阅读说明：本技术 发光元件 (Light emitting element ) 是由 白鸟美樱 秋野喜彦 福岛大介 于 2019-12-19 设计创作，主要内容包括：本发明提供一种发光效率优异的发光元件。本发明的发光元件依次具有阴极、含有具有交联基团的化合物和磷光发光性过渡金属络合物的第1有机层、含有与所述具有交联基团的化合物相同的化合物的交联体的第2有机层、以及阳极,所述第1有机层中含有的所述具有交联基团的化合物的比例相对于第1有机层的总质量为2～10质量％。具有交联基团的化合物任选为选自由式(XL-1)～式(XL-19)所示的交联基团构成的交联基团组中的至少一种具有交联基团的化合物。(The invention provides a light-emitting element with excellent light-emitting efficiency. The light-emitting element comprises a cathode, a1 st organic layer containing a compound having a crosslinking group and a phosphorescent transition metal complex, a 2 nd organic layer containing a crosslinked product of the same compound as the compound having a crosslinking group, and an anode in this order, wherein the proportion of the compound having a crosslinking group contained in the 1 st organic layer is 2 to 10% by mass relative to the total mass of the 1 st organic layer. The compound having a crosslinking group is optionally at least one compound having a crosslinking group selected from the group consisting of crosslinking groups represented by the formulae (XL-1) to (XL-19).)

1. A light-emitting element comprising a cathode, a1 st organic layer containing a compound having a crosslinking group and a phosphorescent transition metal complex, a 2 nd organic layer containing a crosslinked product of the same compound as the compound having a crosslinking group, and an anode in this order, wherein the proportion of the compound having a crosslinking group contained in the 1 st organic layer is 2 to 10% by mass relative to the total mass of the 1 st organic layer.

2. The light-emitting element according to claim 1,

the compound having a crosslinking group is at least one compound having a crosslinking group selected from the group consisting of the crosslinking groups of the formulae (XL-1) to (XL-19);

in the formulae (XL-1) to (XL-19), R^XLRepresents a methylene group, an oxygen atom or a sulfur atom, n^XLRepresents an integer of 0 to 5; at R^XLWhen a plurality of them are present, they are optionally the same or different; at n^XLWhen a plurality of them are present, they are optionally the same or different; h 1 represents a bonding site; these crosslinking groups optionally have a substituent, and in the case where there are plural substituents, the plural substituents are optionally bonded to each other and form a ring together with the carbon atom to which each is bonded.

3. The light-emitting element according to claim 2,

the compound having a crosslinking group is a polymer compound having a constituent unit represented by formula (1) or formula (1');

in the formula (1), nA represents an integer of 0-5, and n represents 1 or 2; in the case where plural nA exist, they are optionally the same or different;

Ar³represents an aromatic hydrocarbon group or a heterocyclic group, these groups optionally having substituents;

L^Arepresents an alkylene group, a cycloalkylene group, an arylene group, a heterocyclic group having a valence of 2, -a group represented by-NR' -and an oxygen atom or a sulfur atom, and these groups other than the oxygen atom and the sulfur atom may have a substituent; r' represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a 1-valent heterocyclic group, and these groups other than the hydrogen atom may have a substituent; at L^AWhen a plurality of them are present, they are optionally the same or different;

x represents a crosslinking group selected from the group of crosslinking groups; when X is plural, they are optionally the same or different;

in the formula (1'), mA represents an integer of 0-5, m represents an integer of 1-4, and c represents an integer of 0 or 1; in the case where there are plural mA, they are optionally the same or different;

Ar⁵represents an aromatic hydrocarbon group, a heterocyclic group, or a group in which an aromatic hydrocarbon ring and a heterocyclic ring are directly bonded, and these groups may have a substituent;

Ar⁴and Ar⁶Each independently represents an arylene group or a 2-valent heterocyclic group, which groups may have a substituent;

Ar⁴、Ar⁵and Ar⁶Optionally each is bonded to a group other than the group bonded to the nitrogen atom to which the group is bonded, either directly or via an oxygen atom or a sulfur atom, to form a ring;

K^Arepresents a group represented by an alkylene group, a cycloalkylene group, an arylene group, a 2-valent heterocyclic group, -NR' -or a group represented by an oxygen atom or a sulfur atom, and these groups other than the oxygen atom and the sulfur atom may have a substituent; r' represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a 1-valent heterocyclic group, and these groups other than the hydrogen atom may have a substituent; at K^AWhen a plurality of them are present, they are optionally the same or different;

x' represents a crosslinking group selected from the group consisting of a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group and a 1-valent heterocyclic group, and these groups other than the hydrogen atom may have a substituent; wherein at least 1X' is a crosslinking group selected from the group of crosslinking groups.

4. The light-emitting element according to any one of claims 1 to 3,

the phosphorescent transition metal complex is a metal complex represented by formula (1-A);

in the formula (1-A), M represents a ruthenium atom, a rhodium atom, a palladium atom, an iridium atom or a platinum atom;

n¹represents an integer of 1 or more, n²Represents an integer of 0 or more; wherein, when M is a ruthenium atom, a rhodium atom or an iridium atom, n is¹+n²Is 3, n is a palladium atom or a platinum atom¹+n²Is 2;

E¹represents a carbon atom or a nitrogen atom; at E¹When a plurality of them are present, they are optionally the same or different;

ring L^1ARepresents a pyridine ring, a diaza-benzene ring, an aza-naphthalene ring, a diaza-naphthalene ring, a triazole ring or a diazole ring, these rings optionally having substituents; when a plurality of the substituents is present, the plurality of substituents are optionally bonded to each other and form a ring together with the atom to which each is bonded; in the ring L^1AWhen a plurality of them are present, they are optionally the same or different;

E^21A、E^22A、E^23Aand E^24AEach independently represents a nitrogen atom or a carbon atom; wherein, the ring L^2ARepresents a benzene ring, a pyridine ring or a diaza-benzene ring; at E^21AIn the case of a nitrogen atom, R is absent^21A(ii) a At E^22AIn the case of a nitrogen atom, R is absent^22A(ii) a At E^23AIn the case of a nitrogen atom, R is absent^23A(ii) a At E^24AIn the case of a nitrogen atom, R is absent^24A(ii) a At E^21A、E^22A、E^23AAnd E^24AWhen a plurality of them are present, each of them is optionally the same or different;

R^21A、R^22A、R^23Aand R^24AEach independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a 1-valent heterocyclic group, a substituted amino group, or a halogen atom, and these groups other than the hydrogen atom may have a substituent; at R^21A、R^22A、R^23AAnd R^24AWhen a plurality of them are present, each of them is optionally the same or different; r^21AAnd R^22A、R^22AAnd R^23A、R^23AAnd R^24AAnd ring L^1AOptionally having substituents and R^21AOptionally each pair is bonded and forms a ring;

A¹-G¹-A²represents an anionic bidentate ligand; a. the¹And A²Each independently represents a carbon atom, an oxygen atom or a nitrogen atom, which are optionally ring-constituting atoms; g¹Represents a single bond, or with A¹And A²Groups of atoms which together form a bidentate ligand; in A¹-G¹-A²When a plurality of them is present, they are optionally the same or different.

5. The light-emitting element according to claim 4,

the metal complex shown in the formula (1-A) is a metal complex shown in a formula (1-B1), a formula (1-B2), a formula (1-B3), a formula (1-B4) or a formula (1-B5);

m, n in the formulae (1-B1) to (1-B5)¹、n²、R^21A、R^22A、R^23A、R^24AAnd A¹-G¹-A²Denotes the same meaning as above;

n¹¹and n¹²Each independently represents 1 or 2; wherein, when M is a ruthenium atom, a rhodium atom or an iridium atom, n is¹¹+n¹²Is 3, n is a palladium atom or a platinum atom¹¹+n¹²Is 2;

R^11B、R^12B、R^13B、R^14B、R^15B、R^16B、R^17Band R^18BEach independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a 1-valent heterocyclic group, a substituted amino group, or a halogen atom, and these groups other than the hydrogen atom may have a substituent; at R^11B、R^12B、R^13B、R^14B、R^15B、R^16B、R^17BAnd R^18BWhen a plurality of them are present, each of them is optionally the same or different;

in the formula (1-B1), R^11BAnd R^12B、R^12BAnd R^13B、R^13BAnd R^14BAnd R^11BAnd R^21AOptionally each pair is bonded and forms a ring; in the formula (1-B2), R^13BAnd R^14B、R^13BAnd R^15B、R^15BAnd R^16B、R^16BAnd R^17B、R^17BAnd R^18BAnd R^18BAnd R^21AOptionally each pair is bonded and forms a ring; in the formula (1-B3), R^11BAnd R^12B、R^12BAnd R^13B、R^13BAnd R^14B、R^11BAnd R^21A、R^13BAnd R^15B、R^15BAnd R^16B、R^16BAnd R^17B、R^17BAnd R^18BAnd R^18BAnd R^21AOptionally each pair is bonded and forms a ring together with each pair of bonded atoms; in the formula (1-B4), R^11BAnd R^18B、R^14BAnd R^15B、R^15BAnd R^16B、R^16BAnd R^17B、R^17BAnd R^18BAnd R^11BAnd R^21AOptionally each pair is bonded and forms a ring; in the formula (1-B5), R^11BAnd R^12B、R^12BAnd R^18B、R^15BAnd R^16B、R^16BAnd R^17B、R^17BAnd R^18BAnd R^11BAnd R^21AOptionally, each pair is bonded and forms a ring.

6. The light-emitting element according to any one of claims 1 to 5,

the 1 st organic layer is in contact with the 2 nd organic layer.

7. A method for manufacturing a light-emitting element, comprising a cathode, a1 st organic layer containing a compound having a crosslinking group and a phosphorescent transition metal complex, a 2 nd organic layer containing a crosslinked product of the same compound as the compound having the crosslinking group, and an anode in this order, wherein the proportion of the compound having the crosslinking group contained in the 1 st organic layer is 2 to 10 mass% based on the total mass of the 1 st organic layer, wherein the 1 st organic layer and the 2 nd organic layer are formed by a coating method.

Technical Field

The present invention relates to a light emitting element.

Background

Light-emitting elements such as organic electroluminescent elements can be suitably used for displays and lighting applications, and have been actively developed in recent years. As the light-emitting element, for example, a light-emitting element having a hole transport layer containing a crosslinked product of a polymer compound having a crosslinking group and a light-emitting layer containing a host material and an iridium complex is known (patent document 1).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2011-

Disclosure of Invention

Problems to be solved by the invention

However, the light-emitting element is not necessarily sufficient in light-emitting efficiency.

Accordingly, an object of the present invention is to provide a light-emitting element having excellent light-emitting efficiency.

Means for solving the problems

The present invention provides the following [1] to [7 ].

[1] A light-emitting element comprising a cathode, a1 st organic layer containing a compound having a crosslinking group and a phosphorescent transition metal complex, a 2 nd organic layer containing a crosslinked product of the same compound as the compound having a crosslinking group, and an anode in this order, wherein the proportion of the compound having a crosslinking group contained in the 1 st organic layer is 2 to 10% by mass relative to the total mass of the 1 st organic layer.

[2] The light-emitting element according to [1], wherein the compound having a crosslinking group is at least one compound having a crosslinking group selected from the group consisting of crosslinking groups represented by formulae (XL-1) to (XL-19).

[ solution 1]

[ formula (XL-1) to formula (XL-19) wherein R^XLRepresents a methylene group, an oxygen atom or a sulfur atom, n^XLRepresents an integer of 0 to 5. At R^XLWhen a plurality of them is present, they are optionally the same or different. At n^XLWhen a plurality of them is present, they are optionally the same or different.

And x1 represents a bonding site.

These crosslinking groups optionally have a substituent, and in the case where there are plural substituents, the plural substituents are optionally bonded to each other and form a ring together with the carbon atom to which each is bonded. ]

[3] The light-emitting element according to [2], wherein the compound having a crosslinking group is a polymer compound having a constituent unit represented by formula (1) or formula (1').

[ solution 2]

[ in the formula (1), nA represents an integer of 0-5, and n represents 1 or 2. In the case where plural nA exist, they are optionally the same or different.

Ar³Represents an aromatic hydrocarbon group or a heterocyclic group, and these groups may have a substituent.

L^ARepresents an alkylene group, a cycloalkylene group, an arylene group, a heterocyclic group having a valence of 2, a group represented by the formula-NR' -, an oxygen atom or a sulfur atom, and these groups other than the oxygen atom and the sulfur atom may have a substituent. R' represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a 1-valent heterocyclic group, and these groups other than the hydrogen atom may have a substituent. At L^AWhen a plurality of them is present, they are optionally the same or different.

X represents a crosslinking group selected from the group of crosslinking groups. When X is present in plural, they are optionally the same or different. ]

[ solution 3]

[ in the formula (1'), mA represents an integer of 0 to 5, m represents an integer of 1 to 4, and c represents an integer of 0 or 1. In the case where there are plural mA's, they are optionally the same or different.

Ar⁵Represents an aromatic hydrocarbon group, a heterocyclic group, or a group in which an aromatic hydrocarbon ring and a heterocyclic ring are directly bonded, and these groups may have a substituent.

Ar⁴And Ar⁶Each independently represents an arylene group or a 2-valent heterocyclic group, which groups may have a substituent.

Ar⁴、Ar⁵And Ar⁶Optionally each bonded to a group other than the group bonded to the nitrogen atom to which the group is bonded, either directly or via an oxygen atom or a sulfur atom, to form a ring.

K^ARepresents a group represented by an alkylene group, a cycloalkylene group, an arylene group, a 2-valent heterocyclic group, -NR' -or a group represented by an oxygen atom or a sulfur atom, and these groups other than the oxygen atom and the sulfur atom may have a substituent. R' represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a 1-valent heterocyclic group, and these groups other than the hydrogen atom may have a substituent. At K^AWhen a plurality of them is present, they are optionally the same or different.

X' represents a crosslinking group selected from the group consisting of a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group and a 1-valent heterocyclic group, and these groups other than the hydrogen atom may have a substituent. Wherein at least 1X' is a crosslinking group selected from the group of crosslinking groups. ]

[4] The light-emitting element according to any one of [1] to [3], wherein the phosphorescent transition metal complex is a metal complex represented by formula (1-A).

[ solution 4]

[ in the formula (1-A), M represents a ruthenium atom, a rhodium atom, a palladium atom, an iridium atom or a platinum atom.

n¹Represents an integer of 1 or more, n²Represents an integer of 0 or more. Wherein, when M is a ruthenium atom, a rhodium atom or an iridium atom, n is¹+n²Is 3, n is a palladium atom or a platinum atom¹+n²Is 2.

E¹Represents a carbon atom or a nitrogen atom. At E¹When a plurality of them is present, they are optionally the same or different.

Ring L^1ARepresents a pyridine ring, a diazepine ring, an azanaphthalene ring, a diazepine ring, a triazole ring or a diazole ring, these rings optionally having substituents. When a plurality of the substituents is present, the plurality of substituents are optionally bonded to each other and form a ring together with the atom to which each is bonded. In the ring L^1AWhen a plurality of them is present, they are optionally the same or different.

E^21A、E^22A、E^23AAnd E^24AEach independently represents a nitrogen atom or a carbon atom. Wherein, the ring L^2ARepresents a benzene ring, a pyridine ring or a diaza-benzene ring. At E^21AIn the case of a nitrogen atom, R is absent^21A. At E^22AIn the case of a nitrogen atom, R is absent^22A. At E^23AIn the case of a nitrogen atom, R is absent^23A. At E^24AIn the case of a nitrogen atom, R is absent^24A. At E^21A、E^22A、E^23AAnd E^24AWhen a plurality of them is present, they are each optionally the same or different.

R^21A、R^22A、R^23AAnd R^24AEach independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a 1-valent heterocyclic group, a substituted amino group, or a halogen atom, and these groups other than the hydrogen atom may have a substituent. At R^21A、R^22A、R^23AAnd R^24AWhen a plurality of them is present, they are each optionally the same or different. R^21AAnd R^22A、R^22AAnd R^23A、R^23AAnd R^24AAnd ring L^1AOptionally having substituents and R^21AOptionally, each pair is bonded and forms a ring.

A¹-G¹-A²Represents an anionic bidentate ligand. A. the¹And A²Each independently represents a carbon atom, an oxygen atom or a nitrogen atom, and these atoms are optionally atoms constituting a ring. G¹Represents a single bond, or with A¹And A²Together forming the radical of a bidentate ligand. In A¹-G¹-A²When a plurality of them is present, they are optionally the same or different.]

[5] The light-emitting element according to [4], wherein the metal complex represented by the formula (1-A) is a metal complex represented by the formula (1-B1), the formula (1-B2), the formula (1-B3), the formula (1-B4), or the formula (1-B5).

[ solution 5]

M, n in formulas (1-B1) to (1-B5)¹、n²、R^21A、R^22A、R^23A、R^24AAnd A¹-G¹-A²The same meaning as above is indicated.

n¹¹And n¹²Each independently represents 1 or 2. Wherein, when M is a ruthenium atom, a rhodium atom or an iridium atom, n is¹¹+n¹²Is 3, n is a palladium atom or a platinum atom¹¹+n¹²Is 2.

R^11B、R^12B、R^13B、R^14B、R^15B、R^16B、R^17BAnd R^18BEach independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a 1-valent heterocyclic group, a substituted amino group or a halogen atom, and these groups other than a hydrogen atom are optionalHas a substituent. At R^11B、R^12B、R^13B、R^14B、R^15B、R^16B、R^17BAnd R^18BWhen a plurality of them is present, they are each optionally the same or different.

In the formula (1-B1), R^11BAnd R^12B、R^12BAnd R^13B、R^13BAnd R^14BAnd R^11BAnd R^21AOptionally, each pair is bonded and forms a ring.

In the formula (1-B2), R^13BAnd R^14B、R^13BAnd R^15B、R^15BAnd R^16B、R^16BAnd R^17B、R^17BAnd R^18BAnd R^18BAnd R^21AOptionally, each pair is bonded and forms a ring.

In the formula (1-B3), R^11BAnd R^12B、R^12BAnd R^13B、R^13BAnd R^14B、R^11BAnd R^21A、R^13BAnd R^15B、R^15BAnd R^16B、R^16BAnd R^17B、R^17BAnd R^18BAnd R^18BAnd R^21AOptionally, each pair is bonded and forms a ring.

In the formula (1-B4), R^11BAnd R^18B、R^14BAnd R^15B、R^15BAnd R^16B、R^16BAnd R^17B、R^17BAnd R^18BAnd R^11BAnd R^21AOptionally, each pair is bonded and forms a ring.

In the formula (1-B5), R^11BAnd R^12B、R^12BAnd R^18B、R^15BAnd R^16B、R^16BAnd R^17B、R^17BAnd R^18BAnd R^11BAnd R^21AOptionally, each pair is bonded and forms a ring.]

[6] The light-emitting element according to any one of [1] to [5], wherein the 1 st organic layer is in contact with the 2 nd organic layer.

[7] A method for manufacturing a light-emitting element, comprising a cathode, a1 st organic layer containing a compound having a crosslinking group and a phosphorescent transition metal complex, a 2 nd organic layer containing a crosslinked product of the same compound as the compound having the crosslinking group, and an anode in this order, wherein the proportion of the compound having the crosslinking group contained in the 1 st organic layer is 2 to 10 mass% with respect to the total mass of the 1 st organic layer, wherein the 1 st organic layer and the 2 nd organic layer are formed by a coating method.

Effects of the invention

According to the present invention, a light-emitting element having excellent light-emitting efficiency can be provided.

Drawings

Fig. 1 is a schematic diagram showing an example of a light-emitting element according to an embodiment of the present invention.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described in detail.

Description of common terms

Terms used in common in the present specification have the following meanings unless otherwise specified.

Me represents a methyl group, Et represents an ethyl group, Bu represents a butyl group, i-Pr represents an isopropyl group, and t-Bu represents a tert-butyl group.

The hydrogen atom may be a deuterium atom or a protium atom.

In the formula representing the metal complex, the solid line representing the bonding of the ligand to the central metal represents a covalent bond or a coordinate bond.

The term "polymer compound" means a compound having a molecular weight distribution and a polystyrene-equivalent number average molecular weight of 1X 10³～1×10⁸The polymer of (1).

The "low molecular weight compound" means a compound having no molecular weight distribution and a molecular weight of 1X 10⁴The following compounds.

The "constituent unit" means that 1 or more units are present in the polymer compound. The presence of 2 or more constituent units in a polymer compound is generally referred to as a "repeating unit".

The "alkyl group" may be any of a straight chain and a branched chain. The number of carbon atoms of the linear alkyl group excluding the number of carbon atoms of the substituent is usually 1 to 50, preferably 3 to 30, and more preferably 4 to 20. The number of carbon atoms of the branched alkyl group excluding the number of carbon atoms of the substituent is usually 3 to 50, preferably 3 to 30, and more preferably 4 to 20.

Examples of the alkyl group optionally having a substituent include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a 2-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a 2-ethylbutyl group, a hexyl group, a heptyl group, an octyl group, a 2-ethylhexyl group, a 3-propylheptyl group, a decyl group, a3, 7-dimethyloctyl group, a 2-ethyloctyl group, a 2-hexyldecyl group, a dodecyl group, and a group in which a hydrogen atom in these groups is substituted with a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a fluorine atom, or the like (for example, a trifluoromethyl group, a pentafluoroethyl group, a perfluorobutyl group, a perfluorohexyl group, a perfluorooctyl group, a 3-phenylpropyl group, a 3- (4-methylphenyl) propyl group, a 3- (3, 5-dihexylphenyl) propyl group, and a 6-ethoxyhexyl group).

The number of carbon atoms of the "cycloalkyl group" is usually 3 to 50, preferably 3 to 30, and more preferably 4 to 20, excluding the number of carbon atoms of the substituent.

The cycloalkyl group may have a substituent, and examples thereof include a cyclohexyl group, a methylcyclohexyl group, and an ethylcyclohexyl group.

The "aryl group" refers to an atomic group remaining after 1 hydrogen atom directly bonded to a carbon atom constituting a ring is removed from an aromatic hydrocarbon. The number of carbon atoms of the aryl group excluding the number of carbon atoms of the substituent is usually 6 to 60, preferably 6 to 20, and more preferably 6 to 10.

The aryl group optionally has a substituent, and examples thereof include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthryl group, a 2-anthryl group, a 9-anthryl group, a 1-pyrenyl group, a 2-pyrenyl group, a 4-pyrenyl group, a 2-fluorenyl group, a 3-fluorenyl group, a 4-fluorenyl group, a 2-phenylphenyl group, a 3-phenylphenyl group, a 4-phenylphenyl group, and groups in which a hydrogen atom in these groups is substituted by an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a fluorine atom, and the like.

The "alkoxy group" may be any of a straight chain and a branched chain. The number of carbon atoms of the linear alkoxy group is usually 1 to 40, preferably 4 to 10, excluding the number of carbon atoms of the substituent. The number of carbon atoms of the branched alkoxy group excluding the number of carbon atoms of the substituent is usually 3 to 40, preferably 4 to 10.

The alkoxy group may optionally have a substituent, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a tert-butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group, a3, 7-dimethyloctyloxy group, a lauryloxy group, and groups in which a hydrogen atom in these groups is substituted with a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a fluorine atom, or the like.

The number of carbon atoms of the "cycloalkoxy group" is usually 3 to 40, preferably 4 to 10, excluding the number of carbon atoms of the substituent.

The cycloalkoxy group may have a substituent, and examples thereof include a cyclohexoxy group and a group in which a hydrogen atom in the cyclohexoxy group is substituted with a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a fluorine atom, or the like.

The number of carbon atoms of the "aryloxy group" is usually 6 to 60, preferably 6 to 48, excluding the number of carbon atoms of the substituent.

The aryloxy group may optionally have a substituent, and examples thereof include a phenoxy group, a 1-naphthoxy group, a 2-naphthoxy group, a 1-anthracenoxy group, a 9-anthracenoxy group, a 1-pyreneoxy group, and groups in which a hydrogen atom is substituted with an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, a fluorine atom, and the like.

The "p-valent heterocyclic group" (p represents an integer of 1 or more) means an atomic group remaining after p hydrogen atoms of hydrogen atoms directly bonded to carbon atoms or hetero atoms constituting a ring are removed from a heterocyclic compound. Among the p-valent heterocyclic groups, "p-valent aromatic heterocyclic groups" are preferred as groups remaining after p hydrogen atoms of hydrogen atoms directly bonded to carbon atoms or hetero atoms constituting the ring are removed from the aromatic heterocyclic compound.

The "aromatic heterocyclic compound" refers to a compound in which a heterocyclic ring itself such as oxadiazole, thiadiazole, thiazole, oxazole, thiophene, pyrrole, phosphole, furan, pyridine, pyrazine, pyrimidine, triazine, pyridazine, quinoline, isoquinoline, carbazole, dibenzophosphole, or the like exhibits aromaticity, and a compound in which an aromatic ring is fused to a heterocyclic ring although the heterocyclic ring itself does not exhibit aromaticity such as phenoxazine, phenothiazine, dibenzoborole, dibenzosilale, benzopyran, or the like.

The number of carbon atoms of the heterocyclic group having a valence of 1 excluding the number of carbon atoms of the substituent is usually 2 to 60, preferably 4 to 20.

The heterocyclic group having a valence of 1 may optionally have a substituent, and examples thereof include a thienyl group, a pyrrolyl group, a furyl group, a pyridyl group, a piperidyl group, a quinolyl group, an isoquinolyl group, a pyrimidyl group, a triazinyl group, and a group in which a hydrogen atom is substituted with an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, or the like.

The "halogen atom" refers to a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

The "amino group" optionally has a substituent, preferably a substituted amino group. The substituent of the amino group is preferably an alkyl group, a cycloalkyl group, an aryl group or a 1-valent heterocyclic group.

Examples of the substituted amino group include a dialkylamino group, a bicycloalkylamino group, and a diarylamino group.

Examples of the amino group include a dimethylamino group, a diethylamino group, a diphenylamino group, a bis (4-methylphenyl) amino group, a bis (4-tert-butylphenyl) amino group, and a bis (3, 5-di-tert-butylphenyl) amino group.

The "alkenyl group" may be any of a straight chain and a branched chain. The number of carbon atoms of the linear alkenyl group excluding the number of carbon atoms of the substituent is usually 2 to 30, preferably 3 to 20. The number of carbon atoms of the branched alkenyl group excluding the number of carbon atoms of the substituent is usually 3 to 30, preferably 4 to 20.

The number of carbon atoms of the "cycloalkenyl group" is usually 3 to 30, preferably 4 to 20, excluding the number of carbon atoms of the substituent.

Examples of the alkenyl group and cycloalkenyl group which may have a substituent include a vinyl group, a 1-propenyl group, a 2-butenyl group, a 3-pentenyl group, a 4-pentenyl group, a 1-hexenyl group, a 5-hexenyl group, a 7-octenyl group, a 1-cyclopentyl-1-yl group, a 1-cyclohexyl-1-yl group, and a group having a substituent described later.

The "alkynyl group" may be any of a straight chain and a branched chain. The number of carbon atoms of the alkynyl group excluding the carbon atoms of the substituent is usually 2 to 20, preferably 3 to 20. The number of carbon atoms of the branched alkynyl group excluding the carbon atoms of the substituent is usually 4 to 30, preferably 4 to 20.

The alkynyl group optionally has a substituent, and examples thereof include an ethynyl group, a 1-propynyl group, a 2-butynyl group, a 3-pentynyl group, a 4-pentynyl group, a 1-hexynyl group, a 5-hexynyl group, and groups having substituents described later.

The term "arylene group" refers to an atomic group remaining after removing 2 hydrogen atoms directly bonded to carbon atoms constituting a ring from an aromatic hydrocarbon. The number of carbon atoms of the arylene group excluding the number of carbon atoms of the substituent is usually 6 to 60, preferably 6 to 30, and more preferably 6 to 18.

The arylene group may have a substituent, and examples thereof include phenylene, biphenyldiyl, naphthalenediyl, anthracenediyl, phenanthrenediyl, dihydrophenanthrenediyl, tetracenediyl, fluorenediyl, pyrenediyl, perylenediyl, perylene-diyl, and the like,The diradicals and the groups having substituents described later are preferably groups represented by the formulae (A-1) to (A-21). The arylene group includes a group in which these groups are bonded to plural.

[ solution 6]

[ solution 7]

[ solution 8]

[ solution 9]

[ solution 10]

[ wherein R and R^aEach independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group having a valence of 1. A plurality of R and R exist^aEach of which is optionally the same or different, R^aOptionally bonded to each other and form a ring together with the respective bonded atoms.]

The number of carbon atoms of the 2-valent heterocyclic group excluding the number of carbon atoms of the substituent is usually 2 to 60, preferably 3 to 20, and more preferably 4 to 15.

The heterocyclic group having a valence of 2 optionally has a substituent, and examples thereof include a group having a valence of 2 obtained by removing 2 hydrogen atoms from a hydrogen atom directly bonded to a carbon atom or a hetero atom constituting the ring, preferably groups represented by formulae (AA-1) to (AA-36), among pyridine, diazabenzene, triazine, azanaphthalene, naphthyridine, carbazole, dibenzofuran, dibenzothiophene, dibenzosilacyclopentadiene, phenoxazine, phenothiazine, acridine, dihydroacridine, furan, thiophene, oxazole, oxadiazole, triazole, 5, 7, 12, 14-tetrahydroquino [2, 3-b ] acridine, oxazole, 1, 3, 4-oxadiazole, thiazole, and 1, 3, 4-thiadiazole. The 2-valent heterocyclic group includes a group in which these groups are bonded in plural.

[ solution 11]

[ solution 12]

[ solution 13]

[ solution 14]

[ solution 15]

[ solution 16]

[ solution 17]

[ wherein R and R^aThe same meaning as above is indicated.]

The "crosslinking group" means a group capable of generating a new bond by being subjected to heating, ultraviolet irradiation, near ultraviolet irradiation, visible light irradiation, infrared irradiation, radical reaction, or the like, and is preferably a crosslinking group represented by the formulae (XL-1) to (XL-19) of the above crosslinking group.

The "substituent" refers to, for example, a halogen atom, a cyano group, an alkyl group, a cycloalkyl group, an aryl group, a 1-valent heterocyclic group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an amino group, a substituted amino group, an alkenyl group, a cycloalkenyl group, or an alkynyl group. The substituents are optionally crosslinking groups. In the present specification, the expression that a group optionally has a substituent means that the group optionally has at least one of the groups listed as the substituent.

< light emitting element >

Next, the light-emitting element of this embodiment will be described.

The light-emitting element of the present embodiment is a light-emitting element which comprises a cathode, a1 st organic layer containing a compound having a crosslinking group and a phosphorescent transition metal complex, a 2 nd organic layer containing a crosslinked product of the same compound as the compound having a crosslinking group, and an anode in this order, wherein the amount of the compound having a crosslinking group contained in the 1 st organic layer is 2 to 10 mass% based on the total mass of the 1 st organic layer.

Examples of the method for forming the 1 st organic layer and the 2 nd organic layer include a dry method such as a vacuum deposition method and a wet method such as a spin coating method and an inkjet printing method, and a wet method is preferable.

When the 1 st organic layer is formed by a wet method, the 1 st ink described later is preferably used.

When the 2 nd organic layer is formed by a wet method, the 2 nd ink described later is preferably used. After the formation of the 2 nd organic layer, heating or light irradiation is performed, whereby the compound having a crosslinking group contained in the 2 nd organic layer can be crosslinked. As a method for crosslinking the compound having a crosslinking group contained in the 2 nd organic layer, heating is preferable. The 2 nd organic layer contains a crosslinked product of a compound having a crosslinking group.

The heating temperature for crosslinking is usually 50 to 300 ℃, preferably 50 to 260 ℃, more preferably 130 to 230 ℃, and further preferably 180 to 210 ℃.

The heating time is usually 0.1 to 1000 minutes, preferably 0.5 to 500 minutes, more preferably 1 to 120 minutes, and still more preferably 10 to 60 minutes.

Examples of the light used for light irradiation include ultraviolet light, near ultraviolet light, and visible light.

< 1 st organic layer >

The 1 st organic layer according to one embodiment of the present invention contains a compound having a crosslinking group and a phosphorescent transition metal complex, and the proportion of the compound having a crosslinking group contained in the 1 st organic layer is 2 to 10% by mass with respect to the total mass of the 1 st organic layer.

Examples of the method of analyzing the component contained in the 1 st organic layer include chemical separation analysis methods such as extraction, instrumental analysis methods such as infrared spectroscopy (also referred to as IR), nuclear magnetic resonance spectroscopy (also referred to as NMR), and mass spectrometry (also referred to as MS), and analytical methods combining the chemical separation analysis methods and the instrumental analysis methods.

For example, in the case of forming the 1 st organic layer by a wet method, the following method can be mentioned as a method for quantifying the compound having a crosslinking group contained in the 1 st organic layer.

First, the 1 st organic layer is separated from the stack of the cathode, the 1 st organic layer, the 2 nd organic layer, and the anode. As a method for separating the 1 st organic layer, a method of dissolving the components of the 1 st organic layer in a solvent such as toluene, xylene, chloroform, or tetrahydrofuran may be mentioned. Then, the mass of the separated 1 st organic layer was measured. Thereafter, the compound having a crosslinking group contained in the separated 1 st organic layer is quantified by analysis by nuclear magnetic resonance spectroscopy or mass spectrometry.

< Compound having crosslinking group >

The compound having a crosslinking group contained in the 1 st organic layer will be described.

In the 1 st organic layer, the 1 st organic layer may contain 1 kind of compound having a crosslinking group alone, or may contain 2 or more kinds.

The "compound having a crosslinking group" is preferably a compound having at least 1 crosslinking group selected from the group consisting of the crosslinking groups represented by the formulae (XL-1) to (XL-19) in terms of further excellent light-emitting efficiency of the light-emitting element.

[ solution 18]

The crosslinking group selected from the group of crosslinking groups is preferably a crosslinking group represented by formula (XL-1) to formula (XL-4), formula (XL-7) to formula (XL-10), or formula (XL-16) to formula (XL-19), more preferably a crosslinking group represented by formula (XL-1), formula (XL-16) to formula (XL-19), still more preferably a crosslinking group represented by formula (XL-1) or formula (XL-17), and still more preferably a crosslinking group represented by formula (XL-17), from the viewpoint of further improving the light emission efficiency of the light-emitting element of the present invention.

The "compound having a crosslinking group" may be a low-molecular compound or a high-molecular compound. The compound having a crosslinking group as the low-molecular compound is, for example, a low-molecular compound having at least 1 crosslinking group selected from the group of crosslinking groups. Examples of the low-molecular-weight compound include low-molecular-weight compounds represented by formulae (3-1) to (3-16).

[ solution 19]

[ solution 20]

[ solution 21]

[ solution 22]

[ solution 23]

The "compound having a crosslinking group" is preferably a polymer compound containing a constituent unit having at least 1 crosslinking group selected from the group of crosslinking groups (hereinafter also referred to as "crosslinking group-containing polymer compound of the 1 st organic layer").

The constituent unit having at least one crosslinking group selected from the group consisting of the crosslinking group-containing polymer compound in the 1 st organic layer is preferably a constituent unit represented by the formula (1) or the formula (1'), and more preferably a constituent unit represented by the formula (1).

[ solution 24]

[ solution 25]

The constituent unit having at least one crosslinking group selected from the group of crosslinking groups may be a constituent unit represented by formula (1 '-1) to formula (1' -5).

[ solution 26]

The crosslinking group-containing polymer compound of the 1 st organic layer may contain 2 or more kinds of constituent units having at least 1 kind of crosslinking group selected from the group of crosslinking groups. In this case, at least 2 preferred crosslinking groups of constituent units having at least 1 crosslinking group selected from the group of crosslinking groups are different from each other. As the combination of the crosslinking groups different from each other, a combination of at least 1 crosslinking group selected from the group consisting of the crosslinking groups represented by the formulae (XL-1), the formulae (XL-2), the formulae (XL-5) to (XL-8) and the formulae (XL-14) to (XL-16) and at least 1 crosslinking group selected from the group consisting of the crosslinking groups represented by the formulae (XL-3), the formulae (XL-4), the formulae (XL-13) and the formulae (XL-17) to (XL-19) is preferable, and a combination of the crosslinking group represented by the formula (XL-1) and the crosslinking group represented by the formula (XL-17) is more preferable.

Constituent Unit represented by formula (1)

nA is preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and still more preferably 0, from the viewpoint of further improving the light-emitting efficiency of the light-emitting element.

N is preferably 2 in terms of more excellent light-emitting efficiency of the light-emitting element.

For Ar³From the viewpoint of further improving the light-emitting efficiency of the light-emitting element, an aromatic hydrocarbon group optionally having a substituent is preferable.

Ar³The number of carbon atoms of the aromatic hydrocarbon group is usually 6 to 60, preferably 6 to 30, and more preferably 6 to 18, excluding the number of carbon atoms of the substituent.

Ar³Examples of the arylene moiety having n substituents removed from the aromatic hydrocarbon group shown and preferred ranges thereof are the same as those of Ar described later^Y1Examples and preferred ranges of the arylene group shown are the same.

Ar³The number of carbon atoms of the heterocyclic group is usually 2 to 60, preferably 3 to 30, and more preferably 4 to 18, excluding the number of carbon atoms of the substituent.

Ar³Examples of the heterocyclic group having a valence of 2 after n substituents are removed from the heterocyclic group shown and preferable ranges thereof are as described below with respect to Ar^Y1Examples of the 2-valent heterocyclic group and preferred ranges thereof are the same.

Ar³Examples of the substituents which the groups shown may have and preferred ranges are as defined below for Ar^Y1Examples and preferred ranges of the substituents which the groups shown may have are the same.

L^AThe number of carbon atoms of the alkylene group is usually 1 to 20 excluding the number of carbon atoms of the substituent. L is^AThe number of carbon atoms of the cycloalkylene group is usually 3 to 20, excluding the number of carbon atoms of the substituent.

L^AThe alkylene group and cycloalkylene group may have a substituent, and examples thereof include a methylene group, an ethylene group, a propylene group, and a propylene groupButyl group, hexylene group, cyclohexylene group, octylene group, and groups in which a hydrogen atom in these groups is substituted with an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a heterocyclic group having a valence of 1, a fluorine atom, or the like.

L^AExamples and preferred ranges of the arylene group and the 2-valent heterocyclic group shown below correspond to those of Ar described later^Y1Examples and preferred ranges of the arylene group and the 2-valent heterocyclic group are the same.

For L^AIn view of ease of production of the crosslinking group-containing polymer compound in the 1 st organic layer, an arylene group or an alkylene group is preferable. These groups optionally have a substituent.

L^AThe substituent optionally having the group shown is preferably a crosslinking group selected from the group consisting of an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a 1-valent heterocyclic group, a substituted amino group, a fluorine atom, a cyano group, or a crosslinking group. These groups optionally further have a substituent.

In terms of more excellent light-emitting efficiency of the light-emitting element, X is preferably a crosslinking group represented by formula (XL-1) to formula (XL-4), formula (XL-7) to formula (XL-10), or formula (XL-16) to formula (XL-19), more preferably a crosslinking group represented by formula (XL-1), formula (XL-16) to formula (XL-19), still more preferably a crosslinking group represented by formula (XL-1) or formula (XL-17), and particularly preferably a crosslinking group represented by formula (XL-17).

The constituent unit represented by the formula (1) is preferably 0.5 to 80 mol%, more preferably 3 to 65 mol%, further preferably 5 to 50 mol%, and particularly preferably 6 to 10 mol% based on the total amount of the constituent units contained in the crosslinking group-containing polymer compound of the 1 st organic layer, from the viewpoint of excellent stability of the crosslinking group-containing polymer compound of the 1 st organic layer.

The constituent unit represented by formula (1) may include only 1 species, or 2 or more species, in the crosslinking group-containing polymer compound in the 1 st organic layer.

In the case where the crosslinking group-containing polymer compound of the 1 st organic layer contains 2 or more kinds of constituent units represented by formula (1), at least 2 kinds of crosslinking groups represented by X among the constituent units represented by formula (1) are preferably different from each other.

Constituent Unit represented by formula (1')

mA is preferably an integer of 0 to 3 in view of further excellent light emission efficiency of the light emitting element.

M is preferably 1 or 2 in terms of more excellent light-emitting efficiency of the light-emitting element.

In the light emitting device of the present invention, c is preferably 0 in terms of ease of production of the crosslinking group-containing polymer compound in the 1 st organic layer and further excellent light emitting efficiency of the light emitting element.

For Ar⁵From the viewpoint of further improving the light-emitting efficiency of the light-emitting element, an aromatic hydrocarbon group optionally having a substituent is preferable.

Ar⁵The definitions and examples of the arylene moiety of the aromatic hydrocarbon group excluding m substituents are as described below with respect to Ar in the formula (X)^X2The definitions and examples of the arylene groups indicated are the same.

Ar⁵The definition and examples of the 2-valent heterocyclic moiety of the heterocyclic group shown in the above formula (X) excluding m substituents are as defined below with respect to Ar in the formula (X)^X2The definitions and examples of the heterocyclic groups having a valence of 2 are the same.

Ar⁵The definition and examples of the 2-valent group of the group obtained by directly bonding the aromatic hydrocarbon ring and the heterocycle excluding m substituents are as described below with respect to Ar in the formula (X)^X2The definitions and examples of the group having a valence of 2 obtained by directly bonding an arylene group to a heterocyclic group having a valence of 2 are the same.

For Ar⁴And Ar⁶In view of further improving the light-emitting efficiency of the light-emitting element, an arylene group optionally having a substituent is preferable.

Ar⁴And Ar⁶The definitions and examples of the arylene group and the 2-valent heterocyclic group shown above are the same as those of Ar in the formula (X) described later^X1And Ar^X3The definitions and examples of the arylene group and the 2-valent heterocyclic group are the same.

K^AAlkylene, cycloalkylene, arylene, anddefinitions and examples of 2-valent heterocyclic radicals are given in connection with L^AThe definitions and examples of the alkylene, cycloalkylene, arylene, and 2-valent heterocyclic group shown are the same.

For K^AIn view of ease of production of the crosslinking group-containing polymer compound in the 1 st organic layer, an arylene group or an alkylene group is preferable. These groups optionally have a substituent.

K^AExamples of the substituents which the illustrated groups may have and preferred ranges and L^AExamples and preferred ranges of the substituents which the groups shown may have are the same.

The definitions and examples of the crosslinking groups represented by X' are the same as those of X described above.

The constituent unit represented by formula (1') is preferably 0.5 to 50 mol% based on the total amount of the constituent units contained in the crosslinking group-containing polymer compound of the 1 st organic layer, from the viewpoint of excellent stability of the crosslinking group-containing polymer compound of the 1 st organic layer.

The constituent unit represented by formula (1') may include only 1 species or 2 or more species in the crosslinking group-containing polymer compound in the 1 st organic layer.

In the case where the crosslinking group-containing polymer compound of the 1 st organic layer contains 2 or more kinds of the constituent unit represented by formula (1 '), at least 2 kinds of the crosslinking groups represented by preferably X ' of the constituent unit represented by formula (1 ') are different from each other.

Preferred embodiment of the constituent unit represented by the formula (1) or (1')

Examples of the constituent unit represented by formula (1) include those represented by formulas (1-1) to (1-30), and examples of the constituent unit represented by formula (1 ') include those represented by formulas (1 ' -1) to (1 ' -9). Among them, the constituent units represented by the formulae (1-1) to (1-9) or (1-30) are preferable, and the constituent units represented by the formulae (1-1) to (1-9) are more preferable.

[ solution 27]

[ solution 28]

[ solution 29]

[ other constituent units ]

The crosslinking group-containing polymer compound of the 1 st organic layer preferably further contains a constituent unit represented by formula (X) in view of excellent hole-transporting properties.

[ solution 30]

[ in the formula (X), a^X1And a^X2Each independently represents an integer of 0 or more.

Ar^X1And Ar^X3Each independently represents an arylene group or a 2-valent heterocyclic group, which groups may have a substituent.

Ar^X2And Ar^X4Each independently represents an arylene group, a 2-valent heterocyclic group, or a 2-valent group in which an arylene group and a 2-valent heterocyclic group are directly bonded, and these groups may have a substituent. At Ar^X2And Ar^X4When a plurality of them is present, they are optionally the same or different.

R^X1、R^X2And R^X3Each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a 1-valent heterocyclic group, and these groups other than the hydrogen atom may have a substituent. At R^X2And R^X3When a plurality of them is present, they are optionally the same or different.]

For a^X1The light-emitting element of the present invention has a further excellent light-emitting efficiencyIn view of this, it is preferably 2 or less, and more preferably 1.

For a^X2In view of further improving the light-emitting efficiency of the light-emitting element of the present invention, the light-emitting element is preferably 2 or less, and more preferably 0.

R^X1～R^X3Preferably an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group having a valence of 1, more preferably an aryl group. These groups optionally have a substituent.

Ar^X1And Ar^X3The arylene group is more preferably a group represented by the formula (A-1) or the formula (A-9), and still more preferably a group represented by the formula (A-1). These groups optionally have a substituent.

Ar^X1And Ar^X3The heterocyclic group having a valence of 2 as represented by the formula (AA-1), the formula (AA-2) or the formulae (AA-7) to (AA-26) is more preferable. These groups optionally have a substituent.

Ar^X1And Ar^X3Preferred is an arylene group optionally having a substituent.

Ar^X2And Ar^X4The arylene group is more preferably a group represented by the formula (A-1), the formula (A-6), the formula (A-7), the formula (A-9) to the formula (A-11) or the formula (A-19), and still more preferably a group represented by the formula (A-9). These groups optionally have a substituent.

Ar^X2And Ar^X4More preferred ranges of the 2-valent heterocyclic group shown and Ar^X1And Ar^X3More preferred ranges of the heterocyclic group having a valence of 2 are the same.

Ar^X2And Ar^X4Among the group having a valence of 2 in which the arylene group and the heterocyclic group having a valence of 2 are directly bonded to each other, more preferable ranges and further preferable ranges of the arylene group and the heterocyclic group having a valence of 2 are respectively shown in the following, and Ar^X1And Ar^X3More preferred ranges and further preferred ranges of the arylene group and the 2-valent heterocyclic group are the same.

As Ar^X2And Ar^X4The group having a valence of 2, in which the arylene group and the heterocyclic group having a valence of 2 are directly bonded to each other, may be represented by, for example, the formula (Ar)^X5-1) to formula (Ar)^X5-4) a group represented by (a) which may have a substituent.

[ solution 31]

[ formula (Ar)^X5In-3), R^XXRepresents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a 1-valent heterocyclic group, and these groups other than the hydrogen atom may have a substituent.]

Ar^X2And Ar^X4Preferred is an arylene group optionally having a substituent.

As Ar^X1～Ar^X4And R^X1～R^X3The substituent optionally contained in the group shown is preferably an alkyl group, a cycloalkyl group or an aryl group, and more preferably an alkyl group. These groups optionally further have a substituent.

The constituent unit represented by formula (X) is preferably a constituent unit represented by formula (X-1) to formula (X-7), more preferably a constituent unit represented by formula (X-4).

[ solution 32]

[ solution 33]

[ chemical 34]

[ solution 35]

[ in formulae (X-1) to (X-7), R^X4And R^X5Each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl groupAn aryloxy group, a halogen atom, a heterocyclic group having a valence of 1 or a cyano group, these groups other than a hydrogen atom optionally having a substituent. There are a plurality of R^X4Optionally the same or different. There are a plurality of R^X5Optionally identical or different, adjacent R^X5Optionally bonded to each other and form a ring together with the carbon atom to which each is bonded.]

The constituent unit represented by the formula (X) is preferably 0.1 to 90 mol%, more preferably 1 to 70 mol%, further preferably 10 to 50 mol%, and particularly preferably 30 to 45 mol% based on the total amount of the constituent units contained in the crosslinking group-containing polymer compound in the 1 st organic layer, from the viewpoint of excellent hole-transporting property.

Examples of the structural unit represented by formula (X) include those represented by formulas (X1-1) to (X1-19), and preferably those represented by formulas (X1-6) to (X1-14).

[ solution 36]

[ solution 37]

[ solution 38]

[ solution 39]

[ solution 40]

[ solution 41]

[ solution 42]

[ solution 43]

In the crosslinking group-containing polymer compound of the 1 st organic layer, the constituent unit represented by the formula (X) may include only 1 type, or may include 2 or more types.

The crosslinking group-containing polymer compound of the 1 st organic layer preferably further contains a constituent unit represented by formula (Y) in view of more excellent light-emitting efficiency of the light-emitting element of the present invention.

The crosslinking group-containing polymer compound of the 1 st organic layer preferably further contains a constituent unit represented by formula (X) and a constituent unit represented by formula (Y) in terms of excellent hole-transporting properties and more excellent light-emitting efficiency of the light-emitting element of the present invention.

[ solution 44]

[ formula (Y) wherein Ar is^Y1Represents an arylene group, a 2-valent heterocyclic group, or a 2-valent group in which an arylene group and a 2-valent heterocyclic group are directly bonded, and these groups may have a substituent.]

Ar^Y1The arylene group is preferably a group represented by the formula (A-1), the formula (A-6), the formula (A-7), the formula (A-9) to the formula (A-11), the formula (A-13) or the formula (A-19), more preferably a group represented by the formula (A-1), the formula (A-7), the formula (A-9) or the formula (A-19), and further more preferably a group represented by the formula (A-1), the formula (A-7), the formula (A-9) or the formula (A-19)The step (A) is preferably a group represented by the formula (A-9). These groups optionally have a substituent.

Ar^Y1The heterocyclic group having a valence of 2 is preferably a group represented by the formula (AA-4), the formula (AA-10), the formula (AA-13), the formula (AA-15), the formula (AA-18) or the formula (AA-20), more preferably a group represented by the formula (AA-4), the formula (AA-10), the formula (AA-18) or the formula (AA-20). These groups optionally have a substituent.

Ar^Y1Among the 2-valent group in which the arylene group and the 2-valent heterocyclic group are directly bonded, more preferable ranges and further preferable ranges of the arylene group and the 2-valent heterocyclic group are the same as those of the above-mentioned Ar group^Y1More preferred ranges and further preferred ranges of the arylene group and the 2-valent heterocyclic group are the same.

As Ar^Y1The group having a valence of 2, which is obtained by directly bonding the arylene group and the heterocyclic group having a valence of 2, includes Ar of the formula (X)^X2And Ar^X4The arylene group shown is the same group as the group having a valence of 2 obtained by directly bonding a heterocyclic group having a valence of 2.

Ar^Y1The substituent which the group shown optionally has is preferably an alkyl group, a cycloalkyl group or an aryl group, more preferably an aryl group, and these groups optionally further have a substituent.

Examples of the constituent unit represented by formula (Y) include those represented by formulas (Y-1) to (Y-7), and the constituent unit represented by formula (Y-2) is preferable from the viewpoint of the light-emitting efficiency of the light-emitting element.

[ solution 45]

[ in the formula (Y-1), R^Y1Represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or a 1-valent heterocyclic group, and these groups other than the hydrogen atom may have a substituent. There are a plurality of R^Y1Optionally identical or different, adjacent R^Y1Optionally bonded to each other and form a ring together with the carbon atom to which each is bonded.]

[ solution 46]

[ in the formula (Y-2), R^Y1The same meaning as above is indicated.

X^Y1represents-C (R)^Y2)₂-、-C(R^Y2)＝C(R^Y2) -or C (R)^Y2)₂-C(R^Y2)

₂-a group as shown.

R^Y2Represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or a 1-valent heterocyclic group, and these groups other than the hydrogen atom may have a substituent.

There are a plurality of R^Y2Optionally identical or different, R^Y2Optionally bonded to each other and form a ring together with the carbon atom to which each is bonded.]

R^Y2Preferably an alkyl, cycloalkyl or aryl group, more preferably an aryl group. These groups optionally have a substituent.

At X^Y1for-C (R)^Y2)₂2R in the group shown^Y2In the combination of (3), it is preferable that both are alkyl groups or cycloalkyl groups, both are aryl groups, and both are heterocyclic groups having a valence of 1, or that one is an alkyl group or a cycloalkyl group and the other is an aryl group or a heterocyclic group having a valence of 1. for-C (R)^Y2)₂2R in the group shown^Y2In the combination of (1), it is preferable that one is an alkyl group or a cycloalkyl group and the other is an aryl group. These groups optionally have a substituent. There are 2R^Y2Optionally bonded to each other and forming a ring together with the respective bonded atoms. At R^Y2When forming a ring, -C (R)^Y2)₂The group represented by-is preferably a group represented by the formula (Y-A1) to the formula (Y-A5). These groups optionally have a substituent.

[ solution 47]

At X^Y1for-C (R)^Y2)＝C(R^Y2) 2R in the group shown^Y2Preferably, both are alkyl or cycloalkyl groups, or one is an alkyl or cycloalkyl group and the other is an aryl group. These groups optionally have a substituent.

At X^Y1for-C (R)^Y2)₂-C(R^Y2)₂4R in the group shown^Y2Preferably, an alkyl group or a cycloalkyl group optionally having a substituent. There are a plurality of R^Y2Optionally bonded to each other and forming a ring together with the respective bonded atoms. At R^Y2When forming a ring, -C (R)^Y2)₂-C(R^Y2)₂The group represented by-is preferably a group represented by the formula (Y-B1) to the formula (Y-B5). These groups optionally have a substituent.

[ solution 48]

[ formula (Y-B1), formula (Y-B2) and formula (Y-B4) wherein R^Y2The same meaning as above is indicated.]

[ solution 49]

[ formulae (Y-3) and (Y-4) wherein R^Y1The same meaning as above is indicated.

R^Y3Represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or a 1-valent heterocyclic group, and these groups other than the hydrogen atom may have a substituent.]

[ solution 50]

[ formula (Y-5) to formula (Y-7) wherein R^Y1The same meaning as above is indicated.

R^Y4Represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or a 1-valent heterocyclic group, and these groups other than the hydrogen atom may have a substituent.]

Examples of the constituent unit represented by formula (Y) include those represented by formulas (Y-11) to (Y-55).

[ solution 51]

[ solution 52]

[ Hua 53]

[ solution 54]

[ solution 55]

[ solution 56]

[ solution 57]

[ solution 58]

[ chemical 59]

[ solution 60]

[ solution 61]

[ solution 62]

[ solution 63]

The crosslinking group-containing polymer compound for the 1 st organic layer contains a constituent unit represented by the formula (Y) and Ar^Y1The arylene constituent unit is preferably 0.5 to 90 mol%, more preferably 30 to 60 mol%, and further preferably 40 to 55 mol% based on the total amount of the constituent units contained in the crosslinking group-containing polymer compound of the 1 st organic layer, from the viewpoint of further improving the light-emitting efficiency of the light-emitting element.

For formula (Y) and Ar^Y1A constituent unit of a 2-valent group in which a 2-valent heterocyclic group or an arylene group is directly bonded to a 2-valent heterocyclic group is preferable in terms of excellent charge transport properties of the crosslinking group-containing polymer compound in the 1 st organic layer,the amount of the crosslinking group-containing polymer compound in the 1 st organic layer is preferably 0.5 to 40 mol%, more preferably 3 to 30 mol%, based on the total amount of the constituent units contained in the crosslinking group-containing polymer compound.

The constituent unit represented by the formula (Y) may include only 1 species or 2 or more species in the crosslinking group-containing polymer compound in the 1 st organic layer.

Examples of the polymer compound having a crosslinking group in the 1 st organic layer include polymer compounds P-1 to P-8 shown in Table 1 below. The "other constituent unit" as used herein means a constituent unit other than the constituent units represented by the formulae (1), (1'), formulae (1 "), formulae (X) and (Y).

[ Table 1]

In the table, p ', q ', r ', s ' and t ' represent molar ratios of the respective constituent units. p ' + q ' + r ' + s ' + t ' + 100, and 70 ≦ p ' + q ' + r ' + s ' ≦ 100. ]

The crosslinking group-containing polymer compound in the 1 st organic layer may be any of a block copolymer, a random copolymer, an alternating copolymer, and a graft copolymer, or may be in other forms, but is preferably a copolymer obtained by copolymerizing a plurality of raw material monomers.

The number average molecular weight of the 1 st organic layer in terms of polystyrene of the crosslinking group-containing polymer compound is preferably 5X 10³～1×10⁶More preferably 1X 10⁴～5×10⁵More preferably 1.5X 10⁴～1×10⁵。

[1 st Process for producing a crosslinked Polymer Compound containing organic layer ]

The polymer compound containing a crosslinking group in the 1 st organic layer can be produced by a known polymerization method described in the chemical review (chem. rev.), volume 109, page 897-1091 (2009), and the like, and examples thereof include a method of polymerizing by a coupling reaction using a transition metal catalyst, such as Suzuki reaction, Yamamoto reaction, Buchwald reaction, Stille reaction, Negishi reaction, and Kumada reaction.

In the above polymerization method, as a method of adding the monomer, there may be mentioned a method of charging all the monomers to the reaction system at once; a method in which after a part of the monomers is charged and reacted, the remaining monomers are charged at once, continuously or in portions; a method of charging the monomer continuously or in portions, and the like.

Examples of the transition metal catalyst include a palladium catalyst and a nickel catalyst.

For the post-treatment of the polymerization reaction, a known method, for example, a method of removing water-soluble impurities by liquid separation, is carried out singly or in combination; a method of adding the reaction solution after the polymerization reaction to a lower alcohol such as methanol, filtering the precipitated precipitate, and drying the precipitate. When the purity of the crosslinking group-containing polymer compound in the 1 st organic layer is low, purification can be performed by a usual method such as recrystallization, reprecipitation, continuous extraction with a soxhlet extractor, or column chromatography.

< phosphorescent transition metal complexes >

A phosphorescent transition metal complex contained in the 1 st organic layer of the light-emitting element according to one embodiment of the present invention will be described.

The "phosphorescent transition metal complex" generally refers to a compound that exhibits phosphorescence at room temperature (25 ℃), and is preferably a metal complex that exhibits luminescence from a triplet excited state at room temperature. The metal complex that emits light from a triplet excited state has a central metal atom and a ligand.

Examples of the central metal atom include metal atoms having an atomic number of 40 or more, which have a spin-orbit interaction when they are formed into a complex, and which can cause intersystem crossing between a singlet state and a triplet state. Examples of the metal atom include a ruthenium atom, a rhodium atom, a palladium atom, an iridium atom, and a platinum atom. From the viewpoint of further improving the light-emitting efficiency of the light-emitting element, an iridium atom or a platinum atom is preferable, and an iridium atom is more preferable.

Examples of the ligand include a ligand which forms at least 1 type of bond selected from a coordinate bond and a covalent bond with the central metal atom. Examples of the bond between the central metal atom and the ligand include a metal-nitrogen bond, a metal-carbon bond, a metal-oxygen bond, a metal-phosphorus bond, a metal-sulfur bond, and a metal-halogen bond. Examples of the ligand include a neutral or anionic monodentate ligand and a neutral or anionic polydentate ligand. The polydentate ligand generally refers to a ligand having two or more teeth and six or less teeth.

The phosphorescent transition metal complex is preferably a metal complex represented by formula (2) in terms of more excellent light-emitting efficiency of the light-emitting element.

[ solution 64]

[ in the formula (2), M represents the same meaning as above.

n¹Represents an integer of 1 or more, n²Represents an integer of 0 or more. Wherein, when M is a ruthenium atom, a rhodium atom or an iridium atom, n is¹+n²Is 3, n is a palladium atom or a platinum atom¹+n²Is 2.

E¹And E²Each independently represents a carbon atom or a nitrogen atom. Wherein E is¹And E²At least one of them is a carbon atom. At E¹And E²When a plurality of them is present, they are each optionally the same or different.

Ring L¹Represents an aromatic heterocyclic ring, the ring optionally having a substituent. When a plurality of the substituents is present, the plurality of substituents are optionally bonded to each other and form a ring together with the atom to which each is bonded. In the ring L¹When a plurality of them is present, they are optionally the same or different.

Ring L²Represents an aromatic hydrocarbon ring or an aromatic heterocyclic ring, and these rings may have a substituent. In the presence of said substituentsIn the case of a plurality of substituents, the substituents are optionally bonded to each other and form a ring together with the atom to which each is bonded. In the ring L²When a plurality of them is present, they are optionally the same or different.

Ring L¹Optionally having substituents and ring L²The substituents optionally present are optionally bonded to each other and form a ring together with the atoms to which each is bonded.

A¹-G¹-A²Represents an anionic bidentate ligand. A. the¹And A²Each independently represents a carbon atom, an oxygen atom or a nitrogen atom, and these atoms are optionally atoms constituting a ring. G¹Represents a single bond, or with A¹And A²Together forming the radical of a bidentate ligand. In A¹-G¹-A²When a plurality of them is present, they are optionally the same or different.]

In view of further improving the current luminance efficiency of the light-emitting element, M is preferably an iridium atom or a platinum atom, and more preferably an iridium atom. The current luminance efficiency is luminance per unit current (cd/a).

In the case where M is a ruthenium atom, a rhodium atom or an iridium atom, n¹Preferably 2 or 3, more preferably 3.

In the case where M is a palladium atom or a platinum atom, n¹Preferably 2.

E¹And E²Preferably a carbon atom.

Ring L¹The number of carbon atoms of the aromatic heterocycle is usually 2 to 60, preferably 3 to 30, and more preferably 4 to 15, excluding the number of carbon atoms of the substituent. Ring L¹Preferably a 5-membered aromatic heterocycle or a 6-membered aromatic heterocycle. Ring L¹More preferably, the aromatic heterocyclic ring is a 5-membered aromatic heterocyclic ring having 2 or more and 4 or less nitrogen atoms as constituent atoms or a 6-membered aromatic heterocyclic ring having 1 or more and 4 or less nitrogen atoms as constituent atoms. These rings optionally have a substituent. Wherein, in the ring L¹In the case of a 6-membered aromatic heterocycle, E¹Preferably a carbon atom.

As a ring L¹Example ofExamples thereof include a diazole ring, a triazole ring, a tetrazole ring, a pyridine ring, a diazepine ring, a triazine ring, an azanaphthalene ring and a diazepine ring, preferably a pyridine ring, a diazepine ring, an azanaphthalene ring, a diazepine ring or an oxadiazole ring, more preferably a pyridine ring, a diazepine ring, an azanaphthalene ring, a diazepine ring, and further preferably a pyridine ring, a quinoline ring or an isoquinoline ring, and these rings may have a substituent.

Ring L²The number of carbon atoms of the aromatic hydrocarbon ring is usually 6 to 60, preferably 6 to 30, and more preferably 6 to 18, excluding the number of carbon atoms of the substituent. As a ring L²The aromatic hydrocarbon ring includes a benzene ring, a naphthalene ring, an indene ring, a fluorene ring, a phenanthrene ring, a dihydrophenanthrene ring, and a ring obtained by fusing 2 or more and 5 or less of these rings, and from the viewpoint of further excellent external quantum efficiency of the light-emitting element, a benzene ring, a naphthalene ring, a fluorene ring, a phenanthrene ring, or a dihydrophenanthrene ring is preferable, a benzene ring, a fluorene ring, or a dihydrophenanthrene ring is more preferable, and a benzene ring is further preferable. These rings optionally have a substituent.

Ring L²The number of carbon atoms of the aromatic heterocycle is usually 2 to 60, excluding the number of carbon atoms of the substituent. As a ring L²Examples of the aromatic heterocyclic ring include a pyrrole ring, a diazole ring, a furan ring, a thiophene ring, a pyridine ring, a diazepine ring, and a ring obtained by fusing 1 to 5 aromatic rings to these rings. These rings optionally have a substituent.

The ring L is further excellent in external quantum efficiency of the light-emitting element²Preferably a benzene ring, a fluorene ring, a dihydrophenanthrene ring, a pyridine ring, a diazepine ring, a carbazole ring, a dibenzofuran ring or a dibenzothiophene ring, more preferably a benzene ring, a pyridine ring or a diazepine ring, and still more preferably a benzene ring. These rings optionally have a substituent.

As a ring L¹And a ring L²The optional substituent is preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a heterocyclic group having a valence of 1, a substituted amino group or a halogen atom, more preferably an alkyl group, a cycloalkyl group, an aryl group, a heterocyclic group having a valence of 1 or a substituted amino group, and further preferably an alkyl group, a cycloalkyl group, an aryl groupPreferred is an alkyl group, an aryl group or a heterocyclic group having a valence of 1, and particularly preferred is an aryl group or a heterocyclic group having a valence of 1. These groups optionally further have a substituent.

In the metal complex represented by the formula (2), the ring L is preferable from the viewpoint of more excellent current luminance efficiency of the light-emitting element¹And a ring L²At least 1 of them has a substituent.

As a ring L¹And a ring L²Among the substituents which may be optionally contained, aryl is preferably phenyl, naphthyl, phenanthryl (Japanese: フェントレニル group), dihydrophenanthryl (Japanese: ジ ヒ ド ロ フェントレニル group) or fluorenyl. Ring L¹And a ring L²The aryl group in the optional substituent is more preferably a phenyl group or a fluorenyl group, and still more preferably a phenyl group. These groups optionally have a substituent.

As a ring L¹And a ring L²The heterocyclic group having a valence of 1 among the optional substituents is preferably a pyridyl group, a pyrimidinyl group, a triazinyl group, a quinolyl group, an isoquinolyl group, a dibenzofuranyl group, a dibenzothienyl group, a carbazolyl group, an azacarbazolyl group, a diazacazolyl group, a phenoxazinyl group, or a phenothiazinyl group, more preferably a pyridyl group, a pyrimidinyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothienyl group, or a carbazolyl group, further preferably a pyridyl group, a pyrimidinyl group, or a triazinyl group, and particularly preferably a triazinyl group. These groups optionally have a substituent.

As a ring L¹And a ring L²The substituent which may be optionally contained is preferably an alkyl group, a cycloalkyl group, an aryl group, a 1-valent heterocyclic group or a substituted amino group, more preferably an alkyl group, a cycloalkyl group or an aryl group, and still more preferably an alkyl group. These groups optionally further have a substituent.

For the ring L¹And a ring L²Among the optionally-contained substituents, an aryl group, a heterocyclic group having a valence of 1, or a substituted amino group is preferable, for example, from the viewpoint of more excellent external quantum efficiency of the light-emitting element, and is preferably a group represented by the formulae (D-A1) to (D-A5) or (D-B1) to (D-B3), more preferably a group represented by the formulae (D-A1), (D-A3) to (D-A5) or (D-B1), and still more preferably a group represented by the formulae (D-A1), (D-A3), or (D-B1)D-A5), particularly preferably a group of the formula (D-A1) or (D-A3).

[ solution 65]

[ solution 66]

[ in the formula, R^p1～R^p4Each independently represents an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group or a halogen atom. At R^p1、R^p2And R^p4When a plurality of them is present, they are each optionally the same or different.

np1 represents an integer of 0 to 5, np2 represents an integer of 0 to 3, np3 represents 0 or 1, and np4 represents an integer of 0 to 4. When there are plural np1 and np2, each of them may be the same or different. ]

In the ring L¹When a plurality of optional substituents are present, they are preferably not bonded to each other and form a ring together with the atom to which each is bonded. In the ring L²When a plurality of optional substituents are present, they are preferably not bonded to each other and form a ring together with the atom to which each is bonded. Preferably a ring L¹Optionally having substituents and ring L²The substituents optionally present do not bond to each other but form a ring together with the atoms to which each is bonded.

[ anionic bidentate ligand ]

As A¹-G¹-A²Examples of the anionic bidentate ligand include ligands represented by the formulae (a-101) to (a-109). Wherein A is¹-G¹-A²The illustrated anionic bidentate ligand is labeled with the angle n¹The ligands defining the number of them are different.

[ solution 67]

[ in formulae (a-101) to (a-109), [ the atom to which a x is added ] represents a coordinating atom. ]

The metal complex represented by the formula (2) is preferably a metal complex represented by the formula (1-a) in view of more excellent light-emitting efficiency of the light-emitting element.

[ solution 68]

For the ring L^1AIn view of further improving the light-emitting efficiency of the light-emitting element, a pyridine ring, a quinoline ring, or an isoquinoline ring is preferable. These rings optionally have a substituent.

Ring L^1AExamples of the optional substituent and preferred ranges and ring L¹And a ring L²Examples and preferred ranges of the optional substituents are the same.

In the ring L^1AWhen a plurality of optional substituents are present, they are preferably not bonded to each other and form a ring together with the atom to which each is bonded.

Ring L^2APreferably a benzene ring.

E^21A～E^24APreferably a carbon atom.

For R^21A～R^24AIn view of further improving the external quantum efficiency of the light-emitting element, a hydrogen atom, an alkyl group, or an aryl group is preferable. These groups other than the hydrogen atom may have a substituent.

R^21AAnd R^24AFurther preferably a hydrogen atom. R^22AFurther preferred is a hydrogen atom or an aryl group optionally having a substituent. R^23AFurther preferred is a hydrogen atom or an alkyl group optionally having a substituent.

Among the metal complexes represented by the formula (1-A), the ring L is preferable from the viewpoint of further excellent light-emitting efficiency of the light-emitting element^1AAt least 1 of which has a substituent, orR^21A～R^24AAt least 1 of (a) is an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a heterocyclic group having a valence of 1, a substituted amino group or a halogen atom.

At R^21A～R^24AWhen at least 1 of (A) is an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a 1-valent heterocyclic group, a substituted amino group, or a halogen atom, R is preferably selected from the viewpoint of further excellent external quantum efficiency of the light-emitting element^22AAnd R^23AAt least 1 of (a) is an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a heterocyclic group having a valence of 1, a substituted amino group or a halogen atom, and more preferably an alkyl group, a cycloalkyl group, an aryl group, a heterocyclic group having a valence of 1 or a substituted amino group. These groups optionally have a substituent.

R^21A～R^24AExamples and preferred ranges of the aryl group, the 1-valent heterocyclic group and the substituted amino group in (1) are respectively related to the ring L¹And a ring L²Examples and preferred ranges of the aryl group, the 1-valent heterocyclic group and the substituted amino group in the optional substituents are the same.

R^21A～R^24AExamples of the optional substituent and preferred ranges and ring L¹And a ring L²Examples of the substituent optionally having and preferred ranges of the substituent optionally further having are the same.

Preferably R^21AAnd R^22A、R^22AAnd R^23A、R^23AAnd R^24AAnd ring L^1AOptionally having substituents and R^21ANot each pair is bonded to form a ring together with the atoms to which each pair is bonded.

The metal complex represented by the formula (1-a) is preferably a metal complex represented by the formula (1-B1) to the formula (1-B5), more preferably a metal complex represented by the formula (1-B1) to the formula (1-B3), and still more preferably a metal complex represented by the formula (1-B3), in view of further improving the light-emitting efficiency of the light-emitting element.

[ solution 69]

[ Metal complexes represented by the formulae (1-B1) to (1-B5) ]

For R^11B～R^18BFrom the viewpoint of further improving the light-emitting efficiency of the light-emitting element, a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, a 1-valent heterocyclic group, or a substituted amino group is preferable, a hydrogen atom, an alkyl group, an aryl group, or a 1-valent heterocyclic group is more preferable, and these groups other than a hydrogen atom may have a substituent.

For R^11BAnd R^14B～R^18BFrom the viewpoint of ease of synthesis of the metal complex, a hydrogen atom or an alkyl group is preferable, and a hydrogen atom is more preferable. These groups other than the hydrogen atom may have a substituent.

For R^12BFrom the viewpoint of further improving the light-emitting efficiency of the light-emitting element, a hydrogen atom is preferable.

For R^13BFrom the viewpoint of further excellent light-emitting efficiency of the light-emitting element, a hydrogen atom, an aryl group, or a 1-valent heterocyclic group is preferable, and these groups other than the hydrogen atom may have a substituent.

R^11B～R^18BExamples and preferred ranges of the aryl group, the 1-valent heterocyclic group and the substituted amino group in (1) are respectively related to the ring L¹And a ring L²Examples and preferred ranges of the aryl group, the 1-valent heterocyclic group and the substituted amino group in the optional substituents are the same.

R^11B～R^18BExamples of the optional substituent and preferred ranges and ring L¹And a ring L²Examples of the substituent optionally having and preferred ranges of the substituent optionally further having are the same.

In the formulae (1-B1) to (1-B5), R is preferably R in order that the light-emitting element has more excellent light-emitting efficiency^11B～R^14B、R^11B～R^18BAnd R^21A～R^24AAt least 1 of (A) is an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a 1-valent heterocyclic group, a substituted amino group or a halogen atom,more preferably R^12B、R^13B、R^22AAnd R^23AAt least 1 of (A) is an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a 1-valent heterocyclic group, a substituted amino group or a halogen atom, and further preferably R^13B、R^22AAnd R^23AAt least 1 of (a) is an alkyl group, a cycloalkyl group, an aryl group, a 1-valent heterocyclic group or a substituted amino group. These groups optionally have a substituent.

In the formulae (1-B1) to (1-B5), R is preferably^11BAnd R^12B、R^12BAnd R^13B、R^13BAnd R^14B、R^11BAnd R^21A、R^13BAnd R^15B、R^15BAnd R^16B、R^16BAnd R^17B、R^17BAnd R^18B、R^18BAnd R^21A、R^11BAnd R^18B、R^14BAnd R^15BAnd R^12BAnd R^18BNot each pair is bonded to form a ring together with the atoms to which each pair is bonded.

Examples of the phosphorescent transition metal complex include metal complexes represented by the following formula.

[ solution 70]

[ solution 71]

[ chemical formula 72]

[ solution 73]

[ chemical formula 74]

Phosphorescent transition metal complexes are available from Aldrich, Luminescence Technology Corp., American Dye Source, etc. The phosphorescent transition metal complex can also be produced by a known method described in the publications such as Journal of the American Chemical Society, Vol.107, 1431-1432(1985), Journal of the American Chemical Society, Vol.106, 6647-6653(1984), Japanese patent application laid-open No. 2004-530254, Japanese patent application laid-open No. 2008-179617, Japanese patent application laid-open No. 2011-105701, Japanese patent application laid-open No. 2007-504272, International publication No. 2006/121811, Japanese patent application laid-open No. 2013-147450, and Japanese patent application laid-open No. 2014-224101.

[ base Material ]

The 1 st organic layer according to one embodiment of the present invention further contains a matrix material having at least 1 function selected from the group consisting of a hole injecting property, a hole transporting property, an electron injecting property, and an electron transporting property, and thereby the light-emitting element is particularly excellent in light-emitting efficiency. In the 1 st organic layer according to one embodiment of the present invention, the host material may contain 1 type alone, or 2 or more types.

The content of the phosphorescent transition metal complex in the 1 st organic layer is usually 0.05 to 80 parts by mass, preferably 0.1 to 50 parts by mass, more preferably 0.5 to 40 parts by mass, and still more preferably 1 to 10 parts by mass, when the total amount of the metal complex and the host material in the 1 st organic layer is 100 parts by mass.

Energy level (T) of lowest excited triplet state for the host material₁) In view of excellent light-emitting efficiency of the light-emitting element, T which is included in the above-mentioned phosphorescent transition metal complex is preferable₁An equivalent energy level, or a higher energy level.

As the host material, a host material exhibiting solubility in a solvent in which the above-described phosphorescent transition metal complex can be dissolved is preferable in terms of being able to fabricate a light-emitting element by a solution coating process.

The matrix material is classified into a low molecular compound and a high molecular compound.

Examples of the low-molecular compound used as the host material include a compound having a carbazole skeleton, a compound having a triarylamine skeleton, a compound having a phenanthroline skeleton, a compound having a triaryltriazine skeleton, a compound having an azole skeleton, a compound having a benzothiophene skeleton, a compound having a benzofuran skeleton, a compound having a fluorene skeleton, a compound having a spirofluorene skeleton, and the like. An example of the low-molecular-weight compound used in the matrix material is a compound represented by the following formula.

[ solution 75]

[ 76]

As the polymer compound used in the matrix material (hereinafter referred to as "polymer matrix"), a polymer compound containing a constituent unit represented by the above formula (Y) is preferable.

The definition, examples, and preferable ranges of the constituent unit represented by the formula (Y) optionally contained in the polymer matrix are the same as those of the constituent unit represented by the formula (Y) optionally contained in the crosslinking group-containing polymer compound of the above-mentioned 1 st organic layer.

For formula (Y) and Ar^Y1The arylene constituent unit is preferably 0.5 to 90 mol%, more preferably 30 to 87 mol%, and further preferably 50 to 85 mol% based on the total amount of the constituent units contained in the polymer matrix, from the viewpoint of further improving the light-emitting efficiency of the light-emitting element of the present embodiment.

For formula (Y) and Ar^Y1The constituent unit of the group having a valence of 2, which is obtained by directly bonding a heterocyclic group having a valence of 2 or an arylene group and a heterocyclic group having a valence of 2, is preferably 0.5 to 40 mol%, more preferably 3 to 30 mol%, and further preferably 5 to 20 mol% based on the total amount of the constituent units contained in the polymer matrix, from the viewpoint of excellent charge transport property of the light-emitting element of the present embodiment.

The constituent unit represented by the formula (Y) may be contained in the polymer matrix in only 1 kind, or may be contained in 2 or more kinds.

The polymer matrix preferably further contains a constituent unit represented by the formula (X) in view of excellent hole-transporting properties.

The definition, examples, preferable ranges, contents, and the like of the constituent unit represented by the formula (X) optionally contained in the polymer matrix are the same as those of the constituent unit represented by the formula (X) optionally contained in the crosslinking group-containing polymer compound of the above-mentioned 1 st organic layer.

In the polymer matrix, the constituent unit represented by the formula (X) may include only 1 species, or may include 2 or more species.

Examples of the polymer matrix include polymer compounds P-9 to P-14 shown in Table 2.

[ Table 2]

In the table, p, q, r, s and t represent the molar ratio of each constituent unit. p + q + r + s + t is 100, and 100. gtoreq + q + r + s. gtoreq 70. The other constituent units mean constituent units other than the constituent unit represented by the formula (Y) and the constituent unit represented by the formula (X). ]

The polymer matrix may be any of a block copolymer, a random copolymer, an alternating copolymer, and a graft copolymer, or may be in other forms, but is preferably a copolymer obtained by copolymerizing a plurality of raw material monomers.

[ method for producing Polymer base Material ]

The polymer matrix of the 1 st organic layer can be produced by the same method as the method for producing the crosslinking group-containing polymer compound of the 1 st organic layer.

[ composition No. 1]

The 1 st organic layer may be a layer containing a composition (hereinafter, also referred to as "1 st composition") containing a compound having a crosslinking group, a phosphorescent transition metal complex, and at least 1 selected from the group consisting of the above-described host material, hole transporting material, hole injecting material, electron transporting material, electron injecting material, fluorescent compound, and antioxidant. The proportion of the compound having a crosslinking group contained in the 1 st composition is 2 to 10% by mass based on the total mass of the 1 st composition.

[ hole transport Material ]

The hole transport material is classified into a low molecular compound and a high molecular compound, and is preferably a high molecular compound. The hole transport material may have a crosslinking group.

Examples of the polymer compound include polyvinylcarbazole and derivatives thereof; polyarylene having an aromatic amine structure in a side chain or a main chain, and a derivative thereof. The polymer compound may be a compound to which an electron accepting site is bonded. Examples of the electron accepting site include fullerene, tetrafluorotetracyanoquinodimethane, tetracyanoethylene, trinitrofluorenone, and the like. The electron accepting site is preferably a fullerene.

The amount of the hole transport material to be blended in the composition 1 is usually 1 to 400 parts by mass, preferably 5 to 150 parts by mass, based on 100 parts by mass of the total of the compound having a crosslinking group and the phosphorescent transition metal complex.

One kind of the hole transport material may be used alone, or two or more kinds may be used in combination.

[ Electron transport Material ]

The electron transport material is classified into a low molecular compound and a high molecular compound. The electron transport material may have a crosslinking group.

Examples of the low-molecular compound include metal complexes having 8-hydroxyquinoline as a ligand, oxadiazoles, anthraquinone dimethanes, benzoquinones, naphthoquinones, anthraquinones, tetracyanoanthraquinone dimethanes, fluorenones, diphenyldicyanoethylenes, diphenoquinones, and derivatives thereof.

Examples of the polymer compound include polyphenylene, polyfluorene, and derivatives thereof. The polymer compound may be doped with a metal.

In the composition 1, the amount of the electron transporting material is usually 1 to 400 parts by mass, preferably 5 to 150 parts by mass, based on 100 parts by mass of the total of the compound having a crosslinking group and the phosphorescent transition metal complex.

One kind of the electron transporting material may be used alone, or two or more kinds may be used in combination.

[ hole-injecting Material and Electron-injecting Material ]

The hole injection material and the electron injection material are each classified into a low molecular compound and a high molecular compound. The hole injection material and the electron injection material may have a crosslinking group.

Examples of the low-molecular-weight compound include metal phthalocyanines such as copper phthalocyanine; carbon; metal oxides of molybdenum, tungsten, and the like; metal fluorides such as lithium fluoride, sodium fluoride, cesium fluoride and potassium fluoride.

Examples of the polymer compound include polyaniline, polythiophene, polypyrrole, polyphenylenevinylene (japanese: ポリフェニレンビニレン), polythienylenevinylene (japanese: ポリチエニレンビニレン), polyquinoline, polyquinoxaline, and derivatives thereof; and a conductive polymer such as a polymer having an aromatic amine structure in a main chain or a side chain.

In the composition 1, the amount of the hole injecting material and the electron injecting material to be blended is usually 1 to 400 parts by mass, preferably 5 to 150 parts by mass, based on 100 parts by mass of the total of the compound having a crosslinking group and the phosphorescent transition metal complex.

The electron-injecting material and the hole-injecting material may be used singly or in combination of two or more.

[ ion doping ]

When the hole injection material or the electron injection material contains a conductive polymer, the conductivity of the conductive polymer is preferably 1 × 10^-5S/cm～1×10³S/cm. In order to set the conductivity of the conductive polymer within this range, an appropriate amount of ions may be doped into the conductive polymer.

The kind of the doped ion is an anion in the case of a hole injection material, and a cation in the case of an electron injection material. Examples of the anion include a polystyrene sulfonate ion, an alkylbenzene sulfonate ion, and a camphor sulfonate ion. Examples of the cation include lithium ion, sodium ion, potassium ion, and tetrabutylammonium ion.

One kind of the doping ions may be used alone, or two or more kinds may be used in combination.

[ fluorescent light-emitting Compound ]

The fluorescent light-emitting compound is classified into a low molecular compound and a high molecular compound. The fluorescent light-emitting compound may have a crosslinking group.

Examples of the low-molecular compound include naphthalene and its derivatives, anthracene and its derivatives, and perylene and its derivatives.

Examples of the polymer compound include polymer compounds containing phenylene, naphthalenediyl, anthracenediyl, fluorenediyl, phenanthrenediyl, dihydrophenanthrenediyl, a group represented by the above formula (X), carbazenediyl, phenoxazinediyl, phenothiazinediyl, pyrenediyl, and the like.

The amount of the fluorescent compound to be blended in the composition 1 is usually 0.1 to 400 parts by mass, preferably 5 to 150 parts by mass, based on 100 parts by mass of the total of the compound having a crosslinking group and the phosphorescent transition metal complex.

The fluorescent light-emitting compound may be used alone or in combination of two or more.

[ antioxidant ]

The antioxidant may be a compound that is soluble in the same solvent as the compound having a crosslinking group and the phosphorescent transition metal complex and does not inhibit light emission and charge transport. Examples of the antioxidant include a phenol antioxidant and a phosphorus antioxidant.

The amount of the antioxidant to be added to the composition 1 is usually 0.001 to 10 parts by mass, based on 100 parts by mass of the total of the compound having a crosslinking group and the phosphorescent transition metal complex.

One antioxidant may be used alone, or two or more antioxidants may be used in combination.

[ ink 1]

A composition containing a compound having a crosslinking group, a phosphorescent transition metal complex, and a solvent (hereinafter also referred to as "1 st ink") can be suitably used in coating methods such as a spin coating method, a casting method, a microgravure coating method, a gravure coating method, a bar coating method, a roll coating method, a wire bar coating method, a dip coating method, a spray coating method, a screen printing method, a flexographic printing method, an offset printing method, an inkjet printing method, a capillary coating method, a nozzle coating method, and the like.

The viscosity of the 1 st ink may be adjusted depending on the type of application method, and is preferably 1 to 20mPa · s at 25 ℃ in the case of application to a printing method such as an inkjet printing method in which a solution passes through an ejection device, from the viewpoint of preventing clogging and flight bending at the time of ejection.

The solvent contained in the 1 st ink is preferably a solvent capable of dissolving or uniformly dispersing the solid components in the ink. Examples of the solvent include chlorine-based solvents such as 1, 2-dichloroethane, 1, 2-trichloroethane, chlorobenzene, and o-dichlorobenzene; ether solvents such as tetrahydrofuran, dioxane, anisole and 4-methylanisole; aromatic hydrocarbon solvents such as toluene, xylene, mesitylene, ethylbenzene, n-hexylbenzene, and cyclohexylbenzene; aliphatic hydrocarbon solvents such as cyclohexane, methylcyclohexane, n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, n-dodecane, and bicyclohexane; ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone, and acetophenone; ester solvents such as ethyl acetate, butyl acetate, ethyl cellosolve acetate, methyl benzoate, and phenyl acetate; polyhydric alcohol solvents such as ethylene glycol, glycerin, and 1, 2-hexanediol; alcohol solvents such as isopropyl alcohol and cyclohexanol; sulfoxide solvents such as dimethyl sulfoxide; amide solvents such as N-methyl-2-pyrrolidone and N, N-dimethylformamide. One solvent may be used alone, or two or more solvents may be used in combination.

The amount of the solvent to be added to the 1 st ink is usually 1000 to 100000 parts by mass, preferably 2000 to 20000 parts by mass, when the total amount of the compound having a crosslinking property, the phosphorescent transition metal complex, and the matrix material is 100 parts by mass.

[2 nd organic layer ]

The 2 nd organic layer of the present invention is a layer containing a crosslinked product of the same compound having a crosslinking group as the compound having a crosslinking group contained in the 1 st organic layer (hereinafter, also referred to as "crosslinked product of the compound of the 2 nd organic layer").

The crosslinked material of the compound of the 2 nd organic layer can be obtained by crosslinking the same compound having a crosslinking group as the compound having a crosslinking group by the above-mentioned method and conditions.

[ composition No. 2]

The 2 nd organic layer may be a layer containing a crosslinked material of the compound including the 2 nd organic layer and a composition of at least 1 material selected from a hole-transporting material (different from the crosslinked material of the compound of the 2 nd organic layer), a hole-injecting material, an electron-transporting material, an electron-injecting material, a light-emitting material, and an antioxidant (hereinafter, also referred to as "the 2 nd composition").

Examples and preferable ranges of the hole transporting material, the electron transporting material, the hole injecting material, the electron injecting material, and the light emitting material contained in the composition No. 2 are the same as examples and preferable ranges of the hole transporting material, the electron transporting material, the hole injecting material, the electron injecting material, and the light emitting material contained in the composition No. 1. In the composition 2, the amounts of the hole transport material, the electron transport material, the hole injection material, the electron injection material, and the light emitting material to be blended are usually 1 to 400 parts by mass, and preferably 5 to 150 parts by mass, respectively, based on 100 parts by mass of the crosslinked compound of the organic layer 2.

Examples and preferred ranges of the antioxidant contained in the composition No. 2 are the same as those of the antioxidant contained in the composition No. 1. The amount of the antioxidant to be added to the composition 2 is usually 0.001 to 10 parts by mass based on 100 parts by mass of the crosslinked product of the compound in the organic layer 2.

As a method for determining whether or not the components contained in the 2 nd organic layer before crosslinking are the same as the compound having a crosslinking group contained in the 1 st organic layer, the following methods can be mentioned. First, the 2 nd organic layer is formed on the anode by a wet method, and the 2 nd organic layer before the crosslinking reaction is dissolved in a solvent such as toluene, xylene, chloroform, or tetrahydrofuran without undergoing the crosslinking reaction, and separated. The separated organic layer 2 before the crosslinking reaction was analyzed by nuclear magnetic resonance spectroscopy or mass spectrometry to determine whether it was the same compound as the compound having a crosslinking group contained in the organic layer 1.

[2 nd ink ]

A composition containing a compound of the 2 nd organic layer and a solvent (hereinafter also referred to as "2 nd ink") can be suitably used in the wet method described in the section 1 of ink. The preferred range of the viscosity of the 2 nd ink is the same as the preferred range of the viscosity of the 1 st ink. Examples and preferred ranges of the solvent contained in the 2 nd ink are the same as those of the solvent contained in the 1 st ink.

The amount of the solvent to be added to the 2 nd ink is usually 1000 to 100000 parts by mass, preferably 2000 to 20000 parts by mass, based on 100 parts by mass of the compound of the 2 nd organic layer.

< layer constitution of light emitting element >

A light-emitting element according to one embodiment of the present invention includes an anode, a cathode, a1 st organic layer, and a 2 nd organic layer. As an example, the light-emitting element 10 shown in fig. 1 has a structure in which a cathode 1, a1 st organic layer 2, a 2 nd organic layer 3, and an anode 4 are sequentially stacked. The light-emitting element according to one embodiment of the present invention may have layers other than the anode, the cathode, the 1 st organic layer, and the 2 nd organic layer.

In the light-emitting element according to one embodiment of the present invention, the 1 st organic layer is usually a light-emitting layer (hereinafter referred to as "1 st light-emitting layer").

In the light-emitting element according to one embodiment of the present invention, the 2 nd organic layer is usually a hole-transporting layer, a 2 nd light-emitting layer, or an electron-transporting layer. The 2 nd organic layer is preferably a hole transport layer or a 2 nd light emitting layer. The 2 nd organic layer is more preferably a hole transport layer.

In the light-emitting element according to one embodiment of the present invention, the 1 st organic layer and the 2 nd organic layer are preferably adjacent to each other in terms of further excellent light-emitting efficiency of the light-emitting element.

In the light-emitting element according to one embodiment of the present invention, the 2 nd organic layer is preferably a layer provided between the anode and the 1 st organic layer, in view of further improving the light-emitting efficiency of the light-emitting element. The 2 nd organic layer is more preferably a hole transport layer or a 2 nd light emitting layer provided between the anode and the 1 st organic layer. The 2 nd organic layer is more preferably a hole transport layer provided between the anode and the 1 st organic layer.

In the 1 st organic layer of the light-emitting element according to one embodiment of the present invention, the compound having a crosslinking group and the phosphorescent transition metal complex may each contain 1 species alone or 2 or more species. In the 2 nd organic layer of the light-emitting element according to one embodiment of the present invention, the crosslinked material of the compound of the 2 nd organic layer may contain 1 kind alone, or may contain 2 or more kinds.

In the light-emitting element according to one embodiment of the present invention, when the 2 nd organic layer is a hole-transporting layer provided between the anode and the 1 st organic layer, it is preferable to further include a hole-injecting layer between the anode and the 2 nd organic layer in order to further improve the light-emitting efficiency of the light-emitting element. In the case where the 2 nd organic layer is a hole transport layer provided between the anode and the 1 st organic layer, it is preferable to further include at least 1 of an electron injection layer and an electron transport layer between the cathode and the 1 st organic layer, from the viewpoint of further improving the light emission efficiency of the light-emitting element.

In the light-emitting element according to one embodiment of the present invention, when the 2 nd organic layer is the 2 nd light-emitting layer provided between the anode and the 1 st organic layer, it is preferable to further include at least 1 of a hole-injecting layer and a hole-transporting layer between the anode and the 2 nd organic layer, from the viewpoint of further improving the light-emitting efficiency of the light-emitting element. In the case where the 2 nd organic layer is the 2 nd light-emitting layer provided between the anode and the 1 st organic layer, it is preferable to further include at least 1 of an electron injection layer and an electron transport layer between the cathode and the 1 st organic layer, from the viewpoint of further improving the light-emitting efficiency of the light-emitting element.

In the light-emitting element according to one embodiment of the present invention, when the 2 nd organic layer is the 2 nd light-emitting layer provided between the cathode and the 1 st organic layer, it is preferable to further include at least 1 of a hole-injecting layer and a hole-transporting layer between the anode and the 1 st organic layer, from the viewpoint of further improving the light-emitting efficiency of the light-emitting element. In the case where the 2 nd organic layer is the 2 nd light-emitting layer provided between the cathode and the 1 st organic layer, it is preferable to further include at least 1 of an electron injection layer and an electron transport layer between the cathode and the 2 nd organic layer, from the viewpoint of further improving the light-emitting efficiency of the light-emitting element.

In the light-emitting element according to one embodiment of the present invention, when the 2 nd organic layer is an electron-transporting layer provided between the cathode and the 1 st organic layer, it is preferable to further include at least 1 of a hole-injecting layer and a hole-transporting layer between the anode and the 1 st organic layer, from the viewpoint of further improving the light-emitting efficiency of the light-emitting element. In the case where the 2 nd organic layer is an electron transport layer provided between the cathode and the 1 st organic layer, it is preferable to further include an electron injection layer between the cathode and the 2 nd organic layer, from the viewpoint of further improving the light-emitting efficiency of the light-emitting element of the present invention.

Specific layer configurations of the light-emitting element in some embodiments of the present invention include, for example, layer configurations shown in (D1) to (D15). The light-emitting element in some embodiments of the present invention generally has a substrate, and may be stacked on the substrate from an anode or from a cathode.

(D1) Anode/2 nd light emitting layer (2 nd organic layer)/1 st light emitting layer (1 st organic layer)/cathode

(D2) Anode/hole transport layer (2 nd organic layer)/1 st light emitting layer (1 st organic layer)/cathode

(D3) Anode/hole injection layer/2 nd light emitting layer (2 nd organic layer)/1 st light emitting layer (1 st organic layer)/cathode

(D4) Anode/hole injection layer/2 nd light emitting layer (2 nd organic layer)/1 st light emitting layer (1 st organic layer)/electron transport layer/cathode

(D5) Anode/hole injection layer/2 nd light emitting layer (2 nd organic layer)/1 st light emitting layer (1 st organic layer)/electron injection layer/cathode

(D6) Anode/hole injection layer/2 nd light emitting layer (2 nd organic layer)/1 st light emitting layer (1 st organic layer)/electron transport layer/electron injection layer/cathode

(D7) Anode/hole injection layer/hole transport layer (2 nd organic layer)/1 st light emitting layer (1 st organic layer)/cathode

(D8) Anode/hole injection layer/hole transport layer (2 nd organic layer)/1 st light emitting layer (1 st organic layer)/electron transport layer/cathode

(D9) Anode/hole injection layer/hole transport layer (2 nd organic layer)/1 st light emitting layer (1 st organic layer)/electron injection layer/cathode

(D10) Anode/hole injection layer/hole transport layer (2 nd organic layer)/1 st light emitting layer (1 st organic layer)/electron transport layer/electron injection layer/cathode

(D11) Anode/hole injection layer/hole transport layer/2 nd light emitting layer (2 nd organic layer)/1 st light emitting layer (1 st organic layer)/electron transport layer/electron injection layer/cathode

(D12) Anode/hole injection layer/hole transport layer (2 nd organic layer)/1 st light emitting layer (1 st organic layer)/2 nd light emitting layer/electron transport layer/electron injection layer/cathode

(D13) Anode/hole injection layer/hole transport layer/1 st light emitting layer (1 st organic layer)/2 nd light emitting layer (2 nd organic layer)/electron transport layer/electron injection layer/cathode

(D14) Anode/hole injection layer/hole transport layer/1 st light emitting layer (1 st organic layer)/electron transport layer (2 nd organic layer)/electron injection layer/cathode

(D15) Anode/hole injection layer/hole transport layer (2 nd organic layer)/2 nd light emitting layer/1 st light emitting layer (1 st organic layer)/electron transport layer/electron injection layer/cathode

(D1) In each of (D15), "/" indicates that the preceding and succeeding layers are stacked adjacent to each other. Specifically, the phrase "2 nd light-emitting layer (2 nd organic layer)/1 st light-emitting layer (1 st organic layer)" means that the 2 nd light-emitting layer (2 nd organic layer) and the 1 st light-emitting layer (1 st organic layer) are stacked adjacent to each other.

In the light-emitting element according to one embodiment of the present invention, the anode, the hole injection layer, the hole transport layer, the 2 nd light-emitting layer, the electron transport layer, the electron injection layer, and the cathode may be provided with 2 or more layers, as necessary.

When a plurality of the anode, the hole injection layer, the hole transport layer, the 2 nd light-emitting layer, the electron transport layer, the electron injection layer, and the cathode are present, they are optionally the same or different.

The thickness of the anode, the hole injection layer, the hole transport layer, the 1 st light-emitting layer, the 2 nd light-emitting layer, the electron transport layer, the electron injection layer and the cathode is usually 1nm to 1 μm, preferably 2nm to 500nm, and more preferably 5nm to 150 nm.

In the light-emitting element of the present invention, the order, number, and thickness of the layers to be stacked may be adjusted in consideration of the light-emitting efficiency, driving voltage, and element life of the light-emitting element.

[2 nd light-emitting layer ]

The 2 nd light-emitting layer is generally a 2 nd organic layer or a layer containing a light-emitting material, and preferably a layer containing a light-emitting material. When the 2 nd light-emitting layer is a layer containing a light-emitting material, examples of the light-emitting material contained in the 2 nd light-emitting layer include the light-emitting material optionally contained in the 2 nd composition. The light-emitting material contained in the 2 nd light-emitting layer may contain 1 kind alone, or may contain 2 or more kinds.

In the case where the light-emitting element according to one embodiment of the present invention includes the 2 nd light-emitting layer and the hole-transporting layer and the electron-transporting layer, which will be described later, are not the 2 nd organic layer, the 2 nd light-emitting layer is preferably the 2 nd organic layer.

[ hole transport layer ]

The hole transport layer is typically a 2 nd organic layer or a layer containing a hole transport material. The hole transport layer is preferably the 2 nd organic layer. When the hole transporting layer is a layer containing a hole transporting material, examples of the hole transporting material include the hole transporting materials optionally contained in the composition 1. The hole transport material contained in the hole transport layer may contain 1 kind alone, or may contain 2 or more kinds.

In the case where the light-emitting element according to one embodiment of the present invention has a hole-transport layer and the above-described 2 nd light-emitting layer and the electron-transport layer described later are not the 2 nd organic layer, the hole-transport layer is preferably the 2 nd organic layer.

[ Electron transport layer ]

The electron transport layer is typically a 2 nd organic layer or a layer containing an electron transport material. The electron transport layer is preferably a layer containing an electron transport material. When the electron transporting layer is a layer containing an electron transporting material, examples of the electron transporting material contained in the electron transporting layer include electron transporting materials optionally contained in the composition 1. The electron-transporting material contained in the electron-transporting layer may contain 1 kind alone, or may contain 2 or more kinds.

In the case where the light-emitting element according to one embodiment of the present invention has an electron transport layer and the 2 nd light-emitting layer and the hole transport layer are not the 2 nd organic layer, the electron transport layer is preferably the 2 nd organic layer.

[ hole injection layer and Electron injection layer ]

The hole injection layer is a layer containing a hole injection material. Examples of the hole injection material contained in the hole injection layer include the hole injection materials optionally contained in the composition 1. The hole injection material contained in the hole injection layer may contain 1 kind alone, or may contain 2 or more kinds.

The electron injection layer is a layer containing an electron injection material. Examples of the electron injecting material contained in the electron injecting layer include the electron injecting materials optionally contained in the composition 1. The electron injection material contained in the electron injection layer may contain 1 kind alone, or may contain 2 or more kinds.

[ substrate/electrode ]

The substrate of the light-emitting element may be any substrate that can be provided with an electrode and does not undergo chemical change when an organic layer is formed. The substrate of the light-emitting element is formed of a material such as glass, plastic, or silicon. In the case of using an opaque substrate, it is preferable that the electrode farthest from the substrate is transparent or translucent.

Examples of the material of the anode include a conductive metal oxide and a translucent metal. The anode is preferably made of indium oxide, zinc oxide or tin oxide; conductive compounds such as Indium Tin Oxide (ITO) and indium zinc oxide; silver and palladium and copper complexes (APC); gold, platinum, silver, copper.

Examples of the material of the cathode include metals such as lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, aluminum, zinc, and indium; alloys of 2 or more of them; alloys of 1 or more of them with 1 or more of silver, copper, manganese, titanium, cobalt, nickel, tungsten, and tin; and graphite intercalation compounds. Examples of the alloy include a magnesium-silver alloy, a magnesium-indium alloy, a magnesium-aluminum alloy, an indium-silver alloy, a lithium-aluminum alloy, a lithium-magnesium alloy, a lithium-indium alloy, and a calcium-aluminum alloy.

In the light-emitting element according to one embodiment of the present invention, at least one of the anode and the cathode is usually transparent or translucent, and preferably the anode is transparent or translucent.

Examples of the method for forming the anode and the cathode include a vacuum deposition method, a sputtering method, an ion plating method, a plating method, and a lamination method.

[ method for manufacturing light-emitting element ]

In the light-emitting element according to one embodiment of the present invention, when a low molecular compound is used as a method for forming each layer such as the 1 st light-emitting layer, the 2 nd light-emitting layer, the hole-transporting layer, the electron-transporting layer, the hole-injecting layer, and the electron-injecting layer, a method starting from a vacuum vapor deposition method of powder or a method starting from film formation in a solution or molten state can be exemplified. When a polymer compound is used, for example, a method of forming a film from a solution or a molten state is mentioned.

The 1 st light-emitting layer, the 2 nd light-emitting layer, the hole transport layer, the electron transport layer, the hole injection layer, and the electron injection layer can be formed by coating methods such as spin coating, inkjet printing, and the like using the 1 st ink, the 2 nd ink, and inks containing the light-emitting material, the hole transport material, the electron transport material, the hole injection material, and the electron injection material described above, respectively.

A method for manufacturing a light-emitting element according to one embodiment of the present invention is a method for manufacturing a light-emitting element which includes a cathode, a1 st organic layer containing a compound having a crosslinking group and a phosphorescent transition metal complex, a 2 nd organic layer containing a crosslinked product of the same compound as the compound having the crosslinking group, and an anode in this order, and in which the proportion of the compound having the crosslinking group contained in the 1 st organic layer is 2 to 10 mass% with respect to the total mass of the 1 st organic layer, wherein the 1 st organic layer and the 2 nd organic layer are formed by a coating method.

[ use of light-emitting element ]

The light-emitting element of the present invention is useful for, for example, displays and lighting.

Examples

The present invention will be described in further detail with reference to examples below, but the present invention is not limited to these examples.

In the examples, the number average molecular weight (Mn) in terms of polystyrene and the weight average molecular weight (Mw) in terms of polystyrene of the polymer compound were determined by Size Exclusion Chromatography (SEC) using tetrahydrofuran as a mobile phase. The measurement conditions of SEC are as follows.

The polymer compound to be measured was dissolved in tetrahydrofuran at a concentration of about 0.05 mass%, and 10. mu.L of SEC was injected. The mobile phase was circulated at a flow rate of 2.0 mL/min. As a column, PLGel MIXED-B (manufactured by Polymer Laboratories) was used. A UV-VIS detector (product name: SPD-10Avp, manufactured by Shimadzu corporation) was used as the detector.

< Synthesis example P-1 > Synthesis of Polymer Compounds P-1 to P-2

The polymer compound P-1 was synthesized according to the method described in Japanese patent application laid-open No. 2011-105701.

Polymer compound P-2 was synthesized according to the method described in International publication No. 2009/157430.

[ solution 77]

[ solution 78]

< Synthesis example M1 > Synthesis of Metal Complex M1

The metal complex M1 was synthesized according to the method described in Japanese patent application laid-open No. 2011-105701.

[ solution 79]

< comparative example 1 > production and evaluation of light-emitting device CD1

(formation of Anode and hole injection layer)

An ITO film was deposited on a glass substrate by a sputtering method to a thickness of 45nm, thereby forming an anode. On the anode, a solution of poly (ethylenedioxythiophene)/polystyrenesulfonic acid (HC Stark, trade name: CLEVIOS P AI4083) was formed into a film with a thickness of 65nm by spin coating, and the film was heated on a hot plate at 200 ℃ for 10 minutes in an atmospheric atmosphere, thereby forming a hole injection layer.

(formation of No. 2 organic layer)

A0.6 mass% xylene solution (hereinafter referred to as "composition P") in which the polymer compound P-1 was dissolved in xylene was prepared. Using the composition P, a film was formed on the hole injection layer by a spin coating method at a thickness of 20nm, and heated on a hot plate for 60 minutes at 180 ℃ in a nitrogen atmosphere, thereby forming a 2 nd organic layer. By this heating, the polymer compound P-1 becomes a crosslinked body.

(formation of No. 1 organic layer)

A 1.6 mass% xylene solution (hereinafter referred to as "composition M") of a mixture of the polymer compound P-2(92.5 parts by mass) and the metal complex M1(7.5 parts by mass) was prepared. Using the composition M, a film was formed on the 2 nd organic layer by a spin coating method at a thickness of 80nm, and heated at 130 ℃ for 10 minutes under a nitrogen atmosphere, thereby forming the 1 st organic layer.

(formation of cathode)

The substrate on which the 1 st organic layer was formed was depressurized to 1.0X 10 in a deposition machine^-4After Pa or less, about 2nm of barium was deposited on the 1 st organic layer as a cathode, and about 80nm of aluminum was deposited thereon. After the vapor deposition, the glass substrate was sealed to produce a light-emitting element D1.

(evaluation of light-emitting element)

By applying a voltage to the light-emitting element CD1, red EL emission having a peak at 615nm was observed. The maximum light emission efficiency of the light-emitting element CD1 was set to 100%.

< comparative example 2 > production and evaluation of light-emitting device CD2

A light-emitting element CD2 was produced in the same manner as in comparative example 1, except that a 1.6 mass% xylene solution of the polymer compound P-1 (hereinafter referred to as "composition N") was prepared, and that the composition M and the composition N (composition M/composition N: 80 mass%/20 mass%) were used instead of the composition M in comparative example 1 (formation of the 1 st organic layer). In the light-emitting element CD2, the polymer compound P-1 contained in the 1 st organic layer was a non-crosslinked material.

By applying a voltage to the light-emitting element CD2, red EL emission having a peak at 615nm was observed. When the maximum light emission efficiency of the light-emitting element CD1 was set to 100%, the maximum light emission efficiency of the light-emitting element CD2 was 89%.

< example 1 > production and evaluation of light-emitting element D1

A light-emitting element D1 was produced in the same manner as in comparative example 1, except that the composition M and the composition N (composition M/composition N: 98 mass%/2 mass%) were used instead of the composition M in comparative example 1 (formation of the 1 st organic layer). In the light-emitting element D1, the polymer compound P-1 contained in the 1 st organic layer was a non-crosslinked material.

When a voltage was applied to the light-emitting element D1, red EL emission having a peak at 615nm was observed. When the maximum light emission efficiency of the light-emitting element CD1 was set to 100%, the maximum light emission efficiency of the light-emitting element D1 was 109%.

< example 2 > production and evaluation of light-emitting element D2

A light-emitting element D2 was produced in the same manner as in comparative example 1, except that the composition M and the composition N (composition M/composition N: 94% by mass/6% by mass) were used in place of the composition M in comparative example 1 (formation of the 1 st organic layer). In the light-emitting element D2, the polymer compound P-1 contained in the 1 st organic layer was a non-crosslinked material.

When a voltage was applied to the light-emitting element D2, red EL emission having a peak at 615nm was observed. When the maximum light emission efficiency of the light-emitting element CD1 was set to 100%, the maximum light emission efficiency of the light-emitting element D2 was 106%.

EXAMPLE 3 production and evaluation of light-emitting element D3

A light-emitting element D3 was produced in the same manner as in comparative example 1, except that the composition M and the composition N (composition M/composition N: 92% by mass/8% by mass) were used in place of the composition M in comparative example 1 (formation of the 1 st organic layer). In the light-emitting element D3, the polymer compound P-1 contained in the 1 st organic layer was a non-crosslinked material.

When a voltage was applied to the light-emitting element D3, red EL emission having a peak at 615nm was observed. When the maximum light emission efficiency of the light-emitting element CD1 was set to 100%, the maximum light emission efficiency of the light-emitting element D3 was 106%.

EXAMPLE 4 production and evaluation of light-emitting element D4

A light-emitting element D3 was produced in the same manner as in comparative example 1, except that the composition M and the composition N (composition M/composition N: 90 mass%/10 mass%) were used instead of the composition M in comparative example 1 (formation of the 1 st organic layer). In the light-emitting element D4, the polymer compound P-1 contained in the 1 st organic layer was a non-crosslinked material.

When a voltage was applied to the light-emitting element D4, red EL emission having a peak at 615nm was observed. When the maximum light emission efficiency of the light-emitting element CD1 was set to 100%, the maximum light emission efficiency of the light-emitting element D4 was 105%.

In table 3, the maximum light emission efficiencies of the light-emitting elements D1 to D4 and CD2 are expressed as relative values with the maximum light emission efficiency of the light-emitting element CD1 being 100%.

[ Table 3]

Industrial applicability

According to the present invention, a light-emitting element having excellent light-emitting efficiency can be provided.

Description of the reference numerals

1 cathode, 21 st organic layer, 3 nd 2 nd organic layer, 4 anode, 10 light emitting element.