KR20230161502A - Polymers and their uses - Google Patents

Abstract

A polymer containing at least one selected from the repeating unit represented by the following formula (1) and the repeating unit represented by the following formula (2) is provided.

Description

Polymers and their uses

The present invention relates to polymers and their uses.

In organic electroluminescence (EL) devices, a charge-transporting thin film made of an organic compound is used as a light-emitting layer or charge injection layer. In particular, the hole injection layer is responsible for transferring charges between the anode and the hole transport layer or light emitting layer, and plays an important function in achieving low voltage driving and high brightness of the organic EL device.

Until now, various inventions have been made to improve the performance of organic EL devices, and efforts have been made to adjust the refractive index of the functional film used for purposes such as improving light extraction efficiency. Specifically, attempts are being made to increase the efficiency of the device by using a hole injection layer or hole transport layer with a relatively high or low refractive index, taking into account the overall configuration of the device or the refractive index of other adjacent members (patent document 1, 2). In this way, the refractive index is an important factor in the design of organic EL devices, and the refractive index is also considered an important physical property value to be considered in materials for organic EL devices.

In addition, because coloring of the charge-transporting thin film used in organic EL devices reduces the color purity and color reproducibility of the organic EL device, recent charge-transporting thin films for organic EL devices have high transmittance in the visible region and high transparency. It is desired to have (see Patent Document 3).

Since organic EL devices are required to have high heat resistance, charge transport materials used in organic EL devices are required to have high heat resistance.

The method of forming the hole injection layer is largely divided into a dry process represented by a deposition method and a wet process represented by a spin coat method. Comparing these processes, the wet process can efficiently produce thin films with high flatness over a large area. Therefore, as organic EL displays are becoming larger in area, there is always a demand for wet process materials that can be formed by a wet process and provide a charge-transporting thin film with excellent refractive index, transparency, and heat resistance.

Japanese Special Gazette No. 2007-536718 Japanese Special Gazette No. 2017-501585 International Publication No. 2013/042623

The present invention has been made in consideration of the above circumstances, and provides an organic EL device that has high heat resistance, good charge transport properties, a high refractive index, and high transparency, and has excellent characteristics when this thin film is applied to a hole injection layer, etc. The purpose is to provide a polymer that can realize.

The present inventors have conducted extensive studies to achieve the above object, and as a result, a charge-transporting varnish containing a polymer having a triarylamine structure, a diaryl ether structure, or a diaryl sulfide structure, and a dialkyl fluorene structure in the side chain, It was discovered that a thin film with high heat resistance, excellent charge transport properties, high transparency and high refractive index was provided, and that when this thin film was applied to a hole injection layer, etc., an organic EL device with excellent characteristics was provided, and the present invention was completed. I ordered it.

That is, the present invention provides the following polymers and their uses.

1. A polymer containing at least one selected from the repeating unit represented by the following formula (1) and the repeating unit represented by the following formula (2).

[In the formula, R ^A is a hydrogen atom or a methyl group. R ¹ to R ⁴ are each independently a single bond or a phenylene group, and some or all of the hydrogen atoms of this phenylene group are cyano group, nitro group, halogen atom, vinyl group, trifluorovinyl group, acryloyl group, or meta. It may be substituted with a cryloyl group, an oxetane group, an epoxy group, an alkyl group with 1 to 20 carbon atoms, or a halogenated alkyl group with 1 to 20 carbon atoms.

X ¹ is -N(Ar ³ )-, -S- or -O-.

X ² is -N(Ar ⁶ )-, -S- or -O-.

Ar ¹ and Ar ⁴ are each independently obtained by removing two hydrogen atoms on the aromatic ring of an arylene group having 6 to 20 carbon atoms, a heteroarylene group having 3 to 20 carbon atoms, or a dialkyl fluorene represented by the formula (3) below. It is a divalent group, and some or all of the hydrogen atoms on the aromatic ring of these groups are cyano group, nitro group, halogen atom, vinyl group, trifluorovinyl group, acryloyl group, methacryloyl group, oxetane group, and epoxy group. , may be substituted with an alkyl group having 1 to 20 carbon atoms or a halogenated alkyl group having 1 to 20 carbon atoms.

Ar ² , Ar ³ , Ar ⁵ and Ar ⁶ are each independently an aryl group having 6 to 20 carbon atoms or a monovalent group obtained by removing one hydrogen atom on the aromatic ring of a dialkyl fluorene represented by the formula (3) below. and some or all of the hydrogen atoms on the aromatic ring of these groups are cyano group, nitro group, halogen atom, vinyl group, trifluorovinyl group, acryloyl group, methacryloyl group, oxetane group, epoxy group, and carbon number 1. It may be substituted with an alkyl group of ~20 carbon atoms or a halogenated alkyl group of 1-20 carbon atoms.

^{When _ _ _ _ _ _} and Ar ⁶ may be bonded to each other to form a ring with the nitrogen atom to which they are bonded.

When R ² is a phenylene group, R ² and Ar ² may be bonded to each other to form a ring with the nitrogen atom, sulfur atom, or oxygen atom to which they are bonded, and when R ⁴ is a phenylene group, R ⁴ and Ar ⁵ may be They may combine with each other to form a ring with the nitrogen atom, sulfur atom, or oxygen atom to which they are bonded.

However, at least one of Ar ¹ to Ar ³ is a group obtained by removing a hydrogen atom on the aromatic ring of dialkyl fluorene represented by the formula (3) below, and at least one of Ar ⁴ to Ar ⁶ is a group of the formula (3) below: It is a group obtained by removing the hydrogen atom on the aromatic ring of the dialkyl fluorene represented by 3).

(In the formula, R ⁵ and R ⁶ are each independently an alkyl group with 1 to 20 carbon atoms, an alkoxy group with 1 to 20 carbon atoms, or an alkyl group with 2 to 20 carbon atoms containing at least one ether structure.)]

2. Polymer of 1, wherein the repeating unit represented by formula (1) is represented by the formula (1A) below, and the repeating unit represented by formula (2) is represented by the formula (2A) below.

(In the formula, R ^A , R ¹ to R ⁴ , and Ar ¹ to Ar ⁶ are the same as above.)

3. A polymer of 1 or 2 where R ¹ and R ³ are single bonds.

4. The polymer of any one of 1 to 3, wherein R ² and R ⁴ are phenylene groups.

5. The polymer of any one of 1 to ⁴ , wherein Ar ¹ and Ar 4 are 9,9-dimethyl-9H-fluorene-2,7-diyl groups.

6. A charge-transporting material made of the polymer of any one of 1 to 5.

7. A charge-transporting material containing the polymer of any one of 1 to 5, and a charge-transporting varnish containing an organic solvent.

8. The charge-transporting varnish of 7, which also contains a dopant.

9. Charge-transporting thin film obtained from the charge-transporting varnish of 7 or 8.

10. Organic EL device equipped with a charge-transporting thin film of 9.

The polymer of the present invention has high heat resistance, high transparency and high refractive index, and has excellent charge transport properties in that it has a triarylamine structure, diaryl ether structure or diaryl sulfide structure and a dialkyl fluorene structure in the side chain. . By using the charge-transporting varnish of the present invention containing such a polymer, a thin film with high heat resistance, high transparency, and high refractive index can be produced. The charge-transporting thin film obtained from the charge-transporting varnish of the present invention can be suitably used as a thin film for electronic devices including organic EL devices, and by using it as a hole injection layer or hole transport layer, especially a hole injection layer, of an organic EL device, its properties are improved. An excellent organic EL device is obtained.

[Polymer]

The polymer of the present invention contains at least one selected from the repeating unit represented by the following formula (1) and the repeating unit represented by the following formula (2).

In formulas (1) and (2), R ^A is a hydrogen atom or a methyl group. R ¹ to R ⁴ are each independently a single bond or a phenylene group, and some or all of the hydrogen atoms of this phenylene group are cyano group, nitro group, halogen atom, vinyl group, trifluorovinyl group, acryloyl group, or meta. It may be substituted with a cryloyl group, an oxetane group, an epoxy group, an alkyl group with 1 to 20 carbon atoms, or a halogenated alkyl group with 1 to 20 carbon atoms.

Examples of the phenylene group include 1,2-phenylene group, 1,3-phenylene group, and 1,4-phenylene group, with 1,4-phenylene group being preferable.

The alkyl group having 1 to 20 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, and sec-butyl group. , linear or branched alkyl groups having 1 to 20 carbon atoms, such as tert-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, and n-decyl group; Cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, bicyclobutyl group, bicyclopentyl group, bicyclohexyl group, bicycloheptyl group Cyclic alkyl groups having 3 to 20 carbon atoms, such as tyl group, bicyclooctyl group, bicyclononyl group, and bicyclodecyl group, are included.

The halogenated alkyl group having 1 to 20 carbon atoms is not particularly limited as long as some or all of the hydrogen atoms of the alkyl group having 1 to 20 carbon atoms are substituted with halogen atoms. Specific examples include trifluoromethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2,2-pentafluoroethyl group, 3,3,3-trifluoropropyl group, 2,2, 3,3,3-pentafluoropropyl group, 1,1,2,2,3,3,3-heptafluoropropyl group, 4,4,4-trifluorobutyl group, 3,3,4, 4,4-pentafluorobutyl group, 2,2,3,3,4,4,4-heptafluorobutyl group, 1,1,2,2,3,3,4,4,4-nonafluo Robutyl group, etc. are mentioned.

A single bond is preferable as R ¹ and R ³ , and a phenylene group is preferable as R ² and R ⁴ .

In formulas (1) and (2), X ¹ is -N(Ar ³ )-, -S-, or -O-. X ² is -N(Ar ⁶ )-, -S- or -O-.

In formulas (1) and (2), Ar ¹ and Ar ⁴ each independently represent an arylene group having 6 to 20 carbon atoms, a heteroarylene group having 3 to 20 carbon atoms, or a dialkyl fluorene represented by the formula (3) below. It is a divalent group obtained by removing two hydrogen atoms on the ring, and some or all of the hydrogen atoms on the aromatic ring of these groups are cyano group, nitro group, halogen atom, vinyl group, trifluorovinyl group, acryloyl group, It may be substituted with a methacryloyl group, an oxetane group, an epoxy group, an alkyl group with 1 to 20 carbon atoms, or a halogenated alkyl group with 1 to 20 carbon atoms. Specific examples of the alkyl group having 1 to 20 carbon atoms and the halogenated alkyl group having 1 to 20 carbon atoms include those similar to those described above.

(In the formula, R ⁵ and R ⁶ are each independently an alkyl group with 1 to 20 carbon atoms, an alkoxy group with 1 to 20 carbon atoms, or an alkyl group with 2 to 20 carbon atoms containing at least one ether structure.)

Examples of the arylene group having 6 to 20 carbon atoms include 1,2-phenylene group, 1,3-phenylene group, 1,4-phenylene group, 1,2-naphthalene-diyl group, 2,3-naphthalenediyl group, 1, 4-naphthalenediyl group, 1,5-naphthalenediyl group, 2,6-naphthalenediyl group, 2,7-naphthalenediyl group, 1,8-naphthalenediyl group, 1,2-anthracenediyl group, 1,3- Anthracene diyl group, 1,4-anthracene diyl group, 1,5-anthracene diyl group, 1,6-anthracene diyl group, 1,7-anthracene diyl group, 1,8-anthracene diyl group, 2,3-anthracene diyl group Examples include diyl group, 2,6-anthracene diyl group, 2,7-anthracene diyl group, 2,9-anthracene diyl group, 2,10-anthracene diyl group, and 9,10-anthracene diyl group.

Examples of the heteroarylene group having 3 to 20 carbon atoms include 9-phenylcarbazole-3,6-diyl group, 9-phenylcarbazole-2,7-diyl group, and 9-phenylcarbazole-3,6-dimethyl-2. , 7-diyl group, groups represented by the following formulas (H1) to (H33), etc.

In formula (3), R ⁵ and R ⁶ are each independently an alkyl group with 1 to 20 carbon atoms, an alkoxy group with 1 to 20 carbon atoms, or an alkyl group with 2 to 20 carbon atoms containing at least one ether structure.

The alkyl group having 1 to 20 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, and sec-butyl group. , linear or branched alkyl groups having 1 to 20 carbon atoms, such as tert-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, and n-decyl group; Cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, bicyclobutyl group, bicyclopentyl group, bicyclohexyl group, bicycloheptyl group Cyclic alkyl groups having 3 to 20 carbon atoms, such as tyl group, bicyclooctyl group, bicyclononyl group, and bicyclodecyl group, are included. Among these, a methyl group and an ethyl group are preferable, and a methyl group is more preferable.

The alkoxy group having 1 to 20 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, 1 to 20 carbon atoms, such as sec-butoxy group, tert-butoxy group, n-pentyl group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, n-nonyloxy group, n-decyloxy group, etc. A linear or branched alkoxy group; Cyclopropyloxy group, cyclobutyloxy group, cyclopentyloxy group, cyclohexyloxy group, cycloheptyloxy group, cyclooctyloxy group, cyclononyloxy group, cyclodecyloxy group, bicyclobutyloxy group, bicyclopentyloxy group cyclic alkoxy groups having 3 to 20 carbon atoms, such as bicyclohexyloxy group, bicycloheptyloxy group, bicyclooctyloxy group, bicyclononyloxy group, and bicyclodecyloxy group.

Examples of the alkyl group having 2 to 20 carbon atoms containing at least one ether structure include a straight-chain or branched alkyl group in which at least one methylene group is replaced with an oxygen atom. However, the methylene group bonded to the fluorene skeleton is not substituted with an oxygen atom, and the adjacent methylene group is not simultaneously substituted with an oxygen atom. Considering the ease of availability of raw material compounds, such groups are preferably those represented by the formula (A), and among these, the groups represented by the formula (B) are more preferable.

(In the formula, R ⁷ represents a straight-chain or branched alkylene group having 1 to 4 carbon atoms, R ⁸ represents a straight-chain or branched alkyl group having 1 to [20-(carbon number of R) x p], and p is an integer from 1 to 9. p is preferably 2 or more, more preferably 3 or more, from the viewpoint of compatibility with the dopant, and preferably 5 or less, more preferably 3 or more, from the viewpoint of ease of availability of the raw material compound. is 4 or less.)

Examples of alkyl groups having 2 to 20 carbon atoms containing at least one ether structure include -CH ₂ OCH ₃ , -CH ₂ OCH ₂ CH ₃ , -CH ₂ O(CH ₂ ) ₂ CH ₃ , -CH ₂ OCH(CH ₃ ) ₂ , -CH ₂ O(CH ₂ ) ₃ CH ₃ , -CH ₂ OCH ₂ CH(CH ₃ ) ₂ , -CH ₂ OC(CH ₃ ) ₃ , -CH ₂ O(CH ₂ ) ₄ CH ₃ , -CH ₂ OCH(CH ₃ )(CH ₂ ) ₂ CH ₃ , -CH ₂ O(CH ₂ ) ₂ CH(CH ₃ ) ₂ , -CH ₂ OCH(CH ₃ )(CH ₂ ) ₃ CH ₃ , -CH ₂ O (CH ₂ ) ₅ CH ₃ , -CH ₂ OCH ₂ CH(CH ₃ )(CH ₂ ) ₂ CH ₃ , -CH ₂ O(CH ₂ ) ₂ CH(CH ₃ )CH ₂ CH ₃ , -CH ₂ O( CH ₂ ) ₃ CH(CH ₃ ) ₂ , -CH ₂ OC(CH ₃ ) ₂ (CH ₂ ) ₂ CH ₃ , -CH ₂ OCH(CH ₂ CH ₃ )(CH ₂ ) ₂ CH ₃ , -CH ₂ OC (CH ₃ ) ₂ CH(CH ₃ ) ₂ , -CH ₂ O(CH ₂ ) ₆ CH ₃ , -CH ₂ O(CH ₂ ) ₇ CH ₃ , -CH ₂ OCH ₂ CH(CH ₂ CH ₃ )(CH ₂ ) ₃ CH ₃ , -CH ₂ O(CH ₂ ) ₈ CH ₃ , -CH ₂ O(CH ₂ ) ₉ CH ₃ , -CH ₂ O(CH ₂ ) ₁₀ CH ₃ , -CH ₂ O(CH ₂ ) ₁₁ CH ₃ , -CH ₂ O(CH ₂ ) ₁₂ CH ₃ , -CH ₂ O(CH ₂ ) ₁₃ CH ₃ , -CH ₂ O(CH ₂ ) ₁₄ CH ₃ , -CH ₂ O(CH ₂ ) ₁₅ CH ₃ , -CH ₂ O(CH ₂ ) ₁₆ CH ₃ , -CH ₂ O(CH ₂ ) ₁₇ CH ₃ , -CH ₂ O(CH ₂ ) ₁₈ CH ₃ , -CH ₂ CH ₂ OCH ₃ , -CH ₂ CH ₂ OCH ₂ CH ₃ , -CH ₂ CH ₂ O(CH ₂ ) ₂ CH ₃ , -CH ₂ CH ₂ OCH(CH ₃ ) ₂ , -CH ₂ CH ₂ O(CH ₂ ) ₃ CH ₃ , -CH ₂ CH ₂ OCH ₂ CH(CH ₃ ) ₂ , -CH ₂ CH ₂ OC(CH ₃ ) ₃ , -CH ₂ CH ₂ O(CH ₂ ) ₄ CH ₃ , -CH ₂ CH ₂ OCH(CH ₃ )(CH ₂ ) ₂ CH ₃ , -CH ₂ CH ₂ OCH ₂ CH(CH ₃ ) ₂ , -CH ₂ CH ₂ O(CH ₂ ) ₂ CH(CH ₃ ) ₂ , -CH ₂ CH ₂ OC(CH ₃ ) ₃ , -CH ₂ CH ₂ OCH(CH ₃ )(CH ₂ ) ₃ CH ₃ , -CH ₂ CH ₂ O(CH ₂ ) ₅ CH ₃ , -CH ₂ CH ₂ OCH(CH ₃ )(CH ₂ ) ₃ CH ₃ , -CH ₂ CH ₂ OCH ₂ CH(CH ₃ )(CH ₂ ) ₂ CH ₃ , -CH ₂ CH ₂ O(CH ₂ ) ₂ CH(CH ₃ )CH ₂ CH ₃ , -CH ₂ CH ₂ O(CH ₂ ) ₃ CH(CH ₃ ) ₂ , -CH ₂ CH ₂ OC(CH ₃ ) ₂ (CH ₂ ) ₂ CH ₃ , -CH ₂ CH ₂ OCH(CH ₂ CH ₃ )(CH ₂ ) ₂ CH ₃ , -CH ₂ CH ₂ OC(CH ₃ ) ₂ CH(CH ₃ ) ₂ , -CH ₂ CH ₂ O(CH ₂ ) ₆ CH ₃ , -CH ₂ CH ₂ O(CH ₂ ) ₇ CH ₃ , -CH ₂ CH ₂ OCH ₂ CH (CH ₂ CH ₃ )(CH ₂ ) ₃ CH ₃ , -CH ₂ CH ₂ O(CH ₂ ) ₈ CH ₃ , -CH ₂ CH ₂ O(CH ₂ ) ₉ CH ₃ , -CH ₂ CH ₂ O(CH ₂ ) ₁₀ CH ₃ , -CH ₂ CH ₂ O(CH ₂ ) ₁₁ CH ₃ , -CH ₂ CH ₂ O(CH ₂ ) ₁₂ CH ₃ , -CH ₂ CH ₂ O(CH ₂ ) ₁₃ CH ₃ , -CH ₂ CH ₂ O(CH ₂ ) ₁₄ CH ₃ , -CH ₂ CH ₂ O(CH ₂ ) ₁₅ CH ₃ , -CH ₂ CH ₂ O(CH ₂ ) ₁₆ CH ₃ , -CH ₂ CH ₂ O(CH ₂ ) ₁₇ CH ₃ , -CH ₂ CH ₂ CH ₂ OCH ₃ , -CH ₂ CH ₂ CH ₂ OCH ₂ CH ₃ , -CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₂ CH ₃ , -CH ₂ CH ₂ CH ₂ OCH (CH ₃ ) ₂ , -CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₃ CH ₃ , -CH ₂ CH ₂ CH ₂ OCH ₂ CH(CH ₃ ) ₂ , -CH ₂ CH ₂ CH ₂ OC(CH ₃ ) ₃ , -CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₄ CH ₃ , -CH ₂ CH ₂ CH ₂ OCH(CH ₃ )(CH ₂ ) ₂ CH ₃ , -CH ₂ CH ₂ CH ₂ OCH ₂ CH(CH ₃ ) ₂ , -CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₂ CH(CH ₃ ) ₂ , -CH ₂ CH ₂ CH ₂ OC(CH ₃ ) ₃ , -CH ₂ CH ₂ CH ₂ OCH(CH ₃ ) (CH ₂ ) ₃ CH ₃ , -CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₅ CH ₃ , -CH ₂ CH ₂ CH ₂ OCH(CH ₃ )(CH ₂ ) ₃ CH ₃ , -CH ₂ CH ₂ CH ₂ OCH ₂ CH(CH ₃ )(CH ₂ ) ₂ CH ₃ , -CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₂ CH(CH ₃ )CH ₂ CH ₃ , -CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₃ CH(CH ₃ ) ₂ , -CH ₂ CH ₂ CH ₂ OC(CH ₃ ) ₂ (CH ₂ ) ₂ CH ₃ , -CH ₂ CH ₂ CH ₂ OCH(CH ₂ CH ₃ )(CH ₂ ) ₂ CH ₃ , -CH ₂ CH ₂ CH ₂ OC(CH ₃ ) ₂ CH(CH ₃ ) ₂ , -CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₆ CH ₃ , -CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₇ CH ₃ , -CH ₂ CH ₂ CH ₂ OCH ₂ CH(CH ₂ CH ₃ )(CH ₂ ) ₃ CH ₃ , -CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , -CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , -CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , -CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , -CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , -CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₃ , -CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH 2 CH 2 OCH ₂ CH ₂ OCH _{2 CH 2 OCH 2} CH _{2 OCH 3} , -CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , -CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , -CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , -CH ₂ CH ₂ CH ₂ OCH ₂ CH 2 CH ₂ OCH ₂ CH ₂ CH ₂ OCH 2 CH ₂ CH _{2 OCH 2} CH ₂ CH _{2 OCH 3} , -CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₂ CH 2 CH ₂ OCH ₂ CH ₂ CH ₂ OCH ₃ , -CH ₂ CH ₂ CH ₂ CH ₂ OCH _{2 CH 2 CH 2} CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH ₃ , -CH ₂ CH ₂ CH ₂ CH ₂ OCH ₂ CH ₂ CH ₂ CH ₂ OCH 2 CH 2 CH ₂ CH _{2 OCH 2} CH ₂ CH ₂ CH _{2 OCH 3} , -CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₃ , -CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₃ , -CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH 2 CH 2 OCH ₂ CH ₂ OCH _{2 CH 2 OCH 2} CH ₂ OCH ₂ CH _{2 OCH 2 CH 3} , -CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₃ , -CH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₃ , -CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₈ CH ₃ , -CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₉ CH ₃ , -CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₀ CH ₃ , -CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₁ CH ₃ , -CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₂ CH ₃ , -CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₃ CH ₃ , -CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₄ CH ₃ , -CH ₂ CH _{2CH 2} O(CH ₂ ) ₁₅ CH ₃ , -CH ₂ CH ₂ CH ₂ O(CH ₂ ) ₁₆ CH ₃ and the like.

As a divalent group obtained by removing two hydrogen atoms on the aromatic ring of dialkyl fluorene represented by formula (3), 9,9-dimethyl-9H-fluorene-2,7-diyl group, 9,9- Diethyl-9H-fluorene-2,7-diyl group, 9,9-dipropyl-9H-fluorene-2,7-diyl group, 9,9-dibutyl-9H-fluorene-2,7- Diyl group, 9,9-dihexyl-9H-fluorene-2,7-diyl group, 9,9-dioctyl-9H-fluorene-2,7-diyl group, 9,9-bis (2-ethyl Hexyl)-9H-fluorene-2,7-diyl group, 9,9-dimethoxy-9H-fluorene-2,7-diyl group, 9,9-diethoxy-9H-fluorene-2,7- Diyl group, 9,9-bis[2-(2-(2-methoxyethoxy)ethoxy)ethyl]-9H-fluorene-2,7-diyl group, etc. are mentioned, but are not limited to these. .

Among these, Ar ¹ and Ar ⁴ are preferably groups obtained by removing two hydrogen atoms on the aromatic ring of dialkyl fluorene represented by formula (3), especially 9,9-dimethyl-9H-fluorene-2, 7-diyl group is preferred.

In formulas (1) and (2), Ar ² , Ar ³ , Ar ⁵ and Ar ⁶ are each independently an aryl group having 6 to 20 carbon atoms or a hydrogen atom on the aromatic ring of dialkyl fluorene represented by formula (3). It is a monovalent group obtained by removing one, and some or all of the hydrogen atoms on the aromatic ring of these groups are cyano group, nitro group, halogen atom, vinyl group, trifluorovinyl group, acryloyl group, and methacryloyl group. , an oxetane group, an epoxy group, an alkyl group having 1 to 20 carbon atoms, or a halogenated alkyl group having 1 to 20 carbon atoms. Specific examples of the alkyl group having 1 to 20 carbon atoms and the halogenated alkyl group having 1 to 20 carbon atoms include those similar to those described above.

Examples of the aryl group having 6 to 20 carbon atoms include phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1-phenanthryl group, and 2-phenanthryl. group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, biphenyl-2-yl group, biphenyl-3-yl group, biphenyl-4-yl group, etc.

Monovalent groups obtained by removing one hydrogen atom on the aromatic ring of dialkyl fluorene represented by formula (3) include 9,9-dimethyl-9H-fluoren-2-yl group and 9,9-dimethyl-9H. -Fluoren-3-yl group, 9,9-diethyl-9H-fluoren-2-yl group, 9,9-diethyl-9H-fluoren-3-yl group, 9,9-dipropyl-9H-flu oren-2-yl group, 9,9-dipropyl-9H-fluoren-3-yl group, 9,9-dibutyl-9H-fluoren-2-yl group, 9,9-dibutyl-9H-fluorene- 3-yl group, 9,9-dihexyl-9H-fluoren-2-yl group, 9,9-dihexyl-9H-fluoren-3-yl group, 9,9-dioctyl-9H-fluorene-2- Diary group, 9,9-dioctyl-9H-fluoren-3-yl group, 9,9-bis(2-ethylhexyl)-9H-fluoren-2-yl group, 9,9-bis(2-ethylhexyl) -9H-fluoren-3-yl group, 9,9-dimethoxy-9H-fluoren-2-yl group, 9,9-dimethoxy-9H-fluoren-3-yl group, 9,9-diethoxy-9H -Fluoren-2-yl group, 9,9-diethoxy-9H-fluoren-3-yl group, 9,9-bis[2-(2-(2-methoxyethoxy)ethoxy)ethyl]-9H -Fluoren-2-yl group, 9,9-bis[2-(2-(2-methoxyethoxy)ethoxy)ethyl]-9H-fluoren-3-yl group, etc. are mentioned, but are limited to these. It doesn't work.

^{When _ _ _ When _ _ _} At this time, the structure of the ring is preferably a carbazole ring.

When R ² is a phenylene group, R ² and Ar ² may be bonded to each other to form a ring with the nitrogen atom, sulfur atom, or oxygen atom to which they are bonded. When R ⁴ is a phenylene group, R ⁴ and Ar ⁵ may be bonded to each other to form a ring with the nitrogen atom, sulfur atom, or oxygen atom to which they are bonded. At this time, the structure of the ring is preferably a carbazole ring, a dibenzothiophene ring, or a dibenzofuran ring.

However, at least one of Ar ¹ to Ar ³ is a group obtained by removing a hydrogen atom on the aromatic ring of dialkyl fluorene represented by formula (3), and at least one of Ar ⁴ to Ar ⁶ is a group of formula (3) It is a group obtained by removing the hydrogen atom on the aromatic ring of dialkyl fluorene represented by .

As the repeating unit represented by formula (1), X ¹ is preferably -N(Ar ³ )-, and as the repeating unit represented by formula (2), X ² is preferably -N(Ar ⁶ )-. That is, the repeating unit represented by formula (1) is preferably represented by the following formula (1A), and the repeating unit represented by formula (2) is preferably represented by the following formula (2A).

(In the formula, R ^A , R ¹ to R ⁴ , and Ar ¹ to Ar ⁶ are the same as above.)

Additionally, the repeating unit represented by formula (2A) is preferably represented by the following formula (2B).

(In the formula, R ³ , R ⁴ and Ar ⁴ to Ar ⁶ are the same as above.)

The polymer of the present invention may contain one or both of the repeating unit represented by formula (1) and the repeating unit represented by formula (2).

Moreover, within the range that does not impair the effect of the present invention, repeating units other than the repeating unit represented by formula (1) and the repeating unit represented by formula (2) may be included. Other repeating units include compounds containing polymerizable functional groups such as acryloyl group, acrylamide group, methacryloyl group, methacrylamide group, vinyl ether group, and maleic anhydride. Additionally, when containing a plurality of repeating units, the polymer of the present invention may be any of random copolymers, alternating copolymers, and block copolymers.

The content of the repeating unit represented by formula (1) and the repeating unit represented by formula (2) is preferably 50 mol% or more, more preferably 80 mol% or more, and 90 mol% of all repeating units contained in the polymer. % or more is more preferable, 95 mol% or more is more preferable, and 100 mol% is most preferable. When containing both the repeating unit represented by formula (1) and the repeating unit represented by formula (2), the content ratio of these units is expressed as the molar ratio: repeating unit represented by formula (1): represented by formula (2) The repeating unit = 1:99 to 99:1 is preferable, 5:95 to 95:5 is more preferable, and 10:90 to 90:10 is even more preferable. In addition, the expression that the content of the repeating unit represented by formula (1) and the repeating unit represented by formula (2) is 100 mol% refers to the impurity repeating unit contained in trace amounts due to impurity monomers in the raw materials or side reactions during polymer synthesis. The existence is not denied. For example, when a polymer is synthesized using only a monomer that provides a repeating unit represented by formula (1) and a monomer that provides a repeating unit represented by formula (2) as raw materials, the formula A polymer having a content of 100 mol% of the repeating unit represented by (1) and the repeating unit represented by formula (2) can be obtained.

The weight average molecular weight (Mw) of the polymer of the present invention is usually 2,000 to 1,000,000, but from the viewpoint of improving the solubility of the polymer and obtaining a varnish with excellent uniformity with good reproducibility, it is preferably 500,000 or less, more preferably 200,000 or less. am. Moreover, the dispersion degree (Mw/Mn) is not particularly limited, but is usually 1.0 to 10.0, preferably 1.1 to 5.0, and more preferably 1.2 to 3.0. In addition, in the present invention, the weight average molecular weight (Mw) and number average molecular weight (Mn) of the polymer are, for example, GPC equipment manufactured by Shimadzu Corporation, autosampler SIL-10AF, Degussa DGU-20As, and column oven CTO. -20A, differential refractive index detector RID-10A (column: Showa Denko Co., Ltd. product, Shodex GPC KF-805L and KF-804L, column temperature 40°C, detector: UV detector (254 nm), eluent: tetrahydrofuran (THF) ), column flow rate: 1.0 mL/min).

[Polymer manufacturing method]

The polymer of the present invention can be produced by polymerizing at least one monomer selected from the monomer represented by the following formula (1') and the monomer represented by the following formula (2').

(In the formula, R ^A , R ¹ to R ⁴ , X ¹ , X ² , Ar ¹ , Ar ² , Ar ⁴ and Ar ⁵ are the same as above.)

The polymerization reaction is not particularly limited, and radical polymerization, anionic polymerization, cationic polymerization, etc. can be employed. Among these, radical polymerization is particularly preferable, and specifically, polymerization may be performed by heating the monomer in a solvent in the presence of a polymerization initiator.

As the polymerization initiator, it can be appropriately selected and used from conventionally known ones. For example, peroxides such as benzoyl peroxide, cumene hydroperoxide, and tert-butyl hydroperoxide; persulfate such as sodium persulfate, potassium persulfate, and ammonium persulfate; Azo-based compounds such as azobisisobutyronitrile (AIBN), azobismethylbutyronitrile, and azobisisovaleronitrile can be mentioned. These may be used individually or in combination of two or more types.

The amount of polymerization initiator used is preferably about 0.01 to 0.05 mol per 1 mol of the monomer. The reaction temperature can be appropriately set from 0°C to the boiling point of the solvent used, and is preferably around 20 to 100°C. The reaction time is preferably about 0.1 to 30 hours.

The solvent used in the polymerization reaction may be appropriately selected from various solvents commonly used in this type of reaction. Specifically, water; Methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, isopentanol, tert-pentanol , alcohols such as 1-hexanol, 1-heptanol, 2-heptanol, 3-heptanol, 2-octanol, 2-ethyl-1-hexanol, benzyl alcohol, and cyclohexanol; ethers such as diethyl ether, diisopropyl ether, dibutyl ether, cyclopentyl methyl ether, tetrahydrofuran, and 1,4-dioxane; Halogenated hydrocarbons such as chloroform, dichloromethane, dichloroethane, and carbon tetrachloride; Ether alcohols such as methyl cellosolve, ethyl cellosolve, isopropyl cellosolve, butyl cellosolve, and diethylene glycol monobutyl ether; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as ethyl acetate, butyl acetate, ethyl propionate, and cellosolve acetate; n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, benzene, toluene, xylene, ethylbenzene, anisole, etc. aliphatic or aromatic hydrocarbons; Acetals such as methylal and diethylacetal; Fatty acids such as formic acid, acetic acid, and propionic acid; Nitropropane, nitrobenzene, dimethylamine, monoethanolamine, pyridine, N-methyl-2-pyrrolidone, N,N-dimethylformamide, dimethyl sulfoxide, acetonitrile, etc. These may be used individually, or two or more types may be mixed and used.

In addition, when the polymer of the present invention contains repeating units other than the repeating unit represented by formula (1) and the repeating unit represented by formula (2), the synthesis method is to provide a repeating unit different from the monomer at the time of polymerization. Polymerization can be done by allowing the following monomers to coexist.

The monomer represented by formula (1') can be synthesized using a conventionally known reaction. An example of the synthetic method includes a method of reacting maleic anhydride with an amine compound represented by the formula (1'') in a solvent, if necessary, in the presence of a catalyst, as shown in Scheme A below.

Scheme A

(Wherein, R ¹ , R ² , X ¹ , Ar ¹ and Ar ² are the same as above.)

Examples of the solvent include acetic acid, toluene, ethyl acetate, tetrahydrofuran, methanol, ethanol, dimethylformamide, and dimethyl sulfoxide.

Examples of the catalyst include acetic acid, sodium acetate, potassium acetate, toluenesulfonic acid, and camphorsulfonic acid. The amount of the catalyst used is preferably 1.0 to 10.0, more preferably 2.0 to 5.0, in molar ratio with respect to the amine compound represented by formula (1''). Additionally, when acetic acid is used as the solvent, a catalyst does not need to be used.

In the above reaction, the introduction ratio of maleic anhydride and the amine compound represented by the formula (1'') is preferably such that the amine compound represented by the formula (1'') is 0.5 to 3.0 in molar ratio with respect to maleic anhydride. And, an amount of 1.0 to 1.5 is more preferable.

The reaction temperature is appropriately set in the range from the melting point to the boiling point of the solvent, taking into consideration the type and amount of the raw material compound or catalyst used, and is usually about 40 to 150°C, preferably 80 to 120°C. In addition, the reaction time cannot be specified uniformly because it varies depending on the raw material compound used or reaction temperature, but is usually about 2 to 24 hours.

After completion of the reaction, post-processing is performed according to a conventional method to obtain the target monomer.

The monomer represented by formula (2') can be synthesized by combining various coupling reactions. As an example of the synthetic method, for example, as shown in Scheme B below, a method of coupling reaction between a styrene compound represented by formula (2'') and an amine compound represented by formula (2''') is given. You can.

Scheme B

(Wherein R ^A , R ³ , R ⁴ , X ² , Ar ⁴ and Ar ⁵ are the same as above.)

In Scheme B, X ^A is any group used in the coupling reaction. Specific examples of such groups include, for example, when using the Suzuki-Miyaura coupling reaction, boronic acid groups such as -B(OH) ₂ and boronic acid ester groups.

In Scheme B, X ^B is each independently a halogen atom or a pseudohalogen group. The halogen atom represented ^by Examples of the pseudohalogen group represented ^by and aromatic sulfonyloxy groups such as benzenesulfonyloxy group and toluenesulfonyloxy group.

The solvent used in the above coupling reaction is not particularly limited as long as it does not adversely affect the reaction, but examples include aliphatic hydrocarbons (pentane, n-hexane, n-octane, n-decane, decalin, etc.), halogenated aliphatics, etc. Hydrocarbons (chloroform, dichloromethane, dichloroethane, carbon tetrachloride, etc.), aromatic hydrocarbons (benzene, nitrobenzene, toluene, o-xylene, m-xylene, p-xylene, mesitylene, etc.), ethers (diethyl ether, diisopropyl) Ether, tert-butylmethyl ether, THF, dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, etc.), amides (N,N-dimethylformamide (DMF), N,N-dimethylacetate amides, etc.), lactams and lactones (N-methylpyrrolidone, γ-butyrolactone, etc.), urea derivatives (N,N-dimethylimidazolidinone, tetramethylurea, etc.), sulfoxides (dimethylsulfoxide, alcohol) phoran, etc.), nitriles (acetonitrile, propionitrile, butyronitrile, etc.), etc. Among these, from the viewpoint of efficiently obtaining the target product, preferred solvents are aliphatic hydrocarbons (pentane, n-hexane, n-octane, n-decane, decalin, etc.), aromatic hydrocarbons (benzene, nitrobenzene, toluene, o-xylene, m -xylene, p-xylene, mesitylene, etc.), ether (diethyl ether, diisopropyl ether, tert-butylmethyl ether, THF, dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, etc. ), and more preferably aromatic hydrocarbons (benzene, nitrobenzene, toluene, o-xylene, m-xylene, p-xylene, mesitylene, etc.), ethers (diethyl ether, diisopropyl ether, tert-butylmethyl ether) , THF, dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, etc.).

Catalysts used in the above coupling reaction include [1,1'-bis(diphenylphosphine)ferrocene]palladium(II)dichloride (PdCl ₂ (dppf)), tetrakis(triphenylphosphine)palladium. (Pd(PPh ₃ ) ₄ ), bis(triphenylphosphine)dichloropalladium (Pd(PPh ₃ ) ₂ Cl ₂ ), bis(benzylideneacetone)palladium (Pd(dba) ₂ ), tris(benzylideneacetone) Palladium catalysts such as dipalladium (Pd ₂ (dba) ₃ ), bis(tri-tert-butylphosphine) palladium (Pd(Pt-Bu ₃ ) ₂ ), palladium(II) acetate (Pd(OAc) ₂ ), etc. can be mentioned. These catalysts may be used with known suitable ligands.

The amount of the catalyst used is preferably 0.01 to 0.2, and more preferably 0.03 to 0.1, in molar ratio with respect to the amine compound represented by formula (2'''). Also, when using a ligand, the amount used can be 0.1 to 3.0 equivalents relative to the metal complex used, but 0.8 to 1.5 equivalents is suitable.

Additionally, a base may be used in the above coupling reaction. Examples of the base include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; Alkoxy alkali metals such as tert-butoxylithium, tert-butoxy sodium, and tert-butoxy potassium; alkali metal carbonates such as sodium carbonate and potassium carbonate; alkali metal bicarbonate such as sodium bicarbonate and potassium bicarbonate; alkaline earth metals such as calcium carbonate; organic lithium such as n-butyllithium, sec-butyllithium, and tert-butyllithium; Amines such as triethylamine, diisopropylethylamine, tetramethylethylenediamine, triethylenediamine, and pyridine may be included, but there is no particular limitation as long as they are used in this type of reaction. In particular, sodium carbonate and potassium carbonate are suitable because they are easy to handle. The amount of the base used is usually about 1 to 20, preferably 4 to 8, in molar ratio with respect to the amine compound represented by formula (2''').

In the above coupling reaction, the introduction ratio of the styrene compound represented by formula (2'') and the amine compound represented by the following formula (2''') is, with respect to the styrene compound represented by formula (2''): The amount of the amine compound represented by the formula (2''') is preferably 0.2 to 2.0 in molar ratio, and the amount of 0.5 to 1.0 is more preferable.

In the above coupling reaction, the reaction temperature is appropriately set in the range from the melting point to the boiling point of the solvent, taking into consideration the type and amount of the raw material compound or catalyst used, and is usually about 20 to 120°C, preferably It is 60~100℃. In addition, the reaction time cannot be specified uniformly because it varies depending on the raw material compound used, reaction temperature, etc., but is usually about 0.5 to 12 hours.

After completion of the reaction, post-processing is performed according to a conventional method to obtain the target monomer.

[Charge transport material]

The polymer of the present invention can be suitably used as a charge transport material, particularly as a hole transport material. In the present invention, charge transport properties are synonymous with conductivity. A charge-transporting material is one that itself has charge-transporting properties. Additionally, the charge-transporting varnish may itself have charge-transporting properties, or the solid film obtained therefrom may have charge-transporting properties.

[Charge transport varnish]

The charge-transporting varnish of the present invention contains a charge-transporting material made of the above polymer and an organic solvent. The above charge-transporting substances may be used individually, or two or more types may be used in combination. The charge-transporting substance may contain a charge-transporting polymer compound other than the above polymer, a charge-transporting low-molecular-weight compound, or a charge-transporting oligomer-compound.

[Organic solvent]

As the organic solvent, a highly polar solvent capable of well dissolving the polymer can be used. Additionally, if necessary, a low polarity solvent may be used because it has better process compatibility than a high polarity solvent. In the present invention, a low polarity solvent is defined as having a relative dielectric constant of less than 7 at a frequency of 100 kHz, and a high polarity solvent is defined as having a relative dielectric constant of 7 or more at a frequency of 100 kHz.

Examples of the low polarity solvent include chlorine-based solvents such as chloroform and chlorobenzene; Aromatic hydrocarbon solvents such as toluene, xylene, tetralin, cyclohexylbenzene, and decylbenzene; Aliphatic alcohol-based solvents such as 1-octanol, 1-nonanol, and 1-decanol; Tetrahydrofuran, dioxane, anisole, 4-methoxytoluene, 3-phenoxytoluene, dibenzyl ether, diethylene glycol dimethyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol butyl methyl Ether-based solvents such as ether; Methyl benzoate, ethyl benzoate, butyl benzoate, isoamyl benzoate, bis(2-ethylhexyl) phthalate, dimethyl phthalate, diisopropyl malonate, dibutyl maleate, dibutyl oxalate, hexyl acetate, propylene glycol monomethyl ether acetate, and ester-based solvents such as ethylene glycol monoethyl ether acetate and diethylene glycol monobutyl ether acetate.

Examples of the highly polar solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylisobutylamide, N-methylpyrrolidone, and 1,3-dimethyl-2-imide. Amide-based solvents such as dazolidinone; Ketone-based solvents such as ethyl methyl ketone, isophorone, and cyclohexanone; Cyano-based solvents such as acetonitrile and 3-methoxypropionitrile; polyhydric alcohol-based solvents such as ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,3-butanediol, and 2,3-butanediol; Diethylene glycol monomethyl ether, diethylene glycol monophenyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, benzyl alcohol, 2-phenoxyethanol, 2-benzyloxyethanol, 3 -Monohydric alcohol-based solvents other than aliphatic alcohols such as phenoxybenzyl alcohol and tetrahydrofurfuryl alcohol; and sulfoxide-based solvents such as dimethyl sulfoxide.

The amount of the organic solvent used is such that the solid content concentration in the varnish of the present invention is usually about 0.1 to 20% by mass, preferably 0.5 to 10% by mass, from the viewpoint of securing a sufficient film thickness while suppressing precipitation of charge-transporting substances. This is the amount. In addition, in the present invention, solid content means components other than the solvent among the components included in the varnish. The above organic solvents may be used individually, or two or more types may be mixed.

The charge-transporting varnish of the present invention may also contain water as a solvent, but usually contains only an organic solvent as a solvent. Additionally, “organic solvent only” means that only organic solvents are intentionally used as solvents, and does not deny the hydration water or solid content of the compound or even the presence of trace amounts of water contained in the organic solvent.

[Dopant (charge-accepting dopant)]

The charge-transporting varnish of the present invention may contain a dopant for the purpose of improving the charge-transporting properties of the thin film obtained from the charge-transporting varnish of the present invention. The dopant is not particularly limited as long as it is soluble in at least one solvent used in the varnish, and either an inorganic dopant or an organic dopant can be used. In addition, a dopant is a substance whose function as a dopant is revealed or improved by losing part of the molecule due to external stimulation, such as heating during firing, in the process of obtaining a charge-transporting thin film, which is a solid film, from varnish. For example, it may be an arylsulfonic acid ester compound in which the sulfonic acid group is protected by a group that is easily desorbed.

As the inorganic dopant, heteropoly acid is preferable, and specific examples thereof include phosphomolybdic acid, siliceous molybdic acid, phosphotungstic acid, phosphotungstomolybdic acid, and silicotungstic acid.

Heteropoly acids have a structure in which a hetero atom is located at the center of the molecule, typically represented by a Keggin type chemical structure represented by the following formula (HPA1) or a Dawson type chemical structure represented by the following formula (HPA2), and include vanadium (V), molybdenum It is a polyacid formed by condensation of isopoly acid, which is an oxyacid such as (Mo) and tungsten (W), and oxyacid of a different element. Examples of such oxyacids of heterogeneous elements mainly include oxyacids of silicon (Si), phosphorus (P), and arsenic (As).

Examples of the heteropoly acids include phosphomolybdic acid, siliceous molybdic acid, phosphotungstic acid, silicotungstic acid, and phosphotungstomolybdic acid. These may be used individually or in combination of two or more types. In addition, the heteropoly acid used in the present invention is available as a commercial product and can also be synthesized by a known method. In particular, when one type of heteropoly acid is used, the one type of heteropoly acid is preferably phosphotungstic acid or phosphomolybdic acid, and phosphotungstic acid is optimal. Moreover, when two or more types of heteropoly acids are used, one of the two or more types of heteropoly acids is preferably phosphotungstic acid or phosphomolybdic acid, and phosphotungstic acid is more preferable.

In addition, in quantitative analysis such as elemental analysis, heteropolyacid may have a large or small number of elements based on the structure expressed by the general formula, as long as it is obtained as a commercial product or synthesized appropriately according to a known synthesis method. , can be used in the present invention.

That is, for example, phosphotungstic acid is generally represented by the chemical formula H ₃ (PW ₁₂ O ₄₀ )·nH ₂ O, and phosphomolybdic acid is represented by the chemical formula H ₃ (PMo ₁₂ O ₄₀ )·nH ₂ O, respectively. In quantitative analysis, , Even if the number of P (phosphorus), O (oxygen), W (tungsten) or Mo (molybdenum) in this formula is large or small, it can be obtained as a commercial product or synthesized appropriately according to a known synthesis method. As long as it is, it can be used in the present invention. In this case, the mass of heteropoly acid specified in the present invention is not the mass (phosphotungstic acid content) of pure phosphotungstic acid in a composite or commercial product, but in the form available as a commercial product and in a form that can be isolated by a known synthetic method, It refers to the total mass including hydration water and other impurities.

Examples of the organic dopant include arylsulfonic acid compounds, arylsulfonic acid esters, and ionic compounds consisting of a predetermined anion and its pair cation.

The arylsulfonic acid compound is preferably one represented by the following formula (A) or (B) from the viewpoint of transparency of the thin film obtained from the charge-transporting varnish of the present invention.

In formula (A), A ¹ is -O- or -S-, but -O- is preferable. A ² is a (p ² +1) valent group derived from naphthalene or anthracene (i.e., a group obtained by removing (p ² + 1) hydrogen atoms from naphthalene or anthracene), but a group derived from naphthalene is preferred. A ³ is a 2-4 valent perfluorobiphenyl group. p ¹ is the number of bonds between A ¹ and A ³ and is an integer that satisfies 2≤p ¹ ≤4. However, it is preferable that A ³ is a divalent perfluorobiphenyl group and p ¹ is 2. p ² is the number of sulfonic acid groups bonded to A ² and is an integer satisfying 1≤p ² ≤4, but 2 is suitable.

In formula (B), A ⁴ to A ⁸ are each independently a hydrogen atom, a halogen atom, a cyano group, an alkyl group with 1 to 20 carbon atoms, a halogenated alkyl group with 1 to 20 carbon atoms, or a halogenated alkenyl group with 2 to 20 carbon atoms, and A At least 3 of ⁴ to A ⁸ are halogen atoms. q is the number of sulfonic acid groups bonded to the naphthalene ring, and is an integer satisfying 1≤q≤4, but 2 to 4 are preferable, and 2 is more preferable.

The alkyl group having 1 to 20 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, and sec-butyl group. , tert-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, n-tride Straight-chain or branched groups such as actual group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-eicosanyl group, etc. Alkyl group; Cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, bicyclobutyl group, bicyclopentyl group, bicyclohexyl group, bicycloheptyl group Cyclic alkyl groups with 3 to 20 carbon atoms, such as tyl group, bicyclooctyl group, bicyclononyl group, and bicyclodecyl group, are included.

As the halogenated alkyl group having 1 to 20 carbon atoms, trifluoromethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group, 3,3,3-trifluoropropyl group, 2,2,3,3 ,3-pentafluoropropyl group, perfluoropropyl group, 4,4,4-trifluorobutyl group, 3,3,4,4,4-pentafluorobutyl group, 2,2,3,3 , 4,4,4-heptafluorobutyl group, perfluorobutyl group, etc. Examples of the halogenated alkenyl group having 2 to 20 carbon atoms include perfluoroethenyl group, 1-perfluoropropenyl group, perfluoroallyl group, and perfluorobutenyl group.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with the fluorine atom being preferred.

Among these, A ⁴ to A ⁸ is a hydrogen atom, a halogen atom, a cyano group, an alkyl group with 1 to 10 carbon atoms, a halogenated alkyl group with 1 to 10 carbon atoms, or a halogenated alkenyl group with 2 to 10 carbon atoms, and among A ⁴ to A ⁸ At least three are preferably fluorine atoms, and are hydrogen atom, fluorine atom, cyano group, alkyl group with 1 to 5 carbon atoms, fluorinated alkyl group with 1 to 5 carbon atoms, or fluorinated alkenyl group with 2 to 5 carbon atoms, and also A ⁴ to A It is more preferable that at least 3 of ⁸ are fluorine atoms, and are hydrogen atom, fluorine atom, cyano group, perfluoroalkyl group of 1 to 5 carbon atoms or perfluoroalkenyl group of 1 to 5 carbon atoms, and also A ⁴ , A It is further preferable that ⁵ and A ⁸ are fluorine atoms. Additionally, a perfluoroalkyl group is a group in which all hydrogen atoms of an alkyl group are substituted with fluorine atoms, and a perfluoroalkenyl group is a group in which all hydrogen atoms of an alkenyl group are substituted with fluorine atoms.

Specific examples of suitable arylsulfonic acid compounds include those shown below, but are not limited to these.

Examples of the arylsulfonic acid ester compound include, in view of the transparency of the thin film obtained from the charge-transporting varnish of the present invention, the arylsulfonic acid ester compound disclosed in International Publication No. 2017/217455, the arylsulfonic acid ester compound disclosed in International Publication No. 2017/217457, The aryl sulfonic acid ester compound described in Japanese Patent Application No. 2017-243631, etc. are mentioned.

Specifically, from the viewpoint of solubility in low polar solvents, the arylsulfonic acid ester compound is preferably represented by any of the following formulas (C) to (E).

In formulas (C) to (E), m is an integer that satisfies 1≤m≤4, but 2 is preferable. n is an integer that satisfies 1≤n≤4, but 2 is preferable.

In formula (C), A ¹¹ is an m-valent group derived from perfluorobiphenyl (that is, a group obtained by removing m fluorine atoms from perfluorobiphenyl). A ¹² is -O- or -S-, with -O- being preferred. A ¹³ is a (n+1) valent group derived from naphthalene or anthracene (i.e., a group obtained by removing (n+1) hydrogen atoms from naphthalene or anthracene), but a group derived from naphthalene is preferred. R ^s1 to R ^s4 are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, and R ^s5 is a monovalent hydrocarbon group having 2 to 20 carbon atoms that may be substituted.

Examples of linear or branched alkyl groups having 1 to 6 carbon atoms represented by R ^s1 to R ^s4 include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-. Butyl group, n-hexyl group, etc. are mentioned. Among these, an alkyl group having 1 to 3 carbon atoms is preferable. In particular, among R ^s1 to R ^s4 , R ^s1 or R ^s3 is a straight-chain alkyl group having 1 to 3 carbon atoms, and the remainder is a hydrogen atom, or R ^s1 is a straight-chain alkyl group having 1 to 3 carbon atoms, and R ^s2 to R ^s4 are hydrogen atoms. It is desirable to be In this case, a methyl group is preferable as a straight-chain alkyl group having 1 to 3 carbon atoms.

The monovalent hydrocarbon group having 2 to 20 carbon atoms represented by R ^s5 may be linear, branched, or cyclic, and specific examples thereof include ethyl group, n-propyl group, isopropyl group, n-butyl group, and isobutyl group. , sec-butyl group, tert-butyl group, etc.; Aryl groups such as phenyl, naphthyl, and phenanthryl groups can be mentioned. Moreover, R ^s5 is preferably a straight-chain alkyl group or phenyl group having 2 to 4 carbon atoms.

In formula (D), A ¹⁴ is an m-valent hydrocarbon group having 6 to 20 carbon atoms containing one or more aromatic rings, which may be substituted, and this hydrocarbon group is a hydrocarbon group having 6 to 20 carbon atoms containing one or more aromatic rings. It is a group obtained by removing m hydrogen atoms from a compound. Examples of the hydrocarbon compounds include benzene, toluene, xylene, ethylbenzene, biphenyl, naphthalene, anthracene, and phenanthrene. Among these, A ¹⁴ is preferably a group derived from benzene, biphenyl, etc.

In addition, the hydrocarbon group represented by A ¹⁴ may have some or all of its hydrogen atoms substituted with a substituent, and such substituents include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a nitro group, a cyano group, a hydroxy group, and an amino group. , silanol group, thiol group, carboxyl group, sulfonic acid ester group, phosphate group, phosphate ester group, ester group, thioester group, amide group, monovalent hydrocarbon group, organoxy group, organoamino group, organosilyl group, organothio group. , acyl groups, sulfo groups, etc.

In formula (D), A ¹⁵ is -O- or -S-, but -O- is preferable.

In formula (D), A ¹⁶ is a (n+1) valent aromatic hydrocarbon group having 6 to 20 carbon atoms, and this aromatic hydrocarbon group is made up of (n+1) hydrogen atoms on the aromatic ring of an aromatic hydrocarbon compound having 6 to 20 carbon atoms. It is a group obtained by removing Examples of the aromatic hydrocarbon compounds include benzene, toluene, xylene, biphenyl, naphthalene, anthracene, and pyrene. Among these, A ¹⁶ is preferably a group derived from naphthalene or anthracene, and more preferably a group derived from naphthalene.

In formula (D), R ^s6 and R ^s7 are each independently a hydrogen atom or a linear or branched monovalent aliphatic hydrocarbon group, and R ^s8 is a linear or branched monovalent aliphatic hydrocarbon group. However, the total number of carbon atoms of R ^s6 , R ^s7 and R ^s8 is 6 or more. The upper limit of the total number of carbon atoms of R ^s6 , R ^s7 and R ^s8 is not particularly limited, but is preferably 20 or less, and more preferably 10 or less.

Specific examples of the linear or branched monovalent aliphatic hydrocarbon groups represented by R ^s6 , R ^s7 and R ^s8 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and sec-butyl group. alkyl groups having 1 to 20 carbon atoms, such as tert-butyl group, n-hexyl group, n-octyl group, 2-ethylhexyl group, and decyl group; 2 to 20 carbon atoms, such as vinyl group, 1-propenyl group, 2-propenyl group, isopropenyl group, 1-methyl-2-propenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, and hexenyl group alkenyl groups, etc. are mentioned. Among these, R ^s6 is preferably a hydrogen atom, and R ^s7 and R ^s8 are each independently preferably an alkyl group having 1 to 6 carbon atoms.

In formula (E), R ^s9 to R ^s13 are each independently a hydrogen atom, a nitro group, a cyano group, a halogen atom, an alkyl group with 1 to 10 carbon atoms, a halogenated alkyl group with 1 to 10 carbon atoms, or a halogenated alkenyl group with 2 to 10 carbon atoms. am.

The alkyl group having 1 to 10 carbon atoms represented by R ^s9 to R ^s13 may be linear, branched, or cyclic, and specific examples thereof include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, Isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-de Examples include practical skills, etc.

The halogenated alkyl group having 1 to 10 carbon atoms represented by R ^s9 to R ^s13 is not particularly limited as long as it is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 10 carbon atoms are substituted with halogen atoms. Specific examples include trifluoromethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2,2-pentafluoroethyl group, 3,3,3-trifluoropropyl group, 2,2, 3,3,3-pentafluoropropyl group, 1,1,2,2,3,3,3-heptafluoropropyl group, 4,4,4-trifluorobutyl group, 3,3,4, 4,4-pentafluorobutyl group, 2,2,3,3,4,4,4-heptafluorobutyl group, 1,1,2,2,3,3,4,4,4-nonafluo Robutyl group, etc. are mentioned.

The halogenated alkenyl group having 2 to 10 carbon atoms represented by R ^s9 to R ^s13 is not particularly limited as long as it is a group in which some or all of the hydrogen atoms of the alkenyl group having 2 to 10 carbon atoms are substituted with halogen atoms, and specific examples include perfluoro. Vinyl group, perfluoro-1-propenyl group, perfluoro-2-propenyl group, perfluoro-1-butenyl group, perfluoro-2-butenyl group, perfluoro-3-butenyl group, etc. You can.

Among these, R ^s9 is preferably a nitro group, a cyano group, a halogenated alkyl group with 1 to 10 carbon atoms, or a halogenated alkenyl group with 2 to 10 carbon atoms, and a nitro group, a cyano group, a halogenated alkyl group with 1 to 4 carbon atoms, or a halogenated alkenyl group with 2 to 4 carbon atoms. A halogenated alkenyl group is more preferable, and a nitro group, cyano group, trifluoromethyl group, and perfluoropropenyl group are even more preferable. As R ^s10 to R ^s13 , a halogen atom is preferable and a fluorine atom is more preferable.

In formula (E), A ¹⁷ is -O-, -S- or -NH-, but -O- is preferred.

In formula (E), A ¹⁸ is a (n+1) valent aromatic hydrocarbon group having 6 to 20 carbon atoms, and this aromatic hydrocarbon group is made up of (n+1) hydrogen atoms on the aromatic ring of an aromatic hydrocarbon compound having 6 to 20 carbon atoms. It is a group obtained by removing Examples of the aromatic hydrocarbon compounds include benzene, toluene, xylene, biphenyl, naphthalene, anthracene, and pyrene. Among these, as A ¹⁸ , a group derived from naphthalene or anthracene is preferable, and a group derived from naphthalene is more preferable.

In formula (E), R ^s14 to R ^s17 each independently represent a hydrogen atom or a linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms. Examples of the monovalent aliphatic hydrocarbon groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, cyclopentyl, n- Alkyl groups having 1 to 20 carbon atoms such as hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, and n-dodecyl group; 2 to 20 carbon atoms, such as vinyl group, 1-propenyl group, 2-propenyl group, isopropenyl group, 1-methyl-2-propenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, and hexenyl group alkenyl groups, etc. are mentioned. Among these, an alkyl group with 1 to 20 carbon atoms is preferable, an alkyl group with 1 to 10 carbon atoms is more preferable, and an alkyl group with 1 to 8 carbon atoms is even more preferable.

In formula (E), R ^s18 is a linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, or -OR ^s19 . R ^s19 is a monovalent hydrocarbon group having 2 to 20 carbon atoms which may be substituted.

Examples of the linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by R ^s18 include those similar to those exemplified in the description of R ^s14 to R ^s17 . When R ^s18 is a monovalent aliphatic hydrocarbon group, R ^s18 is preferably an alkyl group with 1 to 20 carbon atoms, more preferably an alkyl group with 1 to 10 carbon atoms, and even more preferably an alkyl group with 1 to 8 carbon atoms.

Examples of the monovalent hydrocarbon group having 2 to 20 carbon atoms represented by R ^s19 include those other than the methyl group among the monovalent aliphatic hydrocarbon groups described above, as well as aryl groups such as phenyl, naphthyl, and phenanthryl groups. Among these, R ^s19 is preferably a straight-chain alkyl group or phenyl group having 2 to 4 carbon atoms.

Additionally, substituents that the monovalent hydrocarbon group may have include a fluorine atom, an alkoxy group having 1 to 4 carbon atoms, a nitro group, and a cyano group.

Specific examples of suitable aryl sulfonic acid ester compounds include those shown below, but are not limited to these.

As an ionic compound consisting of the above-mentioned predetermined anion and its pair cation, it consists of a monovalent or divalent anion represented by the following formula (F1) and a pair cation represented by any of formulas (F2) to (F6). Electrically neutral onium borate salts are preferred.

In formula (F1), A ^r11 to A ^r16 each independently represent an aryl group that may have a substituent or a heteroaryl group that may have a substituent. L is an alkylene group, -NH-, an oxygen atom, a sulfur atom, or -CN ⁺ -.

Examples of the aryl group include aryl groups having 6 to 20 carbon atoms. Specific examples thereof include phenyl group, tolyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1-phenanthryl group, 2-phenanthryl group, 3- Phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, etc. can be mentioned. Among these, phenyl group, tolyl group, and naphthyl group are preferable.

Examples of the heteroaryl group include heteroaryl groups having 2 to 20 carbon atoms. Specific examples thereof include 2-thienyl group, 3-thienyl group, 2-furanyl group, 3-furanyl group, 2-oxazolyl group, 4-oxazolyl group, 5-oxazolyl group, 3-isoxazolyl group, 4- Isoxazolyl group, 5-isoxazolyl group, 2-thiazolyl group, 4-thiazolyl group, 5-thiazolyl group, 3-isothiazolyl group, 4-isothiazolyl group, 5-isothiazolyl group , 2-imidazolyl group, 4-imidazolyl group, 2-pyridyl group, 3-pyridyl group, 4-pyridyl group, 2-pyrazyl group, 3-pyrazyl group, 5-pyrazyl group, 6-pyrazyl group, 2-pyrimidyl group, 4-pyrimidyl group, 5-pyrimidyl group, 6-pyrimidyl group, 3-pyridyl group, 4-pyrimidyl group, 5-pyrimidyl group, 6-pyrimidyl group, 1, 2,3-triazine-4-diyl, 1,2,3-triazine-5-diyl, 1,2,4-triazine-3-diyl, 1,2,4-triazine-5-diyl, 1,2,4-triazine-6-yl group, 1,3,5-triazine-2-yl group, 1,2,4,5-tetrazine-3-yl group, 1,2,3,4-tetra Jin-5-yl group, 2-quinolinyl group, 3-quinolinyl group, 4-quinolinyl group, 5-quinolinyl group, 6-quinolinyl group, 7-quinolinyl group, 8-quinolinyl group, 1- Isoquinolinyl group, 3-isoquinolinyl group, 4-isoquinolinyl group, 5-isoquinolinyl group, 6-isoquinolinyl group, 7-isoquinolinyl group, 8-isoquinolinyl group, 2-quinolinyl group Noxanyl group, 5-quinoxanyl group, 6-quinoxanyl group, 2-quinazolinyl group, 4-quinazolinyl group, 5-quinazolinyl group, 6-quinazolinyl group, 7-quinazolinyl group, 8-quinazolinyl group , 3-cinnolinyl group, 4-cinnolinyl group, 5-cinnolinyl group, 6-cinnolinyl group, 7-cinnolinyl group, 8-cinnolinyl group, etc.

Examples of the substituent include a halogen atom, nitro group, cyano group, alkyl group with 1 to 20 carbon atoms, alkenyl group with 2 to 20 carbon atoms, and alkynyl group with 2 to 20 carbon atoms.

The alkyl group having 1 to 20 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, and sec-butyl group. , linear or branched alkyl groups having 1 to 20 carbon atoms, such as tert-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, and n-decyl group; Cyclic alkyl groups with 3 to 20 carbon atoms, such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, and cyclodecyl group, are included. Among these, an alkyl group with 1 to 18 carbon atoms is preferable, and an alkyl group with 1 to 8 carbon atoms is more preferable.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

The alkenyl group having 2 to 20 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include ethenyl group, n-1-propenyl group, n-2-propenyl group, 1-methylethenyl group, n -1-butenyl group, n-2-butenyl group, n-3-butenyl group, 2-methyl-1-propenyl group, 2-methyl-2-propenyl group, 1-ethylethenyl group, 1-methyl-1 -propenyl group, 1-methyl-2-propenyl group, n-1-pentenyl group, n-1-decenyl group, etc.

The alkynyl group having 2 to 20 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include ethynyl group, n-1-propynyl group, n-2-propynyl group, n-1-butynyl group, n -2-butynyl group, n-3-butynyl group, 1-methyl-2-propynyl group, n-1-pentynyl group, n-2-pentynyl group, n-3-pentynyl group, n-4-pentynyl group, 1-methyl-n-butynyl group, 2-methyl-n-butynyl group, 3-methyl-n-butynyl group, 1,1-dimethyl-n-propynyl group, n-1-hexynyl group, n-1-decy Nil group, etc. can be mentioned.

The aryl group and heteroaryl group preferably have one or two or more electron-withdrawing groups as substituents. Among the above-mentioned substituents, examples of the electron-withdrawing group include a halogen atom, a nitro group, and a cyano group. A halogen atom is preferable, and a fluorine atom is particularly preferable.

In formula (F1), L is an alkylene group, -NH-, an oxygen atom, a sulfur atom, or -CN ⁺ -, but -CN ⁺ - is preferable.

The alkylene group may be linear, branched, or cyclic, and examples thereof include alkylene groups having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms. Specific examples include methylene group, methylmethylene group, dimethylmethylene group, ethylene group, trimethylene group, propylene group, tetramethylene group, pentamethylene group, and hexamethylene group.

Examples of the anion represented by the formula (F1) that can be suitably used in the present invention include those represented by the formula (F1'), but are not limited to this.

In the present invention, the above-mentioned onium borate salts may be used individually or in combination of two or more types. Additionally, if necessary, other known onium borate salts may be used together. Additionally, the onium borate salt can be synthesized by referring to known methods described in, for example, Japanese Patent Application Laid-Open No. 2005-314682.

In order to facilitate dissolution into the charge-transporting varnish, the onium borate salt may be dissolved in an organic solvent in advance when preparing the varnish. Examples of such organic solvents include carbonates such as propylene carbonate, ethylene carbonate, 1,2-butylene carbonate, dimethyl carbonate, and diethyl carbonate; Ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone; Ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, dipropylene glycol, monomethyl ether of dipropylene glycol monoacetate, monoethyl ether, monopropyl ether, monobutyl polyhydric alcohols and their derivatives such as ether or monophenyl ether; Cyclic ethers such as dioxane; Ethyl formate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, methyl acetoacetate, ethyl acetoacetate, ethyl pyruvate, ethyl ethoxyacetate, methyl methoxypropionate, ethyl ethoxypropionate. , 2-hydroxypropionate methyl, 2-hydroxypropionate ethyl, 2-hydroxy-2-methylpropionate ethyl, 2-hydroxy-3-methylbutanoate methyl, 3-methoxybutyl acetate, 3-methyl-3 -Esters such as methoxybutyl acetate; and aromatic hydrocarbons such as toluene, xylene, 3-phenoxytoluene, 4-methoxytoluene, methyl benzoate, cyclohexylbenzene, tetralin, and isophorone. These solvents may be used individually or in combination of two or more types. The amount used is preferably 15 to 1,000 parts by mass, and more preferably 30 to 500 parts by mass, based on 100 parts by mass of the onium borate salt.

The content of the dopant cannot be collectively specified because it varies depending on the type of dopant or the desired degree of charge transport, but is usually in the range of 0.0001 to 1000 in terms of mass ratio to the charge transport material.

The charge-transporting varnish of the present invention may further contain an organic silane compound for the purpose of adjusting the film properties of the resulting charge-transporting thin film. Examples of the organic silane compound include dialkoxysilane compounds, trialkoxysilane compounds, or tetraalkoxysilane compounds. In particular, the organic silane compound is preferably a dialkoxysilane compound or a trialkoxysilane compound, and a trialkoxysilane compound is more preferable. Organic silane compounds may be used individually, or may be used in combination of two or more types.

The content of the organic silane compound is usually about 0.1 to 50% by mass relative to the total mass of the charge-transporting material and the dopant, but it suppresses a decrease in the charge-transporting property of the resulting thin film and further improves hole injection made of the charge-transporting thin film of the present invention. Considering increasing the hole injection ability into the layer (e.g., hole transport layer or light emitting layer) laminated on the side opposite to the anode so as to be in contact with the layer, the amount is preferably about 0.5 to 40% by mass, more preferably 0.8 to 30% by mass. %, more preferably about 1 to 20 mass %.

The method for preparing the charge-transporting varnish is not particularly limited, and examples include a method of adding the above polymer and, if necessary, a dopant, etc. to an organic solvent in a random order or simultaneously. In addition, when there are multiple organic solvents, the polymer and, if necessary, dopants, etc. may first be dissolved in one type of organic solvent, and then another organic solvent may be added thereto, or the polymer and the desired amount may be added to a mixed solvent of a plurality of organic solvents. Accordingly, dopants, etc. may be dissolved sequentially or simultaneously.

From the viewpoint of obtaining a thin film with high flatness with good reproducibility, the charge transport varnish of the present invention is preferably dissolved in an organic solvent with the polymer and, if necessary, a dopant, etc., and then filtered using a filter of the submicrometer order. .

The viscosity of the charge-transporting varnish of the present invention is typically 1 to 50 mPa·s at 25°C. Additionally, the surface tension of the charge-transporting varnish of the present invention is typically 20 to 50 mN/m at 25°C. In addition, the viscosity is a value measured with a TVE-25 type viscometer manufactured by Toki Sangyo Co., Ltd. The surface tension is a value measured with an automatic surface tension meter CBVP-Z type manufactured by Kyowakai Chemical Co., Ltd. The viscosity and surface tension of the varnish can be adjusted by considering various factors such as the desired film thickness and changing the types of solvents, their ratios, and solid concentration as described above.

In the charge-transporting varnish of the present invention, the solid content is usually uniformly dispersed or dissolved in an organic solvent.

[Charge transport thin film]

The charge-transporting thin film of the present invention can be formed by applying the charge-transporting varnish of the present invention onto a substrate and baking it.

Methods for applying varnish include, but are not limited to, dip method, spin coat method, transfer printing method, roll coat method, brushing, inkjet method, spray method, and slit coat method. Depending on the application method, it is desirable to control the viscosity and surface tension of the varnish.

Additionally, the firing atmosphere of the charge-transporting varnish after application is not particularly limited, and a thin film with a uniform film-forming surface and high charge-transporting properties can be obtained not only in an air atmosphere but also in an inert gas such as nitrogen or in a vacuum. Depending on the type of dopant used together, a thin film with charge transport properties may be obtained with good reproducibility by baking the varnish in an atmospheric atmosphere.

The firing temperature is appropriately set within the range of about 100 to 260°C, taking into account the use of the resulting thin film, the degree of charge transport properties imparted to the resulting thin film, the type and boiling point of the solvent, etc., and the resulting thin film is used to heat the organic EL device. When used as an injection layer, the temperature is preferably about 140 to 250°C, and the temperature is more preferably about 145 to 240°C. In addition, for the purpose of achieving higher uniform film forming properties during firing or advancing the reaction on the substrate, a temperature change of two or more stages may be made, and heating may be performed using a suitable device such as a hot plate or oven, for example. .

The film thickness of the charge-transporting thin film is not particularly limited, but when used as a functional layer provided between the anode and the light-emitting layer, such as a hole injection layer, hole transport layer, or hole injection and transport layer of an organic EL device, 5 to 300 nm is preferable. Methods for changing the film thickness include changing the solid content concentration in the varnish or changing the amount of liquid on the substrate at the time of application.

The charge-transporting thin film of the present invention exhibits a refractive index of 1.6 or more and an extinction coefficient of 0.030 or less as the average value of the wavelength range of 400 to 800 nm. In some embodiments, it exhibits a refractive index of 1.65 or more, and in other embodiments, a refractive index of 1.70 or more, In some embodiments, the extinction coefficient is 0.020 or less, and in other embodiments, the extinction coefficient is 0.015 or less. In addition, in the present invention, the refractive index and extinction coefficient can be measured using, for example, a multiple incidence spectroscopic ellipsometer VASE manufactured by J.A. Woolam.

[Organic EL device]

The organic EL device of the present invention has a pair of electrodes, and has a functional layer made of the charge-transporting thin film of the present invention between these electrodes.

Representative structures of organic EL elements include (a) to (f) below, but are not limited to these. Additionally, in the following configuration, if necessary, an electron blocking layer or the like may be provided between the light emitting layer and the anode, and a hole blocking layer or the like may be provided between the light emitting layer and the cathode. Additionally, the hole injection layer, the hole transport layer or the hole injection and transport layer may have a function as an electron blocking layer, etc., and the electron injection layer, the electron transport layer or the electron injection and transport layer may have a function as a hole blocking layer and the like. Additionally, it is possible to provide arbitrary functional layers between each layer as needed.

(a) Anode/hole injection layer/hole transport layer/light-emitting layer/electron transport layer/electron injection layer/cathode

(b) Anode/hole injection layer/hole transport layer/light emitting layer/electron injection and transport layer/cathode

(c) Anode/hole injection transport layer/light emitting layer/electron transport layer/electron injection layer/cathode

(d) Anode/hole injection and transport layer/light emitting layer/electron injection and transport layer/cathode

(e) Anode/hole injection layer/hole transport layer/light emitting layer/cathode

(f) Anode/hole injection transport layer/light emitting layer/cathode

“Hole injection layer,” “hole transport layer,” and “hole injection and transport layer” are layers formed between a light-emitting layer and an anode, and have the function of transporting holes from the anode to the light-emitting layer. When only one layer of hole-transporting material is provided between the light-emitting layer and the anode, it is a “hole injection and transport layer,” and when two or more layers of hole-transporting material are provided between the light-emitting layer and the anode, the layer close to the anode is a “hole injection and transport layer.” It is an “injection layer,” and the other layers are a “hole transport layer.” In particular, the hole injection (transport) layer is a thin film that not only has excellent hole acceptance from the anode, but also has excellent hole injection properties into the hole transport (light emitting) layer.

“Electron injection layer,” “electron transport layer,” and “electron injection and transport layer” are layers formed between a light-emitting layer and a cathode, and have the function of transporting electrons from the cathode to the light-emitting layer. When only one layer of electron-transporting material is provided between the light-emitting layer and the cathode, it is an “electron injection and transport layer,” and when two or more layers of electron-transporting material are provided between the light-emitting layer and the cathode, the layer close to the cathode is the “electron injection and transport layer.” It is an “injection layer,” and the other layers are “electron transport layers.”

The “light-emitting layer” is an organic layer with a light-emitting function, and when a doping system is used, it contains a host material and a dopant material. At this time, the host material mainly promotes recombination of electrons and holes and has the function of confining excitons in the light-emitting layer, and the dopant material has the function of efficiently emitting excitons obtained through recombination. In the case of phosphorescent devices, the host material mainly has the function of confining excitons generated from dopants within the light-emitting layer.

The charge-transporting thin film of the present invention can be suitably used as a functional layer provided between an anode and a light-emitting layer in an organic EL device, and can be more suitably used as a hole injection layer, a hole transport layer, and a hole injection and transport layer, and as a hole injection layer. It can be used even more suitably.

When producing an organic EL device using the charge-transporting varnish of the present invention, the materials and production methods used include the following, but are not limited to these.

An example of a method for manufacturing an organic EL device having a hole injection layer made of a charge-transporting thin film obtained from the charge-transporting varnish of the present invention is as follows. In addition, it is desirable to previously clean the electrode with alcohol, pure water, etc., or surface treat it with UV ozone treatment, oxygen-plasma treatment, etc., to the extent that it does not adversely affect the electrode.

On the anode substrate, a hole injection layer is formed using the charge-transporting varnish of the present invention by the above method. This is introduced into a vacuum deposition apparatus, and a hole transport layer, a light emitting layer, an electron transport layer/hole blocking layer, an electron injection layer, and a cathode metal are sequentially deposited. Alternatively, in this method, a composition for forming a hole transport layer containing a hole transporting polymer and a composition for forming a light emitting layer containing a light emitting polymer are used as an alternative to forming the hole transport layer and the light emitting layer by vapor deposition, and these layers are formed by a wet process. . Additionally, if necessary, an electron blocking layer may be provided between the light emitting layer and the hole transport layer.

Examples of the anode material include transparent electrodes such as indium tin oxide (ITO) and indium zinc oxide (IZO), metal anodes made of metals such as aluminum, and alloys thereof, and those that have been subjected to planarization treatment. desirable. Polythiophene derivatives or polyaniline derivatives having high charge transport properties can also be used. Additionally, other metals constituting the metal anode include gold, silver, copper, indium, and alloys thereof, but are not limited to these.

Materials forming the hole transport layer include (triphenylamine)dimer derivatives, [(triphenylamine)dimer]spirodimer, N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl) -benzidine (α-NPD), 4,4',4''-tris[3-methylphenyl(phenyl)amino]triphenylamine (m-MTDATA), 4,4',4''-tris[1-naph Triarylamines such as tyl(phenyl)amino]triphenylamine (1-TNATA), 5,5''-bis-{4-[bis(4-methylphenyl)amino]phenyl}-2,2':5' and oligothiophenes such as 2''-terthiophene (BMA-3T).

Materials for forming the light-emitting layer include metal complexes such as aluminum complexes of 8-hydroxyquinoline, metal complexes of 10-hydroxybenzo[h]quinoline, bistyrylbenzene derivatives, bistyrylarylene derivatives, and (2-hydroxyl). Low-molecular-weight light-emitting materials such as metal complexes of roxyphenyl)benzothiazole and silol derivatives; Poly(p-phenylenevinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene], poly(3-alkylthiophene), polyvinylcarboxylic Systems in which a light-emitting material and an electron transfer material are mixed with a polymer compound such as Bazole can be mentioned, but are not limited to these.

In addition, when forming the light-emitting layer by vapor deposition, it may be co-deposited with a light-emitting dopant, and the light-emitting dopant may be a metal complex such as tris(2-phenylpyridine)iridium(III) (Ir(ppy) ₃ ) or a naphtha such as rubrene. Condensed polycyclic aromatic rings such as Cene derivatives, quinacridone derivatives, and perylene are included, but are not limited to these.

Materials forming the electron transport layer/hole blocking layer include, but are not limited to, oxidiazole derivatives, triazole derivatives, phenanthroline derivatives, phenylquinoxaline derivatives, benzimidazole derivatives, and pyrimidine derivatives. .

Materials forming the electron injection layer include metal oxides such as lithium oxide (Li ₂ O), magnesium oxide (MgO), and alumina (Al ₂ O ₃ ), and metal fluorides such as lithium fluoride (LiF) and sodium fluoride (NaF). can be mentioned, but it is not limited to these.

Examples of the cathode material include aluminum, magnesium-silver alloy, aluminum-lithium alloy, etc., but are not limited to these.

Materials forming the electron blocking layer include, but are not limited to, tris(phenylpyrazole)iridium.

Examples of the hole-transporting polymer include poly[(9,9-dihexylfluorenyl-2,7-diyl)-co-(N,N'-bis{p-butylphenyl}-1,4-diaminophenylene) ], poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(N,N'-bis{p-butylphenyl}-1,1'-biphenylene-4,4 -diamine)], poly[(9,9-bis{1'-penten-5'-yl}fluorenyl-2,7-diyl)-co-(N,N'-bis{p-butylphenyl} -1,4-diaminophenylene)], poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzidine]-end capped with polysilsesquioxane, poly [(9,9-didioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(p-butylphenyl))diphenylamine)] and the like.

Examples of the luminescent polymer include polyfluorene derivatives such as poly(9,9-dialkylfluorene) (PDAF), and poly(2-methoxy-5-(2'-ethylhexoxy)-1,4-phenylenevinyl. Examples include polyphenylenevinylene derivatives such as ren) (MEH-PPV), polythiophene derivatives such as poly(3-alkylthiophene) (PAT), and polyvinylcarbazole (PVCz).

Since the materials constituting the anode, cathode, and the layer formed between them differ depending on whether a device having a bottom emission structure or a top emission structure is to be manufactured, the material is selected appropriately by taking that into consideration. .

Typically, in devices with a bottom emission structure, a transparent anode is used on the substrate side, and light is extracted from the substrate side, whereas in devices with a top emission structure, a reflective anode made of metal is used, and the light is extracted from the substrate side. Light is extracted from the transparent electrode (cathode) side. Therefore, for example, when talking about anode materials, transparent anodes such as ITO are used when manufacturing devices with a bottom emission structure, and reflective anodes such as Al/Nd are used when manufacturing devices with a top emission structure. .

In order to prevent deterioration of properties, the organic EL device of the present invention may be sealed with a catcher or the like according to a conventional method as necessary.

(Example)

Hereinafter, the present invention will be described in more detail through examples, but the present invention is not limited to the following examples. Additionally, the device used is as follows.

(1) ¹ H-NMR: Nuclear magnetic resonance spectrometer AVANCE III HD 500MHz manufactured by Bruker Biospin Co., Ltd.

(2) Substrate cleaning: Made by Joshu Sangyo Co., Ltd., substrate cleaning device (reduced pressure plasma method)

(3) Application of varnish: Mikasa Co., Ltd. product, spin coater MS-A100

(4)Film thickness measurement: Fine shape measuring instrument Surfcoder ET-4000, manufactured by Kosaka Kenkyusho Co., Ltd.

(5) Fabrication of single-layer devices (SLD) and hole-only devices (HOD): Multifunctional deposition equipment system C-E2L1G1-N, manufactured by Choshu Sangyo Co., Ltd.

(6) Measurement of electrical characteristics of SLD and HOD: EHC Co., Ltd., multi-channel IVL measurement device

(7) Measurement of refractive index and extinction coefficient: Multiple incident angle spectroscopic ellipsometer VASE manufactured by J.A. Ulam.

(8) Measurement of TG-DTA: Differential heat thermogravimetric analyzer TG8120, manufactured by Rigaku Co., Ltd.

(9) Measurement of weight average molecular weight (Mw) and number average molecular weight (Mn): GPC device manufactured by Shimadzu Corporation, autosampler SIL-10AF, Degusa DGU-20As, column oven CTO-20A, differential refractive index detector RID -10A (Column: Showa Denko Co., Ltd., Shodex GPC KF-805L and KF-804L, column temperature 40°C, detector: UV detector (254 nm), eluent: THF, column flow rate: 1.0 mL/min)

Reagents and solvents used in the synthesis include Pd(dba) ₂ , Pd(dppf)Cl ₂ ·CH ₂ Cl ₂ , potassium acetate, bis(pinacolato)diborone, 2-amino-N-[(1,1' -Biphenyl)-4-yl]-N-(4-bromophenyl)-9,9dimethylfluorene, trimethyl borate, lithium bis(trimethylsilyl)amide 1.3mol/L tetrahydrofuran solution, maleic anhydride, trimethylbenzene Ethylamine, 4-vinylphenylboronic acid, tetrakistriphenylphosphine palladium, and anisole are from Tokyo Kasei Kogyo Co., Ltd., toluene, hexane, ethyl acetate, ethanol, acetonitrile, dimethylformamide, and methanol are from Junsei. Those manufactured by Kagaku Co., Ltd., AIBN and tri-tert-butylphosphonium tetrafluoroborato are manufactured by Fujifilm Wako Chemical Co., Ltd., sodium carbonate, dioxane, butyllithium 1.56 mol/L hexane solution, dichloro Methane and silica gel N60 were from Kanto Chemical Co., Ltd., 1-bromo-4-(1-propen-2-yl)benzene was from Merck, and 3-(7-bromo-9,9) -Dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole and 2-bromo-7-iodo-9,9-dimethyl-9H-fluorene are manufactured by Suna Tech Inc. did.

[1] Synthesis of monomers

[Comparative Synthesis Example 1] Synthesis of monomer M-X

4-Aminotriphenylamine was synthesized by a method similar to the method of Synthesis Example 1 of International Publication No. 2014/132834. Additionally, as a ligand, triphenyl-tert-butylphosphonium tetrafluoroborato was used instead of tri(tert-butyl)phosphine.

To the branched flask, 5.00 g of 4-aminotriphenylamine and 2.06 g of maleic anhydride were added and stirred well, 35 mL of acetic acid was slowly added thereto, and stirring was continued until the mixture was uniformly dispersed.

Next, the temperature of the obtained mixture was raised to 120°C, heated to reflux for 20 hours, and the reaction mixture was left to cool. The reaction mixture left to cool was added to 300 mL of water, 300 mL of ethyl acetate was added thereto, a liquid separation treatment was performed, and the organic layer was recovered.

The recovered organic layer was sequentially washed with water and saturated saline solution, and then the solvent was removed from the washed organic layer under reduced pressure to obtain a crude product. This crude product was purified by silica column chromatography (developing solvent: hexane/ethyl acetate = 4/1 (v/v)) to obtain the target monomer M-X (amount 5.00 g, yield 76%).

[Synthesis Example 1] Synthesis of monomer M-A

(1) Synthesis of 3-(7-amino-9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole

In a reaction vessel, 10 g 3-(7-bromo-9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole, 0.89 g Pd(dba) ₂ and triphenyl-tert. - 0.45 g of butylphosphonium tetrafluoroborate was added, and the inside of the reaction vessel was degassed and then placed in a nitrogen atmosphere.

Next, 74 mL of toluene was added to the reaction vessel, and while stirring the mixture in the flask, 26.1 mL of a 1.3 mol/L tetrahydrofuran solution of lithium bis(trimethylsilyl)amide (equivalent to 33.93 mmol of lithium bis(trimethylsilyl)amide) was slowly added thereto. I did it. Then, the mixture in the flask was stirred for 20 hours while tracking the reaction by TLC, and after confirming the disappearance of the raw material 4-bromo-N,N-diphenylaniline, the reaction mixture was cooled to 0°C. 100 mL of 1N aqueous hydrochloric acid solution was added to the cooled reaction mixture to adjust the pH of the mixture to 3, and then an aqueous sodium chloride solution (concentration of 2 mol/L) was added to adjust the pH of the mixture to 12.

This pH-adjusted mixture was suction filtered using KC floc, the KC floc was washed with toluene, and this toluene was also recovered as a filtrate. The aqueous layer and the organic layer of the filtrate were divided, the aqueous layer was mixed well with toluene to recover the toluene, combined with the organic layer of the filtrate, washed with water, and the solvent was removed under reduced pressure to obtain a crude product. The obtained crude product was purified by column chromatography (column: SiO ₂ , developing solvent: hexane/ethyl acetate = 4/1 (triethylamine, 1%)), and 3-(7-amino-9,9-dimethyl- 9H-fluoren-2-yl)-9-phenyl-9H-carbazole was obtained (yield 7.52 g, yield 94%).

(2) Synthesis of monomer M-A

Same method as Comparative Synthesis Example 1 except that 3-(7-amino-9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole was used instead of 4-aminotriphenylamine Monomer MA was obtained (yield 3.24 g, yield 50%). The ¹ H-NMR spectrum of monomer MA is shown below.

[Synthesis Example 1-2] Synthesis of monomer M-B

In a branched flask, 4.6 g of 4-vinylphenylboronic acid, 8 g of 3-(7-bromo-9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole, tetra 0.54 g of kistriphenylphosphine palladium, 4.94 g of sodium carbonate, 105 mL of toluene, 25 mL of ethanol, and 23 mL of water were added and stirred well. The resulting mixture was heated to 80°C and stirred for 2 hours.

After cooling to room temperature, the aqueous layer of the two separated reaction mixture was recovered, the recovered aqueous layer was well mixed with toluene to recover this toluene, the recovered toluene and the organic layer of the reaction mixture were combined, and this was washed with saturated saline solution. Afterwards, the solvent was removed under reduced pressure, and the crude product was obtained. The obtained crude product was added to acetonitrile and stirred at room temperature for 1 hour, and the dissolved solid was recovered by filtration. The recovered solid was dried under reduced pressure to obtain monomer MB (yield 5.49 g, yield 66%). The ¹ H-NMR spectrum of monomer MB is shown below.

[Synthesis Example 1-3] Synthesis of monomer M-C

(1) Synthesis of 1,4-diaminobenzene-N ¹ -[(1,1'-biphenyl)-4-yl]-N ¹ -9,9-dimethylfluorene

In a reaction vessel, 7 g 2-amino-N-[(1,1'-biphenyl)-4-yl]-N-(4-bromophenyl)-9,9dimethylfluorene, Pd(dba) ₂ 0.39 g and 0.20 g of triphenyl-tert-butylphosphonium tetrafluoroborato were added, and the inside of the reaction vessel was degassed and then placed in a nitrogen atmosphere.

Next, 130 mL of toluene was added to the reaction vessel, and while stirring the mixture in the flask, 11.5 mL of a 1.3 mol/L tetrahydrofuran solution of lithium bis(trimethylsilyl)amide (equivalent to 14.91 mmol of lithium bis(trimethylsilyl)amide) was slowly added thereto. I did it. Then, the mixture in the flask was stirred for 30 hours while tracking the reaction by TLC, and the raw material 2-amino-N-[(1,1'-biphenyl)-4-yl]-N-(4-bromophenyl) )-9,9 After confirming the disappearance of dimethylfluorene, the reaction mixture was cooled to 0°C. 100 mL of 1 N aqueous hydrochloric acid solution was added to the cooled reaction mixture to adjust the pH of the mixture to 3, and then an aqueous sodium chloride solution (concentration of 2 mol/L) was added to adjust the pH of the mixture to 12.

The mixture with this pH adjusted was suction filtered using KC floc, the KC floc was washed with toluene, and this toluene was also recovered as a filtrate. The aqueous layer and the organic layer of the filtrate were divided, the aqueous layer was mixed well with toluene to recover the toluene, combined with the organic layer of the filtrate, washed with water, and the solvent was removed under reduced pressure to obtain a crude product. The obtained crude product was dissolved in 5 g of toluene, added dropwise to 100 g of hexane, and stirred at room temperature.

Finally, the precipitated solid was recovered by filtration, and the recovered solid was dried under reduced pressure to obtain 1,4-diaminobenzene-N ¹ -[(1,1'-biphenyl)-4-yl]-N ¹ -9,9 dimethyl fluorene was obtained (yield 4.84 g, yield 79%).

(2) Synthesis of monomer M-C

Instead of 4-aminotriphenylamine, 1,4-diaminobenzene-N ¹ -[(1,1'-biphenyl)-4-yl]-N ¹ -9,9-dimethylfluorene (4.84 g) Monomer MC was obtained in the same manner as Comparative Synthesis Example 1 except for what was used (yield 2.61 g, yield 46%). The ¹ H-NMR spectrum of monomer MC is shown below.

[Synthesis Example 1-4] Synthesis of monomer M-D

(1) Synthesis of (4-([1,1'-biphenyl]-4-yl(9,9-dimethyl-9H-fluoren-2-yl)amino)phenyl)boronic acid

In a reaction vessel, add 5 g of 2-amino-N-[(1,1'-biphenyl)-4-yl]-N-(4-bromophenyl)-9,9-dimethylfluorene and 20 g of tetrahydrofuran. After addition, the inside of the reaction vessel was cooled to -78°C, degassed, and then placed in a nitrogen atmosphere.

Next, while stirring the mixture in the reaction vessel, 7.15 mL of a 1.56 mol/L butyllithium hexane solution (equivalent to 11.13 mmol of butyllithium) was slowly added. Then, the mixture was stirred for 1 hour while maintaining the inside of the reaction vessel at -78°C. After that, 1.3 mL of trimethyl borate was slowly added while stirring the mixture in the reaction vessel. Then, the inside of the reaction vessel was returned to room temperature from -78°C, and the mixture was stirred for 2 hours. 1 N aqueous solution of hydrochloric acid was added to the reaction mixture until the pH of the mixture reached 3.

The reaction mixture was divided into an aqueous layer and an organic layer, the aqueous layer was mixed with dichloromethane to recover the dichloromethane, combined with the organic layer, washed with water, and the solvent was removed under reduced pressure to obtain a crude product. The obtained crude product was dissolved in 5 g of dichloromethane, added dropwise to 50 g of hexane, and stirred at room temperature.

Finally, the precipitated solid was recovered by filtration, and the recovered solid was dried under reduced pressure to produce (4-([1,1'-biphenyl]-4-yl-(9,9-dimethyl-9H-fluorene) -2-yl) amino) phenyl) boronic acid was obtained (yield 3.26 g, yield 70%).

(2) Synthesis of 2-bromo-9,9-dimethyl-9H-fluorene-N ¹ -[(1,1'-biphenyl)-4-yl]-N ¹ -9,9-dimethylfluorene

In a reaction vessel, 3.26 g of (4-([1,1'-biphenyl]-4-yl-(9,9dimethyl-9H-fluoren-2-yl)amino)phenyl)boronic acid, 2-bromo 2.71 g of -7-iodo-9,9-dimethyl-9H-fluorene, 0.24 g of tetrakistriphenylphosphine palladium, and a mixed solvent of toluene and ethanol (4/1 (V/V)) were added to the reaction vessel. After degassing the inside, a nitrogen atmosphere was created.

Next, while stirring the mixture in the reaction vessel, 10 mL of a 2M aqueous sodium carbonate solution prepared in advance was added. Then, the mixture in the reaction vessel was stirred for 3 hours while refluxing.

The reaction mixture was divided into an aqueous layer and an organic layer, the aqueous layer was mixed well with toluene to recover the toluene, combined with the organic layer, washed with water, and the solvent was removed under reduced pressure to obtain a crude product. The obtained crude product was dissolved in 5 g of toluene, added dropwise to 50 g of methanol, and stirred at room temperature.

Finally, the precipitated solid was recovered by filtration, and the recovered solid was dried under reduced pressure to obtain 2-bromo-9,9-dimethyl-9H-fluorene-N ¹ -[(1,1'-biphenyl) -4-yl]-N ¹ -9,9-dimethylfluorene was obtained (yield 3.26 g, yield 70%).

(3) Synthesis of 2-amino-9,9-dimethyl-9H-fluorene-N ¹ -[(1,1'-biphenyl)-4-yl]-N ¹ -9,9-dimethylfluorene

In a reaction vessel, 2-bromo-9,9-dimethyl-9H-fluorene-N ¹ -[(1,1'-biphenyl)-4-yl]-N ¹ -9,9-dimethylfluorene 5.0 g, 0.20 g of Pd(dba) ₂ and 0.10 g of triphenyl-tert-butylphosphonium tetrafluoroborato were added, and the inside of the reaction vessel was degassed and then placed in a nitrogen atmosphere.

Next, 70 mL of toluene was added to the reaction vessel, and while stirring the mixture in the flask, 6.0 mL of a 1.3 mol/L tetrahydrofuran solution of lithium bis(trimethylsilyl)amide (equivalent to 7.82 mmol of lithium bis(trimethylsilyl)amide) was slowly added thereto. I did it. Then, the mixture in the flask was stirred for 20 hours while tracking the reaction by TLC, and the raw material 2-bromo-9,9-dimethyl-9H-fluorene-N ¹ -[(1,1'-biphenyl)- After confirming the disappearance of 4-yl]-N ¹ -9,9-dimethylfluorene, the reaction mixture was cooled to 0°C. 20 mL of 1 N aqueous hydrochloric acid solution was added to the cooled reaction mixture to adjust the pH of the mixture to 3, and then an aqueous sodium chloride solution (concentration of 2 mol/L) was added to adjust the pH of the mixture to 12.

The mixture with this pH adjusted was suction filtered using KC floc, the KC floc was washed with toluene, and this toluene was also recovered as a filtrate. The aqueous layer and the organic layer of the filtrate were divided, the aqueous layer was mixed well with toluene to recover the toluene, combined with the organic layer of the filtrate, washed with water, and the solvent was removed under reduced pressure to obtain a crude product. The obtained crude product was dissolved in 5 g of toluene, added dropwise to 100 g of hexane, and stirred at room temperature.

Finally, the precipitated solid was recovered by filtration, and the recovered solid was dried under reduced pressure to obtain 2-amino-9,9-dimethyl-9H-fluorene-N ¹ -[(1,1'-biphenyl)- 4-yl]-N ¹ -9,9-dimethylfluorene was obtained (quantity 4.81 g, yield 100%).

(2) Synthesis of monomers M-D

2-Amino-9,9-dimethyl-9H-fluorene-N ¹ -[(1,1'-biphenyl)-4-yl]-N ¹ -9,9-dimethyl instead of 4-aminotriphenylamine Monomer MD was obtained in the same manner as in Comparative Synthesis Example 1 except that fluorene (4.8 g) was used (quantity 3.28 g, yield 61%). The ¹ H-NMR spectrum of monomer MD is shown below.

[Synthesis Example 1-5] Synthesis of monomer M-E

(1) 3-(9,9-dimethyl-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-fluoren-2-yl)- Synthesis of 9-phenyl-9H-carbazole

In a reaction vessel, 10 g of 3-(7-bromo-9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole, 5.4 g of bis(pinacolato)diborone, and Pd. (dppf) 0.32 g of Cl ₂ ·CH ₂ Cl ₂ , 4.8 g of potassium acetate, and 80 mL of dioxane were added, and the inside of the reaction vessel was degassed and then placed in a nitrogen atmosphere.

Next, the temperature inside the reaction vessel was raised to 100°C. Then, the mixture in the flask was stirred for 5 hours while tracking the reaction by TLC, and the raw material 3-(7-bromo-9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H- After confirming the disappearance of carbazole, the reaction mixture was allowed to cool to room temperature.

This cooled reaction mixture was suction filtered using KC floc, the KC floc was washed with toluene, and this toluene was also recovered as a filtrate. The aqueous layer and the organic layer of the filtrate were separated, the aqueous layer was mixed well with toluene to recover the toluene, combined with the organic layer of the filtrate, washed with water, and the solvent was removed under reduced pressure to obtain the crude product as a solid.

The obtained crude product was ground in a mortar, added to 250 g of a mixed solvent of methanol and ethyl acetate (4/1 (V/V)), and stirred at room temperature. Finally, the solid was recovered by filtration, the recovered solid was dried under reduced pressure, and 3-(9,9-dimethyl-(4,4,5,5-tetramethyl-1,3,2-dioxaborolane- 2-yl)-9H-fluoren-2-yl)-9-phenyl-9H-carbazole was obtained (quantity 10.57 g, yield 97%).

(2) Synthesis of monomer M-E

In a reaction vessel, 4.0 g of 1-bromo-4-(1-propen-2-yl)benzene, 3-(9,9-dimethyl-(4,4,5,5-tetramethyl-1,3,2) Add 10.57 g of -dioxaborolan-2-yl)-9H-fluoren-2-yl)-9-phenyl-9H-carbazole, 0.65 g of tetrakistriphenylphosphine palladium, 5.6 g of sodium carbonate, and 200 mL of toluene. After degassing the reaction vessel, a nitrogen atmosphere was created.

Next, the temperature inside the reaction vessel was raised to 80°C. Then, the mixture in the reaction vessel was stirred for 5 hours while tracking the reaction by TLC, and the raw material 3-(9,9-dimethyl-(4,4,5,5-tetramethyl-1,3,2-dioxa) After confirming the disappearance of borolan-2-yl)-9H-fluoren-2-yl)-9-phenyl-9H-carbazole, the reaction mixture was allowed to cool to room temperature.

This cooled reaction mixture was suction filtered using KC floc, the KC floc was washed with toluene, and this toluene was also recovered as a filtrate. The aqueous layer and the organic layer of the filtrate were separated, the aqueous layer was mixed well with toluene to recover the toluene, combined with the organic layer of the filtrate, washed with water, and the solvent was removed under reduced pressure to obtain the crude product as a solid.

The obtained crude product was ground in a mortar, added to 200 g of acetonitrile, and stirred at room temperature. Finally, the solid was recovered by filtration, and the recovered solid was dried under reduced pressure to obtain monomer ME (yield 6.73 g, 65% yield). The ¹ H-NMR spectrum of monomer ME is shown below.

[2] Synthesis of polymers and their evaluation

(1) Synthesis of polymers

[Comparative Example 1] Synthesis of polymer P-X

2.0 g of monomer M-X, 0.10 g of AIBN, and 11.9 g of dimethylformamide were placed in a reaction vessel, and the inside of the reaction vessel was replaced with nitrogen, followed by stirring at 80°C for 20 hours.

After the reaction mixture was allowed to cool to room temperature, the reaction mixture was added dropwise to 140 g of a mixed solvent of methanol and ethyl acetate (5/2 (V/V)) and stirred at room temperature.

Finally, the precipitated solid was recovered by filtration, and the recovered solid was dried under reduced pressure to obtain polymer X (amount: 1.8 g, yield: 90%). As a result of GPC measurement, the Mn of polymer X was 2,600 and the Mw was 3,300.

[Example 1-1] Synthesis of polymer P-A

3.0 g of monomer M-A, 0.150 g of AIBN, and 13 g of dimethylformamide were placed in a reaction vessel, and the inside of the reaction vessel was replaced with nitrogen, followed by stirring at 80°C for 20 hours.

After the reaction mixture was allowed to cool to room temperature, the reaction mixture was added dropwise to 150 g of a mixed solvent of methanol and ethyl acetate (1/1 (V/V)) and stirred at room temperature.

Finally, the precipitated solid was recovered by filtration, and the recovered solid was dried under reduced pressure to obtain polymer A (yield: 2.1 g, yield: 71%). As a result of GPC measurement, the Mw of polymer A was 3,900, and the dispersion degree Mw/Mn was 1.26.

[Example 1-2] Synthesis of polymer P-B

1.0 g of monomer M-B, 0.030 g of AIBN, and 7.6 g of anisole were placed in a reaction vessel, and the inside of the reaction vessel was replaced with nitrogen, followed by stirring at 80°C for 7 hours.

After the reaction mixture was allowed to cool to room temperature, the reaction mixture was added dropwise to 50 g of ethyl acetate and stirred at room temperature.

Finally, the precipitated solid was recovered by filtration, and the recovered solid was dried under reduced pressure to obtain polymer P-B (yield: 0.62 g, yield: 62%). As a result of GPC measurement, the Mw of polymer P-B was 15,400, and the dispersion degree Mw/Mn was 1.57.

[Example 1-3] Synthesis of polymer P-C

1.0 g of monomer M-C, 0.050 g of AIBN, and 5.3 g of dimethylformamide were placed in a reaction vessel, and the inside of the reaction vessel was replaced with nitrogen, followed by stirring at 80°C for 20 hours.

After the reaction mixture was allowed to cool to room temperature, the reaction mixture was added dropwise to 75 g of a mixed solvent of ethyl acetate and dimethylformamide (5/1 (V/V)) and stirred at room temperature.

Finally, the precipitated solid was recovered by filtration, and the recovered solid was dried under reduced pressure to obtain polymer P-C (amount: 0.87 g, yield: 87%). As a result of GPC measurement, the Mw of polymer P-C was 4,700 and the dispersion degree Mw/Mn was 1.50.

[Example 1-4] Synthesis of polymer P-D

1.0 g of monomer M-D, 0.080 g of AIBN, and 5.3 g of dimethylformamide were placed in a reaction vessel, and the inside of the reaction vessel was replaced with nitrogen, followed by stirring at 80°C for 20 hours.

After the reaction mixture was allowed to cool to room temperature, the reaction mixture was added dropwise to 75 g of a mixed solvent of ethyl acetate and dimethylformamide (5/1 (V/V)) and stirred at room temperature.

Finally, the precipitated solid was recovered by filtration, and the recovered solid was dried under reduced pressure to obtain polymer P-D (amount: 0.42 g, yield: 42%). As a result of GPC measurement, the Mw of polymer P-D was 4,000, and the dispersion degree Mw/Mn was 1.12.

[Example 1-5] Synthesis of polymer P-E

1.5 g of monomer M-E, 0.150 g of AIBN, and 8.3 g of anisole were placed in a reaction vessel, and the inside of the reaction vessel was replaced with nitrogen, followed by stirring at 80°C for 20 hours.

After the reaction mixture was allowed to cool to room temperature, the reaction mixture was added dropwise to 50 g of ethyl acetate and stirred at room temperature.

Finally, the precipitated solid was recovered by filtration, and the recovered solid was dried under reduced pressure to obtain polymer P-E (yield: 0.50 g, yield: 33%). As a result of GPC measurement, the Mw of polymer P-E was 2,000, and the dispersion degree Mw/Mn was 1.05.

[Example 1-6] Synthesis of copolymer P-AB

In a reaction vessel, 0.5 g of monomer M-A, 0.5 g of monomer M-B, 0.050 g of AIBN, and 4.1 g of anisole were placed, and the inside of the reaction vessel was replaced with nitrogen, followed by stirring at 80°C for 20 hours.

After the reaction mixture was allowed to cool to room temperature, the reaction mixture was added dropwise to 50 g of a mixed solvent of methanol and ethyl acetate (1/4 (V/V)) and stirred at room temperature.

Finally, the precipitated solid was recovered by filtration, and the recovered solid was dried under reduced pressure to obtain copolymer P-AB (yield: 0.78 g, yield: 78%). As a result of GPC measurement, the Mw of copolymer P-AB was 147,000, and the dispersion degree Mw/Mn was 2.26.

[Example 1-7] Synthesis of copolymer P-AE

In a reaction vessel, 0.72 g of monomer M-A, 0.75 g of monomer M-E, 0.147 g of AIBN, and 8.1 g of anisole were placed, and the inside of the reaction vessel was replaced with nitrogen, followed by stirring at 80°C for 20 hours.

After the reaction mixture was allowed to cool to room temperature, the reaction mixture was added dropwise to 50 g of a mixed solvent of methanol and ethyl acetate (1/4 (V/V)) and stirred at room temperature.

Finally, the precipitated solid was recovered by filtration, and the recovered solid was dried under reduced pressure to obtain copolymer P-AB (amount: 1.18 g, yield: 73%). As a result of GPC measurement, the Mw of copolymer P-AB was 33,000, and the dispersion degree Mw/Mn was 5.19.

[Example 1-8] Synthesis of copolymer P-CB

In a reaction vessel, 0.5 g of monomer M-C, 0.5 g of monomer M-B, 0.050 g of AIBN, and 7.0 g of anisole were placed, and the inside of the reaction vessel was replaced with nitrogen, followed by stirring at 80°C for 20 hours.

After the reaction mixture was allowed to cool to room temperature, the reaction mixture was added dropwise to 50 g of a mixed solvent of methanol and ethyl acetate (1/4 (V/V)) and stirred at room temperature.

Finally, the precipitated solid was recovered by filtration, and the recovered solid was dried under reduced pressure to obtain copolymer P-CB (yield: 0.42 g, yield: 42%). As a result of GPC measurement, the Mw of copolymer P-CB was 277,000, and the dispersion degree Mw/Mn was 3.38.

[Example 1-9] Synthesis of copolymer P-DB

0.6 g of monomer M-D, 0.45 g of monomer M-B, 0.050 g of AIBN, and 5.49 g of anisole were placed in a reaction vessel, and the inside of the reaction vessel was replaced with nitrogen, followed by stirring at 80°C for 20 hours.

After the reaction mixture was allowed to cool to room temperature, the reaction mixture was added dropwise to 50 g of a mixed solvent of methanol and ethyl acetate (1/4 (V/V)) and stirred at room temperature.

Finally, the precipitated solid was recovered by filtration, and the recovered solid was dried under reduced pressure to obtain copolymer P-DB (amount: 0.25 g, yield: 24%). As a result of GPC measurement, the Mw of copolymer P-DB was 74,000, and the dispersion degree Mw/Mn was 3.10.

(2) Evaluation of heat resistance

TG was measured using Monomer M-A, Polymer P-A, Polymer P-B, Polymer P-C, Polymer P-D, Polymer P-E, Copolymer P-AE, and Polymer P-X. Under atmospheric air, the temperature was raised to 500°C at a temperature increase rate of 10°C/1 minute, and the temperature at which the weight was reduced by 5% was measured. The results are shown in Table 1. Also, if the weight loss at 500°C was less than 5%, it was written as >500.

compound 5% weight loss temperature (℃) M-A >500 P-A >500 P-B 431 P-C 413 P-D 431 P-E 389 P-AE 418 P-X 370

The polymer of the present invention exhibited superior heat resistance than the polymer of the comparative example. In addition, the monomer of the polymer of the present invention also showed excellent heat resistance.

[3] Preparation and evaluation of charge-transporting varnish

(1) Preparation of charge-transporting varnish

[Example 2-1]

124 mg of polymer P-A and 292 mg of arylsulfonic acid ester SE-A were added to a mixed solvent of 5 g of triethylene glycol butyl methyl ether, 3 g of butyl benzoate, and 2 g of dimethyl phthalate, and stirred to dissolve at room temperature. The obtained solution was filtered using a PTFE filter with a pore diameter of 0.2 μm, and charge-transporting varnish A was obtained. Additionally, aryl sulfonic acid ester SE-A was synthesized according to the method described in International Publication No. 2017/217455. Additionally, the structure of arylsulfonic acid ester SE-A is shown below.

[Example 2-2]

139 mg of polymer P-B and 278 mg of arylsulfonic acid ester SE-A were added to 10 g of 4-methoxytoluene and stirred to dissolve at room temperature. The obtained solution was filtered using a PTFE filter with a pore diameter of 0.2 μm, and charge-transporting varnish B was obtained.

[Example 2-3]

139 mg of copolymer P-AB and 292 mg of arylsulfonic acid ester SE-A were added to 10 g of 4-methoxytoluene and stirred to dissolve at room temperature. The obtained solution was filtered using a PTFE filter with a pore diameter of 0.2 μm, and charge-transporting varnish C was obtained.

[Example 2-4]

208 mg of polymer P-C and 208 mg of arylsulfonic acid ester SE-A were added to 10 g of 4-methoxytoluene and stirred to dissolve at room temperature. The obtained solution was filtered using a PTFE filter with a pore diameter of 0.2 μm, and charge-transporting varnish D was obtained.

[Example 2-5]

139 mg of polymer P-D and 278 mg of arylsulfonic acid ester SE-A were added to 10 g of 4-methoxytoluene and stirred to dissolve at room temperature. The obtained solution was filtered using a PTFE filter with a pore diameter of 0.2 μm, and charge-transporting varnish E was obtained.

[Example 2-6]

139 mg of polymer P-E and 278 mg of arylsulfonic acid ester SE-A were added to 10 g of 4-methoxytoluene and stirred to dissolve at room temperature. The obtained solution was filtered using a PTFE filter with a pore diameter of 0.2 μm, and charge-transporting varnish F was obtained.

[Example 2-7]

139 mg of copolymer P-AE and 278 mg of aryl sulfonic acid ester SE-A were added to 10 g of 4-methoxytoluene and stirred to dissolve at room temperature. The obtained solution was filtered using a PTFE filter with a pore diameter of 0.2 μm, and charge-transporting varnish G was obtained.

[Example 2-8]

139 mg of copolymer P-CB and 278 mg of arylsulfonic acid ester SE-A were added to 10 g of 4-methoxytoluene and stirred to dissolve at room temperature. The obtained solution was filtered using a PTFE filter with a pore diameter of 0.2 μm, and charge-transporting varnish H was obtained.

[Example 2-9]

139 mg of copolymer P-DB and 278 mg of arylsulfonic acid ester SE-A were added to 10 g of 4-methoxytoluene and stirred to dissolve at room temperature. The obtained solution was filtered using a PTFE filter with a pore diameter of 0.2 μm, and charge-transporting varnish I was obtained.

[Comparative Example 2]

186 mg of polymer P-X and 340 mg of arylsulfonic acid ester SE-A were added to a mixed solvent of 5 g of triethylene glycol butyl methyl ether, 3 g of butyl benzoate, and 2 g of dimethyl phthalate, and stirred to dissolve at room temperature. The obtained solution was filtered using a PTFE filter with a pore diameter of 0.2 μm, and charge-transporting varnish J was obtained.

(2) Evaluation of refractive index (n) and extinction coefficient (k)

Charge-transporting varnishes A to D were applied to a quartz substrate using a spin coater, and then sequentially heated at 120°C for 1 minute and 200°C for 15 minutes under an air atmosphere to form a uniform thin film of 50 nm on the quartz substrate. formed.

Using the obtained quartz substrate with a thin film, the average refractive index (n) in a wavelength of 400 to 800 nm and the average extinction coefficient (k) in a wavelength of 400 to 800 nm were measured. The results are shown in Table 2.

Charge transport varnish n k Example 2-1 A 1.655 0.016 Example 2-2 B 1.725 0.010 Example 2-3 C 1.716 0.011 Comparative example 2 J 1.629 0.023

As shown in Table 2, the charge-transporting thin film of the present invention had a higher refractive index and lower extinction coefficient than the comparative example. Also, the value was high with a refractive index of 1.65 or more and a low extinction coefficient of 0.020 or less. This is because the skeleton containing alkyl fluorene has high refraction and high transparency.

[4] Fabrication and characteristic evaluation of SLD

[Example 3]

Charge-transporting varnish A was applied on the ITO substrate using a spin coater, and then sequentially heated at 120°C for 1 minute and 230°C for 15 minutes under an air atmosphere to form a charge-transporting thin film with a film thickness of 50 nm on the ITO substrate. formed. Additionally, as an ITO substrate, a 25 mm x 25 mm x 0.7t glass substrate with a patterned ITO film with a thickness of 50 nm formed on the surface was used, and impurities on the surface were removed with an O ₂ plasma cleaning device (150 W, 30 seconds) before use.

On this, an aluminum thin film with a thickness of 80 nm was formed at 0.2 nm/sec using a vapor deposition device (vacuum degree: 1.0 x 10 ^-5 Pa). After that, it was sealed with a sealing substrate to prevent property deterioration due to the influence of oxygen, water, etc. in the air. Sealing was performed in the following procedure. In a nitrogen atmosphere with an oxygen concentration of 2 ppm or less and a dew point of -76°C or less, the SLD was placed between the sealing substrates, and the sealing substrates were bonded together with an adhesive (Moresco Moisture Cut WB90US(P), manufactured by Moresco Co., Ltd.). At this time, a catcher (HD-071010W-40 manufactured by Dynic Co., Ltd.) was placed into the sealing substrate together with the SLD. The bonded sealing substrate was irradiated with UV light (wavelength: 365 nm, irradiation amount: 6,000 mJ/cm ² ) and then annealed at 80°C for 1 hour to cure the adhesive.

The current density was measured when a voltage of 4V was applied to the manufactured SLD. The results are shown in Table 3.

Current density (mA/cm ³ ) Example 3 213

As shown in Table 3, the charge-transporting thin film produced from the charge-transporting varnish of the present invention exhibited good charge-transporting properties.

[5] Fabrication and characteristic evaluation of HOD

[Examples 4-1 to 4-6]

Charge-transporting varnishes C, D, E, G, H, and I were each applied on an ITO substrate using a spin coater, and then sequentially heated at 120°C for 1 minute and 180°C for 15 minutes under an air atmosphere to form ITO. A charge-transporting thin film with a film thickness of 50 nm was formed on the substrate. Additionally, as an ITO substrate, a 25 mm x 25 mm x 0.7t glass substrate with a patterned ITO film with a thickness of 150 nm formed on the surface was used, and impurities on the surface were removed with an O ₂ plasma cleaning device (150 W, 30 seconds) before use.

On top of this, a thin film of α-NPD with a film thickness of 30 nm is formed at 0.2 nm/sec using a vapor deposition device (vacuum degree of 1.0×10 ^-5 Pa), and on top of this, a thin film of aluminum with a film thickness of 80 nm is formed at 0.2 nm/sec. formed. It was sealed with a sealing substrate in the same manner as in Example 1-1, and HOD was obtained.

The current density was measured when a voltage of 4V was applied to the manufactured HOD. The results are shown in Table 4.

Charge transport varnish Current density (mA/cm ³ ) Example 4-1 C 1394 Example 4-2 D 1030 Example 4-3 E 250 Example 4-4 G 276 Example 4-5 H 1180 Example 4-6 I 163

As shown in Table 4, the charge-transporting thin film produced from the charge-transporting varnish of the present invention exhibited good hole injection properties for α-NPD, which is frequently used as a hole transport layer.

Claims (10)

A polymer comprising at least one selected from the repeating unit represented by the following formula (1) and the repeating unit represented by the following formula (2).

[In the formula, R ^A is a hydrogen atom or a methyl group. R ¹ to R ⁴ are each independently a single bond or a phenylene group, and some or all of the hydrogen atoms of this phenylene group are cyano group, nitro group, halogen atom, vinyl group, trifluorovinyl group, acryloyl group, or meta. It may be substituted with a cryloyl group, an oxetane group, an epoxy group, an alkyl group with 1 to 20 carbon atoms, or a halogenated alkyl group with 1 to 20 carbon atoms.
X ¹ is -N(Ar ³ )-, -S- or -O-.
X ² is -N(Ar ⁶ )-, -S- or -O-.
Ar ¹ and Ar ⁴ are each independently obtained by removing two hydrogen atoms on the aromatic ring of an arylene group having 6 to 20 carbon atoms, a heteroarylene group having 3 to 20 carbon atoms, or a dialkyl fluorene represented by the formula (3) below. It is a divalent group, and some or all of the hydrogen atoms on the aromatic ring of these groups are cyano group, nitro group, halogen atom, vinyl group, trifluorovinyl group, acryloyl group, methacryloyl group, oxetane group, and epoxy group. , may be substituted with an alkyl group having 1 to 20 carbon atoms or a halogenated alkyl group having 1 to 20 carbon atoms.
Ar ² , Ar ³ , Ar ⁵ and Ar ⁶ are each independently an aryl group having 6 to 20 carbon atoms or a monovalent group obtained by removing one hydrogen atom on the aromatic ring of a dialkyl fluorene represented by the formula (3) below. and some or all of the hydrogen atoms on the aromatic ring of these groups are cyano group, nitro group, halogen atom, vinyl group, trifluorovinyl group, acryloyl group, methacryloyl group, oxetane group, epoxy group, and carbon number 1. It may be substituted with an alkyl group of ~20 carbon atoms or a halogenated alkyl group of 1-20 carbon atoms.
^{When _ _ _ _ _ _} and Ar ⁶ may be bonded to each other to form a ring with the nitrogen atom to which they are bonded.
When R ² is a phenylene group, R ² and Ar ² may be bonded to each other to form a ring with the nitrogen atom, sulfur atom, or oxygen atom to which they are bonded, and when R ⁴ is a phenylene group, R ⁴ and Ar ⁵ may be They may combine with each other to form a ring with the nitrogen atom, sulfur atom, or oxygen atom to which they are bonded.
However, at least one of Ar ¹ to Ar ³ is a group obtained by removing a hydrogen atom on the aromatic ring of dialkyl fluorene represented by the formula (3) below, and at least one of Ar ⁴ to Ar ⁶ is a group of the formula (3) below: It is a group obtained by removing the hydrogen atom on the aromatic ring of the dialkyl fluorene represented by 3).

(In the formula, R ⁵ and R ⁶ are each independently an alkyl group with 1 to 20 carbon atoms, an alkoxy group with 1 to 20 carbon atoms, or an alkyl group with 2 to 20 carbon atoms containing at least one ether structure.)] The polymer according to claim 1, wherein the repeating unit represented by formula (1) is represented by the following formula (1A), and the repeating unit represented by formula (2) is represented by the following formula (2A).

(In the formula, R ^A , R ¹ to R ⁴ , and Ar ¹ to Ar ⁶ are the same as above.) The polymer according to claim 1 or 2, wherein R ¹ and R ³ are single bonds. The polymer according to any one of claims 1 to 3, wherein R ² and R ⁴ are phenylene groups. The polymer according to any one of claims 1 to 4, wherein Ar ¹ and Ar ⁴ are 9,9-dimethyl-9H-fluorene-2,7-diyl groups. A charge-transporting material consisting of the polymer of any one of claims 1 to 5. A charge-transporting varnish containing a charge-transporting material containing the polymer of any one of claims 1 to 5, and an organic solvent. The charge-transporting varnish according to claim 7, further comprising a dopant. A charge-transporting thin film obtained from the charge-transporting varnish of claim 7 or 8. An organic electroluminescent device comprising the charge-transporting thin film of claim 9.