JP4517620B2 - Microcapsule type electrophoretic display panel and manufacturing method thereof - Google Patents

Description

  The present invention relates to a microcapsule electrophoretic display panel having a high moisture blocking function for a microcapsule display layer and operating with stable characteristics, and a method for manufacturing the same.

  As a flat panel display device, a liquid crystal display device (LCD) is now widely used in various applications because it is thin and can be miniaturized. As another display method aiming at further thinner and lower power consumption than such an LCD, a display device using an electrophoretic phenomenon has been developed.

  As one of display devices using the electrophoresis phenomenon, a microcapsule electrophoresis system has been put into practical use. In this type of display device, positive and negatively charged white and black particles are placed in a microcapsule filled with a transparent solvent, and an image is formed by pulling up each particle to the display surface by applying an external voltage. It is. Since the size of the microcapsule is as small as several tens μm to several hundred μm, when the microcapsule is dispersed in a transparent binder, it can be coated like ink. This ink is called electronic ink because an image can be drawn by applying a voltage from the outside.

  When this electronic ink is coated on a transparent resin film on which a transparent electrode is formed and bonded to a substrate on which an electrode circuit for driving an active matrix is formed, an active matrix display panel as shown in Patent Document 1, for example, can be obtained. it can. In general, a component in which a transparent resin film on which a transparent electrode is formed is coated with electronic ink is called a “front plate”, and a substrate on which an electrode circuit for driving an active matrix is formed is called a “back plate”.

  In the microcapsule type electrophoretic display device configured as described above, the seal on the side of the panel is not sufficient, and moisture such as water vapor enters the microcapsule display layer formed by the coating of electronic ink, and the electrical There is a problem of deteriorating the physical characteristics.

That is, the upper surface of the panel is covered with a transparent resin film, and the lower surface is blocked with a substrate. However, since it is difficult to seal the side of the panel, the moisture that enters from the side cannot be sufficiently blocked. It was.
JP 2000-221546 A

  The present invention has been made under the circumstances as described above, effectively blocking the ingress of moisture from the side surface, and effectively preventing the deterioration of the characteristics of the microcapsule display layer due to the ingress of moisture into the microcapsule display layer. It is an object of the present invention to provide a microcapsule type electrophoretic display panel and a method for manufacturing the same.

  In order to solve the above-described problems, the present invention provides a substrate, a microcapsule display layer disposed in a region excluding the peripheral portion on the substrate, and the microcapsule display layer attached to the microcapsule display layer. A transparent resin film having a transparent electrode layer, and a water vapor-blocking resin layer having a width of 0.5 to 1.5 mm, filled in a gap between a peripheral portion on the substrate and the transparent electrode layer, The water vapor blocking resin layer includes a first water vapor blocking resin layer formed on the substrate side, and a second water vapor blocking resin layer formed on the transparent electrode layer side for blocking water vapor and protecting the transparent electrode layer. The first water vapor blocking resin layer and the second water vapor blocking resin layer are cured by irradiation with heat or ultraviolet rays, and are made of an acrylic resin or methacrylic resin. Resin or Epoxy Providing microcapsule electrophoretic display panel characterized by comprising a resin.

  Moreover, this invention consists of acrylic resin, methacrylic resin, or epoxy resin which hardened | cured by irradiation of the heat | fever or an ultraviolet-ray in the peripheral part on the transparent electrode layer of the transparent resin film which has a transparent electrode layer, width 0.5 Forming a second water vapor blocking resin layer of 1.5 mm, forming a microcapsule display layer in a region on the transparent electrode layer where the second water vapor blocking resin layer is not formed, and forming the transparent resin film An acrylic resin, a methacrylic resin, or an epoxy resin that is coated on the substrate with the microcapsule display layer side and cured by heat or ultraviolet irradiation in the gap between the second water vapor blocking resin layer and the substrate A microcapsule type electrophoretic display panel manufacturing method is provided, which is filled with a first water vapor blocking resin layer having a width of 0.5 to 1.5 mm.

According to the microcapsule-type electrophoretic display panel of the present invention configured as described above and the manufacturing method thereof , water vapor having a two-layer structure is formed in the gap between the peripheral edge on the substrate and the transparent electrode layer of the transparent resin film. Filled with a barrier resin layer, it effectively blocks moisture from entering the microcapsule display layer and effectively prevents deterioration of the characteristics of the microcapsule display layer due to moisture entering the microcapsule display layer. I can do it.

  In the microcapsule type electrophoretic display panel of the present invention, a transparent resin protective film can be deposited on the transparent resin film via an adhesive layer. According to such a configuration, the protection function for the microcapsule display layer can be greatly enhanced, and damage to the microcapsule display layer due to external impact can be effectively prevented.

The width of the water vapor blocking resin layer filled in the gap is 0.5 to 1.5 mm . When the width of the water vapor blocking resin layer is within this range, the water vapor blocking resin layer can be easily filled and moisture can be effectively prevented from entering the microcapsule display layer. It becomes.

Since the second water vapor blocking resin layer is formed at the peripheral edge of the transparent electrode layer, the transparent electrode layer is protected and the damage to the transparent electrode layer is effectively prevented when the microcapsule display layer at the peripheral edge is removed. Can be prevented.

  The thickness of the transparent electrode layer is desirably 10 nm or more. Thereby, the intrusion of moisture through the transparent electrode layer can be effectively blocked.

The microcapsule display layer is formed on the transparent electrode layer where the second water vapor blocking resin layer is not formed by laser irradiation or wiping, or the second water vapor blocking resin layer is formed. This can be done by forming a microcapsule display layer in a pattern in a region on the transparent electrode layer that is not present.

  According to the present invention, the first water vapor-blocking resin layer is filled in the gap between the peripheral portion on the substrate and the transparent electrode layer of the transparent resin film, so that the water can effectively enter the microcapsule display layer. Thus, a microcapsule electrophoretic display panel is provided that can effectively prevent deterioration of the characteristics of the microcapsule display layer due to the intrusion of moisture into the microcapsule display layer. In addition, the microcapsule type electrophoretic display panel according to the present invention further includes forming a second water vapor blocking resin layer on the periphery of the transparent electrode layer of the transparent resin film, thereby providing moisture to the microcapsule display layer. Intrusion of the transparent electrode layer can be effectively prevented, and when the microcapsule display layer at the peripheral portion is removed, the transparent electrode layer is protected, and damage to the transparent electrode layer can be effectively prevented. Also play.

  The best mode for carrying out the present invention will be specifically described below with reference to the drawings.

  FIG. 1 is a cross-sectional view illustrating a manufacturing process of a microcapsule type electrophoretic display panel according to an embodiment of the present invention.

  As shown in FIG. 1A, first, electronic ink is applied by screen printing on the surface of the transparent electrode layer 1 of the transparent resin film 2 made of polyethylene terephthalate having the transparent electrode layer (ITO film) 1 formed on the surface. Printing is performed to form the microcapsule display layer 3. Next, the first adhesive layer 4 is formed on the surface of the microcapsule display layer 3 to obtain the front plate 5.

  In this case, printing of electronic ink is performed on the transparent electrode layer 1 of the transparent resin film 2, but since the transparent resin film 2 is thin, operation by winding is possible, and printing of electronic ink is performed continuously. Thus, it is possible to perform with good workability.

  As the transparent resin film 2, in addition to polyethylene terephthalate, polymethyl methacrylate, polycarbonate, polyethylene naphthalate, polypropylene, nylon-6, nylon-66, polyvinylidene chloride, polyethersulfone, or the like can be used. The film thickness of the transparent resin film 2 is preferably about 25 to 250 μm. When the film thickness of the transparent resin film 2 is thick, it is difficult to wind up, which adversely affects the workability of electronic ink printing. On the other hand, when the film thickness of the transparent resin film 2 is too thin, the moisture blocking function is lowered and the protection function of the microcapsule display layer 3 against impact is insufficient.

  The transparent electrode layer 1 can be a common electrode having the same potential on the entire surface. The film thickness of the transparent electrode layer 1 is preferably 10 nm or more, more preferably about 100 nm, in order to have sufficient water vapor barrier properties.

  As the first adhesive layer 4, a known pressure-sensitive adhesive or heat-sensitive adhesive can be used. These can be used in the form of a single-sided adhesive tape or a double-sided adhesive tape having release paper on the adhesive surface. That is, the first adhesive layer 4 is affixed to the microcapsule display layer 3 with the adhesive on the non-adhesive side of the single-sided adhesive tape, or is peeled off and attached to the microcapsule display layer 3 with one release tape of the double-sided adhesive tape. Can be formed. The thickness of the first adhesive layer 4 is preferably about 10 to 50 μm.

  As described above, after the first adhesive layer 4 is provided on the microcapsule display layer 3 to form the front plate 5, the front plate 5 is cut into a predetermined size.

  Next, the first adhesive layer 4 and the microcapsule display layer 3 corresponding to the peripheral portion of the panel are removed, and the peripheral region 6 of the transparent electrode layer 1 is exposed, whereby the structure shown in FIG. The front plate 5 is obtained. The removal of the first adhesive layer 4 and the microcapsule display layer 3 can be performed by laser irradiation, so-called laser ablation, or by wiping with a nonwoven fabric or the like. As a laser used for laser ablation, a carbon dioxide gas laser, a YAG laser, an excimer laser, a wavelength variable die laser, or the like can be appropriately selected.

  The width of the peripheral region 6 from which the first adhesive layer 4 and the microcapsule display layer 3 are removed is preferably 0.5 to 1.5 mm. If the width of the peripheral region 6 is less than 0.5 mm, it becomes difficult to sufficiently prevent moisture from entering the microcapsule display layer 3. If the width exceeds 1.5 mm, the first water vapor blocking resin layer described later is used. Filling becomes difficult.

  Instead of removing the first adhesive layer 4 and the portion on the peripheral region 6 of the microcapsule display layer 3 formed on the entire surface of the transparent electrode layer 1, the microcapsule display layer 3 and the first adhesive layer 4 are removed. The structure shown in FIG. 1A can also be obtained by forming a pattern in a region excluding the peripheral region 6 corresponding to the peripheral portion of the panel on the transparent electrode layer 1.

  Next, as shown in FIG. 1 (b), the front plate 5 is attached to the substrate 7. Affixing can be performed, for example, by removing the release paper, adhering the adhesive surface of the first adhesive layer 4 to the substrate 7, and pressing or heating. The substrate 7 is a glass substrate or a resin film having an electrode layer (not shown) on the surface, and the electrode layer on the surface is patterned independently for each pixel as a pixel electrode, and a thin film transistor, a signal electrode, and a scanning electrode (not shown) Can be used.

Thus, since the part on the peripheral area | region 6 of the 1st contact bonding layer 4 and the microcapsule display layer 3 is removed when the front plate 5 is affixed on the board | substrate 7, the board | substrate 7 and transparent electrode layer in the part are removed. A gap is formed between 1. This gap is filled with a water vapor blocking resin. The water vapor blocking resin that can be used is desirably a resin having a water vapor blocking function and a low viscosity so that it can be easily filled. Further, it is desirable that the resin is cured by irradiation with heat or ultraviolet rays after filling. As such a resin, a heat or ultraviolet curable acrylic resin, a methacrylic acid resin, an epoxy resin, or the like can be used, and it is particularly preferable to use an acrylic resin. The water vapor blocking function preferably has a water vapor transmission coefficient of 0.6 g · mm / m ² · day or less, and the viscosity is preferably 2000 Pa · s or less.

  The filling of the water vapor blocking resin into the gap can be performed by, for example, a general dispenser. The water vapor blocking resin filled in the gap is cured by heating or irradiation with ultraviolet rays, whereby the first water vapor blocking resin layer 8 is formed.

  Next, as shown in FIG. 1C, a transparent resin protective film 10 is deposited on the transparent resin film 2 of the laminate obtained as described above via a second adhesive layer 9. The second adhesive layer 9 is preferably highly self-holding and highly elastic. The second adhesive layer 9 having high elasticity can serve not only as a mere adhesive action but also as a cushion that softens the impact received by the transparent resin protective film 10. Specific materials for the second adhesive layer 9 include silicon rubber, chloroprene rubber, ethylene-propylene rubber, fluorine rubber, acrylic rubber, butyl rubber and the like, and the film thickness is preferably 25 μm or more. . The upper limit of the thickness of the second adhesive layer 9 is not particularly limited in terms of performance, but is about 250 μm from the viewpoint of productivity.

As the transparent resin protective film 10, polyethylene terephthalate, polymethyl methacrylate, polycarbonate, polyethylene naphthalate, polypropylene, nylon-6, nylon-66, polyvinylidene chloride, polyethersulfone, or the like can be used. In particular, in order to effectively prevent moisture from entering from the upper side (display surface side), it is desirable that the water vapor permeability is 0.1 g / m ² · day or less. In addition, water vapor permeability is a value when measured with the front plate 5 side facing the sensor side of the measuring instrument.

  The film thickness of the transparent resin protective film 10 is preferably about 100 to 250 μm. When the thickness of the transparent resin protective film 10 is too thin, the protective function of the microcapsule display layer 3 is insufficient, and when it is too thick, it is difficult to produce a uniform film and the visibility is also lowered.

  A functional layer 11 having a specific function such as an antiglare film, an antireflection film, or a hard coat may be provided on the surface of the transparent resin protective film 10. The anti-glare film is a film that has irregularities on the surface and scatters external light on the irregular surface, and the anti-reflection film reflects using interference of reflected light generated at the interface between the laminated layers. It attenuates light. The hard coat is a hard resin film having a high cross-linking density and has scratch resistance similar to that of glass. These functional layers 11 can be formed by a known method using a known material.

  The microcapsule-type electrophoretic display panel obtained as described above and shown in FIG. 1C has a first water vapor blocking resin in the gap between the substrate 7 and the transparent resin film 2 at the peripheral edge of the panel. Since the layer 8 is filled, the penetration of moisture into the microcapsule display layer 3 from the side of the panel is effectively blocked, and the characteristics of the microcapsule display layer 3 are deteriorated due to the penetration of moisture into the microcapsule display layer 3. Can be effectively prevented.

  FIG. 2 is a cross-sectional view showing a microcapsule type electrophoretic display panel according to another embodiment of the present invention. In the microcapsule type electrophoretic display panel shown in FIG. 2, the second water vapor blocking resin layer 12 is formed on the transparent electrode layer 1 in the region to be filled with the first water vapor blocking resin layer 8. Yes. As a material of the second water vapor blocking resin layer 12, an acrylic resin, a methacrylic resin, an epoxy resin, or the like can be used. In particular, it is desirable to be cured by irradiation with heat or ultraviolet rays. Although the film thickness of the 2nd water vapor | steam barrier resin layer 12 is not specifically limited, Usually, it is preferable that it is about 3-15 nm.

  Before forming the microcapsule display layer 3, the second water vapor blocking resin layer 12 should be filled with the first water vapor blocking resin layer 8 corresponding to the peripheral edge of the panel on the transparent electrode layer 1. Formed in the region. That is, the second water vapor blocking resin layer 12 is formed, for example, by applying the second water vapor blocking resin by screen printing or the like and then curing it by heating or irradiating ultraviolet rays.

  After the second water vapor blocking resin layer 12 is formed, the microcapsule display layer 3 and the first adhesive layer 4 are formed on the second water vapor blocking resin layer 12 and the exposed transparent electrode layer 1, Further, as described above, the first adhesive layer 4 and the microcapsule display layer 3 corresponding to the peripheral edge of the panel are removed. At this time, since the second water vapor blocking resin layer 12 is formed on the transparent electrode layer 1 corresponding to the portion to be removed, the transparent electrode layer 1 is prevented from being damaged. That is, the second water vapor blocking resin layer 12 serves as a protective layer for the transparent electrode layer 1.

  In the form shown in FIGS. 1 and 2, the transparent resin protective film 10 is formed on the transparent resin film 2 via the second adhesive layer 9, but the book of preventing moisture from entering from the peripheral edge of the panel. The transparent resin protective film 10 is not always necessary to achieve the main object of the invention. That is, it is possible to adopt a configuration as shown in FIGS.

  In the microcapsule-type electrophoretic display panel described above, the microcapsules included in the microcapsule display layer 3 include, for example, a methacrylic acid resin, urea resin, gum arabic or the like as a capsule shell 111 as shown in FIG. Inside, white particles 113 made of titanium oxide and black particles 114 made of carbon black are enclosed in a state of being dispersed in a highly viscous dispersion medium 112 such as silicone oil. Titanium oxide, which is a white particle 113, has a positive charge, while carbon black, which is a black particle 114, has a negative charge.

  A display body using such a microcapsule type electrophoresis system including the microcapsules 110 operates as follows.

  That is, as shown in the schematic diagram of FIG. 6, an electric field is applied to the transparent electrode layer 1 on the transparent resin film 2 side and the electrode layer 21 on the substrate 7 side, the transparent electrode layer 1 being a negative electrode, and the electrode layer 21 being a positive electrode. In this case, the positively charged white particles 113 are drawn to the transparent electrode layer 1 side, and the negatively charged black particles 114 are drawn to the electrode layer 21 side. The part looks white.

  Conversely, when the transparent electrode layer 1 is a positive electrode and the electrode layer 21 is a negative electrode, the positively charged white particles 113 are attracted to the electrode layer 21 side, and the negatively charged black particles 114 are transparent. Since it is drawn to the electrode layer 1 side, when viewed from above the transparent electrode layer 1 side, the portion looks black.

  As shown in the schematic side sectional view of FIG. 7, the microcapsule display layer 3 includes a large number of microcapsules 110, the transparent electrode layer 1 is a common electrode having the same potential, and the electric field of each address electrode of the electrode layer 21 is By controlling, it is possible to display desired characters and figures as white and black pixels by moving particles in the microcapsule based on the above-described principle.

  Similarly, the electrode layer 21 is used as a common electrode (the potential is set to zero), and the electric field of each address electrode on the transparent electrode 1 side is controlled (a positive or negative potential is applied), so You may make it display a desired image by moving particle | grains.

  Various diameters of the microcapsules can be adopted. However, when a diameter of about 40 μm to about 100 μm is adopted, sufficient resolution and responsiveness can be obtained. The resolution of the display image mainly depends on the arrangement of the electrodes in the electrode layer. However, if the diameter of the microcapsules is small, the movement speed of the microcapsules in the dispersion medium increases, and as a result, the response at the time of display is excellent. There are benefits.

  In the above example, an example of monochrome (monochrome) image display has been described. However, in the case of color image display, R (red), G (green), and B (blue) colors divided in units of pixels are used. A color image display can be realized by providing the color filter having the color filter on the transparent electrode 1 side to which an electric field can be applied in units of pixels.

  A paper-like electronic display can be realized by producing a flexible material and patterning electrodes and the like on a plastic film by a printing method or a vapor deposition method. The display screen size can be created in any size according to the application and demand.

  In the microcapsule display layer 3, there is no problem in display even if the position of the microcapsule 110 is slightly changed. Therefore, it is possible to bend and use it by attaching it to a curved surface.

  In the microcapsule-type electrophoretic display panel, each particle is dispersed in a highly viscous dispersion medium. Therefore, once the electric field is applied, the position of the particle does not change even when the power is turned off. In this way, the display image does not disappear even when the display is turned off. It has non-volatility (memory property), so it is only necessary to apply an electric field at the time of initial display or rewriting, and it is necessary for display compared to a normal display device. It requires less power and can save a lot of power.

  Further, in the display panel, there is no problem in display even if the position of the microcapsules 110 is slightly changed. Therefore, by using a material that makes the entire display including the transparent electrode layer 1 and the electrode layer 21 thin and portable, flexibility such as paper can be provided.

  Since the microcapsule type electrophoretic display panel of the present invention has excellent water vapor barrier properties and moisture resistance, it can be widely used as a display panel in various applications.

9 is a cross-sectional view illustrating a manufacturing process of a microcapsule type electrophoretic display panel according to one embodiment of the present invention. FIG. Sectional drawing which shows the microcapsule type | mold electrophoretic display panel which concerns on the other form of this invention. Sectional drawing which shows the microcapsule type | mold electrophoretic display panel which concerns on the other form of this invention. Sectional drawing which shows the microcapsule type | mold electrophoretic display panel which concerns on the other form of this invention. FIG. 3 is a diagram schematically illustrating a microcapsule included in a microcapsule display layer of a microcapsule electrophoretic display panel according to one embodiment of the present invention. The perspective view which represents typically an example of the display form of the microcapsule display layer of the microcapsule type | mold electrophoretic display panel which concerns on one form of this invention. FIG. 6 is a side cross-sectional view schematically illustrating an example of a display form of a microcapsule display layer of a microcapsule type electrophoretic display panel according to an embodiment of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Transparent electrode layer (ITO film), 2 ... Transparent resin film, 3 ... Microcapsule display layer, 4 ... 1st contact bonding layer, 5 ... Front plate, 6 ... Removal region, 7 ... substrate, 8 ... first water vapor blocking resin layer, 9 ... second adhesive layer, 10 ... transparent resin protective film, 11 ... functional layer, 12. 2nd water vapor blocking resin layer, 21 ... electrode layer, 210 ... microcapsule, 111 ... capsule shell, 112 ... dispersion medium, 113 ... white particles, 114 ...・ Black particles.

Claims (8)

A substrate, a microcapsule display layer disposed in a region excluding the peripheral portion on the substrate, a transparent resin film having a transparent electrode layer on the microcapsule display layer, which is deposited on the microcapsule display layer; and A water vapor blocking resin layer having a width of 0.5 to 1.5 mm filled in a gap between a peripheral edge on the substrate and the transparent electrode layer is provided, and the water vapor blocking resin layer is disposed on the substrate side. Two layers comprising a formed first water vapor blocking resin layer and a second water vapor blocking resin layer formed on the transparent electrode layer side for blocking water vapor and protecting the transparent electrode layer The first water vapor blocking resin layer and the second water vapor blocking resin layer have a structure, and are made of an acrylic resin, a methacrylic resin, or an epoxy resin cured by irradiation with heat or ultraviolet rays. My Rokapuseru type electrophoretic display panel.   2. The microcapsule type electrophoretic display panel according to claim 1, further comprising a transparent resin protective film deposited on the transparent resin film via an adhesive layer. The microcapsule type electrophoretic display panel according to claim 1, wherein the transparent electrode layer has a thickness of 10 nm or more. A transparent resin film having a transparent electrode layer is formed of an acrylic resin, a methacrylic resin, or an epoxy resin, which is cured by irradiation with heat or ultraviolet rays, on the peripheral edge portion on the transparent electrode layer . And forming a microcapsule display layer in a region on the transparent electrode layer where the second water vapor barrier resin layer is not formed, and the microcapsule display layer side of the transparent resin film Is made of an acrylic resin, a methacrylic resin, or an epoxy resin, which is cured by irradiation of heat or ultraviolet rays in the gap between the second water vapor blocking resin layer and the substrate . A method for producing a microcapsule type electrophoretic display panel, comprising filling a 5-1.5 mm first water vapor blocking resin layer. 5. The information according to claim 4 , wherein the formation of the microcapsule display layer in the region on the transparent electrode layer where the second water vapor blocking resin layer is not formed is performed by laser irradiation or wiping. Manufacturing method of display member. The formation of the microcapsule display layer in the region on the transparent electrode layer where the second water vapor blocking resin layer is not formed is the region on the transparent electrode layer where the second water vapor blocking resin layer is not formed. The method for producing an information display member according to claim 4 , wherein the microcapsule display layer is formed in a pattern.   The method for producing a microcapsule type electrophoretic display panel according to claim 4, wherein a transparent resin protective film is deposited on the transparent resin film via an adhesive layer. The method of manufacturing a microcapsule type electrophoretic display panel according to any one of claims 4 to 7 , wherein the transparent electrode layer has a thickness of 10 nm or more.

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