JP5181500B2 - Display element and manufacturing method thereof - Google Patents

Description

The present invention relates to a display device, manufacturing how the display device, an image display device and an image display system.

  An electrophoretic display is a non-luminescent device based on the electrophoretic phenomenon of a suspension in which charged dye particles are suspended in a solvent. An electrophoretic display usually has two plates with electrodes arranged opposite each other and separated by a spacer, one of the electrodes is usually transparent. The suspension is held between the two plates. At this time, when a voltage difference is applied between the two electrodes, the charged dye particles move to one side, and either the color of the charged dye particles or the color of the solvent is observed depending on the polarity of the voltage difference. be able to.

  In Patent Document 1, there are a plurality of cup-shaped recesses formed by microembossing or image exposure, and the recesses are filled with a dispersion of charged dye particles dispersed in a dielectric solvent or solvent mixture. A polymeric sealing layer formed by curing an overcoat layer of a sealing composition having a low specific gravity and at least partially immiscible with the dispersion over the dispersion confines the dispersion within the recess. An electrophoretic display attached in such a manner as to be sealed is disclosed.

  However, since the recesses are formed by microembossing or image exposure, there is a problem that it is difficult to make the cell walls that partition adjacent recesses thinner. The thickness of the cell wall affects the display characteristics. When the cell wall is thick, the area of the display portion is reduced, and the display characteristics such as reflectance and contrast are deteriorated.

  Furthermore, since the recess is formed by microembossing or image exposure, there is a problem that it is difficult to make the bottom of the recess thinner. In the case of micro-embossing, a concave portion is formed by pressing a mold against a film and transferring the shape of the mold, so that the lower limit of the thickness of the film is about 100 μm. Furthermore, since the recess is formed in such a film, it is difficult to make the thickness of the bottom of the recess 10 μm or less. In the case of image exposure, since a resist film is formed on the film and a recess is formed in the resist, the thickness of the bottom of the recess is the thickness of the film. Furthermore, since it is difficult to handle a film having a thickness of 10 μm or less, it is difficult to make the thickness of the bottom of the concave portion 10 μm or less. For this reason, the drive voltage for driving the charged dye particles filled in the recesses cannot be reduced. Further, when the bottom of the recess is the display surface, the reflectance is lowered.

  On the other hand, if the cell walls that partition adjacent recesses and the bottom of the recesses are made thin, there is a problem that the strength against warping and bending is insufficient.

Also, after filling the concave portions with the dispersion of charged pigment particles, it is necessary to seal with a polymeric sealing layer to prevent the dielectric solvent from drying, but the reflectivity decreases when the polymeric sealing layer is thick However, there is a problem that the drive voltage increases.
Japanese Patent No. 3680996

In view of the problem of the prior art described above it has for its object to provide a method for producing a highly reflective display element及 beauty the display element. Further, the present invention aims at providing an image display system including an image display device and the image display device having the display device.

In the display device according to the first aspect of the present invention, the display element includes a hollow structure in which a plurality of cells having through-holes are arranged in a planar shape, and the plurality of wall surfaces facing each other of the hollow structure are provided with the plurality of The cell has an opening of a through hole, and one of the wall surfaces having the opening is joined to a transparent conductive film, and one or more white particles and / or colored particles are contained in the through hole. It has the dispersion liquid disperse | distributed in a solvent, It is characterized by the above-mentioned. Thus, it is possible to provide a highly reflective display element.

According to a second aspect of the present invention, in the display element according to the first aspect of the present invention, the thickness of the partition wall separating the through holes of the adjacent cells is 0.01 μm or more and 10 μm or less. Thereby, a display element having a high reflectance and excellent contrast can be obtained.

According to a third aspect of the present invention, in the display element according to the first or second aspect, the wall surface having the opening is 0.01 μm or more and 10 μm or less. As a result, a display element having a high reflectance and a low driving voltage can be obtained.

According to a fourth aspect of the present invention, in the display element according to any one of the first to third aspects, an intersection of the wall surface having the opening and the partition wall separating the through hole of the adjacent cell is provided. When viewed in cross-section, it is a curve having a radius of curvature of 0.1 μm to 50 μm. As a result, a display element having high reflectivity and high strength against warping and bending can be obtained.

According to a fifth aspect of the present invention, in the display element according to any one of the first to fourth aspects, the hollow structure is made of a material obtained by drying a plastic material. Thereby, the intensity | strength with respect to the curvature and bending of a hollow structure can be improved.

According to a sixth aspect of the present invention, in the display element according to the fifth aspect, the plastic material contains a water-soluble resin. Thereby, the solvent resistance of a hollow structure can be improved.

According to a seventh aspect of the present invention, in the display element according to any one of the first to fourth aspects, the hollow structure is made of a material obtained by UV-curing a plastic material. Thereby, the intensity | strength with respect to the curvature and bending of a hollow structure, and solvent resistance can be improved.
According to an eighth aspect of the present invention, in the display element according to any one of the first to seventh aspects, the opening portion of the wall surface not joined to the transparent conductive film is insoluble in the electrode or the solvent. It is sealed with resin. Thereby, the leakage of the content of a through-hole can be suppressed.
According to a ninth aspect of the present invention, in the display element according to the eighth aspect, the resin is a film having a thickness of not less than 0.1 μm and not more than 10 μm. As a result, the reflectance can be increased and the drive voltage can be decreased.

According to a tenth aspect of the present invention, in the method for manufacturing a display element according to any one of the first to ninth aspects, a space is formed in the concave portion of the substrate on which a plurality of independent concave portions are formed. A step of forming a first film having plasticity on the surface of the substrate having a recess, and a step of forming a second film on the surface of the first film that is not formed on the substrate; The step of stretching the first film by expanding the gas present in the space, and bonding the first film and the second film by curing the stretched first film It has the process to perform. Thus, it is possible to provide a method for producing a highly reflective display element.

The invention according to claim 11 is the method for manufacturing a display element according to claim 10 , wherein the first film contains an ultraviolet curable resin, and the second film contains the ultraviolet curable resin . It transmits ultraviolet rays to be cured. Thereby, the solvent resistance of a hollow structure can be improved.

A twelfth aspect of the present invention is the method for manufacturing a display element according to any one of the first to ninth aspects, wherein a space is formed in the concave portion of the substrate on which a plurality of independent concave portions are formed. A step of forming a first film having plasticity on a surface of the substrate having a recess, a step of stretching the first film by expanding a gas existing in the space, and the first disposing a solvent capable of dissolving or swelling the film in the second film, can be dissolved or swelled the first membrane of the first membrane said second film is the stretch and contacting the surface of the solvent, such are arranged, by removing the solvent capable of dissolving or swelling the first layer, the step of bonding said first membrane and said second membrane It is characterized by having. Thereby, the manufacturing method of the hollow structure composite body which can be applied to a display element with a high reflectance by this can be provided.

A thirteenth aspect of the present invention is the display element manufacturing method according to the twelfth aspect of the present invention, further comprising a step of removing a part of the stretched first film, and the second film of the second film . The first film from which the part has been removed is brought into contact with a surface on which a solvent capable of dissolving or swelling one film is disposed. Thereby, the thickness of the wall surface of a hollow structure can be made thin.

According to a fourteenth aspect of the present invention, in the method for manufacturing a display element according to the twelfth or thirteenth aspect , the first film contains a water-soluble resin, and the first film can be dissolved or swollen. A possible solvent is characterized by containing water. Thereby, the solvent resistance of a hollow structure can be improved.

The invention of claim 15 is an image display device, and wherein the display device according to any one of claims 1 to 9, further comprising a means for applying a voltage to the display element. Thereby, the image display apparatus which is excellent in display characteristics or durability can be provided.

According to a sixteenth aspect of the present invention, in the image display device, the display element according to any one of the first to seventh aspects and a means for applying a voltage to the display element are provided, and the transparent conductive film The opening of the unbonded wall surface is sealed by means for applying a voltage to the display element. Thereby, the image display apparatus which is excellent in display characteristics or durability can be provided.

According to a seventeenth aspect of the present invention, in the image display system, the image display device according to the fifteenth or sixteenth aspect is provided. Thereby, the image display system excellent in display characteristics or durability can be provided.

According to the present invention can provide a method for producing a highly reflective display element及 beauty the display element. Further, the present invention can provide an image display system including an image display device and the image display device having the display device.

  Next, the best mode for carrying out the present invention will be described with reference to the drawings.

  The display element of the present invention has a hollow structure in which a plurality of cells having through-holes are arranged in a planar shape, and openings of through-holes possessed by the plurality of cells are formed on two opposing wall surfaces of the hollow structure. One of the wall surfaces having an opening is bonded to the transparent conductive film, and the through hole has a solvent in which one or more white particles and / or colored particles are dispersed. The opening of the wall surface not joined to the transparent conductive film may be sealed with a resin insoluble in a solvent in which one or more white particles and / or colored particles are dispersed, or may be an electrode. It may be sealed.

  The display element of the present invention preferably has at least one of the following features (1) to (3).

(1) The thickness of a partition wall (hereinafter referred to as a cell wall) that separates through-holes of adjacent cells is 0.01 to 10 μm, preferably 0.05 to 5 μm. (2) An opening of a hollow structure is provided. The wall surface thickness is 0.01 to 10 μm, preferably 0.05 to 5 μm. (3) When the cross section of the wall surface having the opening with the cell wall is viewed in cross section, the radius of curvature is 0.1 to 50 μm. In addition, it is preferably a curve of 1 to 10 μm. The thickness, the radius of curvature, etc. of each part can be measured by observing the cross section of the display element, the hollow structure, etc. with a scanning electron microscope or the like. The average value obtained by measuring 10 or more arbitrary locations.

  FIG. 1 shows an example of a hollow structure used in the present invention. The hollow structure 10 has a plurality of regular quadrangular prism-shaped cells 11 having through-holes, and the plurality of cells 11 are arranged in a planar shape. The through-holes of adjacent cells 11 are partitioned by cell walls 12. ing. Furthermore, each cell 11 has an opening 14 a on the upper wall surface 13 of the hollow structure 10 and an opening 14 b on the lower wall surface 15. Further, a cross section of the intersection 16a of the upper wall surface 13 with the cell wall 12 and the intersection 16b of the lower wall surface 15 with the cell wall 12 is a curved line. When the intersection 16a is a cross-sectional curve, the cell wall 12 means a region not including a curve, that is, a region below the inflection point, and the upper wall surface 13 is above the cell wall 12. Means the area. When the intersecting portion 16b is a sectional view curve, the cell wall 12 means a region not including a curve, that is, a region above the inflection point, and the lower wall surface 15 is below the cell wall 12. Means the area.

  FIG. 2 shows another example of the hollow structure used in the present invention. The hollow structure 20 includes a plurality of regular hexagonal columnar cells 21 having through holes, the plurality of cells 21 are arranged in a planar shape, and the through holes of adjacent cells 21 are partitioned by cell walls 22. ing. Further, each cell 21 has an opening 24 a on the upper wall surface 23 of the hollow structure 20 and an opening 24 b on the lower wall surface 25. Further, a cross-sectional view of the intersecting portion 26a of the upper wall surface 23 with the cell wall 22 and the intersecting portion 26b of the lower wall surface 25 with the cell wall 22 is a curved line.

  In addition, the hollow structure used by this invention is not limited to the hollow structure shown in FIG.1 and FIG.2, The magnitude | size of each cell may be non-uniform | heterogenous. Further, the intersecting portion may not be a sectional view curve.

  The display element having the feature (1) will be described with reference to a hollow structure (sheet having a honeycomb structure) shown in FIG. Since the thickness of the cell wall 22 of the hollow structure 20 is 0.01 to 10 μm, preferably 0.05 to 5 μm, the display characteristics of the display element having the hollow structure 20 can be improved. Since the cell wall 22 is a portion that does not contribute to display, the reflectance and contrast are improved by being thinned. When the thickness of the cell wall 22 is less than 0.01 μm, the strength of the hollow structure 20 becomes weak, and when it exceeds 10 μm, the characteristics are deteriorated in terms of reflectance and contrast.

  The display element having the feature (2) will be described with reference to the hollow structure (sheet having a honeycomb structure) shown in FIG. Since the thickness of the upper wall surface 23 and the lower wall surface 25 of the hollow structure 20 are 0.01 to 10 μm, preferably 0.05 to 5 μm, the display characteristics of the display element having the hollow structure 20 are improved. Can be improved. Thinning the upper wall surface 23 and the lower wall surface 25 is advantageous in terms of reflectivity and driving voltage. If the thickness of the upper wall surface 23 and the lower wall surface 25 is less than 0.01 μm, the strength of the hollow structure 20 becomes weak, and if it exceeds 10 μm, the characteristics are degraded in terms of reflectance and drive voltage.

  The display element having the feature (3) will be described with reference to a hollow structure (sheet having a honeycomb structure) shown in FIG. When the hollow structure 20 is viewed in cross-section, the intersecting portions 26a and 26b are curves having a radius of curvature of 0.1 to 50 μm, preferably 1 to 10 μm, so that the display characteristics and strength of the display element having the hollow structure 20 are obtained. Can be improved. As a result, sufficient strength can be obtained even when the display element is bent and used. Thus, the strength can be improved by providing the intersecting portions 26 a and 26 b thicker than the cell wall 22. If the radius of curvature is less than 0.1 μm, the display element is light enough to warp, but not strong enough to be rounded, and if it exceeds 50 μm, the display characteristics, particularly in terms of reflectivity, deteriorate. .

  In the present invention, as described above, when the opening portion of the wall surface not bonded to the transparent conductive film is sealed with resin, the resin sealing the opening portion has a thickness of 0.1 to 10 μm. The film is preferably 0.5 to 5 μm.

  A display element having such characteristics will be described with reference to a hollow structure (sheet having a honeycomb structure) shown in FIG. The hollow structure 20 has a solvent in which one or more white particles and / or colored particles are dispersed in the through hole of each cell 21, and the opening 24 a or 24 b of each cell 21 is insoluble in this solvent. Sealed with resin. Since the resin for sealing the opening 24a or 24b is a film having a thickness of 0.1 to 10 μm, preferably 0.5 to 5 μm, the display characteristics of the display element having the hollow structure 20 can be improved. it can. Note that reducing the thickness of the resin is advantageous in terms of reflectivity and driving voltage. When the film thickness is less than 0.1 μm, the strength is weakened.

  In the present invention, the hollow structure is preferably made of a material obtained by drying a plastic material. The material having plasticity is not particularly limited, but preferably contains a water-soluble resin. Examples of water-soluble resins include polyvinyl alcohol, polyvinyl pyrrolidone, polyurethane, pullulan, albumin, CMC, polyacrylic acid, cellulose, starch, gelatin, alginate, guar gum, gum arabic, carrageenan, tragacanth, pectin, dextrin, casein, collagen, Polyvinyl methyl ether, carboxyvinyl polymer, sodium polyacrylate, polyethylene glycol, ethylene oxide, agar, locust bean gum, xanthan gum, cyclodextrin, tannic acid, karaya gum, julan gum, far selelain, tant gum, lecithin, chitin, chitosan, sodium chondroitin sulfate , Lignin sulfonic acid, methylcellulose, hydroxymethylcellulose, polyacrylamide, poly Chiren'imin, polyacrylic acid dimethylaminoethyl, poly dimethylaminoethyl methacrylate, polyethylene oxide, polyallylamine, and the like, may be used in combination. The water-soluble resin referred to here means a resin that dissolves or swells in water.

  The hollow structure is preferably made of a material obtained by ultraviolet curing a plastic material. At this time, the plastic material preferably contains an ultraviolet curable resin such as a urethane acrylic resin, an epoxy acrylic resin, or an alkoxy acrylic resin.

  In the present invention, the solvent in which one or more kinds of white particles and / or colored particles are dispersed is not particularly limited, and examples of the white particles include inorganic particles such as titanium oxide and alumina, and organic particles such as polyvinyl naphthalene. Examples of the colored particles include carbon black, azo pigments, phthalocyanine pigments, quinacridone pigments, anthraquinone pigments, dioxazine pigments, dyed lake pigments, and solvents include silicone oil and isoparaffin hydrocarbons. Can be mentioned.

  In FIG. 3, an example of the manufacturing method of the hollow structure used by this invention is shown. In order to manufacture a hollow structure, a substrate 31 having a plurality of independent recesses 31a and having a narrow opening 31b of the recess 31a is used (see FIG. 3A). First, the film | membrane 32 which has plasticity is formed on the board | substrate 31 by apply | coating using a slit coater etc. (refer FIG.3 (b)). At this time, at least a ventilation space may be provided on the side where the plastic film 32 is formed and dried. Next, when the substrate 31 on which the plastic film 32 is formed is placed in a vacuum chamber or the like and at least the side on which the plastic film 32 is formed is in a reduced pressure state, the air held in the recess 31a expands. To do. At this time, since the recess 31a is sealed with the plastic film 32, the plastic film 32 is stretched and deformed by the expansion of air, and the intermediate body 33 is formed on the substrate 31 (FIG. 3C). )reference). Finally, when peeled from the substrate 31, a plurality of cells having holes are arranged in a planar shape, and an intermediate body 33 having an opening on the upper wall surface is obtained (see FIG. 3D). At this time, when a substrate 31 (see FIG. 4A) having concave portions 31a arranged in a square lattice is used, an intermediate body (see FIG. 5A) in which square prismatic cells are arranged in a square lattice. ), And using a substrate 31 (see FIG. 4B) having recesses 31a arranged in a hexagonal close-packed lattice, an intermediate body in which regular hexagonal columnar cells are arranged in a hexagonal close-packed lattice ( FIG. 5B is obtained.

  The depth d of the hole of the intermediate body 33 can be appropriately adjusted depending on the degree of vacuum to be reduced. That is, when the vacuum is high, the amount of expansion of the air in the recess 31a is large, so the depth d is large. When the vacuum is low, the expansion of the recess 31a is small, and the depth d is small. When the vacuum is further increased, the amount of expansion of the air in the recess 31a is increased, the ceiling 33a of the intermediate body 33 is thinned, and an opening is finally formed. In this way, a plurality of cells having through holes are arranged in a planar shape, and a hollow structure (see FIG. 6) having openings on the upper wall surface and the lower wall surface is obtained. 6A shows a hollow structure in which regular quadrangular prismatic cells are arranged in a square lattice, and FIG. 6B shows a hexagonal prismatic cell arranged in a hexagonal close-packed lattice. It is a hollow structure.

  As the substrate 31, in addition to a nickel substrate, a silicon substrate, a glass substrate formed with a resist pattern, a copper-clad plate (copper / polyimide laminated substrate), an etched glass substrate, polyimide, PTE, acrylic, etc. A resin substrate can be used. In addition, it is preferable that the recessed part 31a of the board | substrate 31 is hydrophobized in order to suppress permeation of a coating liquid.

  The cell wall of the intermediate body 33, the thickness of the upper wall surface and the lower wall surface, and the curvature radius of the curve when the intersection of the cell wall and the upper wall surface and the lower wall surface are viewed in cross section are as follows. It can be controlled by the thickness, material, and decompression conditions (atmospheric pressure). The thinner the film 32 having plasticity, the smaller the thickness of each part and the smaller the radius of curvature. Further, the lower the pressure at the time of decompression, the smaller the thickness of each part and the smaller the radius of curvature. Furthermore, as the viscosity of the plastic film 32 is smaller, the thickness of each portion becomes thinner and the radius of curvature becomes smaller.

  In the present invention, as a method of forming the opening in the lower wall surface of the intermediate body 33, in addition to the above-described method, a method of mechanically removing the opening to form the opening, or the intermediate body 33 is water-soluble. When it has, the method of dissolving in water and forming an opening part is mentioned. When mechanically removing the lower wall surface, the adhesive sheet is brought into contact with the lower wall surface of the intermediate body 33, and then the adhesive sheet is peeled off, whereby the lower wall surface is sheared and an opening is formed. Is done. When the lower wall surface is dissolved in water, water is generated on the lower wall surface by condensation, steam, water droplet spraying, etc., dissolved in water, or water diluted in a solvent such as ethanol is dissolved in the lower wall. By generating it on the wall surface, the lower wall surface is self-contracted and an opening is formed. Thus, the hollow structure used by this invention is obtained by forming an opening part in the wall surface of the lower part of the intermediate body 33. FIG.

  In addition, the cell wall, the upper wall surface, and the lower wall surface of the hollow structure (and the intermediate body) are formed by the surface tension of a plastic material, and thus have a recess formed by microembossing or image exposure. Compared with the structure, the thickness can be reduced. The shape of the hollow structure (and intermediate) is difficult to form by microembossing or image exposure.

  Examples of the image display device of the present invention include a display having the display element of the present invention and a drive element for applying a voltage to the display element. At this time, in the display element of the present invention, an image display device in which an opening portion of a wall surface not bonded to the transparent conductive film is sealed with a driving element instead of an electrode or a resin can be used. In addition, examples of the image display system of the present invention include specific system application examples of the image display apparatus such as an electronic book, an advertisement display system, a timetable system, and recycled paper having the image display apparatus of the present invention.

  The display element of the present invention has a hollow structure composite in which one of the wall surfaces having openings of the hollow structure is bonded to the transparent conductive film. Such a hollow structure composite is a hollow structure composite of the present invention. It can manufacture using the manufacturing method of a structure composite_body | complex.

  In the first embodiment of the method for producing a hollow structure composite of the present invention, the surface having the recesses of the substrate is plastic so that a space is generated in the recesses of the substrate in which a plurality of independent recesses are formed. Forming the first film, forming the second film on the surface of the first film not formed on the substrate, and expanding the gas existing in the space, thereby And a step of bonding the first film and the second film by curing the stretched first film. At this time, the first film preferably contains a photocurable material such as an ultraviolet curable resin, whereby the first film can be cured by light irradiation. The second film preferably transmits light for curing the first film, whereby the first film can be cured by light irradiation from above the second film. Thus, the hollow structure composite body formed in the board | substrate can be peeled and used from a board | substrate.

  In the second embodiment of the method for producing a hollow structure composite of the present invention, the surface having the concave portion of the substrate is plastic so that a space is generated in the concave portion of the substrate in which the plurality of independent concave portions are formed. A step of forming one film, a step of stretching the first film by expanding a gas present in the space, and a solvent capable of dissolving or swelling the first film in the second film The step of placing, the step of bringing the stretched first membrane into contact with the surface of the second membrane where the solvent is placed, and the step of joining the first membrane and the second membrane by removing the solvent Have Thus, the hollow structure composite body formed in the board | substrate can be peeled and used from a board | substrate. At this time, a part of the stretched first film may be removed to form an opening in advance, and then the first film and the second film may be joined. When removing a part of the first film, the above-mentioned method of mechanically removing the first film to form an opening, and when the first film has water solubility, It is possible to use a method of dissolving and forming the opening. The stretched first film may be peeled off from the substrate and then carried on a carrier to be joined to the second film.

  The hollow structure composite of the present invention that can be produced in this way has a hollow structure in which a plurality of cells having through-holes are arranged in a plane, and is formed on two wall surfaces of the hollow structure. The plurality of cells have through-hole openings, and one of the wall surfaces having the openings is joined to a predetermined member. In addition, if the member joined to one of the wall surfaces which have an opening part is a member which can be joined, a shape, a material, etc. will not be specifically limited. The hollow structure composite of the present invention may have a fluid in the through hole. Such a fluid is not particularly limited as long as it does not dissolve the member joined to one of the hollow structure and the wall surface having the opening.

(Production of intermediates)
The intermediate body 33 was manufactured using the manufacturing method of the hollow structure shown in FIG. First, a plastic film 32 is formed by applying an aqueous solution of about 5 to 30% by weight of gelatin MC-243 (manufactured by Zerais) as a plastic material on the substrate 31 using a slit coater. did. Next, the substrate 31 on which the plastic film 32 was formed was decompressed in a vacuum chamber, and the air in the recess was expanded. At this time, the residual water in the gelatin was evaporated in vacuum, and completely dried and solidified.

As described above, the thickness h of the cell walls 0.01 to 5 [mu] m, the thickness _{i a} of the upper wall is 0.01 to 2 [mu] m, the length j of one side of the opening is 140 .mu.m, the top wall When the crossing portion of the cell wall was cross-sectionally viewed, an intermediate body 33 (see FIG. 7) having a curve with a radius of curvature of 0.1 to 20 μm was obtained.
Example 1
A sealing block 42 for sealing the opening of the intermediate body 33 was provided in a humidifying container 41 having a temperature of 30 ° C. and a humidity of 80 to 99%. Next, the intermediate body 33 was installed in the sealing block 42 in the humidification container 41 (refer Fig.8 (a)). In addition, the temperature of the intermediate body 33 needs to be lower than the humidification container 41, and was set to 20 ° C. Since the temperature of the intermediate body 33 is lower than that of the humidifying container 41, water droplets 43 are generated on the intermediate body 33 and condensation occurs. In addition, since the opening part of the intermediate body 33 is sealed, dew condensation does not occur inside the intermediate body 33. Further, the ceiling 33 a of the intermediate body 33 which has condensed is dissolved in the water droplets 43. Here, since the intermediate body 33 is formed by stretching under the pressure of air, the gelatin molecules are oriented in the plane direction and internal stress is generated. In this state, the ceiling portion 33a is melted and the rigidity is lowered, so that self-shrinkage (see an arrow in the figure) occurs due to surface tension, and an opening is formed (see FIG. 8B). In particular, since the wall surface of the center part of the ceiling part 33a of the intermediate body 33 is thin, it opens from the center part. In this way, a hollow structure 44 (see FIG. 6) was formed (see FIG. 8 (c)). After condensation for a predetermined time so that the target opening shape was obtained, the hollow structure 44 was taken out from the humidification container 41 and dried in order to stop the opening. At this time, in the hollow structure 44, the thickness of the lower wall surface is 0.01 to 2 μm, and when the cross section of the lower wall surface and the cell wall is viewed in cross-section, the hollow structure 44 is a curve having a curvature radius of 0.1 to 20 μm. there were.

  The thinner the ceiling 33a of the intermediate body 33, the shorter the opening. Specifically, when the thickness of the ceiling portion 33a was 0.05 μm, the opening was made in 20 seconds. Moreover, compared with Example 2 mentioned later, the opening surface of the hollow structure 44 was a smooth shape.

Next, a film 51 with a transparent conductive film at 20 ° C. is placed in a humidifying container 41 having a temperature of 30 ° C. and a humidity of 80 to 99%, and when a suitable amount of water droplets 43 are generated and condensed, the hollow structure 44 is humidified. 41 (see FIG. 9A). At this time, the temperature of the hollow structure 44 needs to be higher than the humidification container 41 so as not to cause condensation, and was set to 50 ° C. In the film with a transparent conductive film, a transparent ITO (Indium Tin Oxide) layer is formed on a transparent PET film by a sputtering method or the like. Next, after the wall surface having the opening of the hollow structure 44 and the ITO layer of the film 51 with the transparent conductive film were brought into contact with each other, the hollow structure 44 was taken out from the humidifying container 41 and dried to obtain the hollow structure composite 52. (See FIG. 9B). At this time, the hollow structure 44 and the transparent conductive film-attached film 51 are bonded without forming an adhesive layer, but are bonded in a state in which the interfaces are in close contact with each other, so that the bonding strength is very strong. In addition, although the hollow structure 44 has two wall surfaces which have an opening part, you may join any wall surface to the film 51 with a transparent conductive film.
(Example 2)
After bringing the adhesive sheet into contact with the ceiling portion 33a of the intermediate body 33 (see FIG. 3C) formed on the substrate 31, the ceiling portion 33a is sheared by peeling off the adhesive sheet, thereby opening the opening portion. Formed. In this way, a hollow structure (see FIG. 6) was formed on the substrate 31, and the hollow structure was peeled from the substrate 31. At this time, the hollow structure has a lower wall surface thickness of 0.01 to 2 μm, and a cross-sectional view of the intersection of the lower wall surface and the cell wall has a curve with a curvature radius of 0.1 to 20 μm. It was.

Next, in the same manner as in Example 1, a hollow structure composite was produced by joining the hollow structure and a film with a transparent conductive film.
(Example 3)
A film 51 with a transparent conductive film at 20 ° C. is placed in a humidification container 41 having a temperature of 30 ° C. and a humidity of 80 to 99%. (See FIG. 10 (a)). At this time, the temperature of the intermediate body 33 needs to be higher than that of the humidifying container 41 so as to prevent condensation, and is set to 50 ° C. Next, after making the wall surface without the opening part of the intermediate body 33 and the ITO layer of the film 51 with the transparent conductive film come into contact with each other, it is taken out from the humidifying container 41 and dried to obtain the hollow structure composite body 52. (See FIG. 10B). Thereby, formation of the hollow structure 44 (refer FIG. 6) which has an opening part in an upper wall surface and a lower wall surface, and joining of the hollow structure 44 and the film 51 with a transparent conductive film were able to be performed simultaneously. As a result, it was possible to reduce the number of processes and reduce the cost for equipment and processing time. In addition, when the intermediate body 33 and the film 51 with a transparent conductive film contact, the ceiling part 33a of the intermediate body 33 self-shrinks and an opening is formed as in the first embodiment. At this time, in the hollow structure composite 52, the thickness of the lower wall surface is 0.01 to 2 μm, and when the cross section of the lower wall surface and the cell wall is viewed in cross section, the curvature radius is 0.1 to 20 μm. It was a curve.
Example 4
A hollow structure composite was manufactured using a part of the method for manufacturing a hollow structure shown in FIG. First, by adding a fluorosurfactant Novec FC-4430 (manufactured by 3M) to epoxy acrylate AQ9 (manufactured by Arakawa Chemical Industries, Ltd.) and reducing the surface tension of the epoxy acrylate, did. Next, a plastic film 32 was formed by applying a plastic material solution onto a substrate 31 having a plurality of independent recesses 31a using a slit coater. Furthermore, the ITO layer of the film 51 with a transparent conductive film that transmits ultraviolet rays was disposed on the film 32 having plasticity. Next, the pressure in the pressure control device 61 is reduced to expand the air in the recess 31a, and when the degree of vacuum reaches about 50 kPa, the ultraviolet ray 62 is irradiated to cure the epoxy acrylate (FIG. 11 (a)). )reference). Thereby, formation of the hollow structure 44 (refer FIG. 6) which has an opening part in an upper wall surface and a lower wall surface, and joining of the hollow structure 44 and the film 51 with a transparent conductive film were able to be performed simultaneously. As a result, it was possible to reduce the number of processes and reduce the cost for equipment and processing time.

As described above, the thickness of the cell walls 0.01 to 5 [mu] m, the thickness _{i b} of the thickness of _{i a} and the lower wall of the upper wall is 0.01 to 1 [mu] m, of one side of the opening length j Is a hollow structure composite body 52 having a curvature radius of 0.1 to 5 μm (see FIG. 11B) when the cross section of the upper wall surface and the lower wall surface with the cell wall is viewed in cross section. was gotten.
(Manufacture of electrophoresis solution)
As white particles, titanium oxide R-960 (manufactured by DuPont) was grafted with lauryl methacrylate on the surface. In addition, as a coloring pigment, a carbon black PRINTEX A (manufactured by Degussa) having a graft polymerized with 2-ethylhexyl methacrylate was used. Next, using a dispersant Span85 (manufactured by ICI) and a charge control agent Spospers 17000 (manufactured by Avisia), white particles and colored particles are ultrasonically dispersed in isoparaffin hydrocarbon Isopar G (manufactured by ExxonMobil). An electrophoresis solution was prepared. The composition of the electrophoresis solution is white particles (40% by weight), colored particles (2% by weight), Span 85 (0.5% by weight), Spsperse 17000 (0.5% by weight), IsoparG (57% by weight). did.
(Example 5)
The hollow structure composite 52 has a cell wall thickness of 2 μm, an upper wall thickness _ia and a lower wall thickness i _b of 1 μm, an opening side j of 140 μm, a through hole When the cross section of the upper wall surface and the lower wall surface intersects with the cell wall is viewed in cross section, the hollow structure 44 (FIG. 6 (FIG. b)) and a film 51 with a transparent conductive film are used. The film 51 with a transparent conductive film has a transparent PET film for protecting the transmission of the display image and the electrophoretic liquid 71 and an ITO layer that is a transparent common electrode.

After injecting the electrophoretic liquid 71 in which the pigment particles move by the image display signal (voltage, current, etc.) into the space in the cell of the hollow structure complex 52, using a slit coater, An aqueous solution of gelatin MC-243 (manufactured by Zerais Co., Ltd.) was applied and dried to form a sealing film 72 having a thickness of 5 μm. (See FIG. 12 (a)). For sealing, in addition to gelatin, a water-soluble resin insoluble in the electrophoretic liquid 64, such as polyurethane or polyvinyl alcohol, can be used. Further, as a coating method, in addition to the slit coating method, a spin coating method, a curtain coating method, or the like may be used. Next, using a slit coater, an epoxy resin was applied on the sealing film 72 to form an adhesive layer 73, and then the sealing film 72 and the electrode 74 were adhered to obtain a display element 75 (FIG. 5). 12 (b)). As the adhesive layer 73, an ultraviolet curing adhesive, a hot melt adhesive, or the like can be used in addition to the epoxy resin. Further, as a coating method, in addition to the slit coating method, a spin coating method, a curtain coating method, or the like may be used.
(Example 6)
An image display device 82 was produced in the same manner as in Example 5 except that a voltage driving circuit 81 for sending an image display signal to the display element was used instead of the electrode 74 (see FIG. 13). As the hollow structure composite 52, the hollow structure composite of Example 3 was used.

When a voltage of 10 V was applied from the voltage driving circuit 81 to the display element, and the white reflectance, black reflectance and contrast were measured using a light quantity measuring device, the white reflectance was 42%, the black reflectance was 1%, and the contrast was 42. Thus, excellent display characteristics equivalent to those of the reference example described later were obtained. In addition, in the image display device 82, the hollow structure 44 was not broken and the film 51 with the transparent conductive film was not peeled against the bending with a curvature of 200 mm.
(Example 7)
An image display device was produced in the same manner as in Example 6 except that the hollow structure composite of Example 4 was used.

When a voltage of 10 V was applied from the voltage driving circuit 81 to the display element, and the white reflectance, black reflectance and contrast were measured using a light quantity measuring device, the white reflectance was 42%, the black reflectance was 1%, and the contrast was 42. Thus, excellent display characteristics equivalent to those of the reference example described later were obtained. Further, in the image display device, the hollow structure 44 was not broken and the film 51 with the transparent conductive film was not peeled against the bending with a curvature of 200 mm.
(Example 8)
The hollow structure composite 52 has a cell wall thickness of 2 μm, an upper wall thickness _ia and a lower wall thickness i _b of 1 μm, an opening side j of 140 μm, a through hole When the cross section of the upper wall surface and the lower wall surface intersects with the cell wall is viewed in cross section, the hollow structure 44 (FIG. 6 (FIG. b)) and a film 51 with a transparent conductive film are used. The film 51 with a transparent conductive film has a transparent PET film for protecting the transmission of the display image and the electrophoretic liquid 71 and an ITO layer that is a transparent common electrode.

An epoxy resin is applied to the upper wall surface of the hollow structure composite 52 using a slit coater to form an adhesive layer 73 (see FIG. 14A), and an image display signal (voltage) is formed in the space in the cell. , Current, etc.) was injected with an electrophoretic liquid 71 in which pigment particles move (see FIG. 14B). As the adhesive layer 73, an ultraviolet curing adhesive, a hot melt adhesive, or the like can be used in addition to the epoxy resin. Further, as a coating method, in addition to the slit coating method, a spin coating method, a curtain coating method, or the like may be used. Next, the hollow structure 44 and the electrode 74 were adhered to obtain a display element 75 (see FIG. 14C).
Example 9
An image display device 82 was produced in the same manner as in Example 5 except that a voltage driving circuit 81 for sending an image display signal to the display element was used instead of the electrode 74 (see FIG. 15). As the hollow structure composite 52, the hollow structure composite of Example 3 was used.

When a voltage of 10 V was applied from the voltage driving circuit 81 to the display element, and the white reflectance, black reflectance and contrast were measured using a light quantity measuring device, the white reflectance was 42%, the black reflectance was 1%, and the contrast was 42. Thus, excellent display characteristics equivalent to those of the reference example described later were obtained. In addition, in the image display device 82, the hollow structure 44 was not broken and the film 51 with the transparent conductive film was not peeled against the bending with a curvature of 200 mm.
(Reference example)
An image display device was produced in the same manner as in Example 6 except that a 10 mm square cell having a depth of 50 μm was used instead of the hollow structure 44.

  When a voltage of 10 V was applied from the voltage driving circuit 81 to the display element and the white reflectance, black reflectance and contrast were measured using a light quantity measuring device, the white reflectance was 43%, the black reflectance was 1%, and the contrast was 43. The display characteristics were obtained.

It is a figure which shows an example of the hollow structure used by this invention, an upper figure is a top view, a middle figure is sectional drawing, and a lower figure is a bottom view. It is a figure which shows the other example of the hollow structure used by this invention, an upper figure is a top view, a middle figure is sectional drawing, and a lower figure is a bottom view. It is a figure which shows an example of the manufacturing method of the hollow structure used by this invention. It is a figure which shows the board | substrate used with the manufacturing method of the hollow structure of FIG. It is a figure which shows the intermediate body obtained with the manufacturing method of the hollow structure of FIG. It is a figure which shows the hollow structure obtained with the manufacturing method of the hollow structure of FIG. It is a figure which shows the intermediate body obtained in the Example. It is a figure which shows the manufacturing method of the hollow structure of Example 1. FIG. 1 is a view showing a method for producing a hollow structure composite of Example 1. FIG. 6 is a view showing a method for producing a hollow structure composite of Example 3. FIG. 6 is a view showing a method for producing a hollow structure composite body of Example 4. FIG. 10 is a diagram showing a method for manufacturing the display element of Example 5. FIG. FIG. 10 is a diagram illustrating an image display device according to a sixth embodiment. 10 is a diagram showing a method for manufacturing the display element of Example 8. FIG. FIG. 10 is a diagram illustrating an image display device according to a ninth embodiment.

Explanation of symbols

10, 20 Hollow structure 11, 21 Cell 12, 22 Cell wall 13, 23 Upper wall surface 14a, 24b, 14a, 24b Opening portion 15, 25 Lower wall surface 16a, 16b, 26a, 26b Intersection 31 Substrate 31a Recess 31b Opening 32 Plastic Film 33 Intermediate 33a Ceiling 41 Humidifying Container 42 Sealing Block 43 Water Drop 44 Hollow Structure 51 Film with Transparent Conductive Film 52 Hollow Structure Composite 61 Pressure Controller 62 Ultraviolet 71 Electrophoretic Liquid 72 Sealing film 73 Adhesive layer 74 Electrode 75 Display element 81 Voltage drive circuit 82 Image display device

Claims (17)

Having a hollow structure in which a plurality of cells having through holes are arranged in a plane;
On the two opposing wall surfaces of the hollow structure, there are openings of through holes of the plurality of cells,
One of the wall surfaces having the opening is joined to the transparent conductive film ,
A display element comprising a dispersion liquid in which one or more kinds of white particles and / or colored particles are dispersed in a solvent in the through hole . Display device according to claim 1, thickness of the partition wall separating the through-hole in which the adjacent cells has is equal to or is 0.01μm or more 10μm or less. The display element according to claim 1, wherein a thickness of the wall surface having the opening is 0.01 μm or more and 10 μm or less. The curved surface having a curvature radius of 0.1 µm or more and 50 µm or less when the cross section of the wall surface having the opening and the partition wall separating the through-holes of the adjacent cells is viewed in cross section. 4. The display element according to any one of 3. The display device according to claim 1, wherein the hollow structure is made of a material obtained by drying a plastic material. The display element according to claim 5, wherein the plastic material contains a water-soluble resin. The display element according to claim 1, wherein the hollow structure is made of a material obtained by ultraviolet-curing a plastic material. The display according to any one of claims 1 to 7, wherein an opening of a wall surface not bonded to the transparent conductive film is sealed with an electrode or a resin insoluble in the solvent. element. The display element according to claim 8 , wherein the resin is a film having a thickness of 0.1 μm to 10 μm. A method for manufacturing a display element according to any one of claims 1 to 9 ,
Forming a first film having plasticity on the surface of the substrate having the recesses so that a space is created in the recess of the substrate on which the plurality of independent recesses are formed;
Forming a second film on the surface of the first film that is not formed on the substrate;
Stretching the first film by expanding the gas present in the space;
A method of manufacturing a display element , comprising: a step of bonding the first film and the second film by curing the stretched first film. The first film contains an ultraviolet curable resin ,
The method for manufacturing a display element according to claim 10 , wherein the second film transmits ultraviolet light that cures the ultraviolet curable resin . A method for manufacturing a display element according to any one of claims 1 to 9 ,
Forming a first film having plasticity on the surface of the substrate having the recesses so that a space is created in the recess of the substrate on which the plurality of independent recesses are formed;
Stretching the first film by expanding the gas present in the space;
Placing a solvent in the second membrane capable of dissolving or swelling the first membrane;
A step of contacting the stretched first film of the solvent capable of dissolving or swelling the first layer of said second film is disposed surface,
Removal of the solvent capable of dissolving or swelling the first layer, a method of manufacturing a display device characterized by having a step of bonding said first membrane and said second membrane. Further comprising removing a portion of the stretched first film;
To claim 12, wherein contacting said second layer first film the first film dissolution or said portion on the surface of the solvent is arranged capable of swelling has been removed The manufacturing method of the display element of description. The first film contains a water-soluble resin ,
The method of manufacturing a display element according to claim 12 or 13 , wherein the solvent capable of dissolving or swelling the first film contains water. A display element according to any one of claims 1 to 9 ,
An image display device comprising means for applying a voltage to the display element. A display element according to any one of claims 1 to 7 ,
Means for applying a voltage to the display element;
An image display device, wherein an opening of a wall surface not bonded to the transparent conductive film is sealed by means for applying a voltage to the display element. The image display system characterized by having an image display apparatus according to claim 15 or 16.

Images