JP2013182841A - Donor film for manufacturing organic el element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a donor film for manufacturing an organic EL element, having such excellent characteristics that the donor film can be optimally used for laser induced thermal imaging (LITI) even when a film in which foreign substances exist is used.SOLUTION: A donor film for manufacturing an organic EL element is formed by laminating a photothermal conversion layer, a peeling layer, an organic layer and a first electrode, in order, on a polyester film including particles with a same particle size in all layers, comprising at least one layer and having a haze of 20% or more.

Description

  The present invention relates to a donor film that can be suitably used for laser-induced thermal imaging (LITI).

In recent years, organic layer patterning technology for full-color organic EL display panels has been actively researched and developed. For example, a transfer method has been proposed as a patterning method that can use a large substrate and can significantly reduce the manufacturing time. In addition, for the purpose of improving the aperture ratio, a structure for extracting light from the direction opposite to the TFT substrate has been proposed.
However, when manufacturing an organic EL device having a structure in which light is extracted from the direction opposite to the TFT substrate by using the above transfer method, it is necessary to form a cathode on the substrate side in advance using a material having poor stability in the air. is there. Such a substrate with a cathode easily oxidizes the cathode and is very difficult to handle. When oxidized, there is a problem in that the light emission characteristics of the organic EL element deteriorate. In order to solve this problem, it is possible to transfer the cathode together with the organic layer, but it is difficult to transfer the cathode and the organic layer together, and even if transferred, the edges of the transferred portion are not aligned neatly (that is, There is also the problem of becoming jagged).
In consideration of such circumstances, a donor film for producing an organic EL element that can prevent deterioration of the light emitting characteristics of the organic EL element by preventing oxidation of the cathode on the substrate has been proposed (Patent Document 1).

  A polyester film is used as a substrate for the donor film. In order to obtain a bright and clear image, a base film used as an optical film is required to have good transparency from its usage pattern and be free from defects such as foreign matter and scratches that affect the image. In recent years, due to its heat resistance and light transmittance, it has been attracting attention as a candidate substrate for a donor film used for OLED EL layer patterning.

  As a required characteristic of the donor film, it is required not to inhibit the laser light during laser patterning. Therefore, it is necessary to eliminate any internal foreign matter such as catalyst metal added at the time of resin polymerization and deteriorated resin produced in an extruder.

  It is possible to reduce the diameter of the filter used in the extruder and remove the causative substance of the internal foreign matter to some extent, but the filter pressure tends to increase, so it may not be possible to extrude. It is virtually impossible to form a film free from foreign matter.

  Further, since inorganic particles generally scatter laser light, a non-particle film is preferred as a donor film. However, even a non-particle film cannot eliminate any internal foreign matter.

JP 2003-77658 A JP 2009-125975 A Special table 2010-509756 gazette JP 2003-168559 A

  The present invention has been made in view of the above circumstances, and the problem to be solved is that it can be suitably used for laser-induced thermal imaging (LITI) even when a film containing foreign matter is used. The object is to provide a donor film for producing an organic EL device having characteristics.

  As a result of intensive studies in view of the above problems, the present inventor has found that the above problems can be easily solved by adopting a specific configuration, and has completed the present invention.

  That is, the gist of the present invention is that a polyester film having a haze of 20% or more comprising at least one layer containing particles of the same particle size in all layers, a photothermal conversion layer, a release layer, an organic layer, and a first electrode in order. It exists in the donor film for organic EL element manufacture characterized by being laminated | stacked.

  ADVANTAGE OF THE INVENTION According to this invention, even if it is a case where the film in which a foreign material exists is used, the donor film for organic electroluminescent element manufacture which has the outstanding characteristic which can be used suitably for a laser induced thermal imaging (LITI) is provided. And its industrial value is high.

  The polyester used for the polyester film in the present invention refers to a polyester obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol. Examples of the aromatic dicarboxylic acid include terephthalic acid and 2,6-naphthalenedicarboxylic acid, and examples of the aliphatic glycol include ethylene glycol, diethylene glycol, and 1,4-cyclohexanedimethanol. Representative polyesters include polyethylene terephthalate (PET), polyethylene-2,6-naphthalenedicarboxylate (PEN), and the like.

  The polyester in the present invention is a conventionally known method, for example, a method of directly obtaining a low-polymerization degree polyester by reaction of a dicarboxylic acid and a diol, or a lower alkyl ester of a dicarboxylic acid and a diol reacted with a conventionally known transesterification catalyst. Then, it can obtain by the method of performing a polymerization reaction in presence of a polymerization catalyst. As the polymerization catalyst, a known catalyst such as an antimony compound, a germanium compound, or a titanium compound may be used. Preferably, the amount of antimony compound is zero or 100% or less as antimony to reduce film dullness. .

  The polyester may be converted into chips after melt polymerization, and further subjected to solid phase polymerization as necessary under heating under reduced pressure or in an inert gas stream such as nitrogen. The intrinsic viscosity of the obtained polyester is preferably 0.40 dl / g or more, and preferably 0.40 to 0.90 dl / g.

  You may mix | blend particle | grains in the polyester layer in this invention with the main objective of providing lubricity. The kind of the particle to be blended is not particularly limited as long as it is a particle capable of imparting slipperiness. Specific examples thereof include silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, and phosphoric acid. Examples thereof include particles of magnesium silicon oxide, kaolin, aluminum oxide, titanium oxide and the like. Further, the heat-resistant organic particles described in JP-B-59-5216, JP-A-59-217755 and the like may be used. Examples of other heat-resistant organic particles include thermosetting urea resins, thermosetting phenol resins, thermosetting epoxy resins, benzoguanamine resins, and the like. Furthermore, precipitated particles obtained by precipitating and finely dispersing a part of a metal compound such as a catalyst during the polyester production process can also be used.

  On the other hand, the shape of the particles to be used is not particularly limited, and any of a spherical shape, a block shape, a rod shape, a flat shape, and the like may be used. Moreover, there is no restriction | limiting in particular also about the hardness, specific gravity, a color, etc.

  Further, the average particle size of the particles used is usually preferably 0.01 to 5 μm. If the average particle size is less than 0.01 μm, the particles tend to aggregate and the dispersibility may be insufficient. On the other hand, if the average particle size exceeds 5 μm, the surface roughness of the film becomes too rough and transparent. It may become inferior.

  Furthermore, the particle content in the polyester is usually in the range of 0.0003 to 1.0% by weight, preferably 0.0005 to 0.5% by weight, based on the total polyester constituting the film. When the particle content is less than 0.0003 wt%, the slipperiness of the film may be insufficient. On the other hand, when the content exceeds 1.0 wt%, the transparency of the film is insufficient. There are cases.

  The method for adding particles to the polyester is not particularly limited, and a conventionally known method can be adopted. For example, it can be added at any stage for producing the polyester, but the polycondensation reaction may proceed preferably after the esterification stage or after the transesterification reaction. Also, a method of blending a slurry of particles dispersed in ethylene glycol or water with a vented kneading extruder and a polyester raw material, or a blending of dried particles and a polyester raw material using a kneading extruder. It is done by methods.

  In addition to the above-mentioned particles, conventionally known antioxidants, heat stabilizers, lubricants, antistatic agents, fluorescent brighteners, dyes, pigments, and the like are added to the polyester film in the present invention as necessary. be able to. Depending on the application, an ultraviolet absorber, particularly a benzoxazinone-based ultraviolet absorber, may be contained.

  The film of the present invention can be formed into a laminated structure using a coextrusion method. In this case, it is preferable that the outermost layer thickness is usually 2 μm or more and ¼ or less of the total thickness on one side only. When the thickness is less than 2 μm, oligomers (cyclic trimers) contained in the inner layer are deposited on the film surface due to heat history during processing, etc., and production line contamination and an increase in the amount of foreign matter on the film surface are observed. On the other hand, if it is thicker than 1/4 of the total thickness, the amount of particles to be blended in the outermost layer may increase and the transparency may be impaired.

  On the other hand, when the present invention is carried out with a single layer, it is also preferable that the film is made to contain no particles as much as possible, and the particles are contained in the front and back coating layers.

  Moreover, when adding additives, such as the said ultraviolet absorber and dye, it is preferable to mix | blend with the intermediate | middle layer of a laminated | multilayer film.

  Hereinafter, although the manufacturing method of a polyester film is demonstrated concretely, as long as the summary of this invention is satisfied, this invention is not specifically limited to the following illustrations.

  First, a dried or undried polyester chip by a known method is supplied to a melt extrusion apparatus and heated to a temperature equal to or higher than the melting point of each polymer and melted. Next, the molten polymer is extruded from a die and rapidly cooled and solidified on a rotary cooling drum so that the temperature is equal to or lower than the glass transition temperature to obtain a substantially amorphous unoriented sheet. In this case, in order to improve the flatness of the sheet, it is preferable to improve the adhesion between the sheet and the rotary cooling drum. In the present invention, an electrostatic application adhesion method and / or a liquid application adhesion method is preferably employed.

  In the present invention, the sheet thus obtained is stretched biaxially to form a film. Specifically describing stretching conditions, the unstretched sheet is preferably stretched 2 to 5 times at 70 to 145 ° C. in the longitudinal direction to form a longitudinal uniaxially stretched film, and then at 90 to 160 ° C. in the lateral direction. It is preferable to perform 2 to 5 times stretching and to perform heat treatment at 200 to 240 ° C. for 10 to 600 seconds. Further, at this time, it is preferable to relax 5 to 20% in the longitudinal direction and / or the transverse direction in the maximum temperature zone of the heat treatment and / or the cooling zone at the heat treatment outlet. Further, it is possible to add re-longitudinal stretching and re-lateral stretching as necessary.

  In the present invention, as described above, two or more polyester melt extruders can be used to form a laminated film of two layers or three or more layers by a so-called coextrusion method. As the layer structure, an A / B structure using an A raw material and a B raw material, or an A / B / A structure, and further using a C raw material to form an A / B / C structure or other film. Can do. For example, the surface shape of the A layer can be designed using specific particles as the A raw material, and a film having an A / B or A / B / A structure can be formed using a raw material not containing particles as the B raw material. In this case, since the raw material of B layer can be selected freely, a cost advantage etc. are large. Further, even if the recycled material of the film is blended with the B layer, the surface roughness can be designed by the surface A layer, so that the cost advantage is further increased.

  In particular, since the film of the present invention is used for optical applications, a hard coat layer, an antireflection layer, an antiglare layer, or the like is provided, or a vapor deposition layer or the like is provided. A coating layer as an undercoat layer can be provided for the purpose of improving adhesion or preventing charging in order to keep the surface clean. In forming such a coating layer, the method of forming a film, in particular, after stretching in the longitudinal direction and before stretching in the lateral direction can form a very thin coating layer, and the coating solution drying and curing reaction Is preferable in that it can be carried out in the film forming process. The coating layer is preferably a combination of a crosslinking agent and various binder resins, and as the binder resin, a polymer selected from polyester, acrylic polymer and polyurethane is usually employed from the viewpoint of adhesiveness. Each of the above polymers shall also include derivatives thereof. The derivative here refers to a polymer obtained by reacting a reactive compound with a copolymer or a functional group with another polymer.

  In addition, you may coat by an offline coat after manufacture of a film as needed. Moreover, it does not matter on one side or both sides. The coating material may be either water-based and / or solvent-based for offline coating, but is preferably water-based or water-dispersed for in-line coating.

  In addition, since the film of the present invention is used for optics, it is also preferable to form a functional multilayer thin film for the purpose of preventing dust reflection due to reflection of external light and static electricity, as well as electromagnetic shielding, in addition to improving adhesiveness. .

  Among the polyesters, acrylic polymers, and polyurethanes that are used as coating agents in the present invention, particularly preferred polymers have a glass transition temperature (Tg) of 0 ° C. or higher, more preferably 40 ° C. or higher. It is a polyurethane having a carboxylic acid residue, at least a part of which is made water-based using an amine or ammonia.

  As the crosslinking agent resin, melamine-based, epoxy-based, and oxazoline-based resins are generally used, but melamine-based resins are particularly preferable from the viewpoints of coatability and durable adhesiveness. The melamine-based resin may be either a monomer, a condensate composed of a dimer or higher multimer, or a mixture thereof.

  In the present invention, it is preferable to contain inorganic particles or organic particles in the coating layer in order to further improve the slipperiness, adhesion and the like. The amount of the particles in the coating agent is usually 0.5 to 10% by weight, preferably 1 to 5% by weight. When the blending amount is less than 0.5% by weight, the blocking resistance may be insufficient. When the blending amount exceeds 10% by weight, the transparency of the film is hindered and the sharpness of the image tends to be lowered.

  Examples of the inorganic particles include silicon dioxide, alumina, zirconium oxide, kaolin, talc, calcium carbonate, titanium oxide, barium oxide, carbon black, molybdenum sulfide, and antimony oxide. Among these, silicon dioxide is easy to use because it is inexpensive and has various particle sizes. On the other hand, examples of the organic particles include polystyrene or polyacrylate polymethacrylate in which a crosslinked structure is achieved by a compound containing two or more carbon-carbon double bonds in one molecule (for example, divinylbenzene).

  The above inorganic particles and organic particles may be surface-treated. Examples of the surface treatment agent include a surfactant, a polymer as a dispersant, a silane coupling agent, a titanium coupling agent, and the like. The content of the particles in the coating layer is preferably 10% by weight or less, more preferably 5% by weight or less as an appropriate addition amount that does not impair the transparency.

  Further, the coating layer may contain an antistatic agent, an antifoaming agent, a coating property improving agent, a thickener, an antioxidant, an ultraviolet absorber, a foaming agent, a dye, a pigment, and the like.

  As long as water is the main medium, the coating agent may contain a small amount of an organic solvent for the purpose of improving dispersion in water or improving the film-forming performance. It is necessary to use the organic solvent as long as it is soluble in water. Examples of the organic solvent include aliphatic or alicyclic alcohols such as n-butyl alcohol, n-propyl alcohol, isopropyl alcohol, ethyl alcohol, and methyl alcohol, glycols such as propylene glycol, ethylene glycol, and diethylene glycol, n-butyl cellosolve, Examples thereof include ketones such as ethyl cellosolve, methyl cellostel, methyl ethyl ketone and acetone, and amides such as N-methylpyrrolidone. These organic solvents may be used in combination of two or more as required.

  As a coating method of the coating agent, for example, a reverse roll coater, a gravure coater, a rod coater, an air doctor coater, or a coating apparatus other than these as shown in Yuji Harasaki, Tsuji Shoten, published in 1979, “Coating Method” Can be used.

  The coating layer may be formed only on one side of the polyester film or on both sides. When formed only on one side, other characteristics can be imparted by forming a coating layer different from the above-mentioned coating layer on the opposite surface as necessary. In addition, in order to improve the applicability | paintability and adhesiveness to the film of a coating agent, you may give a chemical process and an electrical discharge process to a film before application | coating. Further, in order to further improve the surface characteristics, a discharge treatment may be performed after the coating layer is formed.

  The thickness of the coating layer is usually 0.01 to 0.5 μm, preferably 0.015 to 0.3 μm as the final dry thickness. When the thickness of the coating layer is less than 0.01 μm, the effect of the present invention may not be sufficiently exhibited. When the thickness of the coating layer exceeds 0.5 μm, the films tend to stick to each other, and particularly when the coated film is re-stretched to increase the strength of the film, it adheres to the roll in the process. There is a tendency to become easy. The above problem of sticking appears particularly when the same coating layer is formed on both sides of the film.

  When such a coating film is applied to an optical application, the coating layer surface coating is problematic when an antireflection layer or the like is provided on the coating layer. The reason for the occurrence of coating leakage is not clear, but foreign matter in the film creates coarse protrusions on the surface of the film, which acts as a core and the coating agent repels and stretches to cause coating leakage or the film surface. There may be a case where the oligomer or dust attached to the core becomes a nucleus and the coating agent repels and disappears from the nucleus. Therefore, it is necessary to form a film under such a condition that dust and foreign matters that can become nuclei are removed as much as possible. Such foreign substances include oligomers adhered or deposited on the film, so that reducing the amount of oligomers contained in the film has the effect of reducing the amount of coating.

  Photothermal conversion layer constituting the donor film of the present invention The photothermal conversion layer is a film having a function of absorbing light and generating heat efficiently. Such a film is not particularly limited, and for example, aluminum, a metal film made of an oxide / sulfide thereof, carbon black, graphite, a film in which an infrared dye is dispersed in a polymer material, or the like can be used.

  The release layer is a layer for receiving the heat generated by the light-to-heat conversion layer to release the transfer layer. The material of the release layer is not particularly limited. For example, poly α-methylstyrene can be used.

  In addition, the peeling layer may be provided with a gas generation layer on it as needed. The gas generating layer is a layer for efficiently transferring by absorbing light or heat and releasing a gas (for example, generating nitrogen gas, etc.) by a decomposition reaction. Examples thereof include pentaerythritol nitrate and trinitrotoluene, but the present invention is not particularly limited thereto.

  In this invention, what formed the photothermal conversion layer and the peeling layer on the polyester film is called a base film.

  As the transfer layer transfer layer, the transfer layer may be composed of the organic layer on the base film and the first electrode, or the transfer layer is composed of the counter electrode, the organic layer and the first electrode on the base film. Also good.

The organic layer may be a single layer structure or a multilayer structure, and the configuration thereof is not particularly limited, and examples thereof include the following configurations.
(1) Organic light emitting layer (2) Electron transport layer (3) Hole transport layer / organic light emitting layer (4) Organic light emitting layer / electron transport layer (5) Hole transport layer / organic light emitting layer / electron transport layer (6 ) Hole injection layer / hole transport layer / organic light emitting layer / electron transport layer (7) Hole injection layer / hole transport layer / organic light emitting layer / blocking layer / electron transport layer

  Organic Light-Emitting Layer The organic light-emitting layer may be a single layer or a multilayer structure. Here, the organic light-emitting layer can be formed by a conventional method. For example, the organic light-emitting material is directly formed by a drive process such as a vacuum evaporation method, an EB method, an MBE method, or a sputtering method. However, the present invention is not particularly limited thereto.

  For example, spin coating method, dip coating method, doctor blade method, discharge coating method, spray coating method, ink jet method, letterpress printing method, intaglio printing method, screen printing method, microgravure using organic light emitting layer forming coating liquid Although it is possible to form a film by a wet process such as a coating method, the present invention is not particularly limited thereto.

  Here, the coating solution for forming an organic light emitting layer is a solution containing at least a light emitting material, may contain one or more kinds of light emitting materials, and further contains a binding resin. Also good. In addition, it may contain a leveling agent, a light emission assisting agent, a charge transport material, an additive (donor, acceptor, etc.), or a light emitting dopant, and the present invention is particularly limited thereto. is not.

  Here, the light emitting material is not particularly limited, and a known light emitting material for an organic EL element can be used. For example, 4,4′-diphenylvinyl) -biphenyl (DPVBi) can be used as the low molecular weight light emitting material. ) Aromatic dimethylidene compounds such as 5-methyl-2- [2- [4- (5-methyl-2-benzoxazolyl) phenyl] vinyl] benzoxazole, 3- (4- Triphenyl derivatives such as biphenylyl) -4-phenyl-5-t-butylphenyl-1,2,4-triazole (TAZ), styrylbenzene compounds such as 1,4-bis (2-methylstyryl) benzene, thiopyrazine Dioxide derivative, benzoquinone derivative, naphthoquinone derivative, anthraquinone derivative, diphenoquinone derivative, fluoro Fluorescent organic materials such as renon derivatives, azomethine zinc complexes, and fluorescent organometallic compounds such as (8-hydroxyquinolinato) aluminum complexes (Alq3).

  On the other hand, examples of the polymer light-emitting material include poly (2-decyloxy-1,4-phenylene) DO-PPP, poly [2,5-bis- [2- (N, N, N-triethylammonium) ethoxy]. -1,4-phenyl-alt-1,4-phenyllene] dipromide (PPP-NEt3 +), 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), etc. , For example, it can be mentioned PPV precursor, PNV precursor, PPP precursor, etc..

  Here, the binding resin is not particularly limited, and examples thereof include polycarbonate and polyester. Here, the solvent is not particularly limited as long as it can dissolve or disperse the light emitting material, and examples thereof include pure water, methanol, ethanol, THF, chloroform, toluene, xylene, and trimethylbenzene. be able to.

  The charge transport layer may be a single layer or a multilayer structure. Here, the charge transport layer can be formed by a conventional method. For example, the charge transport material is directly formed by a dry process such as a vacuum evaporation method, an EB method, an MBE method, or a sputtering method. However, the present invention is not particularly limited thereto.

  Further, for example, using a coating liquid for charge transport layer formation, spin coating method, dip coating method, doctor blade method, discharge coating method, spray coating method, ink jet method, letterpress printing method, intaglio printing method, screen printing method, Although it is possible to form a film by a wet process such as a micro gravure coating method, the present invention is not particularly limited thereto.

  The coating solution for forming a charge transport layer is a solution containing at least a charge transport material, may contain one or more kinds of charge transport materials, and further contains a binding resin. May be. In addition, a leveling agent, an additive (donor, acceptor, etc.) may be contained, and the present invention is not particularly limited thereto.

  Although it does not specifically limit as a charge transport material here, The well-known charge transport material for organic EL elements and organic photoconductors can be used. For example, as a hole transport material, an inorganic p-type semiconductor material, a porphyrin compound, N, N′-bis- (3-methylphenyl) one N, N′-bis- (phenyl) -benzidine (TPD), N, Low molecular weight materials such as aromatic tertiary amine compounds such as N′-di (naphthalen-1-yl) -N, N′-diphenyl-benzidine (NPD), hydrazone compounds, quinacridone compounds, styrylamine compounds, polyaniline ( PANI), 3,4-polyethylenedioxythiophene / polystyrene sulfonate (PEDT / PSS), poly [triphenylamine derivatives] (Poly-TPD), polyvinylcarbazole (PVCz) and other polymer materials, poly (p- Phenylene vinylene) precursor (Pre-PPV), poly (p-naphthalene vinylene) precursor (Pr) -PNV) and the like polymeric material precursor, such as.

  On the other hand, as the electron transport material, for example, low molecular weight materials such as inorganic n-type semiconductor materials, oxadiazole derivatives, triazole derivatives, thiopyrazine dioxide derivatives, benzoquinone derivatives, naphthoquinone derivatives, anthraquinone derivatives, diphenoquinone derivatives, fluorenone derivatives, A polymer material such as poly [oxadiazole [(Poly-OXZ)] can be given.

  Here, the binding resin is not particularly limited, and examples thereof include polycarbonate and polyester. Here, the solvent is not particularly limited as long as it can dissolve or disperse the charge transport material, and examples thereof include pure water, methanol, ethanol, THF, chloroform, xylene, and trimethylbenzene. Can do.

  The blocking layer may be a single layer or a multilayer structure. The coating solution for forming a blocking layer is a solution containing at least a charge blocking material, may contain one or more kinds of charge blocking materials, and further contains a binding resin. Also good. In addition, a leveling agent or the like may be contained, and the present invention is not particularly limited to these.

  Here, as the charge blocking material, a known charge blocking material for an organic EL device can be used, and is not particularly limited. For example, 4,7-diphenyl-1,10-phenanthroline, 2,9-dimethyl-1, Examples thereof include 10-phenanthroline.

  Here, the binding resin is not particularly limited, and examples thereof include polycarbonate and polyester. Here, the solvent is not particularly limited as long as it can dissolve or disperse the charge blocking material, and examples thereof include pure water, methanol, ethanol, THF, chloroform, xylene, and trimethylbenzene. Can do.

  As the first electrode, a material conventionally used as a cathode can be used. The thickness of the first electrode can be about 50 nm or less. This is a preferable condition for clearly transferring the first electrode onto the second electrode of the organic EL element substrate by a transfer method. Specifically, the first electrode preferably has a thickness of about 0.1 to 50 nm, more preferably about 0.1 to 10 nm.

  The first electrode can be composed of a plurality of layers. Moreover, the at least 1 layer which comprises a 1st electrode may consist of an insulator. The insulator may be made of an alkali metal or an alkaline earth metal. Further, at least one layer constituting the first electrode may be made of a metal layer having a work function of 1 eV to 4 eV. The metal layer may be made of lithium or barium.

Here, specifically, the first electrode may be a single layer, but it is preferable to form a multilayer structure using a more stable metal. For example, a single layer film made of a metal having a low work function (an alkali metal such as Ca, Ce, Cs, Rb, Li, or Ba or an alkaline earth metal), or an insulator (an alkali such as LiF, Li ₂ O, or BaF ₂₎ A single layer film made of a metal or an alkaline earth metal) may be used, or a laminated film of a metal having a low work function and a stable metal (Al, Ag, etc.) or the insulator and a stable metal (Al , Ag, etc.) may be used. Moreover, although these materials can be formed by EB, sputtering, resistance heating vapor deposition, etc., this invention is not limited to these.

  The first electrode may be patterned. Specifically, particularly when a substrate on which a TFT is formed is used as the substrate, the first electrode is patterned in a stripe shape in advance to prevent a short circuit due to the first electrode between pixels. The first electrode may be transferred to a rectangular shape by irradiating a laser in the direction perpendicular to the first electrode, or transferring by transferring heat, or the first electrode patterned into a rectangular shape from the beginning is used. Transfer may be performed by irradiating a laser or radiating heat.

  In the case where a substrate with TFT is used as the substrate, the thickness of the first electrode may be reduced to such an extent that no short circuit occurs between pixels in order to prevent a short circuit due to the first electrode between pixels.

As the counter electrode, a conventional electrode material can be used. A metal having a high work function (Au, Pt, Ni, etc.), or a transparent electrode (ITO, IDIXO (registered trademark of Idemitsu Kosan Co., Ltd.) Indium oxide (In ₂ O ₃ ), an electrode material (such as SnO _{2 in} which about 10 wt% of zinc oxide (ZnO) is added) can be used. These materials can be formed by EB, sputtering, resistance heating vapor deposition, or the like, but the present invention is not limited to these. It is also possible to perform patterning by photolithography.

  In addition, as a method for forming a transfer layer on the base film, the transfer layer is formed on the base film by forming the constituent material of the organic layer and the constituent material of the first electrode by a conventional drive process or wet process. However, the present invention is not particularly limited to these.

  For example, the constituent material of the organic layer and the constituent material of the first electrode can be directly applied by a drive process such as vapor deposition, MBE, ion beam method, sputtering method, or the constituent material of the organic layer and the constituent material of the first electrode. The transfer layer is formed by depositing each dissolved or dispersed coating solution by a wet process such as spin coating, doctor blade, dip coating, micro gravure coating, discharge coating, spray coating, or inkjet. It is possible to form a film.

  In addition, a counter electrode can be formed on the base film before forming the organic layer as the transfer layer. However, in the transfer layer according to the present invention, it is necessary to form the first electrode on the organic layer after forming the organic layer. Here, the environment in which the organic layer is formed is not particularly limited, but it is preferable to form the film in an inert gas such as nitrogen or argon in consideration of the hygroscopicity of the film and the alteration of the material. .

  In addition, after the organic film is formed, heat drying is preferably performed for the purpose of removing the residual solvent. Here, the environment for drying is not particularly limited, but it is preferably performed in an inert gas such as nitrogen or argon from the viewpoint of preventing deterioration of the organic material used. More preferably, it is more preferably carried out under reduced pressure, but the present invention is not particularly limited thereto.

  As the substrate for the organic EL element, a substrate having a second electrode with a thickness of about 100 to 500 nm on the surface in advance can be used. Here, the second electrode may be made of a conductive material. However, when the first electrode is reduced to about 50 nm or less according to the present invention, it is difficult to add sufficient conductivity only with the first electrode, so it is necessary to provide sufficient conductivity with the second electrode. Preferably, the film thickness should be about 100 nm or more. This is because if the electrode is not sufficiently conductive, a voltage drop occurs at the electrode, leading to an increase in power consumption. Specifically, the second electrode may be formed from a stable metal such as a material containing aluminum or silver. The organic EL element substrate may further include a switching element made of a thin film transistor (TFT).

  The embodiments of the layers constituting the organic EL element manufacturing donor film and the organic EL element substrate of the present invention have been described in detail above. In this invention, the organic EL element has a second electrode on the surface thereof. A first electrode, an organic layer, and a counter electrode are sequentially stacked on the substrate, and at least the first electrode and the organic layer among these layers are transferred from the transfer layer of the donor film.

  Therefore, other layers may be formed by conventional methods, such as spin coating method, dating method, doctor blade method, discharge coating method, spray coating method, etc., ink jet method, letterpress printing, intaglio printing method Further, it can be formed by a wet process such as a printing method such as a screen printing method or a micro gravure printing method, or a dry process such as a vacuum evaporation method, an EB method, an MBE method or a sputtering method.

  Embodiments of the organic EL display panel manufactured using the above-described donor film for manufacturing an organic EL element and the substrate for an organic EL element and the organic EL display panel manufactured by the manufacturing method will be described in detail.

  In the method for producing an organic EL display panel using the donor film of the present invention, the above-mentioned donor film for producing an organic EL element is attached onto an organic EL element substrate having the second electrode 10 on the surface, and then the donor A transfer layer in the donor film is transferred onto the substrate by irradiating a laser beam from the back surface of the film (or radiating a heat source), further removing the base film and, if necessary, a counter electrode (not shown). An organic EL display panel is manufactured by forming. That is, the cathode of the organic EL display panel manufactured by the above manufacturing method is composed of the second electrode on the organic EL element substrate and the first electrode transferred from the transfer layer.

  Here, the transfer process is preferably performed in an inert gas or in a vacuum. Moreover, it is preferable to clean the second electrode before attaching the donor film for manufacturing an organic EL element. Specifically, for example, IPA cleaning for the purpose of removing dust or the like adhering to the second electrode, UV ozone treatment or plasma treatment for the purpose of improving adhesion with a donor film for manufacturing an organic EL element, second electrode It is preferable to perform a cleaning process such as reverse sputtering for the purpose of removing the insulating layer formed on the surface.

  Here, a multilayer film composed of organic layers is laminated on an organic EL element substrate by repeating the transfer process using organic layers having different characteristics formed on different base films. Can do.

  Specifically, for example, a donor film for an organic EL device in which a hole injection material is formed on a base film, a donor film for an organic EL device in which a hole transport material is formed on a base film, and light emission on the base film A donor film for an organic EL device in which a material is formed, a donor film for manufacturing an organic EL device in which an electron transport material is formed on a base film, and the like can be used.

  However, it is necessary to form the organic EL element manufacturing donor film used for transferring the layer laminated on the second electrode of the organic EL element substrate so that the first electrode is the uppermost layer of the transfer layer. There is. For example, when the electron transport layer is transferred onto the second electrode, an organic layer in which an electron transport layer made of an electron transport material is formed on the base film and the first electrode is formed on the electron transport layer. It is necessary to use a donor film for manufacturing an EL element. When the light emitting layer is transferred onto the second electrode, a light emitting layer made of a light emitting material is formed on the base film, and the first electrode is formed on the light emitting layer. It is necessary to use a donor film.

  Also, organic red light emitting multilayer film (for example, consisting of hole transport layer / red light emitting layer / first electrode), organic green light emitting multilayer film (for example, consisting of hole transport layer / green light emitting layer / first electrode), The organic blue light emitting multilayer film (for example, consisting of a hole transport layer / blue light emitting layer / first electrode) is formed on the base film by using a donor film for manufacturing an organic EL device, and the transfer process is repeated to repeat the organic process. A multicolor organic EL element comprising red, green, and blue light emitting multilayer films can be formed on the EL element substrate, but the present invention is not particularly limited thereto.

  Moreover, a polarizing plate can be provided on the light emission side of the organic EL display panel manufactured by the above manufacturing method. As the polarizing plate that can be used in the present invention, any combination of a conventional linear deflection plate and a 1 / 4λ plate may be used. Thereby, the contrast can be improved.

  Moreover, the organic EL display panel manufactured by the said manufacturing method can also seal the opposite side to the board | substrate for organic EL elements with a sealing film or a sealing substrate. As a material of the sealing film or the sealing substrate, a material conventionally used as a sealing film or a sealing substrate can be used.

  For example, an inert gas such as nitrogen gas or argon gas may be sealed with glass, metal, or the like. In this case, it is also possible to mix a moisture absorbent such as barium oxide in the inert gas. Alternatively, a resin may be applied directly on the counter electrode by spin coating, or a sealing film may be formed by attaching a resin film, or silicon nitride or the like may be formed on the counter electrode by a plasma CVD method. Although it is good also as a sealing film, this invention is not limited to these. As a result, it is possible to prevent oxygen and moisture from entering the organic EL element from the outside, which is very desirable for improving the life.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example, unless the summary is exceeded. The measuring method used in the present invention is as follows.

(1) Measurement of Intrinsic Viscosity of Polyester 1 g of polyester was accurately weighed and dissolved by adding 100 ml of a mixed solvent of phenol / tetrachloroethane = 50/50 (weight ratio), and measured at 30 ° C.

(2) Film haze The film turbidity was measured with an integrating sphere turbidimeter NDH-300A manufactured by Nippon Denshoku Industries Co., Ltd. according to JIS-K7105.

(3) Dispersibility of the particles in the film The dispersibility of the particles added in the biaxially stretched film was determined by observing with a microscope.

(4) YAG laser transfer energy measurement It measured with the power meter (The product made by GENTEC, TPM300).

(5) Processing suitability The substrate from which the donor film was peeled was observed using an optical microscope to observe whether or not the transfer layer was transferred onto the substrate (the presence or absence of the transfer layer), and evaluated according to the following indicators.
A: Normal transfer (90% or more)
○: Partial transfer failure (60% or more and less than 90%)
Δ: Transfer defect (30% or more and less than 60%)
X: Transfer addition (less than 30%)

Examples and Comparative Examples are shown below, and the method for producing the polyester used in the Examples and Comparative Examples is as follows.
<Manufacture of polyester>
<Method for producing polyester (A)>
Using 100 parts by weight of dimethyl terephthalate and 60 parts by weight of ethylene glycol as starting materials, 0.09 parts by weight of magnesium acetate tetrahydrate as a catalyst is placed in the reactor, the reaction start temperature is set to 150 ° C., and the methanol is distilled off gradually. The reaction temperature was raised to 230 ° C. after 3 hours. After 4 hours, the transesterification reaction was substantially terminated. After 0.04 part of ethyl acid phosphate was added to this reaction mixture, 0.03 part of antimony trioxide was added and a polycondensation reaction was carried out for 4 hours. That is, the temperature was gradually raised from 230 ° C. to 280 ° C. On the other hand, the pressure was gradually reduced from normal pressure, and finally 0.3 mmHg. After the start of the reaction, the reaction was stopped at a time corresponding to an intrinsic viscosity of 0.68 due to a change in stirring power of the reaction vessel, and the polymer was discharged under nitrogen pressure. The intrinsic viscosity of the obtained polyester (A) was 0.68.

<Method for producing polyester (B)>
In the method for producing polyester (A), after adding 0.04 part of ethyl acid phosphate, 0.6 part of silica particles having an average particle diameter of 2.2 μm dispersed in ethylene glycol and 0.03 part of antimony trioxide are added. In addition, polyester (B) was obtained using the same method as the production method of polyester (A) except that the polycondensation reaction was stopped at the time corresponding to the intrinsic viscosity of 0.66. The obtained polyester (B) had an intrinsic viscosity of 0.66.

<Method for producing polyester (C)>
In the production method of polyester (B), polyester (B) was used except that 0.04 part of ethyl acid phosphate was added and then 1.0 part of silica particles having an average particle diameter of 3.2 μm dispersed in ethylene glycol was added. Polyester (C) was obtained using the same method as the production method. The obtained polyester (B) had an intrinsic viscosity of 0.65.

<Method for producing polyester (D)>
In the method for producing polyester (A), the starting material is 100 parts by weight of dimethyl terephthalate, 60 parts by weight of ethylene glycol and 2 parts by weight of diethylene glycol, and the method for producing polyester (A) is used except that germanium oxide is used as a polymerization catalyst. A polyester (D) was obtained using the same method as described above. In addition, the addition method of germanium oxide employ | adopted the well-known method, The addition amount was 100 ppm with respect to the raw material weight as germanium. The intrinsic viscosity of the obtained polyester (D) was 0.68.

<Method for producing single-layer polyester film 1>
The mixed raw materials in which the polyesters (A) and (B) described above are mixed at a ratio of 50% and 50%, respectively, are supplied to a vent type twin screw extruder, melted at 285 ° C., extruded in a single layer configuration, and extruded from a die. An unstretched sheet was obtained by cooling and solidifying on a cooling roll whose surface temperature was set to 40 ° C. using an electrostatic application adhesion method. Next, the film was stretched 3.4 times in the longitudinal direction at a film temperature of 84 ° C. using the roll peripheral speed difference, then led to a tenter, stretched 3.8 times at 120 ° C. in the transverse direction, and heat-treated at 232 ° C. Thereafter, the film was relaxed 2.3% in the lateral direction to obtain a single-layer polyester film 1 having a thickness of 100 μm.

<Method for producing laminated polyester film 1>
The mixed raw materials obtained by mixing the above polyesters (A) and (B) at 50% and 50%, respectively, are used as the raw material for the A layer, and the polyesters (B) and (D) are mixed at 50% and 50%, respectively. Using the mixed raw material as the raw material for the B layer, each is supplied to two vent type twin screw extruders and melted at 285 ° C., respectively, and the A layer is the outermost layer (surface layer) and the B layer is the intermediate layer The unstretched sheet was obtained by co-extrusion with a three-layer (A / B / A) layer configuration, extrusion from a die, and cooling and solidification on a cooling roll having a surface temperature set to 40 ° C. using an electrostatic application adhesion method. Next, the film was stretched 3.4 times in the longitudinal direction at a film temperature of 84 ° C. using the roll peripheral speed difference, then led to a tenter, stretched 3.8 times at 120 ° C. in the transverse direction, and heat-treated at 232 ° C. Thereafter, the film was relaxed 2.3% in the lateral direction to obtain a laminated polyester film 1 having a thickness of 100 μm.

<Method for producing laminated polyester film 2>
A laminated polyester film 2 having a thickness of 100 μm was obtained in the same manner as in <Method for producing laminated polyester film 1> except that polyester (D) was used as a raw material for the B layer.

<Method for producing laminated polyester film 3>
Polyester having a thickness of 100 μm in the same manner as in <Production method of laminated polyester film 1> except that the mixed raw materials obtained by mixing polyesters (C) and (D) at a ratio of 50% and 50%, respectively, were used as the raw material for the B layer. A film was obtained.

<Method for producing single-layer polyester film 2>
Single-layer polyester film 2 having a thickness of 100 μm in the same manner as in <Production method of single-layer polyester film 1> except that polyester (A) and (B) are mixed raw materials in proportions of 80% and 20%, respectively. Got.

Example 1:
A single-layer polyester film 1 is used as a base film, and a thermosetting epoxy resin in which carbon particles are mixed as a heat conversion layer is coated to a film thickness of 5 μm and cured at room temperature. Next, a poly α-methylstyrene film is coated to a thickness of 1 μm as a heat propagation and release layer to form a base film.
Next, a light emitting layer having a thickness of 80 nm was formed on the base film with a micro gravure coater using the blue light emitting layer forming coating solution. Here, as the blue light emitting layer forming coating solution, PDAF was dissolved in xylene at a solid content of 1 wt%. In addition, the viscosity of the coating liquid at this time was 2.8 cps. Next, this film was heated at 90 ° C. for 1 hour in a high purity nitrogen atmosphere to remove the solvent in the light emitting layer. Next, a 40 nm film was formed on the film of Example 1 on this light emitting layer using a resistance heating vapor deposition device to form a hole transport layer. This was used as a donor film. Next, a 20 nm hole transport layer is formed with a spin coater using a hole transport layer forming coating solution made of PEDOT / PSS on a substrate in which ITO having a length of 20 mm and a width of 100 μm is arranged at a pitch of 200 μm. Heat drying at 1 ° C. for 1 minute was performed in high purity nitrogen. Next, after the donor film is brought into close contact with the substrate at a pressure of 2 kg using a roller, the ITO film on the substrate is scanned with a YAG laser to transfer a transfer layer composed of a light emitting layer and a hole transport layer. After transfer with an energy of 0.6 J / cm ² , the donor film was peeled from the substrate.

Example 2:
It processed by the method similar to Example 1 except having used the laminated polyester film 1 as a base film.

Comparative Example 1:
Processing was performed in the same manner as in Example 1 except that the laminated polyester film 2 was used as the base film.

Comparative Example 2:
Processing was performed in the same manner as in Example 1 except that the laminated polyester film 3 was used as the base film.

Comparative Example 3:
It processed by the method similar to Example 1 except having used the single layer polyester film 2 as a base film.

  The layer structure, haze, particle dispersibility, and processing suitability of the obtained film are shown in Table 1 below. It can be seen that the film satisfying the requirements of the present invention has good processing suitability.

  The donor film of the present invention can be suitably used for organic EL production. .

Claims (3)

A feature is that a photothermal conversion layer, a release layer, an organic layer, and a first electrode are sequentially laminated on a polyester film having a haze of 20% or more and comprising at least one layer containing particles of the same particle size in all layers. Donor film for manufacturing organic EL elements. The donor film for producing an organic EL device according to claim 1, wherein the particles are inorganic particles. The donor film for producing an organic EL device according to claim 1, wherein the particles are silica particles.