JP2012204060A - Letterpress for printing and method for manufacturing the same, and method for manufacturing organic electroluminescence device - Google Patents

Abstract

An object of the present invention is to cause collapse of an alignment pattern due to a local excessive push-in amount due to foreign object biting or the like, a printed matter having an unclear alignment pattern caused by uneven dislocation of a light emitting material, a convex portion of a printed image, There has been a need to eliminate the disadvantage that a clear substrate cannot be obtained because the alignment mark is pushed in and printing does not cover the entire surface evenly.
In a relief printing plate having an alignment mark outside a print image area and having an in-area convex part for forming a print image, the out-of-area convex part is formed outside the print image area, Provided are a relief printing plate, a method for producing the same, and a method for producing an organic electroluminescence device, wherein a concave alignment mark is provided in the convex part.
[Selection] Figure 2

Description

  The present invention relates to a relief printing plate for forming a detailed pattern on a substrate having a relatively high hardness such as glass by a relief printing method, and a method for producing the relief relief plate, and in particular, a method for producing a relief printing plate for forming an organic electroluminescence element. About.

  An organic electroluminescence element (hereinafter referred to as an organic EL element) is an element in which an organic light emitting layer made of an organic light emitting material is formed between two opposing electrodes, and light is emitted by passing a current through the organic light emitting layer. In order to emit light efficiently, the thickness of the light emitting layer is important, and it is necessary to form a thin film of about 100 nm. Furthermore, in order to make this a display capable of color display, it is necessary to pattern the organic EL element with high definition.

  Organic light-emitting materials include low-molecular materials and high-molecular materials. When low-molecular materials are used, a light-emitting layer as an organic pattern layer is usually obtained by vacuum deposition using a mask. This method is excellent in that the light emitting layer can be formed in a uniform thickness. However, if the substrate on which the low molecular weight material is deposited is large, a mask with a large size will be used. However, since it is difficult to manufacture a mask with excellent pattern accuracy and a large size, light is emitted at a predetermined position on the substrate. The layer may not be formed.

  Therefore, recently, a method of using a polymer material as an organic light emitting material, dissolving the organic light emitting material in a solvent to form a coating liquid, and forming a thin film by a wet coating method or a printing method has been tried. . As the wet coating method for forming a thin film, there are a spin coating method, a bar coating method, a protruding coating method, a dip coating method, and the like. It is difficult with the wet coating method. Therefore, it is effective to form a thin film by a printing method that is good at coating patterning.

  Since a glass substrate is often used as a substrate in an organic EL display, a method using a hard plate such as a metal printing plate such as a gravure printing method is not suitable, and an offset printing method using an elastic rubber plate In addition, a relief printing method using a photosensitive resin plate mainly composed of rubber or other resin is optimal. As attempts of these printing methods, a method by offset printing (Patent Document 1), a method by letterpress printing (Patent Document 2), and the like have been proposed.

JP 2001-93668 A JP 2001-155858 A

In producing a printing relief plate having convex portions made of the resin material, a photolithography method (photolithographic method) using a photosensitive resin as the resin material is used. In forming a relief printing plate by photolithography, a resin material (plate material) in which a photosensitive resin layer is formed on a base material by applying various printing methods or spin coating is used to form a light shielding portion and a light transmitting portion. By using the mask to be exposed, and then developing, a convex portion is formed to form a relief printing plate. When a positive type photosensitive resin is used, a portion irradiated with light that has passed through the light transmitting portion of the mask in the exposure step is softened, and the softened portion is removed in the development step. In addition, when a negative photosensitive resin is used for the photosensitive resin, a portion irradiated with light that has passed through the light transmitting portion of the mask is cured by the exposure process, and a portion that is not irradiated with light by the developing process (uncured) Part) is removed.

  When the relief printing method is used for fine patterning in the electronics field, the shape of the printing pattern and the uniformity of the printing pressure associated therewith are required. In addition, it is necessary to use alignment marks in order to maintain the positional accuracy of the pattern, and to maintain the positional relationship between the attached plate and the printing press accurately.

  Although printing pressure management is determined by the amount of pressing from the position of the kiss touch, there is a possibility that the plate pattern will buckle due to excessive local printing pressure due to foreign object biting due to the plate cylinder tilt. On the other hand, the alignment mark shape may be difficult or unrecognizable on printed matter.

  When a relief printing plate is used, it is related that a fine pattern is difficult to control when the light emitting material is transferred, and a clear print pattern cannot be obtained.

  The present invention has been devised in view of the above problems, and forms a high-definition print pattern required for organic EL, etc., makes it possible to recognize a kiss touch in advance for a relief printing configuration for printing, and alignment. By improving the mark recognition, it is possible to find more efficient printing conditions than before, and to improve the yield of the printed material.

  That is, the invention according to claim 1 of the present invention is a relief printing plate having an alignment mark outside the print image area and having an in-area convex part for forming the print image, outside the print image area. There is provided a relief printing plate, wherein a convex part is formed, and a concave alignment mark is provided in the convex part outside the region.

  The invention according to claim 2 of the present invention provides the printing relief printing plate according to claim 1, wherein the height of the convex portion outside the region is higher than the convex portion within the region.

  The invention according to claim 3 of the present invention is characterized in that the height difference between the height of the outer convex portion and the height of the inner convex portion is 5 μm or more and 10 μm or less. Providing letterpress.

  The invention according to claim 4 of the present invention provides the relief printing plate according to claim 3, wherein the height of the convex portion in the region is 20 μm or more and 100 μm or less.

  The invention according to claim 5 of the present invention provides the printing relief plate according to any one of claims 1 to 4, wherein the convex portion outside the region is transparent.

  In the invention according to claim 6 of the present invention, the convex portion outside the region is constituted by a first photosensitive resin layer and a second photosensitive resin layer, and the convex portion within the region is constituted by a second photosensitive resin layer. A relief printing plate according to any one of claims 1 to 5 is provided.

  In the invention according to claim 7 of the present invention, in the first photosensitive resin layer, a particle group having a particle diameter of 3 μm or less and a particle diameter of 0.1 μm or less is dispersed by 50% by weight or more. A relief printing plate according to claim 6 is provided.

In the invention according to claim 8 of the present invention, the transmittance of the first exposed resin layer is an OD value of 3.
The relief printing plate according to claim 6 or 7, wherein the relief printing plate is 0 or more.

The invention according to claim 9 of the present invention is the method for producing a relief printing plate according to any one of claims 1 to 8,
In turn,
A second photosensitive resin layer forming step of forming a second photosensitive resin layer on the substrate;
A first photosensitive resin layer forming step of forming a first photosensitive resin layer made of a photosensitive resin having a photosensitive condition different from the photosensitive condition of the second photosensitive resin layer on the second photosensitive resin layer;
A first photosensitive resin layer forming step of exposing and developing only the first photosensitive resin layer to form a first photosensitive resin layer;
A second photosensitive resin layer forming step of exposing and developing the second photosensitive resin layer to form a second photosensitive resin layer;
A method for producing a relief printing plate, comprising:

  The invention according to claim 10 of the present invention is characterized in that the second photosensitive resin layer is made of a negative type or a positive type photosensitive resin, and the second photosensitive resin layer is made of a positive type or a negative type. A method for producing a relief printing plate according to claim 9 is provided.

  The invention according to claim 11 of the present invention claims at least one of light emission auxiliary layers such as an organic light emitting layer, a hole transport layer, a hole injection layer, an electron transport layer, an electron injection layer, and a charge generation layer. 1. A method for producing an organic electroluminescent device, which is formed by printing with a convex portion in a region of a printing relief printing plate according to any one of 1 to 8.

  The invention according to claim 12 of the present invention provides the method for producing an organic electroluminescent device according to claim 11, wherein the printing is performed while recognizing an alignment mark.

  According to the present invention, a high-definition print pattern of a substrate is formed by a relief printing method.

  This makes it possible to recognize the kiss touch beforehand by using the structure of the relief printing plate of the present invention, and to improve the printable condition than before by improving the recognition of the alignment mark, thereby improving the yield of printed matter. Can improve.

  When an alignment mark shape, for example, a cross shape, was produced by the printing relief plate of the present invention, a good recognition result was obtained.

  In the case of the plate structure of the present invention, since the alignment mark is a concave portion, the alignment pattern collapses due to excessive local pressing amount due to foreign matter biting, etc., which is characteristic for printing when the alignment mark is a convex portion. It is considered that the printed matter having an unclear alignment pattern caused by non-uniform dislocation of the light emitting material is improved.

  In addition, since the outer convex portion is provided outside the print image area, for example, on the outer periphery, only the in-region convex mark and the convex alignment mark that is the print image are pushed in, and printing is performed evenly on the entire surface. The problem that a clear printed material could not be obtained because it was not applied was solved.

  In particular, since the height of the convex portion outside the region is higher than the convex portion within the region, the convex portion within the region, which is a print image, can easily be printed over the entire surface, so that a clear substrate can be obtained. It is done. In this way, the push amount can be set by providing the height difference.

  This is preferably the case where the height difference between the height of the outer convex portion and the height of the inner convex portion is 5 μm or more and 10 μm or less. When the height difference is 10 μm or more, the printing pressure is hardly evenly applied to the entire surface due to the printing pattern, and a clear printed material may not be obtained.

  When the height of the in-region convex portion is 20 μm or less, there are many variations in the formation of the in-region convex portion, and in particular, in the case of the photolithography method, the variation is likely to occur. On the other hand, when the thickness is 100 μm or more, for example, a pattern tends to buckle in the development process of the photolithography method, and transfer unevenness is also seen on the printing material, which may become unstable.

Such a relief printing plate, specifically, a second photosensitive resin layer forming step of forming a second photosensitive resin layer on the substrate,
A first photosensitive resin layer forming step of forming a first photosensitive resin layer made of a photosensitive resin having a photosensitive condition different from the photosensitive condition of the second photosensitive resin layer on the second photosensitive resin layer;
A first photosensitive resin layer forming step of exposing and developing only the first photosensitive resin layer to form a first photosensitive resin layer;
A second photosensitive resin layer forming step of exposing and developing the second photosensitive resin layer to form a second photosensitive resin layer;
Thus, an accurate relief printing plate can be provided.

  Further, since the out-of-region convex portion is transparent, it is possible to print while aligning with the alignment mark.

Moreover, such a manufacturing method is specifically,
It can be easily manufactured by forming the outer convex portion from the first photosensitive resin layer and the second photosensitive resin layer, and the inner convex portion from the second photosensitive resin layer.

  In the first photosensitive resin layer, it is preferable that a particle group having a particle diameter of 3 μm or less and a particle diameter of 0.1 μm or more is dispersed in an amount of 50% by weight or more. When the diameter is 3 μm or more, the adhesiveness of the resin is deteriorated, and the printability and photolithographic properties are easily deteriorated. Further, in the case of 50% by weight or less, there was a case where the light shielding property was impaired.

  In addition, when the OD value of the transmittance is less than 3.0, a case where the pattern is exposed in the photolithography process due to impairing the light-shielding property is seen, so 3.0 or more is preferable.

  Moreover, when manufacturing a relief printing plate for forming an organic EL element or the like, a high-definition printing pattern is possible by using each of these resins.

It is a creation flowchart of the letterpress for printing concerning the present invention. It is sectional drawing of the relief printing plate which concerns on this invention. It is a photomask used when producing the relief printing plate according to the present invention, wherein (i) is for the first photosensitive resin layer exposure, and (ii) is for the second photosensitive resin layer exposure. BRIEF DESCRIPTION OF THE DRAWINGS It is the relief printing plate which concerns on this invention, (a) is a top view, (b) is sectional drawing. It is perspective explanatory drawing which showed an example of organic electroluminescent element preparation by the relief printing method which concerns on this invention. It is explanatory drawing which showed an example of the organic EL element which concerns on this invention in the cross section.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to only the embodiments described below.

  FIG. 1 is a flow chart for producing a printing relief plate according to the present invention, and FIG. 2 is a sectional view of the printing relief plate of the present invention. The printing relief printing plate can be formed by a method in which a photosensitive resin is molded into a plate shape by exposure and development, or a method that is formed by shaving with a laser or a metal sword, or the like. However, in view of the ease of the method, a method of patterning a layer made of a photosensitive resin by a photolithography method is desirable, and a layer in direct contact with the light emitting material is more preferably solvent resistant.

  When applying a photolithographic method using a photosensitive resin as a convex pattern formation method, the convex portion of the relief plate is removed from the plate-shaped photosensitive resin laminate in which the substrate, the solvent-resistant layer, and the photosensitive resin layer are sequentially laminated. It is most desirable to form. As a method for molding the solvent-resistant layer and the photosensitive resin layer, known methods such as an injection molding method, a protruding molding method, a laminating method, a bar coating method, a slit coating method, and a comma coating method can be used.

  As a resin used as a material for forming the in-region convex portions and the external convex portions that are convex portions of the printing relief plate of the present invention, nitrile rubber is used as a polymer as a main component in the case of using a photosensitive resin. In addition to rubber such as silicone rubber, isoprene rubber, styrene butadiene rubber, butadiene rubber, chloroprene rubber, butyl rubber, acrylonitrile rubber, ethylene propylene rubber, urethane rubber, polyethylene, polystyrene, polybutadiene, polyvinyl chloride, polyvinylidene chloride, poly Select one or more of synthetic resins such as vinyl acetate, polyamide, polyurethane, polyethersulfone, polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, and polyvinyl alcohol, natural polymers such as cellulose, etc. However, when applying a coating solution such as an organic light emitting material, from the viewpoint of solvent resistance to organic solvents, fluorine-based elastomers, polytetrafluoroethylene, polyvinylidene fluoride, poly (vinylidene fluoride) and their A fluororesin such as a copolymer is desirable.

  In addition, by containing at least one kind soluble in water-soluble solvents such as polyamide, polyurethane, polyvinyl alcohol, cellulose acetate succinate, partially saponified polyvinyl acetate, cationic piperazine-containing polyamide and derivatives thereof Since development using water becomes possible, it is most desirable to select and use one or more of these.

  A photopolymerization initiator is added to the photosensitive resin for polymerization of the photosensitive resin. As an example, if it is suitable for this use, there will be no restriction | limiting in particular, The thing reported to various literature can be used. Examples of the photopolymerization initiator include acetophenone, benzophenone, benzyldimethylketanol, 2-chlorothioxanthone, 2-ethylanthraquinone, diethylthioxanthone (Kayacure DETX: manufactured by Nippon Kayaku), 1-hydroxycyclohexyl phenyl ketone (Irgacure 184). : Ciba Specialty Chemicals), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone (Irgacure 369: Ciba Specialty Chemicals), 2,2-dimethoxy-1,2- Diphenylethane-1-one (Irgacure 651: manufactured by Ciba Specialty Chemicals), bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Irgacure 819: Ciba Specialty Chemicals) Mikals), 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one (Irgacure 907: manufactured by Ciba Specialty Chemicals) or biimidazole compounds, and the like. It is not something. Further, these photopolymerization initiators may be used by appropriately mixing a plurality of them as necessary.

For the first photosensitive resin, commonly used pigments and dyes may be used,
For example, for black pigments, examples of black pigments include titanium black, synthetic iron black, and carbon black. Examples of carbon black varieties include furnace blacks such as SAF, ISAF, HAF, FEF, and SRF, thermal blacks such as FT and MT, and acetylene black. These carbon blacks may be used alone or in combination of two or more.

In addition, as an example of the black dye, the color index name (CI Name) is Acid.
Examples include Blackl, AcidBlack2, AcidBlack48, ModernBlack1, DisperseBIackl, and ReactiveBIack5. Moreover, it is not limited to black type | system | group, You may combine the particle | grains of various pigments and dyes.

  As an exposure method used for forming a convex pattern (outer region convex portion 21 and inner region convex portion 22 in FIG. 4) of the first photosensitive resin layer 1 and the second photosensitive resin layer 2, a substrate and a photomask are used. There are a contact exposure method in which contact is completely made and a proximity exposure method in which a little distance is provided so as not to damage the photomask. When glass is used for the mask substrate of the photomask, it is difficult to adhere the photomask and the relief printing resin material for printing due to the mixing of bubbles, and damage to the surface due to contact is also considered. The resin material should be separated. However, in the contact exposure method, since exposure light spreads in the direction of light, light is scattered between the photomask and the resin material, and accurate patterning cannot be performed. Therefore, it is preferable to perform exposure by a proximity exposure method in which the directions of exposure light are aligned. Further, the photomask used in the present invention is chrome plated so that the first photosensitive resin layer 8 is exposed in FIG. 3 (i) and the second photosensitive resin layer 9 is exposed in FIG. 3 (ii). However, this is a system in which the second photosensitive resin layer 9 is a positive type and the first photosensitive resin layer 8 is a negative type, and is not limited thereto.

  As a development method, the photomask is removed from the resin relief plate and development is performed. The uncured portion of the photosensitive resin layer is removed by development, and a printing relief plate which is the resin relief plate of the present invention is obtained. At this time, when using a water-developing type resin relief printing plate in which the polymer component that can be dissolved and removed with pure water after exposure is made of a water-soluble polymer, pure water is used as the developer. When an alkaline developer is used, a developer such as NaOH or TMAH can be used. Further, the liquid properties suitable for each of the positive type and the negative type may be different, and baking or post-exposure may be performed for the purpose of further curing the resin layer after development.

  According to the present invention, the outer region convex portion 21 and the inner region convex portion 22 shown in FIG. 4A can be formed by repeating this exposure and development. A cross-sectional view at that time is as shown in FIG. 4A and 4B, the shape of the outer convex portion 21 and the inner convex portion 22, and the first exposed resin layer 31 and the second photosensitive resin layer that should have the corresponding shapes. Although the shapes of 32 do not match, this is a conceptual drawing difference for easy understanding. In an actual letterpress for printing, of course, in FIGS. 4 (a) and 4 (b) It has a shape that does not cause wrinkles.

  In order to make the most of the advantages of the present invention, it is desirable that the first photosensitive resin layer 8 be negative and the second photosensitive resin layer 9 be positive. However, the present invention is not limited to this.

  Since the convex portions and the solvent-resistant layer of the printing relief plate of the present invention are for printing a coating liquid prepared by dispersing or dissolving the organic light emitting material in a solvent, the resin used is an organic light emitting material. It may not contain photosensitive components such as a photo-curing agent or a photo-polymerization initiator that inhibits light emission. When producing a relief printing plate for this application, the cured resin is resistant to organic solvents. It is good to have. From this point of view, as the polymer that is the main component of the resin, fluororesin such as fluorine elastomer, polytetrafluoroethylene, polyvinylidene fluoride, polyhexavinylidene fluoride and copolymers thereof, polyamide, polyvinyl alcohol Those soluble in water-soluble solvents such as cellulose acetate succinate, partially saponified polyvinyl acetate, and cationic piperazine-containing polyamide can be used.

  The material of the base material 5 on which the convex pattern of the relief printing plate of the present invention is formed is only required to have mechanical strength against printing, such as polyethylene, polystyrene, polybutadiene, polyvinyl chloride, polyvinylidene chloride, polyacetic acid. Known synthetic resins such as vinyl, polyamide, polyethersulfone, polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, and polyvinyl alcohol, known metals such as iron, copper, and aluminum, or laminates thereof can be used. Those that retain high dimensional stability are desirable. Therefore, metal is preferably used as the material used as the base material, and examples include iron, aluminum, copper, zinc, nickel, titanium, chromium, gold, silver, alloys thereof, and laminates. In particular, a steel base material or an aluminum base material containing iron as a main component can be suitably used from the viewpoint of workability and economy.

  The material of the solvent resistant layer 3 may be any resin that is resistant to the solvent and can be dispersed, such as fluorine elastomer, polytetrafluoroethylene, poly (vinylidene fluoride), poly (hexavinylidene fluoride), and copolymers thereof. Even if the same material as that of the resin layer 1 is used, such as a resin that is soluble in a water-soluble solvent such as a polyamide resin, polyamide, polyvinyl alcohol, cellulose acetate succinate, partially saponified polyvinyl acetate, or cationic piperazine-containing polyamide. good.

  Next, a method for manufacturing an organic EL device will be described as an example of a method for manufacturing an electronic device using the relief printing plate according to the present invention. In addition, the manufacturing method of the electronic device thru | or organic EL device which concerns on this invention is not limited only to the specific manufacturing method illustrated below.

  Therefore, using the relief printing plate patterned according to the present invention, it is possible to produce a printed matter that forms an ink pattern on the surface of a substrate to be printed that requires high accuracy, such as an electrode substrate for an organic EL display, by the relief printing method. The manufacturing method will be described below.

  FIG. 5 shows a schematic diagram of a relief printing apparatus used for producing the printed matter of the present invention. A printing substrate 45 is fixed to the surface plate 44. The printing relief plate 41 patterned according to the present invention is fixed to the plate cylinder 42. The printing relief plate 41 is in contact with the anilox roll 43 which is an ink supply body. The anilox roll 43 is supplied from the ink replenishing device through the liquid passing portion 47.

  First, ink passes through the liquid replenishing unit 47 from the ink replenishing device, replenishes ink to the anilox roll 43, and excess ink out of the ink supplied to the anilox roll 43 is removed by doctoring or the like. As the ink replenishing device, a dripping type ink replenishing device, a fountain roll, a slit coater, a die coater, a cap coater such as a cap coater, or a combination thereof may be used. For doctoring, a known object such as a doctor roll can be used in addition to the doctor blade. The anilox roll 43 can be made of chromium or ceramics. Further, instead of the cylindrical anilox roll, it is also possible to use a flat anilox plate as the ink supply to the printing relief plate.

The ink uniformly held by the doctor on the surface of the anilox roll 43 that is an ink supply body to the printing relief plate is transferred and supplied to the projection pattern of the printing relief plate 41 attached to the plate cylinder 42. Then, as the plate cylinder 42 rotates, the convex pattern of the printing relief plate 41 and the substrate move relative to each other while being in contact with each other, and the ink is transferred to a predetermined position of the printing substrate 45 on the surface plate 44 to be printed. An ink pattern is formed on the surface. After the ink pattern is provided on the substrate to be printed, a drying step using an oven or the like can be provided as necessary.

  In addition, when printing the ink on the printing relief plate on the printing substrate 45, a method of moving the surface plate 44 on which the printing substrate 45 is fixed in accordance with the rotation of the plate cylinder 42 may be used. A printing unit including the plate cylinder 42, the printing relief plate 41, the anilox roll 43, and the ink replenishing device in the upper part of FIG. 5 may be moved in accordance with the rotation of the plate cylinder 42. In the printing relief plate of the present invention, a resin layer may be formed on the plate cylinder 42 and directly made to form a projection pattern.

  Note that FIG. 5 shows a sheet-fed relief printing apparatus that forms an ink pattern on a substrate to be printed one by one. However, in the method for producing a printed material according to the present invention, the substrate to be printed can be wound in a web shape. In some cases, a roll-to-roll relief printing apparatus can be used. When a roll-to-roll type letterpress printing apparatus is used, it is possible to continuously form an ink pattern and to reduce the manufacturing cost.

  Next, a method for producing an organic EL element will be described as an example of a method for producing a printed material using a relief printing plate patterned according to the present invention. The present invention is not limited to this.

  FIG. 6 shows an explanatory cross-sectional view of the organic EL element of the present invention. There are a passive matrix type and an active matrix type as a driving method of the organic EL element, but the organic EL element of the present invention can be applied to either a passive matrix type organic EL element or an active matrix type organic EL element. .

  The passive matrix method is a method in which stripe-shaped electrodes are opposed to each other so as to be orthogonal to each other, and light is emitted at the intersection, whereas the active matrix method uses a so-called thin film transistor (TFT) substrate in which a transistor is formed for each pixel. Thus, the light is emitted independently for each pixel.

  As shown in FIG. 6, the organic EL device of the present invention has a first electrode 59 in a stripe shape as an anode on a substrate 60. The partition wall 58 is provided between the first electrodes, and preferably covers the end portion of the first electrode for the purpose of preventing a short circuit due to burrs at the end portion of the first electrode.

  The organic EL device of the present invention has an organic EL layer composed of an organic light emitting layer and a light emission auxiliary layer on the first electrode 59 and in a region (light emitting region L, pixel portion) partitioned by the partition wall 58. ing. The organic EL layer sandwiched between the electrodes may be composed of an organic light emitting layer alone, or may be composed of a laminated structure of an organic light emitting layer and a light emission auxiliary layer. Examples of the light emission auxiliary layer include a hole transport layer, a hole injection layer, an electron transport layer, an electron injection layer, and a charge generation layer. FIG. 4 shows a configuration having a laminated structure of a hole transport layer 55 which is a light emission auxiliary layer and organic light emitting layers (51, 52, 53). A hole transport layer 55 is provided on the first electrode 59, and a red (R) organic light-emitting layer 51, a green (G) organic light-emitting layer 52, and a blue (B) organic light-emitting layer 53 are provided on the hole transport layer 55, respectively. Is provided.

Next, the 2nd electrode 54 is arrange | positioned as a cathode so as to oppose the 1st electrode 59 which is an anode on an organic luminescent medium layer. In the case of the passive matrix method, the second electrode is provided in a stripe shape so as to be orthogonal to the first electrode having a stripe shape. In the case of the active matrix method, the second electrode is formed on the entire surface of the organic EL element. Further, although not shown, a sealing body such as a glass cap is provided on the entire effective pixel in order to prevent moisture and oxygen in the environment from entering the first electrode, the organic light emitting layer, the light emitting auxiliary layer, and the second electrode. It is provided and bonded to the substrate via an adhesive.

  The organic EL device of the present invention includes at least a substrate, a patterned first electrode supported by the substrate, an organic light emitting layer, and a second electrode. Contrary to FIG. 4, the organic EL element of the present invention may have a structure in which the first electrode is a cathode and the second electrode is an anode. In addition, in order to protect the organic light emitting medium layer and the electrode from the ingress of external oxygen and moisture in place of a sealing body such as a glass cap, a sealing layer having a function of a passivation layer and a protective layer for protecting from external stress, or both, is provided. You may provide a stop base material.

  Next, the manufacturing method of an organic EL element is demonstrated.

  As the substrate according to the present invention, any substrate can be used as long as it has an insulating property. In the case of a bottom emission type organic EL element that extracts light from the substrate side, it is necessary to use a transparent substrate.

  For example, a glass substrate or a quartz substrate can be used as the substrate. Further, it may be a plastic film or sheet such as polypropylene, polyethersulfone, polycarbonate, cycloolefin polymer, polyacrylate, polyamide, polymethyl methacrylate, polyethylene terephthalate, or polyethylene naphthalate. Metal oxide thin film, metal fluoride thin film, metal nitride thin film, metal oxynitride thin film, or polymer resin film for the purpose of preventing moisture from entering the organic light emitting medium layer in these plastic films and sheets You may utilize what laminated | stacked these as a board | substrate.

  In addition, it is more preferable to reduce the moisture adsorbed on the inside or the surface of the substrate as much as possible by performing a heat treatment on these substrates in advance. Further, in order to improve the adhesion depending on the material to be laminated on the substrate, it is preferable to use after performing surface treatment such as ultrasonic cleaning treatment, corona discharge treatment, plasma treatment, UV ozone treatment.

  Further, a thin film transistor (TFT) can be formed on these to form a substrate for an active matrix organic EL element.

  When the partition wall forming material is a photosensitive material, the entire surface of the forming material solution is coated by a slit coating method or a spin coating method, and then patterning is performed by a photolithography method such as exposure and development. In the case of the spin coating method, the height of the partition wall can be controlled by conditions such as the number of rotations when spin coating, but there is a limit height in one coating, and if it is higher than that, multiple spin coatings are performed. Use an iterative approach.

  When the barrier rib is formed by a photolithography method using a photosensitive material, its shape can be controlled by exposure conditions and development conditions. For example, when a negative photosensitive resin is applied, exposed and developed, and then post-baked to obtain a partition wall, if the shape of the partition wall end portion is to have a forward tapered shape, development under this development condition The type, concentration, temperature, or development time of the liquid may be controlled. If the development conditions are mild, the partition wall ends have a forward taper shape, and if the development conditions are severe, the partition wall ends have a reverse taper shape.

Further, when the partition wall forming material is SiO ₂ or TiO ₂ , it can be formed by a dry film forming method such as a sputtering method or a CVD method. In this case, patterning of the partition walls can be performed by a mask or a photolithography method.

  Next, an organic EL layer composed of an organic light emitting layer and a light emission auxiliary layer is formed. The organic EL layer sandwiched between the electrodes may be composed of an organic light emitting layer alone, an organic light emitting layer and a hole transport layer, a hole injection layer, an electron transport layer, an electron injection layer, a charge generation layer, etc. It is good also as a laminated structure with the light emission auxiliary layer for assisting light emission. The hole transport layer, hole injection layer, electron transport layer, electron injection layer, and charge generation layer are appropriately selected as necessary.

  In the present invention, at least one of the organic EL layers composed of a light emitting auxiliary layer such as an organic light emitting layer, a hole transport layer, a hole injection layer, an electron transport layer, an electron injection layer, and a charge generation layer is used as an organic EL layer material. It can be applied when printing is formed above the first electrode by letterpress printing using the letterpress printing plate of the present invention using an ink dissolved or dispersed in a solvent. Hereinafter, in the present invention, a case where an organic light emitting ink in which an organic light emitting material is dissolved or dispersed in a solvent is used will be described.

  The organic light emitting layer is a layer that emits light when an electric current is passed. Organic light-emitting materials formed by the organic light-emitting layer include 9,10-diarylanthracene derivatives, pyrene, coronene, perylene, rubrene, 1,1,4,4-tetraphenylbutadiene, tris (8-quinolato) aluminum complex, tris (4-methyl-8-quinolato) aluminum complex, bis (8-quinolato) zinc complex, tris (4-methyl-5-trifluoromethyl-8-quinolato) aluminum complex, tris (4-methyl-5-cyano-) 8-quinolate) aluminum complex, bis (2-methyl-5-trifluoromethyl-8-quinolinolate) [4- (4-cyanophenyl) phenolate] aluminum complex, bis (2-methyl-5-cyano-8-quinolinolate) ) [4- (4-cyanophenyl) phenolate] aluminum complex, Lis (8-quinolinolato) scandium complex, bis [8- (para-tosyl) aminoquinoline] zinc complex and cadmium complex, 1,2,3,4-tetraphenylcyclopentadiene, poly-2,5-diheptyloxy- A low molecular weight light emitting material such as para-phenylene vinylene can be used.

  Also, coumarin phosphors, perylene phosphors, pyran phosphors, anthrone phosphors, polyphyrin phosphors, quinacridone phosphors, N, N′-dialkyl-substituted quinacridone phosphors, naphthalimide phosphors, A material obtained by dispersing a low molecular weight light emitting material such as an N, N′-diaryl-substituted pyrrolopyrrole fluorescent material or a phosphorescent light emitting material such as an Ir complex in a polymer can be used. As the polymer, polystyrene, polymethyl methacrylate, polyvinyl carbazole and the like can be used.

  Further, poly (2-decyloxy-1,4-phenylene) (DO-PPP) and poly [2,5-bis- [2- (N, N, N-triethylammonium) ethoxy] -1,4-phenyl- PPP derivatives such as alto-1,4-phenyllene] dibromide, poly [2- (2′-ethylhexyloxy) -5-methoxy-1,4-phenylenevinylene] (MEHPPV), poly [5-methoxy- ( 2-propanoxysulfonide) -1,4-phenylenevinylene] (MPS-PPV), poly [2,5-bis- (hexyloxy) -1,4-phenylene- (1-cyanovinylene)] (CN— Polymer light-emitting materials such as PPV), poly (9,9-dioctylfluorene) (PDAF), and polyspirofluorene may be used. Examples thereof include polymer precursors such as a PPV precursor and a PPP precursor. Other existing light emitting materials can also be used.

  Examples of the hole transport material forming the hole transport layer include metal phthalocyanines such as copper phthalocyanine and tetra (t-butyl) copper phthalocyanine, and metal-free phthalocyanines, quinacridone compounds, 1,1-bis (4-di-p -Tolylaminophenyl) cyclohexane, N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1′-biphenyl-4,4′-diamine, N, N′-di (1- Naphthyl) -N, N′-diphenyl-1,1′-biphenyl-4,4′-diamine and other aromatic amine-based low molecular hole injection transport materials, polyaniline, polythiophene, polyvinylcarbazole, poly (3,4 -Ethylenedioxythiophene) and polymer hole transport materials such as polystyrene sulfonic acid mixtures, thiophene oligomer materials, and other existing positive It can be selected from among transport material.

  Examples of the electron transport material for forming the electron transport layer include 2- (4-bifinylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (1 -Naphthyl) 1,3,4-oxadiazole, oxadiazole derivatives, bis (10-hydroxybenzo [h] quinolinolato) beryllium complexes, triazole compounds, and the like can be used.

  Solvents that dissolve or disperse the organic light emitting material include toluene, xylene, acetone, hexane, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methanol, ethanol, isopropyl alcohol, ethyl acetate, butyl acetate, 2-methyl- (t-butyl) Benzene, 1,2,3,4-tetramethylbenzene, pentylbenzene, 1,3,5-triethylbenzene, cyclohexylbenzene, 1,3,5-tri-isopropylbenzene and the like can be used alone or in combination. . Moreover, surfactant, antioxidant, a viscosity modifier, a ultraviolet absorber, etc. may be added to organic luminescent ink as needed.

  Examples of the solvent for dissolving or dispersing the hole transport material and the electron transport material include, for example, toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methanol, ethanol, isopropyl alcohol, ethyl acetate, butyl acetate, water and the like Alternatively, a mixed solvent thereof can be used. In particular, water or alcohols are suitable when forming a hole transport material into an ink.

  The organic light emitting layer and the light emission auxiliary layer are formed by a wet film forming method. Note that in the case where these layers have a laminated structure, it is not necessary to form all of the layers by a wet film formation method. Wet film formation methods include spin coating, die coating, dip coating, discharge coating, pre-coating, roll coating, bar coating, and other coating methods, letterpress printing, inkjet printing, offset printing, gravure Examples of the printing method include a printing method. In particular, when patterning organic light emitting layers of three colors of RGB, it can be selectively formed on the pixel portion by a printing method, and an organic EL element capable of color display can be manufactured. The film thickness of the organic light emitting medium layer is 1000 nm or less, preferably 50 nm to 150 nm, even when formed by a single layer or stacked layers.

  Again, the present invention is not only for forming an organic light emitting layer by a relief printing method using an organic light emitting ink, but also for a hole transport layer or an electron transport layer by a relief printing method using a hole transport ink or an electron transport ink. It can also be used when forming a light emission auxiliary layer.

  Next, a second electrode is formed. When the second electrode is a cathode, a material having high electron injection efficiency is used as the material. Specifically, a single metal such as Mg, Al, or Yb is used, and a compound such as Li, oxidized Li, or LiF is sandwiched by about 1 nm at the interface in contact with the light emitting medium, and Al or Cu having high stability and conductivity is laminated. Use. Or, in order to achieve both electron injection efficiency and stability, one or more metals such as Li, Mg, Ca, Sr, La, Ce, Er, Eu, Sc, Y, Yb, etc., which have low work function, and stable Ag, Al An alloy system with a metal element such as Cu is used. Specifically, alloys such as MgAg, AlLi, and CuLi can be used. Further, in the case of a top emission type organic EL device, the cathode needs to have transparency, and for example, transparency can be achieved by a combination of these metals and a transparent conductive layer such as ITO.

As a method for forming the second electrode, a dry film formation method such as a resistance heating vapor deposition method, an electron beam vapor deposition method, a reactive vapor deposition method, an ion plating method, or a sputtering method can be used. Moreover, when it is necessary to make a 2nd electrode into a pattern, it can pattern by a mask etc. The thickness of the second electrode is preferably 10 nm to 1000 nm. In the present invention, the first electrode can be a cathode and the second electrode can be an anode.

  As an organic EL element, it is possible to emit light by sandwiching an organic light emitting layer between electrodes and letting an electric current flow. However, some of the organic light emitting material, the light emission auxiliary layer forming material, and the electrode forming material contain moisture in the atmosphere. Since it is easily deteriorated by oxygen, a sealing body is usually provided for shielding from the outside.

  For example, the sealing body includes a first electrode, an organic light emitting layer, a light emitting auxiliary layer, and a substrate on which the second electrode is formed. Then, sealing is performed by adhering a peripheral portion of the second electrode through a cap, a substrate, and an adhesive so that a recess is formed above the second electrode.

  In addition, the sealing body is provided with a resin layer on a sealing material with respect to the substrate on which, for example, the first electrode, the organic light emitting layer, the light emission auxiliary layer, and the second electrode are formed. It is also possible to carry out by bonding the substrates.

At this time, the sealing material needs to be a base material having low moisture and oxygen permeability. Examples of the material include ceramics such as alumina, silicon nitride, and boron nitride, glass such as alkali-free glass and alkali glass, metal foil such as quartz, aluminum, and stainless steel, and moisture-resistant film. Examples of moisture-resistant films include films formed by CVD of SiOx on both sides of plastic substrates, films with low permeability and water-absorbing films, or polymer films coated with a water-absorbing agent. The water vapor transmission rate is preferably 10 ⁻⁶ g / m ² / day or less.

  Examples of the resin layer include a photo-curing adhesive resin made of an epoxy resin, an acrylic resin, a silicone resin, a thermosetting adhesive resin, a two-component curable adhesive resin, and an ethylene ethyl acrylate (EA) polymer. Examples thereof include acrylic resins, vinyl resins such as ethylene vinyl acetate (EVA), thermoplastic resins such as polyamide and synthetic rubber, and thermoplastic adhesive resins such as acid-modified products of polyethylene and polypropylene. Examples of methods for forming a resin layer on a sealing material include solvent solution method, extrusion lamination method, melting / hot melt method, calendar method, nozzle coating method, screen printing method, vacuum laminating method, hot roll laminating method, etc. Can be mentioned. A material having a hygroscopic property or an oxygen absorbing property may be contained as necessary. Although the thickness of the resin layer formed on a sealing material is arbitrarily determined by the magnitude | size and shape of the organic EL element to seal, about 5-500 micrometers is desirable.

  The substrate on which the first electrode, the organic light emitting layer, the light emission auxiliary layer, and the second electrode are formed and the sealing body are bonded together in a sealing chamber. When the sealing body has a two-layer structure of a sealing material and a resin layer, and a thermoplastic resin is used for the resin layer, it is preferable to perform only pressure bonding with a heated roll. When a thermosetting adhesive resin is used, it is preferable to perform heat curing at a curing temperature after pressure bonding with a heated roll. In the case where a photocurable adhesive resin is used, curing can be performed by further irradiating light after pressure bonding with a roll. Note that although the resin layer is formed over the sealing material here, the resin layer can be formed over the substrate and bonded to the sealing material.

  Before or instead of sealing with a sealing body, for example, as a passivation film, it is also possible to form a sealing body with an inorganic thin film, such as a silicon nitride film having a thickness of 150 nm using a CVD method. It is also possible to combine these.

  Specific examples of the present invention will be described below, but the present invention is not limited thereto.

Example 1
<Preparation of light emitting layer forming coating solution>
The polymeric fluorescent substance was dissolved in xylene so that the concentration of the coating solution was 1.0% by weight to prepare a light emitting layer forming coating solution. As the polymeric fluorescent substance, a light emitting material made of a poly (paraphenylene vinylene) derivative was used.

<Preparation of transferred substrate (device substrate)>
Prepare a base material (manufactured by Geomat Co., Ltd.) on which a ITO film with a surface resistivity of 15Ω is formed on a 150 mm square, 0.4 mm thick glass substrate, and transport holes using a spin coater on the base material. As a layer, poly (3,4) ethylenedioxythiophene / polystyrene sulfonic acid (PEDOT / PSS) was formed to a thickness of 100 nm. Furthermore, the PEDOT / PSS thin film thus formed was dried at 100 ° C. under reduced pressure for 1 hour to produce a transfer substrate (device substrate).

<Preparation of printing letterpress>
A steel material having a thickness of 250 μm is used as the base plate 5 for printing, and the second photosensitive resin and the first photosensitive resin are sequentially applied by spin coating, and the second photosensitive resin layer and the first photosensitive resin are coated. A resin layer was formed. After coating, the exposure relief development was repeated sequentially, and the relief printing plate which consists of a 1st exposed resin layer and a 2nd exposed resin layer was formed by the photolitho method.

In this example, a black pigment mainly composed of carbon as light shielding particles was dispersed in a negative first photosensitive resin layer. The second photosensitive resin layer was composed of a positive type photosensitive resin layer mainly composed of polyamide, and was exposed and developed to form a relief printing plate.
Note that TMAH was used as the alkaline developer for the developer of the first photosensitive resin, and pure water was used for the developer of the second photosensitive resin.

  In addition, a cross alignment mark is formed outside the print image area, which is an outer area convex portion composed of the first photosensitive resin layer and the second photosensitive resin layer, and in which there is no second photosensitive resin layer in the outer convex area. It has been. Further, the in-region convex portion for forming the print image is composed only of the second exposed resin layer.

<Production of organic EL device>
An organic EL device was produced using the relief printing plates having different layer structures formed as described above. About each of the said relief printing plates, the relief printing plate was fixed to the printing cylinder of the printing machine using the double-sided tape, and it printed on the to-be-transferred substrate using said light emitting layer forming coating liquid. For printing, 100 sheets were continuously printed. After the light emitting layer was printed, it was dried at 130 ° C. for 1 hour. After drying, a 10 nm-thick calcium film was formed on the light-emitting layer formed by printing, and then silver was vacuum-deposited thereon by 300 nm to produce an organic EL device.

(Comparative Example 1)
Next, a comparative example is shown.

  In Comparative Example 1, a printing image of only the second exposed resin layer 2 and a printing relief plate having only a cross alignment mark were used in the same manner as the plate in the example.

  The results of alignment mark visibility in Example 1 and Comparative Example 1 are shown below.

When the shape of the alignment mark cross was created with the relief printing plate of the present invention, good recognition results were obtained.

  However, the alignment mark cross of Comparative Example 1 has a part that is missing and may not be an accurate cross. Since the visibility of the alignment mark is deteriorated, it takes time to read the alignment mark, and extra production time is required. Moreover, there is a concern that productivity may be impaired due to erroneous recognition of the alignment mark.

  Also, when setting the pressing amount of the plate before the start of printing, if it is set by pressing from the kiss touch position, when the plate cylinder tilts, due to an error in the pressing amount, due to contact with the substrate, Collapse of convex patterns and alignment marks that form a printed image occurs. In the case of the relief printing plate according to the present invention, since the cross alignment mark is a concave portion, the alignment pattern is not collapsed due to the excessive push-in amount characteristic of the printing of the convex portion, and the transition of the light emitting material is uneven. It is considered that the printed matter of the unclear alignment pattern generated in (1) is improved. In addition, by setting the kiss touch position from the outer peripheral portion where the first exposed resin layer is also not directly pressed into the convex pattern portion, it is composed only of the second exposed resin layer at the position where the pressing is performed from 10 μm to 20 μm. The convex pattern that forms the print image can be printed, and the push-in amount can be set accordingly.

  When the first exposed resin layer was 10 μm or more, the printing pressure was not evenly applied to the entire surface, so that a clear printed material could not be obtained. If the second exposed resin layer is 20 μm or less, there are many variations in the formation of the convex pattern, and if it is 100 μm or more, the pattern tends to buckle during the development process of the photolithography method, and there is no uneven transfer on the substrate. It was stable.

  In addition, since the particle diameter of the particles dispersed in the first exposed resin layer is 3 μm or more, the adhesiveness of the resin is deteriorated, leading to deterioration of patterning property, printability and photolithography property. Further, in the case of 50% by weight or less, there was a case where the light shielding property was impaired.

  Further, when the OD value was 3.0 or less, there was a case where the pattern was exposed in the photolithography process by impairing the light shielding property.

DESCRIPTION OF SYMBOLS 1 ... 1st photosensitive resin layer 2 ... 2nd photosensitive resin layer 3 ... Solvent-resistant layer 4 ... Adhesive layer 5 ... Base material 6 ... Photomask 7 ... Exposure light 8 ... First photosensitive resin layer 9 ... Second photosensitive resin layer second layer convex part 11 ... Alignment mark part on photomask 12..., Light shielding part 13... Stripe pattern part on photomask 21... Convex part outside area 22. .... First exposed resin layer 32 ... Second exposed resin layer 33 ... Solvent resistant layer 34 ... Adhesive layer 35 ... Base material 41 ...・ Letter for printing 42 ... Plate cylinder 43 ... Anilox roll 44 ... Surface plate 45 ... Substrate 46 ... Ink chamber 47 ... ... Liquid passage part 51 ... Organic light emitting layer 52 ... Organic light emitting layer 53 ... Organic light emitting layer 54 ... Second electrode layer 55 ... Positive Hole transport layer 56 ... Resin layer 57 ... Sealing material 58 ... Partition 59 ... First electrode 60 ... Substrate

Claims (12)

  In a relief printing plate having an alignment mark outside the print image area and having an in-area convex part for forming a print image, an out-of-area convex part is formed outside the print image area, and in the out-of-area convex part A relief printing plate having a concave alignment mark.   2. The relief printing plate according to claim 1, wherein a height of the convex portion outside the region is higher than a convex portion within the region.   3. The relief printing plate according to claim 2, wherein a difference in height between the height of the outer convex portion and the height of the inner convex portion is 5 μm or more and 10 μm or less.   The relief printing plate according to claim 3, wherein a height of the in-region convex portion is 20 µm or more and 100 µm or less.   The relief printing plate according to any one of claims 1 to 4, wherein the convex portion outside the region is transparent.   The said area | region convex part is comprised from the 1st photosensitive resin layer and the 2nd photosensitive resin layer, and the said area | region convex part is comprised from the 2nd photosensitive resin layer, The any one of Claim 1 to 5 characterized by the above-mentioned. Letterpress for printing.   7. The relief printing plate according to claim 6, wherein a particle group having a particle diameter of 3 μm or less and a particle diameter of 0.1 μm or less is dispersed in the first photosensitive resin layer by 50% by weight or more.   The relief printing plate according to claim 6 or 7, wherein the transmittance of the first exposed resin layer is 3.0 or more in terms of OD value. A method for producing a relief printing plate according to any one of claims 1 to 8,
In turn,
A second photosensitive resin layer forming step of forming a second photosensitive resin layer on the substrate;
A first photosensitive resin layer forming step of forming a first photosensitive resin layer made of a photosensitive resin having a photosensitive condition different from the photosensitive condition of the second photosensitive resin layer on the second photosensitive resin layer;
A first photosensitive resin layer forming step of exposing and developing only the first photosensitive resin layer to form a first photosensitive resin layer;
A second photosensitive resin layer forming step of exposing and developing the second photosensitive resin layer to form a second photosensitive resin layer;
A method for producing a relief printing plate, comprising:   10. The method for producing a relief printing plate according to claim 9, wherein the second photosensitive resin layer is made of a negative type or positive type photosensitive resin, and the second photosensitive resin layer is made of a positive type or a negative type.   The printing relief printing plate according to any one of claims 1 to 8, wherein at least one of light emitting auxiliary layers such as an organic light emitting layer, a hole transport layer, a hole injection layer, an electron transport layer, an electron injection layer, and a charge generation layer is in the region of the relief printing plate according to any one of claims 1 to 8. A method for producing an organic electroluminescence device, wherein the organic electroluminescence device is printed by a convex portion.   12. The method of manufacturing an organic electroluminescent device according to claim 11, wherein the printing is performed while recognizing an alignment mark.