Preparation method of electronic paper microcup array with high dielectric performance

Abstract

The present invention provides a method for preparing an electronic paper microcup array with high dielectric properties. A required microcolumn array graphic structure is processed on the surface of ITO transparent conductive glass; then a suspension obtained by mixing a photocurable polymer prepolymer, barium titanate nanoparticles, and a photocuring agent is spin-coated on the microcolumn array graphic structure to obtain a coating, and ITO transparent conductive glass is covered on the coating; then, alternating current is passed through the upper and lower two pieces of ITO transparent conductive glass sandwiching the suspension coating, and a composite polymer is formed by electric field induction. Finally, after the composite polymer is cured by ultraviolet light, the upper and lower two pieces of ITO transparent conductive glass are removed, and the microcup array film with an ordered structure is demolded. The microcup array has higher dielectric properties and light transmittance. When it is prepared into an electronic paper device, the movement rate of conductive particles is greatly increased, the display refresh rate is improved, and a faster response speed can be exhibited.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer composite materials and relates to a preparation method of an electronic paper component. Background Art

[0002] Electronic paper, also called digital paper, is an ultra-thin and ultra-light display screen, which can be understood as "a display screen as thin, flexible and rewritable as paper". Figuratively speaking, electronic paper is a thin film, and a layer of charged substance "coated" on the film is electronic ink. Compared with traditional paper or flat displays, electronic paper has the advantages of high resolution, high contrast, low power consumption and bistability, and has broad application prospects in the market. It can be applied not only to outdoor billboards and wearable device displays, but also has broad application prospects in the fields of medical and health or military. To achieve the display of electronic paper, relatively low driving voltage, fast response time, and high brightness and contrast are often required. For microcup-type electronic paper, first, electronic ink containing conductive particles is injected into a microcup array, then the cup mouths are encapsulated, and then two electrodes are respectively placed on the upper and lower surfaces of the microcup array containing electronic ink. By applying voltage, black and white particles can be driven to move up and down to achieve the display effect.

[0003] The refresh rate and driving voltage of electronic paper display are closely related to the material and structure of the encapsulation layer / microcup array. The driving voltage applied between the two electrodes is partly distributed to the bottom of the microcup, partly to the encapsulation layer, and partly to the electrophoresis solution. Due to the low dielectric performance of the microcup array, the voltage share distributed to the bottom of the cup and the encapsulation layer is high, and the voltage share distributed to both ends of the electrophoresis solution is low. As a result, for the electronic paper device prepared from this microcup array, the movement rate of conductive particles is reduced, the refresh rate of the display is low, and the response speed is slow. Moreover, with the current microcup array manufacturing process, the template and the microcup array are easily damaged and deformed during demolding. Summary of the Invention

[0004] To solve the problems that the low dielectric performance of the microcup array described in the background art leads to a decrease in the movement rate of conductive particles of the electronic paper prepared therefrom, a low refresh rate of the display, and a slow response speed, the present invention provides a preparation method of an electronic paper microcup array with high dielectric performance.

[0005] The method of the present invention includes the following steps:

[0006] Step 1: After spin-coating a photoresist on the surface of ITO transparent conductive glass using a spin coater and drying it, place an optical mask plate on the photoresist, dry it again after ultraviolet exposure, and develop it to obtain the required microcolumn array graphic structure;

[0007] Step 2: Mix the following components in weight percentages evenly and ultrasonically disperse to remove bubbles to obtain a suspension: 55 - 85% of a photocurable polymer prepolymer, 10 - 35% of nanometer barium titanate, 3% - 5% of a photoinitiator, and 0 - 10% of a reactive diluent;

[0008] Step 3: Spin-coat the suspension on the micro-column array pattern structure to obtain a coating, and cover an ITO transparent conductive glass on the coating;

[0009] Step 4: Connect the upper and lower pieces of ITO transparent conductive glass through a conductive tape or a conductive copper foil and apply an alternating current power supply for a period of time. A composite polymer is formed by induction of the alternating current electric field. After ultraviolet curing the composite polymer while keeping the voltage unchanged, remove the upper and lower pieces of ITO transparent conductive glass, and demold to obtain a micro-cup array film with an ordered structure.

[0010] Further, in the above Step 1, the micro-column structure of the micro-column array pattern structure is square, regular hexagon, circular, equilateral triangle or irregular triangle. The column height of the micro-column is 30 - 50 μm, the side length / diameter is 10 - 100 μm, and the spacing is 1 - 20 μm.

[0011] Furthermore, the micro-column structure of the micro-column array pattern structure is a regular hexagon, the column height of the micro-column is 40 μm, the side length is 50 μm, and the spacing is 10 μm.

[0012] Furthermore, in the above Step 2, the photocurable polymer prepolymer is a photocurable acrylate prepolymer, a photocurable polyurethane prepolymer or a photocurable epoxy resin prepolymer with a viscosity of 300 - 500 Pa·s.

[0013] Furthermore, the photocurable polymer prepolymer is a photocurable polyurethane prepolymer, and its structure is:

[0014]

[0015] Among them, R1, R2, and R3 are all alkyl groups containing 1 - 6 carbon atoms.

[0016] Furthermore, in the above Step 2, the nanometer barium titanate is spherical barium titanate with a diameter < 100 nm or fibrous barium titanate with a diameter < 20 nm and a length < 2 μm.

[0017] Furthermore, in the above Step 2, the reactive diluent is 1,6 - hexanediol diacrylate. This is because, when the reactive diluent uses a monomer containing more functional groups, in addition to increasing the reaction activity, it can also endow the cured film with a crosslinked structure; after polymerization, a monofunctional monomer can only obtain a linear polymer, while a multifunctional monomer can obtain a highly crosslinked network.

[0018] Further, in the second step, the weight percentages of the components are as follows: photocurable polymer prepolymer 80%, nano-barium titanate 15%, and photoinitiator 5%.

[0019] Further, in the second step, the components are stirred evenly by a magnetic stirrer, subjected to ultrasonic dispersion at a power of 600 - 800 w for 10 - 15 min, and then defoamed for 10 - 15 min at a rotational speed of 1800 - 2000 r / min by a vacuum defoaming machine to remove air bubbles.

[0020] Further, in the third step, the thickness of the coating obtained by spin-coating the suspension is 30 - 60 μm.

[0021] Further, in the fourth step, the electric field strength of the alternating current is 200 - 600 V / mm, the frequency is 10 - 1000 HZ, the power-on duration is 3 - 5 min, and ultraviolet light curing is carried out under ultraviolet light with a wavelength of 320 - 400 nm and a power of 700 - 1000 W for 3 - 5 min.

[0022] Compared with the prior art, in the present invention, a required micro-column array graphic structure is processed on the surface of ITO transparent conductive glass; then a suspension obtained by mixing a photocurable polymer prepolymer, nano-barium titanate, and a photoinitiator is spin-coated on the micro-column array graphic structure to obtain a coating, and the ITO transparent conductive glass is covered on the coating; then, alternating current is applied to the upper and lower two pieces of ITO transparent conductive glass sandwiching the suspension coating, and a composite polymer is formed by electric field-induced molding. Finally, after the composite polymer is cured by ultraviolet light, the upper and lower two pieces of ITO transparent conductive glass are removed, and demolding is carried out to obtain a micro-cup array film with an ordered structure. Under the action of the electric field, nano-particles of nano-barium titanate with high dielectric properties in the suspension can be closely arranged along the electric field direction in the polymer prepolymer or solvent matrix through polarization to form a chain structure, so that the obtained composite polymer is an isotropic nano-composite material with an ordered arrangement along the material thickness direction. Compared with the blend homogeneous composite material currently used in micro-cup arrays, the isotropic nano-composite material with an ordered arrangement in the thickness direction of the present invention has higher dielectric properties and light transmittance. When the micro-cup array with an ordered structure of the present invention is prepared into an electronic paper device, the movement rate of conductive particles is greatly increased, the display refresh rate is improved, and a faster response speed can be exhibited. In addition, the micro-cup array of the present invention is not easily damaged and deformed during demolding of the conductive metal plate template and the micro-cup structure. The obtained micro-cup array not only has a uniform and ordered arrangement of structure size, but also does not require complex preparation processes and harsh operating conditions, nor does it require remaking the template due to damage to the conductive metal plate template, greatly reducing the preparation cost and improving the preparation efficiency, and can be applied to mass production. Description of the Drawings

[0023] Figure 1Schematic diagram of the preparation process of the present invention.

[0024] Figure 2 Front view of the microcup array of Example 1 under an optical microscope.

[0025] Figure 3 Comparison diagram of cross-sectional scanning electron microscope images of the microcup array composite film before and after energization in Example 1.

[0026] Figure 4 Optical microscope images of the cross-section along the thickness direction of the microcup arrays of Comparative Example 1 and Example 1, (a) is Comparative Example 1, and (b) is Example 1.

[0027] Figure 5 Comparison diagram of the dielectric constants of the microcup arrays prepared in Example 1, Comparative Example 1, and Comparative Example 2.

[0028] Figure 6 Comparison diagram of the response times of the electronic paper devices prepared from the microcup arrays of Example 1, Comparative Example 1, and Comparative Example 2. Detailed implementation manners

[0029] In order to make the technical problems, technical solutions, and beneficial effects to be solved by the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and 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.

[0030] The present invention provides a method for preparing a microcup array of electronic paper with high dielectric performance, and the preparation process is as Figure 1 shown, and the specific steps are as follows.

[0031] Step 1: Spin-coat a photoresist on the surface of the ITO transparent conductive glass using a spin coater. After drying, place the optical mask plate on the photolithography machine, expose it to ultraviolet light, and then dry it again. After development, the required microcolumn array graphic structure can be obtained.

[0032] Specifically, spin-coat the photoresist SU83050 on the surface of the ITO transparent conductive glass using a spin coater. By controlling the spin-coating parameters: 500 r / min for 30 s in the forward rotation and 3000 r / min for 30 s in the reverse rotation, a 30-μm-thick photoresist can be obtained; then perform drying treatment. Place the ITO transparent conductive glass spin-coated with the photoresist on the heating table, bake it at 95°C for 30 min and then take it off. Place the optical mask plate on the photoresist and expose it for 80 s on the ultraviolet exposure machine; perform drying treatment again, bake it at 65°C for 1 min and at 95°C for 4 min in sequence, and then develop it in the SU8 developer solution to obtain the required microcolumn array graphic structure;

[0033] Specifically, the micro-column structure of the micro-column array pattern structure is square, regular hexagon, circle, equilateral triangle or irregular triangle. The column height of the micro-column is 30-50 μm, the side length / diameter is 10-100 μm, and the spacing is 1-20 μm. Preferably, the micro-column structure of the micro-column array pattern structure is a regular hexagon, the column height of the micro-column is 40 μm, the side length is 50 μm, and the spacing is 10 μm.

[0034] Step 2: Mix the following components in weight percentages evenly: 55-85% of photocurable polymer prepolymer, 10-35% of nano-barium titanate, 3%-5% of photoinitiator, and 0-10% of reactive diluent, and perform ultrasonic dispersion to remove bubbles to obtain a suspension.

[0035] Specifically, the photocurable polymer prepolymer is a photocurable acrylate prepolymer, a photocurable polyurethane prepolymer or a photocurable epoxy prepolymer with a viscosity of 300-500 Pa·s. The nano-barium titanate is spherical barium titanate with a diameter <100 nm or fibrous barium titanate with a diameter <20 nm and a length <2 μm. The photoinitiator is 2-hydroxy-2-methylpropiophenone. The reactive diluent is 1,6-hexanediol diacrylate.

[0036] Preferably, the photocurable polymer prepolymer is a photocurable polyurethane prepolymer, and its structure is:

[0037]

[0038] Among them, R1, R2, and R3 are all alkyl groups containing 1-6 carbon atoms.

[0039] For the polymer prepolymer, the longer the chain length, the larger the molecular weight, the stronger the polarity, and the best mechanical flexibility, which is more conducive to the ordered arrangement of the composite polymer along the material thickness direction. Therefore, in this photocurable polyurethane prepolymer, R1, R2, and R3 are all preferably alkyl groups containing 6 carbon atoms.

[0040] Specifically, the components are stirred evenly by a magnetic stirrer, ultrasonically dispersed at a power of 600-800 w for 10-15 min, and then defoamed by a vacuum defoamer at a rotational speed of 1800-2000 r / min for 10-15 min to remove bubbles.

[0041] Preferably, the weight percentages of the components are: 80% of photocurable polymer prepolymer, 15% of nano-barium titanate, and 5% of photoinitiator.

[0042] Step 3: Spin-coat the suspension on the micro-column array pattern structure to obtain a coating, and cover the coating with ITO transparent conductive glass.

[0043] Among them, the thickness of the coating is 30-60 μm. The thickness of the coating is preferably 50 μm.

[0044] Step 4: Connect the upper and lower ITO transparent conductive glasses through conductive tape or conductive copper foil and apply an alternating current power supply for a certain period of time. A composite polymer is formed by induction of the alternating current electric field. After ultraviolet curing the composite polymer while keeping the voltage unchanged, remove the upper and lower ITO transparent conductive glasses, and demold to obtain a microcup array film with an ordered structure.

[0045] Specifically, the electric field strength of the alternating current is 200 - 600 V / mm, the frequency is 10 - 1000 HZ, the power-on duration is 3 - 5 min, and the ultraviolet curing is carried out under ultraviolet light with a wavelength of 320 - 400 nm and a power of 700 - 1000 W for 3 - 5 min. Preferably, an alternating current with an electric field strength of 400 V / mm and a frequency of 100 Hz is used, and the power-on duration is preferably 3 min.

[0046] The present invention will be further described below in conjunction with specific examples and comparative examples.

[0047] Raw materials used: The conductive metal plate uses a metal nickel template, a transparent conductive glass template, which are purchased externally; a photocurable acrylate prepolymer, a photocurable polyurethane prepolymer, and a photocurable epoxy prepolymer with a viscosity of 300 - 500 Pa·s; the photocuring agent uses 2-hydroxy-2-methylpropiophenone; nanometer barium titanate.

[0048] Example 1

[0049] Use a spin coater to spin-coat photoresist SU83050 on the surface of the ITO transparent conductive glass. By controlling the spin-coating parameters: 500 r / min for 30 s in the forward rotation and 3000 r / min for 30 s in the reverse rotation, a 30-μm-thick photoresist is obtained; then perform a drying treatment. Place the ITO transparent conductive glass spin-coated with the photoresist on a heating table, bake it at 95°C for 30 min and then take it down. Place the optical mask template on the photoresist and perform exposure on an ultraviolet exposure machine for 80 s; perform a drying treatment again. Bake it at 65°C for 1 min and 95°C for 4 min in sequence, and then develop it in SU8 developer to obtain the required microcolumn array graphic structure. The microcolumn structure of the microcolumn array graphic structure is a regular hexagon, the column height of the microcolumn is 40 μm, the side length is 50 μm, and the spacing is 10 μm.

[0050] Mix 80 g of photocurable polyurethane prepolymer, 15 g of nanometer barium titanate, and 5 g of photocuring agent, stir evenly with a magnetic stirrer, ultrasonically disperse it at a power of 700 w for 10 min, and defoam it at 2000 revolutions per minute with a vacuum defoamer for 10 minutes to remove bubbles, obtaining a suspension. Among them, the nanometer barium titanate is spherical barium titanate with a diameter <50 nm.

[0051] Spin-coat the suspension on the micro-column array pattern structure to obtain a coating with a thickness of 50 μm. The periphery of the coating can be sealed with an insulating film 50 μm thick to prevent the diffusion of the liquid mixture of the suspension. Then, cover the coating with ITO transparent conductive glass.

[0052] Connect the upper and lower ITO transparent conductive glasses through conductive tape or conductive copper foil and apply an alternating current power supply for a certain period of time. The electric field strength is 400 V / mm, the frequency is 100 HZ, and the energization time is 3 min. A composite polymer is formed by induction of the alternating current electric field. While keeping the voltage unchanged, irradiate it with ultraviolet light with a wavelength of 360 nm and a power of 700 W for 3 min. After curing the composite polymer with ultraviolet light, remove the upper and lower ITO transparent conductive glasses and demold to obtain a micro-cup array film with an ordered structure.

[0053] Example 2

[0054] In this example: The micro-column structure of the micro-column array pattern structure is a regular polygon. The column height of the micro-column is 50 μm, the side length is 60 μm, and the spacing is 15 μm; 75 g of photo-curable acrylate prepolymer, 20 g of nano-barium titanate, and 5 g of photo-curing agent; the others are the same as in Example 1.

[0055] Example 3

[0056] In this example: The micro-column structure of the micro-column array pattern structure is circular. The column height of the micro-column is 30 μm, the diameter is 40 μm, and the spacing is 15 μm; 65 g of photo-curable epoxy resin prepolymer, 30 g of nano-barium titanate, and 5 g of photo-curing agent; the others are the same as in Example 1.

[0057] Comparative Example 1

[0058] In this comparative example: Instead of forming the composite polymer by induction of the alternating current electric field, directly cure the suspension with ultraviolet light to obtain a micro-cup array.

[0059] Comparative Example 2

[0060] In this comparative example, pure polyurethane is used to make the micro-cup array.

[0061] Using the micro-cup arrays prepared in Examples 1-3, Comparative Example 1 and Comparative Example 2, prepare an electronic paper device. Coating the electronic ink into the micro-cup array through slit coating, and then coating the mixture of polyurethane prepolymer and initiator on the surface of the micro-cup array. The thickness of the encapsulation is 2 μm to obtain the corresponding electronic paper device.

[0062] The front view of the optical microscope of the micro-cup array prepared in Example 1 is as Figure 2 shown. The micro-cup structure is a regular hexagon, with a complete structure, uniform size, orderly arrangement, and no obvious defects.

[0063] The comparison diagram of the cross-sectional scanning electron microscope images of the microcup array composite film before and after energization in Example 1 is as Figure 3 shown. Figure 3 (a) is the cross-sectional scanning electron microscope image of the microcup array composite film before energization. It can be seen that the nano-barium titanate particles with high dielectric performance are randomly mixed in it, without an obvious ordered structure. Figure 3 (b) is the cross-sectional scanning electron microscope image of the microcup array composite film after energization. Compared with the former, it can be clearly seen that the nano-barium titanate with high dielectric performance shows an ordered arrangement structure under the action of the electric field and still maintains this structure after curing.

[0064] The optical microscope images of the cross-sections along the thickness direction of the microcup arrays in Comparative Example 1 and Example 1 are as Figure 4 shown. Figure 4 (a) In Comparative Example 1, due to the absence of an electric field, the nano-barium titanate is uniformly mixed in the polymer without an obvious ordered structure. Figure 4 (b) In Example 1, under the action of the electric field, the nano-barium titanate nanoparticles in the suspension can be closely arranged along the electric field direction in the polymer prepolymer or solvent matrix through polarization, forming a chain structure, that is, the nano-barium titanate shows an ordered structure in the polymer, penetrating the upper and lower poles. Compared with Comparative Example 1, this structure can significantly enhance its dielectric performance.

[0065] The comparison diagram of the dielectric constants of the microcup arrays prepared in Example 1, Comparative Example 1, and Comparative Example 2 is as Figure 5 shown. It can be seen that the dielectric performance of the microcup array in Example 1 is greatly improved compared with Comparative Example 1 and Comparative Example 2.

[0066] The comparison diagram of the response times of the electronic paper devices prepared from the microcup arrays in Example 1, Comparative Example 1, and Comparative Example 2 is as Figure 6 shown. It can be seen that the response time of the electronic paper device prepared from the microcup array in Example 1 is greatly improved compared with Comparative Example 1 and Comparative Example 2.

[0067] It is found that increasing the dielectric constant of the polymer layer can improve the response speed of the particles. The reason is that the bottom of the cup and the encapsulation layer are in close contact with the electrode surface respectively. After energization, under the action of the electric field, the polymer is polarized, generating induced electrons opposite to the electrode on the side in contact with the electrode, and generating induced charges the same as the electrode on the side close to the electrophoresis solution. The polymer surface covered with these charges is equivalent to an extended electrode, attracting the particles with opposite charges, thus improving the movement rate of the particles. Therefore, the higher the dielectric constant of the microcup array, that is, the higher the dielectric performance, the faster the response speed of the conductive particles of the prepared electronic paper device.

[0068] Under the action of an electric field, nanoparticles of barium titanate nanometer with high dielectric properties in the suspension can be closely arranged along the direction of the electric field in the polymer prepolymer or solvent matrix through polarization to form a chain structure. Thus, the obtained composite polymer is an isotropic nanocomposite material with an ordered arrangement in the thickness direction of the material. Compared with the blend homogeneous composite material currently used in the microcup array, the isotropic nanocomposite material with an ordered arrangement in the thickness direction of the present invention has higher dielectric properties and light transmittance. When the microcup array with an ordered structure of the present invention is prepared into an electronic paper device, the movement rate of the conductive particles is greatly increased, the display refresh rate is improved, and a faster response speed can be exhibited. In addition, the microcup array of the present invention is not easily damaged or deformed during demolding of the conductive metal plate template and the microcup structure. The obtained microcup array not only has a uniform and ordered arrangement of the structure size, but also does not require a complex preparation process and strict operating conditions, nor does it require remaking the template due to damage to the conductive metal plate template, greatly reducing the preparation cost and improving the preparation efficiency, and can be applied to mass production.

[0069] The above-described 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 foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A preparation method of an electronic paper microcup array with high dielectric performance, characterized in that It includes the following steps: Step 1: After spin-coating a photoresist on the surface of an ITO transparent conductive glass using a spin coater and drying it, place an optical mask on the photoresist, dry it again after ultraviolet exposure, and develop it to obtain the required micro-column array graphic structure; Step 2: Mix the following components in weight percentages evenly and ultrasonically disperse to remove bubbles to obtain a suspension: 55 - 85% of a photocurable polymer prepolymer, 10 - 35% of nano-barium titanate, 3% - 5% of a photoinitiator, and 0 - 10% of a reactive diluent; the photocurable polymer prepolymer is a photocurable polyurethane prepolymer with a viscosity of 300 - 500 Pa·s, and its structure is: wherein, R1, R2, and R3 are all alkyl groups containing 1 - 6 carbon atoms; the nano-barium titanate is spherical barium titanate with a diameter < 100 nm or fibrous barium titanate with a diameter < 20 nm and a length < 2 μm; Step 3: Spin-coat the suspension on the micro-column array graphic structure to obtain a coating, and cover an ITO transparent conductive glass on the coating; Step 4: Connect the upper and lower two pieces of ITO transparent conductive glasses through a conductive tape or a conductive copper foil and apply an alternating current power supply for a certain period of time. A composite polymer is formed by induction of the alternating current electric field. After keeping the voltage unchanged, the composite polymer is cured by ultraviolet light, and then the upper and lower two pieces of ITO transparent conductive glasses are removed, and demolding is carried out to obtain a micro-cup array film with an ordered structure.

2. The preparation method of an electronic paper microcup array with high dielectric properties according to claim 1, characterized in that: In the said Step 1, the micro-column structure of the micro-column array graphic structure is square, regular hexagon, circle, equilateral triangle or irregular triangle, the column height of the micro-column is 30 - 50 μm, the side length / diameter is 10 - 100 μm, and the spacing is 1 - 20 μm.

3. The preparation method of an electronic paper microcup array with high dielectric properties according to claim 2, characterized in that: The micro-column structure of the micro-column array graphic structure is a regular hexagon, the column height of the micro-column is 40 μm, the side length is 50 μm, and the spacing is 10 μm.

4. The preparation method of an electronic paper microcup array with high dielectric properties according to any one of claims 1-3, characterized in that: In the said Step 2, the reactive diluent is 1,6 - hexanediol diacrylate.

5. The preparation method of an electronic paper microcup array with high dielectric properties according to claim 4, characterized in that: In the said Step 2, the weight percentages of the components are: 80% of the photocurable polymer prepolymer, 15% of nano-barium titanate, and 5% of the photoinitiator.

6. The preparation method of an electronic paper microcup array with high dielectric properties according to claim 5, characterized in that: In the said Step 2, the components are stirred evenly by a magnetic stirrer, ultrasonically dispersed at a power of 600 - 800 w for 10 - 15 min, and then defoamed by a vacuum defoamer at a rotation speed of 1800 - 2000 r / min for 10 - 15 min to remove bubbles.

7. The preparation method of an electronic paper microcup array with high dielectric properties according to claim 6, characterized in that: In the said Step 3, the thickness of the coating obtained by spin-coating the suspension is 30 - 60 μm.

8. The preparation method of an electronic paper microcup array with high dielectric properties according to claim 7, characterized in that: In the said Step 4, the electric field strength of the alternating current is 200 - 600 V / mm, the frequency is 10 - 1000 HZ, the power-on duration is 3 - 5 min, and in the ultraviolet light curing, ultraviolet light with a wavelength of 320 - 400 nm and a power of 700 - 1000 W is used to irradiate for 3 - 5 min.

Images