JP2009070905A - Coating liquid for forming organic electroluminescence layer and method for producing organic electroluminescence display device - Google Patents

Abstract

An organic EL layer having high uniformity in thickness is provided.
The coating liquid for forming an organic electroluminescence layer according to the present invention is a liquid in which an organic electroluminescence material is contained in a solvent or dispersion medium containing a fluorocarbon. _{Fluorocarbons, n-C 4 F 9 OCH} 3, (CF 3) 2 CFCF 2 OCH 3 hydrofluoroether such, _{or, CF 3 CF 2 C (O} ) CF (CF 3) be a fluoroalkyl ketone _2, such as Is also possible. The boiling point of the fluorocarbon is preferably 45 ° C. or more and 65 ° C. or less.
[Selection] Figure 3

Description

  The present invention relates to a coating liquid for forming an organic electroluminescence layer used for forming an organic electroluminescence (EL) layer, and a method for manufacturing an organic electroluminescence display device using the coating liquid for forming the organic electroluminescence layer About.

  In the manufacturing process of the organic electroluminescence display device, as described in Patent Document 1 and Patent Document 2, a solution containing a hole injection material or an organic electroluminescence light-emitting material in a solvent is used by using an inkjet printer or the like. It is applied to a pixel electrode or the like surrounded by adjacent banks.

  However, when a hole injection layer forming coating solution in which the hole injection layer is dispersed in water is used, the solution may crawl onto the wall surface of the bank, and the film thickness at the peripheral edge of the pixel electrode may increase. As a result, the voltage applied to the organic electroluminescent light-emitting layer formed by being laminated thereon becomes non-uniform, and when such an organic electroluminescent light-emitting layer emits light, uneven light emission occurs. Further, even when xylene, toluene, or the like is used as a solvent for the coating liquid for forming an organic electroluminescence light emitting layer, such a non-uniform film thickness may occur.

JP-A-11-040358 JP-A-11-054270

  This invention is made | formed in view of such a subject, The coating liquid for organic electroluminescent layer formation which can obtain an organic electroluminescent layer with little light emission nonuniformity, and the organic using such a coating liquid It is an object of the present invention to provide a method for manufacturing an electroluminescence display device. Moreover, it aims at providing the manufacturing method of the organic electroluminescent display apparatus using the coating liquid for organic electroluminescent layer formation excellent in the uniformity of thickness, and such a coating liquid.

In order to achieve the above object, a coating solution for forming an organic electroluminescence layer according to the first aspect of the present invention comprises:
It is a liquid material in which an organic electroluminescent material is contained in a solvent or dispersion medium containing a fluorocarbon.

  It is also possible that the fluorocarbon is a hydrofluoroether.

  It is also possible that the fluorocarbon is a fluoroketone.

  Further, the boiling point of the fluorocarbon may be 45 ° C. or more and 65 ° C. or less.

In order to achieve the above object, a method of manufacturing an organic electroluminescence display device according to the second aspect of the present invention includes:
A coating liquid for forming an organic electroluminescence layer, which is a liquid in which an organic electroluminescence material is contained in a solvent or dispersion medium containing a fluorocarbon,
Applying to a predetermined region on the substrate to form an organic electroluminescence layer.

  It is also possible that the fluorocarbon is a hydrofluoroether.

  It is also possible that the fluorocarbon is a fluoroketone.

  Further, the boiling point of the fluorocarbon may be 45 ° C. or more and 65 ° C. or less.

  By using the coating liquid for forming an organic electroluminescence layer according to the present invention, an organic electroluminescence layer having excellent thickness uniformity can be obtained. In addition, the organic electroluminescence display device manufactured by the method for manufacturing an organic electroluminescence display device according to the present invention has less light emission unevenness.

[Organic electroluminescence display]
First, an organic EL display device 800 manufactured by a method for manufacturing an organic electroluminescence (hereinafter referred to as organic EL) display device according to an embodiment will be described.

As shown in FIG. 1A, the organic EL display device 800 includes a glass substrate 110, a pixel electrode (anode) 120, a hole injection layer 190, a bank 130, an organic EL light emitting layer 140, and an interlayer. An insulating film 150, an upper electrode (cathode) 160, and a sealing glass 170 are included.
In the embodiment of the present invention, the organic EL layer has a two-layer structure of the hole injection layer 190 and the organic EL light emitting layer 140, but an electron injection layer may be provided as the organic EL layer. Therefore, a three-layer structure of the hole injection layer 190, the organic EL light emitting layer 140, and the electron injection layer may be used, or a two-layer structure including the organic EL light emitting layer 140 and the electron injection layer may be used. A single layer structure composed of the EL light emitting layer 140 may be used. The layer structure of the organic EL layer can be arbitrarily set.

The light emission method of the organic EL display device 800 is a bottom emission type. As will be described later, the organic EL layer is formed by a nozzle printing method using the organic EL layer forming coating liquid according to the embodiment.
The coating liquid for forming an organic EL layer is a liquid in which an organic EL material is contained in a solvent or a dispersion medium. The organic EL material includes materials having a property of transporting carriers (a hole injection material, an electron injection material, etc.) in addition to the organic EL light emitting material.

  On the glass substrate 110, a pixel electrode 120 made of ITO (Indium Tin Oxide) and an interlayer insulating film 150 are provided. The interlayer insulating film 150 electrically insulates adjacent pixel electrodes 120 from each other. A bank 130 functioning as a partition is provided on the interlayer insulating film 150. On the pixel electrode 120 in the opening surrounded by the bank 130, the hole injection layer 190, the organic EL light emitting layer 140, and the upper electrode 160 are laminated in this order. Further, a sealing glass 170 is provided on the upper electrode 160 via an adhesive layer 180.

[Coating liquid for forming hole injection layer]
Next, the hole injection layer forming coating solution used for forming the hole injection layer by a nozzle printing method or the like will be described.

  As shown in Chemical Formula 1, the hole injection material is a mixture of PEDOT (polyethylenedioxythiophene) and PSS (polystyrene sulfonic acid), which are polythiophene derivatives. In order to prevent compatibility with the organic EL light emitting layer, gamma-glycidyloxypropyltrimethoxysilane is added as a silane coupling agent that is crosslinked by heat treatment.

Hydrofluoroether which is a mixture containing 50% by weight of methylnonafluoroisobutyl ether ((CF ₃ ) ₂ CFCF ₂ OCH ₃ ) and methyl nonafluorobutyl ether (n—C ₄ F ₉ OCH ₃ ) as liquid media, respectively. Is used. The boiling point of this mixture is 61 ° C. and the ozone depletion potential (ODP) is zero.

  Then, a hole injection layer forming coating solution is formed by containing 30% by weight of the hole injection material in the liquid medium. The concentration is desirably 20% by weight to 80% by weight. This is because if the concentration is lower than 20% by weight, the number of coatings increases in order to obtain a required film thickness, which may deteriorate the production efficiency. On the other hand, if the concentration is higher than 80% by weight, the hole injection layer is increased. This is because the viscosity of the forming coating solution becomes high and it may be difficult to apply the hole injection layer forming coating solution.

[Coating liquid for forming an organic EL light emitting layer]
Next, the organic EL light emitting layer forming coating solution used for forming the organic EL light emitting layer by a nozzle printing method or the like will be described.

  The organic EL light emitting material uses poly (paraphenylene vinylene) (PPV) as a green light emitting material. Then, fluorescent dyes such as quinacridone, rubrene, DCJT and derivatives thereof are added. Since these fluorescent dyes are low molecules, they are soluble or dispersible in a liquid, and have good compatibility with PPV and can easily form a light emitting layer.

The liquid medium is a mixture of hydrofluoroether containing 50% by weight of methylnonafluoroisobutyl ether ((CF ₃ ) ₂ CFCF ₂ OCH ₃ ) and methyl nonafluorobutyl ether (n-C ₄ F ₉ OCH ₃ ). use.

  And the coating liquid for organic EL light emitting layer formation is formed by containing 2.0 weight% of organic EL light emitting materials. The concentration is desirably 0.5% by weight to 5.0% by weight. This is because if the concentration is lower than 0.5% by weight, the number of coating times of the coating liquid for forming the organic EL light emitting layer may be increased in order to obtain a required film thickness, while the concentration is lower than 5.0% by weight. This is because the viscosity of the coating liquid for forming an organic EL light emitting layer may be increased if it is increased.

[Method for Manufacturing Organic EL Display Device]
Next, a method for manufacturing the organic EL display device 800 using the hole injection layer forming coating solution and the organic EL light emitting layer forming coating solution according to the above-described embodiment will be described.

  First, an ITO film is formed on the glass substrate 110 with a uniform thickness by sputtering or vapor deposition. Then, for the ITO film formation, pixel electrodes 120 are formed in stripes at predetermined intervals on the glass substrate 110 by photolithography using a phenol novolac resin or the like as a resist. The thickness of the pixel electrode 120 is 30 nm to 100 nm. Note that the pixel electrode 120 can be formed by performing wet etching treatment, dry etching treatment, or the like.

  Next, an interlayer insulating film 150 is formed on the glass substrate 110 provided with the pixel electrode 120. The interlayer insulating film 150 is provided in a region between the pixel electrodes 120 of the glass substrate 110, and prevents a short circuit between adjacent pixel electrodes 120 by covering the periphery of the pixel electrode 120. The interlayer insulating film 150 has a stitch shape having a plurality of openings and is formed of a film having a thickness of 150 nm to 300 nm. Interlayer insulating film 150 is formed of a silicon compound such as silicon nitride or silicon oxide, for example.

  Next, the bank 130 is formed on the interlayer insulating film 150. The bank 130 is formed by, for example, irradiating a positive photosensitive resin such as polyimide with light through a photomask. The bank 130 is a boundary region (a region between the pixel electrodes 120) between a plurality of display pixels that are two-dimensionally arranged on the organic EL display device 800, and extends in the column direction of the organic EL display device 800 (FIG. 1B). As shown in (), it is arranged so as to have a planar pattern of a fence shape or a lattice shape.

  Then, the pixel electrode 120 is made lyophilic by oxygen plasma treatment or UV ozone treatment. By performing this oxygen plasma treatment or UV ozone treatment, the hole injection material applied to the pixel electrode 120 spreads over the entire pixel electrode 120 and a uniform film thickness can be formed.

Next, the hole injection layer forming coating liquid according to the above-described embodiment is applied onto the pixel electrode 120 surrounded by the bank 130 by the nozzle printing method. As shown in FIGS. 2A and 2B, the coating liquid for forming a hole injection layer is continuously applied from the nozzle coater 400 in the column direction of the organic EL display device 800 (in the direction of the arrow 200). .
After the application, the hole injection layer 190 is formed by drying on a hot plate under a temperature condition of 100 ° C. or higher.

  Next, the organic EL light emitting layer forming coating liquid according to the embodiment is applied on the formed hole injection layer 190. Application is continuously performed from the nozzle coater 400. The application is desirably performed in a nitrogen gas atmosphere. The organic EL light emitting material may change its characteristics when it comes into contact with oxygen, water vapor or the like. Therefore, it becomes possible to make the characteristic change of the organic EL light emitting material difficult to occur by applying in a nitrogen gas atmosphere.

  The viscosity of the organic EL light emitting layer forming coating solution is 4 mPa · s. The viscosity of the coating liquid for forming an organic EL light emitting layer is 1 to 20 mPa · s, preferably 2 to 8 mPa · s. When the viscosity is less than 1 mPa · s, not only is it difficult to control the discharge amount, but there is a possibility that a sufficient film thickness cannot be formed because the solid concentration is too low. On the other hand, if the viscosity of the coating liquid for forming the organic EL light emitting layer is larger than 20 mPa · s, there is a possibility that the nozzle coater 400 cannot be smoothly discharged, and it is necessary to change the specifications of the apparatus such as enlarging the nozzle coater 400. sell.

  After the coating liquid for forming the organic EL light emitting layer is applied, the organic EL light emitting layer is removed by drying with a hot plate in a nitrogen atmosphere or drying with a sheathed heater in vacuum to remove the residual liquid. 140 is formed.

  Thereafter, the upper electrode 160 having a thickness of, for example, 100 nm is provided on the organic EL light emitting layer 140. The upper electrode 160 can be formed using, for example, a resistance heating vapor deposition method, an electron beam vapor deposition method, a sputtering method, or an ion plating method.

  Then, an adhesive layer 180 is provided on the upper electrode 160, and a sealing glass 170 is formed on the adhesive layer 180. Specifically, an adhesive made of an epoxy-based ultraviolet curable resin is applied to one surface of the sealing glass 170 using a dispenser. Then, the surface of the sealing glass 170 on which the adhesive is applied and the surface on which the upper electrode 160 is disposed are aligned and bonded together, and ultraviolet rays are irradiated to cure the adhesive. As a result, the adhesive becomes the adhesive layer 160, and the surface on which the sealing glass 170 and the upper electrode 160 are disposed is fixed. Thereby, the organic EL display device 800 shown in the above-described embodiment is formed.

  The thickness uniformity of the hole injection layer 190 and the organic EL light emitting layer 140 formed in the above-described method for manufacturing an organic EL display device is high. This is because the hole injection layer or the coating liquid for forming an organic EL light emitting layer according to this embodiment uses a solvent or dispersion medium containing fluorocarbon (an organic compound having a carbon-fluorine bond). Therefore, the evaporation rate of the solvent or dispersion medium of the coating liquid for forming the organic EL light emitting layer or hole injection layer according to this embodiment is faster than the evaporation rate of water. Therefore, it dries quickly and reduces the amount of creeping on the wall of the bank. As shown in FIG. 3A, the hole injection layer forming coating solution 520 according to the embodiment has a small amount of creeping at the end of the pixel electrode 120. On the other hand, as shown in FIG. 3B, the hole injection layer forming coating solution using water as a solvent or dispersion medium has a large amount of creeping up at the end of the pixel electrode 120. However, the coating liquid for forming a hole injection layer according to the present embodiment has excellent uniformity in the thickness of the hole injection layer because the amount of creeping onto the wall surface of the bank is small.

  As shown in FIG. 4A, the organic EL light emitting layer forming coating liquid material 530 according to this embodiment also has a small amount of creeping at the end of the coated surface. On the other hand, as shown in FIG.4 (b), the coating liquid for organic electroluminescent light emitting layer formation which uses water as a solvent or a dispersion medium has much creeping amount in the edge part of a coating surface. Therefore, the coating liquid for forming an organic EL light emitting layer according to the present embodiment has high uniformity of the thickness of the organic EL light emitting layer, and can reduce light emission unevenness.

  Here, the boiling point of the fluorocarbon is preferably 45 ° C. or higher and 65 ° C. or lower. When the boiling point of the fluorocarbon is higher than 65 ° C., the evaporation rate of the solvent or the dispersion medium may be slowed depending on the amount of the fluorocarbon contained. On the other hand, when the boiling point of the fluorocarbon is lower than 45 ° C., the unit This is because there is a possibility that the amount of evaporation per time may increase, so that it may be difficult to store the coating solution.

The fluorocarbon of the coating liquid for forming an organic EL light emitting layer or hole injection layer according to this embodiment has an ozone depletion coefficient of zero. Here, the ozone destruction coefficient means a relative value when the ozone destruction amount per unit weight of trichloromonofluoromethane (CFC-11: CCl ₃ F) is 1. The ozone depletion coefficient of zero means that there is no ozone depletion action or that the ozone depletion coefficient is 0.01 or less even if there is an ozone destruction action. Since the ozone destruction coefficient of fluorocarbon in the coating liquid for forming an organic EL light emitting layer or hole injection layer according to the present embodiment is zero, there is little adverse effect on the global environment even if it is evaporated. Note that CF ₃ CF ₂ C (O) CF (CF ₃ ) _{2 has} a global warming potential (GWP) of 1, and has excellent environmental characteristics. Here, the global warming potential is a relative value of the degree of warming due to emission per kilogram of gas over a specific accumulated time and the degree of warming due to emission per kilogram of CO ₂ .

[Other Embodiments]
In the above-described embodiment, methyl nonafluoroisobutyl ether ((CF ₃ ) ₂ CFCF ₂ OCH ₃ ) and methyl nona are used as the liquid medium used for the hole injection layer forming coating solution or the organic EL light emitting layer forming coating solution. Hydrofluoroether which is a mixture containing 50% by weight of fluorobutyl ether (n-C ₄ F ₉ OCH ₃ ) was used. However, it is not limited to this.

CHF ₂ CF ₂ OCH ₂ CF ₃ can also be used as a liquid medium used for the hole injection layer forming coating solution or the organic EL light emitting layer forming coating solution. The boiling point of CHF ₂ CF ₂ OCH ₂ CF ₃ is 56.2 ° C. It is also possible to use CF ₃ CHFCF ₂ OCH ₃ as the liquid medium. The boiling point of CF ₃ CHFCF ₂ OCH ₃ is 54.3 ° C. It is also possible to use CF ₃ CF ₂ CH ₂ OCHF ₂ as the liquid medium. The boiling point of CF ₃ CF ₂ CH ₂ OCHF ₂ is 45.9 ° C. It is also possible to use CF ₃ CH ₂ OCF ₂ CH ₂ F as the liquid medium. The boiling point of CF ₃ CH ₂ OCF ₂ CH ₂ F is 65.0 ° C. _{Furthermore, n-C 3 F 7 OCH} 3, (CF 3) 2 CFOCH 3, n-C 4 F 9 OC 2 H 5, (CF 3) 2 CFCF 2 OC 2 H 5, (CF 3) 3 COCH 3 CH ₃ O (CF ₂ ) ₄ OCH ₃ and CH ₃ O (CF ₂ ) ₆ OCH ₃ can be used.

It is also possible to use CF ₃ CF ₂ C (O) CF (CF ₃ ) ₂ as the liquid medium. CF ₃ CF ₂ C (O) CF (CF ₃ ) _{2 has} a boiling point of 49 ° C. and an ozone depletion coefficient of zero. In addition, the global warming potential of CF ₃ CF ₂ C (O) CF (CF ₃ ) ₂ is 1. It is also possible to use CF ₃ C (O) CH ₂ C (O) CF ₃ as the liquid medium. Boiling point of _{CF 3 C (O) CH 2} C (O) CF 3 is 68 to 71 ° C.. Furthermore, (CF ₃ ) ₂ CFC (O) CF (CF ₃ ) ₂ , CF ₃ (CF ₂ ) ₂ C (O) CF (CF ₃ ) ₂ , CF ₃ (CF ₂ ) ₃ C (O) CF ( CF ₃ ) ₂ , CF ₃ (CF ₂ ) ₅ C (O) CF ₃ , CF ₃ CF ₂ C (O) CF ₂ CF ₂ CF ₃ , CF ₃ C (O) CF (CF ₃ ) ₂ , perfluorocyclohexanone, etc. Can also be used. Furthermore, HCF ₂ CF ₂ C (O) CF (CF ₃ ) ₂ , C ₂ H ₅ C (O) CF (CF ₃ ) ₂ , CF ₂ CF ₂ C (O) CH ₃ , (CF ₃ ) ₂ CFC (O) CH ₃ , CF ₃ CF ₂ C (O) CHF ₂ , CF ₃ CF ₂ C (O) CH ₂ F, CF ₃ CF ₂ C (O) CH ₂ CF ₃ , CF ₃ CF ₂ C ( _{O) CH 2 CH 3, CF} 3 CF 2 C (O) CH 2 CHF 2, CF 3 CF 2 C (O) CH 2 CHF 2, CF 3 CF 2 C (O) CH 2 CH 2 F, CF 3 CF ₂ C (O) CHFCH ₃ , CF ₃ CF ₂ C (O) CHFCHF ₂ , CF ₃ CF ₂ C (O) CHFCH ₂ F, CF ₃ CF ₂ C (O) CF ₂ CH ₃ , CF ₃ CF ₂ C ( _{O) CF 2 CHF 2, CF} 3 CF 2 C (O) CF _{CH 2 F, (CF 3)} 2 CFC (O) CHF 2, (CF 3) 2 CFC (O) CH 2 F, CF 3 CF (CH 2 F) C (O) CHF 2, CF 3 CF (CH 2 F) C (O) and CH ₂ F and _{CF 3 CF (CH 2 F)} C (O) CF 3 and the like may also be used.

  In the above-described embodiment, the fluorocarbon is hydrofluoroether or fluoroketone, but is not limited thereto. Examples of the fluorocarbon include pentafluorobutane such as 1,1,1,2,2-pentafluorobutane (boiling point: 40 ° C.), 1,1,1,2,3,3,4-heptafluorobutane (boiling point: 42 ° C.), 1,1,1,2,3,4,4-heptafluorobutane (boiling point: 48 ° C.), 1,1,2,2,3,4,4-heptafluorobutane (boiling point: 57 ° C.) ), Heptafluorobutane such as 1,1,2,2,3,3,4,4-octafluorobutane (boiling point: 44 ° C.), 2-trifluoromethyl-1,1, Hexafluoropentane such as 1,2,4,4-hexafluoropentane (boiling point: 46 ° C.), 1,1,1,2,2,5,5,5-octafluoropentane (boiling point: 49 ° C.), 2-trifluoromethyl-1,1,1, Octafluoropentane such as 2,3,3,4,4-octafluoropentane (boiling point: 55 ° C.), 1,1,1,2,2,3,4,5,5,5-decafluoropentane ( Decafluoropentane such as boiling point: 55 ° C), Octafluorohexane such as 2-trifluoromethyl-1,1,1,4,4,5,5,5-octafluorohexane (boiling point: 57 ° C), Fluorohexane such as 2-trifluoromethyl-1,1,1,2,3,4,5,5,5-nonafluorohexane (boiling point: 65 ° C.), 2-trifluoromethyl-1,1,1 , 3,3,4,4,5,5,5-decafluorohexane (boiling point: 62 ° C), 1,1,2,2-tetrafluorocyclobutane (boiling point: 50 ° C), 1, 2, 3, 3, 4, - hexafluoro cyclobutane (boiling point 63 ° C.) and the like may also be used.

Furthermore, as fluorocarbons, chlorofluorocarbons can also be suitably used, for example, trichlorotrifluoroethane _{(CClF 2} -CCl 2 F: boiling 47.6 ° C.) and the like can be used. Furthermore, it is not limited to a chloro system, and a bromine system can also be suitably used. For example, dibromotetrafluoroethane (CBrF ₂ -CBrF ₂ : boiling point is 47.2 ° C.) can be used.

The coating liquid in the above-described embodiment was obtained by containing an organic EL light emitting material or a hole injection material in a solvent or dispersion medium containing a fluorocarbon. But the coating liquid which made the hole transport material contain the solvent or dispersion medium containing a fluorocarbon can also be used for the manufacturing process of an organic electroluminescence display.
As the hole transport material, polyaniline derivatives, polythiophene derivatives, polyvinyl carbazole (PVK) derivatives, poly (3,4-ethylenedioxythiophene) (PEDOT), and the like can be used. For the fluorocarbon as the solvent or dispersion medium, for example, various hydrofluoroethers, fluoroketones, and the like can be used. A coating liquid in which a hole transport material is dissolved or dispersed in a fluorocarbon-containing solvent or dispersion medium has a small amount of solution rising to the bank wall surface.

  In the above-described embodiment, poly (paraphenylene vinylene) (PPV) is used as the green light emitting material. However, it is not limited to this. As an organic compound capable of forming a light emitting layer, in addition to PPV, polyalkylthiophene such as PTV (poly (2,5-thienylene vinylene)), PFV (poly (2,5-furylene vinylene)), poly Polyarylene vinylene such as paraphenylene and polyalkylfluorene, pyrazoline dimer, quinolidinecarboxylic acid, benzopyrylium perchlorate, benzopyranoquinolidine, phenanthroline europium complex and the like can be used. Among these, those made of a polymer organic compound are preferable. The polymer organic compound is excellent in film formability, and the durability of the light emitting layer is very good. As precursors of PPV derivatives, MO-PPV (poly (2,5-dimethoxy-1,4-phenylenevinylene)) precursor, CN-PPV (poly (2,5-bishexyloxy-1,4- It is also possible to use a phenylene- (1-cyanovinylene)) precursor or the like.

  In the above embodiment, a green light emitting material is used as the organic EL light emitting material. However, it is not limited to this. A red light emitting material can also be used as the organic EL light emitting material. The red light emitting material is obtained by adding rhodamine 101, which is a low molecular fluorescent dye, to the PPV precursor ink composition. As the fluorescent dye used for the red light emitting layer, DCM, a rhodamine or rhodamine derivative, perylene, or the like, which is a laser dye, can be used. Since these fluorescent dyes are low in molecule, they are soluble in a solvent, have good compatibility with PPV and the like, and can easily form a uniform and stable light emitting layer. Examples of the rhodamine derivative fluorescent dye include rhodamine B, rhodamine B base, rhodamine 6G, rhodamine 101 perchlorate and the like.

  A blue light emitting material can also be used as the organic EL light emitting material. As the blue light emitting material, a material obtained by dissolving polydioctylsulfurene in xylene is used. As the fluorescent dye, distyryl biphenyl and its derivatives are preferably used. Coumarin, Coumarin-1, Coumarin-6, Coumarin-7, Coumarin 120, Coumarin 138, Coumarin 152, Coumarin 153, Coumarin 311, Coumarin 314, Coumarin 334, Coumarin 337, Coumarin 343, and the like can also be used. Furthermore, tetraphenylbutadiene (TPB) or a TPB derivative can be used.

  In the above embodiment, the hole injection material was a mixture of PEDOT and PSS. However, the present invention is not limited to this, and the hole injection material may be PEDOT alone. Further, a starburst type compound (m-MTDATA) as shown in Chemical Formula 2 can be used as the hole injection material. A starburst molecule is a group of molecules synthesized as an organic amorphous material, and can form a uniform film because of its amorphous nature. In addition, changes in the film structure such as crystallization due to heat generated during driving hardly occur.

  In addition to fluorocarbons, gamma butyl lactone, N-methylpyrrolidone (NMP), 1,3-dimethyl-2-imidazolidinone as a solvent or dispersion medium containing a hole injection material or an organic electroluminescent light emitting material Aprotic cyclic polar solvents such as (DMI) and its derivatives, glycol ether acetic acid such as carbitol acetate (CA) and butyl carbitol acetate (BCA), methanol (MeOH), ethanol (EtOH), propyl It is also possible to use lower alcohol such as alcohol, water or the like. In addition, a surfactant, an antioxidant, a viscosity modifier, an ultraviolet absorber and the like can be added as necessary.

  In the above-described embodiment, the organic EL layer has a two-layer structure of the hole injection layer 190 and the organic EL light emitting layer 140. However, the organic EL layer may have a layer structure in which an electron injection layer is added as the organic EL layer. Therefore, it is also possible to use fluorocarbons or the like as a solvent or dispersion medium containing the electron injection material. When fluorocarbons are used as the solvent or dispersion medium containing the electron injection material, the coating liquid for forming the electron injection layer is applied to the bank wall surface as in the effect of the organic EL light emitting layer and the hole injection layer according to this embodiment. As a result, it is possible to expect an effect that the uniformity of the thickness of the electron injection layer is excellent.

Examples of the coating liquid for forming the hole injection layer will be described below.
Example 1
The coating solution for forming the hole injection layer was prepared as follows.
First, a PEDOT and PSS mixture was prepared as a hole injection material. To this was added gamma-glycidyloxypropyltrimethoxysilane.
Next, it is a mixture as a liquid medium containing 50% by weight of methyl nonafluoroisobutyl ether ((CF ₃ ) ₂ CFCF ₂ OCH ₃ ) and methyl nonafluorobutyl ether (n-C ₄ F ₉ OCH ₃ ), respectively. Hydrofluoroether was prepared.
A coating solution for forming a hole injection layer was prepared by adding the prepared hole injection material to the hydrofluoroether as the mixture. The prepared coating solution for hole injection layer formation was 30% by weight of PEDOT / PSS, 69.9% by weight of hydrofluoroether, and 0.1% by weight of gamma-glycidyloxypropyltrimethoxysilane.
For application to the pixel electrode 120, an ink jet printer (manufactured by Brother) was used. Prior to coating, the surface of the pixel was hydrophobized by continuous treatment with oxygen gas plasma and methane tetrafluoride gas plasma. The plasma treatment may be performed in any atmosphere in vacuum or air. The coating solution for forming the hole injection layer was continuously discharged from the nozzle.
After coating, the liquid medium remaining in vacuum at room temperature was removed, and then the cohesiveness and flatness of the hole injection layer formed by heat treatment in the atmosphere at 180 ° C. for 10 minutes were observed with a microscope. The amount of creeping up at the end of the pixel electrode 120 was small.

(Example 2)
The same as Example 1 except that CHF ₂ CF ₂ OCH ₂ CF ₃ was used as the liquid medium. When the cohesiveness and flatness of the formed hole injection layer were observed with a microscope, the amount of creeping up at the end of the pixel electrode 120 was small.

(Example 3)
Same as Example 1 except that CF ₃ CHFCF ₂ OCH ₃ was used as the liquid medium. When the cohesiveness and flatness of the formed hole injection layer were observed with a microscope, the amount of creeping up at the end of the pixel electrode 120 was small.

Example 4
Similar to Example 1 except that CF ₃ CF ₂ CH ₂ OCHF ₂ was used as the liquid medium. When the cohesiveness and flatness of the formed hole injection layer were observed with a microscope, the amount of creeping up at the end of the pixel electrode 120 was small.

(Example 5)
The same as Example 1 except that CF ₃ CH ₂ OCF ₂ CH ₂ F was used as the liquid medium. When the cohesiveness and flatness of the formed hole injection layer were observed with a microscope, the amount of creeping up at the end of the pixel electrode 120 was small.

(Example 6)
The same as Example 1 except that CF ₃ CF ₂ C (O) CF (CF ₃ ) ₂ was used as the liquid medium. When the cohesiveness and flatness of the formed hole injection layer were observed with a microscope, the amount of creeping up at the end of the pixel electrode 120 was small.

(Example 7)
Similar to Example 1 except that CF ₃ C (O) CH ₂ C (O) CF ₃ was used as the liquid medium. When the cohesiveness and flatness of the formed hole injection layer were observed with a microscope, the amount of creeping up at the end of the pixel electrode 120 was small.

Next, examples of the coating liquid for forming an organic EL light emitting layer will be described.
(Example 8)
The coating liquid for organic EL light emitting layer formation was adjusted as follows.
First, poly (paraphenylene vinylene) (PPV) was used as a green light emitting material as an organic EL light emitting material. To this was added quinacridone.
Next, it is a mixture as a liquid medium containing 50% by weight of methyl nonafluoroisobutyl ether ((CF ₃ ) ₂ CFCF ₂ OCH ₃ ) and methyl nonafluorobutyl ether (n-C ₄ F ₉ OCH ₃ ), respectively. Hydrofluoroether was prepared.
A coating liquid for forming an organic EL light emitting layer was prepared by containing the adjusted organic EL light emitting material in a hydrofluoroether as a mixture. The prepared coating liquid for forming an organic EL light emitting layer had a PPV of 2.0% by weight, a hydrofluoroether solvent of 97.0% by weight, and quinacridone of 1.0% by weight.
For application onto the hole injection layer, an inkjet printer (manufactured by Brother) was used in the same manner as in Example 1.
After coating, the cohesiveness and flatness of the organic EL light-emitting layer formed by heat treatment in an inert gas atmosphere (for example, N ₂ ) at 150 ° C. were observed with a microscope, and then crawls up at the edge of the coated surface. The amount was small.

Example 9
Similar to Example 8 except that CHF ₂ CF ₂ OCH ₂ CF ₃ was used as the liquid medium. When the cohesiveness and flatness of the formed organic EL light emitting layer were observed with a microscope, the amount of creeping up at the end of the coated surface was small.

(Example 10)
Same as Example 8 except that CF ₃ CHFCF ₂ OCH ₃ was used as the liquid medium. When the cohesiveness and flatness of the formed organic EL light emitting layer were observed with a microscope, the amount of creeping up at the end of the coated surface was small.

(Example 11)
Same as Example 8 except that CF ₃ CF ₂ CH ₂ OCHF ₂ was used as the liquid medium. When the cohesiveness and flatness of the formed organic EL light emitting layer were observed with a microscope, the amount of creeping up at the end of the coated surface was small.

Example 12
Similar to Example 8 except that CF ₃ CH ₂ OCF ₂ CH ₂ F was used as the liquid medium. When the cohesiveness and flatness of the formed organic EL light emitting layer were observed with a microscope, the amount of creeping up at the end of the coated surface was small.

(Example 13)
Similar to Example 8 except that CF ₃ CF ₂ C (O) CF (CF ₃ ) ₂ was used as the liquid medium. When the cohesiveness and flatness of the formed organic EL light emitting layer were observed with a microscope, the amount of creeping up at the end of the coated surface was small.

(Example 14)
Similar to Example 8 except that CF ₃ C (O) CH ₂ C (O) CF ₃ was used as the liquid medium. When the cohesiveness and flatness of the formed organic EL light emitting layer were observed with a microscope, the amount of creeping up at the end of the coated surface was small.

It is a figure explaining the organic electroluminescence display created with the manufacturing method of the organic electroluminescence display concerning an embodiment, (a) is a sectional view and (b) is a top view. It is a figure explaining a mode that the coating liquid for positive hole injection layer formation is apply | coated with a nozzle coater, (a) is sectional drawing, (b) is a top view. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which illustrates typically the apply | coated coating liquid for positive hole injection layer formation, (a) is a coating liquid which concerns on embodiment containing a fluorocarbon, (b) is a comparative example containing water. This is a coating liquid. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which illustrates typically the apply | coated coating liquid for organic electroluminescent light emitting layer formation, (a) is a coating liquid which concerns on embodiment containing a fluorocarbon, (b) is a comparative example containing water. This is a coating liquid.

Explanation of symbols

DESCRIPTION OF SYMBOLS 110 ... Glass substrate, 120 ... Pixel electrode, 130 ... Bank, 140 ... Organic EL light emitting layer, 150 ... Interlayer insulating film, 160 ... Upper electrode, 170 ... Sealing glass, 180 ... Adhesive layer, 190 ... Hole injection layer, 400 ... Nozzle coater, 800 ... Organic EL display device

Claims (8)

A liquid containing an organic electroluminescent material in a solvent or dispersion medium containing a fluorocarbon.
A coating liquid for forming an organic electroluminescence layer, characterized in that The fluorocarbon is a hydrofluoroether;
The coating liquid for forming an organic electroluminescence layer according to claim 1. The fluorocarbon is a fluoroketone;
The coating liquid for forming an organic electroluminescence layer according to claim 1. The fluorocarbon has a boiling point of 45 ° C. or more and 65 ° C. or less.
The coating solution for forming an organic electroluminescence layer according to any one of claims 1 to 3. A coating liquid for forming an organic electroluminescence layer, which is a liquid containing an organic electroluminescence material in a solvent or dispersion medium containing a fluorocarbon,
Applying to a predetermined region on the substrate to form an organic electroluminescence layer,
A method for producing an organic electroluminescence display device. The fluorocarbon is a hydrofluoroether;
The method for producing an organic electroluminescence display device according to claim 5. The fluorocarbon is a fluoroketone;
The method for producing an organic electroluminescence display device according to claim 5. The fluorocarbon has a boiling point of 45 ° C. or more and 65 ° C. or less.
The method for manufacturing an organic electroluminescence display device according to any one of claims 5 to 7, wherein:

Images