JP2018045033A - Electrophoretic display device, manufacturing method for the same, and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophoretic display device having excellent display quality by defining the moisture content contained in electrophoretic dispersion liquid filled in each cell partitioned by partition walls in an appropriate range, and a manufacturing method for the electrophoretic display device capable of manufacturing the electrophoretic display device and an electronic apparatus excellent in reliability.SOLUTION: An electrophoretic display device 10 includes: a first substrate; a second substrate disposed so as to face the first substrate; partition walls 35 being disposed between the first substrate and the second substrate and partitioning a space therebetween into a plurality of cells 36; and electrophoretic dispersion liquid 37 being disposed in the plurality of cells 36 and containing electrophoretic particles 34 and a dispersion medium 15. The dispersion medium 15 contains a first material having a first molecular weight and a second material having a second molecular weight having a molecular weight greater than the first molecular weight. The second material is present at end portions of the second substrate side of the partition walls 35.SELECTED DRAWING: Figure 4

Description

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

  2. Description of the Related Art Conventionally, an electrophoretic display device using particle electrophoresis is known, and this electrophoretic display device is excellent in that it has portability and power saving.

  In this electrophoretic display device, a voltage is applied between a pixel electrode and a common electrode facing each other with an electrophoretic dispersion liquid containing electrophoretic particles interposed therebetween, so that charged electrophoretic particles such as black particles and white particles are spatially separated. The image is formed in the display area by moving the image automatically. As an electrophoretic display device, for example, a configuration in which a pair of pixel substrate and counter substrate is partitioned into a plurality of spaces by partition walls, and an electrophoretic dispersion liquid containing electrophoretic particles and a dispersion medium is enclosed in each space Things are known.

  Such an electrophoretic display device is provided on a pixel substrate in order to seal an electrophoretic dispersion liquid (electrophoretic ink) inside a space (cell) without any gap as described in Patent Document 1, for example. A technique for joining the top of the partition wall and a sealing layer formed on the counter substrate is disclosed.

  In the electrophoretic display device having such a configuration, a pixel substrate provided with a partition wall is prepared, and after the electrophoretic dispersion liquid is filled in a space defined by the partition wall on the pixel substrate, a sealing layer is provided. It is manufactured by bonding the opposite substrates.

  However, in such a method for manufacturing an electrophoretic display device, constituent materials (structural materials) constituting each part of the electrophoretic display device are used in a pre-process for sealing the electrophoretic dispersion liquid in a cell serving as a closed space. As a result, the charged state of the electrophoretic particles contained in the electrophoretic dispersion liquid is caused by moisture intruding into the electrophoretic dispersion liquid from the absorbed or adsorbed constituent material. Change. Therefore, there is a problem that the electrophoretic particles are aggregated and the electrophoretic particles are fixed to the electrode, and as a result, the display quality of the electrophoretic display device is impaired.

JP 2015-138220 A

  An object of the present invention is to provide an electrophoretic display device having excellent display quality by setting the amount of water contained in an electrophoretic dispersion filled in each cell partitioned by a partition wall to an appropriate range. An object of the present invention is to provide an electrophoretic display device manufacturing method capable of manufacturing an electrophoretic display device and an electronic apparatus having excellent reliability.

  Such an object has been made to solve at least a part of the above-described problems, and is achieved by the present invention described below.

The electrophoretic display device of the present invention includes a first substrate,
A second substrate disposed opposite the first substrate;
A partition wall disposed between the first substrate and the second substrate and partitioned into a plurality of cells;
An electrophoretic dispersion liquid disposed in a plurality of the cells and containing electrophoretic particles and a dispersion medium;
The dispersion medium contains a first material having a first molecular weight and a second material having a second molecular weight that is larger than the first molecular weight.
The second material is present at an end of the partition on the second substrate side.

  Accordingly, the amount of water contained in the electrophoretic dispersion filled in each cell partitioned by the partition walls can be regulated within an appropriate range, and an electrophoretic display device having excellent display quality can be obtained. .

  In the electrophoretic display device according to the aspect of the invention, it is preferable that the electrophoretic display device includes a sealing layer disposed between the partition wall and the second substrate.

  As described above, the electrophoretic display device of the present invention is suitably applied when the sealing layer disposed between the partition and the second substrate is provided.

  In the electrophoretic display device according to the aspect of the invention, it is preferable that the sealing layer is a stacked body in which a first sealing layer and a second sealing layer are stacked in this order from the second substrate side.

  Thus, when the sealing layer is composed of the laminate, the electrophoretic display device of the present invention is more preferably applied.

  In the electrophoretic display device of the present invention, it is preferable that the first material and the second material have the same structure.

  Thereby, in the dispersion medium contained in the electrophoretic dispersion liquid, the second material is more reliably dissolved in the first material.

  In the electrophoretic display device of the present invention, it is preferable that both the first material and the second material are silicone oil.

  Thereby, the second material can be dissolved in the first material, and as a result, the excellent dispersibility of the electrophoretic particles can be maintained.

The method for producing an electrophoretic display device of the present invention includes an electrophoretic particle including a dispersion medium containing a first material having a first molecular weight, a second material having a second molecular weight larger than the first molecular weight, and electrophoretic particles. Forming a partition on the first substrate for partitioning into a plurality of cells filled with the electrophoretic dispersion;
Forming a moisture sealing layer containing a second material having a second molecular weight larger than the first molecular weight on at least one of the second substrate and the partition;
Injecting a dispersion liquid in which the electrophoretic particles are dispersed in the first material into the cell;
A step of bonding the partition wall and the second substrate so that the moisture sealing layer is interposed.

  Accordingly, the amount of water contained in the electrophoretic dispersion filled in each cell partitioned by the partition walls can be regulated within an appropriate range, and thus an electrophoretic display device having excellent display quality is manufactured. Can do.

  In the method for manufacturing an electrophoretic display device according to the aspect of the invention, it is preferable that the moisture sealing layer has an average thickness of 1 μm to 5 μm.

  As a result, the content of the second material in the dispersion medium when the moisture sealing layer is dissolved in the dispersion medium is set within an appropriate range, and the viscosity of the dispersion medium is set within an appropriate range. Therefore, the electrophoretic particles can be migrated with excellent electrophoretic characteristics in the electrophoretic dispersion medium.

  In the method for manufacturing an electrophoretic display device according to the aspect of the invention, it is preferable that the partition walls have an average height of 10 μm to 150 μm.

  Thereby, the thickness of the electrophoretic layer formed in the cells partitioned by the partition walls is also set to be approximately equal to the average height.

An electronic apparatus according to the present invention includes the electrophoretic display device according to the present invention.
As a result, the electronic device has excellent reliability.

It is a perspective view which shows embodiment of the electronic device by which the electrophoretic display apparatus of this invention is mounted. It is an equivalent circuit diagram showing an embodiment of an electrical configuration of the electrophoretic display device of the present invention. It is a schematic plan view which shows embodiment of the structure of the electrophoretic display device of this invention. FIG. 4 is a cross-sectional view taken along line A-A ′ of the electrophoretic display device shown in FIG. 3. FIG. 4 is a schematic plan view showing a structure around a sealing layer and a seal portion in the electrophoretic display device shown in FIG. 3. FIG. 6 is a B-B ′ line cross-sectional view of the electrophoretic display device shown in FIG. 5. FIG. 6 is an enlarged plan view showing an enlarged C part of the electrophoretic display device shown in FIG. 5. It is an expanded sectional view which expands and shows the F section of the electrophoretic display device shown in FIG. It is a flowchart which shows the 1st manufacturing method of the electrophoretic display device of this invention in order of a process. It is a figure for demonstrating the 1st manufacturing method of the electrophoretic display device of this invention. It is a figure for demonstrating the 1st manufacturing method of the electrophoretic display device of this invention. It is a figure for demonstrating the 1st manufacturing method of the electrophoretic display device of this invention. It is a figure for demonstrating the 1st manufacturing method of the electrophoretic display device of this invention. It is a figure for demonstrating the 1st manufacturing method of the electrophoretic display device of this invention. It is a figure for demonstrating the 1st manufacturing method of the electrophoretic display device of this invention. It is a figure for demonstrating the 1st manufacturing method of the electrophoretic display device of this invention. It is a figure for demonstrating the 1st manufacturing method of the electrophoretic display device of this invention. It is a flowchart which shows the 2nd manufacturing method of the electrophoretic display device of this invention in order of a process. It is a figure for demonstrating the 2nd manufacturing method of the electrophoretic display device of this invention. It is a figure for demonstrating the 2nd manufacturing method of the electrophoretic display device of this invention. It is a figure for demonstrating the 2nd manufacturing method of the electrophoretic display device of this invention. It is a figure for demonstrating the 2nd manufacturing method of the electrophoretic display device of this invention. It is a figure for demonstrating the 2nd manufacturing method of the electrophoretic display device of this invention. It is a figure for demonstrating the 2nd manufacturing method of the electrophoretic display device of this invention. It is a figure for demonstrating the 2nd manufacturing method of the electrophoretic display device of this invention. It is a figure for demonstrating the 2nd manufacturing method of the electrophoretic display device of this invention.

  Hereinafter, an electrophoretic display device, an electrophoretic display device manufacturing method, and an electronic apparatus according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

  In the following embodiments, for example, when “on the substrate” is described, the substrate is disposed so as to be in contact with the substrate, or is disposed on the substrate via another component, or the substrate. It includes a case where a part is arranged on the top and a part is arranged via another component.

<Electronic equipment>
First, prior to describing the electrophoretic display device and the method of manufacturing the electrophoretic display device of the present invention, an electronic apparatus including the electrophoretic display device of the present invention will be described.

  FIG. 1 is a perspective view showing an embodiment of an electronic apparatus equipped with the electrophoretic display device of the present invention. Note that the drawings to be used (including FIG. 1 and the drawings shown below) are appropriately enlarged or reduced so as to be recognized.

  As shown in FIG. 1, the electronic device 100 includes an electrophoretic display device 10 and an interface for operating the electronic device 100. Specifically, this interface is, for example, the operation unit 110 and includes a switch and the like.

  The electrophoretic display device 10 is a display module that includes the display region E and includes the electrophoretic display device of the present invention. The display area E includes a plurality of pixels, and an image is displayed on the display area E by electrically controlling these pixels. Therefore, the electronic device 100 including the electrophoretic display device 10 has excellent reliability.

  In addition to the electronic paper (EPD: Electronic Paper Display) shown in FIG. 1, the electronic device 100 including the electrophoretic display device 10 is a watch, a re-stable device, a smartphone, a tablet terminal, a television, a viewfinder type, and a direct monitor view. It can be applied to a type of video tape recorder, car navigation device, pager, electronic notebook, calculator, electronic newspaper, word processor, personal computer, workstation, videophone, POS terminal, touch panel and the like.

<Electrophoretic display device>
Next, the electrophoretic display device 10 (electrophoretic display device of the present invention) included in the electronic apparatus 100 will be described.

  2 is an equivalent circuit diagram showing an embodiment of the electrical configuration of the electrophoretic display device of the present invention, FIG. 3 is a schematic plan view showing an embodiment of the structure of the electrophoretic display device of the present invention, and FIG. FIG. 5 is a cross-sectional view taken along the line AA ′ of the electrophoretic display device shown in FIG. 3. FIG. 5 is a schematic plan view showing the structure around the sealing layer and the seal portion in the electrophoretic display device shown in FIG. FIG. 7 is a cross-sectional view taken along the line BB ′ of the electrophoretic display device shown in FIG. 5, FIG. 7 is an enlarged plan view showing the portion C of the electrophoretic display device shown in FIG. 5, and FIG. It is an expanded sectional view which expands and shows the F section of the electrophoretic display device shown. 5-8, illustration of an insulating layer, wiring, an electrode, etc. is abbreviate | omitted.

  As shown in FIG. 2, the electrophoretic display device 10 includes a plurality of data lines 12 and a plurality of scanning lines 13, and the pixels 11 are arranged at portions where the data lines 12 and the scanning lines 13 intersect. . Specifically, the electrophoretic display device 10 includes a plurality of pixels 11 arranged in a matrix along data lines 12 and scanning lines 13. Each pixel 11 has an electrophoretic dispersion liquid including a dispersion medium 15 and electrophoretic particles 34 disposed between the pixel electrode 21 and the common electrode 22.

  The pixel electrode 21 is connected to the data line 12 via the transistor 16 (TFT 16). The gate electrode of the TFT 16 is connected to the scanning line 13. Note that FIG. 2 is an example, and other elements such as a storage capacitor may be incorporated as necessary.

  As shown in FIGS. 3 and 4, the electrophoretic display device 10 includes an element substrate 51, a counter substrate 52 disposed so as to face the element substrate 51, and the element substrate 51 and the counter substrate 52. A partition wall 35 that is arranged and divided into a plurality of cells 36, an electrophoretic layer 33 that is arranged in the plurality of cells 36 and is composed of an electrophoretic dispersion liquid 37 containing the electrophoretic particles 34 and the dispersion medium 15, and the partition walls And a sealing layer 42 disposed between the counter substrate 52 and the counter substrate 52.

  In the present embodiment, the element substrate 51 is applied as the first substrate in the present invention, and the counter substrate 52 is applied as the second substrate in the present invention.

  On the first substrate 31 provided in the element substrate 51, for example, made of a glass substrate having translucency, the pixel electrode 21 is arranged corresponding to each pixel 11.

  More specifically, as shown in FIGS. 3 and 4, the pixels 11 (pixel electrodes 21) are formed in a matrix in a plan view, for example. As the material of the pixel electrode 21, for example, a light transmissive material such as ITO (indium tin oxide added with tin) is used.

  A circuit part (not shown) is provided between the first base material 31 and the pixel electrode 21, and the TFT 16 and the like are formed in the circuit part. The TFT 16 is electrically connected to each pixel electrode 21 via a contact portion (not shown). Although not shown, in the circuit portion, various wirings (for example, the data line 12 and the scanning line 13) and elements (for example, capacitive elements) are arranged in addition to the TFT 16. A first insulating layer 32 is formed on the entire surface of the first base 31 including the pixel electrode 21. Note that the first insulating layer 32 may be omitted.

  For example, a common electrode provided in common corresponding to the plurality of pixels 11 on the second base material 41 (on the dispersion medium 15 side in FIG. 4) made of a glass substrate having translucency provided in the counter substrate 52. 22 is formed. As the common electrode 22, for example, a light transmissive material such as ITO is used.

  Further, in the present embodiment, a first sealing layer 42 a is formed on the common electrode 22 (on the dispersion medium 15 side in FIG. 4) provided in the counter substrate 52. Furthermore, a second sealing layer 42b is formed on the first sealing layer 42a. The first sealing layer 42a and the second sealing layer 42b are collectively referred to as a sealing layer 42. The sealing layer 42 will be described in detail later.

An electrophoretic layer 33 is provided between the first insulating layer 32 and the sealing layer 42.
The electrophoretic layer 33 is composed of an electrophoretic dispersion liquid 37 including at least one or more electrophoretic particles 34 and a dispersion medium 15 in which the electrophoretic particles 34 are dispersed, and the electrophoretic dispersion liquid 37 (the dispersion medium 15 and the dispersion medium 15). A space (electrophoretic particles 34) partitioned (divided) by a first insulating layer 32, a second sealing layer 42b, and partition walls 35 (ribs) provided on the first substrate 31 ( It is formed by filling in the cell 36 which is a region.

  As shown in FIG. 3, the partition wall 35 is interposed between the element substrate 51 and the counter substrate 52 and is formed in a grid pattern. In addition, it is preferable that the partition 35 is translucent materials, such as an acrylic resin and an epoxy resin. By using such a translucent material, it is possible to accurately suppress or prevent the partition wall 35 from being reflected in the image displayed in the display area E. Further, since these light-transmitting materials are materials having a low hygroscopic property or a low adsorptive property, the moisture adsorbed on the partition wall 35 is accurately suppressed from moving into the electrophoretic dispersion 37 in the cell 36. Or it can be prevented.

The width of the partition wall 35 is preferably set to 3 μm or more and 10 μm or less.
In this embodiment, the pixel electrode 21 is disposed in each pixel 11 and the partition wall 35 (rib) is disposed in each pixel electrode 21. However, the present invention is not limited to this, and a plurality of pixels ( For example, partition walls 35 (ribs) may be formed every 2 to 20 pixels.

  Further, when the element substrate 51 and the counter substrate 52 are bonded together, the upper portion of the partition wall 35 comes into contact with the counter substrate 52 (specifically, the sealing layer 42), so that the height of the partition wall 35 (actually, The cell gap between the element substrate 51 and the counter substrate 52 can be determined based on the frame partition wall 61) shown in FIG.

  Hereinafter, a region surrounded by the partition wall 35 is referred to as a cell 36. One cell 36 includes a partition wall 35, a pixel electrode 21, a common electrode 22 (sealing layer 42), and an electrophoretic layer 33.

  Furthermore, the average height of the partition walls 35 is set to be approximately equal to the average thickness of the electrophoretic layer 33 partitioned by the partition walls 35, and is preferably 10 μm or more and 150 μm or less, for example, 20 μm or more and 100 μm or less. More preferably, the thickness is particularly preferably set to about 30 μm. Thereby, it is possible to display white display and black display by movement of the electrophoretic particles 34 with excellent contrast.

  In the present embodiment, as shown in FIG. 4, white particles and black particles are shown as the electrophoretic particles 34.

  For example, when a voltage is applied between the pixel electrode 21 and the common electrode 22, the electrophoretic particles 34 are electrically directed toward one of the electrodes (the pixel electrode 21 and the common electrode 22) according to the electric field generated therebetween. Run. For example, when the white particles have a positive charge, when the pixel electrode 21 is set to a negative potential, the white particles move to the pixel electrode 21 side (lower side) and gather to display black. On the contrary, when the pixel electrode 21 is set to a positive potential, the white particles move to the common electrode 22 side (upper side) and gather to display white. In this manner, desired information (image) is displayed according to the presence or absence or the number of white particles gathering on the display-side electrode. Here, although white particles or black particles are used as the electrophoretic particles 34, other colored particles may be used.

  Further, as the electrophoretic particles 34, inorganic pigment-based particles, organic pigment-based particles, polymer fine particles, or the like can be used, and two or more kinds of various particles may be mixed and used. The average particle size of the electrophoretic particles 34 is, for example, about 0.05 μm to 10 μm, and preferably about 0.2 μm to 2 μm.

  Further, the content of the white particles is within 30% of the total weight of the dispersion medium 15, the white particles and the black particles, that is, the electrophoretic dispersion, and the content of the black particles is the dispersion medium 15, the white particles, The total weight of black particles, that is, within 10% with respect to the electrophoretic dispersion. By allocating in this way, the reflectance becomes 40% or more and the black reflectance becomes 2% or less, and the display performance can be improved.

  In the present embodiment, as the dispersion medium 15 for making the electrophoretic dispersion liquid 37 in which the electrophoretic particles 34 are dispersed, a medium having a boiling point of 100 ° C. or higher and a relatively high insulating property is preferably used.

  Examples of the dispersion medium include cellosolves such as butyl cellosolve, esters such as butyl acetate and higher fatty acid esters, ketones such as dibutyl ketone, aliphatic hydrocarbons (liquid paraffin) such as pentane, and alicyclic rings such as cyclohexane. Formula hydrocarbons, aromatic hydrocarbons such as xylene, halogenated hydrocarbons such as methylene chloride, aromatic heterocycles such as pyridine, nitriles such as acetonitrile, and amides such as N, N-dimethylformamide Such organic solvents or silicone oils can be mentioned, and these can be used alone or as a mixture.

  Among these, as the dispersion medium, those containing silicone oil as a main component are preferable. Since the dispersion medium containing silicone oil as a main component has a high effect of suppressing aggregation of the electrophoretic particles 34, it is possible to suppress the display performance of the electrophoretic display device 10 shown in FIG. Silicone oil has the advantage that it has excellent weather resistance and has high safety because it does not have an unsaturated bond.

  As described above, the electrophoretic particles 34 dispersed in the dispersion medium 15 have a positive or negative charge so that they can be electrophoresed toward one of the electrodes. It is defined by the amount of moisture taken in by the migrating particles 34 and contained in the dispersion medium 15. Therefore, the amount of water contained in the dispersion medium 15 is preferably set to about 300 ppm to 1000 ppm, more preferably about 400 ppm to 700 ppm. In addition, when a silicone oil (the following first material and second material) as a main component is used as the dispersion medium 15, the silicone oil is a highly hygroscopic or adsorptive material. Setting within the above range is required as an element for obtaining electrophoretic particles 34 having excellent electrophoretic properties.

  In the present invention, the amount of water contained in the dispersion medium 15 can be set within the above range. In the present invention, the dispersion medium 15 includes the first material having the first molecular weight and the first molecular weight among the materials described above. The second molecular weight second material having a molecular weight higher than that of the second molecular weight is included, but the detailed description thereof will be made in a method for manufacturing an electrophoretic display device to be described later.

  The dispersion medium 15 contains the first material having the first molecular weight and the second material having the second molecular weight having a molecular weight larger than the first molecular weight, so that the water contained in the dispersion medium 15 is contained. In addition to being able to set the amount within the above range, there is also an advantage that the retention is improved when displaying white or black. This is because the dispersion medium 15 includes a second material having a second molecular weight larger than the first molecular weight in addition to the first material having the first molecular weight, so that the thixotropy of the dispersion medium 15 is good. Therefore, it is presumed that the retention at the start of electrophoresis of the electrophoretic particles 34 is excellent, and as a result, the retention at the time of white display or black display is improved. Further, the dispersibility of the electrophoretic particles 34 in the electrophoretic dispersion liquid 37 is improved.

  Further, in the dispersion medium 15, for example, a charge made of particles such as an electrolyte, a surfactant (anionic or cationic), a metal soap, a resin material, a rubber material, an oil, a varnish, a compound, or the like is necessary. Various additives such as a control agent, a lubricant, a stabilizer, and various dyes may be added.

  As shown in FIGS. 5 and 6, the electrophoretic display device 10 has a display area E and a frame area E1 (outer peripheral area) surrounding the display area E. The frame region E1 includes a dummy pixel region D which is a region that does not contribute to display in the electrophoretic layer 33, a frame partition 61 (outer peripheral partition) disposed outside the dummy pixel region D, and an outer side of the frame partition 61. And a seal portion 14 disposed on the surface.

  The width of the frame region E1 is, for example, about 1 mm. Further, the width of the dummy pixel region D is, for example, 80 μm. On the display area E side of the dummy pixel area D, the rib width (the width of the top portion 35 ′) of the partition wall provided with the partition wall 35a formed in the same shape as the partition wall 35 arranged in the display area E is 3 μm or more. It is preferably about 10 μm or less. The distance between adjacent partition walls is preferably set to about 100 μm or more and 300 μm or less.

  A frame partition wall 61 is provided outside the dummy pixel region D. The frame partition wall 61 can be dammed so that the dispersion medium 15 does not flow outside, and is used to adjust the cell gap, and is disposed so as to surround the dummy pixel region D. The frame partition 61 is usually made of the same material as the partition 35 of the display area E.

  The width W1 of the frame partition wall 61 is preferably set to about 100 μm to 300 μm.

  Further, the height of the frame partition wall 61 is, for example, preferably about 10 μm to 200 μm, and more preferably about 20 μm to 100 μm. Accordingly, the frame partition wall 61 can function as a gap material that defines the thickness of the electrophoretic layer 33, and the thickness of the electrophoretic layer 33 can be easily set within the above-described range.

  The frame partition wall 61 is also used to prevent the first sealing material 14a disposed adjacent to the display area E from protruding.

  In the present embodiment, the seal portion 14 includes a first seal material 14a and a second seal material 14b as shown in FIG. The first sealing material 14 a is used to bond the element substrate 51 and the counter substrate 52 together, and is provided so as to surround the frame partition wall 61.

  The width W2 of the first sealing material 14a is preferably set to about 150 μm or more and 600 μm or less. Moreover, the viscosity of the 1st sealing material 14a is 300,000 Pa * s or more and 1 million Pa * s or less, for example, Preferably, it is about 400,000 Pa * s. By using the first sealing material 14a having such a viscosity, the contact area between the element substrate 51 and the counter substrate 52 can be kept large when the element substrate 51 and the counter substrate 52 are bonded together.

  The second sealing material 14b is used to seal between the element substrate 51 and the counter substrate 52, and is disposed so as to surround the first sealing material 14a.

  The width W3 of the second sealing material 14b is preferably set to about 150 μm or more and 600 μm or less. Moreover, the viscosity of the 2nd sealing material 14b is 100 Pa.s or more and 500 Pa.s or less, for example, Preferably, it is about 400 Pa.s. By using the second sealing material 14b having such a viscosity, the second sealing material 14b can be inserted between the element substrate 51 and the counter substrate 52 around the first sealing material 14a. Therefore, the adhesive strength of the second sealing material 14b can be improved. Moreover, it becomes possible to suppress moisture from entering the inside through the second sealing material 14b and the first sealing material 14a from the outside, and a highly reliable seal structure can be obtained.

  In the sealing part 14 as described above, the first sealing material 14a is preferably composed of various curable resins such as an ultraviolet curable resin and a thermosetting resin. Thereby, the element substrate 51 and the counter substrate 52 can be reliably and firmly bonded.

  Moreover, as a constituent material of the second sealing material 14b, at least one of acrylic resin and epoxy resin is preferably used. Since the second sealing material 14b made of such a resin material is a material having low hygroscopicity or low adsorptivity, the electrophoretic dispersion liquid 37 from the outside of the electrophoretic display device 10 through the second sealing material 14b. It is possible to accurately suppress or prevent moisture from moving to the side.

  In addition, the seal part 14 may omit the first seal material 14a depending on the constituent material of the second seal material 14b, in addition to the case where the seal member 14 is provided separately as in the case of the first seal material 14a and the second seal material 14b. The second sealing material 14b may be constituted by a single body.

  As shown in FIGS. 6 and 8, in the display region E, the counter substrate 52 is provided with a sealing layer 42, whereby the sealing layer 42 is provided between the top 35 ′ of the partition wall 35 and the counter substrate 52. Is arranged. That is, the electrophoretic display device 10 includes the sealing layer 42 disposed between the partition wall 35 and the counter substrate 52.

  As a result, a space (closed space) defined by the sealing layer 42, the first insulating layer 32, and the partition walls 35 (ribs) is formed, and the electricity containing the dispersion medium 15 and the electrophoretic particles 34 is formed in this space. By filling the electrophoretic dispersion liquid 37, the electrophoretic dispersion liquid 37 including the dispersion medium 15 and the electrophoretic particles 34 can not go back and forth between the adjacent cells 36.

  At this time, as shown in FIGS. 6 and 8, in this embodiment, the contact surface between the sealing layer 42 and the electrophoretic layer 33 (the contact surface between the first sealing layer 42a and the second sealing layer 42b). Of these, the portion that overlaps the partition wall 35 in plan view is located closer to the second base material 41 (counter substrate 52) in a cross-sectional view than the portion that does not overlap the partition wall 35 in plan view. The top portion 35 ′ bites (embeds) the sealing layer 42. In this way, by causing the top portion 35 ′ to bite into the sealing layer 42, electrophoresis filled in the closed space defined by the sealing layer 42, the first insulating layer 32, and the partition wall 35, that is, the cell 36. It is possible to accurately suppress or prevent the dispersion liquid 37 from going back and forth between the adjacent cells 36.

  In this embodiment, as described with reference to FIG. 4, such a sealing layer 42 includes the first sealing layer 42 a and the second sealing layer 42 b in this order from the counter substrate 52 (second substrate) side. It is comprised by the laminated body laminated | stacked.

  In such a laminate, a portion of the contact surface between the first sealing layer 42a and the second sealing layer 42b where the top portion 35 'does not bite (a portion that does not overlap with the partition wall 35 in plan view) and a top portion 35' , The top portion 35 'is positioned on the second base material 41 side as shown in FIG. Then, the amount t2 of the partition wall 35 that bites into the sealing layer 42, that is, the distance between the portion of the second sealing layer 42b on the side of the electrophoretic layer 33 where the top portion 35 'does not bite and the top portion 35'. Is, for example, preferably 1 μm to 5 μm. Thereby, it is possible to more accurately suppress or prevent the electrophoresis dispersion liquid 37 from going back and forth between the adjacent cells 36.

  In the sealing layer 42 composed of the first sealing layer 42a and the second sealing layer 42b, the elastic modulus of the first sealing layer 42a is preferably 5 MPa or more and 40 MPa or less. The elastic modulus of the second sealing layer 42b is preferably 50 MPa or more and 10 GPa or less. By making the first sealing layer 42a and the second sealing layer 42b have the above elastic modulus, the elastic modulus of the laminate, that is, the entire sealing layer 42, is 1 MPa or more and 100 MPa. It can be easily set within the following range, and the top portion 35 'of the partition wall 35 is bitten into the sealing layer 42 without bending the top portion 35' of the partition wall 35 or damaging the second sealing layer 42b. In other words, the sealing layer 42 can be deformed by the top portion 35 ′ of the partition wall 35.

  Furthermore, the thickness of the first sealing layer 42a is preferably 2.5 μm or more and 20 μm or less, and the thickness of the second sealing layer 42b is preferably 0.05 μm or more and 1.0 μm or less. Thereby, in the laminated body, when the portion where the top portion 35 ′ does not bite and the top portion 35 ′ of the contact surfaces of the first sealing layer 42 a and the second sealing layer 42 b are compared, as shown in FIG. 8. It can be set relatively easily in the configuration in which the top portion 35 ′ is located on the second base material 41 side. Further, the elastic modulus of the laminated body of the first sealing layer 42a and the second sealing layer 42b, that is, the sealing layer 42 as a whole can be easily set within a range of 1 MPa or more and 100 MPa or less. When the thickness of the second sealing layer 42b is as thin as 0.5 μm or less, the elastic modulus of the second sealing layer 42b is as high as about 10 GPa, and the second sealing layer 42b Even if it is hard, the elastic modulus of the sealing layer 42 as a whole may not be affected.

  When the thicknesses of the first sealing layer 42a and the second sealing layer 42b are set as described above, the first sealing layer 42a has a higher elastic modulus than the second sealing layer 42b. It is preferable that the first sealing layer 42a is formed using a low material, that is, the elastic modulus of the first sealing layer 42a is lower than that of the second sealing layer 42b. As a result, even if the width of the top portion 35 ′ of the partition wall 35 is reduced to be within a range of 3 μm to 10 μm, the top portion 35 ′ is not bent and the second sealing layer 42b is not damaged. The top portion 35 ′ can bite into the sealing layer 42.

The volume resistivity of the first sealing layer 42a is preferably 1 × 10 ⁷ Ω · cm to 5 × 10 ¹⁰ Ω · cm, and the volume resistivity of the second sealing layer 42b is 1 × 10. It is preferably ⁷ Ω · cm or more and 2 × 10 ¹¹ Ω · cm or less. By making the first sealing layer 42a and the second sealing layer 42b have the volume resistivity as described above, the volume resistivity of the laminate, that is, the sealing layer 42 as a whole, is 1 It can be easily set within the range of 10 ⁷ Ω · cm or more and 1 × 10 ¹² Ω · cm or less, and therefore, the sealing layer 42 is interposed between the pixel electrode 21 and the common electrode 22. Thus, it is possible to accurately suppress or prevent the mobility of the electrophoretic particles 34 from being lowered.

  In the sealing layer 42 (laminated body) as described above, the first sealing layer 42a is preferably made of a material that is more flexible than the second sealing layer 42b, and the top portion 35 'of the partition wall 35 is more easily bite. Specifically, examples of the constituent material of the first sealing layer 42a include NBR (acrylonitrile / butadiene rubber), urethane rubber, isoprene rubber, butadiene rubber, chloroprene rubber, styrene / butadiene rubber, hydrin rubber, and nitrile rubber. 1 type or 2 types or more of these can be used in combination. Among these, NBR or hydrin rubber is preferable. According to NBR and hydrin rubber, the elastic modulus of the first sealing layer 42a can be easily adjusted by changing the vulcanization conditions and adding a filler to the first sealing layer 42a. Therefore, the top portion 35 ′ can bite into the sealing layer 42.

  Examples of the filler added to the first sealing layer 42a include silica, mica, alumina, titanium oxide, silicon nitride, and the like, and one or more of these can be used in combination. .

  For example, the constituent material of the second sealing layer 42b is selected so that the second sealing layer 42b can function as a sealing layer for preventing the first sealing layer 42a from eluting into the dispersion medium 15. Specifically, examples of the constituent material of the second sealing layer 42b include nonpolar polymers such as polyethylene and polypropylene in addition to PVA (polyvinyl alcohol). Two or more kinds can be used in combination. Among these, PVA is preferable. Since these materials (especially PVA) are less likely to elute into the dispersion medium 15, problems of the electrophoretic display device 10 can be suitably reduced. Moreover, since PVA is a material with low adhesiveness, the electrophoretic particles 34 can be prevented from adhering to the second sealing layer 42b.

  Note that the second sealing layer 42b may contain an additive for softening the material of the second sealing layer 42b. As this additive, glycerol is mentioned, for example. The additive is preferably added in an amount of about 5 wt% to 50 wt% with respect to the solid content of PVA. Thereby, even if a material having an elastic modulus of 600 MPa or more is selected as the material of the second sealing layer 42b, it can be suitably used as the second sealing layer 42b. In the present embodiment, as the material of the second sealing layer 42b, a material in which glycerin is added to PVA having an elastic modulus of 692 MPa at room temperature (25 ° C.) and the elastic modulus at room temperature is 75 MPa is used.

Moreover, an additive is not limited to glycerol, For example, you may use what mixed 1 type, or 2 or more types selected from polyethyleneglycol, glycerol, urea, polyethylene oxide, and polypropylene glycol.
The light transmittance of the sealing layer 42 is 99% for PVA and 99% for NBR.

  In the sealing layer 42 configured as described above, the first sealing layer 42a and the second sealing layer 42b forming the stacked body are made of the above-described constituent materials in order to exhibit their respective functions. However, these materials are relatively hygroscopic or adsorptive materials. Therefore, if the electrophoretic display device 10 is formed in a state where at least one of the first sealing layer 42 a and the second sealing layer 42 b is hygroscopic or adsorbed, the electrophoretic dispersion liquid 37 is formed from the sealing layer 42. Moisture permeates (transfers) inside, and as a result, it becomes difficult to set the amount of water contained in the dispersion medium 15 within an appropriate range. Specifically, as described above, it is difficult to set the pressure to preferably about 300 ppm to 1000 ppm, more preferably about 400 ppm to 700 ppm. Therefore, a change occurs in the charge amount of the electrophoretic particles contained in the electrophoretic dispersion liquid 37, and as a result, aggregation of the electrophoretic particles and sticking of the electrophoretic particles to the electrode occur. Since a change occurs in the electrophoretic characteristics of the electrophoretic particles when a voltage is applied between the electrode 21 and the common electrode 22, there arises a problem that the display quality of the electrophoretic display device is impaired.

  On the other hand, in the present invention, the dispersion medium 15 contains the first material having the first molecular weight and the second material having the second molecular weight larger than the first molecular weight. Although the above-described problems can be solved, details thereof will be described in the following method for manufacturing an electrophoretic display device.

  That is, in the present invention, when the electrophoretic display device 10 includes the sealing layer 42 and the sealing layer 42 is configured by a laminate of the first sealing layer 42a and the second sealing layer 42b. The above-described problems can be solved by suitably applying the dispersion medium 15 containing the first material and the second material, but details thereof will be described in the manufacture of the electrophoretic display device described below. The method will be described.

  The sealing layer 42 is provided as a stacked body of the first sealing layer 42a and the second sealing layer 42b, and depending on the constituent material of the second sealing layer 42b, the first sealing layer 42a. May be omitted and may be constituted by a single layer of the second sealing layer 42b, or may be constituted by a laminate of three or more layers.

  The average thickness t1 of the sealing layer 42 is preferably, for example, about 2.5 μm to 30 μm, and more preferably about 2.5 μm to 10 μm.

Furthermore, the sealing layer 42 preferably has a volume resistivity lower than that of the electrophoretic dispersion. As a result, even if the sealing layer 42 is interposed between the pixel electrode 21 and the common electrode 22, the electrophoresis in the electrophoresis layer 33 is caused by the resistance value in the sealing layer 42 becoming too large. It is possible to accurately suppress or prevent the mobility of the particles 34 from being lowered. Specifically, the volume resistivity of the sealing layer 42 is preferably 1 × 10 ⁷ Ω · cm to 1 × 10 ¹² Ω · cm, and preferably 1 × 10 ⁸ Ω · cm to 1 × 10 ¹⁰ Ω. -More preferably, it is cm or less.

  Further, as shown in FIGS. 6 and 7, the end portion of the sealing layer 42 is disposed, for example, between the outermost partition wall 35a of the display region E and the frame partition wall 61, that is, in the range of the dummy pixel region D. Has been. The sealing layer 42 is slightly larger than the display area E and has a size such that the end portion does not enter the display area E even if the size varies.

  Further, when an adhesive is used as the material for forming the sealing layer 42, impurities such as reactive monomers that are not completely cured, for example, contained in the adhesive are eluted into the dispersion liquid. The electrophoretic particles 34 may adhere to the electrophoretic particles 34 contained in the electrophoretic dispersion liquid and affect the electrophoretic properties of the electrophoretic particles 34. However, in the present embodiment, the sealing layer 42 includes the first sealing layer 42 a and the second sealing layer 42 b, and the second sealing layer 42 b is disposed at a portion in contact with the electrophoretic particles 34. doing. Therefore, such a problem can be reduced.

  In addition, when the sealing layer 42 is formed only from a material having a high elastic modulus, if the width of the top portion 35 ′ of the partition wall 35 is too narrow, the top portion 35 ′ may not bite into the sealing layer 42 and may be bent. Then, it is considered that a gap is generated between the top 35 ′ of the partition wall 35 and the sealing layer 42, and the electrophoretic particles 34 move between the adjacent cells 36. However, as in the present embodiment, the sealing layer 42 is formed by the first sealing layer 42a and the second sealing layer 42b, and the respective elastic modulus and thickness are set in a suitable range. Such problems can also be suppressed.

  Next, a manufacturing method for manufacturing the electrophoretic display device 10 having such a configuration (a manufacturing method of the electrophoretic display device of the present invention) will be described.

<Method for Manufacturing Electrophoretic Display Device>
(First manufacturing method)
First, a first manufacturing method for manufacturing the electrophoretic display device 10 will be described.

  FIG. 9 is a flowchart showing the first manufacturing method of the electrophoretic display device of the present invention in the order of steps. 10 to 17 are views for explaining a first manufacturing method of the electrophoretic display device of the present invention.

Hereinafter, a first manufacturing method of the electrophoretic display device will be described with reference to FIGS.
[1] First, an element substrate 51 (first substrate) is prepared, and then a partition wall 35 is formed on the element substrate 51 to divide (provide) the cells into a plurality of cells 36 filled with the electrophoretic dispersion liquid 37. . As the electrophoretic dispersion liquid 37, in the present invention, the dispersion medium 15 containing the first material having the first molecular weight and the second material having the second molecular weight larger than the first molecular weight, the electrophoretic particles 34, Is filled in the cell 36.

  [1-1] First, the TFT 16 and the pixel electrode 21 made of a light transmissive material such as ITO are formed on the first base material 31 made of a light transmissive material such as glass (step S11).

  Specifically, the TFT 16, the pixel electrode 21, and the like are formed on the first base material 31 using a well-known film formation technique, photolithography technique, and etching technique. In the following description using the cross-sectional views, the description and illustration of the TFT 16 and the like excluding the pixel electrode 21 are omitted.

[1-2] Next, the first insulating layer 32 is formed on the first base material 31 (step S12).
The manufacturing method of the first insulating layer 32 is not particularly limited. For example, an insulating material is applied on the first base material 31 by using a spin coating method, and then the insulating material is dried. Can be formed.
Thus, the element substrate 51 (first substrate) is completed.

  [1-3] Next, partition walls are formed on the element substrate 51 (specifically, the first insulating layer 32) (step S13).

  More specifically, as shown in FIG. 10, various partition walls including a partition wall 35, a partition wall 35 a, and a frame partition wall 61 are formed at the same time.

  The partition walls 35 and 35a and the frame partition wall 61 can be collectively formed using, for example, a well-known film formation technique, a photolithography technique, and an etching technique.

  Thus, by simultaneously forming the partition walls 35 and 35a and the frame partition wall 61 with the same material, these can be manufactured efficiently.

The partition wall 35 is made of a material that does not dissolve in the dispersion medium 15, and it does not matter whether the material is organic or inorganic. Specifically, examples of organic materials include urethane resin, urea resin, acrylic resin, polyester resin, silicone resin, acrylic silicone resin, epoxy resin, polystyrene resin, styrene acrylic resin, polyolefin resin, butyral resin, vinylidene chloride resin, Examples include melamine resin, phenol resin, fluororesin, polycarbonate resin, polysulfone resin, polyether resin, polyamide resin, and polyimide resin. These resin simple substance or 2 or more types of composite agents are used.
Thus, the element substrate 51 (first substrate) provided with the partition walls 35 is completed.

  [2] Next, a counter substrate 52 is prepared, and then a sealing layer 42 for sealing the electrophoretic dispersion 37 in the cell 36 is formed on the counter substrate 52, and then the sealing layer A moisture sealing layer 44 is formed on 42.

  That is, the moisture sealing layer 44 containing the second material having the second molecular weight larger than the first molecular weight is formed on the counter substrate 52 (second substrate) via the sealing layer 42.

  In the present embodiment, the step [2] constitutes a step of forming the moisture sealing layer 44 containing the second material on at least one of the counter substrate 52 (second substrate) and the partition.

[2-1] First, the common electrode 22 is formed on the second base material 41 (step S21).
Specifically, the common electrode 22 is formed on the entire surface of the second base material 41 made of a translucent material such as a glass substrate by using a well-known film forming technique.
Thus, the counter substrate 52 (second substrate) is completed.

  [2-2] Next, the sealing layer 42, that is, the first sealing layer 42a and the second sealing layer 42b are formed on the common electrode 22 (step S22, step S23).

  As a method for forming the first sealing layer 42a and the second sealing layer 42b, as shown in FIG. 11, for example, NBR (acrylonitrile butadiene rubber) is formed on the counter substrate 52 by a coating method such as spin coating. Thereafter, PVA (polyvinyl alcohol) is similarly formed by a coating method. As described above, additives such as glycerin are added to PVA.

  Further, by using an etching method, PVA and NBR are patterned corresponding to the shapes of the first sealing layer 42a and the second sealing layer 42b to be formed, so that the first sealing layer 42a and the second sealing layer 42 are formed. The stop layer 42b is obtained. Note that the present invention is not limited to the coating method and may be formed using a printing method.

  Further, after forming the sealing layer 42 including the first sealing layer 42a and the second sealing layer 42b, the sealing layer 42 is baked. When the constituent materials included in the first sealing layer 42a and the second sealing layer 42b are as described above, these are materials having relatively high hygroscopicity or adsorptivity. Therefore, the sealing layer 42 is baked for the purpose of adjusting the amount of moisture contained in the sealing layer 42.

  The temperature at which the sealing layer 42 is fired varies slightly depending on the constituent material of the sealing layer 42, but is preferably 70 ° C or higher and 150 ° C or lower, more preferably 80 ° C or higher and 110 ° C or lower. . Moreover, although the time to bake is not specifically limited, For example, it is preferable that it is 0.5 to 10 hours, and it is more preferable that it is 1 to 3 hours.

  [2-3] Next, a moisture sealing layer 44 containing a second material having a second molecular weight larger than the first molecular weight as a main material is formed on the sealing layer 42 (step S24).

  The moisture sealing layer 44 can be formed by using the coating method, the etching method, the printing method, or the like mentioned in the method for forming the first sealing layer 42a and the second sealing layer 42b.

  Further, the moisture sealing layer 44 may include the second material alone, and includes the first material and various additives added to the dispersion medium 15 described above in addition to the second material. It may be.

  Here, the sealing layer 42 formed in the step [2-2] is baked after the formation to adjust the amount of water. In the next step [3], the sealing layer 42 is opposed to the element substrate 51. When the fired sealing layer 42 is exposed to the atmosphere until the substrate 52 is bonded, the sealing layer 42 again absorbs moisture contained in the atmosphere. Therefore, when the electrophoretic display device 10 is formed in this state, water enters (transfers) from the sealing layer 42 into the electrophoretic dispersion liquid 37, and as a result, the amount of water contained in the dispersion medium 15 is appropriately set. It becomes difficult to set the range, that is, preferably about 300 ppm to 1000 ppm, more preferably about 400 ppm to 700 ppm.

  On the other hand, since the moisture sealing layer 44 is formed on the sealing layer 42 after firing, the sealing layer 42 can be accurately suppressed or prevented from being exposed to the atmosphere. The amount of water contained in the dispersion medium 15 can be set to an appropriate range as in the above range. Therefore, a change occurs in the charge amount of the electrophoretic particles 34 contained in the electrophoretic dispersion liquid 37, and as a result, the aggregation of the electrophoretic particles 34 and the adhesion of the electrophoretic particles 34 to the electrodes are accurately generated. It can be suppressed or prevented. Accordingly, since the electrophoretic characteristics of the electrophoretic particles 34 do not change when a voltage is applied between the pixel electrode 21 and the common electrode 22, the electrophoretic display device 10 maintains excellent display quality. Become.

  Further, a material containing a second material having a second molecular weight that is higher in molecular weight than the first material having the first molecular weight contained in the dispersion medium 15 as a main material is formed as a moisture sealing layer 44 on the sealing layer 42. Thus, when the moisture sealing layer 44 is exposed to the atmosphere, it is possible to accurately suppress or prevent the moisture sealing layer 44 from volatilizing. Furthermore, since the material having a high molecular weight is selected as the second material among the constituent materials of the dispersion medium 15, the moisture sealing layer 44 is opposed to the element substrate 51 in the next step [3]. When the substrate 52 is bonded, the electrophoretic particles 34 can be dissolved in the dispersion liquid dispersed in the first material without remaining on the sealing layer 42. Therefore, it is possible to accurately suppress or prevent adverse effects on the electrophoretic characteristics of the electrophoretic particles 34 in the electrophoretic layer 33. The dispersion medium 15 contains the first material having the first molecular weight and the second material having the second molecular weight by the dissolution of the moisture sealing layer 44.

  Furthermore, in the next step [3], from the viewpoint that the moisture sealing layer 44 is dissolved in the dispersion medium 15, the first material and the second material have different molecular weights, but the composition thereof It is preferred that the main chains have the same structure. Thereby, the moisture sealing layer 44 can be reliably dissolved in the dispersion medium 15 without remaining on the sealing layer 42.

  In the present specification, the phrase “the first material and the second material have the same structure” means that the molecular structures of these main chains (main skeletons) are the same. The side chains and substituents provided may be the same or different.

  As the dispersion medium 15, as described above, silicone oil is preferably used. Therefore, both the first material and the second material are preferably silicone oil.

  Thus, when silicone oil is selected as the dispersion medium 15 (first material), the moisture sealing layer 44 is dissolved in the first material by selecting silicone oil as the second material, As a result, the excellent dispersibility of the electrophoretic particles 34 can be maintained.

  The first material has a first molecular weight with a viscosity of about 2 mPa · s to 10 Pa · s, and the second material has a viscosity of about 100 Pa · s to 1000 Pa · s. Those having a second molecular weight are preferably used. By selecting the first material and the second material having such a viscosity, the electrophoretic particles 34 can be migrated in the dispersion medium 15 with excellent electrophoretic characteristics, and the moisture sealing layer 44. Can be appropriately suppressed or prevented from volatilizing in the atmosphere.

  Furthermore, as described above, the average height of the partition walls 35 is set to be approximately equal to the average thickness of the electrophoretic layer 33 partitioned by the partition walls 35, for example, preferably 10 μm to 150 μm, more preferably 20 μm to 100 μm. Particularly preferably, the thickness is set to about 30 μm. On the other hand, the average thickness of the moisture sealing layer 44 is preferably set to about 1 μm to 5 μm, more preferably about 3 μm. Accordingly, in the next step [3], the content of the second material in the dispersion medium 15 when the moisture sealing layer 44 is dissolved in the dispersion medium 15 is set within an appropriate range, and the dispersion medium It is possible to accurately suppress or prevent the viscosity of 15 from greatly changing from about 2 mPa · s to 10 Pa · s, which is the viscosity of the first material. Therefore, the electrophoretic particles 34 can be migrated in the dispersion medium 15 with excellent migration characteristics.

  The counter substrate 52 (second substrate) on which the sealing layer 42 and the moisture sealing layer 44 are formed is completed through the above steps [2-1] to [2-3].

  [3] Next, the electrophoretic display device 10 is obtained by bonding the element substrate 51 and the counter substrate 52 with reference to FIGS. 9 and 12 to 17. Hereinafter, this method will be described.

  [3-1] First, as shown in FIG. 12, the first sealing material 14a is applied to the outer periphery of the frame partition wall 61 in the atmosphere (step S31).

  As the material of the first sealing material 14a, for example, a liquid curable resin such as an ultraviolet curable resin and a thermosetting resin (Kayatron) having a relatively high viscosity is used. The viscosity of the first sealing material 14a is, for example, 300,000 Pa · s to 1,000,000 Pa · s, preferably 400,000 Pa · s. The width of the first sealing material 14a when applied is a width that can withstand vacuum, and is, for example, about 200 μm or more and 600 μm or less.

  [3-2] Next, in the display area E on the element substrate 51, that is, in the area surrounded by the frame partition wall 61, as shown in FIG. A dispersion containing the first material of the first material and the second material contained in the medium 15 is applied (step S32).

  As a result, the dispersion liquid in which the electrophoretic particles 34 are dispersed in the first material is injected into the cell 36 partitioned by the element substrate 51 and the partition wall 35.

  As a coating method, for example, a dispenser is used. A die coater or the like can also be applied. When silicone oil is used as the first material and the dispersion medium 15 containing the first material, the viscosity of the silicone oil is, for example, 2 mPa · s or more and 10 Pa · s or less. As the amount of the first material, when the element substrate 51 and the counter substrate 52 are bonded together, the sum of the first material and the moisture sealing layer 44 containing the second material as a main material is the frame partition wall 61. The amount of liquid that fills the inside of the box. In the present embodiment, the height of the frame partition wall 61 is, for example, about 15 μm to 45 μm.

  In addition, by forming the frame partition wall 61, it is possible to prevent the first sealing material 14a from entering the display area E side and spreading. Moreover, it can regulate so that the width | variety of the 1st sealing material 14a may not become larger than predetermined width. Thereby, the strength of the first sealing material 14a can be sufficiently ensured.

  [3-3] Next, as shown in FIG. 14, the moisture sealing layer 44 provided on the counter substrate 52 and the partition wall 35 provided on the element substrate 51 are arranged so as to face each other, and then shown in FIG. As described above, the dispersion liquid containing the electrophoretic particles 34 and the first material and the moisture sealing layer 44 are sealed between the element substrate 51 and the counter substrate 52 (first sealing; step S33).

That is, the partition 35 and the counter substrate 52 are bonded so that the moisture sealing layer 44 is interposed.
At this time, the element substrate 51 and the counter substrate 52 are brought close to each other so that the top portion 35 ′ of the partition wall 35 bites into (be buried in) the sealing layer 42 (and the moisture sealing layer 44). In other words, of the contact surface between the first sealing layer 42a and the second sealing layer 42b, a portion that overlaps the partition wall 35 in a plan view and a portion that does not overlap the partition wall 35 in a plan view are compared in a cross-sectional view. At this time, the counter substrate 52 is pressed by applying the pressure X to the element substrate 51 until the portion overlapping the partition wall 35 in plan view is positioned closer to the second base material 41 than the portion that is not.

  At this time, the frame partition wall 61 also functions as a spacer that defines a cell gap between the element substrate 51 and the counter substrate 52.

  When the counter substrate 52 is pressed against the element substrate 51, the first sealing material 14 a is crushed, and the dispersion liquid containing the electrophoretic particles 34 and the first material and the moisture sealing layer 44 are combined with the frame partition wall 61 and the first partition wall 61. It is pushed and filled inside the sealing material 14a. At this time, the top portion 35 ′ of the partition wall 35 provided in the display region E contacts the moisture sealing layer 44 provided on the counter substrate 52 side and further bites into the sealing layer 42. Thereby, the dispersion liquid containing the electrophoretic particles 34 and the first material and the moisture sealing layer 44 are sealed in each cell 36. Furthermore, in each cell 36, the water sealing layer 44 is dissolved in the dispersion liquid, whereby the dispersion medium 15 containing the first material and the second material is obtained. Thereby, the electrophoresis dispersion liquid 37 including the electrophoresis particles 34 and the dispersion medium 15 is sealed for each cell 36. Further, the top portion 35 ′ (end portion on the counter substrate 52 side) of the partition wall 35 is configured to bite into the sealing layer 42 provided on the counter substrate 52 side. The second material exists (remains) at the end). That is, the second material exists (remains) at the interface between the top 35 ′ of the partition wall 35 and the sealing layer 42 (an example of a structural material).

  It should be noted that the moisture sealing layer 44 in the dispersion liquid containing the first material and the electrophoretic particles 34 in each cell 36 may be actively performed by the contact of the moisture sealing layer 44 with the dispersion liquid. Alternatively, it may be passively performed so as to apply fine vibrations such as ultrasonic waves in a state where the moisture sealing layer 44 is in contact with the dispersion.

  As described above, the element substrate 51 and the counter substrate 52 are bonded together by causing the partition wall 35 to bite into the sealing layer 42 provided on the counter substrate 52.

  At this time, the moisture sealing layer 44 is formed on the sealing layer 42 through the step [2-3], and moisture absorption in the sealing layer 42 is appropriately suppressed. By carrying out this step [3-3] while maintaining the state, the content of water contained in the electrophoresis dispersion liquid 37 is set within an appropriate range. Therefore, since the change in the electrophoretic characteristics of the electrophoretic particles 34 is accurately suppressed or prevented, the electrophoretic display device 10 in which excellent display quality is maintained is manufactured.

  After that, as shown in FIG. 16, if the first sealing material 14a is an ultraviolet curable resin, the first sealing material 14a is cured by irradiating with ultraviolet rays Y. Moreover, if it is a thermosetting resin, it will be hardened by heating.

  The cell gap when the element substrate 51 and the counter substrate 52 are bonded together is about 20 μm or more and 50 μm or less, and the width of the crushed first sealing material 14 a is, for example, 200 μm or more and 500 μm or less.

[3-4] Next, as shown in FIG. 17, in the atmosphere, the second sealing material 14b is applied and bonded to the outer periphery of the first sealing material 14a (second sealing; step S34).
Thereby, the element substrate 51 and the counter substrate 52 can be firmly bonded and fixed.

  Specifically, the second sealing material 14b does not contain moisture and has a relatively low viscosity, and it is important that the second sealing material 14b enters the gap, such as an acrylic resin or an epoxy resin. In addition, the viscosity of the 2nd sealing material 14b is lower than the viscosity of the 1st sealing material 14a, for example, is 100 Pa.s or more and 500 Pa.s or less, Preferably, it is about 400 Pa.s. The width of the second sealing material 14b is, for example, about 300 μm or more and 500 μm or less.

As a method for applying the second sealing material 14b, for example, a dispenser, a die coater, or the like is used. As described above, the space sandwiched between the element substrate 51 and the counter substrate 52 is sealed as shown in FIG. Then, it cuts into the shape of a product as needed.
Through the above steps, the electrophoretic display device 10 is obtained.

(Second manufacturing method)
Moreover, the electrophoretic display device 10 can also be manufactured using a second manufacturing method as described below.

  FIG. 18 is a flowchart showing the second manufacturing method of the electrophoretic display device of the present invention in the order of steps. 19 to 26 are views for explaining a second manufacturing method of the electrophoretic display device of the present invention.

  Hereinafter, a second manufacturing method of the electrophoretic display device will be described with reference to FIGS.

  [1 ′] First, an element substrate 51 (first substrate) is prepared, and then, partition walls 35 and 35a for partitioning (providing) the cells into a plurality of cells 36 filled with the electrophoretic dispersion 37 on the element substrate 51. Then, various partition walls including the frame partition wall 61 are formed, and then the moisture sealing layer 44 is formed on the frame partition wall 61 among the various partition walls.

  That is, among the various partition walls, the moisture sealing layer 44 containing the second material having the second molecular weight higher than the first molecular weight is selectively formed on the frame partition wall 61 (partition wall).

  In the present embodiment, the step [1 '] includes a step of forming the moisture sealing layer 44 containing the second material on at least one of the counter substrate 52 (second substrate) and the partition.

  [1-1 '] First, the TFT 16 and the pixel electrode 21 made of a light transmissive material such as ITO are formed on the first base material 31 made of a light transmissive material such as glass (step S11').

  Specifically, the TFT 16, the pixel electrode 21, and the like are formed on the first base material 31 using a well-known film formation technique, photolithography technique, and etching technique.

  [1-2 '] Next, the first insulating layer 32 is formed on the first base material 31 (step S12').

The manufacturing method of the first insulating layer 32 is not particularly limited. For example, an insulating material is applied on the first base material 31 by using a spin coating method, and then the insulating material is dried. Can be formed.
Thus, the element substrate 51 (first substrate) is completed.

  [1-3 '] Next, various partition walls are formed on the element substrate 51 (specifically, the first insulating layer 32) (step S13').

  More specifically, various partition walls including the partition wall 35 of the display region E, the outermost partition wall 35a of the display region E, and the frame partition wall 61 provided outside thereof are formed simultaneously.

  The partition walls 35 and 35a and the frame partition wall 61 can be collectively formed using, for example, a well-known film formation technique, a photolithography technique, and an etching technique.

  [1-4 ′] Next, as shown in FIG. 19, the moisture sealing layer 44 containing a second material having a second molecular weight larger than the first molecular weight as a main material, the partition walls 35, 35 a and the frame partition walls. It forms on the frame partition 61 among 61 (step S14 ').

  The moisture sealing layer 44 can be selectively formed on the frame partition wall 61 using various coating methods, various printing methods, and the like.

  The element substrate 51 (first substrate) on which the partition walls 35 and 35a and the frame partition wall 61 and the moisture sealing layer 44 are formed through the above steps [1-1 ′] to [1-4 ′]. Is completed.

  [2 ′] Next, a counter substrate 52 is prepared, and then a sealing layer 42 for sealing the electrophoretic dispersion liquid 37 in the cell 36 is formed on the counter substrate 52.

[2-1 ′] First, the common electrode 22 is formed on the second base material 41 (step S21 ′).
Specifically, the common electrode 22 is formed on the entire surface of the second base material 41 made of a translucent material such as a glass substrate by using a well-known film forming technique.
Thus, the counter substrate 52 (second substrate) is completed.

  [2-2 '] Next, the sealing layer 42, that is, the first sealing layer 42a and the second sealing layer 42b are formed on the common electrode 22 (Step S22', Step S23 ').

  As a method for forming the first sealing layer 42a and the second sealing layer 42b, as shown in FIG. 20, for example, NBR (acrylonitrile butadiene rubber) is formed on the counter substrate 52 by a coating method such as spin coating. Thereafter, PVA (polyvinyl alcohol) is similarly formed by a coating method. As described above, additives such as glycerin are added to PVA.

  Further, by using an etching method, PVA and NBR are patterned corresponding to the shapes of the first sealing layer 42a and the second sealing layer 42b to be formed, so that the first sealing layer 42a and the second sealing layer 42 are formed. The stop layer 42b is obtained. Note that the present invention is not limited to the coating method and may be formed using a printing method.

  Through the steps [2-1 ′] to [2-2 ′], the counter substrate 52 (second substrate) on which the sealing layer 42 is formed is completed.

  [3 '] Next, the electrophoretic display device 10 is obtained by bonding the element substrate 51 and the counter substrate 52 with reference to FIGS. 18 and 21 to 26. Hereinafter, this method will be described.

  [3-1 '] First, as shown in FIG. 21, the first sealing material 14a is applied to the outer periphery of the frame partition wall 61 in the atmosphere (step S31').

  As the material of the first sealing material 14a, for example, a liquid curable resin such as an ultraviolet curable resin and a thermosetting resin (Kayatron) having a relatively high viscosity is used. The viscosity of the first sealing material 14a is, for example, 300,000 Pa · s to 1,000,000 Pa · s, preferably 400,000 Pa · s. The width of the first sealing material 14a when applied is a width that can withstand vacuum, and is, for example, about 200 μm or more and 600 μm or less.

  [3-2 ′] Next, in the display area E on the element substrate 51, that is, in the area surrounded by the frame partition wall 61, as shown in FIG. 22, the electrophoretic particles 34 including white particles and black particles, A dispersion containing the first material is applied (step S32 ′).

  As a result, the dispersion liquid in which the electrophoretic particles 34 are dispersed in the first material is injected into the cell 36 partitioned by the element substrate 51 and the partition wall 35.

  As a coating method, for example, a dispenser is used. A die coater or the like can also be applied. In addition, when silicone oil is used as the first material and thus the dispersion medium 15, the viscosity of the silicone oil is, for example, not less than 2 mPa · s and not more than 10 Pa · s. As the amount of the first material, when the element substrate 51 and the counter substrate 52 are bonded together, the sum of the first material and the moisture sealing layer 44 containing the second material as a main material is the frame partition wall 61. The amount of liquid that fills the inside of the box. In the present embodiment, the height of the frame partition wall 61 is, for example, about 15 μm to 45 μm.

  In addition, by forming the frame partition wall 61, it is possible to prevent the first sealing material 14a from entering the display area E side and spreading. Moreover, it can regulate so that the width | variety of the 1st sealing material 14a may not become larger than predetermined width. Thereby, the strength of the first sealing material 14a can be sufficiently ensured.

  [3-3 ′] Next, as shown in FIG. 23, the sealing layer 42 provided on the counter substrate 52 and the partition wall 35 provided on the element substrate 51 are disposed so as to face each other, and then, as shown in FIG. As described above, the dispersion liquid containing the electrophoretic particles 34 and the first material and the moisture sealing layer 44 are sealed between the element substrate 51 and the counter substrate 52 (first sealing; step S33 ′). .

  At this time, the element substrate 51 and the counter substrate 52 are brought close to each other so that the top portion 35 ′ of the partition wall 35 bites into (be buried in) the sealing layer 42. In other words, of the contact surface between the first sealing layer 42a and the second sealing layer 42b, a portion that overlaps the partition wall 35 in a plan view and a portion that does not overlap the partition wall 35 in a plan view are compared in a cross-sectional view. At this time, the counter substrate 52 is pressed by applying the pressure X to the element substrate 51 until the portion overlapping the partition wall 35 in plan view is positioned closer to the second base material 41 than the portion that is not.

  At this time, the frame partition wall 61 also functions as a spacer that defines a cell gap between the element substrate 51 and the counter substrate 52.

  When the counter substrate 52 is pressed against the element substrate 51, the first sealing material 14 a is crushed, and the dispersion liquid containing the electrophoretic particles 34 and the first material and the moisture sealing layer 44 are combined with the frame partition wall 61 and the first partition wall 61. It is pushed and filled inside the sealing material 14a. At this time, the top portion 35 ′ of the partition wall 35 provided in the display region E bites into the sealing layer 42 provided on the counter substrate 52 side. At this time, in each cell 36 of the display region E and in the cells of the dummy pixel region D, the water-sealing layer 44 formed on the frame partition wall 61, the electrophoretic particles 34, and the dispersion liquid containing the first material Are sealed. Further, in each cell 36 of the display area E and in the cells of the dummy pixel area D, the moisture sealing layer 44 dissolves in the dispersion liquid containing the electrophoretic particles 34 and the first material, so that the first material and the first material The dispersion medium 15 contains two materials. Thereby, the electrophoretic dispersion liquid 37 containing the electrophoretic particles 34 and the dispersion medium 15 is sealed in each cell 36 of the display area E and in the cells of the dummy pixel area D. Further, since the frame partition wall 61 is joined to the common electrode 22 provided on the counter substrate 52 side, the second material exists (residual) at the top of the frame partition wall 61 (the end portion on the counter substrate 52 side). To do. That is, the second material exists (remains) at the interface between the frame partition wall 61 and the common electrode 22 (an example of a structural material).

  In the second manufacturing method, the moisture sealing layer 44 formed on the frame partition wall 61 and the frame partition wall 61 and the first sealing material before the top 35 ′ of the partition wall 35 bites into the sealing layer 42. 14a is pushed out into the region inside the frame partition wall 61, and then spreads wet along the upper surface of the second sealing layer 42b. Therefore, when the top 35 ′ of the partition wall 35 bites into the sealing layer 42, the moisture sealing layer 44 is dissolved in the dispersion liquid containing the electrophoretic particles 34 and the first material in each cell 36. As a result, the dispersion medium 15 including the first material and the second material is completed.

  As described above, the element substrate 51 and the counter substrate 52 are bonded together by causing the partition wall 35 to bite into the sealing layer 42 provided on the counter substrate 52.

  At this time, the moisture sealing layer 44 is formed on the frame partition wall 61 through the step [1-4 ′]. The moisture sealing layer 44 has a sealing property for sealing moisture. The material of the first sealing material 14a is, for example, a liquid curable resin such as an ultraviolet curable resin and a thermosetting resin (Kayatron) having a relatively high viscosity. Depending on the type of the material, the hygroscopic property may be used. Or it may show adsorptivity. Therefore, the first sealing material 14a may contain moisture. Even in such a case, the cell 36 is filled from the first sealing material 14a side beyond the moisture sealing layer 44. It is possible to suppress moisture from moving to the dispersion medium side. Therefore, by carrying out this step [3-3 ′] while maintaining this state, the water content contained in the electrophoretic dispersion liquid 37 can be set within an appropriate range. Therefore, since it is possible to accurately suppress or prevent the change in the electrophoretic characteristics of the electrophoretic particles 34, the electrophoretic display device 10 in which excellent display quality is maintained is manufactured.

  Thereafter, as shown in FIG. 25, if the first sealing material 14a is an ultraviolet curable resin, the first sealing material 14a is baked after being irradiated with ultraviolet rays Y and cured. Further, if it is a thermosetting resin, it is cured by heating and fired. Thereby, the element substrate 51 and the counter substrate 52 can be joined via the first sealing material 14a, and moisture contained in the first sealing material 14a can be removed.

  The cell gap when the element substrate 51 and the counter substrate 52 are bonded together is about 20 μm or more and 50 μm or less, and the width of the crushed first sealing material 14 a is, for example, 200 μm or more and 500 μm or less.

  In FIG. 24, when the counter substrate 52 is pressed by applying a pressure X to the element substrate 51, it is assumed that all of the moisture sealing layer 44 formed on the frame partition wall 61 is enclosed in the cell 36. Although described, it is not limited to this case, the moisture sealing layer 44 may remain between the frame partition wall 61 and the first sealing material 14a.

  [3-4 '] Next, as shown in FIG. 26, the second sealing material 14b is applied and bonded to the outer periphery of the first sealing material 14a in the atmosphere (second sealing; step S34').

  Thereby, since the element substrate 51 and the counter substrate 52 can be firmly bonded and fixed, the movement of moisture toward the electrophoretic dispersion 37 through the second sealing material 14b is prevented.

  Specifically, the second sealing material 14b does not contain moisture and has a relatively low viscosity, and it is important that the second sealing material 14b enters the gap, such as an acrylic resin or an epoxy resin. In addition, the viscosity of the 2nd sealing material 14b is lower than the viscosity of the 1st sealing material 14a, for example, is 100 Pa.s or more and 500 Pa.s or less, Preferably, it is about 400 Pa.s. The width of the second sealing material 14b is, for example, about 300 μm or more and 500 μm or less.

As a method for applying the second sealing material 14b, for example, a dispenser, a die coater, or the like is used. Thus, as shown in FIG. 26, the space sandwiched between the element substrate 51 and the counter substrate 52 is sealed. Then, it cuts into the shape of a product as needed.
Through the above steps, the electrophoretic display device 10 is obtained.

  Note that the electrophoretic display device 10 is not necessarily manufactured by the first and second manufacturing methods of the electrophoretic display device described above. For example, the electrophoretic display device 10 is electrically connected to the dispersion medium 15 including the first material and the second material. An electrophoretic dispersion liquid 37 in which the electrophoretic particles 34 are dispersed is prepared in advance, and then the electrophoretic dispersion liquid 37 is filled in the cell 36, and then the element substrate 51 and the counter substrate 52 are joined together to perform electrophoresis. The electrophoretic display device 10 may also be manufactured by a method for manufacturing the display device 10.

  The electrophoretic display device of the present invention, the method for manufacturing the electrophoretic display device, and the electronic apparatus have been described based on the illustrated embodiments. However, the electrophoretic display device of the present invention is not limited to this. The configuration of each unit can be replaced with any configuration having the same function. In addition, any other component may be added to the present invention.

  In the embodiment described above, the partition walls 35 have a lattice shape, but the shape of the partition walls 35 in plan view is not particularly limited. For example, it may be configured in a honeycomb shape, a polygonal shape, a round shape, a triangular shape, or the like.

  Further, the partition wall 35 and the frame partition wall 61 are not limited to be disposed on the element substrate 51 side, and the partition wall 35 and the frame partition wall 61 may be disposed on the counter substrate 52 side.

  Moreover, the 1st base material 31 and the 2nd base material 41 should just use the material which has a light transmittance on the display side, and may be made to use a plastic substrate other than a glass substrate.

  Furthermore, it is not limited to using the frame partition 61 as a spacer. In order to define the cell gap between the element substrate 51 and the counter substrate 52, for example, when another member is provided as a spacer, the height of the frame partition wall 61 may be equal to the height of the partition wall 35.

  Further, in the method for manufacturing an electrophoretic display device of the present invention, for any purpose, a step before the step [1], between the steps [1] [1 ′] and the steps [2] [2 ′], [ 2] [2 ′] and steps [3] [3 ′] may be added as intermediate steps, or after steps [3] [3 ′].

  Furthermore, in the manufacturing method of the electrophoretic display device of the present invention, the moisture sealing layer 44 is selectively formed on the frame partition wall 61 among the partition walls 35 and 35a and the frame partition wall 61 in the second manufacturing method described above. Thus, the electrophoretic display device 10 is manufactured. However, the present invention is not limited to this, and the electrophoretic display device 10 is manufactured by forming the moisture sealing layer 44 on both the partition walls 35 and 35a and the frame partition wall 61. You may do it. However, by selecting the latter, there is an advantage that the contents of the first material and the second material contained in the electrophoretic dispersion liquid 37 sealed for each cell 36 can be made uniform.

  In the method for manufacturing an electrophoretic display device of the present invention, the first manufacturing method and the second manufacturing method described above may be combined. That is, the electrophoretic display device 10 may be manufactured by forming the moisture sealing layer 44 on both the sealing layer 42 and the various partition walls including the partition walls 35, 35 a and the frame partition wall 61.

  Further, the partition wall 35 is not limited to being formed using a photolithography method, and may be formed by a printing process such as a nanoimprint method, a screen printing method, a relief printing method, or a gravure printing method.

Next, specific examples of the present invention will be described.
1. Manufacture of evaluation samples (sample No. 1; equivalent to examples)

  <1> First, a glass substrate having an average thickness of 0.5 mm was provided as the first base material 31 and a flat plate electrode was provided on the lower surface side. Next, after a resin layer (31 μm) made of urethane resin is formed on the first base material 31, the resin layer is etched to form partition walls 35 having a width of 5 μm and a height of 31 μm in a lattice shape. Formed.

  <2> Next, a glass substrate having an average thickness of 0.5 mm was prepared as the second base material 41, and a plate electrode was prepared on the lower surface side. Next, the first sealing layer 42 a and the second sealing layer 42 b were formed on the second base material 41 to form the sealing layer 42. Thereafter, the sealing layer 42 was baked under conditions of 100 ° C. × 2 hours.

  The first sealing layer 42a and the second sealing layer 42b are formed by forming NBR on the second base material 41 by a spin coating method and then forming PVA by a spin coating method. went. The thicknesses of the first sealing layer 42a and the second sealing layer 42b obtained at this time were 2 μm and 0.3 μm, respectively. The elastic modulus at 25 ° C. of the first sealing layer 42a was 15 MPa.

  <3> Next, a moisture sealing layer 44 was further formed on the sealing layer 42 formed on the second substrate 41.

  The moisture sealing layer 44 was formed by forming a silicone oil (viscosity: 500 Pa · s) as the second material on the sealing layer 42 by spin coating. The thickness of the moisture sealing layer 44 obtained at this time was 3 μm.

  <4> Next, Kayatron, which is a liquid epoxy resin, was applied to the outer periphery of the partition wall 35 on the first base material 31 as the first sealing material 14a. Thereafter, injection is performed by applying a dispersion liquid containing electrophoretic particles 34 and silicone oil (viscosity: 2 mPa · s) as a first material in a recess formed by the first base material 31 and the partition wall 35. did.

<5> Next, in the step <4>, the steps <2> to the step described above with respect to the first substrate 31 in which the dispersion is filled in the recess formed by the first substrate 31 and the partition wall 35. In step <3>, the first base material 31 and the second base material 41 on which the sealing layer 42 and the moisture sealing layer 44 are formed are arranged so that the partition wall 35 and the moisture sealing layer 44 face each other. Two base materials 41 were bonded together. In this bonding, the counter substrate 52 is pressed against the element substrate 51 until the top 35 ′ of the partition wall 35 bites into the sealing layer 42 in a vacuum negative pressure environment of 500 Pa, and then the first sealing material 14 a is exposed to ultraviolet rays. Was performed by irradiating and curing. The thickness of the electrophoretic layer 33 formed by the top 35 ′ of the partition wall 35 biting into the sealing layer 42 was 30 μm.
By going through the above steps, sample No. One evaluation sample was produced.

(Sample No. 2; equivalent to comparative example)
Except that the formation of the moisture sealing layer 44 on the sealing layer 42 in the step <3> was omitted, the sample Nos. In the same manner as in sample 1, sample no. Two evaluation samples were produced.

2. Evaluation Sample No. 1 evaluation sample and sample No. 1 With respect to the two samples for evaluation, the white reflectance when displaying white and the black reflectance when displaying black were measured, and the contrast was calculated therefrom.

  As a result, sample no. In the sample for evaluation 1, the contrast was more than 20%, whereas the sample No. In the sample for evaluation 2, the contrast was less than 15%.

  Sample No. 1 evaluation sample and sample No. 1 Each of the samples for evaluation 2 was decomposed and the amount of water contained in the dispersion medium was measured. In the sample for evaluation 1, the sample No. 1 was about 500 ppm. In the sample for evaluation 2, it was over 3000 ppm.

  From these, sample no. In the sample for evaluation 1, by providing the moisture sealing layer 44 that covers the sealing layer 42, the migration of moisture from the sealing layer 42 into the electrophoretic dispersion liquid 37 is reduced. . The result which the sample for evaluation of 1 showed the outstanding display quality was obtained. In contrast, sample no. In the evaluation sample of 2, the formation of the moisture sealing layer 44 is omitted, so that moisture moves from the sealing layer 42 into the electrophoretic dispersion 37. The result presumed that the display quality of the sample for evaluation 2 was impaired was obtained.

DESCRIPTION OF SYMBOLS 10 ... Electrophoretic display device 11 ... Pixel, 12 ... Data line, 13 ... Scanning line, 14 ... Seal part, 14a ... 1st sealing material, 14b ... 2nd sealing material, 15 ... Dispersion medium, 16 ... Transistor, 21 ... Pixel electrode, 22 ... Common electrode, 31 ... First substrate, 32 ... First insulating layer, 33 ... Electrophoresis layer, 34 ... Electrophoretic particles, 35 ... Partition, 35 '... Top, 35a ... Partition, 36 ... Cell: 37 ... Electrophoretic dispersion liquid, 41 ... Second base material, 42 ... Sealing layer, 42a ... First sealing layer, 42b ... Second sealing layer, 44 ... Moisture sealing layer, 51 ... Element substrate, 52 ... Counter substrate, 61 ... Frame partition, 100 ... Electronic device, 110 ... Operating unit, D ... Dummy pixel area, E ... Display area, E1 ... Frame area, t1 ... Average thickness, t2 ... Biting amount, W1 ... Width , W2 ... width, W3 ... width, X ... pressure, Y ... UV

Claims (9)

A first substrate;
A second substrate disposed opposite the first substrate;
A partition wall disposed between the first substrate and the second substrate and partitioned into a plurality of cells;
An electrophoretic dispersion liquid disposed in a plurality of the cells and containing electrophoretic particles and a dispersion medium;
The dispersion medium contains a first material having a first molecular weight and a second material having a second molecular weight that is larger than the first molecular weight.
The electrophoretic display device, wherein the second material is present at an end of the partition on the second substrate side.   The electrophoretic display device according to claim 1, further comprising a sealing layer disposed between the partition wall and the second substrate.   The electrophoretic display device according to claim 2, wherein the sealing layer is a stacked body in which a first sealing layer and a second sealing layer are stacked in this order from the second substrate side.   The electrophoretic display device according to claim 1, wherein the first material and the second material have the same structure.   The electrophoretic display device according to claim 1, wherein the first material and the second material are both silicone oil. To divide into a plurality of cells filled with an electrophoretic dispersion liquid containing a first medium material having a first molecular weight and a dispersion medium containing a second material having a second molecular weight larger than the first molecular weight and electrophoretic particles. Forming a partition wall on the first substrate;
Forming a moisture sealing layer containing a second material having a second molecular weight larger than the first molecular weight on at least one of the second substrate and the partition;
Injecting a dispersion liquid in which the electrophoretic particles are dispersed in the first material into the cell;
A method for manufacturing an electrophoretic display device, comprising: bonding the partition and the second substrate so that the moisture sealing layer is interposed.   The method for manufacturing an electrophoretic display device according to claim 6, wherein the moisture sealing layer has an average thickness of 1 μm to 5 μm.   The method for manufacturing an electrophoretic display device according to claim 6, wherein the partition walls are formed with an average height of 10 μm to 150 μm.   An electronic apparatus comprising the electrophoretic display device according to claim 1.

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