JP5708677B2 - ORGANIC ELECTROLUMINESCENT ELEMENT AND LIGHTING DEVICE - Google Patents

Description

  The present invention relates to an organic electroluminescence element and a lighting device using the element.

  As a light-emitting electronic display device, there is an electroluminescence display (hereinafter abbreviated as ELD). As a constituent element of ELD, an inorganic electroluminescence element (hereinafter also referred to as an inorganic EL element) and an organic electroluminescence element (hereinafter also referred to as an organic EL element) can be given. Inorganic EL elements have been used as planar light sources, but an alternating high voltage is required to drive the light emitting elements.

  On the other hand, an organic electroluminescence device has a structure in which a light emitting layer containing a light emitting compound is sandwiched between a cathode and an anode, and excitons (exciton) are injected by injecting electrons and holes into the light emitting layer and recombining them. ), Which emits light by using light emission (fluorescence / phosphorescence) when the exciton is deactivated, and can emit light at a voltage of several V to several tens of V, and further self-emission. Since it is a type, it has a wide viewing angle, high visibility, and since it is a thin-film type completely solid element, it has attracted attention from the viewpoints of space saving, portability, and the like.

  Another major feature of the organic electroluminescence element is that it is a surface light source, unlike main light sources that have been put to practical use, such as light-emitting diodes and cold-cathode tubes. Applications that can effectively utilize this characteristic include illumination light sources and various display backlights. In particular, it is also suitable to be used as a backlight of a liquid crystal full color display whose demand has been increasing in recent years.

  Conventionally, glass has been used as a substrate used in such elements because of its low thermal stability, high transparency, and low water vapor permeability. However, glass originally has the characteristics of being easy to break and relatively heavy, and in order to be used in various applications, a flexible, flexible and light-breaking substrate is required. Use a transparent plastic substrate. Has been proposed and adopted in some areas. Here, as an element configuration, a transparent electrode is generally arranged on the plastic substrate. However, when the plastic substrate is used, cracks occur in the electrode layer from the bent portion due to its flexibility, or the electrode layer peels off due to heat shrinkage, which is a property of plastic, and the element The problem of causing a leak and a short circuit will arise. This is a fatal problem that was not assumed when the glass substrate was used.

  Recently, a plastic film with improved heat resistance by a technique called an organic-inorganic polymer hybrid in which a metal oxide is mixed and compatible with a resin such as polyvinyl alcohol, polyvinyl acetate, polyvinyl pyrrolidone, polyimide, and polyamide on a nanoscale. It is disclosed (see Patent Document 1). Some of these organic-inorganic hybrid films have been disclosed (see Patent Document 2). Since these films have excellent heat resistance and optical properties such as birefringence, liquid crystal displays. As a moisture-proof film and a conductive film used for an electronic display film such as an element or an organic EL element, a preferable polymer film replacing glass or the like is preferable. However, these films have problems such as low transmittance, and there are problems such as variations in these characteristics.

  In applying the organic EL panel as described above to a display device, stable light emission of the three primary colors of RGB is an indispensable condition. However, in an organic EL panel, a non-light emitting point called a dark spot is generated by long-time driving, and the growth of the dark spot is one of the causes for shortening the lifetime of the organic EL panel. It is known that a dark spot is generally generated in a size that cannot be seen with the naked eye immediately after driving, and grows by continuous driving using this as a core. Further, it is known that dark spots are generated even in a storage state where driving is not performed and grows with time.

  There are various causes of dark spots, but cracks in the electrode layer, peeling of the electrode layer from the substrate, etc. due to external stress such as bending, deterioration with time, or differences in the coefficient of thermal expansion are considered. . As an external factor, crystallization of the organic layer due to the penetration of moisture and oxygen into the organic electroluminescence element, peeling of the electrode, etc., and as an internal factor, a short due to crystal growth of the metal constituting the electrode, It is considered that the organic layer is crystallized or deteriorated due to heat generated by light emission.

  In particular, when an organic electroluminescence element is configured using a resin substrate, the intrusion of moisture and oxygen into the organic electroluminescence element through the resin substrate is considered to be one of the major causes of dark spot generation, in order to suppress this. In addition, a method of forming an organic electroluminescence element including an electrode layer after forming a barrier film of inorganic oxide, inorganic nitride, inorganic carbide, etc. on a resin substrate is widely used. The occurrence of cracks in the barrier film, peeling of the barrier film from the substrate, and the like due to stress, deterioration with time, difference in thermal expansion coefficient, and the like have been problems.

  Technical studies are being conducted to improve the adhesion between the substrate and the barrier film or electrode layer, and to prevent the electrode layer or barrier film from cracking or peeling from the substrate. For example, a technique using a gas barrier resin base material in which the elastic modulus and compression stress of a gas barrier layer in which at least two ceramic layers containing silicon oxide are laminated is adjusted (see Patent Document 3), a highly smoothing layer, A technique using a high smooth gas barrier film in which an intermediate layer and a gas barrier layer are laminated has been reported (see Patent Document 4). Furthermore, for example, a technique for forming a zinc oxide-based transparent conductive film by coating a hard coat layer on a transparent resin substrate made of an acrylic resin and a polylactic acid-based resin (see Patent Document 5), A technique for forming a conductive layer after forming an intermediate layer having an inorganic compound film on the outermost surface and a graft polymer layer bonded thereto has been reported (see Patent Document 6). However, the implementation of these technologies is accompanied by an increase in costs due to the complexity of the manufacturing process, and fine adjustment of the technical configuration requirements is required, which is easy to implement and improves the adhesion to the substrate. There was a need for improved means to do this.

JP 2000-122038 A JP 2003-82118 A JP 2008-56967 A JP 2008-246893 A JP 2008-1003008 A JP 2008-207401 A

  The present invention has been made in view of the above problems, and an object of the present invention is to improve film adhesion between a transparent resin substrate and an electrode layer or a barrier layer in an organic electroluminescence element using a transparent resin substrate, Use organic electroluminescence elements with improved quality, no cracks in electrode layers and barrier layers, no peeling from transparent resin substrate, no leakage or short-circuiting of the elements, suppression of dark spots, and improved bending resistance It is to provide a lighting device.

  The above object of the present invention can be achieved by the following constitution.

1. In the organic electroluminescence device having an anode and a cathode on a transparent resin substrate, and having at least one organic layer including a light emitting layer between the anode and the cathode, the transparent resin substrate and the organic layer It has the anode or the cathode as an inorganic functional layer between the transparent resin substrate and adjacent to the inorganic functional layer between the inorganic functional layer, the surface-treated average particle size of 1~100nm An organic electroluminescence device comprising a metal oxide nanoparticle-containing layer having a haze value of less than 3% in which metal oxide nanoparticles are dispersed in an active ray curable resin at a content of 5 vol% or more and 50 vol% or less .

  2. 2. The organic electroluminescence device according to 1, wherein the metal oxide nanoparticles are surface-treated by bonding with a silane coupling agent.

  3. The metal oxide nanoparticles are Li, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Y, Nb, One or more metals selected from the group consisting of Zr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, La, Ta, Hf, W, Ir, Tl, Pb, Bi and rare earth metals 3. The organic electroluminescence device as described in 1 or 2 above, which comprises a metal oxide.

  4). Any one of said inorganic functional layers joined to the said transparent resin substrate through the said metal oxide nanoparticle content layer is a gas barrier layer, The said any one of 1-3 characterized by the above-mentioned. Organic electroluminescence element.

5. 5. The organic electroluminescence element according to 4 above, wherein the gas barrier layer contains SiO ₂ , SiN, or SiC.

6). 6. The organic electroluminescence device according to any one of 1 to 5, wherein the metal oxide nanoparticles include ZrO ₂ or TiO ₂ .

  7). 7. The organic electroluminescence device according to any one of 1 to 6, wherein the metal oxide nanoparticles have an average particle size of 1 nm to 100 nm.

  8). 8. The organic electroluminescence device according to any one of 1 to 7, wherein the metal oxide nanoparticles have an average particle size of 5 nm to 50 nm.

  9. Content of the said metal oxide nanoparticle in the said metal oxide nanoparticle content layer is 10 vol%-30 vol%, The organic electroluminescent element of any one of said 1-8 characterized by the above-mentioned.

  10. The organic electroluminescence device according to any one of 1 to 9, wherein the content of the metal oxide nanoparticles in the metal oxide nanoparticle-containing layer is 10 vol% to 20 vol%.

  11. 11. The organic electroluminescence device according to any one of 1 to 10, wherein the metal oxide nanoparticle-containing layer is substantially transparent.

  12 The organic electroluminescent element of any one of said 1-11 is used, The illuminating device characterized by the above-mentioned.

  According to the present invention, the film adhesion between the transparent resin substrate and the electrode layer or the barrier layer is improved, there is no crack of the electrode layer or the barrier layer or peeling from the transparent resin substrate, and there is no leakage or short circuit of the element, and high quality. In addition, an organic electroluminescence element in which dark spots are suppressed and bending resistance is improved, and a lighting device using the element can be provided.

  Hereinafter, although the form for implementing this invention is demonstrated, this invention is not limited to these.

  The organic electroluminescence device of the present invention is an organic electroluminescence device having an anode and a cathode on a transparent resin substrate, and having at least one organic layer including a light emitting layer between the anode and the cathode. And having at least one inorganic functional layer between the transparent resin substrate and the organic layer, and having a metal oxide nanoparticle-containing layer between the transparent resin substrate and the inorganic functional layer. And

  In the present invention, in particular, at least one inorganic functional layer is provided between the transparent resin substrate and the organic layer, and the metal oxide nanoparticle-containing layer is provided between the transparent resin substrate and the inorganic functional layer. That is, having at least one inorganic functional layer between the transparent resin substrate and the organic layer, wherein the transparent resin substrate and at least one of the inorganic functional layers contain metal oxide nanoparticles. By bonding through the layers, the film adhesion between the transparent resin substrate and the electrode layer or barrier layer is improved, and there is no cracking of the electrode layer or barrier layer or peeling from the transparent resin substrate. An organic electroluminescence device having no short circuit, high quality, suppressed dark spots, and improved bending resistance can be obtained.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail.

[Transparent resin substrate]
<Transparent resin film>
A resin film is used for the transparent resin substrate used in the organic electroluminescence element of the present invention. Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate propionate (CAP), Cellulose esters such as cellulose acetate phthalate and cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide, polyether Sulfone (PES), polyphenylene sulfide, polysulfones, polyether Cycloolefin resins such as Luimide, polyether ketone imide, polyamide, fluororesin, nylon, polymethyl methacrylate, acrylic or polyarylate, Arton (trade name, manufactured by JSR) or Apel (trade name, manufactured by Mitsui Chemicals), etc. Can be mentioned. In the present invention, a polyester film such as polyethylene terephthalate or polyethylene naphthalate is preferably used, and a stretched polyethylene naphthalate film is particularly preferable in terms of heat resistance.

  In the present invention, the refractive index of the transparent resin film is preferably 1.60 or more, more preferably 1.70 or more and 1.80 or less.

  In the present invention, the thickness of the transparent resin film is preferably from 50 μm to 250 μm, and more preferably from 75 μm to 200 μm.

  In the transparent resin substrate of the present invention, being transparent means that the light transmittance of visible light (wavelength 450 nm to 650 nm) is 70% or more, preferably 80% or more, and 90% or more. More preferably.

[Metal oxide nanoparticles containing layer]
In the present invention, the transparent resin substrate and at least one of the inorganic functional layers are bonded via a metal oxide nanoparticle-containing layer.

  In the metal oxide nanoparticle-containing layer according to the present invention, it is preferable that metal oxide nanoparticles are dispersed in a resin, and the metal oxide nanoparticle-containing layer is substantially transparent.

  In the present invention, being substantially transparent means that the turbidity (haze value) of all rays is less than 3%, and more preferably less than 1%.

  When carrying out haze evaluation as a transparency test of an inorganic functional layer, the haze value is measured by using T-2600DA manufactured by Tokyo Denshoku Industries Co., Ltd. according to ASTM-D1003-52. Can be obtained.

《Metal oxide nanoparticles》
The metal oxide nanoparticles used in the present invention may have an average particle size of 0.01 nm or more and 400 nm or less. Preferably, they are 1 nm-100 nm, More preferably, they are 5 nm-50 nm. An average particle diameter of 1 nm or more is preferable from the viewpoint of particle dispersion. On the other hand, the average particle size is preferably 100 nm or less from the viewpoint of the transparency of the obtained adhesion improving layer. Here, an average particle diameter means the average value of the diameter (sphere conversion particle diameter) when each particle is converted into the sphere of the same volume.

  In the present invention, the particle size can be measured by preparing a dispersion using an appropriate solvent and measuring the dynamic light scattering particle size distribution. The average particle diameter can be obtained as the median diameter of the particle diameter corresponding to 50% of the distribution curve on the sieve.

  In the metal oxide nanoparticle-containing layer of the present invention, by dispersing the metal oxide nanoparticles in the resin, the metal oxide nanoparticle-containing layer is interposed between the metal oxide nanoparticle-containing layer and the transparent resin substrate. It is possible to obtain a bond having sufficient adhesion between the inorganic functional layer and the inorganic functional layer. Moreover, since it does not have light scattering properties in the range of the average particle diameter of the metal oxide nanoparticles, it does not hinder transparency. Regarding the method of containing light scattering particles and fillers in the visible light region with the aim of improving the light scattering function, for example, there is a technique described in JP-A-2005-038661, but the metal oxide nanoparticle-containing layer is transparent. This is different from the present invention because problems such as deterioration of the performance occur.

  As the metal oxide nanoparticles used in the present invention, it is preferable to appropriately select and use those which do not cause absorption, light emission, fluorescence or the like in the wavelength region used as an optical element.

As the metal constituting the metal oxide nanoparticles, Li, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, One or two selected from the group consisting of Y, Nb, Zr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, La, Ta, Hf, W, Ir, Tl, Pb, Bi and rare earth metals A metal oxide that is a metal of more than one species can be used. Specifically, for example, titanium oxide, zinc oxide, aluminum oxide (alumina), zirconium oxide, hafnium oxide, niobium oxide, tantalum oxide, magnesium oxide, oxidation Barium, indium oxide, tin oxide, lead oxide, and double oxides composed of these oxides, lithium niobate, potassium niobate, lithium tantalate, aluminum mag Siumu oxide in particles and composite particles (MgAl 2 _{O 4)} or the like, the refractive index are those satisfying 1.6, of these particles, inexpensive, selecting particles for safety reasons Considering the ease of particle size reduction, TiO ₂ , Al ₂ O ₃ , LiNbO ₃ , Nb ₂ O ₅ , ZrO ₂ , Y ₂ O ₃ , MgO, ZnO, SnO ₂ , Bi ₂ O ₃ , ITO, CeO ₂ , AlN, diamond, and KTaO ₃ are preferable, and zirconium oxide (ZrO ₂ ) or titanium oxide (TiO ₂ ) is more preferable.

As a preparation method of metal oxide nanoparticles, spraying the raw material of metal oxide nanoparticles in the gas phase,
It is possible to obtain fine particles by firing. Furthermore, a method of preparing particles using plasma, a method of ablating raw material solids with a laser or the like to make fine particles, a method of oxidizing evaporated metal gas to prepare fine particles, and the like can be suitably used. In addition, as a method for preparing in a liquid phase, it is possible to prepare a metal oxide nanoparticle dispersion liquid dispersed almost as primary particles using a sol-gel method or the like. Alternatively, it is possible to obtain a dispersion having a uniform particle size by using a reaction crystallization method utilizing a decrease in solubility.

  The particles obtained in the liquid phase are preferably dried and fired to stably bring out the function of the metal oxide nanoparticles. For drying, means such as freeze drying, spray drying, and supercritical drying can be applied, and the firing is performed not only by raising the temperature while controlling the atmosphere but also by using an organic or inorganic sintering inhibitor. It is preferable.

In the metal oxide nanoparticle-containing layer according to the present invention, the content of the metal oxide nanoparticles is preferably 5 vol% or more and 50 vol% or less. In particular, when metal oxide nanoparticles having an average particle size of 50 nm or less are used, it is preferably 50 vol% or less, and in view of securing moldability (fluidity, no cracking), it is preferably 30 vol% or less. . In particular, when the content of the metal oxide nanoparticles exceeds 30 vol%, it is preferable to improve the affinity with the resin by performing a surface treatment on the surface of the metal oxide nanoparticles. On the other hand, from the viewpoint of improving adhesion by containing metal oxide nanoparticles, a certain amount of content is required, preferably 5 vol% or more, and more preferably 10 vol% or more. From the standpoint of ensuring moldability and improving adhesion, the content of the metal oxide nanoparticles is preferably 10 vol% to 30 vol%, more preferably 10 vol% to 20 vol%. The volume fraction of the metal oxide nanoparticles referred to here is that the resin containing the metal oxide nanoparticles that constitutes the metal oxide nanoparticle-containing layer is taken out in an arbitrary volume, and the volume is defined as Ycm ^3. When the specific gravity of the metal oxide nanoparticles contained in a is a and the total content is x grams, it is obtained by the formula (x / a) / Y × 100.

  The content of the metal oxide nanoparticles can be determined by taking out and quantifying the metal oxide nanoparticles contained in the resin, and observing a semiconductor crystal image with a transmission electron microscope (TEM) (EDX (energy dispersion type) It is also possible to obtain information on the semiconductor crystal composition by local elemental analysis such as an X-ray analyzer), or the content mass of a predetermined composition obtained by elemental analysis of ash contained in a given resin composition and crystals of the composition It can be calculated from the specific gravity.

<Surface treatment agent>
Since the metal oxide nanoparticles need to be uniformly dispersed with the resin, it is preferable that the surface treatment is performed in order to increase the affinity with the resin. For the bonding between the necessary surface treating agent and the particle surface, the following introduction methods are conceivable, but not limited to them.

A. Physical adsorption (secondary binding activator treatment)
B. Utilization reaction of surface chemical species (covalent bond with surface hydroxyl group)
C. Surface introduction and reaction of active species (introduction of active sites such as radicals and graft polymerization, high energy ray irradiation and graft polymerization)
D. Resin coating (encapsulation, plasma polymerization)
E. Deposition immobilization (deposition of sparingly soluble organic acid salts)
Further specific examples are as follows.

(1) Silane coupling agent A condensation reaction or a hydrogen bond between a silanol group and a hydroxyl group on the particle surface is used. Examples include vinylsilazane, trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, trimethylalkoxysilane, dimethyldialkoxysilane, methyltrialkoxysilane, hexamethyldisilazane, and the like. Trimethylmethoxysilane, dimethyldimethoxysilane, methyltrimethoxy Silane, hexamethyldisilazane and the like are preferably used.

(2) Other coupling agents Titanate, aluminate, and zirconate coupling agents are also applicable. Further, zircoaluminate, chromate, borate, stannate, isocyanate and the like can be used. A diketone coupling agent can also be used.

(3) Surface adsorbents Alcohols, nonionic surfactants, ionic surfactants, carboxylic acids, amines and the like are applicable.

(4) Resin-based surface treatment After introducing active species to the particle surface by the methods (1) to (3) above, a method of providing a polymer layer on the surface by graft polymerization, or a pre-synthesized polymer dispersant adsorbed to the particle surface , There is a method of combining. In order to provide a polymer layer more firmly on the particle surface, graft polymerization is preferable, and grafting at a high density is particularly preferable.

<< Method for Producing Resin Containing Metal Oxide Nanoparticles >>
In the production of the resin containing the metal oxide nanoparticles according to the present invention, first, after preparing a composite material precursor (a molten state when using a thermoplastic resin, an uncured state when using a curable resin) It is formed by applying on the substrate.

  Particularly when a curable resin is used, the composite material precursor may be prepared by mixing the curable resin dissolved in an organic solvent and the fine particles according to the present invention, and then removing the organic solvent, or curing. It may be prepared by adding and mixing the metal oxide nanoparticles according to the present invention in a monomer solution which is one of the raw materials of the conductive resin, followed by polymerization. Alternatively, it may be prepared by melting an oligomer in which a monomer is partially polymerized or a low molecular weight polymer, and adding and mixing the metal oxide nanoparticles according to the present invention.

  Examples of the organic solvent used herein include lower alcohols having about 1 to 4 carbon atoms, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, esters such as methyl acetate and ethyl acetate, and hydrocarbons such as toluene and xylene. However, it is not particularly limited as long as it has a boiling point lower than that of the monomer and is compatible with these monomers.

  In particular, in the present invention, a method of polymerizing after adding the metal oxide nanoparticles according to the present invention in the monomer solution is preferable, and in particular, a highly viscous solution in which the monomer and the metal oxide nanoparticles according to the present invention are mixed. It is preferable to mix them while giving a shear while cooling. At this time, it is also important to adjust the viscosity so that the dispersion of the metal oxide nanoparticles according to the present invention in the curable resin is optimized. Examples of the method for adjusting the viscosity include adjustment of the particle size, surface state, and addition amount of the metal oxide nanoparticles according to the present invention, addition of a solvent and a viscosity modifier, and the like. Since the surface of the particles can be easily modified depending on the structure, it is possible to obtain an optimum kneaded state.

  In the case of compounding by giving a share, the metal oxide nanoparticles according to the present invention can be added in a powder or aggregated state. Or it is also possible to add in the state disperse | distributed in the liquid. When adding in the state disperse | distributed in the liquid, it is preferable to deaerate after mixing.

  When adding in the state disperse | distributed in a liquid, it is preferable to disperse | distribute aggregated particles to a primary particle beforehand, and to add. Various dispersing machines can be used for dispersion, but a bead mill is particularly preferable. There are various kinds of beads, but those having a small size are preferable, and those having a diameter of 0.001 to 0.5 mm are particularly preferable.

  The metal oxide nanoparticles according to the present invention are preferably added in a surface-treated state, but a method such as an integral blend in which a surface treatment agent and fine particles are added simultaneously to form a composite with a curable resin. It is also possible to use.

<< Resin monomer used for resin containing metal oxide nanoparticles >>
The resin used for the adhesion improving layer according to the present invention is preferably a curable resin. More preferably, an actinic radiation curable resin is used. The actinic radiation curable resin is mainly composed of a resin that cures through a crosslinking reaction or the like by irradiation with actinic rays such as ultraviolet rays or electron beams. As the actinic radiation curable resin, a component containing a monomer having an ethylenically unsaturated double bond is preferably used, and the metal oxide nanoparticle-containing layer is cured by irradiation with actinic radiation such as ultraviolet rays or electron beams. It is formed. Typical examples of the actinic radiation curable resin include an ultraviolet curable resin and an electron beam curable resin, and a resin curable by ultraviolet irradiation is preferable.

  Examples of the monomer having an ethylenically unsaturated double bond used in the actinic radiation curable resin include monofunctional monomers such as ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, and N-vinylpyrrolidone. Alternatively, urethane (meth) acrylate, polyester (meth) acrylate, polymethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, polyethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di ( (Meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, isocyanuric acid modified di (or tri) Examples thereof include polyfunctional monomers such as acrylate and fluorene acrylate.

  Moreover, the polymerization initiator generally used can be used as a polymerization initiator preferably used in order to make active ray hardening advantageous. Representative examples thereof include benzoin and benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy Acetophenones such as 2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone; 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1 -Aminoacetophenones such as 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1; 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiarybutylanthraquinone Anthraquinones such as 1-chloroanthraquinone; thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone; ketals such as acetophenone dimethyl ketal and benzyldimethyl ketal Benzophenones such as benzophenone; or xanthones; (2,6-dimethoxybenzoyl) -2,4,4-pentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4 , 6-trimethylbenzoyldiphenylphosphine oxide, phosphine oxides such as ethyl-2,4,6-trimethylbenzoylphenylphosphinate; 2-hydroxy-2-methyl-1-phenyl Nyl-propan-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, etc. These known photopolymerization initiators can be used alone or in combination of two or more thereof.

<Application of metal oxide nanoparticle-containing layer>
The film thickness of the metal oxide nanoparticle-containing layer is preferably 1 μm to 100 μm, more preferably 2 μm to 50 μm, from the viewpoint of imparting sufficient film properties such as durability, impact resistance, optical properties, and adhesion. is there. The refractive index of the metal oxide nanoparticle-containing layer is preferably adjusted from the viewpoint of optical properties and film physical properties so as to reduce the difference between the refractive index of the transparent resin substrate to be used and the inorganic functional layer. The refractive index difference between the metal oxide nanoparticle-containing layer according to the present invention, the transparent resin substrate, and the inorganic functional layer is preferably within ± 0.2, more preferably within ± 0.15, and further within ± 0.1. Preferably, it has the almost same refractive index, and most preferably. These metal oxide nanoparticle-containing layers can be applied by a known method such as a gravure coater, a dip coater, a reverse coater, a wire bar coater, a die coater, or an ink jet method.

As a light source for curing the ultraviolet curable resin by a photocuring reaction to form the metal oxide nanoparticle-containing layer, any light source that generates ultraviolet light can be used without limitation. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used. Irradiation conditions vary depending on each lamp, but the irradiation amount of active rays is usually 5 to 500 mJ / cm ² , preferably 5 to 150 mJ / cm ² , and particularly preferably 20 to 100 mJ / cm ² .

[Inorganic functional layer]
The inorganic functional layer according to the present invention means that the inorganic material content (mass%) constituting the organic electroluminescence device is 50% or more, and the physical, electrical / electronic, chemical It refers to a layer that imparts a target or optical effect. The inorganic material content (% by mass) is preferably 70% or more, and more preferably 80% or more. Examples of the inorganic functional layer include a conductive layer, a barrier layer against gas or water, an insulating layer, a flat / smoothing layer, a hard coat layer, a reflective layer, a light shielding layer, a light guide / waveguide layer, a light scattering / diffusion layer, etc. Examples include various optical property adjusting layers for imparting directivity to light or amplifying / attenuating light, charge injection / transport layers, and the like, and a conductive layer or a barrier layer is preferable. Furthermore, two or more inorganic functional layers according to the invention may be present, and inorganic functional layers having different functions can be combined. In the present invention, it is one preferred embodiment that a barrier layer is bonded to the substrate via a metal oxide nanoparticle-containing layer, and further a conductive layer is formed on the barrier layer.

When the inorganic functional layer according to the present invention is a conductive layer, for example, sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / Aluminum oxide (Al ₂ O ₃ ) mixture, indium, lithium / aluminum mixture, rare earth metal, or carbon, aluminum, vanadium, iron, cobalt, nickel, copper, zinc, tungsten, silver, platinum, tin, gold, etc. Conductivity such as metal and compounds such as these alloys, metal oxides such as tin oxide, indium oxide, antimony oxide, zinc oxide and zirconium oxide, and conductive metal compounds such as solid solutions and mixtures thereof. Compounds etc. can be used Is preferably a light transmissive conductive layer, and may be indium oxide (ITO), indium-zinc oxide (IZO), or gallium-doped zinc oxide (GZO). More preferably, it is a light-transmitting conductive layer.

  In the present invention, the light transmissive conductive layer is preferably used as an anode. The anode may be formed by depositing a thin film by the above-mentioned electrode material that can be used for the conductive layer by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method, or the pattern accuracy is not much required. If not (about 100 μm or more), a pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material. Alternatively, for example, when an applicable material such as an organic compound is used, a wet film forming method such as a printing method or a coating method can be used. The sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually selected in the range of 10 to 1000 nm, preferably 10 to 200 nm.

  In the present invention, the refractive index of the transparent electrode is preferably 1.5 or more and 2.0 or less, more preferably 1.6 or more and 1.9 or less.

  When the inorganic functional layer according to the present invention is a barrier layer, it is more preferably a gas barrier layer. As the gas barrier inorganic layer of the organic electroluminescence element, a highly transparent layer is preferably used. Specific examples of such an inorganic layer include SiO2, SiN, and SiC. As a method for forming a gas barrier film made of an inorganic material as described above on a plastic film, physical vapor deposition methods (PVD method) such as vacuum deposition, sputtering method, ion plating method, heat, light, plasma, etc. There are three types of coating methods such as chemical vapor deposition method (CVD method) using sol-gel and the like, and sol-gel method. However, since it is difficult to obtain a dense thin film having a high gas barrier property by the coating method, the method for forming an inorganic thin film having a high gas barrier property on a plastic film is actually limited to the PVD method and the plasma CVD method. Among these, the plasma CVD method is most preferable because it can obtain a thin film having high adhesion to organic substances such as a plastic film and an organic resin layer. Further, among the plasma CVD methods, the atmospheric pressure plasma CVD method in which an inorganic thin film is formed by generating plasma under atmospheric pressure is most preferable. In the plasma CVD method under atmospheric pressure, the mean free path of particles is very short, the resulting inorganic thin film has no directionality, and the film thickness is extremely uniform, so that defects are hardly generated in the inorganic thin film. This is because the in-plane distribution of gas barrier properties can also be reduced. <Atmospheric pressure plasma CVD method> An apparatus for forming an inorganic thin film by an atmospheric pressure plasma CVD method is described in detail in JP-A-2006-236747. In addition, in this invention, the atmospheric pressure vicinity represents the pressure of 20 kPa-110 kPa, More preferably, it is 93 kPa-104 kPa.

[Organic EL device]
Preferred specific examples of the layer structure of the organic EL element are shown below.

(I) Anode / light emitting layer / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer / electron transport layer / cathode (iii) Anode / hole transport layer / light emitting layer / hole blocking layer / electron Transport layer / cathode (iv) Anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) Anode / anode buffer layer / hole transport layer / light emitting layer / hole Blocking layer / electron transport layer / cathode buffer layer / cathode Here, the light emitting layer preferably contains at least two kinds of light emitting materials having different emission colors, and a single layer or a light emitting layer comprising a plurality of light emitting layers A unit may be formed. The hole transport layer also includes a hole injection layer and an electron blocking layer.

<Light emitting layer>
The light emitting layer according to the present invention is a layer that emits light by recombination of electrons and holes injected from the electrode, the electron transport layer, or the hole transport layer, and the light emitting portion is in the layer of the light emitting layer. May be the interface between the light emitting layer and the adjacent layer.

  The light emitting layer according to the present invention is not particularly limited in its configuration as long as the contained light emitting material satisfies the above requirements.

  Moreover, there may be a plurality of layers having the same emission spectrum and emission maximum wavelength.

  It is preferable to have a non-light emitting intermediate layer between each light emitting layer.

  The total thickness of the light emitting layers in the present invention is preferably in the range of 1 to 100 nm, and more preferably 30 nm or less because a lower driving voltage can be obtained. In addition, the sum total of the film thickness of the light emitting layer as used in the field of this invention is a film thickness also including the said intermediate | middle layer, when a nonluminous intermediate | middle layer exists between light emitting layers.

  The thickness of each light emitting layer is preferably adjusted to a range of 1 to 50 nm, more preferably adjusted to a range of 1 to 20 nm. There is no particular limitation on the relationship between the film thicknesses of the blue, green and red light emitting layers.

  For the production of the light emitting layer, a light emitting material or a host compound, which will be described later, is formed by forming a film by a known thinning method such as a vacuum deposition method, a spin coating method, a casting method, an LB method, an ink jet method, or the like. it can.

  In the present invention, a plurality of light emitting materials may be mixed in each light emitting layer, and a phosphorescent light emitting material and a fluorescent light emitting material may be mixed and used in the same light emitting layer.

  In the present invention, the structure of the light-emitting layer preferably contains a host compound and a light-emitting material (also referred to as a light-emitting dopant compound) and emits light from the light-emitting material.

  As the host compound contained in the light emitting layer of the organic EL device according to the present invention, a compound having a phosphorescence quantum yield of phosphorescence emission at room temperature (25 ° C.) of less than 0.1 is preferable. More preferably, the phosphorescence quantum yield is less than 0.01. Moreover, it is preferable that the volume ratio in the layer is 50% or more among the compounds contained in a light emitting layer.

  As the host compound, known host compounds may be used alone or in combination of two or more. By using a plurality of types of host compounds, it is possible to adjust the movement of charges, and the organic EL element can be made highly efficient. Moreover, it becomes possible to mix different light emission by using multiple types of luminescent material mentioned later, and can thereby obtain arbitrary luminescent colors.

  The host compound used in the present invention may be a conventionally known low molecular compound or a high molecular compound having a repeating unit, and a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (evaporation polymerizable light emitting host). )But it is good.

  As the known host compound, a compound that has a hole transporting ability and an electron transporting ability, prevents the emission of light from being increased in wavelength, and has a high Tg (glass transition temperature) is preferable. Here, the glass transition point (Tg) is a value obtained by a method based on JIS-K-7121 using DSC (Differential Scanning Colorimetry).

  Specific examples of known host compounds include compounds described in the following documents. For example, Japanese Patent Application Laid-Open Nos. 2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860 Gazette, 2002-334787 gazette, 2002-15871 gazette, 2002-334788 gazette, 2002-43056 gazette, 2002-334789 gazette, 2002-75645 gazette, 2002-338579 gazette. No. 2002-105445, No. 2002-343568, No. 2002-141173, No. 2002-352957, No. 2002-203683, No. 2002-363227, No. 2002-231453. No. 2003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-286061, No. 2002-280183, No. 2002-299060. 2002-302516, 2002-305083, 2002-305084, 2002-308837, and the like.

  Next, the light emitting material will be described.

  As the light-emitting material according to the present invention, a fluorescent compound or a phosphorescent material (also referred to as a phosphorescent compound or a phosphorescent compound) is used.

  In the present invention, a phosphorescent material is a compound in which light emission from an excited triplet is observed. Specifically, it is a compound that emits phosphorescence at room temperature (25 ° C.), and the phosphorescence quantum yield is 0 at 25 ° C. A preferred phosphorescence quantum yield is 0.1 or more, although it is defined as 0.01 or more compounds.

  The phosphorescent quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of Experimental Chemistry Course 4 of the 4th edition. The phosphorescence quantum yield in a solution can be measured using various solvents. However, when a phosphorescent material is used in the present invention, the phosphorescence quantum yield (0.01 or more) is achieved in any solvent. Just do it.

  There are two types of light emission of the phosphorescent material. In principle, the carrier recombination occurs on the host compound to which the carrier is transported to generate an excited state of the host compound, and this energy is transferred to the phosphorescent material. Energy transfer type to obtain light emission from the phosphorescent light emitting material, and another one is that the phosphorescent light emitting material becomes a carrier trap, and recombination of carriers occurs on the phosphorescent light emitting material, and light emission from the phosphorescent light emitting material is obtained. Although it is a trap type, in any case, the excited state energy of the phosphorescent material is required to be lower than the excited state energy of the host compound.

  The phosphorescent light-emitting material can be appropriately selected from known materials used for the light-emitting layer of the organic EL element, and is preferably a complex compound containing a group 8-10 metal in the periodic table of elements. More preferably, an iridium compound, an osmium compound, or a platinum compound (platinum complex compound), or a rare earth complex, and most preferably an iridium compound.

  A fluorescent substance can also be used for the organic electroluminescent element according to the present invention. Representative examples of fluorescent emitters (fluorescent dopants) include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes. Examples thereof include dyes, perylene dyes, stilbene dyes, polythiophene dyes, and rare earth complex phosphors.

  Conventionally known dopants can also be used in the present invention. For example, International Publication No. 00/70655 pamphlet, JP-A Nos. 2002-280178, 2001-181616, 2002-280179, 2001 181617, 2002-280180, 2001-247859, 2002-299060, 2001-313178, 2002-302671, 2001-345183, 2002. No. 324679, International Publication No. 02/15645, JP 2002-332291 A, 2002-50484, 2002-332292, 2002-83684, JP 2002-540572, JP 2 No. 02-117978, No. 2002-338588, No. 2002-170684, No. 2002-352960, Pamphlet of International Publication No. 01/93642, JP 2002-50483, No. 2002-1000047. No. 2002-173684, No. 2002-359082, No. 2002-17584, No. 2002-363552, No. 2002-184582, No. 2003-7469, No. 2002-525808. JP-A 2003-7471, JP-T 2002-525833, JP-A 2003-31366, JP-A 2002-226495, JP-A 2002-234894, JP-A 2002-2335076, JP-A 2002-24175 Gazette, 2001-319779, 2001-319780, 2002-62824, 2002-1000047, 2002-203679, 2002-343572, 2002-203678. A gazette etc. are mentioned.

  In the present invention, at least one light emitting layer may contain two or more kinds of light emitting materials, and the concentration ratio of the light emitting materials in the light emitting layer may vary in the thickness direction of the light emitting layer.

《Middle layer》
In the present invention, a case where a non-light emitting intermediate layer (also referred to as an undoped region) is provided between the light emitting layers will be described.

  The non-light emitting intermediate layer is a layer provided between the light emitting layers in the case of having a plurality of light emitting layers.

  The film thickness of the non-light emitting intermediate layer is preferably in the range of 1 to 20 nm, and further in the range of 3 to 10 nm suppresses interaction such as energy transfer between adjacent light emitting layers, and the current of the device This is preferable because a large load is not applied to the voltage characteristics.

  The material used for the non-light emitting intermediate layer may be the same as or different from the host compound of the light emitting layer, but may be the same as the host material of at least one of the adjacent light emitting layers. preferable.

  The non-light-emitting intermediate layer may contain a non-light-emitting layer, a compound common to each light-emitting layer (for example, a host compound), and each common host material (where a common host material is used) In the case where the physicochemical characteristics such as phosphorescence emission energy and glass transition point are the same, or the molecular structure of the host compound is the same, etc.) The barrier is reduced, and the effect of easily maintaining the injection balance of holes and electrons even when the voltage (current) is changed can be obtained. Furthermore, by using a host material having the same physical characteristics or the same molecular structure as the host compound contained in each light-emitting layer in the undoped light-emitting layer, device fabrication, which is a major problem in conventional organic EL device fabrication, is achieved. Complexity can also be eliminated.

  When the organic EL device is used in the present invention, since the host material is responsible for carrier transport, a material having carrier transport capability is preferable. Carrier mobility is used as a physical property representing carrier transport ability, but the carrier mobility of an organic material generally depends on the electric field strength. Since a material having a high electric field strength dependency easily breaks the balance between injection and transport of holes and electrons, it is preferable to use a material having a low electric field strength dependency of mobility for the intermediate layer material and the host material.

  On the other hand, in order to optimally adjust the injection balance of holes and electrons, it is also preferable that the non-light emitting intermediate layer functions as a blocking layer described later, that is, a hole blocking layer and an electron blocking layer. It is done.

<< Injection layer: electron injection layer, hole injection layer >>
The injection layer is provided as necessary, and there are an electron injection layer and a hole injection layer, and as described above, it exists between the anode and the light emitting layer or the hole transport layer and between the cathode and the light emitting layer or the electron transport layer. May be.

  An injection layer is a layer provided between an electrode and an organic layer in order to reduce drive voltage and improve light emission luminance. “Organic EL element and its forefront of industrialization (issued by NTT Corporation on November 30, 1998) 2), Chapter 2, “Electrode Materials” (pages 123 to 166) in detail, and includes a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer).

  The details of the anode buffer layer (hole injection layer) are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like. As a specific example, copper phthalocyanine is used. Examples thereof include a phthalocyanine buffer layer represented by an oxide, an oxide buffer layer represented by vanadium oxide, an amorphous carbon buffer layer, and a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.

  The details of the cathode buffer layer (electron injection layer) are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc. . The buffer layer (injection layer) is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 μm although it depends on the material.

<Blocking layer: hole blocking layer, electron blocking layer>
The blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film as described above. For example, it is described in JP-A Nos. 11-204258, 11-204359, and “Organic EL elements and their forefront of industrialization” (issued by NTT, Inc. on November 30, 1998). There is a hole blocking (hole blocking) layer.

  In a broad sense, the hole blocking layer has a function of an electron transport layer and is composed of a hole blocking material having a function of transporting electrons and having a remarkably small ability to transport holes, while transporting electrons. By blocking holes, the recombination probability of electrons and holes can be improved. Moreover, the structure of the electron carrying layer mentioned later can be used as a hole-blocking layer concerning this invention as needed. The hole blocking layer is preferably provided adjacent to the light emitting layer.

  On the other hand, the electron blocking layer, in a broad sense, has a function of a hole transport layer, and is made of a material having a function of transporting holes while having a remarkably small ability to transport electrons, while transporting holes. By blocking electrons, the probability of recombination of electrons and holes can be improved. Moreover, the structure of the positive hole transport layer mentioned later can be used as an electron blocking layer as needed. The film thickness of the hole blocking layer and the electron transport layer according to the present invention is preferably 3 to 100 nm, and more preferably 5 to 30 nm.

《Hole transport layer》
The hole transport layer is made of a hole transport material having a function of transporting holes, and in a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer. The hole transport layer can be provided as a single layer or a plurality of layers.

  The hole transport material has any one of hole injection or transport and electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples thereof include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.

  The above-mentioned materials can be used as the hole transport material, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound.

  Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl; N, N'-diphenyl-N, N'- Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' − (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4′-N, N-diphenylaminostilbenzene; N-phenylcarbazole, and also two of those described in US Pat. No. 5,061,569. Having a condensed aromatic ring in the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-3086 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 8 are linked in a starburst type ( MTDATA) and the like.

  Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used. In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.

  JP-A-11-251067, J. Org. Huang et. al. A so-called p-type hole transport material described in a book (Applied Physics Letters 80 (2002), p. 139) can also be used. In the present invention, it is preferable to use these materials because a light-emitting element with higher efficiency can be obtained.

  The hole transport layer can be formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. it can. Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The hole transport layer may have a single layer structure composed of one or more of the above materials.

  Alternatively, a hole transport layer having a high p property doped with impurities can be used. Examples thereof include JP-A-4-297076, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.

  In the present invention, it is preferable to use a hole transport layer having such a high p property because a device with lower power consumption can be produced.

《Electron transport layer》
The electron transport layer is made of a material having a function of transporting electrons, and in a broad sense, an electron injection layer and a hole blocking layer are also included in the electron transport layer. The electron transport layer can be provided as a single layer or a plurality of layers.

  Conventionally, in the case of a single electron transport layer and a plurality of layers, an electron transport material (also serving as a hole blocking material) used for an electron transport layer adjacent to the light emitting layer on the cathode side is injected from the cathode. As long as it has a function of transferring electrons to the light-emitting layer, any material can be selected and used from among conventionally known compounds. For example, nitro-substituted fluorene derivatives, diphenylquinone derivatives Thiopyrandioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives and the like. Furthermore, in the above oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group can also be used as an electron transport material. Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq ₃ ), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) Aluminum, tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), etc., and the central metals of these metal complexes are In, Mg Metal complexes replaced with Cu, Ca, Sn, Ga, or Pb can also be used as electron transport materials. In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transporting material. Further, the distyrylpyrazine derivatives exemplified as the material of the light emitting layer can also be used as the electron transport material, and inorganic semiconductors such as n-type-Si and n-type-SiC can be used as well as the hole injection layer and the hole transport layer. It can be used as an electron transport material.

  The electron transport layer can be formed by thinning the electron transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

  Further, an electron transport layer having a high n property doped with impurities can also be used. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.

  In the present invention, it is preferable to use an electron transport layer having such a high n property because an element with lower power consumption can be manufactured.

"anode"
As the anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such electrode materials include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO. Alternatively, an amorphous material such as In ₂ O ₃ —ZnO capable of forming a transparent conductive film may be used.

  For the anode, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method, or when pattern accuracy is not so high (about 100 μm or more) A pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material.

  Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film-forming methods, such as a printing system and a coating system, can also be used. When light emission is extracted from the anode, it is desirable that the transmittance be greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually selected in the range of 10 to 1000 nm, preferably 10 to 200 nm.

"cathode"
As the cathode, a material having a work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like. Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred. The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as a cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 nm to 200 nm. In order to transmit the emitted light, if either one of the anode or the cathode of the organic EL element is transparent or translucent, the light emission luminance is improved, which is convenient.

  Moreover, after producing the said metal by the film thickness of 1 nm-20 nm to a cathode, the transparent or semi-transparent cathode can be produced by producing the electroconductive transparent material quoted by description of the anode on it, By applying this, an element in which both the anode and the cathode are transmissive can be manufactured.

[Light extraction]
The organic EL element emits light inside a layer having a refractive index higher than that of air (refractive index is about 1.7 to 2.1) and can extract only about 15% to 20% of the light generated in the light emitting layer. It is generally said. This is because light incident on the interface (interface between the transparent substrate and air) at an angle θ greater than the critical angle causes total reflection and cannot be taken out of the device, or between the transparent electrode or light emitting layer and the transparent substrate. This is because the light is totally reflected between the light and the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes in the direction of the element side surface.

  As a method for improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (US Pat. No. 4,774,435), A method of improving efficiency by providing a light collecting property to a substrate (Japanese Patent Laid-Open No. 63-314795), a method of forming a reflective surface on a side surface of an element (Japanese Patent Laid-Open No. 1-220394), and light emission from a substrate A method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between the bodies (Japanese Patent Laid-Open No. 62-172691), a flat having a lower refractive index between the substrate and the light emitter than the substrate A method of introducing a layer (Japanese Patent Laid-Open No. 2001-202827), a method of forming a diffraction grating between any one of a substrate, a transparent electrode layer and a light emitting layer (including between the substrate and the outside) (Japanese Patent Laid-Open No. 11-283951) Gazette).

  In the present invention, these methods can be used in combination with the organic EL device of the present invention. However, a method of introducing a flat layer having a lower refractive index than the substrate between the substrate and the light emitter, or a substrate, transparent A method of forming a diffraction grating between any layers of the electrode layer and the light emitting layer (including between the substrate and the outside) can be suitably used.

  In the present invention, by combining these means, it is possible to obtain an element having higher luminance or durability.

  When a medium having a low refractive index is formed between the transparent electrode and the transparent substrate with a thickness longer than the wavelength of light, the light extracted from the transparent electrode has a higher extraction efficiency to the outside as the refractive index of the medium is lower.

  Examples of the low refractive index layer include aerogel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of the transparent substrate is generally about 1.5 to 1.7, the low refractive index layer preferably has a refractive index of about 1.5 or less. Further, it is preferably 1.35 or less.

  The thickness of the low refractive index medium is preferably at least twice the wavelength in the medium. This is because the effect of the low refractive index layer is diminished when the thickness of the low refractive index medium is about the wavelength of light and the electromagnetic wave that has exuded by evanescent enters the substrate.

  The method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving light extraction efficiency. This method uses the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction such as first-order diffraction and second-order diffraction. Light that cannot be emitted due to total internal reflection between layers is diffracted by introducing a diffraction grating in any layer or medium (in a transparent substrate or transparent electrode), and the light is removed. I want to take it out.

  The introduced diffraction grating desirably has a two-dimensional periodic refractive index. This is because light emitted from the light-emitting layer is randomly generated in all directions, so in a general one-dimensional diffraction grating having a periodic refractive index distribution only in a certain direction, only light traveling in a specific direction is diffracted. Therefore, the light extraction efficiency does not increase so much. However, by making the refractive index distribution a two-dimensional distribution, light traveling in all directions is diffracted, and light extraction efficiency is increased.

  As described above, the position where the diffraction grating is introduced may be in any of the layers or in the medium (in the transparent substrate or in the transparent electrode), but is preferably in the vicinity of the organic light emitting layer where light is generated.

  At this time, the period of the diffraction grating is preferably about 1/2 to 3 times the wavelength of light in the medium.

  The arrangement of the diffraction grating is preferably two-dimensionally repeated, such as a square lattice, a triangular lattice, or a honeycomb lattice.

《Light scattering function》
The light emitting side of the organic electroluminescence device of the present invention can be provided with a light scattering function for the purpose of relaxing total reflection at the interface that occurs when the light taken into the transparent substrate is taken out. Examples of the light scattering function include a method of providing a known light extraction film having a light scattering function on the light emission surface of the organic EL element, and a method of containing a light scattering filler in the transparent substrate. When the light-scattering filler is contained in the transparent substrate, the layer to be contained may be either an adhesion improving layer or a transparent film, and a known filler made of an inorganic or polymer is used as the light-scattering filler. be able to. Examples of inorganic compounds include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, and calcium phosphate. Can be mentioned. Examples of the polymer include silicone resin, fluororesin, and acrylic resin. When these fillers are added to the metal oxide nanoparticle-containing layer or transparent film of the present invention, the addition amount is preferably 0.1 to 30% by mass, but may be adjusted according to the degree of light scattering.

<Condenser sheet>
The organic EL device of the present invention is processed on the light extraction side of the substrate so as to provide, for example, a microlens array structure, or combined with a so-called condensing sheet, for example, with respect to a specific direction, for example, the device light emitting surface. By condensing in the front direction, the luminance in a specific direction can be increased.

  As an example of the microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are two-dimensionally arranged on the light extraction side of the substrate. One side is preferably 10 μm to 100 μm. If it becomes smaller than this, the effect of diffraction will generate | occur | produce and color, and if too large, thickness will become thick and is not preferable.

  As the condensing sheet, for example, a sheet that is put into practical use in an LED backlight of a liquid crystal display device can be used. As such a sheet, for example, a brightness enhancement film (BEF) manufactured by Sumitomo 3M Limited can be used. As the shape of the prism sheet, for example, the base material may be formed by forming a △ -shaped stripe having a vertex angle of 90 degrees and a pitch of 50 μm, or the vertex angle is rounded and the pitch is changed randomly. Other shapes may be used.

  Moreover, in order to control the light emission angle from a light emitting element, you may use together a light diffusing plate and a film with a condensing sheet. For example, a diffusion film (light-up) manufactured by Kimoto Co., Ltd. can be used.

[Method for producing organic EL element]
As an example of the method for producing an organic EL device according to the present invention, a method for producing an organic EL device comprising an anode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode will be described. .

  First, a thin film made of a desired electrode material, for example, a material for an anode is formed on a suitable support substrate by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably 10 to 200 nm to produce an anode. . Next, an organic compound thin film of a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, and an electron transport layer, which are organic EL element materials, is formed thereon.

As a method of thinning the organic compound thin film, there are a vapor deposition method, a sputtering method, a wet method, etc. as described above, but vacuum vapor deposition is easy because a homogeneous film is easily obtained and pinholes are not easily generated. Method and wet method are preferable, and wet method is more preferable. Examples of wet methods include spin coating, casting, die coating, blade coating, roll coating, ink jet, printing, spray coating, curtain coating, and the like, and a precise thin film can be formed. From the viewpoint of high productivity, a method having high suitability for a roll-to-roll method such as a die coating method, a roll coating method, an ink jet method, or a spray coating method is preferable. Different film forming methods may be applied for each layer. When employing a vapor deposition method for film formation, the vapor deposition conditions vary depending on the type of compound used, but generally a boat heating temperature of 50 to 450 ° C., a degree of vacuum of 10 ⁻⁶ to 10 ⁻² Pa, and a vapor deposition rate of 0.01 to It is desirable to select appropriately within the range of 50 nm / second, substrate temperature −50 to 300 ° C., film thickness 0.1 nm to 5 μm, preferably 5 to 200 nm.

  After these layers are formed, a thin film made of a cathode material is formed thereon by a method such as vapor deposition or sputtering so as to have a thickness of 1 μm or less, preferably in the range of 50 to 200 nm, and a cathode is provided. Thus, a desired organic EL element can be obtained. The organic EL element is preferably produced from the hole injection layer to the cathode consistently by a single evacuation, but may be taken out halfway and subjected to different film forming methods. At that time, it is necessary to consider that the work is performed in a dry inert gas atmosphere.

  In addition, it is also possible to reverse the production order and produce the cathode, the electron injection layer, the electron transport layer, the light emitting layer, the hole transport layer, the hole injection layer, and the anode in this order. When a DC voltage is applied to the multicolor liquid crystal display device thus obtained, light emission can be observed by applying a voltage of about 2 to 40 V with the positive polarity of the anode and the negative polarity of the cathode. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

[Use]
The organic electroluminescence element according to the present invention can be used as a lighting device, a display device, a display, and various light sources. Examples of light sources include home lighting, interior lighting, clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources for optical storage media, light sources for electrophotographic copying machines, light sources for optical communication processors, and light sources for optical sensors. Although it is not limited to this, it can be effectively used for a backlight of a liquid crystal display device combined with a color filter and a light source for illumination.

[Lighting device]
The organic EL material according to the present invention can also be applied to an organic EL element that emits substantially white light as a lighting device. A plurality of light emitting colors are simultaneously emitted by a plurality of light emitting materials to obtain white light emission by color mixing. The combination of a plurality of emission colors may include three emission maximum wavelengths of the three primary colors of blue, green, and blue, or two using the relationship of complementary colors such as blue and yellow, blue green and orange, etc. The thing containing the light emission maximum wavelength may be used.

  In addition, a combination of light emitting materials for obtaining a plurality of emission colors includes a combination of a plurality of phosphorescent or fluorescent materials (light emitting dopants), a light emitting material that emits fluorescent or phosphorescent light, and the light emission. Any combination of a dye material that emits light from the material as excitation light may be used, but in the white organic EL device according to the present invention, a method of combining a plurality of light-emitting dopants is preferable.

  As a layer structure of the organic EL element for obtaining a plurality of emission colors, a method of having a plurality of emission dopants in one emission layer, a plurality of emission layers, and an emission wavelength of each emission layer. Examples thereof include a method in which different dopants are present, and a method in which minute pixels that emit light at different wavelengths are formed in a matrix.

  In the white organic EL element concerning this invention, you may pattern by a metal mask, the inkjet printing method, etc. as needed at the time of film-forming. When patterning, only the electrode may be patterned, the electrode and the light emitting layer may be patterned, or the entire element layer may be patterned.

  The light emitting material used for the light emitting layer is not particularly limited. For example, in the case of a backlight in a liquid crystal display element, a platinum complex or a known light emitting material is used so as to be adapted to a wavelength range corresponding to a CF (color filter) characteristic. Any one of them may be selected and combined to whiten.

  Thus, in addition to the display device and the display, the white light-emitting organic EL element is used as a liquid crystal display as a kind of lamp such as various light-emitting light sources and lighting devices, home lighting, interior lighting, and exposure light source. It is also useful for display devices such as device backlights.

  In addition, backlights such as clocks, signboard advertisements, traffic lights, light sources such as optical storage media, light sources for electrophotographic copying machines, light sources for optical communication processing machines, light sources for optical sensors, etc. There are a wide range of uses such as household appliances.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these. Unless otherwise specified, “part” or “%” in the examples represents “part by mass” or “% by mass”.

Example 1
<< Preparation of Transparent Film 105 with Metal Oxide Nanoparticle-Containing Layer >>
<Preparation of metal oxide nanoparticles (zirconia particles)>
Zirconia particles having an average particle size of 0.5 nm, 1 nm, 5 nm, 30 nm, 50 nm, and 100 nm were prepared by the method described in JP-A-2006-143535. In addition, zirconia particles having an average particle diameter of 400 nm and 500 nm were prepared using the method described in International Publication No. 09/099184 pamphlet.

(Surface treatment for zirconia particles)
While adding 10 g of the above-mentioned zirconia particles to 100 ml of toluene containing 2 g of phenyltrimethoxysilane (manufactured by Shin-Etsu Chemical) and 0.1 g of methacryloxypropyltrimethoxysilane, while dispersing using 0.03 mm zirconia beads under nitrogen After heating to 100 ° C. to obtain a uniform dispersion, it was heated to reflux for 5 hours under nitrogen as it was to obtain a toluene dispersion of surface-treated zirconia particles.

(Particle dispersion in resin)
A curable resin monomer (fluorene acrylate) and the surface-treated zirconia particle dispersion are mixed so that the zirconia particle content in the metal oxide nanoparticle-containing layer is 20 vol%, and a polymerization initiator (1-hydroxy-cyclohexyl- 3% (addition amount) of phenyl-ketone) was added to the curable resin monomer and dissolved.

<< Preparation of Transparent Film 105 with Metal Oxide Nanoparticle-Containing Layer >>
The resin prepared by the above method in which zirconia particles having an average particle diameter of 0.5 nm are dispersed is formed to have a film thickness of 10 μm on one side of 125 μm thick biaxially stretched PEN (manufactured by Teijin DuPont; refractive index 1.75). And cured by irradiating with ultraviolet rays to obtain a transparent film 105 with a metal oxide nanoparticle-containing layer. The refractive index of the adhesion improving layer was 1.75.

<< Production of Transparent Film 106 to 119 with Metal Oxide Nanoparticle-Containing Layer >>
In the production of the transparent film 105 with a metal oxide nanoparticle-containing layer, for the metal oxide nanoparticle-containing layer, the type, average particle diameter, content, and film thickness of the metal oxide nanoparticles were changed as shown in Table 1. Except for the above, transparent films 106 to 119 with a metal oxide nanoparticle-containing layer were produced in the same manner.

<< Production of Transparent Film 104 with Resin Layer >>
In the production of the transparent film 105 with a metal oxide nanoparticle-containing layer, a transparent film 104 with a resin layer was produced in the same manner except that a resin not mixed with the surface-treated zirconia dispersion was applied.

<< Production of Substrates 104 to 119 with Inorganic Functional Layer (Conductive Layer (Anode)) >>
100 nm of ITO (indium tin oxide; refractive index 1.85) is formed on the transparent film 104 with resin layer and the transparent film 105 to 119 with metal oxide nanoparticle-containing layer prepared above by sputtering, and patterning is performed. Then, the substrate provided with the ITO transparent electrode was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, UV ozone cleaned for 5 minutes, and the substrate 104 with an inorganic functional layer (conductive layer (anode)). -119 were made.

<< Production of Substrate 101 with Inorganic Functional Layer (Conductive Layer (Anode)) >>
In the production of the substrate 104 to 119 with an inorganic functional layer (conductive layer (anode)), a non-alkali glass substrate (thickness) is used instead of the transparent film 104 with a resin layer and the transparent films 105 to 119 with a metal oxide nanoparticle-containing layer. In other words, ITO (indium tin oxide; refractive index: 1.85) is sputtered on a glass substrate in the same manner as the fabrication of the substrates 104 to 119 with an inorganic functional layer (conductive layer). After 100 nm film formation and patterning, the substrate provided with this ITO transparent electrode was subjected to ultrasonic cleaning with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaning for 5 minutes, and an inorganic functional layer (conductive layer) A substrate 101 with (anode) was manufactured.

<< Production of Substrate 102 with Inorganic Functional Layer (Conductive Layer (Anode)) >>
Except for using a PET film (thickness: 125 μm) as the substrate, it is the same as the production of the substrate 101 with the inorganic functional layer (conductive layer (anode)), that is, sputtered on the PET film (thickness: 125 μm) substrate. After forming ITO (indium tin oxide; refractive index 1.85) 100 nm by patterning and patterning, the substrate provided with this ITO transparent electrode was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV. Ozone cleaning was performed for 5 minutes to produce a substrate 102 with an inorganic functional layer (conductive layer (anode)).

<< Production of Substrate 103 with Inorganic Functional Layer (Conductive Layer (Anode)) >>
Except for using 125 μm thick biaxially stretched PEN (manufactured by Teijin DuPont; refractive index 1.75) for the substrate, the same as the production of the substrate 101 with the inorganic functional layer (conductive layer (anode)), that is, After the ITO (indium tin oxide; refractive index: 1.85) film was formed to a thickness of 100 nm on the 125 μm biaxially stretched PEN substrate by sputtering, the substrate provided with the ITO transparent electrode was superposed with isopropyl alcohol. The substrate 103 with an inorganic functional layer (conductive layer (anode)) was manufactured by sonic cleaning, drying with dry nitrogen gas, and UV ozone cleaning for 5 minutes.

<< Production of Organic EL Elements 101-119 >>
On the board | substrates 101-119 with an inorganic functional layer (conductive layer (anode)), the organic EL element was formed with the following method, respectively, and the organic EL elements 101-119 were produced.

<Preparation of hole injection layer>
A solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron PAl 4083) to 70% with pure water on each of the substrates 101 to 119 at 3000 rpm for 30 seconds. After film formation by a spin coating method, the substrate was dried at a substrate surface temperature of 200 ° C. for 1 hour to provide a hole injection layer having a thickness of 30 nm.

<< Preparation of hole transport layer >>
This substrate was transferred to a glove box under a nitrogen atmosphere in accordance with JIS B9920 with a measured cleanliness of class 100, a dew point temperature of −80 ° C. or lower, and an oxygen concentration of 0.8 ppm. A coating solution for a hole transport layer was prepared as follows in a glove box, and applied with a spin coater under conditions of 1500 rpm and 30 seconds. This substrate was dried by heating at a substrate surface temperature of 150 ° C. for 30 minutes to provide a hole transport layer. The film thickness was 20 nm when it apply | coated and measured on the conditions with the board | substrate prepared separately.

(Coating liquid for hole transport layer)
Monochlorobenzene 100g
Poly- (N, N′-bis (4-butylphenyl) -N, N′-bis (phenyl) benzidine) (ADS254BE: manufactured by American Die Source) 0.5 g
<Production of light emitting layer>
Next, a light emitting layer coating solution was prepared as described below, and applied with a spin coater under the conditions of 2000 rpm and 30 seconds. Furthermore, it heated at the substrate surface temperature of 120 degreeC for 30 minutes, and provided the light emitting layer. When the coating was performed under the same conditions on a separately prepared substrate and measured, the film thickness was 40 nm. In addition, among the following light emitting layer composition, it was HA which showed the lowest Tg, and it was 132 degreeC.

(Light emitting layer coating solution)
Butyl acetate 100g
HA 1g
DA 0.11g
DB 0.002g
D-C 0.002g

<< Production of electron transport layer >>
Subsequently, the coating liquid for electron carrying layers was prepared as follows, and it apply | coated on the conditions of 1500 rpm and 30 seconds with a spin coater. Furthermore, it heated for 30 minutes at the substrate surface temperature of 120 degreeC, and provided the electron carrying layer. The film thickness was 30 nm when it applied and measured on the conditions prepared with the board | substrate prepared separately.

(Coating liquid for electron transport layer)
2,2,3,3-tetrafluoro-1-propanol 100 g
ET-A 0.75g

<< Production of Electron Injection Layer and Cathode >>
Next, the substrate provided up to the electron transport layer was moved to a vapor deposition machine without being exposed to the atmosphere, and the pressure was reduced to 4 × 10 ⁻⁴ Pa. Note that potassium fluoride and aluminum were each placed in a tantalum resistance heating boat and attached to a vapor deposition machine.

  First, a resistance heating boat containing potassium fluoride was energized and heated to provide 3 nm of an electron injection layer made of potassium fluoride on the substrate. Subsequently, a resistance heating boat containing aluminum was energized and heated, and a cathode having a film thickness of 100 nm made of aluminum was provided at a deposition rate of 1 to 2 nm / second.

<Evaluation>
The following evaluation was performed about the organic EL elements 101-119 produced using the board | substrates 101-119 with an inorganic functional layer and the board | substrates 101-119 with an inorganic functional layer which were produced by said method.

<< Evaluation of transparent substrate with inorganic functional layer >>
<Adhesion test of inorganic functional layer>
A cross-cut test based on JIS K5400 was performed as an adhesion test of the inorganic functional layer. On the surface of the formed inorganic functional layer, 11 single-blade razor blades were cut at 90 degrees with respect to the surface, 11 by 1 mm vertically and horizontally, and 100 1 mm square grids were produced. A commercially available cellophane tape was affixed on this, and one end of the tape was peeled off vertically by hand, and the ratio of the area where the thin film was peeled to the affixed tape area from the score line was evaluated according to the following rank.
5: Not peeled at all 4: The peeled area ratio was less than 1% 3: The peeled area ratio was less than 5% 2: The peeled area ratio was less than 10% 1 : The ratio of the peeled area was 20% or more.
<Haze test of inorganic functional layer>
Haze evaluation was performed as a transparency test of the inorganic functional layer. The haze value of the substrate can be obtained by measuring one film sample according to ASTM-D1003-52 using T-2600DA manufactured by Tokyo Denshoku Industries Co., Ltd. The haze value was evaluated according to the following rank.
5: Haze value was less than 1% 4: Haze value was less than 2% 3: Haze value was less than 3% 2: Haze value was less than 5% 1: Haze value was 5 % Or more.

  In practice, it is a level with no problem at rank 3 or higher.

<< Evaluation of organic EL elements >>
<DS (dark spot) test>
A luminescence photograph is taken after heating the produced organic EL element in a GB (glove box) environment at 70 ° C. for 60 hours. The ratio of the black spot area to the total issuance area is determined from photographic image analysis.

5: No black spots were generated and the black spot area was 0%. 4: Black spots were generated and the black spot area was less than 2%. 3: Black spots were generated and the black spot area was less than 5%. Black spots were generated and the black spot area was less than 10%. 1: Black spots were generated and the black spot area was 10% or more.

TiO ₂ : Titanium oxide (average particle size 9 nm), manufactured by Sakai Chemical Industry Co., Ltd., trade name: Powdered titanium oxide SSP-25
Al ₂ O ₃ : Alumina (average particle size 31 nm), manufactured by CI Kasei Co., Ltd., trade name: Nano Tek
As is apparent from Table 1, in the case of the sample according to the present invention, it is preferable to use metal oxide nanoparticles having an average particle size of 0.01 nm to 400 nm and a content of 5 vol% to 50 vol. %, The substrate with an inorganic functional layer (conductive layer (anode)) using the metal oxide nanoparticle-containing layer (adhesion improving layer) of the present invention, and the organic EL element are adhesive test, haze It can be seen that both the test and the DS (dark spot) test are excellent for comparison.

  Among them, the metal oxide nanoparticle-containing layer (adhesion improving layer) of the present invention, preferably using a metal oxide nanoparticle having an average particle size of 1 nm to 400 nm and having a content of 5 vol% to 50 vol%. ) Using an inorganic functional layer (conductive layer (anode)) and an organic EL element are rank 3 or higher in any of the adhesion test, haze test, and DS (dark spot) test. It showed excellent performance.

  Furthermore, as a result of cross-sectional observation of a DS (dark spot) portion, film peeling was observed between the inorganic functional layer and the substrate. It can be said that the film peeling portion is the same as the leak portion.

Example 2
<< Preparation of Substrate 202 with Inorganic Functional Layer (Gas Barrier Layer) >>
A silicon oxide film (gas barrier layer) was formed on the transparent film 110 with a metal oxide nanoparticle-containing layer obtained in Example 1. That is, using a direct current high voltage stabilized power supply KHD-1530PN manufactured by Kasuga Electric as a direct current power source, a direct current bias of −5 kV to +5 kV is applied to the support electrode 10 holding the adhesion improving layer, and the following silicon oxide layer forming gas is applied. The substrate 202 with an inorganic functional layer (gas barrier layer) was produced by forming a silicon oxide layer using as follows.
<Silicon oxide layer forming gas>
Discharge gas: Argon 99.3% by volume
Cracked gas: 0.5% by volume of hydrogen
Source gas: TEOS (tetraethoxysilane) 0.2% by volume
Vaporization temperature: 30 ° C
The film formation rate (DR) of the silicon oxide layer under each film formation condition was calculated, and film formation was performed by adjusting the film formation time so that the silicon oxide layer was 100 nm. The film thickness was measured using FE3000 manufactured by Otsuka Electronics.

<< Production of Substrate 201 Without Inorganic Functional Layer (Gas Barrier Layer) >>
In the production of the inorganic functional layer 202, a film that does not form an inorganic functional layer (silicon oxide film), that is, the transparent film 110 with a metal oxide nanoparticle-containing layer obtained in Example 1 was designated as 201.

<< Production of Substrate 203 with Inorganic Functional Layer (Gas Barrier Layer) >>
On the transparent film 110 with a metal oxide nanoparticle content layer obtained in Example 1, a SiN film (gas barrier layer) was formed. That is, using a DC high-voltage stabilized power supply KHD-1530PN made by Kasuga Electric as a DC power supply, a DC bias of −5 kV to +5 kV is applied to the support electrode 10 holding the adhesion improving layer, and the following SiN layer forming gas is used. Using this, the SiN layer was formed as follows, and a substrate 203 with an inorganic functional layer (gas barrier layer) was produced.
<SiN layer forming gas>
Discharge gas: Argon 99.30% by volume
Cracked gas: Hydrogen 0.50% by volume
Source gas: 0.03 vol% NH ₃
Source gas: 0.14% by volume of SiH ₄
Vaporization temperature: 30 ° C
The deposition rate (DR) of the SiN layer under each deposition condition was calculated, and deposition was performed by adjusting the deposition time so that the SiN layer was 100 nm. The film thickness was measured using FE3000 manufactured by Otsuka Electronics.

<< Production of Substrate 204 with Inorganic Functional Layer (Gas Barrier Layer) >>
An SiC film (gas barrier layer) was formed on the metal oxide nanoparticle-containing layer-containing transparent film 110 obtained in Example 1. That is, using a DC high-voltage stabilized power supply KHD-1530PN manufactured by Kasuga Electric as a DC power supply, a DC bias of −5 kV to +5 kV is applied to the support electrode 10 holding the adhesion improving layer, and the following silicon oxide layer forming gas is applied. A substrate 204 with an inorganic functional layer (gas barrier layer) was produced by forming a SiC layer as follows.
<SiC layer forming gas>
Discharge gas: Argon 99.30% by volume
Cracked gas: Hydrogen 0.50% by volume
Source gas: 0.15% by volume of SiH ₄
Source gas: C ₃ H ₈ 0.05% by volume
Vaporization temperature: 30 ° C
The film formation rate (DR) of the SiC layer under each film formation condition was calculated, and film formation was performed by adjusting the film formation time so that the SiC layer became 100 nm. The film thickness was measured using FE3000 manufactured by Otsuka Electronics.

<< Preparation of inorganic functional layer (conductive layer: anode layer) >>
On the substrate 201 without the inorganic functional layer (gas barrier layer) and the substrates 202, 203, 204 with the inorganic functional layer (gas barrier layer) prepared above, ITO (indium tin oxide; refractive index 1.85) is made by 100 nm by sputtering. After patterning the filmed substrate, the substrate provided with this ITO transparent electrode was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and UV ozone cleaned for 5 minutes to obtain an inorganic functional layer (no gas barrier layer) , A substrate 201 with a conductive layer (anode layer), and substrates 202, 203, and 204 with an inorganic functional layer (gas barrier layer and a conductive layer (anode layer) thereon) were prepared.

<< Production of Organic EL Elements 201-204 >>
Substrate 201 with inorganic functional layer (without gas barrier layer, conductive layer: with anode layer) prepared above, substrates 202, 203, 204 with inorganic functional layer (gas barrier layer and conductive layer (anode layer) thereon) Further, organic EL elements were formed in the same manner as in the method described in Example 1, and organic EL elements 201 to 204 were produced.

<Evaluation>
Evaluation was performed in the same manner as in Example 1 for the organic EL elements 201 to 204 that were produced using the substrates 201 to 204 with the inorganic functional layer and the substrates 201 to 204 with the inorganic functional layer that were produced by the method described above.

  The results are shown in Table 2.

  As is apparent from Table 2, in the present invention, as the inorganic functional layer, the metal oxide nanoparticle-containing layer (adhesion improving layer) of the present invention is further darkened by considering a gas barrier layer (inorganic functional layer). It can be seen that the spot can be particularly improved.

Claims (4)

In the organic electroluminescence device having an anode and a cathode on a transparent resin substrate, and having at least one organic layer including a light emitting layer between the anode and the cathode, the transparent resin substrate and the organic layer It has the anode or the cathode as an inorganic functional layer between the transparent resin substrate and adjacent to the inorganic functional layer between the inorganic functional layer, the surface-treated average particle size of 1~100nm An organic electroluminescence device comprising a metal oxide nanoparticle-containing layer having a haze value of less than 3% in which metal oxide nanoparticles are dispersed in an active ray curable resin at a content of 5 vol% or more and 50 vol% or less .   The organic electroluminescence device according to claim 1, wherein the metal oxide nanoparticles are surface-treated by bonding with a silane coupling agent.   The metal oxide nanoparticles are Li, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Y, Nb, One or more metals selected from the group consisting of Zr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, La, Ta, Hf, W, Ir, Tl, Pb, Bi and rare earth metals The organic electroluminescent element according to claim 1, comprising a metal oxide. The organic electroluminescent element of any one of Claims 1-3 is used, The illuminating device characterized by the above-mentioned.