JP2012039161A - Organic electroluminescent element, display device and lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electroluminescent element coating dispersion liquid and an organic electroluminescent element non-aqueous dispersion liquid, which have sufficient dispersion stability of dispersion, to provide an organic EL element which shows high external extraction quantum efficiency and has long emission lifetime by using the coating dispersion liquid or non-aqueous coating dispersion liquid, and to provide a lighting device and a display device including the organic EL element.SOLUTION: The organic electroluminescent element has at least an anode and a cathode on a support substrate and an organic compound layer including a light emitting layer between the anode and the cathode. The light emitting layer includes light-emitting dopant consisting of at least one organic iridium complex dispersed by at least one nonionic dispersion stabilizer except for an organometallic complex in the organic electroluminescent element.

Description

  The present invention relates to a coating dispersion for an organic electroluminescence element, a non-aqueous coating dispersion for an organic electroluminescence element, an organic electroluminescence element, a display device, and a lighting device.

  Conventionally, there is an electroluminescence display (ELD) as a light-emitting electronic display device. Examples of the constituent elements of ELD include inorganic electroluminescent elements and organic electroluminescent elements (hereinafter also referred to as organic EL elements). Inorganic electroluminescent 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 EL element has a configuration in which a light emitting layer containing a compound that emits light is sandwiched between a cathode and an anode, and injects electrons and holes into the light emitting layer to recombine excitons. This is an element that emits light by utilizing the emission of light (fluorescence / phosphorescence) when this exciton is deactivated, and can emit light at a voltage of several volts to several tens of volts. Therefore, 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 and portability.

  For the development of organic EL elements for practical use in the future, organic EL elements that emit light efficiently and with high luminance with lower power consumption are desired. For example, stilbene derivatives, distyrylarylene derivatives or A technique for doping a trisstyrylarylene derivative with a small amount of a phosphor to improve emission luminance and extend the lifetime of the device (see, for example, Patent Document 1), and using 8-hydroxyquinoline aluminum complex as a host compound. A device having an organic light emitting layer doped with a trace amount of a phosphor (see, for example, Patent Document 2), a device having an organic light emitting layer doped with a quinacridone dye as a host compound using 8-hydroxyquinoline aluminum complex ( For example, see Patent Document 3).

  In the technique disclosed in the above-mentioned patent document, when the emission from the excited singlet is used, the generation ratio of the singlet exciton and the triplet exciton is 1: 3, so the generation probability of the luminescent excited species is 25%. Since the light extraction efficiency is about 20%, the limit of the external extraction quantum efficiency (ηext) is set to 5%.

  However, since Princeton University has reported on organic EL devices that use phosphorescence from excited triplets (see, for example, Non-Patent Document 1), research on materials that exhibit phosphorescence at room temperature has become active. (For example, refer nonpatent literature 2 and patent literature 4.). When excited triplets are used, the upper limit of internal quantum efficiency is 100%, so in principle the luminous efficiency is four times that of excited singlets, and the performance is almost the same as that of cold cathode tubes. It can be applied to and attracts attention. For example, many compounds have been studied for synthesis centering on heavy metal complexes such as iridium complexes (see, for example, Non-Patent Document 3).

  Currently, further enhancement of light emission efficiency and long life of organic EL elements using phosphorescence is being actively studied. One example is the multilayered element structure. Early organic EL devices have a single-layer structure in which a light-emitting layer is sandwiched between an anode and a cathode. In this case, carrier injection, movement, and light emission must all be performed using only the light-emitting layer, and the efficiency is very low. It was. After that, organic EL devices have expanded into multi-layer (laminated structure) devices that have separated functions such as carrier injection, movement, block, and light emission, and have made great progress in terms of higher efficiency and longer life. .

  On the other hand, in increasing the area of an organic EL element, it is known that the production by vacuum vapor deposition, which is common in the production of an organic EL element using a low molecular weight compound, has problems in terms of equipment and energy efficiency. Therefore, it is considered that a printing method including an ink jet method or a screen printing method or a coating method such as spin coating or cast coating is desirable.

  For example, when a white light emitting device is manufactured, a plurality of luminescent compounds having different emission maximum wavelengths must be provided in the light emitting layer. Particularly in the case of a phosphorescent light emitting device, a plurality of phosphorescent compounds are formed by vacuum evaporation. It is difficult to deposit the conductive dopant at the same ratio every time, and it is expected that there will be a problem in the yield during manufacturing. However, the organic EL element is formed by the printing method or the coating method using a material having excellent solvent solubility. If it becomes possible to prepare the phosphorescent dopant in the same ratio, any solution of the organic EL element to be manufactured can be prepared by preparing a solution in which the phosphorescent dopant is mixed in the same ratio. Thus, it becomes possible to stably produce a white light-emitting organic EL element having the same luminescent color.

  The development of the above-mentioned multilayer (laminated structure) device is a solution for improving the light emission efficiency and extending the life of the coating method, but in the case of the coating method, the surface of the lower layer thin film is disturbed by the upper coating solvent. Therefore, it is very difficult to form a laminated film required for the organic EL element. Therefore, there is a strong demand for means and methods for solving this problem and stacking.

  On the other hand, as an EL element approach that takes advantage of the advantages of the coating method, by mixing multiple functional materials such as carrier transport materials and light-emitting materials into the coating solution, the initial stage is achieved without multilayering as in the vapor deposition system. As in the case of this organic EL element, it has been reported that high efficiency can be achieved with a single layer structure in which a light emitting layer is sandwiched between an anode and a cathode. (2004, 53rd Polymer Symposium, Proceedings 1R14) However, the required elements such as higher efficiency of light emission and longer life are still not sufficient, and further improvements are required.

  Although this coating method has many advantages, there are many problems, and means and materials for solving these problems are strongly desired.

Japanese Patent No. 3093796 Japanese Unexamined Patent Publication No. 63-264692 JP-A-3-255190 US Pat. No. 6,097,147

M.M. A. Baldo et al. , Nature, 395, 151-154 (1998) M.M. A. Baldo et al. , Nature, 403, 17, 750-753 (2000) S. Lamansky et al. , J .; Am. Chem. Soc. , 123, 4304 (2001)

  An object of the present invention is to provide a coating dispersion for an organic electroluminescence device and a non-aqueous dispersion for an organic electroluminescence device having good dispersion stability of the dispersion, and the coating dispersion or the non-aqueous coating dispersion It is to provide an organic EL element that exhibits high external extraction quantum efficiency and has a long light emission lifetime, and provides an illumination device and a display device including the organic EL element.

The object of the present invention has been achieved by the following constitutions (1) to (7).
(1) In an organic electroluminescent device having at least an anode and a cathode on a support substrate and having an organic compound layer including a light emitting layer between the anode and the cathode,
The light-emitting layer contains a light-emitting dopant composed of at least one organic iridium complex dispersed with at least one nonionic dispersion stabilizer excluding an organometallic complex.
(2) In an organic electroluminescence device having an organic compound layer including at least an anode and a cathode on a support substrate, and a light emitting layer between the anode and the cathode,
The light emitting layer contains a light emitting dopant composed of at least two kinds of organic iridium complexes dispersed with at least one kind of nonionic dispersion stabilizer excluding an organometallic complex.
(3) In an organic electroluminescence device having an organic compound layer including at least an anode and a cathode on a support substrate, and a light emitting layer between the anode and the cathode,
The light-emitting layer contains a light-emitting dopant composed of at least three types of organic iridium complexes dispersed with at least one type of nonionic dispersion stabilizer excluding an organometallic complex.
(4) The at least one nonionic dispersion stabilizer excluding the organometallic complex is polyethylene glycol, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxypropylcellulose, or hydroxypropylmethylcellulose (1) to ( The organic electroluminescent element according to any one of 3).
(5) The organic electroluminescence element according to any one of (1) to (4), which emits white light.
(6) A display device comprising the organic electroluminescence element according to any one of (1) to (5).
(7) An illumination device comprising the organic electroluminescence element according to any one of (1) to (5).
In addition, about the following 1-15, it is a structure used as a reference.

  1. A coating dispersion for an organic electroluminescent element, comprising at least one organic electroluminescent element material and at least one nonionic dispersion stabilizer.

  2. A coating dispersion for an organic electroluminescence device, comprising at least two types of materials for an organic electroluminescence device and at least one nonionic dispersion stabilizer.

  3. 3. The coating dispersion liquid for organic electroluminescence elements according to 1 or 2, wherein at least one of the materials for organic electroluminescence elements is an organometallic complex.

  4). 4. The organic electroluminescent device according to 3 above, wherein the metal involved in the complex formation of the organometallic complex is any one transition metal belonging to groups 8 to 10 of the periodic table, Al or Zn. Application dispersion.

  5. 5. The coating dispersion liquid for an organic electroluminescence element according to 4, wherein the metal is Ir, Pt, Rh, Ru, Os, Al or Zn.

  6). A non-aqueous coating dispersion for an organic electroluminescence device, comprising at least one material for an organic electroluminescence device and at least one nonionic dispersion stabilizer.

  7). A non-aqueous coating dispersion for an organic electroluminescence device, comprising at least two types of materials for an organic electroluminescence device and at least one nonionic dispersion stabilizer.

  8). 8. The non-aqueous coating dispersion for organic electroluminescence elements according to 6 or 7, wherein at least one of the materials for organic electroluminescence elements is an organometallic complex.

  9. 9. The organic electroluminescent device according to 8, wherein the metal involved in complex formation of the organometallic complex is any one metal belonging to Groups 8 to 10 of the periodic table, Al or Zn. Non-aqueous coating dispersion.

  10. 10. The non-aqueous coating dispersion for an organic electroluminescence device as described in 9 above, wherein the metal is Ir, Pt, Rh, Ru, Os, Al or Zn.

11. In an organic electroluminescence device having at least an anode and a cathode on a support substrate, and an organic compound layer including a light emitting layer between the anode and the cathode,
Through the step of applying the coating dispersion liquid for organic electroluminescence elements according to any one of 1 to 5 or the non-aqueous coating dispersion liquid for organic electroluminescence elements according to any one of 6 to 10, An organic electroluminescence device, wherein the light emitting layer is formed.

12 The support substrate has at least an anode and a cathode, an organic compound layer including a light emitting layer between the anode and the cathode, and an anode buffer layer between the anode and the organic compound layer, or In an organic electroluminescence device having a cathode buffer layer between a cathode and the organic compound layer,
The light emitting layer is coated with the coating dispersion liquid for organic electroluminescence elements according to any one of 1 to 5 or the non-aqueous coating dispersion liquid for organic electroluminescence elements according to any one of 6 to 10. An organic electroluminescence device formed by performing the step of:

  13. 13. The organic electroluminescence device as described in 11 or 12 above, which emits white light.

  14 14. A display device comprising the organic electroluminescence element according to any one of 11 to 13.

  15. 14. An illumination device comprising the organic electroluminescence element according to any one of 11 to 13.

  According to the present invention, there are provided a coating dispersion for an organic electroluminescence device and a non-aqueous dispersion for an organic electroluminescence device having good dispersion stability of the dispersion, and using the coating dispersion or the non-aqueous coating dispersion, An organic EL element having a high external extraction quantum efficiency and a long emission lifetime was provided, and an illumination device and a display device including the organic EL element could be provided.

It is the schematic diagram which showed an example of the display apparatus comprised from an organic EL element. It is a schematic diagram of a display part. It is a schematic diagram of a pixel. It is a schematic diagram of a passive matrix type full-color display device. It is the schematic of an illuminating device. It is sectional drawing of an illuminating device.

  In the coating dispersion liquid for organic EL elements of the present invention, it has the structure described in any one of the structures 1 to 5, and in the non-aqueous coating dispersion liquid for organic EL elements of the present invention, the structure 6 The dispersion according to any one of No. 10 to No. 10 can be used to obtain a dispersion having good dispersion stability of the dispersion, and using the dispersion, the external extraction quantum efficiency is high and light emission is achieved. An organic EL element having a long life could be obtained. In addition, by using the organic EL element, the present inventors have succeeded in obtaining a high-luminance display device and a lighting device. Here, the coating dispersion liquid for organic EL elements and the non-aqueous dispersion liquid for organic EL elements are also simply referred to as a dispersion liquid.

  Hereinafter, details of each component according to the present invention will be sequentially described.

  First, the process of reaching the dispersion of the present invention will be described here.

  The inventors of the present invention have made various studies on the above-mentioned problems, and in the formation of the constituent layers of the organic EL element, studied the formation of layers by coating (also referred to as film formation), and led to coating using a dispersion liquid. In the background, there was a problem related to the production of the constituent layer of the organic EL element that emits white light.

  More specifically, for example, when a white light emitting device is manufactured, a plurality of light emitting compounds having different emission maximum wavelengths must be installed in the light emitting layer, and in particular, for a device using a phosphorescent light emitting material. In some cases, it is indispensable to control the deposition of a plurality of phosphorescent dopants at the same ratio each time by the vacuum deposition method, but the adjustment operation is extremely difficult, and there is a problem that the yield in manufacturing is difficult to increase. .

  In addition, there is a method in which the light emitting layer is formed by uniform solution coating instead of vapor deposition. For example, the host compound and the light emitting dopant are indispensable requirements for forming the light emitting layer. In many cases, the organometallic complex or the like exhibiting an excellent function as a solvent differs greatly from the host compound in solubility in a solvent.

  In addition, the solution coating in a uniform system has a problem of selecting an appropriate solvent (a substantially limited solvent must be used), and even if a solvent is found, an organic metal Since the solubility of the complex in the solvent is basically low (slightly soluble), it is necessary to assume the use of a very large amount of solvent for coating, which is a big problem from the viewpoint of production.

  Against the background of the above problems, as a result of continuing studies, for the production of organic EL elements, the coating dispersion liquid for organic EL elements of the present invention described in Structures 1 to 5 or any one of Structures 6 to 10 is used. The non-aqueous coating dispersion liquid for organic EL elements of the present invention described in the item has been found to be extremely useful.

  Moreover, the effect on the structural layer formation of an organic EL element obtained by using the dispersion liquid of this invention is shown below.

  (A) In the case of a multilayer structure, a laminated structure can be constructed without disturbing the lower layer by applying the dispersion of the present invention.

  (B) Even in the production of a device having a single layer structure in which a light emitting layer is sandwiched between an anode and a cathode by using a plurality of functional materials such as an electron transport material, a hole transport material, and a light emitting material (light emitting dopant) as a dispersion. A great effect can be obtained in increasing the efficiency of light emission.

  (C) In a solution system in which a mixture of a plurality of types is dissolved, the solubility and compatibility are different from each other, so that it is not a uniform monodispersed state but a state like a cluster in which several molecules are aggregated. It is expected that). In particular, this tendency is remarkable in organometallic complexes such as luminescent dopants that serve as luminescent components, and concentration quenching is likely to occur, resulting in a major problem when aiming at higher efficiency. Cheap. In such a case, particularly with a light-emitting dopant (organometallic complex) that is often contained at a low concentration, there is a problem that the concentration distribution of the light-emitting dopant in the light-emitting layer tends to be extremely nonuniform in the layer.

  On the other hand, in the dispersion liquid of the present invention (the organic EL element material is dispersed in a fine particle state), particularly in a dopant material having a low mixing ratio, distribution (isolation) is ideally dispersed in each particle. Therefore, the generation of the above-described clusters can be suppressed, so that it was possible to obtain a remarkable effect in improving the external quantum efficiency of the device and extending the light emission lifetime, which are the objects of the present invention. .

<< Coating dispersion for organic EL element, non-aqueous coating dispersion for organic EL element >>
Each of the coating dispersion for organic EL elements and the non-aqueous coating dispersion for organic EL elements of the present invention will be described.

  The coating dispersion liquid for organic EL elements according to Configuration 1 of the present invention and the non-aqueous coating dispersion liquid for organic EL elements according to Configuration 6 of the present invention are each at least one organic electroluminescence element material, It is characterized by containing at least one nonionic dispersion stabilizer.

  The organic EL element material being in a dispersed state means that at least one of the materials related to the constituent layers of the organic EL element is present as a solid content, and the solid content is dispersed in the form of fine particles in the dispersion. It is preferable.

  Here, the organic electroluminescent element material is a material related to a constituent layer of the organic EL element of the present invention, which will be described later, and specifically, a constituent layer (anode, cathode, organic compound layer, etc.) of the organic EL element. ) (Also referred to as compounds, components, etc.).

  By using a nonionic dispersion stabilizer, diffusion of counter ions does not occur as in ionic dispersion stabilizers such as cationic or anionic, so that it has a good effect on the lifetime of the organic electroluminescence device to be produced. Bring.

(Method for preparing coating dispersion for organic EL element, non-aqueous coating dispersion for organic EL element)
As a preparation method of each of the coating dispersion liquid for organic EL elements and the non-aqueous coating dispersion liquid for organic EL elements, a conventionally known method for producing a dispersion liquid can be applied. For example, there are dispersion by a physical force using a homogenizer (high pressure, ultrasonic wave, etc.), a bead mill, a jet mill, and an optimizer, and emulsification dispersion. In addition to the above method, in the case of a polymer material, polymer fine particles are synthesized by a method such as gas phase polymerization, emulsion polymerization, suspension polymerization and the like, and this is dispersed in a dispersion (in some cases, redispersion may be necessary). And can be used for coating according to the present invention.

  In preparing the fine particle dispersion, the above method may be used alone, or a plurality of methods may be used in combination (also referred to as combined). Moreover, a conventionally known reprecipitation method (for example, a method described in Chemistry and Industry, page 137, 2002) or the like may be applied as a method for preparing the nanoparticles.

(Non-aqueous dispersion: The dispersion is dispersed in a non-aqueous solvent)
In dispersing the organic EL device material according to the present invention, a non-aqueous dispersion prepared using a non-aqueous solvent described later as a dispersion medium can be mentioned as a preferred embodiment. Here, the non-aqueous dispersion is a non-aqueous dispersion described later as a dispersion solvent in the dispersion (in the case of using a plurality of types of dispersion solvents, the dispersion solvent is a main component of 50% by volume or more). Represents a dispersion prepared using a solvent, and a non-aqueous solvent other than water, preferably an alcohol, nitrile or hydrocarbon solvent (specifically, an aromatic solvent shown below) Or the like).

  In addition, as a combination of the forming material of the anode, the cathode, the organic compound layer, and the solvent described in the constituent layers of the organic EL element, which will be described later, an optimal combination is appropriately selected according to the type of the organic compound layer. Is preferred.

  In the preparation of the non-aqueous dispersion, it is preferable to adjust the solid content in the dispersion to a range of 0.01% to 50% by weight of the total weight of the dispersion. It is preferable to adjust the particle size to be 1 μm or less.

(Non-aqueous solvent)
The nonaqueous solvent according to the present invention will be described.

  In preparing a coating solution (which may be a solution or a dispersion), one of preferred embodiments according to the present invention is to use a non-aqueous solvent.

  Here, the non-aqueous solvent represents a solvent that does not substantially contain water, but “a solvent that does not substantially contain water has a water content of 0.1% by mass or less”. A non-aqueous solvent is defined, and the water content in the solvent can be measured by a conventionally known Karl Fischer moisture meter, a commercially available automatic moisture measuring device, or the like.

(Solvent used for preparation of coating dispersion for organic EL element, non-aqueous coating dispersion for organic EL element)
There is no particular limitation on the solvent used for the preparation of the dispersion (generally referred to as a dispersion for organic EL element coating dispersion or non-aqueous coating dispersion for organic EL element), and it can be appropriately selected. For example, halogen solvents such as chloroform, carbon tetrachloride, dichloromethane, 1,2-dichloroethane, dichlorobenzene, dichlorohexanone, ketones such as acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, n-propyl methyl ketone, cyclohexanone, etc. Solvents, aromatic solvents such as benzene, toluene, xylene, ester solvents such as ethyl acetate, n-propyl acetate, n-butyl acetate, methyl propionate, ethyl propionate, γ-butyrolactone, diethyl carbonate, tetrahydrofuran, dioxane Ether solvents such as dimethyl Examples include amide solvents such as formamide and dimethylacetamide, alcohol solvents such as methanol, ethanol, 1-butanol and ethylene glycol, nitrile solvents such as acetonitrile and propionitrile, dimethyl sulfoxide, water, and mixed solvents thereof. It is done.

  Among these, as the solvent, alcohol solvents such as water, methanol, 1-butanol and ethylene glycol, ether solvents such as tetrahydrofuran and dioxane, amide solvents such as dimethylformamide and dimethylacetamide, mixed solvents thereof and the like Is used, a hydrophilic dispersion is obtained.

  Among them, when preparing a dispersion, any dispersion solvent may be used as long as it does not dissolve the dispersion medium, but alcohol solvents and nitrile solvents are preferable, and methanol, ethanol, acetonitrile, and propionitrile are more preferable. .

  Moreover, as a boiling point of a solvent, 60 to 200 degreeC is preferable, More preferably, it is the range of 80 to 180 degreeC.

(Measuring method of average particle diameter and average particle diameter of dispersed particles in dispersion)
By using these methods, it is possible to produce a dispersion liquid (nanoparticle dispersion liquid) containing nanoparticles having a nano-sized particle diameter, and when forming the constituent layers of the organic EL element of the present invention by coating. It is effective, and various characteristics (luminance, light emission lifetime, etc.) of the obtained device are extremely good.

  Here, the average particle diameter of the dispersed particles in the dispersion according to the present invention is preferably in the range of 1 nm to 200 nm, more preferably in the range of 5 nm to 100 nm, and particularly preferably in the range of 10 nm to 60 nm.

  By appropriately selecting or combining the above-described methods depending on the material for the organic EL element, a nanoparticle dispersion liquid suitable for forming a constituent layer of the organic EL element can be prepared.

  Here, the particle size of the fine particles in the dispersion was measured with a Zetasizer 1000HS manufactured by Malvern. The concentration of the dispersion can be appropriately adjusted with the same solvent used for the dispersion solvent depending on the use conditions.

(Concentration of dispersion in dispersion)
In the measurement of the concentration of the organic EL element material in the dispersion (also referred to as dispersion concentration or fine particle dispersion concentration), the solid content concentration was obtained, and this value was used as the concentration of the dispersion.

(Measurement of solid content)
5 g of the dispersion was weighed and dried under reduced pressure at 100 ° C. for 3 hours, and the mass of the residue was measured. At this time, the concentration of the dispersion (solid content concentration) was determined using the following general formula.

Solid content concentration (%) = residue mass (g) / 5 (g) × 100
(Viscosity of dispersion)
The viscosity of the dispersion of the present invention is preferably 0.5 mPa · s to 500 mPa · s, more preferably 1 mPa · s from the viewpoint of reducing coating unevenness during drying and facilitating adjustment of the dry film thickness. It is preferable to adjust to a range of ˜100 mPa · s.

  The viscosity of the dispersion can be appropriately adjusted to a desired range by adjusting the temperature, pressure, etc. when coating with the dispersion, and the viscosity can be adjusted to a conventionally known rotational viscometer or B type. It can be measured using a viscometer or the like.

  Moreover, the kind of dispersion liquid can be suitably selected according to the constituent material of the organic EL element, and may be a hydrophilic dispersion liquid or a lipophilic dispersion liquid.

(Dispersion application method, application method)
When coating using the dispersion, for example, by a wet coating method such as a dipping method, a spin coating method, a casting method, a die coating method, a roll coating method, a blade coating method, a bar coating method, a gravure coating method, etc. It can be suitably performed. Among these, it is preferable to use a coater as the coating means, and it is particularly preferable to use a discharge type coater among the coaters.

  In the case of using a discharge type coater, a mode in which a precision diaphragm pump is provided and the coating liquid is discharged by driving the precision diaphragm pump is preferable.

  In this case, the discharge amount of the coating solution can be easily controlled, can be applied over a large area, and can be applied precisely, in a thin layer, and in any shape, so that it has high luminance and excellent luminous efficiency. This is very advantageous in that a light emitting element can be obtained efficiently at low cost.

(Drying after applying dispersion)
The drying conditions are not particularly limited, but it is preferable to employ a temperature, pressure, etc. in a range that does not damage the coated layer.

  In addition, when the dispersion is applied, it is preferable to form a constituent layer of the organic EL element after application, after drying of the solvent or while drying, and in the case of performing heating film formation, the main constituent of the constituent layer is formed. A temperature higher than the glass transition point (Tg) of the material of the component (this main component is also the main component in the solid content dispersed (partially partially dissolved) in the dispersion) It is preferable to form a film.

<Dispersion stabilizer>
The nonionic dispersion stabilizer according to the present invention will be described.

  As the dispersion stabilizer according to the present invention, conventionally known nonionic dispersion stabilizers (also referred to as surfactants) can be used. For example, JP-A-52-92716, International Publication No. 88 / Non-ionic surfactants existing in nature such as known nonionic surfactants described in pamphlet No. 04794 and other known polymers such as polyethylene glycol, polyvinyl alcohol, polyvinylpyrrolidone, hydroxypropylcellulose, hydroxypropylmethylcellulose, etc. Molecular compounds can be appropriately selected and used. When a solvent is used as the dispersion medium, polyvinyl butyral, butylethyl cellulose, methacrylate copolymer, maleic anhydride ester copolymer, polystyrene and butadiene-styrene copolymer, etc., and nonionic organic dispersion described in JP-A-2005-272755 Agents, nonionic surfactants, etc., and classified according to their structure into ester type, ether type, ester / ether type, and others. The ester type is a polyhydric alcohol such as glycerin, sorbitol, sucrose, etc. And a fatty acid ester-linked structure such as polyethylene glycol fatty acid ester, glycerin ester, polyglycerin ester, sorbitan ester, propylene glycol ester, and sucrose ester.

  The ether type is a typical nonionic surfactant produced by addition polymerization of ethylene oxide (ethylene oxide) to a raw material having a hydroxyl group, such as higher alcohols and alkylphenols. Polyoxyethylene alkyl and alkyl Examples include phenyl ether, alkylallyl formaldehyde condensed polyoxyethylene ether, polyoxyethylene polyoxypropylene block copolymer, polyoxyethylene polyoxypropyl alkyl ether, and the like.

  The ester / ether type is a fatty acid or polyhydric alcohol fatty acid ester added with ethylene oxide, and has both an ester bond and an ether bond in the molecule. The polyoxyethylene ether of glycerin ester and the polyoxyethylene of sorbitan ester Examples include ethylene ether and polyoxyethylene ether of sorbitol ester.

  Other types include fatty acid alkanolamides in which a lipophilic group and a hydrophilic group are bonded by an amide bond, and alkylpolyglucosides using saccharides (such as glucose) as a raw material.

  These nonionic surfactants are commercially available and can be easily obtained. Specifically, acylsorbitan, Tween surfactant, Triton surfactant, Triton X -100, Triton X-45, Triton X-114, Triton X-102, Triton X-165, Nonidet P-40, Tween 20, Tween 40, Tween 60, Tween 80, etc., nonionic surfactants (polyoxyethylene alkyl ether, poly Oxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylphenyl ether, polyoxyethylene alkylamine, polyoxyethylene alkylamide, etc.) It can be used alone or two or more.

  As described above, these nonionic dispersion stabilizers do not diffuse counterions of the dispersion stabilizer itself like ionic dispersion stabilizers such as cationic and anionic, so that the organic EL element Has a positive effect on life.

  In addition, as the nonionic dispersion stabilizer according to the present invention, some of the organometallic complexes according to the present invention (the organometallic complex will be described in detail separately) can be preferably used.

  Hereinafter, although the specific example of the organometallic complex preferably used as a dispersion stabilizer is shown, this invention is not limited to these.

  The amount of the dispersion stabilizer according to the present invention is any one of the coating dispersion liquid for organic EL elements according to any one of configurations 1 to 5 of the present invention, or the configuration 6 to 10 of the present invention. From the viewpoint of improving the dispersion stability of the non-aqueous coating dispersion for organic EL devices described in 1., the range of 0.1% by mass to 30% by mass is usually preferable, more preferably Is in the range of 5% to 20% by weight.

《Materials for organic electroluminescence elements》
An organic electroluminescence element material (also referred to as an organic EL element material) according to the dispersion of the present invention will be described.

  The organic EL element material contained in a dispersed state (also referred to as a dispersion) in the dispersion liquid of the present invention is used for forming the constituent layer at the constituent layer of the organic EL element described later. Examples include materials (compounds). The details of the material will be described later. For example, an organic compound layer (anode buffer forming material, hole transporting material, light emitting material (host compound, light emitting dopant, etc.), hole blocking material, electron transporting material, hole blocking material. In the case where organic materials are used for the materials constituting the anode blocking material, the cathode blocking layer, the cathode buffer layer, etc., they are also included in the category of the organic compound layer). It is done.

  The formation of the constituent layer relating to the organic EL element of the present invention (herein, the constituent layers are an anode, a cathode, an organic compound layer, etc., and details will be described in the constituent layer of the organic EL element). The coating using the dispersion liquid of the invention is not particularly limited, and can be applied to any of the constituent layers.

<Organic metal complex>
Among the organic EL device materials according to the present invention, from the viewpoint of preferably obtaining the effects of the present invention, such as improvement of the external extraction quantum efficiency of the device and the extension of the light emission lifetime, It is preferable to use an organometallic complex, more preferably, the metal for forming the complex is preferably any one metal belonging to Groups 8 to 10 of the periodic table, Al or Zn, and particularly preferably. The metal is Ir, Pt, Al or Zn.

  In addition, the organometallic complex according to the present invention can be used for all the constituent layers of the organic compound layer of the organic EL element. In particular, when it is used as a material for forming the light emitting layer of the organic EL element, it will be described later. A dopant compound (a light emitting dopant, also simply referred to as a dopant) is preferable, and a phosphorescent organometallic complex (also referred to as a phosphorescent compound) is more preferable.

(Phosphorescent organometallic complex)
The phosphorescent organic metal complex according to the present invention (the phosphorescent organic metal complex will be described in detail later) is used as a dispersion (dispersion) when forming the light emitting layer, and a dopant is incorporated into the light emitting layer. About the merit, the present inventors consider as follows.

  Conventionally, when a component layer of an element is formed using an organometallic complex (phosphorescent organometallic complex is also in this category) as an element material, methods such as vapor deposition (sputtering, etc.) or coating using a solution have been used. It has been used.

  Compared with the vapor deposition method, especially in view of the application in solution system, which is superior in cost merit, conventionally, in order to dissolve the organometallic complex, a polar solvent is generally used in the trader. It was the target.

  However, by using a polar solvent in which the organometallic complex is easy to dissolve, the inclusion type organometallic complex or dendrimer structure, which is said to have a high concentration quenching suppression effect among conventional organic EL element materials, In the case of the light-emitting compound possessed, the organometallic complex having a ligand containing a polymer chain, etc., there was a problem that the original concentration quenching suppression function was not sufficiently exhibited.

  Therefore, rather than dissolving the organometallic complex, by using it as a fine particle dispersion (fine particle dispersion), an inclusion type organometallic complex or an organometallic complex having a ligand containing a polymer chain is inherently produced. The present inventors have found that the concentration quenching suppression function possessed is sufficiently exhibited.

  Furthermore, when an organometallic complex is used as a dispersion (dispersion) rather than as a solution, optimization (tuning) adjustment for individual materials can be made by changing the average particle size and dispersion concentration, and control of thin film properties In addition, it was possible to obtain the merit of manufacturing an organic EL element.

  In addition, dispersion systems can have intermolecular interactions in the micro range compared to homogeneous solution systems, which makes it easy to optimize (tune) thin film properties for individual materials. The effects of the present invention can be obtained more preferably.

  The solvent for dispersing the phosphorescent organometallic complex in fine particles is not particularly limited as long as it is a dispersible solvent, and the above non-aqueous solvent and the solvent used for preparing the dispersion can be used. In order to obtain the maximum effect described in the present invention, it is preferable to use a nonpolar solvent, alcohol, water or the like, which is generally considered a poor solvent, as a dispersion solvent.

《Composite》
The phosphorescent organic metal complex (which will be described in detail later) contained in the dispersion (which may be a fine particle dispersion) is an inclusion of the phosphorescent organic metal complex. It may be included in the compound to form a complex.

  The complex is preferably present in a state in which a clathrate is encapsulated with a phosphorescent organometallic complex (also referred to as a light-emitting dopant, which will be described later). The inclusion compound preferably has a hole transporting group or an electron transporting group. The hole transporting group and the electron transporting group will be described in the case of an inclusion compound.

  Furthermore, the clathrate compound can be used in the form of a polymer having a partial structure having an clathrate function as a repeating unit.

  The inventors of the present invention achieved the above problems by improving the external extraction quantum efficiency and emission lifetime of the element, reducing the driving voltage, etc. by the organic EL element produced using the composite of the present invention. The background is shown below.

  A conventionally known light-emitting compound having a dendrimer structure (here, a dendrimer has a dendron (also called a dendritic molecule) in its molecule) and an organic fluorescent dye included in a cyclodextrin derivative. In an organic light-emitting device using a fluorescent color conversion film having a fluorinated organic fluorescent dye or an organic electroluminescence device characterized by containing an inclusion complex of an organic compound and a cyclodextrin, each luminescent compound is encapsulated. Inclusion effect due to inclusion in the internal space of the contact compound (also known as wrinkle effect, suppression of concentration quenching due to steric factors preventing access to dopants, prevention of material degradation, device stability Improvement) etc., but on the other hand, the efficiency of recombination of holes and electrons, which is indispensable for light emission of organic EL elements, is reduced. Smooth energy transfer from the excited triplet state of the host compound formed by recombination of holes and electrons to the phosphorescent compound (organometallic complex) is suppressed, and it is preferable that the luminous efficiency is decreased and the driving voltage is increased. There was a tendency for a new phenomenon to be invited.

  As a result of various studies, the present inventors consider that the adjustment of the balance between the inclusion effect and the charge injection is the key to solving the above-mentioned problem, and as a means for adjusting the balance, the molecules between the inclusion compound and the organometallic complex are intermolecular. Focusing on the action (here, the intermolecular interaction indicates the degree of inclusion of the organometallic complex by the inclusion compound).

  And, as a parameter representing the strength of the intermolecular interaction, the degree of inhibition of concentration quenching of each of the organometallic complex and the complex (in the present invention, the concentration indicating concentration quenching is calculated from the fluorescence intensity measurement. It is possible to estimate the state of balance between the clathrate effect and the charge injection by measuring the clathrate compound, which will be described in detail below.

  In addition to various display devices and displays, the composite according to the present invention is used as a material for forming various types of light sources, lighting devices, home lighting, interior lighting, and exposure light sources. It is also useful as a material, and is also useful as a forming material for a display device such as a backlight of a liquid crystal display device. Among them, it is preferably used as a material for forming an organic EL element used in the above display device and lighting device. In particular, as a material for forming a light emitting layer (details of the light emitting layer will be described later) which are constituent layers of the organic EL element. Preferably used.

  In the synthesis of the complex, the clathrate compound is clathrated with the phosphorescent organometallic complex, but a conventionally known clathrate (the clathrate compound has a guest molecule in the internal space of the clathrate compound). The complex used in the present invention can be synthesized by referring to synthetic methods (in the state of incorporation) (these syntheses are well-known synthetic methods for those skilled in the art).

<< inclusion compound >>
The clathrate compound used in the present invention will be described.

  The inclusion compound used in the present invention is a compound having an inclusion function as shown below.

(Inclusion)
The inclusion used in the present invention is a bond such as ionic bond force, ion-dipole interaction, hydrogen bond, charge transfer interaction, coordination bond, van der Waals force, π-π interaction (π stack), etc. A phenomenon in which a complex is formed by surrounding a compound in which an inclusion compound is included by force (in the present invention, a compound in which a phosphorescent organometallic complex is included) is shown.

  In the present invention, the state in which the inclusion compound surrounds the guest molecule is a state in which the guest compound is completely or partially taken into the internal space of the inclusion compound. Including a case where a molecular assembly is formed by the intermolecular interaction, and a state where the guest compound is not completely taken into the internal space of the inclusion compound is included. In the present invention, the effect described in the present invention (improvement of external extraction quantum efficiency) can be more preferably obtained when the guest compound molecules are not completely taken into the internal space of the clathrate compound.

(How to check the inclusion)
As a method for confirming whether the phosphorescent organometallic complex according to the present invention is included in a clathrate compound to form a complex or is present in an uninclusion body state, a conventionally known clathrate is used. General body confirmation methods can be used.

  For example, by performing inclusion in a solvent system in which the clathrate compound dissolves but the organometallic complex does not dissolve, the formation of the clathrate can be confirmed with the disappearance of the organometallic complex in the solution.

As a more quantitative confirmation means, ¹ H-NMR (Nuclear Magnetic Resonance Analysis) or ¹³ C-NMR (Nuclear Magnetic Resonance Analysis) or the like is used, so that it exists as a single organometallic complex or is included. It can be quantitatively confirmed whether or not a complex is formed with the compound.

  The balance between the inclusion effect and the charge injection, that is, the magnitude of the intermolecular interaction between the inclusion compound and the organometallic complex is calculated by calculating the degree of inhibition of concentration quenching, which will be described in detail below. (Also called the degree of concentration quenching suppression) can be confirmed.

  Hereinafter, the degree of inclusion will be described.

《Calculation method of degree of inclusion (inhibition level of concentration quenching)》
As a method of calculating the degree of inclusion, the concentration indicating concentration quenching is measured from the fluorescence intensity measurement of the complex and the organometallic complex in the non-inclusion state, the degree of suppression of concentration quenching is calculated, and the degree of inclusion is calculated. Estimated.

  Specifically, it can be calculated by the following operation. The synthesized complex (also referred to as clathrate) was purified by gel filtration chromatography, column chromatography, or the like, then fluorescence was measured at different concentrations (N = 3 for each measurement), and the average value was used. .

  The concentration [C] indicating concentration quenching was determined from the fluorescence intensity at each concentration. Similarly, the concentration [C0] indicating concentration quenching of the organometallic complex of the non-inclusion body serving as a blank is determined, and when the relationship between the two is (C / C0)> 1.1, the inclusion body (organic Metal complex is included by the inclusion compound). Here, in this invention, it is preferable that the value of (C / C0) is 1.2 or more, More preferably, it is the range of 1.4-3.0.

  The concentration of the phosphorescent dopant in the clathrate can be determined and calculated by ICP (inductively coupled plasma) emission analysis, which is a well-known inorganic metal quantitative method.

  From the above, the present inventors considered the balance between the inclusion effect and the charge injection by considering the intermolecular interaction between the inclusion compound and the organometallic complex from the above-mentioned inclusion degree (concentration quenching suppression degree). And an organic EL device having a long light emission lifetime has been developed while taking advantage of the high light emission efficiency of the phosphorescent organic EL device. Moreover, it turned out that the organic EL element of this invention shows the outstanding characteristic that a drive voltage is also low.

  In addition, as one method for controlling the inclusion state of the organometallic complex in a complex formed by an inclusion compound and a phosphorescent organometallic complex that is clathrated with the inclusion compound, And a phosphorescent dopant combination, for example, a clathrate and an organometallic complex (phosphorescent dopant) at the time of clathration, such as 1: 1 clathrate and 2: 1 clathrate The inclusion ratio with can be adjusted. As described above, as a result of the control of the inclusion state (specifically, the balance adjustment between the inclusion effect and the intermolecular interaction), the external extraction quantum efficiency and In addition to improving the light emission lifetime, the effect of reducing the driving voltage of the element can also be realized.

《Specific examples of inclusion compounds》
The inclusion compound used in the present invention refers to a compound having the inclusion function shown below, for example, crown ether derivative, cyclophane derivative, calixarene derivative, carbon nanotube derivative, cyclodextrin derivative, cyclotriphosphazene derivative. , Cryptand derivatives, potando derivatives and the like, among which calixarene derivatives, crown ether derivatives and cyclodextrin derivatives are preferred, and calixarene derivatives and crown ether derivatives are more preferred.

  Further, calixarene derivatives, crown ether derivatives, and cyclodextrin derivatives that are preferably used as clathrate compounds used in the present invention will be specifically described below.

(Calixarene derivative)
The calixarene derivative used in the present invention is a general term for compounds having a cyclic structure in which a phenol derivative is bonded with an alkylene group or an oxyalkylene group, as represented by the following general formula (A). The phenolic hydroxyl group may be substituted with a substituent.

  In general formula (A), A and L represent a bivalent coupling group, and R represents a hydrogen atom or a substituent. n represents an integer of 1 to 9, and Z represents a residue of a fluorescent compound or a residue of a phosphorescent compound.

  In the general formula (A), examples of the divalent linking group represented by A and L include hydrocarbon groups such as alkylene groups, alkenylene groups, alkynylene groups, and arylene groups, as well as the alkylene groups and the alkenylene groups. In the alkynylene group and the arylene group, each of them may contain a hetero atom (for example, a nitrogen atom, a sulfur atom, a silicon atom, etc.), or a thiophene-2,5-diyl group or pyrazine-2. It may be a divalent linking group derived from a compound having an aromatic heterocycle (also referred to as a heteroaromatic compound), such as a 1,3-diyl group, or a chalcogen atom such as oxygen or sulfur. Good. Further, it may be a group such as an alkylimino group, a dialkylsilanediyl group, or a diarylgermandiyl group that connects and connects heteroatoms.

  Furthermore, examples of the divalent linking group represented by A and L include, for example, a carbazole ring, a carboline ring, a diazacarbazole ring (also referred to as a monoazacarboline ring, and one of the carbon atoms constituting the carboline ring is a nitrogen atom) The aromatic structure such as triazole ring, pyrrole ring, pyridine ring, pyrazine ring, quinoxaline ring, thiophene ring, oxadiazole ring, dibenzofuran ring, dibenzothiophene ring, indole ring, etc. A divalent group derived from an aromatic heterocyclic ring selected from a ring group can be used.

  Furthermore, you may have a substituent represented by R mentioned later.

  In the general formula (A), the substituent represented by R is an alkyl group (for example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group). , Tridecyl group, tetradecyl group, pentadecyl group etc.), cycloalkyl group (eg cyclopentyl group, cyclohexyl group etc.), alkenyl group (eg vinyl group, allyl group etc.), alkynyl group (eg ethynyl group, propargyl group etc.) ), Aryl groups (for example, phenyl group, naphthyl group, etc.), aromatic heterocyclic groups (for example, furyl group, thienyl group, pyridyl group, pyridazinyl group, pyrimidinyl group, pyrazinyl group, triazinyl group, imidazolyl group, pyrazolyl group, Thiazolyl, quinazolinyl, carbazolyl, carbolinyl, dia A carbazolyl group (indicating that one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), a phthalazinyl group, etc., a heterocyclic group (eg, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group) Group), alkoxy group (for example, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) Etc.), aryloxy groups (eg phenoxy group, naphthyloxy group etc.), alkylthio groups (eg methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group etc.), cycloalkylthio group ( Example For example, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group) , Dodecyloxycarbonyl group etc.), aryloxycarbonyl group (eg phenyloxycarbonyl group, naphthyloxycarbonyl group etc.), sulfamoyl group (eg aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group) Hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminos Sulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenyl) Carbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (eg, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide Groups (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexyl group) Rubonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl) Group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc. ), Ureido groups (eg, methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, octylureido) , Dodecylureido group, phenylureido group, naphthylureido group, 2-pyridylaminoureido group, etc.), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group) , Phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.) Arylsulfonyl group or heteroarylsulfonyl group (for example, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), Mino group (for example, amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino group, 2-pyridylamino group), halogen atom (For example, fluorine atom, chlorine atom, bromine atom, etc.), fluorinated hydrocarbon group (for example, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophenyl group, etc.), cyano group, nitro group, hydroxy Group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.).

  These substituents may be further substituted with the above substituents. In addition, a plurality of these substituents may be bonded to each other to form a ring.

  In the general formula (A), examples of the fluorescent compound used as a residue of the fluorescent compound represented by Z include a dye, a fluorescent compound, or a fluorescent compound described in a fluorescent dopant (also referred to as a fluorescent compound) described later. Specific examples of the luminescent dopant are given, and the phosphorescent compound used as the residue of the phosphorescent compound represented by Z is described in the phosphorescent compound (also referred to as phosphorescent dopant) described later. And the like.

  Specific examples of the calixarene derivative used in the present invention are listed below, but the present invention is not limited to these.

  In CA-1, A represents CH or N, R represents a hydrogen atom, a methyl group, or an acetyl group, and n represents an integer of 1 to 6.

(Crown ether derivative)
The crown ether derivative used in the present invention is a cyclic polyether as represented by the following general formula (B) or general formula (C), in which the entire ring becomes a polydentate ligand, and metal ions And a general name of compounds having a function of clathrating with organic ions, and some or all of them may be substituted with nitrogen or sulfur instead of oxygen atoms.

  In each of the general formula (B) and general formula (C), L represents a single bond or a divalent linking group, and Ch represents an oxygen atom or a sulfur atom. m represents an integer of 1 to 9, n represents an integer of 1 to 3, and Z represents a residue of a fluorescent compound or a residue of a phosphorescent compound.

  In each of the general formula (B) and general formula (C), the divalent linking group represented by L has the same meaning as the divalent linking group represented by A and L in the general formula (A). is there.

  In each of the general formula (B) and general formula (C), the fluorescent compound used as the residue of the fluorescent compound represented by Z is described in a fluorescent dopant (also referred to as a fluorescent compound) described later. Specific examples of the dye, the fluorescent compound, or the fluorescent dopant are given.

  In each of the general formula (B) and general formula (C), the phosphorescent compound used as the residue of the phosphorescent compound represented by Z is a phosphorescent compound (also referred to as a phosphorescent dopant) described later. And the like.

  Moreover, the crown ether derivative represented by each of the general formulas (B) and (C) may have a substituent R included in the calixarene derivative represented by the general formula (A).

  Specific examples of the crown ether derivative used in the present invention are listed below, but the present invention is not limited to these.

  In each of CE-1 and CE-2, which are the specific examples described above, A represents CH or N, and n represents an integer of 1 to 9.

(Cyclodextrin derivative)
The cyclodextrin derivative used in the present invention is a general term for compounds having a structure in which a plurality of D-glucopyranose groups are cyclized by α-1,4 glycosidic bonds as represented by the following general formula (D). is there. The primary and secondary hydroxyl groups present in the molecule may be substituted with a substituent.

  In the general formula (D), R represents a hydrogen atom or a substituent, and Z represents a residue of a fluorescent compound or a residue of a phosphorescent compound.

  In the general formula (D), the substituent represented by R has the same meaning as the substituent represented by R in the general formula (A).

  In the general formula (D), examples of the fluorescent compound used as a residue of the fluorescent compound represented by Z include a dye, a fluorescent compound, or a fluorescent compound described in a fluorescent dopant (also referred to as a fluorescent compound) described later. Specific examples of the ionic dopant are listed.

  In the general formula (D), examples of the phosphorescent compound used as a residue of the phosphorescent compound represented by Z include the compounds described in the phosphorescent compound (also referred to as phosphorescent dopant) described later. .

  Hereinafter, although the preferable specific example of the cyclodextrin derivative used for this invention is shown, this invention is not limited to these.

  In CD-1 and 2, Ac represents an acetyl group.

  Moreover, it is preferable that the clathrate compound used for this invention has a positive hole transport group or an electron transport group from a viewpoint of the luminous efficiency improvement of an element. Below, the hole transportable group and electron transportable group which the clathrate compound used for this invention has are demonstrated.

(Hole transporting group possessed by the inclusion compound)
The hole transporting group possessed by the clathrate compound used in the present invention will be described.

  The hole transporting group possessed by the clathrate compound used in the present invention is derived from a hole transporting material contained in a hole transporting layer used as a constituent layer of the organic EL device of the present invention described later. Substituents are preferably used.

  The hole transport material containing the substituent (hole transportable group) as a partial structure in the molecule has either hole injection or transport or electron barrier property, and is either organic or inorganic. For example, a triazole derivative, an oxadiazole derivative, an imidazole derivative, a carbazole derivative, a carboline derivative, a diazacarbazole derivative (here, diazacarbazole is a carbon constituting a carboline ring of the carboline derivative. One of the atoms is replaced by a nitrogen atom.), Polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazones Invitation , Stilbene derivatives, silazane derivatives, aniline-based copolymers, and conventionally known materials such as conductive polymer oligomers, particularly thiophene oligomers, porphyrin compounds, aromatic tertiary amine compounds and styrylamine compounds, aromatic And tertiary amine compounds.

  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 two more described in US Pat. No. 5,061,569 Having a condensed aromatic ring of, 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.

<< Constitutional layer of organic EL element, organic compound layer, inorganic compound layer >>
The constituent layer of the organic EL element of the present invention, the organic compound layer according to the constituent layer, the inorganic compound layer, and the organic EL element material contained in the constituent layer will be described.

  As the layer structure of the organic EL device of the present invention, for example, as shown in the following (i), when the organic compound layer is only a light emitting layer, as shown in the following (viii), as the organic compound layer, an anode buffer layer , A hole transport layer, a light emitting layer, a hole blocking layer, an electron transport layer, a cathode buffer layer, and the like, and the like. As described in the following (i), a configuration in which only the light emitting layer is provided as the organic compound layer between the anode and the cathode may be used, but each is shown in the following (ii) to (viii) Such an element having a multilayer structure is preferable.

Here, the light emitting layer described in the following (i) contains at least two kinds of organic EL element materials according to the present invention, and at least one of the organic EL element materials contains a light emitting dopant. In addition to the two organic element material punts, the organic compound layer forming material (for example, anode buffer layer forming material, hole transport material, light emitting material (host compound, light emitting dopant, etc.), hole blocking material , An electron transport material, a hole blocking material, an electron blocking material, etc.), a material for forming an inorganic compound layer, or the like.
(I) Anode / light emitting layer / cathode (ii) Anode / anode buffer layer / light emitting layer / cathode buffer layer / cathode (iii) anode / light emitting layer / electron transport layer / cathode (iv) anode / hole transport layer / light emission Layer / cathode (v) anode / hole transport layer / light emitting layer / electron transport layer / cathode (vi) anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode (vii) anode / positive Hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (viii) anode / anode buffer layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / Cathode (organic compound layer)
Examples of the organic compound layer according to the organic EL device of the present invention include a hole transport layer, a light emitting layer, a hole blocking layer, an electron transport layer, and the like in the above layer configuration. If an organic compound contained in a constituent layer of the organic EL element such as an electron injection layer is contained, it is defined as an organic compound layer. Furthermore, when an organic compound is used for the anode buffer layer, the cathode buffer layer, etc., the anode buffer layer and the cathode buffer layer each form an organic compound layer.

  The organic compound layer includes a layer containing an “organic EL element material that can be used for a constituent layer of an organic EL element” described later.

(Inorganic compound layer)
The inorganic compound layer used in the organic EL device of the present invention is a main component of an inorganic compound as a constituent component of the constituent layer (here, the main component indicates a case where 50% by mass or more of the entire layer is contained). The layer in the case of forming is shown, and specifically, the case where an inorganic compound is used for forming the anode buffer layer, the cathode buffer layer and the like in the above layer configuration can be mentioned.

《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.

  Examples of the hole transport layer used in the present invention include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazoles. Conventionally known materials such as derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers, may be used.

  As the hole transport material, those described above can be used, 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 two more described in US Pat. No. 5,061,569 Having a condensed aromatic ring of, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-308 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 88 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.

  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 nm-200 nm. This hole transport layer may have a single layer structure composed of one or more of the above materials.

  Hereinafter, although the specific example of the compound preferably used for formation of the positive hole transport layer of the organic EL element of this invention is given, this invention is not limited to these.

《Electron transport layer》
The electron transport layer used in the present invention is only required to have a function of transmitting electrons injected from the cathode to the light emitting layer, and as the material thereof, any one of conventionally known compounds is selected and used. be able to. The electron transport layer contains 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.

  Examples of materials used for this electron transport layer (hereinafter referred to as electron transport materials) include heterocyclic tetracarboxylic acid anhydrides such as nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, naphthalene perylene, carbodiimides, Examples include fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, and oxadiazole derivatives. Furthermore, in the 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.

  Or metal complexes of 8-quinolinol derivatives, such as tris (8-quinolinol) aluminum (Alq3), 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, Cu , Ca, Sn, Ga, or Pb can also be used as an electron transport material.

  In addition, metal-free or metal phthalocyanine, and those having the terminal substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transporting material. Alternatively, the distyrylpyrazine derivative exemplified as the material for the light-emitting layer can also be used as an electron transport material, and, like the hole injection layer and the hole transport layer, inorganic such as n-type-Si and n-type-SiC A semiconductor can also be used as an electron transport material.

  The electron transport layer can be formed by forming the above compound by a known thin film forming method such as a vacuum deposition method, a spin coating method, a casting method, or an LB method.

(Film thickness of electron transport layer)
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 nm-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

  Hereinafter, although the specific example of the compound preferably used for formation of the electron carrying layer of the organic EL element of this invention is given, this invention is not limited to these.

<Light emitting layer>
The light emitting layer used in the present invention will be described.

  The light emitting layer used in 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. Alternatively, it may be the interface between the light emitting layer and the adjacent layer.

  For the light-emitting layer used in the present invention, the composite of the present invention (the above-mentioned clathrate compound is clathrated with the above organometallic complex (phosphorescent light-emitting dopant) that emits phosphorescence) is used. Thus, an organic EL element with high luminous efficiency and a long lifetime can be produced.

  There are two types of light emission of phosphorescent compounds in principle. One is the recombination of carriers on the host compound to which carriers are transported to generate an excited state of the host compound, and this energy is phosphorescent. An energy transfer type in which light emission from the phosphorescent compound is obtained by transferring to the compound, and the other is that the phosphorescent compound becomes a carrier trap, and carrier recombination occurs on the phosphorescent compound, and the phosphorescent compound In any case, the excited state energy of the phosphorescent compound is lower than the excited state energy of the host compound.

  In the present invention, the phosphorescent maximum wavelength of the phosphorescent compound is not particularly limited. In principle, the phosphorescent compound can be obtained by selecting a central metal, a ligand, a ligand substituent, and the like. However, it is preferable that the phosphorescent compound has a maximum phosphorescence emission wavelength of 380 nm to 480 nm.

  Examples of such phosphorescent emission wavelengths include organic EL elements that emit blue light and organic EL elements that emit white light. These elements should be operated with lower emission voltage and lower power consumption. Can do.

  In addition, by using a plurality of phosphorescent compounds, it is possible to mix different light emission, thereby obtaining an arbitrary emission color. White light emission is possible by adjusting the kind of phosphorescent compound and the amount of doping, and can also be applied to illumination and backlight.

《Host compound》
The host compound used in the present invention is a compound having a phosphorescence quantum yield of phosphorescence emission of less than 0.01 at room temperature (25 ° C.) among compounds contained in the light emitting layer.

  In the light emitting layer used in the present invention, a plurality of known host compounds may be used in combination as a host compound. 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. As these known host compounds, compounds having a hole transporting ability and an electron transporting ability, preventing the emission of longer wavelengths, and having a high Tg (glass transition temperature) are preferable.

  Specific examples of known host compounds include compounds described in the following documents.

  JP-A-2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860, 2002-334787, 2002-15871, 2002-334788, 2002-43056, 2002-334789, 2002-75645, 2002-338579, 2002-105445 gazette, 2002-343568 gazette, 2002-141173 gazette, 2002-352957 gazette, 2002-203683 gazette, 2002-363227 gazette, 2002-231453 gazette, No. 003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-286061, No. 2002-280183, No. 2002-299060, No. 2002. -302516, 2002-305083, 2002-305084, 2002-308837, and the like.

  The light emitting layer may further contain a compound having a fluorescence maximum wavelength as a fluorescent dopant. In this case, energy transfer from the host compound and the phosphorescent compound to the fluorescent dopant allows electroluminescence as an organic EL element to be emitted from a compound having a fluorescent maximum wavelength (fluorescent dopant). A compound having a fluorescence maximum wavelength is preferably a compound having a high fluorescence quantum yield in a solution state. Here, the fluorescence quantum yield is preferably 10% or more, particularly preferably 30% or more. Specific compounds having a maximum fluorescence wavelength include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes, Examples include perylene dyes, stilbene dyes, and polythiophene dyes. The fluorescence quantum yield can be measured by the method described in 362 (1992 edition, Maruzen) of Spectroscopic II of the Fourth Edition Experimental Chemistry Course 7.

  The color emitted in this specification is the spectral radiance meter CS-1000 (Minolta) in FIG. 4.16 on page 108 of “New Color Science Handbook” (Edited by the Japan Society for Color Science, University of Tokyo Press, 1985). It is determined by the color when the measured result is applied to the CIE chromaticity coordinates.

  The light emitting layer can be formed by forming the above compound by a known thinning method such as a vacuum deposition method, a spin coating method, a casting method, an LB method, or an ink jet method. Although the film thickness as a light emitting layer does not have a restriction | limiting in particular, Usually, 5 nm-5 micrometers, Preferably it is chosen in the range of 5 nm-200 nm. The light emitting layer may have a single layer structure in which these phosphorescent compounds and host compounds are composed of one or more kinds, or may have a laminated structure composed of a plurality of layers having the same composition or different compositions. Good.

  Hereinafter, although the specific example of the compound preferably used as a host compound of the light emitting layer of the organic EL element of this invention is given, this invention is not limited to these.

<< Phosphorescent compound (phosphorescent dopant, phosphorescent dopant) >>
The phosphorescent compound used in the present invention is preferably selected from the following organometallic complexes that exhibit phosphorescence emission (also referred to as phosphorescent compounds).

  For example, an iridium complex described in JP-A No. 2001-247859, represented by a formula as described in International Publication No. 00 / 70,655 pamphlet, pages 16 to 18, for example, tris (2-phenylpyridine) Examples of the dopant include platinum complexes such as iridium and the like, osmium complexes, and 2,3,7,8,12,13,17,18-octaethyl-21H, 23H-porphyrin platinum complexes. By using such a phosphorescent compound as a dopant, a light-emitting organic EL device with high internal quantum efficiency can be realized.

  The phosphorescent compound used in the present invention is preferably a complex compound containing any one metal belonging to Group 8, 9 or 10 of the periodic table, more preferably an iridium compound. , An osmium compound, a platinum compound (platinum complex compound), or a rare earth complex.

  In the phosphorescent compound (phosphorescent compound) used in the present invention, light emission from the excited triplet is observed, and the phosphorescent quantum yield is preferably 0.001 or more at 25 ° C. More preferably, the phosphorescence quantum yield is 0.01 or more, and particularly preferably 0.1 or more.

  The phosphorescence 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. Although the phosphorescence quantum yield in a solution can be measured using various solvents, the phosphorescence quantum yield should just be achieved in any solvent.

  Hereinafter, although the specific example of the compound preferably used as a phosphorescent compound (it is also called a phosphorescence emitting compound, a light emission dopant, etc.) of the light emitting layer of the organic EL element of this invention is given, this invention is not limited to these.

  Each of the above organometallic complexes may be used alone or in combination of two or more compounds. These compounds are described in, for example, Inorg. Chem. Reference can be made to the method described in Vol. 40, 1704 to 1711.

  As the phosphorescent compound (phosphorescent compound) of the present invention, a blue light-emitting orthometal complex as described below is preferably used as a so-called blue light-emitting dopant in which light emission from an excited triplet is blue.

  In addition, as the phosphorescent compound according to the present invention, a dendrimer-type phosphorescent organic metal complex represented by the following general formula (E) can be used.

General formula (E)
P-[(Dendron) m] n
In the general formula (E), dendron represents a dendritic molecule represented by the following general formula (F), n represents an integer greater than 0, m represents an integer greater than 0 and less than n. To express. P represents a phosphorescent organometallic complex that serves as a core.

  In the general formula (F), Ar represents a trivalent group derived from an aromatic hydrocarbon ring or an aromatic heterocyclic ring. Represents an aromatic heterocycle, and X represents a single bond or a divalent linking group that binds to the phosphorescent organometallic complex P, which serves as the core. n represents the number of branches (also called the number of generations).

  In the general formula (F), examples of the aromatic hydrocarbon ring represented by Ar include a benzene ring, a biphenyl ring, a naphthalene ring, an azulene ring, an anthracene ring, a phenanthrene ring, a pyrene ring, a chrysene ring, a naphthacene ring, a triphenylene ring, o-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen ring, picene ring, pyrene ring, Examples include a pyranthrene ring and anthraanthrene ring. In addition, these rings may further have a substituent represented by R in the general formula (A).

  In the general formula (E), examples of the aromatic heterocycle represented by Ar include a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, and a benzimidazole. Ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indazole ring, indazole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, cinnoline ring, quinoline ring, isoquinoline Ring, phthalazine ring, naphthyridine ring, carbazole ring, carboline ring, diazacarbazole ring (showing a ring in which one of the carbon atoms of the hydrocarbon ring constituting the carboline ring is further substituted with a nitrogen atom).

  In addition, these rings may further have a substituent represented by R in the general formula (A).

  In the general formula (F), the divalent linking group represented by X has the same meaning as the divalent linking group represented by A in the general formula (A).

  Hereinafter, although the specific example of a dendrimer represented by general formula (E) is shown, this invention is not limited to these.

  The phosphorescent compounds used in the present invention are described in, for example, Organic Letter, vol. 16, p 2579-2581 (2001), Inorganic Chemistry, Vol. 30, No. 8, 1685-1687 (1991), J. MoI. Am. Chem. Soc. , 123, 4304 (2001), Inorganic Chemistry, Vol. 40, No. 7, pages 1704-1711 (2001), Inorganic Chemistry, Vol. 41, No. 12, pages 3055-3066 (2002) , New Journal of Chemistry. 26, page 1171 (2002), and further by applying a method such as a reference described in these documents.

  In addition, for example, J. et al. Am. Chem. Soc. 123, 4304-4312 (2001), International Publication No. 00/70655 pamphlet, No. 02/15645 pamphlet, JP-A No. 2001-247859, No. 2001-345183, No. 2002-117978, 2002-170684, 2002-203678, 2002-235076, 2002-302671, 2002-324679, 2002-332291, 2002-332292, Examples include iridium complexes represented by general formulas described in 2002-338588 and the like, iridium complexes exemplified as specific examples, iridium complexes represented by formula (IV) described in JP-A-2002-8860, and the like. It is done.

<< Fluorescent dopant (also called fluorescent compound) >>
In addition to the dopant made of a phosphorescent compound, the organic EL device of the present invention may further contain a fluorescent dopant. Typical examples of the fluorescent dopant include a coumarin dye and a pyran dye. Dye, cyanine dye, croconium dye, squalium dye, oxobenzanthracene dye, fluorescein dye, rhodamine dye, pyrylium dye, perylene dye, stilbene dye, polythiophene dye, or rare earth complex phosphor And other known fluorescent compounds.

  Hereinafter, although the preferable specific example of the fluorescent dopant used for this invention is given, this invention is not limited to these.

<Blocking layer: hole blocking layer, electron blocking layer>
The hole blocking layer is an electron transport layer in a broad sense, and is made of a material that has a function of transporting electrons and has a very small ability to transport holes. By blocking holes while transporting electrons, And the recombination probability of holes can be improved.

  The hole blocking layer has a role of blocking the holes moving from the hole transport layer from reaching the cathode and a compound that can efficiently transport the electrons injected from the cathode toward the light emitting layer. It is formed. The physical properties required of the material constituting the hole blocking layer are higher than the ionization potential of the light emitting layer in order to have high electron mobility and low hole mobility and to efficiently confine holes in the light emitting layer. It is preferable to have a value of ionization potential or a band gap larger than that of the light emitting layer. Use of at least one of styryl compounds, triazole derivatives, phenanthroline derivatives, oxadiazole derivatives, and boron derivatives as the hole blocking material is also effective in obtaining the effects of the present invention.

  Examples of other compounds include exemplified compounds described in JP-A Nos. 2003-31367, 2003-31368, and Japanese Patent No. 2721441.

  On the other hand, the electron blocking layer is a hole transport layer in a broad sense, made of a material that has a function of transporting holes and has a very small ability to transport electrons, and blocks electrons while transporting holes. Thus, the probability of recombination of electrons and holes can be improved.

  The hole blocking layer and the electron blocking layer can be formed by thinning the above material by a known method such as a vacuum deposition method, a spin coating method, a casting method, an ink jet method, or an LB method. .

"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 an electrode substance include conductive transparent materials such as metals such as Au, CuI, indium tin oxide (ITO), SnO ₂ , and ZnO. Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ —ZnO) capable of forming a transparent conductive film may be used. For the anode, a thin film may be formed by depositing these electrode materials 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 the pattern accuracy is not required (100 μm or more) Degree), a pattern may be formed through a mask having a desired shape when the electrode material is deposited or sputtered. When light emission is extracted from the anode, it is desirable that the transmittance is 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 nm to 1000 nm, preferably 10 nm to 200 nm.

"cathode"
On the other hand, as the cathode, a material having a low 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, a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function value than this, such as a magnesium / silver mixture, magnesium, from the viewpoint of electron injectability and durability against oxidation, etc. / 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 emission luminance is advantageously improved.

  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.

<< Method for forming electrodes by coating >>
A method for forming electrodes (cathode, anode, etc.) according to the present invention will be described.

  The electrode is usually formed by sputtering ITO (indium tin oxide) on a glass substrate or vacuum deposition of a metal such as aluminum or calcium, but coating (solution coating, dispersion coating, etc.) As an electrode forming method, a method using a PEDOT derivative as an electrode (Japanese Patent Publication No. 2005-501373 and US Pat. No. 5,035,926, etc.), a method of forming a circuit by applying a conductive paste (Japanese Patent Laid-Open No. 2002-324966) Etc.), and these methods can be used.

  Next, an injection layer, a blocking layer, an electron transport layer and the like used as the constituent layers of the organic EL element of the present invention will be described.

<< Buffer layer >>: Anode buffer layer, cathode buffer layer An injection layer is provided as necessary, and includes a cathode buffer layer (electron injection layer) and an anode buffer layer (hole injection layer). You may exist between a positive hole transport layer and between a cathode and a light emitting layer or an electron carrying layer.

  The buffer layer is a layer that is provided between the electrode and the organic layer in order to lower the driving voltage and improve the light emission luminance. “The organic EL element and the forefront of its industrialization (November 30, 1998, issued by NTT Corporation) 2), Chapter 2, “Electrode Materials” (pages 123 to 166) in detail, and includes an anode buffer layer and a cathode buffer layer.

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

  Among the above, for example, an oxide buffer layer containing vanadium oxide as a main component is defined as the inorganic compound layer.

  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. A metal buffer layer typified by lithium fluoride, an alkali metal compound buffer layer typified by lithium fluoride, an alkaline earth metal compound buffer layer typified by magnesium fluoride, an 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.

  Among the above, for example, a metal buffer layer typified by strontium and aluminum, an alkali metal compound buffer layer typified by lithium fluoride, an alkaline earth metal compound buffer layer typified by magnesium fluoride, and aluminum oxide A representative oxide buffer layer or the like is an inorganic compound layer according to the present invention.

<< Substrate (also referred to as substrate, substrate, support, etc.) >>
The organic EL device of the present invention is preferably formed on a substrate.

  The substrate of the organic EL device of the present invention is not particularly limited to the type of glass, plastic, etc., and is not particularly limited as long as it is transparent. Examples of substrates that are preferably used include glass, quartz, A light transmissive resin film can be mentioned. A particularly preferable substrate is a resin film that can give flexibility to the organic EL element.

  Examples of the resin film include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), and cellulose triacetate. Examples thereof include films having (TAC), cellulose acetate propionate (CAP) and the like. In addition, an inorganic or organic film or a hybrid film of both may be formed on the surface of the resin film.

  The external extraction efficiency at room temperature for light emission of the organic electroluminescence device of the present invention is preferably 1% or more, more preferably 5% or more. Here, the external extraction quantum efficiency (%) = the number of photons emitted to the outside of the organic EL element / the number of electrons sent to the organic EL element × 100.

  In addition, a hue improvement filter such as a color filter may be used in combination, or a color conversion filter that converts the emission color from the organic EL element into multiple colors using a phosphor. In the case of using a color conversion filter, the λmax of light emission of the organic EL element is preferably 480 nm or less.

<< Organic EL element materials that can be used in the constituent layers of organic EL elements >>
Furthermore, the compound applicable as a constituent material of the structural layer of the organic EL element of this invention is demonstrated concretely. In addition, the compound shown below can be used for any layer of the organic compound layer according to the present invention as long as it does not affect the performance of the organic EL device of the present invention.

(Vinyl monomer)
Examples of the vinyl monomer used in the present invention include compounds represented by the following general formula (1), but the present invention is not limited to these.

  In the general formula (1), R represents a hydrogen atom or a methyl group, and A represents a divalent linking group or a single bond. Z represents a residue of a fluorescent compound or a phosphorescent compound residue (also referred to as a phosphorescent compound residue, which may have an organometallic complex in the molecular structure).

  In the general formula (1), examples of the divalent linking group represented by A include hydrocarbon groups such as alkylene groups, alkenylene groups, alkynylene groups, and arylene groups, as well as the alkylene groups, the alkenylene groups, and the alkynylene groups. In the arylene group, each of them may contain a hetero atom (for example, a nitrogen atom, a sulfur atom, a silicon atom, etc.), or a thiophene-2,5-diyl group or pyrazine-2,3-diyl. It may be a divalent linking group derived from a compound having an aromatic heterocycle such as a group (also referred to as a heteroaromatic compound), or a chalcogen atom such as oxygen or sulfur. Moreover, the group connected through a hetero atom, such as an alkylimino group, a dialkylsilanediyl group or a diarylgermandiyl group, may be used.

  Furthermore, examples of the divalent linking group represented by A include, for example, a carbazole ring, a carboline ring, a diazacarbazole ring (also referred to as a monoazacarboline ring, and one of carbon atoms constituting the carboline ring is replaced by a nitrogen atom. From a group of aromatic heterocycles such as triazole ring, pyrrole ring, pyridine ring, pyrazine ring, quinoxaline ring, thiophene ring, oxadiazole ring, dibenzofuran ring, dibenzothiophene ring, indole ring, etc. A divalent group derived from a selected aromatic heterocycle can be used.

  Furthermore, in the said general formula (A), you may have a substituent represented by R.

  In the general formula (1), examples of the fluorescent compound used for the residue of the fluorescent compound include the compounds described in the above fluorescent dopant (also referred to as a fluorescent compound), rare earth complex phosphors, and other known fluorescence. Compound.

  In the general formula (1), as the phosphorescent compound used for the phosphorescent compound residue, an organometallic complex described in the above phosphorescent compound, a compound described in a conventionally known document, or the like can be used. .

  Although the specific example of the vinyl monomer used for this invention below is shown, this invention is not limited to these.

(Vinyl polymer)
As the vinyl polymer used in the present invention, a compound having a repeating unit represented by the following general formula (2) can be used. The compound may be a homopolymer or other copolymerizable monomer. A copolymer may be used.

  In the general formula (2), R represents a hydrogen atom or a methyl group, and A represents a divalent linking group or a single bond. Z represents a residue of a fluorescent biocompound or a phosphorescent compound residue (also referred to as a phosphorescent compound residue, which may have an organometallic complex in the molecular structure).

  In the general formula (2), the divalent linking group represented by A has the same meaning as the divalent linking group represented by A in the general formula (1).

  In the general formula (2), the fluorescent compound residue and phosphorescent compound residue represented by Z are the fluorescent compound residue and phosphorescent group represented by Z in the general formula (1), respectively. Each is synonymous with a compound residue.

  Examples of the copolymerizable monomer (also referred to as a monomer) include, for example, methacrylic acid and ester derivatives thereof (methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, i-butyl methacrylate, methacrylic acid). t-butyl, octyl methacrylate, cyclohexyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, tetrahydrofurfuryl methacrylate, benzyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, etc.), or Acrylic acid and its ester derivatives (methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, i-butyl acrylate, t-butyl acrylate, octyl acrylate, acrylic acid Chlohexyl, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, 2-ethoxyethyl acrylate, diethylene glycol ethoxylate acrylate, 3-methoxybutyl acrylate, benzyl acrylate, dimethylamino acrylate Ethyl, diethylaminoethyl acrylate, etc.), alkyl vinyl ethers (methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, etc.), alkyl vinyl esters (vinyl formate, vinyl acetate, vinyl butyrate, vinyl caproate, vinyl stearate, etc.), acrylonitrile, vinyl chloride And styrene.

  Although the specific example of the vinyl polymer used for this invention below is shown, this invention is not limited to these.

(Condensation polymer)
Examples of the condensation polymer used in the present invention include compounds represented by the following general formula (3), but the present invention is not limited thereto.

  In the general formula (3), [Ar] n represents an aromatic hydrocarbon ring or an aromatic heterocyclic ring having n substitutable sites. Z represents a fluorescent compound residue or a phosphorescent compound residue, and m of the n substitutable sites of Ar are linked via K. K represents a divalent linking group or a single bond. n represents a number from 1 to 3, and m represents a number from 1 to n. Here, when there are a plurality of Z and K, each may be independently the same or different. L is a divalent linking group selected from the linking group group 1 described below.

  In the general formula (3), examples of the aromatic hydrocarbon ring represented by Ar include a benzene ring, biphenyl ring, naphthalene ring, azulene ring, anthracene ring, phenanthrene ring, pyrene ring, chrysene ring, naphthacene ring, triphenylene ring, o-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen ring, picene ring, pyrene ring, Examples include a pyranthrene ring and anthraanthrene ring. In addition, these rings may further have a substituent represented by R in the general formula (A).

  In the general formula (3), examples of the aromatic heterocycle represented by Ar include a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, and a benzimidazole. Ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indazole ring, indazole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, cinnoline ring, quinoline ring, isoquinoline Ring, phthalazine ring, naphthyridine ring, carbazole ring, carboline ring, diazacarbazole ring (showing a ring in which one of the carbon atoms of the hydrocarbon ring constituting the carboline ring is further substituted with a nitrogen atom).

  In addition, these rings may further have a substituent represented by R in the general formula (A).

  In the general formula (3), the divalent linking group represented by K has the same meaning as the divalent linking group represented by A in the general formula (1).

  In the general formula (3), the fluorescent compound residue and phosphorescent compound residue represented by Z are the fluorescent compound residue and phosphorescent group represented by Z in the general formula (1), respectively. Each is synonymous with a compound residue.

  In the general formula (3), the divalent linking group represented by L is selected from the following linking group group 1.

  In the linking group group 1, R1 to R4 each represents an alkyl group, an aromatic hydrocarbon group, or an aromatic heterocyclic group.

In the linking group group 1, examples of the alkyl group represented by R _{1 to} R ₄ include a methyl group, an ethyl group, a propyl group, an isopropyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, A dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, etc. are mentioned. These may further have a substituent represented by R in the general formula (A).

In the linking group group 1, examples of the aromatic hydrocarbon group represented by R _{1 to} R ₄ include a phenyl group, a p-chlorophenyl group, a mesityl group, a tolyl group, a xylyl group, a naphthyl group, an anthryl group, and an azulenyl group. Group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group and the like.

  These groups may further have a substituent represented by R in the general formula (A).

In the linking group group 1, examples of the aromatic heterocyclic group represented by R _{1 to} R ₄ include a pyridyl group, a pyrimidinyl group, a furyl group, a pyrrolyl group, an imidazolyl group, a benzoimidazolyl group, a pyrazolyl group, a pyrazinyl group, Triazolyl group (for example, 1,2,4-triazol-1-yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group , Flazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (carbon constituting the carboline ring of the carbonyl group) One of the atoms replaced by a nitrogen atom), quinoxalini Group, pyridazinyl group, triazinyl group, quinazolinyl group, and phthalazinyl group.

  These groups may further have a substituent represented by R in the general formula (A).

  Hereinafter, although the specific example of the condensation polymer represented by General formula (3) is shown, this invention is not limited to these.

<< Method for producing organic EL element >>
As an example of the method for producing the organic EL device of the present invention, a method for producing an organic EL device comprising an anode / anode buffer layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode. explain.

  First, a method of vapor deposition, sputtering, solution coating, dispersion coating or the like on a suitable substrate so that a thin film made of a desired electrode material, for example, a material for an anode, is 1 μm or less, preferably 10 nm to 200 nm. To form an anode. Next, organic compound layers (layers such as an anode buffer layer, a hole transport layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and a cathode buffer layer, each containing a material constituting the organic EL element are formed thereon. The layers are preferably formed by a coating method (also referred to as a wet process, which will be described in detail below) using the dispersion of the present invention.

  The organic EL device material contained in the dispersion is a compound suitable for the functional expression of each organic compound layer (for example, a hole transporting material for a hole transporting layer and a host compound for a light emitting layer). And a light-emitting dopant and an electron transporting layer are selected.

  Examples of coating methods (wet processes) that are preferably used for forming these organic compound layers (also referred to as organic compound thin films) include spin coating methods, casting methods, ink jet methods, and printing methods). The spin coating method, the ink jet method, and the printing method are particularly preferably used because they are easily formed and pinholes are hardly generated.

Further, a different film forming method may be applied for each layer. When employing a vacuum vapor deposition method, a sputtering method, or the like for film formation, the vapor deposition conditions vary depending on the type of compound used, but generally a boat heating temperature of 50 ° C. to 450 ° C., and a degree of vacuum of 10 ⁻⁶ Pa to 10 ^−2. It is desirable to appropriately select Pa, vapor deposition rate of 0.01 nm / second to 50 nm / second, substrate temperature of −50 ° C. to 300 ° C., film thickness of 0.1 nm to 5 μm, preferably 5 nm to 200 nm.

  After forming these layers, 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 film thickness of 1 μm or less, preferably in the range of 50 to 200 nm. By providing, a desired organic EL element can be obtained.

<< Display device, lighting device >>
The display device (monochromatic or multicolored) and lighting device of the present invention will be described.

  The multicolor display device of the present invention is provided with a shadow mask only when the light emitting layer is formed, and the other layers are common, so that patterning of the shadow mask or the like is unnecessary, and the evaporation method, the casting method, the spin coating method, the ink jet method on one side. A film can be formed by a method, a spray method, a printing method, or the like.

  When patterning is performed only on the light emitting layer, the method is not limited. However, a vapor deposition method, an inkjet method, and a printing method are preferable. In the case of using a vapor deposition method, patterning using a shadow mask is preferable.

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

  The display device of the present invention can be used as a display device, a display, and various light emission sources. In a display device or a display, full-color display is possible by using three types of organic EL elements of blue, red, and green light emission.

  Examples of the display device and display include a television, a personal computer, a mobile device, an AV device, a character broadcast display, and an information display in an automobile. In particular, it may be used as a display device for reproducing still images and moving images, and the driving method when used as a display device for reproducing moving images may be either a simple matrix (passive matrix) method or an active matrix method.

  The lighting device of the present invention includes home lighting, interior lighting, clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources of optical storage media, light sources of electrophotographic copying machines, light sources of optical communication processors, light sensors Although a light source etc. are mentioned, it is not limited to this.

  Further, the organic EL element according to the present invention may be used as an organic EL element having a resonator structure.

  Examples of the purpose of use of the organic EL element having such a resonator structure include a light source of an optical storage medium, a light source of an electrophotographic copying machine, a light source of an optical communication processing machine, and a light source of an optical sensor. It is not limited. Moreover, you may use for the said use by making a laser oscillation.

  The organic EL element of the present invention may be used as one kind of lamp for illumination or exposure light source, a projection device for projecting an image, or a display for directly viewing a still image or a moving image. It may be used as a device (display). When used as a display device for reproducing moving images, the driving method may be either a simple matrix (passive matrix) method or an active matrix method. Alternatively, a full-color display device can be manufactured by using three or more organic EL elements of the present invention having different emission colors. Alternatively, it is possible to make a single color emission color, for example, white emission, into BGR using a color filter to achieve full color. Further, it is possible to convert the emission color of the organic EL to another color by using a color conversion filter, and in this case, λmax of the organic EL emission is preferably 480 nm or less.

  An example of a display device having the organic EL element of the present invention as a configuration will be described with reference to the drawings.

  FIG. 1 is a schematic diagram illustrating an example of a display device including organic EL elements. It is a schematic diagram of a display such as a mobile phone that displays image information by light emission of an organic EL element.

  The display 1 includes a display unit A having a plurality of pixels, a control unit B that performs image scanning of the display unit A based on image information, and the like.

  The control unit B is electrically connected to the display unit A, and sends a scanning signal and an image data signal to each of the plurality of pixels based on image information from the outside. The pixels for each scanning line are converted into image data signals by the scanning signal. In response to this, light is sequentially emitted and image scanning is performed to display image information on the display unit A.

  FIG. 2 is a schematic diagram of the display unit A.

  The display unit A includes a wiring unit including a plurality of scanning lines 5 and data lines 6, a plurality of pixels 3 and the like on a substrate. The main members of the display unit A will be described below. FIG. 2 shows a case where the light emitted from the pixel 3 is extracted in the direction of the white arrow (downward).

  The scanning lines 5 and the plurality of data lines 6 in the wiring portion are each made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a grid pattern and are connected to the pixels 3 at orthogonal positions (details are shown in FIG. Not shown).

  When a scanning signal is applied from the scanning line 5, the pixel 3 receives an image data signal from the data line 6 and emits light according to the received image data. Full color display is possible by appropriately arranging pixels in the red region, the green region, and the blue region that emit light on the same substrate.

  Next, the light emission process of the pixel will be described.

  FIG. 3 shows a schematic diagram of a pixel.

  The pixel includes an organic EL element 10, a switching transistor 11, a driving transistor 12, a capacitor 13, and the like. A full color display can be performed by using red, green, and blue light emitting organic EL elements as the organic EL elements 10 in a plurality of pixels, and juxtaposing them on the same substrate.

  In FIG. 3, an image data signal is applied from the control unit B to the drain of the switching transistor 11 through the data line 6. When a scanning signal is applied from the control unit B to the gate of the switching transistor 11 via the scanning line 5, the driving of the switching transistor 11 is turned on, and the image data signal applied to the drain is supplied to the capacitor 13 and the driving transistor 12. Is transmitted to the gate.

  By transmitting the image data signal, the capacitor 13 is charged according to the potential of the image data signal, and the drive of the drive transistor 12 is turned on. The drive transistor 12 has a drain connected to the power supply line 7 and a source connected to the electrode of the organic EL element 10, and the power supply line 7 connects to the organic EL element 10 according to the potential of the image data signal applied to the gate. Current is supplied.

  When the scanning signal is moved to the next scanning line 5 by the sequential scanning of the control unit B, the driving of the switching transistor 11 is turned off. However, even if the driving of the switching transistor 11 is turned off, the capacitor 13 maintains the potential of the charged image data signal, so that the driving of the driving transistor 12 is kept on and the next scanning signal is applied. Until then, the light emission of the organic EL element 10 continues. When the scanning signal is next applied by sequential scanning, the driving transistor 12 is driven according to the potential of the next image data signal synchronized with the scanning signal, and the organic EL element 10 emits light.

  That is, the organic EL element 10 emits light by the switching transistor 11 and the drive transistor 12 that are active elements for the organic EL element 10 of each of the plurality of pixels, and the light emission of the organic EL element 10 of each of the plurality of pixels 3. It is carried out. Such a light emitting method is called an active matrix method.

  Here, the light emission of the organic EL element 10 may be light emission of a plurality of gradations by a multi-value image data signal having a plurality of gradation potentials, or on / off of a predetermined light emission amount by a binary image data signal. But you can.

  The potential of the capacitor 13 may be held continuously until the next scanning signal is applied, or may be discharged immediately before the next scanning signal is applied.

  In the present invention, not only the active matrix method described above, but also a passive matrix light emission drive in which the organic EL element emits light according to the data signal only when the scanning signal is scanned.

  FIG. 4 is a schematic view of a passive matrix display device. In FIG. 4, a plurality of scanning lines 5 and a plurality of image data lines 6 are provided in a lattice shape so as to face each other with the pixel 3 interposed therebetween.

  When the scanning signal of the scanning line 5 is applied by sequential scanning, the pixels 3 connected to the applied scanning line 5 emit light according to the image data signal. In the passive matrix system, the pixel 3 has no active element, and the manufacturing cost can be reduced.

  The organic EL element material of 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. As a combination of a plurality of luminescent colors, those containing three luminescence maximum wavelengths of three primary colors of blue, green, and blue may be used. 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 electroluminescence device according to the present invention, a method of combining a plurality of light-emitting dopants is preferable.

  As a layer structure of an organic electroluminescence device 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 in each emission layer And a method of forming minute pixels emitting light having different wavelengths in a matrix.

  In the white organic electroluminescence device according to the present invention, patterning may be performed by a metal mask, an ink jet printing method, or the like at the time of film formation, if necessary. 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, the platinum complex according to the present invention is known so as to be suitable for the wavelength range corresponding to the CF (color filter) characteristics. Any one of the light emitting materials may be selected and combined to be whitened.

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

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

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these. The structural formulas of the compounds used in the examples are shown below.

Example 1
As described below, dispersions 1 to 3 for organic EL elements of the present invention (also referred to as dispersions 1 to 3), non-aqueous dispersion 4 for organic EL elements of the present invention (also referred to as dispersion 4), Comparative dispersions 5 were each prepared.

<< Preparation of coating dispersion 1 for organic EL elements >>
0.2 g of CBP and 0.012 g of PD-1 were dissolved in 4 ml of tetrahydrofuran (THF) to prepare a THF solution. Next, 16 ml of water in which 0.05 g of polyvinyl alcohol (number average molecular weight 10,000; 80% hydrolyzed) as a dispersion stabilizer is dissolved is vigorously stirred, and the above THF solution is added thereto. Was added using a microsyringe and further dispersed at 40 ° C. and 10,000 rpm for 10 minutes to obtain a dispersion 1.

  The average particle size of the dispersion in the obtained dispersion was 80 nm.

<< Preparation of coating dispersion 2 for organic EL element >>
In the preparation of the coating dispersion liquid 1 for organic EL elements, the coating dispersion liquid 2 for organic EL elements was prepared in exactly the same manner except that the dispersion stabilizer was changed to sodium dodecylbenzenesulfonate.

  The average particle size of the dispersion in the obtained dispersion was 80 nm.

<< Preparation of coating dispersion 3 for organic EL element >>
In the preparation of the coating dispersion liquid 1 for organic EL elements, the coating dispersion liquid 3 for organic EL elements was prepared in exactly the same manner except that the dispersion stabilizer was changed to stearyltrimethylammonium hexafluorophosphoric acid.

  The average particle size of the dispersion in the obtained dispersion was 100 nm.

<< Preparation of non-aqueous dispersion 4 for organic EL element >>
0.2 g of CBP and 0.012 g of PD-1 were dissolved in 4 ml of tetrahydrofuran (THF). Next, 20 ml of xylene in which 0.05 g of VP-21 (number average molecular weight 2,000) and 0.05 g of polyethylene glycol (number average molecular weight 2,000) were dissolved was vigorously stirred, and the above THF solution was added thereto. Was added using a microsyringe, and dispersion was performed for 5 minutes using an ultrasonic dispersing machine (UH-150 type, manufactured by SMT Co., Ltd.) to prepare a non-aqueous dispersion 4 for an organic EL device.

  The average particle size of the dispersion in the obtained dispersion was 60 nm.

Example 2
<< Preparation of Organic EL Element 1-1 >>: Preparation by Dispersion Application Substrate (100 nm × 100 mm × 1.1 mm glass substrate made of ITO (indium tin oxide) as a film having a thickness of 100 nm as an anode (NA Techno-Glass NA-) 45) After patterning, the transparent support substrate provided with the ITO transparent electrode was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

  On this transparent support substrate, a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Baytron, Baytron PAl 4083) to 70% by mass with pure water at 3000 rpm for 30 seconds. Then, the film was formed by spin coating and then dried at 200 ° C. for 1 hour to provide a 30 nm-thick hole transport layer.

  On this hole transport layer, the dispersion 1 was formed into a film by spin coating under the condition of 2000 rpm for 30 seconds, and vacuum-dried at 80 ° C. for 1 hour to serve as a layer smoothing treatment to emit light having a film thickness of 50 nm. Layered.

This is attached to a vacuum deposition apparatus, and then the vacuum chamber is depressurized to 4 × 10 ⁻⁴ Pa, 10 nm of calcium is deposited as a cathode buffer layer and 110 nm of aluminum is deposited as a cathode to form a cathode, and the organic EL element 1-1 is formed. Produced.

<< Production of Organic EL Elements 1-2 to 1-4 >>
In the production of the organic EL element 1-1, organic EL elements 1-2 to 1-4 were produced in the same manner except that the dispersion 1 was changed to the dispersions 2 to 4, respectively.

<< Preparation of Organic EL Element 2-1 >>: Preparation by Solution Application Substrate (100 nm × 100 mm × 1.1 mm glass substrate made of ITO (indium tin oxide) as a film having a thickness of 100 nm as an anode (NA-45 manufactured by NH Techno Glass) Then, the transparent support substrate provided with the ITO transparent electrode was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

  On this transparent support substrate, a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Baytron, Baytron PAl 4083) to 70% by mass with pure water at 3000 rpm for 30 seconds. Then, the film was formed by spin coating and then dried at 200 ° C. for 1 hour to provide a first hole transport layer having a thickness of 30 nm.

  On this first hole transport layer, a solution of 20 mg of VM-3 dissolved in 3 ml of dichlorobenzene was formed into a film by spin coating under the condition of 2000 rpm and 30 seconds, and vacuum-dried at 60 degrees for 1 hour, A 40-nm-thick second hole transport layer was provided.

  On this 2nd hole transport layer, the non-aqueous dispersion liquid 4 for organic EL elements was formed into a film by spin coat method on condition of 2000 rpm and 30 second, and it vacuumed at 80 degreeC for 1 hour also as the smoothing process of a layer It dried and it was set as the light emitting layer with a film thickness of 50 nm.

  Furthermore, the dispersion 5 prepared as described below was formed into a film by spin coating under the condition of 2000 rpm and 30 seconds, and vacuum-dried at 80 ° C. for 1 hour to serve as a layer smoothing treatment. The electron transport layer was made.

  This is attached to a vacuum deposition apparatus, and then the vacuum chamber is decompressed to 4 × 10 −4 Pa, and 10 nm of calcium is deposited as a cathode buffer layer and 110 nm of aluminum is deposited as a cathode to form a cathode, thereby producing an organic EL element 2-1. did.

(Preparation of dispersion 5 (BCP dispersion))
In the preparation of the non-aqueous dispersion 4 for the organic EL device of Example 1, the dispersion was adjusted in exactly the same manner except that CBP and PD-1 were changed to bathocuproine (BCP).

  The average particle diameter of the dispersion in the obtained dispersion liquid was 50 nm in average particle diameter, and the dispersion stability was similar to that of the non-aqueous dispersion liquid 4 for organic EL elements.

<< Evaluation of Organic EL Elements 1-1 to 1-4 and 2-1 >>
When evaluating the obtained organic EL elements 1-1 to 1-4 and 2-1, the non-light-emitting surface of each organic EL element after production was covered with a glass case, and a glass substrate having a thickness of 300 μm was sealed. As a sealing material, an epoxy-based photo-curing adhesive (Lux Track LC0629B manufactured by Toagosei Co., Ltd.) is applied as a sealing material, and this is overlaid on the cathode and brought into close contact with the transparent support substrate. It was irradiated with UV light, cured and sealed, and an illumination device as shown in FIGS. 5 and 6 was formed and evaluated.

  FIG. 5 shows a schematic diagram of a lighting device, in which the organic EL element 101 is covered with a glass cover 102 (note that the sealing operation with the glass cover is performed without bringing the organic EL element 101 into contact with the atmosphere. A glove box in an atmosphere (performed in an atmosphere of high-purity nitrogen gas having a purity of 99.999% or more) Fig. 6 shows a cross-sectional view of the lighting device, in which Fig. 6 is a cathode, and 106 is an organic EL layer. 107 are transparent electrodes (on the glass substrate), and the glass cover 102 is filled with nitrogen gas 108 and provided with a water catching agent 109.

《External extraction quantum efficiency》
About the produced organic EL element, external extraction quantum efficiency (%) when ^2.5 mA / cm ² constant current was applied in a dry nitrogen gas atmosphere at 23 ° C. was measured. For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Co., Ltd.) was used.

<Luminescent life>
When driving at a constant current of ^2.5 mA / cm ^{2 in} a dry nitrogen gas atmosphere at 23 ° C., the time required for the luminance to drop to half of the luminance immediately after the start of light emission (initial luminance) was measured. Was used as an index of life as a half-life time (τ _0.5 ). Similarly, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Co., Ltd.) was used for the measurement.

  The measurement results of the external extraction quantum efficiencies and light emission lifetimes of the organic EL elements 1-1 to 1-4 and 2-1 were relative evaluated when the organic EL element 1-2 was set to 100.

  The obtained results are shown in Table 1 below.

  From Table 1, it is clear that the organic EL device of the present invention is improved in both efficiency and lifetime as compared with the comparison. This is thought to be because counterion diffusion does not occur with nonionic dispersion stabilizers compared to ionic dispersion stabilizers (such as cationic and anionic). Further, as is clear from the organic EL element (1-4), a more remarkable improvement in the lifetime was recognized by using a non-aqueous dispersion system.

  On the other hand, it is generally said that an organic EL element using a coating method at the time of film formation is inferior in terms of light emission efficiency and light emission life to that using only a vapor deposition method. Then, by laminating by applying the dispersion, the effect of the present invention can be further utilized, and the light emission efficiency and the light emission lifetime almost equal to those of the device prepared by the corresponding vapor deposition method were exhibited.

Example 3
<Production of full-color display device>
(Blue light emitting organic EL device)
Using the dispersion 4B (for blue) prepared in the same manner as in the non-aqueous coating dispersion 4 for organic EL elements prepared in Example 1, except that PD-1 was changed to PD-9, Example Blue light emitting organic EL element 2-1B (blue) was produced in the same manner as in the production of 2 organic EL element 2-1.

(Green light-emitting organic EL device)
The organic EL element 2-1 produced in Example 2 was used as the green light-emitting organic EL element.

(Red light emitting organic EL device)
In the non-aqueous dispersion 4 for an organic EL device prepared in Example 1, the dispersion 4R (for red) prepared in the same manner as in Example 2 except that PD-1 was changed to PD-6. A red light-emitting organic EL element 2-1R (red) was produced in the same manner as in the production of the organic EL element 2-1.

  The red, green and blue light-emitting organic EL elements are juxtaposed on the same substrate to produce an active matrix type full-color display device having the form shown in FIG. 1, and FIG. 2 shows the display of the produced display device. Only the schematic diagram of part A is shown. That is, a wiring portion including a plurality of scanning lines 5 and data lines 6 on the same substrate, and a plurality of juxtaposed pixels 3 (light emission color is a red region pixel, a green region pixel, a blue region pixel, etc.) The scanning lines 5 and the plurality of data lines 6 in the wiring portion are each made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a lattice shape and are connected to the pixels 3 at the orthogonal positions ( Details are not shown). The plurality of pixels 3 are driven by an active matrix system provided with an organic EL element corresponding to each emission color, a switching transistor as an active element, and a driving transistor, and a scanning signal is applied from a scanning line 5. Then, an image data signal is received from the data line 6 and light is emitted according to the received image data. In this way, a full color display device was produced by appropriately juxtaposing the red, green, and blue pixels.

  It was confirmed that by driving the full-color display device, a full-color moving image display having a high light emission efficiency and a long light emission life can be obtained.

Example 4
<Production of white lighting device>
In the same manner as in the non-aqueous coating dispersion 4 for organic EL elements prepared in Example 1, except that PD-1 was changed to PD-1, PD-6, and PD-9, the prepared dispersion 4W (white) The white light emitting organic EL element 2-1W (white) was produced in the same manner as in the production of the organic EL element 2-1 of Example 2.

  When evaluating the obtained organic EL element 2-1W, the non-light emitting surface was covered with a glass case in the same manner as in Example 1 to obtain a lighting device. The illuminating device could be used as a thin illuminating device that emits white light with high luminous efficiency and long emission life.

DESCRIPTION OF SYMBOLS 1 Display 3 Pixel 5 Scan line 6 Data line 7 Power supply line 10 Organic EL element 11 Switching transistor 12 Drive transistor 13 Capacitor A Display part B Control part 107 Glass substrate 106 with a transparent electrode Organic EL layer 105 Cathode 102 Glass cover 108 Nitrogen gas 109 Water catcher

Claims (7)

In an organic electroluminescence device having at least an anode and a cathode on a support substrate, and an organic compound layer including a light emitting layer between the anode and the cathode,
The light-emitting layer contains a light-emitting dopant composed of at least one organic iridium complex dispersed with at least one nonionic dispersion stabilizer excluding an organometallic complex. In an organic electroluminescence device having at least an anode and a cathode on a support substrate, and an organic compound layer including a light emitting layer between the anode and the cathode,
The light emitting layer contains a light emitting dopant composed of at least two kinds of organic iridium complexes dispersed with at least one kind of nonionic dispersion stabilizer excluding an organometallic complex. In an organic electroluminescence device having at least an anode and a cathode on a support substrate, and an organic compound layer including a light emitting layer between the anode and the cathode,
The light-emitting layer contains a light-emitting dopant composed of at least three types of organic iridium complexes dispersed with at least one type of nonionic dispersion stabilizer excluding an organometallic complex. The at least one nonionic dispersion stabilizer excluding the organometallic complex is polyethylene glycol, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxypropylcellulose, or hydroxypropylmethylcellulose. 2. The organic electroluminescence device according to item 1. The organic electroluminescence element according to any one of claims 1 to 4, wherein the organic electroluminescence element emits white light. A display device comprising the organic electroluminescence element according to claim 1. An illuminating device comprising the organic electroluminescence element according to claim 1.

Images