JP2006248139A - Blanket and manufacturing method of organic electroluminescence element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blanket having a solvent absorbing property for keeping the shape of an ink on the blanket by absorbing the solvent of the ink and an ink peeling off property in order that the ink is all printed from the blanket to the substrate to be printed in combination and in which components other than a material is not transferred from the blanket to the substrate to be printed. <P>SOLUTION: The shape of the ink pattern is kept when the ink 22 is printed to the substrate 25 to be printed by an offset printing method and all the ink is printed onto the substrate 25 to be printed and contamination is not transferred to the substrate 25 to be printed by arranging the ink repellent material on the surface of the blanket 21 in the state securing the same by chemical bond. Particularly, the high-resolution pattern of an organic luminescent layer can be obtained when the organic luminescent ink 22 constituted by dissolving or dispersing an organic luminescent material in the solvent is printed onto the substrate to be printed by the offset printing method. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a blanket used for offset printing and a method for manufacturing an organic EL element.

  In the field of electronic parts, there are various techniques for forming fine image patterns made of resin, such as photolithography, but in recent years, electronic parts have been actively manufactured using printing in terms of cost. There is a growing demand for further miniaturization of printing. For example, for a color filter that is a liquid crystal member, a method of manufacturing a color filter by printing three colors of red, green, and blue by an offset printing method using an offset blanket whose silicone rubber is a surface printing layer has been proposed ( For example, Patent Document 1).

  In an organic EL element, 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. The film thickness is important, and it is necessary to form a thin film of about 100 nm. Further, in order to make this a display, it is necessary to pattern it with high definition. Organic light-emitting materials used in organic EL devices include low-molecular materials and high-molecular materials. In general, low-molecular materials are formed into a thin film in a vacuum by resistance heating vapor deposition or the like. At this time, a fine pattern mask is used. Although patterning is performed, this method has a problem that patterning accuracy is less likely to be obtained as the substrate becomes larger.

  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 (ink), and forming a thin film by a wet coating 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. However, it is considered difficult to form a thin film by a printing method that is good at coating and patterning.

  There are various printing methods such as a gravure printing method, a screen printing method, an offset printing method, and a relief printing method. As an attempt by these printing methods, an offset printing method (for example, Patent Document 2), a relief printing plate, and the like. A printing method (for example, Patent Document 3) has been proposed.

The offset printing method is a method in which a blanket having a smooth rubber layer is used, an ink pattern is formed on the surface of the blanket (rubber layer), and the patterned ink on the blanket is printed on the substrate to be printed. The ink pattern has good pattern accuracy and film thickness accuracy, and the printed substrate material is not limited. In the offset printing method, in order to form a pattern with high definition on a substrate to be printed, it is necessary to maintain the shape of the ink pattern on the blanket constant in a semi-dried state. Is important to absorb. In addition, when ink patterned on a blanket is printed on a substrate to be printed, ink is generated between the substrate to be printed and the blanket, and therefore, the releasability between the blanket and the ink is important.
JP-A-5-229277 JP 2001-93668 A JP 2001-155858 A

  Therefore, the blanket, which is the printing surface, absorbs the solvent of the ink and maintains the shape of the ink on the blanket in a semi-dry state, and the ink is peeled off so that the ink is completely printed from the blanket to the printed substrate. Performance is required.

  Currently, rubber materials are used for the printing surface of blankets used in offset printing. In particular, many silicone rubbers are used, but depending on the ink, when the silicone rubber is used as the printing surface, the adhesion between the ink and the silicone rubber is high, and the ink pattern peels off from the blanket printing surface when printing on the substrate to be printed. Accordingly, there is a problem that the blanket surface remains without being printed on the substrate to be printed.

  Conversely, when fluororubber with high surface free energy and good releasability from ink is used on the blanket printing surface, the ink solvent is not absorbed by the blanket due to high ink repellency, and an ink pattern is formed on the printing surface. It becomes difficult to do. In particular, in the letterpress reverse offset printing method, there is a step of forming an ink layer over the entire effective surface of the blanket. However, ink repellency occurs and a uniform ink coating film cannot be formed.

  Further, in the field of electronic components, if contamination other than materials is mixed in the electronic component, the reliability of the electronic component is lowered. Therefore, it is necessary to prevent contamination from entering the electronic component.

  Therefore, the problem of the present invention is a blanket that combines the solvent absorption performance for absorbing the ink solvent and maintaining the shape of the ink on the blanket, and the ink peeling performance for printing all the ink from the blanket to the substrate to be printed. Another object of the present invention is to provide a blanket in which components other than ink are not transferred from the blanket to the substrate to be printed during offset printing.

  Accordingly, in order to solve the above problems, the invention according to claim 1 is to form an ink pattern on the blanket surface by an offset printing method using an ink made of a pattern forming material, and form an ink pattern on the substrate to be printed from the blanket surface. The blanket is a blanket having an ink repellent material on the blanket surface, and the ink repellent material is fixed by chemical bonding with the blanket surface.

  The invention according to claim 2 is the blanket according to claim 1, wherein the ink repellent material is a fluorine-based material.

  The invention according to claim 3 is the blanket according to claim 1 or 2, wherein the reactive group chemically bonded to the blanket surface of the ink repellent material is alkoxysilane.

  The invention according to claim 4 is the blanket according to any one of claims 1 to 3, wherein a printing surface of the blanket is a silicone rubber layer.

  The invention according to claim 5 provides the blanket according to any one of claims 1 to 4, wherein the offset printing method is a letterpress reverse offset printing method.

  According to a sixth aspect of the present invention, an organic light emitting ink is formed on a blanket surface by an offset printing method using an organic light emitting ink obtained by dissolving or dispersing an organic light emitting material in a solvent, and the substrate to be printed from the blanket surface. When the organic light emitting ink pattern was printed thereon, offset printing was performed using the blanket according to any one of claims 1 to 4.

  According to the present invention, when printing ink on a substrate to be printed by the offset printing method, the shape of the ink pattern is maintained, and all the ink is printed on the substrate to be printed. On the other hand, it was possible to obtain a blanket in which contamination did not transfer. Using the blanket of the present invention, when an organic light emitting ink obtained by dissolving or dispersing an organic light emitting material in a solvent is printed on a substrate to be printed by an offset printing method, a high-definition organic light emitting layer pattern can be obtained. did it.

  In the present invention, the rubber material used as the rubber layer of the blanket printing surface may be a known material, specifically, nitrile rubber, chloroprene rubber, butadiene rubber, styrene butadiene rubber, natural rubber, ethylene propylene rubber, Examples include butyl rubber, silicone rubber, and fluoro rubber. These rubber materials are selected according to the ink and the solvent used in the ink, and preferably have a solvent absorbability. In selecting a rubber material, it is preferable to refer to the contact angle between the rubber material and the solvent and the solubility parameter (SP value) of both. When the solvent is an organic solvent, silicone rubber is preferable because it has a solvent absorbability and a wide variety of blankets. Any silicone rubber may be used as long as it is printable, but an RTV (room temperature curing) type addition-type silicone rubber material does not generate a by-product and is preferable in terms of dimensional stability.

  The rubber layer alone can be used as a blanket, but the rubber layer may be provided on the base substrate. The rubber layer made of a rubber material can be cured on the base substrate, or the rubber material on the film can be bonded to the base substrate. The base substrate may be a flexible film because it is attached to the plate cylinder at the time of printing, but a polyester film such as polyethylene terephthalate is preferable from the viewpoint of cost and dimensional stability. Moreover, a primer layer and an adhesive layer are provided between the base substrate and the silicone rubber layer as necessary. Further, a cushion layer is provided under the base substrate as necessary. A sponge-like material can be used for the cushion layer.

  The ink repellent material may be any material having a reactive group that is fixed to the ink repellent portion and the blanket surface by chemical bonding. The ink repellent part is appropriately selected according to the type of ink solvent. For example, if the ink is hydrophilic, the ink repellent component may be hydrophobic, and conversely if the ink is hydrophobic, the ink repellent component may be hydrophilic. In particular, since ink repellency is exhibited with respect to most inks, the ink repellent portion preferably has fluorine. Moreover, as a reactive group fixed to the blanket surface by a chemical bond, what is necessary is just to chemically bond with the blanket surface, and an alkoxysilane group and a thiol group are mentioned. Among these, many alkoxysilane groups used for the silane coupling agent are preferably used when they are reacted with OH groups on the surface of glass or metal to form an organic monomolecular film. That is, many types of fluorine-based silane coupling agents are preferable as the ink repellent material.

  When the blanket surface has few OH groups and does not react with the alkoxysilane group, the blanket printing surface is eliminated by performing a surface treatment such as plasma treatment or corona treatment. These surface treatments may be performed in an oxygen (O 2) or ozone (O 3) atmosphere.

  In the blanket in which the fluorine-based silane coupling agent is fixed by chemical bonding in this way, the fluorine-based silane coupling agent exists as a monomolecular film, and the printing surface is ink-removed by the fluorine-based silane coupling agent. Combines both performance and solvent absorption by the rubber layer. In addition, many structures with fluorine, which is the ink repellent part of the fluorine-based silane coupling agent, can be selected, the molecular length of the monomolecular film can be easily adjusted, and the OH group (reaction point with the silane coupling agent on the blanket printing surface) ) Can be changed by various surface treatments, and the density of the fluorinated silane coupling agent on the printed surface can be easily adjusted.

  In the present invention, since the ink repellent material and the blanket surface are fixed by a chemical bond, it is possible to prevent the ink repellent material from being transferred to the substrate to be printed at the time of offset printing, and defects caused by contamination of electronic components Can be prevented. For example, when forming an organic light emitting layer by offset printing of an organic light emitting ink made of an organic light emitting material, if the ink repellent material and the blanket are not fixed by a chemical bond, the ink repellent material is mixed into the organic light emitting ink and the organic light emitting layer Cause light emission failure. Also, in portions other than the organic light emitting pattern, the blanket comes into contact with the substrate to be printed during offset printing, and the ink-repellent material is transferred to the substrate to be printed, which may cause repelling in the next coating process. .

  As the offset printing method, there are an intaglio offset printing method and a letterpress reverse printing method. Both use a blanket that prints a smooth rubber layer, but the intaglio offset printing method applies ink to the intaglio printing plate from the ink supply means and fills only the intaglio indentations with ink. It comprises a step of patterning ink, a step of transferring an ink pattern from the intaglio to the blanket surface, and a step of printing the patterned ink on the substrate to be printed from the blanket surface. On the other hand, in the letterpress reverse offset printing method, the ink patterning process is different.

  FIG. 1 shows a schematic diagram of a letterpress reverse offset printing apparatus. First, the ink 22 is applied to the entire effective surface of the blanket placed on the copper plate 20 from an ink supply means (not shown) and semi-dried to form a coating film. In addition, after forming an ink coating film on a blanket, you may install a blanket in a plate cylinder. Next, the plate copper 20 is rotated, the removal plate 23 on which the negative pattern of the pattern to be formed on the substrate to be printed is bonded to the blanket 21, and the stage 24 to which the removal plate 23 is fixed is moved in accordance with the rotation of the plate copper. . At this time, the ink 22 pressure-bonded to the convex portion of the removal plate is removed from the blanket and transferred to the convex portion of the removal plate 23, and a desired ink 22 pattern is formed on the blanket (FIGS. 1A and 1B). )). Next, the printing copper 20 is rotated, the printed substrate and the blanket 21 are pressure-bonded, and the stage 24 to which the printed substrate 25 is fixed is moved in accordance with the rotation of the printing copper. At this time, the pattern of the ink 22 on the blanket is printed on the printing substrate 25 (FIGS. 1C and 1D).

  In FIG. 2, the mechanism is such that the removal plate and the stage with the substrate to be printed move in accordance with the rotation of the plate copper, but the stage may be fixed and the mechanism in which the plate copper moves in accordance with the rotation of the plate copper. As mentioned above, the printing apparatus of the letterpress reverse offset printing method firstly applies the ink to the entire effective surface of the blanket, removes unnecessary portions of the ink from the blanket with the removal plate, and after the transfer removal process, The process of pressing the blanket against the substrate to be printed and separating it to print the pattern from the blanket to the printing machine plate is one cycle.

  In the letterpress reverse offset printing method, there is a step of applying ink to the entire effective surface of the blanket, and solvent absorbability is important. The present invention is applicable to both the intaglio offset printing method and the reverse relief printing method.

  Next, the structure of the organic EL element will be described. In FIG. 2, the schematic cross section which shows the organic EL element which concerns on this invention is shown. This organic EL element includes a translucent substrate 11, a transparent conductive layer 12, a hole injection layer 13, an organic light emitting medium layer 14, and a cathode layer 15.

  In this organic EL element, as the translucent substrate 11, a glass substrate or a plastic film or sheet can be used. If a plastic film is used, a polymer EL element can be produced by winding, and the element can be provided at low cost. As the plastic, for example, polyethylene terephthalate, polypropylene, cycloolefin polymer, polyamide, polyethersulfone, polymethyl methacrylate, polycarbonate and the like can be used. Moreover, you may laminate | stack other gas barrier films, such as a ceramic vapor deposition film, a polyvinylidene chloride, a polyvinyl chloride, an ethylene-vinyl acetate copolymer saponified material, on the side which does not form the transparent conductive layer 12 into a film.

  Examples of the material of the transparent conductive layer 12 include a composite oxide of indium and tin (hereinafter referred to as ITO). In addition, a semi-transparent metal such as aluminum, gold, or silver, or an organic semiconductor such as polyaniline may be used. In addition, as the material of the hole injection layer 13, a conductive polymer material such as a polyaniline derivative, a polythiophene derivative, a polyvinylcarbazole (PVK) derivative, a mixture of poly (3,4-ethylenedioxythiophene) and polystyrenesulfonic acid, or the like. Is mentioned.

  The organic light emitting medium layer 14 is a layer containing an organic light emitting layer containing an organic light emitting material, and emits light when a current flows. Examples of polymeric organic light-emitting materials include, for example, coumarin-based, perylene-based, pyran-based, anthrone-based, porphyrene-based, quinacridone-based, N, N′-dialkyl-substituted quinacridone-based, naphthalimide-based, N, N′-diaryl-substituted Fluoropyrrole-based, iridium complex-based and other luminescent dyes are dispersed in polymers such as polystyrene, polymethylmethacrylate, polyvinylcarbazole, and polyarylene-based, polyarylene vinylene-based, and polyfluorene-based polymer materials. Can be mentioned.

  In addition to the organic light emitting layer containing an organic light emitting material, the organic light emitting medium layer 14 includes a hole injection layer, a hole transport layer, an electron block layer, a hole block layer, an electron transport layer, and an electron injection layer, as necessary. It is possible to take a laminated structure including. In the case where the organic light emitting medium layer 14 is provided with a hole injection layer, a hole transport layer, an electron block layer, a hole block layer / electron transport layer / electron injection layer, this layer is also formed when these layers are formed. The manufacturing method of the invention can be applied.

  The hole injection layer, the hole transport layer, and the electron block layer are layers having a material having a hole transport property and / or an electron block property, and holes from the transparent conductive layer 12 to the organic light-emitting medium layer 14 are respectively used. This layer lowers the injection barrier, advances holes injected from the transparent conductive layer 12 in the direction of the cathode layer 15, and prevents the electrons from moving in the direction of the transparent conductive layer 12 while passing through the holes. is there.

  Examples of materials used for these layers include polymer materials such as polyaniline derivatives, polythiophene derivatives, polyvinylcarbazole (PVK) derivatives, and mixtures of poly (3,4-ethylenedioxythiophene) and polystyrenesulfonic acid. In addition, polyamines such as polyparaphenylene (PPP), polyarylene vinylenes such as polyphenylene vinylene (PPV), conductive polymers such as polyarylene vinylene (PPV), or polymers such as polystyrene (PS), arylamines, carbazole derivatives, aryl A mixture of materials exhibiting low-molecular hole-transporting properties and electron-blocking properties such as sulfides, thiophene derivatives, and phthalocyanine derivatives may be used.

  The hole blocking layer and the electron transporting layer are layers having a material having an electron transporting property and / or a hole blocking property, and each forwards electrons injected from the cathode layer 15 toward the transparent conductive layer 12. It is a layer that plays a role of preventing holes from traveling toward the cathode layer 15 while passing electrons. Materials used for these layers include those having electron transport properties such as electron transporting polysilane, polysilole, and boron-containing polymer, polyarylenes such as polyparaphenylene (PPP), and polyphenylenes such as polyphenylene vinylene (PPV). Conductive polymers such as arylene vinylenes or polymers such as polystyrene, 7,7,8,8-tetracyanoquinodimethane (TCNQ) derivative charge transfer complexes, silole derivatives, arylboron derivatives, bisphenanthroline, etc. A mixture of materials having electron transport properties or hole blocking properties such as pyridine derivatives, perfluorinated oligophenylene derivatives, and oxadiazole derivatives may be used.

  The electron injection layer is a layer having a material having an electron injection property, and is a layer that plays a role of lowering an electron injection barrier from the cathode layer 15 to the organic light emitting medium layer 14. As the material used for this layer, in addition to the same materials as those used for the electron transport layer described above, alkali metal or alkaline earth metal salts and oxides such as lithium fluoride and lithium oxide, and polystyrene (PS A material mixed with a polymer material such as) may be used.

  As the material of the cathode layer 15, materials corresponding to the light emission characteristics of the organic light emitting medium layer 14 can be used. For example, simple metals such as lithium, magnesium, calcium, ytterbium, and aluminum, and stable metals such as gold and silver can be used. And alloys thereof. Alternatively, a conductive oxide such as indium, zinc, or tin can be used.

  The hole injection layer 13 is formed using an ink containing the conductive polymer material as the polymer EL material ink. First, a light-transmitting substrate with a transparent conductive layer is prepared, the transparent conductive layer is etched into a predetermined pattern, and then a conductive polymer material is formed on the light-transmitting substrate on which the transparent conductive layer is formed in a pattern. A hole injection layer is provided by printing an ink containing. Thus, the to-be-printed substrate which has a translucent substrate, a transparent conductive layer, and a hole injection layer is obtained.

  The organic light emitting layer in the organic light emitting medium layer 14 is formed using an organic light emitting ink. The organic light emitting ink is obtained by dissolving or dispersing the above-described organic light emitting material in a solvent. Solvents that dissolve or disperse the organic light emitting 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 alone or a mixed solvent thereof. Etc. Moreover, surfactant, antioxidant, a viscosity modifier, a ultraviolet absorber, etc. may be added to organic luminescent ink as needed.

  Next, the manufacturing method of an organic EL element is shown. First, a light-transmitting substrate with a transparent conductive layer is prepared, the transparent conductive layer is etched into a predetermined pattern, and then a conductive polymer material is formed on the light-transmitting substrate on which the transparent conductive layer is formed in a pattern. A hole injection layer is provided by printing an ink containing. Thus, the to-be-printed substrate which has a translucent substrate, a transparent conductive layer, and a hole injection layer is obtained. An organic light emitting ink made of an organic light emitting material is sequentially printed on the hole injection layer on the substrate to be printed to provide an organic light emitting layer. After the organic light emitting layer is formed, the organic EL element can be obtained by drying and providing a cathode layer thereon.

  The blanket of the present invention can be applied not only to the manufacture of an organic EL element but also to pattern printing of black (black matrix), red, green, and blue in a color filter that is a liquid crystal member.

  A 0.1 wt% Novec HFE-7100 of (tridecafluoro-1,1,2,2-tetrahydrooctyl) triethoxysilane is formed on the surface of a sheet (thickness 2 mm) of silicone rubber (GESE Silicone Corp. TSE3466). The solution (manufactured by Sumitomo 3M) was applied by dip coating. Then, it heated at 120 degreeC for 1 hour, and was made to dry and react. This sheet was rinse-washed with Novec HFE-7100 to remove excess fluorine compound, and an intended blanket having an outermost surface layer was obtained.

  Next, a toluene solution of poly (2-methoxy-5- (2′-ethylhexyloxy) -1,4-phenylenevinylene), which is a polyarylene vinylene polymer light emitter, is applied to a bar coater on the surface of the blanket described above. And applied. The ink coating was uniformly applied on the blanket, and no coating unevenness such as a melon pattern due to ink repelling was observed. This ink coating was dried to form a semi-dry ink coating. Next, the blanket was wound around the plate cylinder so that the ink coating film was located outside.

Further, a glass substrate with ITO was prepared, and the ITO was etched into a predetermined pattern. Next, on the etched transparent conductive layer, a mixture of poly (3,4-ethylenedioxythiophene) and polystyrenesulfonic acid was printed on the pattern by a gravure printing method to provide a hole injection layer having a thickness of 50 nm. . Thus, the to-be-printed substrate which has a translucent board | substrate, a transparent conductive layer, and a positive hole injection layer was obtained.

  Next, after the ink coating film on the blanket was patterned with a removal plate, it was pressure-bonded to the hole injection layer of the substrate to be printed with a pressing member. Subsequently, the roll around which the blanket was wound was rotated, and the substrate to be printed was moved in parallel in accordance with the rotation, and the ink coating was sequentially printed on the substrate to be printed to provide the snow medium layer. As a result, the ink coating film was completely printed on the substrate to be printed. The printed board was dried at nitrogen or 130 ° C. for 1 hour. The thickness of the organic light emitting layer after drying was 100 nm. Next, lithium fluoride and aluminum were provided as a cathode layer by vacuum deposition at 0.5 nm and 200 nm, respectively, to obtain an organic EL element.

  When a voltage of 8 V was applied to the obtained organic EL element, it showed patterned luminescence of 100 cd / m2. When this organic EL element was observed, no light emission unevenness was observed.

(Comparative Example 1)
A sheet of silicone rubber (GE Toshiba Silicone TSE3466) (thickness 2 mm) was used as it was as a blanket without being subjected to silane coupling treatment, and a printing experiment similar to the above example was performed. As a result, an ink coating film having no uniform unevenness was obtained, but it was not completely printed on the substrate to be printed, and white spots were generated in some places.

  When a voltage of 8 V was applied to the obtained organic EL element, a short circuit occurred and no light emission was observed at a portion where white spots were present.

(Comparative Example 2)
100 parts by weight of Viton E-60C (fluorine rubber manufactured by DuPont), 30 parts by weight of MT black, 6 parts by weight of calcium hydroxide, and 3 parts by weight of magnesia were mixed to obtain a fluororubber composition. This was put into acetone and mixed and stirred well so as to be uniformly dispersed to obtain a dispersion. The dispersion obtained in the above step was applied onto the aluminum plate using a knife coater on the surface of a silicone rubber (GE Toshiba Silicone TSE3466) sheet (thickness 2 mm), acetone was dried, and 200 ° C. It was heated in an oven for 10 minutes and vulcanized to obtain a blanket having an outermost surface layer having a thickness of 0.1 mm. The blanket was peeled off immediately because of poor adhesion between the silicone rubber and fluororubber as a support.

  Therefore, a printing experiment similar to that in the above example was performed using the fluororubber obtained in the process alone as a blanket. As a result, immediately after the ink application, toluene, which is an ink solvent, was not absorbed by the blanket, and a melon pattern due to repelling occurred. After the ink coating was semi-dried and patterned with a removal plate, printing was performed on the substrate to be printed. Printing was completed completely, but the melon pattern was printed on the substrate to be printed as it was.

  When a voltage of 8 V was applied to the obtained organic EL device, a short circuit occurred at a portion where the coating film was thin due to ink repelling, and no light emission was observed.

Schematic diagram of letterpress reverse offset printing apparatus in the present invention Schematic sectional view of an organic EL device according to the present invention

Explanation of symbols

20 .. Plate cylinder 21. Silicone blanket 22 Organic light emitting ink 23 Removal plate 24 Stage 25 Printed substrate 10 Organic EL element 11 Translucent substrate 12 Transparent conductive layer 13 .. Hole injection layer 14. Polymer light emitting medium layer 15.. Cathode layer

Claims (6)

  A blanket for forming an ink pattern on a blanket surface by an offset printing method using ink made of a pattern forming material, and printing the ink pattern on the substrate to be printed from the blanket surface. A blanket characterized in that the ink repellent material is fixed by chemical bonding with the blanket surface.   The blanket according to claim 1, wherein the ink repellent material is a fluorine-based material.   The blanket according to claim 1 or 2, wherein the reactive group chemically bonded to the blanket surface of the ink repellent material is alkoxysilane.   The blanket according to any one of claims 1 to 3, wherein a printing surface of the blanket is a silicone rubber layer.   The blanket according to any one of claims 1 to 4, wherein the offset printing method is a relief reverse printing method.   When an organic light emitting ink pattern obtained by dissolving or dispersing an organic light emitting material in a solvent is used to form an organic light emitting ink pattern on the blanket surface by the offset printing method and printing the organic light emitting ink pattern from the blanket surface onto the substrate to be printed A method for producing an organic EL element, wherein offset printing is performed using the blanket according to claim 1.

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