TWI644154B - Color display panel and method for preparing the same - Google Patents

Abstract

The invention provides a multicolor display panel and a method of manufacturing the same. The multi-color display panel is formed in a microcapsule-type electrophoretic display panel of multi-color display, and has a structure in which an existing black-and-white microcapsule-type electrophoretic display panel and a color filter are superimposed, thereby coloring and improving display brightness. The problem of low or narrow viewing angles.

The microcapsule layer is formed by laminating a color filter layer and a transparent electrode layer on a transparent substrate and directly laminating a microcapsule layer on the transparent electrode layer, and the microcapsule layer is a color filter and a back electrode plate. The color filter with microcapsules is formed by dispersing microcapsules into a binder resin, and the microcapsules enclose a dispersion in which electrophoretic particles are dispersed in a transparent dispersion medium, and the electric field is changed by applying a voltage to change the optical The reflective property is formed by arranging pixel electrodes on the back substrate via an adhesive layer on the aforementioned microcapsule layer.

Description

Multicolor display panel and method of manufacturing same

The present invention relates to a microcapsule type electrophoretic display panel, relating to a multicolor display panel which is constituted by a structure in which an electrophoretic ink is enclosed in a microcapsule, and the microcapsules are disposed in a transparent group. The counter electrode plate is further formed of a multicolor display panel which can be multicolor displayed by using a color filter, and a method of manufacturing the same.

In recent years, with the development of information equipment, information display has various forms. The mainstream of the display panel as variable information is a CRT (Cathode Ray Tube) and a liquid crystal using a backlight. However, when a CRT or a light-emitting display such as a backlit liquid crystal display is used for a long period of time, the burden on the eyes is large and it seems to be fatigued, and it is not suitable for applications such as continuous reading of documents for a long time.

In addition, a liquid crystal display of a type that does not use a backlight has a problem that the image is significantly dark due to the use of a polarizing plate, and has a problem of poor visibility. In addition, the display images of these displays have no memory, and the display image disappears while the supply of electric energy is stopped. Even if it is used for a long time, the eyes that look at things are not easily fatigued, the visibility is good, the power consumption is small, and a display having image memory is necessary.

Therefore, as a reflective display device having a small burden on the eyes, for example, as disclosed in Patent Document 1, an electrophoretic display panel having a pair of counter electrodes and an electrophoretic type disposed between the electrodes is proposed. Display layer. Similarly to the printed paper surface, the electrophoretic display panel displays characters or images by reflected light, so that the burden on the eyes is small, and it is suitable for the operation of continuously watching the screen for a long time.

The electrophoretic display panel is based on the principle that a voltage is applied to a dispersion of dispersed charged particles to change an electric field to move the charged particles, and an image can be displayed. In the electrophoretic display panel, the colored charged particles are enclosed in microcapsules, and the microcapsules are disposed between a pair of counter electrodes, and the microcapsule-type electrophoretic display panel has the advantages of low driving voltage, high flexibility, and the like. Practical and further development.

In addition to the display of portable information devices such as PDAs (portable information terminals) or e-books, it will be further popular in the future: printing newspapers, books, magazines, posters, etc., and printing from printers to paper. The hard copy is converted to display on the display. At this time, the electrophoretic panel is applied. The electrophoretic panel is generally a two-color display mainly composed of white and black display, and various colors are required in recent years in order to display the above-mentioned magazine or color print.

In order to multicolor the electrophoretic panel, it is disclosed that two or more types of multicolor electrophoretic particles are used. For example, in Patent Document 2, a pattern is formed by photolithography, and in Patent Document 3, an inkjet is used in addition to the photolithography method. A technique in which electrophoretic particles are disposed in predetermined pixels. Further, Patent Document 4 discloses a display panel which can accurately display a plurality of microcapsules at a desired position by forming an element frame for accommodating the microcapsules in advance, thereby displaying the plurality of colors. However, the method of arranging the multi-color microcapsules in a predetermined pixel is compared with a conventional photoresist or the like, and the actual situation is that the steps are both complicated and complicated, and the technical difficulty is large.

For this reason, Patent Document 5 discloses a method in which a color filter substrate is bonded to a black-and-white electrophoretic display panel so that multi-color display can be performed without requiring positional accuracy between the microcapsules and the pixels. However, in this method, since a separately manufactured color filter substrate is bonded to a black-and-white electrophoretic display panel as a reflective display panel, it is necessary to insert an adhesive layer for bonding in the middle, whereby the display brightness is low, and The color filter substrate is difficult to bond and has a problem of low productivity.

In addition, since there is a distance between the color filter layer and the electrophoretic layer display layer, visual differences in color due to different viewing angles result in the loss of the so-called electronic paper having no observation angle effect. In order to solve the above problem, the actual situation is to try to improve the display brightness and the viewing angle by optimizing the color filter, but it has not been greatly improved.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 50-015115

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2002-365668

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2003-156770

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2003-295234

[Patent Document 5] Japanese Patent Laid-Open Publication No. 2003-161964

The present invention has been made in view of the above problems, and an object thereof is to provide a multicolor display panel and a method of manufacturing the same, which are formed by superimposing a conventional black and white microcapsule type electrophoretic display panel in a microcapsule type electrophoretic display panel of multicolor display. And the structure of the color filter, so that it can be colored, and the problem of low display brightness or narrow viewing angle can be improved.

The invention of claim 1 of the present invention is a multicolor display panel which is a transparent substrate, a color filter layer, a transparent electrode layer, a microcapsule layer, a binder layer, and a back electrode plate. a multi-color display panel formed by sequentially laminating, wherein the microcapsule layer is directly laminated on the transparent electrode layer; the microcapsule layer is formed by dispersing microcapsules in a binder resin; and the microcapsules are encapsulated in a transparent dispersion The dispersion liquid formed by dispersing the electrophoretic particles in the medium changes the optical reflection property by the electric field change caused by the application of the voltage, and the electrode plate is an electrode plate on which the pixel electrode is disposed on the rear substrate.

The multi-color display panel according to the first aspect of the invention is characterized in that the electrophoretic particles are particles having two different surface charges, one of which is Colored particles, the other is white particles.

According to a third aspect of the invention, the multi-color display panel according to the first aspect of the invention is characterized in that the microcapsule layer is formed with a smooth layer for reducing irregularities of the microcapsules. .

Next, the invention of claim 4 of the present invention is a method of manufacturing a multicolor display panel, comprising: (a) a step of providing a color filter layer on a transparent substrate; (b) a step of disposing a transparent electrode layer on the color filter layer; (c) a step of directly coating a microcapsule layer on the transparent electrode layer to form a microcapsule layer, the microcapsule layer dispersing the microcapsule in a binder resin Formed in the microcapsules, encapsulating a dispersion in which electrophoretic particles are dispersed in a dispersion medium, changing an optical reflection property by a change in electric field caused by application of a voltage; (d) a step of laminating a layer of a binder on the microcapsule layer; (e) a step of laminating the adhesive layer between the microcapsule layer and the pixel electrode surface, wherein the pixel electrode surface is a pixel of a back electrode plate formed by disposing a pixel electrode on a back substrate Electrode surface.

According to a fifth aspect of the invention, the method of manufacturing the multi-color display panel according to the fourth aspect of the invention, further comprising the step of forming the microcapsule layer for reducing micro The step of smoothing the uneven layer of the capsule ink.

The method of manufacturing a multicolor display panel according to claim 4, wherein the step of laminating the adhesive layer on the microcapsule layer includes the method of manufacturing the multicolor display panel according to the fourth aspect of the invention. a step of forming a binder on a peelable resin substrate on which a conductive layer is formed, and laminating the formed adhesive sheet onto the microcapsule layer; and applying a voltage to the transparent electrode layer and the conductive layer to evaluate the micro At the stage of driving the capsule layer, the peelable resin substrate on which the conductive layer is formed is peeled off and removed before the step of laminating the pixel electrode surface of the back electrode plate.

In the multicolor display panel of the present invention, by directly forming a microcapsule layer on the transparent electrode layer provided on the color filter layer, the distance between the microcapsule layer as the display surface and the color filter layer can be made very close. Ground configuration. As a result, the structure of the present invention does not have an undesired layer such as a binder between the microcapsule layer and the color filter layer, as compared with the conventional display panel formed by laminating a separately manufactured color filter substrate. The reflected light reflected by the capsule layer passes through the minimum layer, and the display brightness is higher than the aforementioned conventional display panel.

In addition, regarding the deviation of the display of the microcapsule layer and the color filter observed due to the separation of the distance between the color filter layer and the microcapsule layer, the microcapsules are also closely adhered to the color filter layer, thereby The aforementioned visual difference was observed without causing narrowing of the viewing angle.

Further, in the multicolor display panel of the present invention, a smoothing layer is formed by coating only the binder resin of the microcapsule ink on the microcapsule layer, and the unevenness of the microcapsule ink is reduced, whereby the adhesive can be directly applied to avoid adhesion. The contact between the agent and the transparent electrode layer causes a problem of poor display, which contributes to improvement in reliability and productivity. Further, since a uniform voltage is applied to the microcapsules, no unevenness is displayed, and the quality of image display is improved.

Further, according to the method of manufacturing a multicolor display panel of the present invention, in the step of laminating the adhesive layer on the microcapsule layer, the driving of the microcapsule layer can be evaluated before the production of the final multicolor display panel, which can be referred to as It is also a suitable solution for quality confirmation. The final multicolor display panel is formed by using an adhesive sheet formed by applying a binder on a peelable resin substrate on which a conductive layer is formed, and a TFT (Thin Film transistor). The substrate or the like is laminated and obtained.

The multicolor display panel of the present invention and a method of manufacturing the same will be described in detail below based on an embodiment.

Fig. 1 is a schematic view showing a configuration example of a multicolor display panel according to an embodiment of the present invention, and Fig. 2 is a schematic view showing an enlarged cross section thereof. As shown in FIGS. 1 and 2, the multicolor display panel of the present invention has a color filter layer (2) and a transparent electrode layer (4) on a transparent substrate (1), and is laminated with color of microcapsules. a cross-sectional structure of the filter and the back electrode plate, wherein the color filter with microcapsules is formed by directly laminating the microcapsule layer (10) on the transparent electrode layer (4), and the microcapsule layer (10) is micro The capsule (5) is dispersed in the binder resin (11), and the microcapsule (5) is sealed with a dispersion in which the electrophoretic particles are dispersed in a transparent dispersion medium, and the electric field is changed by applying a voltage to change the optical reflection property. The microcapsule; the back electrode plate is formed of a back substrate (50) on which the pixel electrode (30) is disposed by the adhesive layer (16) on the microcapsule layer (10).

Further, although not shown, a surface smoothing layer coated with only a binder resin for reducing the unevenness of the microcapsules (5) may be provided on the microcapsule layer (10) as needed.

As the transparent substrate (1), a glass plate such as soda lime glass, low alkali borosilicate glass or alkali-free borosilicate glass or polyethylene terephthalate (PET) and polycarbonate, polyfluorene can be used. Resin sheets such as imine, polyethylene naphthalate, polyether oxime, acrylic resin, polyvinyl chloride.

In the multicolor display panel of the present invention, the shape of the color filter layer (2) is not particularly limited, and a suitable shape can be suitably used, for example, a filter segment of a fine strip (striped) shape is parallel. Or it may be configured in a cross-over configuration, or a fine filter segment may be configured in a vertical and horizontal array configuration. A plurality of coloring patterns are provided in the color filter layer (2) used in the present invention, and colored pixels are disposed in the image regions. The colored pixel is colored with transmitted light on each pixel, and is generally arranged in three colors of red (R), green (G), and blue (B) corresponding to the three primary colors of light, or yellow (Y), magenta (M). ), the colored pixels of the three primary colors of cyan (C).

The color filter layer is generally produced by dispersing and mixing a coloring photosensitive resin such as a pigment or a dye, or a transparent photosensitive resin onto a photosensitive resin, by spin coating or spin coating. The substrate is coated to have a uniform thickness, and after drying to remove the remaining solvent, the active film is irradiated with an ultrahigh pressure mercury lamp by proximity exposure (close exposure) or the like by photolithography to a mask of a desired shape. Curing (negative type) or increasing the alkali solubility (positive type), removing the dissolved portion such as an alkali solution, thereby performing development and post-baking, and repeating the necessary number of such operations. Further, in the present invention, the above production method is not particularly limited.

Then, after the surface is polished and planarized as needed on the color filter layer (2), a transparent electrode layer (4) is provided. A material which can be used as a transparent electrode material is, for example, a transparent conductive oxide such as ITO or the like, such as indium oxide, tin oxide or zinc oxide. The transparent electrode can be formed by a conventional technique such as a vapor deposition method, a sputtering method, or a CVD method.

Hereinafter, the display principle of the microcapsule-containing color filter constituting the multicolor display panel of the present invention will be briefly described.

As shown in Fig. 2, the pixel electrode (30) of the back substrate (50) is connected to a switching element (not shown) of each pixel electrode, and a positive and negative voltage can be applied between the pixel electrode (30) and the transparent electrode layer (4). In order to display an image, generally, the pixel electrode (30) is connected to a power supply of an active matrix type driving circuit structure. If a voltage is applied to the pixel electrode (30), the electric field applied to the microcapsule layer (10) changes. When the pixel electrode (30) is a positive electrode, the negatively charged particles in the microcapsule (5) move toward the pixel electrode (30) side on the back side, and the positively charged particles move to the front transparent electrode layer (4) side. Similarly, if the pixel electrode (30) is a negative electrode, the positively charged particles move to the pixel electrode side, and the negatively charged particles move toward the transparent electrode layer (4) side. Here, for example, if it is assumed that the black particles are positively charged and the white particles are negatively charged, the display color is the color of the particles moving toward the front transparent electrode layer (4) side, and the light from the observation side is reflected thereon, and the reflected light passes. The colored pattern of the opposing color filter layer can thereby display the desired text or image in color.

Next, materials and members used in the multicolor display panel of the present invention will be further described.

The microcapsule (5) used in the formation of the color filter with microcapsules is composed of colored particles (6), white particles (7), a transparent dispersion medium (8), and a microcapsule shell (9).

In general, the microcapsules used in the microcapsule-type electrophoretic display panel are purified by a sieving method or a specific gravity separation method, and have an average particle diameter of 30 to 100 μm, and have an average particle diameter of 10 μm or less with respect to the average particle diameter of the capsule. The proportion of microcapsules of particle size is at least over 50%. The microcapsules used in the multicolor display panel of the present invention are also the same.

As the microcapsule dispersion, an aqueous solvent such as an alcohol is used, and if there is no particular problem, water is used.

As the transparent dispersion medium (8), it is selected from an insulating liquid which can carry a charged particle well and stably, that is, an organic solvent which is substantially insoluble in water. For example, a solvent formed by using an aliphatic hydrocarbon, an aromatic hydrocarbon, an alicyclic hydrocarbon, a halogenated hydrocarbon, various esters, an alcohol solvent, or other fat, alone or in a suitable mixture, may be used.

In addition to the inorganic pigment such as inorganic carbon, the colored particles (6) are fine powders such as glass or resin, and composites thereof. Further, the multicolor display panel of the present invention which performs multicolor display by a color filter generally uses black particles of carbon black.

As the white particles (7), a known white inorganic pigment such as titanium oxide, ceria, alumina or zinc oxide, an organic compound such as a vinyl acetate emulsion, and a composite thereof are used.

Further, the colored particles (6) and the white particles (7) can be treated with various surfactants, dispersants, organic and inorganic compounds, metals, and the like as needed, thereby imparting not only a desired surface charge but also an increase in surface charge. Dispersion stability in the transparent dispersion medium (8).

The dispersion A in which the colored particles (6) and the white particles (7) are dispersed in the transparent dispersion medium (8) is subjected to a phase separation method such as a hybrid coacervation method, a surface polymerization method, an in-situ polymerization method, and dissolution and dispersion. A known method such as a cooling method is enclosed in the microcapsules. The shell (9) of the microcapsule is, for example, a film of rubber or gelatin.

The microcapsule dispersion in which the microcapsules having different particle size distributions are dispersed is dispersed, and a thickener, a surfactant, and a binder resin (11) are mixed to prepare a microcapsule ink.

A dielectric resin such as polylactic acid, phenol resin, polypropylene resin, acrylic resin, or urethane resin is used as the binder resin (11) of the microcapsule ink.

Further, when two or more types of microcapsule inks are blended, when they are mixed, the density of the mixed inks is adjusted to be equal in order to prevent a change in ink density after mixing.

As described above, the microcapsule layer (10) is a transparent electrode layer (4) of a transparent substrate (1) formed of a glass substrate or a resin substrate in which a color filter layer (2) and a transparent electrode layer (4) are provided in advance. It is formed by directly coating the aforementioned microcapsule ink. The coating is carried out using a coating device such as a screen printing method, a micro gravure coater, a contact roll coater, a comma coater, a slit coater, a bar coater, or a curtain coater.

Since the microcapsule layer (10) formed as described above has irregularities on the surface, it is difficult to make the distance between the electrodes sandwiching the microcapsules constant. Therefore, a surface smoothing ink can be applied on the microcapsule layer (10) to form a surface smoothing layer. By forming the surface smoothing layer, the adhesive can be directly coated on the surface smoothing layer. This can avoid the problem that if the adhesive is directly applied without the surface smoothing layer and the uncoated position such as pinholes is present on the microcapsule layer (10), the adhesive directly contacts the transparent electrode layer on the side of the color filter ( 4), the conductivity changes, it is difficult to apply a voltage on the microcapsules, and the result is unclear.

The surface smoothing ink is formed by dispersing a resin as a binder in a solvent. The binder component is preferably a resin having the same dielectric constant as the binder component used in the binder resin component or the binder layer used in the microcapsule ink. In particular, the optimum composition of the binder resin used in the microcapsule ink and the adhesive layer is the same as that of the surface smoothing ink.

When a resin having a different dielectric constant is used, a resin having a different dielectric constant is laminated between the electrodes, and the thickness of each resin is different depending on the size of the microcapsules present in the portion. If so, since the dielectric constant of each resin is different, the voltage applied to the microcapsules is difficult to be uniform over the entire screen area.

As the solvent for the surface smoothing ink, those used in the microcapsule ink can be used, and an aqueous solvent such as another alcohol can also be used.

The coating of the surface smoothing ink is applied using a coating device such as a curtain coater or a slit die coater. The coating method of cutting the coating liquid such as blade coating cannot be used because the microcapsules in the microcapsule layer are broken.

The thickness of the surface smoothing layer is preferably from 10 to 30 μm. When it is 10 μm or less, the unevenness on the surface of the microcapsules is not smooth. On the other hand, when it is 30 μm or more, the distance between the electrodes is wide, which causes the driving voltage to rise.

The surface smoothing layer is formed as above to sufficiently evaporate the solvent, thereby forming a color filter with microcapsules. The color filter with microcapsules and the back electrode plate on which the pixel electrode is disposed on the back substrate are bonded to each other by the adhesive layer to match the color pattern (pixel) of the color filter and the pixel electrode of the back electrode. The layers are laminated to complete the electrophoretic multicolor display panel of the present invention.

The material which can be used as the binder is preferably a synthetic resin-based binder such as a urethane resin-based binder or an acrylic resin-based binder. Particularly preferred is a binder using a high dielectric resin.

The binder may also be directly applied to the above microcapsule layer or the pixel electrode. In the manufacturing method of the present invention, it is preferably coated on the resin release substrate on which the conductive layer is formed between the ruthenium film and the resin substrate, and the microcapsule ink is used. A binder of the same composition as the binder resin to be used is used as a binder sheet. By using a binder having the same composition as the binder resin used in the microcapsule ink, there are the advantages of improving the affinity of the resin interface, making it difficult to cause peeling, and applying it to the microcapsules because the dielectric constant is similar. The voltage is easy to be fixed in the plane.

Further, by peeling the substrate by using a resin which forms a conductive layer between the ruthenium film and the resin substrate, the above-mentioned adhesive sheet can be laminated on the color filter with microcapsules to form a multilayer substrate, that is, a so-called color filter electrophoretic display method The front panel performs drive evaluation and quality confirmation. Further, since the conductive layer herein does not need to be transparent, it may be a film formed by vapor deposition or electrodeposition to form a metal such as copper or aluminum, and a film coated with a conductive polymer.

Example

Hereinafter, specific embodiments of the present invention will be described.

<Example 1>

A titanium oxide powder (white particles) having an average particle diameter of 3 μm covered with a polyethylene resin and a carbon black powder (black particles) having an average particle diameter of 4 μm surface-treated with alkyltrimethylammonium chloride in a transparent dispersion medium Disperse in tetrachloroethylene to obtain a dispersion A. In this case, the white particles are negatively charged and the black particles are positively charged.

Next, gelatin and sodium polystyrene sulfonate were dissolved in water to prepare an aqueous solution, and the dispersion A was mixed. After the liquid temperature was adjusted to 40 ° C, the liquid temperature was maintained, and the mixture was stirred by a homogenizer to obtain an O/W emulsion. liquid.

Next, the obtained O/W emulsion and an aqueous solution in which gum arabic was dissolved in water were mixed at 40 ° C using a disperser, and the pH of the solution was adjusted to 4 while maintaining the liquid temperature at 40 ° C using acetic acid. A microcapsule with gelatin-arab gum as a shell material is formed by a complex coacervation method.

Then, after the liquid temperature was lowered to 5 ° C, a 37 mass% formalin solution was added to solidify the wall material of the microcapsule shell to obtain a dispersion in which dispersed white particles (titanium oxide particles) and black particles (carbon black particles) were enclosed. A microcapsule.

The microcapsules thus obtained were sieved to have a uniform particle size such that the average particle diameter was 60 μm and the ratio of the microcapsules having a particle diameter of 50 to 70 μm was 50% or more.

Next, the microcapsules having the above uniform particle size were used as a solid component, and an aqueous dispersion of microcapsules having a solid content of 40% by mass was adjusted. The aqueous dispersion, a urethane-based binder (CP-7050, manufactured by DIC Corporation) having a solid content of 25% by mass, a surfactant, a thickener, and pure water were mixed to prepare a microcapsule ink.

On the other hand, a color filter was produced by the following method. The parts described herein are all parts by mass. First, 50 parts of butyl methacrylate, 20 parts of methyl methacrylate, and 30 parts of acrylic acid were copolymerized with cyclohexanone as a solvent to prepare an acrylic resin.

An acrylic resin solution was prepared in an amount of 47 parts of the acrylic resin, and 20 parts of a red pigment (Pigment Red 22) was mixed therein, and dispersed by bead milling for 1 hour. Thereafter, 4 parts of dipentaerythritol, 4 parts of hexaacrylate, and 0.3 parts of bis(2,4,6-trimethylbenzylidene)-benzene as a photopolymerization initiator were mixed by a disperser. A phosphine oxide to prepare a red photoresist material.

The red photoresist material was spin-coated on a transparent glass substrate, allowed to stand at room temperature for 5 minutes, and the surface of the film was smoothed, and then dried at 70 ° C for 20 minutes to form a red photoresist layer.

Then, a mask is closely adhered to the red photoresist layer, and the mask is repeatedly formed by sandwiching a light-shielding portion having a lateral direction of 280 μm with an exposure portion stripe pattern of 100 mm in length × 110 μm in width, and an exposure amount is obtained by an ultrahigh pressure mercury lamp. The conditions of 150 mJ/cm ² were closely exposed.

After the exposure, a mist of a 1% sodium carbonate aqueous solution having a temperature of 20 ° C was sprayed at a discharge pressure of 1 kg/cm ² , and spray development was carried out for 20 seconds to remove the unexposed portion, thereby exposing the glass substrate.

The glass substrate after the development treatment was dried, and then heated at 230 ° C for 1 hour to carry out a solid film treatment to obtain a red pattern having a film thickness of 1.1 μm.

Next, on the glass substrate on which the red pattern was formed, a green pigment (Pigment Green 7) was used as a color material, and a green photoresist material was produced in the same composition as the above-described red photoresist, and a green photoresist layer was formed using the material.

Then, the same mask as described above was placed at a position shifted by 130 μm from the position where the red pattern was formed in the horizontal axis direction, and was closely exposed and exposed under the conditions of an exposure amount of 200 mJ/cm ² .

After the exposure, a 1% sodium carbonate aqueous solution having a temperature of 20 ° C was sprayed at a discharge pressure of 1 kg/cm ² , and spray development was carried out for 30 seconds to remove the unexposed portion, thereby exposing the glass substrate.

After drying the glass substrate after the development treatment, the film was heated at 230 ° C for 1 hour in the same manner as described above, and subjected to a solid film treatment to obtain a green pattern having a film thickness of 1.2 μm.

Then, in the same manner as described above, a blue pigment (Pigment Blue 15:6) was used as a color material to produce a blue photoresist material, and a blue pattern having a film thickness of 1.1 μm was obtained.

Thus, a coloring pattern of three colors was formed on the glass substrate, and a transparent electrode layer made of ITO was formed on the entire surface of the color filter layer thus formed by sputtering.

Next, the microcapsule ink was applied onto the transparent electrode layer of the substrate having the color filter layer and the transparent electrode layer on the transparent glass substrate by a slot coater, and after coating, it was dried at 60 ° C for 10 minutes to obtain a tape. Micro-capsule color filter.

Then, on the microcapsule layer of the above-mentioned microcapsule-containing color filter, a urethane-based adhesive having a solid content of 25% by mass was applied by using a slit die coater (CP-7050, manufactured by DIC Corporation). As a surface smoothing ink, it was dried to obtain a microcapsule color filter having a smooth surface layer.

Further, 100 nm thick aluminum was vapor-deposited on one side, and then a peel-coated side of a 50 μm-thick polyethylene terephthalate sheet on which a bismuth release coating layer was provided was applied, and a 25 μm-thick polyester-amine was applied. A urethane-based adhesive that adjusts the adhesive sheet.

Next, the above-mentioned adhesive sheet was bonded to the color filter with microcapsules having the surface smoothing layer to obtain a color filter electrophoretic display type front panel. Next, a polyester-urethane-based adhesive was left, and a 50 μm-thick polyethylene terephthalate sheet provided with a bismuth-based release coating was peeled off, and the alignment marks of the color filters were superposed on the back surface. The pixel electrode surface of the electrode plate is bonded at a pressure of 0.50 MP to obtain a multi-color display panel as a microcapsule-type electrophoretic display panel with a color filter of the present invention. The back electrode plate is on a glass substrate as a TFT substrate. There is a pixel electrode composed of ITO having a circuit structure of an active matrix type driving method formed using a thin film transistor.

<Comparative Example 1>

The ITO coated surface of a 50 μm-thick polyethylene terephthalate sheet (PET) (41) provided with a transparent electrode layer (4) of ITO on one side was coated with a slot coater and used in Example 1. The same microcapsule ink, after coating, was dried at 60 ° C for 10 minutes to obtain a microcapsule-type electrophoretic layer. On the microcapsule-type electrophoresis layer, a surface smoothing layer was provided in the same manner as in Example 1, and the same electrode sheet as in Example 1 was used, and the pixel electrode surface of the back electrode plate was bonded at a pressure of 0.50 MP to obtain a microcapsule. The electrophoretic display panel has a pixel electrode on a glass substrate as a TFT substrate, and the pixel electrode is composed of ITO having an active matrix type driving circuit structure formed using a thin film transistor. Next, using the same adhesive sheet as in Example 1, the color filter layer of the colored pattern of three colors formed on the glass substrate produced in Example 1 was subjected to the following operation to obtain a color filter of Comparative Example 1. Microcapsule type electrophoretic display panel. Among them, the polyethylene terephthalate sheet side was superposed on the color filter by the positioning marks of the color filter, and bonded to the TFT substrate used in Example 1.

<Comparative Example 2>

On the pixel electrode surface of the back electrode plate, the same microcapsule ink as used in Example 1 was applied using a slit die coater having a pixel electrode on a glass substrate as a TFT substrate, and the pixel electrode was made of a film. The ITO structure of the circuit structure of the active matrix type driving method of the transistor was dried at 60 ° C for 10 minutes after coating to obtain a microcapsule-type electrophoretic layer integrally formed with the TFT substrate. On the microcapsule-type electrophoretic layer integrally formed with the TFT substrate, a smooth surface layer was provided in the same manner as in Example 1, and then a transparent electrode layer of the substrate produced in Example 1 was used using the same adhesive sheet as in Example 1. The microcapsule-type electrophoretic display panel with a color filter of Comparative Example 2 was obtained by laminating one side, and the substrate had a color filter layer and a transparent electrode layer on a transparent glass substrate.

A voltage of about ±15 V was applied between the front transparent electrode and the back surface pixel electrode on the display panels of Example 1 and Comparative Examples 1 and 2 manufactured by a standard voltage-current generating device (manufactured by Yokogawa Electric Co., Ltd.). To evaluate the actual display properties. In addition, the color difference meter CR-400 (manufactured by Konica Minolta Co., Ltd.) was used to measure the reflectance at the time of color display (in the case of white display) and black display, and the reflectance at the time of contrast = color (white)/black display Reflectance evaluates contrast. Then, the visual brightness L* was measured using the same device.

As a result, the distance between the transparent electrode layer and the pixel electrode layer of the display panel of Example 1 and Comparative Examples 1 and 2 was substantially the same, and the black particles and white particles in any of the microcapsules were oriented according to the electric field when voltage was applied. The two electrodes move differently from each other to achieve multi-color display with slightly the same contrast. However, the display panels of Comparative Examples 1 and 2 have a larger distance between the color filter layer and the microcapsule layer than the display panel of Example 1, and the optical angle due to the PET film and the adhesive layer, the viewing angle Deviated from the front, thus causing a result of low display brightness. In addition, the display panels of Comparative Examples 1 and 2 produced a large color deviation when viewed from the front and the lateral direction, and the angle of the display panel was significantly reduced. However, the multicolor display panel of the present invention of Example 1 can also improve the visual angle. Color parallax for excellent display color.

1. . . Transparent substrate

2. . . Color filter layer

4. . . Transparent electrode layer

5. . . Microcapsules

6. . . Colored particles

7. . . White particles

8. . . Transparent dispersion medium

9. . . Microcapsule shell

10. . . Microcapsule layer

11. . . Adhesive resin

16. . . Adhesive layer

17. . . Peeling layer

18. . . Conductive layer

19. . . Peeling substrate

20. . . Adhesive sheet

30. . . Pixel electrode

41. . . PET

50. . . Back substrate

Fig. 1 is a schematic cross-sectional view showing the structure of a multicolor display panel according to an embodiment of the present invention.

Fig. 2 is a schematic view showing the configuration of a multicolor display panel of an embodiment of the present invention by an enlarged cross section.

Fig. 3 is a schematic view showing an example of a panel structure of an intermediate step of the method of manufacturing a multicolor display panel of the present invention.

4(a) and 4(b) are schematic cross-sectional views illustrating the structure of a conventional multicolor display panel.

Claims (3)

A method for manufacturing a multicolor display panel, comprising: (a) a step of providing a color filter layer on a transparent substrate; (b) a step of disposing a transparent electrode layer on the color filter layer; c) a step of directly coating the microcapsule ink on the transparent electrode layer to form a microcapsule layer formed by dispersing the microcapsules in a binder resin, the microcapsules being encapsulated in a transparent dispersion medium a dispersion of electrophoretic particles, which changes optical reflection properties by a change in electric field caused by application of a voltage; (d) a step of laminating an adhesive layer on the microcapsule layer; and (e) the aforementioned microcapsules via the aforementioned adhesive layer The step of laminating the layer and the pixel electrode surface is a pixel electrode surface of the back electrode plate on which the pixel electrode is disposed on the back substrate. A method of producing a multicolor display panel according to claim 1, further comprising the step of forming a smoothing layer for reducing irregularities of the microcapsule ink on the microcapsule layer. The method for manufacturing a multicolor display panel according to claim 1, wherein the step of laminating the adhesive layer on the microcapsule layer comprises: forming a binder on the peelable resin substrate on which the conductive layer is formed, and forming the adhesive a step of laminating the adhesive sheet onto the microcapsule layer; then applying a voltage to the transparent electrode layer and the conductive layer, evaluating the stage of driving the microcapsule layer, and laminating the surface of the pixel electrode surface of the back electrode plate Previously, the peelable resin substrate on which the above-mentioned conductive layer was formed was peeled off and removed.