JP2011227109A - Manufacturing method of display sheet, display sheet, display device and electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of display sheet which enables manufacturing of display sheet with high contrast by arraying micro capsules in a state of contacting one another in a surface direction and arraying them in a line without overlapping in a thickness direction, the display sheet manufactured by the method, a reliable display device, and a reliable electronic device.SOLUTION: A manufacturing method of display sheet comprises: a step of supplying a surface of a substrate 12 with an application liquid 100 which consists of a plurality of dispersed micro capsules 40 enclosing an electrophoretic dispersion liquid 10 including at least one kind of electrophoretic particle 5; a step of applying a pressure to the application liquid 100 in a thickness direction of the substrate 12; and a step of moving the micro capsules 40 located with an overlap with other micro capsules 40 in the thickness direction of the substrate 12 in the application liquid 100, toward the substrate 12.

Description

  The present invention relates to a display sheet manufacturing method, a display sheet, a display device, and an electronic apparatus.

Generally, it is known that when an electric field is applied to a dispersion system in which fine particles are dispersed in a liquid, the fine particles move (migrate) in the liquid by Coulomb force. This phenomenon is called electrophoresis. In recent years, an electrophoretic display device that displays desired information (image) using this electrophoresis has attracted attention as a new display device.
This electrophoretic display device has characteristics such as a display memory property and a wide viewing angle property in a state where voltage application is stopped, and a high-contrast display with low power consumption.

The electrophoretic display device is a reflective display that uses natural light as a light source. And in order to implement | achieve high visibility, implement | achieving high transparency of a transmission part, the high reflectance of a reflection part, and the high absorption rate of an absorption part is calculated | required.
As a conventional electrophoretic display device, Patent Document 1 discloses that a microcapsule-containing layer including a plurality of microcapsules and a binder is formed on a substrate, and then another substrate is disposed on the microcapsule-containing layer. An electrophoretic display device in which the substrate and the microcapsule-containing layer are joined is disclosed.

Here, in order to obtain excellent display characteristics (especially high display contrast), the microcapsule is almost spherical in a state where the microcapsule-containing layer is held between two substrates, and the microcapsule is oriented in the plane direction. On the other hand, it is necessary to arrange them in contact with each other and to arrange them in one row (that is, a single layer) without overlapping in the thickness direction.
For this reason, in Patent Document 1, a wall portion for defining a region in which microcapsules are arranged is provided on a substrate, and a coating liquid (dispersion liquid) in which a plurality of microcapsules are dispersed inside the wall portion is excessive. The excess microcapsules contained in the supplied coating solution are removed using a squeegee, so that the surface of the coating solution is smoothed and the microcapsules are arranged in a single layer.

  However, in such a method, even though the microcapsules can be arranged in a single layer, the microcapsules cannot be arranged in contact with each other in the plane direction (that is, uniformly). Specifically, among the plurality of microcapsules in the coating solution applied to the substrate, the layer formed by the aggregation of the microcapsules located closest to the substrate is defined as the first layer and overlaps the microcapsules included in the first layer. The layer formed by assembling the microcapsules positioned as described above will be described as the second layer. In Patent Document 1, the second layer is removed using a squeegee and only the first layer is left, so that the microcapsules are simply separated. Arrange in layers.

Here, in the first layer in a state where the coating liquid is supplied onto the substrate, the microcapsules are coarse and dense, and there is a region where the microcapsules are arranged sufficiently densely, There are also areas where the microcapsules are not located (although there is sufficient space to place the microcapsules). Therefore, in order to arrange the microcapsules in the first layer in contact with each other in the plane direction (that is, uniformly), for example, the microcapsules in the second layer are arranged by the microcapsules in the first layer. It is necessary to move to an area that is not done. However, in Patent Document 1, as described above, since the second layer is simply removed by the squeegee, the microcapsules are not compensated in the region where the microcapsules in the first layer are not arranged.
Therefore, in the manufacturing method of Patent Document 1, even though the microcapsules can be arranged in a single layer, the microcapsules cannot be arranged in contact with each other with respect to the surface direction, and thus an electrical device having high contrast. An electrophoretic display cannot be manufactured.

JP 2007-133109 A

  An object of the present invention is to produce a display sheet having high contrast by arranging microcapsules in contact with each other in the plane direction and in a row without overlapping in the thickness direction. An object of the present invention is to provide a display sheet manufacturing method, a display sheet manufactured by the display sheet manufacturing method, a highly reliable display device, and a highly reliable electronic device.

Such an object is achieved by the present invention described below.
In the method for producing a display sheet of the present invention, a coating liquid in which a plurality of microcapsules in which an electrophoretic dispersion liquid containing at least one type of electrophoretic particles is encapsulated is dispersed on a substrate is supplied to the coating liquid. On the other hand, there is a step of applying a pressure in the thickness direction of the substrate and moving the microcapsule positioned in the coating solution so as to overlap another microcapsule in the thickness direction of the substrate toward the substrate. It is characterized by that.
Thus, a display sheet having high contrast can be manufactured by arranging the microcapsules in a state of being in contact with each other in the plane direction and in a row without overlapping in the thickness direction. it can.

The method for producing a display sheet of the present invention includes a wall portion forming step of providing a wall portion defining a region in which the microcapsules are disposed on the first substrate;
A coating solution supply step for supplying the coating solution to the inside of the wall;
The microcapsule positioned so as to overlap the other microcapsules in the coating solution by applying pressure in the thickness direction of the first substrate to the coating solution supplied to the inside of the wall portion Moving the microcapsule toward the first substrate; and
And a substrate bonding step of bonding the second substrate to the first substrate through the coating liquid by applying a pressure in the thickness direction of the first substrate.
Accordingly, since the microcapsule can move only inside the wall portion, the microcapsules are more reliably arranged in contact with each other in the plane direction, and 1 without overlapping in the thickness direction. Can be arranged in columns.

In the manufacturing method of the display sheet of this invention, it is preferable that the said board | substrate joining process utilizes the said wall part as a spacer, and joins a 1st board | substrate and a said 2nd board | substrate via this spacer.
Thereby, breakage, destruction, deformation, etc. of the microcapsule can be effectively prevented, and the gap (separation distance) between the first substrate and the second substrate can be set to a desired distance.

In the manufacturing method of the display sheet of this invention, it is preferable that the said spacer functions as a sealing part which suppresses deterioration of the said microcapsule.
Thereby, manufacture of a display sheet can be simplified and the number of parts can be reduced.
In the display sheet manufacturing method of the present invention, it is preferable that the pressure applied in the substrate bonding step is equal to the pressure applied in the microcapsule rearrangement step.
Accordingly, the first substrate and the second substrate can be firmly bonded while maintaining the shape of the microcapsule (that is, while preventing destruction of the microcapsule).

In the display sheet manufacturing method of the present invention, it is preferable to have a wall portion removing step of removing the wall portion prior to the substrate bonding step.
Thereby, the freedom degree of selection of the constituent material of a wall part expands.
In the display sheet manufacturing method of the present invention, the pressure applied in the substrate bonding step is preferably smaller than the pressure applied in the microcapsule rearrangement step.
Thereby, the first substrate and the second substrate can be firmly bonded while preventing the microcapsule from being broken.

The manufacturing method of the display sheet of the present invention includes a coating liquid supply step of supplying the coating liquid to a microcapsule arrangement region set as a region where the microcapsules are arranged on the first substrate;
The micro liquid crystal is positioned so as to overlap with the other micro capsules in the coating liquid by applying a pressure in the thickness direction of the first substrate to the coating liquid supplied to the micro capsule placement region. A microcapsule rearrangement step of moving the capsule toward the first substrate;
A wall portion forming step of forming a wall portion so as to surround the microcapsule arrangement region;
And a substrate bonding step of bonding the second substrate to the first substrate through the coating liquid by applying a pressure in the thickness direction of the first substrate.
As a result, the microcapsules can be more reliably arranged in contact with each other in the plane direction and arranged in a line without overlapping in the thickness direction.

In the display sheet manufacturing method of the present invention, it is preferable that the pressure applied in the substrate bonding step is larger than the pressure applied in the microcapsule rearrangement step.
As a result, the microcapsules can be arranged in contact with each other in the plane direction while maintaining the shape, and arranged in a row without overlapping in the thickness direction.

The method for producing a display sheet of the present invention includes a wall portion forming step of providing a wall portion defining a region in which the microcapsules are disposed on the first substrate;
A coating solution supply step for supplying the coating solution to the inside of the wall;
By applying a pressure in the thickness direction of the first substrate, the second substrate is bonded to the first substrate via the coating solution and overlaps with the other microcapsules in the coating solution. And a substrate bonding step of moving the microcapsules positioned in this manner toward the first substrate.
As a result, the microcapsules can be more reliably arranged in contact with each other in the plane direction and arranged in a line without overlapping in the thickness direction.

In the display sheet manufacturing method of the present invention, it is preferable that the microcapsules have a spherical shape and maintain the spherical shape even after the substrate bonding step.
This improves the pressure resistance and bleed resistance of the microcapsules.
The display sheet of the present invention is manufactured by the display sheet manufacturing method of the present invention.
Thereby, a display sheet having a high contrast is obtained.
The display device of the present invention includes the display sheet of the present invention.
As a result, a display device having high contrast and excellent reliability can be obtained.
An electronic apparatus according to the present invention includes the display device according to the present invention.
Thereby, an electronic device having high contrast and excellent reliability can be obtained.

It is sectional drawing which shows typically 1st Embodiment of the display apparatus of this invention. It is sectional drawing which shows the action | operation of the display apparatus shown in FIG. It is a schematic diagram for demonstrating the manufacturing method of the display apparatus shown in FIG. It is a schematic diagram for demonstrating the manufacturing method of the display apparatus shown in FIG. It is a schematic diagram for demonstrating the manufacturing method of the display apparatus shown in FIG. It is a schematic diagram for demonstrating the manufacturing method of the display apparatus concerning 2nd Embodiment of this invention. It is a schematic diagram for demonstrating the manufacturing method of the display apparatus concerning 2nd Embodiment of this invention. It is a schematic diagram for demonstrating the manufacturing method of the display apparatus concerning 3rd Embodiment of this invention. It is a schematic diagram for demonstrating the manufacturing method of the display apparatus concerning 3rd Embodiment of this invention. It is a schematic diagram for demonstrating the manufacturing method of the display apparatus concerning 4th Embodiment of this invention. It is a perspective view which shows embodiment at the time of applying the electronic device of this invention to electronic paper. It is a figure which shows embodiment at the time of applying the electronic device of this invention to a display. It is a top view which shows the area which measured contrast.

Hereinafter, a display sheet, a display device, and an electronic device of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
1. First, a display device (display device of the present invention) to which the display sheet of the present invention is applied will be described.

<First Embodiment>
FIG. 1 is a cross-sectional view schematically showing a first embodiment of the display device of the present invention, and FIG. 2 is a cross-sectional view showing the operation of the display device shown in FIG. In the following description, for convenience of explanation, the upper side in FIG. 1 will be described as “upper” and the lower side as “lower”.
A display device (electrophoretic display device) 20 shown in FIG. 1 includes a display sheet (front plane) 21 and a circuit board (back plane) 22.

The display sheet (electrophoretic display sheet) 21 is provided on the substrate 12 including the flat base 2 and the second electrode 4 provided on the lower surface of the base 2, and the microcapsule 40 and the binder 41 are provided on the substrate 12. And a sealing portion 7 that hermetically seals a gap between the substrate 12 and the circuit board 22.
On the other hand, the circuit board 22 includes a counter substrate 11 including a flat base 1 and a plurality of first electrodes 3 provided on the upper surface of the base 1, and the counter substrate 11 (base 1), for example, And a circuit (not shown) including a switching element such as a TFT.

Hereinafter, the structure of each part is demonstrated sequentially.
The base 1 and the base 2 are each composed of a sheet-like (flat plate) member, and have a function of supporting and protecting each member disposed therebetween. Each of the base portions 1 and 2 may be either flexible or hard, but is preferably flexible. By using the bases 1 and 2 having flexibility, it is possible to obtain a display device 20 having flexibility, that is, for example, a display device 20 useful in constructing electronic paper.

  When each base part (base material layer) 1 and 2 has flexibility, as a constituent material thereof, for example, polyester such as PET (polyethylene terephthalate) and PEN (polyethylene naphthalate), polyolefin such as polyethylene, modified Polyolefin, polyamide, thermoplastic polyimide, polyether, polyether ether ketone, various thermoplastic elastomers such as polyurethane, chlorinated polyethylene, etc., or copolymers, blends, polymer alloys, etc. mainly composed of these. These can be used alone or in combination of two or more.

The average thicknesses of the bases 1 and 2 are appropriately set depending on the constituent materials, applications, and the like, and are not particularly limited. However, when having flexibility, the average thickness is about 20 μm or more and 500 μm or less. Preferably, it is about 25 μm or more and 250 μm or less. Thereby, size reduction (especially thickness reduction) of the display apparatus 20 can be achieved, aiming at harmony with the softness | flexibility of the display apparatus 20, and intensity | strength.
The first electrode 3 and the second electrode 4 that form a layer (film shape) are provided on the surfaces of the bases 1 and 2 on the side of the microcapsule 40, that is, on the upper surface of the base 1 and the lower surface of the base 2, respectively. ing.

  When a voltage is applied between the first electrode 3 and the second electrode 4, an electric field is generated between them, and this electric field acts on electrophoretic particles 5 described later in the microcapsule 40. In the present embodiment, the second electrode 4 is a common electrode, the first electrode 3 is an individual electrode (pixel electrode connected to a switching element) divided in a matrix (matrix), A portion where two electrodes 4 and one first electrode 3 overlap constitute one pixel. Note that the second electrode 4 may also be divided into a plurality of parts in the same manner as the first electrode 3. Alternatively, the first electrode 3 may be divided into stripes, and the second electrode may be similarly divided into stripes and arranged so as to intersect with each other.

The constituent materials of the electrodes 3 and 4 are not particularly limited as long as they are substantially conductive, for example, metal materials such as gold, silver, copper, aluminum or alloys containing these, carbon black, etc. An ionic substance such as NaCl, Cu (CF ₃ SO ₃ ) _{2 in} a matrix resin such as a carbon-based material such as polyacetylene, polyfluorene or a derivative thereof, or a matrix resin such as polyvinyl alcohol or polycarbonate. Various conductive materials such as dispersed ion conductive polymer materials, conductive oxide materials such as indium oxide (IO), indium tin oxide (ITO), fluorine-doped tin oxide (FTO), etc. One or more of these can be used in combination.

The average thickness of the electrodes 3 and 4 is appropriately set depending on the constituent material and application, and is not particularly limited, but is preferably about 0.01 μm or more and 10 μm or less, preferably 0.02 μm or more and 5 μm. More preferably, it is about the following.
Here, among the bases 1 and 2 and the electrodes 3 and 4, the base and the electrodes (in the present embodiment, the base 2 and the second electrode 4) arranged on the display surface side each have light transmittance. That is, it is made substantially transparent (colorless transparent, colored transparent or translucent). Thereby, the state of the electrophoretic particles 5 in the electrophoretic dispersion 10, that is, the information (image) displayed on the display device 20 can be easily recognized visually.
In the display sheet 21, a display layer 400 is provided in contact with the lower surface of the second electrode 4. The display layer 400 has a configuration in which a plurality of microcapsules 40 each enclosing the electrophoretic dispersion 10 in a capsule body 401 are held by a binder 41.

  As shown in FIG. 1, the microcapsule 40 is a single layer (one by one without overlapping in the thickness direction) between the counter substrate 11 and the substrate 12 so as to be parallel in the vertical and horizontal directions, and the display layer 400. It is arrange | positioned in the whole thickness direction. That is, the microcapsules 40 in the display layer 400 are adjacent to each other in the surface direction and are arranged in a single layer without being stacked in the thickness direction.

Further, even when the microcapsule 40 is sandwiched between the counter substrate 11 and the substrate 12, the microcapsule 40 is substantially spherical (spherical) without being compressed (pressed) in the vertical direction.
Here, when the display device 20 is incorporated in electronic paper that requires flexibility, the display device 20 is similarly bent each time the electronic paper is bent. A pressure is applied between 22 and the display sheet 21. At this time, as shown in FIG. 1, since the microcapsule 40 is in point contact with both the first electrode 3 and the second electrode 4, the load (per unit area) of the contacting portion ( In particular, a pressure of about 0.2 MPa or more and 1.5 MPa or less is applied. Even when such a pressure is applied between the circuit board 22 and the display sheet 21, the microcapsule 40 preferably has a strength that maintains a spherical shape between the counter substrate 11 and the substrate 12. . By adopting such a configuration, both the pressure resistance and bleed resistance of the microcapsule 40 can be improved, so that the display device 20 can be driven stably for a long period of time.

  Specifically, the capsule strength of the microcapsule 40 is preferably 0.6 MPa or more, more preferably 1.0 MPa or more, and further preferably 3.0 MPa or more. The upper limit of the capsule strength is not particularly limited, but is about 50 MPa, for example. In addition, the capsule strength of the microcapsule 40 means the compressive strength per microcapsule measured using a micro compression tester (for example, product name: MCT-W500, manufactured by Shimadzu Corporation).

  Further, the microcapsule 40 has a capsule strength that is not crushed even when the steel ball is dropped from a height of preferably 10 cm or more, more preferably 20 cm or more, and even more preferably 30 cm or more in the steel ball drop test. preferable. In general, when the microcapsule 40 has only a capsule strength that is crushed when the steel ball is dropped from a height lower than the above height in the steel ball drop test, the display device 20 using such a microcapsule 40 is used. If it is accidentally dropped, the microcapsule 40 may be crushed by the impact of the drop, and there is a possibility that data display at that portion (pixel) cannot be performed. In the steel ball drop test, after placing the display device 20 on a butadiene rubber having a thickness of 3 mm, a steel ball having a diameter of 11 mm and a mass of 5.468 g is placed on the display layer 400 of the display device 20 from an arbitrary height. It is performed by observing with a light microscope the microcapsules 40 that are vertically dropped and are present at the location where the steel ball hits.

  In addition, the microcapsule 40 has a certain degree of flexibility, and its shape changes depending on the external pressure. Therefore, the microcapsule 40 is not particularly limited. It is preferable that it is a shape. That is, it is preferable that the microcapsule 40 exists between the counter substrate 11 and the substrate 12 (in the display layer 400) while maintaining a more spherical shape.

  The degree of the spherical shape of the microcapsule 40 can be expressed by using the ratio of the width of the microcapsule 40 and the height of the microcapsule 40 (the width of the microcapsule 40 / the height of the microcapsule 40) as an index. The width of the microcapsules 40 / the height (average value) of the microcapsules 40 is, for example, the average value of the particle diameter in the display layer 400 with respect to the height (thickness direction) and width (plane direction) of each microcapsule 40. Each is obtained and the ratio (width / height) of these average values is obtained.

  The width of the microcapsules 40 thus obtained / the height (average value) of the microcapsules 40 is not particularly limited, but is preferably about 1.0 or more and 1.2 or less, preferably 1.0 or more. More preferably, it is about 1.15 or less. When the width of the microcapsule 40 / the height of the microcapsule 40 is within the above range, the microcapsule 40 exists between the counter substrate 11 and the substrate 12 in a state of maintaining a substantially spherical shape. Can be said. In this way, the microcapsules 40 that maintain a substantially spherical shape are arranged in the display layer 400 such that those adjacent in the surface direction are in contact with each other and are not stacked in the thickness direction. Accordingly, the display device 20 including the display layer 400 exhibits high contrast.

  The particle size of the microcapsule 40 is not particularly limited, but is preferably about 5 μm or more and 300 μm or less, more preferably about 10 μm or more and 200 μm or less, and about 15 μm or more and 150 μm or less. Further preferred. If the particle size of the microcapsule 40 is less than 5 μm, depending on the hue, particle size and amount (number) of the electrophoretic particles 5 accommodated in the microcapsule 40, a sufficient display density may not be obtained. There is. On the contrary, when the particle size of the microcapsule exceeds 300 μm, the capsule strength of the microcapsule 40 may be reduced depending on the configuration of the microcapsule 40 (constituent materials, etc.). The electrophoretic properties of the electrophoretic particles 5 in the electrophoretic dispersion 10 are not sufficiently exhibited, and the starting voltage for display may be increased. The particle size of the microcapsule 40 is a laser diffraction / scattering particle size distribution measuring device (for example, product name: LA-910, manufactured by Horiba, Ltd., product name: Cole Counter Multisizer 3, Beckman Coulter Co. Means the volume average particle diameter measured by the company).

  Further, the variation coefficient of the particle size of the microcapsule 40 (that is, the narrowness of the particle size distribution) is not particularly limited, but is preferably 30% or less, more preferably 20% or less, and 10% or less. More preferably. When the variation coefficient of the particle size of the microcapsule 40 exceeds 30%, there are few microcapsules 40 having an effective particle size, and it may be necessary to use a large number of microcapsules. Further, even when the same voltage is applied between the first electrode 3 and the second electrode 4, the magnitude of the applied electric field differs between the plurality of microcapsules 40, and the display characteristics are deteriorated. There is a fear.

Note that the particle size of the microcapsules 40 and the coefficient of variation thereof greatly depend on the particle size and particle size distribution of the dispersion liquid dispersed in the aqueous medium when the microcapsules 40 are manufactured. Therefore, the microcapsule 40 having a desired particle diameter and its coefficient of variation can be obtained by appropriately adjusting the dispersion conditions of the dispersion.
In such a microcapsule 40, as shown in FIG. 1, a capsule body (shell) 401 enclosing the electrophoretic dispersion liquid 10 containing the electrophoretic particles 5 includes a first capsule layer 402 and the first capsule layer 402. The second capsule layer 403 is disposed outside the capsule layer 402. By forming the capsule body 401 with two layers of a first capsule layer 402 having a spherical shell shape and a second capsule layer 403 provided so as to cover the outer side, the capsule body 401 is provided with these 2 layers. The characteristic which each layer has can be provided synergistically.

  Examples of the constituent material of the first capsule layer 402 include an amino resin having a mercapto group. Such an amino resin has a property of being highly impervious and hardly causing the electrophoretic dispersion 10 to exude. On the other hand, an example of a constituent material of the second capsule layer 403 is an epoxy resin. Epoxy resins are excellent in chemical resistance and mechanical properties. In addition, the amino resin constituting the first capsule layer 402 and the epoxy resin constituting the second capsule layer 403 are firmly bonded to each other via a mercapto group, and the capsule strength is improved. Therefore, the microcapsules 40 having such a configuration are unlikely to cause the electrophoretic dispersion 10 to exude and are not destroyed by a laminating pressure applied when the display device 20 is manufactured. Therefore, the display device 20 including the display layer 400 containing the microcapsules 40 can express high contrast and can be used for a long time (for example, at 60 ° C. and 90% RH for 24 hours). Even if left for a long time, a low leakage current value is exhibited. Further, for example, even in a form mixed with a binder resin, that is, in the form of a coating solution or a display sheet, it can be stably stored at room temperature for a long period.

  In order to chemically bond the first capsule layer 402 and the second capsule layer 403 via a mercapto group, for example, in the step of forming the first capsule layer 402 described later, a mercapto group, a carboxyl group, and A compound having a sulfo group is added to the core material dispersion to form the first capsule layer 402 into which the mercapto group is introduced, and then the second capsule layer 403 composed of an epoxy resin material. May be formed.

  The thickness of the capsule body 401 (in this embodiment, the sum of the thickness d1 of the first capsule layer 402 and the thickness d2 of the second capsule layer 403) is not particularly limited, but is 0.1 μm in a wet state. The thickness is preferably 5 μm or less, more preferably 0.1 μm or more and 4 μm or less, and further preferably 0.1 μm or more and 3 μm or less. When the thickness of the capsule body 401 is small, there is a possibility that sufficient capsule strength cannot be obtained depending on the combination of the constituent materials of the first capsule layer 402 and the second capsule layer 403. On the contrary, when the capsule body 401 is thick, depending on the combination of the constituent materials of the first capsule layer 402 and the second capsule layer 403, the transparency is lowered and the contrast of the electrophoretic display device is lowered. May be incurred.

  Further, when the thickness of the first capsule layer 402 is d1 and the thickness of the second capsule layer 403 is d2, the ratio d1 / d2 is about 1/0 or more and 1.0 or less. Is more preferably about 1/0 or more and 1 / 0.5 or less, and further preferably about 1/0 or more and 1 / 0.3 or less. By satisfying such a relationship, it is possible to reliably impart the characteristics of both the first capsule layer 402 and the second capsule layer 403 to the capsule body 401.

In the present embodiment, the capsule body 401 has a two-layer configuration including the first capsule layer 402 and the second capsule layer 403. However, the present invention is not limited to such a two-layer configuration. A multi-layer structure having more than one layer may be used.
In the electrophoretic dispersion liquid 10 enclosed in the capsule body 401, at least one type of electrophoretic particles 5 (in this embodiment, two types of colored particles 5b and white particles 5a) are dispersed in the liquid phase dispersion medium 6 ( Suspended).

For example, the electrophoretic particles 5 are dispersed in the liquid phase dispersion medium 6 by combining one or more of paint shaker method, ball mill method, media mill method, ultrasonic dispersion method, stirring dispersion method, and the like. be able to.
As the liquid phase dispersion medium 6, a medium having a low solubility in the capsule body 401 and a relatively high insulating property is preferably used. Examples of the liquid phase dispersion medium 6 include various types of water (for example, distilled water and pure water), alcohols such as methanol, cellosolves such as methyl cellosolve, esters such as methyl acetate, ketones such as acetone, Aliphatic hydrocarbons such as pentane (liquid paraffin), alicyclic hydrocarbons such as cyclohexane, aromatic hydrocarbons such as benzene, halogenated hydrocarbons such as methylene chloride, and aromatic heterocycles such as pyridine , Nitriles such as acetonitrile, amides such as N, N-dimethylformamide, carboxylate, silicone oil or other various oils, and the like can be used alone or as a mixture.

  Among them, the liquid phase dispersion medium 6 is preferably a material mainly composed of aliphatic hydrocarbons (liquid paraffin) or silicone oil. The liquid phase dispersion medium 6 containing liquid paraffin or silicone oil as a main component has a high aggregation suppressing effect on the electrophoretic particles 5 and has low affinity with the constituent material of the capsule body 401 (low solubility). preferable. Thereby, it can prevent or suppress more reliably that the display performance of the display apparatus 20 deteriorates with time. In addition, liquid paraffin or silicone oil is preferable from the viewpoint of excellent weather resistance and high safety because it does not have an unsaturated bond.

  Further, in the liquid phase dispersion medium 6 (electrophoretic dispersion liquid 10), for example, a surfactant (anionic or cationic) such as an electrolyte or an alkenyl succinate, a metal soap, a resin material, if necessary. Various additives such as a charge control agent composed of particles such as rubber materials, oils, varnishes, and compounds, a dispersant such as a silane coupling agent, a lubricant, and a stabilizer may be added. When the liquid phase dispersion medium 6 is colored, various dyes such as anthraquinone dyes, azo dyes, and indigoid dyes may be dissolved in the liquid phase dispersion medium 6 as necessary.

  The electrophoretic particles 5 are particles that have a charge and can be electrophoresed in the liquid phase dispersion medium 6 when an electric field is applied. Any electrophoretic particle 5 may be used as long as it has a charge. Although there is no particular limitation, at least one of pigment particles, resin particles, or composite particles thereof is preferably used. used. These particles have the advantage that they are easy to manufacture and the charge can be controlled relatively easily.

  Examples of the pigment constituting the pigment particles include black pigments such as aniline black, carbon black, titanium black and copper chromite, white pigments such as titanium oxide and antimony oxide, azo pigments such as monoazo, isoindolinone, Yellow pigments such as yellow lead, red pigments such as quinacridone red and chrome vermilion, blue pigments such as phthalocyanine blue and indanthrene blue, green pigments such as phthalocyanine green, etc. They can be used in combination.

Examples of the resin material constituting the resin particles include acrylic resin, urethane resin, urea resin, epoxy resin, polystyrene, polyester, and the like, and one or more of these are combined. Can be used.
The composite particles include, for example, those in which the surface of the pigment particles is coated with a resin material or other pigment, those in which the surface of the resin particles is coated with a pigment, or a mixture in which the pigment and the resin material are mixed at an appropriate composition ratio. The particle | grains comprised by these, etc. are mentioned.
Examples of particles obtained by coating the surface of pigment particles with other pigments include those obtained by coating the surface of titanium oxide particles with silicon oxide or aluminum oxide. Such particles are suitable as white particles 5a. Used. Further, the carbon black particles or particles covering the surface thereof are suitably used as the colored particles (black particles) 5b.

Further, the shape of the electrophoretic particles 5 is not particularly limited, but is preferably spherical.
In consideration of dispersibility in the liquid phase dispersion medium 6, the electrophoretic particles 5 are preferably smaller, and specifically, the average particle diameter is about 10 nm or more and 500 nm or less. It is more preferable that it is about 20 nm or more and 300 nm or less. By setting the average particle diameter of the electrophoretic particles 5 within the above range, aggregation of the electrophoretic particles 5 and sedimentation in the liquid phase dispersion medium 6 can be reliably prevented and dispersed in the liquid phase dispersion medium 6. As a result, it is possible to suitably prevent the display quality of the display device 20 from deteriorating.

  In the case of using two different types of particles as in the present embodiment, the average particle size of the two types of particles is made different. In particular, the average particle size of the white particles 5a is larger than the average particle size of the colored particles 5b. It is preferable to set. Thereby, the display contrast of the display device 20 can be further improved, and the holding characteristics can be improved. Specifically, the average particle diameter of the colored particles 5b is preferably about 20 nm to 100 nm, and the average particle diameter of the white particles 5a is preferably about 150 nm to 300 nm. The particle diameter of the electrophoretic particles means a volume average particle diameter measured with a dynamic light scattering particle size distribution analyzer (for example, product name: Microtrac UPA-EX250, manufactured by Nikkiso Co., Ltd.).

  The specific gravity of the electrophoretic particles 5 is preferably set to be approximately equal to the specific gravity of the liquid phase dispersion medium 6. Thereby, even after the application of voltage between the electrodes 3 and 4 is stopped, the electrophoretic particles 5 can stay in a certain position in the liquid phase dispersion medium 6 for a long time. That is, a memory property can be given to the display device 20, and displayed information is held for a long time.

  The binder 41 included in the display layer 400 is, for example, for the purpose of bonding the counter substrate 11 and the substrate 12, the purpose of fixing the microcapsules 40 between the counter substrate 11 and the substrate 12, and the purpose of fixing the microcapsules 40 to each other. , For the purpose of ensuring insulation between the first electrode 3 and the second electrode 4. Thereby, the durability and reliability of the display device 20 can be further improved.

The binder 41 has only a resin material (insulating or minute current) that has excellent affinity (adhesion) with the counter substrate 11, the second electrode 4, and the capsule body 401 (microcapsule 40) and has excellent insulating properties. A flowing resin material) is preferably used.
Examples of the binder 41 include (meth) acrylic resins, (meth) acrylic urethane resins, polyvinyl chloride resins, polyvinylidene chloride resins, melamine resins, urethane resins, styrene resins, and alkyds. Resin, phenol resin, epoxy resin, polyester resin, polyvinyl alcohol resin, (meth) acrylic silicone resin, alkylpolysiloxane resin, silicone resin, silicone alkyd resin, silicone urethane resin, silicone polyester Resin, synthetic resin binder such as polyalkylene glycol resin, ethylene-propylene copolymer rubber, polybutadiene rubber, styrene-butanediene rubber, synthetic rubber such as acrylonitrile-butadiene rubber, or natural rubber binder Examples thereof include thermoplastic or thermosetting polymer binders such as cellulose nitrate, cellulose acetate butyrate, cellulose acetate, ethyl cellulose, hydroxypropylmethyl cellulose, and hydroxyethyl cellulose, and one or more of these are used in combination. be able to.

  Of these binders 41, the dispersibility of the microcapsules 40 is relatively good, and furthermore, the (meth) acrylic resin and the polyester-based resin are excellent in adhesion to the counter substrate 11, the substrate 12, and the microcapsules 40. Resins, urethane resins, and polyalkylene glycol resins are preferably used, and (meth) acrylic resins are particularly preferably used.

  Furthermore, the sealing part 7 is provided between the board | substrate 12 and the opposing board | substrate 11, and along those edge parts. The second electrode 4 and the display layer 400 are hermetically sealed by the sealing portion 7. Accordingly, it is possible to prevent moisture from entering the display device 20 (display sheet 21) and to more reliably prevent the display performance of the display device 20 (display sheet 21) from deteriorating.

  Examples of the constituent material of the sealing portion 7 include thermoplastic resins such as acrylic resins, urethane resins, and olefin resins, epoxy resins, melamine resins, thermosetting resins such as phenol resins, and the like. Various resin materials etc. are mentioned, Among these, it can use combining 1 type (s) or 2 or more types. In addition, the sealing part 7 should just be provided as needed, and can also be abbreviate | omitted.

2. Operation Method of Display Device Such a display device 20 operates as follows.
When a voltage is applied between the first electrode 3 and the second electrode 4 of the display device 20, an electric field is generated between them. In accordance with this electric field, the electrophoretic particles 5 (colored particles 5b, white particles 5a) move (electrophoresis) toward one of the electrodes 3 and 4.

For example, when white particles 5a having a positive charge are used, and colored particles (black particles) 5b are negatively charged, as shown in FIG. 2A, the first electrode 3 is set to a positive potential. Then, the white particles 5 a move to the second electrode 4 side and gather at the second electrode 4. On the other hand, the colored particles 5 b move to the first electrode 3 side and gather at the first electrode 3. For this reason, when the display device 20 is viewed from above (display surface side), the color of the white particles 5a can be seen, that is, white can be seen.
On the contrary, as shown in FIG. 2B, when the first electrode 3 is set to a negative potential, the white particles 5 a move to the first electrode 3 side and gather on the first electrode 3. . On the other hand, the colored particles 5 b move to the second electrode 4 side and gather at the second electrode 4. For this reason, when the display device 20 is viewed from above (display surface side), the color of the colored particles 5b can be seen, that is, black can be seen.

In such a configuration, display is performed by appropriately setting the charge amount of the electrophoretic particles 5 (white particles 5a, colored particles 5b), the polarity of the electrodes 3 or 4, the potential difference between the electrodes 3 and 4, and the like for each pixel. On the display surface of the device 20, a desired image is displayed according to the combination of the colors of the white particles 5 a and the colored particles 5 b, the number of particles gathered on the electrodes 3 and 4, and the like.
Here, in the display device 20, since the microcapsules 40 in the display layer 400 are adjacent to each other in the surface direction and are arranged without being stacked in the thickness direction. The display device 20 including the display layer 400 can exhibit high contrast.

  In the display device 20, the microcapsules 40 contained in the display layer 400 are present in a spherical shape, so that the pressure resistance and the bleed resistance are excellent. Therefore, even when the display device 20 is operated as described above or while the display device 20 is stored, even when an impact is applied to the display device 20 or the display surface is pressed, the microcapsule 40 is used. Can be prevented and the electrophoretic dispersion liquid 10 can be prevented from being lost, and can operate stably for a long period of time.

3. Method for Manufacturing Display Device Such a display device 20 can be manufactured as follows.
Hereinafter, a method for manufacturing the display device 20 (a method for manufacturing a display sheet of the present invention) will be described with reference to FIGS. 3 to 5 are schematic views for explaining a method of manufacturing the display device shown in FIG. In the following description, the upper side in FIGS. 3 to 5 is referred to as “upper” and the lower side is referred to as “lower”.

  The manufacturing method of the display device 20 shown in FIG. 3 to FIG. The liquid preparation step [A2], the wall forming step [A3] for providing the wall 8 defining the region S1 in which the microcapsules 40 are disposed on the substrate (first substrate) 12, and the inside of the wall 8 The coating liquid supply process [A4] for supplying the microcapsule dispersion 100 to the microcapsule, the microcapsule rearrangement process [A5] for moving and rearranging the microcapsules 40 in the microcapsule dispersion 100, and the thickness direction of the substrate 12 Circuit board 22 (second substrate) is bonded to substrate 12 via microcapsule dispersion liquid 100 (display layer 400). And a plate-bonding step [A6].

Hereinafter, each step will be described.
[A1] Microcapsule production process [A1-1] Formation of first capsule layer First, microcapsules enclosing the electrophoretic dispersion 10 in the first capsule layer 402 are obtained. Hereinafter, for convenience of explanation, this microcapsule is referred to as a “microcapsule precursor”.

  The first capsule layer 402 can be formed, for example, using the electrophoretic dispersion 10 as a core substance and using various microencapsulation techniques. The microencapsulation method (method of encapsulating the electrophoretic dispersion 10 in the first capsule layer 402) is not particularly limited, and examples thereof include an interfacial polymerization method, an in-situ polymerization method, a phase separation method (or a core cell). Various microencapsulation methods such as a basation method), an interfacial precipitation method, and a spray drying method can be used. This microencapsulation method may be appropriately selected according to the constituent material of the first capsule layer 402 and the like.

  For example, when an amino resin such as a melamine resin or a urea resin is used as a constituent material of the first capsule layer 402, it is preferable to use a coacervation method. According to the coacervation method, a droplet of the electrophoretic dispersion 10 serving as a core substance and an initial condensation compound obtained by reacting an amino resin monomer and formaldehyde are allowed to coexist in an aqueous medium, and electrophoresis is performed. A microcapsule precursor can be reliably formed by forming an amino resin layer (first capsule layer 402) by subjecting the initial condensation compound to a condensation reaction in the vicinity of the surface of the droplets of the dispersion 10.

Hereinafter, a formation method for forming the first capsule layer 402 (microcapsule precursor) made of an amino resin using a coacervation method will be described in detail.
<I> Preparation of Core Material Dispersion Liquid First, an electrophoretic dispersion liquid 10 composed of electrophoretic particles 5 and a liquid phase dispersion medium 6 serving as a core material is dispersed in an aqueous medium. A core material dispersion in which droplets are dispersed is obtained. As this aqueous medium, for example, water or a mixed solvent of water and a hydrophilic organic solvent can be used.

  Examples of the hydrophilic organic solvent mixed with the mixed solvent include alcohols such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, and allyl alcohol, ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, pentanediol, Glycols such as hexanediol, heptanediol, dipropylene glycol, ketones such as acetone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, esters such as methyl formate, ethyl formate, methyl acetate, methyl acetoacetate, diethylene glycol monomethyl ether , Diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, ethylene glycol monomethyl ether, ethylene glycol Bruno ethers such as ethyl ether and dipropylene glycol monomethyl ether and the like, can be used singly or in combination of two or more of them.

When a mixed solvent of water and a hydrophilic organic solvent is used, the blending amount of water in the mixed solvent is preferably 70% by mass or more and 95% by mass or less, and is 75% by mass or more and 95% by mass or less. Is more preferably 80% by mass or more and 95% by mass or less.
The aqueous medium may further contain other solvents in addition to water and hydrophilic organic solvents.
Examples of other solvents include hexane, cyclopentane, pentane, isopentane, octane, benzene, toluene, xylene, ethylbenzene, aminyl squalene, petroleum ether, terpene, castor oil, soybean oil, paraffin, kerosene, and the like. One or more of these can be used in combination.

When using another solvent, the content of the other solvent in the aqueous medium is preferably 30% by mass or less, more preferably 25% by mass or less, and further preferably 20% by mass or less.
The amount of the core material dispersed in the aqueous medium is not particularly limited, but is preferably 5 parts by mass or more and 70 parts by mass or less, and 8 parts by mass or more and 65 parts by mass or less with respect to 100 parts by mass of the aqueous medium. More preferably, it is 10 parts by mass or more and 60 parts by mass or less. If the amount of the core material dispersed is small, it takes a long time to form the first capsule layer 402, and the microcapsule precursor having the desired particle size is not sufficiently prepared. If the diameter distribution becomes wide, the production efficiency may be reduced. On the contrary, if the amount of dispersion of the core substance is large, there is a possibility that the microcapsules may not be obtained due to aggregation of the core substance or suspension of the aqueous medium in the core substance.

Moreover, when dispersing a core substance in an aqueous medium, you may use a dispersing agent as needed. Examples of the dispersant include water-soluble polymers such as polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC), gelatin, gum arabic, soybean polysaccharide, soybean protein, and agar, anionic surfactants, and cationic surfactants. , Surfactants such as amphoteric surfactants and nonionic surfactants can be used, and one or more of these can be used in combination.
The amount of the dispersant added to the aqueous medium is not particularly limited, but is appropriately adjusted within a range not inhibiting the formation of the first capsule layer.

<Ii> Production of Initial Condensation Compound The initial condensation compound is obtained by a condensation reaction between a monomer of an amino resin and formaldehyde.
Examples of the monomer include melamine and amino compounds such as urea compounds such as urea and thiourea, and one or a combination of two or more can be used depending on the constituent material of the target capsule layer.

For example, when melamine is used as a monomer, an initial composite compound that provides a melamine resin is obtained, and when any urea compound is used, an initial composite compound that provides a urea resin is obtained. Moreover, when melamine and a urea compound are used in combination, an initial composite compound that gives a resin in which a melamine resin and a urea resin are mixed is obtained.
The reaction between a monomer and formaldehyde is generally performed using water as a solvent. Specifically, the monomer is added to the aqueous formaldehyde solution, or the aqueous formaldehyde solution is added to the monomer and mixed. As a result, the monomer and formaldehyde undergo a condensation reaction, and an aqueous solution of the initial condensation compound is obtained. This condensation reaction is preferably carried out with stirring using, for example, a stirring device.

  The molar ratio (monomer / formaldehyde) of the monomer and formaldehyde subjected to this condensation reaction is not particularly limited, but is preferably 1 / 0.5 or more and 1/10 or less, and is 1/1 or more and 1/8 or less. More preferably, it is 1/1 or more and 1/6 or less. When the monomer / formaldehyde molar ratio is small, the amount of unreacted formaldehyde increases, and the reaction efficiency may decrease. On the other hand, when the monomer / formaldehyde molar ratio is large, the amount of unreacted monomers increases and the reaction efficiency may decrease.

The initial concentration of monomer and formaldehyde (concentration at the time of preparation) in this reaction system is preferably higher as long as the reaction is not hindered.
The reaction temperature in this condensation reaction is not particularly limited, but is preferably 55 ° C or higher and 85 ° C or lower, more preferably 60 ° C or higher and 80 ° C or lower, and 65 ° C or higher and 75 ° C or lower. Is more preferable. The condensation reaction is stopped, for example, by an operation such as cooling the reaction solution to room temperature (for example, 25 ° C. or higher and 30 ° C. or lower) when the reaction end point is recognized. The reaction time is not particularly limited, and can be appropriately set according to the charged amount.

<Iii> Formation of first capsule layer Next, the initial condensation compound obtained in <ii> is gradually added to the core material dispersion obtained in step <i>. As a result, the initial condensing compound is adsorbed on the surface of the droplet of the electrophoretic dispersion 10 and undergoes a condensation reaction. As a result, a resin layer (first capsule layer 402) is formed on the surface of the droplets of the electrophoretic dispersion 10, and a microcapsule precursor enclosing the electrophoretic dispersion 10 is obtained.

  The amount of the initial condensation compound added to the core material dispersion is not particularly limited, but is preferably 0.5 parts by mass or more and 10 parts by mass or less with respect to 1 part by mass of the core substance, More preferably, it is 0.5 parts by mass or more and 5 parts by mass or less, and further preferably 0.5 parts by mass or more and 3 parts by mass or less. The thickness of the first capsule layer 402 can be easily controlled by adjusting the amount of the initial condensation compound added. When the amount of the initial condensation compound is small, it is difficult to form the first capsule layer 402 with a sufficient thickness, and depending on the type of amino compound used, the pressure resistance and bleed resistance of the resulting microcapsules 40 are insufficient. There is a risk. Further, when the amount of the initial condensing compound added is large, the first capsule layer 402 to be formed becomes thick, and thus the flexibility and transparency of the first capsule layer 402 may be insufficient. .

The method for adding the initial condensation compound to the core material dispersion is not particularly limited, and may be batch addition or sequential addition (continuous addition and / or intermittent addition). In addition, when adding an initial condensation compound, it is preferable to carry out, stirring using a stirring apparatus.
In addition, a mercapto (thiol) group is preferably introduced into the first capsule layer 402. Accordingly, the first capsule layer 402 and the second capsule layer 403, which will be described later, can be chemically bonded to each other via the mercapto group, so that the first capsule layer 402, The adhesion with the second capsule layer 403 can be improved.

Such introduction of a mercapto group into the first capsule layer 402 is performed by, for example, adding a carboxyl group (—COOH group) capable of reacting with a core substance dispersion liquid with a mercapto group (—SH group) and an amino group of an initial condensation compound. ) And / or a compound having a sulfo group (—SO ₃ H group) (thiol compound) is added, and the first capsule layer 402 is formed.

  Specific examples of the thiol compound include cysteine (2-amino-3-mercaptopropionic acid), mercaptoacetic acid, mercaptopropionic acid, mercaptobenzoic acid, mercaptosuccinic acid, mercaptoethanesulfonic acid, mercaptopropanesulfonic acid, These alkali metal salts, alkaline earth metal salts, ammonium salts and the like can be mentioned, and one or more of these can be used in combination. Among these, L-cysteine is preferably used because it is easily available.

  The amount of the thiol compound added to the core material dispersion is not particularly limited, but is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the initial condensation compound, and is 1 part by mass or more and 10 parts by mass or more. More preferably, it is 1 part by mass or more and 5 parts by mass or less. When the addition amount of the thiol compound is small, the amount of mercapto groups introduced into the first capsule layer 402 decreases, and the effect of introducing mercapto groups, that is, the second capsule layer 403 is added to the first capsule layer 402. A sufficient bonding effect cannot be obtained. Moreover, when there is much addition amount of a thiol compound, the intensity | strength of the 1st capsule layer 402 formed may fall, and there exists a possibility that pressure | voltage resistance and bleeding resistance may be insufficient.

The method for adding the thiol compound to the core material dispersion is not particularly limited. For example, after adding the initial condensation compound to the core material dispersion, the mixture is sufficiently stirred, and then the thiol compound is added in the form of an aqueous solution. Is preferred.
The reaction temperature for forming the first capsule layer 402 is not particularly limited, but is preferably 25 ° C. or higher and 85 ° C. or lower, more preferably 30 ° C. or higher and 80 ° C. or lower, and 35 ° C. or higher. More preferably, it is 75 ° C. or lower. The reaction time is not particularly limited, and can be appropriately set according to the charged amount.

  In addition, after the condensation reaction, an aging step in which the reaction solution is allowed to stand at a predetermined temperature may be performed. The aging temperature is not particularly limited, but for example, it is preferably a temperature that is the same as or slightly higher than the reaction temperature when performing the condensation reaction. The aging time is not particularly limited, but is preferably 0.5 hours or more and 7 hours or less, and more preferably 1 hour or more and 5 hours or less.

  The microcapsule precursor obtained as described above may be subjected to the next step in a state of being dispersed in an aqueous medium for the purpose of classification and washing, and may be subjected to an aqueous system by a method such as suction filtration or natural filtration. You may make it use for the following process, after isolate | separating from a medium. However, from the viewpoint of surely preventing the first capsule layer 402 from being damaged or destroyed by an impact or pressure during filtration, it is preferable that the first capsule layer 402 be used for the next step without being separated from the aqueous medium.

<Iv> Classification and washing of microcapsule precursor Next, the microcapsule precursor is classified and washed.
The classification method of the microcapsule precursor is not particularly limited, and examples thereof include a sieve type, a filter type, a centrifugal sedimentation type, and a natural sedimentation type. Among these, when the particle diameter of the microcapsule precursor to be recovered is relatively large, it is preferable to use a sieve type.
Although it does not specifically limit as a washing | cleaning method of a microcapsule precursor, For example, a centrifugal sedimentation type, a natural sedimentation type, etc. are mentioned. Among these, when the particle size of the microcapsule precursor is relatively large, it is preferable to use a natural sedimentation method in order to prevent damage and destruction of the microcapsule precursor. Note that the cleaning is not limited to one time but may be performed a plurality of times.

[A1-2] Formation of Second Capsule Layer Next, a second capsule layer 403 is formed on the outer peripheral surface of the microcapsule precursor (first capsule layer 402) obtained in the step [A1-1]. Then, the microcapsules 40 enclosing the electrophoretic dispersion 10 are obtained.
In the second capsule layer 403, for example, a resin prepolymer is gradually added to a capsule dispersion liquid in which a microcapsule precursor is dispersed in an aqueous medium, and the prepolymer adsorbed on the surface of the microcapsule precursor is obtained. It can be formed by a polymerization reaction. As a result, the second capsule layer 403 is formed on the surface of the microcapsule precursor, and the microcapsules 40 enclosing the electrophoretic dispersion 10 are obtained.

Examples of the aqueous medium in which the microcapsule precursor is dispersed include the same aqueous medium in which the electrophoretic dispersion liquid is dispersed in the step [A1-1].
In addition, when the microcapsule precursor obtained in the step [A1-1] is in a state of being dispersed in an aqueous medium, it may be used as it is as a capsule dispersion, and concentrated or diluted as necessary. After that, it may be used as a capsule dispersion.

The prepolymer gives a resin by a polymerization reaction, and examples thereof include a resin monomer, an oligomer, or a mixture thereof.
Specifically, the prepolymer is appropriately selected according to the constituent material of the second capsule layer 403. For example, when the second capsule layer 403 is made of an epoxy resin, the compound containing an epoxy group (Epoxy compound) is used.
By configuring the second capsule layer 403 with an epoxy resin, the second capsule layer 403 is surely superior in elasticity compared to the first capsule layer 402 configured with an amino resin. Become. Furthermore, when the first capsule layer 402 has a structure having a mercapto group, the second capsule layer 403 is chemically bonded to the surface of the first capsule layer 402 via the mercapto group. As a result, the microcapsule 40 having excellent strength can be obtained.

The epoxy compound is not particularly limited, and an epoxy compound having at least one epoxy group in one molecule can be used. Among them, a water-soluble epoxy compound having two or more epoxy groups is preferably used.
Specifically, examples of the epoxy compound include sorbitol polyglycidyl ether, sorbitan polyglycidyl ether, polyglycerol polyglycidyl ether, and the like, and one or more of these can be used in combination.

  The weight average molecular weight of the epoxy compound is preferably about 300 or more and 100,000 or less, more preferably about 300 or more and 75000 or less, and further preferably about 300 or more and 50000 or less. If the mass average molecular weight of the epoxy compound is small, the strength of the formed second capsule layer 403 may be insufficient depending on the type of the epoxy compound used. On the contrary, if the mass average molecular weight of the epoxy compound is large, the viscosity of the reaction system becomes high and stirring may be difficult.

  The addition amount of the epoxy compound added to the capsule dispersion is not particularly limited, but is preferably 0.5 parts by mass or more and 10 parts by mass or less with respect to 1 part by mass of the microcapsule precursor. More preferably, it is 0.5 parts by mass or more and 5 parts by mass or less, and further preferably 0.5 parts by mass or more and 3 parts by mass or less. By adjusting the addition amount of the epoxy compound, the thickness of the second capsule layer 403 can be easily controlled. If the addition amount of the epoxy compound is small, it is difficult to form the second capsule layer 403 with a sufficient thickness, and the pressure resistance of the obtained microcapsules 40 may be insufficient. Moreover, when there is much addition amount of an epoxy compound, there exists a possibility that the thickness of the 2nd capsule layer 403 formed may become large too much, and a softness | flexibility and transparency may become inadequate.

  The method for adding the epoxy compound to the capsule dispersion is not particularly limited. For example, the epoxy compound is preferably added to the capsule dispersion in the form of an aqueous solution. Addition may be either batch addition or sequential addition (continuous addition and / or intermittent addition). Moreover, when adding an epoxy compound, it is preferable to carry out, stirring using a conventionally well-known stirring apparatus.

  The capsule dispersion preferably contains a crosslinking agent. Thereby, the second capsule layer 403 having a crosslinked structure can be obtained. By forming a crosslinked structure in the second capsule layer 403, the strength of the second capsule layer 403, and hence the strength of the entire capsule body 401, is improved, so that the microcapsule 40 can be separated or washed thereafter. In addition, the capsule body 401 can be effectively prevented from being damaged or broken.

As the crosslinking agent, when the prepolymer is an epoxy compound, for example, sodium diethyldithiocarbamate (including hydrate), diethylammonium diethyldithiocarbamate (including hydrate), dithiooxalic acid, dithiocarbonate, etc. 1 type or 2 types or more of these can be used in combination.
The addition amount of the crosslinking agent added to the capsule dispersion is not particularly limited, but is preferably 1 part by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the epoxy compound, and 5 parts by mass or more and 90 parts by mass. More preferably, it is 10 parts by mass or more and 80 parts by mass or less. When the addition amount of the crosslinking agent is small, the effect of increasing the strength of the second capsule layer 403 cannot be obtained sufficiently. Moreover, when there is much addition amount of a crosslinking agent, a crosslinking agent reacts with the epoxy group of an epoxy compound excessively, and the softness | flexibility of the 2nd capsule layer 403 may fall.

When adding the crosslinking agent to the capsule dispersion, the crosslinking agent may be added together with the epoxy compound, or may be added before or after the addition of the epoxy compound. For example, it is preferable to add an aqueous solution of an epoxy compound to the capsule dispersion, add a little time, and then drop the crosslinking agent in the form of an aqueous solution while stirring.
The reaction temperature for forming the second capsule layer 403 is not particularly limited, but is preferably 25 ° C. or higher and 80 ° C. or lower, more preferably 30 ° C. or higher and 70 ° C. or lower, and 35 ° C. As described above, the temperature is more preferably 60 ° C. or lower. The reaction time is not particularly limited, and can be appropriately set according to the charged amount.

  Further, after the second capsule layer 403 is formed, an aging step of leaving the reaction solution at a predetermined temperature may be performed. The aging temperature is not particularly limited, but is preferably the same as or slightly higher than the temperature at which the second capsule layer 403 is formed, for example. The aging time is not particularly limited, but is preferably 0.5 hours or more and 5 hours or less, more preferably 1 hour or more and 3 hours or less.

The microcapsules 40 obtained as described above may be subjected to the next step in a state of being dispersed in the aqueous medium. After being separated from the aqueous medium by a method such as suction filtration or natural filtration, the microcapsules 40 are transferred to the next step. However, when the microcapsules 40 are in a dry state, the solvent of the electrophoretic dispersion liquid may leach out from the capsule body 401 and evaporate, so that the microcapsules 40 may be deformed. Therefore, the microcapsules 40 are separated from the aqueous medium. It is preferable to use for the following process, without doing.
The obtained microcapsules 40 are preferably classified and washed. Thereby, the microcapsule 40 with a narrow particle size distribution and few impurities can be obtained.
As the classification method and the washing method, for example, the same method as in the above-mentioned step [A1-1] can be mentioned.

[A2] Preparation Step of Microcapsule Dispersion Next, the binder 41 is prepared, and the binder 41 and the microcapsules 40 prepared in the step [A1] are mixed to prepare the microcapsule dispersion 100. The microcapsule dispersion liquid 100 may be mixed with a solvent such as ethanol, if necessary, whereby the viscosity of the microcapsule dispersion liquid 100 can be lowered, and the microcapsule dispersion liquid 100 can be used as a substrate. 12 can be supplied easily.

  The content of the microcapsule 40 in the microcapsule dispersion 100 is preferably about 50 wt% or more and 95 wt% or less, and more preferably about 70 wt% or more and 90 wt% or less. In the display layer 400, when the content of the microcapsules 40 is set in the above range, the microcapsules 40 are in contact with each other in the plane direction and do not overlap in the thickness direction (single layer). In the next step [A3], the microcapsules 40 are moved (rearranged) and are very advantageous.

  Further, in the next step [A3], from the viewpoint of moving (rearranging) the microcapsules 40 and arranging them, the binder 41 to be prepared has the glass transition temperature of the above-mentioned one, and the lower limit is usually − It is 50 ° C, preferably -45 ° C, more preferably -40 ° C, and the upper limit is usually 10 ° C, preferably 5 ° C, more preferably 0 ° C. If the glass transition temperature of the binder 41 is less than −50 ° C., the adhesion between the circuit board 22 (counter substrate 11) and the substrate 12 may be reduced. On the other hand, when the glass transition temperature of the binder 41 exceeds 10 ° C., the microcapsules 40 are difficult to move in the microcapsule dispersion 100 in the step [A5].

  The binder 41 having such a glass transition temperature is made of a material having higher flexibility than a material having relatively high rigidity. Specifically, among the binders 41 described above, examples of the highly flexible binder 41 include polyalkylene glycol resins and (meth) acrylic resins having an alkyl group having 2 or more carbon atoms as side chains. 1 type or 2 types or more of these can be used in combination.

  Among these, as the binder 41 having high flexibility, those containing a glycol chain, that is, polyalkylene glycol resins are preferably used. Particularly, polyalkylene glycol resins having a weight average molecular weight of 200 or more and 100,000 or less are used. Preferably used. The polyalkylene glycol resin having such a weight average molecular weight has excellent adhesion to the substrate 12 and the microcapsules 40 are easy to move in the microcapsule dispersion 100 in the step [A4]. The overlapping of the microcapsules 40 in the thickness direction can be reliably prevented.

[A3] Wall Forming Step Next, as shown in FIGS. 3A and 3B, the microcapsule dispersion 100 is supplied onto the substrate 12 (on the second electrode 4) in the next step [A4]. The wall portion 8 is formed in a frame shape so as to surround the entire periphery of the region S1 to be provided (that is, the microcapsule 40 is to be provided), and the region S1 in which the microcapsule 40 is provided is defined. In the present embodiment, the region S1 has a rectangular shape in plan view, and the walls 8 are formed on the four sides of the rectangular region S1. 3A is a plan view of the substrate 12, and FIG. 3B is a cross-sectional view taken along line AA in FIG. 3A.

  Here, in the present embodiment, by using the wall portion 8 as the sealing portion 7, the number of parts is reduced and the manufacturing of the display device 20 is simplified. In the present embodiment, the wall 8 is used as a spacer in step [A6], thereby effectively preventing breakage, destruction, deformation, and the like of the microcapsule 40. In the present embodiment, in step [A5], the wall portion 8 is used as a stopper for preventing excessive pressing of the pressing substrate 19 to be described later on the substrate 12, and thereby in step [A5]. The microcapsule 40 is effectively prevented from being damaged or broken.

  Such a wall portion 8 may be formed by any method. For example, the wall portion 8 may be formed into a frame shape by a method such as fusion such as heat fusion, adhesion such as an adhesive tape, an adhesive, or an adhesive. A method of fixing a member, a method of forming by printing such as an ink-jet method, a method of leaving a frame-shaped portion by performing machining, etching, laser processing, etc. on the first base 1 Can be formed.

  In addition, when using the wall part 8 as the sealing part 7 like this embodiment (namely, when making the wall part 8 exhibit the function which prevents the deterioration of the microcapsule 40), as a constituent material of the wall part 8, Examples include various resin materials such as thermoplastic resins such as acrylic resins, urethane resins and olefin resins, epoxy resins, melamine resins, and thermosetting resins such as phenol resins. 1 type or 2 types or more can be used in combination. Thereby, it is possible to prevent moisture from entering the display device 20 and effectively prevent the microcapsule 40 from deteriorating.

  Further, the height of the wall portion 8 (length in the thickness direction of the substrate 12) is not particularly limited, but when the particle size (volume average particle size) of the microcapsules 40 is R, 0.5R or more, It is preferably about 1.0R or less, more preferably about 1.0R. By setting the height of the wall portion 8 within the above range, when the pressure is applied to the microcapsule dispersion 100 in the steps [A5] and [A6], the pressure can be prevented from becoming an excessive force. In other words, it is possible to effectively prevent the microcapsule 40 from being damaged due to an excessive force applied to the microcapsule 40. In addition, when pressure is applied to the microcapsule dispersion liquid 100 in steps [A5] and [A6], the microcapsule 40 is prevented from moving beyond the wall portion 8 to the outside of the wall portion 8. Can do.

[A4] Coating Solution Supply Step The microcapsule dispersion liquid 100 is supplied on the substrate 12 and inside the wall portion 8 (ie, the region S1) formed in the previous step [A3].
A method for supplying the microcapsule dispersion 100 onto the substrate 12 is not particularly limited, and various coating methods such as a spin coating method, a dip coating method, a spray coating method, a die coating method, and a comma coating method can be used.

Here, the number N1 of the microcapsules 40 included in the microcapsule dispersion liquid 100 supplied onto the substrate 12 is about the maximum number Nmax of the microcapsules 40 that can be arranged in a single layer inside the wall portion 8. Is preferred. Specifically, the number N of the microcapsules 40 is preferably 0.9 Nmax or more and 1.1 Nmax or less, more preferably 1.0 Nmax or more and 1.1 Nmax or less, and 1.0 Nmax. Is more preferable. By setting the number N in the above range, when the microcapsules 40 are arranged in a single layer in the wall portion 8, the plurality of microcapsules 40 are arranged so that the adjacent microcapsules 40 are in contact with each other, and While maintaining the shape (spherical shape), it can be arranged closest.
Note that the amount of the microcapsule dispersion 100 supplied onto the substrate 12 may be such that the number N of the microcapsules 40 falls within the above-described numerical range. For example, the particle size (volume average particle size) of the microcapsules 40 And the number of microcapsules 40 present per unit volume of the microcapsule dispersion 100 may be calculated.

[A5] Microcapsule Rearrangement Step Next, a pressing substrate 19 having a flat plate shape is prepared and arranged so as to overlap the microcapsule dispersion liquid 100 supplied onto the substrate 12. Then, as shown in FIG. 4A, the substrate 12 and the pressing substrate 19 are pressed in the direction in which they approach each other, that is, in the thickness direction of the substrate 12. Thereby, since the microcapsule dispersion liquid is pressurized in the thickness direction of the substrate 12, the microcapsules 40 ′ (40) existing so as to overlap the microcapsule dispersion liquid 100 in the thickness direction of the substrate 12. When the microcapsule 40 ′ is moved, the microcapsules 40 ′ are moved in the direction of the surface of the substrate 12 due to the movement of the microcapsules 40 ′. The microcapsule 40 ″ moves to S11, and the microcapsule 40 is compensated for in the defect portion S11. As a result, as shown in FIG. 4B, the microcapsules 40 are monolayered in the microcapsule dispersion 100, and the arrangement density of the microcapsules 40 is made uniform. That is, the microcapsules 40 are arranged in contact with each other with respect to the surface direction of the substrate 12 and are arranged in a line without overlapping in the thickness direction. Thereby, the display layer 400 is obtained.

  In particular, in this embodiment, since the movement of the microcapsule 40 is limited by the wall portion 8, that is, the microcapsule 40 can be moved only inside the wall portion 8, the wall portion can be more reliably obtained. 8, the microcapsules 40 can be arranged in contact with each other with respect to the surface direction of the substrate 12, and can be arranged in one row (that is, a single layer) without overlapping in the thickness direction. Further, since the wall portion 8 is used as a stopper for restricting the movement of the pressing substrate 19, excessive pressure application to the microcapsule 40 by the pressing substrate 19 is prevented, and destruction of the microcapsule 40 is effectively prevented. can do.

  As in the present embodiment, by using a pressing substrate 19 having a flat plate shape and pressurizing the microcapsule dispersion liquid 100 in the thickness direction of the substrate 12, the second electrode 4 of the substrate 12 is applied. Each part of the supplied microcapsule dispersion 100 can be uniformly pressurized. Therefore, in each part of the microcapsule dispersion liquid 100, the microcapsules 40 are reliably arranged in contact with each other with respect to the surface direction of the substrate 12, and reliably arranged in one row without overlapping in the thickness direction. Can be arranged.

The pressing substrate 19 is not particularly limited, but a substrate that can be easily peeled off from the display layer 400 formed by pressing in the thickness direction of the substrate 12 is used. Specifically, for example, a base material (base material) A material having a release agent layer formed on the surface thereof is preferably used.
As the base material, for example, at least one of PET, high pressure method low density polyethylene, high density polyethylene, linear low density polyethylene, ethylene-vinyl acetate copolymer resin, unstretched polypropylene, stretched polypropylene and stretched nylon is used. Examples of the main material include plastic film, kraft paper, polyethylene laminated paper, polypropylene laminated paper, and nonwoven fabric.

Further, the thickness of the base material is preferably about 10 μm or more and 250 μm or less, and more preferably about 50 μm or more and 200 μm or less.
Although it does not specifically limit as a mold release agent layer, What is comprised as a main material at least 1 sort (s) of a silicone type mold release agent, a fluorine type mold release agent, and a modified silicone type mold release agent is mentioned.
The thickness of the release agent layer is preferably about 0.01 μm or more and 2 μm or less, and more preferably about 0.1 μm or more and 1 μm or less.

By using the pressing substrate 19 having such a configuration, the pressing substrate 19 can be reliably peeled from the display layer 400 without a part of the display layer 400 adhering to the pressing substrate 19.
In addition, when using what does not have a mold release agent layer as the board | substrate 19 for a press, it is preferable to form an uneven surface on the surface of the board | substrate 19 for a press. That is, it is preferable to emboss the surface of the pressing substrate 19. Thereby, since the function similar to a mold release agent layer can be provided to the surface in which the uneven surface was formed, the pressing substrate 19 can be easily peeled from the display layer 400.

  The method for pressurizing the microcapsule dispersion 100 in the thickness direction of the substrate 12 is not particularly limited, and examples thereof include various laminating methods using a single wafer vacuum laminator, a metal roller laminator, a rubber roller laminator, and the like. It is done. According to the laminating method, each part of the microcapsule dispersion liquid 100 supplied onto the second electrode 4 of the substrate 12 can be pressed with a uniform pressing force. An apparatus to which such a laminating method is applied is not particularly limited, and examples thereof include a roll laminator (product name: VA-700DFR, manufactured by Taisei Laminator Co., Ltd.).

  In addition, when the pressure is applied in the thickness direction of the substrate 12, the magnitude of the pressure applied between the substrates 12 varies depending on the strength of the microcapsules 40. For example, when the strength of the microcapsules is about 3.0 MPa Is preferably set to about 0.3 MPa or more and 1.5 MPa or less, more preferably about 0.3 MPa or more and 1.0 MPa or less. That is, the magnitude of the pressure is preferably set to about 0.1 to 0.5 times the strength of the microcapsule 40, and is set to about 0.1 to 0.33 times. Is more preferable. When such a pressure is applied between the substrate 12 and the pressing substrate 19, the microcapsules 40 contained in the microcapsule dispersion liquid 100 are substantially spherical without being compressed (pressed) in the vertical direction. While maintaining the (spherical shape), the microcapsule 40 moves in the microcapsule dispersion 100 (binder 41). Finally, in the microcapsule dispersion 100, the microcapsules 40 are in the plane direction of the substrate 12. They are arranged in contact with each other and arranged in a line without overlapping in the thickness direction.

  The temperature of the microcapsule dispersion 100 when pressurizing the microcapsule dispersion 100 is not particularly limited, but is preferably set to about 50 ° C. or more and 150 ° C. or less, and is set to about 70 ° C. or more and 100 ° C. or less. Is more preferable. By setting the temperature within such a temperature, the microcapsule 40 can be smoothly moved in the microcapsule dispersion 100 by pressurizing the microcapsule dispersion 100 in the thickness direction of the substrate 12.

In addition, when the microcapsule dispersion liquid 100 is pressurized in the thickness direction of the substrate 12, vibration may be applied to the microcapsule dispersion liquid 100. Thereby, the distribution of the microcapsules 40 in the surface direction of the substrate 12 can be made more uniform. The application of vibration to the microcapsule dispersion liquid 100 is preferably performed by applying an ultrasonic wave to the microcapsule dispersion liquid 100, and the frequency of the ultrasonic wave is 1 × 10 ⁵ Hz or more and 1 × 10 ⁸ Hz. It is preferable to set within the following range, and it is more preferable to set within the range of 1 × 10 ⁵ Hz or more and 5 × 10 ⁷ Hz or less.

  Further, after the microcapsule dispersion liquid 100 is pressurized in the thickness direction of the substrate 12, it is preferable to shift the substrate 12 and the pressing substrate 19 in the surface direction while maintaining this state, and then the surface direction. More preferably, the substrate 12 and the pressing substrate 19 are further displaced in a direction perpendicular to the surface direction. Thereby, the distribution of the microcapsules 40 in the surface direction of the substrate 12 can be made particularly uniform.

  The distance by which the substrate 12 and the pressing substrate 19 are displaced in the plane direction is such that the microcapsule 40 rotates once, specifically, for example, when the diameter of the microcapsule 40 is about 40 μm, it is 100 μm or more and 200 μm or less. Is preferably about 120 μm or more and 150 μm or less. Thereby, the said effect can be exhibited more notably now.

[A6] Substrate Bonding Step Next, as shown in FIG. 5, the circuit board 22 is placed on the display layer 400 formed in the previous step [A5] with the first electrode 3 side facing the display layer 400 side. Overlapping. Next, the circuit board 22 and the display sheet 21 are pressed in the direction in which they approach each other, that is, in the thickness direction of the board 12. Thereby, the display sheet 21 and the circuit board 22 are joined.

In the present embodiment, as described above, the wall portion 8 is used as a spacer that defines the separation distance between the display sheet 21 and the circuit board 22, so that the microcapsule 40 can be effectively damaged, broken, deformed, and the like. This can be prevented, and the distance between the first electrode 3 and the second electrode 4 can be set to a desired distance, so that the drive of the display device 20 can be stabilized.
Moreover, in this embodiment, since the wall part 8 is utilized as the sealing part 7 as mentioned above, manufacture of the display apparatus 20 can be simplified and the number of parts can be reduced.

  The magnitude of the pressure applied when joining the circuit board 22 and the display sheet 21 is preferably substantially equal to the pressure applied to the microcapsule dispersion 100 in the step [A5]. In the present embodiment, as in the step [A5], since the step [A6] is also performed with the wall portion 8 formed, by setting the pressure in this step to the same level as the step [A5], With the shape of the microcapsule 40 maintained in a spherical shape (that is, while preventing the microcapsule 40 from being broken), the circuit board 22 and the display sheet 21 can be firmly bonded using the adhesive force of the binder 41. .

  The method of pressing the circuit board 22 in the thickness direction of the board 12 is not particularly limited, and for example, the pressing board 19 used in the step [A5] can be used. Further, for example, various laminating methods using a single-wafer vacuum laminator, a metal roller laminator, a rubber roller laminator, or the like can also be used. According to the laminating method, each part of the circuit board 22 and the display sheet 21 can be pressed with a uniform pressing force. An apparatus to which such a laminating method is applied is not particularly limited, and examples thereof include a roll laminator (product name: VA-700DFR, manufactured by Taisei Laminator Co., Ltd.).

Through the above steps, the display device 20 is obtained.
In the display device 20 thus obtained, the microcapsules 40 contained in the display layer 400 are spherical, and in the display layer 400, the microcapsules 40 are in contact with each other with respect to the surface direction of the display layer 400. They are arranged in a state and arranged in one row without overlapping in the thickness direction. As a result, the display device 20 can exhibit excellent (high) contrast.

Second Embodiment
Next, a second embodiment of the display device of the present invention will be described.
6 and 7 are schematic views for explaining a method for manufacturing a display device according to the second embodiment of the present invention.
Hereinafter, the manufacturing method of the display device according to the second embodiment will be described focusing on differences from the above-described embodiment, and the description of the same matters will be omitted.

The display device manufacturing method according to the second embodiment of the present invention is the display of the first embodiment, except that it includes a wall portion removing step for removing the wall portion and a sealing portion forming step for forming the sealing portion. It is the same as the manufacturing method of the apparatus. In addition, the same code | symbol is attached | subjected to the structure similar to 1st Embodiment mentioned above.
In the present embodiment, the display device 20 is manufactured as follows. That is, the manufacturing method of the display device 20 includes a microcapsule manufacturing process [B1] for manufacturing the microcapsules 40, a microcapsule dispersion preparing process [B2] for preparing the microcapsule dispersion 100 including the microcapsules 40, and the substrate 12. On top of this, a wall forming step [B3] for providing the wall 8 defining the region S1 in which the microcapsules 40 are disposed, and a coating liquid supplying step [B4] for supplying the microcapsule dispersion 100 to the inside of the wall 8 A microcapsule rearrangement step [B5] for moving and rearranging the microcapsules 40 in the microcapsule dispersion 100, a wall portion removal step [B6] for removing the wall portion 8 from the substrate 12, and By applying pressure in the thickness direction, the circuit board 22 is connected to the board 12 via the microcapsule dispersion 100 (display layer 400). A case that the substrate bonding step [B7], and a sealing portion formation process [B8] to form the sealing portion 7 so as to cover the periphery of the display layer 400.

Here, since the processes [B1] to [B5] are the same as the processes [A1] to [A5] of the first embodiment described above, the description thereof will be omitted, and the processes [B6] to [B] will be described below. B8] will be described in detail.
[B6] Wall Part Removal Step In this step, the wall part 8 is removed from the substrate 12. That is, the state shown in FIG. 6A is changed to the state shown in FIG. Although it does not specifically limit as a removal method of the wall part 8, The following methods are preferable. That is, for example, in the step [B3], the frame-shaped wall portion 8 is bonded to the substrate 12 through an adhesive whose adhesive strength disappears when irradiated with ultraviolet rays, and in this step [B6], the adhesive is irradiated with ultraviolet rays. The method of removing the wall part 8 by irradiating is preferable. Thereby, the wall part 8 can be removed easily.

  By providing this step, the degree of freedom in selecting the constituent material of the wall 8 is expanded. That is, in the first embodiment, since the wall portion 8 is used as the sealing portion 7, the constituent material of the wall portion 8 needs to be a material that can fulfill the function of the sealing portion 7. Although the degree of freedom has been reduced, in this embodiment, since the wall 8 is not used as the sealing portion 7, the degree of freedom in selecting the constituent material of the wall 8 is greater than that in the first embodiment.

[B7] Substrate Bonding Step Next, as shown in FIG. 7A, the counter substrate 11 (circuit substrate 22) is moved to the previous step [B5] with the first electrode 3 side facing the display layer 400 side. Overlap on the formed display layer 400. Next, the counter substrate 11 and the display sheet 21 are pressed in the direction in which they are close to each other, that is, in the thickness direction of the substrate 12. Thereby, the display sheet 21 and the counter substrate 11 are joined.

  The magnitude of the pressure applied when bonding the counter substrate 11 and the display sheet 21 is preferably lower than the pressure applied to the microcapsule dispersion 100 in the step [B5]. Specifically, when the strength of the capsule body 401 of the microcapsule 40 is about 3.0 MPa, it is preferably set to about 0.1 MPa or more and 0.3 MPa or less. That is, the magnitude of the pressure is preferably set to about 0.03 to 0.1 times the strength of the microcapsule 40. When such a pressure is applied between the substrate 12 and the counter substrate 11, it is possible to firmly bond the counter substrate 11 and the display sheet 21 while preventing the microcapsule 40 from being broken.

[B8] Sealing Part Formation Step Next, as shown in FIG. 7B, the sealing part 7 is formed along the edges of the substrate 12 and the counter substrate 11. This is between the substrate 12 and the counter substrate 11, and is formed by supplying a material for forming the sealing portion 7 along these edges with a dispenser, for example, and solidifying or curing the material. can do.
Also by such 2nd Embodiment, the effect similar to 1st Embodiment can be exhibited.

<Third Embodiment>
Next, a third embodiment of the display device of the present invention will be described.
8 and 9 are schematic views for explaining a method for manufacturing a display device according to the third embodiment of the present invention.
Hereinafter, the manufacturing method of the display device according to the third embodiment will be described with a focus on differences from the above-described embodiment, and description of similar matters will be omitted.

The manufacturing method of the display device according to the third embodiment of the present invention is the same as the manufacturing method of the display sheet of the first embodiment except that the order of the wall forming process for forming the wall is different. In addition, the same code | symbol is attached | subjected to the structure similar to 1st Embodiment mentioned above.
In the present embodiment, the display device 20 is manufactured as follows. That is, the manufacturing method of the display device 20 includes a microcapsule manufacturing process [C1] for manufacturing the microcapsules 40, a microcapsule dispersion preparing process [C2] for preparing the microcapsule dispersion 100 including the microcapsules 40, and the substrate 12. Above, a coating liquid supplying step [C3] for supplying the microcapsule dispersion 100 to the region S1 set as a region where the microcapsules 40 are disposed, and the microcapsules 40 are moved and rearranged in the microcapsule dispersion 100. By applying a pressure in the thickness direction of the substrate 12, the microcapsule rearrangement step [C 4], the wall forming step [C 5] for forming the wall 8 so as to surround the periphery of the region S 1 on the substrate 12, A substrate for bonding the circuit substrate 22 to the substrate 12 via the microcapsule dispersion 100 (display layer 400). And a focus step [C6].
Here, the steps [C1], [C2], and [C6] are the same as the steps [A1], [A2], and [A6] of the first embodiment described above, and thus the description thereof is omitted. The steps [C3] to [C5] will be described in detail.

[C3] Coating Solution Supply Step In this step, as shown in FIG. 8A, the microcapsule dispersion liquid 100 is supplied to a region (microcapsule placement region) S1 set on the substrate 12. The amount of the microcapsule dispersion 100 to be supplied is the same as that described in the first embodiment.
[C4] Microcapsule Rearrangement Step Next, as shown in FIG. 8B, the microcapsule dispersion 100 is pressurized in the thickness direction of the substrate 12 using the pressing substrate 19. Thereby, similarly to the process [A5] of the first embodiment, the microcapsules 40 are made into a single layer in the microcapsule dispersion liquid 100, and the arrangement density of the microcapsules 40 is made uniform. That is, the microcapsules 40 are arranged in contact with each other with respect to the surface direction of the substrate 12 and are arranged in a line without overlapping in the thickness direction. Thereby, the display layer 400 is obtained.

  The magnitude of the pressure applied to rearrange the microcapsules 40 is the pressure applied to the microcapsule dispersion 100 in step [C6] (ie, in step [A6] of the first embodiment described above). The pressure applied is preferably lower than the applied pressure. Specifically, when the strength of the capsule body 401 of the microcapsule 40 is about 3.0 MPa, it is preferably set to about 0.1 MPa or more and 0.3 MPa or less. That is, the magnitude of the pressure is preferably set to about 0.03 to 0.1 times the strength of the microcapsule 40. When such a pressure is applied between the substrate 12 and the pressing substrate 19, the microcapsules 40 contained in the microcapsule dispersion liquid 100 are substantially spherical without being compressed (pressed) in the vertical direction. While maintaining the (spherical shape), the microcapsule 40 moves in the microcapsule dispersion 100 (binder 41). Finally, in the microcapsule dispersion 100, the microcapsules 40 are in the plane direction of the substrate 12. They are arranged in contact with each other and arranged in a line without overlapping in the thickness direction. Further, the movement of the microcapsules 40 in the surface direction of the substrate 12 is suppressed, and the microcapsules 40 are uniformly arranged over the entire region S1.

[C5] Wall Forming Step Next, as shown in FIG. 9, the wall 8 is formed so as to surround the periphery of the display layer 400. In the present embodiment, the wall portion 8 is used as the sealing portion 7 as in the first embodiment.
According to the third embodiment, the same effect as that of the first embodiment can be exhibited.

<Fourth embodiment>
Next, a display device according to a fourth embodiment of the invention will be described.
FIG. 10 is a schematic view for explaining the method for manufacturing the display device according to the fourth embodiment of the present invention.
Hereinafter, a method for manufacturing a display device according to the fourth embodiment will be described focusing on differences from the above-described embodiments, and description of similar matters will be omitted.

The display device manufacturing method according to the fourth embodiment of the present invention is the same as the display sheet manufacturing method of the first embodiment, except that the microcapsule rearrangement step and the substrate bonding step are one step. It is. In addition, the same code | symbol is attached | subjected to the structure similar to 1st Embodiment mentioned above.
In the present embodiment, the display device 20 is manufactured as follows. That is, the manufacturing method of the display device 20 includes a microcapsule manufacturing process [D1] for manufacturing the microcapsules 40, a microcapsule dispersion preparing process [D2] for preparing the microcapsule dispersion 100 including the microcapsules 40, and the substrate 12. A wall forming step [D3] for providing a wall 8 defining the region S1 on which the microcapsules 40 are disposed, and a coating liquid supplying step [D4] for supplying the microcapsule dispersion 100 to the inside of the wall 8 are provided. Then, the pressure in the thickness direction of the substrate 12 is applied to the microcapsule dispersion 100 supplied to the region S1, the microcapsules 40 are rearranged, and the circuit board 22 is placed in the microcapsule dispersion 100 (display layer 400). ) Through a substrate bonding step [D5] for bonding to the substrate 12.
Here, since the steps [D1] to [D4] are the same as the steps [A1] to [A4] of the first embodiment described above, the description thereof is omitted, and the details of the step [D5] are described below. Explained.

[D5] Substrate Bonding Step First, in a state where the microcapsule dispersion liquid 100 is supplied onto the substrate 12, the first electrode 3 side faces the display layer 400 side as shown in FIG. The substrate 11 (circuit substrate 22) is overlaid on the microcapsule dispersion 100 (substrate 12). Next, the counter substrate 11 and the display sheet 21 are pressed in the direction in which they are close to each other, that is, in the thickness direction of the substrate 12. As a result, the counter substrate 11 and the substrate 12 are bonded together via the display layer 400, and the microcapsules 40 are rearranged in the microcapsule dispersion liquid 100. That is, the microcapsule dispersion 100 is pressurized in the thickness direction of the substrate 12, and the microcapsules 40 ′ (40) existing so as to overlap the microcapsule dispersion 100 move in the thickness direction of the substrate 12. As a result, the microcapsule 40 ′ is moved in the direction of the surface of the substrate 12 due to the movement of the microcapsule 40 ′. The microcapsule 40 ″ is moved, and the microcapsule 40 is filled in the defect portion S11. As a result, the microcapsules 40 are monolayered in the microcapsule dispersion 100, and the arrangement density of the microcapsules 40 is made uniform. Thereby, as shown in FIG.10 (b), the display apparatus 20 is obtained.

The magnitude of the pressure applied in this step varies depending on the strength of the microcapsule 40. For example, when the strength of the microcapsule is about 3.0 MPa, the pressure is set to about 0.3 MPa or more and 1.5 MPa or less. It is preferable that the pressure is set to about 0.3 MPa or more and 1.0 MPa or less. That is, the magnitude of the pressure is preferably set to about 0.1 to 0.5 times the strength of the microcapsule 40, and is set to about 0.1 to 0.33 times. Is more preferable. When such a pressure is applied between the substrate 12 and the counter substrate 11, the microcapsules 40 contained in the microcapsule dispersion liquid 100 are substantially spherical (without being compressed (pressed) in the vertical direction). The microcapsules 40 are moved in the microcapsule dispersion 100 (binder 41) while maintaining the spherical shape. Finally, in the microcapsule dispersion 100, the microcapsules 40 are mutually in the plane direction of the substrate 12. They are arranged in contact with each other and arranged in a line without overlapping in the thickness direction. Further, the counter substrate 11 and the substrate 12 can be bonded more firmly.
According to the fourth embodiment, the same effect as that of the first embodiment can be exhibited.

<Electronic equipment>
The display device 20 as described above can be incorporated into various electronic devices. Hereinafter, the electronic apparatus of the present invention including the display device 20 will be described.
<< Electronic Paper >>
First, an embodiment when the electronic apparatus of the present invention is applied to electronic paper will be described.

FIG. 11 is a perspective view showing an embodiment when the electronic apparatus of the present invention is applied to electronic paper.
An electronic paper 600 shown in FIG. 11 includes a main body 601 composed of a rewritable sheet having the same texture and flexibility as paper, and a display unit 602. In such electronic paper 600, the display unit 602 includes the display device 20 as described above.

<< Display >>
Next, an embodiment when the electronic apparatus of the present invention is applied to a display will be described.
FIG. 12 is a diagram showing an embodiment when the electronic apparatus of the present invention is applied to a display. Among these, (a) in FIG. 12 is a sectional view and (b) is a plan view.
A display (display device) 800 shown in FIG. 12 includes a main body 801 and an electronic paper 600 that is detachably attached to the main body 801. The electronic paper 600 has the same configuration as described above, that is, the configuration shown in FIG.

  The main body 801 has an insertion port 805 into which the electronic paper 600 can be inserted on its side (right side in FIG. 12A), and two pairs of transport rollers 802a and 802b are provided inside. Yes. When the electronic paper 600 is inserted into the main body 801 through the insertion port 805, the electronic paper 600 is installed in the main body 801 in a state of being sandwiched between the transport roller pairs 802a and 802b.

  A rectangular hole 803 is formed on the display surface side of the main body 801 (the front side in FIG. 12B), and a transparent glass plate 804 is fitted in the hole 803. . Thereby, the electronic paper 600 installed in the main body 801 can be viewed from the outside of the main body 801. That is, in the display 800, the display surface is configured by visually recognizing the electronic paper 600 installed in the main body 801 on the transparent glass plate 804.

Further, a terminal portion 806 is provided at the leading end portion (left side in FIG. 12) of the electronic paper 600 in the insertion direction, and the terminal is provided inside the main body portion 801 with the electronic paper 600 installed on the main body portion 801. A socket 807 to which the unit 806 is connected is provided. A controller 808 and an operation unit 809 are electrically connected to the socket 807.
In such a display 800, the electronic paper 600 is detachably installed on the main body 801, and can be carried and used while being detached from the main body 801.

In such a display 800, the electronic paper 600 is configured by the electrophoretic display device 20 as described above.
Note that the electronic apparatus of the present invention is not limited to the application to the above, and for example, a television, a viewfinder type, a monitor direct view type video tape recorder, a car navigation device, a pager, an electronic notebook, a calculator, an electronic Examples include newspapers, word processors, personal computers, workstations, videophones, POS terminals, and devices equipped with touch panels. The display device 20 of the present invention can be applied to the display units of these various electronic devices. It is.

  As mentioned above, although the manufacturing method of the display sheet, display sheet, display apparatus, and electronic device of this invention were demonstrated based on embodiment of illustration, this invention is not limited to this, The structure of each part is the same It can be replaced with any configuration having the above function. In addition, any other component may be added to the present invention. Further, the display device of the present invention may be a combination of any two or more configurations (features) of the above embodiments.

  In the above-described embodiment, for example, when a wiring or the like is exposed on the surface of the counter substrate on the display layer side, the wall does not contact the wiring when the wall and the counter substrate are joined. As described above, the wall portion may be formed. Thereby, since a wall part can also be comprised with the material which has electroconductivity, the freedom degree of selection of the constituent material of a wall part increases. When the wall is made of an insulating material, the wall may be in contact with the wiring.

Next, specific examples of the present invention will be described. However, the present invention is not limited to these examples.
1. Manufacture of display device A display device was manufactured as follows.
<Example 1>
(A1) Production of microcapsules (A1-1) Preparation of electrophoretic dispersion liquid In a separable flask having a capacity of 300 ml equipped with a stirring blade, a thermometer, and a cooling tube, dodecyl methacrylate, 2-ethylhexyl acrylate, glycidyl methacrylate 2 g of an acrylic polymer (mass average molecular weight 3,300) composed of (composition ratio 80: 15: 5), 20 g of carbon black (MA-100R, manufactured by Mitsubishi Chemical Corporation), 78 g of Isopar M (manufactured by Exxon Chemical) Further, 800 g of zirconia beads having a diameter of 1 mm were charged. While stirring at a rotational speed of 300 rpm, the polymer grafting was performed by reacting at 160 ° C. for 2 hours. After the treatment, 100 g of Isopar M (Exxon Chemical Co., Ltd.) was further added and mixed thoroughly. Thereafter, beads made of zirconia were separated to obtain a dispersion liquid of carbon black subjected to polymer grafting (here, an epoxy group of an acrylic polymer was reacted with a carboxy group present on the surface of the carbon black). On the other hand, in a separable flask having a capacity of 300 ml equipped with a stirring blade, 50 g of titanium oxide (Taipec CR90, manufactured by Ishihara Sangyo Co., Ltd.), dodecyl methacrylate, 2-ethylhexyl acrylate, methacryloxypropyltrimethoxysilane (composition ratio 80) : 15: 5) Acrylic polymer (mass average molecular weight 6,800) 5 g and hexane 100 g were charged, placed in a 55 ° C. ultrasonic bath (BRANSON 5210, manufactured by Yamato Scientific Co., Ltd.), and ultrasonically dispersed while stirring. The treatment was performed for 2 hours. This separable flask was transferred to a 90 ° C hot water bath, the solvent was distilled off, and the powdered titanium oxide was taken out of the flask and transferred to a vat, followed by heat treatment at 150 ° C for 5 hours in a dryer. It was. The heat-treated titanium oxide was dispersed in 100 g of hexane, centrifuged with a centrifugal settling machine, and washed with titanium oxide three times, and then dried at 100 ° C. A 300 ml separable flask equipped with a stirring blade was charged with 50 g of washed titanium oxide and 50 g of Isopar M (manufactured by Exxon Chemical Co., Ltd.), and placed in an ultrasonic bath (BRANSON 5210, Yamato Scientific Co., Ltd.) at 55 ° C. The mixture was stirred and subjected to ultrasonic dispersion for 2 hours to disperse the polymer-grafted titanium oxide (here, the hydroxy group present on the surface of the titanium oxide was reacted with the silyl group of the acrylic polymer). A liquid was obtained. In a 200 ml mayonnaise bin, 6.0 g of the above polymer grafted carbon black dispersion, 75 g of the above polymer grafted titanium oxide dispersion, and 19 g of Isopar M (Exxon Chemical Co., Ltd.) were charged. To obtain a dispersion for an electrophoretic display device.

(A1-2) Preparation of aqueous suspension of electrophoretic dispersion 60 g of 10 wt% gum arabic aqueous solution was weighed into a 500 ml beaker, and 50 g of the electrophoretic dispersion obtained in the step (A1-1) was stirred with a disper. Addition and suspension operation were performed to obtain an aqueous suspension of the electrophoretic dispersion.
(A1-3) Formation of first capsule layer A 100 ml round bottom separable flask was charged with 5 g of melamine, 5 g of urea, 20 g of a 27 wt% aqueous formaldehyde solution and 1 g of 25 wt% aqueous ammonia, and the temperature was raised to 70 ° C. while stirring. It was. The whole became transparent at around 65 ° C. during the temperature increase. After raising the temperature to 70 ° C. and holding at that temperature for 1 hour, the mixture was cooled to 30 ° C. to obtain an initial condensation compound of melamine, urea and formaldehyde.

  Next, this initial condensate was added to the aqueous suspension of the electrophoretic dispersion obtained in the step (A1-2) held at 40 ° C., and the mixture was stirred for 2 hours at the same temperature. The temperature was raised and the mixture was aged for 2 hours at the same temperature, and then cooled to room temperature. Through the above steps, a first capsule layer made of melamine resin was formed, and a microcapsule precursor dispersion containing an electrophoretic dispersion was obtained. After adding 1 L of deionized water to the whole microcapsule dispersion and mixing it uniformly, the sedimentation of the microcapsule precursor, which was allowed to stand, was confirmed, and the operation of removing the supernatant was performed several times for washing. As a result of measuring the particle size of the microcapsule precursor, the volume average particle size was 42 μm.

(A1-4) Formation of second capsule layer Deionized water was added to the total amount of the microcapsule precursor obtained in the previous step (A1-3) to a 300 ml separable flask to make the total amount 200 g. The microcapsule precursor dispersion was heated to 40 ° C. with stirring, and 20 g of an epoxy compound [manufactured by Nagase ChemteX Corporation, “Denacol EX521 (polyglycerol polyglycidyl ester)”] was dispersed in 50 g of water. The solution was added dropwise over 10 minutes. After maintaining at the same temperature for 30 minutes, 1 g of 2.5 wt% sodium diethyldithiocarbamate aqueous solution was added as a cross-linking agent and reacted for 2 hours. Next, the temperature was raised to 50 ° C., and aging was performed for 2 hours at the same temperature, whereby a second capsule layer made of an epoxy resin was formed on the surface of the microcapsule precursor (first capsule layer).

  Through the above steps, a microcapsule that encapsulates the electrophoretic dispersion in a capsule body composed of the first capsule layer and the second capsule layer was obtained. This microcapsule dispersion was subjected to wet classification using a mesh having an opening of 38 μm and a mesh having an opening of 32 μm to obtain a microcapsule having a volume average particle size of 37.29 μm (CV value 8.18%). The particle size distribution was measured using a laser diffraction / scattering particle size distribution measuring device (product name: LA-910, manufactured by Horiba, Ltd.). The CV value represents (standard deviation / average particle diameter) × 100.

(A2) Preparation of microcapsule dispersion Next, the microcapsules obtained in the step (A1) and the binder were mixed at a weight ratio of 10: 3 to prepare a microcapsule dispersion. As the binder, a mixture in which butyl acrylate, 2-ethylhexyl acrylate, and polyethylene glycol (Mw = 2000) were mixed at a weight ratio of 50: 47: 3 was used.

(A3) Formation of Display Layer (A3-1) Formation of Wall Next, a PET-ITO substrate (product name: NXC1, manufactured by Toray Industries, Inc., ITO) on which an ITO film is formed on a base material composed of PET (Thickness: 125 μm) was prepared. Next, a wall portion was formed on the surface of the ITO side of the PET-ITO substrate so as to define a region in which the microcapsules are disposed. The wall portion was formed by adhering a frame-shaped member composed mainly of an epoxy resin to a PET-ITO substrate using an adhesive. The height of the wall portion was 18.8 μm.
(A3-2) Supply of microcapsule dispersion Next, the microcapsule dispersion obtained in the step (A2) was supplied to the inside of the wall portion formed on the PET-ITO substrate.

(A3-3) Rearrangement of microcapsules Next, a sheet with a release agent layer (product name: SK Separator K-80HS, Sanei Co., Ltd.) so as to overlap the microcapsule dispersion supplied on the PET-ITO substrate. Made by Kaken Co., Ltd., base material: kraft paper, release agent layer: silicone release agent, and then using a roll laminator (product name: VA-700DFR, manufactured by Taisei Laminator Co., Ltd.) In a state where the microcapsule dispersion was held between the PET-ITO substrate and the sheet with the release agent layer, the microcapsule dispersion was pressurized in the thickness direction of the PET-ITO substrate. In addition, the conditions of the roll laminator when the microcapsule dispersion was pressurized were as follows.

<Conditions for laminating equipment>
・ Lamination pressure: 0.4 MPa
・ Lamination temperature: 70 ℃
Sheet transport speed: 5 cm / min The display layer formed between the PET-ITO substrate and the sheet with the release agent layer has a length of 136.2 mm, a width of 102.3 mm, and an average thickness of 50 μm. It was.
Next, the sheet with a release agent layer was peeled from the microcapsule dispersion, thereby obtaining a display layer.

(A3-4) Bonding LTPS Substrate (Circuit Substrate) Next, an LTPS substrate (Low-Temperature Polycrystalline Silicon substrate: circuit substrate) prepared in advance is placed so as to overlap the display layer, and then a roll laminator (product name) : VA-700DFR, manufactured by Taisei Laminator Co., Ltd.), the LTPS substrate was bonded onto the display layer. The circuit board uses a 2T1C configuration TFT, the number of pixels is VGA (480 × 640), the pixel pitch is 96 μm (264 dpi), the screen size is 46.0 mm × 61.4 mm, and the substrate size is 75.0 mm × 51. 2 mm.
In addition, the conditions of the roll laminator at the time of bonding a circuit board to a display layer were as showing below.

<Conditions for laminating equipment>
・ Lamination pressure: 0.4 MPa
・ Lamination temperature: 70 ℃
-Sheet conveyance speed: 5 cm / min Thereby, the display apparatus of Example 1 was obtained.

<Example 2>
A display device of Example 2 was obtained in the same manner as in Example 1 except that the process for forming the display layer was different from that in Example. Below, the formation process of the display layer of a present Example is demonstrated.
(B3) Formation of Display Layer (B3-1) Formation of Wall Part A wall part was formed in the same manner as in Example 1.

(B3-2) Supply of microcapsule dispersion Next, in the same manner as in Example 1, a wall portion was formed.
(B3-3) Rearrangement of microcapsules Next, rearrangement of microcapsules was performed in the same manner as in Example 1.
(B3-4) Removal of wall Next, the wall formed in (B3-1) was removed.

(B3-5) Bonding LTPS Substrate Next, an LTPS substrate is arranged so as to overlap the display layer, and then LTPS is used using a roll laminator (product name: VA-700DFR, manufactured by Taisei Laminator Co., Ltd.). The substrate was bonded onto the display layer. The conditions of the roll laminator when the LTPS substrate was bonded to the display layer were as shown below.
<Conditions for laminating equipment>
・ Lamination pressure: 0.2 MPa
・ Lamination temperature: 70 ℃
-Sheet conveyance speed: 5 cm / min (B3-6) Formation of sealing part Next, (meth) acrylic-type resin was supplied to the circumference | surroundings of the display layer with the dispenser, and the sealing part was formed.
Thereby, the display device of Example 2 was obtained.

<Example 3>
A display device of Example 3 was obtained in the same manner as in Example 1 except that the process for forming the display layer was different from that in Example. Below, the formation process of the display layer of a present Example is demonstrated.
(C3) Formation of display layer (C3-1) Supply of microcapsule dispersion The microcapsule dispersion was supplied to a region (microcapsule placement region) set on the surface of the PET-ITO substrate on the ITO side.

(C3-2) Rearrangement of microcapsules Next, a sheet with a release agent layer (product name: SK Separator K-80HS, Co., Ltd.) so as to overlap the microcapsule dispersion supplied on the PET-ITO substrate. Sanei Kaken Co., Ltd., base material: kraft paper, release agent layer: silicone release agent) is placed, and then a roll laminator (product name: VA-700DFR, manufactured by Taisei Laminator Co., Ltd.) is used. The microcapsule dispersion was pressurized in the thickness direction of the PET-ITO substrate in a state where the microcapsule dispersion was held between the PET-ITO substrate and the release agent layer-attached sheet. In addition, the conditions of the roll laminator when the microcapsule dispersion was pressurized were as follows.

<Conditions for laminating equipment>
・ Lamination pressure: 0.2 MPa
・ Lamination temperature: 70 ℃
Sheet transport speed: 5 cm / min The display layer formed between the PET-ITO substrate and the sheet with the release agent layer has a length of 136.2 mm, a width of 102.3 mm, and an average thickness of 50 μm. It was.

(C3-3) Formation of Wall Part Next, a wall part was formed so as to surround the periphery of the display layer. The wall portion was formed in the same manner as in Example 1 (A-2).
(C3-4) Bonding of LTPS Substrate Next, in the same manner as in Example 1, the LTPS substrate was bonded to the display layer.
Thereby, the display device of Example 3 was obtained.

<Example 4>
A display device of Example 4 was obtained in the same manner as in Example 1 except that the process for forming the display layer was different from that in Example. Below, the formation process of the display layer of a present Example is demonstrated.
(D3) Formation of Display Layer (D3-1) Formation of Wall Part A wall part was formed in the same manner as in Example 1.
(D3-2) Supply of microcapsule dispersion Next, in the same manner as in Example 1, a microcapsule dispersion was supplied into the wall.

(D3-3) Joining LTPS Substrate Next, an LTPS substrate is placed so as to overlap the microcapsule dispersion supplied on the PET-ITO substrate, and then a roll laminator (product name: VA-700DFR, Taisei Laminator) The microcapsule dispersion was pressurized in the thickness direction of the PET-ITO substrate with the microcapsule dispersion held between the PET-ITO substrate and the LPTS substrate. In addition, the conditions of the roll laminator when the microcapsule dispersion was pressurized were as follows.

<Conditions for laminating equipment>
・ Lamination pressure: 0.4 MPa
・ Lamination temperature: 70 ℃
Sheet transport speed: 5 cm / min Further, the formed display layer had a length of 136.2 mm × width of 102.3 mm × an average thickness of 50 μm.
Thereby, the display device of Example 4 was obtained.

<Comparative Example 1>
A display device of Comparative Example 1 was obtained in the same manner as in Example 1 except that the process of forming the display layer was different from that in Example. Below, the formation process of the display layer of this comparative example is demonstrated.
(E3) Formation of display (E3-1) Supply of microcapsule dispersion The microcapsule dispersion was supplied to a region (microcapsule placement region) set on the surface of the PET-ITO substrate on the ITO side.

(E3-2) Rearrangement of microcapsules Next, a sheet with a release agent layer (product name: SK Separator K-80HS, Co., Ltd.) so as to overlap the microcapsule dispersion supplied on the PET-ITO substrate. Sanei Kaken Co., Ltd., base material: kraft paper, release agent layer: silicone release agent) is placed, and then a roll laminator (product name: VA-700DFR, manufactured by Taisei Laminator Co., Ltd.) is used. The microcapsule dispersion was pressurized in the thickness direction of the PET-ITO substrate in a state where the microcapsule dispersion was held between the PET-ITO substrate and the release agent layer-attached sheet. In addition, the conditions of the roll laminator when the microcapsule dispersion was pressurized were as follows.

<Conditions for laminating equipment>
・ Lamination pressure: 0.4 MPa
・ Lamination temperature: 70 ℃
Sheet transport speed: 5 cm / min Further, the display layer formed between the PET-ITO substrate and the sheet with the release agent layer had a length of 30 mm × width of 30 mm × an average thickness of 50 μm.

(E3-3) Bonding LTPS Substrate Next, an LTPS substrate is placed so as to overlap the display layer formed on the PET-ITO substrate, and then a roll laminator (product name: VA-700DFR, Taisei Laminator (stock) The microcapsule dispersion was pressurized in the thickness direction of the PET-ITO substrate with the microcapsule dispersion held between the PET-ITO substrate and the LTPS substrate. In addition, the conditions of the roll laminator when the microcapsule dispersion was pressurized were as follows.

<Conditions for laminating equipment>
・ Lamination pressure: 0.4 MPa
・ Lamination temperature: 70 ℃
-Sheet conveyance speed: 5 cm / min (E3-4) Formation of sealing part Next, (meth) acrylic-type resin was supplied to the circumference | surroundings of the display layer with the dispenser, and the sealing part was formed.
Thereby, the display device of Comparative Example 1 was obtained.

2. Evaluation (2-1) State of Microcapsule in Display Layer For each example and comparative example, the state of the microcapsule in the display layer before and after the relocation of the microcapsule by pressurization was performed using a digital microscope ( It observed using the product name: VHX-600 (made by Keyence Corporation), and a lens (product name: VH-Z100, made by Keyence Corporation). The measurement results are shown in Table 1 below.

(2-2) Contrast Evaluation With respect to the display devices obtained in the examples and comparative examples, the reflectances of white and black when a DC voltage of 15 V was applied between both electrodes for 400 msec were respectively measured by Macbeth spectrophotometry. The Y value (luminous reflectance) was measured using a densitometer (product name: SpectroEye, manufactured by GretagMacbeth), and the contrast was determined by the following formula (1). The Y values for white and black were measured separately by switching and applying the poles. Moreover, the reflectance of white and black was measured in five areas (1) to (5) as shown in FIG.
Contrast = (white Y value) / (black Y value) (1)
The evaluation results are shown in Table 2 below.

As is clear from Table 1, in each of the examples and comparative examples, the microcapsules overlap in the thickness direction in the microcapsule dispersion before pressurization of the microcapsule dispersion by the roll laminator. However, the overlap in the thickness direction of the microcapsules was eliminated by pressing with a roll laminator, and it was found that the microcapsules were arranged in a row.
Further, as is clear from Table 2, in each example, each area (1) to (5) has high contrast, whereas in Comparative Example 1, all the areas (1) to (( In 5), it was found that the contrast was lower than that of the example, and in particular, in the edge areas (2) to (5), the contrast was lower than that of the example.

  DESCRIPTION OF SYMBOLS 1 ... Base part 2 ... Base part 3 ... 1st electrode 4 ... 2nd electrode 5 ... Electrophoretic particle 5a ... White particle 5b ... Colored particle 6 ... Liquid phase dispersion medium 7 ... Sealing 8: Wall 10: Electrophoretic dispersion 100: Microcapsule dispersion 11: Opposed substrate 12 ... Substrate 19 ... Pressing substrate 20 ... Display device 21 ... Display sheet 22 ... Circuit board 40, 40 ', 40 "... Microcapsule 400 ... Display layer 401 ... Capsule body 402 ... First capsule layer 403 ... Second capsule layer 41 ... Binder 600 ... Electronic paper 601 ... Body 602 ... Display unit 800 ... Display 801 ... Main body 802a, 802b ... Transport roller pair 803 ... Hole 804 ... Transparent glass plate 805 ... Insertion slot 06 ‥‥ terminal portion 807 ‥‥ socket 808 ‥‥ controller 809 ‥‥ operation unit S1 ‥‥ region S11 ‥‥ defect

Claims (14)

  A coating liquid is provided by dispersing a plurality of microcapsules in which an electrophoretic dispersion liquid containing at least one type of electrophoretic particles is encapsulated on the substrate, and the coating liquid is disposed in the thickness direction of the substrate. A method for producing a display sheet, comprising a step of applying pressure to move the microcapsule positioned in the coating solution so as to overlap another microcapsule in the thickness direction of the substrate toward the substrate. . A wall forming step of providing a wall defining a region on which the microcapsules are disposed on the first substrate;
A coating solution supply step for supplying the coating solution to the inside of the wall;
The microcapsule positioned so as to overlap the other microcapsules in the coating solution by applying pressure in the thickness direction of the first substrate to the coating solution supplied to the inside of the wall portion Moving the microcapsule toward the first substrate; and
A display sheet manufacturing method comprising: a substrate bonding step of bonding a second substrate to the first substrate through the coating liquid by applying a pressure in a thickness direction of the first substrate. Method.   The manufacturing method of the display sheet according to claim 2, wherein in the substrate bonding step, the wall portion is used as a spacer, and the first substrate and the second substrate are bonded via the spacer.   The said spacer functions as a manufacturing method of the display sheet of Claim 3 which functions as a sealing part which suppresses deterioration of the said microcapsule.   The manufacturing method of the display sheet according to claim 3 or 4, wherein the pressure applied in the substrate bonding step is equal to the pressure applied in the microcapsule rearrangement step.   The manufacturing method of the display sheet of Claim 2 which has a wall part removal process of removing the said wall part prior to the said board | substrate joining process.   The manufacturing method of the display sheet according to claim 6, wherein the pressure applied in the substrate bonding step is smaller than the pressure applied in the microcapsule rearrangement step. A coating liquid supplying step of supplying the coating liquid to a microcapsule disposition area set as an area for disposing the microcapsule on the first substrate;
The micro liquid crystal is positioned so as to overlap with the other micro capsules in the coating liquid by applying a pressure in the thickness direction of the first substrate to the coating liquid supplied to the micro capsule placement region. A microcapsule rearrangement step of moving the capsule toward the first substrate;
A wall portion forming step of forming a wall portion so as to surround the microcapsule arrangement region;
A display sheet manufacturing method comprising: a substrate bonding step of bonding a second substrate to the first substrate through the coating liquid by applying a pressure in a thickness direction of the first substrate. Method.   The display sheet manufacturing method according to claim 8, wherein a pressure applied in the substrate bonding step is larger than the pressure applied in the microcapsule rearrangement step. A wall portion forming step of providing a wall portion defining a region in which the microcapsules are disposed on the first substrate;
A coating solution supply step for supplying the coating solution to the inside of the wall;
By applying a pressure in the thickness direction of the first substrate, the second substrate is bonded to the first substrate via the coating solution and overlaps with the other microcapsules in the coating solution. And a substrate bonding step of moving the microcapsules positioned in this manner toward the first substrate.   The method for manufacturing a display sheet according to claim 1, wherein the microcapsule has a spherical shape and maintains the spherical shape even after the substrate bonding step is completed.   A display sheet manufactured by the method for manufacturing a display sheet according to claim 1.   A display device comprising the display sheet according to claim 12.   An electronic apparatus comprising the display device according to claim 13.

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