JP2012013790A - Manufacturing method and manufacturing apparatus of electronic paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of electronic paper capable of ensuring bond of a bulkhead even through a simple process.SOLUTION: A manufacturing method includes: a bulkhead forming step for forming a bulkhead on one substrate in a predetermined pattern; a bonding layer forming step for forming a bonding layer on the bulkhead; a display medium packing step for packing a display medium in an area zoned by the bulkhead after the bonding layer is formed; a temporarily sealing step for temporarily sealing the display medium by putting the other substrate parallel on the bonding layer on the bulkhead; an other-substrate bonding step for sealing the temporarily sealed display medium by bonding the other substrate on the bonding layer on the bulkhead.

Description

  The present invention relates to a manufacturing method for manufacturing electronic paper.

  Electronic paper is a device that displays information using particle movement in air or in a solvent. Usually, the movement state of the particles between the two substrates is controlled so that a desired display is realized.

  Electronic paper can enjoy advantages such as visibility at the printed matter level (easy to eyes), ease of information rewriting, low power consumption, and light weight, leading to energy and resource savings.

  However, in electronic paper, display defects, particularly contrast reduction, may occur due to sedimentation or uneven distribution of particles. In order to prevent this phenomenon, it is employed to form a partition wall between the upper and lower electrode substrates to divide the particle movement space into minute spaces. This minute space is called a cell or a pixel. In each cell, moving particles or ink containing moving particles is sealed.

  Here, when the material used as the substrate is a film, the film is relatively easily deformed, so that there is a problem that a gap is easily generated between the partition wall and the electrode substrate. Therefore, it is important to securely bond between the partition wall and the electrode substrate to prevent ink from passing and moving between the partition wall and the electrode substrate.

  Japanese Patent Laying-Open No. 2006-184893 (Patent Document 1) discloses a method of manufacturing an electronic paper by forming an adhesive layer on a top surface of a partition wall formed on a substrate with high accuracy and low cost. Specifically, a method is disclosed in which a roll coated with an adhesive (ultraviolet curable resin or thermosetting resin) is rotated to transfer the adhesive onto partition walls at room temperature.

JP 2006-184893 A

  The present inventor has found that there is a problem associated with volatilization of the solvent of the adhesive in the technique disclosed in Japanese Patent Application Laid-Open No. 2006-184893 (Patent Document 1). That is, due to the volatilization of the solvent of the adhesive, the surface after application of the adhesive may become uneven, and in that case, the adhesion becomes incomplete. Further, it has been found that the adhesive solvent volatilizes into the in-cell area or the pixel area other than the desired application location, thereby degrading the display quality.

  The present invention has been made based on such circumstances, and its purpose is to apply the adhesive only to the partition walls while being a simple process, and to securely bond the partition walls to the electrode substrate. An object of the present invention is to provide an electronic paper manufacturing method that can be used.

  The present invention is a method of manufacturing an electronic paper in which a display medium is sealed between two opposing substrates, at least one of which is transparent, and the display medium displays predetermined information. A partition formation step of forming a partition in a predetermined pattern on the substrate; an adhesive layer formation step of forming an adhesive layer on the partition; and the display in an area partitioned by the partition after the adhesive layer is formed A display medium disposing step of disposing a medium; a temporary sealing step of temporarily sealing the display medium by placing the other substrate in parallel on the adhesive layer on the partition; A second substrate bonding step of sealing the display medium that has been temporarily sealed by bonding the other substrate on the bonding layer, wherein the heat sealing agent is formed in the bonding layer forming step. Using transfer film In the electronic paper manufacturing method, the second substrate bonding step includes a heating step of softening the heat sealing agent transferred as an adhesive layer to obtain an adhesive force. is there.

  According to the present invention, by using a heat sealant as an adhesive, the partition and the other substrate can be reliably bonded to each other with a simple process. In addition, by using a transfer film when heat-transferring the heat sealant, high-precision alignment on the partition wall is unnecessary, but the heat-seal agent can be reliably thermally transferred only to the partition wall upper surface. Then, after the other substrate is placed in parallel on the adhesive layer on the partition, the other substrate is bonded, thereby significantly reducing the risk of bubbles being mixed into the display medium in the other substrate bonding step. can do.

  Prior to finding out the effectiveness of the temporary sealing process according to the present invention, the inventor of the present invention prevents a mixture of bubbles in the display medium in the other substrate bonding process by filling a large amount of the display medium. Although measures have been taken, such measures have caused the problem of loss of display media and the problem of contamination by display media. The temporary sealing process according to the present invention brings about a remarkable effect of eliminating these problems, and leads to resource saving by reducing the loss of the display medium.

  In addition, as a display method of the electronic paper of the present invention, a known method can be applied. For example, an electrophoresis method, a twist ball method, a powder movement method (an electronic powder fluid method, a charged toner type method), a liquid crystal A display method, a thermal method (coloring method, light scattering method), an electrochromic method, an electrowetting method, a magnetophoresis method, and the like are applicable.

  The temporary sealing step is preferably performed in a reduced pressure atmosphere. In such a case, the risk of bubbles being mixed into the display medium can be further reduced.

  Preferably, the other substrate bonding step further includes a thermocompression bonding step of thermocompression bonding the peripheral portions of both substrates. In this case, the other substrate is more reliably bonded.

  In addition, preferably, the adhesive layer forming step further includes a heat peeling step for peeling the transfer film while heating. According to such a heat peeling process, it becomes easy to obtain a desired shape accuracy for the partition pattern.

  Preferably, in the adhesive layer forming step, the heat sealant is made of a thermoplastic material. When the heat sealant thermally transferred as the adhesive layer is made of a thermoplastic material, there is no tack (stickiness) at room temperature, which is very convenient for handling. Further, since there is no tack (stickiness), the subsequent display medium arranging step is easy. For example, even if the display medium is arranged using a squeegee or the like, the display medium does not adhere to the heat sealant.

  When the heat sealant is made of a thermoplastic material, the other substrate is securely bonded by heating the heat sealant, so that the bonded portion may be peeled even if the other substrate is deformed. In other words, there is no gap that undesirably moves the display medium. Further, since there is no possibility that impurities enter the partition area (for example, cell) when the other substrate is bonded, there is no risk of deterioration in display quality. And since the heat sealant after bonding the other substrate has no tack at room temperature, the display medium will not adhere to the heat sealant, which also reduces the display quality. There is no fear.

  Preferably, the other substrate bonding step is a heating and pressing step in which a predetermined pressure is further applied to obtain an adhesive force. In this case, the other substrate is more reliably bonded.

  Preferably, the heat sealing agent has a thickness of 1 to 100 μm. More preferably, it is 1-50 micrometers, Most preferably, it is 1-10 micrometers.

  Preferably, the partition wall has a thickness of 5 to 100 μm. More preferably, it is 10-50 micrometers.

  Further, the present invention is an apparatus for manufacturing electronic paper, in which a display medium is sealed between two opposing substrates, at least one of which is transparent, and the display medium displays predetermined information, A partition forming device that forms a partition with a predetermined pattern on one substrate, an adhesive layer forming device that forms an adhesive layer on the partition, and an area partitioned by the partition after the adhesive layer is formed. A display medium placement device for placing the display medium; a temporary sealing device for temporarily sealing the display medium by placing the other substrate in parallel on the adhesive layer on the partition; A second substrate bonding apparatus that seals the display medium that has been temporarily sealed by bonding the other substrate onto the bonding layer, wherein the bonding layer forming apparatus is formed with a heat sealant. Use transfer film An electronic paper manufacturing apparatus having a configuration for thermally transferring a heat sealant, wherein the other substrate bonding apparatus has a structure for softening the heat sealant transferred as an adhesive layer. is there.

  The temporary sealing device is preferably operated under a reduced pressure atmosphere. In such a case, the risk of bubbles being mixed into the display medium can be further reduced.

  Preferably, the other substrate bonding apparatus further includes a thermocompression bonding apparatus that thermocompresses the peripheral portions of both substrates. In this case, the other substrate can be more reliably bonded.

  Preferably, the adhesive layer forming apparatus is configured to further peel off the transfer film while heating. According to such a heat peeling process, it becomes easy to obtain a desired shape accuracy for the partition pattern.

  Preferably, in the adhesive layer forming apparatus, the heat sealant is made of a thermoplastic material. When the heat sealant thermally transferred as the adhesive layer is made of a thermoplastic material, there is no tack (stickiness) at room temperature, which is very convenient for handling. Further, since there is no tack (stickiness), the subsequent display medium arranging step is easy. For example, even if the display medium is arranged using a squeegee or the like, the display medium does not adhere to the heat sealant.

  When the heat sealant is made of a thermoplastic material, the other substrate is securely bonded by heating the heat sealant, so that the bonded portion may be peeled even if the other substrate is deformed. In other words, there is no gap that undesirably moves the display medium. Further, since there is no possibility that impurities enter the partition area (for example, cell) when the other substrate is bonded, there is no risk of deterioration in display quality. And since the heat sealant after bonding the other substrate has no tack at room temperature, the display medium will not adhere to the heat sealant, which also reduces the display quality. There is no fear.

  The other substrate bonding apparatus is preferably configured to further apply a predetermined pressing force.

  According to the present invention, although it is a simple process, the adhesive can be applied only on the partition wall, and the partition wall can be reliably bonded to the electrode substrate.

FIG. 1 is a flowchart schematically showing a method for producing electronic paper according to an embodiment of the present invention. FIG. 2 is a diagram schematically showing an example of the partition wall forming step. FIG. 3 is a diagram schematically showing an example of the adhesive layer forming step. FIG. 4 is a diagram schematically showing an example of the display medium arranging step. FIG. 5 is a schematic view for explaining the function of the conductive paste. Drawing 6 is a figure showing roughly the temporary sealing process of an up-and-down base material pasting process. FIG. 7 is a diagram schematically showing the other substrate (upper substrate) bonding step in the upper and lower base material bonding step. FIG. 8 is a schematic view for explaining an example of a transfer film peeling step.

  FIG. 1 is a flowchart schematically showing a method for producing electronic paper according to an embodiment of the present invention. FIG. 2 is a diagram schematically showing an example of the partition wall forming step. As shown in FIG. 2, first, ultraviolet rays (UV) are generally formed on the upper surface of a lower substrate 11 (one substrate: backplane base material (BP)) generally placed in a horizontal direction by, for example, photolithography. The partition walls 12 are formed in a predetermined pattern by exposure by exposure → development → firing. The partition wall 12 is a member that defines lower surfaces and side surfaces of a plurality of cells to be described later. The thickness of the partition wall is 5 to 100 μm, preferably 10 to 50 μm.

  Next, an adhesive layer is formed on the partition wall 12 (adhesive layer forming step). FIG. 3 is a diagram schematically showing an example of the adhesive layer forming step. In the adhesive layer forming step shown in FIG. 3, first, a heat seal agent 22 (hereinafter also referred to as “adhesive layer”) is applied to a transfer film substrate 21 made of, for example, a polyethylene terephthalate (PET) film. A transfer film 20 is created. The heat sealing agent 22 is applied with a thickness of 1 to 100 μm. Preferably, it is applied with a thickness of 1 to 50 μm, particularly preferably with a thickness of 1 to 10 μm. As will be described later, the heat sealant 22 is made of a thermoplastic resin.

  Then, the surface of the transfer film 20 on the heat sealant side is placed on the partition wall 12, and the softening temperature is set while only the weight of the transfer film 20 is applied or while receiving a predetermined pressing force. It is heated to a temperature exceeding (heat bonding: thermal transfer). Thereafter, when the transfer film 20 is peeled off, the heat sealant 22 remains in a state of being thermally transferred onto the partition wall 12.

  The pressing force here is preferably 0.01 to 0.7 MPa, and particularly preferably 0.1 to 0.4 MPa. When the pressing force is small, the transfer of the heat sealant from the transfer film is insufficient. On the other hand, if the pressing force is too large, the heat sealing agent may be crushed and enter the cell, or a heat sealing agent other than the partition wall pattern may be transferred.

  In addition, as long as the effect of the present invention is exhibited, the heat sealant 22 may be thermally transferred onto all the partition walls 12, or the heat sealant 22 may be thermally transferred only onto some of the partition walls 12. For example, the heat sealant 22 may be thermally transferred only onto the peripheral partition wall 12.

  Returning to FIG. 1, after the adhesive layer (heat sealant) 22 is formed, the ink 13 as a display medium is disposed in each partition 12 or each region partitioned by the partition 12 and the adhesive layer 22 (display medium). Placement process). FIG. 4 is a diagram schematically showing an example of the display medium arranging step. Here, (1) the ink 13 is dropped from the dispenser 31 or the ink jet or die coat, (2) the ink 13 is applied by the central squeegee 32, the doctor blade, or the doctor knife so as to be in-plane uniform, and (3) Both ends squeegee 33a, 33b or doctor blade, doctor knife, the material is urethane rubber, silicon rubber, synthetic rubber, metal, plastic, etc., the excess ink that protrudes is scraped off. The collected excess ink is wiped off.

  Returning to FIG. 1, after the display medium arranging step, a conductive paste applying step is performed. FIG. 5 is a schematic view for explaining the function of the conductive paste. The conductive paste 14 is a metal paste such as a silver paste, and is applied to a predetermined position by, for example, a dispenser 41 or ink jet, tampo printing, pad printing, or stacking printing. As shown in FIG. 5, the conductive paste 14 functions as a wiring for applying a voltage to an upper substrate 16 (the other substrate: front plane base material (FP)) described later.

  Thereafter, the upper substrate 16 facing the lower substrate 11 is bonded onto the adhesive layer 22 on the partition wall 12 (upper and lower substrate bonding step). Thereby, each upper surface of a some cell is prescribed | regulated and a display medium (ink 13) is sealed in each cell.

  Here, the upper and lower board | substrate bonding processes of this Embodiment are demonstrated in detail using FIG.6 and FIG.7. As shown in FIG.6 and FIG.7, the upper-lower board | substrate bonding process includes the temporary sealing process (FIG. 6) and the other board | substrate adhesion process (FIG. 7). The other substrate is the upper substrate 16 in the present embodiment.

  In the temporary sealing step, the upper metal plate 71 is fixed to the upper surface of the upper substrate 16 (the other substrate) and the lower metal plate 72 is fixed to the lower surface of the lower substrate 11 as shown in FIG. Above the metal plate 71, a convex balloon 75 is positioned on the lower side that is fixed to the balloon-fixing metal plate 73 and can be expanded and contracted. The balloon 75 is made of, for example, a silicone sheet.

  When the balloon 75 is inflated, the upper metal plate 71 descends toward the lower metal plate 72 while maintaining parallelism with the lower metal plate 72 and the balloon fixing metal plate 73. In order to maintain such a parallel relationship, guide rail mechanisms (not shown) extending in the vertical direction are provided at the four corners of the upper metal plate 71.

  The upper metal plate 71, the lower metal plate 72, the balloon fixing metal plate 73, the balloon 75, and a guide rail mechanism (not shown) are components of the temporary sealing device. In the present embodiment, these components are installed in the vacuum chamber 80 and operate in a reduced pressure atmosphere (preferably a vacuum atmosphere).

  The temporary sealing process is performed as follows. That is, the upper metal plate 71 is fixed to the upper surface of the upper substrate 16 (the other substrate), the lower metal plate 72 is fixed to the lower surface of the lower substrate 11, and the balloon fixed metal plate 73 is positioned above the upper metal plate 71. A fixed inflatable / deflated balloon 75 is positioned. These environmental atmospheres are reduced to a reduced pressure atmosphere by evacuation of the vacuum chamber 80. Under such a reduced pressure atmosphere, the balloon 75 starts to expand. As the balloon 75 presses the upper metal plate 71 downward, the upper metal plate 71 starts to descend. At this time, the upper metal plate 71 is lowered by a guide rail mechanism (not shown) while maintaining parallelism with the lower metal plate 72 and the balloon fixing metal plate 73. Thereby, the upper substrate 16 (the other substrate) is placed in parallel on the adhesive layer 22 on the partition wall 12, and the ink 13 can be temporarily sealed without mixing bubbles in the ink 13.

  Thereafter, the pressing force of the upper metal plate 71 is released as the balloon 75 contracts. Thereafter, the upper metal plate 71 and the lower metal plate 72 are removed from each substrate.

  In the present embodiment, the parallelism between the bonding layer 22 on the partition wall 12 and the bonding surface of the upper substrate 16 is highly accurate by bonding between the two metal plates of the upper metal plate 71 and the lower metal plate 72. And can be bonded without warping. In the present embodiment, since the heat sealing agent as an adhesive layer is made of a thermoplastic resin, it has no tack (stickiness) at room temperature and is weakly adhesive. Since there is an escape route for the bubbles when pressed, it is possible to reduce bubble contamination.

  Note that the temporary sealing step is a mechanism that allows the upper substrate 16 to be placed in parallel on the adhesive layer 22 on the partition wall 12. The upper metal plate 71 may be pressed against the lower metal plate 72 by a generally used press device without being limited to the defensible balloon 75.

  Subsequently, in the other substrate bonding step, as shown in FIG. 7, the heat sealing agent 22 transferred as an adhesive layer is heated to obtain an adhesive force. Specifically, the partition wall temporarily sealing the ink 13 by heating and softening the heat sealant 22 from the periphery to a temperature exceeding the softening temperature while applying a predetermined laminating pressure by the laminator 91. 12 and the upper substrate 16 are firmly bonded. From the results, the substrate bonded to the partition wall 12 through the heat seal 22 is referred to as the upper substrate 16, and the substrate on which the partition wall 12 is directly formed is referred to as the lower substrate 11. .

  In the present embodiment, after bonding by the laminator 91, a thermocompression bonding process is further performed in which the four sides (peripheral parts) of both the substrates 11 and 16 are thermocompression bonded. Specifically, a hot plate 92 is laid under the four sides (peripheral parts) of both substrates 11 and 16, and the lamination pressure is applied to the four sides of both substrates 11 and 16 with metal pieces 93 from the inside to the outside. Will be implemented. When such a thermocompression bonding process is performed, both the substrates 11 and 16 are bonded more firmly.

  Thereafter, as shown in FIG. 1, the sheet is cut into a predetermined size by a cutting device 51 such as a guillotine, an upper blade slide device, a laser cutting device, or a laser cutter, and thereafter, a peripheral sealing process is performed to obtain a desired electronic Paper manufacturing is complete.

  According to the present embodiment, by using the heat sealant 22 as an adhesive, the partition 12 and the upper substrate 16 for cell formation can be reliably bonded while being a simple process. In addition, by using the transfer film 20 when the heat sealant 22 is thermally transferred, high-precision alignment on the partition wall 12 is unnecessary, but the heat seal agent 22 can be reliably thermally transferred only to the upper surface of the partition wall 12.

  Further, when the heat sealant 22 thermally transferred as an adhesive layer is made of a thermoplastic material, the heat sealant 22 has no tack (stickiness) at room temperature, and is very convenient to handle. Further, since there is no tack (stickiness), the subsequent display medium arranging step is easy. Specifically, even when the display medium is arranged using a squeegee, a doctor blade, a doctor knife, or the like, the display medium (ink 13) does not adhere to the heat sealant 22.

  In the case where the heat sealant 22 is made of a thermoplastic material, the upper substrate 16 is reliably bonded to the partition wall 12 by heating the heat sealant 22, so that even if the upper substrate 16 is deformed, the bonded portion Does not peel off, that is, there is no air gap that causes the display medium to move undesirably. In addition, since there is no possibility of impurities entering the cell when the upper substrate 16 is bonded, there is no risk of deterioration in display quality. Since the heat sealant 22 after the upper substrate 16 is bonded does not have tack at room temperature, the display medium does not adhere to the heat sealant 22, and display quality is also improved in this respect. There is no risk of decline.

  Since the upper substrate (other substrate) 16 is placed in parallel on the adhesive layer 22 on the partition wall 12 and then the upper substrate 16 is bonded, the display medium in the other substrate bonding step (FIG. 7). The risk of bubbles being mixed into (ink 13) can be significantly reduced. Therefore, the conventional measures of filling the ink 13 in a large amount are unnecessary, and the problem of loss of the ink 13 and the problem of contamination by the ink 13 can be remarkably improved.

  Moreover, the temporary sealing process (FIG. 6) of this Embodiment is performed in the pressure-reduced atmosphere. In this case, the risk of bubbles being mixed into the display medium (ink 13) can be further reduced.

  The display medium used in the present invention is appropriately selected according to the display method of electronic paper. As a display method of electronic paper, known ones can be applied, for example, electrophoresis method, twist ball method, powder movement method (electronic powder fluid method, charged toner type method), liquid crystal display method, thermal method. (Coloring method, light scattering method), electrochromic method, electrowetting method, magnetophoresis method and the like. Hereinafter, in the embodiment of the present invention, a display medium when used in electrophoretic electronic paper will be described as an example.

  Next, an example actually performed to confirm that there is no deterioration in display quality will be described.

  The lower substrate 11 of this example was an electrode substrate in which a Cu electrode was provided on a polyethylene terephthalate (PET) film (manufactured by Teijin DuPont) having a thickness of 100 μm.

On the lower substrate 11, a negative photosensitive resin material (DuPont MRC dry film resist Co., Ltd. dry film resist) is laminated to a thickness of 30 μm, prebaked at 100 ° C. for 1 minute, and then exposed. By using a mask (exposure amount: 500 mJ / cm ² ), followed by spray development using a 1% KOH aqueous solution for 30 seconds and post-baking at 200 ° C. for 60 minutes, the partition wall 12 is formed. It was done. The formed partition wall 12 had a lattice shape with a pitch of 600 μm and an opening of 90%.

  A polyethylene terephthalate (PET) film (manufactured by Teijin DuPont) having a thickness of 50 μm is used as the transfer film substrate 21, and a heat sealant 22 (Byron UR1400, manufactured by Toyobo Co., Ltd.) is applied to the film by a die coater and dried. It was done. Thus, a roll-shaped transfer film 20 having a 10 μm adhesive layer 22 was produced.

  Then, with the transfer film 20 placed on the upper surface of the partition wall 12, the periphery of the heat sealant 22 is heated to a temperature exceeding its softening temperature, for example, about 100 degrees, while further applying a predetermined pressing force. As a result, the heat sealant 22 was thermally transferred onto the partition wall 12.

  The thickness of the heat sealant 22 was 10 μm. The partition wall 12 had a thickness of 29 μm.

  Subsequently, an ink 13 having the following components is used as a display medium, dropped from the dispenser 31, and squeezed with a central squeegee 32 (Neurong squeegee 1: made of urethane resin), and in each cell. Filled. Excess ink that protruded in the substrate width direction was scraped off by another squeegee 33a, 33b (Nelogue Squeegee 2: made of urethane resin), and further wiped off by a roll wiper 34.

<Ink component>
・ Electrophoretic particles (titanium dioxide): 60 parts by weight ・ Dispersion liquid: 40 parts by weight Subsequently, a silver paste (manufactured by Fujikura Kasei) is dispensed on a part of the outer periphery of the pattern (square area of 2 mm × 2 mm). Spot application by 41.

  Next, an indium tin oxide (ITO) vapor deposition film (thickness 0.2 μm) is provided as a transparent electrode on one surface of a 100 μm thick polyethylene terephthalate (PET) film (manufactured by Teijin DuPont) as the upper substrate 16. An electrode substrate was used and placed on the adhesive layer 22. Specifically, after the temporary sealing step as shown in FIG. 6 is performed in a reduced pressure atmosphere, the other substrate bonding step as shown in FIG. 7 is performed at an atmospheric pressure (normal pressure atmosphere) of about 100 degrees. It was implemented. As a result, the adhesive layer 22 firmly bonded the partition wall 12 and the upper substrate 16. As the transparent electrodes of the upper and lower substrates, indium tin oxide (ITO), zinc oxide (ZnO), tin oxide (SnO), etc. are formed by a general film forming method such as sputtering, vacuum evaporation method, CVD method or the like. The

  On the other hand, the pressing force by the laminator 91 in the substrate bonding step is preferably 0.01 to 0.7 MPa, and particularly preferably 0.1 to 0.4 MPa. If the pressing force is small, the upper and lower substrates do not adhere sufficiently. On the other hand, if the pressing force is too large, the adhesive may collapse and enter the cell, causing particles to adhere to it, or causing the ink to flow out, reducing the contrast and adversely affecting the display performance. There is.

After that, it is cut to a predetermined size, and an ultraviolet curable resin (LCB-610, manufactured by EACH Sea Co., Ltd.) is applied around the upper and lower electrode substrates 11 and 16 using a dispenser (not shown). And then cured by exposure to ultraviolet rays (exposure amount 700 mJ / cm ² ) (peripheral sealing treatment).

  Regarding the electronic paper obtained as described above, the contrast after applying a DC voltage of 80 V between the upper and lower electrodes was observed, but it was very good.

  In the above embodiment, Byron UR1400 (manufactured by Toyobo) is applied to the transfer film 20 as the heat seal agent 22, Byron UR3200 (manufactured by Toyobo) may be used instead of Byron UR1400. Even when Byron UR3200 is used, about 100 degrees is adopted as the temperature for heat bonding. According to the present inventors, it has been found that if the temperature of the heat bonding is too high, “undulation” occurs due to material shrinkage, and the adhesion to the substrate is impaired. According to the present inventors, 150 degrees or less is preferable, 120 degrees or less is more preferable, and 80 degrees or less is still more preferable.

  However, it has been found that when Byron UR3200 is used, the desired shape accuracy cannot be obtained for the partition pattern if the transfer film 20 is peeled off at room temperature.

And this inventor discovered that also in the case of peeling of the transfer film 20, it is effective to raise temperature by heating.

  Specifically, as shown in FIG. 8, when the transfer film 20 is peeled off, the heat sealing agent 22 can be heated by the upper and lower heating rolls 61 via the transfer film base 21 and the lower substrate 11. It was effective. The experimental results relating to the heating temperature in this case are shown as a table below.

Items relating to transferability include shape accuracy of the partition pattern (×: no transfer, △: partial transfer, ○: full transfer), presence or absence of liquid dripping in the partition (×: liquid dripping, ○: no liquid dripping), Four items are evaluated: presence / absence of stringing (×: threading present, Δ: partially threading present, ○: threading absent), film thickness variation (×: variation present, ○: no variation) It was done. Moreover, adhesiveness was also evaluated (x: not adhered, Δ: easily peeled, ○: good adhesiveness).

The three items of the partition pattern shape accuracy, the presence or absence of dripping in the partition walls, and the presence or absence of stringing were evaluated by appearance observation using an optical microscope. The film thickness variation was evaluated based on the measurement results using a Dectac stylus profilometer. The adhesion was evaluated based on a T-shaped peel test according to JIS standard K6854-3 using Tensilon.

  From the experimental results shown in the table, it can be seen that heating at the time of peeling of the transfer film 20 is effective for improving transferability or adhesiveness. In particular, it can be seen that heating to about 100 degrees is preferable.

  In FIG. 8, the transfer film base material 21 is guided on a trajectory that floats upward from the horizontal trajectory (approximately 90 degrees in angle), but the lower substrate 11 travels in the horizontal trajectory. Separation can also be realized by guiding on an orbit that sinks downward (approximately 90 degrees in angle). In that case, there is a difference in the influence of gravity, but no difference occurred in the experimental results regarding the temperature suitable for peeling.

  Furthermore, in the said aspect, although the heat sealing agent is once heat-bonded, the step of heating and peeling again is taken, but suitable heating temperature is substantially equal between heat-bonding and heat peeling. From the result, it was confirmed that the heat bonding and the heat peeling can be carried out simultaneously in a fusion manner. Specifically, immediately after being heated for bonding, the transfer film base material 21 is guided so as to float upward from the horizontal track, or the lower substrate 11 is sinked downward from the horizontal track. It is possible to carry out the heat bonding and the heat peeling at the same time in an integrated manner.

  Next, the materials or characteristics of each member of the electronic paper as the production target of the present invention will be described in more detail.

  As the lower substrate 11, a substrate in which an electrode is formed of a conductive material such as a metal on the surface of a resin film, a resin plate, glass, epoxy glass (glass epoxy), ceramics, or the like can be used. Alternatively, a metal plate or a light transmissive substrate may be used. As an opaque base material, an opaque glass base material having a rough surface on the other surface different from the electrode surface, an opaque base material with a metal film deposited on the other surface different from the electrode surface, dyes and pigments An opaque resin base material kneaded with can be used.

  The thickness of the lower substrate 11 is preferably 10 μm to 1 mm. If it is thinner than 10 μm, the strength as a panel cannot be obtained and the risk of breakage increases. On the other hand, if it is thicker than 1 mm, the panel weight becomes too heavy and the handling becomes inconvenient and the cost also increases. Because. A suitable thickness range that is difficult to break and easy to handle is about 50 μm to 300 μm.

  The surface of the lower substrate 11 may be subjected to an oxidation preventing process by a plating process. Further, a barrier layer may be provided on the back surface (outside) of the lower substrate 11. The function of the barrier layer is to prevent display deterioration caused by the ink adsorbing moisture. The barrier layer may be transparent on the upper substrate, transparent or opaque on the lower substrate, and obtained by depositing an inorganic film. Or the film in which the barrier layer was previously formed may be bonded together. The electrode pattern of the lower substrate 11 can be formed by a photolithography method, a laser drawing method, an ink jet method, a screen printing method, a flexographic printing method, or the like. A TFT substrate may be used as the lower substrate 11.

  The lower substrate 11 can be applied in either a roll shape or a sheet shape.

  The partition wall 12 can be made of an ultraviolet curable resin, a thermosetting resin, a room temperature curable resin, or the like, and is preferably formed to a thickness of 5 to 100 μm as described above. If the thickness is 5 μm or less, the amount of ink to be filled is small and sufficient display characteristics, in particular, contrast cannot be obtained. On the other hand, if the thickness is 100 μm or more, the panel is too thick and the drive voltage increases excessively. From the viewpoint that good display characteristics can be obtained at a low driving voltage, a thickness in the range of 10 to 50 μm is preferable.

  The pattern shape of the partition wall 12 is basically arbitrary such as a circle, a lattice, or a polygon. The aperture ratio is preferably 70% or more, and particularly preferably 90% or more. The higher the aperture ratio, the wider the displayable area, so that high contrast can be obtained.

  As a method for forming the partition wall 12, a mold transfer method such as embossing as well as a photolithography method may be employed. Further, a method of manufacturing a mesh processed structure as a partition and sticking it to the lower substrate 11 may be employed.

  The heat sealant 22 is preferably a material using a thermoplastic material, has a property of being softened by heating and solidifying upon cooling, and a material whose plasticity is reversibly maintained when cooling and heating are repeated. It is. When a heat seal agent made of a thermoplastic material is used as an adhesive, the heat seal agent solidified on the transfer film substrate is softened by heating it to a temperature exceeding its softening temperature, and the upper surface of the partition wall The heat sealant can be reliably thermally transferred only. Further, since the heat sealant after the thermal transfer is cooled to room temperature and solidified again, tackiness (stickiness) is eliminated, and handling convenience is extremely good. Further, since there is no tack (stickiness), the display medium filled in the cell does not adhere to the heat sealant. Then, the heat sealing agent on the upper surface of the partition wall is heated again to a temperature exceeding the softening temperature to be softened, and thus has a tack (stickiness), so that the other substrate is securely bonded. Since the heat sealant after bonding the other substrate does not have tack (stickiness) again at room temperature, the display medium is not bonded to the heat sealant, and there is no possibility of deterioration in display quality. Specifically, thermoplastic base polymers such as ethylene-vinyl acetate copolymer, polyester, polyamide, polyolefin, polyurethane, natural rubber, styrene-butadiene block copolymer, styrene-isoprene block copolymer, styrene-ethylene. A resin mainly composed of a thermoplastic elastomer such as a butylene-styrene block copolymer or a styrene-ethylene-propylene-styrene copolymer, and a tackifier resin or a plasticizer is mainly used.

  The softening temperature of the heat sealing agent 22 may be the glass transition temperature (Tg) or the melting temperature (Tm) of the heat sealing agent 22 depending on the type of the heat sealing agent 22, and is preferably 150 ° C. or lower, more preferably 120 ° C. or lower. 80 ° C. or less is particularly preferable. In particular, if the softening temperature of the heat sealant 22 is higher than the glass transition temperature of the base films 11 and 16, the base films 11 and 16 may shrink and wrinkles may occur, which is not preferable. Furthermore, when the softening temperature of the heat sealant 22 is high, the adhesiveness between the ribs and the substrate is lowered due to the undulation caused by the shrinkage of the substrate films 11 and 16, and the ribs are peeled off from the substrate when thermally peeling. . Further, the thermal decomposition temperature of the ink 13 (here, the thermal decomposition means that the chemical properties (modes) of the ink 13 change due to volatilization of the solvent, additives, particles, etc. contained in the ink 13 by heating. If the temperature at which the heat sealant 22 softens is higher than that of the heat sealant 22, the display performance may be deteriorated due to thermal decomposition of the ink 13.

  As described above, the heat sealing agent 22 is preferably formed to a thickness of 1 to 100 μm. If it is 1 μm or less, sufficient adhesion performance cannot be obtained. On the other hand, when the thickness is 100 μm or more, the thickness of the panel is too thick, and the drive voltage increases too much. From the viewpoint of good adhesion and good display characteristics at a low driving voltage, a thickness in the range of 1 to 50 μm is preferable, and a thickness in the range of 1 to 10 μm is particularly preferable.

  In order to increase the adhesion between the partition wall 12 and the heat sealant 22, the partition wall 12 may be subjected to a surface treatment by ultraviolet irradiation, plasma treatment, or the like, or a primer may be formed. Alternatively, a silane coupling agent may be added to the heat sealing agent 22.

  As described above, the display medium is appropriately selected according to the display method of the electronic paper.

  The electrophoresis method uses an electrophoresis phenomenon in which charged particles dispersed in a solvent move between electrodes by an electric field. Examples of the electrophoresis method include a microcapsule method and a microcup method.

  In the microcapsule method, charged white particles and black particles and a transparent dispersion medium in which these particles are dispersed are encapsulated in a microcapsule made of a transparent resin, and an electric field is applied to the white particles and the black particles. The black and white display or gradation is expressed by moving up and down.

  In the microcup method, a dispersion medium colored with a dye and charged white particles are arranged in a cell partitioned by cup-shaped depressions (microcups), and the white particles are moved up and down by applying an electric field. Thus, white or the color of the dispersion medium is displayed.

  Since the configuration, material, and formation method of such an electrophoretic display medium can be the same as those described in, for example, Japanese Patent Laid-Open No. 2000-56341, description thereof is omitted here. To do.

  In the electropowder fluid method, white and black electropowder fluids that have intermediate characteristics between particles and liquids, have high fluidity comparable to that of floating states, and react sensitively to electricity are placed in the air. By applying an electric field, black and white display or gradation is expressed by moving the white and black electropowder fluid up and down. The configuration, material, and formation method of such an electronic granular material type display medium can be the same as those described in, for example, Japanese Patent Application Laid-Open No. 2003-322883, and therefore described here. Is omitted.

  The twisting ball system is a system in which a spherical body or a cylindrical body that are painted in two colors are rotated by an electric field and displayed. The configuration, material, and formation method of such a twisting ball type display medium can be the same as those described in, for example, Japanese Patent Application Laid-Open No. 2006-47614, and the description is omitted here. To do.

  The electrowetting method employs a structure in which a reflective film, a transparent electrode, and a fluororesin layer are laminated on a substrate, and colored oil and water are sealed thereon. Normally, the fluororesin layer is hydrophobic and covered with oil, but when a voltage is applied to the electrode, the fluororesin layer changes to hydrophilic, and water pushes the oil to the end of the electrode, causing the color of the reflective film By appearing, two-color display is realized. The configuration, material, and formation method of such an electrowetting type display medium can be the same as those described in, for example, JP 2005-517993 A, and the description here Omitted.

  As the upper substrate 16, a transparent film made of PE, PET, PES, PEN or the like and a transparent electrode made of ITO, ZnO or the like can be typically used. The transparent electrode can be formed by a coating method, a vapor deposition method, or the like.

  The thickness of the upper substrate 16 is preferably 10 μm to 1 mm, similarly to the thickness of the lower substrate 11. If it is thinner than 10 μm, the strength as a panel cannot be obtained and the risk of breakage increases. On the other hand, if it is thicker than 1 mm, the panel weight becomes too heavy and the handling becomes inconvenient and the cost also increases. Because. A suitable thickness range that is difficult to break and easy to handle is about 50 μm to 300 μm.

  Additional functional layers can be added to the upper substrate 16. For example, a barrier film can be attached to the surface of the upper substrate 16. Even if a transparent film in which a barrier layer of a transparent inorganic film is previously formed by vapor deposition or the like is employed as the upper substrate 16, the same function can be exhibited. Alternatively, an ultraviolet cut film can be attached to the surface of the upper substrate 16. Even if the surface of the upper substrate 16 is subjected to another ultraviolet ray cutting process, the same function can be exhibited. As other surface coat layers, an AG layer (antiglare layer), an HC layer (scratch prevention layer), an AR layer (antireflection layer) and the like can be added.

  The upper substrate 16 can be applied in either a roll shape or a sheet shape.

  The peripheral sealant can be constituted by a thermosetting resin, a room temperature curable resin, a heat seal resin, or the like in addition to the ultraviolet curable resin. They are applied to the periphery of the upper and lower electrode substrates 11, 16 by a dispenser, by various printing methods, or by thermocompression bonding.

11 Lower substrate (backplane base material)
12 Partition 13 Ink (display medium)
16 Upper substrate (front plane base material)
20 Transfer film 21 Transfer film substrate 22 Heat seal agent (adhesive layer)
31 Dispenser 32 Central Squeegee (Squeegee 1)
33a, 33b Both-end squeegee (squeegee 2)
34 Roll wiper 41 Dispenser 51 Cutting device 61 Heating roll 71 Upper metal plate 72 Lower metal plate 73 Balloon fixing metal plate 75 Balloon 80 Vacuum chamber 91 Laminator 92 Hot plate 93 Metal piece

Claims (6)

A method of manufacturing an electronic paper, wherein a display medium is sealed between two opposing substrates, at least one of which is transparent, and the display medium displays predetermined information,
A partition formation step of forming a partition in a predetermined pattern on one substrate;
An adhesive layer forming step of forming an adhesive layer on the partition;
A display medium disposing step of disposing the display medium in an area partitioned by the partition after the adhesive layer is formed;
A temporary sealing step of temporarily sealing the display medium by placing the other substrate in parallel on the adhesive layer on the partition;
A second substrate bonding step of sealing the display medium that has been temporarily sealed by bonding the second substrate on the adhesive layer on the partition;
With
The adhesive layer forming step is performed by thermally transferring the heat sealant using a transfer film on which the heat sealant is formed,
The other substrate bonding step includes a heating step of obtaining an adhesive force by softening the heat sealant transferred as an adhesive layer. The method for producing electronic paper according to claim 1, wherein the temporary sealing step is performed in a reduced-pressure atmosphere. The method for producing electronic paper according to claim 1, wherein the other substrate bonding step further includes a thermocompression bonding step of thermocompression bonding the peripheral portions of both substrates. An apparatus for manufacturing electronic paper, in which a display medium is sealed between two opposing substrates, at least one of which is transparent, and the display medium displays predetermined information,
A barrier rib forming apparatus for forming barrier ribs in a predetermined pattern on one substrate;
An adhesive layer forming apparatus for forming an adhesive layer on the partition;
A display medium placement device that places the display medium in a region partitioned by the partition after the adhesive layer is formed;
A temporary sealing device for temporarily sealing the display medium by placing the other substrate in parallel on the adhesive layer on the partition;
The other substrate bonding apparatus for sealing the display medium that has been temporarily sealed by bonding the other substrate on the adhesive layer on the partition;
With
The adhesive layer forming apparatus has a configuration in which the heat sealant is thermally transferred using a transfer film on which the heat sealant is formed,
The other substrate bonding apparatus has a configuration for softening the heat sealant transferred as an adhesive layer. The electronic paper manufacturing apparatus according to claim 4, wherein the temporary sealing device operates in a reduced pressure atmosphere. 6. The electronic paper manufacturing apparatus according to claim 4, wherein the other substrate bonding apparatus further includes a thermocompression bonding apparatus that thermocompresses the peripheral portions of both substrates.

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