JP2007095517A - Pattern formation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pattern formation method capable of reducing the working hours and the amount of use of ink by preparing a dummy substrate, performing printing to the dummy substrate, swelling the silicone rubber layer of a blanket by an ink solvent, and reducing unneeded printing, such as a blind print, for confirming the transfer state of ink; in a letterpress reversing offset print method for adhering a removal plate, having an irregular surface with a non-image line section as a projection and an image line section as a recess so that an ink layer opposes the projection, selectively transferring the ink layer of the non-image line section adhering to the projection to the letterpress for removing from the blanket, adhering the blanket in which the ink layer of the non-image line section has been removed to a substrate to be printed, and transferring ink on the blanket existing at the image line section to the substrate to be printed. <P>SOLUTION: In the pattern formation method, the silicone rubber layer of the blanket is swollen by a solvent, and the swollen silicone rubber layer has an ink layer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pattern forming method using a letterpress reverse offset printing method. Examples of the printed matter on which the ink pattern is formed by the pattern forming method include an organic electroluminescence element (hereinafter referred to as an organic EL element), and an organic light emitting medium layer of the organic EL element is formed by a letterpress reverse printing method. Moreover, as said printed matter, a color filter, a circuit base material, a thin-film transistor, a microlens, a biochip etc. other than an organic EL element can be illustrated as printed matter.

  For example, in the 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 thickness of the light emitting layer is important, and it is necessary to make the thin film about 100 nm. Further, in order to make this a display, it is necessary to pattern it with high definition. The organic light emitting material forming the organic light emitting layer of the organic EL element includes two types of materials, low molecular weight type and high molecular weight type. When an organic light emitting layer is formed using a low molecular weight material, it is generally formed by vapor deposition. For this reason, there was a restriction on the enlargement of the screen. On the other hand, the high molecular weight material can be made into an ink by dissolving in a solvent. Therefore, the organic light emitting layer can be formed by coating or printing, which is advantageous for increasing the screen size and cost.

  When manufacturing an organic EL element, it is necessary to make the film thickness of an organic light emitting layer into a thin film of about 100 nm. Further, in order to make this a display, it is necessary to pattern it with high definition. For this reason, as a film forming method, a printing method suitable for performing painting or patterning is suitable. In particular, since an organic EL element or a display often uses a glass substrate, an offset printing method using a rubber blanket or a relief printing method using a rubber plate or a photosensitive resin plate having the same elasticity is preferable. Actually, as an attempt by these printing methods, a method by offset printing, a method by letterpress printing, and the like have been proposed.

  Furthermore, there are offset printing methods called intaglio offset printing methods and letterpress reverse printing methods. The intaglio offset printing method and the relief reversal offset printing method are both common by transferring a patterned ink onto a substrate to be printed using a blanket having a smooth rubber layer and a silicone rubber layer as a printing surface. However, the process of patterning the ink is different.

  The relief reversal offset printing method is a method in which ink is applied from the ink supply means to the entire effective surface of the blanket, and the blanket is pressed against a removal plate having a convex portion in which the pattern formed on the substrate to be printed is a negative pattern. By separating, the ink is removed from the blanket with a negative pattern and a desired pattern is formed on the blanket, and the blanket is pressed against the substrate to be printed, and then separated, and the ink pattern on the blanket is printed on the substrate to be printed (For example, refer to Patent Documents 1 and 2).

This letterpress reversal offset printing method can control the ink application state and the ink transfer state independently, so the uniformity of the ink film is good and good transfer without stringing phenomenon is realized at low printing pressure. it can. Therefore, it is an advantageous method for forming a light emitting layer of an organic EL element having a small thickness and a slight distortion that leads to defective light emission.
JP 2003-17248 A JP 2004-178915 A

  The silicone rubber layer serving as the contact surface with the ink in the blanket needs to have an ability to absorb the ink solvent to some extent in order to uniformly form the ink layer with a constant film thickness. However, if the absorption capacity is large, the ink on the blanket dries quickly, and the ink layer on the blanket is patterned with the problem that the ink is not accurately transferred to the convex part of the removal plate. There was a problem that the ink on the blanket could not be accurately transferred onto the substrate to be printed. Note that “not correctly transferred” means that all or part of the ink on the blanket does not transfer to the convex portion of the removal plate or the substrate to be printed, but to the ink on the blanket that is transferred. In addition, there is also a phenomenon in which stringing occurs between the ink on the removed plate or the substrate to be printed and the pattern is destroyed.

  In particular, in an organic EL element, since the organic light emitting layer is provided with a thickness of 50 to 100 nm, printing is performed by a letterpress reverse printing method using an organic light emitting ink in which an organic light emitting forming material is dissolved or dispersed in a solvent. When the organic light emitting layer is formed on the substrate, the ink formed on the blanket is very thin, so that the ink layer on the blanket is quickly dried.

  For the drying of the ink layer on the blanket, a dummy substrate has been prepared so far, printing is performed on the dummy substrate, and the silicone rubber layer of the blanket is swollen by the solvent of the ink, thereby changing the ink transfer state. “Empty printing” to confirm. Then, after confirming the ink transfer state by blank printing, a pattern was formed on the substrate to be printed. However, if you perform blank printing, the production efficiency will decrease, and organic light emitting materials are very expensive, and the organic light emitting materials are wasted due to blank printing, so you do not want to perform blank printing. There is no request.

  The present invention has been made in view of the above circumstances, and by reducing unnecessary printing, a pattern forming method capable of reducing the man-hour and amount of ink used, and an organic EL manufactured using the same An object is to provide an element.

  In order to solve the above-mentioned problems, the invention according to claim 1 is a blanket having an effective surface with an easily peelable ink layer and a silicone rubber layer as the outermost layer, a non-image area as a protrusion, and an image area as a recess. From the blanket, the removed plate having the concavo-convex surface is closely attached so that the ink layer and the convex portion face each other, and the ink layer of the non-image portion that is in close contact with the convex portion is selectively transferred to the relief plate. In the relief reverse printing method in which the blanket from which the ink layer in the non-image area is removed is brought into close contact with the substrate to be printed, and the ink on the blanket existing in the image area is transferred to the substrate to be printed. Then, after the silicone rubber layer of the blanket was swollen with a solvent, an ink layer was provided on the effective surface of the swollen silicone rubber layer.

  The invention according to claim 2 is the pattern forming method according to claim 1, wherein the solvent for swelling the silicone rubber layer of the blanket contains at least one of the solvents contained in the ink.

  The invention according to claim 3 is the pattern forming method according to claim 1 or 2, wherein the solvent for swelling the silicone rubber layer of the blanket contains a solvent having a boiling point of 150 ° C or higher. .

  The invention according to claim 4 is characterized in that the mass of the silicone rubber layer swollen by the solvent is 120% to 220% with respect to the mass of the silicone rubber layer before swelling. Any one of the pattern forming methods described above was used.

  The invention according to claim 5 comprises an organic light emitting medium layer including at least a pixel electrode, a counter electrode, and an organic light emitting layer, and causes the organic light emitting layer to emit light by flowing current from both electrodes to the organic light emitting layer. 5, at least one of the organic light emitting medium layers is formed using the pattern forming method according to claim 1, using an ink obtained by dissolving or dispersing the organic light emitting medium layer forming material in a solvent. This is a method for producing an organic EL element.

  According to the present invention, it is possible to improve production efficiency by reducing empty printing, and it is possible to reduce the amount of ink used.

  In addition, since the solvent to be swollen contains at least one of the solvents contained in the ink, the solvent to be swollen and the solvent in the ink exhibit affinity, and the ink on the blanket is repelled by the swollen solvent. Can be prevented from being formed.

  Further, by using a solvent having a boiling point of 150 ° C. or higher as the solvent to be swelled, the solvent in the blanket silicone rubber layer can be prevented from evaporating, and the blanket silicone rubber layer can maintain the swollen state for a long time. .

  In addition, by controlling the weight of the blanket by determining the mass of the silicone rubber layer of the blanket to be 120% to 220% of the mass of the silicone rubber layer before the swelling, it is possible to judge a swelling state that can be easily transferred. Became possible.

  An inexpensive printed material could be obtained by forming an ink pattern on the substrate to be printed using these methods. In particular, in an organic EL element, it was possible to obtain an inexpensive organic EL element by forming at least one of the organic light emitting medium layers using the pattern forming method of the present invention.

  Embodiments of the present invention will be described below.

  The printed matter according to the present invention can be suitably used as an optical component constituting the display screen of the display. As an optical component, an organic EL element can be illustrated, for example, and the color filter which comprises a color liquid crystal display can be illustrated. In addition, examples of the printed material according to the present invention include a circuit substrate, a thin film transistor, a microlens, and a biochip.

  An explanatory cross-sectional view of a blanket used in the letterpress reverse offset printing method of the present invention is shown in FIG. The blanket includes a base substrate 1 that is attached to a blanket cylinder (not shown) during printing, and a silicone rubber layer 2 that covers the base substrate 1 and is formed with an ink layer containing a solvent.

  The base substrate 1 may be a flexible sheet because it is attached to the blanket cylinder, but a polyester film such as a polyethylene terephthalate film is preferable from the viewpoint of cost and dimensional stability. Moreover, you may provide the primer layer for adhere | attaching both suitably between the base part 1 and the silicone rubber layer 2 as needed. Moreover, you may provide a cushion layer in the contact part of the base base material 1 and a blanket cylinder as needed. As the cushion layer, a sponge-like material or the like can be used.

  The silicone rubber material of the silicone rubber layer 2 is formed by mixing a main agent and a curing agent, applying the mixture on the base substrate 1 and curing it. Any silicone rubber material may be used as long as it is printable, but an RTV (room temperature curing) type addition type silicone rubber material is preferable because it does not generate a byproduct and has good dimensional stability. The silicone rubber layer may have a single layer configuration or a multilayer configuration.

  The silicone rubber layer 2 may be formed by bonding the base material 1 after curing the silicone rubber material with a mold. It is also possible to form a blanket with only the silicone rubber layer 2 and attach it to the blanket cylinder.

  Further, the silicone rubber layer 2 obtained by applying and curing a silicone rubber material on the base substrate 1 is poured onto the base substrate 1 after being cured by pouring the silicone rubber material into a mold. It is preferable because the surface smoothness of the surface is better than the obtained silicone rubber layer.

  Next, the relief reversal offset printing method of the present invention will be described. A schematic diagram of a letterpress reverse offset printing apparatus is shown in FIG.

  A blanket 13 is attached to the blanket cylinder 12 so that the outermost surface becomes a transfer surface. Then, an organic luminescent ink is applied to the effective surface of the blanket 13 from an ink supply means (not shown) to form an ink layer 17 on the blanket 13 as shown in FIG.

  In this state, the blanket cylinder 12 is rotated so that the convex portion of the removal plate 19 on which the negative pattern is formed by the convex portion and the blanket 10 are pressure-bonded, and the stage 11 on which the removal plate 19 is fixed is aligned with the rotation of the blanket cylinder 12. Move. At this time, as shown in FIG. 2B, the portion of the ink layer 17 that is pressure-bonded to the convex portion of the removal plate 19 is removed from the blanket 13 and transferred to the convex portion of the removal plate 19. On the other hand, a desired ink pattern composed of the remaining portion of the ink layer 17 is formed on the blanket 13.

  Next, as shown in FIG. 3C, the blanket cylinder 12 is rotated to crimp the printed substrate 16 and the blanket 13, and the stage 11 on which the printed substrate 16 is fixed is aligned with the rotation of the blanket cylinder 12. Move. Thus, as shown in FIG. 3D, the pattern of the coating film 17 formed on the blanket 13 is printed on the substrate 15 to be printed.

  In the present invention, the blanket is previously swollen with a solvent. A known solvent is used as the solvent for swelling, but it is preferable that at least one of the solvents contained in the ink is included in order to obtain affinity with the ink. Moreover, as a solvent to swell, it is preferable to include a solvent having a boiling point of 150 ° C. or higher in order to maintain the wet state of the blanket.

  The mass of the swollen silicone rubber layer is preferably 120% to 220% with respect to the mass of the silicone rubber layer before swelling. When the mass is less than 120%, since the blanket is not sufficiently swollen, the ink is dried on the blanket and cannot be accurately transferred during printing. Moreover, when mass exceeds 220%, it will exceed the solvent absorption capability of a silicone rubber layer, and an ink layer may not be formed on a blanket by ink repellency.

  Examples of means for swelling the silicone rubber layer of the blanket include dipping, spraying, die coating, and gravure coating. It is also possible to use ink supply means in a letterpress reverse printing apparatus. The blanket may be before or after being mounted on the blanket cylinder.

  Next, the manufacturing method of the organic EL element of this invention is demonstrated. FIG. 3 shows an explanatory cross-sectional view of the organic EL device of the present invention.

  The organic EL element of the present invention has a pixel electrode 22 on a substrate 21, and an organic light emitting medium layer including an organic light emitting layer is formed thereon. A counter electrode 25 is formed on the organic light emitting medium layer. The organic light emitting medium layer may be an organic light emitting layer alone, but in addition to the organic light emitting layer, a hole transport layer, a hole injection layer, an electron transport layer, and an electron injection layer are provided for the purpose of assisting light emission in the organic light emitting layer. It is provided as appropriate. In FIG. 1, it is set as the 2 layer structure of the positive hole transport layer 3 and the organic light emitting layer (241,242,243). In FIG. 1, the organic light emitting layer has three colors of a red organic light emitting layer (241), a green organic light emitting layer (242), and a blue organic light emitting layer (243). A partition wall is provided between the pixel electrodes as necessary.

  As the substrate, any substrate can be used as long as it is an insulating substrate. In the case of the bottom emission method in which light is extracted from the substrate side, it is necessary to use a transparent substrate. For example, a glass substrate or a plastic film or sheet can be used. If a plastic film is used, an organic EL element can be manufactured by winding, and the element can be provided at a low cost. As the plastic, for example, polyethylene terephthalate, polypropylene, cycloolefin polymer, polyamide, polyethersulfone, polymethyl methacrylate, polycarbonate and the like can be used. In the case of a top emission method in which light is extracted from the side opposite to the substrate, an opaque substrate can be used.

  Moreover, it is preferable to reduce the water | moisture content adsorb | sucked in the board | substrate inside or the surface as much as possible by heat-processing these board | substrates beforehand. 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.

  In addition, a thin film transistor (TFT) may be formed on these substrates to form an active matrix driving substrate. The TFT material may be an organic TFT such as polythiophene, polyaniline, copper phthalocyanine or perylene derivative, or may be amorphous silicon or polysilicon TFT.

  Next, an anode is formed on the substrate as a pixel electrode. Metal composite oxides such as ITO (indium tin composite oxide), IZO (indium zinc composite oxide), and zinc aluminum composite oxide can be used as the anode material. A dry coating method can be used as a forming method. For example, resistance heating vapor deposition, electron beam vapor deposition, reactive vapor deposition, ion plating, and sputtering. Then, a photoresist can be applied to the vacuum-formed metal oxide film, exposed and developed, and processed into a pattern by wet etching or dry etching. In order to reduce the resistance, a metal such as copper, chromium, aluminum, titanium, or a laminate thereof can be partially provided as an auxiliary electrode on the transparent electrode.

  Next, an organic light emitting medium layer is formed. The organic light emitting medium layer may be composed of an organic light emitting layer alone, or an organic light emitting layer and a layer for assisting light emission such as a hole transport layer, a hole injection layer, an electron transport layer, and an electron injection layer. A laminated structure may be used. The hole transport layer, hole injection layer, electron transport layer, and electron injection layer are appropriately selected.

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

  Further, coumarin phosphors, perylene phosphors, pyran phosphors, anthrone phosphors, polyphyrin phosphors, quinacridone phosphors, N, N′-dialkyl-substituted quinacridone phosphors, naphthalimide phosphors, A material obtained by dispersing a low molecular weight light emitting material such as an N, N′-diaryl-substituted pyrrolopyrrole-based fluorescent pair or a phosphorescent light emitter 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, it may be a polymer light emitting material such as polyarylene, polyarylene vinylene, polyfluorene, polyphenylene vinylene, polyparaphenylene vinylene, polythiophene or polyspiro. In addition, a material obtained by dispersing or copolymerizing the low molecular material in these high molecular materials, or other existing light emitting materials can be used.

  As a material for the hole transport layer, 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, Aromatic amine low molecular hole injection and transport materials such as N′-diphenyl-1,1′-biphenyl-4,4′-diamine, polyaniline, polythiophene, polyvinylcarbazole, poly (3,4-ethylenedioxythiophene) ) And polystyrene sulfonic acid and other polymer hole transport materials, polythiophene oligomer materials, and other existing hole transport materials It is possible to choose from.

  As a material for the electron transport layer, 2- (4-bifinylyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (1-naphthyl)- 1,3,4-oxadiazole, an oxadiazole derivative, a bis (10-hydroxybenzo [h] quinolinolato) beryllium complex, a triazole compound, or the like can be used.

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

  Solvents that dissolve or disperse the hole transport material and 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, etc. Alternatively, a mixed solvent thereof can be used. In particular, water or alcohols are suitable.

  As a method for forming the organic light emitting layer, the letterpress reverse printing method of the present invention can be used. At this time, as the solvent for swelling the blanket, a solvent in which the organic light emitting material is dissolved or separated can be used. For example, toluene, xylene, acetone, hexane, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methanol, ethanol, isopropyl alcohol, ethyl acetate, butyl acetate, water, 2-methyl- (t-butyl) benzene, 1, 2, 3 , 4-tetramethylbenzene, pentylbenzene, 1,3,5-triethylbenzene, cyclohexylbenzene, 1,3,5-tri-isopropylbenzene. In particular, 2-methyl- (t-butyl) benzene, 1,2,3,4-tetramethylbenzene, pentylbenzene, 1,3,5-triethylbenzene, cyclohexylbenzene, 1,3 having a boiling point of 150 ° C. or higher. , 5-tri-isopropylbenzene is preferably used.

  Moreover, a wet coating method is mentioned as a formation method of a positive hole transport layer and an electron carrying layer. As the wet coating method, there are coating methods such as a spin coating method, a die coating method, a dip coating method, a discharge coating method, a pre-coating method, a roll coating method, and a bar coating method. Moreover, you may utilize the printing method of a relief printing method and the inkjet printing method. Moreover, you may use the offset printing method of this invention.

  Next, a cathode is formed as a counter electrode. As the cathode material, a substance having high electron injection efficiency is used. 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. Alternatively, 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, and Yb having a 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. In the case of the top emission method, the counter electrode needs to have transparency. For example, a transparent electrode can be obtained by a combination of a layer made of these metals or metal alloy materials and a transparent conductive material such as ITO.

  As a method for forming the counter electrode, 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 depending on the material. The thickness is preferably about 10 nm to 1 μm. In the present invention, the pixel electrode is an anode and the counter electrode is a cathode. However, the pixel electrode may be a cathode and the counter electrode may be an anode.

  And it seals through an adhesive agent with a glass cap etc., and prevents deterioration of the cathode and the light emitting medium layer due to moisture and oxygen. The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  100 parts by weight of TSE3032 (A) (GE Toshiba Silicone two-part silicone rubber main component) and 10 parts by weight of TSE3032 (B) (GE Toshiba Silicone two-part silicone rubber curing agent) are mixed to form a silicone rubber composition. Got. This composition was applied onto a PET base material as a base portion using a knife coater and heated at 70 ° C. for 2 hours to cause a curing reaction. After that, it was soaked in a vat containing cyclohexylbenzene for 1 hour. When the mass of the silicone rubber layer after swelling was measured, it was 145% with respect to the mass of the silicone rubber layer before swelling. Thereby, a swollen blanket was obtained.

  On the other hand, a glass substrate with ITO was prepared as a substrate, and the ITO was etched into a predetermined pattern to form a transparent conductive layer. Then, on the transparent conductive layer, a mixture of poly (3,4-ethylenedioxythiophene) and polystyrenesulfonic acid was applied by a spin coating method to provide a hole transport layer having a thickness of 50 nm. Thus, the to-be-printed substrate which has a board | substrate, a transparent conductive layer, and a positive hole transport layer was obtained.

  Also, poly (2-methoxy-5- (2′-ethylhexyloxy) -1,4-phenylenevinylene), which is a polyarylene vinylene polymer light-emitting material, is dissolved in 1,3,5-triethylbenzene, and organic A luminescent ink was obtained.

  The obtained blanket was mounted on a blanket cylinder, and an organic light-emitting ink was pattern-printed on the substrate to be printed by the above-described method using a relief printing offset printing apparatus. At this time, patterning could be performed from the first printing without stringing due to drying of the ink. And the organic light emitting layer was formed by heating and vacuum-drying with respect to the to-be-printed substrate in which the organic light emitting ink was printed.

  Further, lithium and aluminum are vacuum-deposited on the substrate to be printed on which the organic light emitting layer is formed to form a thin film having a thickness of 0.5 nm and 100 nm, respectively, and a cathode layer is provided to obtain the organic EL element 1. It was. When a voltage of 8 V was applied to the obtained organic EL element, it showed patterned luminescence of 100 cd / m2.

(Comparative example)
Similarly to the actual example, 100 parts by weight of TSE3032 (A) (two-part silicone rubber main component made by GE Toshiba Silicone) and 10 parts by weight of TSE3032 (B) (two-part silicone rubber curing agent made by GE Toshiba Silicone) were similarly used. The resulting silicone rubber composition was applied onto a PET substrate using a knife coater and heated at 70 ° C. for 2 hours to cause a curing reaction.

  Using the resulting blanket, the organic light-emitting ink was printed on the substrate to be printed without swelling the blanket with a solvent. As a result, the ink film was stringed up to the 15th printing and the pattern could be formed accurately. There wasn't.

It is explanatory drawing sectional drawing of the blanket of this invention. It is a schematic diagram of the relief printing apparatus of the present invention. It is explanatory sectional drawing of the organic EL element of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Silicone rubber layer 2 Base base material 11 Stage 12 Blanket cylinder 13 Blanket 16 Printed substrate 17 Ink layer 19 Removal plate 21 Substrate 22 Pixel electrode 23 Counter electrode 241 Red organic light emitting layer 242 Green organic light emitting layer 243 Blue organic light emitting layer 25 Cathode

Claims (5)

The ink layer comprises a blanket having an effective surface with an easily peelable ink layer and the outermost layer being a silicone rubber layer, and a removal plate having a concavo-convex surface with a non-image area as a protrusion and a image area as a recess. And the convex portion are in close contact with each other, and the ink layer of the non-image area in close contact with the convex portion is selectively transferred to the relief plate and removed from the blanket. In the letterpress reverse offset printing method in which the removed blanket is brought into close contact with the substrate to be printed, and the ink on the blanket existing on the image line portion is transferred to the substrate to be printed.
A method for forming a pattern, comprising the step of swelling a silicone rubber layer of the blanket with a solvent and then providing an ink layer on an effective surface of the swollen silicone rubber layer.   The pattern forming method according to claim 1, wherein the solvent that swells the silicone rubber layer of the blanket includes at least one of the solvents contained in the ink.   The pattern forming method according to claim 1, wherein the solvent for swelling the silicone rubber layer of the blanket includes a solvent having a boiling point of 150 ° C. or higher.   The pattern forming method according to claim 1, wherein the mass of the silicone rubber layer swollen by the solvent is 120% to 220% with respect to the mass of the silicone rubber layer before swelling. In an organic EL element comprising an organic light emitting medium layer including at least a pixel electrode, a counter electrode, and an organic light emitting layer, and causing an organic light emitting layer to emit light by passing a current from both electrodes to the organic light emitting layer,
Forming at least one of the organic light emitting medium layers using the pattern forming method according to any one of claims 1 to 4, using an ink obtained by dissolving or dispersing an organic light emitting medium layer forming material in a solvent. A method for producing an organic EL element, which is characterized.

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