JP2012190988A - Organic electronics material, ink composition, organic electronics element, organic electroluminescent element, display element, lighting device, and display unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electronics material capable of achieving layer formation by application method and low-temperature curing of the formed layer, and to provide an organic electronics element using the same.SOLUTION: The present invention provides: an organic electronics material containing a) charge transporting compound with at least one cation polymerizable substituent group, b) cationic polymerization initiator, and c) radical polymerization initiator; and an organic electronics element having a layer formed by applying and depositing the organic electronics material on a substrate. It is preferable to include at least one of aromatic amine, carbazole, and thiophene compound as the charge transporting compound.

Description

  The present invention relates to an organic electronics material, an ink composition, an organic electronics element using the organic electronics material, an organic electroluminescence element (hereinafter also referred to as an organic EL element), a display element, an illumination device, and a display device. .

  Organic electronics elements are elements that perform electrical operations using organic substances, and are expected to exhibit features such as energy saving, low cost, and flexibility, and are attracting attention as a technology that can replace conventional inorganic semiconductors based on silicon. ing.

  Among organic electronics elements, organic EL elements are attracting attention as applications for large-area solid-state light sources as an alternative to incandescent lamps and gas-filled lamps, for example. It is also attracting attention as the most powerful self-luminous display that can replace the liquid crystal display (LCD) in the flat panel display (FPD) field, and its commercialization is progressing.

  Organic EL elements are roughly classified into two types, low molecular organic EL elements and polymer organic EL elements, depending on the materials and film forming methods used. High-molecular organic EL elements are composed of high-molecular materials, and can be used for simple film formation such as printing and ink-jet compared to low-molecular organic EL elements that require vacuum-based film formation. Therefore, it is an indispensable element for future large-screen organic EL displays.

  Although research has been conducted energetically for both low-molecular organic EL elements and high-molecular organic EL elements, low luminous efficiency and short element lifetime are still serious problems. As one means for solving this problem, multilayering is performed in the low molecular organic EL element.

  Since the low molecular organic EL element is formed by vapor deposition, multilayering can be easily achieved by performing vapor deposition while sequentially changing the compounds to be used. On the other hand, since a polymer type organic EL element is formed using a wet process such as printing or ink jetting, in order to make a multilayer, a layer already formed is not changed when a new layer is formed. A method is needed. The reason why it is difficult to form a multilayer in the polymer organic EL element is that the lower layer formed earlier is dissolved when the upper layer is formed.

In order to deal with this problem, studies using compounds with greatly different solubilities have been made. As a typical example, a hole injection layer made of polythiophene: polystyrene sulfonic acid (PEDOT: PSS), which is formed using an aqueous dispersion, and light emission, which is formed using an aromatic organic solvent such as toluene. An element having a two-layer structure of layers is exemplified. In this case, since the PEDOT: PSS layer is not dissolved in toluene, a two-layer structure can be produced.
However, it is difficult to remove water, which causes deterioration of the characteristics of the organic electronics element. In addition, water removal requires high temperature and long time drying, making it difficult to produce an organic electronic device on a resin base material, and severe restrictions on the process such as reduced pressure conditions.
Further, as an example using an organic solvent, a method of selecting a solvent that does not affect the previously formed lower layer is disclosed (see Patent Document 1).

However, in such a method, since the solvent that can be used is limited to a solvent that does not dissolve the lower layer, there is a problem that the selection range of the material is reduced. In addition, some erosion of the lower layer occurs during the formation of the upper layer.
As another method for forming a multilayer structure, a method using a crosslinking reaction is disclosed. Patent Document 2 discloses a method of cross-linking and insolubilizing triphenylamine-containing ether polyetherketone by ultraviolet irradiation. In order to sufficiently insolubilize by this method, it is necessary to irradiate with ultraviolet rays for a long time, and there is a problem that triphenylamine and the like are decomposed.

  Patent Document 3, Patent Document 4, Non-Patent Document 1, and Non-Patent Document 2 disclose multilayering by cross-linking of oxetane groups. Since these methods use a photoinitiator, there is a concern about deterioration due to light. Insufficient insolubilization at low temperatures does not proceed, and there are problems such as restrictions on the application of resin substrates that require low temperature curing, and problems such as deterioration of organic EL characteristics due to mixing of the upper and lower layers when forming the upper layer is there.

JP 2003-07763 A Japanese Patent No. 3634433 Japanese Patent Laid-Open No. 2004-199935 Special table 2007-514298

Macromol. Rapid Commun. 20, 224-228 (1999) Nature, 421 (2003) 829-833.

In view of the above-described conventional problems, the present invention provides a material for organic electronics capable of forming a layer by a coating method and capable of curing the formed layer at a low temperature, an ink composition containing the organic electronics material, and the organic electronics. An object of the present invention is to provide an organic electronic device using the material.
It is another object of the present invention to provide an organic electroluminescence element, a display element, a lighting device, and a display device that are excellent in luminous efficiency and lifetime characteristics.

As a result of intensive studies, the present inventors have found that organic electronics containing a) a charge transporting compound having one or more cationically polymerizable substituents, b) a cationic polymerization initiator, and c) a radical polymerization initiator. The present inventors have found that the above-mentioned problems can be solved by using a material for organic electronics containing the present invention.
That is, the present invention is as follows.

(1) a) a charge transporting compound having one or more cationically polymerizable substituents;
b) a cationic polymerization initiator;
c) a radical polymerization initiator;
A material for organic electronics, comprising:

(2) The material for organic electronics according to (1), wherein the charge transporting compound contains at least one of an aromatic amine, a carbazole, and a thiophene compound.

(3) The organic electronic material as described in (1) or (2) above, wherein the charge transporting compound is a polymer or an oligomer.

(4) An ink composition comprising the organic electronic material according to any one of (1) to (3) and a solvent.

(5) An organic electronics element comprising a layer formed by applying the organic electronics material according to any one of (1) to (3) above onto a substrate.

(6) The organic electronics element as described in (5) above, wherein the deposited layer is polymerized.

(7) The organic electronic device according to (6), wherein another layer is formed on the polymerized layer to form a multilayer.

(8) The organic electronic device according to any one of (5) to (7), wherein the substrate is a resin film.

(9) An organic electroluminescence device comprising a layer formed of the organic electronics material according to any one of (1) to (3).

(10) An organic electroluminescence device comprising at least a substrate, an anode, a hole injection layer, a polymerization layer, a light emitting layer and a cathode, wherein the polymerization layer is any one of (1) to (3) An organic electroluminescent element, which is a layer formed of the material for organic electronics described in 1.

(11) An organic electroluminescence device comprising at least a substrate, an anode, a polymerization layer, a hole transport layer, a light emitting layer, and a cathode, wherein the polymerization layer is any one of (1) to (3). An organic electroluminescent element, which is a layer formed of the material for organic electronics described in 1.

(12) The organic electroluminescent element according to any one of (9) to (11), wherein the light emission color of the organic electroluminescent element is white.

(13) The organic electroluminescent element according to any one of (9) to (12), wherein the substrate is a flexible substrate.

(14) The organic electroluminescent element according to any one of (9) to (12), wherein the substrate is a resin film.

(15) A display device comprising the organic electroluminescence device according to any one of (9) to (14).

(16) A lighting device comprising the organic electroluminescent element according to any one of (9) to (14).

(17) A display device comprising the illumination device according to (16) and a liquid crystal element as a display unit.

  According to the present invention, a layer can be formed by a coating method, and the organic electronics material and ink composition capable of curing the formed layer at a low temperature, and an organic electronics element and an organic electro A luminescence element, a display element, a lighting device, and a display device can be provided.

<Materials for organic electronics>
The material for organic electronics of the present invention contains a) a charge transporting compound having one or more cationically polymerizable substituents, b) a cationic polymerization initiator, and c) a radical polymerization initiator. It is said.
Below, each component of the material for organic electronics of this invention is explained in full detail.

[A) Charge transporting compound]
In the present invention, the “charge transporting compound” refers to a compound having a charge transporting unit. In the present invention, the “charge transporting unit” is an atomic group having the ability to transport holes or electrons, and will be described in detail below.

  The a) charge transporting compound according to the present invention is not particularly limited as long as it has one or more cationically polymerizable substituents and the ability to transport holes or electrons. It preferably contains at least one of carbazole and thiophene compounds. For example, it preferably has a partial structure represented by the following general formulas (1) to (58).

(-R ¹ wherein each E is ^{independently, -OR 2, -SR 3, -OCOR} 4, -COOR 5, -SiR 6 R 7 R 8, the general formula (59) - (61) (where R ^{1 to} R ¹¹ represent a hydrogen atom, a linear, cyclic or branched alkyl group having 1 to 22 carbon atoms, or an aryl group or heteroaryl group having 2 to 30 carbon atoms, and a, b and c are Represents an integer greater than or equal to 1. Here, the aryl group is an atomic group obtained by removing one hydrogen atom from an aromatic hydrocarbon, and may have a substituent, and the heteroaryl group refers to a heteroatom. It is an atomic group obtained by removing one hydrogen atom from an aromatic compound and may have a substituent.) Or a cationically polymerizable substituent. Ar each independently has 2 carbon atoms. ~ 30 arylene groups or heteroaryl An arylene group is an atomic group obtained by removing two hydrogen atoms from an aromatic hydrocarbon and may have a substituent, for example, phenylene, biphenyl-diyl, terphenyl-diyl, naphthalene- Examples include diyl, anthracene-diyl, tetracene-diyl, fluorene-diyl, phenanthrene-diyl, etc. A heteroaryl group is an atomic group obtained by removing two hydrogen atoms from an aromatic compound having a heteroatom and having a substituent. For example, pyridine-diyl, pyrazine-diyl, quinoline-diyl, isoquinoline-diyl, acridine-diyl, phenanthroline-diyl, furan-diyl, pyrrole-diyl, thiophene-diyl, oxazole-diyl, oxa Diazole-diyl, thiadiazole-diyl, triazol Ru-diyl, benzoxazole-diyl, benzooxadiazole-diyl, benzothiadiazole-diyl, benzotriazole-diyl, benzothiophene-diyl, etc. X and Z are each independently a divalent linking group, especially Although there is no limitation, a group in which one hydrogen atom is further removed from a group having one or more hydrogen atoms in R or a group exemplified by the following linking group group (A) is preferred, where x is 0 to 2. Y represents the trivalent linking group, and Y represents a group obtained by removing two hydrogen atoms from a group having two or more hydrogen atoms in R).

Linking group (A)

  In the present invention, the charge transporting compound is preferably a polymer or an oligomer from the viewpoints of solubility and film formability.

  In addition, the charge transporting compound (polymer or oligomer) according to the present invention preferably has a number average molecular weight of 1,000 or more and 1,000,000 or less from the viewpoint of solubility in a solvent and film-forming property. More preferably, it is 2,000-900,000 or less, More preferably, it is 3,000-800,000 or less. If it is smaller than this, the compound will be easily crystallized, resulting in poor film-forming properties. On the other hand, if it is larger than this, the solubility in a solvent is lowered, and it becomes difficult to produce a coating solution or a coating ink.

  In addition, the charge transporting compound (polymer or oligomer) according to the present invention preferably includes a repeating unit represented by the following general formulas (1a) to (84a).

Further, in the present invention, the charge transporting compound (polymer or oligomer) is for changing the solubility, one or more of E is the "cationic polymerizable substituent (cationic polymerizable substituent)". Here, the “cationically polymerizable substituent” means an epoxy compound (an alicyclic epoxy compound or glycidyl ether), an oxetane compound, or a vinyl ether. In order to greatly change the solubility, it is preferable that two or more of E are substituents capable of cationic polymerization, and these may be the same or different.

  In addition to the above repeating units, the charge transporting compound (polymer or oligomer) according to the present invention, in addition to the above repeating units, is used to adjust the solubility, heat resistance, and electrical characteristics. The copolymer which has a structure represented by 28 as a copolymer repeating unit may be sufficient. In this case, the copolymer may be a random, block or graft copolymer, or may be a polymer having an intermediate structure thereof, for example, a random copolymer having a block property. In addition, the polymer or oligomer used in the present invention may have branching in the main chain and may have three or more terminals.

[B) Cationic polymerization initiator]
The b) cationic polymerization initiator according to the present invention may be any one that expresses the ability to polymerize a substituent capable of cationic polymerization by application of heat, light, microwave, radiation, electron beam, and a combination thereof. Conventionally known compounds can be used. The cationic polymerization initiator is not particularly limited, but is preferably one that initiates polymerization by irradiation, light irradiation or heating, one that initiates polymerization by light irradiation (hereinafter referred to as a photoinitiator), heating It is more preferable from the viewpoint that the polymerization can be easily started, in which the polymerization is started by (hereinafter referred to as a thermal initiator). The photoinitiator is not particularly limited as long as it exhibits the ability to polymerize a substituent capable of being polymerized by light irradiation of 200 nm to 800 nm, and the thermal initiator by heating at 300 ° C. or less. When the polymerizable substituent is an oxetane group, an ionic compound comprising a counter cation and a counter anion is preferable from the viewpoint of reactivity, and details thereof will be described below.

(Anti-cation)
Counter cations include H ⁺ , carbenium ion, ammonium ion, anilinium ion, pyridinium ion, imidazolium ion, pyrrolidinium ion, quinolinium ion, imonium ion, aminium ion, oxonium ion, pyrinium ion , Chromenilium, k santylium ion, iodonium ion, sulfonium ion, phosphonium ion, tropylium ion, cation having a transition metal, etc., and H +, carbenium ion, anilinium ion, aminium ion, Iodonium ions, sulfonium ions, phosphonium ions, and tropylium ions are preferred. From the viewpoint of compatibility with storage stability, iodonium ions and sulfonium ions are more preferable.

(Counter anion)
The counter anion may be any conventionally known anion, such as halogen ions such as F ⁻ , Cl ⁻ , Br ⁻ and I ⁻ ; OH ⁻ ; ClO ₄ ⁻ ; FSO ₃ ⁻ , ClSO ₃ ⁻ , Sulfonic acid ions such as CH ₃ SO ₃ ⁻ , C ₆ H ₅ SO ₃ ⁻ , CF ₃ SO ₃ ^— ; Sulfate ions such as HSO ₄ ⁻ , SO ₄ ²⁻ ; HCO ₃ ⁻ , CO ₃ ^2−, etc. Carbonate ions; Phosphate ions such as H ₂ PO ₄ ⁻ , HPO ₄ ²⁻ , PO ₄ ³⁻ ; Fluorophosphate ions such as PF ₆ ⁻ and PF ₅ OH ⁻ , [(CF ₃ CF ₂ ) ₃ PF ₃ ] ⁻ , [(CF ₃ CF ₂ CF ₂ ) ₃ PF ₃ ] ⁻ , [((CF ₃ ) ₂ CF) ₃ PF ₃ ] ⁻ , [((CF ₃ ) ₂ CF) ₂ PF ₄ ] ⁻ , _[((CF 3) CFCF _{2) 3} PF _3] ^- and _{[((CF 3) 2 CFCF} 2) 2 PF 4] - a fluorinated alkyl fluorophosphate ions such ^{_{as; (CF 3 SO 2) 3}} C -, (CF 3 SO 2 ) Boron ions such as fluoroalkanesulfonylmethides such as ₂ N ⁻ , imide ions, BF ₄ ⁻ , B (C ₆ F ₅ ) ₄ ⁻ , B (C ₆ H ₄ CF ₃ ) ₄ ⁻ , SbF ₆ ⁻ , Fluoroantimonate ions such as SbF ₅ OH ^— or fluoroarsenate ions such as AsF ₆ — and AsF ₅ OH—, AlCl ₄ ⁻ , BiF ₆ , etc. Since it becomes a polymerization initiator that can be cured at low temperature, fluorophosphate ions such as PF ₆ ⁻ and PF ₅ OH ^— , [(CF ₃ CF ₂ ) ₃ PF _{3 ^{] -, [(CF 3 CF}} 2 CF 2) 3 PF 3] -, [((CF 3) 2 CF) 3 PF 3] -, [((CF 3) 2 CF) 2 PF 4] -, [( (CF ₃ ) ₂ CFCF ₂ ) ₃ PF ₃ ] ^— and [((CF ₃ ) ₂ CFCF ₂ ) ₂ PF ₄ ] ^— and other fluorinated alkyl fluorophosphate ions; (CF ₃ SO ₂ ) ₃ C ⁻ , Fluoroalkanesulfonylmethides such as (CF ₃ SO ₂ ) ₂ N ^— , imide ions, borate ions such as BF ₄ ⁻ , B (C ₆ F ₅ ) ₄ ⁻ , and B (C ₆ H ₄ CF ₃ ) ₄ ⁻ And fluoroantimonate ions such as SbF ₆ ⁻ and SbF ₅ OH ^— are preferred.

  Moreover, when the said initiator is a photoinitiator, in order to improve photosensitivity, you may use together with a photosensitizer. Examples of the photosensitizer include anthracene derivatives and thioxanthone derivatives.

  The blending ratio of the cationic polymerization initiator is 0.1 when the mass of the charge transporting compound and the cationic polymerizable compound or the charge transporting compound having one or more cationic polymerizable substituents is 100% by mass. It is preferably in the range of -30% by mass, more preferably in the range of 0.2-25% by mass, and particularly preferably in the range of 0.5-20% by mass. If the blending ratio of the polymerization initiator is less than 0.1% by mass, the change in solubility is not sufficient, so that lamination tends to be difficult, and if it exceeds 30% by mass, the polymerization initiator remaining in the thin film and / or Or there exists a tendency for element characteristics to fall with decomposition products.

[C) Radical polymerization initiator]
As the c) radical polymerization initiator according to the present invention, a known compound such as a conventionally known peroxide or azo compound can be used.
Specifically, cumylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxyneodecanoate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylper Oxyneodecanoate, t-butylperoxyneodecanoate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl -2,5-di (2-ethylhexanoylperoxy) hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyneohepta Noate, t-amylperoxy-2-ethylhexanoate, di-t-butylperoxyhexahydroterephthalate, -Amylperoxy-3,5,5-trimethylhexanoate, 3-hydroxy-1,1-dimethylbutylperoxyneodecanoate, 1,1,3,3-tetramethylbutylperoxy-2-ethyl Hexanoate, t-amylperoxyneodecanoate, t-amylperoxy-2-ethylhexanoate, 2,2′-azobis-2,4-dimethylvaleronitrile, 1,1′-azobis (1 -Acetoxy-1-phenylethane), 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), dimethyl-2,2'-azobisisobutyronitrile, 4,4′-azobis (4-cyanovaleric acid), 1,1′-azobis (1-cyclohexanecarbonitrile), t-hexylperoxyisopropyl monocarbonate , T-butylperoxymaleate, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2,5-dimethyl-2,5-di (3-methyl Benzoylperoxy) hexane, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxybenzoate, Examples include dibutyl peroxytrimethyl adipate, t-amyl peroxy normal octoate, t-amyl peroxy isononanoate, and t-amyl peroxybenzoate. These compounds may be used alone or in combination of two or more.
Among these, it is preferable that the 1 minute half-life temperature of a radical polymerization initiator is 90-175 degreeC.

  The addition amount of the radical polymerization initiator is 0.1 when the mass of the charge transporting compound and the cationic polymerizable compound, or the charge transporting compound having one or more cationic polymerizable substituents is 100% by mass. It is preferably in the range of ˜30% by mass, more preferably in the range of 0.2-20% by mass, and particularly preferably in the range of 0.5-15% by mass. When the blending ratio of the radical polymerization initiator is less than 0.1% by mass, it tends to be difficult to initiate the polymerization reaction at a low temperature. When the addition amount of the radical polymerization initiator exceeds 30% by mass, the storage stability is improved. It tends to decrease.

  The trigger for initiating polymerization is not particularly limited as long as it exhibits the ability to polymerize a polymerizable substituent by application of heat, light, microwave, radiation, electron beam, etc. It is preferable that the polymerization is initiated by heating, and heating is most preferable.

<Organic electronics elements>
The organic electronics element of the present invention is characterized by having a layer formed by applying the organic electronic material of the present invention on a substrate.

Examples of the method of applying the organic electronics material of the present invention to a substrate include a method of preparing an ink composition containing the organic electronics material and applying it to the substrate. The ink composition, that is, the ink composition of the present invention can be prepared as follows.
The ink composition of the present invention comprises the organic electronics material of the present invention described above and a solvent, and other additives such as polymerization inhibitors, stabilizers, thickeners, gelling agents, flame retardants, and antioxidants. An agent, an anti-reducing agent, an oxidizing agent, a reducing agent, a surface modifier, an emulsifier, an antifoaming agent, a dispersant, a surfactant, and the like may be included. Examples of the solvent include water, alcohols such as methanol, ethanol and isopropyl alcohol, alkanes such as pentane, hexane and octane, cyclic alkanes such as cyclohexane, aromatic solvents such as benzene, toluene, xylene, mesitylene, tetralin and diphenylmethane, ethylene Aliphatic ethers such as glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol-1-monomethyl ether acetate, 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenetole, 2-methoxytoluene, 3-methoxytoluene , 4-methoxytoluene, 2,3-dimethylanisole, aromatic ethers such as 2,4-dimethylanisole, ethyl acetate, n-butyl acetate, ethyl lactate, n-butyl lactate Aliphatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, n-butyl benzoate, N, N-dimethylformamide, N, N-dimethylacetamide, etc. Amide solvents, others, dimethyl sulfoxide, tetrahydrofuran, acetone, chloroform, methylene chloride and the like can be mentioned, but preferably aromatic solvents, aliphatic esters, aromatic esters, aliphatic ethers, aromatic ethers can be used. .
In the ink composition, the content of the organic electronics material with respect to the solvent is preferably 0.1 to 30% by mass from the viewpoint of being applicable to various coating processes.

The organic electronics element of the present invention can be insolubilized in various solvents by polymerizing and curing a layer of an organic electronics material formed on a substrate. Therefore, when the coating layer is further formed on the polymerized layer, the polymerized layer is not dissolved, so that the components of each layer can be multilayered without being mixed. As a result, deterioration of element characteristics can be prevented.
The organic electronics element of the present invention includes a layer formed using the material for organic electronics of the present invention, and the layer can be polymerized and cured at a low temperature, for example, a substrate having low heat resistance (for example, a resin film (details) As will be described later))), a wide variety of substrates can be selected.

<Organic EL device>
The organic electronics element of the present invention is characterized by having a layer (hereinafter also referred to as a polymerization layer) formed from the organic electronics material of the present invention described above. The organic EL device of the present invention is not particularly limited as long as it includes a light emitting layer, a polymerized layer, an anode, a cathode, and a substrate. Other elements such as a hole injection layer, an electron injection layer, a hole transport layer, and an electron transport layer are used. It may have a layer. In particular, an embodiment in which at least a substrate, an anode, a hole injection layer, a polymerization layer, a light emitting layer and a cathode are laminated, and an embodiment in which at least a substrate, an anode, a polymerization layer, a hole transport layer, a light emitting layer and a cathode are laminated preferable. Hereinafter, each layer will be described in detail. Hereinafter, each layer will be described in detail.

[Light emitting layer]
The material used for the light emitting layer may be a low molecular compound, a polymer or an oligomer, and a dendrimer or the like can also be used. Examples of low molecular weight compounds that utilize fluorescence include perylene, coumarin, rubrene, quinacrine, dye laser dyes (eg, rhodamine, DCM1, etc.), aluminum complexes (eg, Tris (8-hydroxyquinolinato) aluminum (III) (Alq ₃ )), Stilbene, and derivatives thereof. Polymers or oligomers that utilize fluorescence include polyfluorene, polyphenylene, polyphenylene vinylene (PPV), polyvinyl carbazole (PVK), fluorene-benzothiadiazole copolymer, fluorene-triphenylamine copolymer, and derivatives thereof. And a mixture can be suitably used.

  On the other hand, in recent years, phosphorescent organic EL devices have been actively developed in order to increase the efficiency of organic EL devices. In the phosphorescent organic EL element, not only singlet state energy but also triplet state energy can be used, and the internal quantum yield can be increased to 100% in principle. In the phosphorescent organic EL device, phosphorescence is extracted by doping a host material with a metal complex phosphorescent material containing a heavy metal such as platinum or iridium as a phosphorescent dopant ((MABaldo et al., Nature, vol. 395, p. 151 (1998), MABaldo et al., Applied Physics Letters, vol. 75, p. 4 (1999), or MABaldo et al., Nature, vol. 403, p. 750 (2000). .).)

Also in the organic EL device of the present invention, it is preferable to use a phosphorescent material for the light emitting layer from the viewpoint of high efficiency. As the phosphorescent material, a metal complex containing a central metal such as Ir or Pt can be preferably used. Specifically, as an Ir complex, for example, FIr (pic) that emits blue light [iridium (III) bis [(4,6-difluorophenyl) -pyridinate-N, C ² ] picolinate], green light is emitted. Ir (ppy) ₃ [Factris (2-phenylpyridine) iridium] (see Non-Patent Document 3 above) or Adachi et al. , Appl. Phys. Lett. 78no. (Btp) ₂ Ir (acac) {bis [2- (2′-benzo [4,5-α] thienyl) pyridinate-N, C3] iridium (acetyl-acetonate) )}, Ir (piq) ₃ [Tris (1-phenylisoquinoline) iridium] and the like.

Examples of the Pt complex include 2,3,7,8,12,13,17, 18-octaethyl-21H, 23H-forminplatinum (PtOEP) that emits red light.
The phosphorescent material can be a small molecule or a dendrite species, such as an iridium nucleus dendrimer. Moreover, these derivatives can also be used conveniently.

Further, in the case where a phosphorescent material is included in the light emitting layer, it is preferable that a host material is included in addition to the phosphorescent material.
The host material may be a low molecular compound or a high molecular compound, and a dendrimer or the like can also be used.

  Examples of the low molecular weight compound include CBP (4,4′-Bis (Carbazol-9-yl) -biphenyl), mCP (1,3-bis (9-carbazolyl) benzene), CDBP (4,4′-Bis). (Carbazol-9-yl) -2,2′-dimethylbiphenyl) and the like, for example, polyvinyl carbazole, polyphenylene, polyfluorene, etc. can be used as the polymer compound, and derivatives thereof can also be used.

The light emitting layer may be formed by a vapor deposition method or a coating method.
When forming by the apply | coating method, an organic EL element can be manufactured cheaply and it is more preferable. In order to form a light emitting layer by a coating method, a solution containing a phosphorescent material and, if necessary, a host material is used, for example, an ink jet method, a casting method, a dipping method, a relief printing, an intaglio printing, an offset printing, a flat printing, a relief printing. It can be carried out by applying on a desired substrate by a known method such as a printing method such as reverse offset printing, screen printing or gravure printing, or spin coating method.

[cathode]
The cathode material is preferably a metal or metal alloy such as Li, Ca, Mg, Al, In, Cs, Ba, Mg / Ag, LiF, and CsF.

[anode]
As the anode, a metal (for example, Au) or other material having metal conductivity, for example, an oxide (for example, ITO: indium oxide / tin oxide), a conductive polymer (for example, a polythiophene-polystyrene sulfonic acid mixture (for example, PEDOT: PSS)) can also be used.

[Electron transport layer, electron injection layer]
Examples of the electron transport layer and the electron injection layer include phenanthroline derivatives (for example, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP)), bipyridine derivatives, nitro-substituted fluorene derivatives, diphenylquinone. Derivatives, thiopyrandioxide derivatives, heterocyclic tetracarboxylic anhydrides such as naphthaleneperylene, carbodiimide, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives (2- (4-Biphenylyl) -5 -(4-tert-butylphenyl-1,3,4-oxadiazole) (PBD)), aluminum complexes (for example, Tris (8-hydroxyquinolinato) aluminum (III) (Alq ₃ )) and the like. Furthermore, in the oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, or a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group can be used.

[substrate]
As the substrate that can be used in the organic EL device of the present invention, the kind of glass, plastic and the like is not particularly limited, and is not particularly limited as long as it is transparent, but glass, quartz, light transmissive A resin film or the like is preferably used. When a resin film is used, flexibility can be given to the organic EL element, which is particularly preferable.

  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 made of (TAC), cellulose acetate propionate (CAP) and the like.

  Moreover, when using a resin film, in order to suppress permeation | transmission of water vapor | steam, oxygen, etc., you may coat and use inorganic substances, such as a silicon oxide and a silicon nitride, on a resin film.

[Luminescent color]
The emission color in the organic EL device of the present invention is not particularly limited, but the white light-emitting device is preferable because it can be used for various lighting devices such as home lighting, interior lighting, clocks, and liquid crystal backlights.

  As a method of forming a white light emitting element, since it is currently difficult to show white light emission with a single material, a plurality of light emitting colors can be simultaneously emitted and mixed using a plurality of light emitting materials. White luminescence is obtained. A combination of a plurality of emission colors is not particularly limited. However, a combination of three emission maximum wavelengths of blue, green, and red, a complementary color relationship such as blue and yellow, yellow green and orange is used. The thing containing two light emission maximum wavelengths is mentioned. The emission color can be controlled by adjusting the type and amount of the phosphorescent material.

<Display element, lighting device, display device>
The display element of the present invention is characterized by including the above-described organic EL element of the present invention.
For example, a color display element can be obtained by using the organic EL element of the present invention as an element corresponding to each pixel of red, green, and blue (RGB).
Image formation includes a simple matrix type in which individual organic EL elements arranged in a panel are directly driven by electrodes arranged in a matrix, and an active matrix type in which thin film transistors are arranged and driven in each element. The former is simple in structure but has a limit on the number of vertical pixels and is used for displaying characters. The latter is used for high-quality displays because the drive voltage is low and the current is small, and a bright high-definition image is obtained.

  The illumination device of the present invention is characterized by including the organic EL element of the present invention described above. Furthermore, the display device of the present invention is characterized by including a lighting device and a liquid crystal element as a display means. The illumination device of the present invention described above may be used as a backlight (white light source), and a display device using a liquid crystal element as a display unit, that is, a liquid crystal display device may be used. This configuration is a configuration in which only the backlight is replaced with the illumination device of the present invention in a known liquid crystal display device, and a known technique can be diverted to the liquid crystal element portion.

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

[Example 1]
A toluene solution (400 μl) of the following compound 1 (5 mg, Mw = 8200, PDI = 1.44) as a charge transporting compound having one or more cationically polymerizable substituents, and the following compound 2 (0 0.5 g) of an ethyl acetate solution (100 μl) and a coating solution obtained by mixing a toluene solution (100 μl) of an aliphatic diacyl peroxide (Perroyl L, Nippon Oil & Fats Co., Ltd.) (0.5 g) as a radical polymerization initiator is 3000 rpm. Was spin coated on a quartz plate. Next, the polymerization reaction was carried out by heating at 120 ° C. for 10 minutes on a hot plate. After heating, the quartz plate was immersed in a mixed solvent of toluene: ethyl acetate (4: 1) for 1 minute for washing. And the residual film rate was measured from the ratio of the absorbance (Abs) of the absorption maximum (λmax) in the UV-vis spectrum before and after washing. The measurement results are shown in Table 1.

[Comparative Example 1]
A polymerization reaction was carried out in the same manner as in Example 1 except that the cationic polymerization initiator was not used, and the remaining film ratio was measured. The measurement results are shown in Table 1.

[Comparative Example 2]
A polymerization reaction was performed in the same manner as in Example 1 except that the radical polymerization initiator was not used, and the remaining film ratio was measured. The measurement results are shown in Table 1.

  From Table 1, it can be seen that the difference in the remaining film ratio between Example 1 and Comparative Examples 1 and 2 is obvious, and in Example 1, the polymerization reaction sufficiently progressed even at a low temperature, and the film was insolubilized.

[Example 2]
The following monomer 1 (4.0 mmol), the following monomer 2 (5.0 mmol), the following monomer 3 (2.0 mmol), and anisole (20 ml) were added to a three-necked round bottom flask, and a further prepared Pd catalyst solution (7. 5 ml) was added. After stirring for 30 minutes, 10% tetraethylammonium hydroxide aqueous solution (20 ml) was added. All solvents were used after degassing with nitrogen bubble for more than 30 minutes. This mixture was heated to reflux for 2 hours. All the operations so far were performed under a nitrogen stream.

  After completion of the reaction, the organic layer was washed with water, and the organic layer was poured into methanol-water (9: 1). The resulting precipitate was suction filtered and washed with methanol-water (9: 1). The resulting precipitate was dissolved in toluene and reprecipitated from methanol. The obtained precipitate was filtered with suction, dissolved in toluene, triphenylphosphine, polymer-bound on styrene-divinylbenzene copolymer (200 mg per 100 mg of polymer, from strem chemicals) was added and stirred overnight. After the stirring, triphenylphosphine, polymer-bound on styrene-divinylbenzene copolymer and insoluble matter were removed by filtration, and the filtrate was concentrated by a rotary evaporator. The residue was dissolved in toluene and then reprecipitated from methanol-acetone (8: 3). The resulting precipitate was filtered by suction and washed with methanol-acetone (8: 3). The obtained precipitate was vacuum-dried to obtain Compound 4. The molecular weight was measured by GPC (polystyrene conversion) using THF as an eluent. The number average molecular weight of the obtained compound 4 was 7,800, and the weight average molecular weight was 31,000.

  As a charge transporting compound having one or more cationically polymerizable substituents, a toluene solution (400 μl) of compound 4 (5 mg), and an ethyl acetate solution (100 μl) of the following compound 5 (0.15 g) as a cationic polymerization initiator, A coating solution in which a toluene solution (100 μl) of aliphatic diacyl peroxide (Perroyl L, Nippon Oil & Fats Co., Ltd.) (0.15 g) was mixed as a radical polymerization initiator was spin-coated on a quartz plate at 3000 rpm. Next, the polymerization reaction was carried out by heating at 120 ° C. for 10 minutes on a hot plate. After heating, the quartz plate was immersed in a mixed solvent of toluene: ethyl acetate (4: 1) for 1 minute for washing. The residual film ratio was measured from the ratio of absorbance (Abs) at the absorption maximum (λmax) in the UV-vis spectrum before and after washing. The measurement results are shown in Table 2.

[Comparative Example 3]
A polymerization reaction was performed in the same manner as in Example 2 except that the cationic polymerization initiator was not used, and the remaining film ratio was measured. The measurement results are shown in Table 2.

[Comparative Example 4]
A polymerization reaction was performed in the same manner as in Example 2 except that the radical polymerization initiator was not included, and the remaining film ratio was measured. The measurement results are shown in Table 2.

  From Table 2, the difference in the remaining film ratio between Example 2 and Comparative Examples 3 and 4 is obvious, and it can be seen that also in Example 2, the polymerization reaction proceeded sufficiently even at a low temperature and the film was insolubilized. .

[Example 3]
Toluene solution (400 μl) of the above compound 1 (5 mg, Mw = 8200, PDI = 1.44) in a dry nitrogen environment on a glass substrate patterned with ITO to a width of 1.6 mm, and the above as a cationic polymerization initiator Coating in which an ethyl acetate solution (100 μl) of compound 2 (0.5 g) and a toluene solution (100 μl) of aliphatic diacyl peroxide (Perroyl L, Nippon Oil & Fats Co., Ltd.) (0.5 g) as a radical polymerization initiator were mixed. The solution was spin coated on a quartz plate at 3000 rpm. Subsequently, the polymerization reaction was carried out by heating at 120 ° C. for 10 minutes on a hot plate to produce a hole injection layer having a thickness of 40 nm. Furthermore, a toluene solution (550 μl) of compound 6 (Mw = 60,000, 5 mg) represented by the following general formula was applied onto the hole injection layer at 3000 rpm to prepare a hole transport layer.

Next, the obtained glass substrate was transferred into a vacuum evaporator, and CBP + Ir (piq) ₃ (40 nm), BAlq (10 nm), Alq ₃ (30 nm), LiF (film thickness 0.5 nm), Al (film thickness 100 nm) ).
After electrode formation, the substrate is moved into a dry nitrogen environment without opening to the atmosphere, and the sealing glass and ITO substrate in which 0.4 mm of counterbore is added to 0.7 mm non-alkali glass are coated with a photocurable epoxy resin. Sealing was performed by using them together to produce a polymer organic EL device having a multilayer structure. Subsequent experiments were performed in the atmosphere at room temperature (25 ° C.). When a voltage was applied using ITO as a positive electrode and Al as a cathode of this organic EL element, red light emission was observed at 5 V, and the current efficiency at a luminance of 1000 cd / m ² was 2.5 cd / A. The current-voltage characteristics were measured with a microammeter 4140B manufactured by Hewlett-Packard Co., and the luminance was measured using a luminance meter Pritchard 1980B manufactured by Photo Research.
Moreover, as a lifetime characteristic, it was 150 hours when the brightness | luminance was measured with Topcon BM-7, applying a constant current, and the time for a brightness | luminance to reduce to half from initial luminance (1000 cd / m < ² >) was measured.

[Comparative Example 5]
An organic EL device was produced in the same manner as in Example 3 except that the hole injection layer was not formed. Red light emission was observed at 9 V, and the current efficiency at a luminance of 1000 cd / m ² was 0.9 cd / A. In addition, as a lifetime characteristic, the luminance was measured with Topcon BM-7 while applying a constant current, and the time for the luminance to be halved from the initial luminance (1000 cd / m ² ) was measured and found to be 10 hours.

[Comparative Example 6]
A PEDOT: PSS dispersion (Stark Vitech, CH8000 LVW233) is spin-coated at 4000 rpm on a glass substrate patterned with ITO to a width of 1.6 mm, and is heated and dried in air at 200 ° C. for 10 minutes. Then, an organic EL device was produced in the same manner as in Example 3 except that a hole injection layer (40 nm) was formed. Red light emission was observed at 4.5 V, and the current efficiency at a luminance of 1000 cd / m ² was 2.0 cd / A. In addition, as a lifetime characteristic, luminance was measured with Topcon BM-7 while applying a constant current, and the time for the luminance to be halved from the initial luminance (1000 cd / m ² ) was measured, and it was 13 hours.

  From the above results, it can be seen that the organic EL element of Example 3 was superior in luminous efficiency and lifetime characteristics to the organic EL elements of Comparative Examples 5 and 6. This is because the hole injection layer formed by using the organic electronics material of the present invention is sufficiently insolubilized, and the hole transport layer is formed thereon. This is probably because it did not change.

Claims (17)

a) a charge transporting compound having one or more cationically polymerizable substituents;
b) a cationic polymerization initiator;
c) a radical polymerization initiator;
A material for organic electronics, comprising:   2. The organic electronic material according to claim 1, wherein the charge transporting compound contains at least one of an aromatic amine, a carbazole, and a thiophene compound.   The organic electronic material according to claim 1, wherein the charge transporting compound is a polymer or an oligomer.   An ink composition comprising the organic electronic material according to claim 1 and a solvent.   An organic electronics element comprising a layer formed by applying the organic electronics material according to claim 1 onto a substrate.   6. The organic electronic device according to claim 5, wherein the deposited layer is polymerized.   7. The organic electronic device according to claim 6, wherein another layer is formed on the polymerized layer to form a multilayer.   The organic electronic element according to claim 5, wherein the substrate is a resin film.   It has a layer formed from the material for organic electronics of any one of Claims 1-3, The organic electroluminescent element characterized by the above-mentioned.   It is an organic electroluminescent element formed by laminating | stacking at least a board | substrate, an anode, a positive hole injection layer, a polymerization layer, a light emitting layer, and a cathode, Comprising: The said polymerization layer is an organic of any one of Claims 1-3. An organic electroluminescence device characterized by being a layer formed of a material for electronics.   It is an organic electroluminescent element formed by laminating | stacking at least a board | substrate, an anode, a polymerization layer, a positive hole transport layer, a light emitting layer, and a cathode, Comprising: The said polymerization layer is an organic of any one of Claims 1-3. An organic electroluminescence device characterized by being a layer formed of a material for electronics.   The organic electroluminescence device according to any one of claims 9 to 11, wherein the emission color of the organic electroluminescence device is white.   The organic electroluminescent element according to any one of claims 9 to 12, wherein the substrate is a flexible substrate.   The organic electroluminescent element according to any one of claims 9 to 12, wherein the substrate is a resin film.   The display element provided with the organic electroluminescent element of any one of Claims 9-14.   The illuminating device provided with the organic electroluminescent element of any one of Claims 9-14.   A display device comprising the illumination device according to claim 16 and a liquid crystal element as a display means.