JP2009016739A - Organic light emitting device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic light emitting device which has an optical output of high efficiency, high brightness and high lifetime and has a stable light emitting surface without any film defects when a film is formed. <P>SOLUTION: The organic light emitting element consists of organic layers sandwiched between a positive electrode and a negative electrode, wherein at least one layer among the organic layers is formed by acrylic thin film containing at least one kind of acrylic compound or an acrylic cured film obtained by curing the acrylic thin film. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an organic light emitting device and a method for manufacturing the same.

  The manufacturing process of the organic light emitting device is classified into a dry method and a wet method. Here, the dry method is a method of forming a thin film using a gas phase process such as a vacuum vapor deposition method mainly using a low molecular weight material in the film forming process. On the other hand, the wet method mainly uses a polymer material in the film forming process, and forms a thin film using a spin coating method, an ink jet coating method, a dispenser coating method, a spray coating method, a dip coating method, or the like. Is the method.

  In dry methods such as vacuum evaporation, the production equipment is batch-type, and in device fabrication, material films are also formed on parts that are not necessary for light emission of the device, and much more material is wasted than necessary. Therefore, this method has a problem in productivity.

  On the other hand, manufacturing by a wet method is less likely to form a film of material in a portion that is not necessary for light emission of the device, and production by continuous processing is possible. For example, application by a droplet discharge method such as an inkjet application method or a dispenser application method can be selected. In these methods, when applying, patterning can be simultaneously performed in which a material is applied only to a portion necessary for light emission of the element, so that the productivity of the element can be greatly improved.

  Therefore, recently, organic layers such as a charge injection layer, a charge transport layer, and a light emitting layer of an organic light emitting element are required to be formed by a wet method with good productivity.

  As a coating-type hole injection material, it is known to use a thin film of a mixture of poly (3,4-ethylenedioxythiophene) and polystyrene sulfonic acid in order to improve charge injection properties. However, devices using these injection materials are excellent in initial characteristics, but there is a problem that luminance deterioration is significant when used for a long time.

  At present, there are only a limited number of charge injection materials and charge transport materials that can be used in the wet method, and even if materials that can be used at present are used, initial characteristics such as light emission efficiency and luminance deterioration due to long-time light emission, etc. There was a problem that durability characteristics were not sufficient.

  Incidentally, a charge transporting material having a polymerizable functional group that can be used in a wet method has been proposed, and Patent Documents 1 to 3 are known as prior arts. However, even if these materials are used, sufficient characteristics have not been obtained.

  On the other hand, an acrylic compound having a charge transporting structure or a cured product thereof has also been proposed, and Patent Documents 4 to 6 are known as prior arts using these for organic light emitting devices. In these prior literatures, examples of a method for curing an acrylic compound include a combination of addition of a crosslinking agent, addition of a polymerization initiator, heating and the like in addition to ultraviolet irradiation. However, there is no description of an example of curing by heating alone without using an initiator or the like.

JP 2001-297882 A JP 2002-212150 A Japanese Patent Laid-Open No. 2004-199935 JP 2000-268974 A JP 2005-340043 A JP 2006-66574 A

  An object of the present invention is to provide an organic light emitting device having a stable light emitting surface with high efficiency, high brightness, extremely long life light output, very few film defects during film formation. is there. Another object of the present invention is to provide an organic light emitting device that is easy to manufacture and can be manufactured by a relatively inexpensive coating method.

  The organic light-emitting device of the present invention comprises an anode, a cathode, and a layer made of an organic compound sandwiched between the anode and the cathode, and at least one of the layers made of the organic compound has the following general formula It is characterized by being formed of an acrylic thin film containing at least one kind of acrylic compound represented by (1) or (2) or an acrylic cured film obtained by curing the acrylic thin film.

(In the formula (1), A ₁₁ and A ₁₂ each represent a divalent hydrocarbon group having 2 to 8 carbon atoms. R ₁₁ and R ₁₂ each represent a hydrogen atom or a methyl group. Ar ₁₁ and Ar ₁₃ is substituted or unsubstituted biphenyl, substituted or unsubstituted fluorene, substituted or unsubstituted fluoranthene, substituted or unsubstituted phenylnaphthalene, substituted or unsubstituted phenanthrene, substituted or unsubstituted dihydrophenanthrene, substituted or .Ar ₁₂ representing the unsubstituted pyrene, a substituted or unsubstituted perylene, a substituted or unsubstituted carbazole, a monovalent substituent selected from a substituted or unsubstituted dibenzofuran, and substituted or unsubstituted dibenzothiophene, substituted or Unsubstituted biphenyl, substituted or unsubstituted fluorene, substituted Is substituted fluoranthene, substituted or unsubstituted phenylnaphthalene, substituted or unsubstituted phenanthrene, substituted or unsubstituted dihydrophenanthrene, substituted or unsubstituted pyrene, substituted or unsubstituted perylene, substituted or unsubstituted benzoanthracene And a divalent substituent selected from substituted or unsubstituted carbazole, substituted or unsubstituted dibenzofuran, and substituted or unsubstituted dibenzothiophene.

(In the formula (2), A ₂₁ and A ₂₂ each represent a divalent hydrocarbon group having 2 to 8 carbon atoms. R ₂₁ and R ₂₂ each represent a hydrogen atom or a methyl group. Ar ₂₁ and Ar ₂₄ is substituted or unsubstituted biphenyl, substituted or unsubstituted fluorene, substituted or unsubstituted fluoranthene, substituted or unsubstituted phenylnaphthalene, substituted or unsubstituted phenanthrene, substituted or unsubstituted pyrene, substituted or unsubstituted A monovalent substituent selected from substituted perylene, substituted or unsubstituted carbazole, substituted or unsubstituted dibenzofuran, substituted or unsubstituted dibenzothiophene, Ar ₂₂ and Ar ₂₃ are substituted or unsubstituted biphenyl, respectively. Substituted or unsubstituted fluorene, substituted or unsubstituted fluoranthene, Substituted or unsubstituted phenylnaphthalene, substituted or unsubstituted phenanthrene, substituted or unsubstituted dihydrophenanthrene, substituted or unsubstituted pyrene, substituted or unsubstituted perylene, substituted or unsubstituted benzoanthracene, substituted or unsubstituted Z ₂₁ represents a divalent substituent selected from carbazole, substituted or unsubstituted dibenzofuran, substituted or unsubstituted dibenzothiophene, and Z ₂₁ represents a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic complex. Represents a cyclic group, and n represents an integer of 1 to 4.)

  According to the present invention, it is possible to provide an organic light emitting device having a stable light emitting surface, having a light output with high efficiency, high brightness, extremely long life, very few film defects during film formation. it can. In addition, according to the present invention, it is possible to provide an organic light emitting device that can be easily manufactured and can be manufactured by a relatively inexpensive coating method. The productivity of the organic light-emitting device of the present invention is improved particularly when the charge injection layer and the charge transport layer are formed by a wet method.

  Hereinafter, the present invention will be described in detail.

  The organic light emitting device of the present invention includes an anode, a cathode, and a layer made of an organic compound sandwiched between the anode and the cathode.

  Hereinafter, the organic light-emitting device of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a first embodiment of the organic light-emitting device of the present invention. In the organic light emitting device 10 of FIG. 1, an anode 2, a light emitting layer 3, and a cathode 4 are sequentially provided on a substrate 1. The organic light emitting device 10 of FIG. 1 is useful when the light emitting layer 3 is composed of an organic compound having all of hole transport ability, electron transport ability, and light emitting performance. Further, it is also useful when an organic compound having any one of the characteristics of hole transport ability, electron transport ability and light emitting performance is mixed.

  FIG. 2 is a cross-sectional view showing a second embodiment of the organic light emitting device of the present invention. In the organic light emitting device 20 of FIG. 2, an anode 2, a hole transport layer 5, an electron transport layer 6 and a cathode 4 are sequentially provided on a substrate 1. This organic light emitting device 20 is useful when a light emitting organic compound having either a hole transporting property or an electron transporting property and an organic compound having only an electron transporting property or only a hole transporting property are used in combination. is there. In the organic light emitting device 20, the hole transport layer 5 or the electron transport layer 6 also serves as a light emitting layer.

  FIG. 3 is a cross-sectional view showing a third embodiment of the organic light-emitting device of the present invention. An organic light emitting device 30 in FIG. 3 is obtained by providing the light emitting layer 3 between the hole transport layer 5 and the electron transport layer 6 in the organic light emitting device 20 in FIG. The organic light emitting device 30 is a device in which the function of transporting carriers and the function of emitting light are separated, and compounds having hole transporting properties, electron transporting properties, and light emitting properties can be used in appropriate combinations. . For this reason, the degree of freedom of material selection is increased, and various compounds having different emission wavelengths can be used, so that the emission hue can be diversified. Furthermore, it is possible to effectively confine each carrier or exciton in the central light emitting layer 3 to improve the light emission efficiency of the organic light emitting device 30.

  FIG. 4 is a cross-sectional view showing a fourth embodiment of the organic light emitting device of the present invention. The organic light emitting device of FIG. 4 is obtained by providing a hole injection layer 7 between the anode 2 and the hole transport layer 5 in the organic light emitting device 30 of FIG. The organic light emitting device 40 is effective in lowering the voltage because the hole injection layer 7 is provided to improve the adhesion between the anode 2 and the hole transport layer 5 or the hole injection property. Further, a buffer layer may be provided in place of the hole injection layer 7, but the function is the same as that of the hole injection layer.

  FIG. 5 is a cross-sectional view showing a fifth embodiment of the organic light-emitting device of the present invention. An organic light emitting device 50 in FIG. 5 is obtained by providing a hole / exciton blocking layer 8 between the light emitting layer 3 and the electron transport layer 6 in the organic light emitting device 30 in FIG. By providing the hole / exciton blocking layer 8, it is possible to prevent holes or excitons from being released from the light emitting layer 3 to the cathode 4 side, which is an effective configuration for improving the light emission efficiency.

  FIG. 6 is a cross-sectional view showing a sixth embodiment of the organic light emitting device of the present invention. The organic light emitting device 60 of FIG. 6 is obtained by providing an electron injection layer 9 between the electron transport layer 6 and the cathode 4 in the organic light emitting device 40 of FIG. The organic light emitting device 60 of FIG. 6 is effective in lowering the voltage of the device because the electron injection layer 9 is provided.

  FIG. 7 is a cross-sectional view showing a seventh embodiment of the organic light-emitting device of the present invention. In the organic light emitting device 70 of FIG. 7, an anode 2, a hole injection layer 7, a light emitting layer 3, an electron injection layer 8, and a cathode 4 are sequentially provided on a substrate 1.

  However, FIG. 1 to FIG. 7 are very basic device configurations, and the organic light-emitting device of the present invention is not limited to these. For example, various layer configurations such as providing an insulating layer, an adhesive layer or an interference layer at the interface between the electrode and the organic layer, and a hole injection layer or a hole transport layer including two layers having different ionization potentials should be adopted. Can do.

  The organic light-emitting device of the present invention is characterized in that at least one of the layers made of an organic compound is formed of an acrylic thin film containing at least one kind of acrylic compound or a cured acrylic film obtained by curing the acrylic thin film. Here, examples of the acrylic compound include a compound represented by the following general formula (1).

In the formula (1), A ₁₁ and A ₁₂ each represent a divalent hydrocarbon group having 2 to 8 carbon atoms.

Examples of the divalent hydrocarbon group having 2 to 8 carbon atoms represented by A ₁₁ and A ₁₂ include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, and an octylene group.

  The divalent hydrocarbon group may have a branch such as a methyl group, an ethyl group, a propyl group, and a butyl group. Further, the above divalent hydrocarbon group may contain one ether bond.

In the formula (1), R ₁₁ and R ₁₂ each represent a hydrogen atom or a methyl group.

In the formula (1), Ar ₁₁ and Ar ₁₃ are each a substituted or unsubstituted biphenyl, substituted or unsubstituted fluorene, a substituted or unsubstituted fluoranthene, substituted or unsubstituted phenyl naphthalene, substituted or unsubstituted phenanthrene, Monovalent substitution selected from substituted or unsubstituted dihydrophenanthrene, substituted or unsubstituted pyrene, substituted or unsubstituted perylene, substituted or unsubstituted carbazole, substituted or unsubstituted dibenzofuran and substituted or unsubstituted dibenzothiophene Represents a group.

Examples of the substituent that the monovalent substituent represented by Ar _{11 or} Ar ₁₃ may have include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a tert-butyl group, and a trifluoromethyl group. Group, benzyl group, phenethyl group, naphthylmethyl group and other aralkyl groups, phenyl group, naphthyl group, anthryl group, pyrenyl group, fluorenyl group and other aromatic hydrocarbon ring groups, carbazolyl group, dibenzofuryl group, dibenzothiophenyl group , Aromatic heterocyclic groups such as thienyl groups, alkoxy groups such as methoxy groups, ethoxy groups and propoxy groups, aryloxy groups such as phenoxy groups and naphthoxy groups, halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms and iodine atoms , A nitro group, a cyano group, and the like.

In the formula (1), Ar ₁₂ is substituted or unsubstituted biphenyl, substituted or unsubstituted fluorene, substituted or unsubstituted fluoranthene, substituted or unsubstituted phenylnaphthalene, substituted or unsubstituted phenanthrene, substituted or unsubstituted Selected from dihydrophenanthrene, substituted or unsubstituted pyrene, substituted or unsubstituted perylene, substituted or unsubstituted benzoanthracene, substituted or unsubstituted carbazole, substituted or unsubstituted dibenzofuran and substituted or unsubstituted dibenzothiophene A divalent substituent is shown.

As the substituent that the divalent substituent represented by Ar ₁₂ may have, an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a tert-butyl group, or a trifluoromethyl group, benzyl Group, aralkyl group such as phenethyl group, naphthylmethyl group, aromatic hydrocarbon ring group such as phenyl group, naphthyl group, anthryl group, pyrenyl group, fluorenyl group, carbazolyl group, dibenzofuryl group, dibenzothiophenyl group, thienyl group Aromatic heterocyclic groups such as, alkoxy groups such as methoxy group, ethoxy group and propoxy group, aryloxy groups such as phenoxy group and naphthoxy group, halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, nitro group And a cyano group.

  Another example of the acrylic compound is a compound represented by the following general formula (2).

In the formula (2), A ₂₁ and A ₂₂ each represent a divalent hydrocarbon group having 2 to 8 carbon atoms.

Examples of the divalent hydrocarbon group having 2 to 8 carbon atoms represented by A ₂₁ and A ₂₂ include a methylene group, an ethylene group, a propylene group, a butylene group, and a pentylene group.

  The divalent hydrocarbon group may have a branch such as a methyl group, an ethyl group, a propyl group, and a butyl group. Further, the above divalent hydrocarbon group may contain one ether bond.

In the formula (2), R ₂₁ and R ₂₂ each represent a hydrogen atom or a methyl group.

In the formula (2), Ar ₂₁ and Ar ₂₄ are each substituted or unsubstituted biphenyl, substituted or unsubstituted fluorene, substituted or unsubstituted fluoranthene, substituted or unsubstituted phenylnaphthalene, substituted or unsubstituted phenanthrene, This represents a monovalent substituent selected from substituted or unsubstituted pyrene, substituted or unsubstituted perylene, substituted or unsubstituted carbazole, substituted or unsubstituted dibenzofuran, substituted or unsubstituted dibenzothiophene.

Examples of the substituent that the monovalent substituent represented by Ar ₂₁ and Ar ₂₄ may have include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and an octyl group, and a benzyl group. , Aralkyl groups such as phenethyl group and naphthylmethyl group, aromatic hydrocarbon ring groups such as phenyl group, naphthyl group, anthryl group, pyrenyl group, fluorenyl group, carbazolyl group, dibenzofuryl group, dibenzothiophenyl group, thienyl group, etc. Aromatic heterocyclic group, alkoxy group such as methoxy group, ethoxy group, propoxy group, aryloxy group such as phenoxy group, naphthoxy group, halogen atom such as fluorine atom, chlorine atom, bromine atom, iodine atom, nitro group, A cyano group etc. are mentioned.

In the formula (2), Ar ₂₂ and Ar ₂₃ are each substituted or unsubstituted biphenyl, substituted or unsubstituted fluorene, substituted or unsubstituted fluoranthene, substituted or unsubstituted phenylnaphthalene, substituted or unsubstituted phenanthrene, Substituted or unsubstituted dihydrophenanthrene, substituted or unsubstituted pyrene, substituted or unsubstituted perylene, substituted or unsubstituted benzoanthracene, substituted or unsubstituted carbazole, substituted or unsubstituted dibenzofuran, substituted or unsubstituted dibenzo Represents a divalent substituent selected from thiophene.

Examples of the substituent that the divalent substituents biphenyl, fluorene, and carbazole represented by Ar ₂₂ and Ar ₂₃ may have include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and an octyl group. Aralkyl groups such as alkyl group, benzyl group, phenethyl group, naphthylmethyl group, aromatic hydrocarbon ring groups such as phenyl group, naphthyl group, anthryl group, pyrenyl group, fluorenyl group, carbazolyl group, dibenzofuryl group, dibenzothiophenyl Group, aromatic heterocyclic group such as thienyl group, alkoxy group such as methoxy group, ethoxy group and propoxy group, aryloxy group such as phenoxy group and naphthoxy group, halogen such as fluorine atom, chlorine atom, bromine atom and iodine atom An atom, a nitro group, a cyano group, etc. are mentioned.

In the formula (2), Z ₂₁ represents a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group.

Examples of the aromatic hydrocarbon ring group represented by Z ₂₁ include a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, and a fluorenyl group.

Examples of the aromatic heterocyclic group represented by Z ₂₁ include a pyridyl group, a thienyl group, a furyl group, and a quinolyl group.

  Examples of the substituent that the aromatic hydrocarbon ring group and aromatic heterocyclic group may have include alkyl groups such as methyl group, ethyl group, propyl group and butyl group, benzyl group, phenethyl group and naphthylmethyl group. Aromatic hydrocarbon ring groups such as aralkyl group, phenyl group, naphthyl group, anthryl group, pyrenyl group, fluorenyl group, aromatic heterocyclic groups such as carbazolyl group, dibenzofuryl group and dibenzothiophenyl group, methoxy group, ethoxy group And alkoxy groups such as propoxy group, aryloxy groups such as phenoxy group and naphthoxy group, halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, nitro group, cyano group and the like.

  In the formula (2), n represents an integer of 1 to 4.

  Specific examples of the acrylic compound represented by formula (1) or formula (2) are shown below. However, the present invention is not limited to these.

  At least one of the organic compound layers is formed of an acrylic thin film formed from the acrylic compound represented by the formula (1) or the formula (2), or an acrylic cured film formed by curing the acrylic thin film. It is what is done. In the organic light emitting device shown in FIGS. 1 to 7, the layer made of an organic compound is a light emitting layer 3, a hole transport layer 5, an electron transport layer 6, a hole injection layer 7, a hole / exciton blocking layer 8 or the like. And the electron injection layer 9 corresponds.

  On the other hand, the acrylic compound represented by the formula (1) or the formula (2) has a triarylamine skeleton having a charge transporting function. For this reason, the acrylic thin film or acrylic cured film formed from the acrylic compound represented by formula (1) or formula (2) preferably forms a charge injection layer or a charge transport layer. More preferably, the hole injection layer 7 is formed.

  The organic light emitting device of the present invention can be used together with a known hole transporting compound, light emitting compound, electron transporting compound or the like.

  Examples of these known compounds are given below.

  Here, when the acrylic compound represented by the formula (1) or (2) is used as a guest of the light emitting layer, the content of the acrylic compound is preferably 0.1 weight based on the total weight of the light emitting layer. % To 50% by weight. More preferably, it is 0.5 wt% or more and 30 wt% or less.

  Further, when the acrylic compound represented by the formula (1) or (2) is used as a host of the light emitting layer, the content of the acrylic compound is preferably 50% by weight or more and 99% based on the total weight of the light emitting layer. .9% by weight or less. More preferably, it is 70 weight% or more and 99.5 weight% or less.

  The constituent material of the anode should have a work function as large as possible. For example, a simple metal such as gold, silver, platinum, nickel, palladium, cobalt, selenium, vanadium or an alloy obtained by combining a plurality of these metals, a metal oxide such as tin oxide, zinc oxide, indium tin oxide (ITO), and zinc indium oxide Can be used. In addition, conductive polymers such as polyaniline, polypyrrole, polythiophene, and polyphenylene sulfide can also be used. These electrode materials may be used alone or in combination of two or more.

  On the other hand, the constituent material of the cathode preferably has a small work function. For example, it is possible to use a simple metal such as lithium, sodium, potassium, cesium, calcium, magnesium, aluminum, indium, silver, lead, tin, chromium, an alloy in which a plurality of these metals are combined, or a salt of these metals. it can. Also, metal oxides such as indium tin oxide (ITO) can be used. Here, the cathode may be composed of a single layer or a plurality of layers.

  Although it does not specifically limit as a board | substrate used with the organic light emitting element of this invention, Transparent substrates, such as opaque board | substrates, such as a metal board | substrate and a ceramic board | substrate, glass, quartz, a plastic sheet, are used. It is also possible to control the color light by using a color filter film, a fluorescent color conversion filter film, a dielectric reflection film or the like on the substrate.

  Note that a protective layer or a sealing layer can be provided for the manufactured element in order to prevent contact with oxygen or moisture. As the protective layer, diamond thin films, inorganic material films such as metal oxides and metal nitrides, polymer films such as fluorine resin, polyparaxylene, polyethylene, silicone resin, polystyrene resin, epoxy resin, phenol resin, urea resin, or the like Examples thereof include a photocurable resin. Further, it is possible to cover glass, a gas-impermeable film, a metal, etc., and to package the element itself with an appropriate sealing resin.

  Next, the manufacturing method of the organic light emitting element of this invention is demonstrated.

  The method for producing an organic light emitting device of the present invention includes the following steps (i) and (ii).

(I) Step of forming an acrylic thin film containing at least one kind of acrylic compound represented by formula (1) or formula (2) by a wet method (ii) Heat polymerization or heat curing of the acrylic thin film in an inert gas In the case of producing an organic light emitting device by a wet method, a polymer material is usually used for reasons such as ease of application and the ability to prepare a coating without crystallization. used.

  Here, in order to improve the light emission efficiency and durability of the organic light emitting element, it is necessary to improve the purity of the organic material constituting the layer, but it is often difficult with a polymer material. That is, in general, in a polymer material, a by-product or a desorption product generated when the material is manufactured, impurities due to a side reaction, a residual catalyst or a polymerization initiator, etc. can be removed from the material. Often difficult. Further, by-products, impurities, residual catalyst, residual polymerization initiator, and the like generated during the production of the material adversely affect luminance characteristics and lifetime characteristics among the characteristics of the organic light emitting device.

  On the other hand, the acrylic compound represented by Formula (1) or Formula (2) exists as a low molecular compound or oligomer. Since this acrylic compound is easier to purify (impurities removal) than a polymer material, an organic layer with high purity can be formed. Therefore, by using these compounds, the problem of removing impurities and the like, which is a problem peculiar to polymer materials, is solved.

  By the way, the acrylic compound shown by Formula (1) or Formula (2) has polymerizable acrylic ester or methacrylic ester. For this reason, an intermolecular crosslinking reaction occurs due to radical polymerization reaction by heating, a polymerization initiator or the like, and the acrylic compound is cured.

  Here, the polymerization reaction of acrylic acid ester groups and methacrylic acid ester groups is difficult to obtain desired polymerization characteristics due to a polymerization inhibition action by oxygen under an ordinary air environment. For this reason, when performing a polymerization reaction, it is necessary to carry out in inert gas.

  When actually carrying out the polymerization reaction, the oxygen concentration in the inert gas is preferably 10 ppm or less. The inert gas is preferably nitrogen or argon.

  On the other hand, when forming an acrylic thin film, it is preferable not to include a polymerization initiator. As a method for overcoming the above-described polymerization inhibitory action by oxygen, a polymerization initiator should usually be included. However, the presence of the polymerization initiator not only lowers the purity of the acrylic compound constituting the layer, but also the polymerization initiator adversely affects the characteristics of the device.

  In addition, the acrylic compound represented by the formula (1) or the formula (2) is heated only without using an initiator, a catalyst, or the like by reducing the oxygen concentration in the production environment to a certain value or less due to structural factors. The polymerization reaction proceeds. Further, the polymerization proceeds at a relatively low heating temperature of 130 ° C. to 200 ° C., and the adverse effect on other parts of the device is small.

  The cured film is an insoluble and infusible organic thin film. Therefore, as a next step, even if another organic layer is laminated on the cured film by a wet method, the cured film is not dissolved by the solvent contained in the paint applied from above. Therefore, an organic light-emitting element having a stable stacked body in which the materials constituting the layers are not mixed can be manufactured.

  Further, even when an organic light emitting element is used, the cured film has a three-dimensional cross-linking structure, so that crystallization due to migration, non-homogenization near the interface, and instability do not occur. Therefore, it is possible to provide an element having higher stability than the case where a low molecular compound is formed as it is.

  In addition, the acrylic compound represented by the formula (1) or the formula (2) also has a feature that it is difficult to generate film defects that are likely to occur when thermosetting.

  This feature is because the acrylic compound represented by the formula (1) or the formula (2) has a triarylamine skeleton having a bulky, rigid, relatively large molecular weight and an alkyl group having an appropriate length.

  Due to this structural feature, the acrylic compound represented by Formula (1) or Formula (2) can achieve both improved heat resistance and compatibility between the compounds. For this reason, it has the characteristic of exhibiting relaxation characteristics of stress and volume shrinkage in the film forming process, and is less likely to cause surface alignment in the temperature rising process due to its heat resistance. For these reasons, the defect of the light emitting surface of the device obtained is also extremely reduced.

  In addition, since the acrylic compound represented by the formula (1) or the formula (2) has a structure in which a conjugated system of π electrons spreads greatly, orbital overlap between molecules is large, in particular, hole injection from an electrode is performed. It is considered that the property and the hole transport property in the layer are improved.

  As described above, the organic light-emitting device of the present invention is formed by a wet method such as a coating method after the acrylic compound represented by formula (1) or formula (2) is in a paint state, followed by a coating film drying step. It is preferable to follow a process of polymerizing and curing to form a functional cured film. On the other hand, since the acrylic compound represented by the formula (1) or the formula (2) has heat reactivity, it is not suitable for film formation by a vapor deposition method.

  When forming a thin film of an acrylic compound represented by formula (1) or formula (2) by a wet method, it is better to prepare a coating composition described below and coat this coating composition. .

  Here, the coating composition contains at least one acrylic compound represented by the formula (1) or the formula (2). If this coating composition is used, it becomes possible to produce a layer made of an organic compound constituting an organic light emitting device, in particular, a charge injection layer or a charge transport layer by a coating method, and it is a relatively inexpensive and large area organic light emitting device. An element can be easily manufactured.

  Examples of the solvent used in the coating composition include hydrocarbon solvents such as toluene, xylene, mesitylene, tetralin, n-dodecylbenzene, and methylnaphthalene, ether solvents such as tetrahydrofuran, dioxane, and diglyme, chloroform, and monochlorobenzene. 1, halogen solvents such as 1,2-dichlorobenzene, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, ester solvents such as methyl acetate, ethyl acetate, n-butyl acetate, methanol, ethanol, n-propanol, etc. Alcohol-based solvents, and the like. These solvents may be used alone or in combination of two or more. Moreover, the film thickness of the acrylic thin film formed from an acrylic compound can be adjusted by adjusting the viscosity of these solvents and the concentration of the acrylic compound in the solution.

  In addition to the acrylic compound represented by the formula (1) or the formula (2), for example, the above-mentioned known hole transporting compound, light emitting compound, electron transporting compound, and the like may be included.

  The content of the acrylic compound represented by formula (1) or formula (2) in the coating composition is preferably 0.05% by weight or more and 20% by weight or less, more preferably 0.1% by weight or more and 5% or less. % By weight or less.

  Examples of the coating method include a casting method, a spin coating method, a slit coater method, a printing method, an ink jet method, a dispensing method, a spray method, a dip method, and an LB film method.

  In the organic light emitting device of the present invention, the acrylic compound represented by the formula (1) or the formula (2) is formed between the anode and the cathode by a wet method such as a coating method. The thickness of the layer containing the acrylic compound is less than 10 μm, preferably 0.5 μm or less, and more preferably 0.005 μm to 0.5 μm.

  In the organic light emitting device of the present invention, the layers other than the layer containing the acrylic compound represented by the formula (1) or (2) may be a dry method such as a general vacuum deposition method or a wet method dissolved in an appropriate solvent. A thin film is formed by, for example. The organic light emitting device of the present invention is preferably characterized in that a light emitting layer is provided so as to be in contact with the hole injection layer, and this light emitting layer is formed by a coating method.

  Specific examples of the wet method include a cast method, a spin coat method, a slit coater method, a printing method, an ink jet method, a dispense method, a spray method, a dip method, and an LB film method.

  In particular, when a film is formed by a coating method, the film can be formed in combination with an appropriate binder resin.

  The binder resin can be selected from a wide range of binder resins. For example, polyvinyl carbazole resin, polycarbonate resin, polyester resin, polyarylate resin, polystyrene resin, polyacrylic resin, polymethacrylic resin, polyvinyl butyral resin, polyvinyl acetal resin, diallyl phthalate resin, phenol resin, epoxy resin, silicone resin, polysulfone Examples thereof include, but are not limited to, resins and urea resins. The form of the binder resin may be a homopolymer or a copolymer polymer. In addition, one type of binder resin may be used alone, or two or more types may be mixed and used.

  The organic light emitting device of the present invention may have a plurality of organic layers in addition to the light emitting layer, for example, a hole injection layer, a hole transport layer, a hole / exciton blocking layer, an electron transport layer, an electron injection layer. Etc. As described above, these layers can be produced by any method such as vacuum vapor deposition or solution coating. When forming an element, the thickness of these layers is less than 5 μm, preferably 1 μm or less, more preferably 5 nm to 500 nm.

  The organic light emitting device of the present invention can constitute a display by being appropriately combined. Specifically, the display of the present invention includes a plurality of organic light emitting elements and driving circuits, and is driven by a passive matrix system or an active matrix system. Hereinafter, application examples of the element of the present invention will be described with reference to the drawings. In the following application examples, the active matrix method is used as the driving method.

  FIG. 8 is a schematic cross-sectional view showing the arrangement of organic light emitting elements on a substrate, circuits arranged outside the organic light emitting elements, and data lines. The circuit includes a TFT and a storage capacitor.

  Although only one organic light emitting element is shown in FIG. 8, when a display is configured, a plurality of organic light emitting elements are two-dimensionally arranged as shown in FIG. The organic compound according to this embodiment is included in this organic compound layer.

  FIG. 9 is a circuit diagram showing details of the configuration of the circuit shown in FIG. The circuit shown in FIG. 9 has a typical circuit configuration called a current programming method. The circuit of the display of the present invention is not limited to this.

  The circuit shown in FIG. 9 includes a drive transistor T1, a switching transistor T2, a storage capacitor Ch, and an organic light emitting element. Since this circuit has a well-known circuit configuration, detailed description of the operation is omitted.

  This organic light emitting element can be used as a light emitting point and used as an exposure light source for a display, an illumination device, or an electrophotographic image forming apparatus.

  Next, the case where the organic light emitting device of the present invention is used for a display will be described.

  FIG. 10 schematically shows a state in which a plurality of organic light emitting elements and circuits shown in FIGS. 8 and 9 are arranged in a two-dimensional manner on the same plane as one pixel, that is, arranged in a matrix.

  The pixel included in the display in FIG. 10 is connected to a gate driver and a source driver through wirings, and enters a light emitting state or a non-light emitting state when a driving pulse is supplied.

  A region where a plurality of such organic light-emitting elements are arranged in the same plane as pixels in the in-plane direction is a display region of the display. That is, the organic light emitting device according to this embodiment can be used in a display area of a display.

  This display may take any form as long as it is a display device for a television or a PC, or a device having a part for displaying an image. For example, a portable display device equipped with this display may be used. Or the display which concerns on this embodiment can be used for electronic imaging devices, such as a digital camera, and the display part of a mobile telephone.

  FIG. 11 shows a configuration in which the display shown in FIG. 10 is made into a panel module. The panel module means a configuration in which parts necessary for connection to an external device such as an interface driver and a connection terminal are provided in addition to the configuration shown in FIG.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

[Synthesis Example 1] Exemplified Compound No. 1 Synthesis of 1-16 In the flask, the following reagents and solvent were charged, and the flask was cooled in an ice water bath.

    Dihydroxy compound represented by the following formula: 1.0 g (1.19 mmol)

トリエチルアミン：０．４２ｇ（４．１７ｍｍｏｌ）
テトラヒドロフラン：１０ｍｌ

Triethylamine: 0.42 g (4.17 mmol)
Tetrahydrofuran: 10ml

  Next, 0.32 g (3.57 mmol) of acrylic acid chloride was dropped into the reaction solution while keeping the temperature of the reaction solution at 10 ° C. or lower. After completion of the dropwise addition, the temperature of the reaction solution was gradually raised, and the reaction was continued for another 30 minutes while maintaining the temperature of the reaction solution at 50 ° C.

  After completion of the reaction, the reaction solution was cooled. Next, 100 ml of ethyl acetate and 50 ml of 10% aqueous sodium hydroxide solution were added to the reaction solution and stirred, and then a liquid separation operation was performed to recover the organic layer. The collected organic layer was further washed twice with 30 ml of ion exchange water and dried over magnesium sulfate.

  Next, the solvent in the organic layer was removed using a rotary evaporator to obtain a crude product. This crude product was purified using silica gel column chromatography. Specifically, about 10 g of silica gel was used, and toluene was initially used as a developing solvent, and a toluene / tetrahydrofuran mixed solvent (mixing ratio: 10/1) was used from the middle.

  Finally, the fraction corresponding to the target compound is recovered, and the solvent is removed under reduced pressure. 0.73 g of 1-16 was obtained. Exemplified Compound No. 1-16 was a light yellow solid which did not show crystallinity.

[Synthesis Example 2] Exemplified Compound No. 2 1-2 Synthesis Each synthesis reagent was used in the following amounts and synthesized in the same manner as in Synthesis Example 1.

  Dihydroxy compound represented by the following structural formula: 1.0 g (1.32 mmol)

トリエチルアミン：０．４７ｇ（４．６２ｍｍｏｌ）
テトラヒドロフラン：１０ｍｌ
アクリル酸クロライド：０．３６ｇ（３．９６ｍｍｏｌ）

Triethylamine: 0.47 g (4.62 mmol)
Tetrahydrofuran: 10ml
Acrylic acid chloride: 0.36 g (3.96 mmol)

  After completion of the reaction, post-treatment was performed in the same manner as in Synthesis Example 1, and purification was performed in the same manner as in Example 1. As a result, the target Exemplified Compound No. 0.77g of 1-2 was obtained.

[Synthesis Example 3] Exemplified Compound No. 1 Synthesis of 1-10 Each synthesis reagent was used in the following amounts, and the synthesis was performed in the same manner as in Synthesis Example 1.

  Dihydroxy compound represented by the following structural formula: 1.0 g (1.30 mmol)

トリエチルアミン：０．４６ｇ（４．５５ｍｍｏｌ）
テトラヒドロフラン：１０ｍｌ
アクリル酸クロライド：０．３５ｇ（３．９ｍｍｏｌ）

Triethylamine: 0.46 g (4.55 mmol)
Tetrahydrofuran: 10ml
Acrylic acid chloride: 0.35 g (3.9 mmol)

  After completion of the reaction, post-treatment was performed in the same manner as in Synthesis Example 1, and purification was performed in the same manner as in Example 1. As a result, the target Exemplified Compound No. 0.75g of 1-2 was obtained.

[Synthesis Example 4] Exemplified Compound No. 1 Synthesis of 1-17 Synthesis was performed in the same manner as in Synthesis Example 1 using each synthesis reagent in the following amounts.

  Dihydroxy compound represented by the following structural formula: 1.0 g (1.14 mmol)

トリエチルアミン：０．４０ｇ（３．９９ｍｍｏｌ）
テトラヒドロフラン：１０ｍｌ
アクリル酸クロライド：０．３１ｇ（３．４２ｍｍｏｌ）

Triethylamine: 0.40 g (3.99 mmol)
Tetrahydrofuran: 10ml
Acrylic acid chloride: 0.31 g (3.42 mmol)

  After completion of the reaction, post-treatment was performed in the same manner as in Synthesis Example 1, and purification was performed in the same manner as in Example 1. As a result, the target Exemplified Compound No. 0.77g of 1-17 was obtained.

[Synthesis Example 5] Exemplified Compound No. 1 Synthesis of 1-19 Each synthesis reagent was used in the following amounts, and the synthesis was performed in the same manner as in Synthesis Example 1. Dihydroxy compound represented by the following structural formula: 1.0 g (1.19 mmol)

トリエチルアミン：０．４２ｇ（４．１８ｍｍｏｌ）
テトラヒドロフラン：１０ｍｌ
メタアクリル酸クロライド：０．３７ｇ（３．５７ｍｍｏｌ）

Triethylamine: 0.42 g (4.18 mmol)
Tetrahydrofuran: 10ml
Methacrylic acid chloride: 0.37 g (3.57 mmol)

  After completion of the reaction, post-treatment was performed in the same manner as in Synthesis Example 1, and purification was performed in the same manner as in Example 1. As a result, the target Exemplified Compound No. 0.78 g of 1-19 was obtained.

[Synthesis Example 6] Exemplified Compound No. 6 Synthesis of 1-21 Synthesis was performed in the same manner as in Synthesis Example 1 using the following amounts of each synthesis reagent.

  Dihydroxy compound represented by the following structural formula: 1.0 g (1.12 mmol)

トリエチルアミン：０．４０ｇ（３．９２ｍｍｏｌ）
テトラヒドロフラン：１０ｍｌ
アクリル酸クロライド：０．３０ｇ（３．３６ｍｍｏｌ）

Triethylamine: 0.40 g (3.92 mmol)
Tetrahydrofuran: 10ml
Acrylic acid chloride: 0.30 g (3.36 mmol)

  After completion of the reaction, post-treatment was performed in the same manner as in Synthesis Example 1, and purification was performed in the same manner as in Example 1. The target exemplified compound No. 0.67g of 1-21 was obtained.

[Synthesis Example 7] Exemplified Compound No. 7 Synthesis of 2-1 Synthesis was performed in the same manner as in Synthesis Example 1 using the following amounts of each synthesis reagent.

  Dihydroxy compound represented by the following structural formula: 0.5 g

トリエチルアミン：０．４０ｇ
テトラヒドロフラン：２０ｍｌ
アクリル酸クロライド０．３０ｇ

Triethylamine: 0.40g
Tetrahydrofuran: 20ml
Acrylic acid chloride 0.30g

  After completion of the reaction, post-treatment was performed in the same manner as in Synthesis Example 1, and purification was performed in the same manner as in Example 1. As a result, the target Exemplified Compound No. 0.36g of 2-1 was obtained.

[Synthesis Example 8] Exemplified Compound No. 8 Synthesis of 2-2 The synthesis was performed in the same manner as in Synthesis Example 1 using the following amounts of each synthesis reagent.

  Dihydroxy compound represented by the following structural formula: 0.5 g

トリエチルアミン：０．４０ｇ
テトラヒドロフラン：３０ｍｌ
アクリル酸クロライド：０．３０ｇ

Triethylamine: 0.40g
Tetrahydrofuran: 30ml
Acrylic acid chloride: 0.30 g

  After completion of the reaction, post-treatment was performed in the same manner as in Synthesis Example 1, and purification was performed in the same manner as in Example 1. As a result, the target Exemplified Compound No. 0.35g of 2-2 was obtained.

Synthesis Example 9 Exemplified Compound No. Synthesis of 2-14 Synthesis was performed in the same manner as in Synthesis Example 1 using the following amounts of each synthesis reagent.

  Dihydroxy compound represented by the following structural formula: 0.5 g

トリエチルアミン：０．４０ｇ
テトラヒドロフラン：２０ｍｌ
メタアクリル酸クロライド０．３０ｇ

Triethylamine: 0.40g
Tetrahydrofuran: 20ml
Methacrylic acid chloride 0.30 g

  After completion of the reaction, post-treatment was performed in the same manner as in Synthesis Example 1, and purification was performed in the same manner as in Example 1. As a result, the target Exemplified Compound No. 0.33g of 2-14 was obtained.

[Example 1]
The organic light emitting device shown in FIG. 7 was produced.

  An indium tin oxide (ITO) film was formed on a glass substrate (substrate 1) by sputtering to form an anode 2. At this time, the film thickness of the anode 2 was 120 nm. Next, this was ultrasonically washed successively with acetone and isopropyl alcohol (IPA), boiled and washed with IPA, and then dried. Further, UV / ozone cleaning was performed. The substrate processed by the above method was used as a transparent conductive support substrate.

  Next, Exemplified Compound No. 1-16 was dissolved in methyl isobutyl ketone to prepare a coating solution having a concentration of 0.5% by weight. This coating solution was formed on the transparent conductive support substrate at a rate of 1000 rpm by a spin coating method (film formation step). Next, the hole injection layer 7 was formed by heating and curing the produced film at 200 ° C. for 30 minutes (heat curing step). At this time, the thickness of the hole injection layer 7 was set to 30 nm. In addition, said film-forming process and heat-curing process were performed in nitrogen atmosphere with an oxygen concentration of 5 ppm. This thermosetting film is a film having a crosslinked structure and is insoluble in a solvent.

  Next, the following (a) to (c) were dissolved in 99 parts by mass of chloroform to prepare a coating solution.

(A) Ir (ppy) ₃ (tris (2-phenylpyridine) iridium) represented by the following formula: 0.01 part by mass

  (B) PBD (2- (4-biphenyl) -5- (4-butylphenyl) -1,3,4-oxadiazole) which is an electron transport compound represented by the following formula: 0.3 part by mass

  (C) PVK (polyvinylcarbazole, Mn = 35,000) represented by the following formula: 0.7 parts by mass

  Next, this coating solution was dropped on the hole injection layer 7 and spin coating was performed at a rotation speed of 1000 rpm for 1 minute to form a thin film as the light emitting layer 3. Then, it heated at 80 degreeC for 30 minute (s), and the solvent in a thin film was evaporated. The film thickness of the light emitting layer 3 after the heat treatment was 50 nm.

Next, on the light emitting layer 3, lithium fluoride was vapor-deposited by the vacuum vapor deposition method, and the electron injection layer 9 was formed. At this time, the thickness of the electron transport layer 9 was 0.5 nm, the degree of vacuum during vapor deposition was 1.0 × 10 ⁻⁴ Pa, and the film formation rate was 0.05 nm / sec.

Furthermore, the metal layer which is the cathode 4 was formed by vapor-depositing aluminum. At this time, the film thickness of the cathode 4 was set to 100 nm, the degree of vacuum during vapor deposition was set to 1.0 × 10 ⁻⁴ Pa, and the film formation rate was set to 1.0 nm / sec to 1.2 nm / sec. Finally, under a nitrogen atmosphere, a protective glass plate was placed and sealed with an acrylic resin adhesive. Thus, an organic light emitting device was obtained.

When a direct current voltage of 8.0 V was applied to the obtained device using an ITO electrode as an anode and an aluminum electrode as a cathode, a current flowed through the device. The current density at this time was 46 mA / cm ² . Also, green light emission luminance 2350cd / m ² could be observed upon application of the DC voltage. Furthermore, was continuously driven element while keeping the current density 30 mA / cm ^2, the initial luminance was 1610cd / m ^2, the luminance after 50 hours was 1400cd / m ^2.

In addition, in the organic light emitting device of the present invention, the state of the light emitting surface was observed with an optical microscope while the device of Example 1 was made to emit light at a luminance of 500 cd / m ² in order to observe the occurrence of film defects in the film forming process. Observation was made to evaluate the presence or absence of film defects. Table 1 shows the evaluation results including the observation results of the uniformity of the light emitting surface.

[Example 2]
In Example 1, the constituent material of the hole injection layer 7 was changed to the exemplified compound No. In place of 1-16, Exemplified Compound No. 1 A device was fabricated in the same manner as in Example 1 except that 1-2 was used. The obtained device was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 3]
In Example 1, the constituent material of the hole injection layer 7 was changed to the exemplified compound No. In place of 1-16, Exemplified Compound No. 1 A device was fabricated in the same manner as in Example 1 except that 1-10 was used. The obtained device was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 4]
In Example 1, the constituent material of the hole injection layer 7 was changed to the exemplified compound No. In place of 1-16, Exemplified Compound No. 1 A device was fabricated in the same manner as in Example 1 except that 1-17 was used. The obtained device was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 5]
In Example 1, the constituent material of the hole injection layer 7 was changed to the exemplified compound No. In place of 1-16, Exemplified Compound No. 1 A device was fabricated in the same manner as in Example 1 except that 1-19 was used. The obtained device was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 6]
In Example 1, the constituent material of the hole injection layer 7 was changed to the exemplified compound No. In place of 1-16, Exemplified Compound No. 1 A device was fabricated in the same manner as in Example 1 except that 1-21 was used. The obtained device was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 7]
In Example 1, the constituent material of the hole injection layer 7 was changed to the exemplified compound No. In place of 1-16, Exemplified Compound No. 1 A device was fabricated in the same manner as in Example 1 except that 2-1. The obtained device was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 8]
In Example 1, the constituent material of the hole injection layer 7 was changed to the exemplified compound No. In place of 1-16, Exemplified Compound No. 1 A device was fabricated in the same manner as in Example 1 except that 2-2 was used. The obtained device was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 9]
In Example 1, the constituent material of the hole injection layer 7 was changed to the exemplified compound No. In place of 1-16, Exemplified Compound No. 1 A device was fabricated in the same manner as in Example 1 except that 2-14 was used. The obtained device was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Reference Example 1]
A device was produced in the same manner as in Example 1 except that the production process (coating process and thermosetting process) of the hole injection layer 7 was performed in a dry air atmosphere with an oxygen concentration of 21%. The obtained device was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 1]
In Example 1, the constituent material of the hole injection layer 7 was changed to the exemplified compound No. Instead of 1-16, 4-polyethylenedioxythiophene / polystyrene sulfonic acid (PEDOT / PSS, trade name: Vitron P Al-4083, manufactured by Bayer) represented by the following formula was used. When forming the hole injection layer 7, a PEDOT / PSS thin film was formed by spin coating, and then heated at 120 ° C. for 30 minutes to a film thickness of 35 nm. Except for these, a device was fabricated in the same manner as in Example 1. The obtained device was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 2]
In Example 1, the constituent material of the hole injection layer 7 was changed to the exemplified compound No. A device was produced in the same manner as in Example 1 except that a compound represented by the following formula was used instead of 1-16. The obtained device was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 3]
In Example 1, the hole injection layer 7 was formed by the following method. That is, the following (a) and (b) were dissolved in 80 parts by mass of chloroform to prepare a coating solution.

  (A) Compound represented by the following formula: 1 part by mass

  (B) 4- (thiophenoxyphenyl) -diphenylsulfonium hexafluoroantimonate: 0.05 parts by mass (photoinitiator)

  Next, this coating solution was dropped onto a transparent conductive support substrate, and a film was formed by spin coating at 1000 rpm for 1 minute. Furthermore, after irradiating UV light of 280 nm with a UV irradiation device for 1 minute, the hole injection layer 7 was formed by heating at 150 ° C. for 10 minutes in a nitrogen atmosphere. At this time, the thickness of the hole injection layer 7 was 30 nm. Except for this, an element was fabricated in the same manner as in Example 1. About the obtained element, it carried out similarly to Example 1. FIG. The results are shown in Table 1.

[Example 10]
An element having the structure shown in FIG. 7 was produced.

  On the glass substrate (substrate 1), indium tin oxide (ITO) was formed by sputtering to form the anode 2. At this time, the film thickness of the anode was set to 120 nm. Next, ultrasonic cleaning was sequentially performed with acetone and isopropyl alcohol (IPA), followed by boiling with IPA and drying. Further, UV / ozone cleaning was performed. The substrate treated as described above was used as a transparent conductive support substrate.

  Next, Exemplified Compound No. 1-16 was dissolved in methyl ethyl ketone to prepare a coating solution having a concentration of 0.5% by weight. Next, this coating solution was applied onto the transparent conductive support substrate by a spin coating method (application step). The number of rotations when applying here was 1000 rpm. Next, it hardened | cured by heating at 200 degreeC for 30 minutes (heat-hardening process). The film thickness of the hole injection layer 7 after curing was 30 nm. In addition, said application | coating process and heat-curing process were performed in nitrogen atmosphere with an oxygen concentration of 5 ppm.

  Next, poly (9,9-dioctyl) fluorene represented by the following formula was dissolved in toluene to prepare a 1 wt% light emitting layer coating solution. This coating solution was spin-coated on the hole injection layer 7 to form a film. Thereafter, the light emitting layer 3 was formed by heating and drying at 80 ° C. for 30 minutes. The film thickness of the light emitting layer 3 after heat drying was 50 nm.

Next, lithium fluoride was deposited on the organic thin film layer by a vacuum deposition method to form the electron injection layer 9. At this time, the thickness of the electron injection layer 9 was 0.5 nm, the degree of vacuum during vapor deposition was 1.0 × 10 ⁻⁴ Pa, and the film formation rate was 0.05 nm / sec.

Next, aluminum was vapor-deposited to form a metal layer that becomes the cathode 4. At this time, the thickness of the cathode 4 was 100 nm, the degree of vacuum during vapor deposition was 1.0 × 10 ⁻⁴ Pa, and the film formation rate was 1.0 nm / sec to 1.2 nm / sec. Finally, a protective glass plate was placed under a nitrogen atmosphere and sealed with an acrylic resin adhesive. An organic light emitting device was obtained as described above.

When a direct current voltage of 6.0 V was applied to the obtained device using an ITO electrode as an anode and an aluminum electrode as a cathode, a current flowed through the device. The current density at this time was a current density of 55 mA / cm ² . Further, blue light emission with a luminance of 1150 cd / m ² was observed when a DC voltage was applied. Further, when the device was continuously driven while maintaining the current density at 30 mA / cm ² , the initial luminance was 750 cd / m ² and the luminance after 100 hours was 610 cd / m ² .

In addition, in the organic light emitting device of the present invention, the state of the light emitting surface was observed with an optical microscope while the device of Example 1 was made to emit light at a luminance of 500 cd / m ² in order to observe the occurrence of film defects in the film forming process. Observation was made to evaluate the presence or absence of film defects. Table 1 also includes the observation results of the uniformity of the light emitting surface.

[Example 11]
In Example 10, the constituent material of the hole injection layer 7 was changed to Exemplified Compound No. In place of 1-16, Exemplified Compound No. 1 A device was fabricated in the same manner as in Example 10 except that 1-2 was used. The obtained device was evaluated in the same manner as in Example 10. The results are shown in Table 2.

[Example 12]
In Example 10, the constituent material of the hole injection layer 7 was changed to Exemplified Compound No. In place of 1-16, Exemplified Compound No. 1 A device was produced in the same manner as in Example 10 except that 1-10 was used. The obtained device was evaluated in the same manner as in Example 10. The results are shown in Table 2.

[Example 13]
In Example 10, the constituent material of the hole injection layer 7 was changed to Exemplified Compound No. In place of 1-16, Exemplified Compound No. 1 A device was fabricated in the same manner as in Example 10 except that 1-17 was used. The obtained device was evaluated in the same manner as in Example 10. The results are shown in Table 2.

[Example 14]
In Example 10, the constituent material of the hole injection layer 7 was changed to Exemplified Compound No. In place of 1-16, Exemplified Compound No. 1 A device was produced in the same manner as in Example 10 except that 1-19 was used. The obtained device was evaluated in the same manner as in Example 10. The results are shown in Table 2.

[Example 15]
In Example 10, the constituent material of the hole injection layer 7 was changed to Exemplified Compound No. In place of 1-16, Exemplified Compound No. 1 A device was fabricated in the same manner as in Example 10 except that 1-21 was used. The obtained device was evaluated in the same manner as in Example 10. The results are shown in Table 2.

[Example 16]
In Example 10, the constituent material of the hole injection layer 7 was changed to Exemplified Compound No. In place of 1-16, Exemplified Compound No. 1 A device was produced in the same manner as in Example 10 except that 2-1. The obtained device was evaluated in the same manner as in Example 10. The results are shown in Table 2.

[Example 17]
In Example 10, the constituent material of the hole injection layer 7 was changed to Exemplified Compound No. In place of 1-16, Exemplified Compound No. 1 A device was fabricated in the same manner as in Example 10 except that 2-2 was used. The obtained device was evaluated in the same manner as in Example 10. The results are shown in Table 2.

[Example 18]
In Example 10, the constituent material of the hole injection layer 7 was changed to Exemplified Compound No. In place of 1-16, Exemplified Compound No. 1 A device was fabricated in the same manner as in Example 10 except that 2-14 was used. The obtained device was evaluated in the same manner as in Example 10. The results are shown in Table 2.

[Reference Example 2]
In Example 10, a device was produced in the same manner as in Example 1 except that the production process (application process and thermosetting process) of the hole injection layer 7 was performed in a dry air atmosphere with an oxygen concentration of 21%. The obtained device was evaluated in the same manner as in Example 10. The results are shown in Table 2.

[Comparative Example 4]
In Example 10, the constituent material of the hole injection layer 7 was changed to Exemplified Compound No. Instead of 1-16, PEDOT / PSS was used. Further, when forming the hole injection layer 7, a PEDOT / PSS thin film was formed by spin coating, and then heated at 120 ° C. for 30 minutes to a film thickness of 30 nm. Except for these, an element was fabricated in the same manner as in Example 10. The obtained device was evaluated in the same manner as in Example 1. The results are shown in Table 2.

[Comparative Example 5]
In Example 10, the constituent material of the hole injection layer 7 was changed to Exemplified Compound No. A device was produced in the same manner as in Example 10 except that the compound used in Comparative Example 2 was used instead of 1-16. The obtained device was evaluated in the same manner as in Example 1. The results are shown in Table 2.

[Comparative Example 6]
A device was fabricated in the same manner as in Example 10, except that the hole injection layer 7 was formed by the same method as in Comparative Example 3 in Example 10. The obtained device was evaluated in the same manner as in Example 1. The results are shown in Table 2.

  ADVANTAGE OF THE INVENTION According to this invention, the organic light emitting element which is highly luminous with high luminous efficiency and has no film forming defect of a light emitting surface can be produced. The organic light emitting device of the present invention can be applied to a display device such as a display panel.

It is sectional drawing which shows 1st embodiment in the organic light emitting element of this invention. It is sectional drawing which shows 2nd embodiment in the organic light emitting element of this invention. It is sectional drawing which shows 3rd embodiment in the organic light emitting element of this invention. It is sectional drawing which shows 4th embodiment in the organic light emitting element of this invention. It is sectional drawing which shows 5th embodiment in the organic light emitting element of this invention. It is sectional drawing which shows 6th embodiment in the organic light emitting element of this invention. It is sectional drawing which shows 7th embodiment in the organic light emitting element of this invention. 1 is a schematic cross-sectional view showing an organic light emitting device according to an embodiment of the present invention, a circuit for driving the organic light emitting device, and wiring. It is a figure which shows the detail of the circuit of FIG. FIG. 10 is a schematic diagram showing a state in which a display is configured by arranging the organic light emitting elements and circuits shown in FIGS. 8 and 9 in a matrix form as one pixel. It is a schematic diagram which shows the structure which made the display shown in FIG. 10 into the panel module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Anode 3 Light emitting layer 4 Cathode 5 Hole transport layer 6 Electron transport layer 7 Hole injection layer (buffer layer)
8 Hole / exciton blocking layer 9 Electron injection layer

Claims (10)

An anode and a cathode;
A layer made of an organic compound sandwiched between the anode and the cathode, and
At least one layer of the organic compound layer is formed of an acrylic thin film containing at least one kind of acrylic compound represented by the following general formula (1) or (2) or an acrylic cured film obtained by curing the acrylic thin film. An organic light emitting device characterized by the above.

(In the formula (1), A ₁₁ and A ₁₂ each represent a divalent hydrocarbon group having 2 to 8 carbon atoms. R ₁₁ and R ₁₂ each represent a hydrogen atom or a methyl group. Ar ₁₁ and Ar ₁₃ is substituted or unsubstituted biphenyl, substituted or unsubstituted fluorene, substituted or unsubstituted fluoranthene, substituted or unsubstituted phenylnaphthalene, substituted or unsubstituted phenanthrene, substituted or unsubstituted dihydrophenanthrene, substituted or Ar ₁₂ represents a monovalent substituent selected from unsubstituted pyrene, substituted or unsubstituted perylene, substituted or unsubstituted carbazole, substituted or unsubstituted dibenzofuran, and substituted or unsubstituted dibenzothiophene. Unsubstituted biphenyl, substituted or unsubstituted fluorene, substituted Is substituted fluoranthene, substituted or unsubstituted phenylnaphthalene, substituted or unsubstituted phenanthrene, substituted or unsubstituted dihydrophenanthrene, substituted or unsubstituted pyrene, substituted or unsubstituted perylene, substituted or unsubstituted benzoanthracene And a divalent substituent selected from substituted or unsubstituted carbazole, substituted or unsubstituted dibenzofuran, and substituted or unsubstituted dibenzothiophene.

(In the formula (2), A ₂₁ and A ₂₂ each represent a divalent hydrocarbon group having 2 to 8 carbon atoms. R ₂₁ and R ₂₂ each represent a hydrogen atom or a methyl group. Ar ₂₁ and Ar ₂₄ is substituted or unsubstituted biphenyl, substituted or unsubstituted fluorene, substituted or unsubstituted fluoranthene, substituted or unsubstituted phenylnaphthalene, substituted or unsubstituted phenanthrene, substituted or unsubstituted pyrene, substituted or unsubstituted A monovalent substituent selected from substituted perylene, substituted or unsubstituted carbazole, substituted or unsubstituted dibenzofuran, substituted or unsubstituted dibenzothiophene, Ar ₂₂ and Ar ₂₃ are substituted or unsubstituted biphenyl, respectively. Substituted or unsubstituted fluorene, substituted or unsubstituted fluoranthene, Substituted or unsubstituted phenylnaphthalene, substituted or unsubstituted phenanthrene, substituted or unsubstituted dihydrophenanthrene, substituted or unsubstituted pyrene, substituted or unsubstituted perylene, substituted or unsubstituted benzoanthracene, substituted or unsubstituted Z ₂₁ represents a divalent substituent selected from carbazole, substituted or unsubstituted dibenzofuran, substituted or unsubstituted dibenzothiophene, and Z ₂₁ represents a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic complex. Represents a cyclic group, and n represents an integer of 1 to 4.)   The organic light emitting device according to claim 1, wherein the acrylic thin film or the cured acrylic film forms a hole injection layer. The method for producing an organic light-emitting element according to claim 1, comprising the following steps (i) and (ii):
(I) Step of forming the acrylic thin film containing at least one kind of the acrylic compound by a wet method (ii) The acrylic thin film is formed by heat polymerization or heat curing of the acrylic thin film in an inert gas. Process   The manufacturing method according to claim 3, wherein an oxygen concentration in the inert gas is 10 ppm or less.   The method according to claim 3 or 4, wherein the inert gas is nitrogen or argon.   The method for producing an organic light-emitting device according to claim 3, wherein a polymerization initiator is not included when the acrylic thin film is formed.   The manufacturing method according to claim 3, wherein a light emitting layer is provided so as to be in contact with the hole injection layer, and the light emitting layer is formed by a coating method.   A display comprising a plurality of the organic light emitting elements according to claim 1 and a plurality of driving circuits.   A panel module comprising the display according to claim 8 and an interface with an external device.   A portable display device equipped with the display according to claim 8.

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