Compound, liquid composition containing the compound, and electroluminescence device

Abstract

To provide means allowing manufacture of an EL device by inkjet.SOLUTION: The invention employs a compound represented by Formula (1), and specifically the compound C-1, for example. In the formula, n is an integer from 3 to 10 inclusive; and X and Y are substituents having a triarylamine moiety.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a compound, as well as a liquid composition and an electroluminescence device containing the compound.

Background Art

[0002] Electroluminescence devices (EL devices) are being actively researched and developed. In particular, EL devices are expected to be used as inexpensive large-area full-color display devices and writing light source arrays of the solid light-emitting type. An EL device is a light-emitting device having a thin film of several nanometers to several hundred nanometers between an anode and a cathode. Further, an EL device usually further has a hole transport layer, a light-emitting layer, an electron transport layer, and the like.

[0003] Among these, as the light-emitting layer, there are a fluorescent light-emitting material and a phosphorescent light-emitting material. A phosphorescent light-emitting material is a material expected to have a higher light-emitting efficiency compared to a fluorescent light-emitting material. Further, in order to cover a wide color gamut, an RGB light source is required to have a narrow half-value width emission spectrum. In particular, deep blue is required for blue, but at present, no device that can satisfy the viewpoints of long life and color purity has been found.

[0004] As a method for solving these problems, there is a light-emitting device that uses "quantum dots", which are inorganic light-emitting substances, as a light-emitting material (Patent Document 1). A quantum dot (QD) is a semiconductor material having a crystal structure with a size of several nanometers and is composed of about several hundred to several thousand atoms. Since the size of the quantum dot is extremely small, the surface area per unit volume is large. For this reason, most of the atoms are present on the surface of the nanocrystal, and it exhibits effects such as quantum confinement. Due to such a quantum confinement effect, the quantum dot can adjust the emission wavelength only by adjusting its size, and has characteristics such as excellent color purity and high photoluminescence (PL) emission efficiency, and thus has attracted much attention. A quantum dot electroluminescence device (QD LED) is known as a basic device having a three-layer structure including a hole transport layer (HTL) and an electron transport layer (ETL) on both sides with a quantum dot light-emitting layer in between.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In recent years, from the viewpoints of increasing the screen size, improving the efficiency of the manufacturing process, and reducing costs, it is desirable to manufacture EL elements by inkjet. On the other hand, in a laminated structure composed of a lower layer (for example, a hole transport layer) and an upper layer (for example, a light-emitting layer), when the lower layer is formed by inkjet, the following two properties are required for the lower layer material. (i) The viscosity of the lower layer ink obtained by dissolving the lower layer material in a solvent is low. (ii) The remaining film ratio of the lower layer is high when forming the upper layer (that is, it has low solubility in the solvent contained in the upper layer ink (has solvent resistance)).

[0007] However, the hole transport material (for example, TFB) described in Patent Document 1 had a problem of not having these properties.

[0008] Therefore, an object of the present invention is to provide a means capable of manufacturing an EL element by inkjet.

Means for Solving the Problems

[0009] The present inventors conducted intensive studies to solve the above problems. As a result, they found that the above problems can be solved by using a compound having a specific structure, and completed the present invention.

[0010] That is, the above object can be achieved by the compound represented by the following formula (1).

[0011]

Chemical formula

[0012] In formula (1), n is an integer of 3 or more and 10 or less, X represents a group represented by the following formula (2), and a plurality of Xs may be the same or different, Y represents a group represented by the following formula (3), and a plurality of Ys may be the same or different.

[0013]

Chemical formula

[0014] In formula (2), R1, R2, and R3 each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, may be the same or different, and may be bonded to each other to form a ring. a and b are each independently an integer of 2 or more and 10 or less. c is an integer of 1 or more and 6 or less.

[0015]

Chemical formula

[0016] In formula (3), R4, R5, and R6 each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, may be the same or different, and may be bonded to each other to form a ring. d is an integer of 1 or more and 5 or less. e and f are each independently an integer of 1 or more and 6 or less.

Advantages of the Invention

[0017] According to the present invention, it is possible to provide a means for manufacturing an EL element by inkjet.

Brief Description of the Drawings

[0018]

Figure 1

Modes for Carrying Out the Invention

[0019] In a first aspect, the present invention provides a compound represented by the following formula (1):

[0020]

Chemical formula

[0021] In formula (1), n is an integer of 3 or more and 10 or less, X represents a group represented by the following formula (2), and a plurality of Xs may be the same or different, Y represents a group represented by the following formula (3), and a plurality of Ys may be the same or different.

[0022]

Chemical formula

[0023] In formula (2), R1, R2, and R3 each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, may be the same or different, and may be bonded to each other to form a ring, a and b are each independently an integer of 2 or more and 10 or less, c is an integer of 1 or more and 6 or less;

[0024]

Chemical formula

[0025] In formula (3), R4, R5, and R6 each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, may be the same or different, and may be bonded to each other to form a ring, d is an integer of 1 or more and 5 or less, e and f are each independently an integer of 1 or more and 6 or less.

[0026] In this specification, the "compound represented by formula (1)" is also referred to as "compound" or "compound according to the present invention".

[0027] In a second aspect, the present invention provides a liquid composition containing the compound according to the present invention and a solvent.

[0028] In a third aspect, the present invention provides an electroluminescence device including a first electrode, a second electrode, and one or more organic films disposed between the first electrode and the second electrode, wherein at least one of the organic films contains a compound according to the present invention. In the present specification, the electroluminescence device is also simply referred to as an "LED". The quantum dot electroluminescence device is also simply referred to as a "QLED". The organic electroluminescence device is also simply referred to as an "OLED".

[0029] The electroluminescence device is manufactured by sequentially laminating a hole transport layer, a light emitting layer, a charge transport layer, and the like. As a method for forming such a laminated structure, currently, a vapor deposition method using a low molecular weight material or a wet method using a high molecular weight material is adopted. Among these, from the viewpoints of increasing the screen size, improving the efficiency, and reducing the cost, the wet method is preferably used. In recent years, since it has become possible to manufacture a higher definition device, it has been desired to adopt an inkjet coating process. However, on the other hand, the design of materials capable of forming a laminated structure has been a major issue.

[0030] Since the compound according to the present invention has the above-described two properties (low viscosity and high residual film ratio), it is possible to manufacture an electroluminescence device by inkjet. The mechanism by which the above-described operational effects are exhibited by the configuration of the present invention is presumed as follows. The compound represented by the above formula (1) has a smaller molecular weight compared to conventional polymer compounds. Further, since it has many rotation axes on the main chain, it can take various structures. Furthermore, since it has a chain structure, there is little entanglement between molecules. Due to these structural characteristics, the compound according to the present invention has excellent solubility and low viscosity when made into a solution. In addition, since the compound represented by the above formula (1) has a chain structure, it is considered to form a packing structure in which molecules are densely arranged (stacked) within the layer. Therefore, even when the film is once formed and then comes into contact with another solvent (for example, when an upper layer ink is applied on the film), it is difficult for the other solvent to enter the gaps between the compounds, and it has excellent solvent resistance. For this reason, even when another layer is formed on the surface of the layer by a wet method, it has a high residual film ratio. The above features are particularly exhibited when the compound according to the present invention is used for the hole transport layer.

[0031] Therefore, according to the compound of the present invention, it is possible to manufacture an electroluminescence device by inkjet.

[0032] Furthermore, it has been found that by applying the compound according to the present invention to an electroluminescent element (particularly the hole transport layer of an electroluminescent element), higher luminous efficiency can be achieved compared to the case of using known materials. Further, by applying the compound according to the present invention to an electroluminescent element (particularly the hole transport layer of an electroluminescent element), it has been found that the durability (luminescence lifetime) can be improved compared to the case of using known materials. The mechanism by which the above-described operational effects are exhibited by the configuration of the present invention is presumed as follows. According to the compound represented by the above formula (1), since the molecules are densely arranged in the layer as described above, the obtained film has excellent hole transport properties. In addition, the compound represented by the above formula (1) has a HOMO level suitable for hole injection into the light emitting layer (particularly the quantum dot light emitting layer). Therefore, high luminous efficiency can be exhibited in an electroluminescent element (particularly a quantum dot electroluminescent element). In addition, the durability (luminescence lifetime) of the electroluminescent element can be improved by the dense film.

[0033] Note that the above mechanism is based on speculation, and the present invention is not limited to the above mechanism in any way.

[0034] Hereinafter, embodiments of the present invention will be described. Note that the present invention is not limited only to the following embodiments. In addition, each drawing is exaggerated for convenience of explanation, and the dimensional ratios of the respective components in each drawing may be different from the actual ones. Further, when the embodiments of the present invention are described with reference to the drawings, the same reference numerals are given to the same elements in the description of the drawings, and duplicate explanations are omitted.

[0035] In this specification, unless otherwise specified, measurements of operations and physical properties are performed under the conditions of room temperature (20°C or higher and 25°C or lower) / relative humidity of 40% RH or higher and 50% RH or lower.

[0036] As used herein, unless otherwise defined, "substituted" means substituted with an alkyl group, a cycloalkyl group, a hydroxyalkyl group, an alkoxyalkyl group, an alkoxy group, a cycloalkoxy group, an alkenyl group, an alkynyl group, an amino group, an aryl group, an aryloxy group, an alkylthio group, a cycloalkylthio group, an arylthio group, an alkoxycarbonyl group, an aryloxycarbonyl group, a hydroxyl group (-OH), a carboxyl group (-COOH), a thiol group (-SH), or a cyano group (-CN). Note that the substituents present in some cases are not the same as the groups being substituted. For example, an alkyl group is not substituted with an alkyl group.

[0037] Here, as the alkyl group as a substituent, it may be either linear or branched, but preferably includes a linear alkyl group having 1 to 20 carbon atoms and a branched alkyl group having 3 to 20 carbon atoms. Specifically, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, tert-pentyl group, neopentyl group, 1,2-dimethylpropyl group, n-hexyl group, isohexyl group, 1,3-dimethylbutyl group, 1-isopropylpropyl group, 1,2-dimethylbutyl group, n-heptyl group, 1,4-dimethylpentyl group, 3-ethylpentyl group, 2-methyl-1-isopropylpropyl group, 1-ethyl-3-methylbutyl group, n-octyl group, 2-ethylhexyl group, 3-methyl-1-isopropylbutyl group, 2-methyl-1-isopropyl group, 1-tert-butyl-2-methylpropyl group, n-nonyl group, 3,5,5-trimethylhexyl group, n-decyl group, isodecyl group, n-undecyl group, 1-methyldecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-icosyl group, etc. can be mentioned.

[0038] Examples of the cycloalkyl group as a substituent include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, etc.

[0039] Examples of the hydroxyalkyl group as a substituent include those in which the above alkyl group is substituted with 1 to 3 (preferably 1 to 2, particularly preferably 1) hydroxyl groups (e.g., hydroxymethyl group, hydroxyethyl group).

[0040] Examples of the alkoxyalkyl group as a substituent include those in which the above alkyl group is substituted with 1 to 3 (preferably 1 to 2, particularly preferably 1) alkoxy groups detailed below.

[0041] The alkoxy group as a substituent may be either linear or branched, and preferably includes a linear alkoxy group having 1 to 20 carbon atoms and a branched alkoxy group having 3 to 20 carbon atoms. For example, methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, 3-ethylpentyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group, dodecyloxy group, tridecyloxy group, tetradecyloxy group, pentadecyloxy group, hexadecyloxy group, heptadecyloxy group, octadecyloxy group, etc. are included.

[0042] Examples of the cycloalkoxy group as a substituent include cyclopropyloxy group, cyclobutyloxy group, cyclopentyloxy group, cyclohexyloxy group, etc.

[0043] Examples of the alkenyl group as a substituent include vinyl group, allyl group, 1-propenyl group, isopropenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 1-pentenyl group, 2-pentenyl group, 3-pentenyl group, 1-hexenyl group, 2-hexenyl group, 3-hexenyl group, 1-heptenyl group, 2-heptenyl group, 5-heptenyl group, 1-octenyl group, 3-octenyl group, 5-octenyl group, etc.

[0044] Examples of the alkynyl group as a substituent include an ethynyl group, 1-propynyl group, 2-propynyl group, 1-butynyl group, 2-butynyl group, 3-butynyl group, 1-pentynyl group, 2-pentynyl group, 3-pentynyl group, 1-hexynyl group, 2-hexynyl group, 3-hexynyl group, 1-heptynyl group, 2-heptynyl group, 5-heptynyl group, 1-octynyl group, 3-octynyl group, 5-octynyl group, and the like.

[0045] Examples of the aryl group as a substituent include an aryl group having 6 to 30 carbon atoms. For example, a phenyl group, naphthyl group, biphenyl group, fluorenyl group, anthryl group, pyrenyl group, azulenyl group, acenaphthylenyl group, terphenyl group, phenanthryl group, and the like can be mentioned.

[0046] Examples of the aryloxy group as a substituent include a phenoxy group, naphthyloxy group, and the like.

[0047] Examples of the alkylthio group as a substituent include a methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, and the like.

[0048] Examples of the cycloalkylthio group as a substituent include a cyclopentylthio group, cyclohexylthio group, and the like.

[0049] Examples of the arylthio group as a substituent include a phenylthio group, naphthylthio group, and the like.

[0050] Examples of the alkoxycarbonyl group as a substituent include a methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, and the like.

[0051] Examples of the aryloxycarbonyl group as a substituent include a phenyloxycarbonyl group, naphthyloxycarbonyl group, and the like.

[0052] [Compound] In a first aspect of the present invention, a compound represented by the following formula (1) is provided. The compound according to the present invention has a low viscosity when made into a solution and a high residual film ratio. Therefore, according to the compound of the present invention, it is possible to manufacture an EL element by inkjet. Further, an electroluminescence element (particularly a quantum dot electroluminescence element) having the compound according to the present invention (particularly in a hole transport layer) is excellent in luminous efficiency and durability (has a long luminous life).

[0053] [Chemical formula]

[0054] In the above formula (1), X represents a group represented by the following formula (2). At this time, a plurality of Xs may be the same or different from each other.

[0055] [Chemical formula]

[0056] In the above formula (2), R1, R2, and R3 each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. At this time, a plurality of R1, a plurality of R2, and a plurality of R3 may be the same or different. Further, R1, R2, and R3 may be bonded to each other to form a ring. The alkyl group having 1 to 10 carbon atoms may be either linear or branched and is not particularly limited. Specific examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a tert-pentyl group, a neopentyl group, a 1,2-dimethylpropyl group, an n-hexyl group, an isohexyl group, a 1,3-dimethylbutyl group, a 1-isopropylpropyl group, a 1,2-dimethylbutyl group, an n-heptyl group, a 1,4-dimethylpentyl group, a 3-ethylpentyl group, a 2-methyl-1-isopropylpropyl group, a 1-ethyl-3-methylbutyl group, an n-octyl group, a 2-ethylhexyl group, a 3-methyl-1-isopropylbutyl group, a 2-methyl-1-isopropyl group, a 1-tert-butyl-2-methylpropyl group, an n-nonyl group, a 3,5,5-trimethylhexyl group, an n-decyl group, and an isodecyl group. Among these, R1, R2, and R3 each independently are preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom, a methyl group, an n-propyl group, an n-hexyl group, still more preferably a hydrogen atom, a methyl group, an n-propyl group, and particularly preferably a hydrogen atom and a methyl group. With such R1, R2, and R3, they have excellent solubility and a low viscosity when made into a solution. Further, since they have excellent solvent resistance, they have a high residual film ratio.

[0057] Here, the forms in which R1, R2, and R3 are bonded to each other to form a ring are not particularly limited. For example, (a1) a form in which two R1s respectively bonded to adjacent benzene rings are bonded to each other to form a ring, (a2) a form in which two R2s respectively bonded to adjacent benzene rings are bonded to each other to form a ring, (a3) a form in which two R3s respectively bonded to adjacent benzene rings are bonded to each other to form a ring, (a4) a form in which R1 and R2 bonded to adjacent benzene rings via a nitrogen atom (N) are bonded to each other to form a ring, (a5) a form in which R1 and R3 bonded to adjacent benzene rings via a nitrogen atom (N) are bonded to each other to form a ring, and (a6) a form in which R2 and R3 bonded to adjacent benzene rings via a nitrogen atom (N) are bonded to each other to form a ring can be mentioned. According to a preferred form, in the forms of (a1) to (a3) above, a methyl group and a hydrogen atom are bonded to each other to form a ring, thereby forming a fluorene structure. According to another preferred form, in the forms of (a4) to (a6) above, a hydrogen atom and a hydrogen atom are bonded to each other to form a ring, thereby forming a carbazole structure.

[0058] In the above formula (2), a and b are each independently an integer of 2 or more and 10 or less. If a and b are less than 2, it becomes difficult to form a packing structure in which molecules are densely arranged (stacked) within the layer, and a sufficient residual film ratio may not be obtained. Further, if a and b are less than 2, the HOMO level of the compound according to the present invention becomes shallow, and sufficient light emission efficiency may not be obtained. If a and b exceed 10, an ink with a low viscosity suitable for inkjet may not be obtained. From the above viewpoints, a and b are each independently preferably one is 2 or more and 10 or less, and the other is 3 or more and 10 or less, more preferably one is 2 or more and 8 or less, and the other is 3 or more and 8 or less, still more preferably one is 2 or more and 6 or less, and the other is 3 or more and 6 or less, particularly preferably one is 2 or more and 4 or less, and the other is 3 or 4. Further, when a and b satisfy the above numerical range, the sum of a and b is preferably 5 or more and 20 or less, more preferably 5 or more and 15 or less, still more preferably 5 or more and 15 or less, and particularly preferably 5 or more and 7 or less.

[0059] In the above formula (2), c is an integer of 1 or more and 6 or less. If c exceeds 6, an ink with a low viscosity suitable for inkjet may not be obtained, or a sufficient residual film ratio may not be obtained. From the above viewpoints, c is preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less, still more preferably 1 or 2, and particularly preferably 2.

[0060] In the above formula (2), * represents a bonding site with Y (a group represented by the following formula (3)).

[0061] In the above formula (1), n is an integer of 3 or more and 10 or less. When n is less than 3, it becomes difficult for the molecules to form a packing structure in which they are densely arranged (stacked) within the layer, and a sufficient residual film ratio may not be obtained. Further, when n is less than 3, the HOMO level of the compound according to the present invention becomes shallow, and sufficient luminous efficiency may not be obtained. When n exceeds 10, an ink having a low viscosity suitable for inkjet may not be obtained. From the above viewpoints, n is preferably 3 or more and 8 or less, more preferably 3 or more and 6 or less, and still more preferably 4 or 5.

[0062] In the above formula (1), Y represents a group represented by the following formula (3). At this time, a plurality of Ys may be the same or different.

[0063]

Chemical formula

[0064] In the above formula (3), R4, R5, and R6 each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. At this time, a plurality of R4, a plurality of R5, and a plurality of R6 may be the same or different. Further, R4, R5, and R6 may be bonded to each other to form a ring. The alkyl group having 1 to 8 carbon atoms may be either linear or branched and is not particularly limited. Specific examples of the alkyl group having 1 to 8 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, tert-pentyl group, neopentyl group, 1,2-dimethylpropyl group, n-hexyl group, isohexyl group, 1,3-dimethylbutyl group, 1-isopropylpropyl group, 1,2-dimethylbutyl group, n-heptyl group, 1,4-dimethylpentyl group, 3-ethylpentyl group, 2-methyl-1-isopropylpropyl group, 1-ethyl-3-methylbutyl group, n-octyl group, 2-ethylhexyl group, 3-methyl-1-isopropylbutyl group, 2-methyl-1-isopropyl group, 1-tert-butyl-2-methylpropyl group. Among these, R4, R5, and R6 each independently are preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and still more preferably a hydrogen atom, a methyl group, or an n-propyl group. With such R4, R5, and R6, they have excellent solubility and low viscosity when made into a solution. Further, since they have excellent solvent resistance, they have a high residual film ratio.

[0065] Here, the forms in which R4, R5, and R6 are bonded to each other to form a ring are not particularly limited. For example, (b1) a form in which two R4s each bonded to adjacent benzene rings are bonded to each other to form a ring, (b2) a form in which two R5s each bonded to adjacent benzene rings are bonded to each other to form a ring, (b3) a form in which two R6s each bonded to adjacent benzene rings are bonded to each other to form a ring, (b4) a form in which R4 and R5 bonded to adjacent benzene rings via a nitrogen atom (N) are bonded to each other to form a ring, (b5) a form in which R4 and R6 bonded to adjacent benzene rings via a nitrogen atom (N) are bonded to each other to form a ring, (b6) a form in which R5 and R6 bonded to adjacent benzene rings via a nitrogen atom (N) are bonded to each other to form a ring can be mentioned. According to a preferred form, in the forms of (b1) to (b3) above, a methyl group and a hydrogen atom are bonded to each other to form a ring, thereby forming a fluorene structure. According to another preferred form, in the forms of (b4) to (b6) above, a hydrogen atom and a hydrogen atom are bonded to each other to form a ring, thereby forming a carbazole structure.

[0066] In the above formula (3), d is an integer of 1 or more and 5 or less. When d exceeds 5, a low-viscosity ink suitable for inkjet may not be obtained. From the above viewpoint, d is preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less, still more preferably 1 or 2, and particularly preferably 1.

[0067] In the above formula (3), e and f are each independently an integer of 1 or more and 6 or less. When e and f exceed 6, a low-viscosity ink suitable for inkjet may not be obtained, or a sufficient residual film ratio may not be obtained. From the above viewpoint, e and f are each independently preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less, still more preferably 1 or 2, and particularly preferably 2.

[0068] In the above formula (3), * represents the bonding site with X (the group represented by the above formula (2)).

[0069] According to a preferred embodiment, in the above formula (1) of the compound according to the present invention, n is 3 or more and 8 or less; in the above formula (2), R1, R2 and R3 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, a and b are each independently 3 or more and 8 or less, and c is 1 or more and 4 or less; in the above formula (3), R4, R5 and R6 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, d is 1 or more and 4 or less, and e and f are each independently 1 or more and 4 or less. According to a more preferred embodiment, in the above formula (1) of the compound according to the present invention, n is 3 or more and 6 or less; in the above formula (2), R1, R2 and R3 are each independently a hydrogen atom, a methyl group, an n-propyl group or an n-hexyl group, a and b are each independently 3 or more and 6 or less, and c is 1 or more and 3 or less; in the above formula (3), R4, R5 and R6 are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, d is 1 or more and 3 or less, and e and f are each independently 1 or more and 3 or less. The compounds according to the above preferred embodiment and the above more preferred embodiment have better solubility and lower viscosity when made into a solution. Further, these compounds have better solvent resistance and a high residual film rate even when another layer is formed on the surface of the layer by a wet method. Furthermore, by applying these compounds to an electroluminescence device, the luminous efficiency and durability (luminescence lifetime) can be improved as compared with the case of using a known material.

[0070] Hereinafter, preferred specific examples of the compound according to the present invention will be described.

[0071]

Chemical formula

[0072] The molecular weight of the compound according to the present invention is not particularly limited, but is preferably 3,000 or more and 10,000 or less, more preferably 3,000 or more and 8,000 or less, and even more preferably 3,000 or more and 6,000 or less. When the molecular weight is 3,000 or more, the residual film ratio can be further improved. When the molecular weight is 10,000 or less, the viscosity of the ink can be further reduced. Unless otherwise specified, the molecular weight (the molecular weights of the compound, low molecular compound, and high molecular compound according to the present invention) in this specification adopts the value measured under the following conditions by gel permeation chromatography.

[0073] The molecular weight was measured using polystyrene as a standard substance by GPC (manufactured by Shimadzu Corporation, trade name: LC-20AD). At this time, the sample to be measured was dissolved in tetrahydrofuran to a concentration of about 0.05% by mass, and 20 μL was injected into the GPC. Tetrahydrofuran (THF) was used as the mobile phase of the GPC and flowed at a flow rate of 1.0 mL / min. As the column, PLgel MIXED-B (manufactured by Polymer Laboratories) was used. As the detector, a UV-VIS detector (manufactured by Shimadzu Corporation, trade name: SPD-10AV) was used.

[0074] The compound according to the present invention can be synthesized by using known organic synthesis methods. Those skilled in the art who refer to the examples described later can easily understand the specific synthesis method of the compound according to the present invention. Specifically, the compound according to the present invention can be produced by reacting the compound represented by the following formula (4) with the compound represented by the following formula (5).

[0075]

Chemical formula

[0076] In the above formulas (4) and (5), X, Y, and n have the same definitions as in the above formula (1). Z1, Z2, and Z1' are each independently a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom, particularly bromine atom) or a group having the following structure. In the following structure, R A ~R Dis independently an alkyl group having 1 to 3 carbon atoms. Preferably, R A ~R D is a methyl group. In the above formula (4), Z1 and Z2 may be the same or different from each other. It is preferable that Z1 and Z2 in the above formula (4) are different from Z1' in the above formula (5).

[0077] [Chemical formula]

[0078] In the present invention, the compound represented by the above formula (4) and the compound represented by the above formula (5) can be synthesized by appropriately combining known synthetic reactions, and their structures can also be confirmed by known methods (for example, NMR, LC-MS, etc.).

[0079] [Composition] The compound according to the present invention may be used as a composition in combination with other compounds. That is, according to one embodiment of the present invention, there is provided a composition containing the compound according to the present invention and a low molecular weight compound having a molecular weight of less than 2000, wherein the content of the low molecular weight compound is 30% by mass or less. By preparing an inkjet ink using the composition according to the present invention, the viscosity of the ink can be further reduced. Further, by forming an organic film (for example, a hole transport layer or a hole injection layer, preferably a hole transport layer) of an electroluminescence element using the composition according to the present invention, the low molecular weight compound can enter the gaps between the compounds according to the present invention to form a dense film. Thereby, the performance of the organic film (for example, the hole transport performance of the hole transport layer or the hole injection performance of the hole injection layer, preferably the hole transport performance of the hole transport layer) can be improved. Thereby, it becomes possible to improve the element performance.

[0080] According to another aspect of the present invention, there is provided a composition comprising a compound according to the present invention and a polymer compound having a molecular weight exceeding 10,000, wherein the content of the polymer compound is 60% by mass or less. By forming an organic film (for example, a hole transport layer or a hole injection layer, preferably a hole transport layer) of an electroluminescence element using the composition according to the present invention, the compound according to the present invention and the polymer compound are intertwined, and the residual film ratio can be further improved. Further, by combining the compound according to the present invention and the polymer compound, the performance of the organic film (for example, the hole transport performance of the hole transport layer or the hole injection performance of the hole injection layer, preferably the hole transport performance of the hole transport layer) can be improved.

[0081] According to a more preferred aspect of the present invention, there is provided a composition comprising a compound according to the present invention, a low molecular weight compound having a molecular weight of less than 2,000, and a polymer compound having a molecular weight exceeding 10,000, wherein the content of the low molecular weight compound is 30% by mass or less and the content of the polymer compound is 60% by mass or less. By using the composition according to the present invention, it is possible to achieve both the improvement of the above-described element performance and the improvement of the residual film ratio.

[0082] In the present specification, the "low molecular weight compound having a molecular weight of less than 2,000" is also simply referred to as "low molecular weight compound" or "low molecular weight compound according to the present invention". The "polymer compound having a molecular weight exceeding 10,000" is also simply referred to as "polymer compound" or "polymer compound according to the present invention". Further, the composition containing the compound according to the present invention, the low molecular weight compound and / or the polymer compound at a predetermined ratio is referred to as "composition" or "composition according to the present invention".

[0083] (Low molecular weight compound) The low molecular weight compound according to the present invention is not particularly limited as long as its molecular weight is less than 2,000. According to a preferred embodiment, it is more preferable that the low molecular weight compound is at least one selected from the compounds represented by the following formulas (J1) to (J3).

[0084] [Chemical formula]

[0085] In the above formula (J1), Ar a and Ar b are each independently a substituted or unsubstituted monovalent aromatic hydrocarbon group or a monovalent aromatic heterocyclic group. Preferably, Ar a and Ar b are a substituted or unsubstituted phenyl group, biphenyl group, or terphenyl group. Ar a and Ar b may be bonded to adjacent aromatic rings to form a ring.

[0086] In the above formula (J1), J is =C(R a )- or =N-, preferably =C(R a )-. At this time, R a is a hydrogen atom, alkyl group, cyano group, monovalent aromatic hydrocarbon group, monovalent aromatic heterocyclic group, hydrocarbon group-substituted silyl group, alkoxy group, or halogen group. A plurality of R a may be bonded to each other to form a ring.

[0087] As the compound represented by the above formula (J1), a compound represented by the following chemical formula (J1-1) is preferable.

[0088] [Chemical formula]

[0089] In the above formula (J1-1), Ar a’ and Ar b’ are groups selected from the following group. Note that the hydrogen atoms contained in the following groups may be substituted by substituents. Also, in the following groups, * represents a bond to the benzene ring carbon of the above formula (J1-1). In the above formula (J1-1), R a are each independently preferably a linear alkyl group having 1 or more and 12 or fewer carbon atoms, more preferably a linear alkyl group having 3 or more and 8 or fewer carbon atoms.

[0090] [Chemical formula]

[0091] Specific examples of the low molecular weight compound represented by the above formula (J1) include compounds represented by the following formulas. These may be used alone or in combination of two or more.

[0092] [Chemical formula]

[0093] [Chemical formula]

[0094] In the above formula (J2), Ar c ~Ar e are each independently a substituted or unsubstituted monovalent aromatic hydrocarbon group or a monovalent aromatic heterocyclic group. Preferably, Ar c ~Ar e are each independently a substituted or unsubstituted phenyl group, biphenyl group, fluorenyl group or dibenzofuranyl group. Ar c ~Ar e may be the same as or different from each other, but at least two of Ar c ~Ar e are preferably the same as each other.

[0095] Specific examples of the low molecular weight compound represented by the above formula (J2) include compounds represented by the following formulas. These may be used alone or in combination of two or more.

[0096] [Chemical formula]

[0097] [Chemical formula]

[0098] In the above formula (J3), Ar f 、Ar g 、Ar i and Ar j are each independently a substituted or unsubstituted monovalent aromatic hydrocarbon group or a monovalent aromatic heterocyclic group. Preferably, Ar f 、Ar g 、Ar i and Ar j are each independently a substituted or unsubstituted phenyl group, biphenyl group or fluorenyl group. Ar f 、Ar g 、Ar i and Ar j may be bonded to each other to form a ring.

[0099] In the above formula (J3), Ar h is a substituted or unsubstituted divalent aromatic hydrocarbon group or a divalent aromatic heterocyclic group. Preferably, Ar h is a phenylene group. Ar h is Ar f 、Ar g 、Ar i and Ar j and may be bonded to form a ring.

[0100] In the above formula (J3), q is an integer of 1 or more and 10 or less, preferably an integer of 2 or more and 5 or less.

[0101] Specific examples of the low molecular weight compound represented by the above formula (J3) include compounds represented by the following formulas. These may be used alone or in combination of two or more.

[0102]

Chemical formula

[0103] In addition to the compounds represented by the above formulas (J1) to (J3), for the low-molecular compound according to the present invention, for example, low-molecular materials described in JP-A-2020-107866 can be appropriately employed.

[0104] When the composition contains a low-molecular compound, the content of the low-molecular compound is preferably 30% by mass or less, more preferably 1% by mass or more and 30% by mass or less, still more preferably 3% by mass or more and 25% by mass or less, and particularly preferably 5% by mass or more and 20% by mass or less, based on 100% by mass of the solid content of the composition. When the content of the low-molecular compound is 30% by mass or less, it is possible to maintain a sufficient residual film ratio. When the content of the low-molecular compound is 1% by mass or more, the viscosity-reducing effect due to the inclusion of the low-molecular compound can be more effectively exerted.

[0105] (High-molecular compound) The high-molecular compound according to the present invention is not particularly limited as long as the molecular weight exceeds 10,000. According to a preferred embodiment, the high-molecular compound preferably contains a structural unit represented by the following formula (4).

[0106]

Chemical formula

[0107] In the above formula (4), A represents a group selected from the following group.

[0108]

Chemical formula

[0109]

Chemical formula

[0110]

Chemical formula

[0111] [Chemistry]

[0112] [Chemistry]

[0113] [Chemistry]

[0114] In the above formula, * represents a bonding site, and Alkyl means being substituted or unsubstituted with an alkyl group. The above alkyl group is preferably a linear or branched alkyl group having 1 to 20 carbon atoms. Specifically, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, tert-pentyl group, neopentyl group, 1,2-dimethylpropyl group, n-hexyl group, isohexyl group, 1,3-dimethylbutyl group, 1-isopropylpropyl group, 1,2-dimethylbutyl group, n-heptyl group, 1,4-dimethylpentyl group, 3-ethylpentyl group, 2-methyl-1-isopropylpropyl group, 1-ethyl-3-methylbutyl group, n-octyl group, 2-ethylhexyl group, 3-methyl-1-isopropylbutyl group, 2-methyl-1-isopropyl group, 1-tert-butyl-2-methylpropyl group, n-nonyl group, 3,5,5-trimethylhexyl group, n-decyl group, isodecyl group, n-undecyl group, 1-methyldecyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-eicosyl group, etc. can be mentioned.

[0115] In the above formula (4), B represents a group selected from the following group.

[0116] [Chemistry]

[0117] In the above formula, A is O, S, or Se. When there are a plurality of Bs, the plurality of Bs may be the same or different. Also, * represents a bonding site, and Alkyl means being substituted or unsubstituted with an alkyl group. As the above alkyl group, the same form as described for A above can be adopted.

[0118] Specifically, the polymer compound represented by the above formula (4) has the following constitutional units.

[0119] [Chemical formula]

[0120] In addition to the compound represented by the above formula (4), the polymer compound according to the present invention can appropriately adopt, for example, poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine)] (TFB) and the polymer materials described in JP-A-2020-107866.

[0121] When the composition contains a polymer compound, the content of the polymer compound is preferably 60% by mass or less, more preferably 1% by mass or more and 60% by mass or less, still more preferably 1% by mass or more and 30% by mass or less, and particularly preferably 5% by mass or more and 20% by mass or less, based on 100% by mass of the solid content mass of the composition. When the content of the polymer compound is 60% by mass or less, the effect of reducing the viscosity of the ink by the compound according to the present invention can be sufficiently exhibited. When the content of the polymer compound is 1% by mass or more, the effect of improving the residual film rate by including the polymer compound can be more exhibited.

[0122] [Liquid composition] The compound or composition according to the present invention (hereinafter also referred to as "the compound / composition according to the present invention") has a low viscosity when made into a solution, and thus is preferably used as an ink for inkjet. That is, according to one embodiment of the present invention, there is provided a liquid composition (hereinafter also referred to as "liquid composition" or "liquid composition according to the present invention") containing the compound or composition according to the present invention and a solvent.

[0123] (Solvent) In the liquid composition according to the present invention, the solvent is not particularly limited. However, considering the solubility of the compound / composition according to the present invention, the solvent is preferably at least one selected from benzene ring-containing compounds, condensed ring-containing compounds (excluding those containing a benzene ring), heterocyclic ring-containing compounds (excluding those containing a benzene ring and / or a condensed ring), ester compounds (excluding those containing a benzene ring, a condensed ring, and / or a heterocyclic ring), and ether compounds (excluding those containing a benzene ring, a condensed ring, a heterocyclic ring, and / or an ester group), and more preferably a benzene ring-containing compound.

[0124] According to a preferred embodiment, the viscosity of the solvent is preferably 1 to 10 mPa·s, more preferably 3 to 7 mPa·s, and still more preferably 3 to 6 mPa·s. The viscosity of the solvent in this specification is the value measured at 25°C by a rheometer (manufactured by Anton-Paar). Specific solvents include 3-phenoxytoluene (viscosity 4.4 mPa·s), methyl benzoate (viscosity 2.3 mPa·s), ethyl benzoate (viscosity 2.0 mPa·s), pentyl benzoate (viscosity 8.5 mPa·s), dichlorobenzene (viscosity 1.32 mPa·s), and mixed solvents thereof. By using such solvents, the viscosity of the liquid composition is further reduced, and it can be preferably used as an ink for inkjet.

[0125] In the liquid composition according to the present invention, the concentration of the compound / composition according to the present invention is not particularly limited, but is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.2% by mass or more and 5% by mass or less, and still more preferably 0.5% by mass or more and 3% by mass or less, based on the liquid composition. If the concentration is 0.1% by mass or more, a sufficient amount of the compound or composition can be applied by the wet method. If the concentration is 10% by mass or less, the viscosity of the liquid composition does not become too high, and it can be preferably used as an ink for inkjet.

[0126] The viscosity of the liquid composition according to the present invention is preferably 10 mPa·s or less, more preferably 0.1 mPa·s or more and 10 mPa·s or less, still more preferably 1 mPa·s or more and 8 mPa·s or less, and even more preferably 2 mPa·s or more and 7 mPa·s or less. If the viscosity is 10 mPa·s or less, it can be preferably used as an ink for inkjet.

[0127] [Electroluminescence element material] According to the compound / composition of the present invention, an electroluminescence element having excellent luminous efficiency and durability (especially luminous lifetime) can be provided. In addition, the compound / composition according to the present invention has a low viscosity when made into a solution and has high solvent resistance for film formation, so film formation by inkjet is possible. Therefore, high definition, large screen size, improved manufacturing efficiency, and cost reduction of the electroluminescence element can be achieved. Therefore, according to a preferred embodiment of the present invention, there is provided an electroluminescence element material containing the compound according to the present invention or the composition according to the present invention. Alternatively, there is provided the use of the compound according to the present invention or the composition according to the present invention as an electroluminescence element material.

[0128] [Electroluminescence element] As described above, the compound or composition according to the present invention is suitably used for an electroluminescence element. Therefore, according to a third aspect of the present invention, there is provided an electroluminescence element including a first electrode, a second electrode, and one or more organic films disposed between the first electrode and the second electrode, wherein at least one of the organic films contains the compound or composition according to the present invention. Such an electroluminescence element can exhibit excellent luminous efficiency and durability (especially luminous lifetime).

[0129] In addition, the compound / composition according to the present invention is excellent in hole injection property and hole mobility. Therefore, it can be suitably used in the formation of any organic film such as a hole injection material, a hole transport material, or a light-emitting material (host). Among these, from the viewpoint of hole transportability, it is suitably used as a hole injection material or a hole transport material, and particularly suitably used as a hole transport material.

[0130] Hereinafter, with reference to FIG. 1, the electroluminescence element according to the present embodiment will be described in detail. FIG. 1 is a schematic diagram showing the electroluminescence element according to the present embodiment. In this specification, the "electroluminescence element" may be abbreviated as "EL element".

[0131] As shown in FIG. 1, the EL element 100 according to the present embodiment includes a substrate 110, a first electrode 120 disposed on the substrate 110, a hole injection layer 130 disposed on the first electrode 120, a hole transport layer 140 disposed on the hole injection layer 130, a light-emitting layer 150 disposed on the hole transport layer 140, an electron transport layer 160 disposed on the light-emitting layer 150, an electron injection layer 170 disposed on the electron transport layer 160, and a second electrode 180 disposed on the electron injection layer 170.

[0132] Here, the compound / composition according to the present invention is contained in any organic film (organic layer) disposed between, for example, the first electrode 120 and the second electrode 180. Specifically, the compound / composition is preferably contained in the hole injection layer 130 as a hole injection material, the hole transport layer 140 as a hole transport material, or the light-emitting layer 150 as a light-emitting material (host). The compound / composition is more preferably contained in the hole injection layer 130 as a hole injection material or the hole transport layer 140 as a hole transport material. The compound / composition is particularly preferably contained in the hole transport layer 140 as a hole transport material. That is, in a preferred embodiment of the present invention, the organic film containing the compound / composition is a hole transport layer, a hole injection layer, or a light-emitting layer. In a more preferred embodiment of the present invention, the organic film containing the compound / composition is a hole transport layer or a hole injection layer. In a particularly preferred embodiment of the present invention, the organic film containing the compound / composition is a hole transport layer.

[0133] In addition, the organic film containing the compound / composition according to the present invention is formed by a coating method (solution coating method). Specifically, the organic film is formed using a solution coating method such as a spin coat method, a casting method, a micro gravure coat method, a gravure coat method, a bar coat method, a roll coat method, a wire bar coat method, a dip coat method, a spry coat method, a screen printing method, a flexographic printing method, an offset printing method, an ink jet printing method, etc.

[0134] In addition, as long as the solvent used in the solution coating method can dissolve the compound / composition, any solvent can be used and can be appropriately selected according to the type of the compound / composition to be used. For example, toluene, xylene, ethylbenzene, diethylbenzene, methylxylene, propylbenzene, cyclohexylbenzene, dimethoxybenzene, anisole, ethoxytoluene, phenoxytoluene (e.g., 3-phenoxytoluene), isopropylbiphenyl, dimethylanisole, phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, dodecylbenzene, etc. can be exemplified. Also, the amount of the solvent used is not particularly limited, but considering the ease of coating etc., the concentration of the compound / composition is preferably 0.1% by mass or more and 10% by mass or less, more preferably about 0.5% by mass or more and 5% by mass or less.

[0135] In addition, the method for forming a layer other than the organic film containing the compound / composition is not particularly limited. The layer other than the organic film containing the compound / composition according to the present invention may be formed, for example, by a vacuum evaporation method or by a solution coating method.

[0136] As the substrate 110, a substrate generally used in an EL element can be used. For example, the substrate 110 may be a glass substrate, a semiconductor substrate such as a silicon substrate, or a transparent plastic substrate, etc.

[0137] On the substrate 110, a first electrode 120 is formed. Specifically, the first electrode 120 is an anode and is formed of a material having a large work function among metals, alloys, or conductive compounds, etc. For example, the first electrode 120 may be formed as a transmissive electrode by indium tin oxide (In2O3 - SnO2: ITO), indium zinc oxide (In2O3 - ZnO), tin oxide (SnO2), zinc oxide (ZnO), etc., which are excellent in transparency and conductivity. Further, the first electrode 120 may be formed as a reflective electrode by laminating magnesium (Mg), aluminum (Al), etc. on the above transparent conductive film. Further, after forming the first electrode 120 on the substrate 110, if necessary, cleaning and UV - ozone treatment may be performed.

[0138] On the first electrode 120, a hole injection layer 130 is formed. The hole injection layer 130 is a layer that facilitates the injection of holes from the first electrode 120, and specifically, it may be formed with a thickness of about 10 nm or more and about 1000 nm or less, more specifically, about 20 nm or more and about 50 nm or less (dry film thickness; the same applies hereinafter).

[0139] The positive hole injection layer 130 can be formed of a known positive hole injection material. Examples of the known positive hole injection materials for forming the positive hole injection layer 130 include, for example, poly(ether ketone)-containg triphenylamine (TPAPEK), 4-isopropyl-4’-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate (PPBI), N,N’-diphenyl-N,N’-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4’-diamine (DNTPD), copper phthalocyanine, 4,4’,4”-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA), N,N’-di(1-naphthyl)-N,N’-diphenylbenzidine (NPB), 4,4’,4”-tris(diphenylamino)triphenylamine (TDATA), 4,4’,4”-tris(N,N-2-naphthylphenylamino)triphenylamine (2-TNATA), polyaniline / dodecylbenzenesulphonic acid, poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulphonate) (poly(3,Examples thereof include poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), and polyaniline / 10-camphorsulfonic acid.

[0140] On the hole injection layer 130, a hole transport layer 140 is formed. The hole transport layer 140 is a layer having a function of transporting holes, and may be formed, for example, with a thickness of about 10 nm or more and about 150 nm or less, more specifically, about 20 nm or more and about 50 nm or less. The hole transport layer 140 is preferably formed into a film by a solution coating method using the compound / composition according to the present invention. According to this method, it is possible to extend the durability (light emission lifetime) of the EL element 100. It is also possible to improve the performance (light emission efficiency) of the EL element 100. It is also possible to improve the current efficiency of the EL element 100 and reduce the driving voltage. In addition, since the hole transport layer can be formed by the solution coating method, it is possible to efficiently form a film over a large area.

[0141] However, when any other organic film of the EL element 100 contains the compound / composition according to the present invention, the hole transport layer 140 may be formed of a known hole transport material. Examples of the known hole transport material include carbazole derivatives such as 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC), N-phenylcarbazole, and polyvinylcarbazole, N,N’-bis(3-methylphenyl)-N,N’-diphenyl-[1,1-biphenyl]-4,4’-diamine (TPD), 4,4’,4”-tris(N-carbazolyl)triphenylamine (TCTA), and N,N’-di(1-naphthyl)-N,N’-diphenylbenzidine (NPB).

[0142] On the hole transport layer 140, a light emitting layer 150 is formed. The light emitting layer 150 is a layer that emits light by fluorescence, phosphorescence, etc., and is formed using a vacuum evaporation method, a spin coating method, an inkjet printing method, etc. The light emitting layer 150 may be formed, for example, with a thickness of about 10 nm or more and about 60 nm or less, more specifically, about 20 nm or more and about 50 nm or less. As the light emitting material of the light emitting layer 150, a known light emitting material can be used. However, the light emitting material contained in the light emitting layer 150 is preferably a light emitting material capable of emitting light from triplet excitons (i.e., phosphorescent emission). In such a case, the driving life of the EL element 100 can be further improved.

[0143] The light-emitting layer 150 is not particularly limited and can have a known configuration. Preferably, the light-emitting layer contains semiconductor nanoparticles or organometallic complexes. That is, in a preferred embodiment of the present invention, the organic film has a light-emitting layer containing semiconductor nanoparticles or organometallic complexes. When the light-emitting layer contains semiconductor nanoparticles, the EL element is a quantum dot electroluminescence element (QLED), a quantum dot light-emitting element, or a quantum dot light-emitting element. When the light-emitting layer contains an organometallic complex, the EL element is an organic electroluminescence element (OLED).

[0144] In the form (QLED) in which the light-emitting layer contains semiconductor nanoparticles, the light-emitting layer is one in which a large number of semiconductor nanoparticles (quantum dots) are arranged in a single layer or multiple layers. Here, the semiconductor nanoparticles (quantum dots) are particles of a predetermined size having a quantum confinement effect. The diameter of the semiconductor nanoparticles (quantum dots) is not particularly limited, but is about 1 nm or more and 10 nm or less.

[0145] The semiconductor nanoparticles (quantum dots) arranged in the light-emitting layer can be synthesized by a wet chemical process, an organometallic chemical vapor deposition process, a molecular beam epitaxy process, or other similar processes. Among them, the wet chemical process is a method of growing particles by putting a precursor substance in an organic solvent.

[0146] In the wet chemical process, when the crystal grows, the organic solvent is naturally coordinated to the surface of the quantum dot crystal and serves as a dispersant, thereby regulating the growth of the crystal. Therefore, in the wet chemical process, compared with vapor deposition methods such as metal organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE), the growth of semiconductor nanoparticles can be controlled easily and at low cost.

[0147] By adjusting the size of semiconductor nanoparticles (quantum dots), the energy band gap can be adjusted, enabling the emission of light in various wavelength bands in the light-emitting layer (quantum dot light-emitting layer). Therefore, by using quantum dots of a plurality of different sizes, a display that emits (or emits) light of multiple wavelengths is enabled. The size of the quantum dots can be selected so that red, green, and blue light is emitted, enabling the construction of a color display. Also, the sizes of the quantum dots can be combined so that various color lights emit white light.

[0148] As the semiconductor nanoparticles (quantum dots), semiconductor materials selected from the group consisting of II-VI group semiconductor compounds; III-V group semiconductor compounds; IV-VI group semiconductor compounds; group IV elements or compounds; and combinations thereof can be used.

[0149] The II-VI group semiconductor compounds are not particularly limited, and examples include binary compounds selected from the group consisting of CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, and mixtures thereof; ternary compounds selected from the group consisting of CdSeS, CdSeTe, CdSTe, ZnSeS, ZnTeSe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, and mixtures thereof; and quaternary compounds selected from the group consisting of CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, and mixtures thereof.

[0150] The III-V semiconductor compounds are selected from the group consisting of binary compounds selected from the group consisting of, but not limited to, for example, GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and mixtures thereof; ternary compounds selected from the group consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, and mixtures thereof; and quaternary compounds selected from the group consisting of GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and mixtures thereof.

[0151] The IV-VI semiconductor compounds can be selected from the group consisting of binary compounds selected from the group consisting of, but not limited to, for example, SnS, SnSe, SnTe, PbS, PbSe, PbTe, and mixtures thereof; ternary compounds selected from the group consisting of SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and mixtures thereof; and quaternary compounds selected from the group consisting of SnPbSSe, SnPbSeTe, SnPbSTe, and mixtures thereof.

[0152] The Group-IV elements or compounds are selected from the group consisting of mono-element compounds selected from the group consisting of, but not limited to, for example, Si, Ge, and mixtures thereof; and binary compounds selected from the group consisting of SiC, SiGe, and mixtures thereof.

[0153] Semiconductor nanoparticles (quantum dots) can have a homogeneous single structure or a core-shell double structure. The core-shell can contain different substances. The substances constituting each core and shell can be composed of different semiconductor compounds. However, the energy band gap of the shell material is larger than that of the core material. Specifically, structures such as ZnTeSe / ZnSe / ZnS, InP / ZnSe / ZnS, CdSe / ZnS, InP / ZnS are preferred.

[0154] For example, the case of fabricating quantum dots having a core (CdSe)-shell (ZnS) structure will be described. First, precursor substances of the core (CdSe), such as (CH3)2Cd (dimethylcadmium) and TOPSe (trioctylphosphine selenide), are injected into an organic solvent using TOPO (trioctylphosphine oxide) as a surfactant to generate crystals. At this time, after maintaining at a high temperature for a certain time so that the crystals grow to a certain size, a precursor substance of the shell (ZnS) is injected to form a shell on the surface of the already generated core. Thereby, CdSe / ZnS quantum dots capped with TOPO can be fabricated.

[0155] In addition, in a form (OLED) in which the light-emitting layer contains an organometallic complex, the light-emitting layer 150 may contain, as a host material, for example, 6,9-diphenyl-9'-(5'-phenyl-[1,1':3',1''-terphenyl]-3-yl) 3,3'-bi[9H-carbazole], 3,9-diphenyl-5-(3-(4-phenyl-6-(5'-phenyl-[1,1':3',1''-terphenyl]-3-yl)-1,3,5,-triazin-2-yl)phenyl)-9H-carbazole, 9,9'-diphenyl-3,3'-bi[9H-carbazole], tris(8-quinolinato)aluminium (Alq3), 4,4'-bis(carbazol-9-yl)biphenyl (CBP), poly(n-vinyl carbazole) (PVK), 9,10-di(naphthalene-2-yl)anthracene (ADN), 4,4',4''-tris(N-carbazolyl)triphenylamine (TCTA), 1,3,5-tris(N-phenyl-benzimidazol-2-yl)benzene (TPBI), 3-tert-butyl-9,10-di(naphth-2-yl)anthracene (TBADN), distyrylarylene (DSA), 4,4'-bis(9-carbazole)-2,2'-dimethyl-biphenyl (dmCBP), and the like.

[0156] In addition, the light-emitting layer 150 may contain, as a dopant material, for example, perylene and its derivatives, rubrene and its derivatives, coumarin and its derivatives, 4-dicyanomethylene-2-(p-dimethylaminostyryl)-6-methyl-4H-pyran (DCM) and its derivatives, bis[2-(4,6-difluorophenyl)pyridinate]picolinate iridium(III) (FIrpic), bis(1-phenylisoquinoline)(acetylacetonate)iridium(III) (Ir(piq)2(acac)), tris(2-phenylpyridine)iridium(III) (Ir(ppy)3), tris(2-(3-p-tolyl)phenyl)pyridine iridium(III), and other iridium (Ir) complexes, osmium (Os) complexes, platinum complexes, etc. Among these, it is preferable that the light-emitting material is a luminescent organometallic complex compound.

[0157] The method for forming the light-emitting layer is not particularly limited. It can be formed by applying a coating solution containing semiconductor nanoparticles or organometallic complexes (solution coating method). At this time, as the solvent constituting the coating solution, it is preferable to select a solvent that does not dissolve the material (hole transport material, particularly a compound / composition) in the hole transport layer.

[0158] An electron transport layer 160 is formed on the light-emitting layer 150. The electron transport layer 160 is a layer having a function of transporting electrons, and is formed using a vacuum evaporation method, a spin coating method, an inkjet method, or the like. The electron transport layer 160 may be formed, for example, with a thickness of about 15 nm or more and about 50 nm or less.

[0159] The electron transport layer 160 may be formed of a known electron transport material. Examples of the known electron transport material include, for example, (8-quinolinolato)lithium (lithium quinolate: Liq), tris(8-quinolinato)aluminium (Alq3), and a compound having a nitrogen-containing aromatic ring. Specific examples of the compound having a nitrogen-containing aromatic ring include, for example, a compound containing a pyridine ring such as 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene, a compound containing a triazine ring such as 2,4,6-tris(3’-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine, 2-(4-(N-phenylbenzoimidazolyl-1-yl-phenyl)-9,10-dinaphthylanthracene, and a compound containing an imidazole ring such as 1,3,5-tris(N-phenyl-benzimidazol-2-yl)benzene (TPBI). The above electron transport material may be used alone or as a mixture of two or more kinds.

[0160] An electron injection layer 170 is formed on the electron transport layer 160. The electron injection layer 170 is a layer having a function of facilitating the injection of electrons from the second electrode 180. The electron injection layer 170 is formed using a method such as vacuum evaporation. The electron injection layer 170 may be formed with a thickness of about 0.1 nm or more and about 5 nm or less, more specifically, about 0.3 nm or more and about 2 nm or less. Any known material can be used as the material for forming the electron injection layer 170. For example, the electron injection layer 170 may be formed of a lithium compound such as (8-quinolinato)lithium (lithium quinolate: Liq) and lithium fluoride (LiF), sodium chloride (NaCl), cesium fluoride (CsF), lithium oxide (Li2O), or barium oxide (BaO).

[0161] The second electrode 180 is formed on the electron injection layer 170. The second electrode 180 is formed using a method such as vacuum evaporation. Specifically, the second electrode 180 is a cathode and is formed of a material having a small work function among metals, alloys, or conductive compounds. For example, the second electrode 180 may be formed as a reflective electrode of a metal such as lithium (Li), magnesium (Mg), aluminum (Al), calcium (Ca), or an alloy such as aluminum-lithium (Al-Li), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag). The second electrode 180 may be formed with a thickness of about 10 nm or more and about 200 nm or less, more specifically, about 50 nm or more and about 150 nm or less. Alternatively, the second electrode 180 may be formed as a transmissive electrode by a thin film of 20 nm or less of the above metal material, a transparent conductive film such as indium tin oxide (In2O3-SnO2) and indium zinc oxide (In2O3-ZnO).

[0162] As an example of the electroluminescence element according to the present invention, the EL element 100 according to the present embodiment has been described above. By providing an organic film (particularly a hole transport layer or a hole injection layer) containing a compound / composition, the durability (luminescence lifetime) can be further improved. Also, the luminous efficiency (current efficiency) can be further improved, and the driving voltage can be reduced.

[0163] Note that the laminated structure of the EL element 100 according to the present embodiment is not limited to the above examples. The EL element 100 according to the present embodiment may be formed with other known laminated structures. For example, in the EL element 100, one or more of the hole injection layer 130, the hole transport layer 140, the electron transport layer 160, and the electron injection layer 170 may be omitted, or additional other layers may be provided. Also, each layer of the EL element 100 may be formed of a single layer or a plurality of layers.

[0164] For example, the EL element 100 may further include a hole blocking layer between the hole transport layer 140 and the light emitting layer 150 in order to prevent excitons or holes from diffusing into the electron transport layer 160. Note that the hole blocking layer can be formed of, for example, an oxadiazole derivative, a triazole derivative, a phenanthroline derivative, or the like.

[0165] Furthermore, the compound / composition according to the present invention can be applied to electroluminescence elements other than the above QLED or OLED. Other electroluminescence elements to which the compound / composition according to the present invention can be applied are not particularly limited, and examples include organic-inorganic perovskite light emitting elements.

[0166] According to the present invention, the electroluminescence device according to this embodiment can be manufactured by inkjet. That is, according to one aspect of the present invention, there is provided a method for manufacturing an electroluminescence device including a first electrode, a second electrode, and one or more organic films disposed between the first electrode and the second electrode, the method including a step of forming a hole transport layer by applying the liquid composition according to the present invention by inkjet and drying the solvent. Further, in this manufacturing method, it is preferable to further include a step of forming a light-emitting layer by applying an ink for a light-emitting layer containing semiconductor nanoparticles and a solvent for a light-emitting layer on the surface of the hole transport layer by a wet method and drying the solvent for the light-emitting layer. As the solvent for the light-emitting layer used at this time, it is preferable to select a solvent that can disperse semiconductor nanoparticles (quantum dots) well and does not dissolve the material (hole transport material, particularly compound / composition) in the hole transport layer as described above. Specifically, the solvent for the light-emitting layer is more preferably at least one selected from hexane, octane, decane, tetradecane, indane, butanol, octanol, cyclohexylbenzene, dodecylbenzene, o-dichlorobenzene, and the like. By this manufacturing method, it becomes easy to increase the screen size of the electroluminescence device. Further, a higher-definition electroluminescence device is provided. Furthermore, the manufacturing efficiency and cost can be reduced.

Example

[0167] The effects of the present invention will be described using the following examples and comparative examples. However, the technical scope of the present invention is not limited only to the following examples. In the following examples, unless otherwise specified, the operations were carried out at room temperature (25 °C). Also, unless otherwise specified, “%” and “ parts” mean “mass %” and “parts by mass”, respectively.

[0168] [Synthesis Example] (Synthesis of Intermediate-1) Intermediate-1 was synthesized according to the following reaction.

[0169] [Chemistry]

[0170] Into a 3L four-necked flask, 4-Bromo-3-methylaniline (449 mmol, 83.5 g), 4-Iodobiphenyl (427.6 mmol, 119.8 g), t-BuONa (641.4 mmol), toluene (1710 ml), and Pd(dppf)Cl2 (21.4 mmol, 15.7 g) were added. The reaction was initiated by heating and stirring at 80 °C under a nitrogen atmosphere. Then, while confirming the progress of the reaction, the temperature was gradually increased, and the mixture was heated and stirred at 100 °C for 5 hours. After completion of the reaction, it was cooled to room temperature and filtered through celite. The filtrate was further filtered using a silica gel short column to remove the origin impurities. After concentration, recrystallization was performed three times using toluene and hexane. Vacuum drying (50 °C, 16 hours) was carried out to obtain Intermediate-1a (yield 101.8 g, yield 67.0%).

[0171] Into a 1L four-necked flask, N-(4-bromo-3-methylphenyl)-[1,1’-biphenyl]-4-amine (170 mmol, 57.5 g), Cl Biphenyl Bpin (178.5 mmol, 56.2 g), 2M aqueous potassium carbonate solution (170 ml), toluene (340 ml), and EtOH (85 ml) were added to the flask. After the sample was uniformly dissolved, Pd(OAc)2 (8.5 mmol, 1.9 g) and P(o-tolyl)3 (13.6 mmol, 4.14 g) were added, and the mixture was heated and stirred at 70 °C for 8 hours under a nitrogen atmosphere. It was cooled to room temperature, diluted with methanol, and the precipitated solid was collected by filtration. The crude product was vacuum dried (50 °C), then heated and dissolved in toluene, and hot filtration was performed through a silica gel short column to remove the origin. After concentration, recrystallization was performed twice using toluene, and then vacuum drying (50 °C, 12 hours) was carried out to obtain Intermediate-1b (yield 59.9 g, yield 78.9%).

[0172] An intermediate-1b (83.2 mmol, 37.1 g) and tert-BuONa (124.85 mmol, 12.0 g) were placed in a three-necked flask, and toluene (420 ml) was added and stirred. Then 2-Bromo-5-iodotoluene (91.6 mmol, 27.2 g) and Pd(dppf)Cl2 (4.16 mmol, 3.05 g) were added, and the mixture was stirred at 120 °C for 3 hours under an inert atmosphere. After cooling to room temperature, toluene was added for dilution, and filtration was carried out using celite (registered trademark, the same hereinafter) to remove insoluble substances. After the filtrate was washed with saturated brine, the organic layer was dried using MgSO4. After concentration, purification was carried out by silica gel chromatography (hexane:toluene = 7:3). After concentration, purification was carried out by recrystallization using ethyl acetate, toluene and acetone. The obtained solid was dried under vacuum (50 °C, 12 hours) to obtain intermediate-1 (yield 30.7 g, yield 60%).

[0173] (Synthesis of Intermediate-2) Intermediate-2 was synthesized according to the following reaction.

[0174] [Chemical formula]

[0175] Dibromodiphenylamine (581.0 mmol, 190.0 g), propylphenylboronic acid (1162 mmol, 190.6 g), and THF (2905 ml) were placed in a 5 L four-necked flask and dissolved. 1162 ml of 2M aq. K2CO3 was added, and then Pd(OAc)2 (34.9 mmol, 7.83 g) and P(o-tolyl)3 (52.3 mmol, 15.92 g) were added and refluxed under a nitrogen atmosphere for 5 hours. After completion of the reaction, the mixture was cooled to room temperature, diluted with toluene, and extracted. After drying using MgSO4, filtration was carried out through a silica gel pad. After removing the solvent under reduced pressure, recrystallization was carried out twice with methanol and dried under vacuum (50 °C, 16 hours) to obtain intermediate-2a (yield 200.3 g, yield 85%).

[0176] Into a 1 L four-necked flask, intermediate-2a (246.6 mmol, 100 g), 2-Bromo-5-iodotoluene (258.9 mmol, 76.87 g), tert-BuONa (493.2 mmol, 47.4 g), and 1,4-dioxane (493 ml) were added, stirred to disperse, and then CuI (7.4 mmol, 1.41 g) and trans-1,2-diaminocyclohexane (37.0 mmol, 4.4 ml) were added, followed by refluxing for 10 hours. After completion of the reaction, it was cooled to room temperature, diluted with toluene, and filtered using celite. After concentration, it was purified by silica gel chromatography (hexane:toluene = 7:3), and then recrystallized from acetone. Vacuum drying (50 °C, 16 hours) was carried out to obtain intermediate-2b (yield 99.2 g, yield 70%).

[0177] Into a 2 L four-necked flask, intermediate-2b (129.3 mmol, 74.3 g), Bis(pinacolate)diboron (142.2 mmol, 36.1 g), potassium acetate (297.4 mmol, 29.1 g), and NMP (650 ml) were added, stirred to disperse, and then PdCl2(dppf) dichloromethane adduct (2.57 mmol, 21.1 g) was added, followed by refluxing for 7 hours under an argon atmosphere. After completion of the reaction, it was cooled to room temperature and filtered using celite. The filtrate was washed three times with pure water, and then the organic layer was dried using MgSO4. After concentration, it was purified by silica gel chromatography (hexane:dichloromethane = 7:3). After concentration, it was dissolved in THF, methanol was added, and recrystallization was carried out. Vacuum drying (50 °C, 16 hours) was carried out to obtain intermediate-2c (yield 65.6 g, yield 81.6%).

[0178] Into a 2L four-necked flask, the intermediate-2c (300.0 mmol, 186.5 g), 4-Bromo-4’-chloro-1,1’-biphenyl (300.0 mmol, 80.3 g), Toluene (600 ml) and Ethanol (150 ml) were added and dispersed. Potassium carbonate (450.0 mmol, 62.2 g) was dissolved in pure water (225 ml), added to the flask, stirred and dispersed, and Pd(OAc)2 (12.0 mmol, 2.69 g) and P(o-tolyl)3 (18.0 mmol, 5.48 g) were added thereto, followed by refluxing for 3 hours under an argon atmosphere. After completion of the reaction, it was cooled to room temperature and filtered using celite. The filtrate was washed three times with pure water, and then the organic layer was dried using MgSO4. After concentration, it was filtered through a silica gel pad. After concentration, recrystallization was carried out using hexane. Vacuum drying (50 °C, 16 hours) was performed to obtain intermediate-2d (yield 168 g, yield 82.1%).

[0179] Into a 1L four-necked flask, the intermediate-2d (246 mmol, 168 g), Bis(pinacolate)diboron (270.6 mmol, 68.7 g), Potassium acetate (492 mmol, 48.3 g), and 1,4-dioxane (492 ml) were added and dispersed. Pd(OAc)2 (4.92 mmol, 1.10 g) and XPhos (9.84 mmol, 4.69 g) were added thereto, followed by refluxing for 4 hours under an argon atmosphere. After completion of the reaction, it was cooled to room temperature and filtered using celite. After concentration, it was filtered through a silica gel pad. After concentration, recrystallization was carried out using toluene and hexane. Vacuum drying (50 °C, 16 hours) was performed to obtain intermediate-2e (yield 164.7 g, yield 86.5%).

[0180] Into a 2L four-necked flask, Intermediate-1 (63.0 mmol, 38.8 g), Intermediate-2e (60.0 mmol, 46.4 g), Toluene (240 ml) and Ethanol (30 ml) were added and dispersed. Potassium carbonate (90.0 mmol, 12.4 g) was dissolved in pure water (45 ml), added to the flask, stirred and dispersed, and Pd(OAc)2 (2.4 mmol, 0.54 g) and P(o-tolyl)3 (3.6 mmol, 1.10 g) were added thereto, followed by refluxing under an argon atmosphere for 4 hours. After completion of the reaction, it was cooled to room temperature and filtered using celite. The filtrate was washed three times with pure water, and then the organic layer was dried using MgSO4. After concentration, it was filtered through a silica gel pad. After concentration, it was purified by silica gel chromatography (hexane:toluene = 6:4). The concentrated solid was dried under vacuum (50 °C, 16 hours) to obtain Intermediate-2f (yield 49.0 g, yield 69.2%).

[0181] Into a 1L four-necked flask, Intermediate-2f (41.5 mmol, 49.0 g), Bis(pinacolate)diboron (53.9 mmol, 13.7 g), Potassium acetate (83.0 mmol, 8.15 g), and 1,4-dioxane (208 ml) were added and dispersed. Pd(OAc)2 (0.83 mmol, 0.186 g) and XPhos (1.66 mmol, 0.791 g) were added thereto, followed by refluxing under an argon atmosphere for 4 hours. After completion of the reaction, it was cooled to room temperature, diluted with toluene, and filtered using celite. After concentration, it was filtered through a silica gel pad. After concentration, it was dissolved in toluene, washed three times with pure water, and then the organic layer was dried using MgSO4. After concentration, it was purified by silica gel chromatography (hexane:toluene = 8:2). The concentrated solid was dried under vacuum (50 °C, 16 hours) to obtain Intermediate-2 (yield 45.0 g, yield 85.1%).

[0182] (Synthesis of Intermediate-3) Intermediate-3 was synthesized according to the following reaction.

[0183]

Chemical formula

[0184] Into a 500 mL four-necked flask, 4,4”-dibromo-1,1’:4’,1”-terphenyl (26 mmol, 10.1 g), Bis(pinacolate)diboron (57.2 mmol, 14.5 g), potassium acetate (104 mmol, 10.2 g), toluene (130 ml) and DMF (130 ml) were added and dispersed. PdCl2(dppf) dichloromethane adduct (5.2 mmol, 3.80 g) was added thereto, and the mixture was heated and stirred at 80 °C for 4 hours under a nitrogen atmosphere. After completion of the reaction, the mixture was cooled to room temperature, diluted with methanol, and the precipitated solid was collected by filtration. The crude product was dried in vacuo (50 °C), then dissolved in chloroform and filtered through a silica gel pad. After concentration, dispersion washing was performed using hexane. The obtained solid was dried in vacuo (50 °C, 16 hours) to obtain Intermediate-3a (yield 10.51 g, yield 83.8%).

[0185] Intermediate-3 was synthesized in the same procedure as the synthesis of Intermediate-2f, except that 10.51 g of Intermediate-3a and 2 equivalents of Intermediate-1 were used relative to Intermediate-3a (yield 23.2 g, yield 82.1%).

[0186] (Synthesis of Intermediate-4) Intermediate-4 was synthesized according to the following reaction.

[0187]

Chemical formula

[0188] Into a 2L four-necked flask, N,N-ditolylamine (50.31 g) and DMF (510 ml) were added, and the mixture was stirred and dissolved under a nitrogen atmosphere. After cooling to 0 °C, a DMF solution (255 mL) of N-bromosuccinimide (90.77 g) was added dropwise. Then, the mixture was stirred at room temperature (25 °C, the same hereinafter) for 5 hours. Pure water (1 L) was added to the reaction solution to precipitate a solid, ultrasonic irradiation was performed for 30 minutes, and the solid was collected by filtration. After vacuum drying (50 °C, 12 hours), the solid was dissolved in THF (1 L) and filtered through a silica gel pad. The solvent was removed under reduced pressure to obtain a crystalline solid. This crude product was heated and dissolved in toluene, hexane was added for recrystallization, and the solid was filtered. After vacuum drying (50 °C, 12 hours), Intermediate-4a was obtained (yield 72.4 g, yield 80%).

[0189] Into a 2L four-necked flask, Intermediate-4a (204 mmol, 72.4 g), Cl biphenyl Bpin (428.4 mmol, 134 g), 2M aqueous solution of potassium carbonate (306 ml), toluene (816 ml), and EtOH (102 ml) were added and dispersed. Then, Pd(OAc)2 (8.16 mmol, 1.83 g) and P(o-tolyl)3 (12.24 mmol, 3.73 g) were added, and the mixture was heated and stirred at 80 °C for 4 hours under a nitrogen atmosphere. After cooling to room temperature, the mixture was diluted with methanol, and the precipitated solid was collected by filtration. The crude product was vacuum dried (50 °C), then heated and dissolved in toluene, and hot filtration was performed through a silica gel short column to remove the origin. After concentration, dispersion washing was performed using methanol. After recrystallization using toluene and hexane, the obtained solid was vacuum dried (50 °C, 12 hours) to obtain Intermediate-4b (yield 63.5 g, yield 54.6%).

[0190] Into a 300 mL four-necked flask, intermediate-4b (10 mmol, 5.71 g), 4-Iodobiphenyl (10.5 mmol, 2.94 g), t-BuONa (15.0 mmol, 1.44 g), toluene (100 ml), and Pd(dppf)Cl2 (0.5 mmol, 0.366 g) were added, and the mixture was heated with stirring at 110 °C for 6 hours under a nitrogen atmosphere. After completion of the reaction, the mixture was cooled to room temperature and filtered through celite. The filtrate was further filtered using a silica gel short column to remove the origin impurities. After concentration, recrystallization was performed three times using toluene and hexane. Vacuum drying (50 °C, 16 hours) was carried out to obtain intermediate-4c (yield 4.11 g, yield 56.9%).

[0191] Intermediate-4d was synthesized in the same procedure as the synthesis of intermediate-3a except that 4,4”-dibromo-1,1’:4’,1”-terphenyl was changed to intermediate-4c (yield 2.5 g, yield 78.0%).

[0192] Into a 100 mL four-necked flask, intermediate-4d (3.3 mmol, 2.97 g), 4-Bromo-4’-chloro-1,1’-biphenyl (7.26 mmol, 1.94 g), 2M aqueous solution of potassium carbonate (13.2 ml), and THF (13.2 ml) were added and dispersed. Then, Pd(OAc)2 (0.17 mmol, 38 mg) and P(o-tolyl)3 (0.26 mmol, 79 mg) were added, and the mixture was heated with stirring at 60 °C for 6 hours under a nitrogen atmosphere. After cooling to room temperature, it was diluted with methanol, and the precipitated solid was collected by filtration. The crude product was vacuum dried (50 °C), and then dispersed and washed with ethyl acetate. The obtained solid was vacuum dried (50 °C, 12 hours) to obtain intermediate-4e (yield 3.20 g, yield 99%).

[0193] Intermediate-4f was synthesized in the same procedure as the synthesis of intermediate-3a except that 4,4”-dibromo-1,1’:4’,1”-terphenyl was changed to intermediate-4e (yield 2.5 g, yield 63.0%).

[0194] Intermediate-4 was synthesized in the same procedure as that for the synthesis of Intermediate-3, except that 2.50 g of Intermediate-4f was used instead of Intermediate-3a. (Yield: 2.43 g, Yield rate: 55.6%).

[0195] (Synthesis of Intermediate-5) Intermediate-5 was synthesized according to the following reaction.

[0196]

Chemical formula

[0197] Intermediate-5a was synthesized in the same procedure as that for the synthesis of Intermediate-4b, except that Intermediate-4a was changed to 4-Dibromo-2,6-diethylbenzene (Yield: 13.1 g, Yield rate: 93%).

[0198] Intermediate-5b was synthesized in the same procedure as that for the synthesis of Intermediate-3a, except that 4,4”-dibromo-1,1’:4’,1”-terphenyl was changed to Intermediate-5a (Yield: 8.7 g, Yield rate: 89%).

[0199] Into a 2 L four-necked flask, Intermediate-1 (18.7 mmol, 11.5 g), Intermediate-5b (8.9 mmol, 6.15 g), Toluene (178 ml) and Ethanol (9 ml) were added and dispersed. Potassium carbonate (35.6 mmol, 4.92 g) was dissolved in pure water (36 ml), added to the flask, stirred and dispersed, and Pd(OAc)2 (0.36 mmol, 81 mg) and P(o-tolyl)3 (0.53 mmol, 161 mg) were added thereto, followed by refluxing under an argon atmosphere for 20 hours. After completion of the reaction, it was cooled to room temperature and filtered using celite. The filtrate was washed three times with pure water, and then the organic layer was dried using MgSO4. After concentration, it was filtered through a silica gel pad. After concentration, it was dispersed and washed with ethyl acetate, and the solid was filtered off. The obtained solid was dried in vacuo (50 °C, 16 hours) to obtain Intermediate-5 (Yield: 4.60 g, Yield rate: 34.3%).

[0200] (Synthesis of Intermediate-6) Intermediate-6 was synthesized according to the following reaction.

[0201]

Chem.

[0202] Intermediate-6a was synthesized in the same procedure as the synthesis of Intermediate-5a except that 4-Dibromo-2,6-diethylbenzene was changed to 4-Dibromo-2,6-dihexylbenzene (yield 3.8 g, yield rate 91%).

[0203] Intermediate-6b was synthesized in the same procedure as the synthesis of Intermediate-3a except that 4,4”-dibromo-1,1’:4’,1”-terphenyl was changed to Intermediate-6a (yield 1.5 g, yield rate 71%).

[0204] Intermediate-6 was synthesized in the same procedure as the synthesis of Intermediate-3 except that 1.0 g of Intermediate-6b was used instead of Intermediate-3a (yield 0.81 g, yield rate 40.5%).

[0205] [Example 1] (Synthesis of Compound C-1) Compound C-1 was synthesized according to the following reaction.

[0206]

Chem.

[0207] To a 500 mL four-necked flask, intermediate-2 (1.05 mmol, 1.34 g), intermediate-3 (0.5 mmol, 649 mg), THF (50 ml) and 2 M aqueous potassium carbonate solution (3 ml) were added, stirred and dispersed. Then, Pd(OAc)2 (0.05 mmol, 11 mg) and SPhos (0.10 mmol, 41 mg) were added, and the mixture was heated and stirred at 60 °C for 6 hours under a nitrogen atmosphere. After the reaction was completed, it was cooled to room temperature, diluted with ethyl acetate and pure water, and then ultrasonically washed for 30 minutes. The precipitate was filtered off and washed with methanol. The crude product was dried under vacuum (50 °C, 12 hours), then dissolved by heating in toluene, and hot filtered through a silica gel short column to remove the origin. After concentration, recrystallization was performed using toluene and ethyl acetate, and the obtained solid was dried under vacuum (50 °C, 12 hours) to obtain compound C-1 (yield 1.64 g). The molecular weight of compound C-1 was measured by GPC using polystyrene as a standard substance, and it was 3500 (theoretical value 3521).

[0208] (Preparation of Composition M-1) Composition M-1 was prepared by mixing compound C-1 and a low molecular weight compound (molecular weight 679) represented by the following formula in a mass ratio of 95:5.

[0209] [Chemical formula]

[0210] (Preparation of Composition M-2) Composition M-2 was prepared by mixing compound C-1 and a high molecular weight compound (molecular weight 12000) represented by the following formula in a mass ratio of 90:10.

[0211] [Chemical formula]

[0212] (Fabrication of Quantum Dot Electroluminescence Device D-1) As the first electrode (anode), a glass substrate with indium tin oxide (ITO) patterned with a film thickness of 150 nm was used. This glass substrate with ITO was sequentially cleaned using a neutral detergent, deionized water, water, and isopropyl alcohol, and then UV-ozone treatment was carried out. Next, poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS) (manufactured by Sigma-Aldrich) was spin-coated on this glass substrate with ITO so that the dry film thickness became 30 nm, and then dried. As a result, a hole injection layer with a thickness (dry film thickness) of 30 nm was formed on the glass substrate with ITO.

[0213] On this hole injection layer, a 1.0 mass% toluene solution of compound C-1 (hole transport material) was spin-coated so that the dry film thickness became 30 nm, and then heat-treated at 230 °C for 60 minutes to form a hole transport layer. As a result, a hole transport layer with a thickness (dry film thickness) of 30 nm was formed on the hole injection layer.

[0214] In cyclohexane, the following structure:

[0215]

Chemical formula

[0216] Red quantum dots of InP / ZnSe / ZnS (core / shell / shell; average diameter = about 10 nm) having the above structure were dispersed in cyclohexane to a concentration of 1.0 mass% to prepare a quantum dot dispersion solution. Note that the hole transport layer (compound C-1) is insoluble in cyclohexane. This quantum dot dispersion solution was spin-coated on the above hole transport layer so that the dry film thickness became 30 nm, and then dried. As a result, a quantum dot light-emitting layer with a thickness (dry film thickness) of 30 nm was formed on the hole transport layer. The light emitted by irradiating the quantum dot dispersion solution with ultraviolet light had a central wavelength of 627 nm and a full width at half maximum of 35 nm.

[0217] The quantum dot light-emitting layer was completely dried. On this quantum dot light-emitting layer, lithium quinolate (Liq) and 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBI) (manufactured by Sigma-Aldrich) as an electron transport material were co-evaporated using a vacuum evaporation apparatus. As a result, an electron transport layer with a thickness of 36 nm was formed on the quantum dot light-emitting layer.

[0218] Using a vacuum evaporation apparatus, lithium quinolate (Liq) was evaporated onto this electron transport layer. As a result, an electron injection layer with a thickness of 0.5 nm was formed on the electron transport layer.

[0219] Using a vacuum evaporation apparatus, aluminum (Al) was evaporated onto this electron injection layer. As a result, a second electrode (cathode) with a thickness of 100 nm was formed on the electron injection layer. Thereby, the quantum dot electroluminescence device D-1 was obtained.

[0220] [Example 2] (Synthesis of Compound C-2) Compound C-2 was synthesized according to the following reaction.

[0221] [Chemical formula]

[0222] Compound C-2 was synthesized in the same procedure as the synthesis of Compound C-1, except that 1.01 g of Intermediate-4 was used instead of Intermediate-3. (Yield 1.6 g, yield rate 82%). When the molecular weight of Compound C-2 was measured by GPC using polystyrene as a standard substance, it was 4200 (theoretical value 4235).

[0223] (Preparation of Composition M-3) Composition M-3 was prepared in the same manner as the preparation of Composition M-1, except that Compound C-1 was changed to Compound C-2.

[0224] (Preparation of Composition M-4) Composition M-4 was prepared in the same manner as the preparation of Composition M-2, except that Compound C-1 was changed to Compound C-2.

[0225] (Fabrication of Quantum Dot Electroluminescence Device D-2) In the (Fabrication of Quantum Dot Electroluminescence Device D-1) of Example 1, the same operations were performed except that Compound C-2 was used instead of Compound C-1, and Quantum Dot Electroluminescence Device D-2 was fabricated.

[0226] [Example 3] (Synthesis of Compound C-3) Compound C-3 was synthesized according to the following reaction.

[0227] [Chemical Formula]

[0228] Compound C-3 was synthesized in the same procedure as the synthesis of Compound C-1, except that 753 mg of Intermediate-5 was used instead of Intermediate-3. (Yield 1.5 g, Yield Rate 80%). The molecular weight of Compound C-3 was measured by GPC using polystyrene as a standard substance, and it was 3700 (theoretical value 3729).

[0229] [Example 4] (Synthesis of Compound C-4) Compound C-4 was synthesized according to the following reaction.

[0230] [Chemical Formula]

[0231] Compound C-4 was synthesized in the same procedure as the synthesis of Compound C-1, except that 0.81 mg of Intermediate-6 was used instead of Intermediate-3. (Yield 1.7 g, Yield Rate 90%). The molecular weight of Compound C-4 was measured by GPC using polystyrene as a standard substance, and it was 3900 (theoretical value 3841).

[0232] [Comparative Example 1] (Preparation of Quantum Dot Electroluminescence Element D-3) In the preparation of the quantum dot electroluminescence element D-1 in Example 1, the same operations were carried out except that poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine)] (TFB) (manufactured by Luminescence Technology Corp.) having the following structure was used instead of compound C-1, and a quantum dot electroluminescence element D-3 was prepared. The weight average molecular weight (Mw) of TFB was measured by GPC using polystyrene as a standard substance and was 320,000.

[0233] [Chemical Formula]

[0234] [Evaluation] [Evaluation of Compounds / Compositions] For each compound / composition, the viscosity and the residual film ratio (%) were evaluated by the following method. The results are shown in Table 1 below.

[0235] (Viscosity) Each compound / composition was dissolved in 3-phenoxytoluene so that the solid content concentration became 1.5% by mass to prepare a liquid composition. For the obtained liquid composition, the viscosity (mPa·s) at 25°C was measured using a rheometer (manufactured by Anton-Paar). If the viscosity is 10 mPa·s or less, it can be said that the compound / composition is suitable for inkjet.

[0236] (Residual Film Ratio) The liquid composition used in the above evaluation (viscosity) was applied onto a quartz substrate by spin coating so as to have a film thickness of 100 nm. By heat-treating this at 230 °C for 60 minutes, a thin film 1 was obtained. A solvent (cyclohexylbenzene, dodecylbenzene) used in the ink for the quantum dot light-emitting layer was dropped onto the surface of the thin film 1. After waiting for 10 seconds in a state where the solvent was on it, spin coating was then performed. By heat-treating this at 230 °C for 60 minutes, a thin film 2 was obtained. For the thin films 1 and 2, the film thickness was measured using an Elipsometer (manufactured by HORIBA JOBIN YVON), and the remaining film ratio was calculated from the following formula.

[0237] [Equation]

[0238] [Table 1]

[0239] As shown in Table 1, since the compound / composition according to the present invention has two appropriateness (low viscosity of the ink and high remaining film ratio) necessary for manufacturing an EL element by inkjet, it was found to be suitable for inkjet.

[0240] [Evaluation of Quantum Dot Electroluminescence Element] For each quantum dot electroluminescence element, the luminous efficiency and the luminous lifetime were evaluated by the following method. The results are shown in Table 2 below.

[0241] (Luminous Efficiency) When a voltage is applied to each quantum dot electroluminescence device, current starts to flow at a certain voltage, and the quantum dot electroluminescence device emits light. Using a DC constant voltage power supply (manufactured by Keyence Corporation, source meter), the voltage of each device was gradually increased, the current value at that time was measured, and the luminance during light emission was measured using a luminance measuring device (manufactured by Topcon, SR-3). Here, the measurement was terminated when the luminance began to decay. The current value per unit area (current density) was calculated from the area of each device, and the luminance (cd / m 2 ) was divided by the current density (A / m 2 ) to calculate the current efficiency (cd / A). Then, the highest current efficiency in the measured voltage range was defined as "cd / A max". Also, assuming Lambertian emission from the spectral radiance luminance spectrum measured by the luminance measuring device, the external quantum efficiency (EQE) (%) at cd / A max was calculated to evaluate the luminous efficiency.

[0242] (Emission lifetime) Using a DC constant voltage power supply (manufactured by Keyence Corporation, source meter), a predetermined voltage was applied to each quantum dot electroluminescence device to cause the quantum dot electroluminescence device to emit light. While measuring the light emission of the quantum dot electroluminescence device with a luminance measuring device (manufactured by Topcon Corporation, SR-3), the current was gradually increased, and when the luminance reached 650 nit (cd / m 2 ), the current was made constant and left. The time until the luminance value measured by the luminance measuring device gradually decreased to 50% of the initial luminance was defined as "LT50 (hr)", and the value obtained by setting the LT50 value of Comparative Example 1 to 100 was defined as "Relative LT (-)".

[0243]

Table 2

[0244] From the results in Table 2 above, it was shown that the quantum dot electroluminescence device of the example can exhibit significantly higher luminous efficiency and durability (especially luminous lifetime) compared to the quantum dot electroluminescence device of the comparative example. In this example, although the red quantum dot electroluminescence device was evaluated, it is considered that the same results as above can be obtained for blue quantum dot electroluminescence devices and the like.

[0245] As described above, the present invention has been described with reference to embodiments and examples. However, the present invention is not limited to specific embodiments and examples, and various modifications and changes are possible within the scope of the invention described in the claims.

Description of Reference Numerals

[0246] 100…Electroluminescence device (EL device), 110…Substrate, 120…First electrode, 130…Hole injection layer, 140…Hole transport layer, 150…Light emitting layer, 160…Electron transport layer, 170…Electron injection layer, 180…Second electrode.

Claims

1. A compound represented by the following formula (1) (excluding polymers containing the unit shown in the following Chemical Formula 1); 【Chemical 1】 In formula (1), n is an integer of 3 or more and 10 or less, X represents a group represented by the following formula (2), and a plurality of Xs may be the same or different, Y represents a group represented by the following formula (3), and a plurality of Ys may be the same or different; 【Chemical 2】 In formula (2), R １ , R ２ and R ３ each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, may be the same or different, and may be bonded to each other to form a ring. a and b are each independently an integer of 2 or more and 10 or less, c is an integer of 1 or more and 6 or less; [Chemical Formula 3] In formula (3), R ４ 、 R ５ and R ６ each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, may be the same or different, and may be bonded to each other to form a ring. d is an integer of 1 or more and 5 or less, e and f are each independently an integer of 1 or more and 6 or less; 【Chemical Formula 4】 In the above Chemical Formula 1, R1 to R4 are the same as or different from each other, and are each independently a substituted or unsubstituted alkyl group having 4 to 30 carbon atoms, L1 to L4 are the same as or different from each other, and are each independently a direct bond; or a substituted or unsubstituted arylene group, Ar1 and Ar2 are the same as or different from each other, and are each independently a substituted or unsubstituted aryl group; or a substituted or unsubstituted heteroaryl group.

2. A compound represented by the following formula (1); 【Chemical Formula 5】 In formula (1), n is an integer of 3 or more and 10 or less, X represents a group represented by the following formula (2), and a plurality of Xs may be the same or different, Y represents a group represented by the following formula (3), and a plurality of Ys may be the same or different; 【Chemical Formula 6】 In formula (2), R1, R2 and R3 each independently represent a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group, and may be the same or different, and may be bonded to each other to form a ring, a and b are each independently an integer of 2 or more and 10 or less, c is an integer of 1 or more and 6 or less; 【Chemical 7】 In formula (3), R4, R5 and R6 each independently represent a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group, and may be the same or different, and may be bonded to each other to form a ring, d is an integer of 1 or more and 5 or less, e and f are each independently an integer of 1 or more and 6 or less.

3. The compound according to claim 1 or 2, having a molecular weight of 3000 or more and 10000 or less.

4. The compound according to any one of claims 1 to 3, and a low molecular weight compound having a molecular weight of less than 2000, and the content of the low molecular weight compound is 30% by mass or less, The low-molecular compound is at least one selected from the compounds represented by the following formulas (J1) to (J3); 【Chemical Formula 8】 In the above formula (J1), Ar ａ and Ar ｂ are each independently a substituted or unsubstituted monovalent aromatic hydrocarbon group or a monovalent aromatic heterocyclic group, and Ar ａ and Ar ｂ may combine with adjacent aromatic rings to form a ring. J is =C(R ａ )- or =N-, where R ａ is a hydrogen atom, an alkyl group, a cyano group, a monovalent aromatic hydrocarbon group, a monovalent aromatic heterocyclic group, a hydrocarbon group-substituted silyl group, an alkoxy group or a halogen group, and a plurality of R ａ may be bonded to each other to form a ring; 【Chemical Formula 9】 In the above formula (J2), Ar ｃ ~Ar ｅ each independently represents a substituted or unsubstituted monovalent aromatic hydrocarbon group or a monovalent aromatic heterocyclic group, and Ar ｃ ~Ar ｅ may be the same as or different from each other; 【Chemical 10】 In the above formula (J3), Ar ｆ 、Ar ｇ 、Ar ｉ and Ar ｊ are each independently a substituted or unsubstituted monovalent aromatic hydrocarbon group or a monovalent aromatic heterocyclic group, and Ar ｆ 、Ar ｇ 、Ar ｉ and Ar ｊ may be bonded to each other to form a ring. Ar ｈ is a substituted or unsubstituted divalent aromatic hydrocarbon group or divalent aromatic heterocyclic group, and Ar ｈ is Ar ｆ Ar ｇ Ar ｉ and Ar ｊ may combine to form a ring, q is an integer of 1 or more and 10 or less. **Claim 5**: The compound according to any one of claims 1 to 4, and a polymer compound having a molecular weight exceeding 10,000 and not exceeding 12,000, wherein the content of the polymer compound is 60% by mass or less, The polymer compound is a compound containing a structural unit represented by the following formula (4) and poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine)], a composition; 【Chemical 11】 In the above formula (4), A represents a group selected from the following group; 【Chemical 12】 【Chemical 13】 【Chemical formula 14】 【Chemical Formula 15】 【Chemical 16】 【Chemical 17】 In the above formula, * is a bonding site, and Alkyl means being substituted or unsubstituted with an alkyl group; In the above formula (4), B represents a group selected from the following group; 【Chemical Formula 18】 In the above formula, A is O, S or Se. When a plurality of Bs exist, the plurality of Bs may be the same or different, * is a bonding site, and Alkyl means being substituted or unsubstituted with an alkyl group. **Claim 6**: The compound according to any one of claims 1 to 3, or the composition according to claim 4 or 5, and a solvent, A liquid composition containing the same. **Claim 7**: An electroluminescence device material containing the compound according to any one of claims 1 to 3, or the composition according to claim 4 or 5. **Claim 8** An electroluminescence device including a first electrode, a second electrode, and one or more organic films disposed between the first electrode and the second electrode, wherein at least one layer of the organic film contains the compound according to any one of claims 1 to 3, or the composition according to claim 4 or 5. **Claim 9** The electroluminescence device according to claim 8, wherein the organic film has a hole transport layer or a hole injection layer. **Claim 10** The electroluminescence device according to claim 8 or 9, wherein the organic film has a light-emitting layer containing semiconductor nanoparticles or an organometallic complex. **Claim 11** A method for manufacturing an electroluminescence device including a first electrode, a second electrode, and one or more organic films disposed between the first electrode and the second electrode, A manufacturing method comprising a step of forming a hole transport layer by applying the liquid composition according to claim 6 by inkjet and drying the solvent.

12. The manufacturing method according to claim 11, further comprising a step of forming a light-emitting layer by applying an ink for a light-emitting layer containing semiconductor nanoparticles and a solvent for a light-emitting layer on the surface of the hole transport layer by a wet method and drying the solvent for the light-emitting layer.

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