JP2020060548A - Film for light-emitting element and light emitting element using the same - Google Patents

Abstract

To provide a method for analyzing a crosslinking group in a film for a light-emitting element.SOLUTION: A method for analyzing a crosslinking group in a film for a light-emitting element, comprises: (1) a step for swelling the film for the light-emitting element with a solvent; and (2) a step for measuring the crosslinking group of the swollen film for the light-emitting element by using nuclear magnetic resonance spectroscopy.SELECTED DRAWING: None

Description

  The present invention relates to a light emitting device film and a light emitting device using the same.

A light emitting element such as an organic electroluminescence element can be suitably used for display and lighting applications. As a film used for a light emitting element, for example, Patent Document 1
2 and 2 propose a membrane in which a polymer compound having a crosslinkable group is crosslinked by heating the polymer compound at 180 ° C. or 230 ° C. for 60 minutes.

International Publication No. 2017/154882 JP, 2011-52229, A

However, the light emitting device manufactured using the above-described film for a light emitting device does not always have sufficient brightness life. Therefore, an object of the present invention is to provide a film for a light emitting device, which is useful for manufacturing a light emitting device having an excellent luminance life.

The present inventors have conducted intensive studies to solve the above problems, and found a method for quantifying the cross-linking group contained in the film for a light emitting device, and further using the method, contained in the film for a light emitting device. It has been found that by setting the amount of the cross-linking group within a predetermined range, it is possible to greatly improve the luminance life of a light emitting device manufactured using the film for a light emitting device. Based on this knowledge,
Further studies were conducted and the present invention was completed.

The present invention provides the following [1] to [8].
[1]
A film for a light emitting device, which comprises a crosslinked product having a crosslinkable group, wherein the crosslinked product having the crosslinkable group is a crosslinked product of a crosslinkable material having a crosslinkable group, and the crosslinkable group contained in the film for the light emitting device is 0. .01
A film for a light emitting device, which has a thickness of 5 mm / g to 0.05 mm / g.
[2]
The cross-linking material is a low-molecular compound having at least one cross-linking group selected from the cross-linking group A, or a polymer compound containing a structural unit having at least one cross-linking group selected from the cross-linking group A. The film for a light emitting device according to [1].
(Crosslinking group A)
[In the formula, R ^XL represents a methylene group, an oxygen atom, a sulfur atom or -CO-, and n ^XL represents 0 to 5
Represents the integer. When there are a plurality of R ^XL , they may be the same or different. The plurality of n ^XL existing may be the same or different. * 1 represents a binding position. These bridging groups may have a substituent, and when a plurality of the substituents are present, they may be bonded to each other to form a ring together with the carbon atom to which they are bonded. ]

[3]
The cross-linking material is a polymer compound containing a constitutional unit having at least one cross-linking group selected from the cross-linking group A, and the constitutional unit is a constitutional unit represented by the formula (Z) or a formula The film for a light emitting device according to [2], which is a structural unit represented by (Z ′).

[In formula, nA represents the integer of 0-5 and n represents the integer of 1-4. When there are a plurality of nAs, they may be the same or different. Ar ³ represents an aromatic hydrocarbon group or a heterocyclic group, and these groups may have a substituent. L ^A represents an alkylene group, a cycloalkylene group, an arylene group, a divalent heterocyclic group, a group represented by —N (R ′) —, an oxygen atom or a sulfur atom, and these groups each have a substituent. You may have. R'represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. When there are a plurality of L ^A , they may be the same or different. X represents a cross-linking group selected from the cross-linking group A group. When there are a plurality of Xs, they may be the same or different. ]

[In formula, mA represents the integer of 0-5, m represents the integer of 1-4, c represents 0 or 1. m
When there are a plurality of A's, they may be the same or different. Ar ⁵ represents an aromatic hydrocarbon group, a heterocyclic group, or a group in which at least one aromatic hydrocarbon group and at least one heterocyclic group are directly bonded, and these groups have a substituent. You may have. Ar ⁴ and Ar ⁶ each independently represent an arylene group or a divalent heterocyclic group, and these groups may have a substituent. Ar ⁴ , Ar ⁵ and Ar ⁶ each form a ring by directly bonding or bonding via an oxygen atom or a sulfur atom to a group other than the group bonded to the nitrogen atom to which the group is bonded. You may have. K ^A is an alkylene group, a cycloalkylene group, an arylene group, 2
Represents a valent heterocyclic group, a group represented by -N (R '')-, an oxygen atom or a sulfur atom, and these groups may have a substituent. R '' is a hydrogen atom, an alkyl group, a cycloalkyl group,
It represents an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. When there are a plurality of K ^A , they may be the same or different. X ′ represents a bridging group selected from the bridging group A group, a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. . When there are a plurality of X's, they may be the same or different. However, at least one X ′ is a bridging group selected from the above-mentioned group A of bridging groups. ]

[4]
The film for a light emitting device according to [2], wherein the cross-linking material is a low molecular weight compound represented by the formula (Z ″).

[In the formula, m ^B1 , m ^B2 and m ^B3 each independently represent an integer of 0 or more and 10 or less. Plural m ^B1s may be the same or different. When there are a plurality of m ^B3 , they may be the same or different. Ar ⁷ represents an aromatic hydrocarbon group, a heterocyclic group, or a group in which at least one aromatic hydrocarbon group and at least one heterocyclic group are directly bonded, and these groups have a substituent. You may have. When there are a plurality of Ar ⁷ , they may be the same or different. L ^B1 represents an alkylene group, a cycloalkylene group, an arylene group, a divalent heterocyclic group, a group represented by —N (R ′ ″) —, an oxygen atom or a sulfur atom, and these groups are substituents. May have. R '''represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. When there are a plurality of L ^B1 , they may be the same or different. X ″ represents a bridging group selected from the group A of bridging groups, a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. Good. A plurality of X ″ s may be the same or different. However, at least one of the plurality of X ″ s present is a cross-linking group selected from the cross-linking group A group. ]

[5]
The bridging group is the formula (XL-1), the formula (XL-16), the formula (XL-17),
[2] to [4] containing a bridging group represented by the formula (XL-18) or the formula (XL-19).
] The film for a light-emitting device according to any one of items

[6]
The method according to any one of [1] to [5], further containing at least one selected from the group consisting of a hole transport material, a hole injection material, an electron transport material, an electron injection material, a light emitting material and an antioxidant. Film for light emitting device.

[7]
It is a light emitting element which has an anode, a cathode, and an organic layer, Comprising: The said organic layer is located between the said anode and the said cathode, The said organic layer is a film for light emitting elements in any one of [1]-[6]. Is a light emitting device.
[8]
A method for analyzing (quantifying) a crosslinkable group in a film for a light emitting device,
(1) a step of swelling the film for a light emitting element with a solvent, and (2) a step of measuring a cross-linking group of the film for a light emitting element thus swollen by using nuclear magnetic resonance spectroscopy
Analytical method including.

According to the present invention, it is possible to provide a film for a light emitting device, which is useful for manufacturing a light emitting device having an excellent luminance life. Further, according to the present invention, it is possible to provide a light emitting device containing the film for a light emitting device.

It is a graph which shows the relationship between content of the bridge | crosslinking group in the film for light emitting elements used in Examples 1-4 and Comparative Examples 1-2, and luminance lifetime (LT95).

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

1. Explanation of Common Terms The terms commonly used in the present specification have the following meanings unless otherwise specified.
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.
The hydrogen atom may be a deuterium atom or a light hydrogen atom.
In the formula representing a metal complex, a solid line representing a bond with a metal means an ionic bond, a covalent bond or a coordinate bond.

A "polymer compound" has a molecular weight distribution and a polystyrene-equivalent number average molecular weight of 1 x 10
^It means a polymer of ³ to 1 × 10 ⁸ .
The polymer compound may be a block copolymer, a random copolymer, an alternating copolymer or a graft copolymer, or may be in another form.
As for the terminal group of the polymer compound, when the polymerizing active group remains as it is, when the polymer compound is used for the production of a light emitting device, the light emitting property or the luminance life may be reduced. Is. The terminal group of the polymer compound is preferably a group which is conjugated to the main chain, and for example, an aryl group or a monovalent heterocyclic group which is bonded to the main chain of the polymer compound through a carbon-carbon bond. Is mentioned.
The “low molecular weight compound” means a compound having no molecular weight distribution and a molecular weight of 1 × 10 ⁴ or less.
The “constituent unit” means a unit present in one or more units in the polymer compound.

The “alkyl group” may be linear or branched. The linear alkyl group has usually 1 to 50 carbon atoms, preferably 3 to 30 carbon atoms, and more preferably 4 to 20 carbon atoms. The branched alkyl group has usually 3 to 50 carbon atoms, preferably 3 to 30 carbon atoms, and more preferably 4 to 20 carbon atoms.
The alkyl group may have a substituent, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, 2-butyl group, isobutyl group, tert-butyl group, pentyl group, isoamyl group, 2-ethylbutyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, 3-propylheptyl group, decyl group, 3,7-dimethyloctyl group, 2-ethyloctyl group, 2-hexyldecyl group, dodecyl group And a group in which a hydrogen atom in these groups is substituted with a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a fluorine atom or the like (for example, a trifluoromethyl group, a pentafluoroethyl group, a perfluorobutyl group , Perfluorohexyl group, perfluorooctyl group, 3-phenylpropyl group, 3- (4-methylphenyl) propyl group, 3- (3,5-di-hexyl Phenyl) propyl group, 6-ethyloxy-hexyl group).
The "cycloalkyl group" has usually 3 to 50 carbon atoms, preferably 3 to 30 carbon atoms,
More preferably, it is 4-20.
The cycloalkyl group may have a substituent, and examples thereof include a cyclohexyl group, a cyclohexylmethyl group, and a cyclohexylethyl group.

The "aryl group" means an atomic group remaining after removing one hydrogen atom directly bonded to a carbon atom constituting a ring from an aromatic hydrocarbon. The number of carbon atoms of the aryl group is usually 6 to 60,
It is preferably 6 to 20, more preferably 6 to 10.
The aryl group may have a substituent, for example, phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthracenyl group, 2-anthracenyl group, 9-anthracenyl group, 1-pyrenyl group, 2 -Pyrenyl group, 4-pyrenyl group, 2-fluorenyl group, 3-fluorenyl group, 4-fluorenyl group, 2-phenylphenyl group, 3-phenylphenyl group, 4-phenylphenyl group, and hydrogen atom in these groups However, examples thereof include a group substituted with an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a fluorine atom and the like.

The "alkoxy group" may be linear or branched. The linear alkoxy group usually has 1 to 40 carbon atoms, and preferably 4 to 10 carbon atoms. The number of carbon atoms of the branched alkoxy group is usually 3 to 40, preferably 4 to 10.
The alkoxy group may have a substituent, for example, a methoxy group, an ethoxy group, a propyloxy group, an isopropyloxy group, a butyloxy group, an isobutyloxy group, a tert-butyloxy group, a pentyloxy group, a hexyloxy group, Heptyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, 3,7-dimethyloctyloxy group, lauryloxy group, and hydrogen atom in these groups, cycloalkyl group, alkoxy group, Examples thereof include a cycloalkoxy group, an aryl group, and a group substituted with a fluorine atom.
The number of carbon atoms of the "cycloalkoxy group" is usually 3 to 40, preferably 4 to 10.
The cycloalkoxy group may have a substituent, and examples thereof include a cyclohexyloxy group.

The "aryloxy group" has usually 6 to 60 carbon atoms, preferably 6 to 48 carbon atoms.
Aryloxy group may have a substituent, for example, phenoxy group, 1-naphthyloxy group, 2-naphthyloxy group, 1-anthracenyloxy group, 9-anthracenyloxy group, 1- Examples thereof include a pyrenyloxy group and groups in which a hydrogen atom in these groups is substituted with an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, a fluorine atom or the like.

The “p-valent heterocyclic group” (p represents an integer of 1 or more) means p from the hydrogen atom directly bonded to the carbon atom or the hetero atom constituting the ring from the heterocyclic compound. Means the rest of the atomic groups excluding the hydrogen atoms. Among p-valent heterocyclic groups, it is the remaining atomic group obtained by removing p hydrogen atoms from the hydrogen atoms directly bonded to the carbon atoms or heteroatoms constituting the ring from the aromatic heterocyclic compound. A "p-valent aromatic heterocyclic group" is preferable.
"Aromatic heterocyclic compound" means a heterocyclic compound such as oxadiazole, thiadiazole, thiazole, oxazole, thiophene, pyrrole, phosphole, furan, pyridine, pyrazine, pyrimidine, triazine, pyridazine, quinoline, isoquinoline, carbazole, and dibenzophosphole. A compound in which the ring itself exhibits aromaticity, and phenoxazine, phenothiazine,
Even if the heterocycle itself such as dibenzoborol, dibenzosilole, benzopyran does not show aromaticity, it means a compound in which an aromatic ring is condensed to the heterocycle.

The monovalent heterocyclic group usually has 2 to 60 carbon atoms, and preferably 4 to 20 carbon atoms.
The monovalent heterocyclic group may have a substituent, for example, a thienyl group, a pyrrolyl group, a furyl group, a pyridyl group, a piperidinyl group, a quinolinyl group, an isoquinolinyl group, a pyrimidinyl group, a triazinyl group, and these A group in which a hydrogen atom in the group is substituted with an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group or the like can be mentioned.

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

The "amino group" may have a substituent, and a substituted amino group is preferable. The substituent which the amino group has is preferably an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group.
Examples of the substituted amino group include a dialkylamino group, a dicycloalkylamino group and a diarylamino group.
Examples of the amino group include a dimethylamino group, a diethylamino group, a diphenylamino group, a bis (4-methylphenyl) amino group, a bis (4-tert-butylphenyl) amino group, a bis (3,
5-di-tert-butylphenyl) amino group may be mentioned.

The “alkenyl group” may be linear or branched. The linear alkenyl group has usually 2 to 30 carbon atoms, and preferably 3 to 20 carbon atoms. The branched alkenyl group has usually 3 to 30 carbon atoms, preferably 4 to 20 carbon atoms.
The number of carbon atoms of the “cycloalkenyl group” is usually 3 to 30, preferably 4 to 20.
The alkenyl group and cycloalkenyl group may have a substituent, for example, vinyl group, 1-propenyl group, 2-propenyl group, 2-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 a substituent are mentioned.

The “alkynyl group” may be linear or branched. The number of carbon atoms in the alkynyl group is
It is usually 2 to 20, preferably 3 to 20. The number of carbon atoms of the branched alkynyl group is usually 4-30, preferably 4-20.
The number of carbon atoms of the "cycloalkynyl group" is usually 4 to 30, preferably 4 to 20.
Alkynyl group and cycloalkynyl group may have a substituent, for example, ethynyl group, 1-propynyl group, 2-propynyl group, 2-butynyl group, 3-butynyl group, 3-pentynyl group, 4- Examples thereof include a pentynyl group, a 1-hexynyl group, a 5-hexynyl group, and groups in which these groups have a substituent.

The "arylene group" means an atomic group remaining after removing two hydrogen atoms directly bonded to carbon atoms constituting a ring from an aromatic hydrocarbon. The arylene group has usually 6 to 60 carbon atoms, preferably 6 to 30 carbon atoms, and more preferably 6 to 18 carbon atoms.
The arylene group may have a substituent, for example, a phenylene group, a naphthalenediyl group, an anthracene diyl group, a phenanthrene diyl group, a dihydrophenanthren diyl group, a naphthacenediyl group, a fluorenediyl group, a pyrenediyl group, a perylene diyl group, And chrysenediyl groups, and groups in which these groups have substituents, preferably of the formula (A
-1) to groups represented by formula (A-20). The arylene group includes a group in which a plurality of these groups are bonded.

[In the formula, R and R ^a each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group. A plurality of R and R ^a may be the same or different, and R ^a may be bonded to each other to form a ring together with the atoms to which they are bonded. ]

The divalent heterocyclic group usually has 2 to 60 carbon atoms, preferably 3 to 20 carbon atoms, and more preferably 4 to 15 carbon atoms.
The divalent heterocyclic group may have a substituent, for example, pyridine, diazabenzene,
Triazine, azanaphthalene, diazanaphthalene, carbazole, dibenzofuran, dibenzothiophene, dibenzosilole, phenoxazine, phenothiazine, acridine, dihydroacridine, furan, thiophene, azole, diazole, triazole, to a carbon atom or a hetero atom constituting a ring. A divalent group obtained by removing two hydrogen atoms from the hydrogen atoms directly bonded to each other is mentioned, and a group represented by formula (AA-1) to formula (AA-34) is preferable. The divalent heterocyclic group includes a group in which a plurality of these groups are bonded.

[In the formula, R and R ^a represent the same meaning as described above. ]

The "crosslinking group" is a group capable of forming a new bond by being subjected to heat treatment, ultraviolet irradiation treatment, near-ultraviolet irradiation treatment, visible light irradiation treatment, infrared irradiation treatment, radical reaction, etc., The crosslinkable group is preferably a crosslinkable group represented by formula (XL-1) to formula (XL-19) of the group A, more preferably formula (XL-1), formula (XL-3) or formula (XL-1). XL-9), formula (X
L-10) and a bridging group represented by formula (XL-16) to formula (XL-19), and more preferably formula (XL-1) and formula (XL-16) to formula (XL-19). ) Is a cross-linking group represented by
A cross-linking group represented by formula (XL-1) or formula (XL-17) is particularly preferable.

In addition, in Formula (XL-2) -Formula (XL-4), a wavy line is an isomer (preferably Z-form or E-form).
Body). When there are a plurality of wavy lines, they may be the same or different.

The "substituent" means, for example, a halogen atom, a cyano group, an alkyl group, a cycloalkyl group,
Aryl group, monovalent heterocyclic group, alkoxy group, cycloalkoxy group, aryloxy group,
It represents an amino group, a substituted amino group, an alkenyl group, a cycloalkenyl group, an alkynyl group or a cycloalkynyl group. The substituent may be a bridging group.

2. Film for light emitting element
2.1 Crosslinked Body Having Crosslinking Group The film for a light emitting device of the present invention is characterized by containing a crosslinked body having a predetermined amount of a crosslinking group (hereinafter, also referred to as “crosslinked body”). The crosslinked body is a crosslinked body obtained by crosslinking a crosslinkable material having a crosslinkable group (hereinafter, also referred to as “crosslinking material”). The crosslinking group contained in the light emitting device film is 0.015 mmol / g to 0.05 mmol / g. When the cross-linking material is cross-linked to obtain the cross-linked product, by selecting the cross-linking conditions, the cross-linking reaction does not proceed completely and the unreacted cross-linking group can remain. The cross-linking group of the cross-linked product is derived from the cross-linking group of the raw material cross-linking material.
The film for a light emitting device of the present invention includes any of the crosslinked material in which the crosslinkable material is crosslinked intramolecularly, crosslinked between molecules, or crosslinked intramolecularly and intermolecularly.
The film for a light emitting device of the present invention is a film obtained by crosslinking a cross-linking material having a cross-linking group by an external stimulus such as heating or light irradiation. Since the film for a light emitting device of the present invention is substantially insolubilized in a solvent, it can be suitably used for laminating a light emitting device described later.

The crosslinking group contained in the film for a light emitting device of the present invention is 0.015 mmol / g to 0.05 mmol / g, preferably 0.018 mmol / g to 0.049 mmol / g, and more preferably 0.030 mmol / g to 0.049. mmol / g, and more preferably 0.035 mmol / g to 0.046 mmol / g. When the cross-linking group (content of the cross-linking group) contained in the light-emitting device film is in this range, the luminance life of the light-emitting device obtained by using the light-emitting device film is significantly improved.

The thickness of the film for a light emitting device of the present invention (the thickness of the film after crosslinking) is usually 1 nm to 10 μm,
The thickness is preferably 2 nm to 500 nm, more preferably 5 nm to 150 nm.

The film for a light-emitting device of the present invention is a composition containing a cross-linking material having a cross-linking group and a solvent (hereinafter,
Say "ink". ), For example, spin coating method, casting method, micro gravure coating method, gravure coating method, bar coating method, roll coating method, wire bar coating method, dip coating method, spray coating method, screen printing method, flexographic printing Method, an offset printing method, an inkjet printing method, a capillary coating method, a nozzle coating method and the like. The viscosity of the ink may be adjusted depending on the type of wet method, but is preferably 1 to 20 mPa · s at 25 ° C.

The solvent contained in the ink is preferably a solvent capable of dissolving or uniformly dispersing the solid content in the ink. Examples of the solvent include chlorinated hydrocarbon solvents, ether solvents, aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, ketone solvents, ester solvents, polyhydric alcohol solvents, alcohol solvents, sulfoxide solvents, amide solvents and water. To be

In the ink, the amount of the solvent used is usually 10 to 1000 parts by mass, preferably 20 to 200 parts by mass, relative to 1 part by mass of the crosslinking material having a crosslinking group.

In the light emitting device film of the present invention, the heating temperature for crosslinking is usually 50 ° C to 300 ° C, preferably 50 ° C to 260 ° C, more preferably 130 ° C to 230 ° C, and further preferably Is 190 ° C to 220 ° C. The heating time is usually 1 minute to 1000 minutes, preferably 5 minutes to 50 minutes.
It is 0 minutes, more preferably 10 minutes to 120 minutes, further preferably 20 minutes to 100 minutes, and particularly preferably 40 minutes to 80 minutes.

In the film for a light emitting device of the present invention, the type of light used for light irradiation for crosslinking is, for example, ultraviolet light, near ultraviolet light, or visible light.

The film for a light emitting device of the present invention is suitable as a hole transport layer or a hole injection layer in a light emitting device.

In the film for a light emitting device of the present invention, at least one selected from the group consisting of a crosslinked body having the above crosslinkable group, a hole transport material, a hole injection material, an electron transport material, an electron injection material, a light emitting material and an antioxidant. It may contain a composition comprising one material. The composition is obtained by, for example, producing a crosslinked product having a crosslinkable group by crosslinking the crosslinkable material having the crosslinkable group, and then mixing a material such as a hole transport material, or a crosslinkable material having the crosslinkable group. It can be manufactured by mixing and a material such as the hole transport material and then crosslinking. However, the hole-transporting material, the hole-injecting material, the electron-transporting material, and the electron-injecting material are different from the crosslinked body of the crosslinked material having a crosslinkable group.

2.2 Crosslinking Material Having Crosslinking Group The crosslinked body having a crosslinking group can be produced, for example, by crosslinking a crosslinking material having a crosslinking group. Examples of the cross-linking material include a polymer compound containing a constitutional unit having a cross-linking group, and a low-molecular compound having a cross-linking group, and a polymer compound containing a constitutional unit having a cross-linking group is preferable.

(1) Polymer Compound Containing Structural Unit Having Crosslinking Group The structural unit having a crosslinking group contained in the polymer compound is preferably a structural unit having at least one crosslinking group selected from the group A of crosslinking groups. , And more preferably, the structural unit represented by the formula (Z) or the structural unit represented by the formula (Z ′). These constituent units will be described later.

The polymer compound may include a structural unit having no crosslinking group, if necessary, in addition to the structural unit having a crosslinking group. Examples of the structural unit having no crosslinking group include a structural unit represented by the formula (Y) and a structural unit represented by the formula (X) described later.

The content (molar fraction) of the structural unit having a crosslinking group is preferably 0.5 to 80 mol% with respect to the total molar amount of the structural units contained in the polymer compound containing the structural unit having a crosslinking group. %, More preferably 3 to 65 mol%, further preferably 5 to 50 mol%. Within this range, the polymer compound will have excellent stability and crosslinkability. As for the structural unit having a cross-linking group, only one type may be contained in the polymer compound, or two or more types may be contained in the polymer compound.

A polymer compound containing a structural unit having a cross-linking group has an excellent hole-transporting property, and therefore a compound represented by the formula (
It preferably contains a structural unit represented by X). The content rate (molar fraction) of the structural unit represented by the formula (X) is preferably 1 to 80 mol% with respect to the total molar amount of the structural units contained in the polymer compound, and more preferably Is 10 to 70 mol%, more preferably 30
Is about 60 mol%. The constitutional unit represented by the formula (X) may be contained alone or in combination of two or more in the polymer compound containing the constitutional unit having a crosslinking group.

The polymer compound containing a structural unit having a cross-linking group is more preferable in terms of the luminance life of the light emitting device of this embodiment, and thus preferably further contains a structural unit represented by the formula (Y). The content (molar fraction) of the structural unit represented by the formula (Y) is preferably 0.5 to 90 mol%, and more preferably 30 to 90 mol% with respect to the total molar amount of the polymer compound. It is 80 mol%. Formula (Y)
In the polymer compound containing the structural unit having a crosslinkable group, only one type of structural unit represented by may be contained, or two or more types may be contained.

The polymer compound containing a structural unit having a cross-linking group is excellent in hole transporting property and more excellent in the luminance life of the light emitting device of the present embodiment. Therefore, the structural unit represented by the formula (X) and the formula It preferably contains a structural unit represented by (Y).

Examples of the polymer compound containing a structural unit having a crosslinking group include polymer compounds P-1 to P-1.
P-8 is mentioned. Here, the "other" means a constitutional unit other than the constitutional units represented by the formula (Z), the formula (Z '), the formula (X), and the formula (Y).

[In the table, p ', q', r ', s', and t'represent the mole fraction (mol%) of each structural unit.
p ′ + q ′ + r ′ + s ′ + t ′ = 100, and 70 ≦ p ′ + q ′ + r ′ + s ′ ≦
100. ]

The polymer compound containing a constitutional unit having a cross-linking group may be any of a block copolymer, a random copolymer, an alternating copolymer and a graft copolymer, and may have other modes. It is preferably a copolymer obtained by copolymerizing a plurality of types of raw material monomers.
The polystyrene-equivalent number average molecular weight of the polymer compound containing a constitutional unit having a cross-linking group is preferably 5 × 10 ³ to 1 × 10 ⁶ , more preferably 1 × 10 ^{4 to} 5 × 10 ⁵ , and further It is preferably 1.5 × 10 ⁴ to 1 × 10 ⁵ .

  The constitutional units represented by formula (X), formula (Y), formula (Z) and formula (Z ') will be described below.

(1-1) Structural unit represented by formula (Y)

Examples of the structural unit having no crosslinking group include structural units represented by the formula (Y).
[In the formula, Ar ^Y1 represents an arylene group, a divalent heterocyclic group, or a divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded, The group of may have a substituent. ]

The arylene group represented by Ar ^Y1 is more preferable in formula (A-1) to formula (A-10), formula (A-19) or formula (A-19) since the light emitting device of the present embodiment has a longer luminance life. A-20) is a group represented by, more preferably, formula (A-1) ~ formula (A-3), formula (A-6) -formula (A-10), formula (A-19). Or a group represented by the formula (A-20), more preferably the formula (A-1), the formula (A-2), the formula (A-7), the formula (A-9) or the formula (A -19) is a group represented by
The divalent heterocyclic group represented by Ar ^Y1 is more preferable in the formula (AA-1) -formula (AA-4) and formula (AA-10) because the light emitting device of the present embodiment has a longer luminance life. ) -Formula (AA-15), Formula (AA-18) -Formula (AA-22), Formula (
AA-33) or a group represented by formula (AA-34), more preferably the formula (AA-4), formula (AA-10), formula (A
A-12) or a group represented by the formula (AA-14).
In the divalent group in which at least one arylene group represented by Ar ^Y1 and at least one divalent heterocyclic group are directly bonded, the preferred range of the arylene group and the divalent heterocyclic group is:
Each is the same as the preferable range of the arylene group and divalent heterocyclic group represented by Ar ^Y1 described above.

Examples of the “divalent group in which at least one kind of arylene group and at least one kind of divalent heterocyclic group are directly bonded” include groups represented by the following formulas, which have a substituent. You may have.

[In the formula, R ^XX represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. ]

R ^XX is preferably an alkyl group, a cycloalkyl group or an aryl group, and these groups optionally have a substituent.

The substituent which the group represented by Ar ^Y1 may have is preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or a substituted amino group, An alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group is more preferable, and an alkyl group, a cycloalkyl group or an aryl group is more preferable, and these groups further have a substituent. May be.
The substituent that the substituent that the group represented by Ar ^Y1 may have may be preferably an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, More preferably, it is an alkyl group or a cycloalkyl group, and these groups may have a substituent, but it is preferable that they have no further substituents.

The constitutional unit represented by the formula (Y) includes, for example, constitutional units represented by the formulas (Y-1) to (Y-7) described later, and the luminance life of the light emitting element of the present embodiment From the viewpoint, preferably the formula (Y-1)
Or a structural unit represented by the formula (Y-2), from the viewpoint of electron transporting property, preferably a structural unit represented by the formula (Y-3) or formula (Y-4), hole From the viewpoint of transportability, preferably formula (Y-5) ~ formula
It is a structural unit represented by (Y-7).

[In the formula,
R ^Y1 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. A plurality of R ^Y1 may be the same or different and may be bonded to each other to form a ring together with the carbon atom to which they are bonded.
X ^{Y1 _{is, -C (R Y2) 2 -}} , - represents a group represented by ^{- C (R Y2) = C} (R Y2) - , or _{^{C (R Y2) 2 -C (}} R Y2) 2. R ^Y2 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. A plurality of R ^Y2 may be the same or different and may be bonded to each other to form a ring together with the carbon atom to which they are bonded. ]

R ^Y1 is preferably a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group,
These groups may have a substituent.
R ^Y2 is preferably an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, more preferably an alkyl group, a cycloalkyl group or an aryl group, and these groups each have a substituent. May be.
Examples and preferred ranges of the substituents that R ^Y1 and R ^Y2 may have are as follows. Examples and preferred ranges of the substituents that the group represented by Ar ^Y1 may further have and preferred Same as range.

In X ^Y1 , the combination of two R ^{Y2 in} the group represented by —C (R ^Y2 ) ₂ — is preferably both alkyl groups or cycloalkyl groups, both aryl groups, and both monovalent heterocycles. A ring group, or one is an alkyl group or a cycloalkyl group and the other is an aryl group or a monovalent heterocyclic group, and more preferably one is an alkyl group or a cycloalkyl group and the other is an aryl group; May have a substituent. Two existing R ^Y2's may be bonded to each other to form a ring together with the atom to which they are bonded, and when R ^Y2 's form a ring, as a group represented by -C (R ^Y2 ) _2- Is preferably a group represented by formula (Y-A1) to formula (Y-A5), more preferably a group represented by formula (Y-A4), and these groups have a substituent. You may have.

In X ^Y1 , the combination of two R ^{Y2 in} the group represented by —C (R ^Y2 ) ═C (R ^Y2 ) — is
Preferably both are an alkyl group or a cycloalkyl group, or one is an alkyl group or a cycloalkyl group and the other is an aryl group, and these groups may have a substituent.

In X ^Y1 , four R ^Y2 in the group represented by —C (R ^Y2 ) ₂ —C (R ^Y2 ) ₂ — are preferably an alkyl group or cycloalkyl group which may have a substituent. Is. A plurality of R ^Y2's may be bonded to each other to form a ring together with the atom to which they are bonded. When R ^Y2 's form a ring, -C (R ^Y2 ) ₂ -C (R ^Y2 ) _2- The group represented is preferably a group represented by formula (Y-B1) to formula (Y-B5), more preferably a group represented by formula (Y-B3), and these groups are It may have a substituent.

[In the formula, R ^Y2 represents the same meaning as described above. ]

The constitutional unit represented by the formula (Y-1) is preferably a constitutional unit represented by the formula (Y-1 ′). formula(
The structural unit represented by Y-2) is preferably a structural unit represented by the formula (Y-2 ′).

[Wherein, R ^Y1 and X ^Y1 have the same meanings as described above. R ^Y11 represents an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. The plurality of R ^Y11 existing may be the same or different. ]

R ^Y11 is preferably an alkyl group, a cycloalkyl group or an aryl group, more preferably an alkyl group or a cycloalkyl group, and these groups may have a substituent.
The examples and preferred ranges of the substituents which R ^Y11 may have are the same as the examples and the preferred ranges of the substituents which the group represented by Ar ^Y1 may further have. Is.

[In the formula, R ^Y1 represents the same meaning as described above. R ^Y3 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. ]

R ^Y3 is preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or a monovalent heterocyclic group, more preferably an aryl group, and these groups have a substituent. May be.
The examples and preferred ranges of the substituents which R ^Y3 may have are the same as the examples and the preferred ranges of the substituents which the group represented by Ar ^Y1 may further have. Is.

[Wherein R ^Y1 has the same meaning as described above. R ^Y4 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. ]

R ^Y4 is preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group or a monovalent heterocyclic group, more preferably an aryl group, and these groups have a substituent. May be.
The examples and preferred ranges of the substituents which R ^Y4 may have are the same as the examples and the preferred ranges of the substituents which the group represented by Ar ^Y1 may further have. Is.

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

(2-2) Structural unit represented by formula (X)

Examples of the structural unit having no crosslinking group include structural units represented by the formula (X).
[In the formula,
a ^X1 and a ^X2 each independently represent an integer of 0 or more.
Ar ^X1 and Ar ^X3 each independently represent an arylene group or a divalent heterocyclic group, and these groups may have a substituent.
Ar ^X2 and Ar ^X4 each independently represent an arylene group, a divalent heterocyclic group, or a divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded. And these groups may have a substituent. When there are a plurality of Ar ^X2 and Ar ^X4 ,
They may be the same or different.
R ^X1 , R ^X2 and R ^X3 are each independently a hydrogen atom, an alkyl group, a cycloalkyl group,
It represents an aryl group or a monovalent heterocyclic group, and these groups may have a substituent. When there are plural R ^X2 and R ^X3 , they may be the same or different. ]

a ^X1 is preferably 2 or less, more preferably 0 or 1, and even more preferably 1 because the light emitting element of the present embodiment has a longer luminance life.
a ^X2 is preferably 2 or less, and more preferably 0, because the light emitting element of the present embodiment has a longer luminance life.

R ^X1 , R ^X2 and R ^X3 are preferably an alkyl group, a cycloalkyl group, an aryl group or 1
It is a valent heterocyclic group, more preferably an aryl group, and these groups may have a substituent.

Examples and preferred ranges of the arylene group represented by Ar ^X1 , Ar ^X2 , Ar ^X3 and Ar ^X4 and the divalent heterocyclic group are the arylene group represented by Ar ^Y1 and the divalent heterocyclic group in the formula (Y), respectively. The same as the examples and preferable ranges of the heterocyclic group.
Examples and preferred examples of the arylene group and the divalent heterocyclic group in the divalent group in which at least one arylene group represented by Ar ^X2 and Ar ^X4 and at least one divalent heterocyclic group are directly bonded. The ranges are the same as the examples and preferred ranges of the arylene group and divalent heterocyclic group represented by Ar ^Y1 in formula (Y), respectively.
The divalent group in which at least one arylene group represented by Ar ^X2 and Ar ^X4 and at least one divalent heterocyclic group are directly bonded is at least Ar ^Y1 in the formula (Y). The same divalent group in which one type of arylene group and at least one type of divalent heterocyclic group are directly bonded can be used.
Ar ^X1 , Ar ^X2 , Ar ^X3 and Ar ^X4 are preferably an arylene group which may have a substituent.

Examples and preferred ranges of the substituents which the groups represented by Ar ^{X1 to} Ar ^X4 and R ^{X1 to} R ^X3 may have include the substituents which the group represented by Ar ^Y1 in the formula (Y) may have. It is the same as the examples and preferable range of the group.

Examples of the constitutional unit represented by the formula (X) include constitutional units represented by the formulas (X1-1) to (X1-15).

(1-3) The structural unit nA represented by the formula (Z) is preferably an integer of 0 to 3, and more preferably an integer of 0 to 2, because the luminance life of the light emitting device of the present embodiment is more excellent. Is.
n is preferably 1 or 2, and more preferably 2 because the light emitting device of the present embodiment has a longer luminance life.

Ar ³ is preferably an aromatic hydrocarbon group which may have a substituent since Ar ³ has a longer luminance life of the light emitting device of the present embodiment.
The aromatic hydrocarbon group represented by Ar ³ has usually 6 to 60 carbon atoms, preferably 6 to 30 carbon atoms, and more preferably 6 to 18 carbon atoms.
Examples and preferred ranges of the arylene group moiety excluding the n substituents of the aromatic hydrocarbon group represented by Ar ³ are the same as the examples and preferred ranges of the arylene group represented by Ar ^Y1 in the formula (Y). Is.
The heterocyclic group represented by Ar ³ has usually 2 to 60 carbon atoms, preferably 3 to 30 carbon atoms.
And more preferably 4-18.
Examples and preferred ranges of the divalent heterocyclic group moiety excluding the n substituents of the heterocyclic group represented by Ar ³ are the divalent heterocyclic group represented by Ar ^Y1 in formula (Y). It is the same as an example and a preferable range.
Examples of the substituent which the group represented by Ar ³ may have and a preferable range thereof are represented by A in formula (Y).
It is the same as the examples and preferred ranges of the substituent that the group represented by r ^Y1 may have.

The number of carbon atoms of the alkylene group represented by L ^A is usually 1 to 20, preferably 1 to 1
5, and more preferably 1-10. The cycloalkylene group represented by L ^A usually has 3 to 20 carbon atoms.
The alkylene group and the cycloalkylene group may have a substituent, for example, a methylene group, an ethylene group, a propylene group, a butylene group, a hexylene group, a cyclohexylene group, an octylene group, and a hydrogen atom in these groups. Is preferably a group substituted with an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group, a fluorine atom or the like.

Examples and preferred ranges of the arylene group represented by L ^A are the same as the examples and preferred ranges of the arylene group represented by Ar ^Y1 in the formula (Y), but the luminance life of the light emitting device of the present embodiment is Since it is excellent, the arylene group represented by L ^A is preferably a phenylene group or a fluorenediyl group, more preferably an m-phenylene group, a p-phenylene group, a fluorene-2,7-diyl group, or It is a fluorene-9,9-diyl group, and these groups may further have a substituent.
Examples and preferred ranges of the divalent heterocyclic group represented by L ^A are the same as the examples and preferred ranges of the divalent heterocyclic group represented by Ar ^Y1 in formula (Y).

L ^A is preferably an arylene group or an alkylene group, more preferably a phenylene group, a fluorenediyl group or an alkylene group, and even more preferably L ^A , because the production of the polymer compound of the present embodiment is facilitated. , An alkylene group, and these groups may have a substituent.
The substituent which the group represented by L ^A may have is preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group, a substituted amino group,
A bridging group selected from a fluorine atom, a cyano group or a bridging group A group, more preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group or a bridging group A group. A cross-linking group selected from the following, more preferably an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, particularly preferably an alkyl group, a cycloalkyl group or an aryl group, and these groups are Further, it may have a substituent.

X is more preferably the formula (XL-1) because the light emitting device of the present embodiment has a longer luminance life.
) -Formula (XL-4), Formula (XL-7) -Formula (XL-10) or Formula (XL-16) -Formula (X
L-19) is a cross-linking group, more preferably formula (XL-1) or formula (XL-3).
Of the formula (XL-9), the formula (XL-10), the formula (XL-16) to the formula (XL-19), and more preferably the formula (XL-1) and the formula (XL-1). XL-16) to Formula (XL-19)
And a cross-linking group represented by formula (XL-1) or (XL-17) is particularly preferable.

(1-4) The structural unit mA represented by the formula (Z ′) is preferably an integer of 0 to 3, and more preferably 0 to 2 because the luminance life of the light emitting device of the present embodiment is more excellent. It is an integer, more preferably 0 or 1, and particularly preferably 0.
m is preferably 1 or 2, and more preferably 2 because the light emitting device of the present embodiment has a longer luminance life.
c is preferably 0, because the production of the polymer compound of the present embodiment is facilitated and the luminance life of the light emitting device of the present embodiment is more excellent.

Ar ⁵ is preferably an aromatic hydrocarbon group which may have a substituent, since Ar ⁵ has a longer luminance life than the light emitting element of the present embodiment.
The definition and example of the arylene group moiety of the aromatic hydrocarbon group represented by Ar ⁵ excluding m substituents are the same as the definition and example of the arylene group represented by Ar ^X2 in the formula (X). .
The definition and example of the divalent heterocyclic group moiety excluding m substituents of the heterocyclic group represented by Ar ⁵ are as follows for the divalent heterocyclic group moiety represented by Ar ^X2 in the formula (X). Same as definition and example.
The definition and examples of the divalent group excluding m substituents of the group in which at least one aromatic hydrocarbon group represented by Ar ⁵ and at least one heterocyclic group are directly bonded are represented by the formula ( Ar in X)
It is the same as the definition and example of the divalent group in which at least one arylene group represented by ^X2 and at least one divalent heterocyclic group are directly bonded.
Ar ⁴ and Ar ⁶ are preferably arylene groups which may have a substituent, because the light emitting device of the present embodiment has a longer luminance life.
The definitions and examples of the arylene groups represented by Ar ⁴ and Ar ⁶ are the same as the definitions and examples of the arylene groups represented by Ar ^X1 and Ar ^X3 in the formula (X).
The definition and example of the divalent heterocyclic group represented by Ar ⁴ and Ar ⁶ are the same as the definition and example of the divalent heterocyclic group represented by Ar ^X1 and Ar ^X3 in the formula (X).
Examples and preferred ranges of the substituents which the groups represented by Ar ^{4 to} Ar ⁶ may have are represented by the formula (Y)
Examples of the substituent that the group represented by Ar ^Y1 may have and the preferable range are the same.

The definitions and examples of the alkylene group, cycloalkylene group, arylene group and divalent heterocyclic group represented by K ^A are respectively the alkylene group, cycloalkylene group and arylene group represented by L ^A in formula (Z). It is the same as the definition and example of the divalent heterocyclic group.
K ^A is preferably an arylene group or an alkylene group, more preferably a phenylene group, a fluorenediyl group or an alkylene group, since K ^A facilitates the production of the polymer compound for the second organic layer, and Preferred is a phenylene group or a methylene group, and these groups may have a substituent.
Examples and preferred ranges of the substituents which the group represented by K ^A may have are L ^A in the formula (Z).
Examples of the substituent which the group represented by may have and the same as the preferable range.

The definition and example of the bridging group represented by X ′ are the same as the definition and example of X in the above formula (Z).

  Examples of the structural unit having a crosslinking group include structural units represented by the following formula.

(1-5) Method for producing polymer compound containing constitutional unit having cross-linking group The polymer compound containing constitutional unit having a cross-linking group is described in Chemical Review (Chem. Rev.), No. 10
It can be produced by a known polymerization method described in Volume 9, 897-1091 (2009) and the like. For example, Suzuki reaction, Yamamoto reaction, Buchwald reaction, Stille reaction, Negishi reaction and Kumada
A method of polymerizing by a coupling reaction using a transition metal catalyst such as a reaction can be mentioned.

In the polymerization method, as a method of charging the monomer, a method of charging the whole amount of the monomer into the reaction system at once, after charging a part of the monomer and reacting, the remaining monomer is collectively charged, Examples thereof include a continuous or divided charging method, a continuous or divided charging method, and the like.

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

A known method can be used for the post-treatment of the polymerization reaction. For example, a method of removing water-soluble impurities by liquid separation, a method of adding a reaction solution after the polymerization reaction to a lower alcohol such as methanol, filtering a deposited precipitate, and then drying, one of these methods or It is possible to combine two or more. When the polymer compound containing a structural unit having a crosslinking group has low purity, it can be purified by a usual method such as recrystallization, reprecipitation, continuous extraction with a Soxhlet extractor, column chromatography and the like.

(2) Low-Molecular Compound Having Cross-Linking Group The low-molecular compound having a cross-linking group is preferably a low-molecular compound represented by the formula (Z ″).

m ^B1 is generally an integer of 0 to 10, and is preferably an integer of 0 to 5, more preferably an integer of 0 to 2 because it facilitates the synthesis of a low-molecular compound having a crosslinking group. It is more preferably 0 or 1, and particularly preferably 0.
m ^B2 is generally an integer of 0 to 10 and is preferably an integer of 0 to 5 because it facilitates the synthesis of a low-molecular compound having a cross-linking group and further improves the luminance life of the light emitting device of this embodiment. Is more preferable, it is an integer of 0 to 3, more preferably 1 or 2, and particularly preferably 1.
m ^B3 is generally an integer of 0 to 5, and is preferably an integer of 0 to 4, more preferably an integer of 0 to 2, since it is easy to synthesize a low-molecular compound having a crosslinking group. It is more preferably 0.

The definitions and examples of the arylene group moiety excluding the m ^B3 substituents of the aromatic hydrocarbon group represented by Ar ⁷ are the same as the definitions and examples of the arylene group represented by Ar ^X2 in formula (X). is there.
The definition and examples of the divalent heterocyclic group moiety of the heterocyclic group represented by Ar ⁷ excluding the m ^B3 substituents are the divalent heterocyclic group moiety represented by Ar ^X2 in the formula (X). Is the same as the definition and example of.
The definition and examples of the divalent group excluding the m ^B3 substituents of the group in which at least one aromatic hydrocarbon group represented by Ar ⁷ and at least one heterocyclic group are directly bonded are represented by the formula: Ar in (X)
It is the same as the definition and example of the divalent group in which the arylene group represented by ^X2 and the divalent heterocyclic group are directly bonded.
The definition and examples of the substituent that the group represented by Ar ⁷ may have are the same as the definition and the example of the substituent that the group represented by Ar ^X2 in the formula (X) may have.
Ar ⁷ is preferably an aromatic hydrocarbon group, since Ar ⁷ is more excellent in the luminance life of the light emitting device of the present embodiment, and the aromatic hydrocarbon group may have a substituent.

The definitions and examples of the alkylene group represented by L ^B1 , the cycloalkylene group, the arylene group and the divalent heterocyclic group are respectively the alkylene group represented by L ^A in the formula (Z), the cycloalkylene group and the arylene group. It is the same as the definition and example of the divalent heterocyclic group.
L ^B1 is preferably an alkylene group, an arylene group or an oxygen atom, more preferably an alkylene group or an arylene group, and further preferably a phenylene group, because it facilitates the synthesis of a low-molecular compound having a crosslinking group. It is a fluorenediyl group or an alkylene group, particularly preferably a phenylene group or an alkylene group, and these groups may have a substituent.

X ″ is preferably a bridging group represented by any of formulas (XL-1) to (XL-19), an aryl group or a monovalent heterocyclic group, and more preferably formula (XL -1), formula (XL-
3), Formula (XL-7) to Formula (XL-10) or Formula (XL-16) to Formula (XL-19).
Or a bridging group represented by formula (XL-1) or (XL-16) to (XL-19), a phenyl group, or a naphthyl group. Or a fluorenyl group, particularly preferably a bridging group represented by the formula (XL-16) or (XL-17), a phenyl group or a naphthyl group, and particularly preferably a formula (XL-16).
) Is a cross-linking group or a naphthyl group, and these groups may have a substituent.

Examples of the low molecular weight compound having a crosslinking group include low molecular weight compounds represented by formulas (3-1) to (3-16).

The low molecular weight compound having a cross-linking group is, for example, Aldrich, Luminescence.
Technology Corp. , American Dye Source, and the like. Alternatively, for example, it can be synthesized according to the methods described in International Publication No. 1997/033193, International Publication No. 2005/035221, and International Publication No. 2005/049548.

2.3 Other Materials Included in Light-Emitting Element Film The light-emitting element film of the present invention may include the above-mentioned crosslinked product having a crosslinkable group, and may include other materials as necessary. Examples of other materials include hole transport materials, hole injection materials, electron transport materials, electron injection materials, light emitting materials, and antioxidants. The film for a light emitting device may further contain at least one material selected from the group consisting of these. When the film for a light-emitting device contains a cross-linked product having a cross-linking group and other materials, the film for a light-emitting device may be, for example, a cross-linked material having a cross-linking group to produce a cross-linked product having a cross-linking group, and then other It can be produced by mixing the above materials, or by mixing a cross-linking material having a cross-linking group with another material and then cross-linking.

[Hole transport material]
The hole transport material is classified into a low molecular weight compound and a high molecular weight compound, and is preferably a high molecular weight compound having a crosslinking group.
Examples of the polymer compound include polyvinylcarbazole and its derivative; polyarylene having an aromatic amine structure in its side chain or main chain and its derivative. The polymer compound may be a compound to which an electron accepting site such as fullerene, tetrafluorotetracyanoquinodimethane, tetracyanoethylene, and trinitrofluorenone is bonded.
In the film for a light emitting device of the present invention, the compounding amount of the hole transporting material is 10% for the crosslinked body having a crosslinking group.
When it is 0 part by mass, it is usually 1 to 400 parts by mass. The hole transport materials may be used alone or in combination of two or more.

[Electron transport material]
Electron transport materials are classified into low molecular weight compounds and high molecular weight compounds. The electron transport material may have a crosslinking group.
As the low molecular weight compound, for example, a metal complex having 8-hydroxyquinoline as a ligand, oxadiazole, anthraquinodimethane, benzoquinone, naphthoquinone, anthraquinone,
Tetracyanoanthraquinodimethane, fluorenone, diphenyldicyanoethylene and diphenoquinone, and derivatives thereof.
Examples of the polymer compound include polyphenylene, polyfluorene, and derivatives thereof. The polymer compound may be doped with a metal.
In the film for a light emitting device of the present invention, the compounding amount of the electron transport material is 10% by weight of the crosslinked body having a crosslinking group.
When it is 0 part by mass, it is usually 1 to 400 parts by mass. The electron transport materials may be used alone or in combination of two or more.

[Hole injection material and electron injection material]
The hole injection material and the electron injection material are classified into a low molecular compound and a high molecular compound, respectively. The hole injection material and the electron injection material may have a crosslinking group.
Examples of the low molecular weight compound include metal phthalocyanines such as copper phthalocyanine; carbon; metal oxides such as molybdenum and tungsten; metal fluorides such as lithium fluoride, sodium fluoride, cesium fluoride and potassium fluoride.
Examples of the polymer compound include polyaniline, polythiophene, polypyrrole, polyphenylene vinylene, polythienylene vinylene, polyquinoline and polyquinoxaline, and derivatives thereof; conductive materials such as polymers containing an aromatic amine structure in its main chain or side chain. Polymers are mentioned.
In the film for a light emitting device of the present invention, the compounding amounts of the hole injecting material and the electron injecting material are each usually 1 to 400 parts by mass when the crosslinked product having a crosslinking group is 100 parts by mass. The hole injection material and the electron injection material may be used alone or in combination of two or more kinds.

[Ion dope]
When the hole injection material or the electron injection material contains a conductive polymer, the electric conductivity of the conductive polymer is preferably 1 × 10 ⁻⁵ S / cm to 1 × 10 ³ S / cm. The conductive polymer can be doped with an appropriate amount of ions in order to set the electric conductivity of the conductive polymer in such a range. The types of ions to be doped are anions for hole injection materials and cations for electron injection materials. Examples of the anion include polystyrene sulfonate ion, alkylbenzene sulfonate ion, and camphor sulfonate ion. Examples of the cation include lithium ion, sodium ion, potassium ion, and tetrabutylammonium ion. The ions to be doped may be used alone or in combination of two or more.

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

In the film for a light emitting device of the present invention, the content of the light emitting material is usually 0.1 to 400 parts by mass with respect to 100 parts by mass of the crosslinked product having a crosslinkable group. The light emitting materials may be used alone or in combination of two or more.

[Antioxidant]
The antioxidant may be any compound as long as it is soluble in the same solvent as the crosslinking material having a crosslinking group and does not inhibit light emission and charge transport, and examples thereof include a phenolic antioxidant and a phosphorus antioxidant.
In the film for a light emitting device of the present invention, the compounding amount of the antioxidant is usually 0.001 to 10 parts by mass with respect to 100 parts by mass of the crosslinked product having a crosslinkable group. The antioxidants may be used alone or in combination of two or more.

3. Analysis of cross-linking group in film for light-emitting device As a method for analyzing the amount of cross-linking group contained in the film for light-emitting device of the present invention, the film for light-emitting device of the present invention is peeled from the substrate, solid-liquid extraction with a solvent Can be carried out and the cross-linking group contained in the insoluble component can be quantified. In the quantitative determination of the cross-linking group contained in the film for a light-emitting element, the light-emitting element after production may be used, or the light-emitting element containing the cross-linked product having the cross-linking group during production may be used. For example, when the light emitting element includes a cathode, the cathode is insoluble in a solvent and therefore needs to be selectively removed. However, the cathode can be removed by peeling it off from the substrate with an adhesive tape or the like.
As a means for peeling the light emitting device film of the present invention from the substrate, for example, the light emitting device film can be collected by scraping it from the substrate with a spatula or the like. When a hydrophilic hole injection layer is provided between the substrate and the light emitting device film of the present invention, the hole injection layer is dissolved by immersing the substrate in a solvent that dissolves the hole injection layer, such as water. By doing so, the light emitting device film of the present invention can be recovered.

Examples of the solvent used for the solid-liquid extraction include chloroform, 1,2-dichloroethane, 1
, 1,2-Trichloroethane, chlorobenzene, o-dichlorobenzene and other chlorinated hydrocarbon solvents; tetrahydrofuran, dioxane, anisole, 4-methylanisole and other ether solvents; toluene, xylene, mesitylene, ethylbenzene, n-hexylbenzene,
Aromatic hydrocarbon solvent such as cyclohexylbenzene; Aliphatic such as cyclohexane, methylcyclohexane, n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, n-dodecane, bicyclohexyl Hydrocarbon solvent; ketone solvent such as acetone, methyl ethyl ketone, cyclohexanone, acetophenone; ethyl acetate, butyl acetate,
Ethyl cellosolve acetate, methyl benzoate, phenyl acetate, etc. ester solvents; ethylene glycol, glycerin, 1,2-hexanediol, etc. polyhydric alcohol solvents; isopropyl alcohol, cyclohexanol, etc. alcohol solvents; dimethyl sulfoxide, etc. sulfoxide solvents Amide solvents such as N-methyl-2-pyrrolidone and N, N-dimethylformamide; and water, and deuterated products thereof. The solvent used for solid-liquid extraction may be used alone or in combination of two or more.
The solvent used for solid-liquid extraction is preferably deuterated, more preferably deuterated tetrahydrofuran, deuterated toluene, deuterated chloroform or deuterated water, and further preferably deuterated tetrahydrofuran and deuterated water.

Examples of the method for quantifying the crosslinking group contained in the film for a light emitting device of the present invention include a method of analyzing by nuclear magnetic resonance spectroscopy or infrared spectroscopy, and preferably by solid state nuclear magnetic resonance spectroscopy. Is the way to do it. As a method of analyzing by solid-state nuclear magnetic resonance spectroscopy, for example, the film for a light-emitting device of the present invention is soaked in a heavy solvent to swell the film for a light-emitting device of the present invention, and then the film is subjected to solid-state nuclear magnetic resonance. A method of measuring by a spectroscopic method can be mentioned. Examples of the heavy solvent that swells the film for a light emitting device of the present invention include heavy tetrahydrofuran, heavy toluene and heavy chloroform, and preferably heavy toluene.

The method for quantifying the crosslinking group contained in the film for a light emitting device of the present invention will be described in detail. First, the mass of the light emitting device film of the present invention dried under reduced pressure is measured, and the dried film is immersed in a heavy solvent for a predetermined time to swell. The immersion time is usually 1 minute to 7 days, preferably 1 hour to 3 days, and more preferably 10 hours to 40 hours. Then, the swollen film for light emitting device of the present invention is put into a sample tube for solid state nuclear magnetic resonance spectroscopy, and ¹ H solid state nuclear magnetic resonance spectroscopy measurement is performed. The amount of the crosslinking group contained in the film for a light emitting device of the present invention is calculated by the external standard method. As the standard, a compound having ¹ H dissolved in the heavy solvent used in the present invention can be used.

An example of analyzing the amount of the cross-linking group contained in the light emitting device film of the present invention will be described in detail in Examples described later.

4. Light-Emitting Element The light-emitting element of the present embodiment is a light-emitting element having an anode, a cathode, and an organic layer, the light-emitting element having the organic layer between the anode and the cathode, and the organic layer of the present invention. A light emitting device including the film for a light emitting device. Examples of the organic layer include a light emitting layer, a hole transport layer, a hole injection layer, an electron transport layer, an electron injection layer, and the like. At least one of these layers is the film for a light emitting device of the present invention.

[Layer structure]
The film for a light emitting device of the present invention is usually one or more layers selected from the group consisting of a light emitting layer, a hole transport layer, a hole injection layer, an electron transport layer and an electron injection layer, and preferably a hole It is a transport layer.
These layers include a light emitting material, a hole transport material, a hole injection material, an electron transport material, and an electron injection material, respectively. For these layers, the light emitting material, the hole transporting material, the hole injecting material, the electron transporting material, and the electron injecting material are dissolved in the above-mentioned solvent to prepare the ink, and the same as the above-mentioned film formation. Can be formed using a method.

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

The materials for the hole transport layer, electron transport layer, light emitting layer, hole injection layer and electron injection layer are, in addition to the materials contained in the film for a light emitting device of the present invention, the above-mentioned hole transport material and electron transport layer, respectively. Examples thereof include materials, light emitting materials, hole injecting materials, electron injecting materials and the like.

The material of the hole transport layer, the material of the electron transport layer, and the material of the light emitting layer are
In order to avoid dissolving the material in the solvent when the material is dissolved in the solvent used for forming the layer adjacent to the hole transporting layer, the electron transporting layer and the light emitting layer, the material contains a crosslinking group. It is preferable to have. After forming each layer using a material having a crosslinking group, the layer can be insolubilized by crosslinking the crosslinking group.

In the light emitting device of the present embodiment, as a method for forming each layer such as a light emitting layer, a hole transport layer, an electron transport layer, a hole injection layer, and an electron injection layer, when a low molecular compound is used, for example, vacuum from powder is used. Examples of the method include a vapor deposition method and a method of forming a film from a solution or a molten state. When a polymer compound is used, for example, a method of forming a film from a solution or a molten state can be used. Order of layers to stack,
The number and thickness are adjusted in consideration of luminous efficiency and luminance life.

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

[Use]
The light emitting element of this embodiment can be used for a display of a computer, a television, a mobile terminal, or the like. The planar light emitting element can be suitably used as a planar light source for a backlight of a liquid crystal display device or a planar light source for illumination. If a flexible substrate is used, it can be used as a curved light source and a display device.

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

In the examples, the polystyrene-equivalent number average molecular weight (Mn) and polystyrene-equivalent weight average molecular weight (Mw) of the polymer compound were determined by the following size exclusion chromatography (SEC) using tetrahydrofuran as the mobile phase. .
The polymer compound to be measured is dissolved in tetrahydrofuran at a concentration of about 0.05% by mass, and S
10 μL was injected into EC. The mobile phase was run at a flow rate of 1.0 mL / min. As a column, P
Lgel MIXED-B (manufactured by Polymer Laboratories) was used. UV-on the detector
A VIS detector (manufactured by Tosoh Corporation, trade name: UV-8320GPC) was used.

<Synthesis of raw material compounds>
The compound M1 was synthesized according to the method described in JP2011-174062A.
Compound M2 was synthesized according to the method described in WO 2005/049546.
The compound M3 was synthesized according to the method described in JP 2008-106241 A.
The compound M4 was synthesized according to the method described in JP 2010-215886 A.
The compound M5 and the compound M7 were synthesized according to the method described in JP 2010-189630 A.
The compound M6 was synthesized according to the method described in International Publication No. 2012/086661.

<Synthesis Example 1> Synthesis of polymer compound HP-1 As polymer compound HP-1, compound M5, compound M6 and compound M7 were used, and
It was synthesized according to the method described in JP-A-12-036388. Mn of polymer compound HP-1
Was 9.6 × 10 ⁴ , and Mw was 2.2 × 10 ⁵ .
The polymer compound HP-1 has a constitutional unit derived from the compound M5, a constitutional unit derived from the compound M6, and a constitutional unit derived from the compound M7 from the theoretical value obtained from the molar ratio of the charged raw materials. , 50:40:10 molar ratio.

<Synthesis Example 2> Synthesis of Metal Complex G1 The metal complex G1 was synthesized according to the method described in International Publication No. 2009/131255.

<Synthesis Example 3> Synthesis of polymer compound HTL-1 Polymer compound HTL-1 was synthesized according to the method described in International Publication No. 2016/047536 using compound M1, compound M2, compound M3 and compound M4. . The polystyrene reduced number average molecular weight and weight average molecular weight of the polymer compound HTL-1 are Mn and Mn, respectively.
= 4.5 × 10 ⁴ and Mw = 1.5 × 10 ⁵ .
The polymer compound HTL-1 comprises a structural unit derived from the compound M1, a structural unit derived from the compound M2, and a structural unit derived from the compound M3, based on the theoretical value obtained from the molar ratio of the charged raw materials, The constitutional unit derived from the compound M4 is a copolymer constituted in a molar ratio of 50: 40: 5: 5.

Example 1 Production and Evaluation of Light Emitting Element D1 (Formation of Anode and Hole Injection Layer)
An anode was formed by attaching an ITO film having a thickness of 45 nm on a glass substrate by a sputtering method. A film of ND-3202 (manufactured by Nissan Kagaku Co., Ltd.), which is a hole injection material, was formed on the anode by spin coating, heated at 50 ° C. for 3 minutes on a hot plate, and further at 240 ° C., 15
A hole injection layer having a thickness of 65 nm was formed by heating for a minute.

(Formation of hole transport layer)
The polymer compound HTL-1 was dissolved in xylene to obtain a 0.7 mass% xylene solution. Using this xylene solution, a film was formed on the hole injection layer by a spin coating method, and heated at 190 ° C. for 60 minutes on a hot plate in a nitrogen gas atmosphere to give a thickness of 20.
nm hole transport layer was formed. By this heating, the polymer compound HTL-1 became a crosslinked body.

(Formation of light emitting layer)
Polymer compound HP-1 and metal complex G1 (polymer compound HP-1 / metal complex G1 = 70
(% By mass / 30% by mass) was dissolved in xylene to obtain a xylene solution having a concentration of 2% by mass. Using this xylene solution, a film was formed on the second organic layer by a spin coating method, and heated at 150 ° C. for 10 minutes in a nitrogen gas atmosphere to form a light emitting layer having a thickness of 80 nm.

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

(Evaluation of light emitting element)
EL light emission was observed by applying a voltage to the light emitting device D1. Initial brightness is 20000 cd /
After setting the current value so as to be m ² , the device was driven at a constant current, and the time until the brightness reached 95% of the initial brightness (hereinafter referred to as “LT95”) was measured. The larger the LT95, the better the luminance life. The results are shown in Table 2.

(Quantification of cross-linking group)
The cross-linking group of the light emitting device D1 was quantified by the following method.
(Process 1)
An anode was formed by attaching an ITO film having a thickness of 45 nm on a glass substrate by a sputtering method. A film of ND-3202 (manufactured by Nissan Chemical Industries, Ltd.), which is a hole injection material, is formed on the anode by a spin coating method, heated on a hot plate at 50 ° C for 3 minutes, and further heated at 240 ° C for 15 minutes. Thus, a layer 1 having a thickness of 65 nm was formed.
(Process 2)
Next, the polymer compound HTL-1 was dissolved in xylene to obtain a 0.7 mass% xylene solution. Using this xylene solution, a film was formed on the layer 1 by a spin coating method, and heated at 190 ° C. for 60 minutes on a hot plate in a nitrogen gas atmosphere to have a thickness of 2
A 0 nm film was formed to obtain a layered product 1. By this heating, the polymer compound HTL-1 became a crosslinked body.
(Process 3)
Next, the film was peeled from the substrate by immersing the obtained laminated body 1 in water. The membrane is recovered, solid-liquid extraction is performed with heavy tetrahydrofuran and heavy water, and the insoluble matter is dried with a vacuum dryer to 100%.
It was dried at 0 ° C. for 60 minutes. After measuring the mass (A) of the dry film, use 1 ml of heavy toluene for the dry film.
It was immersed in it for 40 hours. The swollen film was filled in a sample tube for solid-state nuclear magnetic resonance spectroscopy having a diameter of 4 mm, and ¹ H solid-state nuclear magnetic resonance spectroscopy measurement was performed under the following conditions.
・ Device: ECA-400 manufactured by JEOL Ltd.
・ Temperature: 50 ℃
・ MAS rotation speed: 5 kHz
・ Observation frequency: 399.78 MHz
・ Chemical shift standard: CH ₃ group of toluene 2.08 ppm

Integrated intensity of the signal derived from the cross-linking group XL-1 (vinyl group) detected at 5.48 ppm (B
1) and the integrated intensity (B17) of the signal derived from the bridging group XL-17 (benzocyclobutenyl group) detected at 2.90 ppm were calculated. ¹ H of XL-1 detected at 5.48 ppm
The number one _{(CH 2 = C H -)} (C1), the number of the ¹ H having a crosslinking group XL-17 which is detected 2.90ppm is four (C17).

Adamantane 0.00062g the (E) was charged to a solid-state nuclear magnetic resonance spectroscopic sample tube having a diameter of 4 mm, a heavy solvent by adding an appropriate amount, under the same conditions as for light-emitting element layer of the present invention swollen, ^{1 H} solid state nuclear Magnetic resonance spectroscopy was performed and the integrated intensity (F) of the adamantane-derived signal was used to determine ¹ H1mo
The integrated intensity per 1 was calculated from the following formula (D).
Integrated intensity per ¹ H ¹ mol (D) = F / (E / 136.23 × 16)

The amount of crosslinking group contained in the film was calculated by the following formula. Table 2 shows the results.
Total amount of cross-linking groups contained in the film = (B1 / C1 / D / A) + (B17 / C17 / D / A)

<Examples 2 to 4 and Comparative Examples 1 to 2> Production and Evaluation of Light-Emitting Elements D2 to D4 and CD1 to CD2 Instead of “heating at 190 ° C. for 60 minutes” in (formation of hole transport layer) of Example 1. , Table 2
Light-emitting elements D2, D3, D4, and
CD1 and CD2 were made. EL light emission was observed by applying a voltage to the light emitting devices D2, D3, D4, CD1 and CD2. The measurement results of LT95 are shown in Table 2.

In addition, “190 ° C., 60 minutes heating” in (Step 2) of quantifying the cross-linking group of the light emitting device D1
Instead of, the heating conditions shown in Table 2 were used, and in the same manner as in Example 1, the light emitting device D2
, D3, D4, CD1 and CD2, the amount of cross-linking groups contained in the film was calculated. The results are shown in Table 2.

In Table 2, the LT95 of the light emitting elements D1 to D4 and the CD2 is shown as a relative value when the LT95 of the light emitting element CD1 is 1.00.

It was found that the light emitting device films used in Examples 1 to 4 contained a predetermined amount of the cross-linking group, and thus had excellent luminance life. That is, it was considered that when the amount of the cross-linking group in the film for a light emitting device is large, the cross-linked product having the cross-linking group is likely to be deteriorated, and the luminance life is shortened. On the other hand, when the amount of the cross-linking group in the light-emitting device film is small, the cross-linking density in the light-emitting device film increases, and the film quality of the light-emitting device film deteriorates accordingly, which is considered to shorten the luminance life.

By using the film for a light emitting device of the present invention, it is possible to manufacture a light emitting device having an excellent brightness life.

Claims (1)

A method for analyzing a crosslinking group in a film for a light emitting device,
(1) a step of swelling the film for a light emitting element with a solvent, and (2) a step of measuring a cross-linking group of the film for a light emitting element thus swollen by using nuclear magnetic resonance spectroscopy
Analytical method including.