JPWO2009069537A1 - Light emitting device material and light emitting device - Google Patents

Abstract

Provided is a light-emitting element material that enables a light-emitting element having high efficiency and durability by using a light-emitting element material containing an anthracene compound represented by the general formula (1), and a light-emitting element using the light-emitting element material. (R1 to R16 may be the same as or different from each other, and each of hydrogen, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkoxy group, an alkylthio group, an aryl group, a heteroaryl group, an amino group, a silyl group, and an adjacent substituent; Selected from the group consisting of a ring structure formed between R9 to R16, wherein any one of R9 to R16 is used for linking to A. R17 to R20 may be the same or different, and may be hydrogen, R21 is selected from the group consisting of an alkyl group, a cycloalkyl group, a heterocyclic group, an alkoxy group, an alkylthio group, an aryl group, a heteroaryl group, an amino group, and a silyl group, wherein R21 is hydrogen, a linear alkyl group, a cycloalkyl group, a complex Between ring group, alkoxy group, alkylthio group, aryl group, heteroaryl group, amino group, silyl group and adjacent substituents The .A selected from the group consisting of ring structures made .n representing the arylene group is 1 or 2 .X is an oxygen atom or a sulfur atom.) ## STR1 ##

Description

  The present invention relates to a light-emitting element material useful as a fluorescent dye or a charge transport material and a light-emitting element using the same, and includes a display element, a flat panel display, a backlight, illumination, an interior, a sign, a signboard, an electrophotographic machine, and light The present invention relates to a light-emitting element that can be used in a field such as a signal generator.

  In recent years, research on organic thin-film light-emitting devices that emit light when electrons injected from a cathode and holes injected from an anode are recombined in an organic light-emitting body sandwiched between both electrodes has been actively conducted. This light-emitting element is characterized by thin light emission with high luminance under a low driving voltage and multicolor light emission by selecting a light-emitting material.

This study was conducted by Eastman Kodak's C.I. W. Since Tang et al. Have shown that organic thin-film light-emitting elements emit light with high brightness, many research institutions have studied. The representative structure of the organic thin film light emitting device presented by the Kodak research group is a hole transporting diamine compound on an ITO glass substrate, tris (8-quinolinolato) aluminum (III) as a light emitting layer, and a cathode. Mg: Ag (alloy) was sequentially provided, and green light emission of 1,000 cd / m ² was possible with a driving voltage of about 10 V (see Non-Patent Document 1).

  In addition, organic thin-film light-emitting elements can be obtained in various emission colors by using various fluorescent materials for the light-emitting layer, and therefore, researches for practical application to displays and the like are actively conducted. Among the three primary color luminescent materials, research on the green luminescent material is the most advanced, and at present, intensive research is being conducted to improve the characteristics of the red and blue luminescent materials.

One of the biggest problems in organic thin-film light-emitting elements is to make the light-emitting efficiency and durability of the element compatible. In particular, with respect to blue light-emitting elements, there are few blue light-emitting materials that provide elements with excellent durability and high reliability. For example, a technique using a styryl derivative (see Patent Document 1) is disclosed. Moreover, although the example which used the anthracene compound substituted by the dibenzofuran (refer patent documents 2-5) for a blue light emitting element is also disclosed, all were not sufficient in coexistence of luminous efficiency and durability.
Japanese Patent No. 3086272 JP 2005-314239 A International Publication No. 05/113531 Pamphlet JP 2007-63501 A JP 2007-238500 A Applied Physics Letters (USA), 1987, 51, 12, 913-915

  As described above, the conventional organic thin-film light-emitting element has not been provided with a blue light-emitting element having high luminous efficiency and excellent durability. Accordingly, an object of the present invention is to provide a light emitting element material that enables a blue light emitting element having high luminous efficiency and excellent durability, and a light emitting element using the same.

  The present invention is a light emitting device material containing an anthracene compound represented by the general formula (1).

R ^{1 to} R ¹⁶ may be the same or different and each represents hydrogen, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkoxy group, an alkylthio group, an aryl group, a heteroaryl group, an amino group, a silyl group, and an adjacent substituent. Selected from the group consisting of ring structures formed between However, any one of R ^{9 to} R ¹⁶ is used for connection with A. R ^{17 to} R ²⁰ may be the same or different from each other, and are selected from the group consisting of hydrogen, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkoxy group, an alkylthio group, an aryl group, a heteroaryl group, an amino group, and a silyl group. To be elected. R ²¹ represents a ring structure formed between hydrogen, a linear alkyl group, a cycloalkyl group, a heterocyclic group, an alkoxy group, an alkylthio group, an aryl group, a heteroaryl group, an amino group, a silyl group, and an adjacent substituent. Selected from the group of A represents an arylene group. n is 1 or 2. X is an oxygen atom or a sulfur atom.

  Further, the present invention is a light-emitting element that has at least a light-emitting layer between an anode and a cathode and emits light by electric energy, and the light-emitting element contains a light-emitting element material represented by the general formula (1). A light-emitting element is characterized.

  INDUSTRIAL APPLICATION This invention can be utilized for a light emitting element etc., and can provide the light emitting element material excellent in thin film stability. Furthermore, a light emitting device having high luminous efficiency and excellent durability can be obtained.

  The anthracene compound represented by the general formula (1) used in the present invention will be described.

R ^{1 to} R ¹⁶ may be the same or different and each represents hydrogen, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkoxy group, an alkylthio group, an aryl group, a heteroaryl group, an amino group, a silyl group, and an adjacent substituent. Selected from the group consisting of ring structures formed between However, any one of R ^{9 to} R ¹⁶ is used for connection with A. R ^{17 to} R ²⁰ may be the same or different from each other, and are selected from the group consisting of hydrogen, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkoxy group, an alkylthio group, an aryl group, a heteroaryl group, an amino group, and a silyl group. To be elected. R ²¹ represents a ring structure formed between hydrogen, a linear alkyl group, a cycloalkyl group, a heterocyclic group, an alkoxy group, an alkylthio group, an aryl group, a heteroaryl group, an amino group, a silyl group, and an adjacent substituent. Selected from the group of A represents an arylene group. n is 1 or 2. X is an oxygen atom or a sulfur atom.

  Among these substituents, the alkyl group is, for example, a saturated aliphatic hydrocarbon group such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, or a tert-butyl group. This may or may not have a substituent. There is no restriction | limiting in particular in the additional substituent in the case of being substituted, For example, an alkyl group, an aryl group, heteroaryl group etc. can be mentioned, This point is common also in the following description. Further, the number of carbon atoms of the alkyl group is not particularly limited, but is usually 1 or more and 20 or less, more preferably 1 or more and 8 or less, and more preferably a methyl group, an ethyl group, or an isopropyl group, from the viewpoint of availability and cost. , Sec-butyl group, tert-butyl group.

  The cycloalkyl group represents a saturated alicyclic hydrocarbon group such as cyclopropyl, cyclohexyl, norbornyl, adamantyl, etc., which may or may not have a substituent. Although carbon number of an alkyl group part is not specifically limited, Usually, it is the range of 3-20.

  A linear alkyl group shows linear saturated aliphatic hydrocarbon groups, such as a methyl group, an ethyl group, n-propyl group, n-butyl group, for example. The number of carbon atoms in the alkyl group moiety is not particularly limited, but is usually in the range of 1 or more and 8 or less from the viewpoint of availability and cost.

  The heterocyclic group refers to an aliphatic ring having atoms other than carbon, such as a pyran ring, a piperidine ring, and a cyclic amide, in the ring, which may or may not have a substituent. . Although carbon number of a heterocyclic group is not specifically limited, Usually, it is the range of 2-20.

  The alkoxy group refers to, for example, a functional group having an aliphatic hydrocarbon group bonded through an ether bond such as a methoxy group, an ethoxy group, or a propoxy group, and the aliphatic hydrocarbon group may have a substituent. It may not have. Although carbon number of an alkoxy group is not specifically limited, Usually, it is the range of 1-20.

  The alkylthio group is a group in which an oxygen atom of an ether bond of an alkoxy group is substituted with a sulfur atom. The hydrocarbon group of the alkylthio group may or may not have a substituent. Although carbon number of an alkylthio group is not specifically limited, Usually, it is the range of 1-20.

  An aryl group shows aromatic hydrocarbon groups, such as a phenyl group, a naphthyl group, a biphenyl group, a phenanthryl group, a terphenyl group, for example. The aryl group may be unsubstituted or substituted. Although carbon number of an aryl group is not specifically limited, Usually, it is the range of 6-40, More preferably, it is the range of 6-12. The aryl group is more preferably a phenyl group, a naphthyl group, or a biphenyl group.

  A heteroaryl group is a cyclic aromatic group having one or more atoms other than carbon such as furanyl group, thiophenyl group, pyrrolyl group, benzofuranyl group, benzothiophenyl group, indolyl group, pyridyl group, quinolinyl group in the ring. This may or may not have a substituent. Although carbon number of a heteroaryl group is not specifically limited, Usually, it is 2 or more and 30 or less range.

  The amino group may or may not have a substituent. Examples of the substituent include an alkyl group, a cycloalkyl group, an aryl group, and a heteroaryl group as described above.

  A silyl group refers to, for example, a functional group having a bond to a silicon atom, such as a trimethylsilyl group, which may or may not have a substituent. Although carbon number of a silyl group is not specifically limited, Usually, it is the range of 3-20. The number of silicon is usually preferably in the range of 1 or more and 6 or less.

Moreover, arbitrary adjacent two substituents (for example, R ¹⁸ and R ^{21 in} the general formula (1)) may be bonded to each other to form a conjugated or non-conjugated condensed ring. As a constituent element of the condensed ring, an element selected from nitrogen, oxygen, sulfur, phosphorus, and silicon may be included in addition to carbon. Further, the condensed ring may be further condensed with another ring.

  The arylene group is a divalent or trivalent group derived from an aromatic hydrocarbon such as a phenylene group, a naphthylene group, a biphenylene group, a phenanthrylene group, or a terphenylene group, which may have a substituent. You don't have to. Although carbon number of an arylene group is not specifically limited, Usually, it is the range of 6-40, More preferably, it is the range of 6-12. The arylene group is more preferably a divalent group derived from a phenyl group (phenylene group) and a divalent group derived from a naphthyl group (naphthylene group).

  In the case where a group that may or may not have a substituent among the above groups has a substituent, the substituted position is not particularly limited. In addition, a plurality of substituents may be included. In this case, a plurality of the same type of substituents may be present or different types of substituents may be included.

  The anthracene compound represented by the general formula (1) of the present invention has an anthracene skeleton and an electron-donating condensed aromatic dibenzofuran skeleton (when X is an oxygen atom) or a dibenzothiophene skeleton (where X is a sulfur atom) in the molecule. In this case, the heat resistance and the charge transportability can be compatible. Furthermore, since A in the general formula (1) is an arylene group, a stable thin film can be formed and long-life light emission is possible. Among these, A is more preferably a phenylene group or a naphthylene group from the viewpoint of availability of raw materials and ease of synthesis.

  In the anthracene compound represented by the general formula (1) of the present invention, when A is connected to the 9th position (carbon position on the center ring) of the anthracene skeleton, a device with high fluorescence quantum yield is obtained. It is important from the viewpoint of improving the stability of the thin film.

The dibenzofuran skeleton or the dibenzothiophene skeleton may be included in the general formula (1) alone or in each case, but X in the general formula (1) is an oxygen atom. A dibenzofuran skeleton is preferable because higher luminous efficiency can be obtained. The number of dibenzofuran skeletons or dibenzothiophene skeletons (value of n) is more preferably 1. In addition, any one of R ^{9 to} R ¹⁶ is used for connection with A, but R ⁹ is preferably used for connection with A in view of availability of raw materials and ease of synthesis.

  In addition, when the general formula A is a phenylene group, the bond position relationship between the dibenzofuran skeleton or the dibenzothiophene skeleton and the anthracene skeleton may be any of the o-position, the m-position, and the p-position. More preferably. Among these, it is particularly preferable to bond to the p-position in that a stable thin film can be formed. In addition, there is no particular limitation on the bonding positional relationship between the dibenzofuran skeleton or the dibenzothiophene skeleton and the anthracene skeleton in the case where the general formula A is a naphthylene group, but it is more preferable to bond at the 2nd and 6th positions of the naphthylene group.

In the anthracene compound represented by the general formula (1) of the present invention, R ²¹ is hydrogen, a linear alkyl group, a cycloalkyl group, a heterocyclic group, an alkoxy group, an alkylthio group, an aryl group, a heteroaryl group, amino Selection from the group consisting of a ring structure formed between a group, a silyl group, and an adjacent substituent is important from the viewpoint of thin film stability when formed into a device. Among them, R ²¹ is more preferably selected from the group consisting of hydrogen, a linear alkyl group, a heterocyclic group, an aryl group, a heteroaryl group, and a ring structure formed between adjacent substituents. Particularly preferred is a ring structure formed between a chain alkyl group, an aryl group or an adjacent substituent. At this time, 10-position of anthracene skeleton substituent phenyl group in (carbon position on the central ring) ^{(R 21} is hydrogen), 2-biphenyl group ^{(R 21} is hydrogen), 4-biphenyl group ^{(R 21} Is a phenyl group), a p-toluyl group (R ²¹ is a methyl group), or a β-naphthyl group (R ²¹ is a ring structure with R ¹⁸ or R ¹⁹ which is an adjacent substituent). This is preferable because the effect of improving stability is further increased.

  Although it does not specifically limit as the above anthracene compounds, Specifically, the following examples are given.

  A known method can be used for the synthesis of the anthracene compound represented by the general formula (1). Examples of the method for introducing a dibenzofuranyl group into an anthracene skeleton include a method using a coupling reaction between a halogenated anthracene derivative and a dibenzofuran metal complex or a dibenzofuranyl aryl metal complex under a palladium or nickel catalyst, or under a palladium or nickel catalyst. Examples include, but are not limited to, a method using a coupling reaction of an anthracenyl metal complex and a halogenated dibenzofuran derivative.

  Next, embodiments of the light-emitting element in the present invention will be described in detail with examples. The light-emitting element of the present invention has an anode and a cathode, and an organic layer interposed between the anode and the cathode. The organic layer includes at least a light-emitting layer, and the light-emitting layer emits light by electric energy.

  The organic layer is composed of only the light emitting layer, 1) a hole transport layer / light emitting layer / electron transport layer, 2) a light emitting layer / electron transport layer, and 3) a hole transport layer / light emitting layer, etc. A configuration is mentioned. Each of the layers may be a single layer or a plurality of layers. When the hole transport layer and the electron transport layer have a plurality of layers, the layers in contact with the electrodes may be referred to as a hole injection layer and an electron injection layer, respectively. In the material, the electron injection material is included in the electron transport material.

  The light-emitting element of the present invention is formed of a light-emitting element material in which the organic layer contains an anthracene compound represented by the general formula (1). The light-emitting element material corresponds to either a compound that emits light by itself or a compound that assists the light emission, and refers to a compound that participates in light emission. Specifically, a hole-transport material, a light-emitting material, and an electron This includes transportation materials.

  The anthracene compound of the present invention may be used as a hole transport material or an electron transport material, but is preferably used as a light emitting material because it has high light emission performance. In addition, the anthracene compound of the present invention exhibits strong light emission in the blue region, and thus is suitably used as a blue light-emitting material, but as a material for green to red light-emitting elements and white light-emitting elements when combined with other light-emitting materials. Can also be used. A white light emitting element is obtained by laminating a plurality of materials having different emission colors. Specifically, a blue light emitting material and a yellow light emitting material, a two-layer laminated system of a light blue light emitting material and an orange light emitting material, and a three layer laminated system of a blue light emitting material, a green light emitting material, and a red light emitting material can be given. Since the anthracene compound of the present invention is suitably used as a blue light emitting material, other different light emitting materials such as 2,3,5,6-1H, 4H-tetrahydro-9- (2′-benzothiazolyl) quinolidino [ Green light emitting material such as 9,9a, 1-gh] coumarin, 1,3,5,7-tetra (4-t-butylphenyl) -8-phenyl-4,4-difluoro-4-bora-3a, 4a A white light emitting element can be obtained by laminating three layers with a red light emitting material such as diaza-s-indacene.

  The anode used in the present invention is not particularly limited as long as it can efficiently inject holes into the organic layer. However, it is preferable to use a material having a relatively large work function, for example, tin oxide, indium oxide, zinc oxide. Conductive metal oxides such as indium and indium tin oxide (ITO), metals such as gold, silver and chromium, inorganic conductive materials such as copper iodide and copper sulfide, conductive polymers such as polythiophene, polypyrrole and polyaniline, etc. Is mentioned. These electrode materials may be used alone, or a plurality of materials may be laminated or mixed.

  The resistance of the anode is not limited as long as a current sufficient for light emission of the light emitting element can be supplied, and is preferably low from the viewpoint of power consumption of the light emitting element. For example, an ITO substrate of 300Ω / □ or less will function as a device electrode, but since it is now possible to supply a substrate of about 10Ω / □, use a low-resistance product of 100Ω / □ or less. Is particularly desirable. The thickness of ITO can be arbitrarily selected according to the resistance value, but is usually used in a range of 100 to 300 nm.

In order to maintain the mechanical strength of the light emitting element, the light emitting element is preferably formed over a substrate. As the substrate, a glass substrate such as soda glass or non-alkali glass is preferably used. As the thickness of the glass substrate, it is sufficient that the thickness is sufficient to maintain the mechanical strength. As for the glass material, alkali-free glass is preferred because it is better that there are fewer ions eluted from the glass. Or, it is also possible to use this because soda lime glass with a barrier coat such as SiO ₂ are also commercially available. Furthermore, if the anode functions stably, the substrate does not have to be glass. For example, the anode may be formed on a plastic substrate. The ITO film forming method is not particularly limited, such as an electron beam method, a sputtering method, and a chemical reaction method.

  The material used for the cathode used in the present invention is not particularly limited as long as it is a substance that can efficiently inject electrons into the organic layer, but is generally platinum, gold, silver, copper, iron, tin, zinc, aluminum, indium, chromium. Lithium, sodium, potassium, cesium, calcium and magnesium, and alloys thereof. Lithium, sodium, potassium, cesium, calcium, magnesium, or alloys containing these low work function metals are effective for increasing the electron injection efficiency and improving device characteristics. However, these low work function metals are often often unstable in the atmosphere. Therefore, a preferable example is a method in which a highly stable electrode is obtained by doping a small amount of lithium or magnesium (1 nm or less in vacuum vapor deposition thickness display) into the organic layer. Also, an inorganic salt such as lithium fluoride can be used. Furthermore, for electrode protection, metals such as platinum, gold, silver, copper, iron, tin, aluminum and indium, or alloys using these metals, inorganic substances such as silica, titania and silicon nitride, polyvinyl alcohol, polyvinyl chloride Lamination of organic polymer compounds such as hydrocarbon polymer compounds is a preferred example. The method for producing these electrodes is not particularly limited as long as conduction can be achieved, such as resistance heating, electron beam, sputtering, ion plating, and coating.

  The hole transport layer is formed by a method of laminating or mixing one or more hole transport materials or a method using a mixture of a hole transport material and a polymer binder. Alternatively, the hole transport layer may be formed by adding an inorganic salt such as iron (III) chloride to the hole transport material. The hole transport material is not particularly limited as long as it is a compound that forms a thin film necessary for manufacturing a light emitting element, can inject holes from the anode, and can further transport holes. For example, 4,4′-bis (N- (3-methylphenyl) -N-phenylamino) biphenyl, 4,4′-bis (N- (1-naphthyl) -N-phenylamino) biphenyl, 4,4 Triphenylamine derivatives such as', 4 "-tris (3-methylphenyl (phenyl) amino) triphenylamine, biscarbazole derivatives such as bis (N-allylcarbazole) or bis (N-alkylcarbazole), pyrazoline derivatives, Heterocyclic compounds such as stilbene compounds, hydrazone compounds, benzofuran derivatives, thiophene derivatives, oxadiazole derivatives, phthalocyanine derivatives, porphyrin derivatives, and polymers, polycarbonates, styrene derivatives, polythiophene, polyaniline having the above monomers in the side chain , Polyfluorene, poly Such alkenyl carbazole and polysilane are preferred.

  In the present invention, the light emitting layer may be either a single layer or a plurality of layers, each formed of a light emitting material (host material, dopant material), which may be a mixture of a host material and a dopant material, or a host material alone. It may be either. That is, in the light emitting element of the present invention, only the host material or the dopant material may emit light in each light emitting layer, or both the host material and the dopant material may emit light. From the viewpoint of efficiently using electric energy and obtaining light emission with high color purity, the light emitting layer is preferably composed of a mixture of a host material and a dopant material. Further, the host material and the dopant material may be either one kind or a plurality of combinations, respectively. The dopant material may be included in the entire host material or may be partially included. The dopant material may be laminated or dispersed. The dopant material can control the emission color. Specifically, blue light emission can be obtained by combining with a dopant material exhibiting strong light emission in the blue region, but a green to red light emission can be obtained in the same manner even in a dopant material exhibiting strong light emission from green to red. it can. If the amount of the dopant material is too large, a concentration quenching phenomenon occurs, so that it is preferably used at 20% by weight or less, more preferably 10% by weight or less with respect to the host material. The doping method can be formed by a co-evaporation method with a host material, but may be pre-mixed with the host material and then simultaneously deposited.

  The light emitting layer in the light emitting device of the present invention contains an anthracene compound represented by the general formula (1). The anthracene compound of the present invention may be used as a dopant material, but is preferably used as a host material because of its excellent thin film stability and charge transportability. When the anthracene compound used in the present invention is used as a host material, a light-emitting element with higher emission efficiency and a longer lifetime can be obtained by combining it with a dopant material that emits strong light in a blue region. Furthermore, the anthracene compound used in the present invention can be suitably combined with a dopant material that exhibits strong light emission in the green to red region.

  The ionization potential of the anthracene compound represented by the general formula (1) of the present invention is not particularly limited, but is preferably 4.5 eV or more and 7.0 eV or less, and more preferably 5.4 eV or more and 6.4 eV or less. . Although the absolute value of the ionization potential may vary depending on the measurement method, the ionization potential of the present invention is an ITO glass substrate using an atmospheric-type ultraviolet photoelectron analyzer (AC-1, manufactured by Riken Kikai Co., Ltd.). It is the value which measured the thin film vapor-deposited on the thickness of 30 nm-100 nm on the top.

  The host material used in the present invention is not necessarily limited to one kind of anthracene compound represented by the general formula (1) of the present invention, and a mixture of a plurality of anthracene compounds of the present invention may be used. One or more kinds may be used as a mixture with the anthracene compound of the present invention. Examples of the host material that can be mixed include a compound having a condensed aryl ring such as pyrene and derivatives thereof, N, N′-dinaphthyl-N, N′-diphenyl-4,4′-diphenyl-1,1′-diamine, and the like. Aromatic amine derivatives, metal chelated oxinoid compounds such as tris (8-quinolinato) aluminum (III), bisstyryl derivatives such as distyrylbenzene derivatives, tetraphenylbutadiene derivatives, indene derivatives, coumarin derivatives, oxadiazole derivatives , Pyrrolopyridine derivatives, perinone derivatives, cyclopentadiene derivatives, oxadiazole derivatives, carbazole derivatives, pyrrolopyrrole derivatives, in the polymer system, polyphenylene vinylene derivatives, polyparaphenylene derivatives, polyfluorene derivatives, polyvinylcarba Lumpur derivatives, polythiophene derivatives are suitably used.

  The dopant material is not particularly limited, but a compound having a condensed aryl ring such as naphthalene, anthracene, phenanthrene, pyrene, triphenylene, perylene, fluorene, indene, or a derivative thereof (for example, 2- (benzothiazol-2-yl) -9, 10-diphenylanthracene, 5,6,11,12-tetraphenylnaphthacene, etc.), furan, pyrrole, thiophene, silole, 9-silafluorene, 9,9′-spirobisilafluorene, benzothiophene, benzofuran, indole, Compounds having heteroaryl rings such as dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyrazine, naphthyridine, quinoxaline, pyrrolopyridine, thioxanthene and their derivatives, borane derivatives, distyrylben Aminostyryl such as 4,4'-bis (2- (4-diphenylaminophenyl) ethenyl) biphenyl, 4,4'-bis (N- (stilben-4-yl) -N-phenylamino) stilbene Derivatives, aromatic acetylene derivatives, tetraphenylbutadiene derivatives, stilbene derivatives, aldazine derivatives, pyromethene derivatives, diketopyrrolo [3,4-c] pyrrole derivatives, 2,3,5,6-1H, 4H-tetrahydro-9- (2 Coumarin derivatives such as' -benzothiazolyl) quinolidino [9,9a, 1-gh] coumarin, azole derivatives such as imidazole, thiazole, thiadiazole, carbazole, oxazole, oxadiazole, triazole and metal complexes thereof and N, N'-diphenyl -N, N'-di (3-methyl Eniru) -4,4' and aromatic amine derivatives typified by diphenyl-1,1'-diamine. Among them, it is preferable to use a condensed aromatic ring derivative having an electron-accepting substituent as a dopant because the effect of the thin film stability of the pyrene compound of the present invention becomes more remarkable. Specifically, pyrene compounds having a benzoazole group represented by 1- (benzoxazol-2-yl) -3,8-bis (4-methylphenyl) pyrene and (6-p-tolylpyren-1-yl) Pyrene compounds having a dimesitylboryl group represented by) -bis (2,4,6-trimethylphenyl) borane are particularly preferred dopants.

  In the present invention, the electron transport layer is a layer in which electrons are injected from the cathode and further transports electrons. The electron transport layer has high electron injection efficiency, and it is desired to efficiently transport injected electrons. Therefore, it is desirable that the electron transport layer is made of a material having a high electron affinity, a high electron mobility, excellent stability, and a trapping impurity that is unlikely to be generated during manufacture and use. However, considering the transport balance between holes and electrons, if the electron transport layer mainly plays a role of effectively preventing the holes from the anode from recombining and flowing to the cathode side, the electron transport Even if it is made of a material that does not have a high capability, the effect of improving the luminous efficiency is equivalent to that of a material that has a high electron transport capability. Therefore, the electron transport layer in the present invention includes a hole blocking layer that can efficiently block the movement of holes as the same meaning.

  The electron transport material used for the electron transport layer is not particularly limited, but is a compound having a condensed aryl ring such as naphthalene, anthracene, or pyrene or a derivative thereof, and styryl typified by 4,4′-bis (diphenylethenyl) biphenyl. Aromatic ring derivatives, perylene derivatives, perinone derivatives, coumarin derivatives, naphthalimide derivatives, quinone derivatives such as anthraquinone and diphenoquinone, phosphorus oxide derivatives, carbazole derivatives and indole derivatives, quinolinol complexes such as tris (8-quinolinolato) aluminum (III) And hydroxyphenyl oxazole complexes such as hydroxy azole complexes, azomethine complexes, tropolone metal complexes and flavonol metal complexes, but because the driving voltage can be reduced, carbon, hydrogen, nitrogen, oxygen Silicon, is composed of elements selected from among phosphorus, it is preferable to use a compound having a heteroaryl ring structure containing electron-accepting nitrogen.

  The electron-accepting nitrogen in the present invention represents a nitrogen atom that forms a multiple bond with an adjacent atom. Since the nitrogen atom has a high electronegativity, the multiple bond has an electron accepting property. Therefore, a heteroaryl ring containing electron-accepting nitrogen has high electron affinity, excellent electron transport ability, and can be used for an electron transport layer to reduce the driving voltage of a light-emitting element. Heteroaryl rings containing electron-accepting nitrogen include, for example, pyridine ring, pyrazine ring, pyrimidine ring, quinoline ring, quinoxaline ring, naphthyridine ring, pyrimidopyrimidine ring, benzoquinoline ring, phenanthroline ring, imidazole ring, oxazole ring, oxalate ring, Examples include a diazole ring, a triazole ring, a thiazole ring, a thiadiazole ring, a benzoxazole ring, a benzothiazole ring, a benzimidazole ring, and a phenanthrimidazole ring.

  Examples of these compounds having a heteroaryl ring structure include benzimidazole derivatives, benzoxazole derivatives, benzthiazole derivatives, oxadiazole derivatives, thiadiazole derivatives, triazole derivatives, pyrazine derivatives, phenanthroline derivatives, quinoxaline derivatives, quinoline derivatives, benzoins. Preferred compounds include quinoline derivatives, oligopyridine derivatives such as bipyridine and terpyridine, quinoxaline derivatives and naphthyridine derivatives. Among them, imidazole derivatives such as tris (N-phenylbenzimidazol-2-yl) benzene, oxadiazole derivatives such as 1,3-bis [(4-tert-butylphenyl) 1,3,4-oxadiazolyl] phenylene, Triazole derivatives such as N-naphthyl-2,5-diphenyl-1,3,4-triazole, phenanthroline derivatives such as bathocuproine and 1,3-bis (1,10-phenanthroline-9-yl) benzene, 2,2 ′ A benzoquinoline derivative such as bis (benzo [h] quinolin-2-yl) -9,9′-spirobifluorene, 2,5-bis (6 ′-(2 ′, 2 ″ -bipyridyl))-1, Bipyridine derivatives such as 1-dimethyl-3,4-diphenylsilole, 1,3-bis (4 ′-(2,2 ′: 6′2 ″ -ta Terpyridine derivatives such as pyridinyl)) benzene, naphthyridine derivatives such as bis (1-naphthyl) -4- (1,8-naphthyridin-2-yl) phenylphosphine oxide are preferably used from the viewpoint of electron transporting capability. Furthermore, 1,3-bis (1,10-phenanthroline-9-yl) benzene, 2,7-bis (1,10-phenanthroline-9-yl) naphthalene, 1,3-bis (2-phenyl-1, Phenanthroline dimers such as 10-phenanthroline-9-yl) benzene, 2,5-bis (6 ′-(2 ′, 2 ″ -bipyridyl))-1,1-dimethyl-3,4-diphenylsilole, etc. This bipyridine dimer has a remarkably high luminous efficiency improvement effect when combined with a light emitting layer containing an anthracene compound represented by the general formula (1), and is particularly preferable.

  Furthermore, since the anthracene compound of the present invention is excellent in thin film stability and charge transportability, excellent characteristics can be obtained when used as a host material, but due to its high charge transportability, it is also suitable as an electron transport material. Used.

  The electron transport material may be used alone, but two or more of the electron transport materials may be mixed and used, or one or more of the other electron transport materials may be mixed with the electron transport material. Also mixed with alkali metal, inorganic salt containing alkali metal, complex of alkali metal and organic matter, alkaline earth metal, inorganic salt containing alkaline earth metal, complex of alkaline earth metal and organic matter, etc. It is also possible to use it. Although the ionization potential of an electron carrying layer is not specifically limited, Preferably it is 5.5 eV or more and 8.0 eV or less, More preferably, it is 5.7 eV or more and 7.5 eV or less.

  The method of forming each of the above layers constituting the light emitting element is not particularly limited, such as resistance heating vapor deposition, electron beam vapor deposition, sputtering, molecular lamination method, coating method, ink jet method, printing method, laser induced thermal transfer method, etc. From this point, resistance heating vapor deposition or electron beam vapor deposition is preferable.

  The thickness of the organic layer depends on the resistance value of the luminescent material and cannot be limited, but is selected from 1 to 1000 nm. The film thicknesses of the light emitting layer, the electron transport layer, and the hole transport layer are each preferably 1 nm to 200 nm, and more preferably 5 nm to 100 nm.

  The light-emitting element of the present invention has a function of converting electrical energy into light. Here, a direct current is mainly used as the electric energy, but a pulse current or an alternating current can also be used. The current value and the voltage value are not particularly limited, but are preferably selected so that the maximum luminance can be obtained with as low energy as possible in consideration of the power consumption and lifetime of the element.

  The light emitting device of the present invention is suitably used as a display for displaying in a matrix and / or segment system, for example.

  In the matrix method, pixels for display are two-dimensionally arranged such as a lattice shape or a mosaic shape, and characters and images are displayed by a set of pixels. The shape and size of the pixel are determined by the application. For example, a square pixel with a side of 300 μm or less is usually used for displaying images and characters on a personal computer, monitor, TV, and a pixel with a side of mm order for a large display such as a display panel. become. In monochrome display, pixels of the same color may be arranged. However, in color display, red, green, and blue pixels are displayed side by side. In the case of color display, there are typically a delta type and a stripe type. The matrix driving method may be either line sequential driving or active matrix. In the line sequential drive, the structure of the light emitting element is simple, but the active matrix may be superior in consideration of operation characteristics. The driving method is properly used depending on the application.

  The segment method is a method in which a pattern is formed so as to display predetermined information, and an area determined by the arrangement of the pattern is caused to emit light. For example, the time and temperature display in a digital clock or a thermometer, the operation state display of an audio device or an electromagnetic cooker, the panel display of an automobile, and the like can be mentioned. The matrix display and the segment display may coexist in the same panel.

  The light emitting device of the present invention is also preferably used as a backlight for various devices. The backlight is used mainly for the purpose of improving the visibility of a display device that does not emit light, and is used for a liquid crystal display device, a clock, an audio device, an automobile panel, a display panel, a sign, and the like. In particular, the light-emitting element of the present invention is preferably used for a backlight for liquid crystal display devices, especially for personal computers for which thinning is being studied. The light-emitting element of the present invention can provide a backlight that is thinner and lighter than conventional ones.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not limited by these Examples. In addition, the number of the compound in each following Example points out the number of the compound described in the above chemical formula. The evaluation method for structural analysis is shown below.

¹ H-NMR was measured with a deuterated chloroform solution using superconducting FTNMR EX-270 (manufactured by JEOL Ltd.).

  HPLC purity was measured with a 0.1 g / L chloroform solution using a high performance liquid chromatograph LC-10 (manufactured by Shimadzu Corporation). As a developing solvent for the column, a mixed solution of 0.1% phosphoric acid aqueous solution and acetonitrile was used.

Synthesis Example 1 (Synthesis Method of Compound [1])
A mixed solution of 9 ml of 9-bromoanthracene, 3.6 g of phenylboronic acid, 12.4 g of tripotassium phosphate, 480 mg of PdCl ₂ (dppf) · CH ₂ Cl ₂ and 120 ml of degassed dimethylformamide under a nitrogen stream was added to 100 The mixture was heated and stirred for 3 hours at ° C. 100 ml of water was poured into the solution, and the precipitate was filtered. The solid separated by filtration was washed with 50 ml of water and 50 ml of methanol, respectively, and then purified by silica gel column chromatography, followed by vacuum drying to obtain 3.9 g of 9-phenylanthracene as a white powder.

  Next, a mixed solution of 3.9 g of 9-phenylanthracene, 3.0 g of N-bromosuccinimide and 150 ml of dimethylformamide was stirred at room temperature for 5 hours under a nitrogen stream. After injecting 100 ml of water, the resulting precipitate was filtered, and the solid was washed with methanol to obtain 4.6 g of 9-bromo-10-phenylanthracene.

Next, 2.0 g of 9-bromo-10-phenylanthracene, 4- [4- (4,4,5,5-tetramethyl- [1,3,2] dioxaborolan-2-yl) phenyl] dibenzofuran2. A mixed solution of 9 g, 3.3 g of tripotassium phosphate, 147 mg of PdCl ₂ (dppf) · CH ₂ Cl ₂ and 36 ml of degassed dimethylformamide was heated and stirred at 100 ° C. for 4 hours under a nitrogen stream. After cooling to room temperature, the obtained crystals were filtered. After sequentially washing with 10 ml of dimethylformamide, 30 ml of water and 30 ml of ethanol, 200 ml of toluene was added and dissolved at 140 ° C. After cooling to 100 ° C., the mixture was filtered using celite. The filtrate was evaporated, 50 ml of methanol was added and filtered. After vacuum drying, 2.4 g of white crystals were obtained. The results of ¹ H-NMR analysis of the obtained powder are as follows, and it was confirmed that the white crystals obtained above were the compound [1].
¹ H-NMR (CDCl ₃ (d = ppm)): 7.34–8.22 (m, 24H).

This compound [1] was used as a light emitting device material after sublimation purification at about 270 ° C. under a pressure of 1 × 10 ⁻³ Pa using an oil diffusion pump. The HPLC purity (area% at a measurement wavelength of 254 nm) was 99.8% before sublimation purification and 99.9% after sublimation purification.

Synthesis Example 2 (Synthesis Method of Compound [2])
A white crystal was obtained by synthesis in the same manner as in Synthesis Example 1 except that 4-methylphenylboronic acid was used instead of phenylboronic acid. The results of ¹ H-NMR analysis of the obtained powder are as follows, and it was confirmed that the white crystals obtained above were the compound [2].
¹ H-NMR (CDCl ₃ (d = ppm)): 2.56 (s, 3H), 7.32-8.21 (m, 23H).

This compound [2] was used as a light emitting device material after sublimation purification at about 260 ° C. under a pressure of 1 × 10 ⁻³ Pa using an oil diffusion pump. The HPLC purity (area% at a measurement wavelength of 254 nm) was 99.7% before sublimation purification and 99.8% after sublimation purification.

Synthesis Example 3 (Synthesis Method of Compound [17])
Synthesis was performed in the same manner as in Synthesis Example 1 except that 2-naphthaleneboronic acid was used in place of phenylboronic acid to obtain white crystals. The results of ¹ H-NMR analysis of the obtained powder are as follows, and it was confirmed that the white crystals obtained above were the compound [17].
¹ H-NMR (CDCl ₃ (d = ppm)): 7.31-8.23 (m, 26H).

This compound [17] was used as a light emitting device material after sublimation purification at about 270 ° C. under a pressure of 1 × 10 ⁻³ Pa using an oil diffusion pump. The HPLC purity (area% at a measurement wavelength of 254 nm) was 99.8% before sublimation purification and 99.9% after sublimation purification.

Synthesis Example 4 (Synthesis Method of Compound [11])
Synthesis was performed in the same manner as in Synthesis Example 1 except that 4-biphenylboronic acid was used in place of phenylboronic acid to obtain white crystals. The results of ¹ H-NMR analysis of the obtained powder are as follows, and it was confirmed that the white crystals obtained above were the compound [11].
¹ H-NMR (CDCl ₃ (d = ppm)): 7.36-8.22 (m, 28H).

This compound [11] was used as a light emitting device material after sublimation purification at about 300 ° C. under a pressure of 1 × 10 ⁻³ Pa using an oil diffusion pump. The HPLC purity (area% at a measurement wavelength of 254 nm) was 99.4% before sublimation purification and 99.9% after sublimation purification.

Synthesis Example 5 (Synthesis Method of Compound [13])
9-bromoanthracene 3.3 g, 2-biphenylboronic acid 3.0 g, potassium fluoride 2.5 g, tri-t-butylphosphine tetrafluoroborate 91 mg, bis (dibenzylideneacetone) palladium (0) 150 mg The mixed solution of 30 ml of vaporized tetrahydrofuran was stirred at room temperature for 20 hours under a nitrogen stream. The solution was filtered using celite. The filtrate was evaporated and the concentrate was purified by silica gel column chromatography and dried in vacuo to give 1.7 g of 9-biphenyl-2-yl-anthracene.

  Next, a mixed solution of 1.7 g of 9-biphenyl-2-yl-anthracene, 993 mg of N-bromosuccinimide and 15 ml of dimethylformamide was stirred at room temperature for 5 hours under a nitrogen stream. 20 ml of water was injected, the resulting precipitate was filtered, the solid was washed with methanol, purified by silica gel column chromatography, dried in vacuo, and 1.8 g of 9-biphenyl-2-yl-10-bromoanthracene. Got.

Next, 1.8 g of 9-biphenyl-2-yl-10-bromoanthracene, 4- [4- (4,4,5,5-tetramethyl- [1,3,2] dioxaborolan-2-yl) phenyl A mixed solution of 1.8 g of dibenzofuran, 2.0 g of tripotassium phosphate, 145 mg of PdCl ₂ (dppf) · CH ₂ Cl ₂ and 26 ml of degassed dimethylformamide was heated and stirred at 100 ° C. for 4 hours under a nitrogen stream. After cooling to room temperature, the obtained crystals were filtered. After sequentially washing with 30 ml of water and 30 ml of ethanol, 200 ml of toluene was added, dissolved at room temperature, and filtered using Celite. The filtrate was evaporated, purified by silica gel column chromatography, and dried under vacuum to obtain 2.5 g of white crystals. The results of ¹ H-NMR analysis of the obtained powder are as follows, and it was confirmed that the white crystals obtained above were the compound [13]. The results of ¹ H-NMR analysis of the obtained powder are as follows, and it was confirmed that the white crystals obtained above were the compound [13].
¹ H-NMR (CDCl ₃ (d = ppm)): 6.88-8.18 (m, 28H).

This compound [13] was used as a light emitting device material after sublimation purification at about 270 ° C. under a pressure of 1 × 10 ⁻³ Pa using an oil diffusion pump. The HPLC purity (area% at a measurement wavelength of 254 nm) was 99.6% before sublimation purification and 99.6% after sublimation purification.

Synthesis Example 6 (Synthesis Method of Compound [79])
Trifluoromethanesulfonic acid-6-bromo-2-naphthyl 5.3 g, 4-dibenzofuranboronic acid 3.2 g, potassium fluoride 2.6 g, tri-t-butylphosphine tetrafluoroborate 103 mg, bis (dibenzylideneacetone ) A mixed solution of 170 mg of palladium (0) and 30 ml of degassed tetrahydrofuran was stirred at room temperature for 9 hours under a nitrogen stream. 30 ml of water was poured into the solution and extracted with 30 ml of toluene. The organic layer was washed twice with 30 ml of water, dried over magnesium sulfate, and filtered using a silica pad. The filtrate was evaporated and the resulting solid was washed thoroughly with methanol and dried in vacuo to give 2.9 g of trifluoromethanesulfonic acid-6-dibenzofuran-4-yl-naphthalen-2-yl ester.

Next, 2.9 g of trifluoromethanesulfonic acid-6-dibenzofuran-4-yl-naphthalen-2-yl ester, 2.0 g of bis (pinacolato) diboron, 1.9 g of potassium acetate, PdCl ₂ (dppf) · CH ₂ Cl ₂ A mixed solution of 163 mg and degassed dimethylformamide 40 ml was heated and stirred at 90 ° C. for 3 hours under a nitrogen stream. 50 ml of water was poured into the solution and extracted with 40 ml of toluene. The organic layer was washed twice with 30 ml of water, dried over magnesium sulfate, and filtered through celite. The filtrate was evaporated, purified by silica gel column chromatography, dried in vacuo, and 4- [6- (4,4,5,5-tetramethyl- [1,3,2] dioxaborolan-2-yl) naphthalene. -2-yl] dibenzofuran 1.7 g was obtained.

Next, instead of 4- [4- (4,4,5,5-tetramethyl- [1,3,2] dioxaborolan-2-yl) phenyl] dibenzofuran, 4- [6- (4,4,5 , 5-tetramethyl- [1,3,2] dioxaborolan-2-yl) naphthalen-2-yl] dibenzofuran was synthesized in the same manner as in Synthesis Example 1 to obtain pale yellow crystals. The results of ¹ H-NMR analysis of the obtained powder are as follows, and it was confirmed that the pale yellow crystal obtained above was Compound [79].
¹ H-NMR (CDCl ₃ (d = ppm)): 7.26-8.24 (m, 26H).

This compound [79] was used as a light emitting device material after sublimation purification at about 275 ° C. under a pressure of 1 × 10 ⁻³ Pa using an oil diffusion pump. The HPLC purity (area% at a measurement wavelength of 254 nm) was 99.4% before sublimation purification and 99.5% after sublimation purification.

Example 1
An ITO conductive film was formed on a 30 × 40 mm glass substrate (Asahi Glass Co., Ltd., 15Ω / □, electron beam vapor-deposited product) at a central portion of the glass substrate to a thickness of 30 nm and a size of 30 × 13 mm to form an anode. . The substrate on which the anode was formed was ultrasonically cleaned with “Semicocrine (registered trademark) 56” (manufactured by Furuuchi Chemical Co., Ltd.) for 15 minutes and then with ultrapure water. Subsequently, it was ultrasonically cleaned with isopropyl alcohol for 15 minutes and then immersed in hot methanol for 15 minutes and dried. Immediately before the device was fabricated, this substrate was subjected to UV-ozone treatment for 1 hour, further placed in a vacuum vapor deposition apparatus, and evacuated until the degree of vacuum in the apparatus became 5 × 10 ⁻⁵ Pa or less. By the resistance heating method, first, copper phthalocyanine was deposited as a hole injecting material at 10 nm, and 4,4′-bis (N- (1-naphthyl) -N-phenylamino) biphenyl was deposited as a hole transporting material at 50 nm. Next, Compound [1] as a host material as a light emitting material and D-1 represented by the following formula as a dopant material were vapor-deposited to a thickness of 35 nm so that the doping concentration was 5%. Next, as an electron transport material, E-1 represented by the following formula was laminated to a thickness of 20 nm. On the organic layer formed as described above, lithium fluoride was vapor-deposited to a thickness of 0.5 nm, and then aluminum was vapor-deposited with a thickness of 1000 nm to form a 5 × 5 mm square device. The film thickness referred to here is a display value of a crystal oscillation type film thickness monitor. When this light emitting device was DC-driven at 10 mA / cm ² , high-efficiency blue light emission with a luminous efficiency of 5.3 lm / W was obtained. When this light emitting device was continuously driven at a direct current of 10 mA / cm ² , the luminance half time was 7500 hours.

Examples 2-6
A light emitting device was fabricated in the same manner as in Example 1 except that the materials listed in Table 1 were used as the host material. The results of each example are shown in Table 1.

Comparative Example 1
A light emitting device was fabricated in the same manner as in Example 1 except that H-1 shown by the following formula was used as the host material. When this light emitting device was DC-driven at 10 mA / cm ² , blue light emission with a luminous efficiency of 2.8 lm / W was obtained. When this light emitting device was continuously driven with a direct current of 10 mA / cm ² , the luminance was reduced by half in 700 hours.

Comparative Examples 2-6
A light emitting device was fabricated in the same manner as in Example 1 except that the materials listed in Table 1 were used as the host material. The results of each comparative example are shown in Table 1. In Table 1, H-2, H-3, H-4, H-5, and H-6 are compounds represented by the following formula.

Example 7
A light emitting device was produced in the same manner as in Example 1 except that D-2 represented by the following formula was used as a dopant material so that the doping concentration was 5%. When this light emitting device was DC-driven at 10 mA / cm ² , high-efficiency blue-green light emission with a light emission efficiency of 4.5 lm / W was obtained. When this light emitting device was continuously driven at a direct current of 10 mA / cm ² , the luminance half time was 4000 hours.

Examples 8-20
A light emitting device was fabricated in the same manner as in Example 1 except that the materials described in Table 2 were used as the host material and the dopant material. The results of each example are shown in Table 2. In Table 2, D-3, D-4, D-5, and D-6 are compounds represented by the following formula.

Example 21
A light emitting device was produced in the same manner as in Example 1 except that E-2 represented by the following formula was used as the electron transport material. When this light emitting device was DC-driven at 10 mA / cm ² , high-efficiency blue light emission with a light emission efficiency of 1.6 lm / W was obtained. When this light emitting element was DC-driven at 10 mA / cm ² , the luminance half time was 4000 hours.

Comparative Example 7
A light emitting device was produced in the same manner as in Comparative Example 5 except that E-2 was used as the electron transport material. When this light emitting device was DC-driven at 10 mA / cm ² , blue light emission with a luminous efficiency of 0.6 lm / W was obtained. When this light emitting device was continuously driven with a direct current of 10 mA / cm ² , the luminance was reduced by half in 2500 hours.

Examples 22-27
A light emitting device was produced in the same manner as in Example 1 except that the materials listed in Table 2 were used as the electron transporting material. The results of each example are shown in Table 2. In Table 2, E-3, E-4, E-5, E-6, and E-7 are compounds represented by the following formulae.

Example 28
A light emitting device was produced in the same manner as in Example 1 except that the dopant material was not used. When this light emitting device was DC-driven at 10 mA / cm ² , blue light emission with a luminous efficiency of 1.2 lm / W was obtained. When this light emitting device was continuously driven at a direct current of 10 mA / cm ² , the luminance half time was 3700 hours.

Example 29
A light emitting device was produced in the same manner as in Example 28 except that the compound [17] was used as the host material. When this light emitting device was DC-driven at 10 mA / cm ² , blue light emission with a luminous efficiency of 1.5 lm / W was obtained. When this light emitting device was continuously driven at a direct current of 10 mA / cm ² , the luminance half time was 4100 hours.

Comparative Example 8
A light emitting device was fabricated in the same manner as in Example 28 except that H-6 was used as the host material. When this light emitting device was DC-driven at 10 mA / cm ² , blue light emission with a luminous efficiency of 0.5 lm / W was obtained. When this light emitting device was continuously driven with a direct current of 10 mA / cm ² , the luminance was reduced by half in 900 hours.

Example 30
A light emitting device was produced in the same manner as in Example 1 except that D-7 shown below was used as a dopant material so that the doping concentration was 2%. When this light emitting device was DC-driven at 10 mA / cm ² , high-efficiency green light emission with a light emission efficiency of 6.0 lm / W was obtained. When this light emitting device was continuously driven at a direct current of 10 mA / cm ² , the luminance half time was 5800 hours.

Example 31
A light emitting device was produced in the same manner as in Example 30 except that the compound [17] was used as the host material. When this light emitting device was DC-driven at 10 mA / cm ² , high efficiency green light emission with a light emission efficiency of 5.7 lm / W was obtained. When this light emitting device was continuously driven at a direct current of 10 mA / cm ² , the luminance half time was 6000 hours.

Example 32
A light emitting device was produced in the same manner as in Example 1 except that D-8 shown below was used as a dopant material so that the doping concentration was 5%. When this light emitting device was DC-driven at 10 mA / cm ² , high efficiency green light emission with a light emission efficiency of 15.0 lm / W was obtained. When this light emitting device was continuously driven at a direct current of 10 mA / cm ² , the luminance half time was 10,000 hours.

Example 33
A light emitting device was produced in the same manner as in Example 1 except that D-9 shown below was used as a dopant material so that the doping concentration was 5%. When this light emitting device was DC-driven at 10 mA / cm ² , high-efficiency green light emission with a light emission efficiency of 14.3 lm / W was obtained. When this light emitting device was continuously driven at a direct current of 10 mA / cm ² , the luminance half time was 11000 hours.

Example 34
The compound [1] as the host material and the compound [1] as the host material and the D-1 as the dopant material are deposited to a thickness of 5 nm so that the doping concentration is 5%. Was made in the same manner as in Example 1 except that D-10 shown below as a dopant material was laminated to a thickness of 30 nm so that the doping concentration was 1%. When this light emitting device was DC-driven at 10 mA / cm ² , high efficiency white light emission with a luminous efficiency of 7.0 lm / W was obtained. When this light emitting device was continuously driven at a direct current of 10 mA / cm ² , the luminance half time was 6900 hours.

Example 35
A light emitting device was produced in the same manner as in Example 34 except that the compound [17] was used as the host material. When this light emitting device was DC-driven at 10 mA / cm ² , high efficiency white light emission with a light emission efficiency of 6.8 lm / W was obtained. When this light emitting device was continuously driven at a direct current of 10 mA / cm ² , the luminance half time was 6500 hours.

  The results of Examples 1-6 and Comparative Examples 1-6 are summarized in Table 1, the results of Examples 7-20 are summarized in Table 2, and the results of Examples 21-35 and Comparative Examples 7-8 are summarized in Table 3.

Example 36
An ITO conductive film was formed on a 30 × 40 mm glass substrate (Asahi Glass Co., Ltd., 15Ω / □, electron beam vapor-deposited product) at a central portion of the glass substrate to a thickness of 30 nm and a size of 30 × 13 mm to form an anode. . The substrate on which the anode was formed was ultrasonically cleaned with acetone and “Semicocrine (registered trademark) 56” (manufactured by Furuuchi Chemical Co., Ltd.) for 15 minutes, respectively, and then with ultrapure water. Subsequently, it was ultrasonically cleaned with isopropyl alcohol for 15 minutes and then immersed in hot methanol for 15 minutes and dried. This substrate was subjected to UV-ozone treatment for 1 hour immediately before producing the device, further placed in a vacuum vapor deposition apparatus, and evacuated until the degree of vacuum in the apparatus became 5 × 10 ⁻⁴ Pa or less. First, 4,4′-bis (N- (m-tolyl) -N-phenylamino) biphenyl was deposited as a hole transport material by a resistance heating method to a thickness of 150 nm. Next, the compound [1] as a host material and D-1 as a dopant material were vapor-deposited to a thickness of 35 nm so that the doping concentration was 5%. Next, E-1 was laminated to a thickness of 20 nm as an electron transport material. The film thickness referred to here is a display value of a crystal oscillation type film thickness monitor. Next, the mask provided with 16 250 μm openings (corresponding to the remaining width of 50 μm and 300 μm pitch) by wet etching on a 50 μm thick Kovar plate was replaced in a vacuum so as to be orthogonal to the ITO stripe. And it fixed with the magnet from the back so that an ITO board | substrate might closely_contact | adhere. And after doping lithium with a 0.5 nm organic layer, aluminum was vapor-deposited 200 nm, and the 32 * 16 dot matrix element was produced. When this element was driven in matrix, characters could be displayed without crosstalk.

  The light emitting device material of the present invention can be used for a light emitting device or the like, and can provide a light emitting device material having excellent thin film stability. According to the present invention, a light emitting device having high luminous efficiency and excellent durability can be obtained. The light-emitting element of the present invention can be used in the fields of display elements, flat panel displays, backlights, illumination, interiors, signs, signboards, electrophotographic machines, optical signal generators, and the like.

Claims (7)

A light emitting device material comprising an anthracene compound represented by the general formula (1).

(R ^{1 to} R ¹⁶ may be the same or different and each represents hydrogen, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkoxy group, an alkylthio group, an aryl group, a heteroaryl group, an amino group, a silyl group, and adjacent substitution. Selected from the group consisting of a ring structure formed with a group, provided that any one of R ^{9 to} R ¹⁶ is used for linking to A. R ^{17 to} R ²⁰ may be the same or different. R ²¹ is selected from the group consisting of hydrogen, alkyl group, cycloalkyl group, heterocyclic group, alkoxy group, alkylthio group, aryl group, heteroaryl group, amino group, and silyl group, and R ²¹ is hydrogen, linear alkyl Groups, cycloalkyl groups, heterocyclic groups, alkoxy groups, alkylthio groups, aryl groups, heteroaryl groups, amino groups, silyl groups and adjacent substituents (A is an arylene group, n is 1 or 2. X is an oxygen atom or a sulfur atom.) The light emitting device material according to claim 1, wherein A is a phenylene group or a naphthylene group. The light emitting device material according to claim 1, wherein X is an oxygen atom. Light emitting device material according to any one of claims 1 to 3 A is characterized by linking at the position of R ^9. A light-emitting element having at least a light-emitting layer between an anode and a cathode and emitting light by electric energy, wherein the light-emitting element contains the light-emitting element material according to claim 1. . 6. The light emitting device according to claim 5, wherein the light emitting layer has a host material and a dopant material, and the light emitting device material represented by the general formula (1) is a host material. There is at least an electron transport layer between the light emitting layer and the cathode, and the electron transport layer contains electron-accepting nitrogen and is further composed of an element selected from carbon, hydrogen, nitrogen, oxygen, silicon, and phosphorus. The light emitting device according to claim 6, comprising a compound having an aryl ring structure.