JP2020167393A - Light emitting element - Google Patents

Abstract

To provide a light emitting element in which initial deterioration is suppressed.SOLUTION: A light emitting element includes an anode, a cathode, and a first layer and a second layer provided between the anode and the cathode, and the first layer is a layer including a specific compound (A) and a specific compound (B) having a condensed heterocyclic skeleton including a boron atom and a nitrogen atom in a ring, and the second layer is a layer formed using a polymer compound including a specific structural unit.SELECTED DRAWING: None

Description

The present invention relates to a light emitting device.

A light emitting element such as an organic electroluminescence element can be suitably used for, for example, a display and lighting.
For example, Patent Document 1 proposes a light emitting device having a first layer containing compound H1 and compound B1 and a second layer containing a crosslinked product of a polymer compound containing a crosslinked structural unit. The compound H1 of Patent Document 1 is a compound that does not satisfy the formula (FH) described later.
Further, in Patent Document 2, a first layer containing a heat-activated delayed fluorescence (TADF) compound T1 and a compound A2 and a second layer containing a crosslinked product of a polymer compound containing a crosslinked structural unit are provided. A light emitting element having a light emitting element has been proposed. The compound T1 of Patent Document 2 is a compound that does not have the condensed heterocyclic skeleton (b) described later.
Further, Patent Document 3 proposes a light emitting device having a light emitting layer containing compound A0 and compound B0 and a hole transport layer formed by using compound HTM-2. The compound HTM-2 of Patent Document 3 is a low molecular weight compound.

International Publication No. 2018/062278 International Bulletin No. 2018/062277 International Publication No. 2016/152418

However, the above-mentioned light emitting element does not always sufficiently suppress initial deterioration.
Therefore, an object of the present invention is to provide a light emitting device in which initial deterioration is suppressed.

As a result of diligent studies to solve the above problems, the present inventors have conducted a first layer containing a specific compound (A) and a specific compound (B), and a first layer containing a specific polymer compound. It has been found that the initial deterioration of the light emitting element is suppressed by the combined use with the two layers, and the present invention has been completed.

［式中、
ｎ^１Ｈは、０以上の整数を表す。
Ａｒ^１Ｈは、芳香族炭化水素から、環を構成する原子に直接結合する水素原子ｎ^１Ｈ個以上を除いた基を表し、この基は置換基を有していてもよい。該置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。
Ｒ^１Ｈは、アリール基、１価の複素環基又は置換アミノ基を表し、これらの基は置換基を有していてもよい。該置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。Ｒ^１Ｈが複数存在する場合、それらは同一でも異なっていてもよい。但し、前記１価の複素環基は、前記縮合複素環骨格（ｂ）とは異なる環骨格を有する。］

［式中、
ａ^Ｘ１及びａ^Ｘ２は、それぞれ独立に、０以上の整数を表す。
Ａｒ^Ｘ１及びＡｒ^Ｘ３は、それぞれ独立に、アリーレン基又は２価の複素環基を表し、これらの基は置換基を有していてもよい。該置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。
Ａｒ^Ｘ２及びＡｒ^Ｘ４は、それぞれ独立に、アリーレン基、２価の複素環基、又は、少なくとも１種のアリーレン基と少なくとも１種の２価の複素環基とが直接結合した２価の基を表し、これらの基は置換基を有していてもよい。該置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。Ａｒ^Ｘ２及びＡｒ^Ｘ４が複数存在する場合、それらは同一でも異なっていてもよい。
Ｒ^Ｘ１、Ｒ^Ｘ２及びＲ^Ｘ３は、それぞれ独立に、水素原子、アルキル基、シクロアルキル基、アリール基又は１価の複素環基を表し、これらの基は置換基を有していてもよい。該置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。Ｒ^Ｘ２及びＲ^Ｘ３が複数存在する場合、それらは同一でも異なっていてもよい。］

［式中、Ａｒ^Ｙ１は、アリーレン基、２価の複素環基、又は、少なくとも１種のアリーレン基と少なくとも１種の２価の複素環基とが直接結合した２価の基を表し、これらの基は置換基を有していてもよい。該置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。］
［２］
前記高分子化合物が、架橋基を有する、［１］に記載の発光素子。
［３］
前記高分子化合物が、式（Ｚ）で表される構成単位及び式（Ｚ’）で表される構成単位からなる群より選択される少なくとも１種の構成単位を更に含む、［２］に記載の発光素子。

［式中、
ｎは１以上の整数を表す。
ｎＡは０以上の整数を表す。ｎＡが複数存在する場合、それらは同一でも異なっていてもよい。
Ａｒ^３は、芳香族炭化水素基、複素環基、又は、少なくとも１種の芳香族炭化水素基と少なくとも１種の複素環基とが直接結合した基を表し、これらの基は置換基を有していてもよい。該置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。
Ｌ^Ａは、アルキレン基、シクロアルキレン基、アリーレン基、２価の複素環基、−Ｎ（Ｒ’）−で表される基、酸素原子又は硫黄原子を表し、これらの基は置換基を有していてもよい。該置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。Ｒ’は、水素原子、アルキル基、シクロアルキル基、アリール基又は１価の複素環基を表し、これらの基は置換基を有していてもよい。該置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。Ｌ^Ａが複数存在する場合、それらは同一でも異なっていてもよい。
Ｘは架橋基を表す。Ｘが複数存在する場合、それらは同一でも異なっていてもよい。］

［式中、
ｍＡ、ｍ及びｃは、それぞれ独立に、０以上の整数を表す。ｍＡが複数存在する場合、それらは同一でも異なっていてもよい。ｍが複数存在する場合、それらは同一でも異なっていてもよい。
Ａｒ^５は、芳香族炭化水素基、複素環基、又は、少なくとも１種の芳香族炭化水素基と少なくとも１種の複素環基とが直接結合した基を表し、これらの基は置換基を有していてもよい。該置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。
Ａｒ^４及びＡｒ^６は、それぞれ独立に、アリーレン基又は２価の複素環基を表し、これらの基は置換基を有していてもよい。該置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。
Ｋ^Ａは、アルキレン基、シクロアルキレン基、アリーレン基、２価の複素環基、−Ｎ（Ｒ’’）−で表される基、酸素原子又は硫黄原子を表し、これらの基は置換基を有していてもよい。該置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。Ｒ’’は、水素原子、アルキル基、シクロアルキル基、アリール基又は１価の複素環基を表し、これらの基は置換基を有していてもよい。該置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。Ｋ^Ａが複数存在する場合、それらは同一でも異なっていてもよい。
Ｘ’は、水素原子、架橋基、アルキル基、シクロアルキル基、アリール基又は１価の複素環基を表し、これらの基は置換基を有していてもよい。該置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。Ｘ’が複数存在する場合、それらは同一でも異なっていてもよい。但し、少なくとも１つのＸ’は、架橋基である。］
［４］
前記架橋基が、架橋基Ａ群から選ばれる架橋基である、［２］又は［３］に記載の発光素子。
（架橋基Ａ群）

［式中、Ｒ^ＸＬは、メチレン基、酸素原子又は硫黄原子を表し、ｎ^ＸＬは、０〜５の整数を表す。Ｒ^ＸＬが複数存在する場合、それらは同一でも異なっていてもよい。ｎ^ＸＬが複数存在する場合、それらは同一でも異なっていてもよい。＊１は結合位置を表す。これらの架橋基は置換基を有していてもよく、該置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する炭素原子とともに環を形成していてもよい。］
［５］
前記Ａｒ^１Ｈにおける前記芳香族炭化水素が、多環式の芳香族炭化水素である、［１］〜［４］のいずれかに記載の発光素子。
［６］
前記Ａｒ^１Ｈにおける前記芳香族炭化水素が、３環式〜５環式の芳香族炭化水素である、［５］に記載の発光素子。
［７］
前記化合物（Ｂ）が、式（１−１）で表される化合物、式（１−２）で表される化合物又は式（１−３）で表される化合物である、［１］〜［６］のいずれかに記載の発光素子。

［式中、
Ａｒ^１、Ａｒ^２及びＡｒ^３は、それぞれ独立に、芳香族炭化水素基又は複素環基を表し、これらの基は置換基を有していてもよい。該置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。
Ｙ^１は、−Ｎ（Ｒｙ）−で表される基を表す。
Ｙ^２及びＹ^３は、それぞれ独立に、単結合、酸素原子、硫黄原子、セレン原子、−Ｎ（Ｒｙ）−で表される基、アルキレン基又はシクロアルキレン基を表し、これらの基は置換基を有していてもよい。該置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。Ｒｙは、水素原子、アルキル基、シクロアルキル基、アリール基又は１価の複素環基を表し、これらの基は置換基を有していてもよい。該置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する原子とともに環を形成していてもよい。Ｒｙが複数存在する場合、同一であっても異なっていてもよい。Ｒｙは、直接結合して又は連結基を介して、Ａｒ^１、Ａｒ^２又はＡｒ^３と結合していてもよい。］
［８］
前記Ｙ^２及び前記Ｙ^３が、−Ｎ（Ｒｙ）−で表される基である、［７］に記載の発光素子。
［９］
前記第１の層が、正孔輸送材料、正孔注入材料、電子輸送材料、電子注入材料、発光材料及び酸化防止剤からなる群より選ばれる少なくとも１種を更に含有する、［１］〜［８］のいずれかに記載の発光素子。
［１０］
前記第１の層と前記第２の層とが隣接している、［１］〜［９］のいずれかに記載の発光素子。
［１１］
前記陽極と前記第１の層との間に、前記第２の層が設けられている、［１］〜［１０］のいずれかに記載の発光素子。 That is, the present invention provides the following [1] to [11].
[1]
A light emitting device including an anode, a cathode, and a first layer and a second layer provided between the anode and the cathode.
The first layer is a layer containing a compound (A) represented by the formula (FH) and a compound (B) having a condensed heterocyclic skeleton (b) containing a boron atom and a nitrogen atom in the ring. Yes,
The second layer is formed by using a polymer compound containing at least one structural unit selected from the group consisting of the structural unit represented by the formula (X) and the structural unit represented by the formula (Y). A light emitting element that is a layer.

[During the ceremony,
n ^1H represents an integer of 0 or more.
Ar ^1H represents a group obtained by removing n ^1H or more hydrogen atoms directly bonded to the atoms constituting the ring from the aromatic hydrocarbon, and this group may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded.
R ^1H represents an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. When there are a plurality of ^R1Hs , they may be the same or different. However, the monovalent heterocyclic group has a ring skeleton different from that of the condensed heterocyclic skeleton (b). ]

[During the ceremony,
a ^X1 and a ^X2 each independently represent an integer of 0 or more.
Ar ^X1 and Ar ^X3 each independently represent an arylene group or a divalent heterocyclic group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded.
Ar ^X2 and Ar ^X4 each independently form an arylene group, a divalent heterocyclic group, or a divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded. Representing, these groups may have substituents. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. When there are a plurality of Ar ^X2 and Ar ^X4 , they may be the same or different.
^RX1 , ^RX2 and ^RX3 independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. When a plurality of ^RX2 and ^RX3 exist, they may be the same or different. ]

[In the formula, Ar ^Y1 represents an arylene group, a divalent heterocyclic group, or a divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded. The group of may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. ]
[2]
The light emitting device according to [1], wherein the polymer compound has a cross-linking group.
[3]
[2] The polymer compound further comprises at least one structural unit selected from the group consisting of the structural unit represented by the formula (Z) and the structural unit represented by the formula (Z'). Light emitting element.

[During the ceremony,
n represents an integer of 1 or more.
nA represents an integer greater than or equal to 0. When there are a plurality of nA, they may be the same or different.
Ar ³ represents an aromatic hydrocarbon group, a heterocyclic group, or a group in which at least one aromatic hydrocarbon group and at least one heterocyclic group are directly bonded, and these groups have a substituent. You may be doing it. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded.
L ^A is an alkylene group, a cycloalkylene group, an arylene group, a divalent heterocyclic group, -N (R ') -, a group represented by an oxygen atom or a sulfur atom, chromatic these groups the substituent You may be doing it. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. R'represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. If L ^A is plurally present, they may be the same or different.
X represents a cross-linking group. When a plurality of X's exist, they may be the same or different. ]

[During the ceremony,
mA, m and c each independently represent an integer of 0 or more. If there are multiple mAs, they may be the same or different. When there are a plurality of m, they may be the same or different.
Ar ⁵ represents an aromatic hydrocarbon group, a heterocyclic group, or a group in which at least one aromatic hydrocarbon group and at least one heterocyclic group are directly bonded, and these groups have a substituent. You may be doing it. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded.
Ar ⁴ and Ar ⁶ each independently represent an arylene group or a divalent heterocyclic group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded.
K ^A is an alkylene group, a cycloalkylene group, an arylene group, a divalent heterocyclic group, -N (R '') -, a group represented by an oxygen atom or a sulfur atom, these groups are substituents You may have. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. R ″ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. If K ^A there are a plurality, they may be the same or different.
X'represents a hydrogen atom, a bridging group, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. If there are multiple X's, they may be the same or different. However, at least one X'is a cross-linking group. ]
[4]
The light emitting device according to [2] or [3], wherein the cross-linking group is a cross-linking group selected from the cross-linking group A group.
(Crosslink group A group)

[In the formula, R ^XL represents a methylene group, an oxygen atom or a sulfur atom, and n ^XL represents an integer from 0 to 5. When a plurality of R ^XLs exist, they may be the same or different. When a plurality of n ^XLs exist, they may be the same or different. * 1 represents the bonding position. These cross-linking groups may have substituents, and if a plurality of the substituents are present, they may be the same or different, and they may be bonded to each other to form a ring with the carbon atom to which each is bonded. You may be. ]
[5]
The light emitting device according to any one of [1] to [4], wherein the aromatic hydrocarbon in Ar ^1H is a polycyclic aromatic hydrocarbon.
[6]
The light emitting element according to [5], wherein the aromatic hydrocarbon in Ar ^1H is a tricyclic to 5-cyclic aromatic hydrocarbon.
[7]
The compound (B) is a compound represented by the formula (1-1), a compound represented by the formula (1-2), or a compound represented by the formula (1-3), [1] to [ 6] The light emitting element according to any one of.

[During the ceremony,
Ar ¹ , Ar ² and Ar ³ each independently represent an aromatic hydrocarbon group or a heterocyclic group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded.
Y ¹ represents a group represented by −N (Ry) −.
Y ² and Y ³ independently represent a single bond, an oxygen atom, a sulfur atom, a selenium atom, a group represented by -N (Ry)-, an alkylene group or a cycloalkylene group, and these groups are substituents. May have. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. Ry represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. When there are a plurality of Ry, they may be the same or different. Ry may be attached directly to Ar ¹ , Ar ² or Ar ³ via a linking group. ]
[8]
The light emitting device according to [7], wherein Y ² and Y ³ are groups represented by −N (Ry) −.
[9]
The first layer further contains at least one selected from the group consisting of hole-transporting materials, hole-injecting materials, electron-transporting materials, electron-injecting materials, luminescent materials, and antioxidants [1] to [ 8] The light emitting element according to any one of.
[10]
The light emitting device according to any one of [1] to [9], wherein the first layer and the second layer are adjacent to each other.
[11]
The light emitting device according to any one of [1] to [10], wherein the second layer is provided between the anode and the first layer.

According to the present invention, it is possible to provide a light emitting device in which initial deterioration is suppressed.

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

<Explanation of common terms>
Unless otherwise specified, the terms commonly used in the present specification have the following meanings.
"Room temperature" means 25 ° C.
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 light hydrogen atom.

By "low molecular compound" does not have a molecular weight distribution, molecular weight means a 1 × 10 ⁴ or less of the compound.
The “polymer compound” means a polymer having a molecular weight distribution and having a polystyrene-equivalent number average molecular weight of 1 × 10 ³ or more (for example, 1 × 10 ³ to 1 × 10 ⁸ ).
The “constituent unit” means a unit existing in one or more in a polymer compound.

The polymer compound may be a block copolymer, a random copolymer, an alternate copolymer, a graft copolymer, or any other embodiment.
The terminal group of the polymer compound is preferably a stable group because if the polymerization active group remains as it is, the light emission characteristics or the luminance life may be lowered when the polymer compound is used for manufacturing a light emitting element. Is. The terminal group of the polymer compound is preferably a group conjugated to the main chain, for example, an aryl group or a monovalent heterocyclic group bonded to the main chain of the polymer compound via a carbon-carbon bond. Examples include groups that are bound to.

The "alkyl group" may be either linear or branched. The number of carbon atoms of the linear alkyl group is usually 1 to 50, preferably 1 to 20, and more preferably 1 to 10, not including the number of carbon atoms of the substituent. The number of carbon atoms of the branched alkyl group is usually 3 to 50, preferably 3 to 20, and more preferably 4 to 10 without including the number of carbon atoms of the substituent.
The alkyl group may have a substituent. Examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, 2-butyl group, isobutyl group, tert-butyl group, pentyl group, isoamyl group, 2-ethylbutyl group, hexyl group and heptyl. Examples thereof include a group, an octyl group, a 2-ethylhexyl group, a 3-propylheptyl group, a decyl group, a 3,7-dimethyloctyl group, a 2-ethyloctyl group, a 2-hexyldecyl group and a dodecyl group. Further, the alkyl group may be a group in which a part or all of hydrogen atoms in these groups are substituted with a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a fluorine atom or the like. Examples of such an alkyl group include a trifluoromethyl group, a pentafluoroethyl group, a perfluorobutyl group, a perfluorohexyl group, a perfluorooctyl group, a 3-phenylpropyl group, and a 3- (4-methylphenyl) propyl group. Groups include 3- (3,5-di-hexylphenyl) propyl group and 6-ethyloxyhexyl group.

The number of carbon atoms of the "cycloalkyl group" is usually 3 to 50, preferably 4 to 10 without including the number of carbon atoms of the substituent. The cycloalkyl group may have a substituent. Examples of the cycloalkyl group include a cyclohexyl group and a methylcyclohexyl group.

The number of carbon atoms of the "alkylene group" is usually 1 to 20, preferably 1 to 15, and more preferably 1 to 10, not including the number of carbon atoms of the substituent. The alkylene group may have a substituent. Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a hexylene group and an octylene group.

The number of carbon atoms of the "cycloalkylene group" is usually 3 to 20, preferably 4 to 10 without including the number of carbon atoms of the substituent. The cycloalkylene group may have a substituent. Examples of the cycloalkylene group include a cyclohexylene group.

"Aromatic hydrocarbon group" means a group obtained by removing one or more hydrogen atoms directly bonded to an atom constituting a ring from an aromatic hydrocarbon. A group obtained by removing one hydrogen atom directly bonded to an atom constituting a ring from an aromatic hydrocarbon is also referred to as an "aryl group". A group obtained by removing two hydrogen atoms directly bonded to an atom constituting a ring from an aromatic hydrocarbon is also referred to as an "arylene group".
The number of carbon atoms of the aromatic hydrocarbon group, not including the number of carbon atoms of the substituent, is usually 6 to 60, preferably 6 to 40, and more preferably 6 to 20.
The "aromatic hydrocarbon group" is, for example, a monocyclic aromatic hydrocarbon (for example, benzene) or a polycyclic aromatic hydrocarbon (for example, bicyclic such as naphthalene and inden). Aromatic hydrocarbons; tricyclic aromatic hydrocarbons such as anthracene, phenanthrene, dihydrophenanthrene and fluorene; tetracyclic aromatic hydrocarbons such as benzoanthrene, benzophenanthrene, benzofluorene, pyrene and fluorantene; dibenzoanthrene , Dibenzophenanthrene, dibenzofluorene, perylene and benzofluorentene and other 5-cyclic aromatic hydrocarbons; 6-ring aromatic hydrocarbons such as spirobifluorene; and benzospirobifluolene and acenaftfluorentene. Aromatic hydrocarbons of the 7-ring type such as, etc.), from which one or more hydrogen atoms directly bonded to the atoms constituting the ring are removed. Aromatic hydrocarbon groups include groups in which a plurality of these groups are bonded. The aromatic hydrocarbon group may have a substituent.

The "alkoxy group" may be either linear or branched. The number of carbon atoms of the linear alkoxy group is usually 1 to 40, preferably 1 to 10, not including the number of carbon atoms of the substituent. The number of carbon atoms of the branched alkoxy group is usually 3 to 40, preferably 4 to 10 without including the number of carbon atoms of the substituent.
The alkoxy group may have a substituent. Examples of the alkoxy group include a methoxy group, an ethoxy group, an isopropyloxy group, a butyloxy group, a hexyloxy group, a 2-ethylhexyloxy group, a 3,7-dimethyloctyloxy group, and a lauryloxy group.
The number of carbon atoms of the "cycloalkoxy group" is usually 3 to 40, preferably 4 to 10 without including the number of carbon atoms of the substituent. The cycloalkoxy group may have a substituent. Examples of the cycloalkoxy group include a cyclohexyloxy group.
The number of carbon atoms of the "aryloxy group" is usually 6 to 60, preferably 6 to 40, and more preferably 6 to 20 without including the number of carbon atoms of the substituent. The aryloxy group may have a substituent. Examples of the aryloxy group include a phenoxy group, a naphthyloxy group, an anthrasenyloxy group, and a pyrenyloxy group.

The "heterocyclic group" means a group obtained by removing one or more hydrogen atoms directly bonded to an atom constituting a ring from a heterocyclic compound. Among the heterocyclic groups, an "aromatic heterocyclic group" is preferable, which is a group obtained by removing one or more hydrogen atoms directly bonded to an atom constituting a ring from an aromatic heterocyclic compound. A group obtained by removing p hydrogen atoms (p represents an integer of 1 or more) directly bonded to an atom constituting a ring from a heterocyclic compound is also referred to as a "p-valent heterocyclic group". A group obtained by removing p hydrogen atoms directly bonded to an atom constituting a ring from an aromatic heterocyclic compound is also referred to as a "p-valent aromatic heterocyclic group".
Examples of the "aromatic heterocyclic compound" include compounds in which the heterocycle itself exhibits aromaticity, such as azole, thiophene, furan, pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene and carbazole, and phenoxazine. , Phenothiazine, benzopyran and the like, even if the heterocycle itself does not exhibit aromaticity, there are compounds in which the aromatic ring is fused to the heterocycle.
The number of carbon atoms of the heterocyclic group is usually 1 to 60, preferably 2 to 40, and more preferably 3 to 20 without including the number of carbon atoms of the substituent. The number of heteroatoms of the aromatic heterocyclic group is usually 1 to 30, preferably 1 to 10, more preferably 1 to 5, and even more preferably 1 to 30, not including the number of heteroatoms of the substituent. Is 1-3.
Examples of the heterocyclic group include a monocyclic heterocyclic compound (for example, furan, thiophene, oxadiazole, thiadiazol, pyrrole, diazole, triazole, tetrazole, pyridine, diazabenzene and triazine) or triazine. Bicyclic heterocyclic compounds such as polycyclic heterocyclic compounds (eg, azanaphthalene, diazanaphthalene, benzofuran, benzothiophene, indol, benzodiazole, benzotriazol and benzothiasiazol; dibenzofuran, dibenzothiophene, Dibenzoborol, dibenzocilol, dibenzophosphol, dibenzoselenophene, carbazole, azacarbazole, diazacarbazole, phenoxazine, phenothiazine, 9,10-dihydroaclydin, 5,10-dihydrophenazine, phenazaborin, phenophosfazine, pheno Tricyclic heterocyclic compounds such as selenazine, phenazacillin, azaanthracene, diazaanthracene, azaphenanthrene and diazaphenanthrene; tetracyclic heterocycles such as hexaazatriphenylene, benzocarbazole, benzonaphthofuran and benzonaphthophene. Cyclic compounds; 5-cyclic heterocyclic compounds such as dibenzocarbazole, indolocarbazole and indenocarbazole; 6-cyclic heterocyclic compounds such as carbazolocarbazole, benzoindrocarbazole and benzoindenocarbazole; Examples thereof include a 7-cyclic heterocyclic compound such as dibenzoindrocarbazole), and examples thereof include a group obtained by removing one or more hydrogen atoms directly bonded to the atoms constituting the ring. The heterocyclic group includes a group in which a plurality of these groups are bonded. The heterocyclic group may have a substituent.

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

The "amino group" may have a substituent, and a substituted amino group (that is, a secondary amino group or a tertiary amino group, more preferably a tertiary amino group) is preferable. As the substituent contained in the amino group, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group is preferable. When a plurality of substituents having an amino group are present, they may be the same and different, or they may be bonded to each other to form a ring with the nitrogen atom to which each is bonded.
Examples of the substituted amino group include a dialkylamino group, a dicycloalkylamino group and a diarylamino group.
Examples of the amino group include a dimethylamino group, a diethylamino group, a diphenylamino group, a bis (methylphenyl) amino group, and a bis (3,5-di-tert-butylphenyl) amino group.

The "alkenyl group" may be either linear or branched. The number of carbon atoms of the linear alkenyl group is usually 2 to 30, not including the number of carbon atoms of the substituent, and is preferably 3 to 20. The number of carbon atoms of the branched alkenyl group is usually 3 to 30, preferably 4 to 20, not including the number of carbon atoms of the substituent.
The number of carbon atoms of the "cycloalkenyl group" is usually 3 to 30, preferably 4 to 20, not including the number of carbon atoms of the substituent.
The alkenyl group and the cycloalkenyl group may have a substituent. Examples of the alkenyl group include a vinyl group, a 1-propenyl group, a 2-butenyl group, a 3-butenyl group, a 3-pentenyl group, a 4-pentenyl group, a 1-hexenyl group, a 5-hexenyl group and a 7-octenyl group. In addition, a group in which a part or all of hydrogen atoms in these groups are substituted with a substituent can be mentioned. Examples of the cycloalkenyl group include a cyclohexenyl group, a cyclohexadienyl group, a cyclooctatrienyl group, a norbornylenyl group, and a group in which a part or all of hydrogen atoms in these groups are substituted with a substituent. ..

The "alkynyl group" may be either linear or branched. The number of carbon atoms of the alkynyl group is usually 2 to 20, preferably 3 to 20, not including the carbon atom of the substituent. The number of carbon atoms of the branched alkynyl group is usually 4 to 30, preferably 4 to 20, not including the carbon atom of the substituent.
The number of carbon atoms of the "cycloalkynyl group" is usually 4 to 30, preferably 4 to 20, not including the carbon atom of the substituent.
The alkynyl group and the cycloalkynyl group may have a substituent. Examples of the alkynyl group include ethynyl group, 1-propynyl group, 2-propynyl group, 2-butynyl group, 3-butynyl group, 3-pentynyl group, 4-pentynyl group, 1-hexynyl group and 5-hexynyl group. In addition, a group in which a part or all of the hydrogen atom in these groups is substituted with a substituent can be mentioned. Examples of the cycloalkynyl group include a cyclooctynyl group.

The "crosslinked group" is a group capable of forming a new bond by subjecting it to heating, ultraviolet irradiation, near-ultraviolet irradiation, visible light irradiation, infrared irradiation, radical reaction, or the like. As the cross-linking group, a cross-linking group selected from the cross-linking group A group (that is, a group represented by any of formulas (XL-1) to (XL-19)) is preferable.

［式中、Ｒ^ＸＬは、メチレン基、酸素原子又は硫黄原子を表し、ｎ^ＸＬは、０〜５の整数を表す。Ｒ^ＸＬが複数存在する場合、それらは同一でも異なっていてもよい。複数存在するｎ^ＸＬは、同一でも異なっていてもよい。＊１は結合位置を表す。これらの架橋基は置換基を有していてもよい。該置換基が複数存在する場合、それらは同一でも異なっていてもよく、互いに結合して、それぞれが結合する炭素原子とともに環を形成していてもよい。］ (Crosslink group A group)

[In the formula, R ^XL represents a methylene group, an oxygen atom or a sulfur atom, and n ^XL represents an integer from 0 to 5. When a plurality of R ^XLs exist, they may be the same or different. A plurality of n ^XLs may be the same or different. * 1 represents the bonding position. These cross-linking groups may have substituents. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the carbon atom to which each is bonded. ]

Examples of the "substituent" include a halogen atom, a cyano group, an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an amino group and a substituted amino group. Examples thereof include an alkenyl group, a cycloalkenyl group, an alkynyl group and a cycloalkynyl group. The substituent may be a cross-linking group. When a plurality of substituents are present, they may be bonded to each other to form a ring together with the atoms to which they are bonded, but it is preferable not to form a ring.

Herein, the absolute value of the difference between the energy level of the energy level and the lowest singlet excited state of the lowest triplet excited state (hereinafter, also referred to as "Delta] E _ST".) Of the calculated value of the following methods Is sought after. First, the ground state of the compound is structurally optimized by the density functional theory at the B3LYP level. At that time, 6-31G * is used as the basis function. Then, using the resulting structure optimized structure, the time-dependent density functional method B3LYP level, calculates a Delta] E _ST compound. However, when 6-31G * contains an atom that cannot be used, LANL2DZ is used for the atom. As the quantum chemistry calculation program, Gaussian09 is used for calculation.

<Light emitting element>
The light emitting device of the present embodiment is a light emitting device having an anode, a cathode, and a first layer and a second layer provided between the anode and the cathode.

(First layer)
The first layer is a layer containing compound (A) and compound (B).
The first layer may contain only one type of compound (A), or may contain two or more types. The first layer may contain only one type of compound (B), or may contain two or more types.

The total content of the compound (A) and the compound (B) in the first layer is not particularly limited as long as the function as the first layer is exhibited. The total content of the compound (A) and the compound (B) in the first layer may be, for example, 1 to 100% by mass based on the total amount of the first layer, and may be 3 to 100% by mass. It is preferably 5 to 100% by mass, more preferably 10 to 100% by mass, 30 to 100% by mass, 50 to 100% by mass, and 80 to 100% by mass. It may be there.

The content of the compound (B) in the first layer is usually 0.001 to 99 parts by mass when the total of the compound (A) and the compound (B) is 100 parts by mass, and is the content of the present embodiment. Since the initial deterioration of the light emitting element is further suppressed, it is preferably 0.01 to 95 parts by mass, more preferably 0.1 to 90 parts by mass, and 0.5 to 85 parts by mass. Further, the content of the compound (B) in the first layer may be 0.005 to 70 parts by mass when the total of the compound (A) and the compound (B) is 100 parts by mass, and is 0. It may be 0.01 to 50 parts by mass, 0.05 to 30 parts by mass, 0.1 to 10 parts by mass, or 0.5 to 5 parts by mass. ..

In the first layer, compound (A) is preferably the host material and compound (B) is preferably the guest material. In this embodiment, the host material is a material that physically, chemically or electrically interacts with the guest material. By this interaction, for example, it is possible to improve or adjust the light emitting property, the charge transport property, or the charge injection property of the composition for a light emitting device of the present embodiment.
Taking the luminescent material as an example, it is possible to make the guest material emit light more efficiently by electrically interacting with the host material and the guest material and efficiently transferring electrical energy from the host material to the guest material. The initial deterioration of the light emitting element of the present embodiment can be further suppressed.

When compound (B) is used as a light emitting material, the maximum peak wavelength of the emission spectrum of compound (B) at 25 ° C. is preferably in the visible light region. In this case, the maximum peak wavelength of the emission spectrum of compound (B) at 25 ° C. is preferably 380 nm or more, more preferably 400 nm or more, still more preferably 420 nm or more, and particularly preferably 440 nm or more. The maximum peak wavelength of the emission spectrum of compound (B) at 25 ° C. is preferably 750 nm or less, more preferably 620 nm or less, still more preferably 570 nm or less, particularly preferably 495 nm or less, and particularly preferably. It is 480 nm or less.
When compound (B) is used as a light emitting material, the half width of the maximum peak of the emission spectrum of compound (B) at 25 ° C. is preferably 50 nm or less, more preferably 40 nm or less, and further preferably 30 nm. It is less than or equal to, and particularly preferably 25 nm or less.
For the maximum peak wavelength of the emission spectrum of the compound at room temperature, the compound is dissolved in an organic solvent such as xylene, toluene, chloroform, tetrahydrofuran, etc. to prepare a dilute solution (1 × ^10-6 % by mass to 1 × 10 ^-3 % by mass). %), It can be evaluated by measuring the PL spectrum of the dilute solution at room temperature. Xylene is preferable as the organic solvent for dissolving the compound.

[Compound (A)]
The compound (A) is preferably a low molecular weight compound.
The molecular weight of compound (A) is usually 1 × 10 ² to 1 × 10 ⁴ , preferably 2 × 10 ^{2 to} 5 × 10 ³ , and more preferably 3 × 10 ² to 2 × 10 ³ . , More preferably 4 × 10 ² to 1 × 10 ³ .

Compound (A) is a compound represented by the formula (FH). The compound (A) is a compound different from the compound (B), and may be, for example, a compound having no condensed heterocyclic skeleton (b).

n ^1H is usually an integer of 10 or less, and since it is easy to synthesize the compound represented by the formula (FH), it is preferably an integer of 7 or less, more preferably an integer of 5 or less, and further. It is preferably an integer of 3 or less. Further, n ^1H is preferably an integer of 1 or more and may be an integer of 2 or more because the initial deterioration of the light emitting element of the present embodiment is further suppressed.

The Ar ^1H is, for example, a group obtained by removing ^1H or more of hydrogen atoms directly bonded to the atoms constituting the ring from the monocyclic aromatic hydrocarbon (hereinafter, “monocyclic aromatic hydrocarbon group””. (Also also referred to as) and a group obtained by removing ^1H or more of hydrogen atoms directly bonded to the atoms constituting the ring from the polycyclic aromatic hydrocarbon (hereinafter, "polycyclic aromatic hydrocarbon group"). It is also referred to as), and since the initial deterioration of the light emitting element of the present embodiment is further suppressed, it is preferably a polycyclic aromatic hydrocarbon group, and these groups have a substituent. May be good. Further, Ar ^1H is preferably a monocyclic aromatic hydrocarbon group because it is easy to synthesize a compound represented by the formula (FH), and this group may have a substituent. ..
Examples of the aromatic hydrocarbon in Ar ^1H include the aromatic hydrocarbon described in the above-mentioned section on aromatic hydrocarbon groups.
The number of carbon atoms of the monocyclic aromatic hydrocarbon group in Ar ^1H is preferably 6 without including the number of carbon atoms of the substituent. In Ar ^1H , the monocyclic aromatic hydrocarbon in the monocyclic aromatic hydrocarbon group is preferably benzene because the initial deterioration of the light emitting element of the present embodiment is further suppressed.
The number of carbon atoms of the polycyclic aromatic hydrocarbon group in Ar ^1H is usually 7 to 60, preferably 8 to 40, more preferably 10 without including the number of carbon atoms of the substituent. It is ~ 30, more preferably 10 to 25, and may be 12 to 20. In Ar ^1H , the polycyclic aromatic hydrocarbon in the polycyclic aromatic hydrocarbon group is preferably a bicyclic to 7 ring type because the initial deterioration of the light emitting element of the present embodiment is further suppressed. It is an aromatic hydrocarbon, more preferably a 2-cyclic to 6-ring aromatic hydrocarbon, and may be a 3- to 5-cyclic aromatic hydrocarbon. In Ar ^1H , the polycyclic aromatic hydrocarbon in the polycyclic aromatic hydrocarbon group further suppresses the initial deterioration of the light emitting element of the present embodiment, and therefore, preferably naphthalene, anthracene, phenanthrene, and fluorene. , Benzoanthrene, benzophenanthrene, benzofluorene, pyrene, fluorene, dibenzoanthrene, dibenzophenanthrene, dibenzofluorene, perylene, benzofluorene, spirobifluorene, benzospirobifluorene or acenaftfluorene, more preferably. , Naphthalene, anthracene, phenanthrene, fluorene, benzoanthrene, benzophenanthrene, benzofluorene, pyrene, fluorentrene, dibenzoanthrene, dibenzophenanthrene, dibenzofluorene, perylene, benzofluorentene or spirobifluorene, more preferably anthrene, Phenanthrene, fluorene, benzoanthrene, benzophenanthrene, benzofluorene, pyrene, fluorene, perylene or benzofluorene, and particularly preferably anthracene, fluorene, benzoanthrene, benzofluorene, fluorentene or benzofluorentene.
Examples of the substituent that Ar ^1H may have include a substituent other than an aryl group, a monovalent heterocyclic group and a substituted amino group, and preferably a halogen atom, a cyano group, an alkyl group and a cyclo. It is an alkyl group, an alkoxy group, a cycloalkoxy group, an alkenyl group or a cycloalkenyl group, more preferably a cyano group, an alkyl group, a cycloalkyl group, an alkoxy group or a cycloalkoxy group, and even more preferably an alkyl group or a cyclo. It is an alkyl group, an alkoxy group or a cycloalkoxy group, particularly preferably an alkyl group or a cycloalkyl group, and these groups may further have a substituent.
Examples and preferable ranges of the substituents that the substituents that Ar ^1H may have may further include the substituents that the substituents that R ^1H may have, which will be described later. It is the same as the example of the group and the preferable range.

R ^1H is preferably an aryl group or a monovalent heterocyclic group, more preferably an aryl group, because the initial deterioration of the light emitting device of the present embodiment is further suppressed, and these groups have a substituent. You may be doing it.
The aryl group in R ^1H is preferably a group obtained by removing one hydrogen atom directly bonded to an atom constituting a ring from a monocyclic or bicyclic to 6-ring aromatic hydrocarbon, and more preferably. Is a group obtained by removing one hydrogen atom directly bonded to an atom constituting the ring from the monocyclic or bicyclic to 5-ringed aromatic hydrocarbons, and more preferably monocyclic or bicyclic. It is a group obtained by removing one hydrogen atom directly bonded to an atom constituting the ring from the aromatic hydrocarbons of the formulas to four rings, and these groups may have a substituent. Since the aryl group in R ^1H further suppresses the initial deterioration of the light emitting element of the present embodiment, preferably benzene, naphthalene, anthracene, phenanthrene, dihydrophenanthrene, fluorene, benzoanthrene, benzophenanthrene, benzofluorene, pyrene, It is a group obtained by removing one hydrogen atom directly bonded to an atom constituting a ring from fluoranthene, dibenzoanthrene, dibenzophenanthrene, dibenzofluorene, perylene, benzofluorentene or spirobifluorene, and more preferably benzene or naphthalene. , Anthracene, phenanthrene, dihydrophenanthrene, fluorene, benzoanthrene, benzophenanthrene, benzofluorene, fluorantene, dibenzofluorene, benzofluorantene or spirobifluorene, except for one hydrogen atom directly bonded to the atoms constituting the ring. It is a group, more preferably a group obtained by removing one hydrogen atom directly bonded to an atom constituting a ring from benzene, naphthalene, dihydrophenanthrene, fluorene or benzofluorene, and particularly preferably a phenyl group or a naphthyl group. These groups may have a substituent.
In the monovalent heterocyclic group in R ^IH, Heterocyclic compounds containing no fused heterocyclic ring skeleton (b), among the heterocyclic compounds described in the section of the heterocyclic group described above, the boron atoms and nitrogen Examples thereof include heterocyclic compounds containing no atom in the ring. Monovalent heterocyclic group in R ^IH preferably does not have a condensed heterocyclic skeleton (b), from monocyclic or bicyclic 6 cyclic heterocyclic compound, directly in the atoms constituting the ring It is a group excluding one hydrogen atom to be bonded, and more preferably, the ring is composed of a monocyclic or bicyclic to 5-cyclic heterocyclic compound containing no fused heterocyclic skeleton (b). It is a group excluding one hydrogen atom directly bonded to an atom, and more preferably, it is a ring from a monocyclic or bicyclic to tetracyclic heterocyclic compound containing no fused heterocyclic skeleton (b). It is a group excluding one hydrogen atom directly bonded to the atoms constituting the above, and these groups may have a substituent. Since the monovalent heterocyclic group in R ^1H further suppresses the initial deterioration of the light emitting element of the present embodiment, preferably, oxadiazol, thiazazole, diazole, triazole, pyridine, diazabenzene, triazine, azanaphthalene, and diah Xanaphthalene, benzodiazol, benzotriazole, dibenzofuran, dibenzothiophene, carbazole, azacarbazole, diazacarbazole, phenoxazine, phenothiazine, 9,10-dihydroaclydin, 5,10-dihydrophenazine, azaanthracene, diazaanthracene, Directly from azaphenanthrene, diazaphenanthrene, benzocarbazole, benzonaphthofuran, benzonaphthophene, dibenzocarbazole, indolocarbazole, indenocarbazole, carbazolocarbazole, benzoindrocarbazole or benzoindenocarbazole to the atoms that make up the ring It is a group excluding one hydrogen atom to be bonded, and more preferably, pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, dibenzofuran, dibenzothiophene, carbazole, phenoxazine, phenothiazine, 9,10-dihydroacrine, benzo. A group obtained by removing one hydrogen atom directly bonded to a ring-constituting atom from carbazole, benzonaphtholfuran, benzonaphthophene, dibenzocarbazole, indolocarbazole or indenocarbazole, and pyridine, diazabenzene, triazine and azanaphthalene. , Diazanaphthalene, dibenzofuran, dibenzothiophene, carbazole, benzocarbazole, benzonaphtholfuran or benzonaphthophene, excluding one hydrogen atom directly bonded to the atoms constituting the ring, and these groups are substituents. May have.
Among the substituted amino groups in R ^1H, the substituent ^contained in the amino group is preferably an aryl group or a monovalent heterocyclic group, more preferably an aryl group, and these groups may further have a substituent. Examples of the aryl group is a substituent having an amino group and preferred ranges are the same as examples of the aryl group and the preferable range of R ^IH. Examples of the monovalent heterocyclic group is a substituent having an amino group and preferred ranges are the same as examples and preferred ranges of the monovalent heterocyclic group in R ^IH.
The substituent that R ^1H may have is preferably a halogen atom, a cyano group, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group. It is more preferably an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and even more preferably an alkyl group, a cycloalkyl group or an aryl group, and these groups are further. It may have a substituent.
Examples and preferred ranges of aryl groups, monovalent heterocyclic groups and substituted amino groups in the substituents that R ^1H may have are examples of aryl groups, monovalent heterocyclic groups and substituted amino groups in R ^1H . And the same as the preferred range.
The substituent that R ^1H may have may further include a halogen atom, a cyano group, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, and 1 It is a valent heterocyclic group or a substituted amino group, more preferably an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and further preferably an alkyl group or a cycloalkyl group. These groups may further have a substituent, but it is preferable that they do not further have a substituent.
Examples and preferred ranges of aryl groups, monovalent heterocyclic groups and substituted amino groups in the substituents that the substituents that R ^1H may have may further have are aryl groups and monovalent groups in R ^1H . It is the same as the example and preferable range of the heterocyclic group and the substituted amino group of.

Examples of the compound (A) include compounds represented by the following formulas and compounds A1 to A18 described later.

In the formula, Z ¹ represents an oxygen atom or a sulfur atom.

[Compound (B)]
The compound (B) is a compound having a condensed heterocyclic skeleton (b) containing a boron atom and a nitrogen atom in the ring.
In compound (B), at least one of the nitrogen atoms contained in the condensed heterocyclic skeleton (b) is preferably a nitrogen atom that does not form a double bond, and the condensed heterocyclic skeleton (b) It is more preferable that all of the contained nitrogen atoms are nitrogen atoms that do not form a double bond.

The number of carbon atoms of the condensed heterocyclic skeleton (b) is usually 1 to 60, preferably 5 to 40, and more preferably 10 to 25, not including the number of carbon atoms of the substituent.
The number of heteroatoms of the condensed heterocyclic skeleton (b) is usually 2 to 30, preferably 2 to 15, more preferably 2 to 10, and even more preferably 2 to 30, not including the number of heteroatoms of the substituent. Is 2 to 5, and particularly preferably 2 or 3.
The number of boron atoms in the fused heterocyclic skeleton (b) is usually 1 to 10, preferably 1 to 5, more preferably 1 to 3, and further, not including the number of boron atoms of the substituent. It is preferably 1.
The number of nitrogen atoms in the condensed heterocyclic skeleton (b) is usually 1 to 20, preferably 1 to 10, more preferably 1 to 5, and even more preferably 1 to 20, not including the number of nitrogen atoms of the substituent. Is 1 to 3, particularly preferably 2.
The condensed heterocyclic skeleton (b) is preferably a 3 to 12 ring-type condensed heterocyclic skeleton, and more preferably a 3- to 6-ring condensed heterocycle, because the initial deterioration of the light emitting element of the present embodiment is further suppressed. It is a skeleton, more preferably a pentacyclic condensed heterocyclic skeleton.

The compound (B) can also be said to be a compound having a heterocyclic group (b') containing a condensed heterocyclic skeleton (b).

The heterocyclic group (b') is a group obtained by removing one or more hydrogen atoms directly bonded to the atoms constituting the ring from a polycyclic heterocyclic compound containing a boron atom and a nitrogen atom in the ring. The group may have a substituent.

The substituents that the heterocyclic group (b') may have include a halogen atom, a cyano group, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, and a monovalent heterocyclic group or a substituent. Amino groups are preferred, alkyl groups, cycloalkyl groups, alkoxy groups, cycloalkoxy groups, aryl groups, monovalent heterocyclic groups or substituted amino groups are more preferred, alkyl groups, aryl groups or substituted amino groups are even more preferred. The group of may further have a substituent.

In the substituent which the heterocyclic group (b') may have, the aryl group is preferably from a monocyclic or bicyclic to 6-ring aromatic hydrocarbon to an atom constituting the ring. A group excluding one directly bonded hydrogen atom, more preferably one hydrogen atom directly bonded to a ring-constituting atom from a monocyclic, bicyclic or tricyclic aromatic hydrocarbon. It is a group excluding one hydrogen atom which is directly bonded to an atom constituting a ring from benzene, naphthalene, anthracene, phenanthrene or fluorene, and more preferably a phenyl group. The group of may have a substituent.

The monovalent heterocyclic group in the substituent that the heterocyclic group (b') may have is preferably a ring from a monocyclic or bicyclic to 6-cyclic heterocyclic compound. A group excluding one hydrogen atom that is directly bonded to a constituent atom, and one hydrogen atom that is directly bonded to a ring-constituting atom from a monocyclic, bicyclic or tricyclic heterocyclic compound. The group is removed, and more preferably, one hydrogen atom directly bonded to an atom constituting a ring from pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, carbazole, dibenzofuran, dibenzothiophene, phenoxazine or phenothiazine is excluded. This group is particularly preferably a group from pyridine, diazabenzene or triazine excluding one hydrogen atom directly bonded to an atom constituting a ring, and these groups may have a substituent.

Among the substituted amino groups in the substituents that the heterocyclic group (b') may have, the substituents contained in the amino group are preferably an aryl group or a monovalent heterocyclic group, more preferably an aryl group, and these. The group of may further have a substituent. Examples and preferred ranges of aryl groups and monovalent heterocyclic groups in the substituents of the amino group are the aryl groups and monovalent heterocyclic groups in the substituents that the heterocyclic group (b') may have, respectively. Same as the group example and preferred range.

The substituent which the heterocyclic group (b') may have further includes a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group and 1 Valuable heterocyclic groups or substituted amino groups are preferred, alkyl groups, cycloalkyl groups, aryl groups, monovalent heterocyclic groups or substituted amino groups are more preferred, alkyl or cycloalkyl groups are even more preferred, and these groups are It may have a substituent, but it is preferable that it does not have a substituent.

Examples and preferred ranges of aryl groups, monovalent heterocyclic groups and substituted amino groups in the substituents which the substituents which the heterocyclic group (b') may have may further have are complex, respectively. It is the same as the example and preferable range of the aryl group, the monovalent heterocyclic group and the substituted amino group in the substituent which the ring group (b') may have.

で表される基を含むことを意味する。 The "nitrogen atom that does not form a double bond" means a nitrogen atom that is single-bonded to each of the other three atoms.
The "in the ring including the nitrogen atom that does not form a double bond", -N in the ring ^(-R N) - (. Wherein, R ^N represents a hydrogen atom or a substituent), or the formula:

It means that it contains a group represented by.

The compound (B) is preferably a thermally activated delayed fluorescence (TADF) compound because the initial deterioration of the light emitting device of the present embodiment is further suppressed.
Delta] E _ST of the compound (B) may be not more than 2.0 eV may be less 1.5 eV, may be less 1.0 eV, may be less 0.80 eV, 0 It may be .60 eV or less, but it is preferably 0.50 eV or less because the initial deterioration of the light emitting element of the present embodiment is further suppressed. Also, Delta] E _ST of compound (B) may be more than 0.001EV may be more than 0.01 eV, may be more than 0.10 eV, it may be more than 0.20eV , 0.30 eV or more, or 0.40 eV or more.

The compound (B) is preferably a low molecular weight compound.
The molecular weight of compound (B) is preferably 1 × 10 ^{2 to} 5 × 10 ³ , more preferably 2 × 10 ^{2 to} 3 × 10 ³ , and even more preferably 3 × 10 ^{2 to} 1.5 × 10. It is ³ , and particularly preferably 4 × 10 ² to 1 × 10 ³ .

The compound (B) is a compound represented by the formula (1-1), the formula (1-2) or the formula (1-3) because the initial deterioration of the light emitting device of the present embodiment is further suppressed. Is preferable, the compound represented by the formula (1-2) or the formula (1-3) is more preferable, and the compound represented by the formula (1-2) is further preferable.

Ar ¹ , Ar ² and Ar ³ are preferably monocyclic, bicyclic or tricyclic aromatic hydrocarbons or monocyclic, because the initial deterioration of the light emitting element of the present embodiment is further suppressed. It is a group obtained by removing one or more hydrogen atoms directly bonded to the atoms constituting the ring from a bicyclic or tricyclic heterocyclic compound, and more preferably a monocyclic aromatic hydrocarbon or a monocyclic ring. It is a group obtained by removing one or more hydrogen atoms directly bonded to the atoms constituting the ring from the heterocyclic compound of the formula, and more preferably hydrogen directly bonded to the atoms constituting the ring from benzene, pyridine or diazabenzene. It is a group excluding one or more atoms, and particularly preferably, it is a group excluding one or more hydrogen atoms directly bonded to the atoms constituting the ring from benzene, and these groups have substituents. May be good.
The examples and preferred ranges of substituents that Ar ¹ , Ar ² and Ar ³ may have are the same as the examples and preferred ranges of substituents that the heterocyclic group (b') may have.

Y ² and Y ³ are preferably a single bond, an oxygen atom, a sulfur atom, a group represented by −N (Ry) − or a methylene group, and more preferably a single bond, an oxygen atom, a sulfur atom or −. It is a group represented by N (Ry) −, more preferably an oxygen atom, a sulfur atom or a group represented by −N (Ry) −, and particularly preferably represented by −N (Ry) −. These groups may have a substituent.
The examples and preferred ranges of substituents that Y ¹ , Y ² and Y ³ may have are the same as the examples and preferred ranges of substituents that the heterocyclic group (b') may have.

Ry is preferably an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, more preferably an aryl group or a monovalent heterocyclic group, still more preferably an aryl group, and these. The group may have a substituent.
Examples and preferred ranges of aryl groups and monovalent heterocyclic groups in Ry include examples of aryl groups and monovalent heterocyclic groups in substituents that the heterocyclic group (b') may have and preferred ranges, respectively. Same as range.
The examples and preferred ranges of substituents that Ry may have are the same as the examples and preferred ranges of substituents that the heterocyclic group (b') may have.

Ry may be attached directly to Ar ¹ , Ar ² or Ar ³ via a linking group, but is preferably not attached. Examples of the linking group include a group represented by -O-, a group represented by -S-, a group represented by -N (Ry)-, an alkylene group, a cycloalkylene group, an arylene group and a divalent group. Examples thereof include a heterocyclic group, preferably a group represented by -O-, a group represented by -S-, a group represented by -N (Ry)-or a methylene group, and these groups are substituted. It may have a group.

Examples of the compound (B) include compounds represented by the following formulas and compounds B1 to B5 described later.

In the formula, Z ¹ represents an oxygen atom or a sulfur atom.

[First composition]
The first layer is at least one selected from the group consisting of compound (A), compound (B), hole transport material, hole injection material, electron transport material, electron injection material, luminescent material and antioxidant. It may be a layer containing a seed and a composition containing the seed (hereinafter, also referred to as "first composition"). However, in the first composition, the hole transporting material, the hole injecting material, the electron transporting material, the electron injecting material and the light emitting material are different from the compound (A) and the compound (B).

-Hole transport materials Hole transport materials are classified into low molecular weight compounds and high molecular weight compounds. The hole transport material may have a cross-linking group.
Examples of low molecular weight compounds include triphenylamine and its derivatives, N, N'-di-1-naphthyl-N, N'-diphenylbenzidine (α-NPD), and N, N'-diphenyl-N, Aromatic amine compounds such as N'-di (m-tolyl) benzidine (TPD) can be mentioned.
Examples of the polymer compound include polyvinylcarbazole and its derivatives; polyarylene having an aromatic amine structure in its side chain or main chain and its derivatives. The polymer compound may be a compound to which an electron accepting site such as fullerene, tetrafluorotetracyanoquinodimethane, tetracyanoethylene and trinitrofluorenone is bound.
When the hole transport material is contained in the first composition, the content of the hole transport material is usually 1 to 1000 mass by mass when the total of the compound (A) and the compound (B) is 100 parts by mass. It is a department.
The hole transporting material may be used alone or in combination of two or more.

-Electron transport materials Electron transport materials are classified into low molecular weight compounds and high molecular weight compounds. The electron transport material may have a cross-linking group.
Examples of low molecular weight compounds include metal complexes having 8-hydroxyquinoline as a ligand, oxadiazole, anthraquinone dimethane, benzoquinone, naphthoquinone, anthraquinone, tetracyanoanthraquinone dimethane, fluorenone, diphenyldicyanoethylene and diphenoquinone. , And these derivatives.
Examples of the polymer compound include polyphenylene, polyfluorene, and derivatives thereof. The polymeric compound may be metal-doped.
When the electron-transporting material is contained in the first composition, the content of the electron-transporting material is usually 1 to 1000 parts by mass when the total of the compound (A) and the compound (B) is 100 parts by mass. is there.
The electron transport material may be used alone or in combination of two or more.

-Hole injection material and electron injection material The hole injection material and electron injection material are classified into low molecular weight compounds and high molecular weight compounds, respectively. The hole injection material and the electron injection material may have a cross-linking group.
Examples of the low molecular weight compound include metal phthalocyanines such as copper phthalocyanine; carbon; metal oxides such as molybdenum and tungsten; and metal fluorides such as lithium fluoride, sodium fluoride, cesium fluoride and potassium fluoride.
Examples of the polymer compound include polyaniline, polythiophene, polypyrrole, polyphenylene vinylene, polythienylene vinylene, polyquinoline and polyquinoxaline, and derivatives thereof; conductivity of polymers containing an aromatic amine structure in the main chain or side chain. Examples include polypolymers.
When the hole-injecting material and / or the electron-injecting material is included in the first composition, the content of the hole-injecting material and the electron-injecting material is 100, which is the total of the compound (A) and the compound (B), respectively. In the case of parts by mass, it is usually 1 to 1000 parts by mass.
The hole injection material and the electron injection material may be used alone or in combination of two or more.

When the ion-doped hole injection material or the electron injection material contains a conductive polymer, the electric conductivity of the conductive polymer is preferably 1 × ^10-5 S / cm to 1 × 10 ³ S / cm. .. In order to keep the electric conductivity of the conductive polymer within such a range, an appropriate amount of ions can be doped into the conductive polymer. The type of ion to be doped 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 polystyrene sulfonate ion, alkylbenzene sulfonic acid ion, and cerebral sulfonic acid ion. Examples of the cation include lithium ion, sodium ion, potassium ion and tetrabutylammonium ion.
The ions to be doped may be used alone or in combination of two or more.

-Light emitting materials Light emitting materials are classified into low molecular weight compounds and high molecular weight compounds. The light emitting material may have a cross-linking group.
Examples of the low molecular weight compound include naphthalene and its derivatives, anthracene and its derivatives, perylene and its derivatives, and triple-term light emitting complexes having iridium, platinum or europium as a central metal.
Examples of the polymer compound include a polymer compound containing a structural unit represented by the formula (Y) and / or a structural unit represented by the formula (X) described later.

When the luminescent material is contained in the first composition, the content of the luminescent material is usually 1 to 1000 parts by mass when the total of the compound (A) and the compound (B) is 100 parts by mass.
The luminescent material 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 compound (A) and compound (B) and does not inhibit light emission and charge transport. For example, phenolic antioxidant and phosphorus-based. Antioxidants can be mentioned.
When the antioxidant is contained in the first composition, the content of the antioxidant is usually 0.001 to 10% by mass when the total of the compound (A) and the compound (B) is 100 parts by mass. It is a department.
The antioxidant may be used alone or in combination of two or more.

[First ink]
The first layer can be formed, for example, by using a composition containing the compound (A), the compound (B), and a solvent (hereinafter, referred to as “first ink”). The first ink is, for example, spin coating method, casting method, micro gravure coating method, gravure coating method, bar coating method, roll coating method, wire bar coating method, dip coating method, spray coating method, screen printing method, flexo. It is suitable for manufacturing a light emitting element using a wet method such as a printing method, an offset printing method, an inkjet printing method, a capillary coating method, or a nozzle coating method. The viscosity of the ink may be adjusted depending on the type of printing method, but is preferably 1 to 20 mPa · s at 25 ° C.
The solvent contained in the first ink is preferably a solvent capable of dissolving or uniformly dispersing the solid content in the ink. Examples of the solvent contained in the first ink include chlorine-based solvents such as 1,2-dichloroethane, 1,1,2-trichloroethane, chlorobenzene and o-dichlorobenzene; tetrahydrofuran, dioxane, anisole, 4-methylanisole and the like. Ether-based solvents; aromatic hydrocarbon-based solvents such as toluene, xylene, mesitylene, ethylbenzene, n-hexylbenzene, cyclohexylbenzene; cyclohexane, methylcyclohexane, n-pentane, n-hexane, n-heptan, n-octane. , N-nonane, n-decane, n-dodecane, bicyclohexyl and other aliphatic hydrocarbon solvents; acetone, methyl ethyl ketone, cyclohexanone, acetophenone and other ketone solvents; ethyl acetate, butyl acetate, ethyl cell solve acetate, benzoic acid Ester solvents such as methyl 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; N- Examples thereof include amide-based solvents such as methyl-2-pyrrolidone and N, N-dimethylformamide. The solvent may be used alone or in combination of two or more.
In the first ink, the content of the solvent is usually 1000 to 100,000 parts by mass when the total of the compound (A) and the compound (B) is 100 parts by mass.
The solvent may be used alone or in combination of two or more.

The first ink may further contain at least one selected from the group consisting of hole transporting materials, hole injecting materials, electron transporting materials, electron injecting materials, luminescent materials and antioxidants.
Examples and preferred ranges of hole-transporting materials, electron-transporting materials, hole-injecting materials, electron-injecting materials, luminescent materials and antioxidants that the first ink may further contain are included in the first composition. The examples and preferred ranges of the hole transporting material, the electron transporting material, the hole injecting material, the electron injecting material, the light emitting material and the antioxidant are the same.
The contents of the hole-transporting material, the electron-transporting material, the hole-injecting material, the electron-injecting material, and the luminescent material, which may be further contained in the first ink, are the sum of the compound (A) and the compound (B), respectively. When is 100 parts by mass, it is usually 1 to 1000 parts by mass. The content of the antioxidant that the first ink may further contain is usually 0.001 to 10 parts by mass when the total of the compound (A) and the compound (B) is 100 parts by mass. ..

(Second layer)
The second layer is a polymer compound containing at least one of the structural unit represented by the formula (X) and the structural unit represented by the formula (Y) (hereinafter, “polymer compound of the second layer”. It is a layer formed by using.).

As used herein, the term "layer formed using" means that a layer is formed using a material for forming the layer. The layer may contain, for example, the material for forming the layer as it is, or the material for forming the layer is insolubilized (for example, the material for forming the layer is intramolecular. It may be contained in a state of being crosslinked between molecules or both of them.
Taking the second layer formed by using the polymer compound of the second layer as an example, the second layer may contain the polymer compound of the second layer as it is, or the second layer may contain the polymer compound of the second layer as it is. The polymer compound of the second layer may be contained in an insolubilized state (for example, the polymer compound of the second layer is cross-linked intramolecularly, intermolecularly, or both).

The second layer may contain only one type of the polymer compound of the second layer, or may contain two or more types. Further, the second layer may be formed by using only one kind of the polymer compound of the second layer, or may be formed by using two or more kinds of the polymer compound of the second layer.

The content of the component derived from the polymer compound of the second layer (for example, the polymer compound of the second layer, the crosslinked body of the polymer compound of the second layer, etc.) in the second layer is It is not particularly limited, and may be a range in which the function as the second layer is exhibited. The content of the component derived from the polymer compound of the second layer in the second layer may be, for example, 1 to 100% by mass, and 10 to 100% by mass based on the total amount of the second layer. It is more preferably 30 to 100% by mass, further preferably 50 to 100% by mass, and particularly preferably 80 to 100% by mass.

(Polymer compound in the second layer)
The polymer compound in the second layer preferably contains a structural unit represented by the formula (Y) because the initial deterioration of the light emitting device of the present embodiment is further suppressed.
Since the polymer compound in the second layer has excellent hole transportability, it preferably contains a structural unit represented by the formula (X).
Since the polymer compound in the second layer has excellent hole transport properties and the initial deterioration of the light emitting device of the present embodiment is further suppressed, the structural unit represented by the formula (X) and the formula (Y) It is preferable to include a structural unit represented by.

When the polymer compound of the second layer contains a structural unit represented by the formula (X), the content of the structural unit represented by the formula (X) is excellent in hole transportability, and therefore the second layer. It is preferably 1 to 100 mol%, more preferably 5 to 90 mol%, more preferably 10 to 80 mol%, still more preferably, based on the total amount of the constituent units contained in the polymer compound of. Is 20-70 mol%.
The structural unit represented by the formula (X) may contain only one type or two or more types in the polymer compound of the second layer.

When the polymer compound in the second layer contains a structural unit represented by the formula (Y) and Ar ^Y1 is an arylene group, the content of the structural unit represented by the formula (Y) is the present embodiment. Since the initial deterioration of the light emitting element of the form is further suppressed, it is preferably 1 to 100 mol%, more preferably 10 to 90 mol%, based on the total amount of the polymer compounds in the second layer. It is more preferably 20 to 80 mol%, and particularly preferably 30 to 70 mol%.
The polymer compound in the second layer contains a structural unit represented by the formula (Y), and Ar ^Y1 is a divalent heterocyclic group, or at least one arylene group and at least one divalent divalent group. When the heterocyclic group is a divalent group directly bonded to the heterocyclic group, the content of the structural unit represented by the formula (Y) is the second because the polymer compound in the second layer has excellent charge transportability. It is preferably 1 to 100 mol%, more preferably 5 to 90 mol%, more preferably 10 to 80 mol%, and further, based on the total amount of the constituent units contained in the polymer compound of the layer. It is preferably 20 to 70 mol%.
The structural unit represented by the formula (Y) may be contained in only one kind or two or more kinds in the crosslinked polymer compound of the second layer.

The total content of the structural unit represented by the formula (X) and the structural unit represented by the formula (Y) contained in the polymer compound of the second layer is the hole transport of the polymer compound of the second layer. Since the properties are excellent and the initial deterioration of the light emitting element of the present embodiment is further suppressed, the amount is preferably 1 to 100 mol% with respect to the total amount of the structural units contained in the polymer compound of the second layer. Yes, more preferably 10 to 100 mol%, more preferably 30 to 100 mol%, still more preferably 50 to 100 mol%.

<Constituent unit represented by formula (Y)>
Since the arylene group represented by Ar ^Y1 further suppresses the initial deterioration of the light emitting element of the present embodiment, the ring is preferably composed of a monocyclic or bicyclic to 6-ring aromatic hydrocarbon. It is a group excluding two hydrogen atoms that are directly bonded to the atoms to be formed, and more preferably, a hydrogen atom that is directly bonded to the atoms constituting the ring from a monocyclic, bicyclic or tricyclic aromatic hydrocarbon. It is a group excluding two atoms, more preferably a group from benzene, naphthalene, anthracene, phenanthrene, dihydrophenanthrene or fluorene, excluding two hydrogen atoms directly bonded to the atoms constituting the ring, and particularly preferably. , Benzene, phenanthrene, dihydrophenanthrene or fluorene, from which two hydrogen atoms directly bonded to the atoms constituting the ring are removed, and these may have substituents.
The divalent heterocyclic group represented by Ar ^Y1 is preferably selected from a monocyclic or bicyclic to 6-cyclic heterocyclic compound because the initial deterioration of the light emitting element of the present embodiment is further suppressed. , A group excluding two hydrogen atoms that are directly bonded to the atoms that make up the ring, more preferably from a monocyclic, bicyclic or tricyclic heterocyclic compound directly to the atoms that make up the ring. It is a group excluding two hydrogen atoms to be bonded, and more preferably from pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, carbazole, dibenzofuran, dibenzothiophene, phenoxazine, phenothiazine or 9,10-dihydroaclydin. It is a group excluding two hydrogen atoms that are directly bonded to the atoms constituting the ring (preferably carbon atom or nitrogen atom, more preferably carbon atom), and particularly preferably pyridine, diazabenzene, triazine, carbazole, dibenzofuran, dibenzo. It is a group obtained by removing two hydrogen atoms directly bonded to a ring-constituting atom (preferably a carbon atom or a nitrogen atom, more preferably a carbon atom) from thiophene, phenoxazine or phenothiazine, and these have substituents. May be.
In the divalent group in which at least one arylene group represented by Ar ^Y1 and at least one divalent heterocyclic group are directly bonded, the preferable ranges of the arylene group and the divalent heterocyclic group are, respectively. This is the same as the preferable range of the arylene group represented by Ar ^Y1 and the divalent heterocyclic group.

Examples of the "divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded" include a group represented by the following formula, which have a substituent. You may be doing it.

Ar ^Y1 is preferably an arylene group which may have a substituent because the initial deterioration of the light emitting device of the present embodiment is further suppressed.

The substituent that the group represented by Ar ^Y1 may have is preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a monovalent heterocyclic group, or a substituted amino group. It is a group or a fluorine atom, more preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and even more preferably an alkyl group or a cycloalkyl group. A group, an aryl group, a monovalent heterocyclic group or a substituted amino group, particularly preferably an alkyl group, a cycloalkyl group or an aryl group, and these groups may further have a substituent.
The aryl group in the substituent which the group represented by Ar ^Y1 may have is preferably a monocyclic type or a bicyclic to 6-ring type because the initial deterioration of the light emitting element of the present embodiment is further suppressed. It is a group obtained by removing one hydrogen atom directly bonded to an atom constituting a ring from the aromatic hydrocarbon of the above, and more preferably, a ring is obtained from a monocyclic, bicyclic or tricyclic aromatic hydrocarbon. It is a group excluding one hydrogen atom directly bonded to the atom constituting the ring, and more preferably one hydrogen atom directly bonded to the atom constituting the ring from benzene, naphthalene, anthracene, phenanthrene, dihydrophenanthrene or fluorene. It is a group excluding benzene, particularly preferably a group obtained by removing one hydrogen atom directly bonded to an atom constituting a ring from benzene, phenanthrene, dihydrophenanthrene or fluorene, and these groups further have a substituent. You may.
The monovalent heterocyclic group in the substituent that the group represented by Ar ^Y1 may have is preferably a monocyclic or bicyclic group because the initial deterioration of the light emitting element of the present embodiment is further suppressed. It is a group obtained by removing one hydrogen atom directly bonded to an atom constituting a ring from a heterocyclic compound having a to 6-ring system, and more preferably a monocyclic, 2-cyclic or 3-cyclic heterocyclic compound. It is a group obtained by removing one hydrogen atom directly bonded to an atom constituting a ring from a compound, and more preferably, pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, carbazole, dibenzofuran, dibenzothiophene, phenoxazine, It is a group obtained by removing one hydrogen atom directly bonded to a ring-constituting atom (preferably a carbon atom or a nitrogen atom, more preferably a carbon atom) from phenothiazine or 9,10-dihydroaclydin, and particularly preferably pyridine. , Diazabenzene, triazine, carbazole, dibenzofuran, dibenzothiophene, phenoxazine or phenothiazine, excluding one hydrogen atom directly bonded to a ring-constituting atom (preferably a carbon atom or a nitrogen atom, more preferably a carbon atom). And these may further have substituents.
Among the substituted amino groups in the substituents that the group represented by Ar ^Y1 may have, as the substituent contained in the amino group, an aryl group or a monovalent heterocyclic group is preferable, an aryl group is more preferable, and these The group may further have a substituent. Examples and preferred ranges of aryl groups and monovalent heterocyclic groups in the substituents of the amino group are the aryl groups and monovalent heterocyclic groups in the substituents that the group represented by Ar ^Y1 may have, respectively. It is the same as the example and the preferable range.

The substituent which the group represented by Ar ^Y1 may have may further have is preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or an aryloxy group. A group, a monovalent heterocyclic group, a substituted amino group or a fluorine atom, more preferably an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and even more preferably an alkyl. It is a group or a cycloalkyl group, and these groups may further have a substituent, but it is preferable that the group does not further have a substituent.
Examples and preferred ranges of the aryl group, the monovalent heterocyclic group and the substituted amino group in the substituent which the group represented by Ar ^Y1 may have may further have are Ar ^Y1 respectively. It is the same as the example and preferable range of the aryl group, the monovalent heterocyclic group and the substituted amino group in the substituent which the group represented by may have.

The structural unit represented by the formula (Y) is preferably the structural unit represented by the formula (Y-1) or (Y-2) because the initial deterioration of the light emitting device of the present embodiment is further suppressed. is there.

During the ceremony
^RY1 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a monovalent heterocyclic group, a substituted amino group or a fluorine atom, and these groups are substituents. May have. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. A plurality of ^RY1s existing may be the same or different, and may be bonded to each other to form a ring together with the carbon atom to which each is bonded.
X ^{Y1 _{is, -C (R Y2) 2 -}} , - represents a group represented by - C (R Y2) = C (R Y2) - , or _{^{-C (R Y2) 2 -C (}} R Y2) 2. ^RY2 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a monovalent heterocyclic group, a substituted amino group or a fluorine atom, and these groups are substituents. May have. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. A plurality of ^RY2s existing may be the same or different, and may be bonded to each other to form a ring together with the carbon atom to which each is bonded.

^RY1 is preferably a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and more preferably a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group. More preferably, it is a hydrogen atom or an alkyl group, and these groups may have a substituent.
^RY2 is preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group, and more preferably an alkyl group, a cycloalkyl group or an aryl group. Alternatively, it is a monovalent heterocyclic group, more preferably an alkyl group, a cycloalkyl group or an aryl group, and these groups may have a substituent.
Examples and preferred ranges of aryl groups, monovalent heterocyclic groups and substituted amino groups in ^RY1 and ^RY2 are the aryl groups, monovalents in the substituents that the group represented by Ar ^Y1 may have, respectively. It is the same as the example and preferable range of heterocyclic group and substituted amino group.
The examples and preferred ranges of substituents that ^RY1 and ^RY2 may have are the same as the examples and preferred ranges of substituents that the group represented by Ar ^Y1 may have.
^XY1 is preferably represented by −C ( ^RY2 ) _2- or −C ( ^RY2 ) ₂₋ C ( ^RY2 ) ₂₋ because the initial deterioration of the light emitting device of the present embodiment is further suppressed. It is a group represented by −C ( ^RY2 ) ₂₋ , more preferably.

Examples of the structural unit represented by the formula (Y) include a structural unit represented by the following formula and a structural unit derived from the compounds M1, M6, M13, M17, M19 and M25 described later. In the following formula, Z ¹ represents an oxygen atom or a sulfur atom. Z ² represents a group represented by -CH = or a group represented by -N =.

<Constituent unit represented by formula (X)>
a ^X1 and a ^X2 are usually integers of 0 to 5, and are preferably integers of 0 to 3, more preferably integers of 0 to 2, because the initial deterioration of the light emitting element of the present embodiment is further suppressed. , More preferably 0 or 1.

^RX1 , ^RX2 and ^RX3 are preferably an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, more preferably an aryl group or a monovalent heterocyclic group, and even more preferably an aryl group. It is a group, and these groups may have a substituent.
Examples and preferred ranges of aryl groups and monovalent heterocyclic groups in ^RX1 , ^RX2 and ^RX3 are aryl groups and monovalent heterocycles in the substituents that the group represented by Ar ^Y1 may have, respectively. It is the same as the example of the ring group and the preferable range.

The examples and preferred ranges of the arylene and divalent heterocyclic groups in Ar ^X1 , Ar ^X2 , Ar ^X3 and Ar ^X4 are the same as the examples and preferred ranges of the arylene and divalent heterocyclic groups in Ar ^Y1 , respectively. is there.
Examples and preferred examples of arylene groups and divalent heterocyclic groups in a divalent group in which at least one arylene group represented by Ar ^X2 and Ar ^X4 and at least one divalent heterocyclic group are directly bonded. The range is the same as the examples and preferred ranges of the arylene group and the divalent heterocyclic group in Ar ^Y1 , respectively.
As a divalent group in which at least one arylene group in Ar ^X2 and Ar ^X4 and at least one divalent heterocyclic group are directly bonded, at least one arylene group in Ar ^Y1 and at least one 2 are used. Examples thereof include those similar to a divalent group in which a valent heterocyclic group is directly bonded.
Ar ^X1 , Ar ^X2 , Ar ^X3 and Ar ^X4 are preferably arylene groups which may have a substituent.

Examples and preferred ranges of Ar ^X1 to Ar ^X4 and ^R X1 ^{to R} groups the substituent which may have represented by ^X3 is and example of a well substituent preferably includes groups represented by ^{Ar Y1} Same as range.

Examples of the structural unit represented by the formula (X) include a structural unit represented by the following formula and a structural unit derived from the compounds M7, M11, M16, M18, M22 and M26 described later. In the following formula, Z ¹ represents an oxygen atom or a sulfur atom.

[Crosslinked polymer compound in the second layer]
The polymer compound in the second layer preferably further contains a cross-linking group because the light emitting device of the present embodiment can be formed by a wet method and the layers can be easily laminated. That is, the polymer compound in the second layer contains at least one of the structural unit represented by the formula (X) and the structural unit represented by the formula (Y), and has a cross-linking group. It is preferably a compound (hereinafter, also referred to as “crosslinked polymer compound of the second layer”).
More specifically, when the second layer contains the polymer compound of the second layer in an insolubilized state, the second layer is formed by using the crosslinked polymer compound of the second layer. It is preferable that the layer is crosslinked, and it is more preferable that the second layer contains the crosslinked polymer compound of the second layer in a crosslinked state.

In the crosslinked polymer compound of the second layer, the crosslinked group is preferable because the crosslinked property of the crosslinked polymer compound of the second layer is more excellent and the initial deterioration of the light emitting element of the present embodiment is further suppressed. Is a cross-linking group selected from the cross-linking group A group (that is, a cross-linking group represented by the formulas (XL-1) to (XL-19)), and more preferably, the formulas (XL-1) and the formula ( XL-3), formula (XL-9), formula (XL-10) or cross-linking groups represented by formulas (XL-16) to formulas (XL-19), more preferably formula (XL-1). ) Or a cross-linking group represented by the formulas (XL-16) to (XL-19), and particularly preferably a cross-linking group represented by the formula (XL-1) or the formula (XL-17).
Among the cross-linking groups selected from the cross-linking group A group, the examples and preferable ranges of the substituents that the cross-linking group may have are the examples of the substituents that the group represented by Ar ^Y1 may have and the preferable range. It is the same.
The crosslinked polymer compound in the second layer may contain only one type of crosslinked group, or may contain two or more types.

Since the crosslinked polymer compound of the second layer has more excellent crosslinkability of the crosslinked polymer compound of the second layer and the initial deterioration of the light emitting element of the present embodiment is further suppressed, the crosslinked group is crosslinked. It is preferably included as a structural unit having a group. That is, the crosslinked polymer compound in the second layer contains at least one of the structural unit represented by the formula (X) and the structural unit represented by the formula (Y), a structural unit having a crosslinking group, and the like. It is preferably a polymer compound containing.

Since the content of the structural unit having a cross-linking group is excellent in the stability and cross-linking property of the cross-linked polymer compound in the second layer, the content of the structural unit is relative to the total amount of the structural units contained in the cross-linked polymer compound in the second layer. , It is preferably 1 to 90 mol%, more preferably 3 to 70 mol%, still more preferably 5 to 50 mol%.
Only one type of the structural unit having a crosslinking group may be contained in the crosslinked polymer compound of the second layer, or two or more types may be contained.

<Constituent unit having a cross-linking group>
The structural unit having a cross-linking group is preferably a structural unit represented by the formula (Z) or a structural unit represented by the formula (Z') because the initial deterioration of the light emitting device of the present embodiment is further suppressed. is there.

The structural unit n represented by the formula (Z) is usually an integer of 1 to 5, and is preferably an integer of 1 to 4 because the initial deterioration of the light emitting element of the present embodiment is further suppressed. It is preferably 1 or 2.
nA is usually an integer of 0 to 5, and is preferably an integer of 0 to 4, more preferably an integer of 0 to 2, because the initial deterioration of the light emitting device of the present embodiment is further suppressed.

Ar ³ is an aromatic hydrocarbon group which may have a substituent because the initial deterioration of the light emitting device of the present embodiment is further suppressed.
Examples of the aromatic hydrocarbon group in Ar ³ include a group obtained by removing n hydrogen atoms from the group described as an arylene group in Ar ^Y1 .
Examples of the heterocyclic group in Ar ³ include a group obtained by removing n hydrogen atoms from the group described as a divalent heterocyclic group in Ar ^Y1 .
As a group in which at least one aromatic hydrocarbon group and at least one heterocyclic group are directly bonded to each other in Ar ³ , at least one arylene group and at least one divalent heterocyclic group in Ar ^Y1 are used. Examples thereof include a group obtained by removing n hydrogen atoms from the group described as a directly bonded divalent group.

Examples and preferred ranges of the arylene group represented by L ^A is the same as examples and preferred ranges of the arylene group represented by Ar ^Y1, since early deterioration of the light emitting device of this embodiment is further suppressed, arylene group represented by L ^a is preferably a phenylene group or a fluorenediyl group, and these groups may further have a substituent.
Examples and preferred ranges of the divalent heterocyclic group represented by L ^A are the same as examples and preferred ranges of the divalent heterocyclic group represented by Ar ^Y1.
L ^A, since the synthesis of the crosslinked polymer compound of the second layer is facilitated, preferably, an arylene group or an alkylene group, more preferably a phenylene group, fluorenediyl group or an alkylene group, these The group of may have a substituent.

R'is preferably an aryl group or a monovalent heterocyclic group, more preferably an aryl group, and these groups may have a substituent.
The examples and preferred ranges of aryl groups and monovalent heterocyclic groups in R'are the same as the examples and preferred ranges of aryl groups and monovalent heterocyclic groups in the substituents that Ar ^Y1 may have, respectively. is there.

Ar ^3, L ^A and examples and preferred ranges of the substituent which may be possessed by the groups represented by R 'are the same as examples and preferred ranges of the substituent which may be possessed by the groups represented by Ar ^Y1 Is.

The examples and preferred ranges of the crosslinked groups in X are the same as the examples and preferred ranges of the crosslinked groups in the crosslinked polymer compound of the second layer.

The structural unit mA represented by the formula (Z') is usually an integer of 0 to 5, and is preferably an integer of 0 to 4 because the initial deterioration of the light emitting element of the present embodiment is further suppressed. It is more preferably an integer of 0 to 2, still more preferably 0 or 1, and particularly preferably 0.
m is usually an integer of 0 to 5, and is preferably an integer of 0 to 4, more preferably an integer of 0 to 2, since the initial deterioration of the light emitting device of the present embodiment is further suppressed. It is preferably 0.
c is usually an integer of 0 to 5, and is preferable because it facilitates the production of the crosslinked polymer compound in the second layer and further suppresses the initial deterioration of the light emitting element of the present embodiment. It is an integer of 2, more preferably 0 or 1, and even more preferably 0.

Ar ⁵ is an aromatic hydrocarbon group which may have a substituent because the initial deterioration of the light emitting device of the present embodiment is further suppressed.
Examples of the aromatic hydrocarbon group in Ar ⁵ include the group described as the arylene group in Ar ^X1 , Ar ^X2 , Ar ^X3 and Ar ^X4 , excluding m hydrogen atoms.
Examples of the heterocyclic group in Ar ⁵ include a group obtained by removing m hydrogen atoms from the group described as a divalent heterocyclic group in Ar ^X1 , Ar ^X2 , Ar ^X3 and Ar ^X4 .
As a group in which at least one aromatic hydrocarbon group and at least one heterocyclic group in Ar ⁵ are directly bonded, at least one arylene group in Ar ^X2 and Ar ^X4 and at least one divalent heterocycle are used. Examples thereof include a group obtained by removing m hydrogen atoms from the group described as a divalent group in which a group is directly bonded.
Ar ⁴ and Ar ⁶ are arylene groups which may have a substituent because the initial deterioration of the light emitting device of the present embodiment is further suppressed.
The examples and preferred ranges of arylene groups in Ar ⁴ and Ar ⁶ are the same as the examples and preferred ranges of arylene groups in Ar ^X1 , Ar ^X2 , Ar ^X3 and Ar ^X4 .
Examples and preferred ranges of divalent heterocyclic groups in Ar ⁴ and Ar ⁶ are the same as examples and preferred ranges of divalent heterocyclic groups in Ar ^X1 , Ar ^X2 , Ar ^X3 and Ar ^X4 .
The examples and preferred ranges of substituents represented by Ar ^{4 to} Ar ⁶ may be the same as the examples and preferred ranges of substituents represented by Ar ^Y1. ..

Examples and preferred ranges of K ^A is the same as the example and preferred ranges of L ^A.
The example and preferred range of R'are the same as the example and preferred range of R'.
Examples and preferred ranges of cross-linking groups at X'are the same as examples and preferred ranges of cross-linking groups represented by X.
Examples and preferred ranges of the aryl group and monovalent heterocyclic group for X 'are each, and examples and preferred ranges of examples and preferred ranges of the heterocyclic group of the aryl group and monovalent in R ^X1, R ^X2 and R ^X3 It is the same.
X'is preferably a cross-linking group, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, more preferably a cross-linking group, an aryl group or a monovalent heterocyclic group, and even more preferably. Is a cross-linking group or an aryl group, and these groups may have a substituent.
The examples of substituents represented by ^{X'and the} preferred range may be the same as the examples and preferred ranges of substituents represented by Ar ^Y1 .

Examples of the structural unit having a cross-linking group include a structural unit represented by the following formula and a structural unit derived from the compounds M8 to M10, M12, M14, M15, M20 and M21 described later. In the following formula, Z ¹ represents an oxygen atom or a sulfur atom. X ^A represents a cross-linking group selected from the cross-linking group A group. If X ^A there are a plurality, they may be the same or different. The preferred range of X ^A is the same as the preferred range of cross-linking groups in the cross-linked polymer compound of the second layer.

Examples of the polymer compound in the second layer include the polymer compounds P-1 to P-10 shown in Table 1. Here, "other" is represented by the structural unit represented by the formula (Z), the structural unit represented by the formula (Z'), the structural unit represented by the formula (X), and the formula (Y). It means a structural unit other than the structural unit.

In Table 1, p', q', r', s'and t'represent the molar ratio (mol%) of each constituent unit. p'+ q'+ r'+ s'+ t'= 100, and 70 ≦ p'+ q'+ r'+ s'≦ 100.

The polymer compound in the second layer may be any of a block copolymer, a random copolymer, an alternating copolymer, a graft copolymer, and other embodiments, but there are a plurality of types. It is preferably a copolymer obtained by copolymerizing the raw material monomer of.
The number average molecular weight in terms of polystyrene of the polymer compound of the second layer is preferably ^{5 × 10 3 ~1 × 10 6} , more preferably from ^{1 × 10 4 ~5 × 10 5} , more preferably 1 .5 × 10 ^{4 to} 1.5 × 10 ⁵ . The polystyrene-equivalent weight average molecular weight of the polymer compound in the second layer is preferably 1 × 10 ⁴ to 2 × 10 ⁶ , more preferably 2 × 10 ⁴ to 1 × 10 ⁶ , and even more preferably 3. It is × 10 ^{4 to} 5 × 10 ⁵ , and particularly preferably 5 × 10 ^{4 to} 3 × 10 ⁵ .

[Method for producing polymer compound in second layer]
The polymer compound in the second layer can be produced by using a known polymerization method described in Chemical Review (Chem. Rev.), Vol. 109, pp. 897-1091 (2009), etc., and the Suzuki reaction. , Yamamoto reaction, Buchwald reaction, Stille reaction, Negishi reaction, Kumada reaction and other coupling reactions using transition metal catalysts are exemplified.

In the above polymerization method, as a method of charging the monomer, a method of charging the entire amount of the monomer in a batch, a method of charging a part of the monomer and reacting, and then collectively charging the remaining monomer. Examples thereof include a method of continuously or separately charging, a method of continuously or dividing the monomer, and the like.

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

The post-treatment of the polymerization reaction is carried out by a known method, for example, a method of removing water-soluble impurities by liquid separation, a reaction solution after the polymerization reaction is added to a lower alcohol such as methanol, the precipitated precipitate is filtered, and then dried. The method of making the mixture is used alone or in combination. When the purity of the polymer compound in the second layer is low, it can be purified by a usual method such as recrystallization, reprecipitation, continuous extraction with a Soxhlet extractor, or column chromatography.

[Second composition]
The second layer is composed of the polymer compound of the second layer and at least one selected from the group consisting of a hole transport material, a hole injection material, an electron transport material, an electron injection material, a light emitting material and an antioxidant. It may be a layer containing a composition containing (hereinafter, also referred to as “second composition”), or may be a layer formed by using the second composition. However, in the second composition, the hole transport material, the hole injection material, the electron transport material, the electron injection material, and the light emitting material are different from the polymer compound in the second layer.

Examples and preferred 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 second composition are the hole-transporting material contained in the first composition. Same as the examples and preferred ranges of electron transport materials, hole injection materials, electron injection materials and luminescent materials. In the second composition, the contents of the hole-transporting material, the electron-transporting material, the hole-injecting material, the electron-injecting material, and the light-emitting material are each based on 100 parts by mass of the total of the polymer compounds in the second layer. In the case, it is usually 1 to 1000 parts by mass.

The examples and preferred ranges of the antioxidants contained in the second composition are the same as the examples and preferred ranges of antioxidants contained in the first composition. In the second composition, the content of the antioxidant is usually 0.001 to 10 parts by mass when the total of the polymer compounds in the second layer is 100 parts by mass.

-Second ink The second layer can be formed, for example, by using a composition containing the polymer compound of the second layer and a solvent (hereinafter, referred to as "second ink"). .. The second ink can be suitably used for the wet method described in the section of the first ink. The preferred range of viscosity of the second ink is the same as the preferred range of viscosity of the first ink. The examples and preferred ranges of the solvent contained in the second ink are the same as the examples and preferred ranges of the solvent contained in the first ink.
In the second ink, the content of the solvent is usually 1000 to 100,000 parts by mass when the polymer compound in the second layer is 100 parts by mass.
The second ink may further contain at least one selected from the group consisting of hole transporting materials, hole injecting materials, electron transporting materials, electron injecting materials, luminescent materials and antioxidants.
Examples and preferred ranges of hole-transporting materials, electron-transporting materials, hole-injecting materials, electron-injecting materials, luminescent materials and antioxidants that the second ink may further contain are included in the second composition. The examples and preferred ranges of the hole transporting material, the electron transporting material, the hole injecting material, the electron injecting material, the light emitting material and the antioxidant are the same.
The content of the hole transporting material, the electron transporting material, the hole injecting material, the electron injecting material, and the light emitting material, which may be further contained in the second ink, is 100 mass each of the polymer compound in the second layer. In terms of parts, it is usually 1 to 1000 parts by mass. The content of the antioxidant that may be further contained in the second ink is usually 0.001 to 10 parts by mass when the polymer compound in the second layer is 100 parts by mass.

<Light emitting element>
The light emitting device of the present embodiment is a light emitting device having an anode, a cathode, and a first layer and a second layer provided between the anode and the cathode.
The light emitting element of the present embodiment may further have a layer other than the first layer and the second layer.

In the light emitting device of the present embodiment, the first layer is usually a light emitting layer (hereinafter, referred to as "first light emitting layer").
In the light emitting device of the present embodiment, the second layer is usually a hole transport layer and a light emitting layer (that is, a light emitting layer separate from the first light emitting layer, and is hereinafter referred to as a "second light emitting layer". It is said) or an electron transport layer, preferably a hole transport layer or a second light emitting layer, and more preferably a hole transport layer.

In the light emitting element of the present embodiment, the first layer and the second layer are preferably adjacent to each other because the initial deterioration of the light emitting element of the present embodiment is further suppressed.
In the light emitting device of the present embodiment, the second layer is preferably a layer provided between the anode and the first layer because the initial deterioration of the light emitting device of the present embodiment is further suppressed. A hole transport layer or a second light emitting layer provided between the anode and the first layer is more preferable, and a hole transport layer provided between the anode and the first layer is further preferable. ..

In the light emitting element of the present embodiment, when the second layer is the second light emitting layer provided between the anode and the first layer, the initial deterioration of the light emitting element of the present embodiment is further suppressed. It is preferable to further have at least one layer of a hole injection layer and a hole transport layer between the anode and the second layer. Further, when the second layer is a second light emitting layer provided between the anode and the first layer, the initial deterioration of the light emitting element of the present embodiment is further suppressed, so that the cathode and the first layer are further suppressed. It is preferable to further have at least one layer of an electron injecting layer and an electron transporting layer between the two.

In the light emitting element of the present embodiment, when the second layer is the second light emitting layer provided between the cathode and the first layer, the initial deterioration of the light emitting element of the present embodiment is further suppressed. It is preferable to further have at least one layer of a hole injection layer and a hole transport layer between the anode and the first layer. Further, when the second layer is a second light emitting layer provided between the cathode and the first layer, the initial deterioration of the light emitting element of the present embodiment is further suppressed, so that the cathode and the second layer are further suppressed. It is preferable to further have at least one layer of an electron injection layer and an electron transport layer between the two.

In the light emitting device of the present embodiment, when the second layer is a hole transport layer provided between the anode and the first layer, the initial deterioration of the light emitting device of the present embodiment is further suppressed, so that the anode It is preferable to further have a hole injection layer between the and the second layer. Further, when the second layer is a hole transport layer provided between the anode and the first layer, the initial deterioration of the light emitting device of the present embodiment is further suppressed, so that the cathode and the first layer are used. It is preferable to further have at least one layer of an electron injecting layer and an electron transporting layer between the two.

In the light emitting device of the present embodiment, when the second layer is an electron transport layer provided between the cathode and the first layer, the initial deterioration of the light emitting device of the present embodiment is further suppressed, so that the anode and the anode are used. It is preferable to further have at least one layer of a hole injection layer and a hole transport layer between the first layer. Further, when the second layer is an electron transport layer provided between the cathode and the first layer, the initial deterioration of the light emitting device of the present embodiment is further suppressed, so that the cathode and the second layer are combined. It is preferable to have an electron injection layer in between.

Specific layer configurations of the light emitting device of the present embodiment include, for example, the layer configurations represented by the following (D1) to (D15). The light emitting element of the present embodiment usually has a substrate, but may be laminated from the anode on the substrate or may be laminated from the cathode on the substrate.

(D1) Electron / hole transport layer (second layer) / first light emitting layer (first layer) / cathode (D2) anode / second light emitting layer (second layer) / first light emission Layer (first layer) / cathode (D3) anode / hole injection layer / second light emitting layer (second layer) / first light emitting layer (first layer) / cathode (D4) anode / positive Pore injection layer / second light emitting layer (second layer) / first light emitting layer (first layer) / electron transport layer / cathode (D5) anode / hole injection layer / second light emitting layer (second 2 layers) / 1st light emitting layer (1st layer) / electron injection layer / cathode (D6) anode / hole injection layer / 2nd light emitting layer (2nd layer) / 1st light emitting layer ( 1st layer) / electron transport layer / electron injection layer / cathode (D7) anode / hole injection layer / hole transport layer (second layer) / first light emitting layer (first layer) / cathode ( D8) Electron / hole injection layer / hole transport layer (second layer) / first light emitting layer (first layer) / electron transport layer / cathode (D9) anode / hole injection layer / hole transport Layer (second layer) / first light emitting layer (first layer) / electron injection layer / cathode (D10) anode / hole injection layer / hole transport layer (second layer) / first light emission Layer (first layer) / electron transport layer / electron injection layer / cathode (D11) anode / hole injection layer / hole transport layer / second light emitting layer (second layer) / first light emitting layer ( 1st layer) / electron transport layer / electron injection layer / cathode (D12) anode / hole injection layer / hole transport layer (second layer) / first light emitting layer (first layer) / second Light emitting layer / electron transport layer / electron injection layer / cathode (D13) anode / hole injection layer / hole transport layer / first light emitting layer (first layer) / second light emitting layer (second layer) ) / Electron transport layer / Electron injection layer / Cathode (D14) Anophode / Hole injection layer / Hole transport layer / First light emitting layer (first layer) / Electron transport layer (second layer) / Electron injection Layer / cathode (D15) anode / hole injection layer / hole transport layer (second layer) / second light emitting layer / first light emitting layer (first layer) / electron transport layer / electron injection layer / cathode

In the above (D1) to (D15), "/" means that the layers before and after the "/" are laminated adjacent to each other. For example, the "hole transport layer (second layer) / first light emitting layer (first layer)" means a hole transport layer (second layer) and a first light emitting layer (first layer). ) Means that they are stacked adjacent to each other.

In the light emitting device of the present embodiment, two or more layers of the anode, the hole injection layer, the hole transport layer, the light emitting layer, the electron transport layer, the electron injection layer, and the cathode may be provided, if necessary. ..
When a plurality of anodes, hole injection layers, hole transport layers, light emitting layers, electron transport layers, electron injection layers and cathodes are present, the materials constituting them may be the same or different.

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

In the light emitting device of the present embodiment, the order, number, and thickness of the layers to be laminated may be adjusted in consideration of the luminous efficiency and initial deterioration of the light emitting device.

[First light emitting layer]
The first light emitting layer is usually the first layer.

[Second light emitting layer]
The second light emitting layer is usually a second layer or a layer containing a light emitting material, and is preferably a layer containing a light emitting material. When the second light emitting layer is a layer containing a light emitting material, examples of the light emitting material contained in the second light emitting layer include a light emitting material which may be contained in the above-mentioned first composition. Be done. The light emitting material contained in the second light emitting layer may be contained alone or in combination of two or more.
When the light emitting device of the present embodiment has a second light emitting layer, and the hole transporting layer and the electron transporting layer described later are not the second layer, the second light emitting layer is the second layer. It is preferable to have.

[Hole transport layer]
The hole transport layer is a second layer or a layer containing a hole transport material, and is preferably a second layer. When the hole transporting layer is a layer containing a hole transporting material, examples of the hole transporting material include a hole transporting material that may be contained in the above-mentioned first composition. The hole transport material contained in the hole transport layer may be contained alone or in combination of two or more.
When the light emitting device of the present embodiment has a hole transport layer, and the second light emitting layer described above and the electron transport layer described later are not the second layer, the hole transport layer is the second layer. Is preferable.

[Electron transport layer]
The electron transport layer is a second layer or a layer containing an electron transport material, and 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 an electron transporting material that may be contained in the above-mentioned first composition. .. The electron transport material contained in the electron transport layer may be contained alone or in combination of two or more.
When the light emitting device of the present embodiment has an electron transport layer and the above-mentioned second light emitting layer and the above hole transport layer are not the second layer, the electron transport layer is the second layer. Is preferable.

[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 a hole injection material that may be contained in the above-mentioned first composition. The hole injection material contained in the hole injection layer may be contained alone or in combination of two or more.

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 an electron-injecting material that may be contained in the above-mentioned first composition. The electron-injected material contained in the electron-injected layer may be contained alone or in combination of two or more.

[Substrate / Electrode]
The substrate in the light emitting element is preferably a substrate that does not chemically change during the formation of the electrode and the formation of the organic layer. The substrate may be, for example, a substrate made of a material such as glass, plastic, or silicon. When an opaque substrate is used, it is preferable that the electrode farthest from the substrate is transparent or translucent.

Examples of the material of the anode include conductive metal oxides and translucent metals, preferably indium oxide, zinc oxide, tin oxide; indium tin oxide (ITO), indium zinc oxide and the like. Conductive compounds; composites of silver, palladium and copper (APC); NESA, gold, platinum, silver, copper.

As the material of the cathode, for example, metals such as lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, aluminum, zinc, indium; two or more alloys among them; one of them. Alloys of more than one species with one or more of silver, copper, manganese, titanium, cobalt, nickel, tungsten and tin; as well as graphite and graphite interlayer compounds. Examples of the alloy include magnesium-silver alloy, magnesium-indium alloy, magnesium-aluminum alloy, indium-silver alloy, lithium-aluminum alloy, lithium-magnesium alloy, lithium-indium alloy, and calcium-aluminum alloy.

In the light emitting device of the present embodiment, at least one of the anode and the cathode is usually transparent or translucent, but it is preferable that 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 laminating method.

[Manufacturing method of light emitting element]
In the light emitting device of the present embodiment, as a method for forming the first layer, the second layer, and the layers other than the first layer and the second layer, when a low molecular weight compound is used, for example, a vacuum vapor deposition method. And the wet method described in the first ink section, and when a polymer compound is used, for example, the wet method described in the first ink section can be mentioned. The first layer, the second layer, and the layers other than the first layer and the second layer are the wet type described in the section of the first ink using the above-mentioned various inks and inks containing various materials. It may be formed by a method or a dry method such as a vacuum vapor deposition method.

The first layer can be formed by, for example, a dry method or a wet method. The first layer is preferably formed by a wet method.

When the first layer is formed by a dry method, examples of the dry method include a vacuum vapor deposition method. When the first layer is formed by a dry method, as a method of forming the first layer by a dry method, for example, a composition containing the compound (A) and the compound (B) is prepared, and then the composition is vapor-deposited. The method for depositing the first composition after producing the above-mentioned first composition, the method for co-depositing the compound (A) and the compound (B), respectively, and the first composition. Examples thereof include a method of co-depositing the compound (A), the compound (B), and various materials.

When the first layer is formed by a wet method, examples of the wet method include the wet method described in the section of the first ink.
When the first layer is formed by a wet method, it is preferable to use the first ink. That is, the first layer is preferably formed by a wet method using the first ink.
The wet method using the first ink usually includes a step of removing the solvent contained in the first ink. Examples of the method for removing the solvent contained in the first ink include natural drying, vacuum drying and heat drying, and natural drying or vacuum drying is preferable. The drying temperature is usually 0 ° C. to 300 ° C., preferably 5 ° C. to 150 ° C., more preferably 10 ° C. to 75 ° C., and even more preferably 15 ° C. to 40 ° C.

The second layer is preferably formed by a wet method.
When the second layer is formed by the wet method, examples of the wet method include the wet method described in the section of the first ink.
When the second layer is formed by a wet method, it is preferable to use a second ink. That is, the second layer is preferably formed by a wet method using a second ink.
The wet method using the second ink usually includes a step of removing the solvent contained in the second ink. The example and preferable range of the method for removing the solvent contained in the second ink are the same as the example and preferable range of the method for removing the solvent contained in the first ink.

For example, when the second ink contains the crosslinked polymer compound of the second layer, after forming the second layer by a wet method using the second ink, heating or light irradiation (preferably heating). By doing so, the crosslinked polymer compound of the second layer contained in the second layer can be crosslinked. When the crosslinked polymer compound of the second layer is contained in the second layer in a state of being crosslinked, the second layer is substantially insolubilized in a solvent. Therefore, the second layer can be suitably used for stacking the layers in the production of the light emitting device of the present embodiment.

The heating temperature for crosslinking is usually 25 ° C. to 300 ° C., preferably 50 ° C. to 260 ° C., more preferably 130 ° C. to 230 ° C., and even more preferably 180 ° C. to 210 ° C. ..
The heating time is usually 0.1 to 1000 minutes, preferably 0.5 to 500 minutes, more preferably 1 to 120 minutes, and even more preferably 10 to 60 minutes. ..
The types of light used for light irradiation are, for example, ultraviolet light, near-ultraviolet light, and visible light.

Examples of the method for analyzing the components contained in the first layer, the second layer, or the layers other than the first layer and the second layer include a chemical separation analysis method such as extraction and infrared spectroscopy. Instrumental analysis methods such as (IR), nuclear magnetic resonance spectroscopy (NMR), and mass spectrometry (MS), and analytical methods that combine chemical separation analysis methods and instrumental analysis methods can be mentioned.

By performing solid-liquid extraction using an organic solvent such as toluene, xylene, chloroform, or tetrahydrofuran on the first layer, the second layer, or the layers other than the first layer and the second layer, It is possible to separate a component that is substantially insoluble in an organic solvent (insoluble component) and a component that is soluble in an organic solvent (dissolving component). The insoluble component can be analyzed by infrared spectroscopy or nuclear magnetic resonance spectroscopy, and the dissolved component can be analyzed by nuclear magnetic resonance spectroscopy or mass spectrometry.

The light emitting element of the present embodiment can be manufactured, for example, by sequentially laminating each layer on a substrate. Specifically, an anode is provided on the substrate, a hole injection layer, a hole transport layer, or the like is provided on the substrate, a light emitting layer is provided on the anode, and an electron transport layer, an electron injection layer, or the like is provided on the light emitting layer. A light emitting element can be manufactured by providing a layer and further laminating a cathode on the layer. As another manufacturing method, a cathode is provided on the substrate, layers such as an electron injection layer, an electron transport layer, a light emitting layer, a hole transport layer, and a hole injection layer are provided on the cathode, and an anode is further provided on the layers. By laminating, a light emitting element can be manufactured. As yet another manufacturing method, it is possible to manufacture by joining the anode-side base material in which each layer is laminated on the anode or the anode and the cathode-side base material in which each layer is laminated on the cathode or the cathode to face each other. it can.

In the production of the light emitting element of the present embodiment, the material used for forming the hole injection layer, the material used for forming the light emitting layer, the material used for forming the hole transport layer, the material used for forming the electron transport layer, and the electrons. When the material used for forming the injection layer is dissolved in the solvent used for forming the hole injection layer, the light emitting layer, the hole transport layer, the electron transport layer and the layer adjacent to the electron injection layer, respectively, the solvent is used. It is preferable that the material is prevented from melting. As a method of avoiding dissolution of the material, i) a method of using a material having a cross-linking group, or ii) a method of providing a difference in the solubility of adjacent layers in a solvent is preferable. In the method of i) above, the layer can be insolubilized by forming a layer using a material having a cross-linking group and then cross-linking the cross-linking group. Further, as the method of ii), for example, when an electron transport layer is laminated on a light emitting layer by utilizing the difference in solubility, electron transport is performed by using an ink having low solubility in the light emitting layer. The layer can be laminated on the light emitting layer.

[Use]
The light emitting element of this embodiment is suitable as a light source for a backlight of a liquid crystal display device, a light source for lighting, an organic EL lighting, a display device for a computer, a television, a mobile terminal, or the like (for example, an organic EL display and an organic EL television). Can be used for.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

In the examples, the polystyrene-equivalent number average molecular weight (Mn) and the polystyrene-equivalent weight average molecular weight (Mw) of the polymer compound were determined by size exclusion chromatography (SEC) using tetrahydrofuran as the 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% by mass, and 10 μL was injected into SEC. The mobile phase was flowed at a flow rate of 2.0 mL / min. PLgel MIXED-B (manufactured by Polymer Laboratories) was used as a column. A UV-VIS detector (manufactured by Shimadzu Corporation, trade name: SPD-10Avp) was used as the detector.

In an embodiment, the calculation of the value of Delta] E _ST compounds, the density of the B3LYP level function method, and the structure optimization of the ground state of the compound, where, as a basis function, using 6-31G *. Then, using a Gaussian09 as a quantum chemistry calculation program, the time-dependent density functional method B3LYP level, was calculated Delta] E _ST compound.

In the examples, the maximum peak wavelength of the emission spectrum of the compound at room temperature was measured at room temperature with a spectrophotometer (manufactured by JASCO Corporation, FP-6500). A xylene solution in which the compound was dissolved in xylene at a concentration of about 8 × 10 ^-4 % by mass was used as a sample. As the excitation light, ultraviolet (UV) light having a wavelength of 325 nm was used.

<Synthesis Example M> Synthesis of Compounds M1 to M26 Compound M1 was synthesized according to the method described in JP-A-2010-189630.
Compound M6 and Compound M7 were synthesized according to the method described in WO 2002/045184.
Compound M8 was synthesized according to the method described in WO 2011/049241.
Compound M9 and Compound M10 were synthesized according to the method described in WO 2013/146806.
Compound M11 was synthesized according to the method described in WO 2005/049546.
Compound M12 was synthesized according to the method described in WO 2015/145871.
Compound M13 was synthesized according to the method described in JP-A-2010-215886.
Compound M14 was synthesized according to the method described in JP-A-2008-106241.
Compound M15 was synthesized according to the method described in JP-A-2010-215886.
Compound M16 was synthesized according to the method described in WO 2016/031639.
Compound M17 and Compound M19 were synthesized according to the method described in JP2011-174062.
Compound M18, compound M22 and compound M26 were synthesized according to the method described in WO 2016/031639.
Compound M20 and Compound M21 were synthesized according to the method described in WO 2013/191088.
Compound M25 was synthesized according to the method described in WO 2002/045184.

<Synthesis Example HTL> Synthesis of Polymer Compounds HTL-1 to HTL-13 Polymer compounds HTL-1 to HTL-13 are synthesized according to the same table using the compounds of the types and molar ratios shown in Table 2. Synthesized by the method. The Mn and Mw of the obtained polymer compounds are as shown in Table 2.
The synthesis of the polymer compound HTL-1 will be described as an example as follows.
The polymer compound HTL-1 was synthesized by using Compound M19, Compound M11, Compound M25 and Compound M14 according to the method described in JP2012-144722. Mn of the polymer compound HTL-1 is 7.8 × 10 ^4, Mw was 2.6 × 10 ^5.
In the theoretical value obtained from the amount of the charged raw material, the polymer compound HTL-1 has a structural unit derived from compound M19, a structural unit derived from compound M11, a structural unit derived from compound M25, and a compound. It is a copolymer having a structural unit derived from M14 in a molar ratio of 50:30: 12.5: 7.5.

<Obtaining and synthesis of compounds HTM-1, HTM-2, H1, T1, A1 to A18 and B1 to B5>
Compound HTM-1, Compound HTM-2, Compound H1, Compound A7, Compound A9, Compounds A13 to A18, and Compound B2 were manufactured by Luminescence Technology.
Compound T1 was synthesized according to the method described in WO 2018/062278.
Compound A1 and Compound A6 were synthesized according to the method described in WO 2017/170314.
Compound A2 was synthesized according to the method described in WO 2007/058368.
Compound A3 was manufactured by Amadis Chemical Co., Ltd.
Compound A4 was synthesized according to the method described in WO 2008/059713.
Compound A5 and Compound A12 were synthesized according to the method described in JP-A-2011-105643.
Compound A8 was synthesized according to the method described in International Publication No. 2010/015306.
Compound A10 was synthesized according to the method described in International Publication No. 2011/070963.
Compound A11 was synthesized according to the method described in International Publication No. 2010/136109.
Compound B1 and Compounds B3 to B5 were synthesized according to the method described in International Publication No. 2015/102118.

The maximum peak wavelength of the emission spectrum of compound B1 at room temperature was 453 nm. The half width of the maximum peak of the emission spectrum of compound B1 at room temperature was 22 nm. Delta] E _ST of Compound B1 was 0.457EV.
The maximum peak wavelength of the emission spectrum of compound B2 at room temperature was 452 nm. The full width at half maximum of the maximum peak of the emission spectrum of compound B2 at room temperature was 22 nm. Delta] E _ST of Compound B2 was 0.494EV.
The maximum peak wavelength of the emission spectrum of compound B3 at room temperature was 452 nm. The full width at half maximum of the maximum peak of the emission spectrum of compound B3 at room temperature was 22 nm. Delta] E _ST of Compound B3 was 0.447EV.
The maximum peak wavelength of the emission spectrum of compound B4 at room temperature was 453 nm. The full width at half maximum of the maximum peak of the emission spectrum of compound B4 at room temperature was 21 nm. Delta] E _ST of Compound B4 was 0.479EV.
The maximum peak wavelength of the emission spectrum of compound B5 at room temperature was 440 nm. The half width of the maximum peak of the emission spectrum of compound B5 at room temperature was 20 nm. Delta] E _ST compound B5 was 0.471EV.

<Example D1> Fabrication and evaluation of light emitting device D1 (formation of anode and hole injection layer)
An anode was formed by attaching an ITO film to a glass substrate to a thickness of 45 nm by a sputtering method. ND-3202 (manufactured by Nissan Chemical Industries, Ltd.), which is a hole injection material, was formed on the anode to a thickness of 35 nm by a spin coating method. The substrate on which the hole injection layer was laminated was heated on a hot plate at 50 ° C. for 3 minutes in an air atmosphere, and further heated at 230 ° C. for 15 minutes to form a hole injection layer.

(Formation of the second layer)
The polymer compound HTL-5 was dissolved in xylene at a concentration of 0.7% by mass. Using the obtained xylene solution, a film was formed on the hole injection layer to a thickness of 20 nm by a spin coating method, and heated on a hot plate at 180 ° C. for 60 minutes in a nitrogen gas atmosphere. Two layers (hole transport layers) were formed. By this heating, the polymer compound HTL-5 was in a crosslinked state.

(Formation of the first layer)
Compound A1 and compound B1 (Compound A1 / Compound B1 = 99% by mass / 1% by mass) were dissolved in toluene at a concentration of 1.5% by mass. Using the obtained toluene solution, a film was formed on the second layer to a thickness of 60 nm by a spin coating method, and heated at 130 ° C. for 10 minutes in a nitrogen gas atmosphere to obtain the first layer ( Light emitting layer) was formed.

(Cathode formation)
The substrate on which the first layer was formed was decompressed to 1.0 × 10 ^-4 Pa or less in the vapor deposition machine, and then sodium fluoride was placed on the light emitting layer at about 4 nm as a cathode, and then the sodium fluoride layer was formed. Aluminum was deposited on top at about 80 nm. After the vapor deposition, the light emitting element D1 was manufactured by sealing the substrate on which the cathode was formed with a glass substrate.

(Evaluation of light emitting element)
EL light emission was observed by applying a voltage to the light emitting element D1. It was driven by a constant current at 100 mA / cm ² , and the time until the brightness became 95% of the initial brightness (hereinafter, also referred to as “LT95”) was measured.

<Examples D2 to D10 and Comparative Examples CD1 to CD3> Preparation and evaluation of light emitting elements D2 to D10 and CD1 to CD3 Instead of "polymer compound HTL-5" in (formation of the second layer) of Example D1. , The materials shown in Table 3 are used, and further, instead of "Compound A1 and Compound B1 (Compound A1 / Compound B1 = 99% by mass / 1% by mass)" in (Formation of the first layer) of Example D1. , Light emitting elements D2 to D10 and CD1 to CD3 were produced in the same manner as in Example D1 except that the materials shown in Table 3 were used.
EL light emission was observed by applying a voltage to the light emitting elements D2 to D10 and CD1 to CD3. The LT95 of the light emitting elements D2 to D10 and CD1 to CD3 were measured.

The results of Examples D1 to D10 and Comparative Examples CD1 to CD3 are shown in Table 3. The relative values of the LT95 of the light emitting elements D1 to D10, the CD2 and the CD3 when the LT95 of the light emitting element CD1 is set to 1 are shown.

<Examples D11 to D21 and Comparative Examples CD4 to CD5> Preparation and evaluation of light emitting elements D11 to D21, CD4 and CD5 Instead of "polymer compound HTL-5" in (formation of second layer) of Example D1. , The materials shown in Table 4 are used, and further, in place of "Compound A1 and Compound B1 (Compound A1 / Compound B1 = 99% by mass / 1% by mass)" in (Formation of the first layer) of Example D1. , "Compound A1 and Compound B2 (Compound A1 / Compound B2 = 99% by mass / 1% by mass)" were used, and light emitting elements D11 to D21, CD4 and CD5 were produced in the same manner as in Example D1.
EL light emission was observed by applying a voltage to the light emitting elements D11 to D21, CD4 and CD5. The LT95 of the light emitting elements D11 to D21, CD4 and CD5 were measured.

The results of Examples D11 to D21 and Comparative Examples CD4 to CD5 are shown in Table 4. The relative values of the LT95 of the light emitting elements D11 to D21 and the CD5 when the LT95 of the light emitting element CD4 is 1.0 are shown.

<Examples D22 to D30 and Comparative Example CD6> Preparation and evaluation of light emitting elements D22 to D30 and CD6 Table 5 shows, instead of "polymer compound HTL-5" in (formation of the second layer) of Example D1. Using the described material, further, instead of "Compound A1 and Compound B1 (Compound A1 / Compound B1 = 99% by mass / 1% by mass)" in (Formation of the first layer) of Example D1, "Compound A1 And Compound B3 (Compound A1 / Compound B3 = 99% by mass / 1% by mass) ”, light emitting elements D22 to D30 and CD6 were produced in the same manner as in Example D1.
EL light emission was observed by applying a voltage to the light emitting elements D22 to D30 and CD6. The LT95 of the light emitting elements D22 to D30 and CD6 were measured.

The results of Examples D22 to D30 and Comparative Example CD6 are shown in Table 5. The relative values of the LT95 of the light emitting elements D22 to D29 and the CD6 when the LT95 of the light emitting element D30 is 1.0 are shown.

<Example D31 and Comparative Example CD7> Preparation and evaluation of light emitting elements D31 and CD7 Instead of the "polymer compound HTL-5" in (formation of the second layer) of Example D1, the materials shown in Table 6 were used. In addition, instead of "Compound A1 and Compound B1 (Compound A1 / Compound B1 = 99% by mass / 1% by mass)" in (Formation of the first layer) of Example D1, "Compound A1 and Compound B4 (Compound A1 and Compound B4) The light emitting elements D31 and CD7 were produced in the same manner as in Example D1 except that "Compound A1 / Compound B4 = 99% by mass / 1% by mass)" was used.
EL light emission was observed by applying a voltage to the light emitting elements D31 and CD7. The LT95 of the light emitting elements D31 and CD7 were measured.

The results of Example D31 and Comparative Example CD7 are shown in Table 6. The relative value of the LT95 of the light emitting element D31 when the LT95 of the light emitting element CD7 is set to 1 is shown.

<Examples D32 to D34 and Comparative Example CD8> Preparation and evaluation of light emitting elements D32 to D34 and CD8 Instead of "polymer compound HTL-5" in (formation of the second layer) of Example D1, "polymer""CompoundHTL-6" is used, and further, instead of "Compound A1 and Compound B1 (Compound A1 / Compound B1 = 99% by mass / 1% by mass)" in (Formation of the first layer) of Example D1, the table is used. Light emitting elements D32 to D34 and CD8 were produced in the same manner as in Example D1 except that the material and composition ratio (% by mass) described in 7 were used.
EL light emission was observed by applying a voltage to the light emitting elements D32 to D34 and CD8. The light emitting elements D32 to D34 and CD8 were driven with a constant current at 100 mA / cm ² , and the time until the brightness became 90% of the initial brightness (hereinafter, also referred to as “LT90”) was measured.

The results of Examples D32 to D34 and Comparative Example CD8 are shown in Table 7. The relative values of LT90 of the light emitting elements D32 to D34 when LT90 of the light emitting element CD8 is set to 1 are shown.

<Examples D35 to D36 and Comparative Example CD9> Preparation and evaluation of light emitting elements D35, D36 and CD9 Instead of "polymer compound HTL-5" in (formation of the second layer) of Example D1, "polymer""CompoundHTL-3" is used, and further, instead of "Compound A1 and Compound B1 (Compound A1 / Compound B1 = 99% by mass / 1% by mass)" in (Formation of the first layer) of Example D1, Table. Light emitting elements D35, D36 and CD9 were produced in the same manner as in Example D1 except that the material and composition ratio (% by mass) described in No. 8 were used.
EL light emission was observed by applying a voltage to the light emitting elements D35, D36 and CD9. The LT95 of the light emitting elements D35, D36 and CD9 were measured.

The results of Examples D35 to D36 and Comparative Example CD9 are shown in Table 8. The relative values of the LT95 of the light emitting elements D35 and D36 when the LT95 of the light emitting element CD9 is set to 1 are shown.

<Examples D37 to D38 and Comparative Example CD10> Preparation and evaluation of light emitting elements D37, D38 and CD10 Instead of "polymer compound HTL-5" in (formation of the second layer) of Example D1, "polymer""CompoundHTL-6" is used, and further, instead of "Compound A1 and Compound B1 (Compound A1 / Compound B1 = 99% by mass / 1% by mass)" in (Formation of the first layer) of Example D1, the table is used. Light emitting elements D37, D38 and CD10 were produced in the same manner as in Example D1 except that the material and composition ratio (% by mass) described in 9 were used.
EL light emission was observed by applying a voltage to the light emitting elements D37, D38 and CD10. The LT90 of the light emitting elements D37, D38 and CD10 were measured.

The results of Examples D37 to D38 and Comparative Example CD10 are shown in Table 9. The relative values of LT90 of the light emitting elements D37 and D38 when LT90 of the light emitting element CD10 is set to 1 are shown.

<Examples D39 to D40 and Comparative Example CD11> Preparation and evaluation of light emitting elements D39, D40 and CD11 Instead of "polymer compound HTL-5" in (formation of the second layer) of Example D1, "polymer""CompoundHTL-3" is used, and further, instead of "Compound A1 and Compound B1 (Compound A1 / Compound B1 = 99% by mass / 1% by mass)" in (Formation of the first layer) of Example D1, Table. Light emitting elements D39, D40 and CD11 were produced in the same manner as in Example D1 except that the material and composition ratio (% by mass) described in Example 10 were used.
EL light emission was observed by applying a voltage to the light emitting elements D39, D40 and CD11. The LT90 of the light emitting elements D39, D40 and CD11 were measured.

The results of Examples D39 to D40 and Comparative Example CD11 are shown in Table 10. The relative values of LT90 of the light emitting elements D39 and D40 when LT90 of the light emitting element CD11 is set to 1 are shown.

<Examples D41 to D49 and Comparative Example CD12> Preparation and evaluation of light emitting elements D41 to D49 and CD12 Instead of "polymer compound HTL-5" in (formation of the second layer) of Example D1, "polymer""CompoundHTL-13" is used, and further, instead of "Compound A1 and Compound B1 (Compound A1 / Compound B1 = 99% by mass / 1% by mass)" in (Formation of the first layer) of Example D1, the table is used. Light emitting elements D41 to D49 and CD12 were produced in the same manner as in Example D1 except that the material and composition ratio (% by mass) described in 11 were used.
EL light emission was observed by applying a voltage to the light emitting elements D41 to D49 and CD12. The LT90 of the light emitting elements D41 to D49 and CD12 were measured.

The results of Examples D41 to D49 and Comparative Example CD12 are shown in Table 11. The relative values of the LT90 of the light emitting elements D41 to D49 are shown when the LT90 of the light emitting element CD12 is 1.0.

<Examples D50 to D52 and Comparative Example CD13> Preparation and evaluation of light emitting elements D50 to D52 and CD13 Table 12 shows, instead of "polymer compound HTL-5" in (formation of the second layer) of Example D1. Using the materials described, further, in place of "Compound A1 and Compound B1 (Compound A1 / Compound B1 = 99% by mass / 1% by mass)" in (Formation of the first layer) of Example D1, Table 12 shows. Light emitting elements D50 to D52 and CD13 were produced in the same manner as in Example D1 except that the materials and composition ratios (% by mass) described were used.
EL light emission was observed by applying a voltage to the light emitting elements D50 to D52 and CD13. The LT90s of the light emitting elements D50 to D52 and CD13 were measured.

The results of Examples D50 to D52 and Comparative Example CD13 are shown in Table 12. The relative values of the LT90 of the light emitting elements D50 to D52 when the LT90 of the light emitting element CD13 is set to 1 are shown.

<Example D53 and Comparative Example CD14> Fabrication and evaluation of light emitting elements D53 and CD14 Instead of the "polymer compound HTL-5" in (formation of the second layer) of Example D1, the materials shown in Table 13 were used. In addition, instead of "Compound A1 and Compound B1 (Compound A1 / Compound B1 = 99% by mass / 1% by mass)" in (Formation of the first layer) of Example D1, "Compound H1, Compound B2 and The light emitting elements D53 and CD14 were produced in the same manner as in Example D1 except that Compound A13 (Compound H1 / Compound B2 / Compound A13 = 81% by mass / 4% by mass / 15% by mass) was used.
EL light emission was observed by applying a voltage to the light emitting elements D53 and CD14. The LT90 of the light emitting element D53 and CD14 was measured.

The results of Example D53 and Comparative Example CD14 are shown in Table 13. The relative value of the LT90 of the light emitting element D53 when the LT90 of the light emitting element CD14 is 1.0 is shown.

<Examples D54 to D58 and Comparative Example CD15> Preparation and evaluation of light emitting elements D54 to D58 and CD15 Instead of "polymer compound HTL-5" in (formation of the second layer) of Example D1, "polymer""CompoundHTL-13" is used, and further, instead of "Compound A1 and Compound B1 (Compound A1 / Compound B1 = 99% by mass / 1% by mass)" in (Formation of the first layer) of Example D1, Table. Light emitting elements D54 to D58 and CD15 were produced in the same manner as in Example D1 except that the material and composition ratio (% by mass) described in Example 14 were used.
EL light emission was observed by applying a voltage to the light emitting elements D54 to D58 and CD15. The light emitting elements D54 to D58 and CD15 were driven with a constant current at 100 mA / cm ² , and the time until the brightness became 97% of the initial brightness (hereinafter, also referred to as “LT97”) was measured.

The results of Examples D54 to D58 and Comparative Example CD15 are shown in Table 14. The relative values of LT97 of the light emitting elements D54 to D58 when LT97 of the light emitting element CD15 is set to 1 are shown.

Claims (11)

A light emitting device including an anode, a cathode, and a first layer and a second layer provided between the anode and the cathode.
The first layer is a layer containing a compound (A) represented by the formula (FH) and a compound (B) having a condensed heterocyclic skeleton (b) containing a boron atom and a nitrogen atom in the ring. Yes,
The second layer is formed by using a polymer compound containing at least one structural unit selected from the group consisting of the structural unit represented by the formula (X) and the structural unit represented by the formula (Y). A light emitting element that is a layer.

[During the ceremony,
n ^1H represents an integer of 0 or more.
Ar ^1H represents a group obtained by removing n ^1H or more hydrogen atoms directly bonded to the atoms constituting the ring from the aromatic hydrocarbon, and this group may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded.
R ^1H represents an aryl group, a monovalent heterocyclic group or a substituted amino group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. When there are a plurality of ^R1Hs , they may be the same or different. However, the monovalent heterocyclic group is a group obtained by removing one hydrogen atom directly bonded to an atom constituting the ring from the heterocyclic compound not containing the condensed heterocyclic skeleton (b), and this group. May have a substituent. ]

[During the ceremony,
a ^X1 and a ^X2 each independently represent an integer of 0 or more.
Ar ^X1 and Ar ^X3 each independently represent an arylene group or a divalent heterocyclic group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded.
Ar ^X2 and Ar ^X4 each independently form an arylene group, a divalent heterocyclic group, or a divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded. Representing, these groups may have substituents. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. When there are a plurality of Ar ^X2 and Ar ^X4 , they may be the same or different.
^RX1 , ^RX2 and ^RX3 independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. When a plurality of ^RX2 and ^RX3 exist, they may be the same or different. ]

[In the formula, Ar ^Y1 represents an arylene group, a divalent heterocyclic group, or a divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded. The group of may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. ] The light emitting device according to claim 1, wherein the polymer compound has a crosslinking group. The second aspect of the present invention, wherein the polymer compound further comprises at least one structural unit selected from the group consisting of the structural unit represented by the formula (Z) and the structural unit represented by the formula (Z'). Light emitting element.

[During the ceremony,
n represents an integer of 1 or more.
nA represents an integer greater than or equal to 0. When there are a plurality of nA, they may be the same or different.
Ar ³ represents an aromatic hydrocarbon group, a heterocyclic group, or a group in which at least one aromatic hydrocarbon group and at least one heterocyclic group are directly bonded, and these groups have a substituent. You may be doing it. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded.
L ^A is an alkylene group, a cycloalkylene group, an arylene group, a divalent heterocyclic group, -N (R ') -, a group represented by an oxygen atom or a sulfur atom, chromatic these groups the substituent You may be doing it. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. R'represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. If L ^A is plurally present, they may be the same or different.
X represents a cross-linking group. When a plurality of X's exist, they may be the same or different. ]

[During the ceremony,
mA, m and c each independently represent an integer of 0 or more. If there are multiple mAs, they may be the same or different. When there are a plurality of m, they may be the same or different.
Ar ⁵ represents an aromatic hydrocarbon group, a heterocyclic group, or a group in which at least one aromatic hydrocarbon group and at least one heterocyclic group are directly bonded, and these groups have a substituent. You may be doing it. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded.
Ar ⁴ and Ar ⁶ each independently represent an arylene group or a divalent heterocyclic group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded.
K ^A is an alkylene group, a cycloalkylene group, an arylene group, a divalent heterocyclic group, -N (R '') -, a group represented by an oxygen atom or a sulfur atom, these groups are substituents You may have. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. R ″ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. If K ^A there are a plurality, they may be the same or different.
X'represents a hydrogen atom, a bridging group, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. If there are multiple X's, they may be the same or different. However, at least one X'is a cross-linking group. ] The light emitting device according to claim 2 or 3, wherein the cross-linking group is a cross-linking group selected from the cross-linking group A group.
(Crosslink group A group)

[In the formula, R ^XL represents a methylene group, an oxygen atom or a sulfur atom, and n ^XL represents an integer from 0 to 5. When a plurality of R ^XLs exist, they may be the same or different. When a plurality of n ^XLs exist, they may be the same or different. * 1 represents the bonding position. These cross-linking groups may have substituents, and if a plurality of the substituents are present, they may be the same or different, and they may be bonded to each other to form a ring with the carbon atom to which each is bonded. You may be. ] The light emitting device according to any one of claims 1 to 4, wherein the aromatic hydrocarbon in Ar ^1H is a polycyclic aromatic hydrocarbon. The light emitting element according to claim 5, wherein the aromatic hydrocarbon in Ar ^1H is a tricyclic to 5-cyclic aromatic hydrocarbon. Claims 1 to 6 wherein the compound (B) is a compound represented by the formula (1-1), a compound represented by the formula (1-2), or a compound represented by the formula (1-3). The light emitting element according to any one of the above.

[During the ceremony,
Ar ¹ , Ar ² and Ar ³ each independently represent an aromatic hydrocarbon group or a heterocyclic group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded.
Y ¹ represents a group represented by −N (Ry) −.
Y ² and Y ³ independently represent a single bond, an oxygen atom, a sulfur atom, a selenium atom, a group represented by -N (Ry)-, an alkylene group or a cycloalkylene group, and these groups are substituents. May have. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. Ry represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different, or they may be bonded to each other to form a ring with the atoms to which each is bonded. When there are a plurality of Ry, they may be the same or different. Ry may be attached directly to Ar ¹ , Ar ² or Ar ³ via a linking group. ] The light emitting device according to claim 7, wherein Y ² and Y ³ are groups represented by −N (Ry) −. Claims 1 to 8 further include the first layer further containing at least one selected from the group consisting of a hole transport material, a hole injection material, an electron transport material, an electron injection material, a light emitting material and an antioxidant. The light emitting element according to any one of the above. The light emitting device according to any one of claims 1 to 9, wherein the first layer and the second layer are adjacent to each other. The light emitting device according to any one of claims 1 to 10, wherein the second layer is provided between the anode and the first layer.