant; 75% solvent; 2% polyacrylate.

[0085] Example 3

[0086] The embodiment of the present application provides a copper phthalocyanine pigment dispersion, which is different from Example 1 in that its modified pigment includes copper phthalocyanine pigment PB15:6 and polymethyl acrylate attached to its surface.

[0087] The main difference between the preparation method of the copper phthalocyanine pigment dispersion and the preparation method of Example 1 is that step (1) is different, specifically: the copper phthalocyanine pigment PB15:6 is aqueous-soluble and filtered, and 120 g of the obtained aqueous filter cake is weighed and added into water for pre-dispersion by stirring, and then 20 g of surface modifier polymethyl acrylate is added, and the mixture is heated at 40° C. for reaction for 8 hours. After the reaction is completed, the product is washed, filtered, and dried to obtain the initial modified pigment.

[0088] Example 4

[0089] The embodiment of the present application provides a copper phthalocyanine pigment dispersion, which is different from Example 1 in that its modified pigment includes copper phthalocyanine pigment PB15:1 and methyl cellulose attached to its surface.

[0090] The main difference between the preparation method of the copper phthalocyanine pigment dispersion and the preparation method of Example 1 is that step (1) is different, specifically: the copper phthalocyanine pigment PB15:1 is aqueous-soluble and filtered, 80 g of the obtained aqueous filter cake is weighed and added into water and stirred for pre-dispersion, then 10 g of surface modifier methyl cellulose is added, and the mixture is heated at 90° C. for reaction for 3 hours. After the reaction is completed, the product is washed, filtered, and dried to obtain the initial modified pigment.

[0091] Example 5

[0092] The present embodiment provides a copper phthalocyanine pigment dispersion, which is different from the embodiment 1 in that the copper phthalocyanine pigment dispersion contains a second dispersant, sodium dodecyl sulfonate. Specifically, based on the total weight of the copper phthalocyanine pigment dispersion being 100%, the dispersion includes the following components in weight percentage: 15% of modified pigment; 5% of first dispersant; 1% of sodium dodecyl sulfonate; 78% of solvent; and 1% of polyacrylate. The types of the modified pigment, the first dispersant, the polyacrylate and the solvent are the same as those in the embodiment 1.

[0093] The preparation method of the copper phthalocyanine pigment dispersion is different from the preparation method of Example 1 in that step (3) is different, specifically: 150g of the modified pigment is mixed with 50g of the first dispersant, 10g of sodium dodecyl sulfate, 10g of polyacrylate, and 780g of solvent propylene glycol methyl ether acetate, and placed in a sand mill for sand grinding. The sand grinding temperature is 20°C, the sand grinding speed is 1500rpm, and the sand grinding time is 12 hours to obtain a copper phthalocyanine pigment dispersion.

[0094] Example 6

[0095] The embodiment of the present application provides a copper phthalocyanine pigment dispersion, which is different from Example 1 in the type of solvent in the copper phthalocyanine pigment dispersion. The solvent of this embodiment includes two components: propylene glycol methyl ether acetate and propylene glycol methyl ether, wherein the mass ratio of propylene glycol methyl ether acetate and propylene glycol methyl ether is 1:1.

[0096] The preparation method of the copper phthalocyanine pigment dispersion is the same as that of Example 1.

[0097] Example 7

[0098] This embodiment provides a copper phthalocyanine pigment dispersion, which is different from the embodiment 1 in that the preparation method of the copper phthalocyanine pigment dispersion does not include a salt milling step, specifically:

[0099] (1) Filter the aqueous solution of copper phthalocyanine pigment PB15:6, weigh 100 g of the obtained aqueous filter cake, add it into water, stir and pre-disperse it, then add 10 g of surface modifier polyethylene glycol, heat and react at 70° C. for 5 hours. After the reaction is completed, wash, filter and dry the product to obtain the initial modified pigment.

[0100] (2) 150 g of the surface modified pigment was mixed with 50 g of the first dispersant, 10 g of polyacrylate, and 790 g of propylene glycol methyl ether acetate solvent, and the mixture was ground in a sand mill. After filtering, a nano-dispersion liquid was obtained. The sand milling temperature was 20° C., the sand milling speed was 1500 rpm, and the sand milling time was 12 hours to obtain a copper phthalocyanine pigment dispersion liquid.

[0101] Comparative Example 1

[0102] This comparative example provides a copper phthalocyanine pigment dispersion, which is different from Example 1 in that the pigment is copper phthalocyanine pigment PB15:6 and has not been surface modified. The preparation method of the copper phthalocyanine pigment dispersion does not include the surface modification step of the copper phthalocyanine pigment, specifically:

[0103] (1) Copper phthalocyanine pigment PB15:6 is mixed with diethylene glycol and micron-grade sodium chloride, and ground in a kneader. The salt grinding temperature is 60°C, the salt grinding speed is 1000 rpm, and the salt grinding time is 12 hours. The initial modified pigment is 100 g, the micron-grade sodium chloride is 500 g, and the diethylene glycol is 800 g. The product is washed and filtered several times until the conductivity of the filtrate is less than 3 μs / cm, and then dried to obtain the modified pigment.

[0104] (2) 150 g of the modified pigment was mixed with 50 g of the first dispersant, 10 g of polyacrylate, and 790 g of propylene glycol methyl ether acetate solvent, and the mixture was ground in a sand mill. After filtering, a nano-dispersion liquid was obtained. The sand milling temperature was 20° C., the sand milling speed was 1500 rpm, and the sand milling time was 12 hours to obtain a copper phthalocyanine pigment dispersion liquid.

[0105] Comparative Example 2

[0106] This comparative example provides a copper phthalocyanine pigment dispersion, which is different from Example 1 in that the copper phthalocyanine pigment dispersion contains a second dispersant, sodium dodecyl sulfonate, but does not contain a first dispersant. Specifically, based on the total weight of the copper phthalocyanine pigment dispersion being 100%, the dispersion includes the following components in weight percentage: 15% of modified pigment; 5% of sodium dodecyl sulfonate; 79% of solvent; and 1% of polyacrylate. The types of the modified pigment, polyacrylate and solvent are the same as those in Example 1.

[0107] The preparation method of the copper phthalocyanine pigment dispersion is different from the preparation method of Example 1 in that step (3) is different, specifically: 150g of the modified pigment is mixed with 50g of sodium dodecyl sulfate, 10g of polyacrylate, and 790g of solvent propylene glycol methyl ether acetate, and placed in a sand mill for sand grinding. The sand grinding temperature is 20°C, the sand grinding speed is 1500rpm, and the sand grinding time is 12 hours to obtain a copper phthalocyanine pigment dispersion.

[0108] Performance Testing

[0109] (1) The particle size of the modified pigment in the copper phthalocyanine pigment dispersion was measured by a nanoparticle size analyzer.

[0110] a) Dilute the sample at a ratio of 1:1000.

[0111] b) Place the cuvette filled with 1 ml of sample in the test chamber.

[0112] c) Select the corresponding parameters and start the test.

[0113] d) Perform three parallel tests and take the average value.

[0114] (2) Contrast detection method

[0115] Follow the steps below to perform the test in order.

[0116] a) Apply color photoresist on a clean glass substrate, and make a color filter that meets the test conditions according to the procedures of pre-coating, exposure, development, and post-baking, and cut it into the size specified in the instrument operating instructions.

[0117] b) Confirm that the power and data lines of the equipment are connected properly and not loose, ensure that the power supply is in a stable state, and ensure that the computer system is working properly.

[0118] c) According to the instrument manual, the contrast meter should be turned on and preheated to a stable state before starting measurement.

[0119] d) Test equipment initial position, light source and internal calibration.

[0120] e) Test with air as the base (without placing any sample) and wait for the instrument test to end. If the air base contrast result is within the range of C ± 1%, the subsequent test data is reliable.

[0121] f) Place the sample on the sample stage of the test equipment so that the light source enters from the glass surface of the sample.

[0122] g) Test the bright state luminance and dark state luminance of the sample.

[0123] h) Data processing

[0124] The contrast ratio is expressed as CR and is expressed as follows:

[0125] CR=L max / L min

[0126] Where:

[0127] CR-contrast ratio;

[0128] L max - Brightness (or brightness when the polarizer is parallel), in candela per square meter (cd / m 2 );

[0129] L min - Dark state brightness (or brightness when the polarizer is vertical), the unit is candela per square meter (cd / m 2 ).

[0130] The performance results are shown in Table 1.

[0131] Table 1

[0132]

[0133] As can be seen from the data in Table 1, the contrast ratios of Examples 1 to 6 are all higher than those of Comparative Examples 1 and 2, indicating that the use of the pigment dispersions of the embodiments of the present application can significantly improve the problem of poor dispersibility, thereby optimizing the contrast performance. Since Comparative Example 1 has no surface modification, the contrast ratio of the pigment dispersion is low, and since Comparative Example 2 has only the second dispersant and no first dispersant, the contrast ratio is also poor, indicating that after surface modification, the combination of the polar group and the first dispersant can effectively improve the dispersion uniformity of the pigment dispersion.

[0134] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A copper phthalocyanine pigment dispersion, characterized in that: Taking the total weight of the copper phthalocyanine pigment dispersion as 100%, the dispersion includes the following components in weight percentage: The modified pigment comprises a copper phthalocyanine pigment and a surface modifier attached to the surface of the copper phthalocyanine pigment, wherein the surface modifier contains a polar group; and the first dispersant contains an amine group.

2. The copper phthalocyanine pigment dispersion according to claim 1, characterized in that The polar group includes at least one of a hydroxyl group, a carboxyl group, a carbonyl group, a thiol group, a urea group, an aldehyde group, and an ester group; Alternatively, the surface modifier includes at least one of polyethylene glycol, polyvinyl alcohol, sodium polyacrylate, polymethyl acrylate, carboxymethyl cellulose, methyl cellulose, dimethyl carbonate, diethyl carbonate, mercaptopropionic acid, mercaptoethanol, glutaraldehyde, 4-hydroxyvaleraldehyde, and ureapropyltriethoxysilane.

3. The copper phthalocyanine pigment dispersion according to claim 1, characterized in that The first dispersants include DISPERBYK-130, DISPERBYK-161, DISPERBYK-162, DISPERBYK-163, DISPERBYK-180, DISPERBYK-182, DISPERBYK-183, DISPERBYK-184, DISPERBYK-185, DISPERBYK-2000, DISPERBYK -2001, DISPERBYK-2020, DISPERBYK-2050, DISPERBYK-2070, DISPERBYK-2150, EFKA-1503, EFK A-4010, EFKA-4020, EFKA-4300, EFKA-4330, EFKA-4340, EFKA-4520, EFKA-4530, Solsperse1800 0, at least one of Solsperse20000, Solsperse21000, Solsperse24000, Solsperse26000, Solsperse27000, Solsperse28000, Solsperse32000, Solsperse36000, Solsperse37000, Solsperse38000, Solsperse41000, Solsperse42000, Solsperse43000, Solsperse46000, Solsperse54000, Solsperse71000, AjisperPB-711, AjisperPB-821, AjisperPB-822, AjisperPB-814, AjisperPB-824; The copper phthalocyanine pigment dispersion further includes a second dispersant containing a sulfonic acid group.

4. The copper phthalocyanine pigment dispersion according to claim 3, characterized in that Based on the total weight of the copper phthalocyanine pigment dispersion as 100%, the weight percentage of the second dispersant is 0.5% to 5% and / or, The second dispersant includes at least one of sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, and acrylic acid-sulfonate copolymer.

5. The copper phthalocyanine pigment dispersion according to any one of claims 1 to 4, characterized in that The particle size of the modified pigment is 25nm to 60nm; and / or, The acid value of the polyacrylate is 30 mgKOH / g to 150 mgKOH / g; and / or, The number average molecular weight of the polyacrylate is 3000 g / mol to 30000 g / mol.

6. The copper phthalocyanine pigment dispersion according to any one of claims 1 to 4, characterized in that The solvent comprises propylene glycol methyl ether acetate and propylene glycol methyl ether, and the mass ratio of the propylene glycol methyl ether acetate to the propylene glycol methyl ether is 2:3 to 3:

2.

7. A method for preparing a copper phthalocyanine pigment dispersion according to any one of claims 1 to 6, characterized in that: The following steps are involved: The copper phthalocyanine pigment is subjected to surface modification treatment by using a surface modifier to obtain an initial modified pigment; The initial modified pigment is mixed with an inorganic salt and a salt-milling solvent, and then subjected to salt-milling treatment, and then washed and dried to obtain a modified pigment; The modified pigment is mixed with a first dispersant, polyacrylate and a solvent to obtain the copper phthalocyanine pigment dispersion.

8. The method for preparing the copper phthalocyanine pigment dispersion according to claim 7, characterized in that: The inorganic salt includes at least one of sodium chloride, calcium chloride, sodium sulfate, potassium chloride and barium chloride; and / or, The salt grinding solvent includes at least one of 2-methoxyethanol, 2-butoxyethanol, 2-(isopentyloxy)ethanol, 2-(hexyloxy)ethanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, and dipropylene glycol monoethyl ether.

9. The method for preparing a copper phthalocyanine pigment dispersion according to claim 7 or 8, characterized in that: The mass ratio of the copper phthalocyanine pigment to the surface modifier is 1:1 to 10:1; and / or, The surface modification treatment is performed at a temperature of 40°C to 100°C and for a time of 2h to 12h; and / or, The mass ratio of the initial modified pigment, the inorganic salt and the salt grinding solvent is 1:(1-5):(5-10); and / or, The mixing process includes mixing the modified pigment, the first dispersant, the polyacrylate and the solvent and then grinding them at a rotation speed of 500 rpm to 3000 rpm.

10. Use of the copper phthalocyanine pigment dispersion according to any one of claims 1 to 6 in a color filter.

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