Polymer and use thereof

Abstract

Provided is a polymer containing at least one selected from a repeat unit represented by formula (1) and a repeat unit represented by formula (2).

Description

Polymers and their uses

[0001] The present invention relates to polymers and their uses.

[0002] In organic electroluminescence (EL) devices, charge-transporting thin films made of organic compounds are used as the light-emitting layer and charge-injection layer. In particular, the hole-injection layer transfers charges between the anode and the hole-transport layer or the light-emitting layer, and plays an important role in achieving low-voltage operation and high brightness of the organic EL device.

[0003] Various approaches have been taken to improve the performance of organic EL devices, and efforts have been made to adjust the refractive index of the functional films used in order to improve light extraction efficiency, etc. Specifically, attempts have been made to improve the efficiency of devices by using hole injection layers or hole transport layers with relatively high or low refractive indices, taking into account the overall configuration of the device and the refractive indices of other adjacent components (Patent Documents 1 and 2). As such, the refractive index is an important factor in the design of organic EL devices, and is considered to be an important physical property that should be taken into consideration when designing materials for organic EL devices.

[0004] Furthermore, because coloring of a charge-transporting thin film used in an organic EL element reduces the color purity and color reproducibility of the organic EL element, in recent years, it has been desired that the charge-transporting thin film for an organic EL element have high transmittance in the visible region and high transparency (see Patent Document 3).

[0005] Since organic EL elements are required to have high heat resistance, the charge transport materials used in organic EL elements are also required to have high heat resistance.

[0006] Methods for forming hole injection layers are broadly divided into dry processes, such as vapor deposition, and wet processes, such as spin coating. Compared to these processes, wet processes are more efficient at producing thin films with high flatness over large areas. Therefore, as organic EL displays continue to grow in size, there is a constant demand for wet process materials that can be formed by wet processes and that provide charge-transporting thin films with excellent refractive index, transparency, and heat resistance.

[0007] JP 2007-536718 A JP 2017-501585 A International Publication No. 2013 / 042623

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a polymer which has high heat resistance, good charge transport properties, and can give a thin film with a high refractive index and high transparency, and which can realize an organic EL device having excellent properties when this thin film is used as a hole injection layer or the like.

[0009] As a result of extensive research to achieve the above object, the present inventors have found that a charge-transporting varnish containing a polymer having a triarylamine structure, a diaryl ether structure or a diaryl sulfide structure and a dialkylfluorene structure in its side chain provides a thin film that is highly heat-resistant and exhibits excellent charge transport properties, and that has high transparency and a high refractive index, and that when this thin film is used as a hole-injection layer or the like, it provides an organic EL device with excellent properties, thereby completing the present invention.

[0010] That is, the present invention provides the following polymer and use thereof: 1. A polymer containing at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2). [In the formula, R A is a hydrogen atom or a methyl group. 1 ~R 4 are each independently a single bond or a phenylene group, and some or all of the hydrogen atoms of the phenylene group may be substituted with a cyano group, a nitro group, a halogen atom, a vinyl group, a trifluorovinyl group, an acryloyl group, a 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. X 1 is -N(Ar 3 )-, -S- or -O-. 2 is -N(Ar 6 )-, -S- or -O-. 1 and Ar 4are each independently a divalent group 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 dialkylfluorene represented by the following formula (3), and some or all of the hydrogen atoms on the aromatic ring of these groups may be substituted with a cyano group, a nitro group, a halogen atom, a vinyl group, a trifluorovinyl group, an acryloyl group, a 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. 2 , Ar 3 , Ar 5 and Ar 6 are each independently a monovalent group obtained by removing one hydrogen atom on the aromatic ring of an aryl group having 6 to 20 carbon atoms or a dialkylfluorene represented by the following formula (3), and some or all of the hydrogen atoms on the aromatic ring of these groups may be substituted with a cyano group, a nitro group, a halogen atom, a vinyl group, a trifluorovinyl group, an acryloyl group, a 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. 1 -N(Ar 3 )-, Ar 2 and Ar 3 and may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded, and X 2 -N(Ar 6 )-, Ar 5 and Ar 6 and may be bonded to each other to form a ring together with the nitrogen atom to which they are attached. 2 is a phenylene group, R 2 and Ar 2 may be bonded to each other to form a ring together with the nitrogen atom, sulfur atom or oxygen atom to which they are bonded, and R 4 is a phenylene group, R 4 and Ar 5 and may be bonded to each other to form a ring together with the nitrogen atom, sulfur atom or oxygen atom to which they are bonded. 1 ~Ar 3At least one of Ar is a group obtained by removing a hydrogen atom on an aromatic ring of a dialkylfluorene represented by the following formula (3), 4 ~Ar 6 At least one of the above is a group obtained by removing a hydrogen atom on an aromatic ring of a dialkylfluorene represented by the following formula (3). (In the formula, R 5 and R 6 are each independently an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkyl group having 2 to 20 carbon atoms and containing at least one ether structure. 2. The polymer of 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 ~R 4 , Ar 1 ~Ar 6 is the same as above.) 3. R 1 and R 3 4. The polymer of 1 or 2, wherein R is a single bond. 2 and R 4 5. The polymer of any one of 1 to 3, wherein Ar is a phenylene group. 1 and Ar 4 is a 9,9-dimethyl-9H-fluorene-2,7-diyl group. 6. A charge transporting material comprising a polymer of any one of 1 to 5. 7. A charge transporting varnish comprising a charge transporting material comprising a polymer of any one of 1 to 5 and an organic solvent. 8. The charge transporting varnish of 7 further comprising a dopant. 9. A charge transporting thin film obtained from the charge transporting varnish of 7 or 8. 10. An organic EL device comprising the charge transporting thin film of 9.

[0011] The polymer of the present invention has high heat resistance, high transparency, and a high refractive index, and has excellent charge transport properties due to the triarylamine structure, diaryl ether structure, or diaryl sulfide structure and the dialkylfluorene 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 a 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 such as organic EL devices. By using the charge-transporting thin film as a hole-injection layer or hole-transport layer, particularly a hole-injection layer, of an organic EL device, an organic EL device with excellent properties can be obtained.

[0012] [Polymer] The polymer of the present invention contains at least one repeating unit selected from the repeating units represented by the following formula (1) and the repeating units represented by the following formula (2).

[0013] In formulas (1) and (2), R A is a hydrogen atom or a methyl group. 1 ~R 4 are each independently a single bond or a phenylene group, and some or all of the hydrogen atoms of the phenylene group may be substituted with a cyano group, a nitro group, a halogen atom, a vinyl group, a trifluorovinyl group, an acryloyl group, a 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.

[0014] Examples of the phenylene group include a 1,2-phenylene group, a 1,3-phenylene group, and a 1,4-phenylene group, with the 1,4-phenylene group being preferred.

[0015] The alkyl group having 1 to 20 carbon atoms may be linear, branched, or cyclic. Specific examples thereof include linear or branched alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl; and cyclic alkyl groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, bicyclobutyl, bicyclopentyl, bicyclohexyl, bicycloheptyl, bicyclooctyl, bicyclononyl, and bicyclodecyl.

[0016] The halogenated alkyl group having 1 to 20 carbon atoms is not particularly limited, so long as it is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 20 carbon atoms have been substituted with halogen atoms. Specific examples thereof include a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2,2-pentafluoroethyl group, a 3,3,3-trifluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a 1,1,2,2,3,3,3-heptafluoropropyl group, a 4,4,4-trifluorobutyl group, a 3,3,4,4,4-pentafluorobutyl group, a 2,2,3,3,4,4,4-heptafluorobutyl group, and a 1,1,2,2,3,3,4,4,4-nonafluorobutyl group.

[0017] R 1 and R 3 is preferably a single bond, and R 2 and R 4 is preferably a phenylene group.

[0018] In formulas (1) and (2), X 1 is -N(Ar 3 )-, -S- or -O-. 2 is -N(Ar 6 )-, -S- or -O-.

[0019] In formulas (1) and (2), Ar 1 and Ar 4are each independently a divalent group 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 dialkylfluorene represented by the following formula (3), and some or all of the hydrogen atoms on the aromatic ring of these groups may be substituted with a cyano group, a nitro group, a halogen atom, a vinyl group, a trifluorovinyl group, an acryloyl group, a 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 described above. (In the formula, R 5 and R 6 are each independently an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkyl group having 2 to 20 carbon atoms and containing at least one ether structure.

[0020] Examples of the arylene group having 6 to 20 carbon atoms include a 1,2-phenylene group, a 1,3-phenylene group, a 1,4-phenylene group, a 1,2-naphthalene-diyl group, a 2,3-naphthalenediyl group, a 1,4-naphthalenediyl group, a 1,5-naphthalenediyl group, a 2,6-naphthalenediyl group, a 2,7-naphthalenediyl group, a 1,8-naphthalenediyl group, a 1,2-anthracene-diyl group, and a 1,3-anthracene-diyl group. anthracenediyl group, a 1,4-anthracenediyl group, a 1,5-anthracenediyl group, a 1,6-anthracenediyl group, a 1,7-anthracenediyl group, a 1,8-anthracenediyl group, a 2,3-anthracenediyl group, a 2,6-anthracenediyl group, a 2,7-anthracenediyl group, a 2,9-anthracenediyl group, a 2,10-anthracenediyl group, and a 9,10-anthracenediyl group.

[0021] Examples of the heteroarylene group having 3 to 20 carbon atoms include a 9-phenylcarbazole-3,6-diyl group, a 9-phenylcarbazole-2,7-diyl group, a 9-phenylcarbazole-3,6-dimethyl-2,7-diyl group, and groups represented by the following formulae (H1) to (H33).

[0022]

[0023]

[0024] In formula (3), R 5 and R 6 are each independently an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkyl group having 2 to 20 carbon atoms and containing at least one ether structure.

[0025] The alkyl group having 1 to 20 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include linear or branched alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl; and cyclic alkyl groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, bicyclobutyl, bicyclopentyl, bicyclohexyl, bicycloheptyl, bicyclooctyl, bicyclononyl, and bicyclodecyl. Of these, methyl and ethyl groups are preferred, and methyl is more preferred.

[0026] The alkoxy group having 1 to 20 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include linear or branched alkoxy groups having 1 to 20 carbon atoms such as a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, an n-pentyl group, an n-hexyloxy group, an n-heptyloxy group, an n-octyloxy group, an n-nonyloxy group, and an n-decyloxy group; Examples of cyclic alkoxy groups having 3 to 20 carbon atoms include propyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy, cycloheptyloxy, cyclooctyloxy, cyclononyloxy, cyclodecyloxy, bicyclobutyloxy, bicyclopentyloxy, bicyclohexyloxy, bicycloheptyloxy, bicyclooctyloxy, bicyclononyloxy, and bicyclodecyloxy.

[0027] The alkyl group having 2 to 20 carbon atoms and containing at least one ether structure includes a linear or branched alkyl group in which at least one methylene group is substituted with an oxygen atom. However, the methylene group bonded to the fluorene skeleton is not substituted with an oxygen atom, and the adjacent methylene groups are not simultaneously substituted with oxygen atoms. As such a group, in consideration of the availability of raw material compounds, a group represented by formula (A) is preferred, and among these, a group represented by formula (B) is more preferred. -(R 7 O) p -R 8 (A) -(CH2CH2O) p -CH3 (B) (wherein, R 7 represents a linear or branched alkylene group having 1 to 4 carbon atoms, R 8 represents a linear or branched alkyl group having 1 to [20 - (number of carbon atoms in R) x p] carbon atoms, where p is an integer of 1 to 9. From the viewpoint of compatibility with the dopant, p is preferably 2 or more, more preferably 3 or more, and from the viewpoint of ease of availability of raw material compounds, p is preferably 5 or less, more preferably 4 or less.

[0028] Examples of alkyl groups having 2 to 20 carbon atoms and containing at least one ether structure include -CH2OCH3, -CH2OCH2CH3, -CHO(CH2)2CH3, -CH2OCH(CH3)2, -CHO(CH2)3CH3, -CH2OCH2CH(CH3)2, -CH2OC(CH3)3, -CHO(CH2)4CH3, -CH2OCH(CH3)(CH2)2CH3, -CHO(CH2)2CH(CH3)2, -CH2OCH(CH3)(CH2)3CH3, -CHO(CH2)5CH3, -CH2OC H2CH(CH3)(CH2)2CH3, -CH2O(CH2)2CH(CH3)CH2CH3, -CH2O(CH2)3CH(CH3)2, -CH2OC(CH3)2(CH2)2CH3, -CH2OCH(CH2CH3)(CH2)2CH3, -CH2 OC(CH3)2CH(CH3)2, -CH2O(CH2)6CH3, -CH2O(CH2)7CH3, -CH2OCH2CH(CH2CH3)(CH2)3CH3, -CH2O(CH2)8CH3, -CH2O(CH2)9CH3, -CH2O(CH2) 10 CH3, -CH2O(CH2) 11 CH3, -CH2O(CH2) 12 CH3, -CH2O(CH2) 13 CH3, -CH2O(CH2) 14 CH3, -CH2O(CH2) 15 CH3, -CH2O(CH2) 16 CH3, -CH2O(CH2) 17 CH3, -CH2O(CH2) 18<h2 style=";text-align:left;direction:ltr">CH3、-CH2CH2OCH3、-CH2CH2OCH2CH3、-CH2CH2O(CH2)2CH3、-CH2CH2OCH(CH3)2、-CH2CH2O(CH2)3CH3、-CH2CH2OCH2CH(CH3)2、-CH2CH2O(CH2)3CH3、-CH2CH2OCH2CH(CH3)2、-CH2CH2OCH(CH3)3、-CH2CH2O(CH2)4CH3、-CH2CH2OCH(CH3)(CH2)2CH3、-CH2CH2OCH2CH(CH3)2、-CH2CH2O(CH2)2CH(CH3)2、-CH2CH2OC(CH3)3、-CH2CH2OCH(CH3)(CH2)3CH3、 -CH2CH2O(CH2)5CH3、-CH2CH2OCH(CH3)(CH2)3CH3、-CH2CH2OCH2CH(CH3)(CH2)2CH3、-CH2CH2O(CH2)2CH(CH3)CH2CH3、-CH2CH2O(CH2)3CH(CH3)2、-CH2CH2OCH(CH3)2(CH2)2CH3、-CH2CH2OCH (CH2CH3)(CH2)2CH3、-CH2CH2OC(CH3)2CH(CH3)2、-CH2CH2O(CH2)6CH3、-CH2CH2O(CH2)7CH3、-CH2CH2OCH2CH(CH2CH3)(CH2)3CH3、-CH2CH2O(CH2)8CH3、-CH2CH2O(CH2)9CH3、-CH2CH2O(CH2)<h2 style=";text-align:left;direction:ltr"> 10 <h2 style=";text-align:left;direction:ltr"> CH3、-CH2CH2O(CH2)<h2 style=";text-align:left;direction:ltr"> 11 <h2 style=";text-align:left;direction:ltr"> CH3、-CH2CH2O(CH2)<h2 style=";text-align:left;direction:ltr"> 12 <h2 style=";text-align:left;direction:ltr"> CH3、-CH2CH2O(CH2)<h2 style=";text-align:left;direction:ltr"> 13 <h2 style=";text-align:left;direction:ltr"> CH3、-CH2CH2O(CH2)<h2 style=";text-align:left;direction:ltr"> 14 <h2 style=";text-align:left;direction:ltr"> CH3、-CH2CH2O(CH2)<h2 style=";text-align:left;direction:ltr"> 15 <h2 style=";text-align:left;direction:ltr"> CH3、-CH2CH2O(CH2)<h2 style=";text-align:left;direction:ltr"> 16 <h2 style=";text-align:left;direction:ltr"> CH3、-CH2CH2O(CH2)<h2 style=";text-align:left;direction:ltr"> 17<h2 style=";text-align:left;direction:ltr">CH3、-CH2CH2CH2OCH3、-CH2CH2CH2OCH2CH3、-CH2CH2CH2O(CH2)2CH3、-CH2CH2CH2OCH(CH3)2、-CH2CH2CH2O(CH2)3CH3、-CH2CH2CH2OCH2CH(CH3)2 、-CH2CH2CH2OC(CH3)3、-CH2CH2CH2O(CH2)4CH3、-CH2CH2CH2OCH(CH3)(CH2)2CH3、-CH2CH2CH2OCH2CH(CH3)2、-CH2CH2CH2O(CH2)2CH(CH3)2、-CH 2CH2CH2OC(CH3)3、-CH2CH2CH2OCH(CH3)(CH2)3CH3、-CH2CH2CH2O(CH2)5CH3、-CH2CH2CH2OCH(CH3)(CH2)3CH3、-CH2CH2CH2OCH2CH(CH3)(CH2)2CH3、-CH2CH2CH2OCH2CH(CH3)(CH2)2CH3、-CH2CH2CH2O(CH2)2CH(CH3)CH2CH3、-CH2CH2CH2O(CH2)3CH(CH3)2、-CH2CH2CH2OCH(CH2CH3)(CH2)2CH3、-CH 2CH2CH2OC(CH3)2CH(CH3)2、-CH2CH2CH2O(CH2)6CH3、-CH2CH2CH2O(CH2)7CH3、-CH2CH2CH2OCH2CH(CH2CH3)(CH2)3CH3、-CH2CH2OCH2CH2OCH3、-CH2CH2OCH2CH2OCH2CH2OCH3、-CH2CH2OCH2CH2OCH2CH2OCH3、-CH2CH2OCH2CH2OCH2CH2OCH3、-CH2CH2OCH2CH2OCH2CH2OCH3、-CH2CH2OCH2CH2OCH2CH2OCH3、-CH2CH2OCH2CH2OCH2CH2OCH2 2CH2OCH2CH2OCH2CH2OCH3、-CH2CH2OCH2CH2OCH2CH2OCH2CH2OCH2CH2OCH2CH2OCH2CH2OCH3、-CH2CH2OCH2CH2OCH2CH2OCH2CH2OCH2CH2OCH2CH2OC H2CH2OCH2CH2OCH3、-CH2CH2CH2OCH2CH2CH2OCH3、-CH2CH2CH2OCH2CH2CH2OCH2CH2CH2OCH3、-CH2CH2CH2OCH2CH2CH2OCH2CH2CH2OCH2CH2CH2OCH3、-CH2CH2CH2OCH2CH2CH2OCH2CH2CH2OCH2CH2CH2OCH2CH2CH2OCH3, -CH2CH2CH2OCH2CH2CH2OCH2CH2CH2OCH2CH2CH2OCH2CH2CH2OCH2CH2CH2OCH3, -CH2CH2CH2CH2OCH2CH2CH2CH2OCH2CH2CH2CH2OCH3, -CH2CH2CH2CH2OCH2CH2CH2CH2OCH2CH2CH2CH2OCH2CH2CH2CH2OCH3, -CH2CH2OCH2CH2OCH2CH2OCH2CH2OCH2CH2OCH2CH2OCH2CH3, -CH2CH2OCH2CH2OCH2CH2OCH2CH2OCH2CH2OCH2CH2OCH2CH2OCH2CH2OCH2CH3, -CH2CH2OCH2CH2OCH2CH2OCH2CH2OCH2CH2OCH2CH2OCH2CH2OCH2CH2OCH2CH2OCH2CH3, -CH2CH2OCH2CH2OCH2CH3, -CH2CH2OCH2CH2OCH2CH2OCH2CH3, -CH2CH2CH2O(CH2)8CH3, -CH2CH2CH2O(CH2)9CH3, -CH2CH2CH2O(CH2), 10 CH3, -CH2CH2CH2O(CH2) 11 CH3, -CH2CH2CH2O(CH2) 12 CH3, -CH2CH2CH2O(CH2) 13 CH3, -CH2CH2CH2O(CH2) 14 CH3, -CH2CH2CH2O(CH2) 15 CH3, -CH2CH2CH2O(CH2) 16 Examples include CH3 and the like.

[0029] Examples of divalent groups obtained by removing two hydrogen atoms on the aromatic ring of dialkylfluorene represented by formula (3) include 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, Examples of such an alkyl group include, but are not limited to, 9-dioctyl-9H-fluorene-2,7-diyl group, 9,9-bis(2-ethylhexyl)-9H-fluorene-2,7-diyl group, 9,9-dimethoxy-9H-fluorene-2,7-diyl group, 9,9-diethoxy-9H-fluorene-2,7-diyl group, and 9,9-bis[2-(2-(2-methoxyethoxy)ethoxy)ethyl]-9H-fluorene-2,7-diyl group.

[0030] Among these, Ar 1 and Ar 4 As the alkyl group, a group obtained by removing two hydrogen atoms on the aromatic ring of dialkylfluorene represented by formula (3) is preferred, and a 9,9-dimethyl-9H-fluorene-2,7-diyl group is particularly preferred.

[0031] In formulas (1) and (2), Ar 2 , Ar 3 , Ar 5 and Ar 6 are each independently a monovalent group obtained by removing one hydrogen atom on the aromatic ring of an aryl group having 6 to 20 carbon atoms or a dialkylfluorene represented by formula (3), and some or all of the hydrogen atoms on the aromatic ring of these groups may be substituted with a cyano group, a nitro group, a halogen atom, a vinyl group, a trifluorovinyl group, an acryloyl group, a 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 described above.

[0032] Examples of the aryl group having 6 to 20 carbon atoms include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthryl group, a 2-anthryl group, a 9-anthryl group, a 1-phenanthryl group, a 2-phenanthryl group, a 3-phenanthryl group, a 4-phenanthryl group, a 9-phenanthryl group, a biphenyl-2-yl group, a biphenyl-3-yl group, and a biphenyl-4-yl group.

[0033] Examples of monovalent groups obtained by removing one hydrogen atom on the aromatic ring of dialkylfluorene represented by formula (3) include 9,9-dimethyl-9H-fluoren-2-yl group, 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-fluoren-2-yl group, 9,9-dipropyl-9H-fluoren-3-yl group, 9,9-dibutyl-9H-fluoren-2-yl group, 9,9-dibutyl-9H-fluoren-3-yl group, 9,9-dihexyl-9H-fluoren-2-yl group, 9,9-dihexyl-9H-fluoren-3-yl group, 9,9-dioctyl-9H-fluoren- 2-yl 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, and the like, but are not limited to these.

[0034] X 1 -N(Ar 3 )-, Ar 2 and Ar 3 may be bonded to each other to form a ring together with the nitrogen atom to which they are attached. 2 -N(Ar 6 )-, Ar5 and Ar 6 may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded. In this case, the ring structure is preferably a carbazole ring.

[0035] R 2 is a phenylene group, R 2 and Ar 2 may be bonded to each other to form a ring together with the nitrogen atom, sulfur atom or oxygen atom to which they are bonded. 4 is a phenylene group, R 4 and Ar 5 may be bonded to each other to form a ring together with the nitrogen atom, sulfur atom or oxygen atom to which they are bonded. In this case, the ring structure is preferably a carbazole ring, a dibenzothiophene ring or a dibenzofuran ring.

[0036] However, Ar 1 ~Ar 3 At least one of Ar is a group obtained by removing a hydrogen atom on an aromatic ring of a dialkylfluorene represented by formula (3), 4 ~Ar 6 At least one of the groups is a group obtained by removing a hydrogen atom on the aromatic ring of a dialkylfluorene represented by formula (3).

[0037] The repeating unit represented by formula (1) is X 1 -N(Ar 3 )- is preferred, and the repeating unit represented by formula (2) is preferably X 2 -N(Ar 6 That is, the repeating unit represented by formula (1) is preferably one represented by the following formula (1A), and the repeating unit represented by formula (2) is preferably one represented by the following formula (2A): (In the formula, R A , R 1 ~R 4 , Ar 1 ~Ar 6 is the same as above.)

[0038] Furthermore, the repeating unit represented by formula (2A) is preferably one represented by the following formula (2B). (In the formula, R 3 , R 4 and Ar 4 ~Ar 6 is the same as above.)

[0039] The polymer of the present invention may contain either a repeating unit represented by formula (1) or a repeating unit represented by formula (2), or may contain both of them.

[0040] Furthermore, the polymer may contain repeating units other than the repeating unit represented by formula (1) and the repeating unit represented by formula (2) within a range that does not impair the effects of the present invention. Examples of other repeating units include compounds containing polymerizable functional groups such as acryloyl groups, acrylamide groups, methacryloyl groups, methacrylamide groups, vinyl ether groups, and maleic anhydride. When multiple repeating units are contained, the polymer of the present invention may be any of a random copolymer, an alternating copolymer, and a block copolymer.

[0041] The content of the repeating units represented by formula (1) and the repeating units represented by formula (2) is preferably 50 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, still more preferably 95 mol% or more, and most preferably 100 mol% of all repeating units contained in the polymer. When both the repeating units represented by formula (1) and the repeating units represented by formula (2) are contained, the molar ratio of these units (repeating units represented by formula (1):repeating units represented by formula (2)) is preferably 1:99 to 99:1, more preferably 5:95 to 95:5, and even more preferably 10:90 to 90:10. The expression that the content of the repeating units represented by formula (1) and the repeating units represented by formula (2) is 100 mol % does not deny the presence of trace amounts of impurity repeating units that result from impurity monomers in the raw materials or side reactions during polymer synthesis. For example, when a polymer is synthesized using only raw materials, such as monomers that provide repeating units represented by formula (1) and monomers that provide repeating units represented by formula (2), a polymer having a content of 100 mol % of repeating units represented by formula (1) and repeating units represented by formula (2) can be obtained.

[0042] 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 reproducibly obtaining a highly uniform varnish, it is preferably 500,000 or less, more preferably 200,000 or less. The dispersity (Mw / Mn) is not particularly limited, but is usually 1.0 to 10.0, preferably 1.1 to 5.0, more preferably 1.2 to 3.0. In the present invention, the weight average molecular weight (Mw) and number average molecular weight (Mn) of the polymer can be measured using, for example, a GPC apparatus manufactured by Shimadzu Corporation, an autosampler SIL-10AF, a degasser DGU-20As, a column oven CTO-20A, and a differential refractive index detector RID-10A (column: Shodex GPC KF-805L and KF-804L manufactured by Showa Denko K.K., column temperature 40°C, detector: UV detector (254 nm), eluent: tetrahydrofuran (THF), column flow rate: 1.0 mL / min).

[0043] [Method for Producing Polymer] The polymer of the present invention can be produced by polymerizing at least one 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 ~R 4 , X 1 , X 2 , Ar 1 , Ar 2 , Ar 4 and Ar 5 is the same as above.)

[0044] The polymerization reaction is not particularly limited, and may be radical polymerization, anionic polymerization, cationic polymerization, etc. Among these, radical polymerization is particularly preferred, and specifically, the monomer may be polymerized by heating in a solvent in the presence of a polymerization initiator.

[0045] The polymerization initiator can be appropriately selected from conventionally known initiators. Examples include peroxides such as benzoyl peroxide, cumene hydroperoxide, and tert-butyl hydroperoxide; persulfates such as sodium persulfate, potassium persulfate, and ammonium persulfate; and azo compounds such as azobisisobutyronitrile (AIBN), azobismethylbutyronitrile, and azobisisovaleronitrile. These may be used alone or in combination of two or more.

[0046] The amount of polymerization initiator used is preferably about 0.01 to 0.05 mol per 1 mol of the monomer. The reaction temperature may be set appropriately between 0°C and the boiling point of the solvent used, but is preferably about 20 to 100°C. The reaction time is preferably about 0.1 to 30 hours.

[0047] The solvent used in the polymerization reaction may be appropriately selected from various solvents commonly used in this type of reaction. Specific examples include water; alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, isopentanol, tert-pentanol, 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; methyl cellosolve, ethyl cellosolve, isopropyl cellosolve, butyl cellosolve, and diethylene glycol. Examples of suitable solvents include ether alcohols such as ethanol 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; aliphatic or aromatic hydrocarbons such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, benzene, toluene, xylene, ethylbenzene, and anisole; acetals such as methylal and diethyl acetal; 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, and acetonitrile. These may be used alone or in combination of two or more.

[0048] When the polymer of the present invention contains a repeating unit other than the repeating unit represented by formula (1) and the repeating unit represented by formula (2), the polymer may be synthesized by polymerizing the repeating unit in the coexistence of the above-mentioned monomer and a monomer that gives the other repeating unit.

[0049] The monomer represented by formula (1') can be synthesized by utilizing a conventionally known reaction. One example of the synthesis method is a method of reacting maleic anhydride with an amine compound represented by formula (1") in a solvent, optionally in the presence of a catalyst, as shown in Scheme A below. (In the formula, R 1 , R 2 , X 1 , Ar 1 and Ar 2 is the same as above.)

[0050] Examples of the solvent include acetic acid, toluene, ethyl acetate, tetrahydrofuran, methanol, ethanol, dimethylformamide, and dimethyl sulfoxide.

[0051] 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 terms of molar ratio relative to the amine compound represented by formula (1''). When acetic acid is used as the solvent, the catalyst may not be used.

[0052] In the reaction, the ratio of maleic anhydride to the amine compound represented by formula (1") is preferably such that the molar ratio of the amine compound represented by formula (1") to maleic anhydride is 0.5 to 3.0, more preferably 1.0 to 1.5.

[0053] The reaction temperature is appropriately set within the range from the melting point to the boiling point of the solvent, taking into consideration the type and amount of the raw material compounds and catalyst used, and is usually about 40 to 150° C., and preferably 80 to 120° C. The reaction time cannot be generally determined because it varies depending on the raw material compounds used, the reaction temperature, etc., but is usually about 2 to 24 hours.

[0054] After the reaction is completed, the target monomer can be obtained by post-treatment according to a conventional method.

[0055] The monomer represented by formula (2') can be synthesized by combining various coupling reactions. One example of the synthesis method is a method of coupling a styrene compound represented by formula (2") with an amine compound represented by formula (2"') as shown in Scheme B below. (In the formula, R A , R 3 , R 4 , X 2 , Ar 4 and Ar 5 is the same as above.)

[0056] In Scheme B, X A is any group used in a coupling reaction. Specific examples of such groups include boronic acid groups such as —B(OH)2 and boronic ester groups when using the Suzuki-Miyaura coupling reaction.

[0057] In Scheme B, X B are each independently a halogen atom or a pseudohalogen group. B Examples of the halogen atom represented by X include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a bromine atom or an iodine atom is preferred. B Examples of the pseudohalogen group represented by the formula (I) include fluoroalkylsulfonyloxy groups such as methanesulfonyloxy group, trifluoromethanesulfonyloxy group, and nonafluorobutanesulfonyloxy group; and aromatic sulfonyloxy groups such as benzenesulfonyloxy group and toluenesulfonyloxy group.

[0058] The solvent used in the coupling reaction is not particularly limited as long as it does not adversely affect the reaction. Examples of the solvent include aliphatic hydrocarbons (pentane, n-hexane, n-octane, n-decane, decalin, etc.), halogenated aliphatic 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 butyl methyl ether, THF, dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, etc.), amides (N,N-dimethylformamide (DMF), N,N-dimethylacetamide, etc.), lactams and lactones (N-methylpyrrolidone, γ-butyrolactone, etc.), urea derivatives (N,N-dimethylimidazolidinone, tetramethylurea, etc.), sulfoxides (dimethyl sulfoxide, sulfolane, etc.), nitriles (acetonitrile, propionitrile, butyronitrile, etc.), and the like. Of 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.), and ethers (diethyl ether, diisopropyl ether, tert-butyl methyl ether, THF, dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, etc.), and more preferred are aromatic hydrocarbons (benzene, nitrobenzene, toluene, o-xylene, m-xylene, p-xylene, mesitylene, etc.) and ethers (diethyl ether, diisopropyl ether, tert-butyl methyl ether, THF, dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, etc.).

[0059] Examples of catalysts used in the coupling reaction include palladium catalysts such as [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride (PdCl2(dppf)), tetrakis(triphenylphosphine)palladium (Pd(PPh3)4), bis(triphenylphosphine)dichloropalladium (Pd(PPh3)2Cl2), bis(benzylideneacetone)palladium (Pd(dba)2), tris(benzylideneacetone)dipalladium (Pd2(dba)3), bis(tri-tert-butylphosphine)palladium (Pd(Pt-Bu3)2), and palladium(II) acetate (Pd(OAc)2). These catalysts may be used together with known appropriate ligands.

[0060] The amount of catalyst used is preferably an amount that provides a molar ratio of 0.01 to 0.2, more preferably 0.03 to 0.1, relative to the amine compound represented by formula (2'''). When a ligand is used, the amount thereof can be 0.1 to 3.0 equivalents relative to the metal complex used, and is preferably 0.8 to 1.5 equivalents.

[0061] A base may be used in the 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 hydrogencarbonates such as sodium hydrogencarbonate and potassium hydrogencarbonate; alkaline earth metal carbonates such as calcium carbonate; organolithium compounds such as n-butyllithium, sec-butyllithium, and tert-butyllithium; and amines such as triethylamine, diisopropylethylamine, tetramethylethylenediamine, triethylenediamine, and pyridine. However, the base is not particularly limited as long as it is used in this type of reaction. Sodium carbonate and potassium carbonate are particularly suitable because of their ease of handling. The amount of the base used is typically about 1 to 20, and preferably 4 to 8, molar ratio relative to the amine compound represented by formula (2''').

[0062] In the coupling reaction, the charging ratio of the styrene compound represented by formula (2") to the amine compound represented by the following formula (2"') is preferably such that the molar ratio of the amine compound represented by formula (2'") to the styrene compound represented by formula (2") is 0.2 to 2.0, and more preferably 0.5 to 1.0.

[0063] In the coupling reaction, the reaction temperature is appropriately set within the range from the melting point to the boiling point of the solvent, taking into consideration the type and amount of the raw material compounds and catalyst used, and is usually about 20 to 120° C., and preferably 60 to 100° C. The reaction time cannot be generally specified because it varies depending on the raw material compounds used, the reaction temperature, etc., but is usually about 0.5 to 12 hours.

[0064] After the reaction is completed, the target monomer can be obtained by post-treatment according to a conventional method.

[0065] [Charge Transporting Material] The polymer of the present invention can be suitably used as a charge transporting material, particularly as a hole transporting material. In the present invention, charge transporting property is synonymous with conductivity. A charge transporting material is a material that has charge transporting property by itself. Furthermore, the charge transporting varnish may be a material that has charge transporting property by itself, or a solid film obtained from the varnish may have charge transporting property.

[0066] [Charge-Transporting Varnish] The charge-transporting varnish of the present invention contains a charge-transporting substance composed of the polymer described above and an organic solvent. The charge-transporting substance may be used alone or in combination of two or more. The charge-transporting substance may also contain a charge-transporting polymer compound other than the polymer described above, a charge-transporting low-molecular-weight compound, or a charge-transporting oligomer compound.

[0067] [Organic Solvent] As the organic solvent, a highly polar solvent capable of dissolving the polymer well can be used. 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 one having a relative dielectric constant of less than 7 at a frequency of 100 kHz, and a high-polarity solvent is defined as one having a relative dielectric constant of 7 or more at a frequency of 100 kHz.

[0068] Examples of the low-polarity solvent include chlorine-based solvents such as chloroform and chlorobenzene; aromatic hydrocarbon-based solvents such as toluene, xylene, tetralin, cyclohexylbenzene, and decylbenzene; aliphatic alcohol-based solvents such as 1-octanol, 1-nonanol, and 1-decanol; ether-based solvents such as tetrahydrofuran, dioxane, anisole, 4-methoxytoluene, 3-phenoxytoluene, dibenzyl ether, diethylene glycol dimethyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, and triethylene glycol butyl methyl ether; and ester-based solvents such as 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, diethylene glycol monoethyl ether acetate, and diethylene glycol monobutyl ether acetate.

[0069] Examples of the highly polar solvent include amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylisobutyramide, N-methylpyrrolidone, and 1,3-dimethyl-2-imidazolidinone; ketone solvents such as ethyl methyl ketone, isophorone, and cyclohexanone; cyano solvents such as acetonitrile and 3-methoxypropionitrile; polyhydric alcohol solvents such as ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, 1,3-butanediol, and 2,3-butanediol; monohydric alcohol solvents other than aliphatic alcohols such as 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-phenoxybenzyl alcohol, and tetrahydrofurfuryl alcohol; and sulfoxide solvents such as dimethyl sulfoxide.

[0070] The amount of the organic solvent used is such that the solids concentration in the varnish of the present invention is generally about 0.1 to 20% by mass, preferably 0.5 to 10% by mass, from the viewpoint of ensuring a sufficient film thickness while suppressing precipitation of the charge transport material. In the present invention, the solids content refers to the components contained in the varnish other than the solvent. The organic solvent may be used alone or in combination of two or more.

[0071] The charge-transporting varnish of the present invention may contain water as a solvent, but typically contains only an organic solvent as a solvent. Note that "only an organic solvent" means that only the organic solvent is intended to be used as a solvent, and does not exclude the presence of trace amounts of water contained in the hydration water of the compound, the solid content, or the organic solvent.

[0072] [Dopant (Charge-Accepting Dopant)] The charge-transporting varnish of the present invention may contain a dopant for the purpose of improving the charge transport 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 both inorganic and organic dopants can be used. Furthermore, the dopant may be a substance that exhibits or improves its dopant function only when a part of the molecule is removed by an external stimulus, such as heating during baking, during the process of obtaining a charge-transporting thin film, which is a solid film, from the varnish, for example, an arylsulfonic acid ester compound protected with a group that easily removes the sulfonic acid group.

[0073] The inorganic dopant is preferably a heteropolyacid, and specific examples thereof include phosphomolybdic acid, silicomolybdic acid, phosphotungstic acid, phosphotungstomolybdic acid, and silicotungstic acid.

[0074] Heteropolyacids are polyacids that have a structure in which a heteroatom 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 are formed by condensing an isopolyacid, which is an oxyacid of vanadium (V), molybdenum (Mo), tungsten (W), etc., with an oxyacid of a different element. Examples of such oxyacids of different elements include oxyacids of silicon (Si), phosphorus (P), and arsenic (As).

[0075] Examples of the heteropolyacid include phosphomolybdic acid, silicomolybdic acid, phosphotungstic acid, silicotungstic acid, and phosphotungstomolybdic acid. These may be used alone or in combination of two or more. The heteropolyacids used in the present invention are commercially available or can be synthesized by known methods. In particular, when one type of heteropolyacid is used, that one type of heteropolyacid is preferably phosphotungstic acid or phosphomolybdic acid, with phosphotungstic acid being most preferred. In addition, when two or more types of heteropolyacids are used, one of the two or more types of heteropolyacids is preferably phosphotungstic acid or phosphomolybdic acid, with phosphotungstic acid being more preferred.

[0076] In addition, the heteropolyacid may be used in the present invention even if it has a large or small number of elements in the structure represented by the general formula in quantitative analysis such as elemental analysis, as long as it is obtained as a commercially available product or is appropriately synthesized according to a known synthesis method.

[0077] For example, phosphotungstic acid generally has the chemical formula H3(PW 12 O 40 )·nH2O, and phosphomolybdic acid has the chemical formula H3(PMo 12 O 40)·nHO, but in quantitative analysis, heteropolyacids having a large or small number of P (phosphorus), O (oxygen), W (tungsten), or Mo (molybdenum) in this formula can be used in the present invention, as long as they are commercially available or appropriately synthesized according to a known synthesis method. In this case, the mass of the heteropolyacid specified in the present invention does not refer to the mass of pure phosphotungstic acid (phosphotungstic acid content) in a synthesized or commercially available product, but rather refers to the total mass, including water of hydration and other impurities, in a form available as a commercially available product or in a form that can be isolated by a known synthesis method.

[0078] Examples of the organic dopant include arylsulfonic acid compounds, arylsulfonic acid esters, and ionic compounds consisting of a predetermined anion and its counter cation.

[0079] As the arylsulfonic acid compound, compounds represented by the following formula (A) or (B) are preferred from the viewpoint of the transparency of the thin film obtained from the charge transporting varnish of the present invention.

[0080] In formula (A), A 1 is —O— or —S—, and —O— is preferred. 2 is derived from naphthalene or anthracene (p 2 +1)valent group (i.e., naphthalene or anthracene to (p 2 +1) a group obtained by removing one hydrogen atom), but a group derived from naphthalene is preferred. 3 is a divalent to tetravalent perfluorobiphenyl group. 1 A 1 and A 3 is the number of bonds with 1 An integer that satisfies ≦4, but A 3 is a divalent perfluorobiphenyl group, and p 1 is preferably 2. 2 A 2 is the number of sulfonic acid groups bonded to p 2 It is an integer satisfying the condition ≦4, with 2 being preferred.

[0081] In formula (B), A 4 ~A 8 are each independently a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 20 carbon atoms, a halogenated alkyl group having 1 to 20 carbon atoms, or a halogenated alkenyl group having 2 to 20 carbon atoms, 4 ~A 8 At least three of the groups are halogen atoms. q is the number of sulfonic acid groups bonded to the naphthalene ring and is an integer satisfying 1≦q≦4, preferably 2 to 4, and more preferably 2.

[0082] The alkyl group having 1 to 20 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group, an n-tridecyl group, an n-tetradecyl group, an n-pentadecyl group, an n-hex ... Examples thereof include linear or branched alkyl groups such as butadecyl, n-octadecyl, n-nonadecyl, and n-eicosanyl groups; and cyclic alkyl groups having 3 to 20 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, bicyclobutyl, bicyclopentyl, bicyclohexyl, bicycloheptyl, bicyclooctyl, bicyclononyl, and bicyclodecyl groups.

[0083] Examples of the halogenated alkyl group having 1 to 20 carbon atoms include a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a perfluoroethyl group, a 3,3,3-trifluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a perfluoropropyl group, a 4,4,4-trifluorobutyl group, a 3,3,4,4,4-pentafluorobutyl group, a 2,2,3,3,4,4,4-heptafluorobutyl group, a perfluorobutyl group, etc. Examples of the halogenated alkenyl group having 2 to 20 carbon atoms include a perfluoroethenyl group, a 1-perfluoropropenyl group, a perfluoroallyl group, a perfluorobutenyl group, etc.

[0084] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being preferred.

[0085] Of these, A 4 ~A 8 is a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, or a halogenated alkenyl group having 2 to 10 carbon atoms, and A 4 ~A 8 At least three of the groups are preferably fluorine atoms, and are selected from the group consisting of a hydrogen atom, a fluorine atom, a cyano group, an alkyl group having 1 to 5 carbon atoms, a fluorinated alkyl group having 1 to 5 carbon atoms, and a fluorinated alkenyl group having 2 to 5 carbon atoms, and A 4 ~A 8 It is more preferable that at least three of A are fluorine atoms, and A is a hydrogen atom, a fluorine atom, a cyano group, a perfluoroalkyl group having 1 to 5 carbon atoms, or a perfluoroalkenyl group having 1 to 5 carbon atoms. 4 , A 5 and A 8 It is more preferable that each of the hydrogen atoms of the alkyl group and the perfluoroalkenyl group is a group in which all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms.

[0086] Specific examples of suitable aryl sulfonic acid compounds include, but are not limited to, those shown below.

[0087] Examples of the aryl sulfonate ester compound include the aryl sulfonate ester compounds disclosed in WO 2017 / 217455, the aryl sulfonate ester compounds disclosed in WO 2017 / 217457, and the aryl sulfonate ester compounds described in Japanese Patent Application No. 2017-243631, from the viewpoint of the transparency of the thin film obtained from the charge-transporting varnish of the present invention.

[0088] Specifically, from the viewpoint of solubility in low-polarity solvents, the arylsulfonic acid ester compound is preferably one represented by any one of the following formulas (C) to (E).

[0089] In formulas (C) to (E), m is an integer satisfying 1≦m≦4, preferably 2. n is an integer satisfying 1≦n≦4, preferably 2.

[0090] In formula (C), A 11 A is an m-valent group derived from perfluorobiphenyl (i.e., a group obtained by removing m fluorine atoms from perfluorobiphenyl). 12 is —O— or —S—, and —O— is preferred. 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), and a group derived from naphthalene is preferred. s1 ~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 an optionally substituted monovalent hydrocarbon group having 2 to 20 carbon atoms.

[0091] R s1 ~R s4 Examples of the linear or branched alkyl group having 1 to 6 carbon atoms represented by the formula (I) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and an n-hexyl group. Among these, an alkyl group having 1 to 3 carbon atoms is preferred. In particular, R s1 ~Rs4 Among them, R s1 or R s3 is a linear alkyl group having 1 to 3 carbon atoms, and the rest are hydrogen atoms, or R s1 is a linear alkyl group having 1 to 3 carbon atoms, and R s2 ~R s4 is preferably a hydrogen atom. In this case, the linear alkyl group having 1 to 3 carbon atoms is preferably a methyl group.

[0092] R s5 The monovalent hydrocarbon group having 2 to 20 carbon atoms represented by the formula (I) may be linear, branched, or cyclic, and specific examples thereof include alkyl groups such as ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl; and aryl groups such as phenyl, naphthyl, and phenanthryl. s5 As the alkyl group, a linear alkyl group having 2 to 4 carbon atoms or a phenyl group is preferred.

[0093] In formula (D), A 14 is an m-valent hydrocarbon group having 6 to 20 carbon atoms and containing one or more aromatic rings, which may be substituted, and this hydrocarbon group is a group obtained by removing m hydrogen atoms from a hydrocarbon compound having 6 to 20 carbon atoms and containing one or more aromatic rings. Examples of the hydrocarbon compound include benzene, toluene, xylene, ethylbenzene, biphenyl, naphthalene, anthracene, and phenanthrene. Among these, A 14 As the alkyl group, groups derived from benzene, biphenyl, etc. are preferred.

[0094] In addition, A 14 In the hydrocarbon group represented by the formula (I), some or all of the hydrogen atoms may be further substituted with a substituent, and examples of such a substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a nitro group, a cyano group, a hydroxy group, an amino group, a silanol group, a thiol group, a carboxy group, a sulfonate ester group, a phosphoric acid group, a phosphate ester group, an ester group, a thioester group, an amide group, a monovalent hydrocarbon group, an organooxy group, an organoamino group, an organosilyl group, an organothio group, an acyl group, and a sulfo group.

[0095] In formula (D), A 15 is —O— or —S—, with —O— being preferred.

[0096] In formula (D), A 16 is an aromatic hydrocarbon group having 6 to 20 carbon atoms and a valence of (n+1), and this aromatic hydrocarbon group is a group obtained by removing (n+1) hydrogen atoms from the aromatic ring of an aromatic hydrocarbon compound having 6 to 20 carbon atoms. Examples of the aromatic hydrocarbon compound include benzene, toluene, xylene, biphenyl, naphthalene, anthracene, and pyrene. Among these, A 16 As the alkyl group, a group derived from naphthalene or anthracene is preferred, and a group derived from naphthalene is more preferred.

[0097] 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, provided that R s6 , R s7 and R s8 The total number of carbon atoms in R is 6 or more. s6 , R s7 and R s8 The upper limit of the total number of carbon atoms is not particularly limited, but is preferably 20 or less, and more preferably 10 or less.

[0098] R s6 , R s7 and R s8 Specific examples of the linear or branched monovalent aliphatic hydrocarbon group represented by the formula (I) include alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-hexyl, n-octyl, 2-ethylhexyl, and decyl groups; and alkenyl groups having 2 to 20 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, isopropenyl, 1-methyl-2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, and hexenyl groups. s6 is preferably a hydrogen atom, and R s7 and R s8are each independently preferably an alkyl group having 1 to 6 carbon atoms.

[0099] In formula (E), R s9 ~R s13 are each independently a hydrogen atom, a nitro group, a cyano group, a halogen atom, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, or a halogenated alkenyl group having 2 to 10 carbon atoms.

[0100] R s9 ~R s13 The alkyl group having 1 to 10 carbon atoms represented by the formula (I) may be linear, branched, or cyclic, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, a cyclopentyl group, an n-hexyl group, a cyclohexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, and an n-decyl group.

[0101] R s9 ~R s13 The halogenated alkyl group having 1 to 10 carbon atoms represented by the formula (I) is not particularly limited as long as it is a group in which some or all of the hydrogen atoms of an alkyl group having 1 to 10 carbon atoms have been substituted with halogen atoms. Specific examples thereof include a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2,2-pentafluoroethyl group, a 3,3,3-trifluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a 1,1,2,2,3,3,3-heptafluoropropyl group, a 4,4,4-trifluorobutyl group, a 3,3,4,4,4-pentafluorobutyl group, a 2,2,3,3,4,4,4-heptafluorobutyl group, and a 1,1,2,2,3,3,4,4,4-nonafluorobutyl group.

[0102] R s9 ~R s13The halogenated alkenyl group having 2 to 10 carbon atoms represented by the formula (I) is not particularly limited as long as it is a group in which some or all of the hydrogen atoms of an alkenyl group having 2 to 10 carbon atoms have been substituted with halogen atoms, and specific examples thereof include a perfluorovinyl group, a perfluoro-1-propenyl group, a perfluoro-2-propenyl group, a perfluoro-1-butenyl group, a perfluoro-2-butenyl group, and a perfluoro-3-butenyl group.

[0103] Of these, R s9 R is preferably a nitro group, a cyano group, a halogenated alkyl group having 1 to 10 carbon atoms, or a halogenated alkenyl group having 2 to 10 carbon atoms, more preferably a nitro group, a cyano group, a halogenated alkyl group having 1 to 4 carbon atoms, or a halogenated alkenyl group having 2 to 4 carbon atoms, and even more preferably a nitro group, a cyano group, a trifluoromethyl group, or a perfluoropropenyl group. s10 ~R s13 As the atom, a halogen atom is preferable, and a fluorine atom is more preferable.

[0104] In formula (E), A 17 is —O—, —S— or —NH—, with —O— being preferred.

[0105] In formula (E), A 18 is an aromatic hydrocarbon group having 6 to 20 carbon atoms and a valence of (n+1), and this aromatic hydrocarbon group is obtained by removing (n+1) hydrogen atoms from the aromatic ring of an aromatic hydrocarbon compound having 6 to 20 carbon atoms. Examples of the aromatic hydrocarbon compound include benzene, toluene, xylene, biphenyl, naphthalene, anthracene, and pyrene. Among these, A 18 As the alkyl group, a group derived from naphthalene or anthracene is preferred, and a group derived from naphthalene is more preferred.

[0106] In formula (E), R s14 ~R s17are each independently a hydrogen atom or a linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms. Examples of the monovalent aliphatic hydrocarbon group include alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, and n-dodecyl; and alkenyl groups having 2 to 20 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, isopropenyl, 1-methyl-2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, and hexenyl. Of these, alkyl groups having 1 to 20 carbon atoms are preferred, alkyl groups having 1 to 10 carbon atoms are more preferred, and alkyl groups having 1 to 8 carbon atoms are even more preferred.

[0107] In formula (E), R s18 represents a linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, or -OR s19 It is. s19 is an optionally substituted monovalent hydrocarbon group having 2 to 20 carbon atoms.

[0108] R s18 As the linear or branched monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms represented by R s14 ~R s17 Examples include those exemplified in the explanation of R. s18 is a monovalent aliphatic hydrocarbon group, R s18 is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, and even more preferably an alkyl group having 1 to 8 carbon atoms.

[0109] R s19 Examples of the monovalent hydrocarbon group having 2 to 20 carbon atoms represented by the formula (I) include the above-mentioned monovalent aliphatic hydrocarbon groups other than the methyl group, as well as aryl groups such as phenyl, naphthyl, and phenanthryl groups. s19 is preferably a linear alkyl group having 2 to 4 carbon atoms or a phenyl group.

[0110] Examples of the substituent 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.

[0111] Specific examples of suitable aryl sulfonate compounds include, but are not limited to, those shown below.

[0112]

[0113] The ionic compound comprising the predetermined anion and its counter cation is preferably an electrically neutral onium borate salt comprising a monovalent or divalent anion represented by the following formula (F1) and a counter cation represented by any one of formulas (F2) to (F6):

[0114]

[0115] In formula (F1), Ar 11 ~Ar 16 are each independently an aryl group which may have a substituent or a heteroaryl group which may have a substituent. L is an alkylene group, —NH—, an oxygen atom, a sulfur atom, or —CN + - is.

[0116] Examples of the aryl group include aryl groups having 6 to 20 carbon atoms. Specific examples include a phenyl group, a tolyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthryl group, a 2-anthryl group, a 9-anthryl group, a 1-phenanthryl group, a 2-phenanthryl group, a 3-phenanthryl group, a 4-phenanthryl group, and a 9-phenanthryl group. Of these, a phenyl group, a tolyl group, and a naphthyl group are preferred.

[0117] Examples of the heteroaryl group include heteroaryl groups having 2 to 20 carbon atoms. Specific examples thereof include a 2-thienyl group, a 3-thienyl group, a 2-furanyl group, a 3-furanyl group, a 2-oxazolyl group, a 4-oxazolyl group, a 5-oxazolyl group, a 3-isoxazolyl group, a 4-isoxazolyl group, a 5-isoxazolyl group, a 2-thiazolyl group, a 4-thiazolyl group, a 5-thiazolyl group, a 3-isothiazolyl group, a 4-isothiazolyl group, a 5-isothiazolyl group, a 2-imidazolyl group, a 4-imidazolyl group, a 2- Pyridyl group, 3-pyridyl group, 4-pyridyl group, 2-pyradyl group, 3-pyradyl group, 5-pyradyl group, 6-pyradyl group, 2-pyrimidyl group, 4-pyrimidyl group, 5-pyrimidyl group, 6-pyrimidyl group, 3-pyridazyl group, 4-pyridazyl group, 5-pyridazyl group, 6-pyridazyl group, 1,2,3-triazin-4-yl group, 1,2,3-triazin-5-yl group, 1,2,4-triazin-3-yl group, 1,2,4-triazin quinolinyl group, 1,2,4-triazin-6-yl group, 1,3,5-triazin-2-yl group, 1,2,4,5-tetrazin-3-yl group, 1,2,3,4-tetrazin-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 , a 6-isoquinolinyl group, a 7-isoquinolinyl group, an 8-isoquinolinyl group, a 2-quinoxanyl group, a 5-quinoxanyl group, a 6-quinoxanyl group, a 2-quinazolinyl group, a 4-quinazolinyl group, a 5-quinazolinyl group, a 6-quinazolinyl group, a 7-quinazolinyl group, an 8-quinazolinyl group, a 3-cinnolinyl group, a 4-cinnolinyl group, a 5-cinnolinyl group, a 6-cinnolinyl group, a 7-cinnolinyl group, and an 8-cinnolinyl group.

[0118] Examples of the substituent include a halogen atom, a nitro group, a cyano group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, and an alkynyl group having 2 to 20 carbon atoms.

[0119] The alkyl group having 1 to 20 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include linear or branched alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl groups; and cyclic alkyl groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, and cyclodecyl groups. Of these, alkyl groups having 1 to 18 carbon atoms are preferred, and alkyl groups having 1 to 8 carbon atoms are more preferred.

[0120] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0121] The alkenyl group having 2 to 20 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include ethenyl, n-1-propenyl, n-2-propenyl, 1-methylethenyl, n-1-butenyl, n-2-butenyl, n-3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylethenyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, n-1-pentenyl, and n-1-decenyl.

[0122] The alkynyl group having 2 to 20 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include an ethynyl group, an n-1-propynyl group, an n-2-propynyl group, an n-1-butynyl group, an n-2-butynyl group, an n-3-butynyl group, a 1-methyl-2-propynyl group, an n-1-pentynyl group, an n-2-pentynyl group, an n-3-pentynyl group, an n-4-pentynyl group, a 1-methyl-n-butynyl group, a 2-methyl-n-butynyl group, a 3-methyl-n-butynyl group, a 1,1-dimethyl-n-propynyl group, an n-1-hexynyl group, and an n-1-decynyl group.

[0123] The aryl group and heteroaryl group preferably have one or more electron-withdrawing groups as substituents. Examples of the electron-withdrawing groups among the substituents include a halogen atom, a nitro group, and a cyano group. A halogen atom is preferred, and a fluorine atom is particularly preferred.

[0124] In formula (F1), L is an alkylene group, —NH—, an oxygen atom, a sulfur atom, or —CN + - but -CN + - is preferred.

[0125] The alkylene group may be linear, branched, or cyclic, and includes alkylene groups having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms. Specific examples thereof include a methylene group, a methylmethylene group, a dimethylmethylene group, an ethylene group, a trimethylene group, a propylene group, a tetramethylene group, a pentamethylene group, and a hexamethylene group.

[0126] Anions represented by formula (F1) that can be suitably used in the present invention include, but are not limited to, those represented by formula (F1').

[0127] In the present invention, the onium borate salt may be used alone or in combination of two or more. If necessary, other known onium borate salts may be used in combination. The onium borate salt can be synthesized by referring to known methods described in, for example, JP-A-2005-314682.

[0128] The onium borate salt may be dissolved in an organic solvent in advance when preparing the charge-transporting varnish to facilitate dissolution in 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; polyhydric alcohols and derivatives thereof such as ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, dipropylene glycol, and the monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, and monophenyl ether of dipropylene glycol monoacetate; dioxanes, methyl ether ... Examples of suitable solvents include cyclic ethers such as methyl ether, methyl 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, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, and 3-methyl-3-methoxybutyl acetate; and aromatic hydrocarbons such as toluene, xylene, 3-phenoxytoluene, 4-methoxytoluene, methyl benzoate, cyclohexylbenzene, tetralin, and isophorone. These solvents may be used alone or in combination of two or more. The amount of the solvent used is preferably 15 to 1,000 parts by mass, more preferably 30 to 500 parts by mass, per 100 parts by mass of the onium borate salt.

[0129] The content of the dopant cannot be generally defined because it varies depending on the type of dopant and the desired degree of charge transportability, but is usually in the range of 0.0001 to 1000 in mass ratio to the charge transporting substance.

[0130] The charge-transporting varnish of the present invention may further contain an organosilane compound for the purpose of adjusting the film properties of the resulting charge-transporting thin film. Examples of the organosilane compound include dialkoxysilane compounds, trialkoxysilane compounds, and tetraalkoxysilane compounds. In particular, dialkoxysilane compounds and trialkoxysilane compounds are preferred as the organosilane compound, and trialkoxysilane compounds are more preferred. The organosilane compounds may be used alone or in combination of two or more.

[0131] The content of the organosilane compound is usually about 0.1 to 50% by mass, based on the total mass of the charge transport material and the dopant. However, taking into consideration the suppression of a decrease in the charge transport property of the resulting thin film and the enhancement of the hole injection ability into a layer (e.g., a hole transport layer or a light-emitting layer) stacked on the opposite side of the anode so as to be in contact with the hole injection layer made of the charge transport thin film of the present invention, the content is preferably about 0.5 to 40% by mass, more preferably about 0.8 to 30% by mass, and even more preferably about 1 to 20% by mass.

[0132] The method for preparing the charge-transporting varnish is not particularly limited, and examples thereof include a method of adding the polymer and, if necessary, a dopant, etc. to an organic solvent in any order or simultaneously. When there are multiple organic solvents, the polymer and, if necessary, a dopant, etc. may first be dissolved in one organic solvent, and then another organic solvent may be added thereto, or the polymer and, if necessary, a dopant, etc. may be dissolved in a mixed solvent of multiple organic solvents sequentially or simultaneously.

[0133] From the viewpoint of obtaining a thin film with higher flatness with good reproducibility, the charge-transporting varnish of the present invention is preferably prepared by dissolving the polymer and, if necessary, a dopant, etc. in an organic solvent, and then filtering the resultant using a filter or the like on the order of submicrometers.

[0134] The viscosity of the charge-transporting varnish of the present invention is typically 1 to 50 mPa·s at 25°C. The surface tension of the charge-transporting varnish of the present invention is typically 20 to 50 mN / m at 25°C. The viscosity is a value measured using a TVE-25 viscometer manufactured by Toki Sangyo Co., Ltd. The surface tension is a value measured using a CBVP-Z automatic surface tensiometer manufactured by Kyowa Interface Science Co., Ltd. The viscosity and surface tension of the varnish can be adjusted by changing the types of solvents mentioned above, their ratios, solids concentration, etc., taking into account various factors such as the desired film thickness.

[0135] In the charge-transporting varnish of the present invention, the solid content is usually uniformly dispersed or dissolved in the organic solvent.

[0136] [Charge-Transporting 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.

[0137] Examples of methods for applying the varnish include, but are not limited to, dipping, spin coating, transfer printing, roll coating, brush coating, inkjet coating, spraying, slit coating, etc. It is preferable to adjust the viscosity and surface tension of the varnish depending on the application method.

[0138] Furthermore, the atmosphere in which the charge-transporting varnish is baked after application is not particularly limited, and a thin film having a uniform film surface and high charge transport properties can be obtained not only in an air atmosphere but also in an inert gas atmosphere such as nitrogen or in a vacuum. Depending on the type of dopant used, a thin film having charge transport properties can be reproducibly obtained by baking the varnish in an air atmosphere.

[0139] The baking temperature is appropriately set within a range of about 100 to 260° C., taking into consideration the use of the resulting thin film, the degree of charge transport property to be imparted to the resulting thin film, the type and boiling point of the solvent, etc. When the resulting thin film is used as a hole injection layer of an organic EL device, the baking temperature is preferably about 140 to 250° C., and more preferably about 145 to 240° C. During baking, the temperature may be changed in two or more stages for the purposes of achieving more uniform film formation or promoting the reaction on the substrate, and heating may be performed using an appropriate device such as a hot plate or an oven.

[0140] The thickness of the charge transport thin film is not particularly limited, but is preferably 5 to 300 nm when used as a functional layer provided between an anode and a light-emitting layer, such as a hole injection layer, a hole transport layer, or a hole injection transport layer of an organic EL device. Methods for changing the film thickness include changing the solids concentration in the varnish and changing the amount of liquid on the substrate during application.

[0141] 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, averaged over a wavelength range of 400 to 800 nm, and in some embodiments exhibits a refractive index of 1.65 or more, in some embodiments exhibits a refractive index of 1.70 or more, and in some embodiments exhibits an extinction coefficient of 0.020 or less, and in some embodiments exhibits an extinction coefficient of 0.015 or less. In the present invention, the refractive index and extinction coefficient can be measured using, for example, a multi-angle spectroscopic ellipsometer VASE manufactured by J.A. Woollam Company.

[0142] [Organic EL Element] The organic EL element of the present invention has a pair of electrodes and a functional layer made of the charge transporting thin film of the present invention between the electrodes.

[0143] Representative configurations of organic EL elements include, but are not limited to, the following (a) to (f). In the following configurations, an electron blocking layer or the like can be provided between the light-emitting layer and the anode, and a hole blocking layer or the like can be provided between the light-emitting layer and the cathode, as necessary. Furthermore, the hole injection layer, the hole transport layer, or the hole injection transport layer may also function as an electron blocking layer or the like, and the electron injection layer, the electron transport layer, or the electron injection transport layer may also function as a hole blocking layer or the like. Furthermore, an arbitrary functional layer can be provided between each layer as necessary. (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 transport layer / cathode (c) anode / hole injection transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode (d) anode / hole injection transport layer / light-emitting layer / electron injection 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

[0144] The terms "hole injection layer," "hole transport layer," and "hole injection transport layer" refer to layers formed between the light-emitting layer and the anode, and have the function of transporting holes from the anode to the light-emitting layer. When only one layer of a hole-transporting material is provided between the light-emitting layer and the anode, it is the "hole injection transport layer." When two or more layers of a hole-transporting material are provided between the light-emitting layer and the anode, the layer closest to the anode is the "hole injection layer," and the remaining layers are "hole transport layers." In particular, the hole injection (transport) layer is a thin film that is excellent not only in the ability to accept holes from the anode but also in the ability to inject holes into the hole transport (light-emitting) layer.

[0145] The terms "electron injection layer," "electron transport layer," and "electron injection transport layer" refer to 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 an electron-transporting material is provided between the light-emitting layer and the cathode, it is the "electron injection transport layer." When two or more layers of an electron-transporting material are provided between the light-emitting layer and the cathode, the layer closest to the cathode is the "electron injection layer," and the other layers are "electron transport layers."

[0146] The "light-emitting layer" is an organic layer that has a light-emitting function, and when a doping system is used, it contains a host material and a dopant material. In this case, the host material mainly functions to promote the recombination of electrons and holes and confine excitons within the light-emitting layer, while the dopant material functions to efficiently emit light from the excitons obtained by recombination. In the case of a phosphorescent element, the host material mainly functions to confine excitons generated by the dopant within the light-emitting layer.

[0147] The charge-transporting thin film of the present invention can be suitably used as a functional layer provided between an anode and an emitting layer in an organic EL device, and can be more suitably used as a hole-injection layer, a hole-transport layer, or a hole-injection-transport layer, and can be even more suitably used as a hole-injection layer.

[0148] When an organic EL device is produced using the charge transporting varnish of the present invention, the materials to be used and the production method thereof include, but are not limited to, those listed below.

[0149] An example of a method for producing 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: It is preferable to previously perform a surface treatment on the electrodes, such as washing with alcohol or pure water, or UV ozone treatment or oxygen-plasma treatment, within a range that does not adversely affect the electrodes.

[0150] A hole injection layer is formed on an anode substrate using the charge transport varnish of the present invention by the above-described method. This is then 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, instead of forming the hole transport layer and the light-emitting layer by deposition in this method, these layers are formed by a wet process using a hole transport layer-forming composition containing a hole transport polymer and a light-emitting layer-forming composition containing a light-emitting polymer. If necessary, an electron blocking layer may be provided between the light-emitting layer and the hole transport layer.

[0151] 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, or alloys thereof, and preferably those that have undergone planarization treatment. Polythiophene derivatives and polyaniline derivatives with high charge transport properties can also be used. Other metals that can be used to make the metal anode include, but are not limited to, gold, silver, copper, indium, and alloys thereof.

[0152] Examples of materials for forming the hole transport layer include triarylamines such as (triphenylamine) dimer derivatives, [(triphenylamine) dimer] spiro dimer, N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-benzidine (α-NPD), 4,4',4''-tris[3-methylphenyl(phenyl)amino]triphenylamine (m-MTDATA), and 4,4',4''-tris[1-naphthyl(phenyl)amino]triphenylamine (1-TNATA), and oligothiophenes such as 5,5''-bis-{4-[bis(4-methylphenyl)amino]phenyl}-2,2':5',2''-terthiophene (BMA-3T).

[0153] Examples of materials for forming the light-emitting layer include, but are not limited to, low-molecular-weight light-emitting materials such as metal complexes such as aluminum complexes of 8-hydroxyquinoline, metal complexes of 10-hydroxybenzo[h]quinoline, bisstyrylbenzene derivatives, bisstyrylarylene derivatives, metal complexes of (2-hydroxyphenyl)benzothiazole, and silole derivatives; and systems in which a light-emitting material and an electron transfer material are mixed with a polymer compound such as poly(p-phenylenevinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene], poly(3-alkylthiophene), or polyvinylcarbazole.

[0154] Furthermore, when forming a light-emitting layer by vapor deposition, it may be co-deposited with a light-emitting dopant. Examples of the light-emitting dopant include, but are not limited to, metal complexes such as tris(2-phenylpyridine)iridium(III) (Ir(ppy)), naphthacene derivatives such as rubrene, quinacridone derivatives, and fused polycyclic aromatic rings such as perylene.

[0155] Examples of materials for forming the electron transport layer / hole blocking layer include, but are not limited to, oxydiazole derivatives, triazole derivatives, phenanthroline derivatives, phenylquinoxaline derivatives, benzimidazole derivatives, and pyrimidine derivatives.

[0156] Examples of materials for forming the electron injection layer include, but are not limited to, metal oxides such as lithium oxide (LiO), magnesium oxide (MgO), and alumina (AlO), and metal fluorides such as lithium fluoride (LiF) and sodium fluoride (NaF).

[0157] The cathode material includes, but is not limited to, aluminum, magnesium-silver alloy, aluminum-lithium alloy, and the like.

[0158] Examples of materials for forming the electron blocking layer include, but are not limited to, tris(phenylpyrazole)iridium.

[0159] 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)], and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzidine]-endcapped with Examples thereof include polysilsesquioxane and poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(p-butylphenyl))diphenylamine)].

[0160] Examples of the light-emitting polymer include polyfluorene derivatives such as poly(9,9-dialkylfluorene) (PDAF), polyphenylenevinylene derivatives such as poly(2-methoxy-5-(2'-ethylhexoxy)-1,4-phenylenevinylene) (MEH-PPV), polythiophene derivatives such as poly(3-alkylthiophene) (PAT), and polyvinylcarbazole (PVCz).

[0161] The materials constituting the anode, cathode and layers formed therebetween differ depending on whether an element having a bottom emission structure or a top emission structure is to be manufactured, and therefore, the materials are selected appropriately taking this into consideration.

[0162] Typically, in bottom-emission devices, a transparent anode is used on the substrate side, and light is extracted from the substrate side, whereas in top-emission devices, a reflective anode made of metal is used, and light is extracted from the transparent electrode (cathode) side opposite the substrate. Therefore, for example, in terms of anode material, a transparent anode such as ITO is used when manufacturing bottom-emission devices, and a reflective anode such as Al / Nd is used when manufacturing top-emission devices.

[0163] The organic EL element of the present invention may be sealed, if necessary, together with a moisture scavenger or the like in accordance with a conventional method in order to prevent deterioration of the characteristics.

[0164] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. The apparatus 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: Substrate cleaning device (low-pressure plasma method), manufactured by Choshu Sangyo Co., Ltd. (3) Varnish application: Spin coater MS-A100, manufactured by Mikasa Co., Ltd. (4) Film thickness measurement: Micro-shape measuring instrument Surfcorder ET-4000, manufactured by Kosaka Laboratory Co., Ltd. (5) Preparation of single-layer element (SLD) and hole-only element (HOD): Multi-function deposition system C-E2L1G1-N, manufactured by Choshu Sangyo Co., Ltd. (6) Measurement of electrical properties of SLD and HOD: Multi-channel IVL measurement device, manufactured by EHC Co., Ltd. (7) Measurement of refractive index and extinction coefficient: Multi-angle spectroscopic ellipsometer VASE, manufactured by J.A. Woollam Co., Ltd. (8) TG-DTA measurement: Rigaku Corporation, differential thermal thermogravimetric analyzer TG8120 (9) Measurement of weight average molecular weight (Mw) and number average molecular weight (Mn): Shimadzu Corporation GPC device, autosampler SIL-10AF, degasser DGU-20As, column oven CTO-20A, differential refractive index detector RID-10A (column: Showa Denko K.K., 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)

[0165] The reagents and solvents used in the synthesis were Pd(dba)2, Pd(dppf)Cl2.CH2Cl2, potassium acetate, bis(pinacolato)diboron, 2-amino-N-[(1,1'-biphenyl)-4-yl]-N-(4-bromophenyl)-9,9-dimethylfluorene, trimethyl borate, lithium bis(trimethylsilyl)amide 1.3 mol / L tetrahydrofuran solution, maleic anhydride, triethylamine, 4-vinylphenylboronic acid, tetrakistriphenylphosphine palladium, and anisole, all of which were manufactured by Tokyo Chemical Industry Co., Ltd.; toluene, hexane, ethyl acetate, ethanol, acetonitrile, dichloromethane, methylparaben ... Methylformamide and methanol were manufactured by Junsei Chemical Co., Ltd., AIBN and tri-tert-butylphosphonium tetrafluoroborate were manufactured by Fujifilm Wako Chemical Co., Ltd., sodium carbonate, dioxane, butyllithium 1.56 mol / L hexane solution, dichloromethane and silica gel N60 were manufactured by Kanto Chemical Co., Ltd., 1-bromo-4-(1-propen-2-yl)benzene was manufactured by 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 were manufactured by Suna Tech Inc.

[0166] [1] Synthesis of Monomers [Comparative Synthesis Example 1] Synthesis of Monomer M-X

[0167] 4-Aminotriphenylamine was synthesized by a method similar to that of Synthesis Example 1 in WO 2014 / 132834. Note that triphetri-tert-butylphosphonium tetrafluoroborate was used as the ligand instead of tri(tert-butyl)phosphine. 5.00 g of 4-aminotriphenylamine and 2.06 g of maleic anhydride were added to a side-arm flask and stirred thoroughly. 35 mL of acetic acid was slowly added thereto, and stirring was continued until the mixture was uniformly dispersed. The resulting mixture was then heated to 120°C and refluxed for 20 hours, and the reaction mixture was allowed to cool. The cooled reaction mixture was added to 300 mL of water, and 300 mL of ethyl acetate was added thereto, followed by separation, and the organic layer was recovered. The recovered organic layer was washed sequentially with water and saturated brine. The solvent was then 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 (yield: 5.00 g, 76%).

[0168] [Synthesis Example 1] Synthesis of Monomer MA (1) Synthesis of 3-(7-amino-9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole

[0169] 10 g of 3-(7-bromo-9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole, 0.89 g of Pd(dba), and 0.45 g of triphetri-tert-butylphosphonium tetrafluoroborate were added to a reaction vessel, and the reaction vessel was degassed and then replaced with 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. The mixture in the flask was then stirred for 20 hours while monitoring the reaction by TLC. After confirming the disappearance of the starting material, 4-bromo-N,N-diphenylaniline, the reaction mixture was cooled to 0°C. To the cooled reaction mixture, 100 mL of 1 N aqueous hydrochloric acid was added to adjust the pH of the mixture to 3. Then, an aqueous sodium chloride solution (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 the toluene was collected as filtrate. The aqueous and organic layers of the filtrate were separated, and the aqueous layer was thoroughly mixed with toluene to recover the toluene. This toluene was combined with the organic layer of the filtrate, washed with water, and then the solvent was removed under reduced pressure to obtain a crude product. The resulting crude product was purified by column chromatography (column: SiO2, developing solvent: hexane / ethyl acetate = 4 / 1 (triethylamine, 1%)) to obtain 3-(7-amino-9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole (yield: 7.52 g, 94%).

[0170] (2) Synthesis of Monomer MA

[0171] Monomer MA was obtained in the same manner as in 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 (yield: 3.24 g, 50%). 1 The H-NMR spectrum is shown below. 1H-NMR (CDCl3, 500Hz) σ 8.41 (1H, d, J=1.5), 8.23 ​​(1H, d, J=7.7), 7.83 (2H, dd, J=8.1, 2.3), 7.77 (1H, d, J=1.2), 7.73-7.70 (2H, m), 7.66-7.60 (4H, m), 7.51-7.48 (2H, m), 7.44 (2H, d, J=3.6), 7.42 (1H, d, J=7.42), 7.34-7.31 (2H, m), 6.89 (2H, s), 1.60 (6H, s)

[0172] [Synthesis Example 1-2] Synthesis of Monomer MB

[0173] A side-arm flask was charged with 4.6 g of 4-vinylphenylboronic acid, 8 g of 3-(7-bromo-9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole, 0.54 g of tetrakistriphenylphosphine palladium, 4.94 g of sodium carbonate, 105 mL of toluene, 25 mL of ethanol, and 23 mL of water, and the mixture was stirred thoroughly. The resulting mixture was heated to 80°C and stirred for 2 hours. After cooling to room temperature, the two separated aqueous layers of the reaction mixture were recovered. The recovered aqueous layer was thoroughly mixed with toluene to recover the toluene. The recovered toluene and the organic layer of the reaction mixture were combined and washed with saturated brine. The solvent was then removed under reduced pressure to obtain a crude product. The resulting crude product was added to acetonitrile and stirred thoroughly at room temperature for 1 hour. The remaining solid was recovered by filtration and dried under reduced pressure to obtain Monomer M-B (yield: 5.49 g, 66%). 1 The H-NMR spectrum is shown below. 1H-NMR (CDCl3, 500Hz) σ 8.42 (1H, d, J=1.5), 8.24 (1H, d, J=7.7), 7.84-7.78 (3H, m), 7.72 (2H, ddd, J=8.3, 8.3, 1.7), 7.68-7.60 (8H, m), 7.52-7.48 (4H, m), 7.44-7.43 (2H, m), 7.34-7.25 (1H, m), 6.78 (1H, q, J=17.6, 10.9), 5.81 (1H, d, J=17.7), 5.29 (1H, d, J=11.0), 1.63 (6H, s)

[0174] [Synthesis Example 1-3] Synthesis of Monomer MC (1) 1,4-diaminobenzene-N 1 -[(1,1'-biphenyl)-4-yl]-N 1 Synthesis of 9,9-dimethylfluorene

[0175] To a reaction vessel, 7 g of 2-amino-N-[(1,1'-biphenyl)-4-yl]-N-(4-bromophenyl)-9,9-dimethylfluorene, 0.39 g of Pd(dba)2, and 0.20 g of triphetri-tert-butylphosphonium tetrafluoroborate were added, and the reaction vessel was degassed and then replaced with 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. The mixture in the flask was stirred for 30 hours while monitoring the reaction by TLC. After confirming the disappearance of the raw material, 2-amino-N-[(1,1'-biphenyl)-4-yl]-N-(4-bromophenyl)-9,9-dimethylfluorene, the reaction mixture was cooled to 0°C. To the cooled reaction mixture, 100 mL of a 1 N aqueous hydrochloric acid solution was added to adjust the pH of the mixture to 3, and then an aqueous sodium chloride solution (concentration: 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 the toluene was also recovered as filtrate. The aqueous and organic layers of the filtrate were separated, the aqueous layer was thoroughly mixed with toluene, and the toluene was recovered. This was combined with the organic layer of the filtrate, washed with water, and then 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, dried under reduced pressure, and 1,4-diaminobenzene-N 1 -[(1,1'-biphenyl)-4-yl]-N 1 -9,9-dimethylfluorene was obtained (yield: 4.84 g, 79%).

[0176] (2) Synthesis of Monomer MC

[0177] Instead of 4-aminotriphenylamine, 1,4-diaminobenzene-N 1 -[(1,1'-biphenyl)-4-yl]-N 1Monomer MC was obtained in the same manner as in Comparative Synthesis Example 1, except that 4.84 g of 9,9-dimethylfluorene was used instead (yield: 2.61 g, 46%). 1 The H-NMR spectrum is shown below. 1 H-NMR (DMSO, 500Hz) σ 7.80 (1H, d, J=8.1), 7.76 (1H, d, J=7.3), 7.67-7.64 (4H, m), 7.52 (1H, d, J=7.4), 7.45 (2H, t, J=7.6), 7.35-7.25 (6H, m), 7.18 (2H, s), 7.17-7.14 (4H, m), 7.07 (1H, d, J=8.1, 2.0), 1.40 (6H, s)

[0178] [Synthesis Example 1-4] Synthesis of Monomer MD (1) Synthesis of (4-([1,1'-biphenyl]-4-yl(9,9-dimethyl-9H-fluoren-2-yl)amino)phenyl)boronic acid

[0179] 5 g of 2-amino-N-[(1,1'-biphenyl)-4-yl]-N-(4-bromophenyl)-9,9-dimethylfluorene and 20 g of tetrahydrofuran were added to a reaction vessel, and the reaction vessel was cooled to -78°C, degassed, and then replaced with a nitrogen atmosphere. Next, while stirring the mixture in the reaction vessel, 7.15 mL of a 1.56 mol / L hexane solution of butyllithium (equivalent to 11.13 mmol of butyllithium) was slowly added. The mixture was stirred for 1 hour while maintaining the temperature in the reaction vessel at -78°C. Subsequently, 1.3 mL of trimethyl borate was slowly added to the mixture in the reaction vessel while stirring. The temperature in the reaction vessel was then returned from -78°C to room temperature, and the mixture was stirred for 2 hours. 1 N aqueous hydrochloric acid was added to the reaction mixture until the pH of the mixture reached 3. The aqueous and organic layers of the reaction mixture were separated, the aqueous layer was thoroughly mixed with dichloromethane, and the dichloromethane was recovered. This was then combined with the organic layer, washed with water, and the solvent was removed under reduced pressure to obtain a crude product. The resulting crude product was dissolved in 5 g of dichloromethane and added dropwise to 50 g of hexane, followed by stirring at room temperature. Finally, the precipitated solid was collected by filtration and dried under reduced pressure to obtain (4-([1,1'-biphenyl]-4-yl-(9,9-dimethyl-9H-fluoren-2-yl)amino)phenyl)boronic acid (yield: 3.26 g, 70%).

[0180] (2) 2-Bromo-9,9-dimethyl-9H-fluorene-N 1 -[(1,1'-biphenyl)-4-yl]-N 1 Synthesis of 9,9-dimethylfluorene

[0181] A reaction vessel was charged with 3.26 g of (4-([1,1'-biphenyl]-4-yl-(9,9dimethyl-9H-fluoren-2-yl)amino)phenyl)boronic acid, 2.71 g of 2-bromo-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)), and the reaction vessel was degassed and then filled with nitrogen. Next, while stirring the mixture in the reaction vessel, 10 mL of a 2 M aqueous sodium carbonate solution prepared in advance was added. The mixture in the reaction vessel was then stirred under reflux for 3 hours. The aqueous and organic layers of the reaction mixture were separated, the aqueous layer was thoroughly mixed with toluene, and the toluene was recovered. This toluene was then combined with the organic layer, washed with water, and the solvent was removed under reduced pressure to obtain a crude product. The crude product obtained was dissolved in 5 g of toluene, added dropwise to 50 g of methanol, and stirred at room temperature. Finally, the precipitated solid was collected by filtration, and the collected 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, 70%).

[0182] (3) 2-amino-9,9-dimethyl-9H-fluorene-N 1 -[(1,1'-biphenyl)-4-yl]-N 1 Synthesis of 9,9-dimethylfluorene

[0183] In a reaction vessel, 2-bromo-9,9-dimethyl-9H-fluorene-N 1 -[(1,1'-biphenyl)-4-yl]-N 15.0 g of 2-bromo-9,9-dimethyl-9H-fluorene, 0.20 g of Pd(dba)2, and 0.10 g of trifetri-tert-butylphosphonium tetrafluoroborate were added, and the reaction vessel was degassed and then filled with nitrogen. 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. The mixture in the flask was stirred for 20 hours while monitoring the reaction by TLC, and the raw material, 2-bromo-9,9-dimethyl-9H-fluorene-N 1 -[(1,1'-biphenyl)-4-yl]-N 1 After confirming the disappearance of 9,9-dimethylfluorene, the reaction mixture was cooled to 0°C. 20 mL of 1N aqueous hydrochloric acid solution was added to the cooled reaction mixture to adjust the pH of the mixture to 3. Then, an aqueous sodium chloride solution (concentration: 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 the toluene was also recovered as filtrate. The aqueous and organic layers of the filtrate were separated, the aqueous layer was thoroughly mixed with toluene, and the toluene was recovered. This toluene was combined with the organic layer of the filtrate, washed with water, and then the solvent was removed under reduced pressure to obtain a crude product. The resulting crude product was dissolved in 5 g of toluene and added dropwise to 100 g of hexane and stirred at room temperature. Finally, the precipitated solid was recovered by filtration, dried under reduced pressure, and 2-amino-9,9-dimethyl-9H-fluorene-N 1 -[(1,1'-biphenyl)-4-yl]-N 1 9,9-Dimethylfluorene was obtained (yield: 4.81 g, 100%).

[0184] (2) Synthesis of Monomer MD

[0185] 2-amino-9,9-dimethyl-9H-fluorene-N instead of 4-aminotriphenylamine 1Monomer MD was obtained in the same manner as in Comparative Synthesis Example 1, except that 4.8 g of -[(1,1'-biphenyl)-4-yl]-N1-9,9-dimethylfluorene was used (yield: 3.28 g, 61%). 1 The H-NMR spectrum is shown below. 1 H-NMR (DMSO, 500Hz) σ 7.96-7.90 (2H, m), 7.81-7.74 (4H, m), 7.68-7.65 (6H, m), 7.53 (1H, d, J=7.3), 7.46 (2H, t, J=7.7), 7.37-7.27 (6H, m), 7.22 (2H, s), 7.20-7.16 (4H, m), 7.08 (1H, dd, J=8.1, 2.1), 1.41 (12H, s)

[0186] [Synthesis Example 1-5] Synthesis of Monomer ME (1) Synthesis of 3-(9,9-dimethyl-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-fluoren-2-yl)-9-phenyl-9H-carbazole

[0187] A reaction vessel was charged with 10 g of 3-(7-bromo-9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole, 5.4 g of bis(pinacolato)diboron, 0.32 g of Pd(dppf)Cl.CHCl, 4.8 g of potassium acetate, and 80 mL of dioxane. The reaction vessel was degassed and then replaced with a nitrogen atmosphere. The temperature inside the reaction vessel was then raised to 100°C. The mixture in the flask was stirred for 5 hours while monitoring the reaction by TLC. After confirming the disappearance of the raw material, 3-(7-bromo-9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole, the reaction mixture was allowed to cool to room temperature. The cooled reaction mixture was suction filtered using KC floc, the KC floc was washed with toluene, and the toluene was collected as filtrate. The aqueous and organic layers of the filtrate were separated, the aqueous layer was thoroughly mixed with toluene, and the toluene was recovered. This was then combined with the organic layer of the filtrate, washed with water, and the solvent was removed under reduced pressure to obtain a crude product as a solid. The resulting crude product was ground in a mortar and 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 and dried under reduced pressure to obtain 3-(9,9-dimethyl-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-fluoren-2-yl)-9-phenyl-9H-carbazole (yield: 10.57 g, 97%).

[0188] (2) Synthesis of Monomer ME

[0189] A reaction vessel was charged with 4.0 g of 1-bromo-4-(1-propen-2-yl)benzene, 10.57 g of 3-(9,9-dimethyl-(4,4,5,5-tetramethyl-1,3,2-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, and the reaction vessel was degassed and then filled with a nitrogen atmosphere. The temperature inside the reaction vessel was then raised to 80°C. The mixture in the reaction vessel was stirred for 5 hours while tracking the reaction by TLC, and after confirming the disappearance of the raw material 3-(9,9-dimethyl-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-fluoren-2-yl)-9-phenyl-9H-carbazole, the reaction mixture was allowed to cool to room temperature. The cooled reaction mixture was suction filtered using KC floc, the KC floc was washed with toluene, and the toluene was also recovered as filtrate. The aqueous and organic layers of the filtrate were separated, the aqueous layer was thoroughly mixed with toluene, the toluene was recovered, and the toluene was combined with the organic layer of the filtrate and washed with water, after which the solvent was removed under reduced pressure to obtain a 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 dried under reduced pressure to obtain Monomer M-E (yield: 6.73 g, 65%). 1 The H-NMR spectrum is shown below. 1 H-NMR (CDCl3, 500Hz) σ 8.42 (1H, d, J=1.4), 8.24 (1H, d, J=7.7), 7.83 (2H, dd,J=10.7, 7.8), 7.78 (1H, d, J=1.1), 7.72 (2H, ddd, J=8.7, 8.7, 1.7), 7.68-7.57 (10H, m), 7.50-7.48 (2H, m), 7.44 (2H, d, J=3.1), 7.34-7.30 (1H, m), 5.46 (1H, s), 5.13 (1H, s), 2.21 (3H, s), 1.63 (6H, s)

[0190] [2] Polymer synthesis and evaluation thereof (1) Polymer synthesis [Comparative Example 1] Synthesis of polymer P-X

[0191] A reaction vessel was charged with 2.0 g of Monomer M-X, 0.10 g of AIBN, and 11.9 g of dimethylformamide. The atmosphere inside the reaction vessel was replaced with nitrogen, and the mixture was stirred at 80°C for 20 hours. The reaction mixture was allowed to cool to room temperature, and then the cooled reaction mixture was added dropwise to 140 g of a mixed solvent of methanol and ethyl acetate (5 / 2 (V / V)), followed by stirring at room temperature. Finally, the precipitated solid was recovered by filtration and dried under reduced pressure to obtain Polymer X (yield: 1.8 g, 90%). GPC analysis revealed that Polymer X had an Mn of 2,600 and an Mw of 3,300.

[0192] [Example 1-1] Synthesis of Polymer PA

[0193] A reaction vessel was charged with 3.0 g of Monomer M-A, 0.150 g of AIBN, and 13 g of dimethylformamide. The atmosphere inside the reaction vessel was replaced with nitrogen, and the mixture was stirred at 80°C for 20 hours. The reaction mixture was allowed to cool to room temperature, and then the cooled reaction mixture was added dropwise to 150 g of a mixed solvent of methanol and ethyl acetate (1 / 1 (V / V)), followed by stirring at room temperature. Finally, the precipitated solid was recovered by filtration and dried under reduced pressure to obtain Polymer A (yield: 2.1 g, 71%). GPC analysis revealed that Polymer A had an Mw of 3,900 and a polydispersity Mw / Mn of 1.26.

[0194] [Example 1-2] Synthesis of polymer PB

[0195] A reaction vessel was charged with 1.0 g of monomer M-B, 0.030 g of AIBN, and 7.6 g of anisole. The atmosphere inside the reaction vessel was replaced with nitrogen, and the mixture was stirred at 80°C for 7 hours. The reaction mixture was allowed to cool to room temperature, and then the cooled 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 dried under reduced pressure to obtain polymer P-B (yield: 0.62 g, 62%). GPC measurement revealed that polymer P-B had an Mw of 15,400 and a polydispersity Mw / Mn of 1.57.

[0196] [Example 1-3] Synthesis of Polymer PC

[0197] A reaction vessel was charged with 1.0 g of monomer M-C, 0.050 g of AIBN, and 5.3 g of dimethylformamide. The atmosphere inside the reaction vessel was replaced with nitrogen, and the mixture was stirred at 80°C for 20 hours. The reaction mixture was allowed to cool to room temperature, and then the cooled reaction mixture was added dropwise to 75 g of a mixed solvent of ethyl acetate and dimethylformamide (5 / 1 (V / V)), followed by stirring at room temperature. Finally, the precipitated solid was recovered by filtration and dried under reduced pressure to obtain polymer P-C (yield: 0.87 g, 87%). GPC analysis revealed that polymer P-C had an Mw of 4,700 and a polydispersity Mw / Mn of 1.50.

[0198] [Example 1-4] Synthesis of polymer PD

[0199] A reaction vessel was charged with 1.0 g of monomer M-D, 0.080 g of AIBN, and 5.3 g of dimethylformamide. The atmosphere inside the reaction vessel was replaced with nitrogen, and the mixture was stirred at 80°C for 20 hours. The reaction mixture was allowed to cool to room temperature, and then the cooled 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 dried under reduced pressure to obtain polymer P-D (yield: 0.42 g, 42%). GPC analysis revealed that polymer P-D had an Mw of 4,000 and a polydispersity Mw / Mn of 1.12.

[0200] [Example 1-5] Synthesis of Polymer PE

[0201] A reaction vessel was charged with 1.5 g of monomer M-E, 0.150 g of AIBN, and 8.3 g of anisole. The atmosphere inside the reaction vessel was replaced with nitrogen, and the mixture was stirred at 80°C for 20 hours. The reaction mixture was allowed to cool to room temperature, and then the cooled 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 dried under reduced pressure to obtain polymer P-E (yield: 0.50 g, 33%). GPC measurement revealed that polymer P-B had an Mw of 2,000 and a polydispersity Mw / Mn of 1.05.

[0202] [Example 1-6] Synthesis of copolymer P-AB

[0203] A reaction vessel was charged with 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. The atmosphere inside the reaction vessel was replaced with nitrogen, and the mixture was stirred at 80°C for 20 hours. The reaction mixture was allowed to cool to room temperature, and then the cooled 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 dried under reduced pressure to obtain copolymer P-AB (yield: 0.78 g, 78%). GPC analysis revealed that the Mw of copolymer P-AB was 147,000, and the polydispersity Mw / Mn was 2.26.

[0204] [Examples 1-7] Synthesis of copolymer P-AE

[0205] A reaction vessel was charged with 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. The atmosphere inside the reaction vessel was replaced with nitrogen, and the mixture was stirred at 80°C for 20 hours. The reaction mixture was allowed to cool to room temperature, and then the cooled 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 dried under reduced pressure to obtain copolymer P-AB (yield: 1.18 g, 73%). GPC analysis revealed that the Mw of copolymer P-AB was 33,000, and the polydispersity Mw / Mn was 5.19.

[0206] [Examples 1-8] Synthesis of copolymer P-CB

[0207] A reaction vessel was charged with 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. The atmosphere inside the reaction vessel was replaced with nitrogen, and the mixture was stirred at 80°C for 20 hours. The reaction mixture was allowed to cool to room temperature, and then the cooled 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 dried under reduced pressure to obtain copolymer P-CB (yield: 0.42 g, 42%). GPC analysis revealed that the Mw of copolymer P-CB was 277,000, and the polydispersity Mw / Mn was 3.38.

[0208] [Examples 1-9] Synthesis of copolymer P-DB

[0209] A reaction vessel was charged with 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. The atmosphere inside the reaction vessel was replaced with nitrogen, and the mixture was stirred at 80°C for 20 hours. The reaction mixture was allowed to cool to room temperature, and then the cooled 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 dried under reduced pressure to obtain copolymer P-DB (yield: 0.25 g, 24%). GPC analysis revealed that the Mw of copolymer P-DB was 74,000, and the polydispersity Mw / Mn was 3.10.

[0210] (2) Evaluation of Heat Resistance TG measurements were carried out 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. The temperature was raised to 500°C at a heating rate of 10°C / minute in the atmosphere, and the temperature at which a 5% weight loss occurred was measured. The results are shown in Table 1. Note that when the weight loss at 500°C was less than 5%, it was recorded as >500.

[0211]

[0212] The polymers of the present invention exhibited superior heat resistance to the comparative polymers, and the monomers of the polymers of the present invention also exhibited superior heat resistance.

[0213] [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 aryl sulfonate 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 dissolved by stirring at room temperature. The resulting solution was filtered using a PTFE filter with a pore size of 0.2 μm to obtain charge-transporting varnish A. The aryl sulfonate ester SE-A ​​was synthesized according to the method described in WO 2017 / 217455. The structure of aryl sulfonate ester SE-A ​​is shown below.

[0214] [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 dissolved by stirring at room temperature. The resulting solution was filtered using a PTFE filter with a pore size of 0.2 μm to obtain charge-transporting varnish B.

[0215] [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 dissolved by stirring at room temperature. The resulting solution was filtered using a PTFE filter with a pore size of 0.2 μm to obtain charge-transporting varnish C.

[0216] [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 dissolved by stirring at room temperature. The resulting solution was filtered using a PTFE filter with a pore size of 0.2 μm to obtain charge-transporting varnish D.

[0217] [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 dissolved by stirring at room temperature. The resulting solution was filtered using a PTFE filter with a pore size of 0.2 μm to obtain charge-transporting varnish E.

[0218] [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 dissolved by stirring at room temperature. The resulting solution was filtered using a PTFE filter with a pore size of 0.2 μm to obtain charge-transporting varnish F.

[0219] [Example 2-7] 139 mg of copolymer P-AE and 278 mg of arylsulfonic acid ester SE-A ​​were added to 10 g of 4-methoxytoluene and dissolved by stirring at room temperature. The resulting solution was filtered using a PTFE filter with a pore size of 0.2 μm to obtain charge-transporting varnish G.

[0220] [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 dissolved by stirring at room temperature. The resulting solution was filtered using a PTFE filter with a pore size of 0.2 μm to obtain charge-transporting varnish H.

[0221] [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 dissolved by stirring at room temperature. The resulting solution was filtered using a PTFE filter with a pore size of 0.2 μm to obtain charge-transporting varnish I.

[0222] 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 the mixture was stirred at room temperature to dissolve. The resulting solution was filtered using a PTFE filter with a pore size of 0.2 μm to obtain charge-transporting varnish J.

[0223] (2) Evaluation of Refractive Index (n) and Extinction Coefficient (k) Each of the charge-transporting varnishes A to D was applied to a quartz substrate using a spin coater, and then heated in an air atmosphere at 120°C for 1 minute and then at 200°C for 15 minutes to form a uniform 50 nm thin film on the quartz substrate. Using the obtained quartz substrate with the thin film, the average refractive index (n) at wavelengths of 400 to 800 nm and the average extinction coefficient (k) at wavelengths of 400 to 800 nm were measured. The results are shown in Table 2.

[0224]

[0225] As shown in Table 2, the charge transporting thin film of the present invention had a higher refractive index and a lower extinction coefficient than the comparative example. The refractive index was high at 1.65 or more, and the extinction coefficient was low at 0.020 or less. This is because the skeleton containing alkylfluorene has a high refractive index and is highly transparent.

[0226] [4] Fabrication and Characterization of SLD [Example 3] Charge-transporting varnish A was applied to an ITO substrate using a spin coater, and then heated in an air atmosphere at 120°C for 1 minute and then at 230°C for 15 minutes, forming a 50-nm-thick charge-transporting thin film on the ITO substrate. The ITO substrate used was a 25 mm x 25 mm x 0.7 mm glass substrate with a patterned 50-nm-thick ITO film formed on its surface. Prior to use, impurities on the surface were removed using an O2 plasma cleaning device (150 W, 30 seconds). A vapor deposition device (vacuum level 1.0 x 10 -5 An 80 nm thick aluminum thin film was formed using a vacuum evaporation method (at 0.2 nm / sec) using a vacuum evaporation method (at 0.2 Pa). The resulting structure was then sealed with a sealing substrate to prevent deterioration of characteristics due to the effects of oxygen, water, etc. in the air. Sealing was performed using 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 Corporation). At this time, a moisture scavenger (HD-071010W-40 manufactured by DYNIC Corporation) was placed inside the sealing substrate together with the SLD. The bonded sealing substrates were irradiated with UV light (wavelength: 365 nm, irradiation dose: 6,000 mJ / cm). 2After this, the adhesive was cured by annealing at 80° C. for 1 hour. The current density was measured when a voltage of 4 V was applied to the fabricated SLD. The results are shown in Table 3.

[0227]

[0228] As shown in Table 3, the charge-transporting thin film prepared from the charge-transporting varnish of the present invention exhibited good charge-transporting properties.

[0229] [5] Preparation and Characterization of HOD [Examples 4-1 to 4-6] Charge-transporting varnishes C, D, E, G, H, and I were each applied to an ITO substrate using a spin coater, and then heated in air at 120°C for 1 minute and then at 180°C for 15 minutes, forming a 50 nm-thick charge-transporting thin film on the ITO substrate. The ITO substrate used was a 25 mm x 25 mm x 0.7 mm glass substrate with a patterned 150 nm-thick ITO film formed on its surface. Prior to use, impurities on the surface were removed using an O2 plasma cleaning device (150 W, 30 seconds). A vapor deposition device (vacuum level 1.0 x 10 -5 A thin film of α-NPD having a thickness of 30 nm was formed at 0.2 nm / sec using a vacuum evaporation method (Pa), and then a thin film of aluminum having a thickness of 80 nm was formed on top of this at 0.2 nm / sec. The result was sealed with a sealing substrate in the same manner as in Example 1-1 to obtain an HOD. The current density was measured when a voltage of 4 V was applied to the fabricated HOD. The results are shown in Table 4.

[0230]

[0231] As shown in Table 4, the charge transporting thin film prepared from the charge transporting varnish of the present invention exhibited good hole injection properties into α-NPD, which is often used as a hole transporting layer.

Claims

1. A polymer comprising at least one repeating unit selected from a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2): 【Chemistry 1】 [In the formula, R A is a hydrogen atom or a methyl group. 1 ~R 4 each independently represents a single bond or a phenylene group, and some or all of the hydrogen atoms of the phenylene group may be substituted with a cyano group, a nitro group, a halogen atom, a vinyl group, a trifluorovinyl group, an acryloyl group, a 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. 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 a divalent group obtained by removing two hydrogen atoms on an aromatic ring of an arylene group having 6 to 20 carbon atoms, a heteroarylene group having 3 to 20 carbon atoms, or a dialkylfluorene represented by the following formula (3), and some or all of the hydrogen atoms on the aromatic ring of these groups may be substituted with a cyano group, a nitro group, a halogen atom, a vinyl group, a trifluorovinyl group, an acryloyl group, a 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. Ar 2 , Ar 3 , Ar 5 and Ar 6 are each independently a monovalent group obtained by removing one hydrogen atom on an aromatic ring of an aryl group having 6 to 20 carbon atoms or a dialkylfluorene represented by the following formula (3), and some or all of the hydrogen atoms on the aromatic ring of these groups may be substituted with a cyano group, a nitro group, a halogen atom, a vinyl group, a trifluorovinyl group, an acryloyl group, a 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. X 1 -N(Ar 3 )-, Ar 2 and Ar 3 and may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded; 2 -N(Ar 6 )-, Ar 5 and Ar 6 may be bonded to each other to form a ring together with the nitrogen atom to which they are attached. R 2 is a phenylene group, R 2 and Ar 2 and may be bonded to each other to form a ring together with the nitrogen atom, sulfur atom or oxygen atom to which they are bonded; R 4 is a phenylene group, R 4 and Ar 5 may be bonded to each other to form a ring together with the nitrogen atom, sulfur atom or oxygen atom to which they are bonded. However, Ar 1 ~Ar 3 At least one of Ar is a group obtained by removing a hydrogen atom on an aromatic ring of a dialkylfluorene represented by the following formula (3), 4 ~Ar 6 At least one of the above is a group obtained by removing a hydrogen atom on an aromatic ring of a dialkylfluorene represented by the following formula (3). 【Chemistry 2】 (In the formula, R 5 and R 6 are each independently an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkyl group having 2 to 20 carbon atoms and containing at least one ether structure.

2. 2. 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). 【Chemistry 3】 (In the formula, R A , R 1 ~R 4 , Ar 1 ~Ar 6 is the same as above.)

3. R 1 and R 3 The polymer according to claim 1 or 2, wherein is a single bond.

4. R 2 and R 4 The polymer according to any one of claims 1 to 3, wherein is a phenylene group.

5. Ar 1 and Ar 4 The polymer according to any one of claims 1 to 4, wherein is a 9,9-dimethyl-9H-fluorene-2,7-diyl group.

6. A charge transporting material comprising the polymer according to any one of claims 1 to 5.

7. A charge transporting varnish comprising a charge transporting substance comprising the polymer according to any one of claims 1 to 5, and an organic solvent.

8. 8. The charge transporting varnish according to claim 7, further comprising a dopant.

9. A charge transporting thin film obtained from the charge transporting varnish according to claim 7 or 8.

10. An organic electroluminescence device comprising the charge transporting thin film according to claim 9.

11. The organic electroluminescence device according to claim 10, wherein the charge transporting thin film is a hole injection layer or a hole transport layer.

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