JP2013073042A - Reflective display panel and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflective display panel having high productivity, which allows for multicolor display with a small parallax error even when observed from an oblique direction.SOLUTION: A reflective display panel comprises a substrate 20 having a plurality of pixel electrodes 21 spaced at a distance on one surface in the thickness direction, an electrophoretic display layer 11 as a reflective display material layer which is formed to cover the surface of the substrate 20 and the pixel electrodes 21, a transparent electrode layer 12 which is formed on the opposite side of the surface of the substrate 20 of the electrophoretic display layer 11, a transparent undercoat layer 14 which is formed on the opposite side of the electrophoretic display layer 11 of the transparent electrode layer 12, and a color filter layer 15 which is formed on the opposite side of the transparent electrode layer 12 of the transparent undercoat layer 14.

Description

  The present invention relates to a reflective display panel, comprising an electrophoretic ink ink enclosed in a microcapsule, and a structure in which one of these microcapsules is disposed between a pair of transparent counter electrode plates, Furthermore, the present invention relates to a reflective display panel that can display multiple colors by forming a color filter, and a manufacturing method thereof.

  In recent years, a liquid crystal using a backlight as an information display panel has been mainstream. However, the burden on the eyes is large, and it is not suitable for applications that keep watching for a long time.

  An electrophoretic display device using a display panel having an electrophoretic display layer provided between a pair of opposed electrodes and between the electrodes has been proposed as a reflective display panel with a small burden on the eyes. . (See Patent Document 1).

  This reflective display panel such as an electrophoretic display panel displays characters and images by reflected light, similar to the printed paper, and is suitable for work that keeps the screen looking for a long time with little load on the eyes. .

  This electrophoretic display panel is based on the principle that an image is displayed by moving charged particles by applying an electric field to a dispersion in which charged particles are dispersed. Among the electrophoretic display panels, microcapsule-type electrophoretic display devices in which colored charged particles are enclosed in microcapsules and the microcapsules are arranged between a pair of opposed electrodes have low driving voltage, high flexibility, etc. Has been commercialized and further developed.

Special table 2010-503895 gazette

  At present, the electrophoretic panel is mainly two-color display mainly for black and white display because of the structure. In the two-color display microcapsule type electrophoretic display panel, for example, a pixel electrode layer of a substrate including a pixel electrode There is a configuration in which a microcapsule type electrophoretic display layer, a transparent electrode, and a transparent substrate are sequentially provided. In recent years, there has been a demand for a color electrophoretic display panel capable of multicolor display from a two-color display microcapsule electrophoretic display panel.

  Here, in order to display the microcapsule type electrophoretic display panel in multicolor, a color filter is provided between the microcapsule electrophoretic display layer and the transparent electrode, between the transparent electrode and the transparent substrate, or on the transparent substrate. By forming the layer, multicolor display can be performed.

  When the electrophoretic display panel is multicolored by providing a color filter layer, it is necessary to align the pattern of the pixel electrode on the substrate and the pattern of the color filter layer. However, when the alignment is performed with reference to the alignment pattern formed on the pixel electrode substrate, the distance between the color filter layer and the alignment pattern is increased, which makes alignment difficult and reduces productivity. A problem occurs.

  Further, when the distance between the color filter layer on which the pattern is formed and the electrophoretic display layer is increased, there is a problem that the color changes when observed from an oblique direction. This also causes a problem of losing the advantages of the electrophoretic display device that the influence of the observation angle is small.

  It is an object of the present invention to provide a reflective display panel capable of multicolor display with high productivity and small color change even when observed from an oblique direction, and a method for manufacturing the same.

In order to solve the above-mentioned problem, the invention according to claim 1 includes a substrate in which a plurality of pixel electrodes are formed on the surface which is one surface in the thickness direction at intervals, the surface of the substrate, and the pixel electrodes A reflective display material layer formed so as to cover the transparent display layer, a transparent electrode layer formed on a surface of the reflective display material layer opposite to the surface of the substrate, and the reflective display material layer of the transparent electrode layer A transparent undercoat layer formed on the surface opposite to the transparent electrode layer, and a color filter layer formed on the surface of the transparent undercoat layer opposite to the transparent electrode layer, and the thickness of the transparent undercoat layer is A reflective display panel having a size of 0.1 μm or more and 100 μm or less was obtained.
According to a second aspect of the present invention, in the reflective display panel according to the first aspect, the thickness of the transparent undercoat layer is not less than 1 μm and not more than 20 μm.
According to a third aspect of the present invention, the reflective display material layer is an electrophoretic display layer in which microcapsules enclosing a dispersion liquid in which electron transfer particles are dispersed in a dispersion medium are fixed with a binder resin. A reflection type display panel according to claim 1 or claim 2 is provided.
Moreover, as invention concerning Claim 4, the protective film is provided in the surface on the opposite side to the said transparent electrode layer of the said transparent undercoat layer, The any one of Claim 1 thru | or 3 characterized by the above-mentioned. A reflective display panel according to item.
According to a fifth aspect of the invention, there is provided a first step of preparing a substrate having a plurality of pixel electrodes formed on the surface, which is one surface in the thickness direction, with a transparent base, A second step of preparing a laminated film in which an undercoat layer, a transparent electrode layer, and a reflective display material layer are laminated in these order; and the reflective display material layers of the laminated film A third step of bonding to the surface of the substrate so as to cover the pixel electrode, a fourth step of peeling the transparent base material from the laminated film, and a color corresponding to the pixel electrode on the transparent undercoat layer And a fifth step of forming a filter layer.
The invention according to claim 6 is the method for producing a reflective display panel according to claim 5, wherein the thickness of the transparent undercoat layer is 0.1 μm or more and 100 μm or less.
Moreover, as invention concerning Claim 7, the peeling layer is formed between the said transparent base material and the said transparent undercoat layer, The said transparent base material is peeled from the said laminated | multilayer film by the said peeling layer, It is characterized by the above-mentioned. The reflective display panel manufacturing method according to claim 5 or 6 is used.
According to an eighth aspect of the present invention, the fifth step is performed by ejecting and printing ink on the transparent undercoat layer by an ink jet method. It was set as the manufacturing method of the reflection type display panel of any one item.
The invention according to claim 9 includes a sixth step of laminating a protective film on the surface of the transparent undercoat layer opposite to the transparent electrode layer after the fifth step. The method for producing a reflective display panel according to any one of claims 5 to 8.
According to a tenth aspect of the present invention, an alignment mark for alignment is formed on the surface of the substrate prepared in the first step at a position separated from the pixel electrode. The lamination film is bonded to the surface of the substrate in a step so that the reflective display material layer of the laminated film and the alignment mark do not overlap with each other, and corresponds to the pixel electrode in the fifth step. 10. The reflective display panel manufacturing method according to claim 5, wherein the color filter layer is formed using the alignment mark as a reference.

  According to the present invention, it is possible to provide a reflective display panel capable of multicolor display with high productivity and small color change even when observed from an oblique direction.

FIG. 1 is an explanatory view of an example of a manufacturing method of a reflective display panel of the present invention. FIG. 2 is a schematic cross-sectional view of the reflective display panel of the present invention.

  A method for manufacturing the reflective display panel of the present invention will be described. FIG. 1 is an explanatory view showing an example of a method for manufacturing a reflective display panel according to the present invention.

Several types of reflective display material layers are known, including an electrophoretic display layer in which microcapsules encapsulating a dispersion liquid in which electron transfer particles are dispersed in a dispersion medium are fixed with a binder resin. Examples of the following electro-optical displays using them include the following.
(A) Rotating two-color member display (b) Electrochromic display (c) Electrowetting display (d) Electrophoretic display In the electrophoretic display layer, an electrophoretic layer forming coating liquid is applied as described later. It is preferable in that the display panel can be manufactured at a lower cost because it can be formed and a roll-to-roll method can be applied.
In this embodiment mode, an electrophoretic display panel in which a layer of a reflective display material is an electrophoretic display layer will be described as an example of the reflective display panel of the present invention.

First, as shown in FIG. 1A, a transparent undercoat layer 14, a transparent electrode layer 12, and a microcapsule in which a dispersion liquid in which electrophoretic particles are dispersed in a dispersion medium are encapsulated in a binder resin. The laminated film 10 including the electrophoretic display layer 11, the adhesive layer 30, and the release conductive release layer 31 fixed in step 1 is prepared. In addition, a substrate 20 having a pixel electrode 21 and a pixel alignment pattern (alignment mark) 22 is prepared.
That is, a laminated film 10 is prepared in which a transparent base material 13, a transparent undercoat layer 14, a transparent electrode layer 12, and an electrophoretic display layer 11 as a reflective display material layer are laminated in this order (first). Step 1).
Also, a substrate 20 is prepared in which a plurality of pixel electrodes 21 are formed on the surface, which is one surface in the thickness direction, at intervals (second step).

Next, as shown in FIG. 1B, the release conductive release layer 31 of the laminated film 10 is peeled off, and the electrophoretic display layer 11 and the pixel electrode 21 of the substrate 20 are bonded by the adhesive layer 30. At this time, the laminated film 10 and the substrate 20 are placed so that the opaque electrophoretic display layer 11 is not disposed above the alignment pattern on the substrate (so that the electrophoretic display layer 11 and the alignment mark 22 do not overlap). Bonding and peeling off the transparent substrate 13.
That is, the electrophoretic display layer 11 of the laminated film 10 is bonded to the surface of the substrate 20 so as to cover the plurality of pixel electrodes 21 (third step), and the transparent base material 13 is peeled from the laminated film 10 (fourth step). Process).

Next, as shown in FIG. 1C, two or more types of inks are printed and ejected on the transparent undercoat layer 14 by an ink jet printing method to form a color filter layer 15 on the transparent undercoat layer 14.
That is, the color filter layer 15 corresponding to the pixel electrode 21 is formed on the transparent undercoat layer 14 (fifth step).
In FIG. 1C, the color filter layer 15 is formed of a red color filter layer 15a, a blue color filter layer 15b, and a green color filter layer 15c. At this time, in forming the color filter layer 15, it is necessary to make the position of the pattern of the pixel electrode 21 on the substrate 20 correspond to the position of the color filter layers 15a, 15b, and 15c.
In the manufacturing method of the present invention, the process of forming the color filter layer 15 after the laminated film 10 and the substrate 20 are bonded together by not arranging the electrophoretic display layer 11 on the alignment mark 22 for pixel alignment. The pattern of the color filter layer 15 corresponding to the pattern of the pixel electrode 21 can be easily formed on the basis of the alignment mark 22. That is, the pattern position of the pixel electrode 21 and the position of the color filter layer 15 can be easily and reliably associated with each other.

Finally, as shown in FIG. 1 (d), a protective film 40 is provided on the transparent undercoat layer 14 and the color filter layers 15a, 15b, 15c, and a reflective display panel is manufactured.
That is, the protective film 40 is laminated on the surface of the transparent undercoat layer 14 opposite to the transparent electrode layer 12 (sixth step).

  FIG. 2 is a schematic cross-sectional view of the reflective display panel of the present invention.

In the reflective display panel of the present invention, a dispersion liquid in which electrophoretic particles are dispersed in a dispersion medium is sealed on a substrate 20 having a pixel electrode 21 and a pixel alignment pattern 22 via an adhesive layer 30. The electrophoretic display layer 11, the transparent electrode layer 12, the transparent base material 13, the undercoat layer 14 including the color filter layers 15a, 15b, and 15c, and the protective film 40 are sequentially provided. At this time, the pattern of the pixel electrode 21 and the color filter layers 15a, 15b, and 15c provided with the electrophoretic display layer 11 interposed therebetween are provided so as to face each other. By matching the pattern of the pixel electrode 21 with the color filter layers 15a, 15b, and 15c in the stacking direction of each layer, multicolor display (color display) is possible.
That is, the reflective display panel is formed so as to cover the substrate 20 in which a plurality of pixel electrodes 21 are formed on the surface, which is one surface in the thickness direction, and the surface of the substrate 20 and the pixel electrodes 21. The electrophoretic display layer 11 as the reflective display material layer, the transparent electrode layer 12 formed on the surface of the electrophoretic display layer 11 opposite to the surface of the substrate 20, and the electrophoretic display layer 11 of the transparent electrode layer 12. A transparent undercoat layer 14 formed on the opposite surface of the transparent undercoat layer 14 and a color filter layer 15 formed on the transparent undercoat layer 14 on the opposite surface of the transparent electrode layer 12.
In the reflective display panel of the present invention, the sealing layer 50 for preventing moisture from entering the electrophoretic display layer may be provided on the side surface of the electrophoretic display layer.

  The operation principle of the reflective display panel of the present invention will be described. The pixel electrode 21 on the substrate 20 is connected to the switching element of each pixel electrode 21, and a positive or negative voltage can be applied between the transparent electrode layer 12. In order to display an image, the pixel electrode 21 is usually connected to a power source having a circuit configuration of an active matrix driving method. When a voltage is applied to the pixel electrode 21, the electric field applied to the microcapsule layer varies. When the pixel electrode 21 is a positive electrode, the negatively charged particles in the microcapsule move to the back pixel electrode 21 side, and the positively charged particles move to the front transparent electrode layer 12 side. To do. Similarly, when the pixel electrode 21 becomes a negative electrode, positively charged particles move to the pixel electrode 21 side, and negatively charged particles move to the transparent electrode layer 12 side. Here, for example, if the black particles are positively charged and the white particles are negatively charged, the display color becomes the color of the particles that have moved to the transparent electrode layer 12 side of the front surface, so that the light from the observation side However, a desired character or image can be displayed in color by passing through the colored pattern of the color filter layer 15 where the reflected light is reflected and the reflected light faces.

  In the reflective display panel and the manufacturing method thereof according to the present invention, only the transparent electrode layer 12 and the transparent undercoat layer 14 exist between the electrophoretic display layer 11 and the color filter layer 15. Since the thickness of the transparent electrode layer 12 is on the order of submicrons, the distance between the electroconductive display layer 11 and the color filter layer 15 is determined by the thickness of the transparent undercoat layer 14. In the present invention, since the distance between the electroconductive display layer 11 and the color filter layer 15 is determined by the thickness of the transparent undercoat layer 14, the thickness of the transparent undercoat layer 14 is reduced. A reflective display panel can be provided in which the distance can be made close and multicolor display can be performed with little change in color even when observed from an oblique direction.

  In the present invention, the color filter layer 15 is preferably formed by printing and discharging a plurality of colors of ink on the transparent undercoat layer 14 by an ink jet printing method. In forming the pattern of the color filter layer 15, in addition to the ink jet printing method, pattern formation by a photolithography method or pattern formation by an offset printing method may be performed.

  In the manufacturing method of the reflective display panel of the present invention, after laminating the laminated film 10 and the substrate 20, the transparent substrate 13 of the laminated film 10 is peeled off, and the color filter layer 15 is formed on the surface of the transparent undercoat layer 14. The color filter layer 15 is preferably formed by printing and discharging a plurality of colors of ink by an ink jet printing method in consideration of handling characteristics of the laminated film 10 and the substrate 20 that are formed. . By forming the color filter layer 15 by the ink jet printing method, alignment of the pattern of the pixel electrode 21 and the pattern of the color filter layer 15 can be facilitated as compared with other pattern forming methods.

  In the reflective display panel and the manufacturing method thereof according to the present invention, it is preferable that the protective film 40 is laminated on the color filter layer 15. By providing the protective film 40, the scratch resistance of the reflective display panel can be improved.

In the reflective display panel of the present invention and the manufacturing method thereof, the thickness of the transparent undercoat layer 14 is preferably in the range of 0.1 μm to 100 μm, and more preferably 1 μm to 20 μm. preferable. As described above, in the present invention, since the distance between the electroconductive display layer 11 and the color filter layer 15 is determined by the thickness of the transparent undercoat layer 14, the distance decreases as the thickness decreases. It is possible to make the color filter layer 15 easy to align and improve productivity, and to provide a reflective display panel capable of multicolor display with little color change even when observed from an oblique direction. On the other hand, when the transparent undercoat layer 14 has a thickness of a certain level or more, the ink can be stably received on the transparent undercoat layer 14. Here, when the thickness of the transparent undercoat layer 14 exceeds 100 μm, the effect of the present invention cannot be made sufficient. On the other hand, when the thickness of the transparent undercoat layer 14 is less than 0.1 μm, the ink may not be sufficiently received when the color filter layer 15 is formed, and the pattern may collapse.
When the thickness of the transparent undercoat layer 14 is 1 μm or more and 20 μm or less, the above-mentioned effect can be obtained more reliably and the ink can be sufficiently received when the color filter layer 15 is formed to stabilize the pattern. It becomes more advantageous in forming.

  The reflection type display panel and the manufacturing method thereof according to the present invention will be described in more detail.

  As the transparent substrate used in the reflective display panel of the present invention, a plastic film such as polyethylene terephthalate (PET), polycarbonate, polyimide, polyethylene naphthalate, polyethersulfone, acrylic resin, polyvinyl chloride, or glass is used. can do. Moreover, in order to perform a peeling process easily, it is preferable that the peeling layers, such as silicone, are provided.

  A transparent undercoat layer 14 is formed on the transparent substrate 13. The transparent undercoat layer 14 is formed by applying a coating liquid for forming a transparent undercoat layer 14 containing a resin on the transparent substrate 13. As the transparent undercoat layer 14, urethane resin, polyester, acrylic resin, vinyl alcohol resin, or the like can be used. Further, the transparent undercoat layer 14 may contain a porous material such as synthetic silica or alumina in order to increase the absorbability of the ink solvent. The transparent undercoat layer 14 can be formed by a screen printing method, an offset printing method, a spin coating method, or intermittent coating using a die, as long as sheet processing is performed. In addition, if continuous processing is performed by roll-to-roll, the transparent undercoat layer 14 can be formed by general-purpose coating techniques such as die coating, comma coating, curtain coating, and gravure coating. Moreover, after the coating liquid for forming the transparent undercoat layer 14 is applied, the coating liquid on the transparent substrate 13 is dried. As a drying method, heating, blowing, or the like can be used. Moreover, as a manufacturing method of this invention, it is preferable to form the transparent undercoat layer 14 by continuous coating by a roll-to-roll system.

  A transparent electrode layer 12 is formed on the transparent undercoat layer 14. As the transparent electrode forming material, a conductive oxide having transparency such as indium oxide-based, tin oxide-based, zinc oxide-based, such as ITO, or a carbon nanotube or a thiophene-based compound can be used. The transparent electrode layer 12 can be formed by a conventional technique such as a dry film forming method such as a vapor deposition method, a sputtering method, or a CVD method, or a wet film forming method using a coating liquid.

  An electrophoretic display layer 11 in which microcapsules are fixed with a binder resin is formed on the transparent electrode layer 12. The electrophoretic display layer 11 is an electrophoretic layer-forming coating solution containing a microcapsule enclosing a dispersion in which electrophoretic particles are dispersed in a dispersion medium, a binder resin, and a solvent. It is formed by applying on the material 13.

The microcapsule used for forming the microcapsule type electrophoretic layer 11 has a structure in which at least two kinds of particles having different electric polarities are dispersed in a transparent dispersion medium in a microcapsule shell.
Examples of the two kinds of particles having different electric polarities enclosed in the microcapsule include a combination of black particles and white particles. It is preferable to use a microcapsule that has been purified by a sieving method, a specific gravity separation method, or the like and has an average particle size of 30 to 100 μm. Moreover, it is preferable that the ratio of the microcapsule having a particle size within 10 μm before and after the average particle size of the microcapsule capsule exceeds 50%.

  For the microcapsule dispersion, an aqueous solvent such as alcohol is used, and water is used if there is no particular problem. As the transparent dispersion medium, for example, aliphatic hydrocarbons, aromatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, various esters, alcohol solvents, other fats, etc. are used alone or as appropriate mixed solvents. use.

  As the black particles, in addition to inorganic pigments such as inorganic carbon, fine powders such as glass or resin, and composites thereof can be used. On the other hand, as white particles, known white inorganic pigments such as titanium oxide, silica, alumina, and zinc oxide, organic compounds such as vinyl acetate emulsion, and composites thereof can be used.

  The black particles and the white particles can be given a desired surface charge by treating the surface of the particles with various surfactants, dispersants, organic and inorganic compounds, metals, and the like, if necessary. In addition, the dispersion stability in the dispersion medium can be improved.

  The dispersion in which the microcapsules are dispersed is enclosed in a microcapsule capsule shell using a known method such as a phase separation method such as a mixed coacervation method, an interfacial polymerization method, an in-situ method, or a solution-dispersion cooling method. It becomes a capsule. For the microcapsule shell, for example, rubber or gelatin can be used.

  Dielectric resins such as polylactic acid, phenol resin, polypropylene resin, and acrylic resin can be used as the binder resin contained in the electrophoretic layer forming coating solution.

  The electrophoretic layer-forming coating solution can be applied using a coating apparatus such as a screen printing method, a micro gravure coater, a kiss coater, a comma coater, a die coater, a bar coder, or a curtain coater. After the electrophoretic layer forming coating solution is applied, the coating solution on the transparent electrode layer 12 is dried. As a drying method, heating, blowing, or the like can be used.

  An adhesive layer 30 is formed on the electrophoretic display layer 11. When the adhesive layer 30 is formed in advance on the release conductive film and pasted to the electrophoretic display layer 11 side of the laminated film 10, the transparent conductive film (transparent electrode layer 12) of the laminated film 10 and the release conductive film A voltage can be applied between the electrophoretic display layer 11 and the electrophoretic display layer 11 can be inspected for defects.

  At this time, it is preferable to use a synthetic resin adhesive such as a urethane resin adhesive and an acrylic resin adhesive that can be used as an adhesive. In particular, an adhesive using a high dielectric resin is preferably used. Examples of the release conductive layer include an ITO layer and a metal thin film.

  In the manufacturing method of the reflective display panel of the present invention, the transparent electrode layer 12 and the electrophoretic display layer 11 on the pixel electrode surface (the surface of the substrate 20) of the substrate 20 including the pixel electrodes 21 and the transparent base material 13. The surface of the electrophoretic display layer 11 of the laminated film 10 including the above is pasted through an adhesive.

  A color filter layer 15 is provided on the surface of the transparent undercoat layer 14 opposite to the surface on which the transparent electrode layer 12 is formed. The color filter layer 15 is formed by applying a plurality of inks to the transparent undercoat layer 14.

  As the ink for forming the color filter layer 15, an ink containing a known color pigment or color dye can be used. The color filter layer 15 colors light for each pixel, and is a three-color pattern of red (R), green (G), and blue (B), or yellow (Y), magenta (M), and cyan (C). These three color patterns can be used. Moreover, the combination of these colors may be sufficient and other colors, such as white (W), may be combined.

  Specific examples of the coloring pigment component include red coloring compositions for forming red coloring layers or red pixels. I. Pigment Red 7, 9, 14, 41, 48: 1, 48: 2, 48: 3, 48: 4, 81: 1, 81: 2, 81: 3, 97, 122, 123, 146, 149, 168, 177, 178, 179, 180, 184, 185, 187, 192, 200, 202, 208, 210, 215, 216, 217, 220, 223, 224, 226, 227, 228, 240, 246, 254, 255, Red pigments such as H.264, 272, and 279 can be used. A yellow pigment and an orange pigment can be used in combination with the red coloring composition.

  Examples of the green coloring composition include C.I. I. Green pigments such as Pigment Green 7, 10, 36, and 37 can be used. The green coloring composition can be used in combination with the same yellow pigment as the red coloring composition.

  Examples of the blue coloring composition include C.I. I. Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 22, 60, 64, 80, etc., preferably C.I. I. Pigment Blue 15: 6 can be used. In addition, C.I. I. Pigment Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, 50 and the like, preferably C.I. I. Pigment Violet 23 can be used in combination.

In the color filter layer 15 constituting the reflective display panel of the present invention, no black matrix is formed to cut each pixel in black. Since the color filter layer 15 of the reflective display panel of the present invention does not form a black matrix, a transparent transparent undercoat layer 14 is formed when the color filter layer 15 is formed, and the transparent transparent undercoat layer 14 is formed in the transparent transparent undercoat layer 14. The method of printing ink by an ink jet method to form a color filter has the highest productivity and can be used preferably.

  As a method for applying the ink to the transparent undercoat layer 14, it is necessary to apply colors separately, so that a screen printing method, an offset printing method, an ink jet method, or the like can be used. Among these, it is preferable to form the color filter layer 15 by printing ink on the transparent undercoat layer 14 using an inkjet method because alignment is easy.

  A known material can be used as the substrate 20 including the pixel electrode 21. The pixel electrode 21 on the substrate 20 is connected to the switching element of each pixel electrode 21, and a positive or negative voltage can be applied between the transparent electrode layer 12. The pixel electrode 21 is connected to a power supply having a circuit configuration of an active matrix driving method.

  The alignment mark 22 as a pattern for alignment provided on the pixel electrode surface (front surface) of the substrate 20 can be patterned on the edge of the pixel electrode 21 simultaneously with the formation of the pixel electrode surface of the substrate 20. Examples of the alignment mark 22 include a cross shape, a round shape, a multiple concentric circle shape, and a wedge shape.

  As the protective film 40, the material shown by the transparent base material 13 can be used, and plastic films, such as a polyethylene terephthalate (PET), a polycarbonate, a polyimide, a polyethylene naphthalate, a polyether sulfone, an acrylic resin, a polyvinyl chloride, or Glass or the like can be used. Further, the protective film 40 contains a hard coat layer for improving the scratch resistance of the surface on the viewer side, an antireflection layer for preventing reflection of the surface, and a metal component considering moisture resistance. A thin film layer may be provided. In addition, the transparent undercoat layer 14 and the protective film 40 are bonded together with a well-known adhesive.

  Resins for sealing the ends of the electrode plates (transparent electrode layer 12 and the plurality of pixel electrodes 21) sandwiching the macrocapsule layer (electrophoretic display layer 11) include polyolefin resins, polyester resins, and polyamide resins, which are thermoplastic resins. , Polyurethane resin, polysilicone type sealant or thermosetting resin epoxy resin, urethane resin, melamine resin, phenol resin, acrylic resin type sealant and the like.

<Example 1>
Disperse titanium oxide powder (white particles) with an average particle diameter of 3 μm coated with a polyethylene resin and carbon black powder (black particles) with an average particle diameter of 4 μm surface-treated with alkyltrimethylammonium chloride in tetrachloroethylene. Obtained. In this case, the white particles are negatively charged and the black particles are positively charged.

  The dispersion was O / W emulsified and microcapsules were formed by a complex coacervation method using gelatin-gum arabic, whereby the dispersion was encapsulated in the microcapsules.

  The microcapsules thus obtained were sieved, and the particle diameters were adjusted so that the ratio of microcapsules having an average particle diameter of 60 μm and a particle diameter of 50 to 70 μm was 50% or more.

  Next, an aqueous dispersion of microcapsules having a solid content of 40% by mass was prepared. An electrophoretic display layer is formed by mixing the aqueous dispersion, a urethane binder having a solid content of 25% by mass (CP-7050, manufactured by Dainippon Ink Co., Ltd.), a surfactant, a thickener, and pure water. A coating liquid was prepared.

  A polyester resin-based receiving liquid NS-141LX (Takamatsu Yushi Co., Ltd.) was continuously applied to the silicone side of the silicone layer / PET film using a comma coater to form a transparent undercoat layer 14 having an average film thickness of 10 μm. Next, an ITO layer was formed by a sputtering method in a synergistic manner to obtain a film composed of PET fill / silicone layer / transparent undercoat layer / ITO layer.

  Subsequently, the microcapsule ink was applied to the ITO layer side of the obtained film with a die, and the aluminum release with silicone with urethane adhesive was bonded to the microcapsule surface, and PET film / silicone layer / ITO layer / A laminated film roll comprising a microcapsule type electrophoretic display layer / aluminum release layer with silicone was obtained.

  The obtained laminated film roll was cut every 500 mm, a voltage was applied between the ITO layer and the aluminum release layer, the electrophoretic display layer 11 was driven, and display defect inspection was performed.

  The obtained laminated film 10 was cut into a size smaller than the substrate 20 provided with the pixel electrodes 21 using a CO2 laser cutting device.

  An active matrix using a thin film transistor by peeling the aluminum release film with silicone on the adhesive side of the laminated film 10 made of the cut PET film / silicone layer / ITO layer / microcapsule type electrophoretic display layer / aluminum release layer with silicone Electrophoretic microcapsules with a transparent undercoat layer bonded to a substrate 20 having a circuit pattern of a type driving system and a substrate 20 having a cross pattern (alignment mark 22) having a total width of 500 μm and a width of 200 μm for alignment at an end portion A substrate was obtained.

  The transparent base material 13 on the transparent undercoat layer 14 side of the obtained electrophoretic microcapsule substrate with a transparent undercoat layer is peeled off, and color-coded printing is performed for each pixel using the inkjet method on the transparent undercoat layer 14. 15 was formed. At this time, alignment was performed using a cross pattern for alignment on the substrate 20. The color filter layer 15 has a red, blue, and green pattern. Subsequently, an adhesive hard coat film KB stick SG90R (Kimoto Co., Ltd.) was laminated on the transparent undercoat layer 14 as the protective film 40. Thus, a reflective display panel was produced.

  When voltage was applied to each pixel of the obtained reflective display panel, color display could be performed. Further, since the electrophoretic display layer 11 and the color filter layer 15 are close to each other, no color unevenness due to parallax was observed.

DESCRIPTION OF SYMBOLS 10 Laminated film 11 Electrophoretic display layer 12 Transparent electrode layer 13 Transparent base material 14 Transparent undercoat layer 15 Color filter layer 15a Red color filter layer 15b Blue color filter layer 15c Green color filter layer 20 Substrate 21 Pixel electrode 22 Alignment mark 30 Adhesion Layer 31 Release conductive release 40 Protective film 50 Sealing layer

Claims (10)

A substrate having a plurality of pixel electrodes formed at intervals on a surface that is one surface in the thickness direction;
A reflective display material layer formed to cover the surface of the substrate and the pixel electrode;
A transparent electrode layer formed on the surface of the reflective display material layer opposite to the surface of the substrate;
A transparent undercoat layer formed on the surface of the transparent electrode layer opposite to the reflective display material layer;
A color filter layer formed on the surface of the transparent undercoat layer opposite to the transparent electrode layer;
The thickness of the transparent undercoat layer is 0.1 μm or more and 100 μm or less,
A reflective display panel characterized by that.   The reflective display panel according to claim 1, wherein the transparent undercoat layer has a thickness of 1 μm to 20 μm.   3. The electrophoretic display layer according to claim 1, wherein the reflective display material layer is an electrophoretic display layer in which microcapsules enclosing a dispersion liquid in which electron transfer particles are dispersed in a dispersion medium are fixed with a binder resin. The reflective display panel as described.   The reflective display panel according to any one of claims 1 to 3, wherein a protective film is provided on a surface of the transparent undercoat layer opposite to the transparent electrode layer. A first step of preparing a laminated film in which a transparent substrate, a transparent undercoat layer, a transparent electrode layer, and a reflective display material layer are laminated in this order;
A second step of preparing a substrate in which a plurality of pixel electrodes are formed at intervals on a surface that is one surface in the thickness direction;
A third step of bonding the reflective display material layer of the laminated film to the surface of the substrate so as to cover the plurality of pixel electrodes;
A fourth step of peeling the transparent substrate from the laminated film;
A fifth step of forming a color filter layer corresponding to the pixel electrode on the transparent undercoat layer,
A method for manufacturing a reflective display panel.   6. The method of manufacturing a reflective display panel according to claim 5, wherein the thickness of the transparent undercoat layer is 0.1 μm or more and 100 μm or less.   The peeling layer is formed between the said transparent base material and the said transparent undercoat layer, The said transparent base material is peeled from the said laminated | multilayer film with the said peeling layer, The Claim 5 or Claim 6 characterized by the above-mentioned. Method for manufacturing a reflective display panel.   8. The reflective display panel according to claim 5, wherein the fifth step is performed by ejecting and printing ink on the transparent undercoat layer by an ink-jet method. 9. Manufacturing method.   The method according to any one of claims 5 to 8, further comprising a sixth step of laminating a protective film on the surface of the transparent undercoat layer opposite to the transparent electrode layer after the fifth step. A method for producing a reflective display panel according to claim 1. An alignment mark for alignment is formed on the surface of the substrate prepared in the first step at a position spaced from the pixel electrode,
Bonding the laminated film to the surface of the substrate in the third step is performed so that the reflective display material layer of the laminated film and the alignment mark do not overlap.
10. The reflective display according to claim 5, wherein the color filter layer corresponding to the pixel electrode in the fifth step is formed based on the alignment mark. 11. Panel manufacturing method.

Images