Differentiated response color electronic ink and preparation method and electrophoretic display device

Abstract

The present application belongs to the technical field of electronic display devices, and particularly relates to color electronic ink with differentiated response, a preparation method and an electrophoretic display device. The present application provides a color electronic ink in which the surface of modified color electrophoretic particles is connected with acidic groups and basic groups, thereby increasing the charge difference between color electrophoretic particles of different colors. When driving the color electronic ink, the response speed between color electrophoretic particles of different colors can be increased, and the mixing of different color electrophoretic particles in the color electronic ink due to similar charge amounts under voltage driving can be reduced, thereby improving the display effect of the color electronic ink, thereby solving the technical problem that the display effect of color electronic ink driven by the electrophoretic particle speed control method needs to be improved.

Description

Technical Field

[0001] The present application belongs to the technical field of electronic display devices, and in particular, relates to color electronic ink with differentiated response, a preparation method, and an electrophoretic display device. Background Art

[0002] Color electrophoretic display is mainly achieved through the color electrophoretic particle speed control method. The electrophoretic particle speed control method accurately regulates the surface charge of the color electrophoretic particles, so that the surface charges of particles of different colors are as differentiated as possible, reducing the large deviation between the display color and the expected color caused by the mixing of different color particles in the color electronic ink due to similar charges under voltage drive.

[0003] However, currently, the color electrophoretic particles are modified by introducing functional groups such as amino groups, carboxyl groups, and ester groups to make the color electrophoretic particles positively or negatively charged. The surface charge of the modified particles obtained by this method is related to the number of functional groups added and the inherent acid-base properties of the functional groups. It is difficult to further increase the surface charge of the color electrophoretic particles. This makes the charge range of the color electrophoretic particles in the current color electronic ink narrow, and the charge difference between different color electrophoretic particles is small, resulting in less than ideal color electrophoretic display effects. Summary of the invention

[0004] In view of this, the present application provides a color electronic ink and a preparation method and a color electrophoretic display device, which are used to solve the technical problem in the prior art that the display effect of color electronic ink driven by the electrophoretic particle velocity control method needs to be improved.

[0005] In a first aspect, the present application provides a color electronic ink, comprising color electrophoretic particles, a charge control agent, an electrophoretic medium, and modified color electrophoretic particles;

[0006] The color electrophoretic particles and the modified color electrophoretic particles are different in color;

[0007] The surface of the colored electrophoretic particles is connected with acidic groups or basic groups;

[0008] The surface of the modified color electrophoretic particle is connected with an acidic group and a basic group;

[0009] The surface of the modified color electrophoretic particle is connected with an acidic group and a basic group;

[0010] The introduction density of the acidic groups is 1 to 300 mmol / cm 3 The introduction density of basic groups is 1 to 250 mmol / cm 3 .

[0011] It should be noted that compared with the colored electrophoretic particles, the modified colored electrophoretic particles are another color.

[0012] Preferably, the acidic groups include acidic groups containing ester groups and / or carboxyl groups, and the acidic groups are introduced at a density of 5.96 to 39.19 mmol / cm 3 ;

[0013] The basic group includes an amino-containing basic group, and the basic group introduction density is 3.41 to 37.49 mmol / cm 3 .

[0014] Preferably, the introduction density of the colored electrophoretic particles is 31.95 to 65.18 mmol / cm 3 -NH2; the modified color electrophoretic particle surface is connected to 33.23mmol / cm 3 -NH2, 15.98~31.95mmol / cm 3 -COOH.

[0015] Preferably, the surface of the colored electrophoretic particles is connected to 31.95mmol / cm 3 -NH2; the modified color electrophoretic particle surface is connected to 33.23mmol / cm 3 -NH2, 31.95mmol / cm 3 -COOH.

[0016] It should be noted that the introduction density is the number of moles of basic or acidic groups introduced per unit volume on the particle surface.

[0017] Preferably, the connection of the acidic group and the basic group is to connect the acidic group by chemical bonding and to connect the basic group by physical adsorption;

[0018] The chemical bonding method for connecting the acidic groups includes connecting the acidic groups through a silane coupling agent.

[0019] Preferably, the connecting of the acidic group and the basic group is connecting the basic group by chemical bonding and connecting the acidic group by physical adsorption;

[0020] The chemical bonding method for connecting the basic groups includes connecting the basic groups through a silane coupling agent.

[0021] Preferably, the acidic group includes γ-methacryloxypropyltrimethoxysilane and methacrylate;

[0022] The basic group includes monoalkenyl succinimide.

[0023] Preferably, the basic group includes γ-aminopropyltriethoxysilane and aminostyrene;

[0024] The acidic group includes polyoxyethylene sorbitan monooleate.

[0025] Preferably, the modified color electrophoretic particles are selected from color pigment particles having acidic groups and basic groups connected to the surface.

[0026] Preferably, the color electrophoretic particles are selected from color pigment particles having acidic groups or basic groups connected to the surface.

[0027] The color pigment particles are selected from any one of iron black, iron brown, chromite, chromate, silicate, chromium oxide green, lead chrome green, copper oxide, titanium yellow, chrome yellow, iron yellow, lead chrome green, manganese violet, iron blue, cobalt blue, zinc white, cadmium yellow, cadmium red, barium sulfate, molybdenum orange, ultramarine, azure blue, emerald green, and emerald green pigment particles;

[0028] The particle size of the color pigment particles is 200-1000nm.

[0029] Preferably, the electrophoretic medium is a non-polar solvent;

[0030] The non-polar solvent is selected from one or more of halogenated hydrocarbons, paraffin, silicone oil, alkane compounds, epoxy compounds, aromatic hydrocarbons, and vinyl ether.

[0031] Preferably, the charge control agent is selected from one or more of organic sulfonate, organic sulfate, organic phosphate, organic phosphate ester, polyester, polyolefin, and polyacrylate charge control agents.

[0032] The second aspect of the present application provides a method for preparing color electronic ink, the preparation method comprising the steps of:

[0033] Step S1-1, dispersing pigment particles, tetraethyl orthosilicate, and ammonia water in a first solvent, and performing a silicon layer treatment to obtain color pigment initial particles having hydroxyl groups on the surface;

[0034] Step S2-1, dispersing color pigment particles containing hydroxyl groups on the surface, a silane coupling agent containing an acidic functional group, and a silane coupling agent containing an unsaturated bond in a first solvent, and performing a coupling reaction to obtain modified color pigment particles;

[0035] Step S3-1, dispersing the modified color pigment particles, the polymer monomer containing the acidic functional group and the initiator in the second solvent, and performing a grafting reaction to obtain the acidic modified color pigment particles;

[0036] Step S4-1, ball-milling the acidic modified color pigment particles and the synergist containing the basic group to obtain modified color electrophoretic particles with acidic groups and basic groups connected on the surface;

[0037] Step S5-1, preparing color electronic ink from modified color electrophoretic particles with acidic groups and basic groups connected to the surface, color electrophoretic particles with acidic groups or basic groups connected to the surface, a charge control agent and an electrophoretic medium.

[0038] The third aspect of the present application provides a method for preparing color electronic ink, the preparation method comprising the steps of:

[0039] Step S1-2, dispersing pigment particles, tetraethyl orthosilicate, and ammonia water in a first solvent, and performing silicon layer treatment to obtain color pigment initial particles having hydroxyl groups on the surface;

[0040] Step S2-2, dispersing the color pigment particles containing hydroxyl groups on the surface, the silane coupling agent containing a basic functional group, and the silane coupling agent containing an unsaturated bond in a first solvent, and performing a coupling reaction to obtain modified color pigment particles;

[0041] Step S3-2, dispersing the modified color pigment particles, the polymer monomer containing the basic functional group and the initiator in the second solvent, and performing a grafting reaction to obtain the basic modified color pigment particles;

[0042] Step S4-2, ball-milling the alkaline modified color pigment particles and the synergist containing an acidic group to obtain modified color electrophoretic particles with acidic groups and alkaline groups connected on the surface;

[0043] Step S5-2: preparing color electronic ink from the modified color electrophoretic particles with acidic groups and basic groups connected to the surface, the color electrophoretic particles with acidic groups or basic groups connected to the surface, the charge control agent and the electrophoretic medium.

[0044] Preferably, in steps S1-1 and 2-1, the first solvent is selected from anhydrous ethanol;

[0045] The unsaturated bond-containing silane coupling agent is selected from vinyl trimethoxy silane and vinyl triethoxy silane;

[0046] Preferably, in steps S1-1 and 2-1, in the coupling reaction, the mass ratio of the pigment particles containing hydroxyl groups on the surface, the first solvent, the silane coupling agent containing acidic functional groups, and the silane coupling agent containing unsaturated bonds is 1:20-30:0.5-2:0.5-2, and the time is 12-36 hours.

[0047] Preferably, the coupling reaction further comprises adding a surfactant;

[0048] The surfactant is selected from sodium dodecylbenzene sulfonate;

[0049] The mass ratio of the pigment particles containing hydroxyl groups on the surface to the surfactant is 1:0.015-0.025.

[0050] Preferably, in steps S2-1 and 2-2, the initiator is selected from azobisisocyanonitrile, azobisisoheptanenitrile, dibenzoyl peroxide or dicumyl peroxide.

[0051] The second solvent is selected from toluene, benzene, xylene, chloroform or tetrachloroethylene.

[0052] Preferably, in steps S3-1 and 3-2, the ball milling container is a ball milling jar, and the ball milling time is 1 to 8 hours; the ball milling solvent is carbon tetrachloride, n-hexane, nonane, decanane, synthetic isomerized paraffin, synthetic paraffin, synthetic cycloalkanes, synthetic alkanes or cyclohexane, straight-chain, branched and cyclic aliphatic hydrocarbons.

[0053] Preferably, in step 4, the electrophoretic medium includes a non-polar solvent.

[0054] It should be noted that, in addition to the non-polar solvent as a dispersion medium, other conventional additives may be added to the electrophoretic medium in the electronic ink as required.

[0055] A fourth aspect of the present application provides an electrophoretic display device, which includes a microcavity encapsulating the above-mentioned color electronic ink.

[0056] It should be noted that since the color electronic ink encapsulated in the electrophoretic display device provided by the present application contains a large amount of charge between the color electrophoretic particles of different colors, when driven, it is beneficial to achieve the differentiation of the response speed of the different color electrophoretic particles, thereby better realizing the color display state of the electronic paper.

[0057] Preferably, the electrophoretic display device can be used as an e-book, bus stop sign, shelf label or smart wearable application.

[0058] In summary, the present application provides a color electronic ink, a preparation method and a color electrophoretic display device, wherein the color electronic ink includes color electrophoretic particles, an electrophoretic medium and modified color electrophoretic particles of a different color from the color electrophoretic particles; wherein the surface of the color electrophoretic particles is connected to an acidic group or a basic group. Compared with the color electrophoretic particles, the surface of the modified color electrophoretic particles is connected to acidic groups and basic groups to increase the effective pH value of the particle surface, so that the particles carry more charge, which is beneficial to increase the difference in the surface charge of particles of different colors in the color electrophoretic display device, reduce the mixing of particles of different colors in the color electronic ink due to similar charge under voltage drive, and improve the display effect of the color electronic ink, thereby solving the technical problem that the display effect of the color electronic ink driven by the electrophoretic particle speed control method needs to be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0060] Figure 1 A schematic diagram of the preparation process of modified color electrophoretic particles in color electronic ink provided in Example 2 of the present application;

[0061] Figure 2 A diagram showing the color electronic ink driving display effect provided in Example 2 of the present application;

[0062] In the figure, 11 is a pigment particle, 12 is a pigment particle containing a silicon layer, 13 is a silane-coupled particle containing an acidic group, 14 is a particle coated with a polymer containing an acidic functional group, and 15 is a particle coated with a synergist containing a basic group. DETAILED DESCRIPTION

[0063] The present application provides a color electronic ink and a preparation method thereof and a color electrophoretic display device, which are used to solve the technical problem in the prior art that the display effect of color electronic ink driven by the electrophoretic particle velocity control method needs to be improved.

[0064] The technical solution of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0065] Example 1

[0066] In view of the fact that the surface charge difference between the color electrophoretic particles of different colors in the existing color electronic ink is not large enough, when the color electrophoretic particles of different colors are driven, the color electrophoretic particles of different colors are mixed with each other due to the similar charge amount, resulting in a poor display effect. Embodiment 1 of the present application provides a color electronic ink; the color electronic ink includes an electrophoretic medium, a charge control agent and color electrophoretic particles, and modified electrophoretic particles. The electrophoretic medium is the electrophoretic medium of the existing electronic ink. The electrophoretic medium includes a non-polar solvent. The non-polar solvent is selected from commonly used halogenated hydrocarbons, paraffin, silicone oil, alkane compounds, epoxy compounds, aromatic hydrocarbons, vinyl ether and other solvents. The charge control agent is a commonly used charge control agent selected from one or more of organic sulfonates, organic sulfates, organic phosphates, organic phosphate esters, polyesters, polyolefins, and polyacrylate charge control agents. The color electrophoretic particles are color particles with acidic groups or basic groups connected to the surface. Color electrophoretic particles, modified color electrophoretic particles are electrophoretic particles with acidic groups and alkaline groups connected to the surface; wherein, compared with color electrophoretic particles with acidic groups or alkaline groups connected to the surface, in the electrophoretic liquid, one functional group (acidic) of the modified color electrophoretic particles connected with acid-base mixed groups can promote the proton transfer process between another functional group (alkaline) and the charge control agent in the electrophoretic liquid, so that the modified color electrophoretic particles further carry more charge, thereby increasing the difference in charge between color electrophoretic particles of different colors in color electronic ink and the modified color electrophoretic particles, and the modified color electrophoretic particles have a higher response speed in the color electronic ink, reducing the mixing of different color particles in the color electronic ink due to similar charge under voltage driving, and improving the display effect of the color electronic ink, thereby solving the technical problem that the display effect of the color electronic ink driven by the electrophoretic particle speed control method needs to be improved.

[0067] Preferably, the acidic groups connected to the surface of the color electrophoretic particles or the surface of the modified color electrophoretic particles are acidic groups containing carboxyl groups, and the basic groups connected are basic groups containing amino groups. The surface of the color electrophoretic particles is connected with 31.95 to 65.18 mmol / cm 3 -NH2; the modified color electrophoretic particle surface is connected to 33.23mmol / cm 3 -NH2, 15.98~31.95mmol / cm 3 -COOH, further preferably the surface of the colored electrophoretic particles is connected to 31.95mmol / cm 3 -NH2; The surface of the modified color electrophoretic particles is connected to 33.23mmol / cm 3 -NH2, 31.95mmol / cm 3The -COOH of the present technical solution can further adjust the ratio of the basic groups and the acidic groups connected to the surface of the modified color electrophoretic particles, thereby further increasing the surface charge of the color electrophoretic particles and improving the display effect of the color ink.

[0068] Preferably, the acidic groups include acidic groups containing ester groups and / or carboxyl groups, and the basic groups include basic groups containing amino groups; the acidic groups containing ester groups and / or carboxyl groups include silane coupling agents containing ester groups and / or carboxyl groups and polymer monomers containing ester groups and / or carboxyl groups; the silane coupling agents containing ester groups and / or carboxyl groups are chemically bonded to the electrophoretic particles through a coupling reaction, and then the polymer monomers containing ester groups and / or carboxyl groups are grafted onto the electrophoretic particles through a grafting reaction, and finally, the amino-containing basic group and other synergists are physically adsorbed onto the electrophoretic particles through ball milling to obtain surface-connected acidic groups and Modified electrophoretic particles with basic groups; the technical solution preferably connects silane coupling agents such as γ-methacryloxypropyltrimethoxysilane, polymer monomers containing groups such as acrylic acid, methacrylic acid, sulfonic acid, ether bonds, and synergists such as sorbitan monooleate (Span80) or sorbitan trioleate (Span85) on the surface of the electrophoretic particles through chemical bonding and physical adsorption; of course, the electrophoretic particles connected by chemical bonding and physical adsorption to other silane coupling agents and polymer monomers containing acidic or basic groups and synergists containing acidic or basic groups are all within the protection scope of this patent.

[0069] Preferably, the present application also provides an alternative technical solution, wherein the amino-containing basic group includes an amino-containing silane coupling agent and an amino-containing polymer monomer, and the ester- and / or carboxyl-containing acidic group includes an ester- and / or carboxyl-containing synergist; the present technical solution preferably connects silane coupling agents such as γ-aminopropyltriethoxysilane or 3-aminopropyltrimethoxysilane, polymer monomers such as aminostyrene, and synergists such as monoolefinic succinimide (T-151) or succinimide (OLOA11000) on the surface of the electrophoretic particles by chemical bonding and physical adsorption; of course, the electrophoretic particles connected by chemical bonding and physical adsorption to other silane coupling agents and polymer monomers containing basic groups and synergists containing acidic groups are all within the scope of protection of this patent.

[0070] Example 2

[0071] Example 2 of the present application provides a method for preparing the color electronic ink described in Example 1. The preparation method includes first preparing modified electrophoretic particles and preparing the modified color electrophoretic particles, the color electrophoretic particle charge control agent and the electrophoretic medium into color electronic ink. The process of preparing the modified color electrophoretic particles into color electronic ink is the same as the process of color electronic ink. The electronic ink used in the present application is composed of Isopar-G containing 3.0% AOT and modified electrophoretic particles. The preparation method of the modified color electrophoretic particles specifically includes a color pigment particle modification step, a coupling reaction step, a grafting reaction step and a ball milling reaction step.

[0072] The color pigment particle modification step includes: dispersing the pigment particles, such as iron oxide pigment particles, in anhydrous ethanol, wherein the mass of the anhydrous ethanol is 20 to 50 times the amount of the iron oxide pigment particles, adding a small amount of ammonia water (approximately 1 to 2 times the amount of the pigment particles) during stirring, and reacting for 1 to 5 hours; then adding tetraethyl orthosilicate (approximately 0.25 to 0.75 times the amount of the pigment particles), and then reacting for 3 to 6 hours; centrifugation and washing for several times, and drying to obtain color pigment particles containing a silicon layer on the outside. Conventional color pigment particles have no hydroxyl groups on the surface, and the color pigment particles are pre-treated by coating with a silicon layer, so that a large number of hydroxyl groups can be produced on the particle surface, which is convenient for the implementation of subsequent modification steps.

[0073] The coupling reaction step comprises: dispersing pigment particles containing a silicon layer, such as iron oxide pigment particles containing a large amount of hydroxyl groups on the surface, in anhydrous ethanol, wherein the mass of the anhydrous ethanol is 20 to 30 times the mass of the titanium dioxide pigment particles, adding a silane coupling agent containing an acidic functional group, such as γ-methacryloxypropyltrimethoxysilane, wherein the mass of the γ-methacryloxypropyltrimethoxysilane is 0.5 to 2 times the mass of the particles, and adding vinyltrimethoxysilane with the same mass as the γ-methacryloxypropyltrimethoxysilane, adding a surfactant SDBS during stirring, wherein the mass of the surfactant SDBS is 0.015 to 0.025 times the mass of the particles, stirring for 12 to 36 hours, centrifuging, washing for multiple times and drying to obtain modified pigment particles.

[0074] The grafting reaction step includes: dispersing the modified pigment particles in a low polarity dispersion solvent of toluene, the mass of which is 5 to 15 times that of the modified pigment particles, adding a polymer monomer containing an acidic functional group, such as methacrylic acid containing an acidic group such as an ester group or a carboxyl group, to the solution, the amount of which is 0.5 to 2 times that of the particles, adding a surfactant SDBS thereto, and raising the temperature to 70°C to 110°C. After stirring for 15 to 30 minutes, a low polarity solvent of toluene containing an initiator AIBN (the amount of the initiator is 0.05 times that of the modified pigment particles) is added dropwise, and the mixture is stirred for 5 to 24 hours with a stirrer, and the reaction is carried out in an inert atmosphere throughout the process. Finally, after the temperature of the reaction container is reduced to room temperature, the reaction mixture is filtered and washed several times with a low polarity solvent, and after drying, the acidic modified pigment particles chemically bonded to the titanium dioxide pigment particles are obtained.

[0075] The ball milling reaction step includes: dispersing the acid modified pigment particles in a non-polar solvent carbon tetrachloride, wherein the amount of the non-polar solvent carbon tetrachloride is 1 to 10 times that of the acid modified pigment particles, placing the mixture containing the acid modified pigment particles in a ball milling jar, and adding ball milling beads, introducing a large number of additional groups on the surface of the acid modified pigment particles by ball milling, and ball milling the acid modified pigment particles and a synergist 15 containing a basic group, such as a synergist monovinyl succinimide containing a basic functional group such as an amino group, for 1 to 8 hours to prepare a particle dispersion, so as to produce a sufficiently close contact between the synergist and the particles, so that a sufficient amount of the synergist monovinyl succinimide is physically adsorbed onto the particle surface, and then centrifugally dried to obtain modified electrophoretic particles with 7.5 mmol / cm3 (unit volume of particle surface) of acidic groups (-COOH) and 7.8 mmol / cm3 (unit volume of particle surface) of basic groups (-NH2) chemically bonded and physically adsorbed.

[0076] Example 3

[0077] Example 3 of the present application provides another method for preparing the color electronic ink described in Example 1. The difference between the preparation method and Example 2 is that the modified color electrophoretic particles used in the color electronic ink are chemically bonded and physically adsorbed to connect 3.75 mmol / cubic centimeter (unit volume of particle surface) of acidic groups (-COOH) and 7.8 mmol / cubic centimeter (unit volume of particle surface) of basic groups (-NH2).

[0078] Example 4

[0079] Example 4 of the present application provides another preparation method for color electronic ink. The difference between the preparation method and Example 3 is that the ball milling reaction step is not included, and the electrophoretic particles are modified through a coupling reaction step and a grafting reaction step. The obtained electrophoretic particles are chemically bonded with 15.3 mmol / cubic centimeter (unit volume of particle surface) of acidic groups (-NH2).

[0080] Example 5

[0081] Example 5 of the present application provides another method for preparing color electronic ink. The difference between the preparation method and Example 3 is that the ball milling reaction step is not included, and the electrophoretic particles are modified through a coupling reaction step and a grafting reaction step. The obtained electrophoretic particles are chemically bonded with 7.5 mmol / cubic centimeter (unit volume of particle surface) of acidic groups (-NH2).

[0082] Experimental Example 1

[0083] Experimental Example 1 of the present application is used to test the charge of the color electrophoretic particles and the modified color electrophoretic particles in the color electronic ink provided in Examples 2-5 to reflect the color display effect of the color electronic ink. The test results are shown in Table 1. It can be seen from Table 1 that compared with the color electrophoretic particles with acidic groups or alkaline groups connected to the surface, the modified color electrophoretic particles connected to acidic groups and alkaline groups have a larger charge. Therefore, when driving the color electronic ink display, compared with the color electrophoretic particles provided in Examples 4-5, the modified color electrophoretic particles in Examples 2-3 have a faster response speed, which reduces the mixing of different color particles in the color electronic ink due to similar charge under voltage drive, thereby improving the display effect of the color electronic ink. The driving display effect test is shown in FIG. Figure 2 .

[0084]

[0085] Table 1

[0086] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A color electronic ink, It is characterized in that It includes color electrophoretic particles, charge control agent, electrophoretic medium and modified color electrophoretic particles; The color electrophoretic particles and the modified color electrophoretic particles are different in color; The surface of the colored electrophoretic particles is connected with acidic groups or basic groups; The surface of the modified color electrophoretic particle is connected with an acidic group and a basic group; The acidic groups include acidic groups containing ester groups and / or carboxyl groups, and the acidic groups are introduced at a density of 5.96 to 39.19 mmol / cm 3 ; The basic group includes an amino-containing basic group, and the basic group introduction density is 3.41-37.49 mmol / cm 3 .

2. A color electronic ink according to claim 1, It is characterized in that The color electrophoretic particles are introduced at a density of 31.95-65.18 mmol / cm 3 -NH 2 The modified colored electrophoretic particles are connected to 33.23 mmol / cm 3 -NH 2 , 15.98~31.95 mmol / cm 3 -COOH.

3. The color electronic ink according to claim 1, It is characterized in that The surface of the colored electrophoretic particles is connected to 31.95 mmol / cm 3 -NH 2 The modified colored electrophoretic particles are connected to 33.23 mmol / cm 3 -NH 2 , 31.95mmol / cm 3 -COOH.

4. The color electronic ink according to claim 1, It is characterized in that The electrophoretic medium is a non-polar solvent; The non-polar solvent is selected from one or more of halogenated hydrocarbons, paraffin, silicone oil, alkane compounds, epoxy compounds, aromatic hydrocarbons, and vinyl ethers; The charge control agent is selected from one or more of organic sulfonate, organic sulfate, organic phosphate, organic phosphate ester, polyester, polyolefin, and polyacrylate charge control agents.

5. The color electronic ink according to claim 1, It is characterized in that The connecting of the acidic group and the basic group is to connect the acidic group by chemical bonding and to connect the basic group by physical adsorption; The chemical bonding method for connecting the acidic groups includes connecting the acidic groups through a silane coupling agent.

6. The color electronic ink according to claim 1, It is characterized in that The connecting of the acidic group and the basic group is to connect the basic group by chemical bonding and to connect the acidic group by physical adsorption; The chemical bonding method for connecting the basic groups includes connecting the basic groups through a silane coupling agent.

7. A method for preparing a color electronic ink according to any one of claims 1 to 5, It is characterized in that Includes steps: Step S1-1, dispersing pigment particles, tetraethyl orthosilicate, and ammonia water in a first solvent, and performing a silicon layer treatment to obtain color pigment initial particles having hydroxyl groups on the surface; Step S2-1, dispersing color pigment particles containing hydroxyl groups on the surface, a silane coupling agent containing an acidic functional group, and a silane coupling agent containing an unsaturated bond in a first solvent, and performing a coupling reaction to obtain modified color pigment particles; Step S3-1, dispersing the modified color pigment particles, the polymer monomer containing the acidic functional group and the initiator in the second solvent, and performing a grafting reaction to obtain the acidic modified color pigment particles; Step S4-1, ball-milling the acidic modified color pigment particles and the synergist containing the basic group to obtain modified color electrophoretic particles with acidic groups and basic groups connected on the surface; Step S5-1, preparing color electronic ink from modified color electrophoretic particles with acidic groups and basic groups connected to the surface, color electrophoretic particles with acidic groups or basic groups connected to the surface, a charge control agent and an electrophoretic medium.

8. A method for preparing a color electronic ink according to any one of claims 1 to 4 or claim 6, It is characterized in that Includes steps: Step S1-2, dispersing pigment particles, tetraethyl orthosilicate, and ammonia water in a first solvent, Adding a silicon layer to obtain color pigment initial particles with hydroxyl groups on the surface; Step S2-2, dispersing the color pigment particles containing hydroxyl groups on the surface, the silane coupling agent containing a basic functional group, and the silane coupling agent containing an unsaturated bond in a first solvent, and performing a coupling reaction to obtain modified color pigment particles; Step S3-2, dispersing the modified color pigment particles, the polymer monomer containing the basic functional group and the initiator in the second solvent, and performing a grafting reaction to obtain the basic modified color pigment particles; Step S4-2, ball-milling the alkaline modified color pigment particles and the synergist containing an acidic group to obtain modified color electrophoretic particles with acidic groups and alkaline groups connected on the surface; Step S5-2: preparing color electronic ink from the modified color electrophoretic particles with acidic groups and basic groups connected to the surface, the color electrophoretic particles with acidic groups or basic groups connected to the surface, the charge control agent and the electrophoretic medium.

9. An electrophoretic display device, It is characterized in that The electrophoretic display device comprises a microcavity encapsulating the electronic ink according to any one of claims 1 to 6 or the color electronic ink prepared by the preparation method according to any one of claims 7 to 8.

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