JP2011216198A - Letterpress printing device, and manufacturing method of organic el panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing device in which a polymer organic EL panel high in film thickness uniformity can be produced inexpensively.SOLUTION: A letterpress printing device is constituted of a rotary form cylinder 102, a letterpress 101, a moving platen 107, a substrate 106 to be printed, and an inking unit 103. A desired pattern is formed by transcribing a light-emitting ink transcribed on a letterpress 101 surface from the inking unit 103 on the substrate 106 to be printed. In order to stably form the ink on the letterpress 101, the ink is preliminarily transcribed on a rotary roll 201 of a preliminary transcription device 200 immediately before printing. By using an organic EL panel substrate as this substrate 106 to be printed, and by using the ink to form an organic light-emitting layer on a substrate as the light-emitting ink for transcription on the letterpress 101, the ink for organic light-emitting layer formation is transcribed on the substrate after preliminary transcription.

Description

  The present invention relates to a printing apparatus for producing a polymer organic EL display panel and a method for producing a polymer organic EL display panel.

  An organic electroluminescence (hereinafter EL) element is a light-emitting element having a structure in which an organic light-emitting layer made of an organic light-emitting material is formed between an anode and a cathode that face each other. In order to obtain efficient light emission, the film thickness of the organic light emitting layer is an important factor for obtaining efficient light emission. Therefore, it is necessary to control the film thickness at about several tens of nm. Further, in order to make this a display, it is necessary to pattern it with high definition.

  The organic light emitting material used for the organic light emitting layer is classified into a low molecular material and a polymer material, and the method of forming the organic light emitting layer differs depending on the type of the organic light emitting material.

  In general, a low molecular weight material forms a thin film on a substrate by resistance heating vapor deposition (vacuum vapor deposition) or the like. When full-coloring the organic EL element, a method is employed in which a luminescent material having a different emission color is deposited on each pixel using a mask having a pattern corresponding to the pixel shape of each color. Although this method is an excellent method for uniformly forming a thin film shape, there is a problem in that the mask pattern accuracy is difficult to be obtained when the deposited substrate becomes large.

  On the other hand, in the case of polymer materials, a method in which an organic light emitting material is dissolved or dispersed in a solvent to form an ink and a thin film is formed by a wet coating method is mainly used. As the wet coating method, there are a spin coating method, a bar coating method, a protruding coating method, a dip coating method, etc., but it is difficult to use these methods for high-definition patterning and color separation for full color. . Therefore, it is considered that pattern printing by an ink jet method or a printing method is effective as a means for patterning the organic light emitting material layer for full color.

  As one of high-definition patterning methods, for example, there is an ink jet method in which an organic light emitting material dissolved in a solvent is jetted onto a substrate from an ink jet nozzle and dried on the substrate (Patent Document 1). In this method, since the ink droplets ejected from the nozzle are spherical, the ink spreads in a circular shape when landing on the substrate, and the formed pattern shape is not linear or has landed. There is a problem that the linearity of the pattern cannot be obtained due to poor accuracy.

  On the other hand, letterpress printing, reversal printing, screen printing, and the like have been proposed as pattern forming methods by printing. In organic EL elements and displays, a glass substrate is often used as a base material, and a method using a hard printing plate made of metal such as a gravure printing method is not suitable. Therefore, a printing method using a rubber printing plate having elasticity, an offset printing method using a rubber printing blanket, a relief printing plate using a photosensitive resin plate mainly composed of elastic rubber or other resin. The printing method is considered an appropriate printing method. Actually, as a trial of these printing methods, a pattern printing method by offset printing (Patent Document 2), a pattern printing method by letterpress printing (Patent Document 3), and the like have been proposed. In particular, the method using relief printing is excellent in pattern formation accuracy and film thickness uniformity, and is most suitable as a method for producing an organic EL element by printing.

  An example of the manufacturing process of the organic EL element by the relief printing method is shown below. First, ink is applied to the surface of an anilox roll having fine holes. Next, the ink applied per unit area of the anilox roll is made uniform by scraping off excess ink on the anilox roll surface with a doctor. Then, the ink on an anilox roll is transcribe | transferred on the printing plate patterned according to the pixel shape of the organic EL element. Finally, the light-emitting layer of the organic EL element is formed by transferring the ink thin film on the printing plate onto the substrate.

  FIG. 1 illustrates an example of a printing process for forming a light emitting portion by a relief printing method. Ink is stored in the ink pan 101 shown in FIG. After the ink is supplied to the anilox roll 103 in the ink pan 101, excess ink is scraped off by the doctor 102, and the ink is stored only inside the hole. The ink inside the hole is transferred onto the image forming portion of the resin relief plate 104 wound around the plate cylinder 105 that rotates relative to the anilox roll 103, and forms a thin film of ink there. Further, the thin film formed on the image forming unit is transferred onto the printing substrate 106 that moves relative to the plate cylinder 105.

  When an organic EL element is produced by a relief printing method, the transfer pattern on the printing plate is arranged with a plurality of transfer patterns for forming the same color light emitting part among a plurality of light emitting parts constituting each pixel of the organic EL element. The organic light emitting layer is obtained by sequentially printing the light emitting portions that emit light of the respective emission colors.

  As described above, in the relief printing method, an ink thin film is formed on the resin relief printing plate by transferring ink from the anilox roll to the resin relief printing, but the ink thin film on the resin relief printing plate in the initial printing process has a constant film thickness. In addition, the ink thin film formed on the substrate to be printed at the initial stage of the printing process has a problem that the film thickness uniformity is low and a transfer defect occurs because the state is unstable with respect to the transfer to the substrate to be printed. .

  Therefore, in the relief printing method, the transfer stability from the resin relief to the substrate to be printed is improved by performing preliminary transfer a plurality of times before printing. However, since the preliminary transfer for producing the organic EL element in the relief printing method is performed on the glass substrate, the ink and the glass substrate used for the preliminary transfer lead to an increase in cost, and the higher-quality organic EL element In the production, the base material on which the preliminary transfer is performed needs to be processed, and there is a problem that the number of steps and the cost increase in the production of the organic EL element using the relief printing method that requires the preliminary transfer.

Japanese Patent Laid-Open No. 10-12377 JP 2001-93668 A JP 2001-155858 A

  The present invention has been made to solve the above-mentioned problems, and by carrying out preliminary transfer of relief printing ink without using a substrate to be printed, a uniform pattern free from transfer defects can be inexpensively formed on the substrate to be printed. An object of the present invention is to provide a relief printing apparatus that can be transferred to the surface and a method for producing an organic EL panel using the relief printing apparatus.

  As means for solving the above-mentioned problems, the invention according to claim 1 is a relief printing apparatus using a relief printing plate as a printing plate, comprising a rotary plate cylinder on which the relief plate is installed, and a substrate to be printed. A substrate surface plate to be placed, an ink supply device that supplies ink to the relief plate, and a preliminary transfer device that contacts the relief plate and transfers ink from the relief plate are provided.

  According to a second aspect of the present invention, in the relief printing apparatus according to the first aspect, the preliminary transfer device includes a liquid storage tank for storing a cleaning liquid, an upper surface exposed from the cleaning liquid, and a lower surface immersed in the cleaning liquid. A rotating roll, a cleaning liquid doctor arranged in the cleaning liquid so as to rub the surface of the rotating roll, a cleaning liquid doctor arranged outside the cleaning liquid so as to further rub the surface of the rotating roll rubbed by the cleaning liquid doctor, A drying nozzle that blows nitrogen or clean air on the surface of the rotating roll rubbed with a doctor outside the cleaning liquid, and the upper surface of the rotating roll is brought into contact with the relief printing plate to transfer the ink supplied on the relief printing plate. The relief printing apparatus is characterized.

  The invention described in claim 3 is the relief printing apparatus according to claim 2, comprising a cleaning liquid supply nozzle for supplying a cleaning liquid into the liquid storage tank, and an overflow pipe for overflowing the cleaning liquid from the liquid storage tank. This is a relief printing apparatus characterized by the above.

  The invention according to claim 4 is the relief printing apparatus according to claim 2 or 3, wherein when the ink is transferred by bringing the relief plate into contact with the upper surface of the rotary roll, the cleaning liquid supply nozzle is The relief printing apparatus is characterized in that the cleaning liquid supplied into the liquid storage tank is discharged onto the surface of the rotating roll onto which ink has been transferred.

  The invention described in claim 5 is a method of manufacturing an organic EL panel in which an organic light emitting layer is formed on a substrate by printing, and the relief printing apparatus according to claim 1, 2, 3, or 4 is used to cover the substrate. As the printing substrate, the ink for forming the organic light emitting layer is transferred to the substrate to be printed, and after the preliminary transfer of the ink for forming the organic light emitting layer to the preliminary transfer device by the letterpress printing device, the letterpress The organic EL panel is formed by forming the organic light emitting layer on the substrate by transferring the ink for forming the organic light emitting layer to the substrate to be printed by a printing apparatus.

  The invention according to claim 6 is the method for manufacturing an organic EL panel according to claim 5, wherein the organic light emitting layer forming ink is preliminarily transferred from the relief printing plate of the relief printing apparatus to the preliminary transfer device at a maximum of 10 times. The organic EL panel manufacturing method is characterized in that the organic light emitting layer forming ink is transferred to the substrate to be printed after being carried out once.

  In the first aspect of the present invention, while the preliminary transfer device is in contact with the relief printing plate and the preliminary transfer of the ink to the preliminary transfer device is being performed, the transfer of the ink to the printed substrate is not performed and the printed substrate is consumed. Not.

  Therefore, the ink transfer can be stabilized by the preliminary transfer without consuming the substrate to be printed at the initial stage of printing where the ink transfer is unstable, and the ink can be stably transferred to the substrate to be printed.

  In the second aspect of the present invention, the ink transferred to the surface of the rotating roll is scraped off in the cleaning liquid by the doctor in the cleaning liquid, so that the scraped coating liquid is not dried and contaminates the rotating roll. Further, the surface of the rotary roll from which ink has been scraped off by the doctor in the cleaning liquid is surely dried because the cleaning liquid adhering to the surface is scraped off by the doctor outside the cleaning liquid and nitrogen or clean air is blown. This makes it possible to keep the surface of the rotating roll clean and dry.

  In addition, by preliminarily transferring to a clean and dry rotating roll, the ink formed on the resin relief printing plate is in an optimum state for transfer. This makes it possible to produce an organic EL element with high film thickness uniformity.

  Furthermore, the substrate used for the preliminary transfer in the past is not necessary, and the process can be reduced.

  In the third aspect of the present invention, the cleaning liquid is supplied to the liquid storage tank and the cleaning liquid overflows from the liquid storage tank while the ink thin film formed on the relief printing plate is preliminarily transferred onto the rotating roll. The cleaning liquid in the liquid tank is appropriately replaced so that it does not become so dirty that the cleaning effect is lost.

  In the invention according to claim 4, since the cleaning liquid supplied to the liquid storage tank is applied to the surface of the rotating roll onto which the ink has been transferred, a higher cleaning effect can be obtained.

  In the invention according to claim 5, since the organic light emitting layer is formed on the substrate of the organic EL panel using the relief printing apparatus according to claim 1, 2, 3 or 4, the organic light emitting layer formation using the preliminary transfer device In the preliminary transfer of the printing ink, an expensive substrate is not consumed by the preliminary transfer. Therefore, an organic light emitting layer with high film thickness uniformity can be formed on the substrate at a low cost.

The invention according to claim 6 is a method of manufacturing an organic EL panel, wherein the preliminary transfer from the inked relief printing plate to the preliminary transfer device is performed 1 to 10 times, and then transferred to the substrate to be printed. By performing the preliminary transfer, there is an effect of improving the transfer stability from the relief printing plate to the substrate to be printed, and this makes it possible to produce an organic EL panel with high film thickness uniformity.
In addition, when a rotating roll immersed in a cleaning agent is used in a preliminary transfer apparatus, the rotating roll after preliminary transfer can be used repeatedly after cleaning, and therefore, an organic film having high film thickness uniformity without using a substrate for preliminary transfer. An EL panel can be manufactured. This makes it possible to manufacture high-quality products at low cost.

It is sectional drawing of an example of the relief printing apparatus used for the manufacturing method of the organic electroluminescent panel of this invention. It is sectional drawing of the preliminary transfer apparatus and the relief printing apparatus used for the manufacturing method of the organic electroluminescent panel of this invention. It is sectional drawing of one Embodiment of the pre-transfer apparatus used for the manufacturing method of the organic electroluminescent panel of this invention. It is sectional drawing of the organic electroluminescent panel manufactured with the manufacturing method of the organic electroluminescent panel of this invention.

  As shown in FIG. 1, a printing apparatus according to an embodiment of the present invention is used for forming a rotary plate cylinder 102 (corresponding to a plate cylinder in claims) and a light emitting pattern formed around the plate cylinder 102. The relief plate 101, the moving surface plate 107 that conveys the printing substrate 106, the anilox roll 104 that supplies ink onto the relief plate 101, the inking unit 103 that supplies ink to the anilox roll 104, and the surplus on the anilox roll 104 A doctor 105 for removing ink is included. Next, each configuration of the present invention will be described in detail.

The plate cylinder 102 is disposed on a moving surface plate 107 and is rotatably supported at a fixed position. The relief plate 101 is mounted on the peripheral surface of the plate cylinder 102. The anilox roll 104 is installed in parallel with the rotation axis of the plate cylinder 102 and in contact with the plate surface on the surface of the relief plate 101. The inking unit 103 is installed so that the anilox roll 104 and the supply port of the inking unit 103 are in contact with each other according to the type of the inking unit 103. The substrate to be printed 106 is placed on a moving surface plate 107. The moving surface plate 107 is installed so as to move horizontally in a direction perpendicular to the rotation axis of the plate cylinder 102.
In addition, the printing apparatus according to the embodiment of the present invention includes a preliminary transfer device 200 that moves with the moving surface plate 107 as shown in FIG. The support base 300 is positioned horizontally below the plate cylinder 102, and the movable surface plate 107 and the preliminary transfer device 200 are perpendicular to the rotation axis of the plate cylinder 102 on the support base 300 via a guide. It is installed so that it can move horizontally.

  In the printing apparatus having the above-described configuration, the ink supplied from the inking unit 103 is uniformly held on the surface of the anilox roll 104 as the anilox roll 104 rotates, and then is applied to the plate surface of the relief plate 101 attached to the plate cylinder 102. Metastasize. The printing substrate 106 is fixed on a slidable moving surface plate 107 and moved to the printing start position while adjusting the position by a position adjusting mechanism between the pattern of the relief plate 101 and the pattern forming position of the printing substrate 106. From the printing start position, the substrate to be printed 106 comes into contact with the convex portion of the relief plate 101 and moves in synchronization with the rotation of the plate cylinder 102, and the ink is transferred from the relief plate 101 to a predetermined position on the substrate 106 to be printed. After the ink pattern is formed on the substrate 106 to be printed, a drying process using an oven or the like can be provided as necessary.

  The anilox roll 104 according to the embodiment of the present invention supplies ink to the relief plate 101 while rotating at the same peripheral speed as the peripheral speed of the plate cylinder 102. The anilox roll 104 can be made of chrome or ceramics, and it is desirable that the outer surface of the anilox roll 104 be formed with patterns such as fine holes, recesses, and cells for holding ink. .

  The inking unit 103 according to the embodiment of the present invention includes an ink reservoir that immerses the lower peripheral surface portion of the anilox roll 104, a coater such as a dripping type inking unit, a fountain roll, a die coater, a cap coater, and the like. Combinations and the like can be used. Further, it is desirable that an ink replenishing device (not shown) for replenishing ink and an ink tank (not shown) for storing ink are connected to the inking unit 103.

  In order to supply ink uniformly on the anilox roll 104, it is desirable to provide a doctor 105. The doctor 105 has a blade shape or a roll shape, and any of them may be used. When the inking unit 103 is an ink reservoir, the doctor 105 is positioned between the ink reservoir and the contact point between the anilox roll 104 and the relief plate 101 in the rotation direction of the anilox roll 104, and scraped ink. Is preferably allowed to fall into the ink reservoir.

  The material of the base material used for the relief plate 101 according to the embodiment of the present invention is only required to have mechanical strength against printing, such as polyethylene, polystyrene, polybutadiene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyamide, Known synthetic resins such as polyethersulfone, polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, and polyvinyl alcohol, known metals such as iron, copper, and aluminum, or laminates thereof can be used.

  As the base material constituting the relief plate 101, one that maintains high dimensional stability is desirable, and a metal is suitably used as the material used as the base material. Examples of the metal used as the base material include iron, aluminum, copper, zinc, nickel, titanium, chromium, gold, silver, alloys thereof, and laminates. In particular, iron is the main component in terms of workability and economy. The steel base material and aluminum base material which can be used can be used suitably.

  When the plate surface of the relief plate 101 is formed of a resin, as a method for forming the protrusions on the plate surface, a photolithography method using a positive photosensitive resin, a photolithography method using a negative photosensitive resin, injection molding, a relief plate Various pattern molding methods such as printing method, intaglio printing method, lithographic printing method, stencil printing method, laser ablation method, etc. can be used. From the viewpoint of high definition of pattern, photolithography method using photosensitive resin In addition, a photolithography method using a negative photosensitive resin capable of forming a relief with the required accuracy is most desirable.

  When the photolithographic method using a photosensitive resin is applied as the convex pattern forming method, the convex of the relief plate 101 is formed from a plate-shaped photosensitive resin laminate in which a base material layer, a reflection suppressing layer, and a photosensitive resin layer are sequentially laminated. It is most desirable to form the part. As a method for molding the photosensitive resin layer, a known method such as an injection molding method, a protruding molding method, a laminating method, a bar coating method, a slit coating method, or a comma coating method can be used.

  When the plate surface of the relief plate 101 is formed of a resin, the resin to be used is only required to have solvent resistance to ink, such as nitrile rubber, silicone rubber, isoprene rubber, styrene butadiene rubber, butadiene rubber, chloroprene rubber, butyl rubber, acrylonitrile rubber, ethylene. In addition to rubbers such as propylene rubber and urethane rubber, polyethylene, polystyrene, polybutadiene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyamide, polyether sulfone, polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polyvinyl alcohol, etc. Synthetic resins, their copolymers, cellulose derivatives, etc., fluoroelastomers, polytetrafluoroethylene, polyvinylidene fluoride, poly (vinylidene fluoride) and their It is possible to select one or more of a fluorine-based resin such as polymer.

  The relief plate 101 according to the embodiment of the present invention is used by winding the relief plate 101 having the projection pattern formed on the substrate as described above around the plate cylinder 102. A convex pattern may be formed on the plate cylinder 102.

  The ink to be used is adjusted to a suitable viscosity in consideration of the coating from the ink supply device 103 to the anilox roll 104 and the transfer from the anilox roll 104 to the relief plate 101, and the viscosity of the ink should be 2 to 120 mPa · s. desirable. In the relief printing method used in the present embodiment, the ink is first transferred from the anilox roll 104 onto the relief plate 101, but after the ink is transferred from the anilox roll 104 onto the relief plate 101 at a viscosity of 120 mPa · s or more, Ink is not leveled sufficiently on the relief plate 101, causing unevenness. In addition, when the pressure is 2 mPa · s or less, the mottling unevenness is likely to occur in the pixel, causing the unevenness.

  The amount of ink transferred from the anilox roll 104 onto the relief plate 101 is determined by the thickness of the film to be formed on the printing substrate 106. By adjusting the ink density and the cell volume of the anilox roll 104, the amount of ink is transferred onto the relief plate 101. It is desirable to make the amount of ink transferred constant.

  In the ink transfer from the anilox roll 104 to the relief plate 101, if the preliminary transfer device 200 does not exist, the ink thin film supplied onto the relief plate 101 at the initial stage of the printing process has a non-uniform film thickness, and the substrate 106 to be printed Therefore, when the transfer to the printing substrate 106 is performed at the initial stage of the printing process, the film thickness uniformity of the ink thin film formed on the printing substrate 106 is low, and the transfer defect is caused. May occur. Therefore, if the preliminary transfer to the printing substrate 106 is performed, the above-mentioned transfer problem at the initial stage of the printing process can be solved. However, in this case, an expensive printing substrate used for the preliminary transfer is used. 106 leads to an increase in cost. Therefore, in the method of manufacturing an organic EL element using the relief printing method of the present invention, the preliminary transfer by the preliminary transfer device 200 is performed before the transfer to the print substrate 106, so that the print substrate 106 is not used. Preliminary transfer can be performed, and problems such as transfer defects at the initial stage of the printing process can be solved.

  An example of the preliminary transfer apparatus 200 according to the embodiment of the present invention is shown in FIG. The preliminary transfer device 200 includes a liquid storage tank 208 for storing the cleaning liquid 213, a rotating roll 201 whose upper surface is exposed from the cleaning liquid 213 and whose lower surface is immersed in the cleaning liquid 213, and the cleaning liquid 213 so as to rub the surface of the rotating roll 201. The cleaning liquid doctor 203 disposed in the cleaning liquid, the cleaning liquid external doctor 205 disposed outside the cleaning liquid 213 so as to further rub the outer periphery of the rotary roll 201 rubbed by the cleaning liquid doctor 203, and the rotation rubbed by the cleaning liquid external doctor 205 A drying nozzle 207 that blows nitrogen or clean air on the surface of the roll 201 is provided, and ink is transferred from the relief plate 101 on which the ink thin film is formed to the upper surface of the rotating roll 201.

  The preliminary transfer device 200 includes a cleaning liquid supply nozzle 202 that supplies the cleaning liquid 213 into the liquid storage tank 208 and an overflow pipe 209 that causes the cleaning liquid 213 to overflow from the liquid storage tank 208. It is desirable that the cleaning liquid supply nozzle 202 is disposed toward the surface of the rotary roll 201 to which the ink has been transferred.

  Further, the preliminary transfer device 200 includes a drain pipe 215 having a drain valve 211 at the bottom of the liquid storage tank 208. When the drain valve 211 is opened, the drain pipe 215 discharges the cleaning liquid 213 from the bottom of the liquid storage tank 208, and when the drain valve 211 is closed, the cleaning liquid 213 is stored in the liquid storage tank 208.

  Next, a preliminary transfer process from the relief plate 101 by the preliminary transfer device 200 will be described.

  First, the cleaning liquid 213 is stored in the liquid storage tank 208. Next, the ink is transferred from the relief plate 101 on which the ink thin film is formed on the rotating roll 201 that is rotating.

  At this time, it is desirable to supply the cleaning liquid 213 from the cleaning liquid supply nozzle 202 again. Accordingly, when the cleaning liquid 213 is supplied while being discharged to the rotary roll 201, a higher cleaning effect can be expected.

The preliminary transfer device 200 moves with the moving surface plate 107 on the support base 300 to a position where the relief plate 101 on the plate cylinder 102 and the rotary roll of the preliminary transfer device are in contact with each other. Then, before the transfer process to the printing substrate 106 on the moving surface plate 107, the rotation of the anilox roll 104, the rotation of the plate cylinder 102, and the rotation of the rotary roll 201 were synchronized and transferred from the anilox roll 104. The ink on the relief plate 101 is transferred onto the rotary roll 201 of the preliminary transfer device 200.
In the preliminary transfer process from the relief plate 101 to the rotating roll 201, it is desirable to adjust the number of times of preliminary transfer in accordance with necessary printing characteristic values such as the number of printed sheets, the film thickness, the plate line width, and the ink viscosity. In order to improve, it is desirable to carry out at least once or more desirably. Here, one preliminary transfer step means that the entire end surface of the relief plate 101 comes into contact with the rotary roll 201.

  The rotating roll 201 to which the ink has been transferred from the relief plate 101 is immersed in the cleaning liquid 213 as the rotating roll 201 rotates, and the ink in the rotating roll 201 is scraped off by the cleaning liquid doctor 203 in the liquid storage tank 208. Since the ink is in the cleaning liquid 213, the ink scraped off does not dry and contaminate the rotary roll 201 or the doctor 203 in the cleaning liquid.

  Next, the cleaning liquid 213 attached to the rotary roll 201 is scraped off by the cleaning liquid external doctor 205 outside the cleaning liquid 213. Thereafter, the surface of the rotating roll 201 is dried by blowing nitrogen or clean air from the drying nozzle 207 toward the surface of the rotating roll 201.

It is desirable that the cleaning liquid 213 is always supplied from the cleaning liquid supply nozzle 202 during the preliminary transfer of ink. Since the surplus is overflowed by the overflow pipe 209, the cleaning liquid 213 in the liquid storage tank 208 is appropriately replaced so that it does not become so dirty that the cleaning effect is lost.
The cleaning liquid supply nozzle 202 and the drying nozzle 207 may have a plurality of cylindrical tubes arranged in parallel, or may have a nozzle shape having a slit having the same length as the width of the rotary roll 201.

  Further, the drain valve 211 is opened as appropriate, the cleaning liquid 213 in the liquid storage tank 208 is discharged from the drain pipe 215, and the cleaning liquid 213 is supplied to the liquid storage tank 208 by the cleaning liquid supply nozzle 202, thereby cleaning the liquid 213 in the liquid storage tank 208. It is desirable that can be replaced with a new solution.

  FIG. 4 shows a schematic cross-sectional view of an organic EL panel manufactured by the printing apparatus of FIG.

  The organic EL panel 400 includes a substrate 401, an anode layer 402, a hole injection layer 403, an organic light emitting layer 404, a cathode layer 405, and a partition wall 406 that partitions pixels.

  When the organic EL panel 400 is a bottom emission type organic EL panel, a translucent material such as a glass substrate or a plastic film or sheet can be used as the substrate 401. If a plastic film is used, an organic light emitting device can be manufactured by winding, and the device can be provided at low cost. As the plastic, for example, polyethylene terephthalate, polypropylene, cycloolefin polymer, polyamide, polyethersulfone, polymethyl methacrylate, polycarbonate and the like can be used. Moreover, you may laminate | stack other gas barrier films, such as a ceramic vapor deposition film, a polyvinylidene chloride, a polyvinyl chloride, and ethylene-vinyl acetate copolymer saponified material, on the side which does not form the anode layer 402 of the board | substrate 401. FIG. Note that in the case of a top emission type organic EL panel, the substrate 401 may not be a light-transmitting material.

  When the organic EL panel 400 is a bottom emission type organic EL panel, the material forming the anode layer 402 includes a transparent material such as a composite oxide of indium and tin (hereinafter referred to as ITO). In addition, a semi-transparent metal such as aluminum, gold, or silver, or an organic compound such as polyaniline may be used. Note that in the case of a top emission type organic EL panel, the anode layer 402 may not be a light-transmitting material.

  As a material for forming the hole injection layer 403, a conductive polymer material such as a polyaniline derivative, a polythiophene derivative, a polyvinylcarbazole derivative, or a mixture of poly (3,4-ethylenedioxythiophene) and polystyrenesulfonic acid may be used. good.

  The organic light emitting layer 404 is a layer that emits light when a voltage is applied, and is a layer formed by using the relief plate 101 according to the present invention by the apparatus shown in FIG. 2, and is a layer formed by drying the coating liquid described above. It is.

  As a material for forming the cathode layer 405, a material corresponding to the light emitting characteristics of the organic light emitting layer 404 may be used. For example, simple metals such as lithium, magnesium, calcium, ytterbium, and aluminum, oxides thereof, and gold, silver An alloy with a stable metal such as is used. Alternatively, a conductive oxide such as indium, zinc, or tin can be used.

In order to form the anode layer 402 and the hole injection layer 403 on the substrate 401, a known method may be used. After forming these, an organic light emitting layer 404 is formed thereon using the apparatus of FIG. Further, a cathode layer 405 is formed thereon. For the formation of the cathode layer 405, known means such as an ink jet method can be used in addition to the vacuum deposition method. The anode layer 402, the hole injection layer 403, the organic light emitting layer 404, the cathode layer 405, and the partition wall 406 are sealed with a sealing substrate 408 attached to the substrate 401 via an adhesive layer 407.
The organic EL panel 400 having the above configuration can be manufactured as follows using the printing apparatus shown in FIG. In other words, the substrate 401 is used as the printing substrate 106 and the ink for forming the organic light emitting layer 404 is transferred to the printing substrate 106 as the ink for forming the organic light emitting layer to the preliminary transfer device 200 by the printing device shown in FIG. After the transfer, the organic light emitting layer 404 can be formed on the substrate 401 by transferring the organic light emitting layer forming ink to the substrate to be printed 106. Here, the preliminary transfer of the organic light emitting layer forming ink is preferably performed 1 to 10 times, and if it is performed more than 10 times, the manufacturing cost of the organic EL panel increases due to consumption of the organic light emitting layer forming ink.

  Although the Example and comparative example which concern on the manufacturing method of the organic electroluminescent panel 400 of this invention are shown below, it is not restricted to this.

(Process for producing printed substrate 106)
A thin film transistor functioning as a switching element provided on a support, a planarizing layer formed thereabove, and a planarized layer formed as a planarized layer and connected to the thin film transistor through a contact hole is provided as a substrate 106 to be printed. An active matrix substrate having a pixel electrode is used. One side of the pixel size is 150 μm square, and the size of the RGB sub-pixel is 50 × 150 μm.

  A partition wall was formed in such a shape as to cover an end portion of the pixel electrode provided on the active matrix substrate and partition the pixel. The partition walls are formed by depositing a positive resist ZWD6216-6 manufactured by ZEON Corporation on the entire surface of the active matrix substrate with a spin coater so that the film thickness after drying is 1 μm, and then by photolithography. A partition wall having a line width of 20 μm was formed on the side.

  A poly- (3,4) -ethylenedioxythiophene / polystyrene sulfonic acid (PEDOT / PSS) 1.5 wt% aqueous solution with a film thickness of 100 nm is formed on the pixel electrode as a hole transport layer by spin coating. did. Further, the PEDOT / PSS thin film thus formed was dried at 100 ° C. under reduced pressure for 1 hour to produce a substrate to be printed 106.

(Process for producing organic light-emitting layer forming ink)
The following polymeric organic light-emitting inks consisting of three colors of red, green and blue (R, G, B) were dissolved in xylene and prepared. The red light emitting ink (R) is a xylene 1 wt% solution of a polyfluorene derivative (red light emitting material manufactured by Sumitomo Chemical Co., Ltd., trade name Red 1100). The green light emitting ink (G) is a 1 wt% xylene solution of a polyfluorene derivative (green light emitting material, trade name Green 1300, manufactured by Sumitomo Chemical Co., Ltd.). The blue light-emitting ink (B) is a 1 wt% xylene solution of a polyfluorene derivative (blue light-emitting material manufactured by Sumitomo Chemical Co., Ltd., trade name Blue 1100).

(Manufacturing process of letterpress 101)
Using 42 nickel material of 250 μm thickness as the base material of the relief plate 101 made of a photosensitive resin, an acrylic binder resin solution in which a black pigment is kneaded on the base material is applied to a dry film thickness of 10 μm and dried. An antireflection layer was formed.

  Mainly water-soluble polyamide, dipentaerythritol hexakisacrylate as radical polymerizable monomer, 2,2-dimethoxy-1,2-diphenylethane-1-one as photopolymerization initiator (manufactured by Ciba Specialty Chemicals) A photosensitive resin composition obtained by kneading the resin is melt-coated on the surface of the substrate so that the total thickness of the plate material is 310 μm, and the photosensitive resin layer is used, and the polyvinyl alcohol solution has a dry film thickness of 1 μm. A polyethylene terephthalate film (film thickness 125 μm: manufactured by Teijin DuPont Films Ltd.) was laminated. Thereby, the photosensitive resin relief printing was formed.

  By using a synthetic quartz base chrome mask as the original pattern of the relief plate 101 and exposing the photosensitive resin relief plate using this mask set in a proximity exposure apparatus, the relief plate 101 on which a desired pattern is formed is obtained. Produced.

(Printing process of organic light emitting layer forming ink)
The relief plate 101 was fixed to the plate cylinder 102 of the sheet-fed printing apparatus. Next, the polymer organic light-emitting ink was supplied to the inking unit tank 103, and the anilox roll 104 was rotated to ink the entire surface. The anilox roll 104 was a 600 line / inch anilox roll. Thereafter, excess ink on the anilox roll 104 was scraped off by a doctor 105 and inked into the convex pattern portion of the relief plate 101.

  Before the ink on the relief printing plate 101 inked as described above is transferred to the printing substrate 106, the ink is preliminarily transferred onto a rotating roll 201 that has been rotated. After the preliminary transfer, the convex pattern portion of the relief plate 101 was inked in the same manner as in the printing process of the organic light emitting layer forming ink. In this example, such preliminary transfer was performed five times.

  After carrying out the preliminary transfer as described above, the printing process of the ink for forming the organic light emitting layer is repeated again, and the inked relief plate 101 is pressed against the substrate to be printed 106, whereby the stripe pattern is formed on the substrate to be printed 106. Printed. By repeating this step for each of the red organic light emitting layer, the green organic light emitting layer, and the blue organic light emitting layer, an organic light emitting layer pattern was obtained. After printing for each color, drying was performed in an oven at 130 ° C. for 1 hour.

  The average film thickness in the panel of each color of the pattern formed as described above was about 70 nm, and both range 3σ indicating the width of the film thickness variation in the panel was about 8 nm.

  Further, an organic EL panel 400 was fabricated by forming a calcium film of 10 nm and a silver film of 300 nm by vacuum deposition on a polymer organic light emitting layer formed by printing, and then sealing with a glass cap.

  When the lighting display of the organic EL panel 400 was confirmed, good light emission was obtained on the entire panel surface.

<Comparative Example 1>
Preliminary transfer was carried out on a glass substrate instead of the rotating roll 201, and an organic EL panel was produced in the same manner as in the previous examples.

  Results equivalent to those in the examples were obtained for the average film thickness in the panel of each color of the formed pattern, range, and 3σ. Moreover, when the lighting display was confirmed about the organic electroluminescent panel produced in this way, favorable light emission was obtained in the whole panel surface. However, since the preliminary transfer was performed on the glass substrate, the cost of the organic EL panel was higher than that of Example 1.

<Comparative example 2>
An organic EL element was produced in the same manner as in the previous examples without performing preliminary transfer.

  It was confirmed that the average film thickness in the panel, the range, and 3σ of each color of the formed pattern were deteriorated as compared with the examples. Moreover, when the lighting display confirmation was performed about the organic electroluminescent panel produced in this way, the light emission failure and light emission nonuniformity resulting from the transfer defect were confirmed.

  Table 1 shows the evaluation results of the printing characteristics of the example and comparative examples 1 and 2.

101 ... letterpress plate 102 ... plate cylinder 103 ... inking unit 104 ... anilox roll 105 ... doctor 106 ... printed substrate 107 ... moving surface plate 200 ... preliminary transfer device 201 ... Rotating roll 202 ... Cleaning liquid supply nozzle 203 ... Doctor in cleaning liquid 204 ... Doctor holder 205 ... Doctor outside cleaning liquid 206 ... Doctor holder 207 ... Drying nozzle 208 ... Storage Liquid tank 209 ... Overflow pipe 210 ... Cleaning liquid supply valve 211 ... Drain valve 212 ... Nitrogen or clean air supply valve 213 ... Cleaning liquid 214 ... Transferred ink 215 ... Drain pipe 300 ... Support base 400 ... Organic EL panel 401 ... Substrate 402 ... Anode layer 403 ... Hole injection 404 ... organic emission layer 405 ... cathode layer 406 ... partition wall 407 ... adhesive layer 408 ... sealing substrate

Claims (6)

A letterpress printing apparatus using a letterpress as a printing plate,
In order to transfer ink from the relief plate in contact with the relief plate, a rotary plate cylinder on which the relief plate is installed, a substrate surface plate on which the substrate to be printed is placed, an ink supply device that supplies ink to the relief plate, And a preliminary transfer device.   The preliminary transfer device includes a liquid storage tank for storing a cleaning liquid, a rotating roll having an upper surface exposed from the cleaning liquid and a lower surface immersed in the cleaning liquid, and a doctor in the cleaning liquid disposed in the cleaning liquid so as to rub the surface of the rotating roll. And a cleaning liquid external doctor disposed outside the cleaning liquid so as to further rub the surface of the rotating roll rubbed by the cleaning liquid doctor, and a drying nozzle for blowing nitrogen or clean air onto the surface of the rotating roll rubbed by the cleaning liquid external doctor, 2. The relief printing apparatus according to claim 1, wherein the ink supplied onto the relief plate is transferred by bringing the relief plate into contact with an upper surface of the rotary roll.   The relief printing apparatus according to claim 2, further comprising: a cleaning liquid supply nozzle that supplies a cleaning liquid into the liquid storage tank; and an overflow pipe that overflows the cleaning liquid from the liquid storage tank.   When transferring the ink by bringing the relief plate into contact with the upper surface of the rotating roll, the cleaning liquid supply nozzle discharges the cleaning liquid supplied into the liquid storage tank onto the surface of the rotating roll to which the ink has been transferred. The relief printing apparatus according to claim 2 or 3, wherein In the manufacturing method of an organic EL panel in which an organic light emitting layer is formed on a substrate by printing,
A preliminary printing by the relief printing apparatus using the relief printing apparatus according to claim 1, 2, 3 or 4, wherein the substrate is a printing substrate and the ink for forming the organic light emitting layer is transferred to the printing substrate. After preliminarily transferring the organic light emitting layer forming ink to a transfer device, the organic light emitting layer is formed on the substrate by transferring the organic light emitting layer forming ink to the printing substrate by the relief printing device. Like,
An organic EL panel manufacturing method characterized by the above.   The organic light emitting layer forming ink is transferred to the substrate to be printed after the organic light emitting layer forming ink is preliminarily transferred 10 times from the relief printing plate of the relief printing apparatus to the preliminary transfer device. The method for producing an organic EL panel according to claim 5.

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