JP2008006690A - Relief printing plate, method for manufacturing printed article, method for manufacturing organic electroluminescent element, and element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a relief printing plate in which no contamination of an organic light emitting layer is caused by eluting from the relief printing plate to prevent degradation in element performance, when manufacturing the organic EL element using a relief printing method, and a method for manufacturing a printed article, a method for manufacturing an organic electroluminescent element using the relief printing plate and an organic EL element manufactured by the manufacturing method. <P>SOLUTION: The relief printing plate is used for forming patterns comprising ink on a printed body surface by supplying the ink to the protruded part 201 of the relief plate to transfer the ink on the protruded part 201 to the printed body. The relief printing plate in which the protruded part 201 of the relief plate is made of a resin and at least the protruded part surface is covered with a barrier layer 300, the method for manufacturing the printed article, the method for manufacturing the organic electroluminescent element using the relief printing plate, and the organic EL element manufactured by the manufacturing method are provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a printing relief plate used in a relief printing method, and a printed matter produced using the printing relief plate. As this printed matter, an organic electroluminescence element can be exemplified, and at least one layer of organic electroluminescence layers such as an organic light emitting layer of the organic electroluminescence element can be formed by a relief printing method. Moreover, as said printed matter, a color filter, a circuit base material, a thin-film transistor, a micro lens, a biochip etc. other than an organic electroluminescent element can be illustrated as printed matter.

  An organic electroluminescence element (hereinafter referred to as an organic EL element) is a light emitting element having a structure in which an organic light emitting layer is sandwiched between an anode and a cathode. Holes are injected from the anode and electrons are injected from the cathode by applying a voltage. This is an element that takes out the energy generated by recombination of the hole-electron pair on or inside the organic light emitting layer as light. Organic EL devices using organic substances in the light emitting layer have been studied for a long time, but their practical application has not progressed due to the problem of light emission efficiency. In contrast, in 1987, C.I. W. Tang proposed an organic electroluminescence device with a laminated structure in which the organic layer is divided into a light emitting layer and a hole transport layer, and confirmed high-efficiency light emission at a low voltage (see Non-Patent Document 1, etc.) and thereafter. There are many studies on organic electroluminescence devices.

Organic materials used for the light emitting layer of the organic EL element are classified into low-molecular materials and high-molecular materials. The method for forming the light emitting layer varies depending on the material. For low molecular weight materials, a method of forming a film mainly by vapor deposition is used, and for high molecular weight materials, a method of dissolving or dispersing in a solvent and applying on a substrate is performed. In addition, as a means for patterning the light emitting layer in order to make the organic EL element full color, when using a low molecular weight material, a mask having a pattern according to a desired pixel shape is used, and different light emitting colors are used. A method of depositing and forming a light emitting material on a portion corresponding to a desired pixel is performed. This method is an excellent method for uniformly forming a thin film in a desired shape, but there is a problem that it is difficult to form a pattern when the substrate to be deposited becomes large in terms of mask accuracy.
On the other hand, when a polymer material is used, an organic polymer light emitting material is converted into an ink by dissolving or dispersing in a solvent, and pattern formation mainly by an ink jet method and pattern formation by printing are proposed. For example, in the ink jet method disclosed in Japanese Patent Laid-Open No. 10-12377 (Patent Document 1), a light emitting material dissolved in a solvent is ejected from an ink jet nozzle onto a substrate and dried on the substrate to form a desired pattern. How to get.
However, since the ink droplets ejected from the nozzle are spherical, the ink spreads in a circular shape when landing on the substrate, the shape of the formed pattern lacks linearity, or the landing accuracy is poor. There is a problem that linearity cannot be obtained. In contrast, for example, in Japanese Patent Laid-Open No. 2002-305077 (Patent Document 2), a bank is formed in advance on a substrate with a material having ink repellency by using photolithography or the like, and ink droplets are landed on the bank. Thus, a method is disclosed in which the ink repels according to the bank shape and a linear pattern is obtained. However, when the repelled ink returns to the inside of the pixel, the ink swells inside the pixel, and there remains a problem that the film thickness of the organic light emitting layer in the pixel varies.

As a pattern forming method by printing, specifically, a method by letterpress printing, a method by offset printing, a method by screen printing, and the like have been proposed. In particular, the relief printing method is excellent in pattern formation accuracy, film thickness uniformity, and the like, and is excellent as a method for producing an organic EL element by printing.
As the relief printing plate used for relief printing, the relief portion should have an appropriate cushioning property, and the relief portion of the relief printing plate is made of a resin material. In this case, the resin material used for the convex portions of the printing relief plate includes a plasticizer added to obtain plasticity, a photosensitive agent for imparting photosensitivity to form the convex portions, and a crosslinking agent. . In addition, some additives such as plasticizers, photosensitizers, and crosslinking agents contained in the resin material forming the convex portions are soluble in the ink solvent, and these ink-soluble additives. May be mixed as an impurity in the organic light emitting layer formed by oozing out from the printing relief printing. Then, there is a problem that the mixed impurities cause deterioration in characteristics of the organic EL element such as efficiency and life.
Japanese Patent Laid-Open No. 10-12377 JP 2002-305077 A C. W. Tang, S.M. A. VanSlyke, Applied Physics Letters, 51, 913, 1987

  The present invention has been made in view of the above circumstances, and its purpose is to prevent the organic light-emitting layer from being contaminated by the eluate from the printing relief printing plate when producing an organic EL device using the relief printing method. Provided are a printing relief plate, a method for producing the same, a method for producing a printed matter, a method for producing an organic electroluminescence device using the printing relief plate, and an organic EL device produced by the production method, capable of preventing performance degradation. There is.

  As a result of intensive studies to overcome the above problems, the present inventors have obtained the present invention.

The invention according to claim 1 is used when supplying ink to the convex portions of the relief printing plate, transferring the ink on the convex portions to the printing medium, and forming a pattern made of the ink on the surface of the printing medium. In letterpress for printing,
The relief printing plate is characterized in that the projections of the relief plate are made of resin, and at least the surface of the projections is covered with a barrier layer.
The invention according to claim 2 is the relief printing plate according to claim 1, wherein the barrier layer is made of an inorganic material.
The invention according to claim 3 is the relief printing plate according to claim 1 or 2, wherein the barrier layer has a thickness of 10 nm to 500 nm.
According to a fourth aspect of the present invention, the ten-point average roughness Rz of the convex surface of the printing relief plate is 25% or less of the length of the shortest side of the convex portion. The relief printing plate according to any one of the above.
The invention according to claim 5 is the printing relief plate according to any one of claims 1 to 4, wherein the convex portions of the printing relief printing plate are formed on a metal substrate.
The invention according to claim 6 is characterized in that the convex portions of the printing relief plate are formed on the substrate independently of the adjacent convex portions. It is the relief printing plate of description.
The invention according to claim 7 is a step of supplying ink from the ink supply body to the convex portion of the printing relief plate according to any one of claims 1 to 6 and the ink on the convex portion of the printing relief plate. And a step of forming an ink pattern on the surface of the printing material by transferring to the surface of the printing material.
The invention according to claim 8 comprises an organic electroluminescent layer including at least a first electrode, a second electrode, and an organic light emitting layer, and causes the organic light emitting layer to emit light by passing a current from both electrodes to the organic light emitting layer. In the method for manufacturing a luminescence element,
A step of supplying an ink obtained by dissolving or dispersing an organic electroluminescent material in a solvent to the convex portion of the printing relief plate according to any one of claims 1 to 6, and the ink on the convex portion of the printing relief plate It is a method for producing an organic electroluminescence element, comprising a step of transferring to the surface of a substrate to be printed and forming at least one layer of the organic electroluminescence layer on the surface of the substrate to be printed.
The invention according to claim 9 comprises an organic electroluminescent layer including at least a first electrode, a second electrode, and an organic light emitting layer, and causes the organic light emitting layer to emit light by passing a current from both electrodes to the organic light emitting layer. In the method for manufacturing a luminescence element,
A step of supplying an organic light emitting ink obtained by dissolving or dispersing an organic light emitting material in a solvent to the convex portion of the printing relief plate according to any one of claims 1 to 6, and an organic light emission on the convex portion of the printing relief plate It is a method for producing an organic electroluminescence element, comprising a step of transferring ink to a surface of a substrate to be printed and forming an organic light emitting layer on the surface of the substrate to be printed.
Invention of Claim 10 supplies the organic light emitting ink formed by melt | dissolving or disperse | distributing an organic light emitting material in the solvent to the convex part of the relief printing plate in any one of Claims 1-6, and the said printing Transferring the organic light-emitting ink on the convex portion of the relief printing plate to the surface of the substrate to be printed, and forming an organic light-emitting layer on the surface of the substrate to be printed;
The printing relief plate is provided with a photosensitive resin layer on a substrate, obtains a plate material, exposes the photosensitive resin layer with a photomask, and develops the exposed plate material to develop a convex portion. The base material is a metal base material, the metal base material is made of an alloy of iron and nickel, and the convex portions of the printing relief plate are independently formed with respect to the adjacent convex portions. It is the manufacturing method of the organic electroluminescent element characterized by being formed on the material.
The invention according to claim 11 is an organic electroluminescence element manufactured by the manufacturing method according to any one of claims 8 to 10.

  In the present invention, the residue derived from the relief printing plate contained in the organic light emitting layer of the organic EL device is desirably 0.01% or less.

  According to the present invention, when an organic EL device is produced using a relief printing method, the organic light-emitting layer is not contaminated by an eluate from the relief printing plate, and the degradation of the device performance can be prevented. A relief printing plate, a production method thereof, a production method of printed matter, a production method of an organic electroluminescence element using the relief printing plate, and an organic EL element produced by the production method can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an explanatory sectional view of an example of the relief printing plate of the present invention. A convex portion (convex portion pattern) 201 is formed on the substrate 200 in both FIG. A barrier layer 300 is further formed on the top of the convex pattern 201. In FIG.1 (b), the convex part pattern is formed on the base material independently with respect to the adjacent convex part pattern. In the present invention, any of the printing relief plates shown in FIGS. 1A and 1B may be used. However, as shown in FIG. 1B, the convex pattern 201 is independent of the adjacent convex pattern. And it is preferable that it is formed on the base material, that is, it is not continuous with the adjacent convex pattern. Convex part patterns as shown in FIG. 1 (a) are continuous, and the convex part pattern as shown in FIG. 1 (b) is adjacent when compared with a plate integrated as a resin layer. In the plate formed on the substrate independently of the pattern, the positional accuracy shift due to the deformation of the resin can be greatly suppressed, and high-definition patterning is possible. In the printing relief printing plate, a resin is preferably used for the convex pattern. However, by forming the pattern independently, deformation of the resin used for the convex pattern due to the solvent of the ink or heat can be suppressed. . In particular, when a metal material instead of a resin material is used as the base material, the deformation of the plate can be suppressed during printing, which can be suitably used.

The barrier layer forming material in the barrier layer 300 is not particularly limited as long as it is resistant to the solvent of the ink and prevents elution of the resin component forming the convex pattern 201 into the ink. A material can be used suitably. Examples of inorganic materials include metal materials such as aluminum, titanium and chromium, metal oxide materials such as indium tin oxide (ITO) and indium zinc oxide, silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, titanium oxide, Ceramic materials such as magnesium oxide can be used.
As a method for forming the barrier layer 300 made of these inorganic materials, a dry film forming method can be used. Examples of the dry film forming method include a resistance heating vapor deposition method, an electron beam vapor deposition method, a DC sputtering method, an RF sputtering method, and the like. Various vacuum film forming means such as a sputtering method, an ECR sputtering method, a counter target sputtering method, a CVD method, and an ion plating method can be used. In addition, when an inorganic material is dissolved or dispersed in a solvent to form a coating liquid, the barrier layer can be provided even by a wet film formation method. As a wet film formation method, it is applied by various application means such as spin coating method, dip coating method, slit coating method, die coating method, roll coating method, spray coating method, and the barrier layer is formed by various processes such as drying and baking. Can be formed. However, when a barrier layer is formed by a wet film formation method, it is soluble in an ink solvent because a solvent is used to form a coating liquid, compared to a case where a barrier layer is formed by a dry film formation method. Often, these components are mixed into the barrier layer. Therefore, a dry film forming method can be suitably used as the barrier film forming method.
Note that the thickness of the barrier layer 300 made of an inorganic material is preferably 10 nm or more and 500 nm or less. When the thickness of the barrier layer is less than 10 nm, the function as a barrier layer cannot be sufficiently achieved. On the other hand, since the barrier layer is a hard film, when it exceeds 500 nm, cracks may occur in the barrier layer or the barrier layer may peel off. In addition, the thickness h of the convex pattern is preferably 0.01 mm or more and 1 mm or less. When the thickness is less than 0.01 mm, it is difficult to form a uniform resin layer thickness, and it becomes difficult to obtain a uniform film thickness of the organic light emitting layer. In addition, when the thickness is 1 mm or more, the influence of deformation of the resin layer on high-definition patterning becomes large. Furthermore, since the strength of the independent pattern portion is not sufficient, the resin layer portion may be destroyed when a strong force is applied from the outside. In addition, in the barrier layer of the relief printing plate of this invention, it should just be formed in the convex part surface which is a contact part with an ink at least. However, the ink supplied to the convex portion of the printing relief plate may also enter the concave portion, and if possible, as shown in FIG. 1, the printing relief plate including not only the convex portion of the printing relief plate but also the concave portion. The entire surface is preferably covered with a barrier layer.

  In the relief printing plate of the present invention, the ten-point average roughness Rz of the convex pattern surface is desirably 25% or less of the length of the shortest side of the convex pattern. FIG. 2 shows an explanatory schematic diagram of the convex pattern and the shortest side in the printing relief plate of the present invention. The shortest side L is the width of the stripe if the convex pattern 222 is striped (FIG. 2A), and the shortest side L is the length of the short side if the convex pattern 222 is rectangular (FIG. 2). 2 (b)), if the convex pattern 222 is a circle, the shortest side L is the length of the diameter, and if the convex pattern 222 is an ellipse, the shortest side L is the short axis length L (FIG. 2). (C)).

  In the present invention, by setting the ten-point average roughness Rz of the convex pattern surface to 25% or less of the length of the shortest side of the convex pattern, the resulting ink pattern has a uniform film thickness, and the pattern shape is also It will be good. The relief printing plate having a smooth surface shape of the present invention requires that the formed layer has a very thin film thickness of 50 to 150 nm, and that the formed layer has a uniform film thickness. It can be suitably used for forming an organic EL layer in an organic EL element.

  The ten-point average roughness Rz on the convex pattern surface can be measured with an apparatus such as an atomic force microscope (AFM), a contact surface shape measuring device, or a non-contact surface shape measuring device.

  For the relief printing plate of the present invention, a plate material in which a resin layer is provided on a substrate can be suitably used. By using such a plate material and making the convex part pattern made of resin, an ink pattern can be formed on a hard printed material such as a glass substrate without damaging the printed material.

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

  In addition, as a base material which comprises the relief printing plate used for this invention, it is requested | required that it should have sufficient rigidity to suppress the dimensional change of a resin part, and that a base material itself cannot change a dimension easily. Moreover, the thing with high tolerance with respect to the solvent contained in ink is desirable. Therefore, a metal is preferably used as the material used as the substrate. Moreover, among the base materials made of a metal material, a steel base material or an aluminum base material can be suitably used from the viewpoint of workability and economy.

In addition, dimensional changes due to temperature changes can be considered as a factor causing dimensional changes in resin plates. However, if the substrate itself is less likely to cause dimensional changes due to temperature, it is also possible to suppress dimensional changes as plates. Therefore, it is desirable that the base material used has a small thermal expansion coefficient. Incidentally, a metal such as iron exhibits a sufficiently low thermal expansion coefficient as compared with a polyester film having a thermal expansion coefficient of 1.00 × 10 ⁻⁴ / K or more, and from this point, it is also suitable as a substrate for the resin plate of the present invention. The metal base material preferably has a thermal expansion coefficient of 1.7 × 10 ⁻⁵ / K or less. More preferably, the thermal expansion coefficient is 3 × 10 ⁻⁶ / K or less. Incidentally, the thermal expansion coefficient of iron is 1.21 × 10 ⁻⁵ / K. Furthermore, iron and nickel alloys exhibit a lower coefficient of thermal expansion than iron. Among them, alloys having a ratio of 64% iron and 36% nickel have a coefficient of thermal expansion less than one-tenth that of iron and general metals. The most preferred alloy shown. The printing relief plate according to the present invention is used by being wound around a cylindrical cylinder, so that it is required to have flexibility. Therefore, in order to use a metal plate as a base material, it is necessary to make the plate as thin as possible. Yes, when using iron or an alloy of iron and nickel, a thickness of 0.1 to 0.2 mm is desirable.

  In the plate material used for the printing relief plate of the present invention, the resin layer provided on the substrate is nitrile rubber, silicone rubber, isoprene rubber, styrene butadiene rubber, butadiene rubber, chloroprene rubber, butyl rubber, acrylonitrile rubber, ethylene propylene rubber. In addition to rubber such as urethane rubber, polyethylene, polystyrene, polybutadiene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyamide, polyurethane, polyethersulfone, polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyvinyl alcohol, etc. One or more types can be selected from these synthetic resins, copolymers thereof, natural polymers such as cellulose, and the like.

  When manufacturing an organic EL element, when printing using an organic light-emitting ink in which an organic light-emitting material is dissolved or dispersed in a solvent, fluorine elastomer or polytetrafluoroethylene is used from the viewpoint of solvent resistance to the organic solvent. Water-soluble solvents such as fluorinated resins such as polyvinylidene fluoride, poly (vinylidene fluoride) and copolymers thereof, polyamide, polyvinyl alcohol, cellulose acetate succinate, partially saponified polyvinyl acetate, and cationic piperazine-containing polyamide It is desirable to use a polymer that is soluble in water. In particular, since aromatic organic solvents such as toluene and xylene are used as solvents for organic light-emitting inks, they exhibit high solvent resistance to aromatic organic solvents and are highly hydrophilic and soluble in water-soluble solvents. A suitable polymer can be used.

  In addition, it is desirable to use a photosensitive resin as the resin layer used in the plate material because a high-definition convex pattern can be easily processed. For example, a monomer containing a polymer and an unsaturated bond and a photopolymerization initiator are formed. A photosensitive resin as an element can be mentioned. At this time, the polymer can be appropriately selected from the resin materials shown above. In addition, as the polymer, a water-soluble polymer can be suitably used in the same manner as described above in that it has high resistance to an organic solvent. In the case where a water-soluble polymer is used, water is used as a developer in a development step described later. Can be used.

  Examples of the water-developable photosensitive resin in the present invention include a type having a hydrophilic polymer, a monomer containing an unsaturated bond, and a photopolymerization initiator as components. In this type, examples of hydrophilic polymers include polyamide, polyvinyl alcohol, and cellulose derivatives. Examples of the monomer containing an unsaturated bond include methacrylates having a vinyl bond, and examples of the photopolymerization initiator include aromatic carbonyl compounds. Among these, a polyamide-based water-developable photosensitive resin is preferable from the viewpoint of printability.

  Water-developable photosensitive resins contain a lot of hydrophilic components, but so-called general printing inks are often water and alcohol, and water-developable photosensitive resin plates are highly hydrophilic. Since the plate swells and deforms during printing, it is difficult to balance hydrophilicity and hydrophobicity. However, in the present invention, since the organic light-emitting ink is composed of an organic solvent, it is preferable that the hydrophilicity is high because the affinity for the organic solvent is low and the ink resistance is high, and both development suitability and ink resistance are easy.

  The solubility parameter (hereinafter referred to as SP value) of toluene is 8.9, and the SP value of xylene is 8.8. On the other hand, the SP value of polyamide (nylon) is 13.6, the SP value of polyvinyl alcohol is 12.6, and the SP value of cellulose is 15.7, which is sufficiently away from the SP values of toluene and xylene. It can be seen that the water-developable photosensitive resin made of these hydrophilic polymers has sufficient resistance to toluene and xylene.

  The above printing relief plate has an expansion rate of 5% or less when immersed in toluene or xylene for 24 hours. Therefore, when the organic light emitting layer is printed continuously for a long time by the relief printing method, the swelling and deformation of the relief relief are reduced, and a desired pattern can be obtained.

  In the case where a convex pattern is formed by photolithography using a photosensitive resin, a method for producing a relief printing plate of the present invention will be described. FIG. 3 shows an explanatory cross-sectional view of a method for producing a printing relief plate. First, as shown in FIG. 3A, a plate material in which a photosensitive resin 202a is formed on one surface on a base material 200 is prepared. Next, as shown in FIG. 3B, a photomask 206 having a light shielding portion 205 and a light transmitting portion and having a pattern formed by the light transmitting portion is disposed on the photosensitive resin 202a. . The photomask has a structure in which a light shielding portion 205 made of, for example, a chromium thin film is patterned on a light-transmitting glass 204, and a portion where the chromium thin film is formed is formed with the light shielding portion 205 and the chromium thin film. The part where there is no light becomes the translucent part.

  Next, as shown in FIG. 3C, exposure is performed by irradiating an active energy ray 207 typified by ultraviolet light through the photomask. At this time, the portion irradiated with the active energy ray through the light transmitting portion of the photomask is cured.

  Next, the photomask is removed from the resin relief printing and development is performed. The uncured portion that has not been irradiated with light by exposure is removed by development, and the relief printing plate of the present invention as shown in FIG. At this time, when using a water-developing printing relief plate in which the uncured portion can be dissolved and removed with water, water is used as the developer. Further, after the development, baking or post-exposure may be performed for the purpose of further curing the resin layer. In addition to the exposure method using a photomask, a light-impermeable layer such as carbon or aluminum is formed on the surface of the photosensitive resin layer, and this is ablated by a laser to form the light-shielding portion 205, followed by exposure. It is also possible to do.

  In addition to the photolithographic method, the convex pattern can be formed by laser ablation or cutting as a method for forming the convex pattern in the printing relief plate of the present invention.

In the relief printing plate of the present invention, the barrier layer forming surface may be subjected to surface treatment after the barrier layer is formed. By performing surface treatment on the surface of the barrier layer, the wettability between the relief printing plate and the light emitting layer ink can be improved. As the surface treatment, plasma treatment, UV treatment, UV ozone treatment, or the like can be used.
When an organic light emitting layer is formed on a substrate to be printed by a relief printing method using an organic light emitting ink, the contact portion between the organic light emitting ink and the relief printing plate, that is, the convex portion of the printing relief plate and the light emitting layer ink. The wettability with is important. When the wettability between the organic light emitting ink and the convex part of the printing relief plate is poor, a predetermined amount of the organic light emitting ink cannot be arranged on the convex part of the printing relief plate, and the light emitting layer formed on the substrate The film thickness may be thinner than the desired film thickness, and the light emitting layer pattern may be missing. Specifically, the contact angle between the organic light-emitting ink and the relief printing plate is preferably from 0 ° to 20 ° or less. When the contact angle between the light emitting layer ink and the printing relief plate exceeds 20 °, as described above, pattern defects such as pattern omission occur in the resulting light emitting layer pattern.
In addition, as a surface treatment, a method of immobilizing a coupling agent on the surface of the barrier layer can be used. For example, when silicon oxide is used for the barrier layer, the silane coupling agent can be immobilized on the barrier layer surface. The silane coupling agent can be immobilized on the barrier layer surface by applying a solution obtained by dissolving the silane coupling agent in a solvent to the relief printing plate surface and then performing a baking treatment. By using a silane coupling agent having a long-chain alkyl group as the silane coupling agent, the wettability of the light emitting layer ink can be improved on the surface of the relief printing plate.

  Next, the manufacturing method of the printed matter which forms an ink pattern on the to-be-printed substrate surface by a relief printing method using the relief printing plate of this invention is shown. FIG. 4 shows a schematic diagram of a relief printing apparatus used for producing the printed material of the present invention. The printing substrate 106 is fixed to the stage 107, the printing relief plate 104 is fixed to the plate cylinder 105, the printing relief plate 104 is in contact with the anilox roll 103 which is an ink supply body, and the anilox roll 103 is replenished with ink. A device 101 and a doctor 102 are provided.

  First, ink is replenished from the ink replenishing device 101 to the anilox roll 103, and excess ink out of the ink 108 supplied to the anilox roll 103 is removed by the doctor 102. The ink replenishing device 101 may be 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. For the doctor 102, a known object such as a doctor roll can be used in addition to the doctor blade. Further, the anilox roll 103 can be made of chromium or ceramics. Further, it is also possible to use a lithographic anilox plate instead of a cylindrical anilox roll as an ink supply to the printing relief plate. The flat anilox plate is disposed, for example, at the position of the substrate 106 to be printed in FIG. Can be done.

  The ink uniformly held by the doctor on the surface of the anilox roll 103 which is an ink supply body to the printing relief plate is transferred and supplied to the projection pattern of the printing relief plate 104 attached to the plate cylinder 105. Then, as the plate cylinder 105 rotates, the convex pattern of the printing relief plate 104 and the substrate move relatively while in contact with each other, and the ink 108 is transferred to a predetermined position on the printing substrate 106 on the stage 107 to be printed substrate. An ink pattern 108a is formed on the substrate. 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.

  Note that when printing the ink on the printing relief plate on the printing substrate, the stage 17 to which the printing substrate 106 is fixed may be moved in accordance with the rotation of the plate cylinder 105. FIG. A printing unit including the upper plate cylinder 105, the printing relief plate 104, the anilox roll 103, and the ink replenishing device 101 may be moved in accordance with the rotation of the plate cylinder. In the printing relief plate of the present invention, a resin layer may be formed on the plate cylinder 15 and directly plate-making to form a projection pattern.

  FIG. 4 shows a sheet-fed relief printing apparatus that forms an ink pattern on the 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 manufacturing an organic EL element will be described as an example of a method for manufacturing a printed material using the relief printing plate of the present invention. The present invention is not limited to this. FIG. 5 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. 5, the organic EL element of the present invention has a first electrode 2 in a stripe shape as an anode on a substrate 1. The partition wall is provided between the first electrodes, and preferably covers the first electrode end portion for the purpose of preventing a short circuit due to burrs or the like at the first electrode end portion.

  And the organic EL element of this invention has the organic EL layer which consists of an organic light emitting layer and a light emission auxiliary layer in the area | region (light emission area | region L, pixel part) on the 1st electrode 2 and divided by the partition 7. 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. In FIG. 5, the structure which consists of a laminated structure of the positive hole transport layer 3 which is a light emission auxiliary layer, and an organic light emitting layer (41, 42, 43) is shown. A hole transport layer 3 is provided on the first electrode 2, and a red (R) organic light-emitting layer 41, a green (G) organic light-emitting layer 42, and a blue (B) organic light-emitting layer 43 are provided on the hole transport layer 3. Is provided.

  Next, the 2nd electrode 5 is arrange | positioned as a cathode so as to oppose the 1st electrode 2 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. 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, contrary to FIG. 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. FIG. 6 shows an explanatory cross-sectional view of an example of the active matrix substrate of the present invention. In the case of the organic EL element substrate of the present invention, the planarization layer 117 is formed on the TFT 120, and the lower electrode (first electrode 2) of the organic EL element is provided on the planarization layer 117. In addition, the TFT and the lower electrode are preferably electrically connected through a contact hole 118 provided in the planarization layer 117. By comprising in this way, the outstanding electrical insulation can be obtained between TFT and an organic EL element.

  The TFT 120 and the organic EL element formed above the TFT 120 are supported by a support 111. The support is preferably excellent in mechanical strength and dimensional stability. Specifically, the materials described above as the substrate can be used.

  As the TFT 120 provided on the support, a known thin film transistor can be used. Specifically, a thin film transistor mainly including an active layer in which a source / drain region and a channel region are formed, a gate insulating film, and a gate electrode can be given. The structure of the thin film transistor is not particularly limited, and examples thereof include a staggered type, an inverted staggered type, a top gate type, and a coplanar type.

The active layer 112 is not particularly limited, and examples thereof include amorphous semiconductor materials such as amorphous silicon, polycrystalline silicon, microcrystalline silicon, cadmium selenide, thiophene oligomers, poly (p-ferylene vinylene), and the like. It can be formed of an organic semiconductor material. These active layers are formed by, for example, depositing amorphous silicon by plasma CVD, ion doping, forming amorphous silicon by LPCVD using SiH ₄ gas, and crystallizing amorphous silicon by solid phase growth. After obtaining silicon, ion doping is performed by ion implantation, LPCVD using Si ₂ H ₆ gas, and amorphous silicon is formed by PECVD using SiH ₄ gas, and laser such as excimer laser is used. After annealing and crystallizing amorphous silicon to obtain polysilicon, polysilicon is laminated by ion doping (low temperature process), low pressure CVD or LPCVD, and thermally oxidized at 1000 ° C. or higher. Gate break Film is formed, an n + polysilicon gate electrode 114 is formed thereon, then, a method of ion doping (high temperature process), and the like by an ion implantation method.

As the gate insulating film 113, a film normally used as a gate insulating film can be used. For example, SiO ₂ formed by PECVD, LPCVD, etc., SiO obtained by thermally oxidizing a polysilicon film ₂ etc. can be used.

  As the gate electrode 114, those normally used as the gate electrode can be used. For example, metals such as aluminum and copper, refractory metals such as titanium, tantalum and tungsten, polysilicon, silicide of refractory metals And polycide.

  The TFT 120 may have a single gate structure, a double gate structure, or a multi-gate structure having three or more gate electrodes. Moreover, you may have a LDD structure and an offset structure. Further, two or more thin film transistors may be arranged in one pixel.

  The display device of the present invention needs to be connected so that the thin film transistor (TFT) functions as a switching element of the organic EL element, and the drain electrode 116 of the transistor and the pixel electrode (first electrode 2) of the organic EL element are electrically connected. Connected. Further, it is generally necessary to use a metal that reflects light as a pixel electrode for taking a top emission structure.

  The TFT 120, the drain electrode 116, and the pixel electrode (first electrode 2) of the organic EL element are connected through a connection wiring formed in a contact hole 118 that penetrates the planarizing film 117.

Regarding the material of the planarizing film 117, inorganic materials such as SiO ₂ , spin-on glass, SiN (Si ₃ N ₄ ), TaO (Ta ₂ O ₅ ), organic materials such as polyimide resin, acrylic resin, photoresist material, and black matrix material are used. Materials and the like can be used. Spin coating, CVD, vapor deposition, etc. can be selected according to these materials. If necessary, a contact hole 118 is formed by dry etching, wet etching, or the like at a position corresponding to the lower TFT 120 after photolithography using a photosensitive resin as the planarizing layer, or once the planarizing layer is formed on the entire surface. Form. The contact hole is then filled with a conductive material to establish conduction with the pixel electrode formed in the upper layer of the planarization layer. The thickness of the planarizing layer is not limited as long as it can cover the lower TFT, capacitor, wiring, etc., and the thickness may be several μm, for example, about 3 μm.

  A first electrode 2 is provided on the substrate. When the first electrode is used as an anode, the material is a metal composite such as ITO (indium tin composite oxide), IZO (indium zinc composite oxide), tin oxide, zinc oxide, indium oxide, zinc aluminum composite oxide. A single layer or a stacked layer of metal materials such as oxide, gold, platinum, and chromium can be used. As a method for forming the first electrode, a dry film forming 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.

  In addition, ITO is preferably used because of its low resistance, solvent resistance, and high transparency when the bottom mission method is adopted. ITO is formed on the glass substrate by sputtering, and is patterned by photolithography to form the first electrode 2.

After the first electrode 2 is formed, the partition wall 7 is formed so as to cover the first electrode edge. The partition 7 needs to have insulating properties, and a photosensitive material or the like can be used. The photosensitive material may be a positive type or a negative type, a photo-curing resin of a photo radical polymerization system, a photo cationic polymerization system, or a copolymer containing an acrylonitrile component, polyvinyl phenol, polyvinyl alcohol. , Novolac resin, polyimide resin, cyanoethyl pullulan, and the like can be used. Further, as a partition wall forming _material, it is also possible to use SiO 2, TiO ₂ or the like.

  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. Is formed by printing above the first electrode by a relief printing method using a resin relief plate having a projection pattern made of resin on a substrate and using a resin dissolved or dispersed in a solvent. Can be applied. 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-quinolate) aluminum complex, bis (8-quinolate) zinc complex, tris (4-methyl-5-trifluoromethyl-8-quinolate) 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, tris (8-quinolinolato) scandium complex Small molecules such as bis [8- (para-tosyl) aminoquinoline] zinc complex and cadmium complex, 1,2,3,4-tetraphenylcyclopentadiene, poly-2,5-diheptyloxy-para-phenylene vinylene System light emitting materials can be used.

  Also, coumarin phosphors, perylene phosphors, pyran phosphors, anthrone phosphors, porphyrin 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] (MEH-PPV), poly [5-methoxy -(2-propanoxysulfonide) -1,4-phenylenevinylene] (MPS-PPV), poly [2,5-bis- (hexyloxy) -1,4-phenylene- (1-cyanovinylene)] ( CN-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 for 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 low molecular hole injection transport materials, polyaniline, polythiophene, polyvinylcarbazole, poly (3,4 -Ethylenedioxythiophene) and polymer sulfonate transport materials such as polystyrene sulfonic acid, thiophene oligomer materials, and other existing hole transport materials. wear.

  As an electron transport material for forming the electron transport layer, 2- (4-bifinylyl) -5- (4-t-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 organic light-emitting materials 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. As the wet film forming method, spin coating method, die coating method, dip coating method, discharge coating method, pre-coating method, roll coating method, bar coating method and the like, relief printing method, inkjet printing method, offset printing method, Examples of the printing method include a gravure 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, or 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. And 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 passing an electric current. 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 the cap and the substrate with an adhesive around the peripheral portion so that the concave portion hits 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 (EEA) 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. In addition, although the resin layer was formed on the sealing material here,
It is also possible to form a resin layer on the substrate and attach it 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.

  The printed matter produced using the relief printing plate of the present invention can be used for producing a color filter or a thin film transistor as a liquid crystal display member in addition to the organic EL element. In the color filter, a method for producing a printed material by a relief printing method using the relief printing plate of the present invention for forming a pattern of a color pattern, a black matrix, a white matrix, or a spacer can be used. In the thin film transistor, a method for producing a printed material by a relief printing method using the relief printing plate of the present invention for pattern formation of a gate electrode, a source electrode, a drain electrode, a gate insulating film, and an organic semiconductor material can be used.

  EXAMPLES The present invention will be further described below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

Example 1
(Preparation of printing letterpress)
A plate material having a polyamide-based photosensitive resin layer on a polyethylene terephthalate (PET) substrate was prepared. The plate material was exposed through a photomask having a 1 cm square organic light emitting layer pattern negative pattern and developed with water to obtain a printing relief plate having a desired organic light emitting layer pattern. Next, a silica thin film was formed on the relief printing plate by plasma CVD. Hexamethyldisiloxane and oxygen were used as source gases. As a reference, a silica thin film was simultaneously formed on a glass substrate, and when the silica thin film on the glass substrate was formed with a stylus type film thickness meter, the film thickness was 50 nm.
(Production of organic electroluminescence device)
A glass substrate having a thickness of 0.7 mm on which ITO (film thickness 110 nm) patterned as a 0.8 mm square was formed as an electrode was thoroughly washed with a neutral detergent, and then ultrasonically washed in the detergent solution for 5 minutes. . Next, after rinsing well with pure water, ultrasonic cleaning was performed with pure water for 10 minutes. After cleaning, moisture on the substrate was sufficiently dried under IPA saturated vapor. On this substrate, a 1.5 wt% aqueous solution of poly (3,4-ethylenedioxythiophene) and polystyrene sulfonic acid (PEDOT / PSS) (CH8000 manufactured by Starck) was applied and baked as a hole transport layer by spin coating. A thin film having a thickness of 40 nm was obtained.
Next, an organic light emitting ink made of a toluene solution of a polyphenylene vinylene (PPV) derivative, which is a green light emitting material, was prepared. This organic light-emitting ink was supplied to a relief printing apparatus, and printed on the hole transport layer through the above-described relief printing plate fixed to an anilox roll and a plate cylinder. The substrate was then vacuum dried to remove the residual solvent, and calcium and aluminum were deposited in this order through a metal mask for forming a cathode pattern by a vacuum deposition method. The calcium deposition rate was 0.1 nm / sec and the film thickness was 5 nm. The aluminum deposition rate was 5 nm and the film thickness was 110 nm. Next, this substrate was sealed with a glass cap with a desiccant attached under nitrogen, and the joint was cured with an ultraviolet curable adhesive to obtain an organic electroluminescence device.

Comparative Example As a comparative example, an organic electroluminescence element was produced using a printing relief plate on which a silica thin film was not formed in the plate production process in the examples. The other device fabrication conditions are the same as those in the example.
The current-luminance characteristics of the fabricated device of Example 1 and the device of Comparative Example 1 were measured with a luminance meter (LS-100 manufactured by Konica Minolta). As a result, the current-luminance efficiency of the device of Example 1 was 7.6 cd / A when a voltage of 5 V was applied. The current-luminance efficiency of the device of the comparative example when the 5V voltage was applied was 4.7 cd / A (see FIG. 7).

Example 2
In order to confirm the concentration of the residue derived from the relief printing plate and its influence, the following experiment was conducted. The plate of the flexographic plate (without silica film) produced in the comparative example was cut and immersed in a petri dish containing toluene, and left for 1 hour. After immersion, the plate was pulled up, and the remaining toluene solution was dried under reduced pressure to remove toluene, and a residue was obtained. Next, this residue and a polyphenylene vinylene (PPV) derivative, which is a green light emitting material, are dissolved in toluene, and the concentration of the residue with respect to the polyphenylene vinylene (PPV) derivative is 1%, 0.1%, 0.01%, 0.001. %, 0.0001% of the organic light emitting layer forming coating solution was prepared. Moreover, the toluene solution of the polyphenylene vinylene (PPV) derivative which does not contain a residue as the comparative example 2 was prepared. The produced solution was subjected to the same process as in Example 1 to obtain an organic electroluminescence device. However, the organic light emitting layer was formed not by letterpress printing but by spin coating. (Film thickness is 70 nm). Table 1 shows the current-luminance efficiency at 5 V of each element.

[Table 1]

  From Table 1, the organic electroluminescent element excellent in electric current-luminance efficiency can be provided by the residue derived from the flexographic plate contained in an organic light emitting layer being 0.01% or less.

Example 3
(Preparation of printing letterpress)
A plate material having a polyamide-based photosensitive resin layer of 0.3 mm on a metal substrate having an alloy of iron and nickel with a nickel content of 36% and a thickness of 0.2 mm was prepared. The plate material was exposed through a photomask and developed with water to obtain a printing relief plate having a stripe-shaped projection pattern. The line width of the convex part of the obtained relief printing plate was 100 μm, and the pitch was 350 μm. Next, a silica thin film was formed on the relief printing plate by plasma CVD. Hexamethyldisiloxane and oxygen were used as source gases. As a reference, a silica thin film was simultaneously formed on a glass substrate, and when the silica thin film on the glass substrate was formed with a stylus type film thickness meter, the film thickness was 50 nm. Moreover, the obtained relief printing plate was formed on the metal base material independently with respect to the adjacent convex part pattern as shown in FIG.1 (b). Further, the ten-point average roughness (Rz) of the convex surface of the printing relief printing plate was measured using a non-contact type surface shape measuring apparatus, and found to be Rz = 0.005 μm. Further, when the contact angle with the green light emitting ink described later was measured with respect to the silica thin film on the glass substrate which had been plasma-treated in the same manner as the letterpress for printing, it was 19 °.

(Production of organic electroluminescence device)
An ITO film was formed on a 300 mm square glass substrate by sputtering, and the ITO film was patterned in a stripe shape by photolithography and etching with an acid solution. The line pattern of the ITO film as the anode was a pattern in which the line width was 100 μm, the space was 50 μm, and the line was formed with 192 lines. On top of this, a PEDOT / PSS 1.5 wt aqueous solution was used to form a film having a thickness of 40 nm by spin coating.
The following organic light-emitting inks comprising three colors of red, green, and blue (RGB) were prepared.
Red luminescent ink (R): 1% by weight toluene solution of polyfluorene derivative (Red luminescent material trade name Red1100 manufactured by Sumitomo Chemical Co., Ltd.)
Green luminescent ink (G): 1% by weight toluene solution of polyfluorene derivative (Green luminescent material, trade name Green 1300, manufactured by Sumitomo Chemical Co., Ltd.)
Blue luminescent ink (B): 1% by weight toluene solution of polyfluorene derivative (blue luminescent material trade name Blue 1100 manufactured by Sumitomo Chemical Co., Ltd.)
The printing relief plate was fixed to a sheet-fed relief printing apparatus, and printing was performed for each color on the substrate to be printed using this and the above organic light-emitting ink. The organic light emitting layer was printed so that the red organic light emitting layer, the green organic light emitting layer, and the blue organic light emitting layer were arranged in a stripe shape. After printing for each color, it was dried in an oven at 130 ° C. for 1 hour. After drying, a 10 nm film of calcium (Ca) was formed on the organic light emitting layer formed by printing, and a 300 nm film of silver (Ag) was further formed thereon. The cathode made of Ca and Ag was formed by a vacuum deposition method, and was formed to be orthogonal to the ITO pattern using a mask. Finally, a full color organic EL device of the present invention was obtained using a glass cap. As a result of confirming the light emission characteristics of the organic EL element, the positional accuracy of the obtained organic light emitting layer pattern was good, and uniform light emission of 103 cd / m ^{2 at} 5 V was observed on the entire surface of the pattern portion.

  As described above, according to the present invention, when an organic EL element is produced using the relief printing method, the organic light emitting layer is not contaminated by the elution from the relief printing plate (for example, elution of residues from the relief printing plate). Is 0.01% or less), a printing relief plate capable of preventing deterioration of device performance, a method for producing a printed material, a method for producing an organic electroluminescence device using the printing relief plate, and an organic material produced by the production method An EL element can be provided.

FIG. 1 is an explanatory sectional view of an example of a relief printing plate according to the present invention. FIG. 2 is an explanatory schematic diagram of the convex pattern and the shortest side in the relief printing plate of the present invention. FIG. 3 is an explanatory sectional view of the method for producing a relief printing plate of the present invention. FIG. 4 is a schematic view of a relief printing apparatus used for producing the printed matter of the present invention. FIG. 5 is an explanatory cross-sectional view of the organic EL device of the present invention. FIG. 6 is an explanatory cross-sectional view of an example of an active matrix substrate. FIG. 7 is a graph showing current-luminance efficiency characteristics of Example 1 and Comparative Example 1.

Explanation of symbols

  200 ... base material, 201 ... convex pattern, 222 ... convex pattern, L ... short side, 202a ... photosensitive resin (uncured), 202b ... convex pattern made of photosensitive resin, 204 ...... Glass, 205 ... Light-shielding part, 206 ... Photomask, 207 ... Active energy ray, 300 ... Barrier layer, 11 ... Ink replenisher, 12 ... Doctor, 13 ... Anilox roll, 14 ... Letterpress for printing, 15 ... plate cylinder, 16 ... substrate to be printed, 17 ... stage, 18 ... ink, 18a ... ink pattern, 1 ... substrate, 2 ... first electrode, 3 ... hole Transport layer 41... Red (R) organic light emitting layer 42. Green (G) organic light emitting layer 43. Blue (B) organic light emitting layer 5 5. Second electrode 7. ... Glass cap, 9 ... Adhesive, 111 ... Support, 1 2 ... Active layer, 113 ... Gate insulating film, 114 ... Gate electrode, 115 ... Interlayer insulating film, 116 ... Drain electrode, 117 ... Planarization layer, 118 ... Contact hole, 119 ... Data line 120 ... TFT.

Claims (11)

In the printing relief plate used when supplying the ink to the relief of the relief plate, transferring the ink in the relief to the printing material, and forming the pattern made of the ink on the printing material surface,
The relief printing plate according to claim 1, wherein the relief portion of the relief plate is made of a resin, and at least the surface of the relief portion is covered with a barrier layer.   The relief printing plate according to claim 1, wherein the barrier layer is made of an inorganic material.   The relief printing plate according to claim 1 or 2, wherein the barrier layer has a thickness of 10 nm to 500 nm.   The printing relief plate according to any one of claims 1 to 3, wherein the ten-point average roughness Rz of the convex surface of the printing relief plate is 25% or less of the length of the shortest side of the convex portion. .   The printing relief plate according to any one of claims 1 to 4, wherein the projections of the printing relief plate are formed on a metal substrate.   The printing relief plate according to any one of claims 1 to 5, wherein the projections of the printing relief plate are formed on the substrate independently of the adjacent projections.   The step of supplying ink from the ink supply to the convex portions of the printing relief plate according to any one of claims 1 to 6, and transferring the ink on the convex portions of the printing relief plate to the surface of the printing substrate And a step of forming an ink pattern on the surface. In the method of manufacturing an organic electroluminescent element comprising an organic electroluminescent layer including at least a first electrode, a second electrode, and an organic light emitting layer, wherein the organic light emitting layer emits light by passing a current from both electrodes to the organic light emitting layer,
A step of supplying an ink obtained by dissolving or dispersing an organic electroluminescent material in a solvent to the convex portion of the printing relief plate according to any one of claims 1 to 6, and the ink on the convex portion of the printing relief plate A method for producing an organic electroluminescent element, comprising a step of transferring to a surface of a substrate to be printed and forming at least one layer of the organic electroluminescent layer on the surface of the substrate to be printed. In the method of manufacturing an organic electroluminescent element comprising an organic electroluminescent layer including at least a first electrode, a second electrode, and an organic light emitting layer, wherein the organic light emitting layer emits light by passing a current from both electrodes to the organic light emitting layer,
A step of supplying an organic light emitting ink obtained by dissolving or dispersing an organic light emitting material in a solvent to the convex portion of the printing relief plate according to any one of claims 1 to 6, and an organic light emission on the convex portion of the printing relief plate A method for producing an organic electroluminescence device, comprising: transferring ink to a surface of a substrate to be printed, and forming an organic light emitting layer on the surface of the substrate to be printed. A step of supplying an organic light emitting ink obtained by dissolving or dispersing an organic light emitting material in a solvent to the convex portion of the printing relief plate according to any one of claims 1 to 6, and an organic light emission on the convex portion of the printing relief plate Transferring the ink to the surface of the substrate to be printed, and forming an organic light emitting layer on the surface of the substrate to be printed;
The printing relief plate is provided with a photosensitive resin layer on a substrate, obtains a plate material, exposes the photosensitive resin layer with a photomask, and develops the exposed plate material to develop a convex portion. The base material is a metal base material, the metal base material is made of an alloy of iron and nickel, and the convex portions of the printing relief plate are independently formed with respect to the adjacent convex portions. A method for producing an organic electroluminescence element, wherein the organic electroluminescence element is formed on a material. An organic electroluminescence device manufactured by the manufacturing method according to claim 8.

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