JP7132969B2 - Method for producing composition for light-emitting device and method for producing light-emitting device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a composition for a light-emitting device and a light-emitting device containing the same.

Light-emitting elements such as organic electroluminescence elements can be suitably used for displays and lighting, for example. 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.

WO2017/170313

However, long-term deterioration of a light-emitting element manufactured using the above composition is not always sufficiently suppressed.
Accordingly, 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 using the composition.

The present inventors have made intensive studies to solve the above problems, and as a result, found that magnesium atoms have a significant effect on long-term deterioration of a light-emitting element in a light-emitting element having an organic layer containing a specific composition. Further, the inventors have found that long-term deterioration of the light-emitting element can be suppressed by setting the amount of magnesium atoms to a specific amount, and have completed the present invention. Note that Patent Document 1 does not describe that the amount of magnesium atoms contained in the composition affects long-term deterioration of the light-emitting element.

［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］
前記水素原子及び炭素原子のみからなる芳香族化合物が式（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、０以上の整数を表す。
Ａｒ^１Ｂは、芳香族炭化水素環を有する化合物から、前記芳香族炭化水素環を構成する炭素原子に直接結合する水素原子ｎ^１Ｂ個以上を除いた基を表す。
Ｒ^１Ｂは、水素原子及び炭素原子のみからなる炭化水素基を表し、この基は、水素原子及び炭素原子のみからなる置換基を更に有していてもよい。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炭素原子とともに環を形成していてもよい。］
［６］
前記芳香族炭化水素環が、２環式～７環式の芳香族炭化水素環である、［５］に記載の発光素子用組成物。
［７］
前記芳香族炭化水素環が、ベンゾフルオレン環、ピレン環、フルオランテン環、ジベンゾフルオレン環、ペリレン環、ベンゾフルオランテン環、スピロビフルオレン環、ベンゾスピロビフルオレン環又はアセナフトフルオランテン環である、［６］に記載の発光素子用組成物。
［８］
前記水素原子及び炭素原子のみからなる炭化水素基が、アルキル基、シクロアルキル基又はアリール基（これらの基は、水素原子及び炭素原子のみからなる置換基を有していてもよい。）である、［５］～［７］のいずれかに記載の発光素子用組成物。
［９］
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］～［８］のいずれかに記載の発光素子用組成物。
［１０］
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］～［９］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。
［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、
水素原子及び炭素原子のみからなる芳香族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マグネシウム原子及び前記ゲスト材料に含まれるマグネシウム原子の総量が０質量ｐｐｂを超え１８０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。
［１２］
前記ゲスト材料準備工程が、
マグネシウム原子が混在した前記水素原子及び炭素原子のみからなる芳香族化合物を準備する準備工程（Ｂ－１）と、
前記工程（Ｂ－１）で準備した前記水素原子及び炭素原子のみからなる芳香族化合物の少なくとも一部を精製して、前記マグネシウム原子の少なくとも一部を除去する工程（Ｂ－２）と、
を含む、［１１］に記載の製造方法。
［１３］
前記ホスト材料準備工程が、
マグネシウム原子が混在した前記ベンゼン環のみが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工程（Ａ－１）と、
前記工程（Ａ－１）で準備した前記ベンゼン環のみが３個以上縮合した縮合環骨格を有する芳香族化合物の少なくとも一部を精製して、前記マグネシウム原子の少なくとも一部を除去する工程（Ａ－２）と、
を含む、［１１］又は［１２］に記載の製造方法。
［１４］
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、
水素原子及び炭素原子のみからなる芳香族化合物を含み、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マグネシウム原子及び前記ゲスト材料に含まれるマグネシウム原子の総量が０質量ｐｐｂを超え１８０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。
［１５］
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、
水素原子及び炭素原子のみからなる芳香族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マグネシウム原子及び前記ゲスト材料に含まれるマグネシウム原子の総量が０質量ｐｐｂを超え１８０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。
［１６］
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、
ゲスト材料として水素原子及び炭素原子のみからなる芳香族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マグネシウム原子及び前記ゲスト材料に含まれるマグネシウム原子の総量が０質量ｐｐｂを超え１８０質量ｐｐｂ以下となるように、前記ベンゼン環のみが３個以上縮合した縮合環骨格を有する芳香族化合物及び前記水素原子及び炭素原子のみからなる芳香族化合物の少なくとも一部を精製する精製工程と、
前記ベンゼン環のみが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前記ホスト材料と前記水素原子及び炭素原子のみからなる芳香族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。
［１７］
前記ベンゼン環のみが３個以上縮合した縮合環骨格を有する芳香族化合物に含まれるマグネシウム原子の含有量を測定するホスト材料測定工程と、
前記水素原子及び炭素原子のみからなる芳香族化合物に含まれるマグネシウ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、［１１］～［１６］のいずれかに記載の製造方法。
［１８］
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、
［１１］～［１７］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 [18].
[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 three or more benzene rings are condensed,
the guest material comprises an aromatic compound consisting only of hydrogen atoms and carbon atoms;
A composition for a light-emitting element, wherein the total amount of magnesium atoms contained in the host material and magnesium atoms contained in the guest material is more than 0 mass ppb and 180 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 element according to [1], wherein the aromatic compound having a condensed ring skeleton in which three or more benzene rings are condensed is a compound represented by formula (FH).

[In the formula,
^n1H represents an integer of 0 or more.
Ar ^1H is an aromatic hydrocarbon having a condensed ring skeleton in which only three or more benzene rings are condensed, and represents a group obtained by removing n ^1H or more hydrogen atoms directly bonded to the carbon atoms constituting the condensed ring skeleton, This group may have a substituent. When there are multiple such substituents, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded.
R ^1H represents an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. When there are multiple such substituents, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. When two or more 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 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 compound consisting only of hydrogen atoms and carbon atoms is a compound represented by formula (FB).

[In the formula,
n ^1B represents an integer of 0 or more.
Ar ^1B represents a group obtained by removing n ^1B or more hydrogen atoms directly bonded to carbon atoms constituting the aromatic hydrocarbon ring from a compound having an aromatic hydrocarbon ring.
R ^1B represents a hydrocarbon group consisting only of hydrogen atoms and carbon atoms, and this group may further have a substituent consisting only of hydrogen atoms and carbon atoms. When there are multiple such substituents, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. When multiple 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 carbon atom to which each is bonded. ]
[6]
The composition for a light emitting device according to [5], wherein the aromatic hydrocarbon ring is a bicyclic to heptacyclic aromatic hydrocarbon ring.
[7]
The aromatic hydrocarbon ring is a benzofluorene ring, pyrene ring, fluoranthene ring, dibenzofluorene ring, perylene ring, benzofluoranthene ring, spirobifluorene ring, benzospirobifluorene ring or acenaphthofluoranthene ring. , the composition for a light-emitting device according to [6].
[8]
The hydrocarbon group consisting only of hydrogen atoms and carbon atoms is an alkyl group, a cycloalkyl group or an aryl group (these groups may have substituents consisting only of hydrogen atoms and carbon atoms). , the composition for a light-emitting device according to any one of [5] to [7].
[9]
Any one of [1] to [8], 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 as described in 1.
[10]
A light-emitting element having an anode, a cathode, and 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 [9].
[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 preparation 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 compound consisting only of hydrogen atoms and carbon atoms;
The host material and the guest material are mixed at a compounding ratio such that the total amount of magnesium atoms contained in the host material and magnesium atoms contained in the guest material is more than 0 mass ppb and 180 mass ppb or less, and a light emitting device a manufacturing process for obtaining a composition for
A method for producing a composition for a light emitting device, comprising:
[12]
The guest material preparation step includes:
A preparatory step (B-1) of preparing an aromatic compound consisting only of hydrogen atoms and carbon atoms mixed with magnesium atoms;
a step (B-2) of purifying at least part of the aromatic compound consisting only of hydrogen atoms and carbon atoms prepared in the step (B-1) to remove at least part of the magnesium atoms;
The manufacturing method according to [11], comprising
[13]
The host material preparation step includes
A step (A-1) of preparing an aromatic compound having a condensed ring skeleton in which only three or more of the benzene rings mixed with magnesium atoms are condensed;
Purifying at least part of the aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed, prepared in the step (A-1), to remove at least part of the magnesium atoms (A -2) and
The manufacturing method according to [11] or [12], comprising
[14]
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 preparation 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 the compounding ratio of the guest material to the host material;
It contains an aromatic compound consisting only of hydrogen atoms and carbon atoms, and is contained in the magnesium atoms contained in the host material and the guest material relative to the total amount of the host material and the guest material when mixed with the host material in the above mixing ratio. a guest material preparation step of preparing a guest material in which the total amount of magnesium atoms exceeds 0 mass ppb and is 180 mass ppb or less;
a manufacturing step of mixing the host material and the guest material at the blending ratio to obtain a composition for a light-emitting element;
A method for producing a composition for a light emitting device, comprising:
[15]
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 compound consisting only of hydrogen atoms and carbon atoms;
a determination step of determining the compounding ratio of the host material to the guest material;
containing an aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed, and when mixed with the guest material at the compounding ratio, magnesium atoms contained in the host material relative to the total amount of the host material and the guest material, and a host material preparation step of preparing a host material in which the total amount of magnesium atoms contained in the guest material exceeds 0 mass ppb and is 180 mass ppb or less;
a manufacturing step of mixing the guest material and the host material at the blending ratio to obtain a composition for a light-emitting element;
A method for producing a composition for a light emitting device, comprising:
[16]
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 preparation 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 preparation step of preparing an aromatic compound consisting only of hydrogen atoms and carbon atoms as a guest material;
a determination step of determining the 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 magnesium atoms contained in the host material and the magnesium atoms contained in the guest material with respect to the total amount of the host material and the guest material is 0 mass ppb. Purification to purify at least a part of the aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed and the aromatic compound consisting only of hydrogen atoms and carbon atoms so that it exceeds 180 mass ppb process and
The host material containing an aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed and the guest material containing an aromatic compound consisting only of hydrogen atoms and carbon atoms are mixed at the compounding ratio. , a manufacturing process for obtaining a composition for a light-emitting device;
A method for producing a composition for a light emitting device, comprising:
[17]
A host material measuring step of measuring the content of magnesium atoms contained in the aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed;
a guest material measuring step of measuring the content of magnesium atoms contained in the aromatic compound consisting only of hydrogen atoms and carbon atoms;
The production method according to any one of [11] to [16], further comprising
[18]
A method for manufacturing a light-emitting device comprising an anode, a cathode, and an organic layer provided between the anode and the cathode,
A method for producing a light-emitting device, comprising forming the organic layer from the composition for a light-emitting device produced by the production method according to any one of [11] to [17].

ADVANTAGE OF THE INVENTION According to this invention, the composition useful for manufacture of the light emitting element by 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 the composition and the method for manufacturing the light-emitting device.

A preferred embodiment of this embodiment will be described in detail below.

<Description of common terms>
Terms commonly used in this specification have the following meanings unless otherwise specified.

"Room temperature" means 25°C.
Me is a methyl group, Et is an ethyl group, Bu is a butyl group, i-Pr is an isopropyl group, and t-Bu is a tert-butyl group.
A hydrogen atom may be a deuterium atom or a protium atom.

A “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 .
A "low-molecular-weight compound" means a compound having no molecular weight distribution and a molecular weight of 1×10 ⁴ or less.
A "structural unit" means a unit that exists at least one in a polymer compound.

The "alkyl group" may be either linear or branched. The number of carbon atoms in the linear alkyl group is generally 1-50, preferably 1-20, more preferably 1-10, not including the number of carbon atoms in the substituents. The number of carbon atoms in the branched alkyl group is usually 3-50, preferably 3-20, more preferably 4-10, not including the number of carbon atoms in the substituent. The alkyl group may have a substituent group, 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, 5-di-hexylphenyl)propyl group and 6-ethyloxyhexyl group.
The number of carbon atoms in the "cycloalkyl group" is usually 3-50, preferably 4-10, not including the number of carbon atoms in the substituents. A cycloalkyl group may have a substituent, and examples thereof include a cyclohexyl group and a methylcyclohexyl group.
The number of carbon atoms in the "alkylene group" is generally 1 to 20, preferably 1 to 15, more preferably 1 to 10, not including the number of carbon atoms in the substituent. The alkylene group may have a substituent, and examples thereof include methylene, ethylene, propylene, butylene, hexylene and octylene groups.
The number of carbon atoms in the "cycloalkylene group" is usually 3 or more and 20 or less, not including the number of carbon atoms in the substituents. The cycloalkylene group may have a substituent, such as a cyclohexylene group.

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

An "alkoxy group" may be either linear or branched. The straight-chain alkoxy group usually has 1 to 40 carbon atoms, preferably 1 to 10 carbon atoms, not including the carbon atoms of the substituents. The number of carbon atoms in the branched alkoxy group is usually 3-40, preferably 4-10, not including the number of carbon atoms in the substituents. Alkoxy groups may have substituents such as methoxy, ethoxy, isopropyloxy, butyloxy, hexyloxy, 2-ethylhexyloxy, 3,7-dimethyloctyloxy, and lauryl. An oxy group can be mentioned.
The number of carbon atoms in the "cycloalkoxy group" is usually 3-40, preferably 4-10, not including the number of carbon atoms in the substituents. A cycloalkoxy group may have a substituent, such as a cyclohexyloxy group.
The number of carbon atoms in the "aryloxy group" is usually 6-60, preferably 6-48, not including the number of carbon atoms in the substituents. The aryloxy group may have a substituent, and examples thereof include phenoxy, naphthyloxy, anthracenyloxy, and pyrenyloxy groups.

A “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 heterocyclic groups, an "aromatic heterocyclic group" is preferred, 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. A group obtained by removing p hydrogen atoms (p represents an integer of 1 or more) directly bonded to carbon atoms or heteroatoms 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 carbon atoms or heteroatoms constituting a ring from an aromatic heterocyclic compound is also referred to as a "p-valent aromatic heterocyclic group".
Examples of the "aromatic heterocyclic compound" include compounds in which the heterocycle itself exhibits aromaticity, such as azole, thiophene, furan, pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, and carbazole, and phenoxazine. , phenothiazine, benzopyran, and the like, compounds in which an aromatic ring is condensed to a heterocyclic ring, even if the heterocyclic ring itself does not exhibit aromaticity.
The number of carbon atoms in the heterocyclic group is generally 1-60, preferably 2-40, more preferably 3-20, not including the number of carbon atoms in the substituent. The number of heteroatoms in the heterocyclic group is generally 1-30, preferably 1-10, more preferably 1-3, not including the number of carbon atoms in the substituent.
The heterocyclic group may have a substituent, for example, monocyclic heterocyclic compounds (e.g. furan, thiophene, oxadiazole, pyrrole, diazole, triazole, tetrazole, pyridine, diazabenzene and triazine ), or polycyclic heterocyclic compounds (for example, bicyclic heterocyclic compounds such as azanaphthalene, diazanaphthalene, benzofuran, benzothiophene, indole, benzodiazole and benzothiadiazole; dibenzofuran , dibenzothiophene, dibenzoborol, dibenzosilol, 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; cyclic heterocyclic compounds; pentacyclic heterocyclic compounds such as dibenzocarbazole, indolocarbazole and indenocarbazole; hexacyclic heterocyclic compounds such as carbazolocarbazole, benzindolocarbazole and benzindenocarbazole compounds; and heptacyclic heterocyclic compounds such as dibenzoindolocarbazole.), groups in which one or more hydrogen atoms directly bonded to the atoms constituting the ring are removed, and these groups may have a substituent. Heterocyclic groups include groups in which multiple of these groups are bonded.

A "halogen atom" means 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). As the substituent of the amino group, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group is preferable. 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.
Substituted amino groups include, for example, dialkylamino groups, dicycloalkylamino groups and diarylamino groups.
Examples of amino groups include dimethylamino group, diethylamino group, diphenylamino group, bis(methylphenyl)amino group, and bis(3,5-di-tert-butylphenyl)amino group.

An "alkenyl group" may be either linear or branched. The straight-chain alkenyl group usually has 2 to 30 carbon atoms, preferably 3 to 20 carbon atoms, not including the carbon atoms of the substituents. The number of carbon atoms in the branched alkenyl group is usually 3-30, preferably 4-20, not including the number of carbon atoms in the substituents.
The number of carbon atoms in the "cycloalkenyl group" is usually 3-30, preferably 4-20, not including the number of carbon atoms in the substituents.
Alkenyl groups and cycloalkenyl groups may have substituents, for example, vinyl group, propenyl group, butenyl group, 3-butenyl group, 3-pentenyl group, 4-pentenyl group, 1-hexenyl group, 5 -hexenyl group, 7-octenyl group, and groups in which these groups have substituents.

An "alkynyl group" may be either linear or branched. The number of carbon atoms in the alkynyl group is usually 2-20, preferably 3-20, not including the carbon atoms of the substituents. The number of carbon atoms in the branched alkynyl group is generally 4-30, preferably 4-20, not including the carbon atoms of the substituents.
The number of carbon atoms in the "cycloalkynyl group" is usually 4-30, preferably 4-20, not including the carbon atoms of the substituents.
Alkynyl groups and cycloalkynyl groups may have substituents, for example, ethynyl group, propynyl group, butynyl group, pentynyl group, hexynyl group, 5-hexynyl group, and these groups have substituents groups.

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

The "substituent" includes, for example, a halogen atom, a cyano group, an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an amino group, a substituted amino group, Alkenyl groups, cycloalkenyl groups, alkynyl groups and cycloalkynyl groups are included. A substituent may be a bridging group. When a plurality of substituents are present, they may bond with each other to form a ring together with the atoms to which they are bonded, but preferably do not form a ring.

The "amount of magnesium atoms" can be measured by the ICP/MS method (inductively coupled plasma mass spectrometry). That is, the "amount of magnesium atoms" means the mass concentration of magnesium atoms measured by the ICP/MS method. Moreover, when the "amount of magnesium atoms" is "0 mass ppb", it means that the mass concentration of magnesium atoms is below the detection limit when measured by the ICP/MS method.

In the composition for a light emitting device of this embodiment, the host material means a material that physically, chemically or electrically interacts with the guest material. This interaction makes it possible to improve or adjust, for example, the emission properties, charge transport properties, or charge injection properties of the composition for a light emitting device of the present embodiment.
In the composition for a light-emitting element of the present embodiment, if the light-emitting material is explained as an example, the host material and the guest material electrically interact with each other, and by efficiently transferring electrical energy from the host material to the guest material, The guest material can be made to emit light more efficiently.

<Host material>
The host material includes an aromatic compound having a condensed ring skeleton in which three or more benzene rings are condensed. An aromatic compound having a condensed ring skeleton in which three or more benzene rings are condensed may contain only one kind of condensed ring skeleton in which three or more benzene rings are condensed, or may contain two or more kinds. You can In addition, the aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed may contain only one condensed ring skeleton in which three or more benzene rings are condensed, or two or more. may contain. 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 an "aromatic compound for host material".

In the condensed ring skeleton of the host material aromatic compound, the number of condensed benzene rings is usually 3 to 10, which is preferable because the long-term deterioration of the light emitting device of the present embodiment is further suppressed. is 3 to 7, more preferably 3 to 5, still more preferably 3 or 4.
The condensed ring skeleton of the host material aromatic compound can also be said to be a condensed ring carbon skeleton in which three or more benzene rings are condensed. The condensed 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 skeleton, since long-term deterioration of the light-emitting element of this embodiment is further suppressed. It is a skeleton or a pyrene skeleton, more preferably an anthracene skeleton.

The aromatic compound for the host material may be an aromatic hydrocarbon having a condensed ring skeleton in which three or more benzene rings are condensed (hereinafter also referred to as "condensed ring-containing aromatic hydrocarbon"), and the aromatic 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 substituted amino group. group, more preferably an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, still more preferably an aryl group or a monovalent heterocyclic group, particularly preferably an aryl group, The group may further have a substituent.
Among the substituents that the condensed ring-containing aromatic hydrocarbon may have, the aryl group is preferably a monocyclic or bicyclic to hexacyclic aromatic hydrocarbon directly attached to a carbon atom constituting the ring. A group excluding one or more bonding hydrogen atoms, more preferably a monocyclic or bicyclic to tetracyclic aromatic hydrocarbon having one or more hydrogen atoms directly bonded to the carbon atoms constituting the ring. is a group excluding, more preferably benzene, naphthalene, dihydrophenanthrene, fluorene or benzofluorene, excluding one or more hydrogen atoms directly bonded to the carbon atoms constituting the ring, particularly preferably a phenyl group or a naphthyl group, and these groups may have a substituent.
Among the substituents that the condensed ring-containing aromatic hydrocarbon may have, the monovalent heterocyclic group is preferably a monocyclic or bicyclic to hexacyclic heterocyclic compound to form a ring. A group excluding one or more hydrogen atoms directly bonded to an atom, more preferably from a monocyclic or bicyclic to tetracyclic heterocyclic compound, a hydrogen atom 1 directly bonded to an atom constituting a ring A group excluding one or more pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, dibenzofuran, dibenzothiophene, carbazole, benzocarbazole, benzonaphthofuran or benzonaphthothiophene, which is directly bonded to a ring-constituting atom. It is a group from which one or more hydrogen atoms have been removed, and these groups may have a substituent.
In the substituted amino group in the substituent optionally possessed by the condensed ring-containing aromatic hydrocarbon, the substituent possessed by the amino group is preferably an aryl group or a monovalent heterocyclic group, more preferably an aryl group. The group may further have a substituent. Examples and preferred ranges of the aryl group, which is the substituent of the amino group, are the same as the examples and preferred range of the aryl group in the substituent which the condensed ring-containing aromatic hydrocarbon may have. Examples and preferred ranges of the monovalent heterocyclic group which is a substituent of the amino group are examples and preferred ranges of the monovalent heterocyclic group in the substituent which the condensed ring-containing aromatic hydrocarbon may have. are the same.

The condensed ring-containing aromatic hydrocarbon preferably has a substituent because the long-term deterioration of the light-emitting device of this embodiment is further suppressed. When the condensed ring-containing aromatic hydrocarbon has a substituent, the total number of substituents that the condensed ring-containing aromatic hydrocarbon has 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 total number of hydrogen atoms, and the same applies hereinafter), and the number is preferably 1 to 15, more preferably 1 to 10, because the host material is easily synthesized, It is more preferably 1 to 7, particularly preferably 1 to 5, and most preferably 1 to 3.

Substituents which the condensed ring-containing aromatic hydrocarbon may further have are preferably halogen atoms, alkyl groups, cycloalkyl groups, alkoxy groups, cycloalkoxy groups, and aryl groups. , 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, still more preferably an alkyl group or a cycloalkyl group These groups may further have a substituent, but preferably have no further substituent.
Examples and preferred ranges of the aryl group, the monovalent heterocyclic group and the substituted amino group in the substituent that the condensed ring-containing aromatic hydrocarbon may further have are The same as the examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in the substituents that the ring-containing aromatic hydrocarbon may have.

Although the host material may further contain a compound other than the aromatic compound for host material, it is preferable that the aromatic compound for host material is the main component. The content of the host material aromatic compound in the host material may be, for example, 10% by mass or more. It is more preferably 70% by mass or more, particularly preferably 90% by mass or more, particularly preferably 95% by mass or more, and may be 100% by mass.
The host material may contain only one type of host material aromatic compound, or may contain two or more types. When the host material further contains a compound other than the aromatic compound for the host material, the host material may contain only one compound other than the aromatic compound for the host material, or may contain two or more kinds of compounds other than the aromatic compound for the host material. good too.

The aromatic compound for the 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"), Small molecule host materials are preferred.

(low-molecular-weight host material)
The molecular weight of the small molecule host material is generally 1×10 ² to 1×10 ⁴ , preferably 2×10 ² to 5×10 ³ , more preferably 3×10 ² to 2×10 ³ . , more preferably 4×10 ² to 1×10 ³ .
The total number of condensed ring skeletons in which only three or more benzene rings are condensed in the low-molecular-weight host material is usually 1 to 10, which further suppresses long-term deterioration of the light-emitting device of the present embodiment. 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 contain only one type of condensed ring skeleton in which three or more benzene rings are condensed, or may contain two or more types. The number is preferably 1 to 5, more preferably 1 to 3, still more preferably 1.
Since the long-term deterioration of the light-emitting device of this embodiment is further suppressed, the low-molecular-weight host material has a condensed ring skeleton in which only three or more benzene rings are condensed, or a condensed ring skeleton in which only three or more benzene rings are condensed. It is preferably contained as a group obtained by removing one or more hydrogen atoms directly bonded to the carbon atoms constituting the condensed ring skeleton from the aromatic hydrocarbon (hereinafter also referred to as "condensed ring-containing aromatic hydrocarbon group"), This group may have a substituent.
The total number of condensed ring-containing aromatic hydrocarbon groups contained in the low-molecular-weight host material is usually 1 to 10, and 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, still more preferably 1 to 3, and particularly preferably 1.
The low-molecular-weight host material may contain only one type of condensed ring-containing aromatic hydrocarbon group, or may contain two or more types thereof. to 5 types, more preferably 1 to 3 types, and still more preferably 1 type.
In the low-molecular-weight host material, examples and preferred ranges of substituents that the condensed ring-containing aromatic hydrocarbon group may have are examples and preferred substituents that the condensed ring-containing aromatic hydrocarbon group may have Same as range.

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

^n1H is usually an integer of 10 or less, preferably an integer of 7 or less, more preferably an integer of 5 or less, since the compound represented by the formula (FH) can be synthesized easily, and further It is preferably an integer of 3 or less. Further, ^n1H is preferably an integer of 1 or more because long-term deterioration of the light-emitting element of this embodiment is further suppressed.

In Ar ^1H , the substituent that the condensed ring-containing aromatic hydrocarbon group may have is a substituent other than an aryl group and a monovalent heterocyclic group, preferably a halogen atom, an alkyl group, or a cycloalkyl 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 that the condensed ring-containing aromatic hydrocarbon group may have are the examples of the substituted amino group in the substituent that the condensed ring-containing aromatic hydrocarbon group may have and the same as the preferred range.
Examples and preferred ranges of the substituents that the condensed ring-containing aromatic hydrocarbon group may further have are the substituents that the condensed ring-containing aromatic hydrocarbon group may have is the same as the example and preferred range of the substituent that may further have.

R ^1H is preferably an aryl group optionally having a substituent, since long-term deterioration of the light-emitting element of this embodiment is further suppressed.
Examples and preferred ranges of the aryl group and monovalent heterocyclic group in R ^1H are respectively examples and Same as the preferred range.
Examples and preferred ranges of substituents that R ^1H may have include examples and preferred ranges of substituents that the substituents that the condensed ring-containing aromatic hydrocarbon may further have and are the same.

Examples of low-molecular-weight host materials 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 multiple Z ¹ 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 , still more preferably 2×10 ⁴ to 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 , still more preferably 5×10 ⁴ to 5×10 ⁵ .
The polymer host material may be any of a block copolymer, a random copolymer, an alternating copolymer, a graft copolymer, or other modes. Copolymers are preferred.
The polymer host material preferably contains a condensed ring skeleton in which only three or more benzene rings are condensed as an aromatic hydrocarbon group having a condensed ring skeleton in which only three or more benzene rings are condensed, and this group is a substituent may have
Since the polymer host material further suppresses long-term deterioration of the light emitting device of this embodiment, it preferably contains a condensed ring-containing aromatic hydrocarbon group in the main chain of the polymer compound. It is more preferable to include a group (a divalent condensed ring-containing aromatic hydrocarbon group) obtained by removing two hydrogen atoms directly bonded to carbon atoms constituting a ring from a hydrocarbon. These groups may have a substituent.
In the polymer host material, the condensed ring-containing aromatic hydrocarbon group further suppresses long-term deterioration of the light-emitting device of this embodiment. Therefore, one or more hydrogen atoms (preferably 5 or less, more preferably 1 to 3, still 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 the long-term deterioration of the light-emitting element of the present embodiment is further suppressed, so it is preferably 1 mol % to 100 mol %, more preferably 10 mol % to 100 mol %, and further It is preferably 30 mol % to 100 mol %.
The polymeric host material may contain only one type of condensed ring-containing aromatic hydrocarbon group, or may contain two or more types. to 5 types, more preferably 1 to 3 types, and still more preferably 1 type.
Examples and preferred ranges of the substituents that the condensed ring-containing aromatic hydrocarbon group may have in the polymer host material are examples and preferred substituents that the condensed ring-containing aromatic hydrocarbon group may have. Same as range.

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

<Guest materials>
Guest materials include aromatic compounds consisting only of hydrogen and carbon atoms. Hereinafter, an aromatic compound composed only of hydrogen atoms and carbon atoms contained in a guest material may be referred to as an "aromatic compound for guest material".
Note that the guest material is different from the host material.
“Aromatic compound consisting only of hydrogen atoms and carbon atoms” means a compound in which all the elements constituting the compound are composed only of hydrogen atoms and carbon atoms, and which have an aromatic hydrocarbon ring in the compound. means.
The aromatic compound consisting only of hydrogen atoms and carbon atoms may contain only one type of aromatic hydrocarbon ring, or may contain two or more types of aromatic hydrocarbon rings. Moreover, the aromatic compound consisting only of hydrogen atoms and carbon atoms may contain only one aromatic hydrocarbon ring, or may contain two or more aromatic hydrocarbon rings.
In the aromatic compound consisting only of hydrogen atoms and carbon atoms, the aromatic hydrocarbon ring contained in the compound includes, for example, the aromatic hydrocarbon rings exemplified in the section of the aromatic hydrocarbon group described above. Since the long-term deterioration of the light-emitting element of the embodiment is further suppressed, it is a monocyclic or bicyclic to heptacyclic aromatic hydrocarbon ring, and these aromatic hydrocarbon rings contain only hydrogen atoms and carbon atoms. You may have a hydrocarbon group consisting of.
In the aromatic compound consisting only of hydrogen atoms and carbon atoms, long-term deterioration of the light-emitting element of the present embodiment is further suppressed. is preferably a group hydrocarbon ring. This polycyclic aromatic hydrocarbon may have a hydrocarbon group consisting only of hydrogen and carbon atoms. Examples of the polycyclic aromatic hydrocarbon ring include the polycyclic aromatic hydrocarbon rings exemplified in the section of the aromatic hydrocarbon group described above, and the long-term deterioration of the light emitting element of the present embodiment is more likely to occur. Since it is suppressed, it is preferably a bicyclic to heptacyclic aromatic hydrocarbon ring, more preferably a tetracyclic to heptacyclic aromatic hydrocarbon ring, still more preferably a benzofluorene ring, pyrene ring, fluoranthene ring, dibenzofluorene ring, perylene ring, benzofluoranthene ring, spirobifluorene ring, benzospirobifluorene ring or acenaphthofluoranthene ring, particularly preferably fluoranthene ring, benzofluoranthene ring or It is an acenaphthofluoranthene ring. These aromatic hydrocarbon rings may have a hydrocarbon group consisting only of hydrogen atoms and carbon atoms.
The hydrocarbon group consisting only of hydrogen atoms and carbon atoms is not particularly limited as long as it is a group consisting only of hydrogen atoms and carbon atoms. Hydrocarbon groups consisting only of hydrogen atoms and carbon atoms include, for example, alkyl groups, cycloalkyl groups, aryl groups, alkenyl groups, cycloalkenyl groups, alkynyl groups and cycloalkynyl groups. An alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, or a cycloalkenyl group is preferable, an alkyl group, a cycloalkyl group, or an aryl group is more preferable, and an aryl group is even more preferable, since long-term deterioration is further suppressed. is. These groups may further have substituents consisting only of hydrogen atoms and carbon atoms.
Examples and preferred range of the aryl group in the hydrocarbon group consisting only of hydrogen atoms and carbon atoms are the same as examples and preferred range of the aryl group in the substituent that the condensed ring-containing aromatic hydrocarbon may have.
In an aromatic compound consisting only of hydrogen atoms and carbon atoms, if the aromatic hydrocarbon ring contained in the compound has a hydrocarbon group consisting only of hydrogen atoms and carbon atoms, the hydrogen atoms and carbon atoms of the aromatic hydrocarbon The total number of hydrocarbon groups consisting only of atoms is usually 1 to 20, and the long-term deterioration of the light emitting device of the present embodiment is further suppressed, so the number is preferably 1 to 10, and more. The number is preferably 1 to 7, more preferably 1 to 5, and particularly preferably 1 to 3.
The substituent consisting only of hydrogen atoms and carbon atoms is not particularly limited as long as it is a group consisting only of hydrogen atoms and carbon atoms. Examples of substituents consisting only of hydrogen atoms and carbon atoms include alkyl groups, cycloalkyl groups, aryl groups, alkenyl groups, cycloalkenyl groups, alkynyl groups and cycloalkynyl groups, preferably alkyl groups and cycloalkyl groups. , an aryl group, an alkenyl group or a cycloalkenyl group, more preferably an alkyl group, a cycloalkyl group or an aryl group. These groups may further have substituents consisting only of hydrogen atoms and carbon atoms, but preferably have no further substituents.
The examples and preferred range of the aryl group in the substituent consisting only of hydrogen atoms and carbon atoms are the same as the examples and preferred range of the aryl group in the substituent which the condensed ring-containing aromatic hydrocarbon may have.

Although the guest material may further contain a compound other than the aromatic compound consisting only of hydrogen atoms and carbon atoms, it is preferably composed mainly of an aromatic compound consisting only of hydrogen atoms and carbon atoms. The content of the aromatic compound consisting only of hydrogen atoms and carbon atoms in the guest material may be, for example, 10% by mass or more. 50% by mass or more is more preferable, 70% by mass or more is still more preferable, 90% by mass or more is particularly preferable, 95% by mass or more is particularly preferable, and it may be 100% by mass.
The guest material may contain only one type of aromatic compound consisting only of hydrogen atoms and carbon atoms, or may contain two or more types. When the guest material further contains a compound other than the aromatic compound consisting only of hydrogen atoms and carbon atoms, the guest material may contain only one compound other than the aromatic compound for the guest material, or two kinds of compounds other than the aromatic compound for the guest material. It may contain more than

The aromatic compound for guest material may be a polymer compound (hereinafter also referred to as "polymer guest material") or a low-molecular compound (hereinafter also referred to as "low-molecular guest material"). , low-molecular-weight 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 , more preferably 3×10 ² to 2×10 ³ . , more preferably 4×10 ² to 1×10 ³ .
The total number of aromatic hydrocarbon rings contained in the low-molecular-weight guest material is usually 1 to 60, and the long-term deterioration of the light-emitting device of the present embodiment is further suppressed. The number is 30, more preferably 1 to 15, still more preferably 1 to 10, and particularly preferably 1 to 6.
The low-molecular-weight guest material may contain only one type of aromatic hydrocarbon ring, or may contain two or more types of aromatic hydrocarbon rings. , more preferably 1 to 8 species, still more preferably 2 to 6 species, and particularly preferably 2 to 4 species.
When at least one of the aromatic hydrocarbon rings contained in the low-molecular-weight guest material is a polycyclic aromatic hydrocarbon ring, the total number of polycyclic aromatic hydrocarbon rings is usually one. The number is preferably 1 to 10, more preferably 1 to 7, even more preferably 1 to 5, because the long-term deterioration of the light emitting element of the present embodiment is further suppressed. 1 to 3, particularly preferably 1 to 3.
Since the long-term deterioration of the light-emitting element of this embodiment is further suppressed, the low-molecular-weight guest material preferably contains an aromatic hydrocarbon ring as an aromatic hydrocarbon group, and is a monocyclic or bicyclic to heptacyclic More preferably, it is included as a group obtained by removing one or more hydrogen atoms directly bonded to the carbon atoms constituting the ring from the aromatic hydrocarbon of the formula. These groups may have hydrocarbon groups consisting only of hydrogen and carbon atoms.
The total number of aromatic hydrocarbon groups contained in the low-molecular-weight guest material is usually 1 to 60, and the long-term deterioration of the light-emitting device of the present embodiment is further suppressed. The number is 30, more preferably 1 to 15, still more preferably 1 to 10, and particularly preferably 1 to 6.
The low-molecular-weight guest material may contain only one aromatic hydrocarbon group, or may contain two or more aromatic hydrocarbon groups. , more preferably 1 to 8 species, still more preferably 2 to 6 species, and particularly preferably 2 to 4 species.
In the low-molecular-weight guest material, at least one of the aromatic hydrocarbon groups is a group obtained by removing one or more hydrogen atoms directly bonded to carbon atoms forming a ring from a polycyclic aromatic hydrocarbon (hereinafter referred to as " Also referred to as "polycyclic aromatic hydrocarbon group"). This group may have a hydrocarbon radical consisting only of hydrogen and carbon atoms.
As the polycyclic aromatic hydrocarbon group, for example, from the polycyclic aromatic hydrocarbons exemplified in the section of the above-mentioned aromatic hydrocarbon group, one hydrogen atom directly bonded to a carbon atom constituting the ring Examples include groups other than those mentioned above, and the long-term deterioration of the light-emitting device of the present embodiment is further suppressed. is a group in which one or more hydrogen atoms are removed, more preferably a group in which one or more hydrogen atoms directly bonded to the carbon atoms constituting the ring are removed from a 4- to 7-ring aromatic hydrocarbon. more preferably a hydrogen atom directly bonded to a carbon atom constituting a ring selected from benzofluorene, pyrene, fluoranthene, dibenzofluorene, perylene, benzofluoranthene, spirobifluorene, benzospirobifluorene or acenaphthofluoranthene It is a group from which one or more hydrogen atoms have been removed, and particularly preferably a group from fluoranthene, benzofluoranthene or acenaphthofluoranthene from which one or more hydrogen atoms directly bonded to carbon atoms constituting the ring have been removed. These groups may have hydrocarbon groups consisting only of hydrogen and carbon atoms.
When the low-molecular guest material contains polycyclic aromatic hydrocarbon groups, the total number of polycyclic aromatic hydrocarbon groups contained in the low-molecular guest material is usually 1 to 20. The number is preferably 1 to 10, more preferably 1 to 7, even more preferably 1 to 5, because the long-term deterioration of the light emitting device of the present embodiment is further suppressed, and particularly The number is preferably 1 to 3.
In the low-molecular guest material, when the aromatic hydrocarbon group has a hydrocarbon group consisting only of hydrogen atoms and carbon atoms, the total number of hydrocarbon groups consisting only of hydrogen atoms and carbon atoms possessed by the aromatic hydrocarbon group is usually 1 to 20, and is preferably 1 to 10, more preferably 1 to 7, since the long-term deterioration of the light emitting element of the present embodiment is further suppressed, and further The number is preferably 1 to 5, and particularly preferably 1 to 3.

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

n ^1B is usually an integer of 20 or less, preferably an integer of 10 or less, more preferably an integer of 7 or less, since the compound represented by the formula (FB) can be synthesized easily, and further An integer of 5 or less is preferable, and an integer of 3 or less is particularly preferable. In addition, ^n1B is preferably an integer of 1 or more because long-term deterioration of the light-emitting element of this embodiment is further suppressed.

Ar ^1B includes, for example, a group obtained by removing n ^1B or more hydrogen atoms directly bonded to carbon atoms constituting a ring from a monocyclic or bicyclic to heptacyclic aromatic hydrocarbon.
Ar ^1B further suppresses long-term deterioration of the light-emitting device of this embodiment, so it is preferably the aforementioned polycyclic aromatic hydrocarbon group, and examples and preferred ranges of this group are the same as described above.

Examples and preferred ranges of the hydrocarbon group consisting only of hydrogen atoms and carbon atoms in R ^1B are the same as described above.

As the low-molecular-weight guest material, among the compounds exemplified as the low-molecular-weight host material, aromatic compounds consisting only of hydrogen atoms and carbon atoms, the compounds represented by the following formulas, and the compounds described in the examples can be used. exemplified. These compounds may have substituents consisting only of carbon and hydrogen atoms.

(Polymer guest material)
The preferred ranges of the polystyrene-equivalent number-average molecular weight and weight-average molecular weight of the polymer guest material are the same as the preferred ranges of the polystyrene-equivalent number-average molecular weight and weight-average molecular weight of the polymer host material, respectively.
The polymeric guest material may be a block copolymer, a random copolymer, an alternating copolymer, a graft copolymer, or may be in another form. Copolymers are preferred.
The polymeric guest material preferably contains an aromatic hydrocarbon ring as an aromatic hydrocarbon group, and this group may have a substituent.
The polymer guest material preferably contains an aromatic hydrocarbon group, more preferably an arylene group, in the main chain of the polymer compound, since long-term deterioration of the light-emitting device of the present embodiment is further suppressed. . These groups may have hydrocarbon groups consisting only of hydrogen and carbon atoms.
In the polymer guest material, the aromatic hydrocarbon group further suppresses long-term deterioration of the light-emitting device of this embodiment. , more preferably 1 to 3, and still more preferably 2).
In the polymer guest material, the content of the aromatic hydrocarbon group is usually 1 mol% to 100 mol% with respect to the total content of all structural units contained in the polymer compound. The long-term deterioration of the light-emitting element is further suppressed, so the content is preferably 30 mol % to 100 mol %, more preferably 60 mol % to 100 mol %, and even more preferably 90 mol % to 100 mol %.
In the polymeric guest material, at least one of the aromatic hydrocarbon groups is preferably a polycyclic aromatic hydrocarbon group having hydrocarbon groups consisting only of hydrogen and carbon atoms. may be
In the polymer guest material, the content of the polycyclic aromatic hydrocarbon group 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 of the light-emitting device of the present embodiment is further suppressed, the content is preferably 10 mol% to 100 mol%, more preferably 30 mol% to 100 mol%, and still more preferably 50 mol% to 100 mol%. %.
The polymeric guest material may contain only one type of aromatic hydrocarbon group, or may contain two or more types of aromatic hydrocarbon groups. 1 to 10 species, more preferably 2 to 8 species, still more preferably 2 to 6 species, and particularly preferably 2 to 4 species.

The polymer guest material may contain constitutional units consisting only of hydrogen atoms and carbon atoms other than aromatic hydrocarbon groups. In the polymer guest material, if the polymer compound contains hydrogen atoms other than aromatic hydrocarbon groups and structural units consisting only of carbon atoms, hydrogen atoms other than aromatic hydrocarbon groups may be present in the main chain of the polymer compound. It preferably contains constitutional units consisting only of atoms and carbon atoms.
Structural units consisting only of hydrogen atoms and carbon atoms other than aromatic hydrocarbon groups include, for example, alkylene groups and cycloalkylene groups, and these groups have hydrocarbon groups consisting only of hydrogen atoms and carbon atoms. may be
In the polymer guest material, the polymer compound may contain only one type of constitutional unit consisting of only hydrogen atoms and carbon atoms other than aromatic hydrocarbon groups, or may contain two or more types thereof.

<Amount of Magnesium Atoms Contained in Guest Material (C ¹ )>
In the composition for a light-emitting device of the present embodiment, the amount (C ¹ ) of magnesium atoms contained in the guest material is generally 0 mass ppb or more and 13000 mass ppb or less with respect to the total amount of the guest material. It should be noted that the phrase "the amount of magnesium atoms contained in the guest material" does not imply that the guest material contains magnesium atoms, and that the guest material may or may not contain magnesium atoms. good. In the guest material of this embodiment, the amount of magnesium atoms is preferably 10,000 mass ppb or less, more preferably 5,000 mass ppb or less, since long-term deterioration of the light-emitting element of this embodiment is further suppressed. It is preferably 1300 mass ppb or less, particularly preferably 1000 mass ppb or less, particularly preferably 500 mass ppb or less, even more preferably 250 mass ppb or less, and even more preferably 180 mass ppb or less. , particularly preferably 130 mass ppb or less. Further, in the guest material of this embodiment, the amount of magnesium atoms is preferably 1 mass ppb or more, more preferably 5 mass ppb or more, since long-term deterioration of the light-emitting element of this embodiment is further suppressed. , more preferably 10 mass ppb or more, particularly preferably 20 mass ppb or more, particularly preferably 35 mass ppb or more, even more preferably 40 mass ppb or more, even more preferably 60 mass ppb or more and particularly preferably 80 mass ppb or more.

The amount (C ¹ ) of magnesium atoms contained in the guest material of the present embodiment is, when there is one type of guest material of the present embodiment, the amount of magnesium atoms of the one type of guest material is C ¹ , and the amount of magnesium atoms of the one type of guest material is C 1. When the guest material of the form is composed of multiple types of compounds having different amounts of magnesium atoms, C1 is calculated according to the amount of magnesium atoms of the multiple types of compounds and the mass ratio of ^each compound. ^A specific method for calculating C1 will be described using Examples D6 and D1, which will be described later.

First, in Example D6, the amount of magnesium atoms in compound EM2 measured by the ICP/MS method is ¹³⁰ mass ppb, so C1 is 130 mass ppb.

Next, in Example D1, the amounts of magnesium atoms in compound EM1 and compound EM2 measured by the ICP/MS method are 31 mass ppb and 130 mass ppb, respectively. Further, the mass ratio of compound EM1 and compound EM2 is compound EM1:compound EM2=9:1.
Therefore, C1 in Example D1 can be determined from the amount of magnesium atoms contained in compound EM1 and compound ^EM2 and the amount of the charge, and is determined as follows.
C ¹ = {31×9/(1+9)}+{130×1/(1+9)}=41 mass ppb

Similarly, C1 in Comparative Example ^CD1 is 31 mass ppb.

<Amount of Magnesium Atoms Contained in Host Material (C ^H )>
In the composition for a light-emitting element of the present embodiment, the amount (C ^H ) of magnesium atoms contained in the host material is generally 0 mass ppb or more and 19000 mass ppb or less with respect to the total amount of the host material. The phrase "the amount of magnesium atoms contained in the host material" does not mean that the host material contains magnesium atoms, and the host material may or may not contain magnesium atoms. good. In the host material of the present embodiment, the amount of magnesium atoms is preferably 10,000 mass ppb or less, more preferably 5,000 mass ppb or less, since long-term deterioration of the light-emitting element of the present embodiment is further suppressed. It is preferably 1900 mass ppb or less, particularly preferably 1000 mass ppb or less, particularly preferably 500 mass ppb or less, even more preferably 190 mass ppb or less, and even more preferably 180 mass ppb or less. , particularly preferably 160 mass ppb or less. In the host material of the present embodiment, the amount of magnesium atoms may be 130 mass ppb or less, 100 mass ppb or less, 70 mass ppb or less, or 30 mass ppb or less. may be 10 mass ppb or less, may be 5 mass ppb or less, may be 1 mass ppb or less, may be 0.1 mass ppb or less, or may be 0 mass It may be ppb.

A specific method for calculating C ^H can be obtained in the same manner as the specific method for calculating C ¹ described above.
For example, in Example D1, ^CH is 0 mass ppb. In Example D6, ^CH is 4.4 mass ppb. In Comparative Example CD1, ^CH is 200 mass ppb.

<How to adjust C ¹ and C ^H >
Methods for preparing C ¹ and C ^H include, for example, 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 Guide (1988) , Kagaku Dojin) and the like.

Purification includes, for example, sublimation, extraction, reprecipitation, recrystallization, chromatography and adsorption.
Purification of the low-molecular-weight guest material and low-molecular-weight host material is preferably sublimation, recrystallization, chromatography or adsorption, more preferably sublimation or recrystallization, and still more preferably, since the amount of magnesium atoms can be further adjusted. is sublimation.
Purification of the polymer guest material and polymer host material is preferably reprecipitation, chromatography or adsorption, since the amount of magnesium atoms can be adjusted.
In purification, when purification is performed twice or more, the methods may be the same or different.

In sublimation, the degree of vacuum and 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, still more 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, still more preferably 100°C to 500°C, and particularly preferably 200°C to 350°C.

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

Examples of solvents used for extraction include alcoholic solvents such as methanol, ethanol, propanol, ethylene glycol, glycerin, 2-methoxyethanol, and 2-ethoxyethanol; diethyl ether, tetrahydrofuran (THF), dioxane, cyclopentylmethyl ether, and diglyme. Halogen solvents such as methylene chloride and chloroform; Nitrile solvents such as acetonitrile and benzonitrile; Hydrocarbon solvents such as hexane, decalin, toluene, xylene and mesitylene; N,N-dimethylformamide, N , N-dimethylacetamide; and acetone, dimethylsulfoxide, and water. A solvent may be used individually by 1 type, or may use 2 or more types together.

The chromatography is preferably column chromatography.
Silica gel or alumina is preferred as a packing material for column chromatography.
Examples of solvents used for chromatography are the same as examples of solvents used for extraction.

Examples of solvents used for reprecipitation and recrystallization are the same as those used for extraction.

For adsorption, treatment with an adsorbent is preferred. Also, the adsorbent is preferably activated carbon, silica gel, alumina or celite.
Treatment with an adsorbent is usually carried out in a solvent. Examples of solvents used for treatment with adsorbents are the same as examples of solvents used for extraction.

<Composition for Light Emitting Element>
The composition for a light-emitting element of this embodiment contains a host material and a guest material.
In the composition for a light-emitting element of this embodiment, each of the host material and the guest material may contain only one type, or may contain two or more types.
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 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 still more 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 still more preferably 420 nm or more and 475 nm or less. is.
The maximum peak wavelength of the emission spectrum of the host material and the guest material is determined by dissolving the object to be measured in an organic solvent such as xylene, toluene, chloroform, tetrahydrofuran, etc. to prepare a dilute solution (1×10 ⁻⁶ mass % to 1× 10 ⁻³ mass %), which can be evaluated by measuring the PL spectrum of the dilute solution at room temperature. Toluene or xylene is preferable as the organic solvent for dissolving the object to be measured.

In the composition for a light emitting element of the present embodiment, the total amount of magnesium atoms contained in the host material and magnesium atoms contained in the guest material is more than 0 mass ppb and 180 mass ppb or less with respect to the total amount of the host material and the guest material. is. Further, in the composition for a light-emitting element of this embodiment, the total amount of magnesium atoms contained in the host material and magnesium atoms contained in the guest material is It is preferably 0.01 mass ppb or more, more preferably 0.1 mass ppb or more, still more preferably 0.5 mass ppb or more, and particularly preferably 1 mass ppb, because long-term deterioration is further suppressed. ppb or more, particularly preferably 2 mass ppb or more, particularly more preferably 4 mass ppb or more, even more preferably 6 mass ppb or more, and particularly preferably 8 mass ppb or more. Further, in the composition for a light-emitting element of this embodiment, the total amount of magnesium atoms contained in the host material and magnesium atoms contained in the guest material is Since long-term deterioration is suppressed, it is preferably 170 mass ppb or less, more preferably 160 mass ppb or less.

The reason why the long-term deterioration of the light-emitting element is suppressed in this embodiment is considered as follows.
The host material 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 guest material aromatic compound contained in the guest compound. On the other hand, the present inventors believe that the aromatic compound for guest material contained as a guest material in the composition for light emitting element of the present embodiment electrically interacts with the aromatic compound for host material contained as a host material. thinking.
Then, the present inventors found that in the composition for a light emitting device of the present embodiment, when the total amount of magnesium atoms contained in the host material and magnesium atoms contained in the guest material exceeds a predetermined upper limit, the above interaction On the other hand, magnesium atoms have an adverse effect, and as a result, the light-emitting properties, charge transport properties, or charge injection properties of the composition for a light-emitting device of the present embodiment are deteriorated, or the charge of the light-emitting device of the present embodiment is reduced. It is thought that long-term deterioration of the light-emitting element of this embodiment is accelerated because the balance is lost.
On the other hand, the present inventors found that in the composition for a light-emitting element of the present embodiment, the total amount of magnesium atoms contained in the host material and magnesium atoms contained in the guest material is at least a predetermined lower limit, and magnesium atoms The above-mentioned interaction is strengthened, and as a result, the light emitting properties, charge transport properties, or charge injection properties of the composition for a light emitting device of the present embodiment are 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 this embodiment is suppressed.
Therefore, based on the above idea, the present inventors have found that in the present embodiment, the total amount of magnesium atoms contained in the host material and the magnesium atoms contained in the guest material is a predetermined amount, so that long-term deterioration of the light emitting element can be prevented. I believe it will have a deterrent effect.

The total amount (mass ^ppb ) of the magnesium atoms contained in the host material and the magnesium atoms contained in the guest material is the ratio of the mass of the host material to the total mass of the host material and the guest material. When the ratio of the total mass of the guest materials to the total mass of the guest materials is W ¹ , it is represented by C ^H W ^H +C ¹ W ¹ .
W ^H is usually 0.01 to 0.9999, and is preferably 0.30 to 0.999 because long-term deterioration of the light emitting element of the present embodiment is further suppressed, and 0.50 to 0.50 It is more preferably 0.995, still more preferably 0.70 to 0.99, and particularly preferably 0.85 to 0.95.
W ¹ is usually 0.0001 to 0.99, and is preferably 0.001 to 0.70 because the long-term deterioration of the light emitting element of this embodiment is further suppressed, and 0.005 to 0.005 0.50 is more preferred, 0.01 to 0.30 is even more preferred, and 0.05 to 0.15 is particularly preferred.

A specific method for calculating W ^H and W ¹ will be described below using Comparative Example CD1 and Example D1.

First, in Comparative Example CD1, the mass ratio of compound H1 (host material) and compound EM1 (guest material) was compound H1:compound EM1=90:10.
Therefore, W ^H and W ¹ in Comparative Example CD1 can be determined from the charged amount, and are determined as follows.
W ^H =90/(90+10)=0.90
W1 = ¹⁰ /(90 + 10) = 0.10

In Example D1, the mass ratio of compound H2, compound EM1, and compound EM2 was compound H2:compound EM1:compound EM2=90:9:1.
Therefore, W ^H and W ¹ in Example D1 can be determined from the amount of charge, and are determined as follows.
W ^H =90/(90+9+1)=0.90
W1=(9+ ¹ )/(90+9+1)=0.10

Similarly, ^WH and W1 in Example ^D5 are determined as follows.
W ^H =(2+88)/(2+88+10)=0.90
W1 = ¹⁰ /(2 + 88 + 10) = 0.10

By calculating C ¹ , C ^H , W ¹ and ^WH as described above, C ^{H WH} + C ¹ W ¹ can be calculated.

For example, C ^H W ^H + C ¹ W ¹ in Comparative Example CD1 is obtained as follows.
C ^H W ^H + C ¹ W ¹ = (200 x 0.90) + (31 x 0.10) = 183 mass ppb

For example, C ^H W ^H + C ¹ W ¹ in Example D1 is obtained as follows.
C ^H W ^H + C ¹ W ¹ = (0 x 0.90) + (41 x 0.10) = 4.1 mass ppb

For example, C ^H W ^H + C ¹ W ¹ in Example D6 is obtained as follows.
C ^H W ^H + C ¹ W ¹ = (4.4 x 0.90) + (130 x 0.10) = 17 mass ppb

C ^H W ^H + C ¹ W ¹ is generally greater than 0 mass ppb and no more than 180 mass ppb. C ^H W ^H + C ¹ W ¹ is preferably 0.01 mass ppb or more, more preferably 0.1 mass ppb or more, since long-term deterioration of the light-emitting element of this embodiment is further suppressed. It is preferably 0.5 mass ppb or more, particularly preferably 1 mass ppb or more, particularly preferably 2 mass ppb or more, even more preferably 4 mass ppb or more, and even more preferably 6 mass ppb or more. and particularly preferably 8 mass ppb or more. In addition, C ^H W ^H + C ¹ W ¹ is preferably 170 mass ppb or less, more preferably 160 mass ppb or less, since long-term deterioration of the light-emitting element of this embodiment is further suppressed.

(other ingredients)
The composition for a light-emitting element of the present embodiment is selected from the group consisting of a host material, a guest material, a hole-transporting material, a hole-injecting material, an electron-transporting material, an electron-injecting material, a light-emitting material, an antioxidant, and a solvent. It may be a composition containing at least one material comprising: However, hole-transporting materials, hole-injecting materials, electron-transporting materials, electron-injecting materials, and light-emitting materials are different from host materials and guest materials.
The composition for a light-emitting device of the present embodiment further contains at least one selected from the group consisting of hole-transporting materials, hole-injecting materials, electron-transporting materials, electron-injecting materials, light-emitting materials, antioxidants and solvents. In that case, it is preferable to adjust the amount of magnesium atoms contained in these by the above-mentioned purification.

[ink]
A composition containing a host material, a guest material, and a solvent (hereinafter referred to as "ink") can be prepared by, for example, spin coating, casting, micro gravure coating, gravure coating, bar coating, roll Coating method, wire bar coating method, dip coating method, spray coating method, screen printing method, flexographic printing method, offset printing method, inkjet printing method, capillary coating method, nozzle coating method, etc. Suitable for fabrication. 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 solvents include chlorine solvents, ether solvents, aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, ketone solvents, ester solvents, polyhydric alcohol solvents, alcohol solvents, sulfoxide solvents, Amide solvents are mentioned.
In the ink, the blending amount of the solvent is usually 1000 parts by mass to 100000 parts by mass when the total of the host material and the guest material is 100 parts by mass.
A solvent may be used individually by 1 type, or may use 2 or more types together.

[Hole transport material]
The hole-transporting material is classified into low-molecular-weight compounds and high-molecular-weight compounds, and is preferably a high-molecular-weight compound having a cross-linking group.
Polymer compounds include, for example, polyvinylcarbazole and derivatives thereof; polyarylenes and derivatives thereof having aromatic amine structures in side chains or main chains. The polymer compound may be a compound having electron-accepting moieties such as fullerene, tetrafluorotetracyanoquinodimethane, tetracyanoethylene and trinitrofluorenone bound thereto.
When the composition for a light-emitting element of the present embodiment contains a hole-transporting material, the amount of the hole-transporting material is usually 1 part by mass when the total of the host material and the guest material is 100 parts by mass. ~400 parts by mass.
The hole transport materials may be used singly 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 cross-linking group.
Examples of low-molecular-weight compounds include metal complexes having 8-hydroxyquinoline as a ligand, oxadiazole, anthraquinodimethane, benzoquinone, naphthoquinone, anthraquinone, tetracyanoanthraquinodimethane, fluorenone, diphenyldicyanoethylene and diphenoquinone. , as well as derivatives thereof.
Polymer compounds include, for example, polyphenylene, polyfluorene, and derivatives thereof. The polymeric compounds may be doped with metals.
When the composition for a light-emitting element of the present embodiment contains an electron-transporting material, the amount of the electron-transporting material is usually 1 part by mass to 400 parts by mass when the total of the host material and the guest material is 100 parts by mass. part by mass.
The electron transport materials may be used singly or in combination of two or more.

[Hole injection material and electron injection material]
Hole-injecting materials and electron-injecting materials are classified into low-molecular-weight compounds and high-molecular-weight compounds, respectively. The hole-injecting material and the electron-injecting material may have cross-linking groups.
Examples of low-molecular compounds include metal phthalocyanines such as copper phthalocyanine; carbon; metal oxides such as molybdenum and tungsten; and metal fluorides such as lithium fluoride, sodium fluoride, cesium fluoride and potassium fluoride.
Polymer compounds include, for example, polyaniline, polythiophene, polypyrrole, polyphenylene vinylene, polythienylene vinylene, polyquinoline and polyquinoxaline, and derivatives thereof; conductive polymers such as polymers containing an aromatic amine structure in the main chain or side chain; and a flexible polymer.
When the composition for a light-emitting device of the present embodiment contains a hole-injection material and/or an electron-injection material, the amount of each of the hole-injection material and the electron-injection material is the total of the host material and the guest material. When 100 parts by mass, it is usually 1 to 400 parts by mass.
Each of the hole injection material and the electron injection material may be used alone or in combination of two or more.

When the ion-doped hole-injection material or electron-injection material contains a conductive polymer, the electrical conductivity of the conductive polymer is preferably 1×10 ⁻⁵ S/cm to 1×10 ³ S/cm. . The conductive polymer can be doped with an appropriate amount of ions in order to set the electrical conductivity of the conductive polymer within this range. The type of ions to be doped is an anion for a hole-injection material, and a cation for an electron-injection material. Examples of anions include polystyrene sulfonate ions, alkylbenzene sulfonate ions, and camphor sulfonate ions. Examples of cations include lithium ion, sodium ion, potassium ion, and tetrabutylammonium ion.
Ions for doping may be used alone or in combination of two or more.

[Light emitting material]
Light-emitting materials are classified into low-molecular-weight compounds and high-molecular-weight compounds. The luminescent material may have a cross-linking group.
Low-molecular-weight compounds include, for example, naphthalene and its derivatives, anthracene and its derivatives, perylene and its derivatives, and triplet emission complexes with iridium, platinum, or europium as the central metal.
Examples of polymer compounds include arylene groups such as phenylene group, naphthalene diyl group, fluorenediyl group, phenanthenediyl group, dihydrophenanthenediyl group, anthracenediyl group and pyrenediyl group; Aromatic amine residues such as groups to be removed; and polymeric compounds containing divalent heterocyclic groups such as carbazoldiyl groups, phenoxazinediyl groups and phenothiazinediyl groups.

When the composition for a light-emitting element of the present embodiment contains a light-emitting material, 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. part by mass.
A luminescent material may be used individually by 1 type, or may use 2 or more types together.

[Antioxidant]
The antioxidant may be any 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. Examples thereof include phenolic antioxidants and phosphorus antioxidants.
In the composition for a light-emitting element of the present embodiment, when an antioxidant is included, the amount of the antioxidant is usually 0.001 parts by mass when the total of the host material and the guest material is 100 parts by mass. ~10 parts by mass.
Antioxidants may be used singly 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 the light-emitting device. The membrane can be made by a wet method, for example, using ink. Also, the film can be produced by, for example, a dry method such as a vacuum deposition method. Examples of methods for forming a film by a dry method include a method of vapor-depositing the composition for a light-emitting element of this embodiment, and a method of co-depositing a host material and a guest material.
The film thickness is typically between 1 nm and 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 this embodiment includes, for example, an anode, a cathode, and an organic layer containing the composition for a light-emitting device of this embodiment provided between the anode and the cathode.

[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-transporting layer, a hole-injecting layer, an electron-transporting layer and an electron-injecting layer. , preferably the light-emitting layer. These layers each contain a light-emitting material, a hole-transporting material, a hole-injecting material, an electron-transporting material, and an electron-injecting material. Each of these layers can be formed from a light-emitting material, a hole-transporting material, a hole-injecting material, an electron-transporting material, and an electron-injecting material using the same method as for the above-described films.

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

Materials for the hole-transporting layer, the electron-transporting layer, the light-emitting layer, the hole-injecting layer, and the electron-injecting layer include, in addition to the composition for a light-emitting element of the present embodiment, the hole-transporting material, electron-transporting material, Light-emitting materials, hole-injection materials, electron-injection materials, and the like can be mentioned.

The materials for the hole-transporting layer, the electron-transporting layer, and the light-emitting layer are selected from the solvents used in forming the layers adjacent to the hole-transporting layer, the electron-transporting layer, and the light-emitting layer, respectively, in the manufacture of the light-emitting device. When dissolved, it is preferred that the material has cross-linking groups to avoid dissolving the material in the solvent. After forming each layer using a material having a cross-linking group, the layer can be made insoluble by cross-linking the cross-linking group.

In the light-emitting device of the present embodiment, as a method for forming each layer such as the light-emitting layer, the hole transport layer, the electron transport layer, the hole injection layer, and the electron injection layer, when using a low molecular compound, for example, vacuum from powder Examples include dry methods such as vapor deposition, and wet methods such as methods by forming a film from a solution or a molten state. In the case of using a polymer compound, examples include a wet method such as a method by forming a film from a solution or a molten state. be done. The order, number and 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 device may be a substrate on which an electrode can be formed and which does not change chemically when the organic layer is formed. In the case of opaque substrates, it is preferred that the electrodes furthest from the substrate be transparent or translucent.
Examples of materials for the anode include conductive metal oxides and translucent metals, preferably indium oxide, zinc oxide, tin oxide; indium tin oxide (ITO), indium zinc oxide, etc. Conductive compounds; silver-palladium-copper composite (APC); NESA, gold, platinum, silver, copper.
Examples of cathode materials 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 species with one or more of silver, copper, manganese, titanium, cobalt, nickel, tungsten, tin; and graphite and graphite intercalation compounds. Examples of alloys include magnesium-silver alloys, magnesium-indium alloys, magnesium-aluminum alloys, indium-silver alloys, lithium-aluminum alloys, lithium-magnesium alloys, lithium-indium alloys, and calcium-aluminum alloys.
Each of the anode and the cathode may have a laminated structure of two or more layers.

The light-emitting device of the present embodiment is suitable as a light source for backlighting of a liquid crystal display device, a light source for lighting, an organic EL lighting, a display device such as a computer, a television, and a mobile terminal (for example, an organic EL display and an organic EL television). can be used for

Although a 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 in which a host material and a guest material are blended.

<Manufacturing method (1)>
In one aspect, a method for producing a composition for a light-emitting element includes a host material preparation 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, and only hydrogen atoms and carbon atoms. a guest material preparation step of preparing a guest material containing an aromatic compound consisting of; A method for producing a composition for a light-emitting element (hereinafter also referred to as “manufacturing method (1)”), comprising: you can

In the production method (1), the host material preparation step includes a step (A-1) of preparing an aromatic compound having a condensed ring skeleton in which only three or more benzene rings mixed with magnesium atoms are condensed, and a step (A- A step (A-2) of purifying at least part of the aromatic compound having a condensed ring skeleton in which only three or more benzene rings prepared in 1) are condensed to remove at least part of the magnesium atoms. can be

In production method (1), the content of magnesium atoms in the aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed and prepared in step (A-1) is not particularly limited, for example, 190 mass. ppb or more, may be 200 mass ppb or more, may be 250 mass ppb or more, may be 500 mass ppb or more, may be 1000 mass ppb or more, or may be 5000 mass ppb or more. 10000 mass ppb or more, 50000 mass ppb or more, or 100000 mass ppb or more. In addition, the upper limit of the content of magnesium atoms in the aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed and prepared in step (A-1) is not particularly limited, and the content is, for example, It may be 10000000 mass ppb or less, 5000000 mass ppb or less, 1000000 mass ppb or less, or 500000 mass ppb or less.

In the production method (1), examples of the purification method in the step (A-2) include the methods exemplified in <Method for adjusting C ¹ and C 3 ^H > above.

In the production method (1), the content of magnesium atoms in the aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed after step (A-2) is usually 0 mass ppb or more and 19000 mass ppb or less. is. The content of magnesium atoms in the aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed after the step (A-2) is preferable because the long-term deterioration of the light emitting device of the present embodiment is further suppressed. is 10000 mass ppb or less, more preferably 5000 mass ppb or less, still more preferably 1900 mass ppb or less, particularly preferably 1000 mass ppb or less, particularly preferably 500 mass ppb or less, particularly preferably It is preferably 190 mass ppb or less, more preferably 180 mass ppb or less, and particularly preferably 160 mass ppb or less. Further, the content of magnesium atoms in the aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed after step (A-2) may be 130 mass ppb or less, or 100 mass ppb or less. 70 mass ppb or less, 30 mass ppb or less, 10 mass ppb or less, 5 mass ppb or less, or 1 mass ppb or less It may be present, may be 0.1 mass ppb or less, or may be 0 mass ppb.

In the production method (1), the guest material preparation step includes a preparation step (B-1) of preparing an aromatic compound consisting only of hydrogen atoms and carbon atoms mixed with magnesium atoms, and a step (B-1). and a step (B-2) of purifying at least part of the aromatic compound consisting only of hydrogen atoms and carbon atoms to remove at least part of the magnesium atoms.

In the production method (1), the content of magnesium atoms in the aromatic compound consisting only of hydrogen atoms and carbon atoms prepared in step (B-1) is not particularly limited, and may be 130 mass ppb or more, and 150 It may be ppb by mass or more, 300 ppb by mass or more, 500 ppb by mass or more, 1000 ppb by mass or more, 5000 ppb by mass or more, or 10000 ppb by mass or more. , 50000 mass ppb or more, or 100000 mass ppb or more. Further, the upper limit of the content of magnesium atoms in the aromatic compound consisting only of hydrogen atoms and carbon atoms prepared in step (B-1) is not particularly limited, and the content is, for example, 10000000 mass ppb or less. 5000000 mass ppb or less, 1000000 mass ppb or less, or 500000 mass ppb or less.

In the production method (1), examples of the purification method in the step (B-2) include the methods exemplified in the above <Method for adjusting C ¹ and C 3 ^H >.

In the production method (1), the content of magnesium atoms in the aromatic compound consisting only of hydrogen atoms and carbon atoms after step (B-2) is usually 0 mass ppb or more and 13000 mass ppb or less. The content of magnesium atoms in the aromatic compound consisting only of hydrogen atoms and carbon atoms after the step (B-2) is preferably 10000 mass ppb or less, since long-term deterioration of the light-emitting device of the present embodiment is further suppressed. more preferably 5000 mass ppb or less, more preferably 1300 mass ppb or less, particularly preferably 1000 mass ppb or less, particularly preferably 500 mass ppb or less, and even more preferably 250 mass ppb or less. , more preferably 180 mass ppb or less, particularly preferably 130 mass ppb or less. Further, the content of magnesium atoms in the aromatic compound consisting only of hydrogen atoms and carbon atoms after the step (B-2) is preferably 1 mass ppb, since long-term deterioration of the light-emitting device of the present embodiment is further suppressed. or more, more preferably 5 mass ppb or more, still more preferably 10 mass ppb or more, particularly preferably 20 mass ppb or more, particularly preferably 35 mass ppb or more, particularly preferably 40 mass ppb or more ppb or more, more preferably 60 mass ppb or more, and particularly preferably 80 mass ppb or more.

In the production method (1), in the production process, considering the amount of magnesium atoms contained in the host material and the amount of magnesium atoms contained in the guest material, the total amount of both is more than 0 mass ppb and 180 mass ppb or less. A host material and a guest material are mixed at a compounding 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 production process of production method (1), the method of mixing the host material and the guest material is not particularly limited. , a method of mixing a host material and a guest material in a solid state, and a method of mixing a host material and a guest material by co-evaporation.

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

<Manufacturing method (2)>
In another aspect, a method for producing a composition for a light-emitting device includes a host material preparation step of preparing a host material containing an aromatic compound having a condensed ring skeleton in which three or more benzene rings are condensed, and a guest for the host material A determination step of determining the compounding ratio of the material, and the magnesium atoms contained in the host material with respect to the total amount of the host material and the guest material when mixed with the host material at the above compounding ratio, including an aromatic compound consisting only of hydrogen atoms and carbon atoms. and a guest material preparation step of preparing a guest material in which the total amount of magnesium atoms contained in the guest material exceeds 0 mass ppb and is 180 mass ppb or less; and a manufacturing step of obtaining the composition for light-emitting elements (hereinafter also referred to as "manufacturing method (2)").

In the production method (2), the host material preparation step includes a step (A-1) of preparing an aromatic compound having a condensed ring skeleton in which only three or more benzene rings mixed with magnesium atoms are condensed, and a step (A- A step (A-2) of purifying at least part of the aromatic compound having a condensed ring skeleton in which only three or more benzene rings prepared in 1) are condensed to remove at least part of the magnesium atoms. can be Steps (A-1) and (A-2) in production method (2) may be the same steps as steps (A-1) and (A-2) in production method (1) described above. .

In the manufacturing method (2), in the determining step, the compounding ratio may be determined according to the characteristics of the light emitting element. In the determination step, for example, the compounding ratio may be determined based on the result of fabricating a light-emitting device using a test composition using materials similar to the host material and guest material described above, and the content of magnesium atoms is 180 mass ppb. The compounding ratio may be determined based on the result of fabricating a light-emitting device with a test composition exceeding .

In the production method (2), in the guest material preparation step, the content of magnesium atoms in the host material prepared in the host material preparation step and the compounding ratio determined in the determination step determine the amount of magnesium allowed in the guest material. Atom content is determined. That is, the guest material preparation step can be said to be a step of preparing a guest material having a content of magnesium atoms within an allowable range.

In the production method (2), the guest material preparation step includes, for example, a preparation step (B-1) of preparing an aromatic compound consisting only of hydrogen atoms and carbon atoms mixed with magnesium atoms, and step (B-1). and a step (B-2) of purifying at least part of the prepared aromatic compound consisting only of hydrogen atoms and carbon atoms to remove at least part of the magnesium atoms. Steps (B-1) and (B-2) in production method (2) may be the same steps as steps (B-1) and (B-2) in production method (1) described above. .

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

The production method (2) may further include the host material measurement step described above. The manufacturing method (2) may further include the guest material measurement step described above. The manufacturing method (2) preferably includes the above-described host material measurement step and the above-described guest material measurement step.
In the production method (2), the host material measurement step and the guest material measurement step are preferably performed before the production step.
In the production method (2), the host material preparation step preferably includes the host material measurement step described above. In the production method (2), the guest material preparation step preferably includes the guest material measurement step described above.

<Manufacturing method (3)>
In still another aspect, the method for producing a composition for a light-emitting element comprises: a guest material preparing step of preparing a guest material containing an aromatic compound consisting only of hydrogen atoms and carbon atoms; Magnesium contained in the host material with respect to the total amount of the host material and the guest material when the aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed and the aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed is included. A host material preparation step of preparing a host material in which the total amount of magnesium atoms contained in the atoms and the guest material exceeds 0 mass ppb and is 180 mass ppb or less; and a manufacturing step of obtaining the composition for light-emitting elements (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 compound composed only of hydrogen atoms and carbon atoms mixed with magnesium atoms, and hydrogen prepared in step (B-1). and a step (B-2) of purifying at least part of the aromatic compound consisting only of atoms and carbon atoms to remove at least part of the magnesium atoms. Steps (B-1) and (B-2) in production method (3) may be the same steps as steps (B-1) and (B-2) in production method (1) described above. .

In the manufacturing method (3), in the determining step, the compounding ratio may be determined according to the characteristics of the light emitting element. In the determination step, for example, the compounding ratio may be determined based on the result of fabricating a light-emitting device using a test composition using materials similar to the above-described host material and guest material, and the content of magnesium atoms is 180 mass ppb. The compounding ratio may be determined based on the result of fabricating a light-emitting device using a test composition exceeding .

In the production method (3), in the host material preparation step, the content of magnesium atoms in the guest material prepared in the guest material preparation step and the compounding ratio determined in the determination step determine the amount of magnesium allowed in the host material. Atom content is determined. That is, the host material preparation step can be said to be a step of preparing a host material having a content of magnesium atoms within an allowable range.

In the production method (3), the host material preparation step includes, for example, a preparation step (A-1) of preparing an aromatic compound having a condensed ring skeleton in which only three or more benzene rings mixed with magnesium atoms are condensed; A step (A-2) of purifying at least a portion of the aromatic compound having a condensed ring skeleton in which only three or more benzene rings prepared in (A-1) are condensed to remove at least a portion of the magnesium atoms; , may contain. Steps (A-1) and (A-2) in production method (3) may be the same steps as steps (A-1) and (A-2) in production method (1) described above. .

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

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

<Manufacturing method (4)>
In still another aspect, a method for producing a composition for a light-emitting device includes a host material preparation step of preparing an aromatic compound having a condensed ring skeleton in which three or more benzene rings are condensed as a host material, and hydrogen as a guest material. A guest material preparation step of preparing an aromatic compound consisting only of atoms and carbon atoms, a determination step of determining the compounding ratio of the host material and the guest material, and when the host material and the guest material are mixed at the above compounding ratio, Condensation in which only three or more benzene rings are condensed so that the total amount of magnesium atoms contained in the host material and the magnesium atoms contained in the guest material with respect to the total amount of the host material and the guest material is more than 0 mass ppb and 180 mass ppb or less A purification step of purifying at least part of an aromatic compound having a ring skeleton and an aromatic compound consisting only of hydrogen atoms and carbon atoms, and a host containing an aromatic compound having a condensed ring skeleton in which three or more benzene rings are condensed. A method for producing a composition for a light-emitting element, comprising: Hereinafter, it may be referred to as “manufacturing method (4)”).

In the production method (4), an aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed, prepared in the host material preparation step, and only hydrogen atoms and carbon atoms prepared in the guest material preparation step. At least one of the aromatic compounds may contain a magnesium atom. That is, the host material preparation step is a step of preparing an aromatic compound having a condensed ring skeleton in which only three or more benzene rings mixed with magnesium atoms are condensed, or the guest material preparation step is a step of preparing a magnesium atom mixed It may be a step of preparing an aromatic compound consisting only of hydrogen atoms and carbon atoms.

In the manufacturing method (4), in the determining step, the compounding ratio may be determined according to the characteristics of the light-emitting element. In the determination step, for example, the compounding ratio may be determined based on the result of fabricating a light-emitting device using a test composition using materials similar to the above-described host material and guest material, and the content of magnesium atoms is 180 mass ppb. The blending ratio may be determined based on the results of fabricating a light-emitting device using a test composition exceeding The compounding ratio may be determined based on the result of fabricating a light-emitting device using a test composition in which a group compound and an aromatic compound consisting only of hydrogen atoms and carbon atoms are mixed.

In the production method (4), in the purification step, at least a portion of an aromatic compound having a condensed ring skeleton in which three or more benzene rings are condensed and an aromatic compound consisting only of hydrogen atoms and carbon atoms is purified. Examples of the purification method include the methods exemplified in <Method for adjusting C ¹ and C ^H > described above. The purification step may be a step of purifying only one of an aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed and an aromatic compound consisting only of hydrogen atoms and carbon atoms, and only benzene rings are purified. It may be a step of purifying both an aromatic compound having a condensed ring skeleton in which three or more condensed rings are condensed and an aromatic compound consisting only of hydrogen atoms and carbon atoms.

In the production method (4), in the production step, an aromatic compound having a condensed ring skeleton in which only three or more benzene rings are condensed and an aromatic compound consisting only of hydrogen atoms and carbon atoms are added in the blending ratio determined in the determination step. to mix. At this time, since the purification process has been performed, the total amount of magnesium atoms contained in the host material and the magnesium atoms contained in the guest material with respect to the total amount of the host material and the guest material is more than 0 mass ppb and 180 mass ppb or less. This makes it possible to obtain a composition for a light-emitting device in which long-term deterioration of the light-emitting device is suppressed.
The method of mixing the host material and the guest material in the production step of production method (4) may be the same as the method of mixing the host material and guest material in the production step of production method (1).

The production method (4) may further include the host material measurement step described above. The production method (4) may further include the guest material measurement step described above. The manufacturing method (4) preferably includes the above-described host material measurement step and the above-described guest material measurement step.
In the manufacturing method (4), it is preferable that the host material measuring step and the guest material measuring step be performed before the manufacturing step.
In production method (4), the host material preparation step or purification step preferably includes the host material measurement step described above. In the production method (4), the guest material preparation step or 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 manufacturing a light-emitting device may include the step of forming the organic layer from the composition for a light-emitting device.
In the method for manufacturing the light-emitting element of the present embodiment, the organic layer can be formed by using, for example, the same method as for forming the above-described film.
In addition, in the method for manufacturing the light-emitting element of this embodiment, the manufacturing method described in the section <Light-emitting element> may be used.
Further, examples of the light-emitting element in the method for manufacturing the light-emitting element of the present embodiment include the light-emitting element described in the above section <Light-emitting element>.

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

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

In this example, the amount of magnesium 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 JP-A-2011-105643.
Compound EM1 was synthesized according to the method described in International Publication No. 2011/137922.

The HPLC area percentage value of compound H1 was greater than 99.5%. In addition, the amount (C ^H ) of magnesium atoms contained in compound H1 was 200 mass ppb.
The HPLC area percentage value of compound EM1 was greater than 99.5%. Further, the amount (C ¹ ) of magnesium atoms contained in compound EM1 was 31 mass ppb.

<Purification of Compound H1 (Synthesis of Compound H2)>
Compound H2 was obtained by repeatedly performing sublimation purification of compound H1 until the amount of magnesium atoms contained in compound H1 was below the detection limit (0 mass ppb). In the sublimation purification, the degree of vacuum was set to 3×10 ⁻³ Pa to 5×10 ⁻³ Pa, and the sublimation temperature was set to 250° C. to 300° C.
The HPLC area percentage value of compound H2 was greater than 99.5%. In addition, the amount (C ^H ) of magnesium atoms contained in compound H2 was below the detection limit (0 mass ppb).

<Purification of Compound EM1 (Synthesis of Compound EM2)>
Compound EM2 was obtained by repeatedly performing sublimation purification of compound EM1. In the sublimation purification, the degree of vacuum was set to 3×10 ⁻³ Pa to 5×10 ⁻³ Pa, and the sublimation temperature was set to 250° C. to 300° C.
The HPLC area percentage value of compound EM2 was greater than 99.5%. The amount (C ¹ ) of magnesium atoms contained in compound EM2 was 130 mass ppb.

The maximum peak wavelength of the emission spectra of compounds H1 and H2 was 421 nm. The maximum peak wavelength of the emission spectra of compounds EM1 and EM2 was 441 nm.

<Example D1> Production and evaluation of light emitting device 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 to a thickness of 35 nm by spin coating. A hole injection layer was formed by heating the substrate having the hole injection layer laminated thereon on a hot plate at 50° C. for 3 minutes and then at 230° C. for 15 minutes in an air atmosphere.

(Formation of hole transport layer)
A polymer compound HTL-1 was dissolved in xylene at a concentration of 0.7% by 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 on a hot plate at 180° C. for 60 minutes in a nitrogen gas atmosphere. 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 %/1 mass %/9 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 reducing the pressure of the substrate on which the light-emitting layer is formed to 1.0×10 ⁻⁴ Pa or less in a vapor deposition machine, sodium fluoride of about 4 nm is deposited on the light-emitting layer as a cathode, and then on the sodium fluoride layer. About 80 nm of aluminum was evaporated. After vapor deposition, the 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 element D1. The device was driven at a constant current of 150 mA/cm ² and the time until the luminance reached 50% (hereinafter also referred to as “LT50”) was measured.

<Examples D2 to D11 and Comparative Example CD1> Production and Evaluation of Light Emitting Elements D2 to D11 and CD1 EM1=90% by mass/1% by mass/9% by mass)”, except that the materials listed in Table 1 were used in the material ratios listed in Table 1. ~D11 and CD1 were generated.
EL emission was observed by applying a voltage to the light emitting elements D2 to D11 and CD1. LT50 of the light-emitting elements D2 to D11 and CD1 was measured.

Table 1 shows the results of Examples D1 to D11 and Comparative Example CD1. Relative values of LT50 of the light-emitting elements D1 to D11 are shown when the LT50 of the light-emitting element CD1 is set to 1.0.

ADVANTAGE OF THE INVENTION According to this invention, the composition useful for manufacture of the light emitting element by which long-term deterioration was suppressed is provided. INDUSTRIAL APPLICABILITY The present invention is industrially useful because the production of a light-emitting device in which long-term deterioration is suppressed has effects such as resource saving and energy saving.

Claims (15)

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 preparation step of preparing a host material;
a guest material preparation step of preparing a guest material containing an aromatic compound consisting only of hydrogen atoms and carbon atoms;
The host material and the guest material are mixed at a compounding ratio such that the total amount of magnesium atoms contained in the host material and magnesium atoms contained in the guest material is more than 0 mass ppb and 180 mass ppb or less, and a light emitting device a manufacturing process for obtaining a composition for
including
The host material preparation step includes:
A step (A-1) of preparing a host material having a magnesium atom content of 200 mass ppb or more;
A step (A-2) of purifying at least part of the host material prepared in the step (A-1) to obtain a host material having a magnesium atom content of 190 mass ppb or less;
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 preparation step of preparing a host material;
a determining step of determining the compounding ratio of the guest material to the host material;
It contains an aromatic compound consisting only of hydrogen atoms and carbon atoms, and is contained in the magnesium atoms contained in the host material and the guest material relative to the total amount of the host material and the guest material when mixed with the host material in the above mixing ratio. a guest material preparation step of preparing a guest material in which the total amount of magnesium atoms exceeds 0 mass ppb and is 180 mass ppb or less;
a manufacturing step of mixing the host material and the guest material at the blending ratio to obtain a composition for a light-emitting element;
including
The host material preparation step includes:
A step (A-1) of preparing a host material having a magnesium atom content of 200 mass ppb or more;
A step (A-2) of purifying at least part of the host material prepared in the step (A-1) to obtain a host material having a magnesium atom content of 190 mass ppb or less;
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 compound consisting only of hydrogen atoms and carbon atoms;
a determination step of determining the compounding ratio of the host material to the guest material;
When mixed with the guest material at the compounding ratio, the total amount of magnesium atoms contained in the host material and magnesium atoms contained in the guest material with respect to the total amount of the host material and the guest material is more than 0 mass ppb and 180 mass ppb or less A host material preparation step of preparing a host material,
a manufacturing step of mixing the guest material and the host material at the blending ratio to obtain a composition for a light-emitting element;
including
The host material preparation step includes:
A step (A-1) of preparing a host material having a magnesium atom content of 200 mass ppb or more;
A step (A-2) of purifying at least part of the host material prepared in the step (A-1) to obtain a host material having a magnesium atom content of 190 mass ppb or less;
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 preparation step of preparing a host material;
a guest material preparation step of preparing an aromatic compound consisting only of hydrogen atoms and carbon atoms as a guest material;
a determination step of determining the 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 magnesium atoms contained in the host material and the magnesium atoms contained in the guest material with respect to the total amount of the host material and the guest material is 0 mass ppb. A purification step of purifying at least a portion of the host material and the aromatic compound consisting only of hydrogen atoms and carbon atoms so that the content is more than 180 mass ppb or less;
a manufacturing step of obtaining a composition for a light-emitting element by mixing the host material and the guest material containing an aromatic compound consisting only of hydrogen atoms and carbon atoms at the blending ratio;
including
The host material preparation step includes:
A step (A-1) of preparing a host material having a magnesium atom content of 200 mass ppb or more;
A step (A-2) of purifying at least part of the host material prepared in the step (A-1) to obtain a host material having a magnesium atom content of 190 mass ppb or less;
A method for producing a composition for a light emitting device, comprising: The step (A-2) is a step of purifying at least part of the host material prepared in the step (A-1) to obtain a host material having a magnesium atom content of 180 mass ppb or less. A method for producing the composition for a light-emitting device according to any one of claims 1 to 4. The step (A-2) is a step of purifying at least part of the host material prepared in the step (A-1) to obtain a host material having a magnesium atom content of 160 mass ppb or less. A method for producing the composition for a light-emitting device according to any one of claims 1 to 5. 7. The method for producing a composition for a light-emitting device according to claim 1, wherein said aromatic compound consisting only of hydrogen atoms and carbon atoms is a low-molecular-weight compound. 8. The method for producing a composition for a light-emitting device according to claim 7, wherein the aromatic compound consisting only of hydrogen atoms and carbon atoms is a compound represented by formula (FB).

[In the formula,
n ^1B represents an integer of 0 or more.
Ar ^1B represents a group obtained by removing n ^1B or more hydrogen atoms directly bonded to carbon atoms constituting the aromatic hydrocarbon ring from a compound having an aromatic hydrocarbon ring.
R ^1B represents a hydrocarbon group consisting only of hydrogen atoms and carbon atoms, and this group may further have a substituent consisting only of hydrogen atoms and carbon atoms. When there are multiple such substituents, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. When multiple 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 carbon atom to which each is bonded. ] 9. The method for producing a composition for a light emitting device according to claim 8, wherein the aromatic hydrocarbon ring is a bicyclic to heptacyclic aromatic hydrocarbon ring. The aromatic hydrocarbon ring is a benzofluorene ring, pyrene ring, fluoranthene ring, dibenzofluorene ring, perylene ring, benzofluoranthene ring, spirobifluorene ring, benzospirobifluorene ring or acenaphthofluoranthene ring. , a method for producing the composition for a light-emitting device according to claim 8 or 9. The hydrocarbon group consisting only of hydrogen atoms and carbon atoms is an alkyl group, a cycloalkyl group or an aryl group (these groups may have substituents consisting only of hydrogen atoms and carbon atoms). , a method for producing the composition for a light emitting device according to any one of claims 8 to 10. The host material preparation step according to any one of claims 1 to 11, further comprising a measuring step of measuring the content of magnesium atoms contained in the host material obtained in step (A-2). and a method for producing a composition for a light-emitting device. The host material preparation step according to any one of claims 1 to 12, further comprising a measurement step of measuring the content of magnesium atoms contained in the host material prepared in step (A-1). A method for producing a composition for a light-emitting device. A composition for a light emitting device produced by the production method according to any one of claims 1 to 13, a hole transport material, a hole injection material, an electron transport material, an electron injection material, a light emitting material, and an antioxidant. and at least one selected from the group consisting of a solvent. A method for manufacturing a light-emitting device comprising an anode, a cathode, and an organic layer provided between the anode and the cathode,
A method for manufacturing a light-emitting device, comprising forming the organic layer from the composition for a light-emitting device manufactured by the manufacturing method according to any one of claims 1 to 14.