JP2020109833A - Light emitting element composition and light emitting element including the same - Google Patents

Abstract

To provide a composition useful for manufacturing a light emitting element in which long-term deterioration is suppressed, and a light emitting element formed using the composition.SOLUTION: A light emitting element composition includes a host material and a guest material, the host material includes an aromatic compound having a condensed ring skeleton in which only 3 or more benzene rings are condensed, the guest material includes an aromatic amine compound, and the total amount of chromium atoms included in the host material and chromium atoms included in the guest material is 10 mass ppb or more and 135 mass ppb or less with respect to the total amount of the host material and the guest material.SELECTED DRAWING: None

Description

The present invention relates to a composition for a light emitting device and a light emitting device containing the composition.

A light emitting element such as an organic electroluminescence element can be suitably used for, for example, a display and illumination. As a material used for a light emitting element, for example, Patent Document 1 proposes a composition containing a compound H0 and a compound EM1.

International Publication No. 2017/170313

However, the light-emitting device manufactured using the above composition is not always sufficient in suppressing long-term deterioration.
Therefore, an object of the present invention is to provide a composition useful for manufacturing a light emitting device in which long-term deterioration is suppressed, and a light emitting device formed by using the composition.

As a result of intensive studies to solve the above problems, the present inventors have found that in a light emitting device including an organic layer containing a specific composition, chromium atoms have a great influence on long-term deterioration of the light emitting device. Furthermore, they have found that long-term deterioration of the light emitting device can be suppressed by adjusting the amount of chromium atoms to a specific amount, and have completed the present invention. Note that Patent Document 1 does not describe that the amount of chromium atoms contained in the composition affects long-term deterioration of the light emitting device.

［式中、
ｎ^１Ｈは、０以上の整数を表す。
Ａｒ^１Ｈは、ベンゼン環のみが３個以上縮合した縮合環骨格を有する芳香族炭化水素から、前記縮合環骨格を構成する炭素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^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。］
［３］
前記縮合環骨格が、ベンゼン環のみが３個以上５個以下縮合した縮合環骨格である、［１］又は［２］に記載の発光素子用組成物。
［４］
前記縮合環骨格が、アントラセン骨格、フェナントレン骨格、ベンゾアントラセン骨格、ベンゾフェナントレン骨格又はピレン骨格である、［３］に記載の発光素子用組成物。
［５］
前記芳香族アミン化合物が式（ＦＢ）で表される化合物である、［１］〜［４］のいずれかに記載の発光素子用組成物。

［式中、
ｎ^１Ｂは、１以上の整数を表す。
Ａｒ^１Ｂは、芳香族炭化水素基又は芳香族複素環基を表し、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^１Ｂは、アミノ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^１Ｂ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。］
［６］
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、酸化防止剤及び溶媒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］〜［５］のいずれかに記載の発光素子用組成物。
［７］
陽極と、陰極と、前記陽極及び前記陰極の間に設けられた有機層とを有する発光素子であり、
前記有機層が、［１］〜［６］のいずれかに記載の発光素子用組成物を含有する層である、発光素子。
［８］
ホスト材料とゲスト材料とが配合された発光素子用組成物の製造方法であって、
ベンゼン環のみが３個以上縮合した縮合環骨格を有する芳香族化合物を含むホスト材料を準備するホスト材料準備工程と、
芳香族アミン化合物を含むゲスト材料を準備するゲスト材料準備工程と、
前記ホスト材料と前記ゲスト材料とを、前記ホスト材料に含まれるクロム原子及び前記ゲスト材料に含まれるクロム原子の総量が１０質量ｐｐｂ以上１３５質量ｐｐｂ以下となる配合比で混合して、発光素子用組成物を得る製造工程と、
を含む、発光素子用組成物の製造方法。
［９］
前記ゲスト材料準備工程が、
クロム原子が混在した前記芳香族アミン化合物を準備する準備工程（Ｂ−１）と、
前記工程（Ｂ−１）で準備した前記芳香族アミン化合物の少なくとも一部を精製して、前記クロム原子の少なくとも一部を除去する工程（Ｂ−２）と、
を含む、［８］に記載の製造方法。
［１０］
前記ホスト材料準備工程が、
クロム原子が混在した前記芳香族化合物を準備する工程（Ａ−１）と、
前記工程（Ａ−１）で準備した前記芳香族化合物の少なくとも一部を精製して、前記クロム原子の少なくとも一部を除去する工程（Ａ−２）と、
を含む、［８］又は［９］に記載の製造方法。
［１１］
ホスト材料とゲスト材料とが配合された発光素子用組成物の製造方法であって、
ベンゼン環のみが３個以上縮合した縮合環骨格を有する芳香族化合物を含むホスト材料を準備するホスト材料準備工程と、
前記ホスト材料に対するゲスト材料の配合比を決定する決定工程と、
芳香族アミン化合物を含み、前記配合比で前記ホスト材料と混合したとき前記ホスト材料及び前記ゲスト材料の総量に対する前記ホスト材料に含まれるクロム原子及び前記ゲスト材料に含まれるクロム原子の総量が１０質量ｐｐｂ以上１３５質量ｐｐｂ以下となる、ゲスト材料を準備するゲスト材料準備工程と、
前記ホスト材料と前記ゲスト材料とを前記配合比で混合して、発光素子用組成物を得る製造工程と、
を含む、発光素子用組成物の製造方法。
［１２］
ホスト材料とゲスト材料とが配合された発光素子用組成物の製造方法であって、
芳香族アミン化合物を含むゲスト材料を準備するゲスト材料準備工程と、
前記ゲスト材料に対するホスト材料の配合比を決定する決定工程と、
ベンゼン環のみが３個以上縮合した縮合環骨格を有する芳香族化合物を含み、前記配合比で前記ゲスト材料と混合したとき前記ホスト材料及び前記ゲスト材料の総量に対する前記ホスト材料に含まれるクロム原子及び前記ゲスト材料に含まれるクロム原子の総量が１０質量ｐｐｂ以上１３５質量ｐｐｂ以下となる、ホスト材料を準備するホスト材料準備工程と、
前記ゲスト材料と前記ホスト材料とを前記配合比で混合して、発光素子用組成物を得る製造工程と、
を含む、発光素子用組成物の製造方法。
［１３］
ホスト材料とゲスト材料とが配合された発光素子用組成物の製造方法であって、
ホスト材料としてベンゼン環のみが３個以上縮合した縮合環骨格を有する芳香族化合物を準備するホスト材料準備工程と、
ゲスト材料として芳香族アミン化合物を準備するゲスト材料準備工程と、
前記ホスト材料と前記ゲスト材料との配合比を決定する決定工程と、
前記配合比で前記ホスト材料と前記ゲスト材料とを混合したとき、前記ホスト材料及び前記ゲスト材料の総量に対する前記ホスト材料に含まれるクロム原子及び前記ゲスト材料に含まれるクロム原子の総量が１０質量ｐｐｂ以上１３５質量ｐｐｂ以下となるように、前記芳香族化合物及び前記芳香族アミン化合物の少なくとも一部を精製する精製工程と、
前記芳香族化合物を含む前記ホスト材料と前記芳香族アミン化合物を含む前記ゲスト材料とを前記配合比で混合して、発光素子用組成物を得る製造工程と、
を含む、発光素子用組成物の製造方法。
［１４］
前記芳香族化合物に含まれるクロム原子の含有量を測定するホスト材料測定工程と、
前記芳香族アミン化合物に含まれるクロム原子の含有量を測定するゲスト材料測定工程と、
を更に含む、［８］〜［１３］のいずれかに記載の製造方法。
［１５］
陽極と、陰極と、前記陽極及び前記陰極の間に設けられた有機層とを含む、発光素子の製造方法であって、
［８］〜［１４］のいずれかに記載の製造方法により製造された発光素子用組成物により、前記有機層を形成させる工程を含む、発光素子の製造方法。 That is, the present invention provides the following [1] to [15].
[1]
A composition for a light emitting device in which a host material and a guest material are blended,
The host material contains an aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed,
The guest material includes an aromatic amine compound,
The composition for a light emitting device, wherein the total amount of chromium atoms contained in the host material and the chromium atoms contained in the guest material is 10 mass ppb or more and 135 mass ppb or less with respect to the total amount of the host material and the guest material. ..
[2]
The composition for a light emitting device according to [1], wherein the aromatic compound is a compound represented by the formula (FH).

[In the formula,
n ^1H represents an integer of 0 or more.
Ar ^1H represents a group obtained by removing from the aromatic hydrocarbon having a condensed ring skeleton in which only 3 or more benzene rings are condensed, a hydrogen atom n ^1H or more directly bonded to a carbon atom constituting the condensed ring skeleton. This group may have a substituent. When a plurality of the substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atom to which they are bonded.
R ^1H represents 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 and may be bonded to each other to form a ring together with the atom to which they are bonded. When a plurality of R ^1H are present, they may be the same or different and may be bonded to each other to form a ring together with the atom to which each is bonded. ]
[3]
The composition for a light-emitting element according to [1] or [2], wherein the condensed ring skeleton is a condensed ring skeleton in which only 3 or more and 5 or less benzene rings are condensed.
[4]
The composition for a light emitting device according to [3], wherein the condensed ring skeleton is an anthracene skeleton, a phenanthrene skeleton, a benzoanthracene skeleton, a benzophenanthrene skeleton, or a pyrene skeleton.
[5]
The composition for a light emitting device according to any one of [1] to [4], wherein the aromatic amine compound is a compound represented by the formula (FB).

[In the formula,
n ^1B represents an integer of 1 or more.
Ar ^1B represents an aromatic hydrocarbon group or an aromatic heterocyclic group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atom to which they are bonded.
R ^1B represents an amino 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 and may be bonded to each other to form a ring together with the atom to which they are bonded. When a plurality of R ^1B are present, they may be the same or different and may be bonded to each other to form a ring together with the atom to which they are bonded. ]
[6]
Any of [1] to [5], 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, an antioxidant and a solvent. The composition for a light emitting device according to.
[7]
An anode, a cathode, and a light emitting device having an organic layer provided between the anode and the cathode,
A light emitting device, wherein the organic layer is a layer containing the composition for a light emitting device according to any one of [1] to [6].
[8]
A method for producing a composition for a light emitting device in which a host material and a guest material are blended,
A host material preparing step of preparing a host material containing an aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed;
A guest material preparation step of preparing a guest material containing an aromatic amine compound,
For a light emitting device, the host material and the guest material are mixed in a mixing ratio such that the total amount of chromium atoms contained in the host material and chromium atoms contained in the guest material is 10 mass ppb or more and 135 mass ppb or less. A manufacturing process for obtaining the composition,
A method for producing a composition for a light emitting device, comprising:
[9]
The guest material preparation step,
A preparatory step (B-1) for preparing the aromatic amine compound in which chromium atoms are mixed,
A step (B-2) of purifying at least a part of the aromatic amine compound prepared in the step (B-1) to remove at least a part of the chromium atom;
The production method according to [8], which comprises:
[10]
The host material preparation step,
A step (A-1) of preparing the aromatic compound in which chromium atoms are mixed,
A step (A-2) of purifying at least a part of the aromatic compound prepared in the step (A-1) to remove at least a part of the chromium atom;
The manufacturing method as described in [8] or [9] containing.
[11]
A method for producing a composition for a light emitting device in which a host material and a guest material are blended,
A host material preparing step of preparing a host material containing an aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed;
A determining step of determining a compounding ratio of the guest material with respect to the host material;
A total amount of chromium atoms contained in the host material and chromium atoms contained in the guest material is 10 mass with respect to the total amount of the host material and the guest material when the aromatic amine compound is mixed with the host material in the compounding ratio. a guest material preparation step of preparing a guest material, which is ppb or more and 135 mass ppb or less;
A step of mixing the host material and the guest material in the mixing ratio to obtain a composition for a light emitting device,
A method for producing a composition for a light emitting device, comprising:
[12]
A method for producing a composition for a light emitting device in which a host material and a guest material are blended,
A guest material preparation step of preparing a guest material containing an aromatic amine compound,
A determining step of determining a compounding ratio of the host material to the guest material,
An aromatic compound having a condensed ring skeleton in which only 3 or more benzene rings are condensed, and when mixed with the guest material at the compounding ratio, the host material and a chromium atom contained in the host material with respect to the total amount of the guest material; A host material preparation step of preparing a host material, wherein the total amount of chromium atoms contained in the guest material is 10 mass ppb or more and 135 mass ppb or less;
A step of mixing the guest material and the host material in the mixing ratio to obtain a composition for a light emitting device,
A method for producing a composition for a light emitting device, comprising:
[13]
A method for producing a composition for a light emitting device in which a host material and a guest material are blended,
A host material preparing step of preparing an aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed as a host material,
A guest material preparing step of preparing an aromatic amine compound as a guest material,
A determining step of determining a compounding ratio of the host material and the guest material,
When the host material and the guest material are mixed at the compounding ratio, the total amount of chromium atoms contained in the host material and the chromium atom contained in the guest material is 10 mass ppb with respect to the total amount of the host material and the guest material. A refining step of purifying at least a part of the aromatic compound and the aromatic amine compound so that the amount becomes 135 mass ppb or less.
A manufacturing step of obtaining a composition for a light emitting device by mixing the host material containing the aromatic compound and the guest material containing the aromatic amine compound at the compounding ratio,
A method for producing a composition for a light emitting device, comprising:
[14]
A host material measuring step of measuring the content of chromium atoms contained in the aromatic compound,
A guest material measuring step of measuring the content of chromium atoms contained in the aromatic amine compound,
The production method according to any one of [8] to [13], further comprising:
[15]
An anode, a cathode, and an organic layer provided between the anode and the cathode, a method for manufacturing a light-emitting element,
A method for producing a light-emitting element, comprising the step of forming the organic layer with the composition for a light-emitting element produced by the production method according to any one of [8] to [14].

ADVANTAGE OF THE INVENTION According to this invention, the composition useful for manufacture of the light emitting element with which long-term deterioration was suppressed can be provided. Further, according to the present invention, a light emitting device containing the composition can be provided. Furthermore, according to the present invention, it is possible to provide a method for manufacturing the composition and the light emitting device.

Hereinafter, a preferred embodiment of the present embodiment will be described in detail.

<Explanation of common terms>
The terms commonly used in the present specification have the following meanings unless otherwise specified.

“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.

The “polymer compound” means a polymer having a molecular weight distribution and a polystyrene-equivalent number average molecular weight of 1×10 ³ to 1×10 ⁸ .
The “low molecular weight compound” means a compound having no molecular weight distribution and a molecular weight of 1×10 ⁴ or less.
The “constituent unit” means a unit present in one or more units in the polymer compound.

The “alkyl group” may be linear or branched. The number of carbon atoms of the straight-chain alkyl group, not including the number of carbon atoms of the substituent, is usually 1 to 50, preferably 1 to 20, and more preferably 1 to 10. 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, not including the number of carbon atoms of the substituent. The alkyl group may have a substituent, for example, methyl group, ethyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, 2- Ethylhexyl group, decyl group, 3,7-dimethyloctyl group, 2-ethyloctyl group, dodecyl group, trifluoromethyl group, 3-phenylpropyl group, 3-(4-methylphenyl)propyl group, 3-(3,3 A 5-di-hexylphenyl)propyl group and a 6-ethyloxyhexyl group can be mentioned.
The number of carbon atoms of the “cycloalkyl group” is usually 3 to 50, preferably 4 to 10, not including the number of carbon atoms of the substituent. The cycloalkyl group may have a substituent, and examples thereof include a cyclohexyl group and a methylcyclohexyl group.
The number of carbon atoms of the "alkylene group" is usually 1 or more and 20 or less, preferably 1 or more and 15 or less, and more preferably 1 or more and 10 or less, not including the number of carbon atoms of the substituent. The alkylene group may have a substituent, and examples thereof 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 or more and 20 or less, not including the number of carbon atoms of the substituent. The cycloalkylene group may have a substituent, and examples thereof include a cyclohexylene group.

The “aromatic hydrocarbon group” means a group obtained by removing one or more hydrogen atoms directly bonded to carbon atoms constituting a ring from aromatic hydrocarbon. A group obtained by removing one hydrogen atom directly bonded to a carbon 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 carbon atoms constituting a ring from an aromatic hydrocarbon is also referred to as "arylene group".
The number of carbon atoms of the aromatic hydrocarbon group is usually 6 to 60, not including the number of carbon atoms of the substituent, preferably 6 to 30, and more preferably 6 to 18.
The “aromatic hydrocarbon group” is, for example, a monocyclic aromatic hydrocarbon (for example, benzene) or a polycyclic aromatic hydrocarbon (for example, a bicyclic group such as naphthalene and indene). Aromatic hydrocarbons; tricyclic aromatic hydrocarbons such as anthracene, phenanthrene, dihydrophenanthrene and fluorene; tetracyclic aromatic hydrocarbons such as benzoanthracene, benzophenanthrene, benzofluorene, pyrene and fluoranthene; dibenzoanthracene , 5-benzoaromatic hydrocarbons such as dibenzophenanthrene, dibenzofluorene, perylene and benzofluoranthene; 6-cyclic aromatic hydrocarbons such as spirobifluorene; and benzospirobifluorene and acenaphthofluoranthene 7 ring aromatic hydrocarbons such as, etc.) and a group in which one or more hydrogen atoms directly bonded to the carbon atoms constituting the ring have been removed, and these groups have a substituent. May be. The aromatic hydrocarbon group includes a group in which a plurality of these groups are bonded.

The "alkoxy group" may be linear or branched. The number of carbon atoms in the straight-chain alkoxy group is usually 1 to 40, preferably 1 to 10, not including the number of carbon atoms in the substituent. The number of carbon atoms of the branched alkoxy group is usually 3 to 40, preferably 4 to 10, not including the number of carbon atoms of the substituent. The alkoxy group may have a substituent, and examples thereof 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 lauryl. An oxy group is mentioned.
The number of carbon atoms of the “cycloalkoxy group” is usually 3 to 40, preferably 4 to 10, not including the number of carbon atoms of the substituent. The cycloalkoxy group may have a substituent, and examples thereof include a cyclohexyloxy group.
The number of carbon atoms of the “aryloxy group” is usually 6 to 60, preferably 6 to 48, not including the number of carbon atoms of the substituent. The aryloxy group may have a substituent, and examples thereof include a phenoxy group, a naphthyloxy group, an anthracenyloxy group, and a pyrenyloxy group.

The “heterocyclic group” means a group obtained by removing one or more hydrogen atoms directly bonded to carbon atoms or heteroatoms constituting a ring from a heterocyclic compound. Among the heterocyclic groups, an “aromatic heterocyclic group”, which is a group obtained by removing one or more hydrogen atoms directly bonded to carbon atoms or heteroatoms constituting a ring from an aromatic heterocyclic compound, is preferable. A group obtained by removing p hydrogen atoms (p represents an integer of 1 or more) directly bonded to a carbon atom or a hetero 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 a carbon atom or a hetero 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 has aromaticity such as azole, thiophene, furan, pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene and carbazole, and phenoxazine. A compound in which a heterocycle is condensed with a heterocycle such as phenothiazine and benzopyran, even though the heterocycle itself does not exhibit aromaticity.
The number of carbon atoms of the heterocyclic group is usually 1 to 60, preferably 2 to 40, more preferably 3 to 20, not including the number of carbon atoms of the substituent. The number of hetero atoms in the heterocyclic group is usually 1 to 30, not including the number of carbon atoms in the substituent, preferably 1 to 10, and more preferably 1 to 3.
The heterocyclic group may have a substituent, for example, a monocyclic heterocyclic compound (for example, furan, thiophene, oxadiazole, pyrrole, diazole, triazole, tetrazole, pyridine, diazabenzene and triazine are Or a polycyclic heterocyclic compound (for example, a bicyclic heterocyclic compound such as azanaphthalene, diazanaphthalene, benzofuran, benzothiophene, indole, benzodiazole and benzothiadiazole; dibenzofuran , Dibenzothiophene, dibenzoborol, dibenzosilole, dibenzophosphole, dibenzoselenophene, carbazole, azacarbazole, diazacarbazole, phenoxazine, phenothiazine, 9,10-dihydroacridine, 5,10-dihydrophenazine, phenazaborine, pheno Tricyclic heterocyclic compounds such as phosphazine, phenoselenazine, phenazacillin, azaanthracene, diazaanthracene, azaphenanthrene and diazaphenanthrene; 4 such as hexaazatriphenylene, benzocarbazole, benzonaphthofuran and benzonaphthothiophene Cyclic heterocyclic compounds; 5-cyclic heterocyclic compounds such as dibenzocarbazole, indolocarbazole and indenocarbazole; 6-ring heterocyclic compounds such as carbazolocarbazole, benzoindrocarbazole and benzoindenocarbazole A compound; and a 7-ring heterocyclic compound such as dibenzoindrocarbazole, etc.), and a group obtained by removing one or more hydrogen atoms directly bonded to the atoms constituting the ring. May have a substituent. The heterocyclic group includes a group in which a plurality of these groups are bonded.

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 is preferably a substituted amino group (that is, a secondary amino group or a tertiary amino group, preferably a tertiary amino group). .. The substituent which the amino group has is preferably an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group. When the amino group has a plurality of substituents, they may be the same or different and may be bonded to each other to form a ring together 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 linear or branched. The number of carbon atoms in the linear alkenyl group is usually 2 to 30, preferably 3 to 20, not including the number of carbon atoms in the substituent. The number of carbon atoms of the branched alkenyl group is usually 3 to 30, not including the number of carbon atoms of the substituent, and preferably 4 to 20.
The number of carbon atoms of the "cycloalkenyl group" is usually 3 to 30, and preferably 4 to 20, not including the number of carbon atoms of the substituent.
The alkenyl group and cycloalkenyl group may have a substituent, and examples thereof include a vinyl group, a propenyl group, a butenyl group, a 3-butenyl group, a 3-pentenyl group, a 4-pentenyl group, a 1-hexenyl group, and a 5 group. Examples include -hexenyl group, 7-octenyl group, and groups in which these groups have a substituent.

The "alkynyl group" may be linear or branched. The number of carbon atoms of the alkynyl group is usually 2 to 20, not including the carbon atoms of the substituents, and preferably 3 to 20. The number of carbon atoms of the branched alkynyl group is usually 4 to 30, and preferably 4 to 20, not including the carbon atoms of the substituents.
The number of carbon atoms of the “cycloalkynyl group” is usually 4 to 30, and preferably 4 to 20, not including the carbon atoms of the substituents.
The alkynyl group and cycloalkynyl group may have a substituent, for example, an ethynyl group, a propynyl group, a butynyl group, a pentynyl group, a hexynyl group, a 5-hexynyl group, and these groups have a substituent. Groups.

The “crosslinking group” is a group capable of forming a new bond by being subjected to heating, ultraviolet irradiation, near-ultraviolet irradiation, visible light irradiation, infrared irradiation, radical reaction, or the like, and preferably has the formula ( B-1) to a group represented by any one of formulas (B-17). These groups may have a substituent.

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

The “amount of chromium atoms” can be measured by the ICP/MS method (inductively coupled plasma mass spectrometry). That is, the "amount of chromium atoms" means the mass concentration of chromium atoms as measured by the ICP/MS method. Further, "the amount of chromium atoms" being "0 mass ppb" means that the mass concentration of chromium atoms is not more than the detection limit when measured by the ICP/MS method.

In the composition for a light emitting device of the present embodiment, the host material means a material that physically, chemically or electrically interacts with the guest material. By this interaction, for example, it becomes possible to improve or adjust the light emitting property, the charge transporting property, or the charge injecting property of the composition for a light emitting device of the present embodiment.
In the composition for a light emitting device of the present embodiment, a light emitting material will be described as an example. The host material and the guest material electrically interact with each other to efficiently transfer electric energy from the host material to the guest material. The guest material can emit light more efficiently.

<Host material>
The host material contains an aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed. The aromatic compound having a condensed ring skeleton in which only 3 or more benzene rings are condensed may contain only one kind of condensed ring skeleton in which only 3 or more benzene rings are condensed, and 2 or more kinds of condensed ring skeletons may be contained. You may stay. The aromatic compound having a condensed ring skeleton in which only 3 or more benzene rings are condensed may contain only one condensed ring skeleton in which 3 or more benzene rings are condensed. May be included. Hereinafter, an aromatic compound having a condensed ring skeleton in which only three or more benzene rings contained in the host material are condensed may be referred to as “aromatic compound for host material”.

In the condensed ring skeleton of the aromatic compound for a host material, the number of condensed benzene rings is usually 3 to 10, which is preferable because long-term deterioration of the light emitting device of the present embodiment is further suppressed. Is 3 to 7, more preferably 3 to 5, and even more preferably 3 or 4.
The condensed ring skeleton of the aromatic compound for a host material can be said to be a condensed ring carbon skeleton in which three or more benzene rings are condensed. The fused ring skeleton is preferably an anthracene skeleton, a phenanthrene skeleton, a benzoanthracene skeleton, a benzophenanthrene skeleton or a pyrene skeleton, and more preferably an anthracene skeleton or a benzoanthracene, because the long-term deterioration of the light emitting element of the present embodiment is further suppressed. A skeleton or a pyrene skeleton, more preferably an anthracene skeleton.

The aromatic compound for a host material may be an aromatic hydrocarbon having a condensed ring skeleton in which only 3 or more benzene rings are condensed (hereinafter, also referred to as “condensed ring-containing aromatic hydrocarbon”). The hydrocarbon may have a substituent. The substituent which the condensed ring-containing aromatic hydrocarbon may have is preferably a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or a substituent. An amino group, more preferably an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, further preferably an aryl group or a monovalent heterocyclic group, and particularly preferably an aryl group. And these groups may further have a substituent.
In the substituent which the condensed ring-containing aromatic hydrocarbon may have, the aryl group is preferably a monocyclic or bicyclic to 6-cyclic aromatic hydrocarbon, and a carbon atom constituting the ring. A group obtained by removing one or more hydrogen atoms directly bonded, more preferably a hydrogen atom 1 directly bonded to a carbon atom constituting a ring from a monocyclic or bicyclic to tetracyclic aromatic hydrocarbon. A group in which one or more hydrogen atoms directly bonded to the carbon atoms constituting the ring are removed from benzene, naphthalene, dihydrophenanthrene, fluorene or benzofluorene is particularly preferable. Is a phenyl group or a naphthyl group, and these groups may have a substituent.
In the substituent which the condensed ring-containing aromatic hydrocarbon may have, the monovalent heterocyclic group preferably forms a ring from a monocyclic or bicyclic to 6-ring heterocyclic compound. Is a group excluding one or more hydrogen atoms directly bonded to the atom, more preferably hydrogen directly bonded to a ring-constituting atom from a monocyclic or bicyclic to tetracyclic heterocyclic compound. A group in which one or more atoms have been removed, and pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, dibenzofuran, dibenzothiophene, carbazole, benzocarbazole, benzonaphthofuran or benzonaphthothiophene can be directly attached to an atom constituting a ring. It is a group excluding one or more hydrogen atoms to be bonded, and these groups may have a substituent.
In the substituted amino group in the substituent which the condensed ring-containing aromatic hydrocarbon may have, as the substituent which the amino group has, an aryl group or a monovalent heterocyclic group is preferable, and an aryl group is more preferable. The group may further have a substituent. The examples and preferable ranges of the aryl group which is the substituent which the amino group has are the same as the examples and the preferable range of the aryl group in the substituent which the fused ring-containing aromatic hydrocarbon may have. Examples and preferred ranges of the monovalent heterocyclic group that is a substituent that the amino group has include examples of the monovalent heterocyclic group in the substituent that the condensed ring-containing aromatic hydrocarbon may have and preferred ranges thereof. Is the same.

The condensed ring-containing aromatic hydrocarbon preferably has a substituent because long-term deterioration of the light emitting device of the present embodiment is further suppressed. When the condensed ring-containing aromatic hydrocarbon has a substituent, the total number of the substituents contained in the condensed ring-containing aromatic hydrocarbon is usually 1 to 20 (provided that the condensed ring-containing aromatic hydrocarbon has The total number of hydrogen atoms is less than or equal to the above, and the same shall apply hereinafter), and it is preferably 1 to 15, more preferably 1 to 10 because the host material is easily synthesized. The number is more preferably 1 to 7, particularly preferably 1 to 5, and particularly preferably 1 to 3.

The substituent which the condensed ring-containing aromatic hydrocarbon optionally has may be preferably a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, or aryl. Group, a monovalent 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 still more preferably an alkyl group or a cyclo group. It is an alkyl group, and these groups may have a substituent, but it is preferable that they do not 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 substituent which the condensed ring-containing aromatic hydrocarbon may further have are It is the same as the examples and preferred ranges of the aryl group, the monovalent heterocyclic group and the substituted amino group in the substituent which the ring-containing aromatic hydrocarbon may have.

The host material may further contain a compound other than the aromatic compound for the host material, but since the long-term deterioration of the light emitting element of the present embodiment is further suppressed, the host material is mainly composed of the aromatic compound for the host material. Preferably. The content ratio of the aromatic compound for a host material in the host material may be, for example, 10% by mass or more, and since the long-term deterioration of the light emitting device of the present embodiment is further suppressed, it is preferably 30% by mass or more, and 50% by mass or more. Mass% or more is more preferable, 70 mass% or more is still more preferable, 90 mass% or more is particularly preferable, 95 mass% or more is particularly preferable, and may be 100 mass%.
The host material may contain only one kind of aromatic compound for host material or may contain two or more kinds thereof. When the host material further contains a compound other than the aromatic compound for host material, the host material may contain only one compound other than the aromatic compound for host material, and may contain two or more compounds. Good.

The aromatic compound for a host material may be a polymer compound (hereinafter, also referred to as “polymer host material”) or a low molecular compound (hereinafter, also referred to as “low molecular host material”), Low molecular weight host materials are preferred.

(Low molecular weight host material)
The molecular weight of the low molecular weight host material 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 . Yes, and more preferably 4×10 ² to 1×10 ³ .
The total number of condensed ring skeletons in which only 3 or more benzene rings are condensed in the low-molecular host material is usually 1 to 10, and long-term deterioration of the light emitting device of the present embodiment is further suppressed. Therefore, the number is preferably 1 to 7, more preferably 1 to 5, still more preferably 1 to 3, and particularly preferably 1.
The low molecular weight host material may include only one kind of a condensed ring skeleton in which only three or more benzene rings are condensed, and may include two or more kinds, but since the low molecular weight host material is easy to synthesize, It is preferably 1 to 5 types, more preferably 1 to 3 types, and still more preferably 1 type.
Since the long-term deterioration of the light emitting device of the present embodiment is further suppressed, the low molecular weight host material has a condensed ring skeleton in which only 3 or more benzene rings are condensed, and a condensed ring skeleton in which only 3 or more benzene rings are condensed. It is preferable to include as a group (hereinafter, also referred to as “condensed ring-containing aromatic hydrocarbon group”) in which one or more hydrogen atoms directly bonded to carbon atoms constituting the condensed ring skeleton are removed from aromatic hydrocarbon. This group may have a substituent.
The total number of the condensed ring-containing aromatic hydrocarbon groups contained in the low molecular weight host material is usually 1 to 10, which is preferable because the long-term deterioration of the light emitting device of the present embodiment is further suppressed. It is 1 to 7, more preferably 1 to 5, further preferably 1 to 3, and particularly preferably 1.
The low-molecular-weight host material may contain only one kind of condensed ring-containing aromatic hydrocarbon group, or may contain two or more kinds thereof, but since the synthesis of the low-molecular-weight host material is easy, one is preferable. To 5 types, more preferably 1 to 3 types, and still more preferably 1 type.
In the low molecular weight host material, examples and preferable ranges of the substituents which the condensed ring-containing aromatic hydrocarbon group may have are preferable examples and preferable ranges of the substituents which the condensed ring-containing aromatic hydrocarbon may have. Same as range.

[Compound Represented by Formula (FH)]
The low molecular weight host material is preferably a compound represented by formula (FH), because long-term deterioration of the light emitting device of the present embodiment is further suppressed.

n ^1H is generally an integer of 10 or less, and is preferably an integer of 7 or less, more preferably an integer of 5 or less, because the compound represented by the formula (FH) can be easily synthesized. It is preferably an integer of 3 or less. Further, n ^1H is preferably an integer of 1 or more because long-term deterioration of the light emitting device of this embodiment is further suppressed.

In Ar ^1H , the substituent which the condensed ring-containing aromatic hydrocarbon group may have is a substituent other than an aryl group and a monovalent heterocyclic group, and preferably a halogen atom, an alkyl group or a cycloalkyl group. It is a group, an alkoxy group, a cycloalkoxy group or a substituted amino group, more preferably an alkyl group or a cycloalkyl group, and these groups may further have a substituent.
Examples and preferred ranges of the substituted amino group in the substituent which the condensed ring-containing aromatic hydrocarbon group may have are the examples of the substituted amino group in the substituent which the condensed ring-containing aromatic hydrocarbon may have. And the same as the preferable range.
Examples of the substituent which the condensed ring-containing aromatic hydrocarbon group may have and the substituent which the condensed ring-containing aromatic hydrocarbon may further have are the substituents which the condensed ring-containing aromatic hydrocarbon may have. Are the same as the examples and preferable ranges of the substituents which may further have.

R ^1H is preferably an aryl group which may have a substituent, because long-term deterioration of the light emitting device of the present embodiment is further suppressed.
Examples and preferred ranges of the aryl group and the monovalent heterocyclic group for R ^1H are, respectively, examples of the aryl group and the monovalent heterocyclic group in the substituent which the condensed ring-containing aromatic hydrocarbon may have, and It is the same as the preferred range.
Examples and preferable ranges of the substituents that R ^1H may have include examples and preferable ranges of the substituents that the condensed ring-containing aromatic hydrocarbon may further have. Is the same.

Examples of the low molecular weight host material include compounds represented by the following formulas and compounds described in Examples. These compounds may have a substituent. In the formula, Z ¹ represents an oxygen atom or a sulfur atom. When a plurality of Z ^1's are present, they may be the same or different.

(Polymer host material)
The polystyrene equivalent number average molecular weight of the polymer host material is preferably 5×10 ³ to 1×10 ⁶ , more preferably 1×10 ^{4 to} 5×10 ⁵ , and further preferably 2×10 ⁴ to. It is 2×10 ⁵ . The polystyrene equivalent weight average molecular weight of the polymer host material is preferably 1×10 ⁴ to 2×10 ⁶ , more preferably 2×10 ⁴ to 1×10 ⁶ , and further preferably 5×10 ⁴ to. It is 5×10 ⁵ .
The polymer host material may be any of block copolymers, random copolymers, alternating copolymers, and graft copolymers, and may be other embodiments, but a plurality of types of raw material monomers may be used. It is preferably a copolymerized copolymer.
The polymer host material is a condensed ring skeleton in which only 3 benzene rings are condensed, and an aromatic hydrocarbon having a condensed ring skeleton in which 3 or more benzene rings are condensed together directly connects to the carbon atoms constituting the condensed ring skeleton. It is preferably contained as a group (fused ring-containing aromatic hydrocarbon group) excluding one or more hydrogen atoms to be bonded, and this group may have a substituent.
The polymer host material preferably contains a condensed ring-containing aromatic hydrocarbon group in the main chain of the polymer compound because the polymer host material further suppresses long-term deterioration of the light emitting device of the present embodiment. A group in which two hydrogen atoms directly bonded to carbon atoms constituting the condensed ring skeleton are removed from an aromatic hydrocarbon having a condensed ring skeleton in which only three or more benzene rings are condensed in the chain (divalent condensation) More preferably, it contains a ring-containing aromatic hydrocarbon group). This group may have a substituent.
In the polymer host material, the condensed ring-containing aromatic hydrocarbon group has one or more hydrogen atoms (preferably, one or more hydrogen atoms) from the compound represented by the formula (FH) because the long-term deterioration of the light emitting device of the present embodiment is further suppressed. It is preferably 5 or less, more preferably 1 to 3, and even more preferably 2).
In the polymer host material, the content of the condensed ring-containing aromatic hydrocarbon group contained in the polymer compound is usually 0.1 mol with respect to the total content of all structural units contained in the polymer compound. % To 100 mol %, and long-term deterioration of the light emitting device of the present embodiment is further suppressed. Therefore, it is preferably 1 mol% to 100 mol %, more preferably 10 mol% to 100 mol %. , And more preferably 30 mol% to 100 mol %.
The polymer host material may contain only one kind of fused ring-containing aromatic hydrocarbon group or may contain two or more kinds thereof, but it is preferable to use one kind because the polymer host material can be easily synthesized. To 5 types, more preferably 1 to 3 types, and still more preferably 1 type.
In the polymer host material, examples and preferable ranges of the substituents that the condensed ring-containing aromatic hydrocarbon group may have include examples and preferable ranges of the substituents that the condensed ring-containing aromatic hydrocarbon may have. Same as range.

The polymer host material may include a constitutional unit other than the condensed ring-containing aromatic hydrocarbon group in the polymer compound, and the polymer compound may have a constitutional unit other than the condensed ring-containing aromatic hydrocarbon group in the main chain of the polymer compound. It preferably contains a structural unit.
Examples of the constituent unit other than the condensed ring-containing aromatic hydrocarbon group include an aromatic hydrocarbon group (preferably an arylene group) other than the condensed ring-containing aromatic hydrocarbon group and a heterocyclic group (preferably a divalent heterocyclic group). Group) and a group obtained by removing one or more hydrogen atoms from the aromatic amine compound (preferably a group obtained by removing two hydrogen atoms), and these groups may have a substituent. The examples and preferred ranges of the substituents are the same as the examples and preferred ranges of the substituents which the fused ring-containing aromatic hydrocarbon may have.
In the polymer host material, a condensed ring-containing aromatic hydrocarbon group contained in the polymer compound, an aromatic hydrocarbon group other than the condensed ring-containing aromatic hydrocarbon group, a heterocyclic group, and a hydrogen atom from an aromatic amine compound. The total content of groups excluding one or more is usually 1 mol% to 100 mol% with respect to the total content of all structural units contained in the polymer compound. Since long-term deterioration is further suppressed, it is preferably 50 mol% to 100 mol%, more preferably 70 mol% to 100 mol%.
The polymer host material may include only one type of structural unit other than the condensed ring-containing aromatic hydrocarbon group in the polymer compound, or may include two or more types thereof.

<Guest material>
The aromatic amine compound includes a skeleton in which an aromatic hydrocarbon group or an aromatic heterocyclic group is substituted with at least one of an amino group and a substituted amino group (hereinafter, also referred to as “aromatic amine skeleton”). Means a compound. The aromatic amine skeleton is preferably a skeleton in which one or more substituted amino groups are substituted on an aromatic hydrocarbon group or an aromatic heterocyclic group, because long-term deterioration of the light emitting device of this embodiment is further suppressed. It is more preferred that the aromatic hydrocarbon group has a skeleton in which one or more substituted amino groups are substituted.
The examples and preferred ranges of the substituted amino group in the aromatic amine compound are the same as the examples and preferred ranges of the substituted amino group in the substituent that the fused ring-containing aromatic hydrocarbon may have.

The aromatic amine compound may contain only one type of substituted amino group or two or more types of substituted amino groups in the compound. In addition, the aromatic amine compound may contain only one of an amino group and a substituted amino group in the compound, may contain only one each, and may contain two or more each. You may stay.
The aromatic amine compound may contain only one kind of aromatic amine skeleton or two or more kinds thereof in the compound. Further, the aromatic amine compound may include only one aromatic amine skeleton in the compound, or may include two or more aromatic amine skeletons.

In the aromatic amine skeleton, the number of amino groups substituted with an aromatic hydrocarbon group or an aromatic heterocyclic group is usually 0 to 10, preferably 0 to 5, The number is preferably 0 to 3, and more preferably 0.
In the aromatic amine skeleton, the number of substituted amino groups substituted with an aromatic hydrocarbon group or an aromatic heterocyclic group is usually 1 to 10 and more long-term deterioration of the light emitting device of this embodiment is more likely to occur. Since it is suppressed, it is preferably 1 to 7, more preferably 1 to 5, and still more preferably 1 to 3.
In the aromatic amine skeleton, the total number of amino groups and substituted amino groups substituted with an aromatic hydrocarbon group or an aromatic heterocyclic group is usually 1 to 10, and the light emitting device of the present embodiment Since the long-term deterioration of is further suppressed, it is preferably 1 to 7, more preferably 1 to 5, and still more preferably 1 to 3.
In the aromatic amine compound, the aromatic hydrocarbon group is preferably a monocyclic or bicyclic to 6-ring aromatic hydrocarbon, because long-term deterioration of the light emitting device of the present embodiment is further suppressed. , A group excluding one or more hydrogen atoms directly bonded to carbon atoms forming a ring, and more preferably a 3-ring to 5-cyclic aromatic hydrocarbon, directly bonded to a carbon atom forming a ring. A group excluding one or more hydrogen atoms, more preferably one or more hydrogen atoms directly bonded to carbon atoms forming a ring from anthracene, phenanthrene, fluorene, benzoanthracene, benzophenanthrene, benzofluorene or pyrene. Is particularly preferable, and a group in which one or more hydrogen atoms directly bonded to carbon atoms constituting the ring are removed from benzoanthracene, benzophenanthrene, or pyrene is particularly preferable. You may have.
In the aromatic amine compound, the aromatic heterocyclic group is, for example, a monocyclic or bicyclic to 7-cyclic aromatic heterocyclic group among the heterocyclic compounds exemplified in the above-mentioned heterocyclic group. A group obtained by removing one or more hydrogen atoms directly bonded to atoms constituting a ring from the formula compound is preferable, and a monocyclic or bicyclic to 6-ring aromatic heterocyclic compound is preferably used to form a ring. Is a group excluding one or more hydrogen atoms that are directly bonded to the atoms that form, and more preferably hydrogen that is directly bonded to the atoms that form the ring from a tricyclic to pentacyclic aromatic heterocyclic compound. A group in which one or more atoms are removed, and more preferably a ring is formed from dibenzofuran, dibenzothiophene, carbazole, azaanthracene, diazaanthracene, azaphenanthrene, diazaphenanthrene, benzocarbazole, benzonaphthofuran or benzonaphthothiophene. It is a group excluding one or more hydrogen atoms directly bonded to the constituent atoms, and these groups may have a substituent.
In the aromatic amine compound, the substituent that the aromatic hydrocarbon group and the aromatic heterocyclic group may have is a substituent other than an amino group and a substituted amino group, preferably a halogen atom, an alkyl group, A cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or a monovalent heterocyclic group, more preferably an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and further preferably It is an alkyl group or a cycloalkyl group, and these groups may further have a substituent.
In the aromatic amine compound, examples and preferred ranges of the aryl group and the monovalent heterocyclic group in the substituent which the aromatic hydrocarbon group and the aromatic heterocyclic group may have are only when the benzene ring is 3 It is the same as the examples and preferable ranges of the aryl group and the monovalent heterocyclic group in the substituent which the aromatic hydrocarbon condensed by one or more may have.
In the aromatic amine compound, examples and preferable ranges of the substituents which the aromatic hydrocarbon group and the aromatic heterocyclic group may further have are as follows. It is the same as the examples and preferable ranges of the substituents which the substituents which the condensed aromatic hydrocarbon may have may further have.

The guest material may further contain a compound other than the aromatic amine compound, but since the long-term deterioration of the light emitting device of the present embodiment is further suppressed, the guest material preferably contains the aromatic amine compound as a main component. The content ratio of the aromatic amine compound in the guest material may be, for example, 10% by mass or more, and the long-term deterioration of the light emitting device of the present embodiment is further suppressed. The above is more preferable, 70% by mass or more is further preferable, 90% by mass or more is particularly preferable, 95% by mass or more is particularly preferable, and may be 100% by mass.
The guest material may contain only one kind of aromatic amine compound, or may contain two or more kinds thereof. When the guest material further contains a compound other than the aromatic amine compound, the guest material may contain only one kind of the compound other than the aromatic amine compound, or may contain two or more kinds thereof.

The aromatic amine compound may be a high molecular compound (hereinafter, also referred to as “high molecular guest material”) or a low molecular compound (hereinafter, also referred to as “low molecular guest material”). Guest materials are preferred.

(Low molecular weight guest material)
The molecular weight of the low molecular weight guest material 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 . Yes, and more preferably 4×10 ² to 1×10 ³ .
The total number of amino groups and substituted amino groups contained in the low-molecular-weight guest material is usually 1 to 20, which is more preferable because long-term deterioration of the light emitting device of the present embodiment is further suppressed. The number is 15, more preferably 1 to 10, further preferably 1 to 5, and particularly preferably 1 to 3.
The total number of amino groups contained in the low molecular weight guest material is usually 0 to 10, preferably 0 to 5, more preferably 0 to 3, and further preferably 0. It is an individual.
The total number of substituted amino groups contained in the low molecular weight guest material is usually 1 to 20, which is preferably 1 to 15 because long-term deterioration of the light emitting device of the present embodiment is further suppressed. Yes, more preferably 1 to 10, more preferably 1 to 5, and particularly preferably 1 to 3.
The low molecular weight guest material may contain only one type of substituted amino group, or may contain two or more types, but it is preferably 1 type to 10 types because the synthesis of the low molecular weight host material is easy. , More preferably 1 to 5 types, still more preferably 1 to 3 types, and particularly preferably 1 type.
The total number of aromatic amine skeletons contained in the low molecular weight guest material is usually 1 to 10 and is preferably 1 to 7 because long-term deterioration of the light emitting device of the present embodiment is further suppressed. Yes, it is more preferably 1 to 5, still more preferably 1 to 3, and particularly preferably 1.
The low molecular weight guest material may contain only one kind of aromatic amine skeleton, or may contain two or more kinds thereof, but it is preferable to use 1 to 5 kinds because it is easy to synthesize the low molecular weight host material. Yes, more preferably 1 to 3 types, and still more preferably 1 type.

[Compound Represented by Formula (FB)]
The low molecular weight guest material is preferably a compound represented by the formula (FB), because long-term deterioration of the light emitting device of the present embodiment is further suppressed.

n ^1B is usually an integer of 1 or more and 10 or less, and is preferably an integer of 1 or more and 7 or less, more preferably 1 or more and 5 or less because the compound represented by the formula (FB) can be easily synthesized. It is the following integers, and more preferably 1 or more and 3 or less.

Ar ^1B is preferably an aromatic hydrocarbon group which may have a substituent, because long-term deterioration of the light emitting device of the present embodiment is further suppressed.
Examples and preferable ranges of the aromatic hydrocarbon group and aromatic heterocyclic group in Ar ^1B are the same as the examples and preferable ranges of the aromatic hydrocarbon group and aromatic heterocyclic group in the aromatic amine compound, respectively.
Examples and preferred ranges of the substituents that Ar ^1B may have are the same as the examples and preferred ranges of the substituents that the aromatic hydrocarbon group and the aromatic heterocyclic group in the aromatic amine compound may have. Is.

R ^1B is preferably a substituted amino group, because it further suppresses long-term deterioration of the light emitting device of the present embodiment, and this group may further have a substituent.
Examples and preferred ranges of the substituted amino group in R ^1B are the same as examples and preferred ranges of the substituted amino group in the aromatic amine compound.
Examples and preferred ranges of the substituent that R ^1B may have include the substituent which the aromatic hydrocarbon group and the aromatic heterocyclic group in the aromatic amine compound may further have. The same as the examples and preferable ranges of the good substituents.

Examples of the low molecular weight guest material include compounds represented by the following formulas and compounds described in Examples. These compounds may have a substituent. In the formula, Z ¹ has the same meaning as described above.

(Polymer guest material)
The preferable ranges of the polystyrene reduced number average molecular weight and the weight average molecular weight of the polymer guest material are the same as the polystyrene reduced number average molecular weight and the weight average molecular weight of the polymer host material, respectively.
The polymer guest material may be any one of a block copolymer, a random copolymer, an alternating copolymer, a graft copolymer, and may be other embodiments, but it is possible to use a plurality of kinds of raw material monomers. It is preferably a copolymerized copolymer.
The polymer guest material can be referred to as a polymer compound including a constitutional unit having an aromatic amine skeleton. The polymer guest material preferably contains an aromatic amine skeleton in the main chain of the polymer compound, because long-term deterioration of the light emitting device of the present embodiment is further suppressed.
In the polymer guest material, since the aromatic amine skeleton further suppresses long-term deterioration of the light emitting device of this embodiment, one or more hydrogen atoms (preferably 5 or less hydrogen atoms) from the compound represented by the formula (FB) is used. And more preferably 1 to 3 and even more preferably 2).
In the polymer guest material, the content of the aromatic amine skeleton contained in the polymer compound is usually 0.1 mol% to 100 mol with respect to the total content of all structural units contained in the polymer compound. %, since the long-term deterioration of the light emitting device of the present embodiment is further suppressed, it is preferably 1 mol% to 100 mol%, more preferably 5 mol% to 100 mol%, and further preferably It is 10 mol% to 100 mol %.
In the polymer guest material, the polymer compound may contain only one kind of aromatic amine skeleton or may contain two or more kinds thereof, but since the polymer guest material is easily synthesized, it is preferable. It is 1 to 5 types, more preferably 1 to 3 types, and further preferably 1 type.
In the polymer guest material, examples and preferred ranges of the substituent that the aromatic amine skeleton may have are the substituents that the aromatic hydrocarbon group and the aromatic heterocyclic group of the aromatic amine compound may have. It is the same as the examples and preferable range of the group.

In the polymer guest material, the polymer compound may contain a constituent unit other than the aromatic amine skeleton, and it is preferable that the main chain of the polymer compound contains a constituent unit other than the aromatic amine skeleton.
Examples of the structural unit other than the aromatic amine skeleton include an aromatic hydrocarbon group (preferably an arylene group) and a heterocyclic group (preferably a divalent heterocyclic group), and these groups have a substituent. You may have. The examples and preferred ranges of the substituents are the same as the examples and preferred ranges of the substituents which the fused ring-containing aromatic hydrocarbon may have.
In the polymer guest material, the total content of the aromatic amine skeleton, the aromatic hydrocarbon group and the heterocyclic group contained in the polymer compound is relative to the total content of all structural units contained in the polymer compound. It is usually 1 mol% to 100 mol%, and long-term deterioration of the light emitting device of the present embodiment is further suppressed. Therefore, it is preferably 50 mol% to 100 mol%, more preferably 70 mol%. ~100 mol%.
In the polymer guest material, the polymer compound may include only one type of structural unit other than the aromatic amine skeleton, or may include two or more types of structural units.

<Amount of chromium atoms contained in guest material (C ¹ )>
In the composition for a light emitting device of the present embodiment, the amount (C ¹ ) of chromium atoms contained in the guest material is usually 0 mass ppb or more and 2500 mass ppb or less with respect to the total amount of the guest material. Note that the phrase “the amount of chromium atoms contained in the guest material” does not mean that the guest material contains chromium atoms, and the guest material may or may not contain chromium atoms. Good. In the guest material of the present embodiment, the amount of chromium atoms is preferably 1000 mass ppb or less, more preferably 500 mass ppb or less, because long-term deterioration of the light emitting device of the present embodiment is further suppressed. It is preferably 250 mass ppb or less, particularly preferably 100 mass ppb or less, particularly preferably 50 mass ppb or less, particularly preferably 25 mass ppb or less, and particularly preferably 15 mass ppb or less. It is particularly preferably 10 mass ppb or less. In the guest material of the present embodiment, the amount of chromium atoms may be, for example, 0.01 mass ppb or more, 0.05 mass ppb or more, and 0.1 mass ppb or more. It may be 0.5 mass ppb or more, 1 mass ppb or more, and 2 mass ppb or more.

As for the amount (C ¹ ) of chromium atoms contained in the guest material of the present embodiment, when the guest material of the present embodiment is one type, the amount of chromium atoms of the one type of guest material becomes C ¹ , When the guest material in the form is composed of a plurality of types of compounds having different amounts of chromium atoms, C ¹ is calculated according to the amount of chromium atoms of the plurality of types of compounds and the mass ratio of each compound. A specific method of calculating C ¹ will be described using Comparative Example CD1 and Example D1 described later.

First, in Comparative Example CD1, since the amount of chromium atoms in the compound EM2 measured by the ICP/MS method is not more than the detection limit, C ¹ is 0 mass ppb.

Next, in Example D1, the amounts of chromium atoms of Compound EM1 and Compound EM2 measured by the ICP/MS method are 27 mass ppb and below the detection limit (that is, 0 mass ppb), respectively. Further, the mass ratio of the compound EM1 and the compound EM2 is compound EM1: compound EM2=1:9.
Therefore, C ¹ in Example D1 can be calculated from the amount of chromium atoms contained in the compound EM1 and the compound EM2 and the charged amount thereof, and is calculated as follows.
C ¹ ={27×1/(1+9)}+{0×9/(1+9)}=2.7 mass ppb

Similarly, C ¹ in Example D3 is 0 mass ppb.

<Amount of Chromium Atoms in Host Material (C ^H )>
In the composition for a light emitting device of the present embodiment, the amount of chromium atoms ( ^CH ) contained in the host material is usually 0 mass ppb or more and 14500 mass ppb or less with respect to the total amount of the host material. The phrase "amount of chromium atoms contained in the host material" does not mean that the host material contains chromium atoms, and the host material may or may not contain chromium atoms. Good. In the host material of the present embodiment, the amount of chromium atoms is preferably 5000 mass ppb or less, more preferably 1450 mass ppb or less, because long-term deterioration of the light emitting device of the present embodiment is further suppressed. It is preferably 500 mass ppb or less, particularly preferably 145 mass ppb or less, particularly preferably 135 mass ppb or less, particularly preferably 125 mass ppb or less, and particularly preferably 70 mass ppb or less. It is particularly preferably 40 mass ppb or less. In the host material of the present embodiment, the amount of chromium atoms is preferably 0.01 mass ppb or more, more preferably 0.1 mass, because long-term deterioration of the light emitting device of the present embodiment is further suppressed. ppb or more, more preferably 0.5 mass ppb or more, particularly preferably 1 mass ppb or more, particularly preferably 3 mass ppb or more, particularly preferably 5 mass ppb or more, and particularly preferably It is preferably 10 mass ppb or more, and particularly preferably 11 mass ppb or more.

The specific calculation method of C ^{H can be obtained in} the same manner as the specific calculation method of C ¹ described above.
For example, C ^H in Comparative Example CD1 is 11 mass ppb. C ^H in Example D1 is 11 mass ppb. C ^H in Example D3 is 14.1 mass ppb.

<Method for reducing C ¹ and C ^H >
Examples of methods for reducing C ¹ and C ^H include purification.
For purification, 4th edition experimental chemistry course (1993, Maruzen), 5th edition experimental chemistry course (2007, Maruzen), new experimental chemistry course (1975, Maruzen), organic chemistry experiment tebiki (1988) , Kagaku Doujin) and the like.

Purification includes, for example, sublimation, extraction, reprecipitation, recrystallization, chromatography and adsorption.
For the purification of the low molecular weight guest material and the low molecular weight host material, the amount of chromium atoms can be further reduced, and therefore, sublimation, recrystallization, chromatography or adsorption is preferable, and sublimation or recrystallization is more preferable. Sublimation is preferred.
The purification of the polymer guest material and the polymer host material is preferably reprecipitation, chromatography or adsorption because the amount of chromium atoms can be further reduced.
When the purification is performed twice or more, those methods may be the same or different.

In sublimation, the degree of vacuum and the sublimation temperature may be appropriately set according to the material to be sublimated. The degree of vacuum is preferably 1×10 ⁻¹⁰ Pa to 1×10 ⁵ Pa, more preferably 1×10 ⁻⁷ Pa to 1×10 ² Pa, and further preferably 1×10 ⁻⁵ Pa to 1 Pa. And particularly preferably 1×10 ⁻⁴ Pa to 1×10 ⁻² Pa. The sublimation temperature is preferably −100° C. to 1000° C., more preferably 0° C. to 700° C., further preferably 100° C. to 500° C., and particularly preferably 200° C. to 350° C.

The extraction is preferably liquid separation or solid-liquid extraction with a Soxhlet extractor.

Examples of the solvent used for extraction include alcohol solvents such as methanol, ethanol, propanol, ethylene glycol, glycerin, 2-methoxyethanol, and 2-ethoxyethanol; diethyl ether, tetrahydrofuran (THF), dioxane, cyclopentylmethyl ether, diglyme. Ether-based solvent such as methylene chloride, chloroform, etc.; Halogen-based solvent such as methylene chloride, chloroform; Nitrile-based solvent such as acetonitrile and benzonitrile; Hydrocarbon-based solvent such as hexane, decalin, toluene, xylene, mesitylene; N,N-dimethylformamide, N , Amide solvents such as N-dimethylacetamide; acetone, dimethyl sulfoxide, and water. The solvent may be used alone or in combination of two or more.

The chromatography is preferably column chromatography.
As the packing material used for column chromatography, silica gel or alumina is preferable.
The example of the solvent used for chromatography is the same as the example of the solvent used for extraction.

The example of the solvent used for reprecipitation and recrystallization is the same as the example of the solvent used for extraction.

As the adsorption, treatment with an adsorbent is preferable. Further, the adsorbent is preferably activated carbon, silica gel, alumina or celite.
The treatment with the adsorbent is usually performed in a solvent. The example of the solvent used for the treatment with the adsorbent is the same as the example of the solvent used for the extraction.

<Composition for light emitting device>
The composition for a light emitting device of the present embodiment contains a host material and a guest material.
In the composition for a light emitting device of the present embodiment, each of the host material and the guest material may contain only one kind, or may contain two kinds or more.
In the composition for a light emitting device of this embodiment, the maximum peak wavelength of the emission spectrum of the host material at room temperature is preferably shorter than the maximum peak wavelength of the emission spectrum of the guest material at room temperature.
In the composition for a light emitting device of the present embodiment, the maximum peak wavelength of the emission spectrum of the host material at room temperature is preferably 300 nm or more and 500 nm or less, more preferably 330 nm or more and 480 nm or less, and further preferably 360 nm or more and 460 nm or less. Is.
In the composition for a light emitting device of the present embodiment, the maximum peak wavelength of the emission spectrum of the guest material at room temperature is preferably 380 nm or more and 500 nm or less, more preferably 400 nm or more and 490 nm or less, and further preferably 430 nm or more and 480 nm or less. Is.
The maximum peak wavelength of the emission spectrum of the host material and the guest material is obtained by dissolving the measurement object in an organic solvent such as xylene, toluene, chloroform, or tetrahydrofuran to prepare a dilute solution (1×10 ⁻⁶ mass% to 1×). ^10-3 mass %), and can be evaluated by measuring the PL spectrum of the dilute solution at room temperature. As the organic solvent that dissolves the measurement target, toluene or xylene is preferable.

In the composition for a light emitting device of the present embodiment, the total amount of chromium atoms contained in the host material and the chromium atoms contained in the guest material is 10 mass ppb or more and 135 mass ppb or less with respect to the total amount of the host material and the guest material. is there. In the composition for a light emitting device of the present embodiment, the total amount of chromium atoms contained in the host material and the chromium atoms contained in the guest material is long-term deterioration of the light emitting device of the present embodiment with respect to the total amount of the host material and the guest material. Is suppressed, it is preferably 10.1 mass ppb or more, more preferably 10.2 mass ppb or more, still more preferably 10.5 mass ppb or more, and particularly preferably 11.0 mass ppb or more. And particularly preferably 11.5 mass ppb or more, particularly preferably 12.0 mass ppb or more, and particularly preferably 12.5 mass ppb or more. In addition, in the composition for a light emitting device of the present embodiment, the total amount of chromium atoms contained in the host material and the chromium atoms contained in the guest material is smaller than that of the light emitting device of the present embodiment with respect to the total amount of the host material and the guest material. Since long-term deterioration is suppressed, it is preferably 130 mass ppb or less, more preferably 120 mass ppb or less, further preferably 115 mass ppb or less, particularly preferably 110 mass ppb or less, and particularly preferably It is 70 mass ppb or less, particularly preferably 40 mass ppb or less, particularly preferably 30 mass ppb or less, and particularly preferably 20 mass ppb or less.

The reason why the long-term deterioration of the light emitting element is suppressed in the present embodiment is considered as follows.
The aromatic compound contained as the host material in the composition for a light emitting device of the present embodiment has a condensed ring skeleton in which only three or more benzene rings are condensed. The present inventors believe that such a condensed ring skeleton electrically interacts with the aromatic amine compound contained in the guest compound. On the other hand, the present inventors believe that the aromatic amine compound contained as a guest material in the composition for a light emitting device of the present embodiment electrically interacts with the aromatic compound contained as a host material.
Then, the present inventors, in the composition for a light emitting device of the present embodiment, when the total amount of chromium atoms contained in the host material and the chromium atoms contained in the guest material exceeds a predetermined upper limit amount, the above-mentioned interaction is caused. On the other hand, the chromium atom has an adverse effect, resulting in deterioration of 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, or the charge of the light emitting device of the present embodiment. It is considered that the light emitting device of the present embodiment is accelerated in the long term because the balance is lost.
On the other hand, when the total amount of chromium atoms contained in the host material and chromium atoms contained in the guest material is at least a predetermined lower limit in the composition for a light emitting device of the present embodiment, the chromium atoms are The above-mentioned interaction is strengthened, and as a result, 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 is improved, or the charge balance of the light emitting device of the present embodiment is improved. Therefore, it is considered that long-term deterioration of the light emitting element of the present embodiment is suppressed.
Therefore, the present inventors based on the above idea, in the present embodiment, by the total amount of chromium atoms contained in the host material and chromium atoms contained in the guest material is a predetermined amount, long-term deterioration of the light emitting element. We believe that the effect of suppression will be obtained.

The total amount of chromium atoms contained in the host material and the chromium atoms contained in the guest material (mass ppb) is such that the mass ratio of the host material to the total mass of the host material and the guest material is ^WH , and the host material and the guest material are When the ratio of the mass of the guest material to the total mass of the above is W ¹ , it is represented by C ^{H WH} +C ¹ W ¹ .
^WH is usually 0.01 to 0.9999, and is preferably 0.30 to 0.999, and is preferably 0.50 to 0, since long-term deterioration of the light emitting device of the present embodiment is further suppressed. It is more preferably 0.995, further preferably 0.70 to 0.99, particularly preferably 0.85 to 0.95.
W ¹ is usually 0.0001 to 0.99, and is preferably 0.001 to 0.70, and 0.005 to 0, because long-term deterioration of the light emitting device of the present embodiment is further suppressed. It is more preferably 0.50, more preferably 0.01 to 0.30, and particularly preferably 0.05 to 0.15.

The W specific method for calculating the ^H and W ¹ with Comparative Example CD1 and Example D1 below, will be described.

First, in Comparative Example CD1, the mass ratio of the compound H2 (host material) and the compound EM2 (guest material) is compound H2:compound EM2=90:10.
Therefore, W ^H and W ¹ in the comparative example CD1 can be determined from the amount of the charge is determined as follows.
^WH =90/(90+10)=0.90
W ¹ =10/(90+10)=0.10.

In Example D1, the mass ratio of the compound H2, the compound EM1, and the compound EM2 is compound H2:compound EM1:compound EM2=90:1:9.
Therefore, W ^H and W ¹ in Example D1 may be determined from the amount of the charge is determined as follows.
^WH =90/(90+1+9)=0.90
W ¹ =(1+9)/(90+1+9)=0.10.

Similarly, ^{W H} and ^{W 1} in the embodiment D3 is calculated as follows.
^WH =(2+88)/(2+88+10)=0.90
W ¹ =10/(2+88+10)=0.10.

As described ^above, by calculating the C ^1, C ^{H, W 1} and ^{W H,} it can be calculated ^{C H W H + C 1 W} 1.

For example, C ^{H WH} +C ¹ W ¹ in Comparative Example CD1 is calculated as follows.
C ^{H WH} +C ¹ W ¹ =(11×0.90)+(0×0.10)=9.9 mass ppb

For example, C ^{H WH} +C ¹ W ¹ in Example D1 is calculated as follows.
C ^{H WH} +C ¹ W ¹ =(11×0.90)+(2.7×0.10)=10.2 mass pp

For example, C ^{H WH} +C ¹ W ¹ in Example D3 is calculated as follows.
C ^{H WH} +C ¹ W ¹ =(14.1×0.90)+(0×0.10)=12.7 mass pp

C ^{H WH} +C ¹ W ¹ is usually 10 mass ppb or more and 135 mass ppb or less. C ^{H WH} +C ¹ W ¹ is preferably not less than 10.1 mass ppb, more preferably not less than 10.2 mass ppb, and even more preferably, since long-term deterioration of the light emitting device of the present embodiment is suppressed. Is 10.5 mass ppb or more, particularly preferably 11.0 mass ppb or more, particularly preferably 11.5 mass ppb or more, particularly preferably 12.0 mass ppb or more, and further particularly preferably Is 12.5 mass ppb or more. Further, C ^{H WH} +C ¹ W ¹ is preferably 130 mass ppb or less, more preferably 120 mass ppb or less, and further preferably 115, because long-term deterioration of the light emitting element of the present embodiment is suppressed. The mass is ppb or less, particularly preferably 110 mass ppb or less, particularly preferably 70 mass ppb or less, particularly preferably 40 mass ppb or less, particularly preferably 30 mass ppb or less, and particularly preferably It is preferably 20 mass ppb or less.

(Other ingredients)
The composition for a light emitting device of the present embodiment is selected from the group consisting of a host material, a guest material, a hole transport material, a hole injection material, an electron transport material, an electron injection material, a light emitting material, an antioxidant and a solvent. It may be a composition containing at least one kind of material described above. However, 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 host material and the guest material.
The composition for a light emitting device of the present embodiment further contains 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, an antioxidant and a solvent. In this case, the amount of chromium atoms contained in these is preferably reduced by the above-mentioned purification.

[ink]
A composition containing a host material, a guest material, and a solvent (hereinafter referred to as “ink”) is, for example, a spin coating method, a casting method, a microgravure coating method, a gravure coating method, a bar coating method, a roll. Of a light emitting element using a wet method such as a coating method, a wire bar coating method, a dip coating method, a spray coating method, a screen printing method, a flexographic printing method, an offset printing method, an inkjet printing method, a capillary coating method, and a nozzle coating method. It is suitable for production. The viscosity of the ink may be adjusted depending on the type of printing method, but is preferably 1 mPa·s to 20 mPa·s at 25°C.
The solvent contained in the ink is preferably a solvent capable of dissolving or uniformly dispersing the solid content in the ink. Examples of the solvent include chlorine-based solvents, ether-based solvents, aromatic hydrocarbon-based solvents, aliphatic hydrocarbon-based solvents, ketone-based solvents, ester-based solvents, polyhydric alcohol-based solvents, alcohol-based solvents, sulfoxide-based solvents, An amide solvent may be used.
In the ink, the blending amount of the solvent is usually 1000 parts by mass to 100000 parts by mass, when the total amount of the host material and the guest material is 100 parts by mass.
The solvent may be used alone or in combination of two or more.

[Hole transport material]
The hole transport material is classified into a low molecular weight compound and a high molecular weight compound, and is preferably a high molecular weight compound having a crosslinking group.
Examples of the polymer compound include polyvinylcarbazole and its derivative; polyarylene having an aromatic amine structure in its side chain or main chain and its derivative. The polymer compound may be a compound having an electron accepting moiety such as fullerene, tetrafluorotetracyanoquinodimethane, tetracyanoethylene and trinitrofluorenone bonded thereto.
In the composition for a light emitting device of the present embodiment, when the hole transport material is contained, the compounding amount of the hole transport material is usually 1 part by mass when the total of the host material and the guest material is 100 parts by mass. To 400 parts by mass.
The hole transport materials may be used alone or in combination of two or more.

[Electron transport material]
Electron transport materials are classified into low molecular weight compounds and high molecular weight compounds. The electron transport material may have a crosslinking group.
Examples of the low molecular weight compound include a metal complex having 8-hydroxyquinoline as a ligand, oxadiazole, anthraquinodimethane, benzoquinone, naphthoquinone, anthraquinone, tetracyanoanthraquinodimethane, fluorenone, diphenyldicyanoethylene and diphenoquinone. , And derivatives thereof.
Examples of the polymer compound include polyphenylene, polyfluorene, and derivatives thereof. The polymer compound may be doped with a metal.
In the composition for a light emitting device of the present embodiment, when an electron transporting material is contained, the compounding amount of the electron transporting material is usually 1 part by mass to 400 when the total of the host material and the guest material is 100 parts by mass. Parts by mass.
The electron transport materials may be used alone or in combination of two or more.

[Hole injection material and electron injection material]
The hole injection material and the electron injection material are classified into a low molecular compound and a high molecular compound, respectively. The hole injection material and the electron injection material may have a crosslinking group.
Examples of the low molecular weight compound include metal phthalocyanines such as copper phthalocyanine; carbon; metal oxides such as molybdenum and tungsten; 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; conductive materials such as polymers containing an aromatic amine structure in its main chain or side chain. Polymers are mentioned.
When the hole injection material and/or the electron injection material are contained in the composition for a light emitting device of the present embodiment, the compounding amounts of the hole injection material and the electron injection material are the total of the host material and the guest material, respectively. When it is 100 parts by mass, it is usually 1 part by mass to 400 parts by mass.
The hole injection material and the electron injection material may be used alone or in combination of two or more kinds.

-Ion Doping When the hole injecting material or the electron injecting material contains a conductive polymer, the electrical conductivity of the conductive polymer is preferably 1 x 10 ^-5 S/cm to 1 x 10 ³ S/cm. .. The conductive polymer can be doped with an appropriate amount of ions in order to set the electric conductivity of the conductive polymer in such a range. The types of ions to be doped are anions for hole injection materials and cations for electron injection materials. Examples of the anion include polystyrene sulfonate ion, alkylbenzene sulfonate ion, and camphor sulfonate 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.

[Luminescent material]
Light emitting materials are classified into low molecular weight compounds and high molecular weight compounds. The light emitting material may have a crosslinking group.
Examples of the low molecular weight compound include naphthalene and its derivatives, anthracene and its derivatives, perylene and its derivatives, and a triplet light emitting complex having iridium, platinum or europium as a central metal.
Examples of the polymer compound include an arylene group such as a phenylene group, a naphthalenediyl group, a fluorenediyl group, a phenanthrenediyl group, a dihydrophenanthrendiyl group, an anthracenediyl group and a pyrenediyl group; and two hydrogen atoms from an aromatic amine. Examples include aromatic amine residues such as removed groups; and polymer compounds containing a divalent heterocyclic group such as carbazolediyl group, phenoxazinediyl group and phenothiazinediyl group.

In the composition for a light emitting device of the present embodiment, when a light emitting material is contained, the content of the light emitting material is usually 0.1 parts by mass to 400 parts by mass when the total of the host material and the guest material is 100 parts by mass. Parts by mass.
The light emitting materials may be used alone or in combination of two or more.

[Antioxidant]
The antioxidant may be a compound that is soluble in the same solvent as the host material and the guest material and does not inhibit light emission and charge transport, and examples thereof include a phenol-based antioxidant and a phosphorus-based antioxidant.
In the composition for a light emitting device of the present embodiment, when an antioxidant is included, the compounding amount of the antioxidant is usually 0.001 part by mass when the total of the host material and the guest material is 100 parts by mass. 10 to 10 parts by mass.
The antioxidants may be used alone or in combination of two or more.

<Membrane>
The film contains the composition for a light emitting device of the present embodiment and is suitable as a light emitting layer in a light emitting device. The film can be formed by a wet method using ink, for example. In addition, the film can be produced by a dry method such as a vacuum vapor deposition method. Examples of the method of forming the film by a dry method include a method of vapor-depositing the composition for a light-emitting device of this embodiment and a method of co-evaporating a host material and a guest material.
The thickness of the film is usually 1 nm to 10 μm.

<Light emitting element>
The light emitting device of this embodiment contains the composition for a light emitting device described above.
The structure of the light emitting device of the present embodiment includes, for example, an anode, a cathode, and an organic layer provided between the anode and the cathode and containing the composition for a light emitting device of the present embodiment.

[Layer structure]
The layer containing the composition for a light emitting device of the present embodiment is usually one or more layers selected from the group consisting of a light emitting layer, a hole transport layer, a hole injection layer, an electron transport layer and an electron injection layer. , And preferably a light emitting layer. These layers include a light emitting material, a hole transport material, a hole injection material, an electron transport material, and an electron injection material, respectively. Each of these layers can be formed using a light-emitting material, a hole-transporting material, a hole-injecting material, an electron-transporting material, and an electron-injecting material by a method similar to that for forming the above-described film.

The light emitting element has a light emitting layer between an anode and a cathode. From the viewpoint of hole injecting property and hole transporting property, the light emitting element of the present embodiment preferably has at least one layer of a hole injecting layer and a hole transporting layer between the anode and the light emitting layer, From the viewpoint of the electron injection property and the electron transport property, it is preferable to have at least one layer of the electron injection layer and the electron transport layer between the cathode and the light emitting layer.

Examples of the material for the hole transport layer, the electron transport layer, the light emitting layer, the hole injection layer, and the electron injection layer include the above-described hole transport material, electron transport material, in addition to the composition for a light emitting device of the present embodiment. Examples thereof include a light emitting material, a hole injection material, an electron injection material and the like.

The material of the hole-transporting layer, the material of the electron-transporting layer, and the material of the light-emitting layer are the solvents used in the formation of the layer adjacent to the hole-transporting layer, the electron-transporting layer, and the light-emitting layer in the production of the light-emitting device, respectively. When soluble, it is preferred that the material have cross-linking groups in order to avoid dissolution of the material in the solvent. After forming each layer using a material having a crosslinking group, the layer can be insolubilized by crosslinking the crosslinking group.

In the light emitting device of the present embodiment, as a method for forming each layer such as a light emitting layer, a hole transport layer, an electron transport layer, a hole injection layer, and an electron injection layer, when a low molecular compound is used, for example, vacuum from powder is used. Examples include dry methods such as vapor deposition, and wet methods such as a method of forming a film from a solution or a molten state. When a polymer compound is used, examples thereof include a wet method such as a method of forming a film from a solution or a molten state. To be The order, the number and the thickness of the layers to be laminated are adjusted in consideration of, for example, luminous efficiency and long-term deterioration.

[Substrate/Electrode]
The substrate in the light emitting element may be any substrate that can form an electrode and does not chemically change when forming an organic layer, and is a substrate made of a material such as glass, plastic, or silicon. In the case of an opaque substrate, the electrode furthest from the substrate is preferably transparent or translucent.
Examples of the material of the anode include conductive metal oxides and semitransparent metals, and preferably indium oxide, zinc oxide, tin oxide; indium tin oxide (ITO), indium zinc oxide, etc. Conductive compound; a complex of silver, palladium, and copper (APC); NESA, gold, platinum, silver, and copper.
Examples of materials for the cathode include metals such as lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, aluminum, zinc and indium; alloys of two or more of them; Alloys of one or more with one or more of silver, copper, manganese, titanium, cobalt, nickel, tungsten, tin; and graphite and graphite intercalation 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.
Each of the anode and the cathode may have a laminated structure of two or more layers.

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

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

For example, one aspect of the present invention may relate to a method for producing a composition for a light emitting device containing a host material and a guest material.

<Production method (1)>
In one aspect, a method for producing a composition for a light emitting device includes a host material preparing step of preparing a host material containing a condensed ring-containing aromatic compound, a guest material preparing step of preparing a guest material containing an aromatic amine compound, The host material and the guest material are mixed at a compounding ratio such that the total amount of chromium atoms contained in the host material and the chromium atoms contained in the guest material is 10 mass ppb or more and 135 mass ppb or less to obtain a composition for a light emitting device. And a manufacturing step (hereinafter, also referred to as “manufacturing method (1)”) of the composition for a light emitting device.

In the production method (1), the host material preparation step includes a step (A-1) of preparing a condensed ring-containing aromatic compound in which chromium atoms are mixed, and a condensed ring-containing aromatic compound prepared in the step (A-1). (A-2) of purifying at least a part of the chromium atom to remove at least a part of the chromium atom.

In the production method (1), the content of chromium atom in the condensed ring-containing aromatic compound prepared in the step (A-1) is not particularly limited and may be, for example, 145 mass ppb or more, and 150 mass ppb or more. And may be 500 mass ppb or more, 1000 mass ppb or more, 5000 mass ppb or more, 10000 mass ppb or more, 50,000 mass ppb or more, It may be 100,000 mass ppb or more. Moreover, the upper limit of the content of chromium atoms in the condensed ring-containing aromatic compound prepared in the step (A-1) is not particularly limited, and the content may be, for example, 100,000,000 mass ppb or less, and 50,000,000 mass. It may be ppb or less, 10,000,000 mass ppb or less, 5,000,000 mass ppb or less, 1,000,000 mass ppb or less, or 500000 mass ppb or less.

Examples of the purification method in the step (A-2) include the methods exemplified in the above-mentioned <C ¹ and C ^H reduction method>.

The content of chromium atoms in the fused ring-containing aromatic compound after the step (A-2) is usually 0 mass ppb or more and 14500 mass ppb or less. The content of chromium atoms in the condensed ring-containing aromatic compound after the step (A-2) is preferably 5000 mass ppb or less, more preferably because the long-term deterioration of the light emitting device of the present embodiment is further suppressed. 1450 mass ppb or less, more preferably 500 mass ppb or less, particularly preferably 145 mass ppb or less, particularly preferably 135 mass ppb or less, and particularly preferably 125 mass ppb or less, and especially It is preferably 70 mass ppb or less, and particularly preferably 40 mass ppb or less. In addition, the content of chromium atoms in the condensed ring-containing aromatic compound after the step (A-2) is preferably 0.01 mass ppb or more because long-term deterioration of the light emitting device of the present embodiment is further suppressed. , More preferably 0.1 mass ppb or more, further preferably 0.5 mass ppb or more, particularly preferably 1 mass ppb or more, particularly preferably 3 mass ppb or more, and particularly more preferably 5 The mass is ppb or more, particularly preferably 10 mass ppb or more, and particularly preferably 11 mass ppb or more.

In the guest material preparing step, a preparing step (B-1) for preparing an aromatic amine compound in which chromium atoms are mixed and at least a part of the aromatic amine compound prepared in the step (B-1) are purified to obtain chromium. A step (B-2) of removing at least a part of the atoms may be included.

The content of chromium atom in the aromatic amine compound prepared in the step (B-1) is not particularly limited, and may be, for example, 25 mass ppb or more, 27 mass ppb or more, and 50 mass ppb or more. May be 100 mass ppb or more, may be 500 mass ppb or more, may be 1000 mass ppb or more, may be 5000 mass ppb or more, may be 10000 mass ppb or more. It may be 50,000 mass ppb or more, and 100,000 mass ppb or more. Moreover, the upper limit of the content of chromium atoms in the aromatic amine compound prepared in the step (B-1) is not particularly limited, and the content may be, for example, 10,000,000 mass ppb or less and 5,000,000 mass ppb or less. Or 1,000,000 mass ppb or less, or 500000 mass ppb or less.

The purification method in the step (B-2), include the method illustrated in the above <method of reducing C ¹ and C ^H>.

The content of chromium atoms in the aromatic amine compound after the step (B-2) is usually 0 mass ppb or more and 2500 mass ppb or less. The content of chromium atoms in the aromatic amine compound after the step (B-2) is preferably 1000 mass ppb or less, more preferably 500 mass, since long-term deterioration of the light emitting device of the present embodiment is further suppressed. ppb or less, more preferably 250 mass ppb or less, particularly preferably 100 mass ppb or less, particularly preferably 50 mass ppb or less, particularly preferably 25 mass ppb or less, particularly preferably still more preferably 25 mass ppb or less. It is 15 mass ppb or less, and particularly preferably 10 mass ppb or less. Further, the content of chromium atoms in the aromatic amine compound after the step (B-2) may be, for example, 0.01 mass ppb or more, may be 0.05 mass ppb or more, and may be 0. It may be 1 mass ppb or more, 0.5 mass ppb or more, 1 mass ppb or more, or 2 mass ppb or more.

In the production method (1), in the production step, the total amount of both is 10 mass ppb or more and 135 mass ppb or less in consideration of the amount of chromium atoms contained in the host material and the amount of chromium atoms contained in the guest material. The host material and guest material are mixed in a ratio. This makes it possible to obtain a composition for a light emitting device capable of suppressing long-term deterioration of the light emitting device.
In the manufacturing process of the manufacturing method (1), the method of mixing the host material and the guest material is not particularly limited. A method of mixing the host material and the guest material in a solid state, a method of mixing the host material and the guest material by co-evaporation, and the like.

The production method (1) may further include a host material measurement step of measuring the content of chromium atoms contained in the fused ring-containing aromatic compound. The production method (1) may further include a guest material measurement step of measuring the content of chromium atoms contained in the aromatic amine compound. The manufacturing method (1) preferably includes a host material measuring step and a guest material measuring step. In the host material measuring step and the guest material measuring step, the ICP/MS method is preferable as the method for measuring the content of chromium atoms.
In the manufacturing method (1), the host material measuring step and the guest material measuring step are preferably performed before the manufacturing step.
In the manufacturing method (1), the host material preparing step preferably includes a host material measuring step. In the manufacturing method (1), the guest material preparing step preferably includes a guest material measuring step.

<Production method (2)>
In another aspect, a method for producing a composition for a light emitting device, a host material preparing step of preparing a host material containing a condensed ring-containing aromatic compound, a determining step of determining a compounding ratio of a guest material to the host material, The total amount of chromium atoms contained in the host material and the chromium atoms contained in the guest material is 10 mass ppb or more and 135 mass ppb with respect to the total amount of the host material and the guest material when the aromatic amine compound is included and mixed with the host material in the above mixing ratio. Production of a composition for a light emitting device, which comprises the following guest material preparation step of preparing a guest material, and a production step of mixing a host material and a guest material in a compounding ratio to obtain a composition for a light emitting element A method (hereinafter, also referred to as “manufacturing method (2)”) may be used.

In the production method (2), the host material preparation step includes a step (A-1) of preparing a condensed ring-containing aromatic compound in which chromium atoms are mixed, and a condensed ring-containing aromatic compound prepared in the step (A-1). (A-2) of purifying at least a part of the chromium atom to remove at least a part of the chromium atom. The step (A-1) and the step (A-2) in the production method (2) may be the same steps as the step (A-1) and the step (A-2) in the above-mentioned production method (1). ..

In the manufacturing method (2), in the determining step, the compounding ratio may be determined according to the characteristics of the light emitting element and the like. In the determining step, for example, the compounding ratio may be determined based on the production result of the light emitting device using the test composition that uses a material similar to the above-mentioned host material and guest material, and the content of chromium atoms is 135 mass ppb. The compounding ratio may be determined based on the results of producing a light emitting device with a test composition exceeding the above.

In the manufacturing method (2), in the guest material preparing step, the chromium content in the host material prepared in the host material preparing step and the chromium content allowed in the guest material are determined by the compounding ratio determined in the determining step. The atomic content is determined. That is, it can be said that the guest material preparation step is a step of preparing a guest material having a chromium atom content within an allowable range.

In the production method (2), the guest material preparation step includes, for example, a preparation step (B-1) for preparing an aromatic amine compound in which chromium atoms are mixed and an aromatic amine compound prepared in the step (B-1). And purifying at least a part thereof to remove at least a part of chromium atoms (B-2). The step (B-1) and the step (B-2) in the manufacturing method (2) may be the same steps as the step (B-1) and the step (B-2) in the manufacturing method (1) described above. ..

In the manufacturing method (2), in the manufacturing step, the host material prepared in the host material preparing step and the guest material prepared in the guest material preparing step are mixed at the compounding ratio determined in the determining step. This makes it possible to obtain a composition for a light emitting device capable of suppressing long-term deterioration of the light emitting device.
The method of mixing the host material and the guest material in the manufacturing step of manufacturing method (2) may be the same as the method of mixing the host material and the guest material in the manufacturing step of manufacturing method (1).

The manufacturing method (2) may further include the host material measuring step described above. The manufacturing method (2) may further include the guest material measuring step described above. It is preferable that the manufacturing method (2) includes the host material measuring step and the guest material measuring step.
In the manufacturing method (2), the host material measuring step and the guest material measuring step described above are preferably performed before the manufacturing step.
In the manufacturing method (2), the host material preparation step preferably includes the host material measurement step described above. In the manufacturing method (2), the guest material preparing step preferably includes the guest material measuring step described above.

<Production method (3)>
In still another aspect, a method for producing a composition for a light emitting device includes a guest material preparing step of preparing a guest material containing an aromatic amine compound, a determining step of determining a compounding ratio of a host material to the guest material, and a condensation step. A total amount of chromium atoms contained in the host material and chromium atoms contained in the guest material is 10 mass ppb or more and 135 mass with respect to the total amount of the host material and the guest material when containing the ring-containing aromatic compound and mixed with the guest material in the above-mentioned mixing ratio. A composition for a light emitting device, which includes a host material preparation step of preparing a host material of ppb or less, and a production step of mixing a guest material and a host material in the above mixing ratio to obtain a composition for a light emitting element. Manufacturing method (hereinafter, also referred to as “manufacturing method (3)”).

In the production method (3), the guest material preparation step includes a step (B-1) of preparing an aromatic amine compound in which chromium atoms are mixed, and at least a part of the aromatic amine compound prepared in the step (B-1). And removing at least a part of chromium atoms (B-2). The step (B-1) and the step (B-2) in the production method (3) may be the same steps as the step (B-1) and the step (B-2) in the above-mentioned production method (1). ..

In the manufacturing method (3), in the determining step, the compounding ratio may be determined according to the characteristics of the light emitting element and the like. In the determining step, for example, the compounding ratio may be determined based on the production result of the light emitting device using the test composition that uses a material similar to the above-mentioned host material and guest material, and the content of chromium atoms is 135 mass ppb. The compounding ratio may be determined based on the results of producing a light emitting device with a test composition exceeding the above.

In the manufacturing method (3), in the host material preparing step, the chromium content in the guest material prepared in the guest material preparing step and the chromium content allowed in the host material are determined by the compounding ratio determined in the determining step. The atomic content is determined. That is, it can be said that the host material preparing step is a step of preparing a host material having a chromium atom content within an allowable range.

In the production method (3), the host material preparing step includes, for example, a preparing step (A-1) for preparing a condensed ring-containing aromatic compound in which chromium atoms are mixed, and a condensed ring containing prepared in the step (A-1). The step (A-2) of purifying at least a part of the aromatic compound to remove at least a part of the chromium atom may be included. The step (A-1) and the step (A-2) in the manufacturing method (3) may be the same as the step (A-1) and the step (A-2) in the manufacturing method (1) described above. ..

In the manufacturing method (3), in the manufacturing step, the guest material prepared in the guest material preparing step and the host material prepared in the host material preparing step are mixed at the compounding ratio determined in the determining step. This makes it possible to obtain a composition for a light emitting device capable of suppressing long-term deterioration of the light emitting device.
The method of mixing the host material and the guest material in the manufacturing step of the manufacturing method (3) may be the same as the method of mixing the host material and the guest material in the manufacturing step of the manufacturing method (1).

The manufacturing method (3) may further include the host material measuring step described above. The manufacturing method (3) may further include the guest material measuring step described above. It is preferable that the manufacturing method (3) includes the host material measuring step and the guest material measuring step.
In the manufacturing method (3), the host material measuring step and the guest material measuring step described above are preferably performed before the manufacturing step.
In the manufacturing method (3), the host material preparation step preferably includes the host material measurement step described above. In the manufacturing method (3), the guest material preparation step preferably includes the guest material measurement step described above.

<Production method (4)>
In still another aspect, a method for producing a composition for a light emitting device includes a host material preparing step of preparing a condensed ring-containing aromatic compound as a host material, and a guest material preparing step of preparing an aromatic amine compound as a guest material. A determination step of determining a compounding ratio of the host material and the guest material, and when the host material and the guest material are mixed at the compounding ratio described above, the chromium atoms and the guest material contained in the host material with respect to the total amount of the host material and the guest material. A condensed ring-containing aromatic compound and an aromatic amine compound at least partly purified so that the total amount of chromium atoms contained in is not less than 10 mass ppb and not more than 135 mass ppb. And a guest material containing an aromatic amine compound are mixed at the above mixing ratio to obtain a composition for a light emitting device, and a method for producing a composition for a light emitting device (hereinafter, referred to as “production method”). (4)”.).

In the production method (4), at least one of the condensed ring-containing aromatic compound prepared in the host material preparation step and the aromatic amine compound prepared in the guest material preparation step may contain a chromium atom. .. That is, the host material preparing step may be a step of preparing a condensed ring-containing aromatic compound in which chromium atoms are mixed, or the guest material preparing step may be a step of preparing an aromatic amine compound in which chromium atoms are mixed. ..

In the manufacturing method (4), in the determining step, the compounding ratio may be determined according to the characteristics of the light emitting element and the like. In the determining step, for example, the compounding ratio may be determined based on the production result of the light emitting device using the test composition that uses a material similar to the above-mentioned host material and guest material, and the content of chromium atoms is 135 mass ppb. The compounding ratio may be determined based on the production result of the light emitting device with the test composition exceeding the above, and a test in which the fused ring-containing aromatic compound and the aromatic amine compound prepared in the host material preparing step and the guest material preparing step are mixed. The compounding ratio may be determined based on the results of producing a light emitting device using the composition for use.

In the production method (4), in the purification step, at least a part of the fused ring-containing aromatic compound and the aromatic amine compound is purified. Examples of the purification method include the methods exemplified in the above <Method for reducing C ¹ and C ^H >. The purification step may be a step of purifying only one of the condensed ring-containing aromatic compound and the aromatic amine compound, or may be a step of purifying both the condensed ring-containing aromatic compound and the aromatic amine compound. ..

In the manufacturing method (4), in the manufacturing step, the fused ring-containing aromatic compound and the aromatic amine compound are mixed at the compounding ratio determined in the determination step. At this time, since the purification step has been performed, the total amount of chromium atoms contained in the host material and the chromium atoms contained in the guest material with respect to the total amount of the host material and guest material is 10 mass ppb or more and 135 mass ppb or less. This makes it possible to obtain a composition for a light emitting device capable of suppressing long-term deterioration of the light emitting device.
The method of mixing the host material and the guest material in the manufacturing step of manufacturing method (4) may be the same as the method of mixing the host material and the guest material in the manufacturing step of manufacturing method (1).

The manufacturing method (4) may further include the above-mentioned host material measuring step. The manufacturing method (4) may further include the guest material measuring step described above. The production method (4) preferably includes the host material measuring step and the guest material measuring step.
In the manufacturing method (4), it is preferable that the host material measuring step and the guest material measuring step are performed before the manufacturing step.
In the manufacturing method (4), the host material preparation step or the purification step preferably includes the host material measurement step described above. In the manufacturing method (2), the guest material preparation step or the purification step preferably includes the guest material measurement step described above.

Another aspect of the present invention relates to a method for manufacturing a light emitting device. This manufacturing method is a method for manufacturing a light emitting device including an anode, a cathode, and an organic layer provided between the anode and the cathode, and is manufactured by any of the above manufacturing methods (1) to (4). The method for producing a light emitting device may include a step of forming an organic layer from the composition for a light emitting device.
In the method of manufacturing the light emitting device of the present embodiment, as the method of forming the organic layer, for example, the same method as the above-described film formation can be used.
Further, in the method for manufacturing the light emitting element of the present embodiment, the manufacturing method described in the above section <Light emitting element> may be used.
Further, as the light emitting element in the method for manufacturing a light emitting element of the present embodiment, for example, the light emitting element described in the above section <Light emitting element> can be mentioned.

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 present example, the maximum peak wavelength of the emission spectrum of the compound was measured at room temperature with a spectrophotometer (FP-6500 manufactured by JASCO Corporation). A xylene solution in which the compound was dissolved in xylene at a concentration of about 0.8×10 ⁻⁴ mass% was used as a sample. UV light having a wavelength of 325 nm was used as the excitation light.

In this example, the amount of chromium atoms contained in the compound was measured by the ICP/MASS method.

<Compound H1 and Compound EM1>
Compound H1 was synthesized according to the method described in JP2011-105643A.
Compound EM1 was synthesized according to the method described in International Publication No. 2011/137922.

The HPLC area percentage value of the compound H1 was 99.5% or more. The amount of chromium atoms contained in the compound H1 ^{(C H)} was 150 mass ppb.
The HPLC area percentage value of the compound EM1 was 99.5% or more. The amount of chromium atoms (C ¹ ) contained in the compound EM1 was 27 mass ppb.

<Purification of Compound H1 (Synthesis of Compound H2)>
Compound H2 was obtained by repeating sublimation purification of compound H1. At the time of the sublimation purification, the degree of vacuum and ^{3 × 10 -3 Pa~5 × 10 -3} Pa, and the sublimation temperature of 250 ° C. to 300 ° C..
The HPLC area percentage value of the compound H2 was 99.5% or more. The amount of chromium atoms contained in the compound H2 ^{(C H)} was 11 mass ppb.

<Purification of Compound EM1 (Synthesis of Compound EM2)>
Compound EM2 was obtained by repeating sublimation purification of compound EM1 until the amount of chromium atoms contained in compound EM1 was below the detection limit (0 mass ppb). At the time of the sublimation purification, the degree of vacuum and ^{3 × 10 -3 Pa~5 × 10 -3} Pa, and the sublimation temperature of 250 ° C. to 300 ° C..
The HPLC area percentage value of the compound EM2 was 99.5% or more. The amount of chromium atoms (C ¹ ) contained in the compound EM2 was below the detection limit (0 mass ppb).

The maximum peak wavelength of the emission spectra of the compounds H1 and H2 was 421 nm. The maximum peak wavelength of the emission spectra of the compounds EM1 and EM2 was 454 nm.

<Example D1> Production and evaluation of light-emitting element D1 (formation of anode and hole injection layer)
An anode was formed by attaching an ITO film with a thickness of 45 nm to a glass substrate by a sputtering method. A film of ND-3202 (manufactured by Nissan Chemical Industries, Ltd.), which is a hole injection material, was formed on the anode by a spin coating method to a thickness of 35 nm. 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 hole transport layer)
The polymer compound HTL-1 was dissolved in xylene at a concentration of 0.7 mass %. Using the obtained xylene solution, a film having a thickness of 20 nm was formed on the hole injection layer by a spin coating method, and heated at 180° C. for 60 minutes on a hot plate in a nitrogen gas atmosphere to form a positive film. A pore transport layer was formed. The polymer compound HTL-1 is the polymer compound of Polymer Example 1 of International Publication No. 2014/102543.

(Formation of light emitting layer)
Compound H2, compound EM2, and compound EM1 (compound H2/compound EM2/compound EM1=90 mass%/9 mass%/1 mass%) were dissolved in toluene at a concentration of 2 mass %. Using the obtained toluene solution, a film having a thickness of 60 nm was formed on the hole transport layer by a spin coating method, and heated at 130° C. for 10 minutes in a nitrogen gas atmosphere to form a light emitting layer. ..

(Formation of cathode)
After depressurizing the substrate on which the light emitting layer was formed to 1.0×10 ⁻⁴ Pa or less in a vapor deposition machine, sodium fluoride was deposited on the light emitting layer as a cathode to a thickness of about 4 nm, and then on the sodium fluoride layer. Aluminum was vapor-deposited by about 80 nm. After vapor deposition, a light emitting device D1 was produced by sealing with a glass substrate.

(Evaluation of light emitting element)
EL light emission was observed by applying a voltage to the light emitting device D1. It was driven at a constant current at 150 mA/cm ² , and the time until the brightness reached 50% (hereinafter, also referred to as “LT50”) was measured.

<Examples D2 to D6 and Comparative Examples CD1 to CD2> Production and Evaluation of Light-Emitting Elements D2 to D6 and CD1 to CD2 “Compound H2, Compound EM2 and Compound EM1 (Compound H2/ Compound EM2/Compound EM1=90% by mass/9% by mass/1% by mass)” in the same manner as in Example D1 except that the materials shown in Table 1 were used in the material ratio shown in Table 1. Light emitting devices D2 to D6 and CD1 to CD2 were manufactured.
EL light emission was observed by applying a voltage to the light emitting devices D2 to D6 and CD1 to CD2. The LT50s of the light emitting devices D2 to D6 and CD1 to CD2 were measured.

The results of Examples D1 to D6 and Comparative Examples CD1 to CD2 are shown in Table 1. The relative value of LT50 of the light emitting elements D1 to D6 and CD1 when the LT50 of the light emitting element CD2 is 1.0 is shown.

According to the present invention, a composition useful for manufacturing a light emitting device in which long-term deterioration is suppressed is provided. The present invention is industrially useful because it has effects of resource saving, energy saving, etc. by manufacturing a light emitting device in which long-term deterioration is suppressed.

Claims (15)

A composition for a light emitting device in which a host material and a guest material are blended,
The host material contains an aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed,
The guest material includes an aromatic amine compound,
The composition for a light emitting device, wherein the total amount of chromium atoms contained in the host material and the chromium atoms contained in the guest material is 10 mass ppb or more and 135 mass ppb or less with respect to the total amount of the host material and the guest material. .. The composition for a light emitting device according to claim 1, wherein the aromatic compound is a compound represented by the formula (FH).

[In the formula,
n ^1H represents an integer of 0 or more.
Ar ^1H represents a group obtained by removing from the aromatic hydrocarbon having a condensed ring skeleton in which only 3 or more benzene rings are condensed, a hydrogen atom n ^1H or more directly bonded to a carbon atom constituting the condensed ring skeleton. This group may have a substituent. When a plurality of the substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atom to which they are bonded.
R ^1H represents 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 and may be bonded to each other to form a ring together with the atom to which they are bonded. When a plurality of R ^1H are present, they may be the same or different and may be bonded to each other to form a ring together with the atom to which each is bonded. ] The composition for a light emitting device according to claim 1, wherein the condensed ring skeleton is a condensed ring skeleton in which only 3 or more and 5 or less benzene rings are condensed. The composition for a light emitting device according to claim 3, wherein the condensed ring skeleton is an anthracene skeleton, a phenanthrene skeleton, a benzoanthracene skeleton, a benzophenanthrene skeleton, or a pyrene skeleton. The composition for a light emitting device according to claim 1, wherein the aromatic amine compound is a compound represented by the formula (FB).

[In the formula,
n ^1B represents an integer of 1 or more.
Ar ^1B represents an aromatic hydrocarbon group or an aromatic heterocyclic group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atom to which they are bonded.
R ^1B represents an amino 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 and may be bonded to each other to form a ring together with the atom to which they are bonded. When a plurality of R ^1B are present, they may be the same or different and may be bonded to each other to form a ring together with the atom to which they are bonded. ] 6. The method according to claim 1, further comprising 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, an antioxidant and a solvent. The composition for a light emitting device according to. An anode, a cathode, and a light emitting device having an organic layer provided between the anode and the cathode,
A light emitting device, wherein the organic layer is a layer containing the composition for a light emitting device according to any one of claims 1 to 6. A method for producing a composition for a light emitting device in which a host material and a guest material are blended,
A host material preparing step of preparing a host material containing an aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed;
A guest material preparation step of preparing a guest material containing an aromatic amine compound,
For a light emitting device, the host material and the guest material are mixed in a mixing ratio such that the total amount of chromium atoms contained in the host material and chromium atoms contained in the guest material is 10 mass ppb or more and 135 mass ppb or less. A manufacturing process for obtaining the composition,
A method for producing a composition for a light emitting device, comprising: The guest material preparation step,
A preparatory step (B-1) for preparing the aromatic amine compound in which chromium atoms are mixed,
A step (B-2) of purifying at least a part of the aromatic amine compound prepared in the step (B-1) to remove at least a part of the chromium atom;
The manufacturing method according to claim 8, further comprising: The host material preparation step,
A step (A-1) of preparing the aromatic compound in which chromium atoms are mixed,
A step (A-2) of purifying at least a part of the aromatic compound prepared in the step (A-1) to remove at least a part of the chromium atom;
The manufacturing method according to claim 8 or 9, which comprises: A method for producing a composition for a light emitting device in which a host material and a guest material are blended,
A host material preparing step of preparing a host material containing an aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed;
A determining step of determining a compounding ratio of the guest material with respect to the host material;
A total amount of chromium atoms contained in the host material and chromium atoms contained in the guest material is 10 mass with respect to the total amount of the host material and the guest material when the aromatic amine compound is mixed with the host material in the compounding ratio. a guest material preparation step of preparing a guest material, which is ppb or more and 135 mass ppb or less;
A step of mixing the host material and the guest material in the mixing ratio to obtain a composition for a light emitting device,
A method for producing a composition for a light emitting device, comprising: A method for producing a composition for a light emitting device in which a host material and a guest material are blended,
A guest material preparation step of preparing a guest material containing an aromatic amine compound,
A determining step of determining a compounding ratio of the host material to the guest material,
An aromatic compound having a condensed ring skeleton in which only 3 or more benzene rings are condensed, and when mixed with the guest material at the compounding ratio, the host material and a chromium atom contained in the host material with respect to the total amount of the guest material; A host material preparation step of preparing a host material, wherein the total amount of chromium atoms contained in the guest material is 10 mass ppb or more and 135 mass ppb or less;
A step of mixing the guest material and the host material in the mixing ratio to obtain a composition for a light emitting device,
A method for producing a composition for a light emitting device, comprising: A method for producing a composition for a light emitting device in which a host material and a guest material are blended,
A host material preparing step of preparing an aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed as a host material,
A guest material preparing step of preparing an aromatic amine compound as a guest material,
A determining step of determining a compounding ratio of the host material and the guest material,
When the host material and the guest material are mixed at the compounding ratio, the total amount of chromium atoms contained in the host material and the chromium atom contained in the guest material is 10 mass ppb with respect to the total amount of the host material and the guest material. A refining step of purifying at least a part of the aromatic compound and the aromatic amine compound so that the amount becomes 135 mass ppb or less.
A manufacturing step of obtaining a composition for a light emitting device by mixing the host material containing the aromatic compound and the guest material containing the aromatic amine compound at the compounding ratio,
A method for producing a composition for a light emitting device, comprising: A host material measuring step of measuring the content of chromium atoms contained in the aromatic compound,
A guest material measuring step of measuring the content of chromium atoms contained in the aromatic amine compound,
The manufacturing method according to claim 8, further comprising: An anode, a cathode, and an organic layer provided between the anode and the cathode, a method for manufacturing a light-emitting element,
A method for manufacturing a light emitting device, comprising the step of forming the organic layer with the composition for a light emitting device manufactured by the manufacturing method according to claim 8.